Study of changes in the expression of immune- checkpoint molecules in gastric cancer cell line treated with Leishmania infantum cell lysis

Abstract

Mediterranean visceral leishmaniasis is a zoonotic disease caused by Leishmania infantum. Iran is one of the endemic regions of this disease. Dogs and canines are the main reservoir hosts of Leishmania infantum. If a patient with visceral leishmaniasis is not treated, it leads to death in 90% of cases. 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 related to immune system checkpoints to inhibit anti-tumor responses. Immunosuppressive molecules are one of the most important obstacles in cancer treatment. These molecules are called immune system checkpoints, which are expressed on cancer cells and bind to their specific receptors on immune system cells and inhibit these cells by activating signaling pathways. PD-L1 and CD80 proteins are among the most important of these molecules, which by their expression, the tumor hinders the response of the immune system, as a result of which the immune system suppresses and grows the tumor. The expression of these molecules is suppressed by miRNAs that control them, and they are probably used as biomarkers of response to treatment. miRs play their functional role in regulating gene expression by binding to the 3′ UTR of the target gene. The aim of this study is to investigate the expression of these genes and their controlling miRNAs in treatment with Leishmania infantum. Material and Methods: cell line was cultured in the relevant culture medium and after treatment with Leishmania infantum for 24 hours, RNA was extracted. Then cDNA was synthesized. Finally, changes in the expression of CD80, PD-L1 genes and their control miRNAs were determined by RT-PCR. Results: The qRT-PCR test showed changes in the expression of CD80 and PD-L1 genes and their controlling miRs in the treatment with Leishmania infantum, which showed a decrease in the expression of CD80 and PD-L1 genes, and a significant increase in the expression of miR-424 and miR-155.