乳腺癌干细胞临床与基础研究的进展

Progress in the Research on Breast Cancer Stem Cells

乳腺癌是一类高度异质性的肿瘤,包括18种组织病理学类型和5种分子亚型。乳腺癌干细胞(CSCs)是乳腺癌组织中极少数具有自我更新能力和多向分化潜能的细胞,具有肿瘤启动作用。CD44^+/cD24^(-/low)表型为乳腺CSCs的标志,大约30%乳腺癌组织中存在CD44^+/cD24^(-/low)表型细胞,CD44^+/CD24^(-/low)表型细胞与病理组织学类型有关,在呈现CD44^+/CD24^(-/low)表型的肿瘤中,浸润性导管癌所占比例最多(78%),其次为髓样癌(11%)和浸润性小叶癌(7%)。CD44^+/CD24^(-/low)表型细胞与乳腺癌的分子亚型有关,在依据基因表达谱得到的5种分子亚型中,CD44^+/CD24^(-/low)表型在基底样癌中最常见。乳腺癌干细胞通常为ER-和PR-的表型,但ER-和PR-的多潜能干细胞能产生ER+,PR+的肿瘤细胞。HER2过表达能够增加CSCs的数量并促进乳腺癌的发生、进展和浸润,但乳腺癌组织中CD44^+/CD24^(-/low)表型通常与HER2低表达或阴性表达呈正相关。迄今有关干细胞与乳腺癌的临床基础研究提出了更多新的问题,引发了更多的思考。

Human breast carcinomas are very heterogeneous, with approximately 18 histological types and at least 5 molecular subtypes. Breast cancer stem cells （CSCs） termed for a small population of cancer cells have self-renewal capacities and the ability to recapitulate all cell types within an individual tumor. They have been demonstrated to have tu- mor-initiating properties in breast cancer. CD44＋/CD24-/Iow is the biological marker for breast CSCs. About 30% of breast cancer patients have CD44＋/CD24-/Iow phenotype. Histopathology is related to CD44＋/CD24-/Iow, in which invasive ductal carcinoma is the highest （78%）, medullary carcinoma （11%） and invasive Iobular carcinoma （7%） are in the next place. CD44＋/CD24-/Iow is related to molecular subtypes in which basal-like type is the most common for CD44＋/CD24-/Iow phe- notype. Breast CSCs are usually ER （-） and PR （-）, but they can divide into ER＋ and PR＋ progeny cells. HER2 overexpres- sion can interact with CSCs pathway and thus contribute to breast tumorgenesis and development. However, CD44 ＋/ GD24-/Iow phenotype is related to HER2-negative breast cancer. This article reviews the progress in the research on breast cancer stem cells and discusses its potential for better diagnosis and treatment of breast cancer.