lncHOTAIR and SNHG-7 expression in correlation to miR-34a expression in gastric cancer pathogenesis

Abstract

Background: gastric cancer (GC) is one of the common cancers with a high mortality rate and complex pathogenesis. In recent years many studies focused on the roles of non-coding RNA in GC biology. Long noncoding RNAs (lnc-RNAs) like HOTAIR and SNHG-7 are a class of non-coding RNA that can affect the cell’s biology by sponging of micro-RNAs. Recent studies reveal the relation between these lnc-RNAs and miR-34a expression which can affect various molecular pathways in malignant cells. Methods: GeneAll Trizol RNA extraction kit (Korea) was used to extract total RNA according to the supplied procedures and gene expression was evaluated. The qRT-PCR assay was performed to evaluate the expression levels of miR-34a, HOTAIR, and SNHG-7 in GC and paired marginal tissue specimens. The AUC of the ROC curve was estimated based on their expression in GC and gastric normal tissues to evaluate their diagnostic accuracy.Results: Expression levels of miR-34a were higher in adjacent marginal samples compared to GC tissue samples. We noted significantly higher levels of HOTAIR expression in GC samples compared to non-tumor adjacent tissue samples and the expression of HOTAIR in GC tissues was negatively correlated with mir-34a. Similarly, we noted GC tissue samples showed higher levels of SNHG-7 expression and that SNHG-7 expression was negatively correlated with mir-34a. Regarding the clinicopathological factors, miR-34a expression was lower in patients with advanced GC, while enhanced expression of HOTAIR and SNHG-7 was noted in these patients. Conclusion: Our findings suggested that miR-34a, HOTAIR, and SNHG-7 expression levels have high potential as diagnostic markers for discriminating GC patients from normal cases. In Addition, there is a negative correlation between miR-34a with two other genes which suggests the regulatory effects of HOTAIR and SNHG-7 on miR-34a.