Cell cycle plasticity driven by MTOR signaling: integral mechanism for resistance to CDK4/6 inhibition
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA454470 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR7089080_1.fastq.gz | Fastqsanger.gz | |||
| SRR7089080_2.fastq.gz | Fastqsanger.gz | |||
| SRR7089090_1.fastq.gz | Fastqsanger.gz | |||
| SRR7089090_2.fastq.gz | Fastqsanger.gz | |||
| SRR7089100_1.fastq.gz | Fastqsanger.gz |
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Project description:Pancreatic ductal adenocarcinoma (PDAC), like many KRAS-driven tumors, preferentially loses CDKN2A to bypass the RB tumor suppressive pathway. This finding and a gene expression profile indicative of a CDK4/6-driven cell cycle suggests that PDAC could be particularly sensitive to CDK4/6 inhibition. Analysis of a panel of patient-derived cell lines and xenografts indicates that many pancreatic cancers have an intrinsic resistance to CDK4/6 inhibition that is not due to known molecular mechanisms. Rather, there is a rapid and potent adaptive response that led to the upregulation of Cyclin D1 and Cyclin E proteins and compromised the suppression of a DNA replication gene expression program. These adaptive responses are dependent on MTOR signaling both in cell and animal studies. Strikingly, combination treatments with MTOR and CDK4/6 inhibitor had potent activity across a large number of patient derived models of PDAC underscoring the potential clinical efficacy.
2019-05-14 | GSE113922 | GEO
Project description:Intrinsic or acquired resistance to clinically approved CDK4/6 inhibitors have emerged as a major obstacle that hinders their utility beyond ER+ breast cancer. Palbociclib-sensitive ER+ breast cancer models and pancreatic ductal adenocarcinoma (PDAC) models were employed to identify functional determinants of response. In all models tested the activation of RB and inhibition of CDK2 activity emerged as determinants of sensitivity. While depleting CDK4 and 6 was sufficient to limit proliferation in specific resistance setting, RB loss renders cells completely CDK4/6 independent. The main down-stream target in this context is the activation status of CDK2 which is suppressed with CDK4/6 inhibition in an RB-dependent fashion. The P27KIP1 protein levels are associated with plasticity/rigidity of the cell cycle and correlates with sensitivity to CDK4/6 inhibiion. Exogenous overexpression and pharmacological induction of P27KIP1 by targeting the MEK/ERK pathway enhances the cytostatic effect of palbociclib. Similar to cell-culture data, in vivo experiments revealed that combination treatment of palbociclib and trametinib in mice bearing PDAC PDXs elicited a robust anti-proliferative effect with a corresponding increase in p27 expression. Mice bearing MCF7 xenografts displayed a durable response in the presence of palbociclib; however, over the course of treatment few cells begin to evade the negative cell-cycle regulation. Based on multispectral staining, the MCF7 tumor cells that underwent RB inactivation in the presence of palbociclib harbored low p27 expression. Finally, we demonstrate that the cell-cycle plasticity that enables tumor models to evade the palbociclib mediated RB activation could be potently targeted using a clinically applicable CDK2 inhibitor.
2020-06-30 | GSE146788 | GEO
Project description:Pancreatic ductal adenocarcinoma (PDAC), like many KRAS-driven tumors, preferentially loses CDKN2A that encodes an endogenous CDK4/6 inhibitor to bypass the RB-mediated cell cycle suppression. Analysis of a panel of patient-derived cell lines and matched xenografts indicated that many pancreatic cancers have intrinsic resistance to CDK4/6 inhibition that is not due to any established mechanism or published biomarker. Rather, there is a KRAS-dependent rapid adaptive response that leads to the upregulation of cyclin proteins, which participate in functional complexes to mediate resistance. In vivo, the degree of response is associated with the suppression of a gene expression signature that is strongly prognostic in pancreatic cancer. Resistance is associated with an adaptive gene expression signature that is common to multiple kinase inhibitors, but is attenuated with MTOR inhibitors. Combination treatment with MTOR and CDK4/6 inhibitors had potent activity across a large number of patient-derived models of PDAC underscoring the potential clinical efficacy.
