口咽癌(oropharyngeal carcinoma)是一种高度异质性疾病,其主要病因是烟草、酒精的滥用或高危人类乳头瘤病毒(human papillomavirus,HPV)感染的结果。HPV阳性口咽癌与HPV阴性口咽癌存在明显的病因、流行病学、预后等方面的差异,因此治...口咽癌(oropharyngeal carcinoma)是一种高度异质性疾病,其主要病因是烟草、酒精的滥用或高危人类乳头瘤病毒(human papillomavirus,HPV)感染的结果。HPV阳性口咽癌与HPV阴性口咽癌存在明显的病因、流行病学、预后等方面的差异,因此治疗上应采取不同的方法。目前已知HPV阳性口咽癌对放射治疗敏感,认为其对放疗敏感可能通过多种机制共同完成。HPV阳性口咽癌存在低表达的野生肿瘤蛋白p35(tumor protein p53,TP53)基因,放射治疗可通过DNA双链断裂损伤方式激活p53并诱导细胞发生凋亡;细胞对DNA损伤存在常见的非同源末端连接(non⁃homologous end joining,NHEJ)修复路径,HPV癌蛋白抑制该路径可使肿瘤对放疗更为敏感;此外,免疫应答在放疗作用下进一步激活也参与对肿瘤的消除作用。本文就HPV阳性口咽癌对放疗敏感的研究进行综述,为未来临床上针对口咽癌不同致病因素及临床分期采取针对性的治疗手段提供科学依据。展开更多
AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity w...AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS： A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa （P〈0.00）. However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses （P〈0.001）. Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION： Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.展开更多
目的观察联合抑制聚腺苷酸二磷酸核糖转移酶-1[poly(ADP-ribose)polymerase-1,PARP-1]及DNA依赖蛋白激酶催化亚单位(catalytic sunbunit of the DNA-dependent protein kinase,DNA-PKcs)对依托泊苷(etoposide,VP-16)作用于急性髓系白血...目的观察联合抑制聚腺苷酸二磷酸核糖转移酶-1[poly(ADP-ribose)polymerase-1,PARP-1]及DNA依赖蛋白激酶催化亚单位(catalytic sunbunit of the DNA-dependent protein kinase,DNA-PKcs)对依托泊苷(etoposide,VP-16)作用于急性髓系白血病KG-1α细胞的影响。方法分别用特异性抑制剂奥拉帕尼(Olaparib,OLA)和Nu7441(NU)抑制PARP-1、DNA-PKcs。将KG-1α细胞设置成对照组、模型组、PARP-1抑制组(PARP-1 inhibition,VP-16+OLA)、DNA-PKcs抑制组(DNA-PKcs inhibition,VP-16+NU)、联合抑制组(combined inhibition,VP-16+OLA+NU)。用四甲基偶氮唑蓝(MTT)法体外检测联合用药对KG-1α细胞增殖抑制的影响;用高内涵荧光成像检测分析不同处理组的γ-H2AX在DNA双链断裂断裂位点的募集情况;用蛋白质印迹法检测细胞凋亡相关蛋白Cleaved caspase-3和Cleaved PARP的表达情况。结果对照组、模型组、PARP-1抑制组、DNA-PKcs抑制组和联合抑制组的增殖抑制率分别为(1.16±1.45)%,(23.88±3.15)%,(28.12±2.28)%,(17.21±0.89)%和(60.72±4.38)%;γ-H2AX阳性细胞百分比分别为γ-H2 AX阳性细胞百分比分别为(1.24±0.07)%,(22.51±2.24)%,(24.55±3.29)%,(23.28±2.48)%和(40.55±1.61)%;Cleaved Caspase-3蛋白相对表达量分别为0.16±0.10,0.61±0.30,1.15±0.64,1.11±0.31和1.72±1.03;Cleaved PARP蛋白相对表达量分别为1.23±0.09,1.45±0.55,2.03±0.84,2.08±0.41和2.66±0.95。模型组分别与对照组、联合抑制组比较,差异均有统计学意义(均P<0.05)。结论联合抑制PARP-1及DNA-PKcs能够在体外增加KG-1α细胞对依托泊苷的敏感性。展开更多
