C12orf59基因与肾癌关系的研究

Our previous transcriptome analysis revealed that open reading frame C12orf59 is expressed at a reduced level in renal cell carcinoma tissues compared to matched normal renal tissues, which is confirmed by quantitative real-time PCR (RT-PCR） and immunohistochemical staining (IHC). C12orf59 is at a low expression level or of no expression in a panel of genital cancer cell lines, which is reversely correlated with the methylation status of CpG islands in its promoter region. These preliminary data suggest that C12orf59 play an important role in the renal cell carcinogenesis. Thus, we hypothesize that C12orf59 functions as a candidate tumor suppressor gene. But, there is no report about C12orf59 in MEDLINE database. .In order to test the hypothesis , we will examine C12orf59 expressions by RT-PCR, Western blot and IHC, and determine the association between its expression and clinicopathological parameters in clinical samples on a large basis; then we will investigate the epigenetic regulation mechanism of C12orf59 in renal cancer by using bisulfite genomic sequencing and chromatin immunoprecipitation; At last we will investigate the biological function and signaling pathway of C12orf59 in renal cancer by the lentiviral expression system, nude model, tandem affinity purification (TAP) combined with liquid chromatography - tandem mass spectrometry (LC-MS/MS). The purpose of this project is to further clarify the roles of C12orf59 in renal cell carcinogenesis and its regulation mechanisms, and provide new clues to early diagnosis and gene therapy for renal cell carcinoma.

前期研究中，通过转录组分析，我们筛选出一个在肾透明细胞癌中表达显著降低的开放阅读框C12orf59。预实验结果证实C12orf59在肾透明细胞癌组织中表达下调；且C12orf59基因在肾癌细胞株中无表达或低表达，并与其启动子区DNA甲基化程度呈负相关。这些结果提示C12orf59基因在肾透明细胞癌发生中具有重要作用，可能是个新候选抑癌基因。但经文献检索，未见有关该基因的报道。为证实此假设，本项目拟采用荧光定量PCR、Western blot、免疫组化、亚硫酸氢盐基因组测序、染色质免疫共沉淀、慢病毒载体和裸鼠成瘤等技术方法分析C12orf59基因在肾透明细胞癌中的表达及其与临床病理特征的相关性、研究其表达缺失或下调的表观机制、探索C12orf59的功能及其发挥作用的信号通路。本项目的顺利完成，将初步揭示C12orf59在肾癌发病中的作用及其机制，为肾癌的早期辅助诊断和基因治疗提供新的线索。

C12orf59广泛表达于各种正常组织，在肾组织中表达最高。C12orf59在透明肾细胞癌中的表达显著下调， 并与与肾透明细胞癌分级、淋巴结转移、远端转移显著相关，是一个独立的肾癌不良预后因子。C12orf59表达下调与UMPP基因无义突变和移码突变有显著相关性，与VHL无义突变和移码突变显著相关。C12orf59两种转录本编码蛋白在细胞中的亚定位不一致，转录本1 主要定位于细胞质中，而转录本2主要要定位于细胞膜和细胞质中。正常肾组织主要表达转录本2。转录本1能促进肾癌细胞的增值、侵袭及迁移；与此相反，而转录本2则起抑癌基因的作用。本项目首次研究了C12orf59的表达及意义，并首次发现C12orf59的不同转录本具有完全不同的功能，这为肿瘤的精准治疗提供了新的思路和线索。