Cartilage protein may lead to breast cancer

A protein which mainly exists in cartilage may also contribute to the development and spread of breast cancer, researchers have found.
The study by researchers from Lund University in Sweden showed that the protein COMP (Cartilage Oligomeric Matrix Protein), which mainly exists in cartilage, can also be found in breast cancer tumours in patients with a poor prognosis.
Studies on mice also showed that COMP contributed to the development and metastasis of the breast cancer.
COMP is a protein that so far has mainly been studied in cartilage tissue, where it helps development of a normal structure of the tissue. COMP is also used as an indicator of cartilage damage in joint diseases.

Through a database search, researchers discovered a clue that suggested COMP may also be linked to breast cancer.
"We did not expect to find COMP in connection with breast cancer, and we were also surprised by the strong effect it had on the development of breast cancer in mice," said Emelie Englund from Lund University.

Results are based on a clinical study of breast tissue from a little more than 600 women with breast cancer. Various amounts of COMP were found in both the tumours and the surrounding tissue, but never in healthy breast tissue, researchers said.
Women with high levels of COMP experienced increased metastasis, less time before a relapse, and increased mortality, they said.

"We saw a clear association between high levels of COMP and a worse breast cancer prognosis. With more research, COMP has the potential of becoming an indicator of aggressive breast cancer, and thereby providing early and valuable information before deciding on an appropriate treatment," said Anna Blom from Lund University.
Following the clinical study, researchers continued with studies on the molecular mechanisms that may explain the effect COMP has on the breast cancer development.
The studies, including one on mice, showed that COMP not only contributed to a more rapid growth of the primary tumour, but also to formation of metastases.

COMP made the cancer cells more resistant to natural cell death, as well as affected the cell metabolism, making the breast environment less favourable to healthy cells, researchers said.
The findings were published in the journal Oncogene.