Unique vulnerability of RAC1-mutant melanoma to combined inhibition of CDK9 and immune checkpoints
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1042851 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:RAC1P29S is the third most prevalent hotspot mutation in sun-exposed melanoma. RAC1 alterations in cancer are correlated with poor prognosis, resistance to standard chemotherapy, and insensitivity to targeted inhibitors. Although RAC1P29S mutations in melanoma and RAC1 alterations in several other cancers are increasingly evident, the RAC1-driven biological mechanisms contributing to tumorigenesis remain unclear. Lack of rigorous signaling analysis has prevented identification of alternative therapeutic targets for RAC1P29S-harboring melanomas. To investigate the RAC1P29S-driven effect on downstream molecular signaling pathways, we generated an inducible RAC1P29S expression melanocytic cell line and performed RNA-sequencing (RNA-seq) coupled with multiplexed kinase inhibitor beads and mass spectrometry (MIBs/MS) to establish enriched pathways from the genomic to proteomic level. Our proteogenomic analysis identified CDK9 as a potential new and specific target in RAC1P29S-mutant melanoma cells.In vitro, CDK9 inhibition impeded the proliferation of in RAC1P29S-mutant melanoma cells and increased surface expression of PD-L1 and MHC Class I proteins.In vivo, combining CDK9 inhibition with anti-PD-1 immune checkpoint blockade significantly inhibited tumor growthonly in melanomas that expressed the RAC1P29Smutation. Collectively, these results establish CDK9 as a novel target in RAC1-driven melanoma that can further sensitize the tumor to anti-PD-1 immunotherapy.
2024-06-12 | GSE248218 | GEO
Project description:Gene expression by RNA Polymerase II (RNAPII) is tightly controlled by Cyclindependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The RNAPII pausing checkpoint, engaged after transcription initiation, is controlled by CDK9 to regulate transcription in metazoans. We discovered that CDK9-mediated RNAPII pause-release is functionally opposed by a protein phosphatase 2A (PP2A) complex. PP2A dynamically competes for key CDK9 substrates, DSIF and RNAPIICTD, and is recruited to transcription pausing sites by the Integrator complex subunit INTS6. INTS6 depletion confers resistance to CDK9 inhibition in a variety of normal and tumor cell lines. Loss of INTS6 abolishes the Integrator-PP2A association leading to unrestrained CDK9 activity, which amplifies transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill MLLrearranged leukemias and solid tumors and provide therapeutic benefit in vivo. These data demonstrate that finely-tuned gene expression relies on the balance of kinase and phosphatase activity at the pausing checkpoint.
2022-08-12 | PXD022962 | Pride
Project description:Gene expression by RNA Polymerase II (RNAPII) is tightly controlled by Cyclin-dependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The RNAPII pausing checkpoint, engaged after transcription initiation, is controlled by CDK9 to regulate transcription in metazoans. We discovered that CDK9-mediated RNAPII pause-release is functionally opposed by a protein phosphatase 2A (PP2A) complex. PP2A dynamically competes for key CDK9 substrates, DSIF and RNAPII-CTD, and is recruited to transcription pausing sites by the Integrator complex subunit INTS6. INTS6 depletion confers resistance to CDK9 inhibition in a variety of normal and tumor cell lines. Loss of INTS6 abolishes the Integrator-PP2A association leading to unrestrained CDK9 activity, which amplifies transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill MLL-rearranged leukemias and solid tumors and provide therapeutic benefit in vivo. These data demonstrate that f inely-tuned gene expression relies on the balance of kinase and phosphatase activity at the pausing checkpoint.
2021-05-23 | GSE163802 | GEO
Project description:Gene expression by RNA Polymerase II (RNAPII) is tightly controlled by Cyclin-dependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The RNAPII pausing checkpoint, engaged after transcription initiation, is controlled by CDK9 to regulate transcription in metazoans. We discovered that CDK9-mediated RNAPII pause-release is functionally opposed by a protein phosphatase 2A (PP2A) complex. PP2A dynamically competes for key CDK9 substrates, DSIF and RNAPII-CTD, and is recruited to transcription pausing sites by the Integrator complex subunit INTS6. INTS6 depletion confers resistance to CDK9 inhibition in a variety of normal and tumor cell lines. Loss of INTS6 abolishes the Integrator-PP2A association leading to unrestrained CDK9 activity, which amplifies transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill MLL-rearranged leukemias and solid tumors and provide therapeutic benefit in vivo. These data demonstrate that f inely-tuned gene expression relies on the balance of kinase and phosphatase activity at the pausing checkpoint.
