Evaluation of a Synthetic Polyethyleneimine Based Polymeric Vector for ING4 Gene Delivery to MCF-7 Breast Cancer Cells

Objectives: Breast cancer is the most common type of cancer among women and the second most common cause of death after lung cancer. The inhibitor of growth (ING) transcript levels are often suppressed in cancer cells, making it a promising candidate for cancer therapy. In this study, we aimed to formulate a polyplex that effectively carries and delivers pING4 to breast cancer cells.

Materials and methods: Polyethyleneimine (PEI)-based non-viral vectors were synthesized and characterized for plasmid DNA delivery. Complexation was achieved via electrostatic interactions between the synthesized polymeric vectors and plasmid DNA. Characterization studies were conducted by testing Sodium dodecyl sulfate-induced complexation, Deoxyribonuclease I protection, and serum stability of the polyplexes. Subsequently, polyplexes were tested on MCF-7 cells for anticancer activity using the XTT cell viability assay. Western blot analysis was performed for the ING4 protein.

Results: Polyplexes carrying the ING4 gene exhibited significantly lower cell viability than control polyplexes (p=0.0067). During the 5-day viability assay, the lowest cell viability was observed on day 4. Approximately 69.11±2.18% cell viability was observed with ING4 treatment and the control group showed no cell death on day 4 (101.53±5.06%). The prepared delivery systems did not show a toxic effect on MCF-7 cells treated alone. In addition, the MCF10A normal mammary cell line was used as a positive control. Western blotting was performed to confirm the overexpression of ING4 protein in the treatment groups. Unlike in the control groups, the overexpression of ING4 was clear in the wells of the treatment group.

Conclusion: Our findings suggest that ING4 gene delivery using prepared PEI-based nonviral delivery systems is a promising approach for breast cancer treatment.