Project description:DNA-PK is a heterotrimeric complex that consists of Ku70 (XRCC6), Ku80 (XRCC5) and DNA-PKcs (PRKDC) subunits. DNA-PK complex is a major player in DNA double strand break (DSB) repair via non-homologous end joining pathway. This process requires all of DNA-PK subunits. Ku70/Ku80 heterodimers firstly bind to DNA-ends at DSB, that increase affinity of DNA-PKcs to DNA-ends. Recruitment of DNA-PKcs subunit to DSB leads to phosphorylation events near DSB, recruitment of another NHEJ-related genes that restore DNA integrity. However, today a lot of evidence demonstrate participation of DNA-PK components in other cellular process, e.g. cytosolic DNA sensing, apoptosis regulation, cellular movement and adhesion. It is important to note that not all subunits of DNA-PK complex are necessary for these process. This demonstrate the independent functions of DNA-PK subunits. Here we for the first time using NGS-sequencing analyzed the transcriptional changes in HEK293T cells under depletion of Ku70, Ku80 or DNA-PKcs to characterize the independent functions of each subunit.
Project description:Here, we show that ivermectin suppress prostate cancer progression by inhibiting AR signaling pathway and attenuate cellular DNA damage repair capacity. We applied an integrated omics profiling including RNA-seq and Thermal proteome, that found pioneer factor Forkhead Box Protein A1 (FOXA1) and Non-homologous End Joining (NHEJ) repair executer Ku70/Ku80 was the direct target of Ivermectin in prostate cancer. Ivermectin binds to these two proteins and block their biological function, which results in blockade of AR signaling transcription and deficiency of DNA double-strand breaks (DSBs) repair system, and thereby leads to G0/G1 arrest and trigger synthetic lethality Our findings demonstrate both the effect and target of Ivermectin in prostate cancer comprehensively and systemically, indicating that use of Ivermectin may constitute a new therapeutic approach for prostate cancer.
Project description:Many metabolism-related genes undergo alternative splicing to generate circular RNAs although their functions remain poorly understood. Here we report that circPRKAA1, a circRNA derived from the α1 subunit of AMPK, fulfils a fundamental role in maintaining lipid homeostasis. CircPRKAA1 expression facilitates fatty acid synthesis and promotes lipid storage through two coordinated functions. First, circPRKAA1 promotes a tetrameric complex between the Ku80/Ku70 heterodimer and the mature form of sterol regulatory element-binding protein-1 (mSREBP1) to enhance the stability of mSREBP1. Secondly, circPRKAA1 selectively binds to the promoters of the ACC1, ACLY, SCD1 and FASN genes to recruit mSREBP1, upregulating their transcription and increasing fatty acid synthesis to promote cancer growth. Moreover, circPRKAA1 biogenesis is negatively regulated by AMPK activity with lower AMPK activation in hepatocellular carcinoma tissues frequently associated with elevated circPRKAA1 expression. Together, this work identifies circPRKAA1 as an integral element of AMPK-regulated reprogramming of lipid metabolism in cancer cells.
Project description:DNA-PK is a heterotrimeric complex that consists of Ku70 (XRCC6), Ku80 (XRCC5) and DNA-PKcs (PRKDC) subunits. The complex is a major player in the repair of DNA double strand break (DSB) via the non-homologous end joining (NHEJ) pathway. This process requires all DNA-PK subunits, since Ku70/Ku80 heterodimer firstly binds to DNA ends at DSB and then recruits DNA-PKcs. Recruitment of the DNA-PKcs subunit to DSB leads to phosphorylation events near DSB and recruitment of other NHEJ-related proteins that restore DNA integrity. However, today a lot of evidence demonstrates participation of the DNA-PK components in other cellular processes, e.g. telomere length maintenance, transcription, metabolism regulation, cytosolic DNA sensing, apoptosis, cellular movement and adhesion. It is important to note that not all the subunits of the DNA-PK complex are necessary for these processes, and the largest number of independent functions has been shown for the Ku70/Ku80 heterodimer and especially the Ku70 subunit. To better understand the role of each DNA-PK subunit in the cell life, we have analyzed transcriptome changes in HEK293T cells depleted of Ku70, Ku80 or DNA-PKcs using NGS-sequencing. Here, for the first time, we present the data obtained from the transcriptome analysis.
Project description:Cytosolic foreign DNA is detected by pattern recognition receptors and mainly induces Type-I IFN production. We found that transfection of different types of DNA into various untreated cells induces Type-III IFN (IFN-lambda1) rather than Type-I IFN, indicating the presence of uncharacterized DNA sensor(s). A pull-down assay using cytosolic proteins identified that Ku70 and Ku80 are the DNA binding proteins. The knockdown studies and the reporter assay revealed that Ku70 is a novel DNA sensor inducing the IFN-lambda1 activation. The functional analysis of IFNL1 promoter revealed that PRDI and ISRE sites are predominantly involved in the DNA-mediated IFNL1 activation. A pull-down assay using nuclear proteins demonstrated that the IFN-lambda1 induction is associated with the activation of IRF-1 and IRF-7. This is the first report of a specific induction of Type-III rather than Type-I IFN and of Ku70 that plays a key role in the activation of innate immune responses. To identify the nature of the anti-HIV mediators associated with the empty vector transfection, we compared patterns of gene expression between untreated and pCMV9-transfected HEK293 cells, using DNA microarray analysis.
