鼻咽癌放疗前、中、后SOD和MT的动态变化及其意义初探

Changes of Superoxide Dismutase(SOD)and Metallothionien(MT )before,during,and after Radiother apy for Nasopharyngeal Carcinoma and Their Significance

背景与目的:超氧阴离子自由基()和羟自由基(OH·)在肿瘤放射治疗过程中起着重要作用,超氧化物歧化酶(superoxidedismutase,SOD)和金属硫蛋白(metallothionein,MT)是和OH·的主要清除酶。目前有关鼻咽癌(nasophary-ngealcarcinoma,NPC)与SOD和MT关系的研究报道极少。本研究旨在了解NPC放疗过程中患者血清SOD活性和肿瘤组织MT表达的动态变化及意义。方法:从2000年12月至2002年1月,分别采用黄嘌呤氧化酶法和免疫组化法检测46例NPC患者放疗前、中、后外周静脉血T-SOD活性及肿瘤组织MT表达的动态变化。取26例确诊未患癌症者作为正常检测对照。结果:32例患者完成了3次T-SOD动态检测,放疗前T-SOD活性为(83.9±19.6)UN/ml,明显低于正常对照的(96.8±23.6)UN/ml(P<0.05)。放疗前、中、后血清T-SOD活性变化:早期(Ⅰ期)患者分别为(77.6±19.1)UN/ml、(87.1±18.6)UN/ml和(96.3±31.6)UN/ml(P>0.05);晚期(Ⅳ期)为(80.1±15.0)UN/ml、(78.0±35.4)UN/ml和(110.6±72.0)UN/ml(P>0.05);放疗近期疗效达CR患者为(79.8±18.2)UN/ml、(87.2±31.7)UN/ml和(94.8±36.3)UN/ml(P>0.05);PR为(98.5±18.6)UN/ml、(62.9±35.3)UN/ml和(79.2±27.3)UN/ml(P>0.05)。其中,27例NPC患者完成了3次MT检测,放疗前NPC组织MT表达率为(39.

BACKGROUND &OBJECTIVE:The superoxide anion()and the hydroxyl radical (OH · )play an important role in the radioth erapy of tumors.The superoxide dismutase(SOD)and the metallothionien(MT )are the main enzymes to clear the and OH · .Up to now,there are few reports on th e relationship between the nasophary ng eal carcinoma (NPC)and SOD or MT.This study was conducted to observe the dy namic chang es of the activity of tota l superoxide dismutase(T-SOD)in the serum and the expression of MT i n the tissue from the NPC patients treated with radiotherapy.METHODS :From December 2000to January 2002,46pat ients with NPC were selected randoml y to test the activity of T-SOD in serum using xanthine oxidase method and th e expression of MT in tissue using immu nohistochemistry before,during ,a nd after radiotherapy.And 26persons withou t cancer were enrolled as normal cont rol.RESULTS :Thirty-two patients were performed3times of examinations of T-SOD activity.The activity of T-SOD befo re radiotherapy (83.9±19.6U N /ml )was lower than normal control (96.8±23.6U N /ml )(P<0.05).The activities of T-SOD in the serum samples before,during ,and after the radiotherapy wer e77.6±19.1,87.1±18.6,and 96.3±31.6in the NPC patients at stag e Ⅰ(P>0.05);80.1±15.0,78.0±35.4,and 110.6±72.0in the NPC patients at stag e Ⅳ(P>0.05);79.8±18.2,87.2±31.7,and 94.8±36.3in the patients with complete response to radiother apy (P>0.05);98.5±18.6,62.9±35.3,and 79.2±27.3in the patients with pa rt response to radiotherapy (P>0.05).Among the 32patients ,27patients we re performed 3times of tests of MT expression.The expression rate of M T in NPC tissues was 39.8±37.8%befor e radiotherapy,and markedly hig her t han the normal control 12.1±22.4%(P<0.05).The expression rates of MT before,d uring ,and after radiotherapy were33.0±42.2%,21.3±36.1%,and 5.0±10.0%in the tissues from the patients at stag e Ⅰ(P<0.05);62.2±40.5%,9.2±12.8%,and 9.2±15.0%in the patients at stag e Ⅳ(P<0.05);42.5±38.6%,19.8±27.5%,and 10.0±13.9%in the patients with complete r esponse to radiotherapy (P<0.05);32.3±37.2%,1.43±2.43%,and 5.4±9.1%in the patients with part response to radiotherapy (P<0.05).CONCLUSION:The test of T-SOD in serum may be helpful for the diag nosis of initial NPC.But the dynamic chang e of the act ivity of total T-SOD in radiotherapy was not o bvious.The expression rates of MT in NPC tissues increased markedly before r adiotherapy,and decreased obvious ly after radiotherapy.