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Eleftherios P Diamandis - One of the best experts on this subject based on the ideXlab platform.

  • biochemical characterization of human tissue kallikrein 15 and examination of its potential role in cancer
    Clinical Biochemistry, 2018
    Co-Authors: Panagiota Filippou, Ioannis Prassas, Annie H Ren, Michail Dimitrios Papaioannou, Sudarshan Bala, Davor Brinc, Theano D Karakosta, Eleftherios P Diamandis
    Abstract:

    Abstract Objective Human tissue kallikrein 15 (KLK15) is the last cloned member of the KLK-related gene family. Despite being implicated in multiple cancers, its pathophysiological role remains unknown. We aimed to biochemically characterize KLK15 and preliminarily study its role in cancer. Design & methods Recombinant KLK15 protein was produced, purified to homogeneity and quantified by mass spectrometry (parallel reaction monitoring analysis). We profiled the enzymatic activity of KLK15 using fluorogenic peptide substrates, and performed kinetic analysis to discover the cleavage sites. As KLK15 has mainly been associated with prostate cancer, we used a degradomic approach and subsequent KEGG pathway analysis to identify a number of putative protein substrates in the KLK15-treated prostate cancer cell line PC3. Results We discovered trypsin-like activity in KLK15, finding that it cleaves preferentially after arginine (R). The enzymatic activity of KLK15 was regulated by different factors such as pH, cations and serine protease inhibitors. Notably, we revealed that KLK15 most likely interacts with the extracellular matrix (ECM) receptor group. Conclusion To our knowledge, this is the first study that experimentally verifies the trypsin-like activity of KLK15. We show here for the first time that KLK15 may be able to cleave many ECM components, similar to several members of the KLK family. Thus the protease could potentially be linked to tumorigenesis by promoting metastasis via this mechanism.

  • Human tissue Kallikreins: Blood levels and response to radiotherapy in intermediate risk prostate cancer
    Radiotherapy and Oncology, 2017
    Co-Authors: Nicola J Nasser, John Thoms, Antoninus Soosaipillai, Melania Pintilie, Eleftherios P Diamandis, Ri Wang, Robert G Bristow
    Abstract:

    Abstract Objectives Kallikreins are serine proteases over expressed in many malignancies. In this study, we measure changes in serum kallikrein (KLKs) levels during intensity-modulated radiotherapy (IMRT) in prostate cancer patients, and find potential correlations between serum kallikrein level and normal tissues toxicity during radiation. Methods Forty-nine patients with prostate cancer were recruited as follows: group 1, definitive standard fractionation IMRT (78Gy in 39 fractions, n =15); group 2, definitive hypofractionated IMRT (60Gy in 20 fractions, n =15); and group 3, IMRT postprostatectomy (66Gy in 33 fractions, n =19). Patients treated with definitive radiation therapy were intermediate risk. Blood samples were collected at baseline and quarterly during IMRT and at each follow-up visit. Acute toxicity was graded weekly during radiotherapy using CTC-AE v4.0 criteria. Multiplexed immunoassays were used to quantify total, free, and intact Prostate Specific Antigen (PSA), as well as Kallikreins 2, 4, 6, and 11. Results The serum kallikreins, PSA (total, free and intact), KLK2, 6, and 11 change significantly after definitive radiotherapy. KLK2 and intact PSA decrease as fast as two weeks after initiation of radiation, while the first significant decrease in total and free PSA is noted only at the completion of radiation. KLK6 and KLK11 surge temporarily during radiation therapy and decrease below baseline levels at 8weeks and 12months, respectively after completion of radiation. KLK4 levels did not change with radiation. There was no correlation between GU or GI toxicities and serum kallikreins. Conclusions PSA, KLK2, 6, and 11, change significantly after definitive prostate radiotherapy, though KLK2 and PSA decrease by the end of the radiation course while KLK6 and KLK11 decrease significantly starting at 2 and 12months, respectively, after radiation. There was no correlation between GU or GI toxicities and serum kallikreins.

  • Kallikrein-related peptidase 7 (KLK7) is a proliferative factor that is aberrantly expressed in human colon cancer.
    Biological chemistry, 2014
    Co-Authors: Francine Walker, Antoninus Soosaipillai, Eleftherios P Diamandis, Katerina Oikonomopoulou, Viktor Magdolen, Pascal Nicole, Abdelhak Jallane, Valentine Mosbach, Dalila Darmoul
    Abstract:

    Emerging evidence indicates that serine proteases of the tissue kallikrein-related peptidases family (KLK) are implicated in tumorigenesis. We recently reported the ectopic expression of KLK4 and KLK14 in colonic cancers and their signaling to control cell proliferation. Human tissue kallikrein-related peptidase 7 (KLK7) is often dysregulated in many cancers; however, its role in colon tumorigenesis has not yet been established. In the present study, we analyzed expression of KLK7 in 15 colon cancer cell lines and in 38 human colonic tumors. In many human colon cancer cells, KLK7 mRNA was observed, which leads to KLK7 protein expression and secretion. Furthermore, KLK7 was detected in human colon adenocarcinomas, but it was absent in normal epithelia. KLK7 overexpression in HT29 colon cancer cells upon stable transfection with a KLK7 expression plasmid resulted in increased cell proliferation. Moreover, subcutaneous inoculation of transfected cells into nude mice led to increased tumor growth that was associated with increased tumor cell proliferation as reflected by a positive Ki-67 staining. Our results demonstrate the aberrant expression of KLK7 in colon cancer cells and tissues and its involvement in cell proliferation in vitro and in vivo. Thus, KLK7 may represent a potential therapeutic target for human colon tumorigenesis.

