Regulation of apoptosis and autophagy by albendazole in human colon adenocarcinoma cells

Albendazole (ABZ) was initially introduced as an anthelmintic, however, many studies have reported with its anticancer effects. We investigated the anti-tumor effects of ABZ in vitro in human colon adenocarcinoma HCT-15, HCT-116, HT-29, and SW480 cell lines in this study. The cytotoxicity of ABZ was analyzed in colon adenocarcinoma cell lines and normal CCD18Co cells. We found that ABZ induced the subG1 arrest during cell cycle progression, increased the late apoptotic cells, shifted of peak TUNEL-labeled cells peak, and induced apoptosis. Then effects on autophagy activation was confirmed by acridine orange (AO), MDC staining, and immunocytochemistry of LC3. It was observed that ABZ can induce the autophagy activation through modulating the levels of LC3, Atg7, and beclin-1. For mechanistic studies, apoptosis blocker (Z-DEVD-FMK) and autophagy inhibitor (3-MA) were used to confirm that whether ABZ has apoptosis and autophagy specific effects, and reversal in both these cell death processes were noted. The effects of ABZ on AMPK, MAPKs, and ULK induction was also evaluated. We noticed that N-acetyl cysteine (NAC), a broad spectrum antioxidant, can effectively inhibit both apoptosis and autophagy. However, ABZ could even recover suppression of apoptosis and autophagy caused by NAC in colon cancer cells. Therefore, ABZ can potentially up-regulate both the apoptosis and autophagy to significantly suppress tumorigenesis in colorectal cancer cell lines.