ABSTRACT
Objective The mechanisms of PCDHA13 promoter methylation in breast cancer have not yet been elucidated at present. This study was to investigate the role of PCDHA13 gene promoter methylation in the development of breast cancer.Methods The methylation state of PCDHA13 gene promoter in human breast cancer tissues was detected by MassARRAY mass spectrum methylation sequencing. 100μmol/L 5-Aza was prepared with culture medium. The ZR-75-1 cells with 60% cell confluence were added to the final concentration of 5 μmol/L(low concentration group) and 10 μmol/L(high concentration group) 5-Aza, and the control group was only added culture medium. Detection of methylation status of PCDHA13 gene promoter in human breast cancer cells by bisulfite sequencing and methylation-specific PCR, and analysis of methylation status and mRNA expression of PCDHA13 gene by semi-quantitative RT-PCR. Western blot, MTT and DAPI staining were used to detect the effect of 5-Aza treatment on proliferation and apoptosis of breast cancer ZR-75-1 cells.Results The methylation degree of PCDHA13 gene promoter in the 1, 4-6, 9, 10 and 11 CpG loci in breast cancer tissues was significantly higher than that in normal breast group \[(0.2639±0.1575) vs (0.1612±0.1706), (0.2509±0.1377) vs (0.1688±0.0992), (0.4204±0.2087) vs (0.2621±0.1731), (0.3761±0.1407) vs (0.2824±0.1486), (0.3922±0.1294) vs (0.3072±0.1496)\], and the difference was statistically significant (P0.05). The expression of PCDHA13 mRNA of ZR-75-1 cells was loss in control group, but the expression of PCDHA13 mRNA was reversed after treated with 5-Aza, and the expression of PCDHA13 mRNA was significantly higher in high concentration group than that in low concentration group(P>0.05). After treated with 5-Aza for 24, 48 and 72 hours, the growth inhibition rates were lower in low concentration group than that in high concentration group (P>0.05). The morphology of the nuclei was basically normal and there was no apoptosis occurred in ZR-75-1 cells. But after treated with 5-Aza, some ZR-75-1 cells showed nuclear condensation, chromatin agglutination and heavy coloration.Conclusion This study showed that the low expression or loss of mRNA is associated with hypermethylation of the PCDHA13 gene promoter in breast carcinoma. The PCHDA13 gene expression can be reversed by 5-Aza in ZR-75-1 cells. The re-expression of PCHAD13 not only inhibit the proliferation of cells, but also promote apoptosis. Abnormal methylation of PCDHA13 may become a potential tumor marker for breast cancer.
ABSTRACT
The intra-arterial thrombolysis is one of the most effective approaches in salvaging brain ischemic penumbra and treating acute cerebral infarction.However,because of the limita- tions of short time windows for treatment,intracerebral hemorrhage after thrombolysis and reocclusion,more clinical studies are needed before this technique is widely developed and applied.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effects of community intervention on risk factors of cerebrovascular disease.</p><p><b>METHODS</b>With cluster sampling, 2,586 and 2,723 women and men aged 35 to 74 were selected randomly as intervention cohort and control cohort, respectively, from about 300 thousand community population in Beijing, Shanghai and Changsha, during 1997 to 2000. Their blood pressure, levels of blood lipid, body mass index (BMI) were measured and status of smoking and alcohol consumption were surveyed as indices of evaluation. Health education for smoking quit, alcohol consumption restriction and reinforced treatment for diabetic and hypertensive patients were implemented in the intervention communities. And, 2,544 and 2,533 persons in the two cohorts responded three years after intervention, and then all the indices mentioned above were measure again for them.</p><p><b>RESULTS</b>Average reduction in systolic blood pressure by 3.21 mm Hg and serum level of total cholesterol by 0.58 mmol/L was achieved in intervention cohort after intervention, but with 0.48 mmol/L increase in triglyceride. Average blood levels of both high density lipoprotein-cholesterol (HDL-C) and glucose increased in the two cohorts after intervention, but with 0.30 mmol/L net increase of blood glucose in control cohort. There was no significant difference in average increase of HDL-C between the two cohorts. BMI increased by 0.56 in control cohort, and no significant change in intervention cohort. Proportion of smoking decreased by 5.4% in men and 2.4% in women of intervention cohort, and no change in control cohort.</p><p><b>CONCLUSION</b>Level of risk factors for cerebrovascular disease reduced significantly with community intervention.</p>