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Subhash C. Chauhan - One of the best experts on this subject based on the ideXlab platform.

  • Biophysical changes caused by altered MUC13 expression in pancreatic cancer cells.
    Micron (Oxford England : 1993), 2020
    Co-Authors: Andrew E. Massey, Kyle Doxtater, Murali M. Yallapu, Subhash C. Chauhan
    Abstract:

    Abstract Background Pancreatic cancer is one of the most lethal cancers in the United States. This is partly due to the difficulty in early detection of this disease as well as poor therapeutic responses to currently available regimens. Our previous reports suggest that mucin 13 (MUC13, a transmembrane mucin common to gastrointestinal cells) is aberrantly expressed in this disease state, and has been implicated with a worsened prognosis and an enhanced metastatic potential in PanCa. However, virtually no information currently exists to describe the biophysical ramifications of this protein. Methods To demonstrate the biophysical effect of MUC13 in PanCa, we generated overexpressing and knockdown model cell lines for PanCa and subsequently subjected them to various biophysical experiments using atomic force microscopy (AFM) and cellular aggregation studies. Results AFM-based nanoindentation data showed significant biophysical effects with MUC13 modulation in PanCa cells. The overexpression of MUC13 in Panc-1 cells led to an expected decrease in modulus, and a corresponding decrease in adhesion. With MUC13 knockdown, HPAF-II cells exhibited an increased modulus and adhesion. These results were confirmed with altered cell-cell adhesion as seen with aggregation assays. Conclusions MUC13 led to significant biophysical changes in PanCa cells and which exhibited characteristic phenotypic changes in cells demonstrated in previous work from our lab. This work gives insight into the use of biophysical measurements that could be used to help diagnose or monitor cancers as well as determine the effects of genetic alterations at a mechanical level.

  • Transmembrane mucin MUC13 distinguishes intraductal papillary mucinous neoplasms from non-mucinous cysts and is associated with high-risk lesions.
    HPB : the official journal of the International Hepato Pancreato Biliary Association, 2018
    Co-Authors: Zachary E. Stiles, Meena Jaggi, Sheema Khan, Stephen W. Behrman, Kurt T. Patton, Subhash C. Chauhan
    Abstract:

    Abstract Background Intraductal papillary mucinous neoplasms (IPMN) are currently managed based on imaging characteristics and cyst fluid sampling. This study was designed to determine if MUC13, a glycoprotein aberrantly overexpressed in pancreatic adenocarcinoma, might aid in distinguishing high-risk lesions (high grade dysplasia/invasive disease) from low-grade lesions. Methods MUC13 immunohistochemical staining was performed on surgically resected formalin-fixed tissue specimens from 49 IPMNs and 23 non-mucinous cysts. Membranous MUC13 expression was measured by H-score, which quantifies staining intensity and the percentage of cells involved (range 0–300). Results MUC13 expression was detected in all IPMNs and was significantly greater than in non-mucinous cysts (median 210 vs 40, p  Conclusion MUC13 expression was significantly greater in high-risk IPMNs in this analysis. The preoperative assessment of MUC13 in cyst fluid samples warrants further investigation.

  • Abstract 198: MUC13 promotes pancreatic tumor-stromal interactions by influencing tumor microenvironment
    Tumor Biology, 2018
    Co-Authors: Sheema Khan, Subhash C. Chauhan, Mohammad Sikander, Murali M. Yallapu, Stephen W. Behrman, Saini Setua, Sonam Kumari, Kyle Doxtater, Shabnam Malik, Meena Jaggi
    Abstract:

    Objective: Pancreatic cancer (PanCa) is the third leading cause of cancer-related deaths in the U.S. MUC13, mucin, is aberrantly expressed in PanCa and its overexpression leads to tumorigenic and metastatic behavior of cancer cells. Herein, we investigate the role of MUC13 in tumor microenvironment (TME) that favors PanCa progression/metastasis and drug resistance. Methods: MUC13 expressing (Panc-1) and knockdown PanCa cells (HPAF-II) and pancreatic stromal cells (PSCs), derived from freshly collected human pancreatic tissues, were utilized for the study. Using immunoblotting, ELISA, qPCR and RT-PCR techniques, we assessed the MUC13-induced alterations in the expression of important molecules that are involved in promotion of pancreatic tumor stromal interactions and drug resistance. Cytation 3 live cell imaging was performed for 3D tumor-stromal cell co-culture and invasion assays. Xenograft mice tumor tissues generated using ectopically expressing MUC13 and null cells were used for the study. Results: Our results demonstrate that MUC13 activates SHH signaling pathway in PanCa cells via upregulation of SHH and its related important downstream targets such as CXCR-4, Gli-1, SMO, PTCH1/2, NFκB and p-AKT in PanCa cells using immunoblotting and PCR. We also observed increased expression of SHH, Gli-1, CXCR-4 and α-SMA in MUC13-expressing xenograft tumors using Immunohistochemistry. Ectopic MUC13-expressing PanCa cells grown in co-culture with PSCs showed enhanced secretion of IL-6 and CXCL-12 (ELISA), increase in invasion (Matrigel invasion assay) and migratory (Boyden chamber assay) potential of both the cultured PanCa as well as stromal cells. Additionally, ectopically MUC13-expressing cells were resistant to treatment with gemcitabine as depicted by proliferation assay and qPCR results showed enhanced expression of ribonucleoside-diphosphate reductase (RRM1/2) and miR-21, which are known to be involved in gemcitabine resistance. Overall, our results suggest that MUC13 modulates tumor-stromal crosstalk, promoting tumor growth, invasion and drug resistance in TME. Conclusion: Our results suggest that MUC13 expression might influence signaling supportive of interactive TME, leading to increased tumor growth and drug resistance. These findings illustrate mechanisms by which MUC13 promotes tumorigenic TME and contributes to PanCa cell survival, metastasis and drug resistance. Citation Format: Sheema S. Khan, Kyle Doxtater, Sonam Kumari, Saini Setua, Mohammed Sikander, Shabnam Malik, Murali Yallapu, Stephen Behrman, Subhash Chauhan, Meena Jaggi. MUC13 promotes pancreatic tumor-stromal interactions by influencing tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 198.

