Aptamer-conjugated nanoliposomes containing COL1A1 siRNA sensitize CRC cells to conventional chemotherapeutic drugs.

COL1A1 is an important extracellular matrix component that is associated with poor prognosis in cancers. In this study, As1411 aptamer-conjugated liposomes were used for targeted siRNA delivery against the COL1A1 gene in colorectal cancer (CRC) cells. Cationic liposomes were synthesized and siRNA loading and conjugation of aptamer were confirmed by gel shift assay and spectrophotometry method. Release of siRNA from liposomes was assessed using dialysis method. Binding and uptake of aptamer-conjugated liposomes to and into cancer cells was assessed by fluorescence microscopy and flowcytometry. Gene expression was evaluated using qRT-PCR. Cell viability, chemosensitivity and apoptosis were determined by MTT assay and Annexin/PI kit. Cellular studies showed that liposomal transfer of COL1A1 siRNA into HCT116 and HEK293 cells significantly reduced the expression level of corresponding gen and cell viability, and significantly increased the sensitivity to chemotherapy drugs while free siRNA had no such effects. Aptamer conjugation was associated with increased cellular effects in HCT116 cells, but not in HEK293 cells. Our study revealed that delivery of COL1A1 siRNA via AS1411-targeted liposomes is a promising therapeutic approach to overcome treatment resistance in CRC.