Novel molecular regulators of breast cancer stem cell plasticity and heterogeneity

Tumors consist of heterogeneous cell populations, and tumor heterogeneity plays key roles in regulating tumorigenesis, metastasis, recurrence and resistance to anti-tumor therapies. More and more studies suggest that cancer stem cells (CSCs) promote tumorigenesis, metastasis, recurrence and drug resistance as well as are the major source for heterogeneity of cancer cells. CD24-CD44+ and ALDH+ are the most common markers for breast cancer stem cells (BCSCs). Previous studies showed that different BCSC markers label different BCSC populations, indicating the heterogeneity of BCSCs. Therefore, defining the regulation mechanisms of hetero-geneous BCSCs is essential for precisely targeting BCSCs and treating breast cancer. In this review, we sum-marized the novel regulators existed in BCSCs and their niches for BCSC heterogeneity which has been discovered in recent years, and discussed their regulation mechanisms and the latest corresponding cancer treatments, which will extend our understanding on BCSC heterogeneity and plasticity, and provide better prognosis prediction and more efficient novel therapeutic strategies for breast cancer.

Automated summary

Tumors are comprised of different cell populations, and the heterogeneity of tumor cells plays crucial roles in tumorigenesis, metastasis, recurrence and resistance to anti-cancer therapies. Cancer stem cells (CSCs) have been found to promote these processes and contribute to tumor heterogeneity. CD24-CD44+ and ALDH+ are commonly used markers for breast cancer stem cells (BCSCs). It has been observed that different markers for BCSCs label distinct subpopulations, indicating the heterogeneity of BCSCs. Therefore, understanding the regulatory mechanisms of heterogeneous BCSCs is essential for targeted therapies and effectively treating breast cancer.