ORCID Profile
0000-0002-2933-6240
Current Organisation
Peter MacCallum Cancer Centre
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Publisher: American Association for Cancer Research (AACR)
Date: 10-2019
DOI: 10.1158/1535-7163.MCT-18-0573
Abstract: Most non–small cell lung cancers (NSCLC) contain nontargetable mutations, including KRAS, TP53, or STK11/LKB1 alterations. By coupling ex vivo drug sensitivity profiling with in vivo drug response studies, we aimed to identify drug vulnerabilities for these NSCLC subtypes. Primary adenosquamous carcinoma (ASC) or adenocarcinoma (AC) cultures were established from KrasG12D/+ Lkb1fl/fl (KL) tumors or AC cultures from KrasG12D/+ 53fl/fl (KP) tumors. Although p53-null cells readily propagated as conventional cultures, Lkb1-null cells required conditional reprograming for establishment. Drug response profiling revealed short-term response to MEK inhibition, yet long-term clonogenic assays demonstrated resistance, associated with sustained or adaptive activation of receptor tyrosine kinases (RTK): activation of ERBBs in KL cultures, or FGFR in AC cultures. Furthermore, pan-ERBB inhibition reduced the clonogenicity of KL cultures, which was exacerbated by combinatorial MEK inhibition, whereas combinatorial MEK and FGFR inhibition suppressed clonogenicity of AC cultures. Importantly, in vivo studies confirmed KL-selective sensitivity to pan-ERBB inhibition, which correlated with high ERBB ligand expression and activation of ERBB receptors, implying that ERBB network activity may serve as a predictive biomarker of drug response. Interestingly, in human NSCLCs, phosphorylation of EGFR or ERBB3 was frequently detected in ASCs and squamous cell carcinomas. We conclude that analysis of in situ ERBB signaling networks in conjunction with ex vivo drug response profiling and biochemical dissection of adaptive RTK activities may serve as a valid diagnostic approach to identify tumors sensitive to ERBB network inhibition.
Publisher: American Society of Hematology
Date: 25-05-2017
DOI: 10.1182/BLOOD-2016-05-718171
Abstract: Inhibition of RNA Pol I by CX-5461 treats aggressive AML and outperforms standard chemotherapy regimens. CX-5461 induces p53-dependent apoptosis, p53-independent cell-cycle defects and differentiation, and reduces LICs.
Publisher: American Association for Cancer Research (AACR)
Date: 14-11-2016
DOI: 10.1158/1078-0432.CCR-16-0124
Abstract: Purpose: The MYC oncogene is frequently overexpressed in prostate cancer. Upregulation of ribosome biogenesis and function is characteristic of MYC-driven tumors. In addition, PIM kinases activate MYC signaling and mRNA translation in prostate cancer and cooperate with MYC to accelerate tumorigenesis. Here, we investigate the efficacy of a single and dual approach targeting ribosome biogenesis and function to treat prostate cancer. Experimental Design:The inhibition of ribosomal RNA (rRNA) synthesis with CX-5461, a potent, selective, and orally bioavailable inhibitor of RNA polymerase I (Pol I) transcription, has been successfully exploited therapeutically but only in models of hematologic malignancy. CX-5461 and CX-6258, a pan-PIM kinase inhibitor, were tested alone and in combination in prostate cancer cell lines, in Hi-MYC- and PTEN-deficient mouse models and in patient-derived xenografts (PDX) of metastatic tissue obtained from a patient with castration-resistant prostate cancer. Results: CX-5461 inhibited anchorage-independent growth and induced cell-cycle arrest in prostate cancer cell lines at nanomolar concentrations. Oral administration of 50 mg/kg CX-5461 induced TP53 expression and activity and reduced proliferation (MKI67) and invasion (loss of ductal actin) in Hi-MYC tumors, but not in PTEN-null (low MYC) tumors. While 100 mg/kg CX-6258 showed limited effect alone, its combination with CX-5461 further suppressed proliferation and dramatically reduced large invasive lesions in both models. This rational combination strategy significantly inhibited proliferation and induced cell death in PDX of prostate cancer. Conclusions: Our results demonstrate preclinical efficacy of targeting the ribosome at multiple levels and provide a new approach for the treatment of prostate cancer. Clin Cancer Res 22(22) 5539–52. ©2016 AACR.
Publisher: American Society of Hematology
Date: 11-04-2013
DOI: 10.1182/BLOOD-2012-08-446096
Abstract: MYC-driven lymphomas demonstrate activation of mTORC1 and an endogenous DNA damage response. BEZ235 inhibits PI3K-related DNA damage response kinases and mTORC1, inducing p53-independent upregulation of proapoptotic BMF.
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.BBADIS.2013.12.009
Abstract: The contribution of the nucleolus to cancer is well established with respect to its traditional role in facilitating ribosome biogenesis and proliferative capacity. More contemporary studies however, infer that nucleoli contribute a much broader role in malignant transformation. Specifically, extra-ribosomal functions of the nucleolus position it as a central integrator of cellular proliferation and stress signaling, and are emerging as important mechanisms for modulating how oncogenes and tumor suppressors operate in normal and malignant cells. The dependence of certain tumor cells to co-opt nucleolar processes to maintain their cancer phenotypes has now clearly been demonstrated by the application of small molecule inhibitors of RNA Polymerase I to block ribosomal DNA transcription and disrupt nucleolar function (Bywater et al., 2012 [1]). These drugs, which selectively kill tumor cells in vivo while sparing normal cells, have now progressed to clinical trials. It is likely that we have only just begun to scratch the surface of the potential of the nucleolus as a new target for cancer therapy, with "suppression of nucleolar stress" representing an emerging "hallmark" of cancer. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.
