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Sven Skog - One of the best experts on this subject based on the ideXlab platform.
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A meta-analysis of serological Thymidine Kinase 1 as a marker for colorectal benign and malignant tumor risk assessment.
Molecular and clinical oncology, 2020Co-Authors: Ailian Hei, Ji Zhou, Sven SkogAbstract:The present study investigated whether a concentration of serum Thymidine Kinase 1 (STK1p) could be used to distinguish between healthy individuals, patients with colorectal benign tumors and individuals with colorectal cancer (CRC). The effectiveness of surgery on patients with CRC was monitored. A total of 20 publications containing patients with CRC (n=1,836), patients with colorectal benign tumors (n=774) and healthy controls (n=1,701) were analysed in the present meta-analysis. The publications were collected from PubMed, Embase, CENTRAL, CNKI, Wanfang, VIP and SinoMed databases from January 1, 2009 until August 31, 2019. Articles were analyzed according to sensitivity (Forest plot) and publication bias (Begg's plot, Egger's linear regression) using fixed or random effect models to calculate the weighted mean difference. Study quality was checked using the Newcastle-Ottawa Scale Document Quality Assessment Scale. The meta-analysis followed the PRISMA statement. The results revealed that STK1p significantly distinguished healthy individuals and those with colorectal benign tumors from patients with CRC, and from patients with benign tumors (P
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The Half-Life of Serum Thymidine Kinase 1 Concentration Is an Important Tool for Monitoring Surgical Response in Patients with Lung Cancer: A Meta-Analysis
Genetic testing and molecular biomarkers, 2017Co-Authors: Xu-dan Lou, Ji Zhou, Sven Skog, Hai-dong WangAbstract:Aims: In this meta-analysis, we evaluated the usefulness of serum Thymidine Kinase 1 concentration (STK1c) for monitoring the outcome of extensive open surgery in patients with lung cancer. We also...
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The proliferation marker Thymidine Kinase 1 in clinical use (Review)
Molecular and clinical oncology, 2012Co-Authors: Ji Zhou, Sven SkogAbstract:Tumor-related biomarkers are used for the diagnosis, prognosis and monitoring of treatments and follow-up of cancer patients, although only a few are fully accepted for the detection of invisible/visible tumors in health screening. Thymidine Kinase 1 (TK1), a cell cycle-dependent and thus a proliferation-related marker, has been extensively studied during the last decades, using both biochemical and immunological techniques. Therefore, TK1 is an emerging potential proliferating biomarker in oncology that may be used for the prognosis and monitoring of tumor therapy, relapse and survival. In addition, TK1 concentration in serum (STK1p) is a useful biomarker in healthy screening for the detection of potential malignancy development as well as the identification of early-stage tumors, with a few false-positive cases (ROC value, 0.96; tumor proliferation sensitivity, 0.80; specificity, 0.99). In this review, we examine results regarding the expression of STK1p and TK1 in relation to cancer patients and STK1p in health screening published between 2000 and 2012. The use of tumor-related markers recommended by international cancer organizations is also discussed. This review provides valuable information for applications in tumor patients, in health screening and for cancer research.
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High Thymidine Kinase 1 (TK1) expression is a predictor of poor survival in patients with pT1 of lung adenocarcinoma
Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine, 2011Co-Authors: Qun-li Shi, Staffan Eriksson, Hang-bo Zhou, Xiao-jun Zhou, Sven SkogAbstract:In this study, we explore the association of Thymidine Kinase 1 (TK1) expression in tumour tissues with clinical pathological parameters and prognosis in patients with pathological T1 (pT1) lung adenocarcinoma. The expression of TK1 was studied by immunohistochemistry techniques in 80 patients with surgically resected pT1 lung adenocarcinoma, retrospectively and at >10-year follow-up. Compared to patients with low TK1 expression [labelling index (LI)
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Elevated serum Thymidine Kinase 1 predicts risk of pre/early cancerous progression.