  • Abstract 5178: MUC13 is a novel molecular signature, for early detection and metastatic colorectal cancer
    Tumor Biology, 2018
    Co-Authors: Manish K. Tripathi, Meena Jaggi, Nadeem Zafar, Zachary E. Stiles, Kyle Doxtater, Chidi Zacheaus, Fatemeh Keramatnia, Mahul B. Amin, Subhash C. Chauhan
    Abstract:

    Objective: Colorectal cancer (CRC) is a leading cause of cancer mortality affecting over a million people every year. Biological markers for early detection and distant metastatic disease in patients with CRC are not well defined. We have identified transmembrane mucin MUC13, which is expressed in normal colon mucosa to be highly expressed in colorectal cancer, but the underlying pathways and the signaling mechanisms involved in CRC pathogenesis are not known. Our studies suggest MUC13 correlation with demographic and clinicopathologic characteristics. Materials and Methods: Retrospective institutional tumor registry was reviewed to identify patients with resected colon adenocarcinoma. Archived FFPE tissue blocks were reviewed by an experienced pathologist. Selected representative tissue blocks were serially sectioned at 4 µm. IHC staining was performed using an in-house MAb for MUC13. Slides were digitally scanned and analyzed qualitatively as well as quantitatively using a modified H-score based on the intensity of expression and percentage of stained cells. MUC13 was correlated with disease stage, aggressiveness and inflammatory markers, indicating poor prognosis in CRC patients. MUC13 splice variants were probed using novel designed probes. MUC13 SNPs were identified using unbiased approach by analyzing dpGAP database. Results: 196 tissues, of which 56.1% were female, 52% were white, and the median age at resection was 70. 38 (19.4%) were stage I, 64 (32.7%) stage II, 84 (42.9%) stage III, and 10 (5.1%) stage IV. 100% of colon adenocarcinoma tissues stained positively for MUC13, including definitive tumor epithelial staining, little-to-no background stromal staining, and mild staining of adjacent normal colon mucosa. Typical colon adenocarcinoma cells exhibited strong apical membranous staining with varying degrees of cytoplasmic staining. Advanced stage tumors were noted to more frequently exhibit basolateral and/or circumferential membranous staining compared to early stage tumors which more frequently displayed apical membrane staining alone. Five MUC13 transcript variants were identified by database analysis. Two of the protein coding MUC13 variants (long and short) showed differential expression in aggressive cell lines and patient tissues. Cyclic turnover between the short and long isoforms were observed during Anoikis resistance, cortisol, alcohol and BAP treatments. SNPs have been associated with increased risk of cancer incidence or fatality. Relevant MUC13 SNPs have been identified through systematic analysis of patient databases (dpGAP database). Verification and correlation of identified SNPs with patient disease stage and prognosis will also be presented. Conclusion: This is the first study to correlate MUC13 expression with disease outcome. Alternative transcripts and single nucleotide polymorphisms gave genetic insight of the role of MUC13 in CRC pathogenesis. Citation Format: Manish K. Tripathi, Chidi Zacheaus, Kyle Doxtater, Zachary Stiles, Fatemeh Keramatnia, Nadeem Zafar, Mahul Amin, Meena Jaggi, Subhash Chauhan. MUC13 is a novel molecular signature, for early detection and metastatic colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5178.

  • MUC13 contributes to rewiring of glucose metabolism in pancreatic cancer
    Oncogenesis, 2018
    Co-Authors: Sonam Kumari, Subhash C. Chauhan, Sheema Khan, Murali M. Yallapu, Subash C. Gupta, Vivek K. Kashyap, Meena Jaggi
    Abstract:

    Pancreatic tumors are rewired for high-glucose metabolism and typically present with exceptionally poor prognosis. Recently, we have shown that MUC13, which is highly expressed in pancreatic tumors, promotes tumor progression via modulation of HER2 receptor tyrosine kinase activity. Herein, we investigate a novel, MUC13-mediated molecular mechanism responsible for higher glucose metabolism in pancreatic tumors. Our results demonstrate that MUC13 expression leads to the activation/nuclear translocation of NF-κB p65 and phosphorylation of IκB, which in turn upregulates the expression of important proteins (Glut-1, c-Myc, and Bcl-2) that are involved in glucose metabolism. MUC13 functionally interacts and stabilizes Glut-1 to instigate downstream events responsible for higher glucose uptake in pancreatic cancer cells. Altered MUC13 expression by overexpression and knockdown techniques effectively modulated glucose uptake, lactate secretion, and metastatic phenotypes in pancreatic cancer cells. NF-κB inhibitor, Sulfasalazine, abrogates the MUC13 and Glut-1 interaction, and attenuates events associated with MUC13-induced glucose metabolism. Pancreatic ductal adenocarcinoma (PDAC) patient tissue samples also show a positive correlation between the expression of these two proteins. These results delineate how MUC13 rewire aberrant glucose metabolism to enhance aggressiveness of pancreatic cancer and revealed a novel mechanism to develop newer therapeutic strategies for this exceptionally difficult cancer.

Sheema Khan - One of the best experts on this subject based on the ideXlab platform.

  • Optical detection of fractal dimensions of MUC13 stained pancreatic tissues for cancer diagnostics
    arXiv: Medical Physics, 2018
    Co-Authors: Prakash Adhikari, Sheema Khan, Aby Panikanthara Binu, Shiva Bhandari, Mina Jaggi, Shubhash C. Chauhan, Prabhakar Pradhan
    Abstract:

    Transmission intensity of a thin tissue sample produce intensity distribution that is proportional to the refractive index pattern in the thin slice, in turn reflects mass density pattern, and using the intensity pattern, fractal dimension can be calculated. In this paper, we report fractal dimension analyses of MUC13 stained pancreatic cancer tissues. Pancreatic cancer is deadliest due to its physical orientation, and no prominent chemical change till the late stages of cancer. The presence of pancreatic cancer can be detected using MUC13, however this fails to explain about the stages of cancer. Here we studied MUC13 expressed cancer tissues and observe their cancer stages by fractal dimension of light transmission intensity. Our results show that an early stage of pancreatic cancer for MUC13 expressed tissue is accurately distinguished by fractal dimension analysis. Further, their application to cancer diagnostics is also discussed in detail.

