Expression of the proto-oncogene Axl in renal cell carcinoma
Expression of the proto-oncogene Axl in renal cell carcinoma
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DOI：
10.1089/10445490360708946
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发表时间：
2003-08-01
影响因子：
3.1
通讯作者：
McGarvey, TW
中科院分区：
文献类型：
--
作者：
Chung, BI;Malkowicz, SB;McGarvey, TW
在这项研究中，我们研究了Axl原癌基因在肾细胞癌（RCC）中的作用。Axl是一种参与骨髓性白血病发生的酪氨酸激酶受体，并且已发现在肺癌和乳腺癌中过表达。Axl已被描述为与其配体Gas-6一起作为促有丝分裂因子沿着。Axl还显示在细胞凋亡、细胞粘附和趋化性中具有作用。在20对匹配的正常肾和透明细胞RCC患者样品中检查Axl RNA转录物的差异表达。我们发现，与正常肾对相比，RCC中Axl mRNA的稳态水平显著增加（Student配对t检验P < 0.001）。肾细胞癌中Axl的表达也明显高于正常肾组织（P < 0.03）。利用蛋白质印迹法测定20对正常/RCC匹配对中的6对中的Axl蛋白水平。总体而言，成对的正常肾和肾肿瘤之间的表达水平没有显著差异，但检测到的Axl蛋白似乎具有略微不同的分子量。为两种已知的Axl变体构建引物，进行RT-PCR，但在每种变体的表达中没有观察到差异。接下来，我们利用构建用于沉默293转化肾细胞系中Axl基因的双链RNA进行基因沉默实验。与对照细胞相比，在RNAi转染的细胞中Axl基因表达降低了50%。此外，进行流式细胞术以确定DNA含量显示，与对照相比，用axl RNAi转染的G1/G 0细胞增加了30%。总之，这些发现表明Axl的过度表达是RCC中增殖表型的一部分。
In this investigation, we examined the role of the Axl proto-oncogene in renal cell carcinoma (RCC). Axl is a tyrosine kinase receptor implicated in myeloid leukogenesis, and has been found to be overexpressed in lung cancers and breast cancers. Axl has been described to act as a mitogenic factor along with its ligand Gas-6. Axl has also shown to have a role in apoptosis, cell adhesion, and chemotaxis. The differential expression of the Axl RNA transcript was examined in 20 pairs of matched normal kidney and clear cell RCC patient samples. We found that there was a significant increase in the steady-state levels of Axl mRNA in the RCC compared with the normal kidney pair (Student's paired t-test P < 0.001). There was also a significant increase in Axl expression overall in RCC compared to normal kidney (P < 0.03). Western blotting was utilized to determine Axl protein levels in six out of the 20 pairs of the normal/RCC matched pairs. Overall, the level of expression was not significantly different between the paired normal kidneys and kidney tumors, but the detected Axl protein appeared to be at slightly different molecular weights. Primers were constructed for the two known Axl variant, RT-PCR performed, but no differences were observed in the expression of each variant. Next, we performed a gene silencing experiment utilizing double-stranded RNA constructed to silence the Axl gene in the 293 transformed kidney cell line. There was a 50% decrease in Axl gene expression in the RNAi transfected over control cells. In addition, flow cytometry performed to determine DNA content showed a 30% increase in G1/G0 cells, which were transfected with axl RNAi compared to control. Altogether, these findings suggest an overexpression of Axl as part of a proliferative phenotype in RCC.