摘要目的 通过观察氟达拉滨对人肾乳头状细胞癌(RPCC)标本和细胞系STAT1表达的影响,探讨氟达拉滨成为新类型放射增敏剂--基因型放射增敏剂的可能性.方法 采用微点阵基因芯片技术对137例人RPCC标本和15例正常肾组织标本进行STAT1表达检测,利用基因芯片操作系统(GCOS 1.4,Affymetfix)以靶信号500作为总体标定值进行质量检验,并利用变性凝胶电泳进行质量评价.用Western印迹法检测人RPCC细胞(SKRC-39)、纤维母细胞(CCL-116)和威尔姆瘤细胞(CRL-1441)株STAT1表达,以及氟达拉滨对SKRC-39细胞±照射后和转染siRNA后的STAT1表达.并用SKRC-39细胞进行成克降法和台盼监染色计数法的氟达拉滨放射增敏实验.结果 人RPCC标本和正常肾组织标本的STAT1表达强度分别为821±66和240±35,人RPCC标本STAT1表达显著增高(t=44.38,P=0.000).Western印迹法枪测结果显示SKRC-39细胞表达STAT1比CRL-1441、CCL-116细胞明显增高;与对照组相比氟达拉滨能显著抑制磷酸化STAT1的表达,照射对磷酸化STAT1几乎无影响,而氟达拉滨和照射共同作用时磷酸化STAT1的表达被显著抑制;经STAT1 siRNA处理后SKRC-39细胞总sTAT1和磷酸化STAT1的表达均被有效抑制.SKRC-39细胞成克隆法放射增敏实验结果显爪经氟达拉滨处理后SKRC-39细胞的放射敏感性显著增加,放射增敏程度与药物浓度呈正相关(5、10ìmol/L的增敏比分别为1.22、1.39).结论 氟达拉滨通过抑制STAT1表达增加了SKRC-39细胞的放射敏感性,因此属于基因型放射增敏剂.

abstractsObjective Renal papillary cell carcinoma(RPCC) has been historically regarded as a radio-resistant malignancy. However, the molecular mechanism underlying its radio-resistance is not well understood. Recently,STAT1, a transcription factor downstream of the IFN-signalling pathway, has been implicated in radioresistance. This study is to investigate the role of STAT1 in "radio-resistant RPCC". Methods The expression of STAT, in 137 human RPCC samples compared with 15 normal kidney tissues was examined by micrearray expression profiling using the Affymetrix HGU133 Plus 2.0 GeneChip oligonucleotide arrays. For in-vltro experiments, human RPCC cell line(SKRC-39), human fibroblast(CCL-116) and human Wiim's tumor cell line(CRL-1441) were used. Western blotting was performed to evaluate total and phosporylated STAT1 expression. RPCC cells were irradiated and compared to controls in clonogenic assays. STAT1 inhibition either with fludarabine or siRNA was done and their effects on radiation-induced cell survival were investigated. Results The STAT1 expression data shows that there was a significant increase in human RPCC when compared to normal kidney tissues (t=44.38,P=0.000). Similarly, the expression of STAT1 was higher in the RPCC cell line when compared to firbroblast and Wilm's tumor cell lines. STAT1 expression was inhibited by beth fludarabine and siRNA. Radiosensitivity in RPCC cell lines was enhanced by both fludarabine and siRNA induced STAT1 inhibition. Conclusions This is the first study reporting the over-expression of STAT1 in human RPCC tissues and human RPCC cell line. Radiesensitization of RPCC is observed via inhibition of STAT1 signaling by fludarabine and siRNA techniques. Our data suggests that STAT1, through IFN-signalling pathway , may play a key role in RPCC radioresistance and manipulation of this pathway may enhance the efficacy of radiotherapy.