Ellen He

Serological Thymidine Kinase 1 is a Biomarker for Early Detection of Tumours—A Health Screening Study on 35,365 People, Using a Sensitive Chemiluminescent Dot Blot Assay

Serological thymidine kinase 1 (STK1) is a reliable proliferation marker for prognosis, monitoring tumour therapy, and relapse. Here we investigated the use of STK1 in health screening for early detection of pre-malignant and malignant diseases. The investigation was based on 35,365 participants in four independent health screening studies in China between 2005–2011. All participants were clinically examined. The concentration of STK1 was determined by a sensitive chemiluminescent dot blot ECL assay. The ROCvalue of the STK1 assay was 0.96. At a cut-off STK1 value of 2.0 pM, the likelihood (+) value was 236.5, and the sensitivity and the specificity were 0.78 and 0.99, respectively. The relative number of city-dwelling people with elevated STK1 values (≥2.0 pM) was 0.8% (198/26,484), while the corresponding value for the group of oil-field workers was 5.8% (514/8,355). The latter group expressed significantly higher frequency of refractory anaemia, fatty liver, and obesity, compared to the city dwellers, but no cases of breast hyperplasia or prostate hyperplasia. Furthermore, people working in oil drilling/oil transportation showed higher STK1 values and higher frequency of pre-malignancies and benign diseases than people working in the oil-field administration. In the STK1 elevated group of the city-dwelling people, a statistically significantly higher number of people were found to have malignancies, pre-malignancies of all types, moderate/severe type of hyperplasia of breast or prostate, or refractory anaemia, or to be at high risk for hepatitis B, compared to people with normal STK1 values (<2.0 pM). No malignancies were found in the normal STK1 group. In the elevated STK1 group 85.4% showed diseases linked to a higher risk for pre-/early cancerous progression, compared to 52.4% of those with normal STK1 values. Among participants with elevated STK1 values, 8.8% developed new malignancies or progress in their pre-malignancies within 5 to 72 months, compared to 0.2% among people with normal STK1 values. People who showed elevated STK1 values were at about three to five times higher risk to develop malignancies compared to a calculated risk based on a cancer incidence rate of 0.2–0.3%. We conclude that serological TK1 protein concentration is a reliable marker for risk assessment of pre/early cancerous progression.

Serological thymidine kinase 1 is a prognostic factor in oesophageal, cardial and lung carcinomas.

In this study we examine the use of the concentration of thymidine kinase 1 in serum (STK1) as a prognostic factor in routine clinical settings. For this purpose we used sera from patients with oesophageal (n=101) and cardial (n=39) carcinomas and nonsmall-cell lung carcinoma (NSCLC) (n=157). Sera from healthy individuals (n=95) were used as controls. STK1 was analysed by a chemiluminiscence dot blot assay. The mean STK1 concentrations and the STK1 positive rates of the patients with oesophageal and cardial carcinomas and with NSCLC were significantly higher as compared with healthy controls (P=0.01). The mean STK1 value of oesophageal carcinoma patients correlated with T-values (P=0.021) and with stage (P<0.005), but not with grade. The mean STK1 value of cardial carcinoma patients did not correlate with grade. No data on stage and T-values were available for these patients, due to advanced disease. The mean STK1 value of NSCLC patients with squamous cell carcinoma was significantly higher as compared with adenocarcinoma type (P=0.024). The mean STK1 value of the NSCLC patients correlated with clinical grade (P=0.006), T-values (P=0.001), stage (P=0.035) and to size of the tumour (P=0.030). The mean STK1 value and the number of STK1 positive patients were also higher in recurrent NSCLC patients. There was a tendency that stage I–II NSCLC patients with an STK1 level above 2 pmol/l showed a higher frequency of recurrence/death than patients below 1 pmol/l. Our results show that STK1 is a useful marker for prognosis in patients with oesophageal, cardial and lung carcinomas.

