Invasiveness of and Drug Sensitivity to Various Anti-cancer Regimens in Five Colorectal Cancer Cell Lines

Abstract

Purpose: Colorectal cancer (CRC) is one of the leading causes of cancer death in South Korea. Angiogenesis has been associated with invasion and metastasis of tumors and with the secretion of various growth factors. Bevacizumab is a humanized monoclonal antibody that recognizes and blocks vascular endothelial growth factor (VEGF) and that targets integrin aVb3 and matrix metalloproteinases (MMPs) as angiogensis inhibitors. The aims of this study were identification of the mechanism of target molecules related to angiogenesis and demonstration of identifiable invasion by using chemotherapeutic regimens in vitro. Methods: The five colorectal cancer cell lines were treated with bevacizumab using standard or combined regimens. The expression of integrin aVb3 was detected and the investigation of apoptosis was done by using flow cytometry. The activations of MMP-2 and MMP-9 were measured by using gelatin zymography. Results: The apoptotic cell death was significantly increased for the combined regimens, especially for FOLFOX (5-FU, leucovorin, and oxaliplatin) with bevacizumab. Bevacizumab inhibited the expression of integrin aVb3 in the HT29 (59%), LoVo (67%), and SW480 (17%) cell lines, but did not in the AMC5 and the RKO cell lines. The activations of MMP-2 and MMP-9 were significantly reduced by treatment with bevacizumab in the HT29 and the LoVo cell lines. In the HT29 and the LoVo cell lines, thus, bevacizumab inhibited invasion and metastasis activity through down-regulation of integrin aVb3 and MMPs. Conclusion: Our results provide biological evidence of potent angiogenic activity and indicate that angiogenesis is a complex process that involves multiple factors, including VEGF, integrin aVb3, and MMPs.