Publisher: Impact Journals, LLC
Date: 06-07-2016
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.CELREP.2016.12.059
Abstract: Lung cancers exhibit pronounced functional heterogeneity, confounding precision medicine. We studied how the cell of origin contributes to phenotypic heterogeneity following conditional expression of Kras
Publisher: American Thoracic Society
Date: 08-2018
Publisher: American Association for the Advancement of Science (AAAS)
Date: 05-2020
Abstract: CDK12 and CDK13 regulate POLII elongation rate and processivity and influence the selection of transcription termination sites.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Springer Science and Business Media LLC
Date: 11-12-2019
DOI: 10.1038/S41375-019-0652-0
Abstract: MCL-1 is one of the most frequently lified genes in cancer, facilitating tumor initiation and maintenance and enabling resistance to anti-tumorigenic agents including the BCL-2 selective inhibitor venetoclax. The expression of MCL-1 is maintained via P-TEFb-mediated transcription, where the kinase CDK9 is a critical component. Consequently, we developed a series of potent small-molecule inhibitors of CDK9, exemplified by the orally active A-1592668, with CDK selectivity profiles that are distinct from related molecules that have been extensively studied clinically. Short-term treatment with A-1592668 rapidly downregulates RNA pol-II (Ser 2) phosphorylation resulting in the loss of MCL-1 protein and apoptosis in MCL-1-dependent hematologic tumor cell lines. This cell death could be attenuated by either inhibiting caspases or overexpressing BCL-2 protein. Synergistic cell killing was also observed between A-1592668 or the related analog A-1467729, and venetoclax in a number of hematologic cell lines and primary NHL patient s les. Importantly, the CDK9 inhibitor plus venetoclax combination was well tolerated in vivo and demonstrated efficacy superior to either agent alone in mouse models of lymphoma and AML. These data indicate that CDK9 inhibitors could be highly efficacious in tumors that depend on MCL-1 for survival or when used in combination with venetoclax in malignancies dependent on MCL-1 and BCL-2.
Publisher: Wiley
Date: 13-02-2013
DOI: 10.1111/FEBS.12135
Abstract: The dysregulation of PI3K/AKT/mTORC1 signalling and/or hyperactivation of MYC are observed in a high proportion of human cancers, and together they form a 'super signalling' network mediating malignancy. A fundamental downstream action of this signalling network is up-regulation of ribosome biogenesis and subsequent alterations in the patterns of translation and increased protein synthesis, which are thought to be critical for AKT/MYC-driven oncogenesis. We have demonstrated that AKT and MYC cooperate to drive ribosomal DNA (rDNA) transcription and ribosome biogenesis, with AKT being essential for rDNA transcription and in vitro survival of lymphoma cells isolated from a MYC-driven model of B-cell lymphoma (Eμ-Myc) [Chan JC et al., (2011) Science Signalling 4, ra56]. Here we show that the allosteric AKT inhibitor MK-2206 rapidly and potently antagonizes rDNA transcription in Eμ-Myc B-cell lymphomas in vivo, and this is associated with a rapid reduction in indicators of disease burden, including spleen weight and the abundance of tumour cells in both the circulation and lymph nodes. Extended treatment of tumour-bearing mice with MK-2206 resulted in a significant delay in disease progression, associated with increased B-cell lymphoma apoptosis. Our findings suggest that malignant diseases characterized by unrestrained ribosome biogenesis may be vulnerable to therapeutic strategies that target the PI3K/AKT/mTORC1/MYC growth control network.
Publisher: American Association for Cancer Research (AACR)
Date: 2016
DOI: 10.1158/2159-8290.CD-14-0673
Abstract: Ribosome biogenesis and protein synthesis are dysregulated in many cancers, with those driven by the proto-oncogene c-MYC characterized by elevated Pol I–mediated ribosomal rDNA transcription and mTORC1/eIF4E-driven mRNA translation. Here, we demonstrate that coordinated targeting of rDNA transcription and PI3K–AKT–mTORC1-dependent ribosome biogenesis and protein synthesis provides a remarkable improvement in survival in MYC-driven B lymphoma. Combining an inhibitor of rDNA transcription (CX-5461) with the mTORC1 inhibitor everolimus more than doubled survival of Eμ-Myc lymphoma–bearing mice. The ability of each agent to trigger tumor cell death via independent pathways was central to their synergistic efficacy. CX-5461 induced nucleolar stress and p53 pathway activation, whereas everolimus induced expression of the proapoptotic protein BMF that was independent of p53 and reduced expression of RPL11 and RPL5. Thus, targeting the network controlling the synthesis and function of ribosomes at multiple points provides a potential new strategy to treat MYC-driven malignancies. Significance: Treatment options for the high proportion of cancers driven by MYC are limited. We demonstrate that combining pharmacologic targeting of ribosome biogenesis and mTORC1-dependent translation provides a remarkable therapeutic benefit to Eμ-Myc lymphoma–bearing mice. These results establish a rationale for targeting ribosome biogenesis and function to treat MYC-driven cancer. Cancer Discov 6(1) 59–70. ©2015 AACR. This article is highlighted in the In This Issue feature, p. 1
Location: Finland
No related grants have been discovered for Jennifer Devlin.