AIM:To investigate whether gene methylation in the peritoneal fluid (PF) predicts peritoneal recurrence in gastric cancer patients.METHODS: The gene methylation of CHFR (checkpoint with forkhead and ring finger domain...AIM:To investigate whether gene methylation in the peritoneal fluid (PF) predicts peritoneal recurrence in gastric cancer patients.METHODS: The gene methylation of CHFR (checkpoint with forkhead and ring finger domains), p16, RUNX3 (runt-related transcription factor 3), E-cadherin, hMLH1 (mutL homolog 1), ABCG2 (ATP-binding cassette, sub-family G, member 2) and BNIP3 (BCL2/adenovirus E1B 19 kDa interacting protein 3) were analyzed in 80 specimens of PF by quantitative methylation-specific polymerase chain reaction (PCR). Eighty patients were divided into 3 groups; Group A (n=35):the depth of cancer invasion was less than the muscularis propria; Group B (n=31): the depth of cancer invasion was beyond the muscularis propria. Both group A and B were diagnosed as no cancer cells in peritoneal cytology and histology; Group C (n=14): disseminated nodule was histologically diagnosed or cancer cells were cytologically defi ned in the peritoneal cavity.RESULTS: The positive rates of methylation in CHFR, E-cadherin and BNIP3 were significantly different among the 3 groups and increased in order of group A, B and C (0%,0% and 21% in CHFR, P<0.05; 20%, 45% and 50% in E-cadherin, P<0.05;26%,35% and 71% in BNIP3, P<0.05). In addition, the multigene methylation rate among CHFR, E-cadherin and BNIP3 was correlated with group A, B and C (9%,19% and 57%, P<0.001). Moreover, the prognosis was analyzed in group B, excluding 3 patients who underwent a non-curative resection. Two of the 5 patients with multigene methylation showed peritoneal recurrence after surgery, while those without or with a single gene methylation did not experience recurrence (P<0.05).CONCLUSION: This study suggested that gene methylation in the PF could detect occult neoplastic cells in the peritoneum and might be a risk factor for peritoneal metastasis.展开更多
AIM:To investigate p16 gene methylation and its expression in 30 patients with sporadic colorectal adenocarcinoma in a North Indian population. METHODS:Methylation specific polymerase chain reaction was used to detect...AIM:To investigate p16 gene methylation and its expression in 30 patients with sporadic colorectal adenocarcinoma in a North Indian population. METHODS:Methylation specific polymerase chain reaction was used to detect p16 gene methylation and immunohistochemistry was used to study the p16 expression in 30 sporadic colorectal tumors as well as adjoining and normal tissue specimens.RESULTS:Aberrant promoter methylation of p16 gene was detected in 12(40%)tumor specimens,whereas no promoter methylation was observed in adjoining and normal tissue.Immunohistochemistry showed expression of p16 protein in 26(86.6%)colorectal tumors whereas complete loss of expression was seen in 4(13.3%)and reduced expression was observed in 12(40%)tumors. In the adjoining mucosa,expression of p16 was in 11 (36.6%)whereas no clear positivity for p16 protein was seen in normal tissue.There was a significant difference in the expression of p16 protein in tumor tissue and adjoining mucosa(P<0.001).The methylation of the p16 gene had a significant effect on the expression of p16 protein(P=0.021).There was a significant association of methylation of p16 gene with the tumor size (P=0.015)and of the loss/reduced expression of p16 protein with the proximal site of the tumor(P=0.047). Promoter methylation and expression of p16 had no relation with the survival of the patients(P>0.05). CONCLUSION:Our study demonstrated that promoter hypermethylation of the p16 gene results in loss/reduced expression of p16 protein and this loss/reduced expression may contribute to tumor enlargement.展开更多
AIM: To investigate clarithromycin resistance positions 2142, 2143 and 2144 of the 23 Sr RNA gene in Helicobacter pylori(H. pylori) by nested-allele specific primer-polymerase chain reaction(nested-ASP-PCR).METHODS: T...AIM: To investigate clarithromycin resistance positions 2142, 2143 and 2144 of the 23 Sr RNA gene in Helicobacter pylori(H. pylori) by nested-allele specific primer-polymerase chain reaction(nested-ASP-PCR).METHODS: The gastric tissue and saliva samples from 99 patients with positive results of the rapid urease test(RUT) were collected. The nested-ASP-PCR method was carried out with the external primers and inner allele-specific primers corresponding to the reference strain and clinical strains. Thirty gastric tissue and saliva samples were tested to determine the sensitivity of nested-ASP-PCR and ASP-PCR methods. Then, clarithromycin resistance was detected for 99 clinical samples by using different methods, including nestedASP-PCR, bacterial culture and disk diffusion. RESULTS: The nested-ASP-PCR method