Cancer cells reprogrammed back to normal: PLEKHA7 stops tumor progression

Credit: Shuttershock
Credit: Shuttershock

Over many years cancer cells have had the upper hand in fully establishing the deadly disease due to their ability to proliferate to a state of immortality. For the first time, scientists from the Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center have made a breakthrough in understanding how brakes can be applied to stop the proliferation of tumor cells and restoring them to a benign state.

E-Catherin and p120 are the two important proteins involved in the growth and proliferation of epithelial cells, these are principally the cells which evolve into the blood vessels, organs and various parts of the body. Normal cells form contacts with each other forming junctions when proliferation stops, cancer cells lack this ability and continue their monstrous growth.

There are two distinct p120 complexes with opposing functions which govern the epithilial cell growth. The principle finding of Prof. Panos Anastasiadis and his team was understanding the mechanism of a protein called PLEKHA7 which recruits a subpopulation of microprocessing RNA’S (miRNA) to a complex within the epithelium and regulates the processing of select miRNA’S thereby suppressing the expression of markers SNAI1, MYC involved in transforming cancer cells. miRNA’s have the ability to signal cells to start or stop their function.

miRNAs regulated by PLEKHA7 provide a mechanistic link in maintaining epithelial homeostasis. PLEKHA7 mediates the suppression growth-related signaling, regulates a set of miRNAs to suppress cellular transformation and maintain the epithelial phenotype thereby ‘halting’ cancer progression.

The results of this new ‘switching off’ mechanism was successfully proven in cancer cell lines of the kidney, breast and intestine and the team hopes to extend this research with more experiments in the future.

“I think in reality it is unlikely that you could reverse tumors by reversing just one mechanism, but it’s a very interesting finding” remarked Dr Chris Bakal, a specialist in how cells change shape to become cancerous, at the Institute for Cancer Research in London. The study is a stepping stone in the race to understand and finding a cure to cancer.

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