Pioneer Transcription Factor GATA2 Promotes CRPC Progression By Repressing Interferon-β Signaling

The androgen deprivation therapy（ADTs）is a frontline therapeutic strategy for prostate cancer（PCa）.However,castration resistance prostate cancer（CRPC）is nearly inevitable developed after 24-36 months of androgen deprivation therapy.The median survival time of CRPC patients usually less than 24 months.Uncovering CRPC genesis and progression mechanisms,searching therapy targets,are pivotal issues.We analyzed the next generation sequencing data of 732 primary PCa patients and 492 CRPC patients,found that GATA2 is highly amplified in CRPC samples and nearly none amplified in primary PCa samples.In the meanwhile,TCGA data indicated GATA2 high-expression group’s disease free and progression free survival time was significantly less than low-expression group,suggesting GATA2 is a driver gene of CRPC.It has been reported GATA2 can interact with AR,regulating AR cistrome ex vivo.GATA2 can also promote IGF2 transcription in AR independent manner,to promote proliferation and drug resistance.However,GATA2’s role in CRPC has not been well studied.By constructing PTEN^PC-/-;GATA2^{PC OE/+}spontaneous tumor model mice,we confirmed GATA2 overexpression could promote CRPC progression by conferring resistance of apoptosis but promoting proliferation.Bulk RNA-seq and gene set enrichment analysis of tumor indicated GATA2 overexpression suppressed many immune response pathways.Real time PCR analysis suggested repressed IFNB1 signaling axis might promote CRPC progression.Recent research reports that the death cells released nuclear acids can be recognized by tumor cells’pattern recognition receptors（PRRs）,triggers type I interferons and ISGs expression,which will lead to tumor cell death and immune cells infiltration.We speculated GATA2 could repress these innate immunity signals to prevent tumor cell death.Analysis of clinical data showed GATA2 expression level is negatively related with IFNB1.Besides,the CD8⁺T cells infiltration is decreased in GATA2 high-expression CRPC.These data indicated GATA2 could promote CRPC progression through repressing IFNB1 signaling axis.To torture the mechanism of GATA2 regulating IFNB1 signaling,we used human PCa cell line LNCa P and PC3 to stimulate this phenomenon by transfecting ds DNA and poly（I:C）.Bulk RNA-seq of LNCa P cells showed identical phenomenon with mice tumors.Knockdown GATA2 didn’t affect IRF3 phosphorylation level.Considering GATA2 is a transcription factor,we performed CUT&Tag experiment.CUT&Tag data and ATAC-seq data showed GATA2 could alter IRF3 cistrome globally,by changing histone H3K27ac modification and chromatin accessibility.Intriguingly,GATA2 bound to IFNB1’s two enhancers and an unknown element.Using CRISPRi experiment to repress accessibility of the element would increase IFNB1 expression,indicating that unknown element is a silencer.These data suggested GATA2 could increase accessibility of silencer to repress interferonβexpression.Blockade IFNAR1 in PTEN^PC-/-spontaneous tumor model mice by tail vein injecting IFNAR1 antibody rescued castration induced tumor regression,identified IFNB1’s function.Flow Cytometry analysis showed that GATA2 over expression reduced Tumor infiltrated CD8⁺T cells.In summary,our work showed GATA2 repress interferonβexpression during castration,to prevent immune response and promote CRPC progression.This work also indicated the possibility of targeting GATA2 to cure CRPC.