Protein regulates tumour cell growth in multiple myeloma

A protein known to be linked to inflammation may play an important role in the progression of some human cancers, scientists have revealed. This could provide a potential target for new cancer treatments.

Researchers from the MD Anderson Cancer Centre discovered that C-reactive protein (CRP) might influence the growth and survival of multiple myeloma tumour cells.

CRP is made in the liver and produced at high levels in patients with infections, inflammatory diseases and some cancers.

Multiple myeloma is a type of cancer that develops from cells in the bone marrow. Patients with multiple myeloma are known to have elevated levels of CRP protein. This was previously thought to be a “marker” of the cancer, but not to have a biological effect on the disease.

The researchers added CRP to cancer cells grown in the lab and found that, at the level found in patients with multiple myeloma, the protein encouraged the cells to multiply and stopped them from dying.

In addition, the researchers discovered that CRP enhances production of a molecule involved in inflammation, called IL-6. CRP also blocked some of the effects of chemotherapy drugs.

The team concluded that CRP is a “critical regulator” of myeloma cell survival, regulating both cancer cell growth and survival. It could therefore be an attractive target for the development of new anti-cancer drugs.

Dr Qing Yi, a researcher at the MD Anderson Cancer Centre, commented: “CRP protects myeloma cells from apoptosis induced by chemotherapy drugs and stimulates myeloma cells to secrete more IL-6, which in turn provides additional protection to myeloma from apoptosis and stimulates liver cells to secrete more CRP.

“Thus, CRP could be a therapeutic target for breaking the vicious circle of myeloma to improve the therapeutic efficacy of currently available treatments.”

The findings are published in the September issue of the journal Cancer Cell.