Zhang Yiyan, Li Jijun, Song Yan, Chen Fengkun, Pei Yin, Yao Fenghua
Department of Nephrology, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, P.R. China.
Mol Med Rep. 2014 Aug;10(2):860-6. doi: 10.3892/mmr.2014.2310. Epub 2014 Jun 10.
The present study was designed to elucidate the expression levels and the proliferative effect of flotillin-1, an integral membrane protein encoded by the FLOT1 gene, in human clear-cell renal cell carcinoma (RCC). Flotillin has been implicated in other types of cancer, but the role of flotillin in RCC has not been established. Immunohistochemistry and western blotting were used to determine FLOT1 protein expression levels in RCC samples from 182 patients who underwent nephrectomy. FLOT1 mRNA expression levels were analyzed using reverse-transcription (RT) and RT-quantitative polymerase chain reaction (PCR). The association between FLOT1 expression levels in the tumor samples and patient survival time was examined using Kaplan‑Meier analysis. To demonstrate the proliferative effect of FLOT1 on RCC cells, a FLOT1 vector was transfected into four RCC cell lines and FLOT1 expression was inhibited using small interfering RNA. The proliferative ability of the RCC cells was investigated using a WST-1 assay and xenograft experiments with BALB/C nude mice. The results demonstrated that FLOT1 expression levels were significantly higher in RCC cell samples from patients than in healthy renal tissue, and the expression levels were associated with tumor stage, size and histological grade. In addition, FLOT1 significantly enhanced the proliferation of RCC cell lines in vitro and in vivo. These findings suggest that FLOT1, which is upregulated in RCC, is involved in RCC cell proliferation, tumorigenesis and progression. Therefore, FLOT1 is an independent prognostic marker and therapeutic target for patients with clear-cell RCC.
本研究旨在阐明由FLOT1基因编码的整合膜蛋白flotillin-1在人透明细胞肾细胞癌（RCC）中的表达水平及其增殖作用。Flotillin与其他类型的癌症有关，但flotillin在RCC中的作用尚未明确。采用免疫组织化学和蛋白质印迹法检测182例行肾切除术患者的RCC样本中FLOT1蛋白的表达水平。使用逆转录（RT）和RT-定量聚合酶链反应（PCR）分析FLOT1 mRNA的表达水平。采用Kaplan-Meier分析检测肿瘤样本中FLOT1表达水平与患者生存时间之间的关联。为了证明FLOT1对RCC细胞的增殖作用，将FLOT1载体转染到四种RCC细胞系中，并使用小干扰RNA抑制FLOT1表达。采用WST-1检测法和对BALB/C裸鼠进行异种移植实验，研究RCC细胞的增殖能力。结果表明，患者RCC细胞样本中FLOT1的表达水平显著高于健康肾组织，且表达水平与肿瘤分期、大小和组织学分级相关。此外，FLOT1在体外和体内均显著增强了RCC细胞系的增殖。这些发现表明，在RCC中上调的FLOT1参与了RCC细胞的增殖、肿瘤发生和进展。因此，FLOT1是透明细胞RCC患者的独立预后标志物和治疗靶点。
