ABSTRACT
<p><b>BACKGROUND</b>Recent researches have found that NiS can cause the malignant transforming activity and carcinogenicity on human bronchial epithelial cells (16HBE). Its molecular mechanism may be involved in mutation of genes and abnormal expression of transcription factors on 16HBE. And so, this study takes advantage of a model of 16HBE transformed by NiS and screens the differentially expressed genes between 16HBE cells and NiS treated 16HBE cells (NiS-16HBE) using cDNA microarray.</p><p><b>METHODS</b>The total RNA was extracted from 16HBE cells and NiS-16HBE cells. The cDNA probes were prepared by labeling with Cy3-dCTP and Cy5-dCTP respectively through reverse transcription. The mixed probes were then hybridized to the cDNA microarray chips containing 4000 human genes. The chips were scanned by ScanArray 4000 laser scanner. The acquired fluorescent signals were analyzed by GenPix Pro 3.0 software. Bioinformation function of those differentially expressed genes was analysed.</p><p><b>RESULTS</b>A total of 151 genes exhibited differential expression between 16HBE cells and NiS-16HBE cells. The expression of 70 genes ( 46.36%) was down-regulated and that of 81 genes (53.64%) was up-regulated.</p><p><b>CONCLUSIONS</b>The regulation of genes including stress response genes, immune related genes, DNA synthesis and repair genes, metabolism genes, pro-oncogenes and tumor suppressor genes may be involved in transforming activity of NiS.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To clone differentially expressed cDNA sequences involved in malignant transformation induced by benzo(a)pyrene metabolite dihydroxyepoxy benzo pyrene (BPDE).</p><p><b>METHOD</b>The malignant transformation of human bronchial epithelial cell line 16HBE induced by BPDE in vitro was used as a model for comparing gene expression between the transformed cells and controls. cDNA representational difference analysis (cDNA-RDA) was performed to isolate differentially expressed cDNA fragment in transformed cells. The cDNA fragments were ligated to pGEM-T vector and transformed into JM109 bacteria. The plasmid DNA were sequenced and compared with data in GenBank by BLASTN.</p><p><b>RESULTS</b>Five cDNA sequences were found to be novel ones and were registered in dbest database, which assigned accession numbers in GenBank are BG354691, BG354692, BG354693, BG354694 and BG354695, respectively. Eight of the remaining cDNA sequences showed sequence homology to those previously reported such as ribosomal protein S23, MLN137, ACTN4, transforming growth factor and G protein gene.</p><p><b>CONCLUSIONS</b>These 13 genes may be involved in BPDE-induced malignant transformation, but their biological characteristics and functions are left to further studies.</p>
Subject(s)
Humans , Benzopyrenes , Metabolism , Pharmacology , Carcinogens , Pharmacology , Cell Transformation, Neoplastic , Genetics , Cells, Cultured , Cloning, Molecular , DNA, Complementary , DNA, Neoplasm , Gene ExpressionABSTRACT
Objective To findout a good method for malignant transformation of human bronchial epithelial cells 16HBE cell induced by anti-benzo (a) pyrene-trans-7,8-dihydrodiol-9,10-epoxide (anti-BPDE) using the objective and simple index:colony forming frequency of cells in semisolid agar culture medium,and to establish a best model of malignant transformation of 16HBE cells.Methods The tests on viable rate and colony formation of 16HBE cells were carried out to determine the exposure doses of anti-BPDE.The l6HBE cells were treated once or several times by anti BPDE at different doses and the transformed foci were observed and assessed at the different stages during the period of the whole experiment.The malignant features of transformed 16HBE cells with a good dose-response relationship were identified by the method of semisolid agar culture.The anti-BPDE induced colony forming frequencies of 16HBE cells in semisolid agar medium in each dose group were statistically compared.Results The best method for malignant transformation of 16HBE cells induced by anti-BPDE was that the 16HBE cells were intermittently treated several times with anti-BPDE at doses of 0.1,0.5,1.0 and 2.0 μmol/L respectively and were inoculated for 15 generations,the related colony forming frequencies were 2.0‰,5.5‰,7.0‰ and 10.5‰respectively with a significant dose-response relation ship and a good linear correlation (r=0.9741,P＜0.05).Conclusion The research infered that the malignant transformation of human bronchial epithelial cell-16HBE cells could be induced successfully by anti-BPDE,a suitable model could be established by anti-BPDE also.
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In the present study, the influence of essential free fatty acids on AFP secretion and cell growth of BEL-7402 human hepatocellular cacinoma cell line was investigated by radiommunoassay. The results demonstrated that 40 - 50?g/ ml concentration of linolenic acid could inhibit the AFP secretion obviously( P 0.05) . All of these studies about anti-cancer effect of linolenic acid will provide the principle for the patient for health care and therapy.
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Objective To investigate the expression changes of translation elongation factor 1?1 in anti-BPDE transformed and carcinoma 16 HBEs. Methods Suppression subtractive hybridization (SSH), bioinformatics and semi-quantitative RT-PCR were applied. The cDNA of anti-BPDE transformed and carcinoma 16 HBE cells were used as tester respectively, and the cDNA of normal 16 HBE was used as driver, the library of subtractive hybridization were profiled and inverted into TA cloning vector after two times of hybridization and two times of PCR. After the screening, sequencing and analysis of sequences, semi-quantitative RT-PCR was performed accompanying to the inner reference of ?-actin. Results 9 differentially expressed fragments were consistent with translation elongation factor 1?1 in different regions in Genbank, and the expressions were up regulated in BPDE transformed and carcinoma 16 HBE cells. Conclusion Translation elongation factor 1?1 may be related to the transforming effect and carcinogenesis of anti-BPDE.