Expression Of MiR-148b In Gastric Cancer

ObjectiveMicroRNA(miRNA) is a class of endogenous, non-coding 21-25 nucleotides RNA, which was discovered in recent years. The "seed region", which is the core sequence that encompasses the first 2-7 nucleotides at the 5'portion of miRNA, is essential for the specific suppression of targe mRNA. Recent studies showed that miRNAs were involved in the regulation of the proliferation, differentiation and apoptosis. Therefore, miRNAs were deemed to play a crucial role in the initiation and progression of human cancers, which could regulate many oncogenes and tumor suppressor genes.Gastric cancer is one of the most common malignancies in the world. Altered expression of miRNAs have been reported in gastric cancer, and may play a critical part in carcinogenesis. With more and more miRNAs were discovered in gastric cancer, miRNAs might play an important role in the diagnosis and therapy of gastric cancer. In the present study, we detected the expression of miR-148b in gastric caner tissues and cell lines relative to their non-tumorous control using quantity real-time PCR. We also studied the correlation between the expression of miR-148b and clinicopathological characteristics of gastric cancer. We want to identify the role of miR-148b in carcinogenesis and development of gastric cancer.MethodsWe detected the relative expression of miR-148b in gastric cancer tissues of 102 patients compared to their matched non-tumor adjacent tissues (NATs) by RNA isolation, Poly(A) tail and real-time RT-PCR. Therefore, the value of the relative expression ratio<0.5 was considered as significant low-expression in cancer relative to the non-tumorous control. The others were considered as meaningless or high-expression. We also analyzed the association between miR-148b expression and clinicopathological characteristics in gastric cancer by Chi-Square Test.ResultsWe found the significant low-expression of miR-148b in gastric cancer tissues relative to their NATs. Among 102 patients with colorectal cancer,62 (60.8%) cases showed a significant low-expression of miR-148b. Low expression of miR-148b was associated with increased tumor size (p=0.017) and macroscopic type (p=0.041). The patients with low expression of miR-148b tended to have larger tumor size (≥6cm) and higher macroscopic type (Borrmann III+IV).ConclusionsMiR-148b was significant down-regulated in gastric cancer tissues relative to their NATs. Low-expression of miR-148b was associated with increased tumor size and macroscopic type.