Role of MYADM in the cholesterol mediated proliferation and metastasis of lung adenocarcinoma
10.3760/cma.j.cn112152-20250304-00085
- VernacularTitle:髓系相关分化标志物在胆固醇介导的肺腺癌增殖和转移中的作用
- Author:
Yuan ZHAO
1
;
Lizhen ZHANG
;
Guangdong CHENG
;
Yawei SUN
;
Jinben MA
;
Yanliang LIN
Author Information
1. 山东第一医科大学附属山东省立医院中心实验室，济南250021
- Publication Type:Journal Article
- Keywords:
Pulmonary adenocarcinoma;
Cholesterol;
Myeloid associated differentiation marker (MYADM);
Monocarboxylate transporter 1 (MCT1);
Proliferation;
Metastasis
- From:
Chinese Journal of Oncology
2025;47(11):1080-1093
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the role and related mechanism of myeloid related differentiation markers (MYADM) in lung adenocarcinoma metastasis induced by high cholesterol diet.Methods:(1) Cell experiments: Using lung adenocarcinoma A549 and H1975 cells, the cells were treated with 0.8 mg/ml cholesterol and then transfected with a lentivirus to knock down MYADM. The overexpression of MYADM was achieved by transfecting the cells with an overexpression plasmid. Western blotting was used to detect the expression levels of MYADM, E-cadherin, β-catenin, MMP-2, MMP-9, and vimentin in the cells. The proliferation ability of the cells was assessed using the plate clonal formation assay, while the migration and invasion ability were evaluated using the Transwell assay. Western blot was used to determine the effects of MYADM knockdown or overexpression on these proteins. Western blot and immunofluorescence assays were conducted to investigate the impact of Akt phosphorylation on the expression of MYADM and Rac1 in cholesterol-treated lung adenocarcinoma cells, as well as the phosphorylation of c-Myc. Western blot was also used to assess the effect of c-Myc knockdown on the expression of MYADM and MCT1 in lung adenocarcinoma cells. Chromatin immunoprecipitation (ChIP) assays were performed to investigate the impact of cholesterol on the binding between c-Myc and the promoters of MYADM and MCT1 in lung adenocarcinoma cells. (2) Animal experiment: A549 cells or A549 cells with MYADM knockdown were intravenously inoculated into BALB/c nude mice, which were then divided into a normal diet group and a high cholesterol diet group. Using a live imaging system, the growth and metastasis of tumors in the mice were monitored. After 42 days, lung tissues were collected for immunohistochemical staining to detect changes in relevant proteins.Results:After cholesterol treatment, the expression level of MYADM in A549 cells increased from 1.00±0.18 to 3.28±0.28 ( P<0.001), and in H1975 cells, it increased from 1.00±0.06 to 2.03±0.10 ( P<0.001). Compared with the control group, the expression of E-cadherin in lung adenocarcinoma cells after MYADM knockdown increased ( P<0.01), while the expressions of β-catenin, MMP-2, MMP-9, and vimentin decreased (all P<0.01). After MYADM knockdown, the number of clonal plates decreased in A549 cells (203±23 vs 60±18, t=8.48, P=0.001) and H1975 cells (298±64 vs 137±51, t=3.41, P=0.271). The number of invasive cells also decreased in A549 cells (212±18 vs 99±34, t=5.09, P=0.007) and H1975 cells (268±34 vs 134±14, t=6.31, P=0.003). Additionally, the number of migratory cells decreased in A549 cells (353±37 vs 124±29, t=8.44, P=0.001) and H1975 cells (279±41 vs 79±19, t=7.67, P=0.002). In the lung adenocarcinoma cells overexpressing MYADM, the expression of E-cadherin decreased ( P<0.01), while the levels of β-catenin, MMP-2, MMP-9, and vimentin increased (all P<0.01). The number of plate clonal colonies formed by lung adenocarcinoma cells overexpressing MYADM increased significantly in A549 cells, (94±26 vs 298±34, t=8.26, P=0.001) and H1975 cells (83±13 vs 331±24, t=15.74, P<0.001). The number of invasive A549 cells also increased (118±17 vs 193±24, t=4.41, P=0.012) and (156±19 vs 321±12, t=12.72, P<0.001). Additionally, the number of migrating cells increased in A549 cells (171±22 vs 284±15, t=7.35, P=0.002) and in H1975 cells (178±7 vs 263±12, t=10.6, P<0.001). Experiments related to the molecular mechanism showed that overexpression of MYADM promotes the expression of MCT1 in lung adenocarcinoma cells (all P<0.01). Cholesterol not only enhances the expression of MYADM in lung adenocarcinoma cells, but also boosts the expression of Rac1 and MCT1, as well as the phosphorylation of Akt and c-Myc (all P<0.05). Immunoprecipitation experiments revealed that in A549 cells treated with cholesterol, MYADM-Rac1 interaction levels increased from (100.0±15.9)% to (191.0±26.7)% ( P=0.007), while in H1975 cells, the levels increased from (100.0±18.2)% to (170.0±27.5)% ( P=0.021). ChIP confirmed that cholesterol treatment enhances the binding of c-Myc to the promoters of MYADM and MCT1. In vivo experiments demonstrated that a high-cholesterol diet promotes the metastasis of lung adenocarcinoma cells in mice, inducing the expression of MYADM, MCT1, and Rac1, as well as the phosphorylation of Akt and c-Myc in mouse lung tissue. Conversely, knocking down MYADM inhibits the metastasis of lung adenocarcinoma cells in mice, suppressing the expression of MYADM, MCT1, and Rac1, as well as the phosphorylation of Akt and c-Myc in mouse lung tissues. Conclusion:Cholesterol may induce lung adenocarcinoma cells proliferation and metastasis by regulating the MYADM/Rac1/Akt/c-Myc/MCT1 axis.
