Chinese researchers have found an RNA biomarker that could predict survival for patients with gastric cancer, according to a paper published in the American Journal of Pathology. Gastric cancer is one of the most common cancers in developing countries. It is often diagnosed at a late stage, and has a high death rate.

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The aim of the research, carried out by a team from the Cancer Research Institute of Southern Medical University and the Third Affiliated Hospital of Kunming Medical University, was to look at the role of miR-506 EMT in gastric cancer, as well as its associations with the clinical outcomes of gastric cancer patients, and its potential role in angiogenesis and the metastasis of gastric cancer cells.

The research, which used quantitative real-time PCR (qPCR) in a blinded manner to detect miR-506 in human gastric cancer samples taken from 84 patients who had undergone cancer surgery. The team found that patients whose primary gastric cancer lesions expressed high levels of miR-506 had a significantly longer survival time compared with patients who had low levels of miR-506 expression. For example, at 60 months, cumulative survival was approximately 80% in the high miR-506 expression group compared to approximately 30% in the low-expression group. This suggests that the level of expression of miR-506, a short stretch of RNA, could stratify patients from early to advanced clinical stages and for overall survival prediction.

Looking at expression of miR-506 in cells from seven gastric cancer cell lines, the researchers found that gastric cancer cells had lower levels of miR-506 than normal stomach tissue, and that miR-506 suppressed tumour growth, blood vessel formation, and metastasis.

“These findings indicate that miR-506 is necessary and sufficient for angiogenesis suppression during gastric cancer progression,” says Xin Song, MD, PhD. “Our study suggests that miR-506 acts as a tumour suppressor in gastric cancer. Additional studies will be needed to explore the potential clinical utility of miR-506 as a potential biomarker for gastric cancer prognosis and as a new potential therapeutic target.”