Asian Pacific journal of cancer prevention : APJCP, 2011Co-Authors: Shouqing Huang, Ji Zhou, Xia Yun, Min Zhang, Jianzh Lin, Na Guo, Song Liu, Sven SkogAbstract:Serological Thymidine Kinase 1 (STK1) is a reliable proliferation marker for prognosis, monitoring tumour therapy, relapse and detection of malignancies. In this study we investigate the use of STK1 in health screening. The concentration of STK1 was determined by a sensitive dot blot ECL assay in 8,135 persons participating in a health screening program. The frequency of persons with elevated STK1 (<2.0 pM) was 1.1%, representing diseases linked to pre/early cancerous progression. One person with malignancy (gastric carcinoma) was found among persons with elevated STK1, but none of persons with normal STK1 values. There was a significantly higher frequency of persons with moderate/severe type of hyperplasia of breast and prostate expressing elevated STK1, compared to persons with normal STK1 values. No significant difference was found concerning mild hyperplasia. Of persons with elevated STK1, 89.2% had diseases linked to risk for pre/early cancerous progression, compared to 41.2% of persons with normal STK1 values. Among the persons with elevated STK1 values, one developed liver carcinoma after 13 months and five persons showed progression in their disease within 19 months (breast and prostate hyperplasia, HBV infection). Serological TK1 may be a reliable marker for risk assessment of pre/early cancerous progression.
Staffan Eriksson - One of the best experts on this subject based on the ideXlab platform.
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The expression and activity of Thymidine Kinase 1 and deoxycytidine Kinase are modulated by hydrogen peroxide and nucleoside analogs.
Nucleosides nucleotides & nucleic acids, 2020Co-Authors: Ren Sun, Staffan Eriksson, Liya WangAbstract:Thymidine Kinase 1 (TK1) and deoxycytidine Kinase (dCK) are required for the activation of Thymidine and deoxycytidine analogs used in antiviral and anticancer therapies. Many anticancer drugs caus...
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Thymidine Kinase 1 is a better prognostic marker than Ki-67 for pT1 adenocarcinoma of the lung
International journal of clinical and experimental medicine, 2014Co-Authors: Biao Liu, Xiao-jun Zhou, Qun-li Shi, Peilin Huang, Staffan ErikssonAbstract:Objectives: The sensitivity and reliability of the biomarkers Thymidine Kinase 1 (TK1) and Ki-67 were studied in relation to clinical features and prognosis of survival for pathological-T1 (pT1) lung adenocarcinoma patients. Methods: TK1 and Ki-67 expression was determined in 80 patients with pT1 adenocarcinoma of the lung and in 20 specimens from normal lung tissues, using immunohistochemistry. Results: TK1 was found in most lung tumor cells both in the cytoplasm and the nuclei. The positive labelling index (LI) for total TK1 was significantly higher than that for Ki-67. There was a significant correlation between the LI of total TK1 and lymph node metastasis, degree of tumor invasion and pathologic stages, which was not found for Ki-67. In addition, the overall 5-year survival of patients was statistically significant different between low and high levels of TK1 expression, but not in cases of Ki-67. A multivariate analysis revealed that expression of TK1, lymph node involvement and TNM pathology staging could serve as independent prognostic factors for the disease progression of pT1 lung adenocarcinoma patients. Conclusions: Compared with Ki-67, TK1 is a more reliable proliferation index in pT1 adenocarcinoma of lung, which can evaluate the invasion and the prognosis of tumor.
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Elevation of serum Thymidine Kinase 1 in a bacterial infection: Canine pyometra
Theriogenology, 2012Co-Authors: Hanan Mohamed Sharif, Liya Wang, Ragnvi Hagman, Staffan ErikssonAbstract:Abstract Pyometra is a bacterial infection of the uterus that is common in dogs and is potentially life-threatening if delayed in diagnosis and/or treatment. Thymidine Kinase 1 (TK1) is a cytosolic enzyme involved in DNA precursor synthesis, and it is also present in serum from patients with malignant diseases. TK1 has been used as a cell proliferation biomarker for many years in human medicine and recently in dogs. However, little is known regarding serum TK1 levels in individuals with bacterial infection. The objective of this study was to determine the activity of serum TK1 in dogs with pyometra and compare it with hematologic and biochemical parameters, e.g., acute phase proteins and inflammatory mediators such as C-reactive protein and Prostaglandin F2α. Serum and plasma TK1 activity of 40 healthy female dogs and 54 dogs with pyometra were analyzed using an optimized [3H]-Thymidine phosphorylation assay. TK1 activities in serum or plasma were significantly higher in dogs with pyometra as compared with healthy female dogs (mean ± SD: 4.0 ± 7.3 pmol/min/mL in the pyometra group and 1.07 ± 0.34 pmol/min/mL in healthy control group). However, there was no difference in TK1 activity between systemic inflammatory response syndrome (SIRS) positive (n = 38) and SIRS negative (n = 16) pyometra cases. Furthermore, the plasma TK1 activity decreased in six and increased in one pyometra patients (n = 10), 24 h after ovariohysterectomy. No significant correlations (P > 0.05) were found between TK1 activity and hematological or other biochemical parameters. In conclusion, the TK1 activity was significantly elevated in dogs with pyometra. Further studies are needed to evaluate the mechanism and role of serum TK1 activity in bacterial infections and its possible diagnostic or prognostic value.
