AIM： TO determine p15 promoter hypermethylation in gastric tumoral tissue and serum samples, its impact on p16-protein expression, and correlation with clinical and histological features. METHODS： Samples were obtai...AIM： TO determine p15 promoter hypermethylation in gastric tumoral tissue and serum samples, its impact on p16-protein expression, and correlation with clinical and histological features. METHODS： Samples were obtained from 52 histologically confirmed cases of gastric adenocarcinoma. Gastric tissue and serum of 50 age- and sex-matched individuals with normal gastroscopy and biopsy were obtained as control samples. Methylation-specific polymerase chain reaction （MSP） was used to evaluate methylation status of p16 promoter, p16-protein expression was analyzed by immunohistochemical staining on paraffin-embedded sections. RESULTS： Methylation was detected in 44.2% （23/52） of tumoral tissues. 60.9% of them were also methylated in serum, i.e., 26.9% of all patients （14/52）. Methylation was not detected in tissue and sera of control samples. p16-protein expression was decreased in 61.5% of cases （32/52）, and was significantly associated with promoter hypermethylation （P 〈 0.001）. Methylation was significantly more frequent in higher pathological grades （P 〈 0.05）. Methylation was not associated with other clinicopathological features and environmental factors including Hpylori infection and smoking. CONCLUSION： p16 promoter hypermethylation is an important event in gastric carcinogenesis. It is the principle mechanism of p16 gene silencing. It is related to malignant tumor behavior. Detection of DNA methylation in serum may be a biomarker for early detection of gastric cancer.展开更多
To determine the possible role of the epigenetic mechanisms in carcinogenesis of the hepatocellular carcinoma, we methylation-profiled the promoter CpG islands of twenty four genes both in HCC tumors and the neighbori...To determine the possible role of the epigenetic mechanisms in carcinogenesis of the hepatocellular carcinoma, we methylation-profiled the promoter CpG islands of twenty four genes both in HCC tumors and the neighboring non-cancerous tissues of twenty eight patients using the methylation-specific PCR (MSP) method in conjunction with the DNA sequencing. In comparison with the normal liver tissues from the healthy donors, it was found that while remained unmethylated the ABL, CAV, EPO, GATA3, LKB1, NEP, NFL, NIS and p27^(KIP1) genes, varying extents of the HCC specific hypermethylation were found associated with the ABO, AR, CSPG2, cyclin al, DBCCR1, GALR2, IRF7, MGMT, MT1A, MYOD1, OCT6, p57^(KIP2), p73, WT1 genes, and demethylation with the MAGEA1 gene, respectively. Judged by whether the hypermethylated occurred in HCC more frequently than in their neighboring normal tissues, the hypermethylation status of the AR, DBCCR1, IRF7, OCT6, and p73 genes was considered as the event specific to the late stage, while that the rest that lacked such a distinguished contrast, as the event specific to the early stage of HCC carcinogenesis. Among all the clinical pathological parameters tested for the association with, the hypermethylation of the cyclin al gene was more prevalent in the non-cirrhosis group (P=0.021) while the hypermethylated p16^(INK4a) gene was more common in the cirrhosis group (P=0.017). The concordant methylation behaviors of nineteen genes, including the four previously studied and their association with cirrhosis has been evaluated by the best subgroup selection method. The data presented in this report would enable us to shape our understanding of the mechanisms for the HCC specific loss of the epigenetic stability of the genome, as well as the strategy of developing the novel robust methylation based diagnostic and prognostic tools.展开更多
Objective To investigate the expression variation of RAR‐β2, RASSF1A, and CDKN2A gene in the process of nickel‐induced carcinogenesis. Methods Nickel subsulfide （Ni 3 S 2 ） at dose of 10 mg was given to Wistar ra...Objective To investigate the expression variation of RAR‐β2, RASSF1A, and CDKN2A gene in the process of nickel‐induced carcinogenesis. Methods Nickel subsulfide （Ni 3 S 2 ） at dose of 10 mg was given to Wistar rats by intramuscular injection. The mRNA expression of the three genes in induced tumors and their lung metastasis were examined by Real‐time PCR. The methylation status of the 5’ region of these genes were detected by Quantitative Real‐time methylation specific PCR. Results The mRNA expressions of the three genes both in muscle and lung tumor were decreased distinctly in comparison with normal tissue. But hypermethylation was found only in muscle tumor. Conclusion These findings suggest that loss of function or decrease of RAR‐β2, RASSF1A, and CDKN2A, as well as the hypermethylation of 5’ region of these genes, are related with nickel exposure.展开更多
