Anticancer Effects of a Benzimidazole Derivative in Colorectal Cancer Cells: Involvement of Autophagy and Apoptosis

Colorectal cancer(CRC) is among the leading causes of cancer-related deaths world-wide, but current chemotherapy strategies are insufficient, necessitating the identifica-tion of novel small molecules that can disrupt multiple survival pathways simultane-ously. In this study, the antiproliferative effects of benzimidazole-palladium complex compounds were evaluated in 4T1, MDA-MB-231, DLD-1, and HT-29 cancer cell lines using MTT assays. The autophagy and apoptosis-inducing capacities of the compounds, which showed significant cytotoxicity in CRC cells, were analyzed in detail using im-munofluorescence and flow cytometry methods. Furthermore, functional assays such as migration, adhesion, and colony formation were further investigated in CRC cells. The benzimidazole derivative drug candidate (3a) significantly reduced cell viability in HT-29 and DLD-1 cells. Mechanistic investigations using immunofluorescence and Annexin V/PI for LC3 and mTOR revealed that 3a triggered a dual response of au-tophagy and apoptosis. In CRC cells, compound 3a significantly impaired metastatic potential by inhibiting migration, colony formation, and cell adhesion. Gene expression analysis also showed that this compound suppressed the AKT/mTOR/STAT3 signaling axis, thereby triggering an autophagic response that compromised cell adhesion and accelerated apoptotic cell death. These findings suggest that compound 3a is a prom-ising anticancer candidate and warrants further mechanistic investigation.