AIM： To determine whether alteration of the mito- chondria DNA （mtDNA） copy number and its oxidative damage index （mtDNA△CT） can be detected by analysis of peripheral blood cells in hepatitis C virus （HCV）- in...AIM： To determine whether alteration of the mito- chondria DNA （mtDNA） copy number and its oxidative damage index （mtDNA△CT） can be detected by analysis of peripheral blood cells in hepatitis C virus （HCV）- infected patients. METHODS： This study enrolled two groups of pa- tients aged 40-60 years： a control group and an HCV- infected group in Department of Gastroenterology and Hepatology in Changhua Christian Hospital. Patients with co-infection with hepatitis B virus or human im- munodeficiency virus, autoimmune disease, malignant neoplasia, pregnancy, thyroid disease, or alcohol con- sumption 〉 40 g/d were excluded. HCV-infected pa- tients who met the following criteria were included： （1） positive HCV antibodies for 〉 6 mo; （2） alanine aminotransferase （ALT） levels more than twice the upper lim- it of normal on at least two occasions during the past 6 mo; and （3） histological fibrosis stage higher than F1. The mtDNA copy number and oxidative damage index of HCV mtDNA （mtDNA△CT） were measured in periph- eral blood leukocytes. The association between mtDNA copy number and mtDNA△CT was further analyzed using clinical data. RESULTS： Forty-seven normal controls （male/female： 26/21, mean age 50.51 ± 6.15 years） and 132 HCV- infected patients （male/female： 76/61, mean age 51.65 ± 5.50 years） were included in the study. The geno- types of HCV-infected patients include type 1a （n = 3）, type 1b （n = 83）, type 2a （n = 32）, and type 2b （n = 14）. Liver fibrosis stages were distributed as follows： F1/F2/F3/F4 = 1/61/45/25 and activity scores were A0/ A1/A2/A3 = 7/45/55/25. There were no age or gender differences between the two groups. HCV-infected pa- tients had higher hepatitis activity （aspartate transami- nase levels 108.77 ± 60.73 vs 23.19 ± 5.47, P 〈 0.01; ALT levels 168.69 ± 93.12 vs 23.15 ± 9.45, P 〈 0.01） and lower platelet count （170.40±58.00 vs 251.24 ± 63.42, P 〈 0.01） than controls. The mtDNA copy num- ber was lower in HCV-infected patients than in controls （173.49 vs 247.93, P 〈 0.05）. The mtDNA△CT was higher in HCV-infected patients than in controls （2.92 vs 0.64, P 〈 0.05）. To clarify the clinical significance of these results in HCV-infected patients, their association with different clinical parameters among HCV-infected pa- tients was analyzed. A negative association was found between mtDNA copy number and elevated aspartate transaminase levels （r = -0.17, P 〈 0.05）. Changes in mtDNA copy number were not associated with HCV RNA levels, HCV genotypes, liver fibrosis severity, or inflammatory activity in the liver biopsy specimen. How- ever, a correlation was observed between mtDNA△CT and platelet count （r = -0.22, P 〈 0.01）, HCV RNA level （r = 0.36, P 〈 0.01）, and hepatitis activity （r = 0.20, P = 0.02）. However, no difference in the change in mtDNA△CT was observed between different fibrosis stages or HCV CONCLUSION： Oxidative stress and mtDNA dam- age are detectable in patient＇s peripheral leukocytes. Increased leukocyte mtDNA△CT correlates with higher HCV viremia, increased hepatitis activity, and lower platelet count.展开更多
Recognition of DNA damage is a critical step for DNA damage-mediated cellular response. XPC is an important DNA damage recognition protein involved in nucleotide excision repair (NER). We have studied the XPC protein ...Recognition of DNA damage is a critical step for DNA damage-mediated cellular response. XPC is an important DNA damage recognition protein involved in nucleotide excision repair (NER). We have studied the XPC protein in cisplatin DNA damaging treatment-mediated cellular response. Comparison of the microarray data from both normal and XPCdefective human fibroblasts identified 861 XPC-responsive genes in the cisplatin treatment (with minimum fold change≥1.5).The cell cycle and cell proliferation-related genes are the most affected genes by the XPC defect in the treatment. Many other cellular function genes, especially the DNA repair and signal transduction-related genes, were also affected by the XPC defect in the treatment. To validate the microarray data, the transcription levels of some microarray-identified genes were also determined by an RT-PCR based real time PCR assay. The real time PCR results are consistent with the microarray data for most of the tested genes, indicating the reliability of the microarray data. To further validate the microarray data, the cisplatin treatment-mediated caspase-3 activation was also determined. The Western blot hybridization results indicate that the XPC defect greatly attenuates the cisplatin treatment-mediated Caspase-3 activation. We elucidated the role of p53 protein in the XPC protein DNA damage recognition-mediated signaling process. The XPC defect reduces the cisplatin treatment-mediated p53 response. These results suggest that the XPC protein plays an important role in the cisplatin treatment-mediated cellular response. It may also suggest a possible mechanism of cancer cell drug resistance.展开更多