Objective: The molecular mechanism of prostate cancer is poorly understood. The aim of the study was to investigate the prevalence and prognostic value of promoter hypermethylation of retinoic acid receptor beta (RARB...Objective: The molecular mechanism of prostate cancer is poorly understood. The aim of the study was to investigate the prevalence and prognostic value of promoter hypermethylation of retinoic acid receptor beta (RARB) and p16 among benign prostatic hyperplasia (BPH) and prostate cancer patients. Methods: In this case-control study, 63 patients were included in three groups; 21 with BPH as the control group, 21 with prostate cancer and good prognostic factors (based on prostate-specific antigen, Gleason score and stage) as good prognosis group, and 21 with prostate cancer and poor prognostic features as poor prognosis group. The prostate biopsy specimen of each individual was examined for hypermethylation of RARB and p16 promoters by methylation specific PCR (MSPCR). Results: Seven (33.3%) patients with good prognosis and 15 (71.4%) patients with poor prognosis were positive for RARB methylation, which were significantly higher than controls (P <0.0001). p16 promoter methylation was shown in 19.0% and 47.6% patients with good and poor prognosis, respectively. The RARB and p16 promoter methylation in the poor prognosis group was significantly higher than that in the good prognosis group (P =0.02 for RARB and P<0.0001 for p16). Conclusion: Hypermethylation of RARB and p16 promoters may predict prognosis in prostate cancer.展开更多
Objective： To study the methylation status of several genes on p53-Bax mitochondrial apoptosis pathway and clinical significance in cholangiocarcinoma. Methods： Promoter hypermethylation of DAPK, p14 and ASC genes w...Objective： To study the methylation status of several genes on p53-Bax mitochondrial apoptosis pathway and clinical significance in cholangiocarcinoma. Methods： Promoter hypermethylation of DAPK, p14 and ASC genes were detected by methylation-specific PCR. p53 gene status （exon 5-8） were examined by automated sequencing, combined with the clinical documents of patients by statistics analysis. Results： （1） We found 66.7% of 36 cases cholangiocarcinoma had methylation of at least one tumor suppressor gene. The frequency of tumor suppressor gene methylation in cholangiocarcinoma was： p14 （24%）, DAPK （30.6%）, TMSI/ASC （36.1%）. The frequency of tumor suppressor gene methylation in tissues near cancer was： DAPK （5.6%）, TMS1/ASC （8.3%）. （2） p53 gene mutations were found in 22 of 36 patients （61.1%）. （3） There were no statistically relationship among the methylation of DAPK, p14 and ASC genes. There were negative relationship differences between the methylation of p14 and p53 gene mutation （P 〈 0.05）. （4） p53 gene mutation combined with the methylation of tumor suppressor were 14 cases （38.9%）. There were statistically differences on extent of pathologic biology, differentiation and invasion （P 〈 0.05）. Conclusion： Our study indicated that methylation of p53-Bax mitochondrial apoptosis pathway in cholangiocarcinoma was a common epigenetic event. Although the methylation of ASC, DAPK genes was low, it might be significance for early diagnosis, p53 gene mutation combined with the methylation of tumor suppressor might be relationship with pathologic biology, it trended to more malignancy.展开更多
基金A grant offered by Mashhad University of Medical Sciences, No. 84129
文摘AIM： TO determine p15 promoter hypermethylation in gastric tumoral tissue and serum samples, its impact on p16-protein expression, and correlation with clinical and histological features. METHODS： Samples were obtained from 52 histologically confirmed cases of gastric adenocarcinoma. Gastric tissue and serum of 50 age- and sex-matched individuals with normal gastroscopy and biopsy were obtained as control samples. Methylation-specific polymerase chain reaction （MSP） was used to evaluate methylation status of p16 promoter, p16-protein expression was analyzed by immunohistochemical staining on paraffin-embedded sections. RESULTS： Methylation was detected in 44.2% （23/52） of tumoral tissues. 60.9% of them were also methylated in serum, i.e., 26.9% of all patients （14/52）. Methylation was not detected in tissue and sera of control samples. p16-protein expression was decreased in 61.5% of cases （32/52）, and was significantly associated with promoter hypermethylation （P 〈 0.001）. Methylation was significantly more frequent in higher pathological grades （P 〈 0.05）. Methylation was not associated with other clinicopathological features and environmental factors including Hpylori infection and smoking. CONCLUSION： p16 promoter hypermethylation is an important event in gastric carcinogenesis. It is the principle mechanism of p16 gene silencing. It is related to malignant tumor behavior. Detection of DNA methylation in serum may be a biomarker for early detection of gastric cancer.
基金supported by the National High Technology Research and Development Program of China(863 Program)(2001AA217011,2002AA2Z3352)the Major State Basic Research Development Program of China (973 Program)(G1998051004)the Science Foundation of Shanghai Municipal Government(02DJ14056)to JingDe ZHU.
