GDF15在大鼠早期肝癌和人小肝癌组织中的表达

Expression of GDF 15 in rat early-stage hepatocellular carcinoma and human small hepatocellular carcinoma

目的:针对前期应用基因芯片(Affymatix Rat 230.2.0)筛选出的大鼠早期肝癌中高表达的人同源基因GDF15(Growth Differentiation Factor15),进一步在人小肝癌组织中检测其表达水平以探讨其作为人小肝癌候选诊断标志物的价值。方法:应用RT-PCR检测GDF15在大鼠早期肝癌结节中的表达以对芯片结果进行初步验证;进一步采用RT-PCR、实时荧光定量PCR对GDF15在随机配对的正常肝脏组织(n=10)与小肝癌(n=10)中基因转录水平半定量和定量检测,同时用免疫组化鉴定其在正常肝脏组织(n=10),癌旁组织(n=26),小肝癌(n=12)及大肝癌(n=14)中蛋白水平的表达。结果:GDF15在大鼠早期肝癌结节中较正常组织表达显著上调(P<0.05),与芯片结果一致。在人小肝癌,其转录及蛋白水平的表达均明显高于正常肝脏组织(P<0.05)。免疫组化结果显示12例小肝癌中10例表达强阳性,其在细胞中的表达定位于细胞浆与细胞外基质。结论:分泌性蛋白GDF15在人小肝癌组织中高表达,提示其具有潜在的小肝癌筛选价值。

Objective：To evaluate the expression level and the diagnostic role of GDF 15 as a potential tumor marker in small hepatocellular carcinoma （SHCC） in human beings. Methods：Based on the previous data of Affymatrix microarrays,which indicated an over-expression of GDF15 in early-stage HCC of rat models,transcription level of GDF15 was examined in both rat models and human SHCC by RT-PCR. Real-time quantitative PCR was used to quantitatively analyze the gene in ten human small hepatocellular carcinoma and ten normal liver tissues,respectively. The protein levels and expression sits were subsequently confirmed in the SHCC, single large hepatocellular carcinoma （SLHCC）, paraneoplastic tissues and normal liver tissues of human by immunohistochemistry （IHC） ,respectively. Results：GDF15 expression was significantly higher in the rat and human SHCC than in the normal liver tissues （P 〈 0.05）. Real-time quantitative PCR and IHC analysis revealed that GDF15 expression was also higher in SHCC than in the paraneoplastic liver tissues and normal liver tissues. GDF15 protein detected in all 12 SHCC was mainly observed in the cytoplasm and extra cellular matrix of tumor cells. Conclusion：The current results showed GDF15 expression was high in the SHCCs and suggested it should be a useful tumor marker in detecting SHCC.