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Homogeneous assay for real-time and simultaneous detection of Thymidine Kinase 1 and deoxycytidine Kinase activities
Analytical biochemistry, 2012Co-Authors: Per Stålhandske, Staffan Eriksson, Liya Wang, Sara Westberg, Henrik Von Euler, Erika Groth, Sven Gustafsson, Johan LennerstrandAbstract:Measurement of Thymidine Kinase-1 (TK1) and deoxycytidine Kinase (dCK) activity may be useful in cancer disease management. Therefore, a one-step homogeneous assay for real-time determination of TK1 and dCK was developed by combining enzyme complementation with fluorescent signal generation using primer extension and a quenched probe oligodeoxyribonucleotide system at 37 °C. Complementation, for producing dCTP and TTP from nucleoside substrates, was carried out by dTMP Kinase and/or UMP/CMP Kinase and nucleoside diphosphate Kinase. dNTP was continuously incorporated into a fixed oligodeoxyribonucleotide primer, template, and probe system, and the fluorescent signal was generated by using the combined actions of primer extension and 5' exonuclease activity of Thermophilus aquaticus (Taq) DNA polymerase for specific relief of fluorescent quenching. Fluorescence was captured at 1-min intervals using a real-time polymerase chain reaction (PCR) instrument. A horizontal threshold line, crossing all sample relative fluorescent units (RFU) values at the level of the RFU of the blank sample at the end of the assay (i.e., 90 min), was drawn, obtaining RFU measurement data in minutes for each sample. Duplex proof of principle was demonstrated by the independent determination of different amounts of dCK and TK1 in combination. R(2) values of 0.90 were demonstrated with Prolifigen TK-REA U/L reference values obtained from pathological canine and human serum samples.
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High Thymidine Kinase 1 (TK1) expression is a predictor of poor survival in patients with pT1 of lung adenocarcinoma
Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine, 2011Co-Authors: Qun-li Shi, Staffan Eriksson, Hang-bo Zhou, Xiao-jun Zhou, Sven SkogAbstract:In this study, we explore the association of Thymidine Kinase 1 (TK1) expression in tumour tissues with clinical pathological parameters and prognosis in patients with pathological T1 (pT1) lung adenocarcinoma. The expression of TK1 was studied by immunohistochemistry techniques in 80 patients with surgically resected pT1 lung adenocarcinoma, retrospectively and at >10-year follow-up. Compared to patients with low TK1 expression [labelling index (LI)
Ji Zhou - One of the best experts on this subject based on the ideXlab platform.
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A meta-analysis of serological Thymidine Kinase 1 as a marker for colorectal benign and malignant tumor risk assessment.
