RNAi-mediated ERBB2 gene knockdown sensitizes human colorectal cancer cells to radiation

This study aimed to investigate the involvement of c-erbB-2, encoded by the receptor tyrosine kinase ERBB2 gene, in the pathogenesis of colorectal cancer and to validate its potential as an anticancer target. Immunohistochemical and histopathological analyses were applied in tissue samples derived from 80 colorectal cancer patients. ERBB2 stable small hairpin RNA (shRNA) knockdown in HT29 human colorectal cancer cells was confirmed by RT-PCR and western blotting. Cell cycle profile and apoptosis were measured using PI or Annexin V-PI dual staining. A significant correlation between ERBB2 levels and Dukes' stage of colorectal cancer, in both the primary malignancy and lymph node metastatic tissues, was observed. ERBB2-depleted HT-29 cells exhibited increased sensitivity to radiation compared to control cells, likely due to enhanced G0/G1 phase cell cycle arrest and apoptosis. ERBB2 may be involved in the malignancy and metastasis of colorectal cancer. Overexpressed ERBB2 may constitute a potential target for colorectal cancer therapy.