Similar Datasets
Project description:CRISPR Cas9-based functional genomics screening is a powerful approach for identifying and characterizing novel oncology drug targets. Here, we elucidate the synthetic lethal mechanism of deubiquitinating enzyme USP1 in cancers with underlying DNA damage vulnerabilities, specifically BRCA1/2 mutant tumors and a subset of BRCA1/2 wild-type (WT) tumors. In sensitive cells, pharmacological inhibition of USP1 leads to decreased DNA synthesis concomitant with the induction of S-phase-specific DNA damage. Genome-wide CRISPR-Cas9 screens identified RAD18 and UBE2K, which promote PCNA mono- and polyubiquitination respectively, as downstream mediators of USP1 dependency. The accumulation of mono- and polyubiquitinated PCNA following USP1 inhibition was associated with a reduction in total PCNA protein levels. Ectopic expression of WT and ubiquitin-dead K164R PCNA reversed USP1 inhibitor sensitivity. Our results demonstrate, for the first time, that USP1 dependency hinges on the aberrant processing of mono- and polyubiquitinated PCNA. Moreover, this mechanism of USP1 dependency extends beyond BRCA1/2 mutant tumors to a novel subset of BRCA1/2 WT cancer enriched in ovarian and lung lineages. We further show PARP and USP1 inhibition are strongly synergistic in BRCA1/2 mutant cell lines and xenograft models. We postulate USP1 dependency unveils a previously uncharacterized vulnerability linked to post-translational modifications of PCNA. Taken together, USP1 inhibition may represent a unique therapeutic strategy for BRCA1/2 mutant tumors and a subset of BRCA1/2 WT tumors.
2022-09-27 | GSE214121 | GEO
Project description:The clinical outcomes of hepatocellular carcinoma (HCC) remain dismal. Elucidating the molecular mechanisms for the progression of aggressive HCC holds the promise for developing novel intervention strategies. The transactivation response element RNA-binding protein (TRBP/TARBP2), a key component of microRNA (miRNA) processing and maturation machinery has exhibited to play conflicting roles in tumor development and progression. We sought to investigate the expression of TARBP2 in HCC using well-characterized HCC cell lines, patient-derived tissues and blood samples. Additionally, the potential prognostic and diagnostic value of TARBP2 in HCC were analyzed using Kaplan-Meier plots and ROC curve. Cell counting kit‐8 (CCK‐8), wound healing and transwell assays examined the ability of TARBP2 to induce cell proliferation, migration, and invasion in HCC cell lines. RNA sequencing was applied to identify the downstream elements of TARBP2. The interaction of potential targets of TARBP2, miR‐145 and serpin family E member 1 (SERPINE1), was assessed using luciferase reporter assay. TARBP2 expression was down-regulated in HCC cell lines relative to normal hepatocyte cells, with a similar pattern further confirmed in tissue and blood samples. Notably, the loss of TARBP2 was demonstrated to promote proliferation, migration, and invasion in HCC cell lines. Interestingly, the reduction of TARBP2 was shown to result in the upregulation of SERPINE1, also known as plasminogen activator inhibitor (PAI-1), which is a vital gene of the HIF-1 signaling pathway. Knockdown of SERPINE1 rescued the TARBP2-lost phenotype. Moreover, TARBP2 depletion induced the upregulation of SERPINE1 through reducing the processing of miR-145, which directly targets SERPINE1. Finally, overexpression of miR-145 repressed SERPINE1 and rescued the functions in sh-TARBP2 HCC cells. Our findings underscore a linear TARBP2-miR-145-SERPINE1 pathway that drives HCC progression, with the potential as a novel intervention target for aggressive HCC.
2021-05-26 | GSE143551 | GEO
Project description:To explore the function of deubiquitinase USP1 in breast cancer cells, we performed RNA sequencing to analyze the expression pattern changes by knockdown of USP1 in MCF7 cells.
2021-03-14 | GSE111838 | GEO
Project description:Acute myeloid leukemia (AML) is a malignant tumor with high recurrence rate and poor prognosis. RNA-binding proteins (RBPs) are essential modulators of transcription and translation played critical roles and frequently dysregulated in AML. Here we show that RBPMS (RNA binding protein with multiple splicing) which is highly expressed in AML and associated with poor prognosis of AML, plays critical roles in leukemogenesis. Our study shows that inhibition of RBPMS abrogates self-renewal of leukemia initiating cells (LICs) and AML development but has little effect on normal hematopoiesis. Mechanistically, RBPMS maintains the stability of the m6A reader IGF2BP3 by USP1-mediated deubiquitination, which promotes the translation of the FOXO1 mRNA in an m6A-dependent manner. Moreover, RBPMS contributes to the progression of leukemia by promoting FOXO1/ENO2/ALDOC regulated glycolysis. Overexpression of FOXO1 has been shown to rescue RBPMS inhibition-induced phenotypes in both leukemia cells and mouse models. We have also designed a specific inhibitor of RBPMS that has therapeutic effects in the AML patient derived xenograft model (PDX) model. We, therefore, we highlight RBPMS as a promising drug target for AML therapy.
