Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.1.21 (thymidine kinase)
 7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is an unmet need to develop imaging methods for the early and objective assessment of breast tumors to therapy. 3'-Deoxy-3'-[18F]fluorothymidine ([18F]FLT)-positron emission tomography represents a new approach to imaging thymidine kinase activity, and hence, cellular proliferation. We compared graphical, spectral, and semiquantitative analytic methodologies for quantifying [18F]FLT kinetics in tumor and normal tissue of patients with locally advanced and metastatic breast cancer. The resultant kinetic parameters were correlated with the Ki-67 labeling index from tumor biopsies. [18F]FLT accumulation was detected in primary tumor, nodal disease, and lung metastasis. In large tumors, there was substantial heterogeneity in regional radiotracer uptake, reflecting heterogeneity in cellular proliferation; radiotracer uptake in primary tumors also differed from that of metastases. [18F]FLT was metabolized in patients to a single metabolite [18F]FLT-glucuronide. Unmetabolized [18F]FLT accounted for 71.54 +/- 1.50% of plasma radioactivity by 90 minutes. The rate constant for the metabolite-corrected net irreversible uptake of [18F]FLT (Ki) ranged from 0.6 to 10.4 x 10(-4) and from 0 to 0.6 x 10(-4) mL plasma cleared/s/mL tissue in tumor (29 regions, 15 patients) and normal tissues, respectively. Tumor Ki and fractional retention of radiotracer determined by spectral analysis correlated with Ki-67 labeling index (r = 0.92, P < 0.0001 and r = 0.92, P < 0.0001, respectively). These correlations were superior to those determined by semiquantitative methods. We conclude that [18F]FLT-positron emission tomography is a promising clinical tool for imaging cellular proliferation in breast cancer, and is most predictive when analyzed by graphical and spectral methods.
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PMID:Quantification of cellular proliferation in tumor and normal tissues of patients with breast cancer by [18F]fluorothymidine-positron emission tomography imaging: evaluation of analytical methods. 1626 37

Results from studies on efficacy of carcinoembryonic antigen (CEA), carbohydrate antigen 15.3 (CA 15.3) and thymidine kinase (TK1) as diagnostic and prognostic tools for primary breast cancer (BC) have presented conflicting results, and usefulness of these markers for clinical use in BC remains unclear. The aim of this study is to evaluate potential of concentration of the sera CEA, CA15.3 and TK1 peptides' use as markers in the diagnosis and prognosis of breast lesions of Libyan patients. Serum tumour markers were studied in 20 healthy subjects, 30 patient with benign lesion diseases and 50 patients with histologically confirmed BC diagnosed at the National Cancer Institute (NCI), Misurata, Libya during the period 2005-2009. The concentrations of the BC patients' cutoff points used for diagnostic and prognostic sensitivity were 8.82 ng/ml, 35.57 U/ml and 32.57 U/mg/protein for CEA, CA15.3 and TK1, respectively. Increased CEA (>8.82 ng/ml), CA 15.3 (>35.57 U/ml) and TK1 (>32.57 U/mg/protein) concentrations were found in 62 %, 70 % and 78 % of the BC patients, respectively. For all three tumour markers, increased concentrations correlated increased tumour size and nodal involvement. Significantly higher serum TK1 levels were found in patients with advanced disease (p < 0.0001) and TK1 levels also correlated with disease-specific survival (DSS, p < 0.07). The combined data set of the three markers' data from three markers increased the diagnostic sensitivity to 90 %. The serum marker analysis for CEA, CA 15.3, and S-TK1 concentrations is shown to be a useful tool for identification of malignant cases in our BC population and for the prognostic evaluation of patients with primary BC. Increased concentrations of the markers were also observed to be higher in patients with advanced tumours and indicative of the development of distant metastasis.
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PMID:Serum tumour markers as a diagnostic and prognostic tool in Libyan breast cancer. 2294 80