B7 Induces Apoptosis in Colorectal Cancer Cells by Regulating the Expression of Caspase-3 and Inhibits Autophagy

Abstract

Xinyi Zhang,1 Fengxi Li,2 Rong Li,1 Nan Zhao,2 Dianfeng Liu,1 Yuelin Xu,2 Lei Wang,2 Dongxu Wang,1 Ruihong Zhao3 1Laboratory Animal Center, College of Animal Science, Jilin University, Changchun, 130062, People’s Republic of China; 2Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun, 130023, People’s Republic of China; 3Department of Gastroenterology Endoscopy Center, The First Hospital of Jilin University, Changchun, 130021, People’s Republic of ChinaCorrespondence: Dongxu Wang, Laboratory Animal Center, College of Animal Science, Jilin University, Changchun, 130062, People’s Republic of China, Tel [phone], Email [email protected] Ruihong Zhao, Department of Gastroenterology Endoscopy Center, The First Hospital of Jilin University, Changchun, 130062, People’s Republic of China, Tel [phone], Email [email protected]: Heterocyclic compounds are organic compounds with heterocyclic structures, which are common in drug molecules. They include pyrazines with diverse functions, including anti-cancer, antimicrobial, antidiabetic, and anticholinergic activities. In this study a new small molecular compound B7 based on tetrazolium substituted pyrazine was synthesized and its effect on the progression of colorectal cancer (CRC) and its potential mechanism were investigated.Methods: We synthesized a series of tetrazolium-substituted pyrazine compounds by chemoenzymatic method. NCM460 (Human), HCT116 (Human), SW480 (Human) cell lines were selected to analyse the inhibitory effect of B7 on CRC by CCK-8, apoptosis, cell migration and invasion, qPCR, Western blotting, molecular docking, immunofluorescence. Moreover, a CRC xenograft model of mice was used to analyzed the role of B7 in vivo.Results: Among these compounds, 3-methyl-5je-6-bis (1H-tetrazole-5-yl) pyrazine-2-carboxylic acid (B7) inhibited CRC cell proliferation and induced apoptosis. The expression of Caspase-3 was increased after B7 treatment. In addition, the mitochondria abnormalities was observed in B7 group due to decrease the expression of Beclin-1. In addition, B7 inhibited the migration and invasion in CRC cells. Finally, the results showed that B7 had anti-tumor activity in CRC xenograft model of mice.Conclusion: In summary, compound B7 was synthesized efficiently using tetrazolium-substituted pyrazine via a chemoenzymatic method. Moreover, B7 have ability to regulate the expression of Caspase-3 which induced apoptosis in CRC cells. In addition, decreased Beclin-1 expression after B7 treatment, indicating inhibited autophagy. This study showed that B7 effectively induced apoptosis and inhibited autophagy in CRC cells.Keywords: pyrazines, tetrazoles, colorectal cancer, apoptosis, autophagy

Keywords

• pyrazines
• tetrazoles
• colorectal cancer
• apoptosis
• autophagy.