Cancer Cells Send Out Bubbles To Grow and Spread
McGill University Health Centre researchers have learned a new mechanism that cancer cells use to spread in the body.
The cancerous cells can “talk” to healthy cells by releasing small packets. The bubble packets contain cancer causing proteins that may trigger cell machinery in normal healthy cells to turn them into cancer cells. This research could change the understanding of how cancerous cells spread and lead to new effective treatments.
The outer membrane of some brain cancer cells are known to express a mutated version of epidermal growth factor receptor (EGFRvIII). Even though this factor (EGFRvIII) is found on a fraction of cancer cells, it strongly influences the malignancy of the whole tumor. The mechanism that these cells used to influence the growth of tumor cells was unknown until this study revealed the small bubbles or packets that the McGill Researchers have discovered.
The McGill University study demonstrates that the abnormal EGFRvIII causes the production of small bubbles or vesicles that stick out on the cell surface and carry abnormal or mutated copies of EGFRvIII on their surfaces. These bubbles are now called “oncosomes”. Oncosomes will move from the cancer cells and they fuse with another cell, which could be a normal healthy cell or a cancer cell. The cancer cell protein ( Oncogenic protein EGFRvIII) then merges with the membrane of the “recipient” cell and causes the healthy cells to act as though they were cancerous. This finding was a surprise and showed a new way that tumor tissues can grow. The changes in the normal cells may be transient but it helps tumors to grow faster.
Dr. Rak stated that this discovery “demonstrates that cancer is a multi-cell process, where the cells talk to one another extensively. This goes against the traditional view that a single ‘mutated’ cancer cell will simply multiply uncontrollably to the point of forming a tumour. This discovery opens exciting new research avenues, but we also hope that it will lead to positive outcomes for patients.”
Lab tests looking at these “bubbles” or oncosomes (containing EGFRvIII or other cancer proteins) in blood of cancer patients could be used as a screening test for a tumor’s biological characteristics instead of having to perform a surgery or biopsy of the tumor.
ref: http://www.muhc.ca/media/news/item/?item_id=100199