Serum thymidine kinase 1 reflects the progression of pre-malignant and malignant tumors during therapy

This study evaluated the clinical utility of serum thymidine kinase 1 (STK1) in following the progression of pre-malignancies and malignancies and in monitoring the response of common carcinomas to therapy within a routine clinical setting. The STK1 concentration levels of patients with malignancies (n=224), pre-malignancies (n=10), non-tumor/non-proliferating diseases (systemic lupus erythematosus, SLE) (n=53), benign tumors (n=20) and healthy volunteers (n=761) were determined by enhanced chemoluminescence dot blot assay. Prior to treatment, STK1 levels in the pre-malignant group alone (3.1±2.3) or in the pre-malignant and malignant groups together (2.3±1.9) were significantly higher than in the benign (1.4±0.8), SLE (1.1±0.8) or healthy volunteer (0.6±0.4) groups (p<0.01). According to ROC analysis, the STK1 assay provided a high degree of discrimination between STK1-positive pre-malignant (0.978) or pre-malignant + malignant (0.941) patients and STK1-negative healthy individuals. After varying treatments (surgery, chemotherapy, X-ray), STK1 levels increased by 40-50% during the first month, then decreased back to normal values or even lower. Following treatment, STK1 levels were significantly increased in squamous cell carcinoma (SCC) as compared to adenocarcinoma (AC) patients. In other types of malignancies, STK1 levels decreased from as early as the first month. The STK1 levels of relapsed treated patients were significantly higher (50-60%) than those of mid/long-term treated patients. In conclusion, the STK1 assay discriminated between patients with malignancies and healthy individuals very well, and is therefore potentially useful for a broad range of clinical applications. For example, it could be used for the evaluation of early tumor progression or of tumor progression during therapy in routine clinical settings, as well as for the screening of healthy individuals.

Thymidine kinase activity in serum of renal cell carcinoma patients is a useful prognostic marker.

It is known that the concentration and activity of the DNA precursor enzyme thymidine kinase 1 (TK1) in serum is significantly elevated in patients with malignancies, as compared with levels in patients with benign tumours and those in healthy individuals. For the first time, the use of serum TK1 as a prognostic marker for patients with renal cell carcinoma (RCC) was examined. Serum TK1 protein (STK1p) concentration and serum TK1 activity (STK1a) were determined by a dot blot chemoluminescence assay and a radio enzyme assay, respectively. There was no correlation between STK1p and STK1a in the same sera from 27 RCC patients. Only one STK1p value as compared with 15 STK1a values was clearly above the cut-off values (2 pmol/l and 6 U/l, respectively) for healthy individuals. STK1a values did not correlate with the level of TK1 expression in tumour sections from the RCC patients, estimated by immunohistochemistry staining. However, there was a significant correlation between STK1a levels and the grade, stage and size of the RCC tumours. The discrepancy between the STK1p and the STK1a results is likely to be because of reduced ability of the TK1 antibody to recognize the STK1 in sera from RCC patients. We conclude that the activity of STK1 is a useful tool for evaluating the prognosis of patients with RCC.

Thymidine kinase 1 expression in atypical ductal hyperplasia significantly differs from usual ductal hyperplasia and ductal carcinoma in situ: A useful tool in tumor therapy management.

Thymidine kinase 1 (TK1) is an enzyme involved in the synthesis of DNA precursors. In studies using immunohistochemistry, it was reported to be a more useful proliferation marker than Ki-67 and PCNA in breast, lung and colorectal carcinoma. In this study, we extend the work of prior breast carcinoma studies by investigating the expression of TK1 in 132 patients with usual ductal hyperplasia (UDH), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). TK1 and Ki-67 expression were determined with monoclonal antibodies using the SP technique. The expression of TK1 was found to be significantly increased in the breast ductal carcinomas in the following manner: UDH<ADH<DCIS<IDC. TK1 expression was correlated with histological grade in DCIS and IDC patients and with pathological stage in IDC patients. The degree of TK1-positive staining in the tumors of patients with ADH, DCIS and IDC was 80-90%, while the corresponding value for UDH patients was less than 5%. TK1 and Ki-67 expression showed very high correlation in the four tumor groups investigated. Since the expression of TK1 varied significantly between the breast ductal subgroups, we concluded that TK1 is a reliable proliferation marker for the determination of breast tumor proliferation, particularly of pre-cancerous lesions (ADH). This may enable timely treatment in the early stages of tumor development using minimal access surgery, thus avoiding extensive radical breast surgery and improving survival rates and the quality of life.