Molecular and clinical oncology, 2020Co-Authors: Ailian Hei, Ji Zhou, Sven SkogAbstract:The present study investigated whether a concentration of serum Thymidine Kinase 1 (STK1p) could be used to distinguish between healthy individuals, patients with colorectal benign tumors and individuals with colorectal cancer (CRC). The effectiveness of surgery on patients with CRC was monitored. A total of 20 publications containing patients with CRC (n=1,836), patients with colorectal benign tumors (n=774) and healthy controls (n=1,701) were analysed in the present meta-analysis. The publications were collected from PubMed, Embase, CENTRAL, CNKI, Wanfang, VIP and SinoMed databases from January 1, 2009 until August 31, 2019. Articles were analyzed according to sensitivity (Forest plot) and publication bias (Begg's plot, Egger's linear regression) using fixed or random effect models to calculate the weighted mean difference. Study quality was checked using the Newcastle-Ottawa Scale Document Quality Assessment Scale. The meta-analysis followed the PRISMA statement. The results revealed that STK1p significantly distinguished healthy individuals and those with colorectal benign tumors from patients with CRC, and from patients with benign tumors (P
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Serum Thymidine Kinase 1 is associated with Gleason score of patients with prostate carcinoma
Oncology letters, 2018Co-Authors: Jianping Zhou, Yu Wang, Keqin Zhang, Junjie Yang, Xinling Zhang, Chunmei Wang, Ji ZhouAbstract:The aim of the present was to assess whether serum Thymidine Kinase 1 (STK1) concentration is a useful biomarker for the screening of benign prostatic hyperplasia (BPH) or prostate malignancy. Serum samples were collected from 123 patients with prostate carcinoma prior to surgery, biopsy or androgen deprivation therapy and at 3, 6 and 10 months following the procedure. A total of 205 patients with BPH and 266 healthy controls were also utilized. STK1 concentration and total prostate-specific antigen (PSA) were measured in patient serum by use of commercial assays. The pathological specimens (obtained from surgery or biopsy) were assessed according to Gleason scores (GS). STK1 concentration and total PSA were significantly higher in patients with prostate carcinoma compared with patients with BPH and healthy individuals. Furthermore, STK1 concentration was associated with Gleason score, while total PSA was not. However, no association was identified between STK1 concentration and total serum PSA. A receiver operating characteristic analysis was performed on STK1 concentrations among patients with prostate carcinoma. The results demonstrated that the sensitivity and specificity were high, with an area under the curve (AUC) of 0.97. Although the sensitivity and specificity of total PSA were also high, the AUC value was relatively low (0.74). The results indicated that STK1 concentration is a more reliable prognostic biomarker than total PSA in respect to the GS system. Additionally, since STK1 concentration is associated with Gleason score, the use of biopsies to determine Gleason score may be replaced to some extent by the STK1 concentration test, thus reducing the discomfort of patients from which biopsies are obtained.
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The Half-Life of Serum Thymidine Kinase 1 Concentration Is an Important Tool for Monitoring Surgical Response in Patients with Lung Cancer: A Meta-Analysis
Genetic testing and molecular biomarkers, 2017Co-Authors: Xu-dan Lou, Ji Zhou, Sven Skog, Hai-dong WangAbstract:Aims: In this meta-analysis, we evaluated the usefulness of serum Thymidine Kinase 1 concentration (STK1c) for monitoring the outcome of extensive open surgery in patients with lung cancer. We also...
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The proliferation marker Thymidine Kinase 1 in clinical use (Review)
Molecular and clinical oncology, 2012Co-Authors: Ji Zhou, Sven SkogAbstract:Tumor-related biomarkers are used for the diagnosis, prognosis and monitoring of treatments and follow-up of cancer patients, although only a few are fully accepted for the detection of invisible/visible tumors in health screening. Thymidine Kinase 1 (TK1), a cell cycle-dependent and thus a proliferation-related marker, has been extensively studied during the last decades, using both biochemical and immunological techniques. Therefore, TK1 is an emerging potential proliferating biomarker in oncology that may be used for the prognosis and monitoring of tumor therapy, relapse and survival. In addition, TK1 concentration in serum (STK1p) is a useful biomarker in healthy screening for the detection of potential malignancy development as well as the identification of early-stage tumors, with a few false-positive cases (ROC value, 0.96; tumor proliferation sensitivity, 0.80; specificity, 0.99). In this review, we examine results regarding the expression of STK1p and TK1 in relation to cancer patients and STK1p in health screening published between 2000 and 2012. The use of tumor-related markers recommended by international cancer organizations is also discussed. This review provides valuable information for applications in tumor patients, in health screening and for cancer research.
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Elevated serum Thymidine Kinase 1 predicts risk of pre/early cancerous progression.
