Similar Datasets
Project description:The tumor suppressor p53 transcriptionally activates target genes to suppress cellular proliferation during stress. p53 has also been implicated in the repression of the proto-oncogene Myc, but the mechanism has remained unclear. Here, we identify Pvt1b, a p53-dependent isoform of the long noncoding RNA (lncRNA) Pvt1, expressed 50 kb downstream of Myc, which becomes induced by DNA damage or oncogenic signaling and accumulates near its site of transcription. We show that production of the Pvt1b RNA is necessary and sufficient to suppress Myc transcription in cis without altering the chromatin organization of the locus. Inhibition of Pvt1b increases Myc levels and transcriptional activity and promotes cellular proliferation. Furthermore, Pvt1b loss accelerates tumor growth, but not tumor progression, in an autochthonous mouse model of lung cancer. These findings demonstrate that Pvt1b acts at the intersection of the p53 and Myc transcriptional networks to reinforce the anti-proliferative activities of p53.
| S-EPMC7184554 | biostudies-literature
Project description:The tumor suppressor p53 transcriptionally activates target genes to suppress cellular proliferation during stress. p53 has also been implicated in the repression of the proto-oncogene Myc, but the mechanism has remained unclear. Here, we identify Pvt1b, a p53-dependent isoform of the long noncoding RNA (lncRNA) Pvt1, expressed 50 Kb downstream of Myc, which becomes induced by DNA damage or oncogenic signaling and accumulates near its site of transcription. We show that production of the Pvt1b RNA is necessary and sufficient to suppress Myc transcription in cis without altering the chromatin organization of the locus. Inhibition of Pvt1b increases Myc levels and transcriptional activity and promotes cellular proliferation. Furthermore, Pvt1b loss accelerates tumor growth, but not tumor progression, in an autochthonous mouse model of lung cancer. These findings demonstrate that Pvt1b acts at the intersection of the p53 and Myc transcriptional networks to reinforce the anti-proliferative activities of p53.
2020-01-20 | GSE142772 | GEO
Project description:P53 activation in response to cellular stress has long been known to result in downregulation of c-myc, a gene that is frequently overexpressed in cancer due to its role in promoting cellular proliferation. However, the mechanism underlying this p53 dependent myc repression is poorly understood. Here we report p53 regulation of the lncRNA PVT1, a neighboring myc gene which is upregulated following p53 activation via p53 binding to a canonical p53 response element (p53RE) in the first intron of PVT1. Specifically, we find that p53 activation results in induction of an isoform of PVT1 initiated from an alternative first exon, which we have termed PVT1alt. When the PVT1 p53RE is mutated and PVT1alt induction is inhibited, we observe increased levels of myc mRNA in cells undergoing DNA damage or oncogenic stress and corresponding increases in cellular proliferation. The PVT1alt RNA is required for this p53-dependent myc repression, suggesting a important growth suppressive role for this lncRNA in the p53 response. Our study reveals a novel mode of myc regulation in cis by an alternative lncRNA isoform, providing insight into an important mechanism of crosstalk between the p53 and myc transcriptional networks.
2020-01-20 | GSE126940 | GEO
Project description:p53 activates the long noncoding RNA Pvt1b to inhibit Myc and suppress tumorigenesis
| PRJNA523830 | ENA
Project description:p53 activates the long noncoding RNA Pvt1b to inhibit Myc and suppress tumorigenesis
| PRJNA599263 | ENA
Project description:p53 activates the long noncoding RNA Pvt1b to inhibit Myc and suppress tumorigenesis
| PRJNA598241 | ENA
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2015-02-01 | E-GEOD-59480 | biostudies-arrayexpress
Project description:p53 plays a central role in tumor suppression. Emerging evidence suggests long noncoding RNA (lncRNA) as an important class of regulatory molecules that control the p53 signaling. Here, we report that the oncogenic lncRNA E2F1 messenger RNA (mRNA) stabilizing factor (EMS) and p53 mutually repress each other's expression. EMS is negatively regulated by p53. As a direct transcriptional repression target of p53, EMS is surprisingly shown to inhibit p53 expression. EMS associates with cytoplasmic polyadenylation element-binding protein 2 (CPEB2) and thus, disrupts the CPEB2-p53 mRNA interaction. This disassociation attenuates CPEB2-mediated p53 mRNA polyadenylation and suppresses p53 translation. Functionally, EMS is able to exert its oncogenic activities, at least partially, via the CPEB2-p53 axis. Together, these findings reveal a double-negative feedback loop between p53 and EMS, through which p53 is finely controlled. Our study also demonstrates a critical role for EMS in promoting tumorigenesis via the negative regulation of p53.
| S-EPMC8784137 | biostudies-literature
Project description:Deregulated expression of c-Myc is an important molecular hallmark of cancer. The oncogenic function of c-Myc has been largely attributed to its intrinsic nature as a master transcription factor. Here, we report the long noncoding RNA (lncRNA) E2F1 messenger RNA (mRNA) stabilizing factor (EMS) as a direct c-Myc transcriptional target. EMS functions as an oncogenic molecule by promoting G1/S cell cycle progression. Mechanistically, EMS cooperates with the RNA binding protein RALY to stabilize E2F1 mRNA, and thereby increases E2F1 expression. Furthermore, EMS is able to connect c-Myc to cell cycle control and tumorigenesis via modulating E2F1 mRNA stability. Together, these findings reveal a previously unappreciated mechanism through which c-Myc induces E2F1 expression and also implicate EMS as an important player in the regulation of c-Myc function.
| S-EPMC6642410 | biostudies-literature
Project description:BackgroundThe functions of long noncoding RNAs (lncRNAs) have been identified in several cancers, but the roles of lncRNAs in colorectal cancer (CRC) are less well understood. The transcription factor MYC is known to regulate lncRNAs and has been implicated in cancer cell proliferation and tumorigenesis.MethodsCRC cells and tissues were profiled to identify lncRNAs differentially expressed in CRC, from which we further selected MYC-regulated lncRNAs. We used luciferase promoter assay, ChIP, RNA pull-down assay, deletion mapping assay, LC-MS/MS and RNA immunoprecipitation to determine the mechanisms of MYC regulation of lncRNAs. Moreover, soft agar assay and in vivo xenograft experiments (four athymic nude mice per group) provided evidence of MYC-regulated lncRNAs in cancer cell transformation and tumorigenesis. The Kaplan-Meier method was used for survival analyses. All statistical tests were two-sided.ResultsWe identified lncRNAs differentially expressed in CRC (P < .05, greater than two-fold) and verified four lncRNAs upregulated and two downregulated in CRC cells and tissues. We further identified MYC-regulated lncRNAs, named MYCLos. The MYC-regulated MYCLos may function in cell proliferation and cell cycle by regulating MYC target genes such as CDKN1A (p21) and CDKN2B (p15), suggesting new regulatory mechanisms of MYC-repressed target genes through lncRNAs. RNA binding proteins including HuR and hnRNPK are involved in the function of MYCLos by interacting with MYCLo-1 and MYCLo-2, respectively. Knockdown experiments also showed that MYCLo-2, differentially expressed not only in CRC but also in prostate cancer, has a role in cancer transformation and tumorigenesis.ConclusionsOur results provide novel regulatory mechanisms in MYC function through lncRNAs and new potential lncRNA targets of CRC.
| S-EPMC4402359 | biostudies-literature