Enhancing doxorubicin's anticancer impact in colorectal cancer by targeting the Akt/Gsk3β/mTOR-SREBP1 signaling axis with an HDAC inhibitor

Colorectal cancer ranks third in global incidence and is the second leading cause of cancer-related mortality. Doxorubicin, an anthracycline chemotherapeutic drug, is integral to current cancer treatment protocols. However, toxicity and resistance to doxorubicin poses a significant challenge to effective therapy. Panobinostat has emerged as a critical agent in colorectal cancer treatment due to its potential to overcome doxorubicin resistance and enhance the efficacy of existing therapeutic protocols. This study aimed to evaluate the capability of panobinostat to surmount doxorubicin toxicity and resistance in colorectal cancer. Specifically, we assessed the efficacy of panobinostat in enhancing the therapeutic response to doxorubicin in colorectal cancer cells and explored the potential synergistic effects of their combined treatment. Our results demonstrate that the combination treatment significantly reduces cell viability and colony-forming ability in colorectal cancer cells compared to individual treatments. The combination induces significant apoptosis, as evidenced by increased levels of cleaved PARP and cleaved caspase-9, while also resulting in a greater reduction in p-Akt/p-GSK-3β/mTOR expression, along with substantial decreases in c-Myc and SREBP-1 levels, compared to monotherapies. Consistent with the <i>in vitro</i> experimental results, the combination treatment significantly inhibited tumor formation in colorectal cancer xenograft nude mice compared to the groups treated with either agent alone. In conclusion, our research suggests that the panobinostat effectively enhances the effect of doxorubicin and combination of two drugs significantly reduced colorectal cancer tumor growth by targeting the Akt/GSK-3β/mTOR signaling pathway, indicating a synergistic therapeutic potential of these two drugs in colorectal cancer treatment.