碳酸酐酶I和Ⅱ在胰腺癌中的表达及临床病理学意义

Clinicopathological significance of the expression of carbonic anhydrase I and Ⅱ in human pancreatic cancer

目的探讨胰腺导管腺癌（PDAC）中碳酸酐酶I（CAI）和Ⅱ（CAⅡ）蛋白和mRNA表达水平及临床病理学意义。方法应用免疫组织化学方法检测57对配对的PDAC及癌旁组织石蜡标本CAI和CAII蛋白表达水平，观察其与PDAC病人临床病理学参数的关系；再以Western印迹和实时定量聚合酶链反应（QRT—PCR）检测16对配对冷冻保存的新鲜PDAC、癌旁组织及三株不同分化程度的胰腺癌细胞系（PANC-1、BxPC-3和SWl990）中CAI和CAⅡ蛋白和mRNA表达。结果免疫组化结果显示：CAI在癌组织中表达高于配对的癌旁组织（t=2．395，P=0．020）；相反，CA11在PDAC组织中表达水平明显低于癌旁组织（t=4．296，P=0．000）。CAI和CAⅡ的表达与肿瘤分化程度呈正相关（x。=7．557，P=0．023；x。=7．822，P=0．020）；cAI表达与胰腺癌血管浸润呈负相关（×。=6．349，P=0．012）。单因素及多因素分析发现cAⅡ是影响胰腺癌患者预后的一个独立因素（P=0．017；P=0．011）。Western印迹和QRT—PCR结果显示：CAI在PDAC及癌旁组织表达差异无统计学意义（t=1．619，P=0．126；t=1．352，P=0．197）；而CAII在PDAC中蛋白和mRNA表达均明显低于配对的癌旁组织（t=3．360，P=0．004；t=2．934，P=0．010）。CAI和CAll蛋白及mRNA水平随细胞分化程度增高表达逐步增强。结论在PDAC中CAI表达上调，CAlI表达下调，两者均与肿瘤分化相关。CA11可以作为评估PDAC患者预后的一个独立指标。

Objective To explore the clinicopathological significance of the expression of carbonic anhydrase I （ CA I ） and carbonic anhydrase Ⅱ （ CA Ⅱ ） protein and mRNA levels in pancreatic ductal adenocarcinoma （PDAC）. Methods The expression of CA I and CA Ⅱ protein in 57 pairs of paraffin- embedded PDAC specimens and adjacent non-cancerous pancreatic tissues were detected by immunohistochemistry. The relationship between the protein expression and clinicopathological characters was analyzed. Western blot and quantitative real-time polymerase chain reaction （QRT-PCR） were used to examine the expression of CA I and CA 11 protein and mRNA levels in 16 paired fresh PDAC specimens, adjacent non-cancerous pancreatic tissues and 3 different differentiated pancreatic cancer cells （PANC-1, BxPC-3 ＆ SW1990）. Results The expression of CA I protein was higher in PDAC compared with that in paired non-cancerous pancreatic tissues （ t = 2. 395, P = 0. 020 ）, whereas, CA 11 expression was significantly lower in PDAC than that in paired non-cancerous pancreatic tissues （ t = 4. 296, P = 0. 000 ）. The expression of CA I and CA Ⅱ protein had a positive correlation with tumor differentiation （ X2 = 7. 557, P = 0. 023 ; X2 = 7. 822, P = 0. 020） and CA I showed a direct negative correlation with vascular invasion （X2 = 6. 349, P = 0. 012）. Univariate and multivariate analysis with clinicopathological characters revealed that the CA Ⅱ expression was an independent prognostic indicator for PDAC patients （ P = 0. 017 ; P = 0.011 respectively）. No significant difference of CA I mRNA and protein expression existed between PDAC and adjacent normal pancreatic tissues （t = 1. 619, P = 0. 126 ; t = 1. 352, P = 0. 197 ） as detected by Western blot and QRT-PCR, but the expression of CA 11 mRNA and protein levels was much lower in PDAC than that in paired non-cancerous pancreatic tissues, respectively （ t = 3. 360, P = O. 004 ; t = 2. 934, P = 0. 010）.Moreover, the mRNA and protein expression of CA I and CA 11 gradually increased with the better differentiation degree of pancreatic cancer cells. Conclusions CA I is up-regulated and CA II down- regulated in PDAC. Both of them are correlated with tumor differentiation. CA Ⅱ expression is an independent prognostic indicator for PDAC patients.