Abstract 135: Myosin 10 suppresses integrin α6β4 expression and drives invasive force generation in Non-small cell lung cancer leader cells

Abstract A major contributor to lung cancer mortality is the late stage at which it is diagnosed. Currently, 5-year survival rates for persons with regional and distant lung cancer metastasis at diagnosis are 29.7% and 4.7%, respectively, compared to 56.3% for persons with localized (non-metastatic) disease. Identifying and therapeutically targeting drivers of lung cancer metastasis can improve overall survival, but few models exist where subpopulations with stable high and low invasive potentials can be easily and reliably isolated. Previous work from our group isolated two stable subpopulations from the H1299 Non-Small Cell Lung Cancer (NSCLC) cell line, highly invasive cells at the front of a pack termed Leaders, and significantly less invasive cells that trail behind termed Followers. H1299 Leaders and Followers have heterogenous transcriptional profiles, biomarkers, genomic methylation patterns, metabolic states, and morphologies. H1299 Leaders express high levels of Myosin 10 (MYO10), an actin-bound myosin motor protein that functions in filopodia and drives collective invasion. To investigate how MYO10 contributes to Leader cell biology and invasion, we generated MYO10 knockout single-cell derived Leader clones utilizing CRISPR-Cas9. Three (3) MYO10-/- knockout and two (2) MYO10+/+ wildtype single-cell derived clones were generated suggesting that MYO10 is not essential for Leader cell survival. In validated clones, WST-8 assays confirmed that proliferation was slightly decreased in MYO10-/- clones relative to their MYO10+/+ controls. Bulk RNA sequencing demonstrated distinct transcriptional profiles of MYO10-/- and MYO10+/+ clones with gene set enrichment analysis revealing activation of extracellular matrix and external encapsulating structure pathways in MYO10-/- clones relative to controls. Western blot of integrin subunits showed increased expression of α6 and β4 subunits with decreased β3 expression in MYO10 knockout clones. Further, DNA-based tension gauge tether (TGT) probes were used to assess cell spread area and force generation, functional readouts of integrin activity. Of note, MYO10-/- clones demonstrate dramatically reduced cell area and tension forces when compared to MYO10+/+ clones. Taken together, these data suggest MYO10 supports integrin-based adhesion and force generation in Leader clones which likely contributes to the highly invasive H1299 Leader cell phenotype. This works serves as a foundation for future studies which aim to elucidate MYO10-dependent mechanisms that drive metastasis in NSCLC. Citation Format: Raaven Goffe, Maia Vierengel, Hiroaki Ogasawara, Henry Claussen, Robert A. Arthur, Khalid Salaita, Adam I. Myosin 10 suppresses integrin α6β4 expression and drives invasive force generation in Non-small cell lung cancer leader cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 135.