Effective targeting of E2F1 transcription factor via siRNA gene electrotransfer in HT-29 colorectal carcinoma xenografts

Colorectal cancer (CRC) remains a significant global health concern, with survival outcomes heavily dependent on the stage at diagnosis. Targeted therapies offer a promising approach to improve patient outcomes, particularly by addressing molecular drivers of tumor progression. One such target is the E2F1 transcription factor, a key regulator of the cell cycle and a contributor to proliferation, differentiation, apoptosis, metastasis, and chemoresistance in CRC. Previous studies have demonstrated the efficacy of E2F1 silencing via siRNA-loaded nanoliposomes in reducing tumor cell growth, but challenges such as immunogenicity and off-target effects have limited their in vivo application. In this study, we evaluated the potential of gene electrotransfer (GET) as a non-viral delivery system for delivery of therapeutic siRNA targeting E2F1 in the HT-29 CRC model. In vitro experiments showed effective silencing of E2F1 expression and a significant reduction in HT-29 cell survival. Subsequent in vivo studies confirmed the therapeutic potential of siE2F1 GET, with results demonstrating tumor growth delay, decreased proliferation, and increased necrosis in the tumors. This study establishes proof-ofprinciple for targeting E2F1 in CRC using GET, showcasing its versatility and therapeutic potential.