Histone variant H3.3 promotes experimental metastasis in alveolar rhabdomyosarcoma [ChIP-Seq]

In this study, we show that histone variant H3.3 is overexpressed in ARMS patient-derived cell lines and patient tumour specimens. Functionally, knockdown of H3F3A significantly impairs the ability of ARMS cells to undertake migration and invasion and reduces Rho activation in vitro. In addition, a striking reduction in metastatic tumour burden and improved survival is apparent in vivo. Through RNA-sequencing and ChIP-sequencing analyses, we identified Melanoma Cell Adhesion Molecule (MCAM/CD146) as a direct downstream target of H3.3. Therefore, this study identifies a novel H3.3- MCAM axis involved in ARMS metastatic phenotypes, and supports the development of MCAM as a therapeutic target for this disease. Overall design: Regions of H3.3 binding in RH41 cells were identified through ChIP-sequencing. H3.3 pulldown was done using ab176840. 10% of total DNA was collected prior to pulldown (as input) and used for sequencing. Two samples of input and 2 ChIP samples were used for analysis. Sequencing was done by Novogene.