Long Intergenic Non-coding RNA — LINC00659 — Expression Changes in Gastric Cancer: Lessons from Northwestern Iran

Abstract

Background: Gastric cancer (GC) is a multifactorial disease caused by environmental, infectious, and genetic factors. Aberrant expression of long non-coding RNAs (lncRNAs) is considered a crucial feature of human cancer. They are excellent candidates as biomarkers for cancer diagnosis and prognosis, as well as potential therapeutic targets for cancer treatment. Objectives: We assessed the expression levels of LINC00659 among GC patients in Ardabil, a high-risk region in Northwestern Iran [age-standardized incidence rates (ASRs) = 51.8/100,000 for males and 24.9/100,000 for females], which has one of the highest rates of cardia GC in the world, to examine its potential as a diagnostic biomarker. Methods: The expression of LINC00659 in tumor and adjacent non-cancerous tissues (ANCTs) (a total of 82 samples) was evaluated using real-time qRT-PCR in Ardabil province patients. The correlation between the LINC00659 expression levels and clinicopathological features was assessed. Results: LINC00659 was down-regulated in more GC samples than controls, but we found no significant association between the LINC00659 expression levels and GC risk between tumor samples compared to controls [fold change (mean ± SE): 0.57 ± 0.13, P = 0.33]. After classifying patients into down-/up-regulation groups, a significant association was observed between LINC00659 expression levels and tumor origin (cardia/non-cardia subsites; P = 0.01). Conclusions: We found a significant association of LINC00659 expression levels with the origin of the tumor. Further research involving a larger sample size that encompasses diverse geographic and ethnic groups within Iran is essential to enhance the validity of the findings and facilitate a deeper understanding of the functional mechanisms of LINC00659 in GC.