Multi-Omics Analysis Identifies MGA as a Negative Regulator of the MYC Pathway in Lung Adenocarcinoma
| Autor: | Jin Zhou, Joshua M. Francis, Montse Sanchez-Cespedes, Xiaoyang Zhang, Matthew Meyerson, Steven A. Carr, Tanya Svinkina, Estrella Aguilera-Jimenez, Namrata D. Udeshi, Manuel Torres-Diz, Diana Cai, Paula Llabata, Yoichiro Mitsuishi, Zhong Wu, Peter S. Choi, Lior Golomb, Yanli Liu |
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| Rok vydání: | 2020 |
| Předmět: |
Cancer Research
Lung Neoplasms Adenocarcinoma of Lung Protein Max Biology Article Receptor tyrosine kinase law.invention Proto-Oncogene Proteins c-myc 03 medical and health sciences 0302 clinical medicine law Cell Line Tumor Basic Helix-Loop-Helix Transcription Factors Transcriptional regulation Humans Molecular Biology Gene Cell Proliferation 030304 developmental biology 0303 health sciences Basic Helix-Loop-Helix Leucine Zipper Transcription Factors RNA Chromatin HEK293 Cells Oncology A549 Cells 030220 oncology & carcinogenesis Mutation Cancer research biology.protein Suppressor Sequence motif |
| Zdroj: | Mol Cancer Res |
| ISSN: | 1557-3125 1541-7786 |
| Popis: | Genomic analysis of lung adenocarcinomas has revealed that the MGA gene, which encodes a heterodimeric partner of the MYC-interacting protein MAX, is significantly mutated or deleted in lung adenocarcinomas. Most of the mutations are loss of function for MGA, suggesting that MGA may act as a tumor suppressor. Here, we characterize both the molecular and cellular role of MGA in lung adenocarcinomas and illustrate its functional relevance in the MYC pathway. Although MGA and MYC interact with the same binding partner, MAX, and recognize the same E-box DNA motif, we show that the molecular function of MGA appears to be antagonistic to that of MYC. Using mass spectrometry–based affinity proteomics, we demonstrate that MGA interacts with a noncanonical PCGF6-PRC1 complex containing MAX and E2F6 that is involved in gene repression, while MYC is not part of this MGA complex, in agreement with previous studies describing the interactomes of E2F6 and PCGF6. Chromatin immunoprecipitation-sequencing and RNA sequencing assays show that MGA binds to and represses genes that are bound and activated by MYC. In addition, we show that, as opposed to the MYC oncoprotein, MGA acts as a negative regulator for cancer cell proliferation. Our study defines a novel MYC/MAX/MGA pathway, in which MYC and MGA play opposite roles in protein interaction, transcriptional regulation, and cellular proliferation. Implications: This study expands the range of key cancer-associated genes whose dysregulation is functionally equivalent to MYC activation and places MYC within a linear pathway analogous to cell-cycle or receptor tyrosine kinase/RAS/RAF pathways in lung adenocarcinomas. |
| Databáze: | OpenAIRE |
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