[Study on invasion and metastasis-associated genes of lung cancer related with NM23-H1 gene].

OBJECTIVE: To study on invasion and metastasis-associated genes of lung cancer related with NM23-H1 gene. METHODS: Human gene expression chip based on the subtracted cDNA libraries was constructed. After microarray hybridization, clones sequencing, sequence homology search, the information of differently expressed genes in human large cell lung cancer cell line of L9981 and L9981-nm23-H1 were obtained and then further confirmed by real-time quantitative PCR. RESULTS: Gene expression profiling chips of differently expressed genes in human large cell lung cancer cell line L9981 and L9981-nm23-H1 were successfully constructed. After microarray hybridization, sequence homology search, 19 differentially expressed genes were observed. After real-time quantitative PCR evaluation, we found that the mRNA of 8 genes including PSMA7, SBDS, ODC1, YARS, CSDA, PTP4A1, SHPRH and TOMM7 was up-regulated in the cell line of L9981 after transfected with NM23-H1 gene, whereas the mRNA of PKM2 and GMNN was down-regulated. CONCLUSION: NM23-H1 gene may be the upstream regulator of metastasis-associated genes, which can regulate the downstream genes to achieve a series of lung cancer metastatic potential.

[Effect of 20(R) ginsenoside Rg3 on protein expression of lung cancer cell line.].

BACKGROUND: Lung cancer is the most dangerous threating tumor to human's health and life. Metastasis is not only the malignant characteristics of lung cancer, but also the chief cause of failure to cure the disease and of high mortality. Ginsenoside Rg3 has been proved to have obvious effect against tumor. The molecular mechanism of Rg3 against lung cancer cell line will be investigated by using two-dimensional gel electrophoresis in this paper. METHODS: The IC50 of Rg3 against human high-metastatic large cell lung cancer cell line 95D was determined by MTT. Then 95D cells were treated with Rg3 at the concentration of 0.1*IC50 for 72 h. The total proteins of 95D cell line treated with Rg3 and not treated were separated and protein profiles were obtained by using immobilized PH gradient (IPG)-based two-dimensional gel electrophoresis. The differential expression proteins of 95D cell line treated with Rg3 and not treated were analyzed using image analysis software.15 of differentially expressed proteins were further identified using MALDI-TOF MS/MS analysis and LC-MS/MS analysis. Protein identification was performed by searching the protein database. RESULTS: The IC50 of Rg3 against 95D cell line was 100 mug/mL. There were 27 differently expressed protein spots through analysis by Image Master Microsoft.15 proteins were identified using mass spectrometry. Chloride intracellular channel protein 1, Ubiquitin-Conjugating Enzyme E2-25 Kda only expressed in control; 14-3-3 protein teta, SKI-interacting protein only expressed in 95D cell line treated by Rg3; Annexin A2, profilin 2 isoform b were downregulated in 95D cell line treated by Rg3; 14-3-3 protein zeta, Eukaryotic translation initiation factor 4H were upregulated in 95D cell line treated by Rg3. CONCLUSIONS: A significantly different expression of proteins were found in 95D cell line treated with Rg3 and those not treated. Most of identified proteins have been reported to be associated with tumor metastasis. The identified proteins will provide the basis for searching potential biomarkers and the molecular mechanism of Rg3 against the metastasis of lung cancer cells.

[Construction of the suppression subtractive cDNA libraries of human large cell lung cancer line L9981 before and after transfection with nm23-H1 gene.].

BACKGROUND: It has been proven that nm23-H1 gene is an important metastaticsuppressed gene of lung cancer. In order to screen the differential expression genes related to nm23-H1 , we constructed the suppression subtractive cDNA libraries of human large cell lung cancer line L9981 transfected and untransfected with nm23-H1 gene by suppression subtractive hybridization (SSH) in this study, which lay a solid foundation for further screening and cloning metastatic-related genes of nm23-H1. METHODS: The forward and reverse suppression subtractive cDNA libraries were constructed in the human large cell lung cancer line L9981 before and after transfection with nm23-H1 gene (L9981 and L9981-nm23-H1) by SSH method. The positive clones were preliminarily screened by bluewhite colony, and precisely identified by PCR. RESULTS: The suppression subtractive cDNA libraries were successfully constructed in the human large cell lung cancer line L9981 transfected and untransfected with nm23-H1 gene (L9981-nm23-H1 and L9981). After the blue-white screening, about three hundred positive clones in the forward subtracted library and four hundred positive clones in the reverse subtracted library were obtained. Ramdom analysis of 96 clones in each library with colony PCR methods showed that 84 clones in the forward subtracted library and 83 clones in the reverse subtracted library contained (300-750) bp inserts. CONCLUSIONS: SSH is proved to be an efficient tool for differential expression gene cloning. The forward and reverse suppression subtractive cDNA libraries of human large cell lung cancer line L9981 transfected and untransfected with nm23-H1 gene (L9981-nm23-H1 and L9981) are successfully constructed by SSH and T/A cloning technology. The expression of nm23-H1 gene in the human large cell lung cancer cell lines may affect the differential expression of some metastatic-related genes.