Asian Pacific journal of cancer prevention : APJCP, 2011Co-Authors: Shouqing Huang, Ji Zhou, Xia Yun, Min Zhang, Jianzh Lin, Na Guo, Song Liu, Sven SkogAbstract:Serological Thymidine Kinase 1 (STK1) is a reliable proliferation marker for prognosis, monitoring tumour therapy, relapse and detection of malignancies. In this study we investigate the use of STK1 in health screening. The concentration of STK1 was determined by a sensitive dot blot ECL assay in 8,135 persons participating in a health screening program. The frequency of persons with elevated STK1 (<2.0 pM) was 1.1%, representing diseases linked to pre/early cancerous progression. One person with malignancy (gastric carcinoma) was found among persons with elevated STK1, but none of persons with normal STK1 values. There was a significantly higher frequency of persons with moderate/severe type of hyperplasia of breast and prostate expressing elevated STK1, compared to persons with normal STK1 values. No significant difference was found concerning mild hyperplasia. Of persons with elevated STK1, 89.2% had diseases linked to risk for pre/early cancerous progression, compared to 41.2% of persons with normal STK1 values. Among the persons with elevated STK1 values, one developed liver carcinoma after 13 months and five persons showed progression in their disease within 19 months (breast and prostate hyperplasia, HBV infection). Serological TK1 may be a reliable marker for risk assessment of pre/early cancerous progression.
Kim L. O'neill - One of the best experts on this subject based on the ideXlab platform.
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Thymidine Kinase 1 through the ages: a comprehensive review.
Cell & bioscience, 2020Co-Authors: Eliza E. Bitter, Michelle H. Townsend, Rachel Erickson, Carolyn Allen, Kim L. O'neillAbstract:Proliferation markers, such as proliferating cell nuclear antigen (PCNA), Ki-67, and Thymidine Kinase 1 (TK1), have potential as diagnostic tools and as prognostic factors in assessing cancer treatment and disease progression. TK1 is involved in cellular proliferation through the recovery of the nucleotide Thymidine in the DNA salvage pathway. TK1 upregulation has been found to be an early event in cancer development. In addition, serum levels of TK1 have been shown to be tied to cancer stage, so that higher levels of TK1 indicate a more serious prognosis. As a result of these findings and others, TK1 is not only a potentially viable biomarker for cancer recurrence, treatment monitoring, and survival, but is potentially more advantageous than current biomarkers. Compared to other proliferation markers, TK1 levels during S phase more accurately determine the rate of DNA synthesis in actively dividing tumors. Several reviews of TK1 elaborate on various assays that have been developed to measure levels in the serum of cancer patients in clinical settings. In this review, we include a brief history of important TK1 discoveries and findings, a comprehensive overview of TK1 regulation at DNA to protein levels, and recent findings that indicate TK1’s potential role in cancer pathogenesis and its growing potential as a tumor biomarker and therapeutic target.
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Abstract 519: Exploring the potential of human nanobodies against Thymidine Kinase 1 for the targeting of lung cancer cells
Experimental and Molecular Therapeutics, 2020Co-Authors: Edwin J. Velazquez, Richard A. Robison, Jordan D. Cress, Kathryn R. Smith, David M. Bellini, Jonathan R. Skidmore, Zachary D. Ewell, Kim L. O'neillAbstract:Single domain antibodies or nanobodies (Nbs) have positively proved effective for the targeting of multiple tumor targets. This study describes the isolation of human Nbs against the tumor proliferation biomarker Thymidine Kinase 1 (TK1). The anti-TK1 Nbs were used to target membrane associated TK1 in the non-small cell lung carcinoma cell lines NCI-H460 and A549 cells. TK1 is a pyrimidine salvage enzyme that is upregulated in malignant tissues. Recently, we have reported the presence of a TK1 form that is associated to the cell membrane in breast, lung and colon tumors as well as leukemia. Our findings suggest that targeting of TK1 in proliferating cancer cells may be an alternative approach for the treatment of cancer. Using phage