CRTC1-MAML2 fusion oncogene-induced transcriptional program is regulated by CREB-dependent and -independent mechanisms
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Jian-Liang Li
PROVIDER: E-GEOD-59795 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Mucoepidermoid carcinomas (MEC) is the most common salivary gland malignancy. To date, advanced and nonresectable MEC have poor prognosis and no effective treatment. The CRTC1-MAML2 fusion oncogene, which is associated with more than 50% of MEC, consists of the N-terminal CREB-binding domain of the CREB transcriptional co-activator CRTC1 and the C-terminal transcriptional activation domain of the Notch transcriptional co-activator MAML2. CRTC1-MAML2 fusion was found to interact with CREB and constitutively activate their transcriptional targets. To investigate the genes and pathways regulated by CRTC1-MAML2 fusion oncogene, gene expression profiling analysis were performed in human fusion-positive MEC cells before and after knockdown of both CRTC1-MAML2 and MAML2 as well as in human fusion-negative salivary gland cancer cells before and after MAML2 knockdown only. This study revealed specific transcriptional program induced by the CRTC1-MAML2 fusion oncogene, which potentially mediates CRC1-MAML2 functions in MEC initiation and maintenance. The information will be useful for developing new approaches to block CRTC1-MAML2 fusion-expressing MEC. The fusion-positive H3118 MEC cells were used in this study. The fusion knockdown was performed with two biological replicates for each group. Since we are unable to obtain any shRNA that causes specific knockdown of CRTC1-MAML2, we utilized pSuperRetro-based retroviruses that express shRNA targeting the MAML2 TAD as well as GFP for fusion knock down, and the retroviruses express shRNA targeting luciferase gene (shLuc) and GFP for the control. Cells were infected with retroviruses and cultured for 48 hours. FACS sorting was performed to obtain GFP-positive cells and thus enrich shRNA-expressing cells. RNA was subsequently harvested for microarray analysis. The shMAML2 retroviruses caused the knockdown of MAML2 and CRTC1-MAML2 fusion in fusion-positive H3118 cells.
2014-04-21 | E-GEOD-46580 | biostudies-arrayexpress
Project description:Mucoepidermoid carcinomas (MEC) is the most common salivary gland malignancy. To date, advanced and nonresectable MEC have poor prognosis and no effective treatment. The CRTC1-MAML2 fusion oncogene, which is associated with more than 50% of MEC, consists of the N-terminal CREB-binding domain of the CREB transcriptional co-activator CRTC1 and the C-terminal transcriptional activation domain of the Notch transcriptional co-activator MAML2. CRTC1-MAML2 fusion was found to interact with CREB and constitutively activate their transcriptional targets. To investigate the genes and pathways regulated by CRTC1-MAML2 fusion oncogene, gene expression profiling analysis were performed in human fusion-positive MEC cells before and after knockdown of both CRTC1-MAML2 and MAML2 as well as in human fusion-negative salivary gland cancer cells before and after MAML2 knockdown only. This study revealed specific transcriptional program induced by the CRTC1-MAML2 fusion oncogene, which potentially mediates CRC1-MAML2 functions in MEC initiation and maintenance. The information will be useful for developing new approaches to block CRTC1-MAML2 fusion-expressing MEC. The fusion-negative HSY parotid adenocarcinoma cells were used in this study. The MAML2 knockdown was performed with two biological replicates for each group. We utilized pSuperRetro-based retroviruses that express shRNA targeting the MAML2 TAD as well as GFP, and the retroviruses express shRNA targeting luciferase gene (shLuc) and GFP for the control. Cells were infected with retroviruses and cultured for 72 hours. FACS sorting was performed to obtain GFP-positive cells and thus enrich shRNA-expressing cells. RNA was subsequently harvested for microarray analysis. The shMAML2 retroviruses caused MAML2 knockdown in fusion-negative HSY cells.
2015-10-30 | E-GEOD-57022 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below.
2014-07-25 | GSE59795 | GEO
Project description:Mucoepidermoid carcinomas (MEC) is the most common salivary gland malignancy. To date, advanced and nonresectable MEC have poor prognosis and no effective treatment. The CRTC1-MAML2 fusion oncogene, which is associated with more than 50% of MEC, consists of the N-terminal CREB-binding domain of the CREB transcriptional co-activator CRTC1 and the C-terminal transcriptional activation domain of the Notch transcriptional co-activator MAML2. CRTC1-MAML2 fusion was found to interact with CREB and constitutively activate their transcriptional targets. To investigate the contribution of the transcription factor CREB to mediate the fusion target gene expression, gene expression profiling analysis were performed in two salivary gland tumor cell lines (including fusion-positive H3118 MEC cells and fusion-negative HSY parotid adenocarcinoma cells) before and after CREB knockdown. This study demonstrated that CRTC1-MAML2 co-activation of CREB is a major mechanism underlying CRTC1-MAML2-mediated transcriptional regulation. Two salivary gland tumor cell lines were used in this study, including fusion-positive H3118 MEC cells and fusion-negative HSY parotid adenocarcinoma cells. The CREB knock down was performed with three biological replicates for each group. Both fusion-positive MEC H3118 cells and fusion-negative parotid adenocarcinoma HSY cells were stably transduced with pLKO.1-based shRNA targeting luciferase gene (shLuc, control) or CREB (shCREB). The cells were independently cultured and RNAs were then harvested 72 hours after transduction for microarray analysis.
