【作者】 王淑云；

【导师】 李福才；

【作者基本信息】 中国医科大学 ， 遗传学， 2006， 硕士

【摘要】 前言 目前研究发现,端粒酶活性在大多数永生细胞及肿瘤细胞中表达增强,与肿瘤的发生有着密切的关系。端粒酶由端粒酶逆转录酶(human telomerase reverse transcriptase,hTERT)、端粒RNA(telomerase RNA)和端粒相关蛋白1(TP1)组成。其中hTERT是调控端粒酶活性和端粒长度的主要因素,在细胞永生化和恶性转化中起关键作用。hTERT的功能受诸多因素的影响,MKRN1(Makorin RING finger protein 1,MKRN1)基因的编码产物是hTERT降解过程中的关键酶,MKRN1基因的过表达可促进hTERT的降解,降低端粒酶的活性和端粒的长度。热休克蛋白90(heat shock protein 90,HSP90)能够与hTERT结合并促进其活性,使端粒增长,抑制Hsp90的功能将促进端粒酶降解。在正常细胞中MKRN1和HSP90基因的表达保持动态平衡,端粒酶活性和端粒长度受这一平衡的调节。目前MKRN1和HSP90基因与肿瘤发生的相关性,以及二者相互作用还不十分清楚。因此,本实验检测MKRN1和HSP90基因在喉鳞状细胞癌(以下简称喉癌)组织及癌旁正常对照组织中的表达,以探讨MKRN1和HSP90基因的相关性及二者在喉癌发生发展中的作用。 实验方法 1.材料 1.1 35例喉癌组织标本来源于中国医科大学附属第一临床学院耳鼻喉科手术切取标本。术前未经化疗或放疗,术后经病理证实均为鳞状细胞癌。 1.2 总RNA提取相关试剂。 1.3 RT-PCR相关试剂。更多还原

【Abstract】 ItruductionTelemorase is positive in the most of immortal cell lines and cacimoma cell which indicated the significant correlation between telomerase activity and carcinoma. Telemorase is composed of hTERT ( human telomerase reverse tran-scriptase) ,hTR( telomerase RNA) and TP1 (telomerase - associated protein 1). In which hTERT plays an important role in regulating telomere length and cell carcinomigenesis. hTERT is,in turn,regulated by a collection of associated factors. Makorin RING finger protein 1 that encoded by gene MKRN1 functions as an E3 ligase and mediates degradation of hTERT . Overexpression of MKRN1 in telomerase positive cells promotes the degradation of hTERT and decreases telomerase activity and subsequently telomere length. The molecular chaperone Hsp90 was another telomerase regulator that play an positive role telomerase activity. Hsp90 binds specifically to hTERT to promote the assembly of active telomerase both in a cell - free system and in intact cells. Disruption of Hsp90 function promotes protesome - mediated degradation of hTERT. The balance between these two genes decides the normal telomerase activity and telomere length, breaking up this balance may lead to disease and cancer. It is still unknown the correlation between MKRN1 and HSP90 , as well as the relationship between these two genes and carcinomigenesis. To investigate if the genes MKRN1 and HSP90 expression was related to laryngeal carcinomigenesis and development, We study the genes expression in Laryngeal Squamous Cell Carcino-ma(LSCC).Materials and methods1. Materials1.1 All 35 LSCC tissues were excised from patients in the first affiliated hospital of China Medical University.1. 2 Reagents for extraction of total RNA.1. 3 Reagents for RT - PCR.2. Methods1) Total RNA was extracted in 35 LSCC and paired adjacent normal tissues as control. The samples that OD260/OD280 > 1. 8 was selected to synthesize cDNA by reverse transcriptation.2 ) PCR was used in gene amplification of MKRNX and HSP90 with p - ac-tin as control.3) Definition of products after electrophoresis.4) SPSS 10. 0 software pack was used in stitistical analysis of the datas.Results1. Down - regulated MKRNX expression was found in 18 tumor tissues (51.4% ) and HSP90 overexpression was found in 16 tumor tissues (45. 7% ) in the 35 LSCC cases. Statistical analysis showed MKRNX expression in tumor tissues was lower than adjacent normal tissues, ( P < 0.01) , HSP90 expression in tumor tissues was higher than adjacent normal tissues(P <0.05) .2. Correlation coefficient between MKRNX and HSP90 expression is r = -0.458(P<0.05).3. HSP90 overexpression was associated with stage of LSCC and age of pa-tients(P <0. 05) . MKRNX expression has no relationship with clinical features of LSCC(P>0.05).ConclusionDown - regulated NKRN and overexpression of HSP90 were found coexisted and correlated to each other in LSCC. Broken of the balance between MKRNX and HSP90 that induced by abnormal expression may play an important role in the carcinomigenesis and development of LSCC.更多还原