摘要目的 探讨细胞外信号调节激酶(ERK)/丝裂原活化蛋白激酶(MAPK)信号通路在哈萨克族食管鳞癌患者组织中的表达变化及意义.方法 采用Western blot技术检测在血清饥饿条件下、U0126梯度浓度处理下,食管癌细胞系EC9706中磷酸化ERK1(p-ERK1)和磷酸化ERK2(p-ERK2)的表达变化.采用实时荧光定量PCR法检测25例哈萨克族食管癌患者肿瘤组织和癌旁正常组织中总ERK1(t-ERK1)和总ERK2(t-ERK2)mRNA的表达变化.采用Western blot技术检测25例哈萨克族食管癌患者肿瘤组织、癌旁正常组织以及5例哈萨克族非食管癌者正常食管组织中t-ERK1、t-ERK2、p-ERK1和p-ERK2蛋白的表达变化.采用免疫组化染色法,在126例石蜡包埋标本(正常食管黏膜19例,食管原位癌55例,食管浸润癌52例)中验证p-ERK1和p-ERK2蛋白的表达变化.结果 在食管癌EC9706细胞中,ERK/MAPK信号通路呈高度活化状态.血清瞬时刺激10 min后,p-ERK1和p-ERK2的表达达到峰值.EC9706细胞在50 μmol/L的U0126处理下,p-ERK1和p-ERK2的表达几乎完全被抑制.t-ERK1 mRNA在25例哈萨克族食管癌患者肿瘤组织中的表达量为1.92±3.49,明显低于癌旁组织(3.67±7.47,P<0.05);t-ERK2 mRNA在食管癌组织和癌旁组织中的表达量差异无统计学意义(P>0.05).t-ERK1和t-ERK2蛋白在食管癌组织、相应癌旁组织和正常食管黏膜组织中的表达差异无统计学意义(P>0.05);但p-ERK1和p-ERK2蛋白在食管癌组织中的表达量(分别为0.87±0.14和0.79±0.10)均明显低于癌旁组织(分别为1.10±0.13和1.32±0.12,P<0.05)和正常食管黏膜组织(分别为1.50±0.22和1.64±0.18,P<0.05).免疫组化染色验证的结果 显示,p-ERK1和p-ERK2蛋白在浸润性食管癌组织中的阳性表达率均为7.7%(4/52),在癌旁正常食管黏膜组织中的阳性表达率均为31.6%(6/19),在食管原位癌组织中的阳性表达率均为85.5%(47/55),不同组织间的表达差异有统计学意义(P<0.05).结论 在食管癌细胞中,ERK/MAPK信号通路呈活化状态.ERK/MAPK信号通路活化水平的改变可能参与了哈萨克族食管癌患者肿瘤的早期发生.

abstractsObjective To investigate the expression variation and significance of ERK1/2 MAPK signaling transduction pathway in the pathogenesis of esophageal squamous cell carcinoma (ESCC) in Kazakh patients. Methods The expression level of p-ERK1/2 after serum starvation and treatment with U0126 inhibitor was detected in esophageal cancer cell line EC9706 by Western blot assay. The mRNA level of total ERK1/2 (t-ERK1/2) and expression level of t-ERK1/2 and p-ERK1/2 proteins of 25 pairs of ESCC and adjacent normal esophageal mucosal tissues of Kazakh patients were examined and identified by real-time quantitative PCR (qRT-PCR) and Western blotting, respectively. The expression of p-ERK1/2 protein was verified by immunohistochemistry in 126 paraffin-embeded specimens, including 19 normal esophageal mucosa, 55 esophageal carcinomas in situ and 52 invasive carcinomas. Results ERK1/2 MAPK signaling transduction pathway was in an active status in the EC9706 cells. The expression level of p-ERK1/2 in Ec9706 cells reached a peak at 10 min after transient serum stimulation, and p-ERK1/2 expression was totally restrained after the treatment with 50 μmol/L U0126. In the 25 pairs of ESCC and adjacent normal mucosa, the t-ERK1 mRNA level was 1.92±3.49 in the ESCC tissues and 3.67±7.47 in the adjacent normal mucosa. The t-ERK1 mRNA level in ESCC tissues was significantly lower than that in adjacent normal mucosa (P<0.05), whereas there was no significant difference of t-ERK2 mRNA level between them(P>0.05). The expression levels of p-ERK1 and p-ERK2 proteins were 0.87±0.14 and 0.79±0.10 in the ESCC tissues, and 1.10±0.13 and 1.32±0.12 in the adjacent normal mucosae. p-ERK1/2 protein in the ESCC tissues was significantly lower than that in the adjacent normal tissue (P<0.01). However, there was no significant difference between their t-ERK1/2 protein levels (P>0.05). In the 126 cases of paraffin-embeded specimens, positive expressions of both p-ERK1 and p-ERK2 in esophageal cancer tissues were 7.7% (4/52), significantly lower than those in adjacent normal mucosa (31.6%, 6/19) and carcinoma in situ (85.5%, 47/55, P<0.05). Conclusions ERK1/2 MAPK signaling pathway is in an active status in esophageal cancer and adjacent normal mucosa. Our results imply that the activation of p-ERK1/2 MAPK signaling transduction pathway plays a role in the early pathogenesis of ESCC in Kazakh patients.