Colorectal cancer (CRC) remains one of the leading causes of mortality worldwide.
Drug repositioning is a promising approach for new
cancer therapies, as it provides the opportunity to rapidly advance potentially promising agents into clinical trials. The FDA-approved anti-helminthic
drug rafoxanide was recently reported to antagonize the oncogenic function of the BRAF V600E
mutant protein, commonly found in
CRCs, as well as to inhibit the proliferation of
skin cancer cells. These observations prompted us to investigate the potential anti-
cancer effects of
rafoxanide in CRC models. We found
rafoxanide inhibited proliferation in CRC cells, but not in normal colonic epithelial cells.
Rafoxanide's anti-proliferative action was associated with marked reduction in
cyclin D1 protein levels and accumulation of cells in the G0/G1 phase. These effects relied on selective induction of the endoplasmic reticulum stress (ERS) response in CRC cells and were followed by
caspase-dependent cell death. Systemic administration of
rafoxanide to Apcmin/+ mice induced to develop
CRCs caused ERS activation, proliferation inhibition and apoptosis induction in the neoplastic cells. Collectively, our data suggest
rafoxanide might be repurposed as an anti-
cancer drug for the treatment of CRC.