  • induction of complement c3a receptor responses by kallikrein related peptidase 14
    Journal of Immunology, 2013
    Co-Authors: Katerina Oikonomopoulou, Eleftherios P Diamandis, Morley D. Hollenberg, Robert A Deangelis, Hui Chen, Danielz Ricklin, John D Lambris
    Abstract:

    Activation of the complement system is primarily initiated by pathogen- and damage-associated molecular patterns on cellular surfaces. However, there is increasing evidence for direct activation of individual complement components by extrinsic proteinases as part of an intricate crosstalk between physiological effector systems. We hypothesized that kallikrein-related peptidases (KLKs), previously known to regulate inflammation via proteinase-activated receptors, can also play a substantial role in innate immune responses via complement. Indeed, KLKs exemplified by KLK14 were efficiently able to cleave C3, the point of convergence of the complement cascade, indicating a potential modulation of C3-mediated functions. By using in vitro fragmentation assays, mass spectrometric analysis, and cell signaling measurements, we pinpointed the generation of the C3a fragment of C3 as a product with potential biological activity released by the proteolytic action of KLK14. Using mice with various complement deficiencies, we demonstrated that the intraplantar administration of KLK14 results in C3-associated paw edema. The edema response was dependent on the presence of the receptor for C3a but was not associated with the receptor for the downstream complement effector C5a. Our findings point to C3 as one of the potential substrates of KLKs during inflammation. Given the wide distribution of the KLKs in tissues and biological fluids where complement components may also be expressed, we suggest that via C3 processing, tissue-localized KLKs can play an extrinsic complement-related role during activation of the innate immune response.

  • Kallikrein-related peptidase signaling in colon carcinoma cells: targeting proteinase-activated receptors.
    Biological Chemistry, 2012
    Co-Authors: Hyunjae Chung, Eleftherios P Diamandis, Magda Hamza, Katerina Oikonomopoulou, Valérie Gratio, Mahmoud Saifeddine, G. Duke Virca, Morley D. Hollenberg, Dalila Darmoul
    Abstract:

    We hypothesized that kallikrein-related peptidase 14 (KLK14) is produced by colonic tumors and can promote tumorigenesis by activating proteinase-activated receptors (PARs). We found that KLK14 is expressed in human colon adenocarcinoma cells but not in adjacent cancer-free tissue; KLK14 mRNA, present in colon cancer, leads to KLK14 protein expression and secretion; and KLK14 signals viaPAR-2 in HT-29 cells to cause (1) receptor activation/internalization, (2) increases in intracellular calcium, (3) stimulation of ERK1/2/MAP kinase phosphorylation, and (4) cell proliferation. We suggest that KLK14, acting via PAR-2, represents an autocrine/paracrine regulator of colon tumorigenesis.

Andreas Scorilas - One of the best experts on this subject based on the ideXlab platform.

  • mrna overexpression of kallikrein related peptidase 14 KLK14 is an independent predictor of poor overall survival in chronic lymphocytic leukemia patients
    Clinical Chemistry and Laboratory Medicine, 2016
    Co-Authors: Christos K Kontos, Panagiotis G Adamopoulos, Sotirios Papageorgiou, Vassiliki Pappa, Andreas Scorilas
    Abstract:

    Tissue kallikrein and kallikrein-related peptidases (KLKs) compose a family of serine endopeptidases with much clinical interest in oncology, as their potential as diagnostic and/or prognostic molecular biomarkers in several human malignancies has already been evidenced. However, none of the members of this family has ever been studied in hematological malignancies. Based on our preliminary results regarding the differential mRNA expression of several KLK genes in peripheral blood mononuclear cells (PBMCs) of patients with chronic lymphocytic leukemia (CLL) compared to healthy blood donors, we decided to study the diagnostic and prognostic potential of KLK14 mRNA expression in CLL.Total RNA was isolated from 69 CLL patients and 31 non-leukemic blood donors. After reverse transcription of poly(A)-RNA, KLK14 mRNA levels were quantified using a sensitive and accurate quantitative real-time PCR (qPCR) methodology.According to ROC analysis, KLK14 mRNA overexpression successfully discriminated CLL patients from normal population (area under the curve [AUC] 0.89, 95% confidence interval [CI] 0.83-0.95, p<0.001). Moreover, although not clearly related to clinical staging or other prognostic factors including IGHV mutational status and CD38 expression, strong KLK14 mRNA expression was shown to predict reduced overall survival of CLL patients (p=0.026) using Kaplan-Meier survival analysis. The unfavorable prognostic value of KLK14 mRNA overexpression in CLL patients' PBMCs was independent of established prognostic factors of the disease, as shown by multivariate Cox regression analysis (hazard ratio [HR] 14.65, 95% CI 1.81-118.36, p=0.012).KLK14 mRNA expression merits further investigation as a potential prognostic biomarker of overall survival of patients with CLL.

