肾细胞癌中脆性组氨酸三联体基因异常及其意义

Alterations of the Human Fragile Histidine Traid Gene in Renal Cell Carcinoma

目的 检测肾细胞癌 (RCC)组织脆性组氨酸三联体 (fragilehistidinetraid ,FHIT)基因蛋白编码外显子及mRNA表达情况 ,了解RCC组织中FHIT基因异常特征 ,探讨FHIT基因与RCC发生发展的关系。方法 收集RCC及相应癌周肾组织标本 ,提取组织DNA及RNA。DIG标记FHIT全长cDNA探针。PCR法扩增FHIT基因E5～E9。扩增产物电泳转膜后行Southernblot杂交。RNA转膜后行Northernbolt杂交。结果 6 8.2 %(1 5 / 2 2 )RCC组织、37.5 % (6 / 1 4 )相应癌周肾组织存在FHIT基因蛋白编码外显子缺失或异常。E5和E8异常(缺失、突变等 )发生率为 40 .9% (9/ 2 2 )和 36 .4% (8/ 2 2 )。 42 .8% (1 2 / 2 8)RCC及 75 % (1 2 / 1 6 )癌周肾组织存在Northernblot阳性条带。FHITmRNA失表达与RCC组织学高分级及临床高分期关系密切 (P <0 .0 5 )。存在FHIT基因蛋白编码外显子缺失或异常的 1 5例RCC中 1 4例 (93.3% )FHIT基因mRNA表达阴性。结论 RCC组织常发生FHIT基因蛋白编码外显子缺失或突变。FHITmRNA失表达与FHIT基因异常基本一致 ,其表达情况可提示患者预后。

Purpose To detect aberrant of fragile histidine traid(FHIT)gene exons in tissues of renal cell carcinoma(RCCs),surrounding RCCs,and normal kidney,in order to understand the features of FHIT gene exons alteration in RCC,to inquire the relationship between FHIT gene alteration and development of RCC. Methods Tissues of RCCs and surrounding neoplasms were obtained from surgical specimens.Genemic DNA and mRNA were purified from tissues.Probes of full length FHIT cDNA and β actin were generated.polymerase chain reaction(PCR) amplications of individual FHIT exons were carried out.PCR products and RNA were transferred to nylon membranes and hybridized with DIG labeled cDNA probes. Results Sixty eight percent of (15/22)RCCs and 37.5%(6/14) of surrounding cancer tissues have alterations of FHIT gene exons for protein.Abnormal of E5 and E8 were 40.9% and 36.4%,respectively.Positive signals of FHIT mRNA were identified in 12(42.8%) samples of RCC,12(75%) tissues of surrounding cancer,and all cases of normal kidney.Meantime,substantially reduced FHIT mRNAs were noted in cancerous tissues.In addition,descending or absent FHIT mRNAs expression were related to high grade and stage of RCCs. Conclusions A large percent of RCC contain deletion or aberrant of FHIT exons for protein.Alterations of FHIT mRNA expression are consistent with lesions at DNA level,and related to high grade and stage of RCC cases.Our results suggest that FHIT may play a role as tumor suppressor gene in renal tumorigenesis.