The Expression And Clinical Significance Of The Serum MiR-200b And MiR-200c In The Gastric Cancer

Purpose: MicroRNAs are small, non-coding RNAs that are critical regulators ofvarious diseases including cancer, and may represent a novel class of cancerbiomarkers. Recent reports have highlighted the tumor suppressor aspects ofmiR-200b and miR-200c. However, the level and clinical relevance of circulatingmiR-200b and miR-200c transcripts in human serum of gastric cancer patients areunclear. The purpose of this study was to identify circulating miR-200b and miR-200ctranscripts in human serum for use as a biomarker for stratification and prediction ofprognosis in gastric cancer.Methods: We analyzed serum levels of miR-200b and miR-200c in96patients withdifferent stages of gastric cancer. Blood samples were collected before surgery andtherapy. Quantitative reverse transcription–polymerase chain reaction of circulatingmiR-200b and miR-200c transcripts was performed directly in serum to improve theefficiency of miRNA assessment.Results: We found that serum miR-200b and miR-200c were downregulated in thegastric cancer group and were significantly associated with the clinical stage andpresence of lymph node metastasis. Furthermore, Kaplan-Meier survival analysesrevealed patients with low miR-200b and miR-200c expression displayed asignificantly poorer prognosis. miR-200b and miR-200c were positive correlativeby Spearman analysis.Conclusions:1. Serum miR-200b and miR-200c expression level were downregulated in gastriccancer patients and had a close correlation to advanced clinical stage and withlymph node metastasis. 2. Serum miR-200b and miR-200c may represent a novel biomarker in gastriccancer patients and that low miR-200b and miR-200c expression are anindependent prognostic factor for survival.