文摘To determine the possible role of the epigenetic mechanisms in carcinogenesis of the hepatocellular carcinoma, we methylation-profiled the promoter CpG islands of twenty four genes both in HCC tumors and the neighboring non-cancerous tissues of twenty eight patients using the methylation-specific PCR (MSP) method in conjunction with the DNA sequencing. In comparison with the normal liver tissues from the healthy donors, it was found that while remained unmethylated the ABL, CAV, EPO, GATA3, LKB1, NEP, NFL, NIS and p27^(KIP1) genes, varying extents of the HCC specific hypermethylation were found associated with the ABO, AR, CSPG2, cyclin al, DBCCR1, GALR2, IRF7, MGMT, MT1A, MYOD1, OCT6, p57^(KIP2), p73, WT1 genes, and demethylation with the MAGEA1 gene, respectively. Judged by whether the hypermethylated occurred in HCC more frequently than in their neighboring normal tissues, the hypermethylation status of the AR, DBCCR1, IRF7, OCT6, and p73 genes was considered as the event specific to the late stage, while that the rest that lacked such a distinguished contrast, as the event specific to the early stage of HCC carcinogenesis. Among all the clinical pathological parameters tested for the association with, the hypermethylation of the cyclin al gene was more prevalent in the non-cirrhosis group (P=0.021) while the hypermethylated p16^(INK4a) gene was more common in the cirrhosis group (P=0.017). The concordant methylation behaviors of nineteen genes, including the four previously studied and their association with cirrhosis has been evaluated by the best subgroup selection method. The data presented in this report would enable us to shape our understanding of the mechanisms for the HCC specific loss of the epigenetic stability of the genome, as well as the strategy of developing the novel robust methylation based diagnostic and prognostic tools.
基金supported by the Natural Science Foundation of China (30570690 and 81041069)the Natural Science Foundation of Shanghai (08ZR1420700)
文摘Objective To investigate the expression variation of RAR‐β2, RASSF1A, and CDKN2A gene in the process of nickel‐induced carcinogenesis. Methods Nickel subsulfide （Ni 3 S 2 ） at dose of 10 mg was given to Wistar rats by intramuscular injection. The mRNA expression of the three genes in induced tumors and their lung metastasis were examined by Real‐time PCR. The methylation status of the 5’ region of these genes were detected by Quantitative Real‐time methylation specific PCR. Results The mRNA expressions of the three genes both in muscle and lung tumor were decreased distinctly in comparison with normal tissue. But hypermethylation was found only in muscle tumor. Conclusion These findings suggest that loss of function or decrease of RAR‐β2, RASSF1A, and CDKN2A, as well as the hypermethylation of 5’ region of these genes, are related with nickel exposure.
文摘Objective: The molecular mechanism of prostate cancer is poorly understood. The aim of the study was to investigate the prevalence and prognostic value of promoter hypermethylation of retinoic acid receptor beta (RARB) and p16 among benign prostatic hyperplasia (BPH) and prostate cancer patients. Methods: In this case-control study, 63 patients were included in three groups; 21 with BPH as the control group, 21 with prostate cancer and good prognostic factors (based on prostate-specific antigen, Gleason score and stage) as good prognosis group, and 21 with prostate cancer and poor prognostic features as poor prognosis group. The prostate biopsy specimen of each individual was examined for hypermethylation of RARB and p16 promoters by methylation specific PCR (MSPCR). Results: Seven (33.3%) patients with good prognosis and 15 (71.4%) patients with poor prognosis were positive for RARB methylation, which were significantly higher than controls (P <0.0001). p16 promoter methylation was shown in 19.0% and 47.6% patients with good and poor prognosis, respectively. The RARB and p16 promoter methylation in the poor prognosis group was significantly higher than that in the good prognosis group (P =0.02 for RARB and P<0.0001 for p16). Conclusion: Hypermethylation of RARB and p16 promoters may predict prognosis in prostate cancer.
基金Supported by a grant from Provinical Natural Science Foundation of Shandong Province,China (No.Y2008C82)
文摘Objective： To study the methylation status of several genes on p53-Bax mitochondrial apoptosis pathway and clinical significance in cholangiocarcinoma. Methods： Promoter hypermethylation of DAPK, p14 and ASC genes were detected by methylation-specific PCR. p53 gene status （exon 5-8） were examined by automated sequencing, combined with the clinical documents of patients by statistics analysis. Results： （1） We found 66.7% of 36 cases cholangiocarcinoma had methylation of at least one tumor suppressor gene. The frequency of tumor suppressor gene methylation in cholangiocarcinoma was： p14 （24%）, DAPK （30.6%）, TMSI/ASC （36.1%）. The frequency of tumor suppressor gene methylation in tissues near cancer was： DAPK （5.6%）, TMS1/ASC （8.3%）. （2） p53 gene mutations were found in 22 of 36 patients （61.1%）. （3） There were no statistically relationship among the methylation of DAPK, p14 and ASC genes. There were negative relationship differences between the methylation of p14 and p53 gene mutation （P 〈 0.05）. （4） p53 gene mutation combined with the methylation of tumor suppressor were 14 cases （38.9%）. There were statistically differences on extent of pathologic biology, differentiation and invasion （P 〈 0.05）. Conclusion： Our study indicated that methylation of p53-Bax mitochondrial apoptosis pathway in cholangiocarcinoma was a common epigenetic event. Although the methylation of ASC, DAPK genes was low, it might be significance for early diagnosis, p53 gene mutation combined with the methylation of tumor suppressor might be relationship with pathologic biology, it trended to more malignancy.
