【作者】 尹海英；

【导师】 许安廷；

【作者基本信息】 山东大学 ， 耳鼻咽喉科学， 2009， 博士

【摘要】 【研究背景与目的】顺铂可抑制癌细胞的DNA复制过程,具有较强的广谱抗癌作用,1995年世界卫生组织对世界上近百种抗癌药物进行评价,顺铂在疗效、市场等综合评价中得分列第二位。另据统计,在我国抗癌化疗治疗方案中以顺铂为主或有顺铂参加配伍的占所有化疗方案的70%—80%。临床广泛用于卵巢癌、前列腺癌、睾丸癌、肺癌、鼻咽癌、食道癌、恶性淋巴瘤、乳腺癌、头颈部鳞癌、甲状腺癌及成骨肉瘤等多种实体肿瘤均能显示疗效。在治疗疾病的同时,顺铂带来了不容忽视的副作用,副作用涉及包括听神经、肾脏、消化道、心脏、骨髓等在内的多个器官,顺铂的临床应用也曾因为其副作用而受到限制,因此,寻找有效的保护剂,减少顺铂的副作用,对于促进顺铂的应用、保护病人具有重要的意义。替普瑞酮在药理学上为萜烯类的一种,最早应用于消化性溃疡的病人,具有广谱抗溃疡作用,后来发现,它对多个器官具有保护作用。研究证明,替普瑞酮对萎缩性胃炎、缺血再灌注心脏损害、内毒素休克、药物性器官损伤等都有保护作用。热休克蛋白是机体在应激情况下迅速合成的一组机体保护性蛋白,具有分子伴侣的活性,它共分为五类,分别为HSP100,HSP90,HSP70,HSP60以及小分子热休克蛋白small Heat Shock Proteins(sHSPs),热休克蛋白70(HSP70)是热休克蛋白家族中最重要的,具有普遍性、高度保守性及应激性,并通过分子伴侣作用、抗氧化作用、协同免疫作用和抗细胞凋亡作用对再次出现的应激有保护耐受作用,且具有交叉耐受性。C反应蛋白(C-reactive protein,CRP)是人类最重要的急性期反应蛋白,它由肝脏产生,急性期浓度可升高上千倍。它已经作为某些炎性疾病的检测指标、评价标准。它可以识别外来物质,激活补体系统;增强条理作用,增强吞噬细胞吞噬作用;与血小板激活因子(RAF)结合,降低炎症反应;与染色体结合,消除坏死组织里的细胞DNA。Caspase(Cysteine aspartic acic specific protease)家族是一个半胱氨酰—天冬氨酸蛋白酶家族,是凋亡和炎症通路的主要介导者,它以无活性的酶原形式合成,可以在特定的切割位点高度选择性地切割某些蛋白质。切割的结果或是活化某种蛋白,或使某种蛋白失活。其中,caspase-3被认为是细胞凋亡过程中最主要的终末剪切酶,也是细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)杀伤机制的重要组成部分。本研究观察替普瑞酮对顺铂致耳毒性是否存在保护作用,并探讨其可能的机理,另外,探讨炎性因子对顺铂耳毒性的作用。以期待寻找一种有效的药物,能减轻顺铂的副作用,使顺铂能更好的发挥药理效用。同时,试图发现一条新的顺铂致耳毒性的作用机制。第一部分替普瑞酮对顺铂耳毒性保护作用的实验研究【目的】建立顺铂致耳毒性模型,观察替普瑞酮对顺铂耳毒性的作用。【方法】将24只豚鼠随机分为四组,分别给予替普瑞酮(600 mg/kg/day×7d)灌胃,而后给予顺铂腹腔注射(6mg/kg/day×3d)(GGA+CDDP组),替普瑞酮(600mg/kg/day×7d)灌胃(GGA组),顺铂腹腔注射(6mg/kg/day×3d)(CDDP组),等量生理盐水腹腔注射(对照组)。于实验前后对每只豚鼠进行体重和ABR的测定,Western blot测定HSP70、CRP在耳蜗组织中的表达和Caspase-3的活性,扫描电镜下观察耳蜗毛细胞的情况。比较豚鼠的听力变化、HSP70和CRP在组织中的表达以及耳蜗的形态学改变。【结果】实验后,CDDP组豚鼠体重(170.50±7.82g)较其它各组均有明显下降,GGA+CDDP组豚鼠体重(272.50±14.82g)虽较正常对照组有所下降,但其下降趋势不如CDDP组明显。CDDP组的听阈(38.33±2.58dB)明显高于其它各组,GGA+CDDP组听阈(18.33±2.58dB)较正常对照有所提高,较CDDP组明显低。GGA+CDDP组中HSP70在耳蜗中的表达(0.47±0.02)明显高于CDDP组(0.30±0.02),而GGA+CDDP组中CRP的表达(0.31±0.02)较CDDP组(0.46±0.02)减少,Caspase-3的活性也明显低于CDDP组。GGA+CDDP组中扫描电镜下丢失外毛细胞比例(0.24±0.02)明显低于CDDP组(0.42±0.02)。【结论】腹腔注射顺铂可导致耳毒性,替普瑞酮对顺铂所致耳毒性具有明显保护作用。第二部分炎症因子对顺铂耳毒性作用机理的实验研究【目的】建立顺铂致耳毒性模型,观察炎症因子对顺铂耳毒性的作用。【方法】将12只豚鼠随机分为两组,分别给予顺铂腹腔注射6mg/kg/day×3d(CDDP组),等量生理盐水腹腔注射(对照组)。于实验前后对每只豚鼠进行体重和ABR的测定,Western blot测定肿瘤坏死因子-α、白介素-6在耳蜗组织中的表达,并在扫描电镜下观察耳蜗毛细胞的情况。比较豚鼠的听力变化、肿瘤坏死因子-α、白介素-6在组织中的表达以及耳蜗的形态学改变。【结果】CDDP组中豚鼠体重(177.83±10.61g)较对照组(340.00±17.60g)有明显下降,听阈(39.17±3.76dB)较对照组(7.50±2.74dB)明显提高,肿瘤坏死因子-α(0.58±0.02)和白介素-6(0.35±0.03)在耳蜗中的表达均明显高于对照组,扫描电镜下毛细胞缺失比例(0.43±0.03)也较对照组明显。【结论】腹腔注射顺铂可导致耳毒性,炎症因子在顺铂所致耳毒性中起到了一定的作用。更多还原

【Abstract】 Cisplatin can suppress the process of DNA replication in cancer cell.It shows a powerful antitumous effect in various cancer cells.World Health Organization(WTO) assessed the antitumor drugs which were up to one hundred in 1995.The result showed that cisplatin was second in the importance of curative effect,market and other aspects. Another statistics showed that 70-80 percent of chemotherapy programs contained cisplatin in our country.Cisplatin was used widely in the tumor therapy including ovarian cancer,prostatic carcinoma,carcinoma of testis,pulmonary carcinoma,nasopharyngeal carcinoma,esophageal carcinoma,Hokdkin’s disease,breast cancer,cervical squamous cell carcinoma,thyroid carcinoma,osteogenic sarcoma and so on.It showed better curative effect.Simultaneously,the curative effect was together with the side effects which could not be neglected.The acoustic nerve,the kidney,the alimentary canal,the heart,the marrow and other