  • Transmembrane mucin MUC13 distinguishes intraductal papillary mucinous neoplasms from non-mucinous cysts and is associated with high-risk lesions.
    HPB : the official journal of the International Hepato Pancreato Biliary Association, 2018
    Co-Authors: Zachary E. Stiles, Meena Jaggi, Sheema Khan, Stephen W. Behrman, Kurt T. Patton, Subhash C. Chauhan
    Abstract:

    Abstract Background Intraductal papillary mucinous neoplasms (IPMN) are currently managed based on imaging characteristics and cyst fluid sampling. This study was designed to determine if MUC13, a glycoprotein aberrantly overexpressed in pancreatic adenocarcinoma, might aid in distinguishing high-risk lesions (high grade dysplasia/invasive disease) from low-grade lesions. Methods MUC13 immunohistochemical staining was performed on surgically resected formalin-fixed tissue specimens from 49 IPMNs and 23 non-mucinous cysts. Membranous MUC13 expression was measured by H-score, which quantifies staining intensity and the percentage of cells involved (range 0–300). Results MUC13 expression was detected in all IPMNs and was significantly greater than in non-mucinous cysts (median 210 vs 40, p  Conclusion MUC13 expression was significantly greater in high-risk IPMNs in this analysis. The preoperative assessment of MUC13 in cyst fluid samples warrants further investigation.

  • Abstract 198: MUC13 promotes pancreatic tumor-stromal interactions by influencing tumor microenvironment
    Tumor Biology, 2018
    Co-Authors: Sheema Khan, Subhash C. Chauhan, Mohammad Sikander, Murali M. Yallapu, Stephen W. Behrman, Saini Setua, Sonam Kumari, Kyle Doxtater, Shabnam Malik, Meena Jaggi
    Abstract:

    Objective: Pancreatic cancer (PanCa) is the third leading cause of cancer-related deaths in the U.S. MUC13, mucin, is aberrantly expressed in PanCa and its overexpression leads to tumorigenic and metastatic behavior of cancer cells. Herein, we investigate the role of MUC13 in tumor microenvironment (TME) that favors PanCa progression/metastasis and drug resistance. Methods: MUC13 expressing (Panc-1) and knockdown PanCa cells (HPAF-II) and pancreatic stromal cells (PSCs), derived from freshly collected human pancreatic tissues, were utilized for the study. Using immunoblotting, ELISA, qPCR and RT-PCR techniques, we assessed the MUC13-induced alterations in the expression of important molecules that are involved in promotion of pancreatic tumor stromal interactions and drug resistance. Cytation 3 live cell imaging was performed for 3D tumor-stromal cell co-culture and invasion assays. Xenograft mice tumor tissues generated using ectopically expressing MUC13 and null cells were used for the study. Results: Our results demonstrate that MUC13 activates SHH signaling pathway in PanCa cells via upregulation of SHH and its related important downstream targets such as CXCR-4, Gli-1, SMO, PTCH1/2, NFκB and p-AKT in PanCa cells using immunoblotting and PCR. We also observed increased expression of SHH, Gli-1, CXCR-4 and α-SMA in MUC13-expressing xenograft tumors using Immunohistochemistry. Ectopic MUC13-expressing PanCa cells grown in co-culture with PSCs showed enhanced secretion of IL-6 and CXCL-12 (ELISA), increase in invasion (Matrigel invasion assay) and migratory (Boyden chamber assay) potential of both the cultured PanCa as well as stromal cells. Additionally, ectopically MUC13-expressing cells were resistant to treatment with gemcitabine as depicted by proliferation assay and qPCR results showed enhanced expression of ribonucleoside-diphosphate reductase (RRM1/2) and miR-21, which are known to be involved in gemcitabine resistance. Overall, our results suggest that MUC13 modulates tumor-stromal crosstalk, promoting tumor growth, invasion and drug resistance in TME. Conclusion: Our results suggest that MUC13 expression might influence signaling supportive of interactive TME, leading to increased tumor growth and drug resistance. These findings illustrate mechanisms by which MUC13 promotes tumorigenic TME and contributes to PanCa cell survival, metastasis and drug resistance. Citation Format: Sheema S. Khan, Kyle Doxtater, Sonam Kumari, Saini Setua, Mohammed Sikander, Shabnam Malik, Murali Yallapu, Stephen Behrman, Subhash Chauhan, Meena Jaggi. MUC13 promotes pancreatic tumor-stromal interactions by influencing tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 198.

  • MUC13 contributes to rewiring of glucose metabolism in pancreatic cancer
    Oncogenesis, 2018
    Co-Authors: Sonam Kumari, Subhash C. Chauhan, Sheema Khan, Murali M. Yallapu, Subash C. Gupta, Vivek K. Kashyap, Meena Jaggi
    Abstract:

    Pancreatic tumors are rewired for high-glucose metabolism and typically present with exceptionally poor prognosis. Recently, we have shown that MUC13, which is highly expressed in pancreatic tumors, promotes tumor progression via modulation of HER2 receptor tyrosine kinase activity. Herein, we investigate a novel, MUC13-mediated molecular mechanism responsible for higher glucose metabolism in pancreatic tumors. Our results demonstrate that MUC13 expression leads to the activation/nuclear translocation of NF-κB p65 and phosphorylation of IκB, which in turn upregulates the expression of important proteins (Glut-1, c-Myc, and Bcl-2) that are involved in glucose metabolism. MUC13 functionally interacts and stabilizes Glut-1 to instigate downstream events responsible for higher glucose uptake in pancreatic cancer cells. Altered MUC13 expression by overexpression and knockdown techniques effectively modulated glucose uptake, lactate secretion, and metastatic phenotypes in pancreatic cancer cells. NF-κB inhibitor, Sulfasalazine, abrogates the MUC13 and Glut-1 interaction, and attenuates events associated with MUC13-induced glucose metabolism. Pancreatic ductal adenocarcinoma (PDAC) patient tissue samples also show a positive correlation between the expression of these two proteins. These results delineate how MUC13 rewire aberrant glucose metabolism to enhance aggressiveness of pancreatic cancer and revealed a novel mechanism to develop newer therapeutic strategies for this exceptionally difficult cancer.

  • Clinical significance of MUC13 in pancreatic ductal adenocarcinoma.
    HPB : the official journal of the International Hepato Pancreato Biliary Association, 2018
    Co-Authors: Sheema Khan, Murali M. Yallapu, Stephen W. Behrman, Nadeem Zafar, Hemendra Ghimire, Shabia Shabir Khan, Saini Setua, Zachary E. Stiles, Peeyush Sahay, Tomoko Ise
    Abstract:

    Abstract Background Poor prognosis of pancreatic cancer (PanCa) is associated with lack of an effective early diagnostic biomarker. This study elucidates significance of MUC13, as a diagnostic/prognostic marker of PanCa. Methods MUC13 was assessed in tissues using our in-house generated anti-MUC13 mouse monoclonal antibody and analyzed for clinical correlation by immunohistochemistry, immunoblotting, RT-PCR, computational and submicron scale mass-density fluctuation analyses, ROC and Kaplan Meir curve analyses. Results MUC13 expression was detected in 100% pancreatic intraepithelial neoplasia (PanIN) lesions (Mean composite score: MCS = 5.8; AUC >0.8, P P P 0.8; P P P (P P 0.001 ) and nuclear MUC13 as strong predictor for cancer aggressiveness and poor patient survival. Conclusion This study provides significant information regarding MUC13 expression/subcellular localization in PanCa samples and supporting the use anti-MUC13 MAb for the development of PanCa diagnostic/prognostic test.

