Effects of HMGA2 siRNA and doxorubicin dual delivery by chitosan nanoparticles on cytotoxicity and gene expression of HT-29 colorectal cancer cell line

OBJECTIVE: Over-expressions of HMGA2, vimentin and MMP-9 and downregulation of E-cadherin occur on colorectal cancer cells followed by a reduction in let-7 as a regulatory factor. In this study, we first used carboxymethyl dextran (CMD)-chitosan nanoparticles (ChNPs) platform to encapsulate HMGA2 siRNA and doxorubicin (DOX), and then, we evaluated the efficacy of the simultaneous delivery of siRNA/drug on viability and gene expression of HT-29 cell lines. METHODS: ChNPs characteristics were determined by a dynamic light scattering and zeta sizer. Morphology of loaded ChNPs was assessed by scanning electron microscopy, and Fourier transform infrared spectroscopy was used to confirm the conjugation of ChNP/siRNA/DOX/CMD. Cell viability and relative mRNA expression were evaluated by MTT assay and real-time PCR, respectively. KEY FINDING: The prepared ChNPs had high efficiency for siRNA and drug encapsulation (78% and 75%) and were stable against serum and heparin. ChNP/siRNA/DOX/CMD was more effective to induce tumour cell death and also could significantly reduce the expressions of HMGA2, vimentin as well as MMP-9 and increase E-cadherin expression. CONCLUSION: In conclusion, our results revealed that dual delivery of a key gene siRNA and appropriate anticancer drug have great impact on the treatment of colorectal cancer.