2023-10-04 | GSE230646 | GEO
Project description:Accumulating evidence suggests that DEAD-box proteins are essential in RNA metabolism and play pivotal roles in cancer progression. However, the mechanisms underlying how DDX24 drives hepatocellular carcinoma (HCC) remain largely unknown. In this study, we demonstrated that DDX24 was an oncogene and identified DDX24 promoted HCC development via interacting with NCL.
2021-01-29 | PXD023321 | Pride
Project description: Not available
| S-EPMC7591989 | biostudies-literature
Project description:Liver cancer claims over 800,000 human deaths each year. Liver cancer is notoriously refractory to conventional therapeutics. Further insight into the etiology carries promise for innovative diagnostics and therapeutics. Tumor progression is governed by interplay between tumor promoting genes and suppressor genes. BRD4, an acetyl-lysine binding protein, plays a critical role in development and human diseases. In many cancer types, BRD4 is overexpressed and promotes activation of a pro-tumor gene network. But the underlying mechanism for BRD4 overexpression remains elusive. As BRD4 has risen as a promising therapeutic target, to understand the mechanism regulating BRD4 protein level will shed insight into BRD4-targeting therapeutics. In this study, we find BRD4 protein level in liver cancer is significantly regulated by P53, the most frequently dysregulated tumor suppressor. We identify a strong negative correlation between protein levels of P53 and BRD4 in liver cancer. We then show P53 promotes BRD4 protein degradation. Mechanistically, P53 represses the transcription of USP1, a deubiquitinase, through P21-RB. We show USP1 is a deubiquitinase of BRD4, which increases its stability. We show the pro-tumor role of USP1 is partially mediated by BRD4 and the USP1-BRD4 axis upholds expression of a group of cancer-related genes. In summary, we identify a functional P53-P21-RB-USP1-BRD4 axis in liver cancer.
2024-01-26 | GSE243936 | GEO
Project description:Ewing sarcoma (EWS) is a malignant pediatric bone cancer. Most Ewing sarcomas are driven by EWS-FLI1 oncogenic transcription factor that plays roles in transcriptional regulation, DNA damage response, cell cycle checkpoint control, and alternative splicing. USP1, a deubiquitylase which regulates DNA damage and replication stress responses, is overexpressed at both the mRNA and protein levels in EWS cell lines compared to human mesenchymal stem cells, the EWS cell of origin. The functional significance of high USP1 expression in Ewing sarcoma is not known. Here, we identify USP1 as a transcriptional target of EWS-FLI1 and a key regulator of EWS cell survival. We show that EWS-FLI1 knockdown decreases USP1 mRNA and protein levels. ChIP and ChIP-seq analyses show EWS-FLI1 occupancy on the USP1 promoter. Importantly, USP1 knockdown or inhibition arrests EWS cell growth and induces cell death by apoptosis. We observe destabilization of Survivin (also known as BIRC5 or IAP4) and activation of caspases-3 and -7 following USP1 knockdown or inhibition in the absence of external DNA damage stimuli. Notably, EWS cells display hypersensitivity to combinatorial treatment of doxorubicin or etoposide, EWS standard of care drugs, and USP1 inhibitor compared to single agents alone. Together, our study demonstrates that USP1 is regulated by EWS-FLI1, the USP1-Survivin axis promotes EWS cell survival, and USP1 inhibition sensitizes EWS cells to standard of care chemotherapy.
2024-01-26 | PXD041033 | Pride
Project description: Not available
| S-EPMC4457509 | biostudies-literature
Project description:Sharpin (Shank-associated RH domain-interacting protein, also known as SIPL1) is a multifunctional molecule that participates in various biological settings, including nuclear factor-κB signaling activation and tumor suppressor gene inhibition. Sharpin is upregulated in various types of cancers, including hepatocellular carcinoma (HCC), and is implicated in tumor progression. However, the exact roles of Sharpin in tumorigenesis and tumor progression remain largely unknown. Here, we report novel mechanisms of HCC progression through Sharpin overexpression. Sharpin was upregulated in human HCC tissues. Increased Sharpin expression enhanced hepatoma cell invasion, whereas decrease in Sharpin expression by RNA interference inhibited invasion. Microarray analysis identified that versican, a chondroitin sulfate proteoglycan that plays crucial roles in tumor progression and invasion, was also upregulated in stably Sharpin-expressing cells. Versican expression increased in the majority of HCC tissues and knocking down of versican greatly attenuated hepatoma cell invasion. Sharpin expression resulted in a significant induction of versican transcription synergistically with Wnt/-catenin pathway activation. Furthermore, Sharpin overexpressing cells had high tumorigenic properties in vivo. These results demonstrate that Sharpin promotes versican expression synergistically with the Wnt/-catenin pathway, potentially contributing to HCC development. A Sharpin/versican axis could be an attractive therapeutic target for this currently untreatable cancer.
2017-01-23 | GSE87149 | GEO