鼻咽癌氧化性DNA损伤及其作用机制的研究

发布时间：2018-04-15 23:20

本文选题：鼻咽癌 + 氧化性DNA损伤　；参考：《广西医科大学》2010年硕士论文

【摘要】： 研究目的：运用双色免疫荧光组织化学方法以及酶联免疫吸附试验分别检测鼻咽癌鼻咽组织及血清中氧化性DNA损伤的情况,并且运用荧光原位杂交技术检测鼻咽癌组织中EB病毒感染的情况,初步探索鼻咽癌的发生和发展是否与氧化性DNA损伤有关及其损伤的可能原因和途径,以期寻找出能够辅助鼻咽癌诊断的生物标志物。方法： (1)选择57例鼻咽癌患者和39例慢性鼻咽炎患者鼻咽部组织,采用双色免疫荧光组织化学方法分别检测8-硝基鸟嘌呤(8-nitroguanine, 8-NitroG),8-羟基脱氧鸟苷(8-hydroxy-2'-deoxyguanosine,8-OHdG)和诱导型一氧化氮合酶(inducible nitric oxide synthase, iNOS)的免疫反应。秩和检验统计学方法分析鼻咽癌和慢性鼻咽炎鼻咽组织之间8-NitroG、8-OHdG和iNOS免疫反应强度的差异。 (2)从57例鼻咽癌中随机选择36例鼻咽癌患者和36例健康人血清标本,采用酶联免疫吸附试验方法(enzyme-linked immunosorbent assay, ELISA)检测血清中8-羟基脱氧鸟苷(8-OHdG)的表达水平。采用成组t检验进行数据的统计学分析。 (3)选择57例鼻咽癌患者和39例慢性鼻咽炎患者鼻咽部组织,采用双色免疫荧光组织化学方法分别检测磷酸化的信号转导及转录激活因子(phosphorylated signal transducers and activators of transcription, p-Stat3),表皮生长因子受体(epidermal growth factor receptor, EGFR)的免疫反应。秩和检验统计学方法分析鼻咽癌和慢性咽炎鼻咽组织之间p-Stat3.EGFR免疫反应强度的差异。 (4)选择57例鼻咽癌患者和39例慢性鼻咽炎患者鼻咽部组织,采用双色免疫荧光组织化学方法分别检测鼻咽癌组织中巨噬细胞的表面抗原CD68及其表达产物IL-6的免疫反应。秩和检验统计学方法分析鼻咽癌和慢性鼻咽炎鼻咽组织之间CD68、IL-6免疫反应强度的差异。 (5)选择57例鼻咽癌患者和39例慢性鼻咽炎患者鼻咽部组织,采用荧光原位杂交法(fluorescent in situ hybridization, FISH)检测鼻咽癌组织中EB病毒转录的核内小RNA(EBV encoded small RNAs, EBER)的免疫反应。秩和检验统计学方法分析鼻咽癌和慢性鼻咽炎鼻咽组织之间EB病毒免疫反应强度的差异。结果： (1)在鼻咽癌患者鼻咽部组织中观测到严重程度的DNA损伤。57例鼻咽癌组织细胞中8-NitroG、8-OHdG和iNOS均为强免疫反应,8-NitroG、8-OHdG阳性率100%,iNOS阳性率94.7%,与39例慢性鼻咽炎组织比较差异显著(P＜0.05)。 (2)36例鼻咽癌患者血清中8-OHdG的平均水平为0.538±0.336ng/ml,而对照组中36例健康人的血清中8-OHdG的平均水平为0.069±0.059ng/ml,鼻咽癌患者血清中8-OHdG水平与健康人比较差异显著(P＜0.05)。 (3)在鼻咽癌患者鼻咽部组织中观测到p-Stat3及EGFR强烈的免疫反应。鼻咽癌组织细胞中p-Stat3及EGFR观察到强免疫反应,p-Stat3、EGFR阳性率均为94.7%,与39例慢性鼻咽炎组织比较差异显著(P＜0.05)。 (4)在鼻咽癌患者鼻咽部组织中观测到CD68、IL-6强烈的免疫反应。57例鼻咽癌组织细胞中CD68、IL-6均为强免疫反应,CD68、IL-6阳性率100%,与39例慢性鼻咽炎组织比较差异显著(P＜0.05)。 (5)在鼻咽癌患者鼻咽部组织中观测到EBER强烈的反应。57例鼻咽癌组织细胞中EBER阳性率100%,均为EB病毒阳性,与39例慢性鼻咽炎组织比较差异显著(P＜0.05)。结论： (1)鼻咽癌组织中有氧化性DNA损伤存在。 (2)氧化性DNA损伤与iNOS的高表达有关。 (3)鼻咽部组织中由于细菌、病毒及寄生虫等引起的炎症反应等病理性刺激,可能会导致诱导型一氧化氮合酶(iNOS)催化产生一氧化氮(nitric oxide, NO),进而产生硝基化及氧化性DNA损伤,导致鼻咽癌的发生和发展。iNOS的高表达可能是由于EB病毒LMP1通过TRAFs上调EGFR表达,EGFR与特定配体EGF或TGF-a结合后,导致细胞内受体区自我磷酸化,并利用其本身的酪氨酸激酶活性活化Stat3 (p-Stat3),从而促进iNOS基因表达。诱导iNOS高表达的另一通路还可能是由于EB病毒作为抗原存在于鼻咽上皮细胞,导致鼻咽部巨噬细胞、T和B淋巴细胞、血管平滑肌细胞和中性粒细胞的聚集并分泌炎性细胞因子如IL-6,通过IL-6/gp130/Jak途径激活Stat3 (p-Stat3),p-Stat3促进iNOS基因表达。由于iNOS的高表达,细胞内NO活性氧增加,通过NO引起DNA损伤,最后诱发癌变。 (4) 8-NitroG、8-OHdG有望成为辅助诊断鼻咽癌的一个生物标志物。更好的理解鼻咽癌中氧化性DNA损伤的作用机制可以为通过分子水平调节炎症的过程以达到癌症预防的目的提供一个新的研究策略。
[Abstract]:Purpose of study :

