Tabriz University of Medical Sciences ImmunoAnalysis 2783-2589 2 1 2022 01 29 B7-H7 Suppression Increases the Expression of CTLA-4 and VISTA Genes in Gastric Cancer Cell Line 1 1 10.34172/ia.2022.01 EN Nadia Bolandi https://orcid.org/0000-0001-6863-7858 Mohammad Hassan Khadem Ansari https://orcid.org/0000-0002-5145-9378 Yousef Rasmi https://orcid.org/0000-0003-1506-1909 Behzad Baradaran https://orcid.org/0000-0002-8642-6795 Journal Article 10.34172/ia.2022.01 2022 01 04 2022 01 29 Gastric cancer (GC) is a multifactorial genetic malignancy that tumor metastasis is one of the principal characteristics of this disease. The B7 family immune checkpoints have important functions in maintaining the immune system's equilibrium that participates in the regulation of invasion, metastasis, and development of tumors. Silencing of gene expression via small interference RNA (siRNA) delivery technology is one of the significant approaches in gene therapy. The main goal of the current study was to determine the effect of B7-H7 suppression by siRNA on the expression of CTLA-4 and VISTA in the MKN-45 GC cell line. For this purpose, MKN-45 cells were transfected with B7-H7-siRNA. Then, transcript levels of CTLA-4 and VISTA genes following the suppression of the B7-H7 gene were investigated using quantitative real-time PCR. This research demonstrated that the transcript levels of CTLA-4 and VISTA were increased after transfection of B7-H7-siRNA compared to the control cells. These experiments revealed that the knockdown of B7-H7 altered the expression of two immune checkpoints in the GC cell line.