ABSTRACT
OBJECTIVE@#To observe the effect of luteolin on the proliferation and expression of OPCML in breast cancer cell line MDA-MB-231.@*METHODS@#Cultured MDA-MB-231 cells were treated with luteolin at the concentrations of 5, 10 and 20 μmol/L for 24 or 48 h. MTT assay was used to detect cell proliferation and flow cytometry was used to detect the cell apoptosis. The expressions of OPCML mRNA and protein were detected using real-time quantitative PCR and Western blotting, respectively. OPCML gene methylation in the promoter region was detected using methylation-specific PCR (MSP), and the activity of methylase in the cells was analyzed.@*RESULTS@#MTT assay showed that treatment with luteolin at 5, 10 and 20 μmol/L for 24 h concentration-dependently decreased the viability of MDA-MB-231 cells ( < 0.05). Flow cytometry also showed that luteolin at different concentrations could induce apoptosis of MDA-MB-231 cells ( < 0.05). Luteolin dose-dependently induced the expression of OPCML mRNA and protein in MDA-MB-231 cells ( < 0.05), down-regulated the methylation status in the promoter region of OPCML gene, up-regulated the level of non-methylated OPCML, and reduced the activity of methylase in the cells ( < 0.05).@*CONCLUSIONS@#Luteolin inhibits the proliferation of MDA-MB-231 breast cancer cells probably by upregulating OPCML expression and its demethylation.
Subject(s)
Humans , Apoptosis , Breast Neoplasms , Cell Adhesion Molecules , Cell Line, Tumor , Cell Proliferation , GPI-Linked Proteins , LuteolinABSTRACT
Background: Promoter methylation of tumor suppressor genes (TSGs) is a well-reported portent in carcinogenesis; hence, it is worthy to investigate this in high-risk Northeast population of India. The study was designed to investigate methylation status of 94 TSGs in esophageal squamous cell carcinoma (ESCC). Further, the effect of OPCML promoter methylation on gene expression was analyzed by immunohistochemistry. Moreover, in silico protein–protein interactions were examined among 8 TSGs identified in the present study and 23 epigenetically regulated genes reported previously by our group in ESCC. Materials and Methods: Methylation profiling was carried out by polymerase chain reaction array and OPCML protein expression was examined by tissue microarray-based immunohistochemistry. Results: OPCML, NEUROG1, TERT, and WT1 genes were found hypermethylated and SCGB3A1, CDH1, THBS1, and VEGFA were hypomethylated in Grade 2 tumor. No significant change in OPCML expression was observed among control, Grade 1, and Grade 2 tumor. Conclusively, hypermethylation of the studied OPCML promoter in Grade 2 tumor produced no effect on expression. Unexpectedly, OPCML expression was downregulated in Grade 3 tumor in comparison to other groups signifying that downregulation of OPCML expression may lead to higher grade of tumor formation at the time of diagnosis of ESCC in patients. Significant interactions at protein level were found as VEGFA:PTK2, CTNNB1:CDH1, CTNNB1:VEGFA, CTNNB1:NEUROG1, CTNND2:CDH1, and CTNNB1:TERT. These interactions are pertinent to Wnt/β-catenin and TGF-β-Smad pathways. Conclusions: Deranged OPCML expression may lead to high-grade ESCC as well as epigenetically regulated genes, that is, CDH1, CTNNB1, CTNND2, THBS1, PTK2, WT1, OPCML, TGFB1, and SMAD4 may alter the Wnt/β-catenin and TGF-β-Smad pathways in ESCC. Further study of these genes could be useful to understand the molecular pathology of ESCC with respect to epithelial-mesenchymal transition (EMT) mediated by Wnt/β-catenin and TGF-β signaling pathways
ABSTRACT
Aim To study tumor suppressor gene OPCML,DAPK methylation changes during the process of CasKi cell apoptosis induced by trichosanthin, and to explore the correlation and the role between cervical cancer cell apoptosis and tumor suppressor gene methylation so as to find new demethylation drugs.Methods ① MTT was applied to assay the inhibition of TCS to CasKi cell proliferation and flow cytometry was used to analyze cervical CasKi cell apoptosis induced by trichosanthin; ② Methylation-specific PCR(MSP) technology was applied to detect cervical cancer and during cell apoptosis process OPCML and DAPK gene promoter methylation status of CpG islands.Results In CasKi cervical cancer cells,OPCML and DAPK gene promoter region showed a high degree of CpG island methylation status, by trichosanthin treatment,the growth of CasKi markedly was inhibited, and flow cytometry analysed the characteristic sub-G1 peak,OPCML and DAPK gene promoter region showed no CpG island methylation of performance.Conclusions During the process of CasKi cell apoptosis induced by trichosanthin,OPCML and DAPK gene demethylated significantly,accordingly, trichosanthin might be a new methylation inhibitor,and there might be some correlation between cell apoptosis and tumor suppressor gene methylation.And OPCML and DAPK gene methylation tests might become new clinical indicators for the early detection of cervical cancer.