display technology, we isolated a total of 237 nanobodies from the Daniel Christ DAb library. After 2-4 rounds of selection the affinity of the nanobodies to TK1 was tested with monoclonal phage ELISA using human recombinant TK1. Ten of the most sensitive anti-TK1 Nbs were then selected and evaluated with dose response curves as possible candidates for preclinical testing. The dose response curves showed R squares values ranging from 0.9738-0.9980 fitting a sigmoidal curve. Thus, indicating a strong antibody dose response relationship specific for TK1. In addition, the specificity of the TK1 antibodies was tested by screening against unrelated proteins and cell lysate from an siRNA TK1 knockdown using monoclonal phage ELISA. Nanobodies showed negligible binding when screened against TK1 non related proteins. Validation of the anti-TK1 Nbs with TK1 siRNA knockdown showed a significant reduction on the Nbs binding compared to wild type. The sensitivity of the anti-TK1 Nbs to detect TK1 was within the nanomolar range (between 100-20 ng/ml) and had thermostable standing temperatures between 50-75 °C. The anti-TK1 Nbs were used to detect membrane associated TK1 in the non-small cell lung carcinoma cell lines NCI-H460 and A549. The phage nanobodies showed binding capacity to TK1 on cancer cells with 30- 60% of positive cells for NCI-H460 and 25 to 40% for A549 cells. Human Nbs represent a valuable resource for the detection and the targeting of TK1 in proliferating tumor cells. Further work is required to enable the exploration of the therapeutic uses of anti-TK1 Nb-based therapies and their incorporation to cell adoptive therapies such as chimeric antigen receptor (CAR) therapies. Citation Format: Edwin J. Velazquez, Jordan D. Cress, Kathryn R. Smith, David M. Bellini, Jonathan R. Skidmore, Zachary D. Ewell, Richard A. Robison, Kim L. O9Neill. Exploring the potential of human nanobodies against Thymidine Kinase 1 for the targeting of lung cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 519.
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Abstract 1213: Thymidine Kinase 1 is on the cell surface of prostate cancer cells
Experimental and Molecular Therapeutics, 2016Co-Authors: Evita G. Weagel, Michelle H. Townsend, Richard A. Robison, Roger Chu, Wei Meng, Rachel A. Brog, Kim L. O'neillAbstract:Thymidine Kinase 1 (TK1) is a salvage pathway enzyme that assists in DNA repair and is characteristically expressed in the cytosol, but it also presents at an abnormally high level in the serum of cancer patients. We developed a unique mouse-anti-human TK1 antibody (A72), and used it in conjunction with Flow Cytometry, Scanning Electron Microscopy (SEM), and Confocal Microscopy, to explore the presence of TK1 on the cell surface of two prostate cancer cell lines, namely PC3 and DU145. Flow Cytometry was performed using a standard protocol. Briefly, cells were stained with A72 conjugated to FITC. Anti-NF-κB-FITC and a non-specific IgG-FITC were used as negative controls. Anti-Na+/K+-ATPase-FITC was used as positive control. Cells were then analyzed using a Flow Cytometer. SEM was carried out by first incubating cells with anti-Na+/K+-ATPase and anti-TK1 conjugated to biotin. After probing with streptavidin-gold solution, cells were imaged to examine the presence of gold particles on cell surface. Our data demonstrated TK1-positive populations after flow cytometry analysis, and the presence of gold particles on the membrane of prostate cancer cells. The presence of TK1 on plasma membrane of PC3 and DU145 was further confirmed by Confocal Microscopy. Cells were first stained with A72-FITC and a red plasma membrane stain, then consecutively imaged with a Confocal Microscope. Results showed that A72-FITC associate with the cells in the same region that the membrane had been stained red, concluding that the A72 binds to the cell membrane. These data strongly suggest that TK1 is located on the surface of prostate cancer cells, and indicate that TK1 may be used as a new immunotherapy target for prostate cancer treatment. Citation Format: Evita G. Weagel, Roger P. Chu, Wei Meng, Rachel A. Brog, Michelle H. Townsend, Richard A. Robison, Kim L. O’Neill. Thymidine Kinase 1 is on the cell surface of prostate cancer cells. [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 1213.
