CASP1在非小细胞肺癌组织中的表达与生物学意义

目的  探讨含半胱氨酸的天冬氨酸蛋白水解酶caspase-1（CASP1）表达在非小细胞肺癌（NSCLC）发生、发展中的作用。方法  收集华北理工大学附属医院2010～2014年确诊为NSCLC患者的肺癌及癌旁组织25对。采用免疫组织化学染色方法，比较CASP1基因在肺癌和癌旁组织以及不同病理类型及分化程度肺癌组织中的表达差异。使用正常和肿瘤组织表达数据库（GENT）提供的数据，分析CASP1在肺癌组织及正常组织中的表达差异。结果  免疫组织化学结果显示，CASP1在肺癌组织中的表达量（0.021±0.004）低于相应的癌旁组织（0.083±0.008），差异有统计学意义（t =-8.554，P =0.000）。进一步对GENT数据库进行分析，发现在U133plus2提供的数据中，CASP1在肺正常组织中的表达量为（1137±42.17），高于其在肺肿瘤组织中的表达量（844±19.35），差异有统计学意义（Z =-7.037，P =0.000）。同样的结果出现在U113A提供的数据中，CASP1在肺正常组织的表达（467±11.19）高于其在肺肿瘤组织（423±8.44）中的表达，差异有统计学意义（Z =-2.898，P =0.004）。不同分化程度肺癌组织的免疫组织化学结果显示，CASP1的表达水平在高分化（0.027±0.006）、中分化（0.017±0.003）、低分化（0.007±0.002）肺癌组织中的差异有统计学意义（F =6.653，P =0.006）。组间比较显示，CASP1在高分化组织中的表达高于其在低分化肺癌组织中的表达，差异有统计学意义（P =0.001），但与中分化组织中的表达比较无统计学意义（P =0.056）。笔者未发现CASP1在肺腺癌（0.019±0.003）和鳞癌（0.012±0.004）中表达差异有统计学意义（t =1.382，P =0.180）。结论  CASP1在非小细胞肺癌组织中表达下调，表明其在NSCLC的发生、发展过程中可能发挥重要作用。

Significance of CASP1 protein expression in non-small cell lung cancer

Objective To explore the role of caspase-1 (CASP1) in the development of non-small cell lung cancer (NSCLC). Methods Lung tumor and adjacent normal samples from 25 NSCLC patients were collected at the Affiliated Hospital of North China University of Science and Technology from 2010 to 2014. CASP1 protein expression was analyzed by immunohistochemistry. Gene expression database of normal and tumor tissues (GENT) was used to analyze the difference of CASP1 expression between lung cancer and normal lung tissues. Results Immunohistochemistry analysis revealed that CASP1 protein expression in the lung tumor tissues (0.021 ± 0.004) was lower than that in the adjacent tissues [(0.083 ± 0.008), t = -8.554, P = 0.000]. Analysis of the CASP1 data from GENT revealed that CASP1 expression in the lung cancer tissues was significantly lower than that in the normal tissues in both U133plus2 (Z = -7.037, P = 0.000) and U133A platforms (Z = -2.898, P = 0.004). The protein expression of CASP1 in the well-differentiated lung cancer (0.027±0.006) was higher than that in the poorly-differentiated lung cancer [(0.007 ± 0.002), P =0.001], but not significantly different from that in the moderately-differentiated lung cancer [(0.017 ±0.003), P = 0.056]. There was no significant difference in the CASP1 expression between the lung adenocarcinoma (0.019 ± 0.003) and squamous cell carcinoma [(0.012 ± 0.004), t = 1.382, P = 0.180]. Conclusions CASP1 expression is down-regulated in non-small cell lung cancer tissues, which indicates that CASP1 protein expression may contribute to the development of NSCLC.