Epigenetic mechanisms of drug resistance: drug-induced DNA hypermethylation and drug resistance.

Epigenetic mechanisms of drug resistance: drug-induced DNA hypermethylation and drug resistance.

In a model system employing Chinese hamster V-79 cells, the DNA synthesis inhibitor 3'-azido-3'-deoxythymidine (BW A509U, AZT) was shown to induce genome-wide DNA hypermethylation, low-frequency silencing of thymidine kinase (TK; EC 2.7.1.21) gene expression, and resistance to AZT. Twenty-four hours of exposure of V-79 cells to 150 microM AZT led to > 2-fold enhancement of genomic 5-methylcytos...

Drug-induced DNA hypermethylation and drug resistance in human tumors.

Drug-induced DNA hypermethylation was observed to constitute one component of the response of human tumor cells to toxic concentrations of commonly used cancer chemotherapy agents. In both human lung adenocarcinoma cells (HTB-54) and human rhabdomyosarcoma cells (CCl-136), pulse exposures to the topoisomerase II inhibitors etoposide and nalidixic acid; to the antibiotic doxorubicin; to the micr...

Drug Resistance

عفونت و تهاجم ارگانیسم های انگلی به بدن، عامل اصلی بیماری و مرگ انسانها از آغاز بشریت بوده است . در حقیقت بسیاری از اشکال حیات بدون غلبه بر ارگانیسم های زنده دیگر، قادر به ادامه زندگی نخواهند بود. انسانها معمولا مستعد تهاجم ارگانیسم های کوچکتری مانند کرمها، آمیب ها، قارچها، باکتریها و ویروسها هستند. این عوامل مکان خاصی را در بدن انتخاب کرده، مواد ضروری لازم برای حیات و تکثیر خود را دریافت نموده...

Mechanisms of Drug Resistance

Progress of research into the problem of resistance to antibiotics is held back by lack of knowledge of the biochemical mechanisms by which these drugs act. Fortunately, it is possible to study some of the mechanisms of drug resistance, even at a biophysical or biochemical level, without necessarily knowing very much about how the drug works—just as it is possible to study (at least at a biolog...

Molecular mechanisms of drug resistance.