In vitro co-delivery of 5-fluorouracil and all-trans retinoic acid by PEGylated liposomes for colorectal cancer treatment

Background Single-target inhibitors have not been successful in cancer treatment due to the development of drug resistance. Nevertheless, therapeutic agents capable of simultaneously inhibiting multiple targets have revealed encouraging results in inducing apoptosis and overcoming drug resistance in cancerous cells. Here, we designed a composite liposomal nano-carrier co-loading 5-Fluorouracil (5-FU) with all-trans retinoic acid (ATRA) to assess anticancer efficacy of the combined drugs in colorectal cancer (CRC).Methods A PEGylated liposomal nano-carrier with phospholipid/cholesterol/DSPE-PEG (2000) was synthesized by the thin film hydration technique for co-delivery of ATRA and 5-FU. After characterizing, the role of 5-FU and ATRA co-loaded liposomal nano-carrier in proliferation, epithelial-mesenchymal transition (EMT), apoptosis, and cancer stem cells (CSCs) were investigated by using colony forming and MTT assay, RT-qPCR and Annexin V/PI kit.Results The average size of liposomes (LPs) was < 150 nm with uniform size distribution. Drug release analyses indicated that both ATRA and 5-FU could simultaneously release from LPs in a sustained release manner. The synergistic inhibitory effects of ATRA and 5-FU loaded in LPs were verified with a combination index of 0.43. Dual drug LPs showed the highest cytotoxicity, enhanced inhibition of cell proliferation, increased apoptotic potential, decreased CSCs, and attenuated EMT-associated biomarkers. Also, dual drug LPs decreased beta-catenin gene expression more than other liposomal formulations.Conclusion These findings suggest that using LPs to achieve a synergistic effect of ATRA and 5-FU is an effectual approach to increase the therapeutic effect of 5-FU toward CRC cells.

Automated summary

This study evaluated the anticancer effect of all-trans retinoic acid (ATRA) and 5-Fluorouracil (5-FU) co-loaded in a composite liposomal nano-carrier in colorectal cancer (CRC) cells. The results showed that the dual drug loaded liposomal nano-carrier exhibited superior cytotoxicity, enhanced inhibition of cell proliferation, increased apoptotic potential, and decreased cancer stem cells (CSCs). Additionally, it also attenuated epithelial-mesenchymal transition (EMT)-associated biomarkers and beta-catenin gene expression.