  • mRNA overexpression of kallikrein-related peptidase 14 (KLK14) is an independent predictor of poor overall survival in chronic lymphocytic leukemia patients.
    Clinical chemistry and laboratory medicine, 2016
    Co-Authors: Christos K Kontos, Panagiotis G Adamopoulos, Sotirios Papageorgiou, Vassiliki Pappa, Andreas Scorilas
    Abstract:

    Tissue kallikrein and kallikrein-related peptidases (KLKs) compose a family of serine endopeptidases with much clinical interest in oncology, as their potential as diagnostic and/or prognostic molecular biomarkers in several human malignancies has already been evidenced. However, none of the members of this family has ever been studied in hematological malignancies. Based on our preliminary results regarding the differential mRNA expression of several KLK genes in peripheral blood mononuclear cells (PBMCs) of patients with chronic lymphocytic leukemia (CLL) compared to healthy blood donors, we decided to study the diagnostic and prognostic potential of KLK14 mRNA expression in CLL.Total RNA was isolated from 69 CLL patients and 31 non-leukemic blood donors. After reverse transcription of poly(A)-RNA, KLK14 mRNA levels were quantified using a sensitive and accurate quantitative real-time PCR (qPCR) methodology.According to ROC analysis, KLK14 mRNA overexpression successfully discriminated CLL patients from normal population (area under the curve [AUC] 0.89, 95% confidence interval [CI] 0.83-0.95, p

  • Significant alterations in the expression pattern of kallikrein-related peptidase genes KLK4, KLK5 and KLK14 after treatment of breast cancer cells with the chemotherapeutic agents epirubicin, docetaxel and methotrexate
    Tumor Biology, 2013
    Co-Authors: Georgia Papachristopoulou, Maroulio Talieri, Andreas Scorilas
    Abstract:

    Given that 1.3 million new cases of breast cancer are universally registered among women and approximately 36 % of the patients die annually, the revelation of new predictive markers for treatment efficiency is of vital importance. Recently, our group has depicted that KLK4 , KLK5 , and KLK14 are differentially expressed in breast carcinoma. The objective of this study was to determine and investigate the expression pattern of the KLK4 , KLK5 , and KLK14 genes in breast cancer cells after treatment with established chemotherapeutic agents. We evaluated these genes’ expression after treatment of the BT-20 cells with epirubicin, docetaxel and methotrexate, determining their cytotoxic effect by MTT and trypan blue assays. The relative quantification of genes’ mRNA levels was performed by using the SYBR Green® chemistry, and the HPRT1 served as an endogenous control gene. The drugs triggered apoptosis in treated cells and induced deregulations in the expression of the above KLKs . The most significant alterations were a 12-fold and tenfold increase of KLK5 in docetaxel and methotrexate-treated cells, respectively, while the KLK4 levels decreased by ten-fold in epirubicin, five-fold in docetaxel and twenty-fold in methotrexate treated-cells, compared to the untreated ones. In the case of KLK14 levels, a twofold increase in epirubicin and threefold decrease in methotrexate-treated cells were observed. Present significant alterations in the expression pattern of KLK4 , KLK5 , and KLK14 could comprise an initial stage for predicting chemotherapy response in breast cancer and should be further investigated as predictive markers in the future.

  • Parallel overexpression and clinical significance of kallikrein-related peptidases 7 and 14 (KLK7KLK14) in colon cancer
    Thrombosis and haemostasis, 2012
    Co-Authors: Marina Devetzi, Andreas Scorilas, Theoni Trangas, Dimitris Xynopoulos, Maroulio Talieri
    Abstract:

    Currently available colon cancer (CC) markers lack sensitivity and specificity. Kallikrein-related peptidases (KLKs) present a new class of biomarkers under investigation for diverse diseases, including cancer. KLKs are co-expressed in various tissues participating in proteolytic cascades. KLK7 in human tumours facilitates metastasis by degrading components of the extracellular matrix. KLK14 promotes tumourigenesis by activating proteinase-activated receptors. In the present study we examined the concomitant expression of KLK7 and KLK14 in245 colonic tissue specimens from 175 patients; 70 were pairs of cancerous-normal tissues, 31 were cancerous tissues and 74 were colonic adenomas. We used quantitative real-time PCR and proved that both genes are up-regulated in CC at the mRNA level. Receiver-operating characteristic (ROC) analysis of our results showed that both genes have discriminatory value between CC and adenoma tissues, with KLK14 obtaining greater distinguishing power (area under the curve [AUC]=0.708 for KLK14; AUC=0.669 for KLK7). Current work showed that the two genes are fairly co-expressed in all three types of colon tissues examined (normal rs=0.667, p

  • The kallikrein-related peptidase 13 (KLK13) gene is substantially up-regulated after exposure of gastric cancer cells to antineoplastic agents
    Tumor Biology, 2012
    Co-Authors: Dimitra Florou, Konstantinos Mavridis, Andreas Scorilas
    Abstract:

