不匹配修复蛋白MLH1抑制了BRCA2缺乏乳腺瘤的复制性压力
Satheesh K Sengodan1, Xiaoju Hu2, Vaishnavi Peddibhotla1
1Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland USA.
The Journal of clinical investigation
|January 25, 2024
概括
失去BRCA2会导致细胞死亡,但MLH1过度表达可以使缺陷细胞存活. MLH1稳定复制叉,抑制基因组的不稳定性,帮助瘤的发展.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 癌症研究 癌症研究
背景情况:
- 对正常细胞来说,BRCA2 (乳腺癌2) 的损失通常是致命的.
- 在BRCA2突变细胞中实现生存和瘤转变的机制尚不清楚.
- BRCA2 缺乏与癌症风险增加有关,特别是ER阳性乳腺癌.
研究的目的:
- 识别BRCA2的基因相互作用体,支持细胞活力.
- 阐明这些相互作用体促进BRCA2缺陷细胞生存的分子机制.
- 了解这些相互作用在BRCA2突变瘤发育和雌激素信号传递中的作用.
主要方法:
- 在BRCA2缺乏细胞中的基因相互作用研究.
- 研究了MLH1 (mutL同源1) 和FEN1 (片内核酶1) 之间的相互作用.
- 评估复制分叉稳定性,R循环形成和基因组不稳定性.
- 使用Brca2缺乏和Mlh1损失的小鼠模型.
- 通过ERα (雌激素受体α) 检查雌激素对MLH1表达的影响.
主要成果:
- 过度表达MLH1支持Brca2-null细胞的活力.
- MLH1与FEN1相互作用,抑制DNA2核酶活性,稳定BRCA2缺乏细胞中的复制分叉.
- MLH1减弱R环,抑制基因组不稳定性,促进细胞存活.
- 在Brca2-突变小鼠中,MLH1的损失是致命的,并且抑制了Brca2-缺乏瘤的生长.
- 雌激素通过ERα诱导MLH1的表达,这可能解释了BRCA2载体中ER阳性乳腺癌的流行率.
结论:
- MLH1在缓解BRCA2缺乏细胞中的复制性压力方面发挥着至关重要的作用.
- MLH1有助于BRCA2缺陷瘤的形成和进展.
- 雌激素-MLH1-ERα通路可能是BRCA2-关联乳腺癌发病的一个关键因素.
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