Researchers at the Whitehead Institute have discovered a differentiated cell in the breast tissue that spontaneously transforms into a stem-like state, the first time it has been observed in mammalian cells. These results refute the dogmatism of science—thinking that differentiation is a single path, and once cells differentiate, they cannot rely on themselves to return to the state of stem cells.
This amazing discovery, published on PNAS, is important for the advancement of cancer treatment, especially the eradication of cancer stem cells.
Robert Weinberg of the Whitehead Institute said that if cancer stem cells are eliminated from a tumor by a specific medium, some of the remaining non-stem tumor cells will be produced by a process of auto-de-differentiation. New cancer stem cells. Cancer stem cells are the only cells that can reseeute tumors in the body.
In the process of differentiation, incompletely differentiated stem cells can be cultivated into many different cell types with specific functions. These differentiated cells can work together to form tissues and organs. In mammary tissue, differentiated basal cells and luminal cells combine to form a milk duct.
The first author of the paper, Christine Chaffer, a postdoctoral researcher at Weinberg Laboratories, analyzed cells from human breast tissue and observed a small amount of basal cells floating freely in tissue culture fluid.
Due to curiosity about abnormal cell behavior, Chaffer embarked on further research to inject floating basal cells into mice. After 12 weeks, the injected basal cells were found to produce a structure similar to the milk duct, including basal and luminal cells, which clearly indicates that the floating cells have been dedifferentiated to stem cells.
Until now, no one has shown that differentiated mammalian cells, like these basal cells, can spontaneously return to the stem cell state. Observing whether the basal cells would become cancer stem cells, Chaffer injected the oncogene into these cells and then injected them into the mice. The tumors in the mice were found to contain cancer stem cells, which were descendants of the original basal cells. This result suggests that basal cells in breast cancer tumors are a previously unknown source of cancer stem cells.
Currently, research on cancer treatment focuses on eliminating cancer stem cells, and Weinberg warns that the plasticity of these basal cells suggests a more complex condition.
Future drug treatments for cancer must eradicate cancer stem cells and eliminate non-stem cells in the tumor, both of which must be eradicated.
Chaffer is focusing on what drives these flexible cells to dedifferentiate and how cancer cells can turn into cancer stem cells.
This plasticity can occur naturally, and it seems that the promoter may be a physiological mechanism for transformation into stem cells. We believe that certain cells are more sensitive to this motility and that the process occurs more frequently in cancer cells.