ABSTRACT
OBJECTIVE: To observe the expression of SFRP1 gene methylation in non-small cell lung cancer (NSCLC), and study the effect of 5-Aza-2-deoxycytidine (5-Aza-CdR) on DNA methylation and expression of SFRP1, p16 and MGMT genes in the human lung cancer cell line SPC-A-1 cells. METHODS: SP immunohistochemistry and methylation-specific PCR were used to detect the SFRP1 methylation in 60 NSCLC cases, and 21 cases of benign lung diseases were used as control group. SPC-A-1 cells were cultured and treated with 5-Aza-CdR. The promoter methylation status of SFRP1, p16 and MGMT genes were detected by methylation-specific polymerase (MSP) chain reaction, and mRNAs were detected by real-time PCR. RESULTS: The positive rate of SFRP1 gene methylation in NSCLC was significantly higher than that in normal lung tissue (58.3% vs. 14.3%; χ(2) = 12.118, P = 0.001). SFRP1 gene methylation was closely correlated with lymph node metastasis and degree of differentiation in NSCLC (P < 0.05). SFRP1 protein expression was correlated with clinical stage, degree of differentiation and lymph node metastasis in NSCLC (P < 0.05). The positive expression of SFRP1 protein in 30 cases of NSCLC tissue containing SFRP1 gene methylation was significantly higher than that in non-methylated NSCLC (68.6% vs. 24.0%; χ(2) = 9.613, P = 0.002). SFRP1 gene methylation was closely correlated with SFRP1 gene protein expression in NSCLC (P < 0.05). Negative expression of SFRP1 protein was correlated with the differentiation, clinical stage, and lymph node metastasis in NSCLC (all P < 0.05). Without 5-Aza-CdR treatment, the expressions of methylation of SFRP1, p16 and MGMT genes and their mRNA were low. After 5-Aza-CdR treatment at different concentrations, their expressions were significantly elevated (all P < 0.05). CONCLUSIONS: SFRP1 gene methylation is closely associated with carcinogenesis and development of NSCLC. 5-Aza-CdR may reverse the methylation of SFRP1, p16 and MGMT genes, and facilitate the re-expression of the anti-oncogenes.
Subject(s)
Antimetabolites, Antineoplastic/pharmacology , Azacitidine/analogs & derivatives , Carcinoma, Non-Small-Cell Lung/pathology , DNA Methylation , Intercellular Signaling Peptides and Proteins/metabolism , Lung Neoplasms/pathology , Membrane Proteins/metabolism , Azacitidine/pharmacology , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Differentiation , Cell Line, Tumor , Cyclin-Dependent Kinase Inhibitor p16/genetics , Cyclin-Dependent Kinase Inhibitor p16/metabolism , DNA Modification Methylases/antagonists & inhibitors , DNA Modification Methylases/genetics , DNA Modification Methylases/metabolism , DNA Repair Enzymes/genetics , DNA Repair Enzymes/metabolism , Decitabine , Female , Gene Expression Regulation, Neoplastic , Humans , Intercellular Signaling Peptides and Proteins/genetics , Lung Neoplasms/metabolism , Lymphatic Metastasis , Male , Membrane Proteins/genetics , Neoplasm Staging , RNA, Messenger/metabolism , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolismABSTRACT
AIM: To investigate the role of transglutaminase 3 (TGM3) gene in human esophageal squamous cell carcinoma (ESCC), and analyze its relationship with clinicopathological parameters. METHODS: Gene expression of TGM3 in fresh esophageal cancer tissues and their corresponding normal mucosas was detected immunohistochemically (IHC) by means of tissue microarray (TMA). Its correlation with clinical characteristics was evaluated and analyzed by univariate analysis. All statistical analyses were performed by SPSS version 10.0. RESULTS: Expression rate of TGM3 was reduced to 81.8% in ESCC. Expression of TGM3 was significantly inversely correlated with histological grade of esophageal carcinoma (in grade I, II and III tumors, the reduced expression was 4/7, 57/71, and 20/21, respectively, P < 0.05), whereas it had no obvious correlations with lymph node metastasis and depth of invasion. CONCLUSION: Reduced expression of TGM3 may play an important role in esophageal carcinogenesis.
Subject(s)
Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/physiopathology , Esophageal Neoplasms/genetics , Esophageal Neoplasms/physiopathology , Transglutaminases/metabolism , Adult , Aged , Biomarkers, Tumor/analysis , Carcinoma, Squamous Cell/pathology , Disease Progression , Esophageal Neoplasms/chemistry , Esophageal Neoplasms/pathology , Female , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , Male , Middle Aged , Neoplasm Staging , Oncogenes/genetics , Oncogenes/physiologyABSTRACT
AIM: To study the expression pattern of Ets-like protein 1 (Elk-1) in human esophageal squamous cell carcinoma (ESCC) and to analyze its relationship with clinicopathologic parameters. METHODS: The expression of Elk-1 in fresh esophageal cancer tissues and their corresponding normal mucosae was detected immunohistochemically (IHC) by means of tissue microarray (TMA). Its correlation with clinical characteristics was evaluated and analyzed by univariate analysis. All statistical analyses were performed by SPSS version 13.0. RESULTS: Expression level of transcription factor Elk-1 increased in 78.5% (84/107) ESCC tissues compared with their matched normal esophageal epithelium. However, the expression of Elk-1 did not show any obvious correlation with degree of differentiation of esophageal carcinoma (in well-differentiated, moderately-differentiated and poorly-differentiated tumors, the increased expression was 7/8, 60/74, and 19/25, respectively, P > 0.05). Moreover, no obvious correlation was found with lymph node metastasis and depth of invasion. CONCLUSION: Increased expression of transcription factor Elk-1 may play an important role in esophageal carcinogenesis.
