Health sciences researcher discovers key to why primary cancer tumours spread

SFU molecular biologist Tim Beischlag has discovered a cellular mechanism that transforms many kinds of primary cancer cells, including those of breast and prostate cancer, into more aggressive cancer cells that can enter the bloodstream and spread to other organs.

While primary tumours of the breast and prostate are not lethal in and of themselves, they can be fatal if the tumour cells metastasize, or spread, to essential organs such as the lungs, liver or brain.

“We’ve demonstrated that the retinoblastoma protein (Rb) plays an important role in regulating the spread of tumour cells, particularly in prostate cancer,” says Beischlag.

The health sciences professor collaborated on some of the research with investigators at SFU, the University of British Columbia and the Vancouver Prostate Centre.

The discovery is significant because scientists can now begin to develop new therapeutic drugs that use this pathway to preferentially attack cancer cells, rather than all cells.

Current cancer treatments, such as chemotherapy, surgery and radiation affect cancerous as well as healthy cells, and are not very effective at preventing metastasis.

In a paper just published in the academic open access journal, Oncotarget, Beischlag describes how loss of the Rb protein is an integral part of a biological mechanism that causes an uncontrolled response to oxygen deprivation in prostate cancer cells. Oxygen deprivation is a characteristic of solid tumours and loss of Rb is an event common to one of the most lethal forms of prostate cancer. This event, in turn, causes prostate cancer cells to become more aggressive, demonstrate metastatic potential, and adopt characteristics associated with an untreatable form of the disease.

Beischlag says his discovery applies to a significant proportion of cancers, including lung, neuro-endocrine and brain cancers.

He suggests the discovery may lead to new drugs that are not just anti-metastatic but that may even shrink primary tumours.

He is now exploring partnership options for developing new therapies based on the discovery.

The research was funded through the Natural Sciences and Engineering Research Council.