Breakthrough In Understanding How Cancer Cells Metastasize

Breakthrough In Understanding How Cancer Cells Metastasize
Lung cancer cell dividing. (Image source)
A protein commonly found in human cells could be an important switch that activates cancer cell metastasis, according to a new study. The finding focuses attention on a biological mechanism that until now was largely overlooked. The discovery of the protein's effect significantly expands our understanding of epithelial cancers such as breast and lung cancer. The findings are published in Journal of Cell Biology.
 
The study examined the function of a protein called DENND2B. During childhood development, DENND2B likely plays a role in the normal migration of cells. In adults, cell migration is greatly reduced, but in the case of cancer, there is unwanted cell migration, contributing to one of the most puzzling aspects of cancer cells - metastasis to new locations.
 
DENND2B activates another protein in the cell called Rab13, which is an enzyme that promotes cell migration. Until now, researchers didn't know how Rab13 was activated to initiate cell migration, but found that Rab13 has an unusually high degree of expression in many forms of cancer, especially epithelial cancers that often metastasize to the brain. They saw that the DENND2B protein was activating Rab13 at the leading edge of the cell, an important point for cell migration.
 
The researchers see Rab13 as a focus for future research into cancer therapies. The team showed a significant result when they injected highly aggressive human breast cancer cells into mice under two conditions - one with cells having high levels of Rab13 protein, and one in which Rab13 was artificially removed.
 
In the case of the cells with reduced Rab13 levels, the cancer either did not grow at all or formed a smaller tumour. Furthermore, the smaller tumour did not metastasize into other tissue.
 
No one had considered targeting Rab13 in relation to cancer before this study, the researchers said, adding that clinical trials involving the discovery are still some time away.
 
Based on material originally posted by McGill University.