| Metastasis is not only the malignant characteristics of lung cancer, but also the key cause of failure to cure and high mortality. It has been proved that lung cancer metastasis is a complex process involving multiple gene and steps. Study on lung cancer metastasis has been focused on molecular pathogenesis for a long time, and outcomes are achieved in gene (DNA) and transcription (mRNA) level. Nm23 gene discovered in recent years is considered as one of the most important tumor metastatic suppressive gene. It has been proved that a close correlation exists between the high metastatic rate and the low expression or alleic deletion of nm23-H1 gene at DNA, mRNA level. But little is known about the molecular mechanism of metastasis suppression by nm23-H1 and the change of protein expression. By the limitation of itself, genomics cannot explain the interaction between proteins or between proteins and other bio-molecules, so the emphasis is gradually shifting to proteome recently. In order to explore what effects willbe achieved after transfection of nm23-Hl gene into human high-metastatic large cell lung cancer cell line L9981 for proteome, what difference of proteome will be existd comparing the human high- and low-metastatic large cell lung cancer cell lines, the difference expression proteins were detected in L9981 (high metastatic cell line with nm23-Hl gene deletion, screened by our laboratory), L9981-nm23-Hl (constructed with transfecting nm23 into L9981), L9981-pLXSN(constructed with transfecting empty vector into L9981) and NL9980(low metastatic) lung cancer cell lines by two dimensional gel electrophoresis. The results were first showed in the world as follows:1. Comparing protein spectrums between L9981 and NL9980 lung cancer cell line, 15 difference protein spots were only existed in L9981, other 27 difference protein spots were only observed in NL9980. Furthermore, 4 protein spots were detected both in L9981 and NL9980 lung cancer cell lines, in which 3 protein spots had higher volume in L9981 than that in NL9980 and the rest one protein spot had higher volume in NL9980 than that in L9981.2. Comparing protein spectrums between L9981 and L9981-nm23-Hl lung cancer cell line, 6 difference protein spots were only existed in L9981, other 17 difference protein spots were only observed in L9981-nm23-Hl lung cancer cell line. Furthermore, 13 protein spots were detected both in L9981 and L9981-nm23-Hl lung cancer cell lines, in which the expression level of 8 protein spots in L9981 were remarkably higher than that in L9981-nm23-Hl and the rest 5 protein spots in L9981-nm23-Hl was significantly higher than that in L9981.3. Comparing protein spectrums between L9981 and L9981-pLXSN lung cancer cell line, 3 difference protein spots were only observed in L9981 lung cancer cell line, other 4 difference protein spots were only detected in L9981-pLXSN lung cancer cell line. Furthermore, 14 protein spots were existed both in L9981 and L9981-pLXSN lung cancer cell lines, in which the expression level of the 9 protein spots in L9981 were significantly higher than that in L9981-pLXSN lung cancer cell line, and the rest 5 protein spots in L9981-pLXSN were remarkably higher than that in L9981 lung cancer cell line.4. Comparing with the primary human large cell lung cancer cell line (L9981), 4 new difference protein spots were detected in protein spectrums of both in L9981-nm23-Hl and L9981-pLXSN lung cancer cell line, and 3 protein spots observed in L9981 were not found both in L9981-nm23-Hl and L9981-pLXSN lung cancer cell line.5. In addition, the experiment conditions of two dimensional gel electrophoresis and the methods of gel image analysis, and the experiment parameter were repeatedly compared, and a suit of experiment methoeds fitting our laboratory was worked out, which settled basis of future research.Conclusions: (1)A difference expression spectrum of protein was exsited among the different human large cell lung cancer cell lines which have different metastatic abilities;(2)After transfection of nm23-Hl gene into the human high-metastatic large cell lung cancer cell line L9981,the protein spectrums were significantly changed in the L9981-nm23-Hl lung cancer cell line transfecting with nm23-Hl gene,in which some proteins were downregulated, some were upregulated, and some new proteins weredetected and some proteins existed in the primary lung cancer cell line L9981 were disappeared in L9981-nm23-Hl cancer cell line; (3)The changes of protein spectrums after transfection of nm23-Hl gene might be related to the effects of regulation of nm23-Hl gene on "lung cancer metastatic suppressor cascade", and it is the base of nm23-Hlgene for reversing the invasive and metastatic phenotype in human high-metastatic large cell lung cancer. |
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