was successfully established to test the resistance mutation points 2142, 2143 and 2144 of the 23 SrR NA gene of H. pylori. Among 30 samples of gastric tissue and saliva, the H. pylori detection rate of nested-ASP-PCR was 90% and 83.33%, while the detection rate of ASP-PCR was just 63% and 56.67%. Especially in the saliva samples, nested-ASP-PCR showed much higher sensitivity in H. pylori detection and resistance mutation rates thanASP-PCR. In the 99 RUT-positive gastric tissue and saliva samples, the H. pylori-positive detection rate by nested-ASP-PCR was 87(87.88%) and 67(67.68%), in which there were 30 wild-type and 57 mutated strains in gastric tissue and 22 wild-type and 45 mutated strains in saliva. Genotype analysis showed that three-points mixed mutations were quite common, but different resistant strains were present in gastric mucosa and saliva. Compared to the high sensitivity shown by nested-ASP-PCR, the positive detection of bacterial culture with gastric tissue samples was 50 cases, in which only 26 drug-resistant strains were found through analyzing minimum inhibitory zone of clarithromycin. CONCLUSION: The nested-ASP-PCR assay showed higher detection sensitivity than ASP-PCR and drug sensitivity testing, which could be performed to evaluate clarithromycin resistance of H. pylori.展开更多
AIM: To evaluate tumor necrosis factor-α converting enzyme(TACE) methylation status in patients with chronic hepatitis B(CHB).METHODS: Eighty patients with hepatitis B e antigen(HBe Ag)-positive CHB, 80 with HBe Ag-n...AIM: To evaluate tumor necrosis factor-α converting enzyme(TACE) methylation status in patients with chronic hepatitis B(CHB).METHODS: Eighty patients with hepatitis B e antigen(HBe Ag)-positive CHB, 80 with HBe Ag-negative CHB, and 40 healthy controls(HCs) were randomly enrolled in this study. Genomic DNA was extracted from peripheral blood mononuclear cells and methylation status of TACE promoter was determined by methylation-specific polymerase chain reaction. The clinical and laboratory parameters were collected.RESULTS: One hundred and thirty of 160 patients with CHB(81.25%) and 38 of 40 HCs(95%) displayed TACE promoter methylation. The difference was significant(χ2 = 4.501, P < 0.05). TACE promoter methylation frequency in HBe Ag-positive CHB(58/80, 72.5%) was significantly lower than that in HBe Ag-negative CHB(72/80, 90%; χ2 = 8.041, P < 0.01) and HCs(χ2 = 8.438, P < 0.01). However, no significant difference was observed in the methylation frequency between HBe Agnegative CHB and HCs(χ2 = 0.873, P > 0.05). In the HBe Ag-positive group, TACE methylation frequency was significantly negatively correlated with HBe Ag(r =-0.602, P < 0.01), alanine aminotransferase(r =-0.461, P < 0.01) and aspartate aminotransferase(r =-0.329, P < 0.01). CONCLUSION: Patients with HBe Ag-positive CHB have aberrant demethylation of the TACE promoter, which may potentially serve as a biomarker for HBe Ag seroconversion.展开更多
基金Supported by Fund from the Department of Surgery,Saga University Faculty of Medicine
文摘AIM:To investigate whether gene methylation in the peritoneal fluid (PF) predicts peritoneal recurrence in gastric cancer patients.METHODS: The gene methylation of CHFR (checkpoint with forkhead and ring finger domains), p16, RUNX3 (runt-related transcription factor 3), E-cadherin, hMLH1 (mutL homolog 1), ABCG2 (ATP-binding cassette, sub-family G, member 2) and BNIP3 (BCL2/adenovirus E1B 19 kDa interacting protein 3) were analyzed in 80 specimens of PF by quantitative methylation-specific polymerase chain reaction (PCR). Eighty patients were divided into 3 groups; Group A (n=35):the depth of cancer invasion was less than the muscularis propria; Group B (n=31): the depth of cancer invasion was beyond the muscularis propria. Both group A and B were diagnosed as no cancer cells in peritoneal cytology and histology; Group C (n=14): disseminated nodule was histologically diagnosed or cancer cells were cytologically defi ned in the peritoneal cavity.RESULTS: The positive rates of methylation in CHFR, E-cadherin and BNIP3 were significantly different among the 3 groups and increased in order of group A, B and C (0%,0% and 21% in CHFR, P<0.05; 20%, 45% and 50% in E-cadherin, P<0.05;26%,35% and 71% in BNIP3, P<0.05). In addition, the multigene methylation rate among CHFR, E-cadherin and BNIP3 was correlated with group A, B and C (9%,19% and 57%, P<0.001). Moreover, the prognosis was analyzed in group B, excluding 3 patients who underwent a non-curative resection. Two of the 5 patients with multigene methylation showed peritoneal recurrence after surgery, while those without or with a single gene methylation did not experience recurrence (P<0.05).CONCLUSION: This study suggested that gene methylation in the PF could detect occult neoplastic cells in the peritoneum and might be a risk factor for peritoneal metastasis.
