Carbenoxolone upregulates TRAIL2 expression and enhances the anti-neoplastic effect of doxorubicin in experimentally induced hepatocellular carcinoma in rats

AIMS: This study investigates the in vivo anticancer activity of carbenoxolone (CBX) and its role in fighting hepatocellular carcinoma (HCC) progression and alleviating resistance against doxorubicin (DOX). Moreover, the molecular mechanism of action of CBX is explored. METHODS: HCC was induced in Sprague Dawley rats via biweekly administration of thioacetamide (TAA) (200 mg/kg) intraperitoneally (i.p.) for 16 weeks after administering a single dose of diethylnitrosamine (DEN) (200 mg/kg, i.p.). A prophylactic model was established by treating rats with i.p. CBX (20 mg/kg/day) for 4 weeks starting on week 13 post-TAA injection. A therapeutic model was established by treating rats with CBX, DOX, or their combination for 7 weeks following 16 weeks of TAA administration. Serum Alpha-fetoprotein (AFP) and biochemical markers of hepatic functions were assessed. Histopathological examinations of hepatic tissues were performed. Immunohistochemical and qRT-PCR analyses were applied to assess the differential expressions of TRAIL/TRAILR2, Bcl-2, TGF-β1, and caspases 3, 8, and 9. RESULTS: CBX markedly improved hepatic functions, reduced serum AFP levels, and alleviated TAA-induced hepatic histopathological alterations. CBX triggered apoptosis as evident by upregulating apoptotic markers: TRAIL/TRAILR2, caspases 3, 8, and 9, and downregulating the antiapoptotic protein Bcl-2. CBX downregulated TGF-β1. Interestingly, CBX/DOX combination mitigated hepatic damage and induced apoptosis in a way that surpassed DOX-only treatment. CONCLUSION: The current study proposes that CBX is a promising anti-tumor compound, which can work effectively under prophylactic and therapeutic modes. Interestingly, CBX enhanced the anti-tumor effect of DOX. CBX exerted these effects via, in part, stimulating TRAIL-induced apoptosis along with attenuating fibrosis.