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Dai W, Jiang Y, Chen K, Qiu J, Sun J, Zhang W, Zhou X, Huang N, Li Y, Li W. Effect of etoposide-induced alteration of the Mdm2-Rb signaling pathway on cellular senescence in A549 lung adenocarcinoma cells. Oncol Lett 2017; 14:3935-3940. [PMID: 28959361 PMCID: PMC5607649 DOI: 10.3892/ol.2017.6684] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/17/2017] [Indexed: 11/06/2022] Open
Abstract
The present study aimed to investigate the effect of various concentrations of etoposide (VP-16) on the E3 ubiquitin-protein ligase Mdm2 (Mdm2)-retinoblastoma (Rb) signaling pathway in the cellular senescence of A549 lung adenocarcinoma cells. A549 cells were randomly divided into the following four groups: Control group (no treatment), group 1 (1 µmol/l VP-16), group 2 (5 µmol/l VP-16) and group 3 (25 µmol/l VP-16). Each group was cultured for 48 h after treatment prior to observation of the alterations to cellular morphology. The cell cycle distribution of each group was also detected by flow cytometry. In addition, the activity of cellular senescence-associated β-galactosidase, and the expression of Mdm2 and phosphorylated (p-) Rb protein, was measured. The percentage of senescent cells was significantly higher following VP-16 treatment compared with the control group. The percentage of G1 phase cells, and p-Rb protein and Mdm2 protein expression were also significantly different following VP-16 treatment compared with the control group. VP-16 increased the activity of β-galactosidase in the A459 cells. VP-16 also decreased the expression level of Mdm2 and p-Rb protein and inhibited cell cycle progression in G1. These results indicate that VP-16 induces the cellular senescence of A549 cells via the Mdm2-Rb signaling pathway. However, further investigations are required to validate the mechanisms underlying these effects of VP-16.
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Affiliation(s)
- Wenjing Dai
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Yi Jiang
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Kairong Chen
- Department of Respiration, People's Hospital of Meishan, Meishan, Sichuan 620000, P.R. China
| | - Jing Qiu
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Jian Sun
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Wei Zhang
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Xiafei Zhou
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Na Huang
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Yunhui Li
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Wancheng Li
- Department of Respiration, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
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Meyer RG, Korn S, Micke P, Becker K, Huber C, Wölfel T, Buhl R. An open-label, prospective phase I/II study evaluating the immunogenicity and safety of a ras peptide vaccine plus GM-CSF in patients with non-small cell lung cancer. Lung Cancer 2007; 58:88-94. [PMID: 17599645 DOI: 10.1016/j.lungcan.2007.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 05/03/2007] [Accepted: 05/13/2007] [Indexed: 01/08/2023]
Abstract
Mutations of the ras gene have been reported in 20-40% of NSCLC patients. If present, they are critical for the malignant phenotype of these tumors. Therefore, targeting them by specific vaccination is a promising therapeutic approach. In a clinical trial we screened for ras mutations in patients with NSCLC. Patients with ras-positive tumors were immunized six times intradermally with a mixture of seven peptides representing the most common ras mutations. Objectives of the study were the feasibility, efficacy and safety of the vaccination. In addition, the induction of a specific immune reaction was investigated by DTH tests, and the induction of peptide-specific T cells was tested in ex vivo IFN-gamma-ELISPOT assays. Five of 18 patients had ras mutations at codon 12. Four of these patients, all with adenocarcinomas (stage I: n=3, stage IV: n=1) entered the study. The patient with stage IV disease withdrew prematurely after the third application because of disease progression associated with pulmonary embolism. Ras-specific T cells were not detected ex vivo. However, one patient developed a positive DTH reaction after the fifth vaccination that increased after the sixth vaccination. Our results are in line with earlier trials reporting ras mutations in 20-40% of NSCLC patients. Vaccination with mutated ras peptides is feasible and well tolerated. One patient revealed a positive DTH test. An ex vivo detectable T cell response was not induced in any of the patients.
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Affiliation(s)
- Ralf G Meyer
- III. Medical Department, Mainz University Hospital, Langenbeckstrasse 1, 55101 Mainz, Germany
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