Two - color immunofluorescence histochemistry and enzyme - linked immunosorbent assay ( ELISA ) were used to detect the oxidative DNA damage in nasopharyngeal tissues and serum of nasopharyngeal carcinoma ( NPC ) .

Method :

( 1 ) The immune responses of 8 - nitroguanine ( 8 - Nitrophenyl , 8 - NitroG ) , 8 - hydroxydeoxyguanosine ( 8 - hydroxy - 2 ' - deoxycytidine , 8 - OHdG ) and inducible nitric oxide synthase ( iNOS ) were detected by two - color immunofluorescence histochemical method in 57 patients with nasopharyngeal carcinoma and 39 patients with chronic rhinopharyngitis .

( 2 ) The expression level of 8 - hydroxydeoxyguanosine ( 8 - OHdG ) in serum was determined by enzyme - linked immunosorbent assay ( ELISA ) from 57 patients with nasopharyngeal carcinoma ( NPC ) and 36 healthy controls .

( 3 ) 57 patients with nasopharyngeal carcinoma and 39 patients with chronic rhinopharyngitis were selected to detect the phosphorylation signal transduction and transcription , p - Stat3 and epidermal growth factor receptor ( EGFR ) by two - color immunofluorescence histochemistry .

( 4 ) 57 patients with nasopharyngeal carcinoma and 39 patients with chronic rhinopharyngitis were selected , the surface antigen CD68 and its expression products IL - 6 were detected by two - color immunofluorescence histochemistry .

( 5 ) To investigate the immune response of EBV encoded small RNAs ( EBER ) and EBV encoded small RNAs ( EBER ) in nasopharyngeal carcinoma ( NPC ) by fluorescence in situ hybridization ( FISH ) in 57 patients with nasopharyngeal carcinoma and 39 patients with chronic rhinopharyngitis .

Results :

The expression of 8 - NitroG , 8 - OHdG and iNOS in 57 patients with NPC were strongly immune , 8 - NitroG , 8 - OHdG was 100 % , and the positive rate of iNOS was 94 . 7 % , which was significantly higher than that in 39 patients with chronic rhinopharyngitis ( P < 0.05 ) .

( 2 ) The average of 8 - OHdG in 36 patients with NPC was 0.538 卤 0.336ng / ml , while the average of 8 - OHdG was 0.069 卤 0.059ng / ml in 36 healthy controls .

( 3 ) p - Stat3 and EGFR were observed in the nasopharyngeal tissues of NPC patients . The positive rates of p - Stat3 and EGFR in NPC tissue cells were 94 . 7 % and 94 . 7 % respectively , compared with 39 patients with chronic rhinopharyngitis ( P < 0.05 ) .

( 4 ) CD68 and IL - 6 were observed in the nasopharyngeal tissues of NPC patients . The positive rates of CD68 and IL - 6 in 57 cases of NPC were strongly immune , and the positive rate of CD68 and IL - 6 was 100 % .

( 5 ) EBER was detected in the nasopharyngeal tissues of NPC patients . The positive rate of EBER in 57 cases of NPC was 100 % , which was EBV positive , which was significantly different from 39 cases of chronic rhinopharyngitis ( P < 0.05 ) .

Conclusion :

( 1 ) There is oxidative DNA damage in nasopharyngeal carcinoma .

( 2 ) Oxidative DNA damage is related to the high expression of iNOS .

( 3 ) The expression of inducible nitric oxide synthase ( iNOS ) in nasopharyngeal epithelial cells induced by bacteria , virus , parasite and so on may lead to nitric oxide ( NO ) induced by inducible nitric oxide synthase ( iNOS ) .

( 4 ) 8 - NitroG , 8 - OHdG is expected to be a biomarker for the diagnosis of nasopharyngeal carcinoma .

【学位授予单位】：广西医科大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R739.63

【参考文献】