Similar Datasets
Project description:MYC is a potent oncogene associated with aggressive disease in many distinct tumor types. Transforming members of the MYC family (MYC, MYCL1, MYCN) encode transcription factors containing six highly conserved regions, termed MYC homology Boxes (MBs). Here, we conduct proteomic profiling of the MB interactomes, demonstrating that half of MYC interactors require one or more MBs for binding. Comprehensive phenotypic analyses revealed that two MBs are universally required for transformation. MBII interaction with acetyltransferase-containing complexes results in histone hyperacetylation and is essential for MYC-dependent tumor initiation. By contrast, MB0 interacts with transcription elongation factors through direct binding to the general transcription factor TFIIF, and deletion of MB0 severely inhibits tumor growth but is dispensable for tumor initiation. Notably, the full transforming activity of MYC can be restored upon co-expression of MB0 and MBII deletion mutants, indicating that these two regions confer unique biological functions, each required for oncogenic MYC activity.
2018-11-08 | GSE117406 | GEO
Project description:MYC is a potent oncogene associated with aggressive disease in many distinct tumor types. Transforming members of the MYC family (MYC, MYCL1, MYCN) encode transcription factors containing six highly conserved regions, termed MYC homology Boxes (MBs). Here, we conduct proteomic profiling of the MB interactomes, demonstrating that half of MYC interactors require one or more MBs for binding. Comprehensive phenotypic analyses revealed that two MBs are universally required for transformation. MBII interaction with acetyltransferase-containing complexes results in histone hyperacetylation and is essential for MYC-dependent tumor initiation. By contrast, MB0 interacts with transcription elongation factors through direct binding to the general transcription factor TFIIF, and deletion of MB0 severely inhibits tumor growth but is dispensable for tumor initiation. Notably, the full transforming activity of MYC can be restored upon co-expression of MB0 and MBII deletion mutants, indicating that these two regions confer unique biological functions, each required for oncogenic MYC activity.
2018-11-08 | GSE117407 | GEO
Project description:MYC protein interactome profiling reveals functionally distinct regions that cooperate to drive tumorigenesis
| PRJNA481994 | ENA
Project description:MYC protein interactome profiling reveals functionally distinct regions that cooperate to drive tumorigenesis (ChIP-Seq)
| PRJNA481997 | ENA
Project description:MYC protein interactome profiling reveals functionally distinct regions that cooperate to drive tumorigenesis (RNA-Seq)
| PRJNA481996 | ENA
Project description:In human breast cancer, overexpression of the protooncogene MET is strongly associated with poor prognosis and high risk of metastasis. It stands out as a reliable prognostic indicator of survival and defines a set of tumors exclusive of those that express HER2 or hormone receptors. Studies have shown that overexpression of mutant forms of MET cause cancer in mice. However, MET mutations have not been found in human breast cancer, and the consequences of overexpression of normal MET are unknown. To investigate the role of MET and other putative oncogenes in breast cancer, we developed an experimental system that involves retroviral delivery of genes into primary mammary epithelial cells, followed by transplantation of the transduced cells into mammary fat pads. Using this approach, we found that overexpression of wild-type MET leads to the development of nonprogressive neoplasms. The lesions progressed to mammary adenocarcinoma when a second protooncogene, MYC, was overexpressed, indicating that MET and MYC cooperate in mammary tumorigenesis. Both the nonprogressive neoplasms and adenocarcinomas display characteristics consistent with transformation and expansion of mammary progenitor cells. The approach described here should provide a useful model with which to efficiently test effects of various genes on tumor development in the breast.
| S-EPMC552784 | biostudies-literature
Project description:Translation initiation is orchestrated by the cap binding and 43S preinitiation complexes (PIC). Eukaryotic initiation factor 1A (EIF1A) is essential for recruitment of the ternary complex and for assembling the 43S PIC. Recurrent EIF1AX mutations in papillary thyroid cancers are mutually exclusive with other drivers, including RAS. EIF1AX mutations are enriched in advanced thyroid cancers, where they display a striking co-occurrence with RAS, which cooperates to induce tumorigenesis in mice and isogenic cell lines. The C-terminal EIF1AX-A113splice mutation is the most prevalent in advanced thyroid cancer. EIF1AX-A113splice variants stabilize the PIC and induce ATF4, a sensor of cellular stress, which is co-opted to suppress EIF2α phosphorylation, enabling a general increase in protein synthesis. RAS stabilizes c-MYC, an effect augmented by EIF1AX-A113splice. ATF4 and c-MYC induce expression of amino acid transporters and enhance sensitivity of mTOR to amino acid supply. These mutually reinforcing events generate therapeutic vulnerabilities to MEK, BRD4, and mTOR kinase inhibitors. SIGNIFICANCE: Mutations of EIF1AX, a component of the translation PIC, co-occur with RAS in advanced thyroid cancers and promote tumorigenesis. EIF1AX-A113splice drives an ATF4-induced dephosphorylation of EIF2α, resulting in increased protein synthesis. ATF4 also cooperates with c-MYC to sensitize mTOR to amino acid supply, thus generating vulnerability to mTOR kinase inhibitors. This article is highlighted in the In This Issue feature, p. 151.