Ilene K Gipson - One of the best experts on this subject based on the ideXlab platform.

  • comparison of the transmembrane mucins muc1 and muc16 in epithelial barrier function
    PLOS ONE, 2014
    Co-Authors: Ilene K Gipson, Sandra Spurrmichaud, Ann Tisdale, Balaraj B Menon
    Abstract:

    Membrane-anchored mucins are present in the apical surface glycocalyx of mucosal epithelial cells, each mucosal epithelium having at least two of the mucins. The mucins have been ascribed barrier functions, but direct comparisons of their functions within the same epithelium have not been done. In an epithelial cell line that expresses the membrane-anchored mucins, MUC1 and MUC16, the mucins were independently and stably knocked down using shRNA. Barrier functions tested included dye penetrance, bacterial adherence and invasion, transepithelial resistance, tight junction formation, and apical surface size. Knockdown of MUC16 decreased all barrier functions tested, causing increased dye penetrance and bacterial invasion, decreased transepithelial resistance, surprisingly, disruption of tight junctions, and greater apical surface cell area. Knockdown of MUC1 did not decrease barrier function, in fact, barrier to dye penetrance and bacterial invasion increased significantly. These data suggest that barrier functions of membrane-anchored mucins vary in the context of other membrane mucins, and MUC16 provides a major barrier when present.

  • membrane tethered mucins have multiple functions on the ocular surface
    Experimental Eye Research, 2010
    Co-Authors: Bharathi Govindarajan, Ilene K Gipson
    Abstract:

    Membrane-tethered mucins are large glycoproteins present in the glycocalyx along the apical surface of all wet-surfaced epithelia of the body, including that of the ocular surface. Originally thought to function only in epithelial surface lubrication and hydration, data now indicate that the mucins are multifunctional molecules, each having unique as well as common functions. This review summarizes current knowledge regarding the three major membrane mucins of the ocular surface, MUC1, MUC4, and MUC16. The mucins vary in their ocular surface distribution, size, structural motifs, and functions. The ectodomains of each are released into the tear film and are, thus, a component of the soluble mucins of the tear film. Both animal and in vitro models for their study are herein described, as are alterations of the mucins in ocular surface disease.

  • effect of pro inflammatory mediators on membrane associated mucins expressed by human ocular surface epithelial cells
    Experimental Eye Research, 2010
    Co-Authors: Annchristin Albertsmeyer, Sandra Spurrmichaud, Vinodh Kakkassery, Olivia Beeks, Ilene K Gipson
    Abstract:

    Membrane-associated mucins are altered on the ocular surface in non-Sjogren's dry eye. This study sought to determine if inflammatory mediators, present in tears of dry eye patients, regulate membrane-associated mucins MUC1 and -16 at the level of gene expression, protein biosynthesis and/or ectodomain release. A human corneal limbal epithelial cell line (HCLE), which produces membrane-associated mucins, was used. Cells were treated with interleukin (IL)-6, -8, or -17, tumor necrosis factor-alpha (TNF-alpha), and Interferon-gamma (IFN-gamma), or a combination of TNF-alpha and IFN-gamma, or IFN-gamma and IL-17, for 1, 6, 24, or 48 h. Presence of receptors for these mediators was verified by RT-PCR. Effects of the cytokines on expression levels of MUC1 and -16 were determined by real-time PCR, and on mucin protein biosynthesis and ectodomain release in cell lysates and culture media, respectively, by immunoblot analysis. TNF-alpha and IFN-gamma each significantly induced MUC1 expression, cellular protein content and ectodomain release over time. Combined treatment with the two cytokines was not additive. By comparison, one of the inflammatory mediators, IFN-gamma, affected all three parameters-gene expression, cellular protein, and ectodomain release-for MUC16. Combined treatment with TNF-alpha and IFN-gamma showed effects similar to IFN-gamma alone, except that ectodomain release followed that of TNF-alpha, which induced MUC16 ectodomain release. In conclusion, inflammatory mediators present in tears of dry eye patients can affect MUC1 and -16 on corneal epithelial cells and may be responsible for alterations of surface mucins in dry eye.

  • release of membrane associated mucins from ocular surface epithelia
    Investigative Ophthalmology & Visual Science, 2008
    Co-Authors: Timothy D Blalock, Sandra Spurrmichaud, Ann Tisdale, Ilene K Gipson
    Abstract:

    PURPOSE Three membrane-associated mucins (MAMs)--MUC1, MUC4, and MUC16--are expressed at the ocular surface epithelium. Soluble forms of MAMs are detected in human tears, but the mechanisms of their release from the apical cells are unknown. The purpose of this study was to identify physiologic agents that induce ocular surface MAM release. METHODS An immortalized human corneal-limbal epithelial cell line (HCLE) expressing the same MAMs as native tissue was used. An antibody specific to the MUC16 cytoplasmic tail was developed to confirm that only the extracellular domain is released into the tear fluid or culture media. Effects of agents that have been shown to be present in tears or are implicated in the release or shedding of MAMs in other epithelia (neutrophil elastase, tumor necrosis factor [TNF]), TNF-alpha-converting enzyme, and matrix metalloproteinase-7 and -9) were assessed on HCLE cells. HCLE cell surface proteins were biotinylated to measure the efficiency of induced MAM release and surface restoration. Effects of induced release on surface barrier function were measured by rose bengal dye penetrance. RESULTS MUC16 in tears and in HCLE-conditioned medium lacked the cytoplasmic tail. TNF induced the release of MUC1, MUC4, and MUC16 from the HCLE surface. Matrix metalloproteinase-7 and neutrophil elastase induced the release of MUC16 but not of MUC1 or MUC4. Neutrophil elastase removed 68% of MUC16, 78% of which was restored to the HCLE cell surface 24 hours after release. Neutrophil elastase-treated HCLE cells showed significantly reduced rose bengal dye exclusion. CONCLUSIONS Results suggest that the extracellular domains of MUC1, MUC4, and MUC16 can be released from the ocular surface by agents in tears. Neutrophil elastase and TNF, present in higher amounts in the tears of patients with dry eye, may cause MAM release, allowing rose bengal staining.

