Centrosomal Localization of DNAJ-PKAc Fusion Heightens PLK1 Inhibitor Sensitivity in Fibrolamellar Cancer
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PROVIDER: PRJNA1051952 | ENA |
REPOSITORIES: ENA
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Project description:Fibrolamellar carcinoma (FLC), a rare and fatal liver cancer lacking effective drug therapy, is driven by the DNAJ-PKAc fusion oncoprotein. However, the underlying mechanism of DNAJ-PKAc's role in FLC tumor growth remains enigmatic. Employing an unbiased systems-based approach, we uncovered a new role of DNAJ-PKAc oncoprotein in FLC and identified downstream kinases involved in this process. Functional screening, coupled with computational analysis, highlighted Polo-like kinase 1 (PLK1) as vital for FLC cell viability. Genetic and pharmacological PLK1 inhibition significantly reduced FLC cell growth, inducing apoptosis. Further studies showed DNAJ-PKAc's centrosomal presence and direct interaction with PLK1, revealing a novel mechanism that promotes PLK1 activation and mitotic progression. Clinical-grade PLK1 inhibitors effectively suppressed FLC tumor growth across multiple preclinical models, including patient-derived xenograft and an orthotopic model of FLC, suggesting promising therapeutic avenues. Our findings underscore the role of DNAJ-PKAc in rewiring signaling networks and highlight valuable clinical implications for PLK1-targeted therapies for FLC.
2023-12-19 | GSE250059 | GEO
Project description:Fibrolamellar carcinoma (FLC) is a rare liver cancer. FLC tumors exclusively produce DNAJ-PKAc, a de novo chimeric enzyme consisting of a chaperonin-binding domain fused to the C subunit of protein kinase A. Biochemical analyses of clinical samples reveal that a unique property of DNAJ-PKAc is the ability to recruit heat shock protein 70 (Hsp70). This cellular chaperonin is frequently up-regulated in cancers. Gene-editing of mouse hepatocytes generated disease-relevant AML12DNAJ-PKAc cell lines. Drug-screening discovered Hsp70 and MEK inhibitor combinations that selectively block proliferation of AML12DNAJ-PKAc cells. Further analyses indicate that the proto-oncogene AKAP-Lbc is upregulated in FLC and functions to cluster DNAJ-PKAc/Hsp70 sub-complexes with a RAF-MEK-ERK kinase module. Phosphoproteomic profiling infers that DNAJ-PKAc biases the signaling landscape toward ERK activation and mobilizes other downstream kinase cascades. We propose that the oncogenic nature of DNAJ-PKAc proceeds through an acquired scaffolding function that permits recruitment of Hsp70 and stabilizes ERK signaling.
2018-11-27 | MSV000083167 | MassIVE
Project description:Raw MS datafiles and MaxQuant search result files for Lauer et. al. "Recruitment of BAG2 to DNAJ-PKAc scaffolds promotes cell survival and resistance to drug-induced apoptosis in fibrolamellar carcinoma"
2023-07-13 | MSV000092440 | MassIVE
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net) | Affymetrix HG-U133 Plus 2.0 : 5 mixed fibrolamellar carcinoma (m-FLC), 17 pure fibrolamellar carcinoma (p-FLC), 7 hepatocelluar carcinoma arising in non-cirrhotic liver (nc-HCC) and 10 non-tumoral livers (NL).
2014-08-15 | E-MTAB-1503 | biostudies-arrayexpress
Project description:Neurospora crassa ZP-pkac-1 Gene Expression Profiling - ZP-pkac-1_1 transcriptome
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Project description:Neurospora crassa ZP-pkac-1 Gene Expression Profiling - ZP-pkac-1_2 transcriptome
| PRJNA583818 | ENA
Project description:Neurospora crassa ZP-pkac-1 Gene Expression Profiling - ZP-pkac-1_3 transcriptome
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Project description:Transcriptional profiling of mouse aortas comparing control wild-type animals with aortas from three different Plk1(+/-) mice. Goal was to determine the effects of Plk1 haploinsufficiency in aorta expression profiles.
2017-07-01 | GSE85199 | GEO
Project description:Fibrolamellar carcinoma (FLC) is a devastating, early-onset rare cancer for which there is no effective standard of care. FLC tumors are initiated and likely also maintained by the fusion oncoprotein DNAJ-PKAc (DP). Strategies to therapeutically target DP are underway but remain challenging. Alternate therapeutic approaches are needed in order to maximize the potential benefit for patients. In this study, to identify candidate compounds for drug repurposing, we re-analyzed publicly available RNA-seq data in FLC and non-malignant liver (NML) tissue. We noted that retinoid metabolism, a normal function of a healthy liver, is strikingly suppressed in FLC, which led to the hypothesis that FLC tumors may be responsive to all-trans retinoic acid (ATRA). To test this hypothesis, we treated FLC tumor cells in culture, established from a patient-derived xenograft (PDX) mouse model, with ATRA and found by RNA-seq that well-established molecular markers of PKA signaling and FLC tumors are significantly reduced. Moreover, ATRA treatment markedly diminished cell viability, proliferation, and colony forming capability. We also demonstrated that ATRA sensitizes FLC cells to apoptotic induction by the TLR3 ligand, poly(I:C). Next, using patient tissue slices, we confirmed that ATRA reduces cell viability only in tumors and not in adjacent NML tissue. Finally, we performed in vivo studies in PDX mice to show that ATRA significantly suppresses FLC tumor growth. These findings motivate a more expansive pre-clinical examination of ATRA, especially in conjunction with TLR3 ligands and possibly other adjuvants, to establish the safety and efficacy of ATRA for FLC clinical trials.
2023-02-13 | GSE224888 | GEO
Project description:Fibrolamellar carcinoma (FLC) is a rare liver cancer that affects adolescents and young adults. Genomic analysis of FLC has revealed a 400 kb deletion in chromosome 19 that leads to the chimeric transcript DNAJB1-PRKACA (DnaJ-PKAc), comprised of the first exon of heat shock protein 40 (DNAJB1) and exons 2-10 of the catalytic subunit of protein kinase A (PRKACA). Here, we report a new zebrafish model of FLC induced by ectopic expression of zebrafish Dnaja-Pkaca (zfDnaJa-Pkaca) in hepatocytes that is amenable to live imaging of early innate immune inflammation. Expression of zfDnaJa-Pkaca in hepatocytes induces hepatomegaly and increased hepatocyte size. In addition, FLC larvae exhibit early innate immune inflammation characterized by early infiltration of neutrophils and macrophages into the liver microenvironment. Increased Caspase-a (the zebrafish homolog for human caspase-1) activity was also found in the liver of FLC larvae, and pharmacological inhibition of Tnf? and caspase-a decreased liver size and inflammation. Overall, these findings show that innate immune inflammation is an early feature in a zebrafish model of FLC and that pharmacological inhibition of TNF? or caspase-1 activity might be targets to treat inflammation and progression in FLC patients.This article has an associated First Person interview with the first author of the paper.
| S-EPMC7197716 | biostudies-literature