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Objective To research the promoter methylation level of RAS association domain family 1A (RASSF1A) and RASSF1A gene mRNA expression level in cervical cancer tissue, and to analyze their relationships with clinicopathological parameters of cervical cancer and the clinical significance.Methods The RASSF1A gene promoter methylation and RASSF1A gene mRNA were detected respectively by methylation specific PCR and quantitative real-time PCR method in 40 cases of cervical cancer tissues and corresponding adjacent tissues.Results RASSF1A mRNA expression level in cervical cancer (0.26±0.05) was significantly lower than that in adjacent tissues (0.28±0.03), and the difference was statistically significant (t=2.27, P=0.026).The methylation rate of RASSF1A gene promoter region (0.71%±0.04%) was significantly higher than that in adjacent tissues (0.66%± 0.03%), and the difference was statistically significant (t=6.78, P=0.000).The expression of RASSF1A mRNA was significantly correlated with pathological differentiation (t=3.31, P=0.002), International Federation of Gynecology and Obstetrics (FIGO) stage (t=2.13, P=0.040), lymphatic metastasis (t=2.56, P=0.015).The promoter methylation level of RASSF1A gene was significantly correlated with pathological differentiation (t=2.08, P=0.045), FIGO stage (t=2.66, P=0.011), lymphatic metastasis (t=2.22, P=0.033), depth of invasion (t=2.12, P=0.041).Conclusion The RASSF1A gene promoter region methylation level and the RASSF1A gene mRNA expression level are associated with the malignant degree of cervical carcinoma.The RASSF1A gene promoter region methylation level may be used as a reference indicator for predicting the risk of metastasis of cervical cancer.
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Objective To evaluate the association between RASSF1A Ala133Ser single nucleotide polymorphism (SNP) and colorectal cancer (CRC) in patients of Han population in north China. Methods RASSF1A SNP was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 109 colon cancer (CC) patients, 67 rectal cancer (RC) patients and 189 age and sex matched healthy people (as controls). Unconditional logistic regression was used to analyze the gene-disease association and gene-sex interaction. Results The RASSF1A Ala133Ser SNP in CRC patients had no significant difference with that in normal control samples, but the interaction of genotype and sex existed in rectal cancer, Ala/Ser +Ser/Ser genotypes of RASSF1A gene increased the risk of rectal cancer in women (OR=3.78, 95%CI 1.31-10.89). Conclusion The RASSF1A 133Ser allele is associated with rectal cancer in women, but not colon cancer.
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Objective To investigate the promoter methylation status of Ras association domain family 1 isoform A (RASSFIA) and adenomatosis polyposis coli promoter (APC) and its association with prostate cancer (PCa), so as to pave a way for early diagnosis of Pea. Methods The prostatie tissues and clinical data were collected from 60 patients with prostate cancer and 40 patients with benign prostatie hyperplasia (BPH) tissues. Bisulphite Sequencing PCR was used to detect the promoter CpG methylation of RASSFIA and APC genes. Results The methylation rates of promoter CG sites of RASSFIA and APC genes in Pea group were significantly higher whan those in the BPH group (RASSFIA: 60. 8% vs 14%; APC: 48. 84% vs 1. 19%, P<0. 05). The methylation rates in RASSFIA and APC genes were significantly associated with PSA, Gleason score, pathologic stage and risk classification of PCa (P< 0.01). Combined detection of methylation status of RASSFIA and APC genes yielded a sensitivity of 95. 74% and a specificity of 82. 90% in differential diagnosis of PCa and BPH. Conclusion The promoter methylation of RASSFIA and APC genes are associated with the development and progression of PCa, and the changes of methylation rate is closely associated with risk classification of PCa. Combined detection of methylation in RASSFIA and APC genes may be a promising method for early diagnosis of prostate carcinoma.
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Objective To determine the aberrant methylation status of RASSF1A,p16 and DAPK gene promoter region in induced sputum from lung cancer patients and the value of their combined detection in diagnosing lung cancers. Methods Methylation-specific PCR (MSP) was used to detect the promoter methylation status of RASSF1A,p16, and DAPK genes in induced sputum and pathological tissues from 82 patients with lung cancers and 25 patients with pulmonary benign lesion.We also analyzed the relation between methylation status and clinical pathological data.Results The positive rates of promoter methylation of RASSF1A,p16, and DAPK genes in pathological tissues from patients with lung cancers were 63.4%,59.8%, and 58.5%, respectively,and those in induced sputum were 54.9%,48.8%,and 51.2%, respectively. The promoter methylation of RASSF1A,p16, and DAPK genes were not detected in patients with pulmonary benign lesion.There was a significant difference between the lung cancer group and pulmonary benign lesion group (P＜0.05). The methylation rate of RASSF1A gene was significantly lower in the middle and high differentiation and non-metastastic lymph node of lung cancer tissues than that in the poor differentiation and the metastatic lymph node of lung cancer tissues(P＜0.05), and was not correlated with age, sex, smoking index, clinical stage, and pathological types.The methylation rate of p16, and DAPK genes was not significantly correlated with all the above mentioned factors (P＞0.05). The methylation rate of joint detecting RASSF1A, p16, and DAPK genes was 73.2%. Conclusion Joint detection for promoter hypermethylation of RASSF1A, p16, and DAPK genes in induced sputum may be used as a simple and effective index of the diagnosis and prognose of lung cancers, and can improve the positive rate.
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0. 05). In glioma, the expression level was higher in glioblastornathan in oligodendroglial tumors (P = 0. 011). While the frequency of promoter methylation of RASSFof RASSF1A gene was 39. 3% . It was not found the promoter methylation in normal brain tissues and U251 cell line. In 11 patients with the aberrant promoter methylation, five showed the gene inactivation (P = 0. 022). Conclusion Aberrant promoter methylation was found in glioma. Although the gene inactivation of RASSF1 A was not so common in glioma, its expression was lower in glioma than in normal brain tissues. Promoter methylation may contribute to the low level or loss of RASSFT A mRNA expression.