A Lysosome independent role for TFEB in activating DNA repair and inhibiting apoptosis in breast cancer cells.

In this study, we examined the role of TFEB in TNBC and its relationship with autophagy and DNA damage induced by DOX. In TNBC cells, TFEB was hypo-phosphorylated and localized to the nucleus upon DOX treatment. TFEB knockdown decreased the viability of TNBC cells while increasing caspase-3 dependent apoptosis. Additionally, inhibition of TFEB-phosphatase calcineurin sensitized cells to DOX-induced apoptosis in a TFEB dependent fashion. Regulation of apoptosis by TFEB was not a consequence of altered lysosomal function, as TFEB continued to protect against apoptosis in the presence of lysosomal inhibitors. RNA-Seq analysis of TFEB knockdown MDA-MB-231 cells identified a significant downregulation in cell cycle and homologous recombination while genes involved in interferon-γ and death receptor signaling were upregulated. In consequence, TFEB knockdown disrupted DNA repair following DOX, as evidenced by persistent γH2A.X detection. Together, these findings describe in TNBC a novel lysosomal independent function for TFEB in responding to DNA damage. PMID: 31820786 [PubMed - as supplied by publisher]
Source: The Biochemical Journal - Category: Biochemistry Authors: Tags: Biochem J Source Type: research