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Microchip immunoaffinity electrophoresis of antibody–Thymidine Kinase 1 complex
Electrophoresis, 2015Co-Authors: Jayson V. Pagaduan, Kim L. O'neill, Madison K. Ramsden, Adam T. WoolleyAbstract:Thymidine Kinase 1 (TK1) is an important cancer biomarker whose serum levels are elevated in early cancer development. We developed a microchip electrophoresis immunoaffinity assay to measure recombinant purified TK1 (pTK1) using an antibody (Ab) that binds to human TK1. We fabricated PMMA microfluidic devices to test the feasibility of detecting Ab-pTK1 immune complexes as a step toward TK1 analysis in clinical serum samples. We were able to separate immune complexes from unbound Abs using 0.5× PBS (pH 7.4) containing 0.01% Tween-20, with 1% w/v methylcellulose that acts as a dynamic surface coating and sieving matrix. Separation of the Ab and Ab-pTK1 complex was observed within a 5 mm effective separation length. This method of detecting pTK1 is easy to perform, requires only a 10 μL sample volume, and takes just 1 min for separation.
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Abstract 1866: Detection of early-stage lung cancer using a novel ELISA for Thymidine Kinase 1
Clinical Research (Excluding Clinical Trials), 2014Co-Authors: Madison K. Ramsden, Melissa M. Alegre, Richard A. Robison, Michael J. Weyant, Daine T. Bennett, Atif Elnaggar, Kim L. O'neillAbstract:Lung cancer is the number one cause of cancer mortality and early detection will increase the survival of this disease. Thymidine Kinase 1 (TK1) is a biomarker indicative of cell proliferation that is elevated in numerous malignancies including lung cancer. TK1 has been found to be elevated early in the development of lung cancer and therefore is an ideal target as an early detection biomarker. We have developed an enzyme-linked immunosorbent assay (ELISA) to detect TK1 in serum. Forty patients with pulmonary nodules and 18 healthy control individuals had serum collected under standard conditions, prior to operative removal of any lesions. All serum samples were analyzed using TK1 radioassay to measure TK1 activity, and TK1 ELISA to measure TK1 concentration. TK1 was significantly elevated in all patients with confirmed lung cancer. This was true even in stage IA, where patients (n=16) had significantly higher TK1 levels than controls. The clearest cut-off was 4.9 nM with an area under the curve of 0.792 for early stage lung cancer. The corresponding sensitivity and specificity was 82.4 and 83.3, respectively. TK1 concentration was a more sensitive and accurate indicator of lung cancer than TK1 activity. Overall, TK1 is significantly elevated in serum of lung cancer patients. This TK1 ELISA is sensitive and specific for detection of lung cancer and further trials with a larger patient base can confirm the potential of this method of detection. Citation Format: Madison K. Ramsden, Melissa M. Alegre, Michael J. Weyant, Daine T. Bennett, Jessica A. Yu, Atif Elnaggar, Richard A. Robison, Kim L. O9Neill. Detection of early-stage lung cancer using a novel ELISA for Thymidine Kinase 1. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1866. doi:10.1158/1538-7445.AM2014-1866
Eric O. Aboagye - One of the best experts on this subject based on the ideXlab platform.
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phosphorylation status of Thymidine Kinase 1 following antiproliferative drug treatment mediates 3 deoxy 3 18f fluoroThymidine cellular retention
PLOS ONE, 2014Co-Authors: Roberta Sala, Quangde Nguyen, Chirag B K Patel, David J Mann, Joachim H G Steinke, Ramon Vilar, Eric O. AboagyeAbstract:Background 3′-Deoxy-3′-[18F]-fluoroThymidine ([18F]FLT) is being investigated as a Positron Emission Tomography (PET) proliferation biomarker. The mechanism of cellular [18F]FLT retention has been assigned primarily to alteration of the strict transcriptionally regulated S-phase expression of Thymidine Kinase 1 (TK1). This, however, does not explain how anticancer agents acting primarily through G2/M arrest affect [18F]FLT uptake. We investigated alternative mechanisms of [18F]FLT cellular retention involving post-translational modification of TK1 during mitosis.
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Abstract 2660: Regulation of 18F-fluoroThymidine uptake by Thymidine Kinase 1 protein phosphorylation.