organs were involved in the side effects which were induced by cisplatin.The clinical application of cisplatin was confined because of the side effects. So,looking for an effectively protective agent in order to relieve the side effects is very important for the clinical application and patients.Geranylgeranylacetone belongs to Terpene in pharmacology.It had a broad-spectrum antiulcer effect and was used on peptic ulcer patients at the very beginning.Then,it was reported to have a protective effect on several organs.It has been proved that it showed an protective effect on the atrophic gastritis,the ischemic-reperfusion heart damage,the endotoxin shock,the medicine inducing organ damage and so on.Heat Shock Protein(HSP) is a kind of protein family which is synthesized under stress.It acts like molecular chaperones and shows protective effects.According to the molecular mass,it can be divided into five species,including HSP100,HSP90,HSP70, HSP60 and small Heat Shock Proteins(sHSPs),HSP70 possesses the characteristics of widespread,high-conservatism and excitability and is capital in the HSP family.It acts like molecular chaperones which can protect other proteins against aggregation, solubilize initial,loose protein aggregates,assist in folding of nascent proteins or in refolding of damaged proteins,target severely damaged proteins to degradation,sequester damaged proteins to larger aggregates in case of excessive damage and inhibit apoptosis.C-Reactive Protein(CRP) is produced by liver during episodes of acute inflammation or infection and generally used as a measure of inflammatory disease.The density during episodes of acute inflammation steps up to thousandfold.In the body,CRP plays the important role of interacting with the complement system,an immunologic defense mechanism.It can identify extraneous material,activate complement system, strengthen cytophagocytesis,bind with Platelet Activation Factor(RAF) and chromosome, depress inflammatory reaction,eliminate the cell deoxyribonucleic acid in the necrotic tissue.Cysteine aspartic acic specific protease(Caspase),a family of cysteinyl aspartate-specific proteases,are central mediators of apoptotic and inflammatory pathways.Caspases are synthesized as inactive proenzymes,which are activated following cleavage at specific aspartate cleavage sites.It can cleavage the proteins with high selectivity at specific aspartate cleavage sites,which lead to activate or deactivate the proteins.Caspase-3 is the key executioners of apoptosis and an important part of cytotoxic T lymphocyte(CTL) mechanism.It is widely distributed,with high expression in cell lines of lymphocytic origin,suggesting that it may be an important mediator of apoptosis in the immune system.In this study,we aim to investigate whether Geranylgeranylacetone plays a protective effect on the ototoxicity induced by cisplatin and approach the conceivable mechanism.Otherwise,we discuss the effect of inflammatory factor on the cisplatin ototoxicity.We look forward to find an effective drug to relieve the side effects of cisplatin and find a mechanism of cisplatin ototoxicity. PartⅠProtective effect of GGA on ototoxicity induced by cisplatinObjective:Geranylgeranylacetone(GGA) has the ability to induce heat shock proteins(HSPs) and to protect cells from apoptotic insults.This study aims to investigate whether