The proliferation marker thymidine kinase 1 level is high in normal kidney tubule cells compared to other normal and malignant renal cells.

The activity of the proliferation related enzyme thymidine kinase 1 (TK1) was reported to be 3-fold higher in extracts from normal kidney tissue as compare to renal carcinoma extracts [3]. To verify these unexpected results, determinations of the protein levels of TK1 in normal kidney and in samples from different types of renal cell carcinoma (RCC) were done with immunohistochemistry and Western blot analysis. Two anti-TK1 peptide antibodies reacting with different TK1 epitops were used. TK1 levels were high in tubule cells as compared to glomerulus cells and connective tissue cells, while an intermediary TK1 was observed in renal cell carcinoma (RCC) cells. Western blot analysis demonstrated high levels of TK1 in extract from normal kidney, and lower levels of TK1 in the RCC extracts. The specificity of TK1 staining was demonstrated in competition experiments with excess TK1 antigen. The high TK1 levels in normal kidney tubule cells suggest that they are in a form of activated G1-state. The relatively low TK1 level in RCC, representing TK1 expression in S-phase cells, is in accordance with the low overall proliferation rate of these tumors. These results suggest that cell cycle regulation of TK1 in normal tubule cells differ from that in other type of normal and malignant renal cells.

Serum TK1 is a more reliable marker than CEA and AFP for cancer screening in a study of 56,286 people

BACKGROUND The World Health Organization (WHO) has estimated that the number of cancer patients will increase by about 70% during the next 25 years world-wide. To deal with this problem, WHO has suggested a focus on prevention of tumor incidence and health screening for early detection of people with tumors. OBJECTIVE To investigate the use of thymidine kinase 1 (TK1), CEA and AFP in serum to discover people with malignant tumors through health cancer screening. METHODS Of a cohort in 486,085 people of a routine health screening at the Health Centre, Fujun 180 Hospital, Quanzhou city, China, 56,286 people were investigated according to the presence of cancer during 2009-2014. The concentration of CEA and AFP were determined by an electrochemiluminescence immunoassay from Roche Diagnostics e601GmbH and STK1 by a commercial kit based on an enhanced chemiluminescent dot blot assay. RESULTS The cancer incident rate increased from 0.048/100,000 to 0.220/100,000. The most common types of tumors were those of the liver, cervix and lung. STK1 correlated to tumor growth rate, was more sensitive than CEA and AFP for discovering people with malignant tumors and more sensitive among people who had diagnosis of malignant tumor. STK1 was also a prognostic biomarker for death at 10-40 months follow-up, while CEA and AFP were not. A combination of these markers increased the sensitivity by about 30%. CONCLUSION STK1 is a reliable biomarker for discovering people with malignant tumors in cancer screening.

Nuclear TK1 expression is an independent prognostic factor for survival in pre-malignant and malignant lesions of the cervix