2015-10-30 | E-GEOD-49673 | biostudies-arrayexpress
Project description:Mucoepidermoid carcinoma (MEC) arises from multiple organs and accounts for the most common types of salivary gland malignancies. Currently, patients with unresectable and metastatic MEC have poor long-term clinical outcomes and no targeted therapies are available. The majority of MEC tumors contain a t(11;19) chromosomal translocation that fuses two genes, CRTC1 and MAML2, to generate the chimeric protein CRTC1-MAML2. CRTC1-MAML2 displays transforming activity in vitro and is required for human MEC cell growth and survival, partially due to its ability to constitutively activate CREB-mediated transcription. Consequently, CRTC1-MAML2 is implicated as a major etiologic molecular event and a therapeutic target for MEC. However, the molecular mechanisms underlying CRTC1-MAML2 oncogenic action in MEC have not yet been systematically analyzed. Elucidation of the CRTC1-MAML2-regulated transcriptional program and its underlying mechanisms will provide important insights into MEC pathogenesis that are essential for the development of targeted therapeutics.Transcriptional profiling was performed on human MEC cells with the depletion of endogenous CRTC1-MAML2 fusion or its interacting partner CREB via shRNA-mediated gene knockdown. A subset of target genes was validated via real-time RT-PCR assays. CRTC1-MAML2-perturbed molecular pathways in MEC were identified through pathway analyses. Finally, comparative analysis of CRTC1-MAML2-regulated and CREB-regulated transcriptional profiles was carried out to assess the contribution of CREB in mediating CRTC1-MAML2-induced transcription.A total of 808 differentially expressed genes were identified in human MEC cells after CRTC1-MAML2 knockdown and a subset of known and novel fusion target genes was confirmed by real-time RT-PCR. Pathway Analysis revealed that CRTC1-MAML2-regulated genes were associated with network functions that are important for cell growth, proliferation, survival, migration, and metabolism. Comparison of CRTC1-MAML2-regulated and CREB-regulated transcriptional profiles revealed common and distinct genes regulated by CRTC1-MAML2 and CREB, respectively.This study identified a specific CRTC1-MAML2-induced transcriptional program in human MEC cells and demonstrated that CRTC1-MAML2 regulates gene expression in CREB-dependent and independent manners. Our data provide the molecular basis underlying CRTC1-MAML2 oncogenic functions and lay a foundation for further functional investigation of CRTC1-MAML2-induced signaling in MEC initiation and maintenance.
| S-EPMC4624166 | biostudies-literature
Project description:Chimeric oncoproteins created by chromosomal translocations are among the most common genetic mutations associated with tumorigenesis. Malignant mucoepidermoid salivary gland tumors, as well as a growing number of solid epithelial-derived tumors, can arise from a recurrent t (11, 19)(q21;p13.1) translocation that generates an unusual chimeric cAMP response element binding protein (CREB)-regulated transcriptional coactivator 1 (CRTC1)/mastermind-like 2 (MAML2) (C1/M2) oncoprotein comprised of two transcriptional coactivators, the CRTC1 and the NOTCH/RBPJ coactivator MAML2. Accordingly, the C1/M2 oncoprotein induces aberrant expression of CREB and NOTCH target genes. Surprisingly, here we report a gain-of-function activity of the C1/M2 oncoprotein that directs its interactions with myelocytomatosis oncogene (MYC) proteins and the activation of MYC transcription targets, including those involved in cell growth and metabolism, survival, and tumorigenesis. These results were validated in human mucoepidermoid tumor cells that harbor the t (11, 19)(q21;p13.1) translocation and express the C1/M2 oncoprotein. Notably, the C1/M2-MYC interaction is necessary for C1/M2-driven cell transformation, and the C1/M2 transcriptional signature predicts other human malignancies having combined involvement of MYC and CREB. These findings suggest that such gain-of-function properties may also be manifest in other oncoprotein fusions found in human cancer and that agents targeting the C1/M2-MYC interface represent an attractive strategy for the development of effective and safe anticancer therapeutics in tumors harboring the t (11, 19) translocation.