GGA has a protective effect on cisplatin(CDDP) ototoxicity.Methods:Twenty-four guinea pigs were divided into four groups randomly.The GGA+CDDP group were administrated GGA(600 mg/kg/day×7d) by intragastric administration,then,cisplatin was given(6mg/kg/day×3d) I.P.The GGA group were only administrated GGA(600 mg/kg/day×7d) by intragastric administration.The CDDP group were only given CDDP(6mg/kg/day×3d) I.P.The control group were given the same dose of 0.9%sodium chloride I.P.The weights were obtained before and after the experiment.The auditory thresholds were assessed using auditory brainstem response (ABR) test before and after the experiment.Hsp70 expression,C-reactive protein(CRP) expression and the activation of Caspase-3 were investigated by Western blot analysis. The amount of hair cells was counted under scanning electron microscopy(SEM).Results:The weight(170.50±7.82g) in the CDDP group was lower than that in the other three groups obviously.Though the weight(252.50±10.37g) in the GGA+CDDP group was lower than that in the GGA group and the control group,the descending tendency was more slow-moving than that in the CDDP group.The auditory threshold in the CDDP group(38.33±2.58dB) was higher than that in the other three groups.The auditory threshold in the GGA+CDDP group(18.33±2.58dB) was higher than that in the control group,but lower than that in the CDDP group.Western blot analysis showed that CRP expression in the GGA+CDDP group(0.31±0.02) was less compared with that in CDDP group(0.46±0.02).Hsp70 expression and the activation of Caspase-3 showed an adverse result.The HSP70 expression in the GGA+CDDP group(0.47±0.02) was more compared with that in the CDDP group(0.30±0.02).The activation of Caspase-3 was lower that that in the CDDP group.The ratio of missing outer hair cells(OHCs) in the CDDP group(0.42±0.02) were significantly higher than that in the GGA+CDDP group (0.24±0.02).Conclusion:Cisplatin showed an ototoxicity used by I.P.It was suggested that GGA had a protective effect on the cisplatin ototoxicity. PartⅡEffect of inflammatory factors on cisplatin ototoxicityObjective:This study aims to model the ototoxicity of cisplatin and investigate whether inflammatory factor has an effect on cisplatin(CDDP) ototoxicity.Methods:Twelve guinea pigs were divided into two groups randomly.The CDDP group were given CDDP(6mg/kg/day×3d) I.P.The control group were given the same dose of 0.9%sodium chloride I.P.The weights were obtained before and after the experiment.The auditory thresholds were assessed using auditory brainstem response (ABR) test before and after the experiment.Tumor necrosis factor-α(TNF-α) expression, IL-6 expression were investigated by Western blot analysis.The amount of hair cells was counted under scanning electron microscopy(SEM).Results:The weight(177.83±10.61g) in the CDDP group was lower than that in the control group(340±17.60g) obviously.The auditory threshold in the CDDP group (39.17±3.76dB) was higher than that in the control group.Western blot analysis showed that TNF-αexpression(0.58±0.02) and IL-6 expression(0.35±0.03) were higher in CDDP group.The ratio of missing outer hair cells(OHCs) in the CDDP group (0.43±0.03) was significantly higher than that in the control group.Conclusion:It was suggested that inflammatory factor had an effect on the cisplatin ototoxicity.更多还原