  • muc16 is lost from the uterodome pinopode surface of the receptive human endometrium in vitro evidence that muc16 is a barrier to trophoblast adherence
    Biology of Reproduction, 2008
    Co-Authors: Ilene K Gipson, Timothy D Blalock, Ann S Tisdale, Sara Allcorn, Anneli Stavreusevers, Sandra Spurrmichaud, Kristina Gemzell
    Abstract:

    In order for the preimplantation embryo to implant into the uterus, the trophoblast cells must initially adhere to the uterine epithelial surface. In preparation, the luminal secretory cells of the epithelium lose their nonadhesive character and their surface microvilli and bulge into the lumen, forming uterodomes (pinopodes; uterodome is used instead of pinopode, since in humans the surface membrane exocytoses rather than endocytoses (Murphy, Hum Reprod 2000; 15:2451–2454). Previous research has led to the hypothesis that loss of the nonadhesive membrane-spanning mucin MUC1 from the uterodome surface allows trophoblast adherence. Immunofluorescence microscopic assay of luminal epithelia on human uterine biopsies taken from LHþ 0t o LH þ13 show that another membrane-spanning mucin, MUC16, was lost from uterodome surfaces in all samples taken during the receptive phase, LHþ 6t o LH þ 8( n¼ 12), and that MUC1 was present on uterodomes in 4 of 12 samples and on all ciliated cells of the epithelium in the receptive phase. Short interfering RNA (siRNA) knockdown of MUC16 in a uterine epithelial cell line ECC-1 that, like uterine epithelium, expresses MUC16 and MUC1 allowed increased adherence of cells of a trophoblast cell line. In parallel experiments, siRNA knockdown of MUC1 did not affect trophoblast cell adherence. These data indicate that MUC16 is a membrane component of the nonreceptive luminal uterine surface, which prevents cell adhesion, and that its removal during uterodome formation facilitates adhesion of the trophoblast. female reproductive tract, implantation, trophoblast, uterus

Meena Jaggi - One of the best experts on this subject based on the ideXlab platform.

  • Transmembrane mucin MUC13 distinguishes intraductal papillary mucinous neoplasms from non-mucinous cysts and is associated with high-risk lesions.
    HPB : the official journal of the International Hepato Pancreato Biliary Association, 2018
    Co-Authors: Zachary E. Stiles, Meena Jaggi, Sheema Khan, Stephen W. Behrman, Kurt T. Patton, Subhash C. Chauhan
    Abstract:

    Abstract Background Intraductal papillary mucinous neoplasms (IPMN) are currently managed based on imaging characteristics and cyst fluid sampling. This study was designed to determine if MUC13, a glycoprotein aberrantly overexpressed in pancreatic adenocarcinoma, might aid in distinguishing high-risk lesions (high grade dysplasia/invasive disease) from low-grade lesions. Methods MUC13 immunohistochemical staining was performed on surgically resected formalin-fixed tissue specimens from 49 IPMNs and 23 non-mucinous cysts. Membranous MUC13 expression was measured by H-score, which quantifies staining intensity and the percentage of cells involved (range 0–300). Results MUC13 expression was detected in all IPMNs and was significantly greater than in non-mucinous cysts (median 210 vs 40, p  Conclusion MUC13 expression was significantly greater in high-risk IPMNs in this analysis. The preoperative assessment of MUC13 in cyst fluid samples warrants further investigation.

  • Abstract 198: MUC13 promotes pancreatic tumor-stromal interactions by influencing tumor microenvironment
    Tumor Biology, 2018
    Co-Authors: Sheema Khan, Subhash C. Chauhan, Mohammad Sikander, Murali M. Yallapu, Stephen W. Behrman, Saini Setua, Sonam Kumari, Kyle Doxtater, Shabnam Malik, Meena Jaggi
    Abstract:

    Objective: Pancreatic cancer (PanCa) is the third leading cause of cancer-related deaths in the U.S. MUC13, mucin, is aberrantly expressed in PanCa and its overexpression leads to tumorigenic and metastatic behavior of cancer cells. Herein, we investigate the role of MUC13 in tumor microenvironment (TME) that favors PanCa progression/metastasis and drug resistance. Methods: MUC13 expressing (Panc-1) and knockdown PanCa cells (HPAF-II) and pancreatic stromal cells (PSCs), derived from freshly collected human pancreatic tissues, were utilized for the study. Using immunoblotting, ELISA, qPCR and RT-PCR techniques, we assessed the MUC13-induced alterations in the expression of important molecules that are involved in promotion of pancreatic tumor stromal interactions and drug resistance. Cytation 3 live cell imaging was performed for 3D tumor-stromal cell co-culture and invasion assays. Xenograft mice tumor tissues generated using ectopically expressing MUC13 and null cells were used for the study. Results: Our results demonstrate that MUC13 activates SHH signaling pathway in PanCa cells via upregulation of SHH and its related important downstream targets such as CXCR-4, Gli-1, SMO, PTCH1/2, NFκB and p-AKT in PanCa cells using immunoblotting and PCR. We also observed increased expression of SHH, Gli-1, CXCR-4 and α-SMA in MUC13-expressing xenograft tumors using Immunohistochemistry. Ectopic MUC13-expressing PanCa cells grown in co-culture with PSCs showed enhanced secretion of IL-6 and CXCL-12 (ELISA), increase in invasion (Matrigel invasion assay) and migratory (Boyden chamber assay) potential of both the cultured PanCa as well as stromal cells. Additionally, ectopically MUC13-expressing cells were resistant to treatment with gemcitabine as depicted by proliferation assay and qPCR results showed enhanced expression of ribonucleoside-diphosphate reductase (RRM1/2) and miR-21, which are known to be involved in gemcitabine resistance. Overall, our results suggest that MUC13 modulates tumor-stromal crosstalk, promoting tumor growth, invasion and drug resistance in TME. Conclusion: Our results suggest that MUC13 expression might influence signaling supportive of interactive TME, leading to increased tumor growth and drug resistance. These findings illustrate mechanisms by which MUC13 promotes tumorigenic TME and contributes to PanCa cell survival, metastasis and drug resistance. Citation Format: Sheema S. Khan, Kyle Doxtater, Sonam Kumari, Saini Setua, Mohammed Sikander, Shabnam Malik, Murali Yallapu, Stephen Behrman, Subhash Chauhan, Meena Jaggi. MUC13 promotes pancreatic tumor-stromal interactions by influencing tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 198.