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Project description:Functional determinants of sensitivity to CDK4/6 inhibition or cell-cycle plasticity
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Project description:Continuous MEK and CDK4/6 inhibition is effective in pre-clinical models, nevertheless, some tumors acquire resistance that was associated with enhanced phospho S6. To characterize the mechanism mediating the upregulation of mTOR-S6 pathway in these tumors, we performed RNA sequencing and targeted panel sequencing on xenograft tumors that progressed on either MEK plus CDK4/6 inhibitors (ComboR) or control diet. Gene set variance analysis (GSVA) revealed distinct gene expression signatures between the two ComboR tumors indicating heterogeneity. However, one of the 44 shared pathways between ComboR1 and ComboR2 included upregulation of an AKT pathway gene signature. By targeted sequencing and RNA sequencing, we observed high copy number change of NRAS in ComboR1 and a third tumor sample isolated from a continuous MEK inhibitor-intermittent CDK4/6 inhibitor schedule. NRAS was confirmed to mediate increased mTOR-S6 pathway activation suggesting that while distinct mechanisms are employed by melanoma tumors to circumvent MEK plus CDK4/6 inhibition, those resistance pathways eventually converge upon phosphorylation of S6 protein.
2018-04-05 | GSE111005 | GEO
Project description:Cyclin-dependent kinases (CDK) are rational cancer therapeutic targets fraught with the development of acquired resistance by tumor cells. Through integrated fluxomics and transcriptomics approaches, we show that the inhibition of CDK4/6 causes enhanced metabolism of glucose, glutamine and amino acids, a metabolic reprogramming directed by the MYC transcription factor. Upon inhibition of CDK4/6, MYC is stabilized and its accumulation induces an upregulation of the mTOR pathway and increased glutamine metabolism and production of α-ketoglutarate, a prolyl hydroxylase substrate that triggers HIF1α hydroxylation and degradation. These MYC-driven adaptations to CDK4/6 inhibition render cells highly sensitive to inhibitors of mTOR and glutaminase and to hypoxia, revealing that drug resistance can mechanistically promote the emergence of new vulnerabilities that can be exploited therapeutically. We used microarrays to detail the global programme of gene expression underlying inhibition of CDK4 and CDK6.
2017-09-15 | GSE84597 | GEO
Project description:CDK4/6 inhibitors arrest the cell cycle in G1-phase. They are licenced to treat breast cancer and are also undergoing clinical trials against a range of other tumour types. To facilitate these efforts, it is important to understand why a temporary cell cycle arrest in G1 causes long-lasting effects on tumour growth. Here we demonstrate that a prolonged G1-arrest following CDK4/6 inhibition downregulates replisome components and impairs origin licencing. This causes a failure in DNA replication after release from that arrest, resulting in a p53-dependent withdrawal from the cell cycle. If p53 is absent, then cells bypass the G2-checkpoint and undergo a catastrophic mitosis resulting in excessive DNA damage. These data therefore link CDK4/6 inhibition to genotoxic stress; a phenotype that is shared by most other broad-spectrum anti-cancer drugs. This provides a rationale to predict responsive tumour types and effective combination therapies, as demonstrated by the fact that chemotherapeutics that cause replication stress also induce sensitivity to CDK4/6 inhibition.
2021-12-20 | PXD023435 | Pride
Project description:The mechanistic target of rapamycin (mTOR) is a central regulator of cell growth and an attractive anti-cancer target that integrates diverse signals to control cell proliferation. Previous studies using mTOR inhibitors have shown that mTOR targeting suppresses gene expression and cell proliferation. To date, however, mTOR targeted therapies in cancer have seen very limited efficacy, and one key issue is related to the development of evasive resistance. In this manuscript, through the use of a gene targeting mouse model, we have found that inducible deletion of mTOR in hematopoietic stem cells (HSCs) results in a loss of quiescence and increased proliferation. Adaptive to the mTOR loss, mTOR-/- HSCs increase chromatin accessibility and activate global gene expression, contrary to the effects of short-term inhibition by mTOR inhibitors. Mechanistically, such genomic changes are due to a rewiring and adaptive activation of the ERK/MNK/eIF4E signaling pathway that enhances the protein translation of RNA polymerase II (RNAP II), which in turn leads to increased c-Myc gene expression, allowing the HSCs to thrive despite loss of a functional mTOR pathway. This adaptive mechanism can also be utilized by leukemia cells undergoing long-term mTOR inhibitor treatment to confer resistance to mTOR drug targeting. The resistance can then be counteracted by MNK, CDK9, or c-Myc inhibition. These results provide new insights into the physiological role of mTOR in mammalian stem cell regulation and implicate a novel mechanism of evasive resistance in the context of mTOR targeting.
2020-12-24 | GSE134316 | GEO
Project description:Impact of CDK4-deficiency on EM-BM-5-myc driven B-lymphoma By crossing mating CDK4 Knockout mice with EM-BM-5-myc mice,We found CDK4-deficiency enhances the EM-BM-5-myc induced B-lymphoma.We further to discover the molecular mechanism B-lymphoma cells form the cdk4+/+ EM-BM-5-myc and cdk4-/-EM-BM-5-myc mice and then culturing for RNA extraction and hybridization on Affymetrix microarrays.
2012-12-16 | E-GEOD-21683 | biostudies-arrayexpress