基金Supported by Changhua Christian Hospital,99-CCH-IPR-12
文摘AIM： To determine whether alteration of the mito- chondria DNA （mtDNA） copy number and its oxidative damage index （mtDNA△CT） can be detected by analysis of peripheral blood cells in hepatitis C virus （HCV）- infected patients. METHODS： This study enrolled two groups of pa- tients aged 40-60 years： a control group and an HCV- infected group in Department of Gastroenterology and Hepatology in Changhua Christian Hospital. Patients with co-infection with hepatitis B virus or human im- munodeficiency virus, autoimmune disease, malignant neoplasia, pregnancy, thyroid disease, or alcohol con- sumption 〉 40 g/d were excluded. HCV-infected pa- tients who met the following criteria were included： （1） positive HCV antibodies for 〉 6 mo; （2） alanine aminotransferase （ALT） levels more than twice the upper lim- it of normal on at least two occasions during the past 6 mo; and （3） histological fibrosis stage higher than F1. The mtDNA copy number and oxidative damage index of HCV mtDNA （mtDNA△CT） were measured in periph- eral blood leukocytes. The association between mtDNA copy number and mtDNA△CT was further analyzed using clinical data. RESULTS： Forty-seven normal controls （male/female： 26/21, mean age 50.51 ± 6.15 years） and 132 HCV- infected patients （male/female： 76/61, mean age 51.65 ± 5.50 years） were included in the study. The geno- types of HCV-infected patients include type 1a （n = 3）, type 1b （n = 83）, type 2a （n = 32）, and type 2b （n = 14）. Liver fibrosis stages were distributed as follows： F1/F2/F3/F4 = 1/61/45/25 and activity scores were A0/ A1/A2/A3 = 7/45/55/25. There were no age or gender differences between the two groups. HCV-infected pa- tients had higher hepatitis activity （aspartate transami- nase levels 108.77 ± 60.73 vs 23.19 ± 5.47, P 〈 0.01; ALT levels 168.69 ± 93.12 vs 23.15 ± 9.45, P 〈 0.01） and lower platelet count （170.40±58.00 vs 251.24 ± 63.42, P 〈 0.01） than controls. The mtDNA copy num- ber was lower in HCV-infected patients than in controls （173.49 vs 247.93, P 〈 0.05）. The mtDNA△CT was higher in HCV-infected patients than in controls （2.92 vs 0.64, P 〈 0.05）. To clarify the clinical significance of these results in HCV-infected patients, their association with different clinical parameters among HCV-infected pa- tients was analyzed. A negative association was found between mtDNA copy number and elevated aspartate transaminase levels （r = -0.17, P 〈 0.05）. Changes in mtDNA copy number were not associated with HCV RNA levels, HCV genotypes, liver fibrosis severity, or inflammatory activity in the liver biopsy specimen. How- ever, a correlation was observed between mtDNA△CT and platelet count （r = -0.22, P 〈 0.01）, HCV RNA level （r = 0.36, P 〈 0.01）, and hepatitis activity （r = 0.20, P = 0.02）. However, no difference in the change in mtDNA△CT was observed between different fibrosis stages or HCV CONCLUSION： Oxidative stress and mtDNA dam- age are detectable in patient＇s peripheral leukocytes. Increased leukocyte mtDNA△CT correlates with higher HCV viremia, increased hepatitis activity, and lower platelet count.
文摘Recognition of DNA damage is a critical step for DNA damage-mediated cellular response. XPC is an important DNA damage recognition protein involved in nucleotide excision repair (NER). We have studied the XPC protein in cisplatin DNA damaging treatment-mediated cellular response. Comparison of the microarray data from both normal and XPCdefective human fibroblasts identified 861 XPC-responsive genes in the cisplatin treatment (with minimum fold change≥1.5).The cell cycle and cell proliferation-related genes are the most affected genes by the XPC defect in the treatment. Many other cellular function genes, especially the DNA repair and signal transduction-related genes, were also affected by the XPC defect in the treatment. To validate the microarray data, the transcription levels of some microarray-identified genes were also determined by an RT-PCR based real time PCR assay. The real time PCR results are consistent with the microarray data for most of the tested genes, indicating the reliability of the microarray data. To further validate the microarray data, the cisplatin treatment-mediated caspase-3 activation was also determined. The Western blot hybridization results indicate that the XPC defect greatly attenuates the cisplatin treatment-mediated Caspase-3 activation. We elucidated the role of p53 protein in the XPC protein DNA damage recognition-mediated signaling process. The XPC defect reduces the cisplatin treatment-mediated p53 response. These results suggest that the XPC protein plays an important role in the cisplatin treatment-mediated cellular response. It may also suggest a possible mechanism of cancer cell drug resistance.
