Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to investigate the clonality in various benign, precancerous and malignant breast lesions, we analyzed small DNA samples from paraffin sections of various breast lesions by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) of the X-chromosome-linked phosphoglycerokinase (PGK) gene. DNA from the lesion as well as from the adjacent normal tissue were analyzed in each case. Two restriction endonucleases. Hpa-II, a methylation sensitive restriction enzyme and Bst XI, a restriction endonuclease, which recognizes this polymorphic site on the PGK gene, were used. Of 19 cases, one case of in situ ductal Ca (DCIS), two cases of invasive ductal Ca and one case of multifocal ductal Ca were shown to be monoclonal. Two cases of intraductal papillomas were found to be polyclonal. One case of atypical ductal hyperplasia showed no conclusive findings. Additionally DNA was not yielded from 3 cases and other 7 cases were not informative, derived from females homozygotes. Further study of a larger number of cases is in progress.
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PMID:Clonal analysis by PCR and RFLP in breast cancer and precancerous lesions. Preliminary data. 904 17

P16(INK4a) is a tumor suppressor gene frequently inactivated by aberrant promoter hypermethylation. In this study, p16(INK4a) methylation was evaluated in intraductal proliferative lesions of the breast, using real-time quantitative polymerase chain reaction (MethyLight) and methylation-sensitive restriction endonuclease polymerase chain reaction. Immunohistochemistry was performed to compare and validate the methylation analysis. P16(INK4a) methylation associated with oncogene cyclinD1 expression, detected through the use of in situ hybridization and immunohistochemistry, was likewise characterized. P16(INK4a) methylation displayed varying significance among different types of intraductal proliferative lesions. Both the positive rate and the median quantitative methylation value increased with the evolution of intraductal proliferative lesions through the use of quantitative and qualitative assays. P16(INK4a) methylation was positively correlated to cyclinD1 overexpression. This study demonstrated that p16(INK4a) methylation served as the silencing mechanism of p16(INK4a) protein expression and played a crucial role in the intraductal proliferative lesions' progression. In the differential diagnosis of intraductal proliferative lesions, quantitative DNA methylation analysis of p16(INK4a) by MethyLight may be used as a surrogate, especially to distinguish atypical ductal hyperplasia from usual ductal hyperplasia and low-grade ductal carcinoma in situ. Furthermore, this study discovered that flat epithelial atypia do not share similar molecular profiles of p16(INK4a) epigenetic modification with atypical ductal hyperplasia and low-grade ductal carcinoma in situ.
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PMID:Methylation of CpG islands of p16(INK4a) and cyclinD1 overexpression associated with progression of intraductal proliferative lesions of the breast. 1865 95