Tumor Biology, 2013Co-Authors: Roberta Sala, Quangde Nguyen, Chirag B K Patel, David J Mann, Joachim H G Steinke, Ramon Vilar, Eric O. AboagyeAbstract:Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Uncontrolled cell proliferation is a hallmark of cancer and its inhibition is desired in cancer therapy. The most widely used radiotracer for proliferation is 18F-fluoroThymidine (18F-FLT). To be retained in cells, 18F-FLT is phosphorylated to thymidylate (dTMP) by Thymidine Kinase 1 (TK1), the rate limiting step in the salvage pathway for DNA synthesis. We studied TK1 protein phosphorylation in mammalian cells, hypothesising that TK1 is subject to different phosphorylations through the cell cycle, which are responsible for the regulation of its activity, therefore modulating 18F-FLT uptake, particularly during G2/M. Using phos-tag™ acrylamide gels we isolated three forms of phosphorylated TK1, one of which was present throughout the cell cycle, but increased during S and G2/M phases, and two phosphorylated forms that appeared upon G2/M arrest. The implications of these phosphorylations on 18F-FLT uptake were tested by conducting FLT cell uptake studies after treating HCT116 human colon cancer cells with cell cycle-arresting drugs. A marked reduction of radiotracer uptake was observed in cells arrested in S phase (aphidicolin) or G2/M phase (nocodazole and paclitaxel), confirming previous findings regarding TK1 phosphorylation during G2/M being responsible of reduced enzymatic activity. Transient transfection of Ost TK1- cells with FLAG-pCMV vectors encoding WT, S13A, S13D or S231A TK1 suggested that S13 phosphorylation occurs throughout the cell cycle and increases upon G2/M arrest after treatment with nocodazole or paclitaxel. Substitution of S231 with alanine (S231A) was linked to G2/M-specific phosphorylation of TK1. Further experiments were performed to assess the role of the two serine phosphorylations on 18F-FLT cell uptake. There was a significant reduction in 18F-FLT uptake in S13A transfected cells compared to WT. S13D and S231A plasmids rescued 18F-FLT uptake almost to levels seen in WT cells, supporting the relevance of S13 and S231 phosphorylation for TK1 enzymatic activity. Nocodazole induced G2/M arrest further reduced 18F-FLT uptake, even in S231A transfection, implicating phosphorylation sites other than those studied here in the reduced TK1 activity. 18F-FLT-PET imaging of HCT116 tumour-bearing nude mice 24h after treatment with 40 mg/kg paclitaxel indicated a significant reduction in tumour 18F-FLT uptake, which correlates with the G2/M-induced reduction in TK1 activity as a result of TK1 phosphorylation. Our present study demonstrates the presence of at least three phosphorylated forms of TK1, which are responsible for the post-translational regulation of TK1 activity, and demonstrates the effect of these modifications on the uptake of 18F-FLT. Citation Format: Roberta Sala, Quang-De Nguyen, Chirag Patel, David Mann, Joachim H. G. Steinke, Ramon Vilar, Eric O. Aboagye. Regulation of 18F-fluoroThymidine uptake by Thymidine Kinase 1 protein phosphorylation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2660. doi:10.1158/1538-7445.AM2013-2660
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the uptake of 3 deoxy 3 18f fluoroThymidine into l5178y tumours in vivo is dependent on Thymidine Kinase 1 protein levels
European Journal of Nuclear Medicine and Molecular Imaging, 2005Co-Authors: Henryk Barthel, Meg Perumal, John R. Latigo, Frank Brady, Sajinder K. Luthra, P B Price, Eric O. AboagyeAbstract:Purpose The aim of this study was to investigate the role of Thymidine Kinase 1 (TK1) protein in 3′-deoxy-3′-[18F]fluoroThymidine ([18F]FLT) positron emission tomography (PET) studies.
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The uptake of 3′-deoxy-3′-[18F]fluoroThymidine into L5178Y tumours in vivo is dependent on Thymidine Kinase 1 protein levels
European journal of nuclear medicine and molecular imaging, 2004Co-Authors: Henryk Barthel, Meg Perumal, John R. Latigo, Frank Brady, Sajinder K. Luthra, Patricia Price, Eric O. AboagyeAbstract:Purpose The aim of this study was to investigate the role of Thymidine Kinase 1 (TK1) protein in 3′-deoxy-3′-[18F]fluoroThymidine ([18F]FLT) positron emission tomography (PET) studies.