    Gastric cancer constitutes one of the most common neoplasms globally. Kallikrein-related peptidases have attracted interest as potential tumor markers and future targets for novel cancer therapeutics. We have recently reported KLK13 clinical importance as a favorable prognostic biomarker for gastric cancer patients’ survival. By aiming to explore how the molecular profile of KLK13 is modified in stomach cancer cells treated with antineoplastic drugs, we examined, for the first time, the mRNA alterations of this gene following gastric cancer cells’ exposure to the prominent chemotherapeutic substances epirubicin, oxaliplatin, or methotrexate. The antiproliferative effects of these agents, on AGS cells’ growth, were determined by the 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide and trypan blue assays. Total RNA, isolated from the harvested cells, was reverse-transcribed to cDNA. KLK13 levels were quantified via real-time PCR using the SYBR Green chemistry. The relative changes of KLK13 expression were calculated with the comparative C _t (2^−ddCt) method. Distinct KLK13 profiles resulted from AGS cells’ incubation with epirubicin or methotrexate for 24, 36, and 48 h. KLK13 expression increased in a time-dependent manner up to 5.70 times (for epirubicin) or 5.76 times (for methotrexate) at 48 h compared with the corresponding untreated cells. According to our results, KLK13 expression is implicated in the molecular pathways that are triggered after administration of anticancer agents on gastric cancer cells. Moreover, our data support the possibility that KLK13 may be exploited as a future molecular predictor of gastric cancer cells’ response to chemotherapy.

George M. Yousef - One of the best experts on this subject based on the ideXlab platform.

  • prognostic significance of human tissue kallikrein related peptidases 11 and 15 in gastric cancer
    Tumor Biology, 2016
    Co-Authors: George M. Yousef, Catherine J. Streutker, David L Kolin, Fabio Rotondo, Mena N Bassily, Kalman Kovacs, Christine Brezdenmasley
    Abstract:

    Human tissue kallikrein-related peptidases (KLK) are a group of 15 serine proteases which have been investigated as potential cancer biomarkers. This study determined the prognostic significance of KLK 11 and 15 expression levels in gastric carcinoma specimens. Expression of KLK11 and KLK15 was assessed by immunohistochemistry staining on a tissue microarray constructed from 113 gastrectomy specimens from patients with gastric carcinoma. To minimize inter-observer variability, expression levels were quantified using an automated algorithm. Epithelial and stromal staining were assessed separately. Both KLK11 and KLK15 were expressed in gastric carcinoma. There was no significant correlation between either KLK11 or KLK15 expression and the presence of lymph node metastases or Lauren classification (intestinal vs. diffuse). Higher levels of KLK11 expression in gastric carcinoma were associated with significantly worse overall survival (p = 0.008), and a multivariate analysis showed that it had prognostic value independent of tumor stage and differentiation (p = 0.004). Variations in KLK15 expression were not significantly associated with prognosis. KLK11 shows promise as a potential independent prognostic marker for gastric carcinoma.

  • Kallikreins are involved in an miRNA network that contributes to prostate cancer progression.
    Biological chemistry, 2014
    Co-Authors: Sara Samaan, Zsuzsanna Lichner, Qiang Ding, Carol Saleh, Joseph N. Samuel, Catherine J. Streutker, George M. Yousef
    Abstract:

    Abstract: MicroRNAs (miRNAs) are short RNA nucleo-tides that negatively regulate their target genes. They are differentially expressed in prostate cancer. Kallikreins are genes that encode serine proteases and are dysregu-lated in cancer. We elucidated a miRNA-kallikrein net-work that can be involved in prostate cancer progression. Target prediction identified 23 miRNAs that are dysregu-lated between high and low risk biochemical failure and are predicted to target five kallikreins linked to prostate cancer; KLK2 , KLK3 , KLK4 , KLK14 and KLK15 . We also identified 14 miRNAs that are differentially expressed between Gleason grades and are predicted to target these kallikreins. This demonstrates that kallikreins are downstream effectors through which miRNAs influ-ence tumor progression. We show, through in-silico and experimental analysis, that miR-378/422a and its gene targets PIK3CG , GRB2 , AKT3 , KLK4 and KLK14 form an integrated circuit in prostate cancer. Our analysis shows that a minisatellite sequence in the kallikrein locus con-sists of a number of microsatellite repeats that represent predicted miRNA response elements. A number of kal-likrein and non-kallikrein prostate cancer-related genes share these microsatellite repeats. We validated some of these interactions in prostate cancer cell lines. Finally, we provide preliminary evidence on the presence of a miRNA-mediated cross-talk between kallikreins, includ-ing a kallikrein pseudogene.

  • The canine kallikrein-related peptidase 14: structural characterization, alternative splicing and differential expression in mammary cancer.
    Gene, 2009
    Co-Authors: Katerina Angelopoulou, Ioannis Prassas, George M. Yousef
    Abstract:

    Abstract Human kallikrein-related peptidases (KLKs) represent a family of 15 serine proteases with diverse roles in many physiological and pathological processes, including carcinogenesis. In the dog, only two KLK genes are known; dKLK1 and canine arginine esterase . Recently, 12 other genes have been predicted using computational methods, but none of them has ever been experimentally validated in canine tissues. In this study we investigated the expression of Canis familiaris KLK14 , (CANFA) KLK14 , in normal and cancerous mammary tissues. First, it was demonstrated that the in-silico determined canine KLK14 mRNA (GenBank accession no: XM_541464) has been wrongfully predicted on its 5′-end (nucleotides 1–88). The (CANFA) KLK14 mRNA sequence presented here, has high homology to its human counterpart and exhibits all defining- KLK features. In addition to the classical form of the gene, five splice variants were also identified. The splicing events involved 5′-truncation or complete elimination of exon 4 and/or retention of intron I. All encoded protein products of the splice variants were predicted to be truncated and catalytically inactive. The classical form and variant 3 were almost ubiquitously expressed in both normal and neoplastic tissues. Variant 1 was predominantly detected in normal tissues. The classical form and variants 1 and 2 exhibited lower expression levels in tumor compared to normal tissues. Moreover, an Ile155Asn polymorphism was identified. This is the first report on the structural characterization, alternative splicing and tissue expression of canine KLK14 mRNA. These findings may form the basis for the establishment of comparative studies investigating KLK functions in health and disease using the dog as a model.

