Targeting c-Myc with antisense oligonucleotides to induce apoptosis in tumor cells.

Abstract

Transcription factors (TFs) play a crucial role in tumorigenesis by driving oncogene expression in key signaling pathways. However, their small size and flat surfaces make them challenging targets for small-molecule inhibitors, while macromolecular therapies struggle to cross the cell membrane. Modulating TF activity at the genetic level offers a promising alternative. Antisense oligonucleotides (ASOs), which regulate protein expression by targeting mRNA, have emerged as effective therapeutics for previously undruggable proteins, including TFs. Over the past two decades, ASO therapeutics have advanced significantly, demonstrating long-lasting efficacy by promoting mRNA degradation. c-Myc, a key regulator of oncogene expression, drives cancer cell growth and proliferation but remains undruggable due to its nuclear localization and dynamic structure. In this study, we utilized our ASO development platform to design ASOs targeting c-Myc. Our sequence optimization algorithm achieved high accuracy, with one of three designed ASOs successfully silencing c-Myc. Ex vivo validation showed that ASO3 inhibited A549 cell growth with an IC₅₀ of 152.5 nM. At the molecular level, ASO3 significantly reduced both c-Myc mRNA and protein expression. Functional assays, including trypan blue exclusion assay and CCK-8, confirmed that ASO3 decreased cell viability, suppressed proliferation, and induced apoptosis. These findings highlight ASO3's therapeutic potential and support further investigation as an anti-cancer agent targeting c-Myc.