Study of the effect of DHA Omega 3 fatty acid on the expression of immune checkpoint and immunomodulator molecules and their related miRNAs in colorectal cancer cell line

Abstract

Tumor escape from the immune system is one of the most important signs of cancer progression. Tumors have the ability to induce the expression of molecules associated with immune system checkpoints to inhibit antitumor responses. Omega-3 fatty acids, which are rich in seafood, have immune-regulating properties. PD-L1, CD39 and CD47 molecules are important inhibitors of the immune system. So, this study was performed to investigate the effect of DHA fatty acid on PD-L1, CD39 and CD47 molecules and their controlling miRNAs in colorectal cancer. Materials & Methods: HT-29 and Caco-2 cell lines were treated with 100 μM DHA for 24 hours under normoxic and hypoxic conditions after reaching a concentration above 80%. Hypoxia conditions were applied using 25 μM Cocl2. After extraction of RNA cells, cDNA was synthesized and finally the expression of PD-L1, CD39 and CD47 genes and their controlling miRNAs including: miR-424, miR-142-3p and miR-133, were examined by quantitative real-time PCR. Results: The findings of this study showed that DHA decreased the expression of these genes in both HT-29 and Caco-2 cell lines in normoxic and hypoxic conditions and also increased the expression of miRNAs.