  • Differential expression of the human kallikrein gene 14 (KLK14) in normal and cancerous prostatic tissues
    The Prostate, 2003
    Co-Authors: George M. Yousef, Andreas Scorilas, Maryellen Polymeris, Klaus Jung, Monika Jung, Carsten Stephan, Glen Kristiansen, Mohamed Abd Ellatif, Eleftherios P Diamandis
    Abstract:

    BACKGROUND. Many members of the human kallikrein gene family are differentially expressed in cancer and a few have potential as diagnostic/prognostic markers. KLK14 is a newlydiscoveredhumankallikreingenethatismainlyexpressedinthecentralnervoussystem and endocrine tissues. Since KLK14 was found to be regulated by steroid hormones in prostate cancer cell lines, we hypothesized that it will be differentially expressed in prostate cancer tissues compared to their normal counterparts. METHODS. Matched prostate tissue samples from the cancerous and non-cancerous parts of the same prostates were obtained from 100 patients who underwent radical prostatectomy. Quantitative analysis of KLK14 expression levels were performed by real-time RT-PCR using SYBR Green I dye on the LightCycler TM system. Associations with clinico-pathological parameters were analyzed. RESULTS. KLK14 overexpression in the cancerous compared to non-cancerous tissue was found in 74% of patients (P 6)comparedto Gleason score ¼6 tumors (P ¼0.027). No correlation was found between KLK14 tissue expression levels and serum prostate-specific antigen. CONCLUSIONS. KLK14 expression is significantly higher in cancerous compared to noncancerous prostatic tissue. The up-regulation of the KLK14 gene in advanced and more aggressive tumors may indicate a possible role for the hK14 protein in tumor spread and opens the possibility of hK14 being a candidate new marker for prostate cancer diagnosis and prognosis. Prostate 56: 287–292, 2003. # 2003 Wiley-Liss, Inc.

  • parallel overexpression of seven kallikrein genes in ovarian cancer
    Cancer Research, 2003
    Co-Authors: George M. Yousef, Antoninus Soosaipillai, Andreas Scorilas, Dionyssios Katsaros, S. Fracchioli, Maryellen Polymeris, George M Yacoub, Cynthia Popalis, Eleftherios P Diamandis
    Abstract:

    Recent evidence suggests that many members of the human kallikrein (KLK) gene family are differentially regulated in ovarian cancer and have potential as diagnostic and/or prognostic markers. We used the serial analysis of gene expression and expressed sequence tag databases of the Cancer Genome Anatomy Project to perform in silico analyses of the expression pattern of the 15 human KLK genes in normal and cancerous ovarian tissues and cell lines. We found that seven KLK genes (KLK5, KLK6, KLK7, KLK8, KLK10, KLK11, and KLK14) are up-regulated in ovarian cancer. Probing 2 normal and 10 ovarian cancer serial analysis of gene expression libraries with gene-specific tags for each KLK indicated that whereas no expression was detected in any normal libraries (with the exception of KLK10 and KLK11), these KLKs were found to be expressed with moderate densities (103–408 tags per million) in 40–60% of the ovarian cancer libraries analyzed. These data were verified by screening the expressed sequence tag databases, where 78 of 79 mRNA clones isolated for these genes were from ovarian cancer libraries. X-profiler comparison of the pools of normal and cancerous ovaries identified a significant difference in expression levels for six of the seven KLKs. We experimentally verified the overexpression of six KLK proteins in cancer versus normal or benign tissues with highly sensitive and specific immunofluorometric assays. A statistically significant stepwise increase in protein levels was found among normal, benign, and cancerous ovarian tissues. The expression of five KLKs showed a strong degree of correlation at the protein level, suggesting the existence of a common mechanism or pathway that controls the expression of this group of adjacent genes during ovarian cancer progression.

Judith A. Clements - One of the best experts on this subject based on the ideXlab platform.

