Effect of cytochrome c modification with co‐polymer on its apoptotic activity for cancer treatment (LB248)

Treating cancer, while avoiding devastating side effects, has been a challenge throughout the years. Active targeted delivery has been extensively studied to overcome the inherent adverse effects of anticancer therapy. The apoptotic protein cytochrome c (cyt c) is highly effective at causing cancer cells cytotoxicity but as most proteins, its delivery is challenging. In this project, we synthesized a co‐polymer of hyaluronic acid (HA) and folic acid (FA) followed by cyt c binding. Both compounds of the co‐polymer were selected due to their receptors overexpression on cancer cells surface allowing endocytosis of the cyt c system. We used TNBSA assay to determine the amount of modified lysines in cyt c when reacted to HA‐FA: 2.1 ± 0.4. The residual activity of the protein was measured before and after its incorporation in HA‐FA using a caspase cascade assay which showed caspase activation by cyt c‐HA‐FA: 105 ± 1 % while HA‐FA did not activate caspase: 1.6 ± 0.8 %. CD spectroscopy showed minor changes in heme group and tertiary structure of cyt c following modification. HeLa cells were incubated with cyt c‐HA‐FA (0.1 mg/ml) to measure cell viability with MTS assay. Cell viability was measured after 2 and 6 hours of incubation: 108 ± 14 % and 83 ± 8 %, respectively. According to these results we successfully synthesized a promising drug delivery system for anticancer applications. Grant Funding Source : Supported by NIH Research Initiative for Scientific Enhancement (RISE) Program with grant number: 2R25GM061151‐12.