文摘口咽癌(oropharyngeal carcinoma)是一种高度异质性疾病,其主要病因是烟草、酒精的滥用或高危人类乳头瘤病毒(human papillomavirus,HPV)感染的结果。HPV阳性口咽癌与HPV阴性口咽癌存在明显的病因、流行病学、预后等方面的差异,因此治疗上应采取不同的方法。目前已知HPV阳性口咽癌对放射治疗敏感,认为其对放疗敏感可能通过多种机制共同完成。HPV阳性口咽癌存在低表达的野生肿瘤蛋白p35(tumor protein p53,TP53)基因,放射治疗可通过DNA双链断裂损伤方式激活p53并诱导细胞发生凋亡;细胞对DNA损伤存在常见的非同源末端连接(non⁃homologous end joining,NHEJ)修复路径,HPV癌蛋白抑制该路径可使肿瘤对放疗更为敏感;此外,免疫应答在放疗作用下进一步激活也参与对肿瘤的消除作用。本文就HPV阳性口咽癌对放疗敏感的研究进行综述,为未来临床上针对口咽癌不同致病因素及临床分期采取针对性的治疗手段提供科学依据。
基金Supported by Italian Ministero della Salute, IRCCS, RC0302TG13 by Ministero dell'Istruzíone, Università e Ricerca scientifica e tecnologica (MIUR), COFIN2002, to the Universita Campus Bio-Medico
文摘AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS： A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa （P〈0.00）. However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses （P〈0.001）. Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION： Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.
文摘目的观察联合抑制聚腺苷酸二磷酸核糖转移酶-1[poly(ADP-ribose)polymerase-1,PARP-1]及DNA依赖蛋白激酶催化亚单位(catalytic sunbunit of the DNA-dependent protein kinase,DNA-PKcs)对依托泊苷(etoposide,VP-16)作用于急性髓系白血病KG-1α细胞的影响。方法分别用特异性抑制剂奥拉帕尼(Olaparib,OLA)和Nu7441(NU)抑制PARP-1、DNA-PKcs。将KG-1α细胞设置成对照组、模型组、PARP-1抑制组(PARP-1 inhibition,VP-16+OLA)、DNA-PKcs抑制组(DNA-PKcs inhibition,VP-16+NU)、联合抑制组(combined inhibition,VP-16+OLA+NU)。用四甲基偶氮唑蓝(MTT)法体外检测联合用药对KG-1α细胞增殖抑制的影响;用高内涵荧光成像检测分析不同处理组的γ-H2AX在DNA双链断裂断裂位点的募集情况;用蛋白质印迹法检测细胞凋亡相关蛋白Cleaved caspase-3和Cleaved PARP的表达情况。结果对照组、模型组、PARP-1抑制组、DNA-PKcs抑制组和联合抑制组的增殖抑制率分别为(1.16±1.45)%,(23.88±3.15)%,(28.12±2.28)%,(17.21±0.89)%和(60.72±4.38)%;γ-H2AX阳性细胞百分比分别为γ-H2 AX阳性细胞百分比分别为(1.24±0.07)%,(22.51±2.24)%,(24.55±3.29)%,(23.28±2.48)%和(40.55±1.61)%;Cleaved Caspase-3蛋白相对表达量分别为0.16±0.10,0.61±0.30,1.15±0.64,1.11±0.31和1.72±1.03;Cleaved PARP蛋白相对表达量分别为1.23±0.09,1.45±0.55,2.03±0.84,2.08±0.41和2.66±0.95。模型组分别与对照组、联合抑制组比较,差异均有统计学意义(均P<0.05)。结论联合抑制PARP-1及DNA-PKcs能够在体外增加KG-1α细胞对依托泊苷的敏感性。
