高转移肺癌细胞株95D中特异表达的C3orf1基因分析

Analysis of C3orf1 gene over-expressed in human lung cancer cell line 95D with high metastatic potential

目的进一步了解肺癌转移的分子机制,筛选高转移肺癌中差异表达的基因。方法利用荧光差异显示技术(DD-PCR)获得差异片段,对这些片段进行克隆和序列分析。通过在GenBank中同源性检索,查找差异片段相对应的同源基因。利用定量PCR检测验证该基因表达的差异性,并对该基因的结构进行预测。结果通过DD-PCR得到9个差异片段,其中一个片段对应于C3orf1基因。定量PCR验证的结果表明,C3orf1基因在高转移肺癌中的表达量显著高于其他被测试的5种肿瘤细胞。该基因的读码框长858bp,编码285个氨基酸,分子量约32200。蛋白质结构预测分析发现,该基因含有7个类似表皮生长信号区,N端有一含有24个氨基酸的信号肽,并且还可能有3个2S-2Fe铁氧化还原蛋白铁硫结合信号区,2个维持自身静态平衡的VWFC信号区和2个硫解酶活性区。结论C3orf1基因在高转移肺癌中异常表达,可能是分泌型的生长因子类蛋白,刺激细胞的生长。

Objective To further define the molecular mechanism involved in the metastasis process in lung cancer and screen out the genes expressed differentially in the lung cancer. Methods mRNA differential display （DD-PCR） was employed to search the specific genes related to metastasis. The highly expressed fragments were cloned and sequenced. Compared with the data in GenBank, the homologous genes were found. The anchor primers were designed to validate the candidates from DD-PCR by real-time PCR. The structure of the gene was prognosticated by software. Results Nine differentially expressed genes were found. One of the nine genes, which named C3orf1 ,showed high different expression within the six tested cancer cells. The gene was 858bp long and encoded 285 amino acids. The molecular weight was about 32.2 kD. Analyzed by the bio-software,it was found that the gene was consisted with seven EGF-like domains （ EGF_1 ）, three 2Fe-2S ferredoxin/iron-sulfur binding regions （2FE2S_FER_1 ） ,two VWFC domains （ VWFC_1 ）, two thiolase active sites （thiolase_3 ） ,and so on. Conclusions The gene C3orf1 is over-expressed in the lung cancer 95D cells. It may encode a familiar secretary growth factor protein and play important role in stimulating growth of the cells.