| S-EPMC4136562 | biostudies-literature
Project description:Mucoepidermoid carcinomas (MEC) is the most common salivary gland malignancy. To date, advanced and nonresectable MEC have poor prognosis and no effective treatment. The CRTC1-MAML2 fusion oncogene, which is associated with more than 50% of MEC, consists of the N-terminal CREB-binding domain of the CREB transcriptional co-activator CRTC1 and the C-terminal transcriptional activation domain of the Notch transcriptional co-activator MAML2. CRTC1-MAML2 fusion was found to interact with CREB and constitutively activate their transcriptional targets. To investigate the genes and pathways regulated by CRTC1-MAML2 fusion oncogene, gene expression profiling analysis were performed in human fusion-positive MEC cells before and after knockdown of both CRTC1-MAML2 and MAML2 as well as in human fusion-negative salivary gland cancer cells before and after MAML2 knockdown only. This study revealed specific transcriptional program induced by the CRTC1-MAML2 fusion oncogene, which potentially mediates CRC1-MAML2 functions in MEC initiation and maintenance. The information will be useful for developing new approaches to block CRTC1-MAML2 fusion-expressing MEC.
2014-04-21 | GSE46580 | GEO
Project description:No effective systemic treatment is available for patients with unresectable, recurrent, or metastatic mucoepidermoid carcinoma (MEC), the most common salivary gland malignancy. MEC is frequently associated with a t(11;19)(q14-21;p12-13) translocation that creates a CRTC1-MAML2 fusion gene. The CRTC1-MAML2 fusion exhibited transforming activity in vitro; however, whether it serves as an oncogenic driver for MEC establishment and maintenance in vivo remains unknown. Here, we show that doxycycline-induced CRTC1-MAML2 knockdown blocked the growth of established MEC xenografts, validating CRTC1-MAML2 as a therapeutic target. We further generated a conditional transgenic mouse model and observed that Cre-induced CRTC1-MAML2 expression caused 100% penetrant formation of salivary gland tumors resembling histological and molecular characteristics of human MEC. Molecular analysis of MEC tumors revealed altered p16-CDK4/6-RB pathway activity as a potential cooperating event in promoting CRTC1-MAML2-induced tumorigenesis. Cotargeting of aberrant p16-CDK4/6-RB signaling and CRTC1-MAML2 fusion-activated AREG/EGFR signaling with the respective CDK4/6 inhibitor Palbociclib and EGFR inhibitor Erlotinib produced enhanced antitumor responses in vitro and in vivo. Collectively, this study provides direct evidence for CRTC1-MAML2 as a key driver for MEC development and maintenance and identifies a potentially novel combination therapy with FDA-approved EGFR and CDK4/6 inhibitors as a potential viable strategy for patients with MEC.
| S-EPMC8119194 | biostudies-literature
Project description:CRTC1-MAML2 fusion oncogene-induced transcriptional program is regulated by CREB-dependent and -independent mechanisms
| PRJNA256213 | ENA
Project description:ObjectiveMucoepidermoid carcinoma (MEC) is the most common malignant tumor of the salivary glands. Tumor stage and grade have historically been important predictors of survival. An oncogenic CRTC1- or CRTC3-MAML2 gene fusion has been identified in a number of MECs. Historically, these gene fusions have been associated with lower grade tumors and better survival. However, reported gene fusion rates and prognosis varies widely across studies, and have not controlled for tumor grade. We sought to identify gene fusion rates and outcomes in our cohort of MEC patients.Materials and methodsAn IRB-approved retrospective cohort of patients with MEC was identified at the University of Michigan. Clinical, histologic, and outcome data was collected from medical records. RNA was isolated from formalin fixed paraffin-embedded tumor sections, and qRT-PCR was performed to identify CRTC1/3-MAML2 gene fusions. Sanger sequencing of qRT-PCR products was used to confirm gene fusions.ResultsOverall, 90 patient MEC tumors were collected (58 low-grade, 25 intermediate-grade, and 7 high-grade). Gene fusions were identified in 59% (53/90) of tumors. On univariate and bivariate analysis, fusion status did not significantly associate with grade or survival.ConclusionWe have identified a high rate of CRTC1/3-MAML2 gene fusions in a large cohort of MEC. We do not identify any correlation between fusion status with tumor grade or survival. These findings suggest further characterization of MECs is needed before considering the CRTC1/3-MAML2 gene fusion as a prognostic biomarker. Additional genetic drivers may account for survival and grade in MECs.
| S-EPMC5433350 | biostudies-literature