  • Pericellular regulation of prostate cancer expressed kallikrein-related peptidases and matrix metalloproteinases by cell surface serine proteases.
    American journal of cancer research, 2017
    Co-Authors: Janet C. Reid, Judith A. Clements, Viktor Magdolen, Admire Matsika, Claire M. Davies, Amy Broomfield, Nigel C. Bennett, Bhuvana Srinivasan, John D Hooper
    Abstract:

    We provide evidence of a pericellular network of proteases that are elevated and co-expressed in prostate cancer. The network involves the membrane bound serine proteases hepsin and TMPRSS2, the secreted kallikrein-related peptidases KLK4 and KLK14, and the secreted matrix metalloproteinases MMP-3 and MMP-9. Western blot analysis of cell lysates, conditioned cell culture media, immunoprecipitates and cell surface proteins, demonstrates a network of interactions centred largely at the plasma membrane, with the Arg/Lys specific proteases hepsin and TMPRSS2 key regulators of the network. Our data demonstrate that like TMPRSS2, hepsin is able to autoactivate. Active hepsin degrades KLK4, generating a cell associated degradation product with corresponding reduction in levels of cell-free KLK4. In contrast hepsin activates KLK14. TMPRSS2 appears to cleave amino terminal to the KLK4 activation site such that it is available for further processing to generate the active KLK4 protease. In contrast with hepsin, TMPRSS2 degrades KLK14. In addition to these direct mechanisms of regulation, hepsin and TMPRSS2 indirectly modulate KLK4 activity by cleaving the KLK4-activating protease MMP-3. Hepsin and TMPRSS2 also activate MMP-9, which similar to MMP-3, associates with the cell surface. Interestingly our data also show that proteolysis occurs between the membrane spanning and catalytic domains of hepsin and TMPRSS2. Hepsin cleavage occurs via an autoproteolytic mechanism, whereas TMPRSS2 cleavage is mediated by KLK14. Hepsin and TMPRSS2 are not shed from the cell surface but proteolysis likely disrupts domains that regulate the proteolytic activity of these proteases. Immunocytochemical analyses demonstrate that hepsin and TMPRSS2 colocalize on the cell surface with the secreted serine proteases KLK4 and KLK14, only in membrane protrusions, suggesting that reciprocal proteolytic interactions occur in defined cellular structures that are important during cancer dissemination for cell migration, invasion and survival. Also of note, immunohistochemical analysis of serial sections of prostate tumor demonstrated significant overlapping expression of the six proteases in vivo. Collectively these data suggest the possibility that the novel proteolytic network identified by us, will be most important during active dissemination of prostate cancers, and that its disruption could inhibit metastasis.

  • The Human Tissue Kallikrein and Kallikrein-related Peptidase Family
    Handbook of Proteolytic Enzymes, 2013
    Co-Authors: Judith A. Clements, John D Hooper, Ying Dong
    Abstract:

    The human kallikrein-related peptidases are a subgroup of trypsin and chymotrypsin-like serine peptidases that are characterized by their homology to tissue kallikrein or kallikrein 1 (KLK1) encoded by the KLK1 gene (reviewed in[1-4]). The human KLK locus spans an approximately 320 kb region on chromosome 19q13.3-13.4 and contains fifteen genes encoding KLK1 and fourteen other kallikrein-related peptidases, KLK2-KLK15, which have been named contiguously in the locus in the order of their discovery [5-8] (Figure 606.1). It is the largest contiguous cluster of serine protease encoding genes in the human genome which has evolved from gene duplication of KLK1 and then subsequent reduplication of the newly evolved KLK genes [2]. The high conservation noted for KLK1-KLK3 (62-77%) reflects the proposed duplication of the KLK1 gene that produced the KLK2 gene which further generated the KLK3 gene. In contrast, the newer KLK4-KLK15 proteases share much less similarity, from 24-66%, although strong homology between KLK4 and KLK5, KLK9 and KLK11, and KLK10 and KLK12 suggests these genes are duplications of each other [2]...

  • Selective Cleavage of Human Sex Hormone-Binding Globulin by Kallikrein-Related Peptidases and Effects on Androgen Action in LNCaP Prostate Cancer Cells
    Endocrinology, 2012
    Co-Authors: Washington Y. Sanchez, John D Hooper, Judith A. Clements, Janet C. Reid, Simon J. De Veer, Joakim E. Swedberg, Eui-ju Hong, Terry Walsh, Geoffrey L. Hammond, Jonathan M. Harris
    Abstract:

    Stimulation of the androgen receptor via bioavailable androgens, including testosterone and testosterone metabolites, is a key driver of prostate development and the early stages of prostate cancer. Androgens are hydrophobic and as such require carrier proteins, including sex hormone-binding globulin (SHBG), to enable efficient distribution from sites of biosynthesis to target tissues. The similarly hydrophobic corticosteroids also require a carrier protein whose affinity for steroid is modulated by proteolysis. However, proteolytic mechanisms regulating the SHBG/androgen complex have not been reported. Here, we show that the cancer-associated serine proteases, kallikrein-related peptidase (KLK)4 and KLK14, bind strongly to SHBG in glutathione S-transferase interaction analyses. Further, we demonstrate that active KLK4 and KLK14 cleave human SHBG at unique sites and in an androgen-dependent manner. KLK4 separated androgen-free SHBG into its two laminin G-like (LG) domains that were subsequently proteolyti...

