Dataset Information

The non-apoptotic function of Caspase-8 in negatively regulating the CDK9 mediated Ser2 phosphorylation of RNA Polymerase II in cervical cancer

ABSTRACT: Cervical cancer is the fourth most frequently diagnosed and fatal gynecological cancer. 15-61% of all cases metastasize and develop chemoresistance, reducing the 5-year survival of cervical cancer patients to as low as 17%. Therefore, unraveling the mechanisms contributing to metastasis is critical in developing better-targeted therapies against it. Here, we have identified a novel mechanism where nuclear Caspase-8 directly interacts with and inhibits the activity of CDK9, thereby modulating RNAPII-mediated global transcription, including those of cell-migration and -invasion-associated genes. Crucially, low Caspase-8 expression in cervical cancer patients leads to poor prognosis, higher CDK9 phosphorylation at Thr186, and increased RNAPII activity in cervical cancer cell lines and patient biopsies. Caspase-NT8 knock-out cells were also more resistant to the small-molecule CDK9 inhibitor BAY1251152 in both 2D- and 3D-culture conditions. Combining BAY1251152 with Cisplatin synergistically overcame chemoresistance of Caspase-8 deficient cervical cancer cells. Therefore, Caspase-8 expression could be a marker in chemoresistant cervical tumors, suggesting CDK9 inhibitor treatment for their sensitization to Cisplatin-based chemotherapy.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell, Cell Culture

DISEASE(S): Cervix Carcinoma

SUBMITTER: Ranadip Mandal

LAB HEAD: Klaus Strebhardt

PROVIDER: PXD038102 | Pride | 2023-03-11

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	MaxQuant_output.zip	Other
	TO_R_Mandal_070619_170719_548_R1_E1.raw	Raw
	TO_R_Mandal_070619_170719_548_R1_E2.raw	Raw
	TO_R_Mandal_070619_170719_548_R1_E3.raw	Raw
	TO_R_Mandal_070619_170719_548_R1_E4.raw	Raw

Items per page:

1 - 5 of 34

Publications

The non-apoptotic function of Caspase-8 in negatively regulating the CDK9-mediated Ser2 phosphorylation of RNA polymerase II in cervical cancer.

Mandal Ranadip R Raab Monika M Rödel Franz F Krämer Andrea A Kostova Izabela I Peña-Llopis Samuel S Häupl Björn B Oellerich Thomas T Gasimli Khayal K Sanhaji Mourad M Becker Sven S Strebhardt Klaus K

Cellular and molecular life sciences : CMLS 20221118 12

Cervical cancer is the fourth most frequently diagnosed and fatal gynecological cancer. 15-61% of all cases metastasize and develop chemoresistance, reducing the 5-year survival of cervical cancer patients to as low as 17%. Therefore, unraveling the mechanisms contributing to metastasis is critical in developing better-targeted therapies against it. Here, we have identified a novel mechanism where nuclear Caspase-8 directly interacts with and inhibits the activity of CDK9, thereby modulating RNA ...[more]

PMID: 36399280

Similar Datasets

Project description:Transcript elongation by RNA polymerase II (RNAPII) is accompanied by conserved patterns of histone modification within transcribed regions, but it remains uncertain how these modifications influence, or are influenced by, properties of the elongation complex. Here we establish an intimate link between Cdk9, the kinase component of positive transcription elongation factor b (P-TEFb), and mono-ubiquitylation of histone H2B (H2Bub1), in the fission yeast Schizosaccharomyces pombe. Mutations that impair Cdk9 function reduce H2Bub1 levels in vivo. Conversely, mutations that prevent H2Bub1 decrease phosphorylation of elongation factor subunit Spt5, a sensitive and specific indicator of Cdk9 activity. Chromatin immunoprecipitation (ChIP) analysis suggests this is due to impaired Cdk9 recruitment to H2Bub1-deficient chromatin. P-TEFb and H2Bub1 pathways also interact genetically: mutation of the histone H2B ubiquitin-acceptor residue decreases the requirement for Cdk9 activity in vivo, and multiple cdk9 mutations suppress morphological defects of H2Bub1-deficient strains. Moreover, H2Bub1 loss causes redistribution of transcribing RNAPII on chromatin that is corrected by a hypomorphic cdk9 mutation. Therefore, whereas mutual dependence of Spt5 phosphorylation and H2Bub1 suggests positive feedback between P-TEFb and the ubiquitylation machinery, mutual suppression by cdk9 and H2Bub1-pathway mutations indicates an antagonistic relationship, whereby the activities must be balanced to properly regulate elongation. In order to study the genome-wide localization of H2Bub1 in Schizosaccharomyces pombe, H2Bub1, H2B-Flag as well as RNAPII (along with associated DNA sequences) were immunoprecipitated using repectively anti-H2Bub1, anti-Flag and anti-8WG16 antibodies. The ChIPs were performed in duplicate from WT cells as well as in the H2B-K119R mutant. The extracted DNA was hybridized to a DNA microarray containing an average of 4 probes per kilobase across the whole yeast genome. The combined datasets are available in the supplemental files of the related publication.