Researchers have discovered a protein that they suggest could identify which cancer cells in a tumor are going to become aggressive and spread to the rest of the body.
The researchers - from Rockefeller University in New York, NY, and the University of Bergen in Norway - report their findings about the protein, called PITPNC1, in the journal Cancer Cell.
First author Dr. Nils Halberg, a molecular biologist at the University of Bergen, says:
"We discovered that the aggressive cancer cells that are spreading in colon, breast and skin cancer contained a much higher portion of the protein PITPNC1 than the non-aggressive cancer cells."
Over 90% of deaths to cancer are caused by metastasis - where so-called aggressive cells leave the original tumor and travel to other parts of the body to set up new tumors. Any discovery about this process helps us get closer to saving millions of lives.
Metastatic cancer has the same name as the cancer the cells originate from. For example, a metastatic tumor in the lung formed by cells that migrated from a breast cancer tumor is called metastatic breast cancer, not lung cancer.
Under a microscope, metastatic cancer cells generally look very similar to the cells of the original tumor. Moreover, metastatic cancer cells and cells of the original cancer often share some molecular features, such as the expression of certain proteins.
Protein controls release of tissue penetration molecules
Dr. Halberg explains there are many different kinds of cell inside a tumor, and while some cells are benign and cause no trouble, others become aggressive and get ready to spread. And it is very hard to predict which cells will become aggressive.
- Virtually all cancers can form metastatic tumors
- The most common sites for metastasis are the bone, liver and lung
- If a new tumor arises in a patient already treated for cancer, it is more likely to be metastatic cancer than a new primary tumor.
In their paper, the team describes how they isolated aggressive cancer cells from metastatic breast, melanoma and colon cancers and discovered they all had a gene that was much more highly expressed than in cells that did not spread. The gene codes for the protein PITPNC1. Dr. Halberg notes that:
"This means we can predict which of the cancer cells are getting aggressive and spread, at a much earlier stage than today."
He and his colleagues also found that the protein has a very specific function in the spread of cancer cells that use blood vessels to migrate to new sites in the body.
To be able to leave the tumor, enter blood vessels and then attach to a new organ, the aggressive cells need to penetrate tissue. Dr. Halberg says they do this by releasing molecules that act like scissors to cut through the matrix of proteins surrounding the cells, and the protein that regulates this process is PITPNC1.
The team hopes the finding will help find treatments that reduce the risk of cancer spread - for instance, after surgery, as Dr. Halberg concludes:
"If we get to the point where we can offer a custom-made therapy that targets the function of this protein, we might be able to stop it spreading."
Earlier this year, Medical News Today learned of a study that suggested barring exit from blood vessels could be another way to stop cancer spread.