| S-EPMC6373451 | biostudies-literature
Project description:The conserved polarity effector proteins PAR-3, PAR-6, CDC-42, and atypical protein kinase C (aPKC) form a core unit of the PAR protein network, which plays a central role in polarizing a broad range of animal cell types. To functionally polarize cells, these proteins must activate aPKC within a spatially defined membrane domain on one side of the cell in response to symmetry-breaking cues. Using the Caenorhabditis elegans zygote as a model, we find that the localization and activation of aPKC involve distinct, specialized aPKC-containing assemblies: a PAR-3-dependent assembly that responds to polarity cues and promotes efficient segregation of aPKC toward the anterior but holds aPKC in an inactive state, and a CDC-42-dependent assembly in which aPKC is active but poorly segregated. Cycling of aPKC between these distinct functional assemblies, which appears to depend on aPKC activity, effectively links cue-sensing and effector roles within the PAR network to ensure robust establishment of polarity.
| S-EPMC5563072 | biostudies-literature
Project description:ObjectiveThe gene encoding the methionine salvage pathway methylthioadenosine phosphorylase (MTAP) is a tumor suppressor gene that is frequently inactivated in a wide variety of human cancers. In this study, we have examined if heterozygosity for a null mutation in Mtap (Mtap(lacZ)) could accelerate tumorigenesis development in two different mouse cancer models, Eμ-myc transgenic and Pten(+/-) .MethodsMtap Eμ-myc and Mtap Pten mice were generated and tumor-free survival was monitored over time. Tumors were also examined for a variety of histological and protein markers. In addition, microarray analysis was performed on the livers of Mtap(lacZ/+) and Mtap (+/+) mice.ResultsSurvival in both models was significantly decreased in Mtap(lacZ/+) compared to Mtap(+/+) mice. In Eµ-myc mice, Mtap mutations accelerated the formation of lymphomas from cells in the early pre-B stage, and these tumors tended to be of higher grade and have higher expression levels of ornithine decarboxylase compared to those observed in control Eµ-myc Mtap(+/+) mice. Surprisingly, examination of Mtap status in lymphomas in Eµ-myc Mtap(lacZ/+) and Eµ-myc Mtap(+/+) animals did not reveal significant differences in the frequency of loss of Mtap protein expression, despite having shorter latency times, suggesting that haploinsufficiency of Mtap may be playing a direct role in accelerating tumorigenesis. Consistent with this idea, microarray analysis on liver tissue from age and sex matched Mtap(+/+) and Mtap(lacZ/+) animals found 363 transcripts whose expression changed at least 1.5-fold (P<0.01). Functional categorization of these genes reveals enrichments in several pathways involved in growth control and cancer.ConclusionOur findings show that germline inactivation of a single Mtap allele alters gene expression and enhances lymphomagenesis in Eµ-myc mice.
| S-EPMC3694069 | biostudies-literature
Project description:Group 3 medulloblastoma is one of the most aggressive types of childhood brain tumors. Roughly 30% of cases carry genetic alterations in MYC, SMARCA4, or both genes combined. While overexpression of MYC has previously been shown to drive medulloblastoma formation in mice, the functional significance of SMARCA4 mutations and their suitability as a therapeutic target remain largely unclear. To address this issue, we combined overexpression of MYC with a loss of SMARCA4 in granule cell precursors. Both alterations did not increase proliferation of granule cell precursors in vitro. However, combined MYC overexpression and SMARCA4 loss successfully induced tumor formation in vivo after orthotopic transplantation in recipient mice. Resulting tumors displayed anaplastic histology and exclusively consisted of SMARCA4-negative cells although a mixture of recombined and non-recombined cells was injected. These observations provide first evidence for a tumor-promoting role of a SMARCA4 deficiency in the development of medulloblastoma. In comparing the transcriptome of tumors to the cells of origin and an established Sonic Hedgehog medulloblastoma model, we gathered first hints on deregulated gene expression that could be specifically involved in SMARCA4/MYC driven tumorigenesis. Finally, an integration of RNA sequencing and DNA methylation data of murine tumors with human samples revealed a high resemblance to human Group 3 medulloblastoma on the molecular level. Altogether, the development of SMARCA4-deficient medulloblastomas in mice paves the way to deciphering the role of frequently occurring SMARCA4 alterations in Group 3 medulloblastoma with the perspective to explore targeted therapeutic options.
| S-EPMC10621315 | biostudies-literature