Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent evidence indicates that oxytocin (OT), in addition to the induction of myometrial and myoepithelial cell contraction, can influence proliferation and differentiation in developing mammary glands and in breast cancer cells, hence the interest in detecting and locating OT receptors (OTRs). We produced rabbit antisera and a monoclonal antibody against a synthetic peptide corresponding to the carboxy terminus of the predicted OTR sequence. We tested their specificity in immunoblasts and immunocytochemical tests. All of the antibodies specifically stained myometrium (at term of pregnancy). In the human breast, OTRs were detected in myoepithelial cells along ducts of normal lobules and in sclerosing adenosis. Intraductal cells in benign hyperplastic lesions were also positive. OTRs were demonstrated in cases of primary and metastatic carcinomas of the breast. In the same tissues, OTR gene expression was shown by reverse transcriptase polymerase chain reaction procedures detecting the specific mRNA. These results suggest that the interaction between OT and its receptors might play a role in the origin and evolution of non-neoplastic lesions and carcinomas of the breast.
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PMID:Immunolocalization and gene expression of oxytocin receptors in carcinomas and non-neoplastic tissues of the breast. 866 75

Telomerase, a cellular reverse transcriptase, has been detected in the majority of human malignant tumors, where it provides an escape mechanism from proliferative limitations due to progressive telomere erosion with each cell division. In this study, we used a non-radioactive telomeric repeat amplification protocol (TRAP) with an internal telomerase assay standard for the detection and semiquantitative analysis of 98 single frozen sections of normal breast tissue and benign and malignant breast lesions on an automated laser-fluorescence sequencer. Telomerase activity was detected in 36 of 40 (90%) infiltrating breast carcinomas, whereas no activity was found in nonmalignant breast tissues including blunt duct adenosis, papilloma, ductal hyperplasia and atypical ductal hyperplasia. However, telomerase activity was detected in 59% of ductal in situ carcinomas, suggesting that telomerase reactivation is an early event in breast carcinogenesis. We found a positive correlation between telomerase activity levels and cell proliferation determined by MIB1 immunostaining. No correlation, however, could be demonstrated between telomerase activity and other known breast cancer prognostic indicators. Telomerase activity was also detected in 60% of fibroadenomas indicating that careful interpretation of analysis of telomerase activity in fine needle aspirates is required, since low telomerase activity may not necessarily be an indicator of malignancy in breast tissue.
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PMID:Telomerase activity in human proliferative breast lesions. 947 5