BackgroundThymidine kinase 1 (TK1) is a proliferation biomarker that has been found useful for prognostication in cancer patients. Here we investigate for the first time the use of TK1 expression as a prognostic factor for patients with premalignant and malignant lesions of the uterine cervix.MethodsTK1 expression was determined by immunohistochemistry in cervical lesions (cervical intraepithelial neoplasia (CIN), n = 216; invasive cervical carcinoma, n = 84). TK1 and Ki-67 expressions and pathological/FIGO stages and age were correlated with 5-year survival by Kaplan-Meier, log rank and COX hazard uni- and multivariate analyses.ResultsTK1 labeling index (LI) was significantly correlated with CIN grades and invasive cervical carcinoma stages, while TK1 labeling intensity was only correlated to CIN grades. TK1 LI was significantly higher compared with Ki-67 LI. TK1 LI correlated significantly to 5-year survival in patients with invasive cervical carcinoma, particularly nuclear TK1 LI. In a multivariate analysis, nuclear TK1 expression was independent prognostic factor in patients with in situ/invasive cervical carcinoma or in invasive cervical carcinoma alone. Interestingly, in invasive cervical carcinoma patients with advanced tumors, nuclear TK1 expression could identify patients with significantly better survival rates (80%), while Ki-67 could not.ConclusionsNuclear TK1 expression in early grade CIN predicts risk for progression to malignancy. Nuclear TK1 expression is also a prognostic factor for treatment outcome, particularly in patients with advanced cervical carcinomas. Nuclear TK1 expression is more useful than Ki-67 and pathological/FIGO stages.

Serum thymidine kinase 1 levels predict cancer‑free survival following neoadjuvant, surgical and adjuvant treatment of patients with locally advanced breast cancer

In this study, the use of serum thymidine kinase 1 protein (STK1p) concentration for the prognosis of the overall survival of patients with locally advanced breast cancer (n=51) following routine treatment (neoadjuvant treatment, surgery and chemotherapy) was investigated. The patients were followed up for 44 months and the STK1p values were determined by a high-sensitivity enhanced chemiluminescence (ECL) dot blot assay. The variables investigated in relation to metastasis and survival were STK1p, clinical stage, tumor size and age, by the Kaplan-Meier method, the log-rank test and Cox uni- and multivariate analyses. Patients with high STK1p values (≥2.0 pM) 3–6 months after surgery exhibited a positive correlation to clinical stage, tumor size, occurrence of metastasis and survival. The hazard risk for the development of metastatic disease and mortality among breast cancer patients was 11–12 times higher in patients with high compared to those with low STK1p values (<2.0 pM). Notably, patients with stage III/IV disease and low STK1p values exhibited statistically significantly improved survival compared to patients with high STK1p values. A multivariate Cox analysis demonstrated that the STK1p levels 6 months after surgery was the only independent prognostic factor for metastasis and survival. In conclusion, STK1p is a prognostic marker in patients with locally advanced breast cancer and it may help identify a subgroup of stage III/IV patients with improved cancer-free survival expectancy, enabling personalized treatment.

A Chemiluminescent Protein Microarray Method for Determining the Seroglycoid Fucosylation Index

The Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3) is widely used to screen for hepatocellular carcinoma (HCC) in Japan and China. We developed a chemiluminescent protein microarray for determining the AFP-L3/AFP index (the ratio of AFP-L3 to total AFP, AFP-L3%) by fixing AFP-specific antibodies and Lens culinaris lectin on aldehyde-coated glass slides. Serum samples were tested for AFP using an enzyme-linked immunosorbent assay (ELISA) to validate the microarray. AFP-L3 was detected using Hotgen Biotech glycosyl capture spin column pretreatment technology and ELISA. When the AFP cut-off value was set to 20 ng/ml, the protein microarray displayed 89.74% sensitivity and 100% specificity for HCC diagnosis, and the ELISA displayed 87.17% sensitivity and 100% specificity. When the AFP-L3% cut-off value was set to 0.1, the protein microarray displayed 56.41% sensitivity and 100% specificity for HCC diagnosis, and the ELISA displayed 53.84% sensitivity and 100% specificity. The ROC curve for the HCC diagnosis showed that the AFP area under the ROC curve (AUC = 0.996; 95% CI: 0.986–1.005) was much higher than that of AFP-L3 (AUC = 0.857; 95% CI: 0.769–0.94) and AFP-L3% (AUC = 0.827; CI: 0.730–0.924). The microarray assay used in this study is a highly sensitive, accurate, and efficient assay for the determination of the AFP-L3%.