Many people have heard of mesotheliomas through frightening television commercials. But little is known about treatment for this cancer, which happens to be one of the most aggressive and lethal of all cancer types. Now, researchers at the University of Bradford in the UK recently published findings
on a drug that could possibly be the first to work against mesothelioma cancer cells. The promising results offer hope to mesothelioma patients who have little to no recourse after diagnosis.
As one of the most aggressive cancer types, mesothelioma is a cancer of the lining of the lung. Uniquely, this cancer is caused by exposure to manmade products containing the carcinogen asbestos. When breathed into the lungs, asbestos fibers get trapped and cause scarring and inflammation, triggering serious health conditions like mesothelioma. Though rare nowadays in the US, cases of mesotheliomas are still rampant in other parts of the world due to unregulated use of materials containing asbestos. The disease has a poor prognosis, with less than one-year survival rates after diagnosis.
The newly identified drug is known as HRX9, and it works by forcing cancer cells to undergo programmed cell death, or apoptosis. Normal cells divide, grow, and die at regularly scheduled time points; however, cancer cells like that in mesothelioma are resistant to signals for cell death.
"Both the immune system and nearby healthy cells send signals instructing damaged and unhealthy cells to undergo apoptosis, which is like programmed 'cell suicide'. But cancer cells have developed a wide range of strategies to ignore these instructions," said Richard Morgan, professor at the University of Bradford's Institute of Cancer Therapeutics, and lead author of the study. Consequently, cancer cells multiple and grow out of control, leading to disease and health complications.
HRX9 targets the HOX gene family, which are involved in cell division. In treatment of HRX9 to mice with human mesothelioma tumors, researchers noticed a dramatic decrease in cancer growth. They also found HRX9 resulted in disintegration of tumor blood vessels, which promoted widespread cancer cell deaths.
"We've effectively knocked out a key defence mechanism in this cancer through targeting the HOX genes," said Morgan.
Further research between mesothelioma and the HOX gene pathway revealed another finding of great interest. Mesothelioma was greatly associated with HOXB4, a member of the HOX gene family. "We examined the amount of HOXB4 protein in tumours of 21 mesothelioma patients and compared it with their length of survival. There was a clear link: the more HOXB4 we found, the shorter time the patient survived, so we may also have found a way to predict which patients have the most aggressive form of this cancer," said Morgan.
The study results are preliminary, but quite promising for mesothelioma patients. Further investigations should include data on the long-term effects of HRX9 in the mouse, and whether the decrease in tumor growths can be sustained over a long period of time.
Additional source: EurekAlert!