在Brca1相关的乳腺瘤发生过程中,R循环功能
Huai-Chin Chiang1, Leilei Qi2, Payal Mitra1
1Department of Biochemistry and Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037.
概括
R环,DNA-RNA结构,有助于基因组不稳定性和与BRCA1相关的乳腺癌. 移除BRCA1缺乏细胞中的R环改变了瘤亚型,这表明R环会影响原始癌细胞.
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:
- R-循环 (DNA-RNA杂交) 涉及到基因组的不稳定性.
- 它们与BRCA1突变相关的雌激素受体阴性乳腺癌有关,这些乳腺癌起源于光原细胞.
- 在瘤发生过程中R环的体内因果关系尚不清楚.
研究的目的:
- 为了研究R环在BRCA1缺陷乳腺瘤发生中的in vivo作用.
- 确定R循环去除如何影响DNA复制应激和修复.
- 分析R循环调制对乳腺瘤亚型和起源细胞的影响.
主要方法:
- 过度表达小鼠Rnaseh1 (Rh1-OE) 以减少brca1缺乏的 (BKO) 小鼠乳腺上皮中的R环.
- 评估DNA复制压力和同质导向修复的评估.
- 对乳腺细胞群的分析 (光原体与成熟的光细胞).
- 监测自发乳腺瘤发生率和亚型 (ERα和孕激素受体表达).
主要成果:
- 在BKO细胞中R环去除加剧了DNA复制压力.
- 双链断裂的同质导向修复在很大程度上不受R环缩小的影响.
- 与BKO.Rh1-OE乳腺相比,BKO-Rh1-OE乳腺显示出较少的光原细胞和更成熟的光细胞.
- 乳腺瘤发病率在BKO和BKO-Rh1-OE之间是相似的,但BKO-Rh1-OE瘤的很大一部分表达了ERα和孕激素受体.
结论:
- 在BRCA1缺乏的背景下,R环不会直接增加乳腺瘤总体发病率.
- R-循环积累影响BRCA1相关的乳腺瘤的起源细胞.
- 调节R环可以改变BRCA1缺陷乳腺癌的亚型,转向ERα阳性表型.
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