GAS8 and GAS8-AS1 expression in gastric cancer

Aim: To evaluate the expression of the growth arrest-specific 8 (GAS8) and its antisense (GAS8-AS1) in gastric cancer. Background: GAS8 exists in a genomic region that is recurrently deleted in breast and prostate cancer. This gene contains a long non-coding RNA, namely GAS8-AS1 whose roles in the regulation of GAS8 has been reported in hepatocytes. GAS8-AS1 has also been regarded as a putative tumor suppressor gene in papillary thyroid cancer and hepatocellular carcinoma. Methods: In the present study, we evaluated expression levels of GAS8 and GAS8-AS1 in 30 gastric cancer tissues and their corresponding adjacent non-cancerous tissues (ANCTs). Results: GAS8 was significantly down-regulated in tumor tissues compared to ANCTs (Expression ratio=0.29, p 0.001). Although the expression of GAS8-AS1 was higher in tumor tissues compared to ANCTs (Expression ratio=2.15), it did not reach the level of significance (p=0.12). GAS8 expression was associated with the site of the primary tumor (p=0.01). GAS8-AS1 expression was significantly higher in tumors with lymphatic/ vascular invasion compared with those without lymphatic/ vascular invasion (p=0.03). Significant pairwise correlations were detected between expression levels of GAS8 and GAS8-AS1 in tumor tissues and ANCTs. Based on the results of the ROC curve, the diagnostic power of transcript levels of GAS8 in gastric tissues was estimated to be 76%. Conclusion: The current study underscores the roles of GAS8 and GAS8-AS1 in gastric carcinogenesis and warrants future functional studies to unravel the underlying mechanism of such contribution.