  • Abstract 5178: MUC13 is a novel molecular signature, for early detection and metastatic colorectal cancer
    Tumor Biology, 2018
    Co-Authors: Manish K. Tripathi, Meena Jaggi, Nadeem Zafar, Zachary E. Stiles, Kyle Doxtater, Chidi Zacheaus, Fatemeh Keramatnia, Mahul B. Amin, Subhash C. Chauhan
    Abstract:

    Objective: Colorectal cancer (CRC) is a leading cause of cancer mortality affecting over a million people every year. Biological markers for early detection and distant metastatic disease in patients with CRC are not well defined. We have identified transmembrane mucin MUC13, which is expressed in normal colon mucosa to be highly expressed in colorectal cancer, but the underlying pathways and the signaling mechanisms involved in CRC pathogenesis are not known. Our studies suggest MUC13 correlation with demographic and clinicopathologic characteristics. Materials and Methods: Retrospective institutional tumor registry was reviewed to identify patients with resected colon adenocarcinoma. Archived FFPE tissue blocks were reviewed by an experienced pathologist. Selected representative tissue blocks were serially sectioned at 4 µm. IHC staining was performed using an in-house MAb for MUC13. Slides were digitally scanned and analyzed qualitatively as well as quantitatively using a modified H-score based on the intensity of expression and percentage of stained cells. MUC13 was correlated with disease stage, aggressiveness and inflammatory markers, indicating poor prognosis in CRC patients. MUC13 splice variants were probed using novel designed probes. MUC13 SNPs were identified using unbiased approach by analyzing dpGAP database. Results: 196 tissues, of which 56.1% were female, 52% were white, and the median age at resection was 70. 38 (19.4%) were stage I, 64 (32.7%) stage II, 84 (42.9%) stage III, and 10 (5.1%) stage IV. 100% of colon adenocarcinoma tissues stained positively for MUC13, including definitive tumor epithelial staining, little-to-no background stromal staining, and mild staining of adjacent normal colon mucosa. Typical colon adenocarcinoma cells exhibited strong apical membranous staining with varying degrees of cytoplasmic staining. Advanced stage tumors were noted to more frequently exhibit basolateral and/or circumferential membranous staining compared to early stage tumors which more frequently displayed apical membrane staining alone. Five MUC13 transcript variants were identified by database analysis. Two of the protein coding MUC13 variants (long and short) showed differential expression in aggressive cell lines and patient tissues. Cyclic turnover between the short and long isoforms were observed during Anoikis resistance, cortisol, alcohol and BAP treatments. SNPs have been associated with increased risk of cancer incidence or fatality. Relevant MUC13 SNPs have been identified through systematic analysis of patient databases (dpGAP database). Verification and correlation of identified SNPs with patient disease stage and prognosis will also be presented. Conclusion: This is the first study to correlate MUC13 expression with disease outcome. Alternative transcripts and single nucleotide polymorphisms gave genetic insight of the role of MUC13 in CRC pathogenesis. Citation Format: Manish K. Tripathi, Chidi Zacheaus, Kyle Doxtater, Zachary Stiles, Fatemeh Keramatnia, Nadeem Zafar, Mahul Amin, Meena Jaggi, Subhash Chauhan. MUC13 is a novel molecular signature, for early detection and metastatic colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5178.

  • MUC13 contributes to rewiring of glucose metabolism in pancreatic cancer
    Oncogenesis, 2018
    Co-Authors: Sonam Kumari, Subhash C. Chauhan, Sheema Khan, Murali M. Yallapu, Subash C. Gupta, Vivek K. Kashyap, Meena Jaggi
    Abstract:

    Pancreatic tumors are rewired for high-glucose metabolism and typically present with exceptionally poor prognosis. Recently, we have shown that MUC13, which is highly expressed in pancreatic tumors, promotes tumor progression via modulation of HER2 receptor tyrosine kinase activity. Herein, we investigate a novel, MUC13-mediated molecular mechanism responsible for higher glucose metabolism in pancreatic tumors. Our results demonstrate that MUC13 expression leads to the activation/nuclear translocation of NF-κB p65 and phosphorylation of IκB, which in turn upregulates the expression of important proteins (Glut-1, c-Myc, and Bcl-2) that are involved in glucose metabolism. MUC13 functionally interacts and stabilizes Glut-1 to instigate downstream events responsible for higher glucose uptake in pancreatic cancer cells. Altered MUC13 expression by overexpression and knockdown techniques effectively modulated glucose uptake, lactate secretion, and metastatic phenotypes in pancreatic cancer cells. NF-κB inhibitor, Sulfasalazine, abrogates the MUC13 and Glut-1 interaction, and attenuates events associated with MUC13-induced glucose metabolism. Pancreatic ductal adenocarcinoma (PDAC) patient tissue samples also show a positive correlation between the expression of these two proteins. These results delineate how MUC13 rewire aberrant glucose metabolism to enhance aggressiveness of pancreatic cancer and revealed a novel mechanism to develop newer therapeutic strategies for this exceptionally difficult cancer.

  • Abstract 51: Role of MUC13 as non-hypoxic stimuli inducing HIF-1α in pancreatic cancer under normoxia
    Molecular and Cellular Biology Genetics, 2016
    Co-Authors: Sonam Kumari, Sheema Khan, Subhash C. Chauhan, Meena Jaggi
    Abstract:

    Objective: Pancreatic cancer is the fourth most common cause of deaths occurring due to cancer, with an overall survival rate of just 5%. MUC13, a transmembrane mucin, is aberrantly expressed in pancreatic cancer, while an altered glucose metabolism is known to facilitate cancer cell survival and proliferation. Hypoxia-inducible factor 1 α (HIF-1 α) plays an important role in reprogramming of cancer cell metabolism by activating the transcription of genes which encode glucose transporters and enzymes involved in glycolysis. Recent reports suggest that several non-hypoxic stimuli such as lipopolysaccharides, thrombin, and angiotensin II can also increase HIF-1α under normoxia. Herein, we investigated the effects of MUC13 expression on glucose metabolism and elucidated underlying signaling mechanisms that might be involved in this process. Methods: MUC13 null pancreatic cancer Panc-1 cells were used for the study. Glucose and Lactate assay were performed in Panc-1 cells stably expressing MUC13 (Panc-1-M13) and vector (Panc-1-V). Cell culture media after 48 hrs was collected to measure the amount of unused glucose and L-lactate concentration using glucose and Lactate assay kits. Immunoblot and semi-quantitative PCR analyses were performed to check the expression of protein and mRNA levels, respectively. Cell proliferation and colony forming assays were performed to determine the effect of MUC13 on cellular growth and cell survival. Results: Our results demonstrate that MUC13 acts as a modulator of the glucose metabolism in pancreatic cancer cells by regulating the expression and activity of hypoxia-inducible factor-1α (HIF-1α) and its downstream targets. We observed increased amount of L-lactate production and glucose consumption in Panc-1-M13 cells as compared to Panc-1-V cells. This facilitates metabolic alterations and help tumor cells survive and proliferate under these conditions as indicated by increased cellular growth pattern in Panc-1-M13 cells. Our results demonstrate increased expression of the downstream targets of HIF-1α, such as cell regulatory (c-Myc), and cell survival (Bcl-2) proteins, while decreased the expression of tumor suppressor/cell cycle inhibitor (p-27) proteins in Panc-1M13 cells. Additionally, an increase in the expression of a critical downstream target of HIF-1α, Glut-1 was observed in Panc-1-M13 cells. Conclusion: Our studies indicate that MUC13 acts as a key regulator of the metabolic process and facilitates metabolic alterations in the non-hypoxic environment that help tumor cells survive and proliferate under these conditions. However, further studies are required to elucidate detailed molecular mechanisms that are involved in MUC13 mediated metabolic remodeling in pancreatic cancer cells. Citation Format: Sonam Kumari, Sheema Khan, Subhash Chauhan, Meena Jaggi. Role of MUC13 as non-hypoxic stimuli inducing HIF-1α in pancreatic cancer under normoxia. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 51.

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  • Abstract 4592: MUC13 interaction with receptor tyrosine kinase HER2 drives pancreatic ductal adenocarcinoma progression
    Molecular and Cellular Biology Genetics, 2016
    Co-Authors: Sheema Khan, Mara C. Ebeling, Mohammad Sikander, Murali M. Yallapu, Tomoko Ise, Satoshi Nagata, Stephen W. Behrman, Nadeem Zafar, Jim Y. Wan, Hemendra Ghimire
    Abstract:

    Background: Pancreatic Ductal Adenocarcinoma (PDAC) is the fourth leading cause of cancer related death in the United States and has a very poor survival rate due to late diagnosis. MUC13 is a recently identified high molecular weight glycoprotein that is upregulated in PDAC and its progression is allowed via alterations of multiple signaling pathways. MUC13 is aberrantly expressed in PDAC and generally correlates with increased expression of HER2, however, the underlying mechanism remains poorly understood. MUC13 consists of three EGF-like domains that may serve as a ligand for EGF receptors, such as HER2, and modulate EGFR signaling pathways. We sought to better characterize the interaction of MUC13 with HER2 in PDAC. Methods: MUC13 and HER2 interaction was studied using reciprocal co-immunoprecipitation, immunofluorescence, proximity ligation, Western blotting, co-capping assays in human PDAC cell lines and immunohistofluorescence techniques in human tissues. Tissue microarrays prepared from formalin-fixed, paraffin-embedded specimens of PDAC were assessed for expression of MUC13 and HER2 using our own laboratory generated anti-MUC13 mouse monoclonal antibody (MAb) through confocal immunofluorescence. The association of MUC13 and HER2 co-localization with nuclear chromatin organization was analyzed to study the stage or degree of aggressiveness of the pancreatic cancer using Dapi stained confocal images of tissues. Results: MUC13 co-localizes and interacts with HER2 in PDAC cell lines. The results from this study demonstrate that MUC13 functionally interacts and activates HER2 at Tyrp1248 in PDAC cells, leading to stimulation of HER2 signaling cascade including, ERK1/2, FAK, AKT and PAK1 as well as regulation of the growth, cytoskeleton remodeling, motility and invasion of PDAC cells - all collectively contributing to PDAC progression. The interaction between MUC13-HER2 binding resulting in their tumorigenic characteristics likely occurs at the 1st and 2nd but not the 3rd domains of MUC13 as the EGF 1 and 2 deletion mutant constructs of MUC13 failed to promote proliferation and invasion of cells. These phenotypic effects of MUC13-HER2 co-localization could be effectively compromised by depleting MUC13. MUC13-HER2 co-localization also held true in PDAC human tissues with a strong functional correlation that contributed to an increased degree of disorder and cancer aggressiveness. Conclusions: 1) MUC13 can be detected in formalin-fixed paraffin-embedded tissues using our anti-MUC13 MAb. 2) MUC13 co-localizes and activates HER2 and its downstream signaling cascade promoting PDAC progression in both cell lines and human tissue. 3) This process is reversed by depletion of MUC13. 4) This MUC13-HER2 interaction may potentially be manipulated for targeted therapeutics in patients harboring PDAC. Citation Format: Sheema Khan, Mara C. Ebeling, Mohammad Sikander, Murali M. Yallapu, Tomoko Ise, Satoshi Nagata, Stephen W. Behrman, Nadeem Zafar, Jim Y. Wan, Hemendra M. Ghimire, Peeyush Sahay, Prabhakar Pradhan, Meena Jaggi, Subhash C. Chauhan. MUC13 interaction with receptor tyrosine kinase HER2 drives pancreatic ductal adenocarcinoma progression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4592.

  • microrna 145 targets MUC13 and suppresses growth and invasion of pancreatic cancer
    Oncotarget, 2014
    Co-Authors: Sheema Khan, Mara C. Ebeling, Mohammad Sikander, Murali M. Yallapu, Stephen W. Behrman, Nadeem Zafar, Mohd Saif Zaman, Neeraj Chauhan, Ashley Yacoubian, Deepak Kumar
    Abstract:

    Pancreatic cancer has a poor prognosis due to late diagnosis and ineffective therapeutic multimodality. MUC13, a transmembrane mucin is highly involved in pancreatic cancer progression. Thus, understanding its regulatory molecular mechanisms may offer new avenue of therapy for prevention/treatment of pancreatic cancer. Herein, we report a novel microRNA (miR-145)-mediated mechanism regulating aberrant MUC13 expression in pancreatic cancer. We report that miR-145 expression inversely correlates with MUC13 expression in pancreatic cancer cells and human tumor tissues. miR-145 is predominantly present in normal pancreatic tissues and early Pancreatic Ductal Adenocarcinoma (PDAC) precursor lesions (PanIN I) and is progressively suppressed over the course of development from PanIN II/III to late stage poorly differentiated PDAC. We demonstrate that miR-145 targets 3' untranslated region of MUC13 and thus downregulates MUC13 protein expression in cells. Interestingly, transfection of miR-145 inhibits cell proliferation, invasion and enhances gemcitabine sensitivity. It causes reduction of HER2, P-AKT, PAK1 and an increase in p53. Similar results were found when MUC13 was specifically inhibited by shRNA directed at MUC13. Additionally, intratumoral injections of miR-145 in xenograft mice inhibited tumor growth via suppression of MUC13 and its downstream target, HER2. These results suggest miR-145 as a novel regulator of MUC13 in pancreatic cancer.

