中文摘要：

目的探讨微小RNA（miRNA）let-7在食管鳞癌细胞及组织中的表达,及let-7与食管鳞癌临床病理的关系。方法在细胞水平,运用实时荧光定量聚合酶链反应（real-time quantitative PCR,qRT-PCR）检测let-7在正常食管鳞状上皮细胞Heepic及食管鳞癌细胞CaES-17、Eca109和KYSE-150中的表达差异;在组织水平,采用qRT-PCR技术检测let-7在15对哈萨克族食管鳞癌组织和癌旁正常组织中的表达,并分析其与食管鳞癌浸润、转移等临床病理的关系。结果 qRT-PCR结果显示,let-7在3个食管鳞癌细胞系中的表达明显低于在正常食管鳞状上皮细胞Heepic中的表达,let-7在食管鳞癌组织中的表达明显低于其在癌旁正常组织中的表达,其相对表达量比值为0.79±0.56,差异有统计学意义（P〈0.05）;let-7在不同性别、分化程度、大体分型、浸润深度及淋巴结转移之间的相对表达量比值均无统计学差异（P〉0.05）。结论 Let-7在正常食管鳞状上皮细胞和食管鳞癌细胞中均有表达,但在食管鳞癌细胞中呈低表达;let-7在食管鳞癌组织和正常食管鳞状上皮组织中均有表达,但在癌组织中呈显著低表达;哈萨克族食管鳞癌患者let-7低表达与其临床病理参数之间无显著相关性;let-7对哈萨克族食管鳞癌的发生起抑制作用,是食管鳞癌的潜在分子标记物。

英文摘要：

Objective To explore expression of micro RNA let-7 in human esophageal squamous cell carcinoma（ESCC） and investigate relationship between let-7 and clinicopathological parameters.Methods Real-time quantitative polymerase chain reaction（qRT-PCR） was taken to detect expression of let-7,in normal esophageal squamous cell line Heepic,three ESCC cell lines（CaES-17,Eca109,KYSE-150） and 15 pairs of ESCC patients and their corresponding normal tissues,and to analyze relationship between let-7 and clinicopathology such as infiltration and metastasis of esophageal squamous cell carcinoma.Results The expression of let-7 in three ESCC cell lines were significantly lower than that in normal esophageal squamous cell line.Moreover,the expression of let-7 in ESCC tissues was significantly lower than that in corresponding normal tissues,the ratio of relative expression was 0.79±0.56.However,there were no differences in the expression of let-7 among different gender,differentiation,morphological type,depth of invasion and lymph node metastasis of ESCC（P 0.05）.Conclusions Let-7 is lower expressed in ESCC both in vivo and in vitro.There is no obvious corelation between let-7 expression in ESCC and the clinicopathological factors of Kazak nationality.Let-7 is a potential molecular marker for the carcinogenesis in ESCC.