BMI1 and Mel-18 Oppositely Regulate Carcinogenesis and Progression of Gastric Cancer
Overview
Oncology
Authors
Affiliations
Background: The BMI1 oncogene is overexpressed in several human malignancies including gastric cancer. In addition to BMI1, mammalian cells also express Mel-18, which is closely related to BMI1. We have reported that Mel-18 functions as a potential tumor suppressor by repressing the expression of BMI1 and consequent downregulation of activated AKT in breast cancer cells. However, the mechanisms of BMI1 overexpression and the role of Mel-18 in other cancers are still not clear. The purpose of this study is to investigate the role of BMI1 and Mel-18 in gastric cancer.
Results: BMI1 was found to be overexpressed in gastric cancer cell lines and gastric tumors. Overexpression of BMI1 correlated with advanced clinical stage and lymph node metastasis; while the expression of Mel-18 negatively correlated with BMI1. BMI1 but not Mel-18 was found to be an independent prognostic factor. Downregulation of BMI1 by Mel-18 overexpression or knockdown of BMI1 expression in gastric cancer cell lines led to upregulation of p16 (p16INK4a or CDKN2A) in p16 positive cell lines and reduction of phospho-AKT in both p16-positive and p16-negative cell lines. Downregulation of BMI1 was also accompanied by decreased transformed phenotype and migration in both p16- positive and p16-negative gastric cancer cell lines.
Conclusions: In the context of gastric cancer, BMI1 acts as an oncogene and Mel-18 functions as a tumor suppressor via downregulation of BMI1. Mel-18 and BMI1 may regulate tumorigenesis, cell migration and cancer metastasis via both p16- and AKT-dependent growth regulatory pathways.
Implication of protein post translational modifications in gastric cancer.
Song H, Zhang M, Guo C, Guo X, Ma Y, Ma Y Front Cell Dev Biol. 2025; 13:1523958.
PMID: 39968176 PMC: 11833226. DOI: 10.3389/fcell.2025.1523958.
Rawal C, Loubiere V, Butova N, Gracia J, Parreno V, Merigliano C Histochem Cell Biol. 2024; 162(1-2):133-147.
PMID: 38888809 PMC: 11227471. DOI: 10.1007/s00418-024-02302-z.
Rawal C, Loubiere V, Butova N, Garcia J, Parreno V, Martinez A Res Sq. 2024; .
PMID: 38746379 PMC: 11092839. DOI: 10.21203/rs.3.rs-4289524/v1.
Gao M, Zhang T, Chen T, Chen Z, Zhu Z, Wen Y Theranostics. 2024; 14(4):1371-1389.
PMID: 38389850 PMC: 10879878. DOI: 10.7150/thno.89878.
Basiri P, Afshar S, Amini R, Soltanian A, Saidijam M, Mahdavinezhad A Int J Mol Cell Med. 2023; 11(4):334-345.
PMID: 37727645 PMC: 10506674. DOI: 10.22088/IJMCM.BUMS.11.4.334.