A team of researchers at Institute of Biochemistry and Cell Biology(SIBCB), Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, reported Oct 19 online in Nature identified multipotent mammary stem cells(MaSCs) that could lead to important treatments for the type of breast cancer that to date have no targeted treatment.
Tissue specific stem cells exist in many organs. Previous research indicated that there might exist a kind of multipotent MaSCs on the basal layer of the epithelium, however no effort succeeded in singling out this versatile type of stem cells from the heterogeneous population.
Under the supervision of Prof. ZENG Yi from SIBCB, Wang Daisong, Cai Cheguo and their colleagues first discovered new populations of multipotent MaSCs in the mammary glands by protein C receptor (Procr) expression. These MaSCs display high regenerative capacity and can differentiate into all lineages of the mammary epithelium. These MaSCs express Procr at their cell surface, which not only serves as a marker for the stem cell identity but also facilitates the isolation of stem cells. These MaSCs exhibit similarities to malignant cells and they could be important in the initiation of breast cancer.
Breast cancers could fall into four different subtypes, drugs are available targeting three receptors However, for the fourth subtype that does not express any of the three receptors, namely the triple-negative breast cancer, no targeted therapy is available. According to the researchers, about 20% breast cancers fall in this subtype and have the highest metastasis rate.
The multipotent MaSCs identified by the team do not express any of the above-mentioned receptors either. This similarity might suggest its possible role in initiation of the triple-negative subtype of breast cancer, and might shed some new light on its treatments.
“Stem cells exist in many adult organs, but breast stem cells could be an important origin for tumors. Breast cancer for which there is no targeted treatment could originate in these stem cells,” explained ZENG Yi.
Their study, entitled "Identification of Multipotent Mammary Stem Cells by Protein C Receptor Expression" was done in collaboration with Prof. YANG Li at CAS-MPG Partner Institute for Computational Biology, and was supported by grants from the Ministry of Science and Technology of China, the National Natural Science Foundation of China, Chinese Academy of Sciences and Shanghai Municipal Science and Technology Commission.
(Image provided by Prof. ZENG Yi`s group)
Appendix：