  • Functions and regulation of MUC13 mucin in colon cancer cells
    Journal of gastroenterology, 2013
    Co-Authors: Brij K. Gupta, Diane M. Maher, Mara C. Ebeling, Susan E. Puumala, Hiroyuki Aburatani, Meena Jaggi, Phillip Stephenson, Michael R. Koch, Subhash C. Chauhan
    Abstract:

    Background MUC13 is overexpressed and aberrantly localized in colon cancer tissue; however, the specific functions and regulation of MUC13 expression are unknown.

  • Abstract 5325: Role of MUC13 in colon cancer progression
    Tumor Biology, 2012
    Co-Authors: Brij K. Gupta, Diane M. Maher, Mara C. Ebeling, Douglas W. Lynch, Micheal R.d Koch, Susan E. Puumala, Hiroyuki Aburatani, Meena Jaggi, Subhash C. Chauhan
    Abstract:

    Colon cancer is the third most commonly diagnosed and second leading cause of cancer related deaths in the United States. Mucin 13 (MUC13), a high molecular weight glycoprotein, is a recently identified transmembrane mucin. While MUC13 is known to be over expressed in gastric and ovarian cancers, limited information about MUC13 is available in colon cancer progression. Therefore, our aim is to investigate the expression profile, potential role and possible regulatory pathways of MUC13 in colon cancer progression. We performed immunohistochemical analysis using MUC13 monoclonal antibody (ppz0020) to determine expression profile and aberrant localization of MUC13 in colon cancer cells. Our results indicate that MUC13 is over expressed in colon cancer predominantly at the apical surface. MUC13 is also aberrantly localized (cytoplasmic and nuclear) in metastasized colon cancer and in liver metastasis. We also correlated MUC13 expression levels with clinico-pathological parameters of patients. Increased MUC13 expression correlated with increased tumor size and poorly differentiated colon cancer. To determine the functional roles of MUC13 we generated stable MUC13 over expressing and MUC13 knock down cells and performed functional assays. Our results demonstrate that MUC13 increased cell proliferation, colony formation, cell migration and cell invasion characteristics of colon cancer cells. In order to investigate proteins that are affected by MUC13, we performed immunoblot assays. Immunoblot analysis revealed that MUC13 increased expression of several proteins that are associated with colon cancer progression and metastasis such as Bmi-1(B cell specific lymphoma moloney murine leukemia integration site-1), TERT (telomerase reverse transcriptase), Shh (sonic hedgehog) and GATA1 (GATA binding protein 1). We also examined potential signaling pathways that may be associated with MUC13 colon carcinogenesis. We found that MUC13 increased expression of mitogen activated kinase (MAPK) pathway members such as ERK-1 and phospho ERK-1. In order to determine potential transcriptions factors that may regulate MUC13 expression, we screened expression of various transcription factors by real time PCR. Significantly high expression of STAT5B (signal transducers and activators of transcription factor 5B) was detected in cell lines expressing endogenously high levels of MUC13. In order to confirm transcription factor STAT5B binding sites in the MUC13 promotor, we performed chromatin immunoprecipitation (CHIP). CHIP analysis revealed that STAT5B binds to the promoter of MUC13. In summary, our study revealed that MUC13 is over expressed in colon cancer and aberrantly localized in metastasis. Over expression of MUC13 increases cell proliferation, colony formation, cell migration, cell invasion and expression of metastasis associated proteins partly via MAPK pathway. MUC13 expression may be regulated through binding of STAT5B to the MUC13 promoter. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5325. doi:1538-7445.AM2012-5325

  • MUC13 mucin augments pancreatic tumorigenesis
    Molecular Cancer Therapeutics, 2012
    Co-Authors: Subhash C. Chauhan, Diane M. Maher, Mara C. Ebeling, Hiroyuki Aburatani, Akira Watanabe, Michael D Koch, Y L Lio, Meena Jaggi
    Abstract:

    The high death rate of pancreatic cancer is attributed to the lack of reliable methods for early detection and underlying molecular mechanisms of its aggressive pathogenesis. Although MUC13, a newly identified transmembrane mucin, is known to be aberrantly expressed in ovarian and gastro-intestinal cancers, its role in pancreatic cancer is unknown. Herein, we investigated the expression profile and functions of MUC13 in pancreatic cancer progression. The expression profile of MUC13 in pancreatic cancer was investigated using a recentlygeneratedmonoclonalantibody(clonePPZ0020)andpancreatic tissuemicroarrays. Theexpressionof MUC13 was significantly (P < 0.005) higher in cancer samples compared with normal/nonneoplastic pancreatic tissues. For functional analyses, full-length MUC13 was expressed in MUC13 null pancreatic cancer cell lines, MiaPaca and Panc1. MUC13 overexpression caused a significant (P < 0.05) increase in cell motility, invasion, proliferation, and anchorage-dependent or -independent clonogenicity while decreasing cell‐cell and cell-substratum adhesion. Exogenous MUC13 expression significantly (P < 0.05) enhanced pancreatic tumor growth and reduced animal survival in a xenograft mouse model. These tumorigenic characteristics correlated with the upregulation/phosphorylation of HER2, p21-activated kinase 1 (PAK1), extracellular signal-regulated kinase (ERK), Akt, and metastasin (S100A4), and the suppression of p53. Conversely, suppression of MUC13 in HPAFII pancreatic cancer cells by short hairpin RNA resulted in suppression of tumorigenic characteristics, repression of HER2, PAK1, ERK, and S100A4, and upregulation of p53. MUC13 suppression also significantly (P < 0.05) reduced tumor growth and increased animal survival. These results imply a role of MUC13 in pancreatic cancer and suggest its potential use as a diagnostic and therapeutic target. Mol Cancer Ther; 11(1); 24–33. � 2011 AACR.