基金Supported by A Senior Research Fellowship of Postgraduate Institute of Medical Education and Research,Chandigarh,India
文摘AIM:To investigate p16 gene methylation and its expression in 30 patients with sporadic colorectal adenocarcinoma in a North Indian population. METHODS:Methylation specific polymerase chain reaction was used to detect p16 gene methylation and immunohistochemistry was used to study the p16 expression in 30 sporadic colorectal tumors as well as adjoining and normal tissue specimens.RESULTS:Aberrant promoter methylation of p16 gene was detected in 12(40%)tumor specimens,whereas no promoter methylation was observed in adjoining and normal tissue.Immunohistochemistry showed expression of p16 protein in 26(86.6%)colorectal tumors whereas complete loss of expression was seen in 4(13.3%)and reduced expression was observed in 12(40%)tumors. In the adjoining mucosa,expression of p16 was in 11 (36.6%)whereas no clear positivity for p16 protein was seen in normal tissue.There was a significant difference in the expression of p16 protein in tumor tissue and adjoining mucosa(P<0.001).The methylation of the p16 gene had a significant effect on the expression of p16 protein(P=0.021).There was a significant association of methylation of p16 gene with the tumor size (P=0.015)and of the loss/reduced expression of p16 protein with the proximal site of the tumor(P=0.047). Promoter methylation and expression of p16 had no relation with the survival of the patients(P>0.05). CONCLUSION:Our study demonstrated that promoter hypermethylation of the p16 gene results in loss/reduced expression of p16 protein and this loss/reduced expression may contribute to tumor enlargement.
基金the Hospital of Qixia in Nanjing for providing sufficient financial support for this study
文摘AIM: To investigate clarithromycin resistance positions 2142, 2143 and 2144 of the 23 Sr RNA gene in Helicobacter pylori(H. pylori) by nested-allele specific primer-polymerase chain reaction(nested-ASP-PCR).METHODS: The gastric tissue and saliva samples from 99 patients with positive results of the rapid urease test(RUT) were collected. The nested-ASP-PCR method was carried out with the external primers and inner allele-specific primers corresponding to the reference strain and clinical strains. Thirty gastric tissue and saliva samples were tested to determine the sensitivity of nested-ASP-PCR and ASP-PCR methods. Then, clarithromycin resistance was detected for 99 clinical samples by using different methods, including nestedASP-PCR, bacterial culture and disk diffusion. RESULTS: The nested-ASP-PCR method was successfully established to test the resistance mutation points 2142, 2143 and 2144 of the 23 SrR NA gene of H. pylori. Among 30 samples of gastric tissue and saliva, the H. pylori detection rate of nested-ASP-PCR was 90% and 83.33%, while the detection rate of ASP-PCR was just 63% and 56.67%. Especially in the saliva samples, nested-ASP-PCR showed much higher sensitivity in H. pylori detection and resistance mutation rates thanASP-PCR. In the 99 RUT-positive gastric tissue and saliva samples, the H. pylori-positive detection rate by nested-ASP-PCR was 87(87.88%) and 67(67.68%), in which there were 30 wild-type and 57 mutated strains in gastric tissue and 22 wild-type and 45 mutated strains in saliva. Genotype analysis showed that three-points mixed mutations were quite common, but different resistant strains were present in gastric mucosa and saliva. Compared to the high sensitivity shown by nested-ASP-PCR, the positive detection of bacterial culture with gastric tissue samples was 50 cases, in which only 26 drug-resistant strains were found through analyzing minimum inhibitory zone of clarithromycin. CONCLUSION: The nested-ASP-PCR assay showed higher detection sensitivity than ASP-PCR and drug sensitivity testing, which could be performed to evaluate clarithromycin resistance of H. pylori.
基金Supported by Key Project of Chinese Ministry of Science and Technology,No.2012ZX10002007 and No.2013ZX10002001National Natural Science Foundation of China,No.81171579,No.81201287 and No.81371832Science and Technology Development Plan of Shandong Province,China,No.2014GSF118068
文摘AIM: To evaluate tumor necrosis factor-α converting enzyme(TACE) methylation status in patients with chronic hepatitis B(CHB).METHODS: Eighty patients with hepatitis B e antigen(HBe Ag)-positive CHB, 80 with HBe Ag-negative CHB, and 40 healthy controls(HCs) were randomly enrolled in this study. Genomic DNA was extracted from peripheral blood mononuclear cells and methylation status of TACE promoter was determined by methylation-specific polymerase chain reaction. The clinical and laboratory parameters were collected.RESULTS: One hundred and thirty of 160 patients with CHB(81.25%) and 38 of 40 HCs(95%) displayed TACE promoter methylation. The difference was significant(χ2 = 4.501, P < 0.05). TACE promoter methylation frequency in HBe Ag-positive CHB(58/80, 72.5%) was significantly lower than that in HBe Ag-negative CHB(72/80, 90%; χ2 = 8.041, P < 0.01) and HCs(χ2 = 8.438, P < 0.01). However, no significant difference was observed in the methylation frequency between HBe Agnegative CHB and HCs(χ2 = 0.873, P > 0.05). In the HBe Ag-positive group, TACE methylation frequency was significantly negatively correlated with HBe Ag(r =-0.602, P < 0.01), alanine aminotransferase(r =-0.461, P < 0.01) and aspartate aminotransferase(r =-0.329, P < 0.01). CONCLUSION: Patients with HBe Ag-positive CHB have aberrant demethylation of the TACE promoter, which may potentially serve as a biomarker for HBe Ag seroconversion.
