PNAS paper shows that reduced quantities of miR-146a decreased silencing of cancer-promoting genes.
Researchers found a mutation through which papillary thyroid carcinoma (PTC), the most common form of thyroid cancer, is passed down through families.
First-degree relatives of PTC patients have a three- to eightfold greater risk of developing the disease than others. Even with this strong genetic component, previous research has not been able to find a mutation that predispose people to the affliction within any of the know tumor-associated genes.
In the current study, investigators examined how these genes are being regulated. They identified a variant in the pre-miR-146a sequence that reduces the quantity of miR-146a, which is needed to regulate other genes. The investigators also showed that when miR-146a levels fall, two specific genes involved in tumor promotion are not inhibited as efficiently, leading to a greater risk of cancer.
The scientists involved in the research were from the Ohio State University, Helsinki University Central Hospital, and Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology. The study was published May 12 in Proceedings of the National Academy of Science.