ARID1A regulates transcription and the epigenetic landscape via POLE and DMAP1 while ARID1A deficiency or pharmacological inhibition sensitizes germ cell tumor cells to ATR inhibition

ABSTRACT: Germ cell tumors (GCTs) are the most common solid malignancies in young men. Although high cure rates can be achieved at early stages, metastases, resistance to cisplatin-based therapy, and late toxicities still represent a lethal threat, arguing for the need of new therapeutic options. In a previous study, we identified downregulation of the chromatin-remodeling SWI/SNF complex member ARID1A as a key event in the mode of action of the histone deacetylase inhibitor romidepsin, subsequently leading to induction of stress, apoptosis and cell cycle regulators. Additionally, ARID1A is mutated in many different tumor types, like bladder, breast or ovarial cancer. There, the loss-of-function mutations re-sensitize these tumor types to various drugs, like EZH2-, PARP-, HDAC-, HSP90- or ATR-inhibitors. Thus, ARID1A presents as a promising target for synthetic lethality and combination therapy. In this study, we deciphered the molecular function of ARID1A and screened for the potential of two pharmacological ARID1A inhibitors as a new therapeutic strategy to treat GCTs. By CRISPR/Cas9, we generated ARID1A-deficient GCT cells and demonstrate that ARID1A regulates transcription, DNA repair and the epigenetic landscape on DNA and histone level via DNA Polymerase POLE and the DNA methyltransferase 1-associated protein DMAP1. Additionally, ARID1A deficiency or pharmacological inhibition considerably sensitized (cisplatin-resistant) GCT cells towards ATR inhibition. Thus, ARID1A might be new combination partner for ATR inhibitors in the treatment of GCTs.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Nina Overbeck  

LAB HEAD: Kai Stühler

PROVIDER: PXD017898 | Pride | 2020-04-14

REPOSITORIES: Pride