Emerging Roles of ACTL6A as an Oncogenic Hub: Transcriptional Regulation and Beyond

The malignant progression of human cancer is dictated by specific regulatory hubs coordinating multiple signaling modules. Identifying key oncogenic hubs of human cancers may lay the groundwork for developing breakthrough therapeutic strategies. Actin-like 6A (ACTL6A; also known as BAF53A) was originally identified as a chromatin remodeling factor involved in the transcriptional regulation of genes, especially in stem and progenitor cells. The preponderance of evidence revealed the overexpression of ACTL6A in most cancers and its crucial role in various malignant phenotypes, including cell-cycle progression, cancer stemness, epithelial-to-mesenchymal transition, redox and glucose metabolism, and DNA replication and repair. Interestingly, emerging data suggest that the oncogenic function of ACTL6A is mediated through diverse mechanisms beyond its canonical function in transcriptional regulation, including notably the stabilization of oncoproteins and stemness factors, such as YAP, VPS72, and MYC. In this review, we describe the isoforms and the putative functional domains of ACTL6A. We summarize the expression pattern and prognostic significance of ACTL6A in human cancers and the upstream regulatory mechanisms of its expression. We summarize recent progress in understanding the diverse pro-oncogenic functions of ACTL6A and emphasize its pleiotropic mechanisms of action as a regulatory hub of cancer stemness and progression. The review highlights the importance and the potential utilities of characterizing ACTL6A, which may imply molecularly informed diagnostics and therapeutics to improve the outcome of patients with cancer.