Nadia Bolandi
1, 2 
, Mohammad Hassan Khadem Ansari
1* , Yousef Rasmi
1, 3 , Behzad Baradaran
2, 4, 5* 1 Department of Biochemistry, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
2 Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
3 Cellular and Molecular Research Center, Urmia University of Medical Sciences, Urmia, Iran.
4 Department of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
5 Pharmaceutical Analysis Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Abstract
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.