University of Texas scientists investigate beta blockers as cancer treatment

A signalling pathway where a master regulator of cancer cell proteins, titled Src, leads to ovarian cancer progression when exposed to stress hormones has been found.

The current issue of Nature Communications revealed the findings, showing that beta blocker drugs mitigate this effect and reduce cancer deaths by an average of 17 per cent.

Src is short for sarcoma and is a proto-oncogene that can become an oncogene due to increased expression involved in the regulation of cell growth and division.

Anil K Sood, professor in MD Anderson's Departments of Gynecologic Oncology and Cancer Biology, led the research, which discovered that noradrenaline (NA; a stress hormone) directly affects tumour growth and spread through beta-adrenergic (ADRB) receptors.

The quantitative analysis that ADRB signalling triggers Src activation via a unique protein kinase A (PKA)-meditated mechanism, which is key to the regulation of cellular activity and cancer metastasis.

Mr Sood explained: "When Src is triggered by stress, it works like a dam letting out water that causes a flood downstream. Src, like the dam, is a master regulator switch that causes a chain reaction in the cells.

Beta blockers can treat a variety of conditions, including heart disease, high blood pressure, glaucoma and migraines.

They work by acting on the ADRB receptors, causing the heart to beat harder and faster under stress, and help to maintain blood flow.

When ADRB receptors on cancer cells are activated, they trigger a chain of events that lead to formation of new blood vessels. These feed tumour growth in a process known as angiogenesis.

Guillermo Armaiz-Pena, Ph.D., instructor of Gynecologic Oncology and Reproductive Medicine and first author of the study, said: "Prior to our work, the concept of stress hormones driving cancer growth was very new and only very limited information about the effect of beta blockers on cancer outcomes in humans has been available.

"This study provides incentive to further explore beta blockers as a possible supplement to traditional cancer therapies."

Posted by Neil Clark