Hepatocellular Carcinoma Specific Transcriptional Interference of c‐Myc promoter by alpha‐fetoprotein and Sendai Virosome Based dsRNA System

• DOI: 10.1096/fasebj.29.1_supplement.lb115
• Publication Date: 2021-06-21T19:09:55Z
• Authors: Mohammad Khalid Z...; Imran Khan; Prashant Mani; Parthaprasad Chat...; Debi P. Sarkar; Subrata Sinha
• Keywords: 0301 basic medicine; 03 medical and health sciences

Objectivec‐Myc is one of the central players of oncogenesis in hepatocellular carcinoma (HCC) and is also required in normal development. Majority of the c‐Myc transcripts are transcribed by its P2 promoter and an upstream ME1a1 site is required in its transcriptional activation. dsRNA also recruits epigenetic silencing complexes inducing long term/heritable transcriptional repression. We devised a novel HCC targeting system and studied its mechanism.MethodsFirstly, the alpha‐fetoprotein (AFP) promoter/enhancer system was used to express shRNA against ME1a1 site. Secondly, we transformed Sendai virus into fusion (F) virosomes for packaging and delivery of AFP promoter/enhancer driven shRNA constructs into liver cells.ResultsFollowing F‐virosomal delivery, shRNA induced heterochromatization (H3K9Me2 and H3K27Me3) and CpG 8,9,10 methylation at the target locus. Following c‐Myc suppression, HCC cells showed decreased cell survival and increased apoptosis. Also, c‐Myc suppressed HCC cells were sensitized to sub lethal doses of 5‐Fluorouracil (5‐FU) and Cisplatin.ConclusionThis system can specifically and prominently repress c‐Myc in HCC cells and could also be used to introduce genes specifically in embryonic liver.Grant Funding Source: Department of Biotechnology, Govt. of India