Study of mechanisms of the highly metastatic feature using human lung cancer sublines with highly metastatic property established

更好地了解转移的关键因素可能有助于设计新的治疗分子靶点。为了确定这些因素，我们在实验转移模型中建立了两个高转移的人肺腺癌细胞系，通过在裸鼠身上重复接种，并使用cDNA阵列比较了具有高转移潜力的腺癌细胞系的两个亚群与亲本细胞系的表达谱；微阵列和宏阵列。微阵列分析发现，5个基因的表达在高转移亚群中显著增强或降低。这些基因的基因组结构将被确定。基质金属蛋白酶-2 （MMP-2）、纤溶酶原激活物抑制剂-1 （PAI-1）、癌胚抗原（CEA）、Fas配体等在高转移亚群中表达上调或下调。这些基因的差异表达通过Northern blot分析或逆转录聚合酶链反应（RT-PCR）证实。这些基因表达的改变似乎促进了这些功能的高度转移表型。为了确定p16INK4甲基化状态以及hBUB1、hMAD2、胰岛素样生长因子2受体基因的基因组状态是否发生在原发性肺癌转移过程中，我们还分析了30例晚期肺癌远处转移的原发、转移性肿瘤组织和正常肺样本。本研究结果表明，p16INK4基因因启动子区超甲基化而失活的肿瘤细胞可能在非小细胞肺癌的转移中具有优势。该基因在高转移潜能细胞系和亲本细胞系的亚群中未发现差异表达。p16INK4基因的表达似乎与该细胞系的高转移表型无关。

A better understanding of the key factors of metastasis may be useful for designing new molecular targets of therapy. In order to identify these factors, we established two highly metastatic human lung adenocarcinoma cell lines in an experimental metastasis model by repeated inoculation in nude mice and compared the expression profiles of two subpopulations of an adenocarcinoma cell line with high metastatic potential, with the parent cell line, using cDNA arrays ; microarray and macroarray. The expression of 5 genes was found to be significantly enhanced or reduced in the highly metastatic subpopulations by microarray. The genomic structure of these genes will be detrmined. The expression of matrix metalloproteinase-2 (MMP-2), plasminogen activator inhibitor-1 (PAI-1), carcinoembryonic antigen (CEA), Fas ligand and etc.were upregulated or downregulated in the highly metastatic subpopulations. The differential expression of these genes was confirmed by Northern blot analysis or reverse transcription-polymerase chain reaction (RT-PCR). Altered expression of these genes seems to promote the highly metastatic phenotype in these function. To determine whether the change in p16INK4 methylation status and the genomic status of hBUB1, hMAD2, Insulin-like growth factor 2 receptor genes occurs during metastasis of primary lung cancers, we also analyzed the primary and metastatic tumor tissues and normal lung samples from 30 cases of advanced lung cancer with distant metastasis. The results of this study indicate that tumor cells in which the p16INK4 gene has been inactivated by hypermethylation of the promoter region could have an advantage in metastasis in non-small cell lung cancers. The differential expression of the gene was not detected among subpopulations with high metastatic potential of the cell line and the parent line. The expression of the p16INK4 gene did not seem to be involved in the highly metastatic phenotype in this cell line.