York University researchers have zeroed in on a genetic process that may allow ovarian cancer to resist chemotherapy. Researchers in the university’s Faculty of Science & Engineering studied a tiny strand of our genetic makeup known as a MicroRNA, involved in the regulation of gene expression. Cancer occurs when gene regulation goes haywire.
“Ovarian cancer is a very deadly disease because it’s hard to detect,” says biology professor Chun Peng, who co-authored the study. “By the time it’s diagnosed, usually it is in its late stages. And by that point there is really no way to treat the disease. Even when the disease is discovered in its early stages, chemotherapy doesn’t always work.”
Chun Peng was among a team of researchers that discovered a receptor, ALK7, which induces cell-death in epithelial ovarian cancer cells. They have now discerned that microRNA 376c targets this crucial receptor, inhibiting its expression and allowing ovarian cancer cells to thrive.
“Our evidence suggests that microRNA 376c is crucial to determining how a patient will respond to a chemotherapeutic agent,” says Chun Peng. “It allows cancer cells to survive by targeting the very process that kills them off.”
In examining tumours taken from patients who were non-responsive to chemotherapy, the researchers found a higher expression of microRNA 376c and a much lower expression of ALK7.
According to Chun Peng, this research is a step towards being able to make chemotherapy drugs more effective in the treatment of the disease.
“Further study is needed, but ultimately if we can introduce anti-microRNAs that would lower the level of those microRNAs that make cancer cells resistant to chemotherapeutic drugs, we will be able to make chemotherapy more effective against ovarian cancer,” adds Chun Peng.