  • Selective cleavage of human sex hormone-binding globulin by kallikrein-related peptidases and effects on androgen action in LNCaP prostate cancer cells
    2012
    Co-Authors: Washington Y. Sanchez, John D Hooper, Judith A. Clements, Janet C. Reid, Simon J. De Veer, Joakim E. Swedberg, Eui-ju Hong, Terry Walsh, Geoffrey L. Hammond, Jonathan M. Harris
    Abstract:

    Free to read on publisher website Stimulation of the androgen receptor via bioavailable androgens, including testosterone and testosterone metabolites, is a key driver of prostate development and the early stages of prostate cancer. Androgens are hydrophobic and as such require carrier proteins, including sex hormone-binding globulin (SHBG), to enable efficient distribution from sites of biosynthesis to target tissues. The similarly hydrophobic corticosteroids also require a carrier protein whose affinity for steroid is modulated by proteolysis. However, proteolytic mechanisms regulating the SHBG/androgen complex have not been reported. Here, we show that the cancer-associated serine proteases, kallikrein-related peptidase (KLK)4 and KLK14, bind strongly to SHBG in glutathione S-transferase interaction analyses. Further, we demonstrate that active KLK4 and KLK14 cleave human SHBG at unique sites and in an androgen-dependent manner. KLK4 separated androgen-free SHBG into its two laminin G-like (LG) domains that were subsequently proteolytically stable even after prolonged digestion, whereas a catalytically equivalent amount of KLK14 reduced SHBG to small peptide fragments over the same period. Conversely, proteolysis of 5α-dihydrotestosterone (DHT)-bound SHBG was similar for both KLKs and left the steroid binding LG4 domain intact. Characterization of this proteolysis fragment by [(3)H]-labeled DHT binding assays revealed that it retained identical affinity for androgen compared with full-length SHBG (dissociation constant = 1.92 nM). Consistent with this, both full-length SHBG and SHBG-LG4 significantly increased DHT-mediated transcriptional activity of the androgen receptor compared with DHT delivered without carrier protein. Collectively, these data provide the first evidence that SHBG is a target for proteolysis and demonstrate that a stable fragment derived from proteolysis of steroid-bound SHBG retains binding function in vitro.

  • Identification and Characterization of KLK14 , a Novel Kallikrein Serine Protease Gene Located on Human Chromosome 19q13.4 and Expressed in Prostate and Skeletal Muscle
    Genomics, 2001
    Co-Authors: John D Hooper, Tracey J. Harvey, Stephen Myers, Linda K Ashworth, Judith A. Clements
    Abstract:

    The kallikreins are a subfamily of serine proteases encoded in human, mouse, and rat by highly conserved tightly clustered multigene families. Here we report the identification and characterization of KLK14, a novel kallikrein gene located within the human kallikrein locus at 19q13.4. KLK14 is approximately 5.4 kb in length spanning seven exons and, by Northern blot analysis, transcribes two alternative transcripts present only in prostate (1.5 kb) and skeletal muscle (1.9 kb). The protein product, K14, predicted to be a 251-amino-acid secreted serine protease with trypsin-like substrate specificity, is translated in vitro with a molecular mass of ∼31 kDa. In situ hybridization revealed that, in prostate, KLK14 is expressed by both benign and malignant glandular epithelial cells, thus exhibiting an expression pattern similar to that of two other prostatic kallikreins, KLK2 and KLK3, which encode K2 and prostate-specific antigen, respectively.

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  • expression profile of human tissue kallikrein 15 provides preliminary insights into its roles in the prostate and testis
    Clinical Biochemistry, 2018
    Co-Authors: Antoninus Soosaipillai, Panagiota Filippou, Annie H Ren, Michail Dimitrios Papaioannou, Dimitrios Korbakis, Roaa Safar
    Abstract:

    Abstract Background Human tissue kallikrein 15 (KLK15) is the latest member of the kallikrein-related peptidase family. Little is known about the pathophysiological roles of KLK15. Previous studies implied a role of KLK15 in prostate cancer . Methods In the present study, we examined KLK15 protein expression using a new immunoassay (ELISA) and immunohistochemistry (IHC). Results Highest KLK15 levels were detected in the testis and seminal fluid, whereas lower levels were observed in prostate and other tissues. Immunohistochemical analysis of testis suggests that KLK15 is strongly expressed in mature spermatids , but not in immature germ cells . KLK15 displayed predominantly nuclear localization in the basal cell layer of the prostatic epithelium. We also measured KLK15 in supernatants of various cell lines. Highest KLK15 levels were primarily detected in prostate cancer cell lines and KLK15 expression was hormone-independent, in contrast to KLK3. Conclusions Collectively, our data provide insights into the localization and possible role of KLK15 in human physiology.

  • Human tissue Kallikreins: Blood levels and response to radiotherapy in intermediate risk prostate cancer
    Radiotherapy and Oncology, 2017
    Co-Authors: Nicola J Nasser, John Thoms, Antoninus Soosaipillai, Melania Pintilie, Eleftherios P Diamandis, Ri Wang, Robert G Bristow
    Abstract:

    Abstract Objectives Kallikreins are serine proteases over expressed in many malignancies. In this study, we measure changes in serum kallikrein (KLKs) levels during intensity-modulated radiotherapy (IMRT) in prostate cancer patients, and find potential correlations between serum kallikrein level and normal tissues toxicity during radiation. Methods Forty-nine patients with prostate cancer were recruited as follows: group 1, definitive standard fractionation IMRT (78Gy in 39 fractions, n =15); group 2, definitive hypofractionated IMRT (60Gy in 20 fractions, n =15); and group 3, IMRT postprostatectomy (66Gy in 33 fractions, n =19). Patients treated with definitive radiation therapy were intermediate risk. Blood samples were collected at baseline and quarterly during IMRT and at each follow-up visit. Acute toxicity was graded weekly during radiotherapy using CTC-AE v4.0 criteria. Multiplexed immunoassays were used to quantify total, free, and intact Prostate Specific Antigen (PSA), as well as Kallikreins 2, 4, 6, and 11. Results The serum kallikreins, PSA (total, free and intact), KLK2, 6, and 11 change significantly after definitive radiotherapy. KLK2 and intact PSA decrease as fast as two weeks after initiation of radiation, while the first significant decrease in total and free PSA is noted only at the completion of radiation. KLK6 and KLK11 surge temporarily during radiation therapy and decrease below baseline levels at 8weeks and 12months, respectively after completion of radiation. KLK4 levels did not change with radiation. There was no correlation between GU or GI toxicities and serum kallikreins. Conclusions PSA, KLK2, 6, and 11, change significantly after definitive prostate radiotherapy, though KLK2 and PSA decrease by the end of the radiation course while KLK6 and KLK11 decrease significantly starting at 2 and 12months, respectively, after radiation. There was no correlation between GU or GI toxicities and serum kallikreins.

  • Kallikrein-related peptidase 7 (KLK7) is a proliferative factor that is aberrantly expressed in human colon cancer.
    Biological chemistry, 2014
    Co-Authors: Francine Walker, Antoninus Soosaipillai, Eleftherios P Diamandis, Katerina Oikonomopoulou, Viktor Magdolen, Pascal Nicole, Abdelhak Jallane, Valentine Mosbach, Dalila Darmoul
    Abstract:

    Emerging evidence indicates that serine proteases of the tissue kallikrein-related peptidases family (KLK) are implicated in tumorigenesis. We recently reported the ectopic expression of KLK4 and KLK14 in colonic cancers and their signaling to control cell proliferation. Human tissue kallikrein-related peptidase 7 (KLK7) is often dysregulated in many cancers; however, its role in colon tumorigenesis has not yet been established. In the present study, we analyzed expression of KLK7 in 15 colon cancer cell lines and in 38 human colonic tumors. In many human colon cancer cells, KLK7 mRNA was observed, which leads to KLK7 protein expression and secretion. Furthermore, KLK7 was detected in human colon adenocarcinomas, but it was absent in normal epithelia. KLK7 overexpression in HT29 colon cancer cells upon stable transfection with a KLK7 expression plasmid resulted in increased cell proliferation. Moreover, subcutaneous inoculation of transfected cells into nude mice led to increased tumor growth that was associated with increased tumor cell proliferation as reflected by a positive Ki-67 staining. Our results demonstrate the aberrant expression of KLK7 in colon cancer cells and tissues and its involvement in cell proliferation in vitro and in vivo. Thus, KLK7 may represent a potential therapeutic target for human colon tumorigenesis.

  • Association between kallikrein-related peptidases (KLKs) and macroscopic indicators of semen analysis: their relation to sperm motility.
    Biological chemistry, 2009
    Co-Authors: Nashmil Emami, Antoninus Soosaipillai, Andreas Scorilas, Tammy Earle, Brendan Mullen, Eleftherios P Diamandis
    Abstract:

    Human kallikrein-related peptidases (KLKs) are a family of proteases, the majority of which are found in seminal plasma and have been implicated in semen liquefaction. Here, we examined the clinical value of seminal KLKs in the evaluation of semen quality and differential diagnosis and etiology of abnormal liquefaction and/or viscosity. KLK1-3, 5-8, 10, 11, 13, and 14 were analyzed, using highly specific ELISA assays. Samples were categorized into four clinical groups, according to their state of liquefaction and viscosity. Data were compared between the clinical groups and in association with other parameters of sperm quality, including number of motile sperms, straight line speed, sperm concentration, volume, pH, and patient age. Seminal KLKs were found to be differentially expressed in the four clinical groups. Combination of KLK2, 3, 13, and 14 and KLK1, 2, 5, 6, 7, 8, 10, 13, and 14 showed very strong discriminatory potential for semen liquefaction and viscosity, respectively. Liquefaction state was associated with several parameters of sperm motility. Finally, KLK14 was differentially expressed in asthenospermic cases. In conclusion, the expression level of several seminal plasma KLKs correlates with liquefaction and viscosity indicators of semen quality and may aid in their differential diagnosis and etiology.

  • The use of kallikrein-related peptidases as adjuvant prognostic markers in colorectal cancer
    British Journal of Cancer, 2009
    Co-Authors: M Talieri, Antoninus Soosaipillai, Andreas Scorilas, Y Zheng, D K Alexopoulou, D Xynopoulos, Eleftherios P Diamandis
    Abstract:

    Several members of the human tissue kallikrein-related peptidase (KLK) family are emerging cancer biomarkers. The aim of this study was to analyse the expression of a panel of KLKs in colorectal cancer and to find out if the multiparametric combination of them can increase the accuracy of prediction of patients survival beyond the traditional clinical information. Nine KLKs (KLK5-8, KLK10, KLK11, KLK13-15) were measured using ELISA assays in cytosolic extracts of 122 colon cancer tissues and their nearby normal mucosa, obtained during surgery. The mean levels of almost all KLKs in tumour tissues were significantly different from their counterparts of normal tissue ( P