Mel-18, a Polycomb Group Protein, Regulates Cell Proliferation and Senescence Via Transcriptional Repression of Bmi-1 and C-Myc Oncoproteins
Overview
Molecular Biology
Affiliations
Polycomb group (PcG) protein Bmi-1 is an important regulator of cell proliferation. It regulates cellular senescence and proliferation of cells via the transcriptional repression of INK4a/ARF locus and other target genes. Here, we report that Mel-18, a PcG ring finger protein (PCGF) transcriptionally down-regulates Bmi-1. Furthermore, the expression of Bmi-1 and Mel-18 inversely correlates in proliferating and senescent human fibroblasts. Bmi-1 down-regulation by Mel-18 results in accelerated senescence and shortening of the replicative life span in normal human cells. Importantly, using promoter-reporter, chromatin immunoprecipitation, and quantitative real-time primary transcript RT-PCR assays, and an RNA interference approach, we demonstrate that Bmi-1 is a bona fide target of c-Myc oncoprotein. Finally, our data suggest that Mel-18 regulates Bmi-1 expression during senescence via down-regulation of c-Myc. These studies link c-Myc and polycomb function in cell proliferation and senescence.
Canonical and non-canonical PRC1 differentially contribute to regulation of neural stem cell fate.
Hoffmann J, Schutze T, Kolodziejczyk A, Kuster K, Krankel A, Reinhardt S Life Sci Alliance. 2025; 8(4).
PMID: 39933923 PMC: 11814486. DOI: 10.26508/lsa.202403006.
Balamurli G, Liew A, Tee W, Pervaiz S Redox Biol. 2024; 78:103441.
PMID: 39612910 PMC: 11629570. DOI: 10.1016/j.redox.2024.103441.
Acute Lymphoblastic Leukemia in a Pediatric Patient With Turnpenny-Fry Syndrome.
Patricio Rodrigues I, Teixeira B, Capela A, Almeida M, Falcao Reis C Cureus. 2024; 16(1):e53099.
PMID: 38283775 PMC: 10822196. DOI: 10.7759/cureus.53099.
Kim K, Moon K, Min K, Jung W, Shin S, Lee S J Pathol Clin Res. 2023; 9(3):236-248.
PMID: 36864013 PMC: 10073934. DOI: 10.1002/cjp2.315.
Bmi-1: A master regulator of head and neck cancer stemness.
Herzog A, Somayaji R, Nor J Front Oral Health. 2023; 4:1080255.
PMID: 36726797 PMC: 9884974. DOI: 10.3389/froh.2023.1080255.