2021-05-23 | GSE163804 | GEO
Project description:Gene expression by RNA Polymerase II (RNAPII) is tightly controlled by Cyclin-dependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The RNAPII pausing checkpoint, engaged after transcription initiation, is controlled by CDK9 to regulate transcription in metazoans. We discovered that CDK9-mediated RNAPII pause-release is functionally opposed by a protein phosphatase 2A (PP2A) complex. PP2A dynamically competes for key CDK9 substrates, DSIF and RNAPII-CTD, and is recruited to transcription pausing sites by the Integrator complex subunit INTS6. INTS6 depletion confers resistance to CDK9 inhibition in a variety of normal and tumor cell lines. Loss of INTS6 abolishes the Integrator-PP2A association leading to unrestrained CDK9 activity, which amplifies transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill MLL-rearranged leukemias and solid tumors and provide therapeutic benefit in vivo. These data demonstrate that f inely-tuned gene expression relies on the balance of kinase and phosphatase activity at the pausing checkpoint.
2021-05-23 | GSE163803 | GEO
Project description:Wholeskin from transgenic mice overexpressing epidermal specific (K14) activated mutant (V12) Rac1 analyzed with Illumina MouseRef8 v2 Gene Expression arrays Three V12 Rac1 7 day old pups compared to three 7 day old litter-mate controls
2016-06-13 | E-GEOD-71683 | biostudies-arrayexpress
Project description:CDK9 is the kinase subunit of P-TEFb that enables RNA polymerase (Pol) II to transit from promoter-proximal pausing to productive elongation. Although considerable interest exists in CDK9 as a therapeutic target, little progress has been made due to the lack of highly selective inhibitors. Here, we describe the development of i-CDK9 as such an inhibitor that potently suppresses CDK9 phosphorylation of substrates and causes genome-wide Pol II pausing. While most genes experience reduced expression, MYC and other primary response genes increase expression upon sustained i-CDK9 treatment. Essential for this increase, the bromodomain protein BRD4 captures P-TEFb from 7SK snRNP to deliver to target genes and also enhances CDK9’s activity and resistance to inhibition. Because the i-CDK9-induced MYC expression and binding to P-TEFb compensate for P-TEFb’s loss of activity, only the simultaneous inhibition of CDK9 and MYC can efficiently induce growth arrest and apoptosis of cancer cells, suggesting the potential of a combinatorial treatment strategy. We used microarrays to examine the global impact on gene expression by imhibiting CDK9 at different time durations. HeLa cell lines treated with CDK9 inhibitor at different time points
2015-06-17 | E-GEOD-60952 | biostudies-arrayexpress
Project description:The therapeutic potential of neurotrophic factors has been hampered by their inability to achieve adequate tissue penetration. Brain blood vessels, however, could be an alternative target for neuro-salvage therapies by virtue of their close proximity to neurons. Here we show that hemizygous deletion of Rac1 in mouse endothelial cells (ECs) attenuates brain injury and edema following focal cerebral ischemia. To explore the mechanisms whereby decrease of Rac1 in ECs provide neuroprotection, ECs were derived from Rac1+/+ and Rac1+/- mice. Microarray analysis was performed to determine the differential gene expression between Rac1+/+ and Rac1+/- ECs. Rac1+/+ and Rac1+/- ECs were cultured to subconfluence. Total RNA was extracted and reverse transcribed. Rac1+/+ (n = 2) and Rac1+/- (n = 2) EC cDNAs were labeled with Cy3 and Cy5, respectively, and equimolar mixtures of labeled Rac1+/+ and Rac1+/- probes were hybridized to 2 slides (sample #21648, #21649). Additionally, Rac1+/+ (n = 2) and Rac1+/- (n=2) EC cDNAs labeled with Cy5 and Cy3 (dye-swapping) were hybridized to 2 slides (sample #21650, #21651). Comparison of signal intensities between Rac1+/+ (channel 2) and Rac1+/- (channel 1) was conducted on each slide (sample), and the ratio of intensities from 4 slides were statistically assessed for each gene feature to investigate differential gene expression.
2009-03-15 | E-GEOD-15003 | biostudies-arrayexpress
Project description:CDK9 is the kinase subunit of P-TEFb that enables RNA polymerase (Pol) II to transit from promoter-proximal pausing to productive elongation. Although considerable interest exists in CDK9 as a therapeutic target, little progress has been made due to the lack of highly selective inhibitors. Here, we describe the development of i-CDK9 as such an inhibitor that potently suppresses CDK9 phosphorylation of substrates and causes genome-wide Pol II pausing. While most genes experience reduced expression, MYC and other primary response genes increase expression upon sustained i-CDK9 treatment. Essential for this increase, the bromodomain protein BRD4 captures P-TEFb from 7SK snRNP to deliver to target genes and also enhances CDK9’s activity and resistance to inhibition. Because the i-CDK9-induced MYC expression and binding to P-TEFb compensate for P-TEFb’s loss of activity, only the simultaneous inhibition of CDK9 and MYC can efficiently induce growth arrest and apoptosis of cancer cells, suggesting the potential of a combinatorial treatment strategy. ChIP-seq of Pol II in HeLa cells before or after i-CDk9 treatment
2015-06-17 | E-GEOD-60953 | biostudies-arrayexpress
Project description:Interactors of double mutant Rac1 (P29S/Q61L) compared to constitutively active Rac1 (Q61L).
2019-11-12 | PXD013941 | Pride