Cancer Stem Cells Created From Normal Stem Cells!
A team of researchers from the University of North Carolina, Chapel Hill have succeeded in turning stem cells that form placenta to triple negative breast cancer (TNBC) cells. According to Gary Johnson, the senior author of this study, for the first time a transformed stem cell has been isolated in this way.
TNBC is an aggressive and highly recurrent type of breast cancer that spreads rapidly from its original site to the surrounding areas. The current study may lead to the development of novel therapeutic strategies aimed at TNBC.
The study was published in the May edition of Cell Stem Cell journal.
During normal development, epithelial stem cells known as trophoblasts form the placental tissue. In this process, they transform themselves into tissue-like (2 or more cells clubbed together) cells. These tissue-like cells revert to their normal shape (individual cells) soon after they reach the uterus.
In the study, the group of scientists changed a single amino acid in the trophoblasts. This change although retained the self renewing capacity of the cells, they exhibited properties similar to the ones found in TNBC cells (highly invasive and highly mobile). The mutant trophoblasts continued invading the uterus unlike normal trophoblasts.
The study revealed that epithelial stem cells go through the same molecular changes during the development of organs as that of the TNBC cells known as epithelial mesenchymal transition (EMT).
According to Nicole Vincent Jordan and Amy N. Abell, the first authors of the study, cancer cells in breast use the same molecular program during tumor metastasis (cancer spreading).
A mouse model of epithelial stem cell EMT was developed specifically for this study. Through this study, 2 proteins CBP and MAP3K4 were identified. These regulate specific gene expressions in trophoblasts during the development of organs. Trophoblasts became hyperinvasive when both these proteins were inactivated.