Joseph P, Muchnok T, Ong T
Molecular Epidemiology Laboratory, Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA.
Mol Carcinog. 2001 Sep;32(1):28-35. doi: 10.1002/mc.1061.
Differential gene expression was studied to understand the potential molecular mechanism responsible for cell transformation and tumorigenesis induced by beryllium. Cell lines were derived from tumors developed in nude mice injected subcutaneously with BALB/c-3T3 cells morphologically transformed with beryllium sulfate. Using the Atlas mouse 1.2 cDNA expression microarray, the expression profiles of 1176 genes, belonging to several different functional categories, were studied in the tumor cells as well as in the nontransformed control cells. Expression of 18 genes belonging to two functional groups was found to be consistently and reproducibly different (at least twofold) in the tumor cells compared with the control cells. The functional groups and the differentially expressed genes are as follows: The cancer-related genes (nine genes) were the ets-related transcription factor activated by ras, colony-stimulating factor, A-myb, sky, cot1, c-fos, c-jun, c-myc, and R-ras proto-oncogenes. The DNA synthesis, repair, and recombination genes (nine genes) were the DNA replication licensing factor MCM4, the DNA replication licensing factor MCM5, the DNA mismatch repair gene PMS2, the DNA excision repair gene, the DNA mismatch repair gene MSH2, the ultraviolet excision repair gene Rad23 DNA ligase 1, Rad51, and Rad52. The differential gene expression profile was confirmed with reverse transcription-polymerase chain reaction using primers specific for the differentially expressed genes. In general, expression of the cancer-related genes was upregulated, while expression of genes involved in DNA synthesis, repair, and recombination was downregulated in the tumor cells compared with the control cells. Using c-fos and c-jun, two of the differentially expressed genes, as model genes, we have found that in the nontransformed BALB/c-3T3 cells, the beryllium-induced transcriptional activation of these genes was dependent on pathways of protein kinase C and mitogen-activated protein kinase and independent of reactive oxygen species. These results indicate that beryllium-induced cell transformation and tumorigenesis are accompanied by and are possibly a product of alterations in expression of genes related to cancer and to DNA synthesis, repair, and recombination.
研究差异基因表达以了解铍诱导细胞转化和肿瘤发生的潜在分子机制。细胞系来源于皮下注射经硫酸铍形态转化的BALB/c - 3T3细胞的裸鼠所形成的肿瘤。使用Atlas小鼠1.2 cDNA表达微阵列，研究了肿瘤细胞以及未转化的对照细胞中属于几个不同功能类别的1176个基因的表达谱。与对照细胞相比，发现属于两个功能组的18个基因在肿瘤细胞中的表达始终且可重复地不同（至少两倍）。功能组和差异表达基因如下：癌症相关基因（9个基因）是由ras激活的ets相关转录因子、集落刺激因子、A - myb、sky、cot1、c - fos、c - jun、c - myc和R - ras原癌基因。DNA合成、修复和重组基因（9个基因）是DNA复制许可因子MCM4、DNA复制许可因子MCM5、DNA错配修复基因PMS2、DNA切除修复基因、DNA错配修复基因MSH2、紫外线切除修复基因Rad23、DNA连接酶1、Rad51和Rad52。使用针对差异表达基因的特异性引物通过逆转录 - 聚合酶链反应证实了差异基因表达谱。一般来说，与对照细胞相比，肿瘤细胞中癌症相关基因的表达上调，而参与DNA合成、修复和重组的基因的表达下调。以两个差异表达基因c - fos和c - jun作为模型基因，我们发现，在未转化的BALB/c - 3T3细胞中，铍诱导的这些基因的转录激活依赖于蛋白激酶C和丝裂原活化蛋白激酶途径，且独立于活性氧。这些结果表明，铍诱导的细胞转化和肿瘤发生伴随着与癌症以及DNA合成、修复和重组相关的基因表达改变，并且可能是这些改变的产物。
