A study on regulation of DNA mismatch repair genes MLH1 and MSH2 in human SCLC cell line H446 under hypoxic condition
- VernacularTitle:缺氧对人小细胞肺癌H446细胞DNA错配修复基因MLH1、MSH2表达的影响及其机制探讨
- Author:
Ruiling GUO
;
Guoming WU
;
Fuyun JI
- Publication Type:Journal Article
- Keywords:
hypoxia;
small cell lung cancer,SCLC;
DNA mismatch repair;
promoter methylation;
5-Aza-CdR
- From:China Oncology
1998;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
Background and purpose:Regulation of MMR activity under hypoxia may play an important role in genetic instability of cancer,but the mechanism is still unclear.We investigated the expression of DNA mismatch repair genes MLH1 and MSH2 in human SCLC cell line H446 under hypoxic condition and explore the role of promoter methylation of genes in hypoxia.Methods:RT-PCR and Western blot were applied to detect MLH1 and MSH2 expression in human SCLC cell line H446 at the mRNA and the protein level,respectively,under either hypoxic condition or after 5-Aza-CdR treatment.Meanwhile,methylation-specific PCR(MSP)was used to determine promoter methylation of MLH1 and MSH2.Results:The expression of MLH1 and MSH2 in H446 cells significantly decreased both at the mRNA and the protein level under hypoxic condition.5-Aza-CdR treatment led to the restoration of MLH1 and MSH2 expression,while,both MLH1 and MSH2 were down-regulated again after removing 5-Aza-CdR.Conclusions:The promoter methylation of MLH1 and MSH2 may play an important role in its defective expression in H446 cells under hypoxic condition.And 5-Aza-CdR could restore MLH1 and MSH2 expression.
