Study of the Effect of Linoleic Acid on the Expression Level of MicroRNA-۱۰۶b and MicroRNA-۲۰a and their Related Target MHC Class I Chain-related Protein A in Docetaxel-treated Gastric Cancer Cells

Background: MicroRNAs are involved in response to therapeutic agents and have the ability to regulate the expression level of the targets associated with cancer growth and progression. As a dangerous signal in tumor cells, increased expression level of MHC class I chain-related protein A (MICA) could activate the immune system and induce responses to tumor cells. We conducted the present research to study the effect of linoleic acid (LA) and docetaxel alone or in combination with miR-۱۰۶b, miR-۲۰a, and MICA expression level in metastatic gastric cancer (GC) cell line MKN-۴۵. Method: The study was an in vitro study using the gastric cancer cell line MKN- ۴۵, which was cultured and treated with docetaxel and LA. Subsequently, the expression level of miR-۱۰۶b, miR-۲۰a, and MICA were assessed with quantitative real-time polymerase chain reaction. Results: MiR-۱۰۶b decreased in LA and LA/docetaxel (P < ۰.۰۰۰۱ and P = ۰.۰۰۲),and increased in docetaxel alone (P = ۰.۰۱). Meanwhile, miR-۲۰a significantly decreased in docetaxel and LA/docetaxel (P < ۰.۰۰۰۱), increased in LA treatment (P = ۰.۰۲). Regarding MICA, it significantly decreased in all the treated cells (P < ۰.۰۰۰۱, p <۰.۰۰۰۱, and P=۰.۰۰۰۲ for docetaxel, LA and docetaxel/LA, respectively) but with different reduction intensities. Conclusion: Using LA or docetaxel alone had a different effect on miR-۱۰۶b, miR-۲۰a, and MICA expression level, yet in a simultaneous treatment, their positive effects were intensified. LA enhanced the effect of docetaxel concerning the expression level of miR-۱۰۶b, miR-۲۰a, and MICA and vice versa, which suggested that LA could be employed as an effective complementary agent in GC along with docetaxel.