RESUMO
BACKGROUND: Endothelin-1 (ET-1) is a peptide overexpressed in gastric cancer (GC) and linked to carcinogenesis and resistance to chemotherapy. Applying microRNAs (miRNAs/miRs) to downregulate ET-1 and reverse resistance to commonly used chemotherapy drugs such as 5-fluorouracil (5-FU) is practical. METHODS: The current study sought to evaluate the miR-648 expression in GC and any plausibility of its replacement, either with or without the combination of chemo agents to downregulate ET-1 expression through interaction with its target gene. To this end, miR-648 and ET-1 expression levels were assessed in GC tissues and adjacent non-tumor tissues driven from 65 patients who had already undergone surgery, fifteen of which had received 5-FU before surgery. The impact of miR-648 and chemo agents on ET-1 expression was measured using qPCR and Western blotting. Further, an MTT assay was conducted to assess its association with cell viability. Ultimately, the association of miR-648 and ET-1 with clinicopathological characteristics was evaluated. RESULTS: The current study revealed that miR-648 was considerably down-regulated, while ET-1 was substantially up-regulated in patients with GC. The 5-FU caused a significant increase in miR-648 and reduced ET-1 expression. It was also determined that overexpression of miR-648 suppressed ET-1 production, notably when combined with 5-FU, leading to survival reduction. These results further showed that miR-648 replacement could sensitize chemoresistant GC cells. Besides, a significant association between ET-1 and miR-648 with clinicopathological features was discovered CONCLUSIONS: miR-648 replacement may serve as a potential oncosuppressive therapeutic approach that warrants further investigation to translate into an effective GC treatment.
