The incidence of tumor and the time of expression, cellular localization and the molecular weight of tumor associated proteins of rat skin tumor induced by 7,12-dimethylbenz[a]anthracene (DMBA) with or without 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were studied. The time of the development of skin tumors in 0.1% DMBA-TPA treated rats was significantly shorter than that in rats which were treated with DMBA alone. In the complete carcinogenesis case, papillomas developed more slowly and were less common and also squamous cell carcinomas appeared much later. From the analysis of the proteins of each experimental group by SDS-PAGE and two dimensional gel electrophoresis, at least three tumor associated proteins were identified (54kd, pl = 5.66; 27kd, pl = 5.85; 11kd, pl = 4.90). Also these proteins were found in rat dorsal skin from 14 days gestation to 21 days postpartum, and disappeared after 28 days. In conclusions, two stage skin carcinogenesis could be successfully demonstrated in Sprague-Dawley rats and abnormal proteins were produced in DMBA or DMBA-TPA induced skin tumor. The tumor associated proteins of skin tumor induced by DMBA or DMBA-TPA were appeared at the late initiation stage or early promotion stage, and they were localized in plasma membrane and were glycoproteins that are thought to be related to the epidermal differentiation process.
9,10-Dimethyl-1,2-benzanthracene ; Animal ; Antigens, Surface/*analysis ; Carcinoma, Squamous Cell/*analysis/chemically induced/pathology ; Cell Membrane/metabolism ; Comparative Study ; Glycoproteins/analysis ; Membrane Proteins/*analysis ; Papilloma/*analysis/chemically induced/pathology ; Rats ; Rats, Inbred Strains ; Skin Neoplasms/*analysis/chemically induced/pathology ; Support, Non-U.S. Gov't ; Tetradecanoylphorbol Acetate

The incidence of tumor and the time of expression, cellular localization and the molecular weight of tumor associated proteins of rat skin tumor induced by 7,12-dimethylbenz[a]anthracene (DMBA) with or without 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were studied. The time of the development of skin tumors in 0.1% DMBA-TPA treated rats was significantly shorter than that in rats which were treated with DMBA alone. In the complete carcinogenesis case, papillomas developed more slowly and were less common and also squamous cell carcinomas appeared much later. From the analysis of the proteins of each experimental group by SDS-PAGE and two dimensional gel electrophoresis, at least three tumor associated proteins were identified (54kd, pl = 5.66; 27kd, pl = 5.85; 11kd, pl = 4.90). Also these proteins were found in rat dorsal skin from 14 days gestation to 21 days postpartum, and disappeared after 28 days. In conclusions, two stage skin carcinogenesis could be successfully demonstrated in Sprague-Dawley rats and abnormal proteins were produced in DMBA or DMBA-TPA induced skin tumor. The tumor associated proteins of skin tumor induced by DMBA or DMBA-TPA were appeared at the late initiation stage or early promotion stage, and they were localized in plasma membrane and were glycoproteins that are thought to be related to the epidermal differentiation process.
9,10-Dimethyl-1,2-benzanthracene ; Animal ; Antigens, Surface/*analysis ; Carcinoma, Squamous Cell/*analysis/chemically induced/pathology ; Cell Membrane/metabolism ; Comparative Study ; Glycoproteins/analysis ; Membrane Proteins/*analysis ; Papilloma/*analysis/chemically induced/pathology ; Rats ; Rats, Inbred Strains ; Skin Neoplasms/*analysis/chemically induced/pathology ; Support, Non-U.S. Gov't ; Tetradecanoylphorbol Acetate

OBJECTIVETo examine and analyze the global gene expression at the different stages of golden hamster cheek pouch mucosa carcinomatous change induced by 9,10-dimethylene-1,2 benzanthracene (DMBA).

METHODSThe model of golden hamster cheek pouch squamous cell carcinoma was induced by DMBA. The RNA of normal mucosa, precancerous lesions and squamous cell carcinoma of fresh tissue of golden hamsters was extracted and purified and the cRNA labeled by fluorescent Cy3 synthesized, which respectively hybridized with the agilent rat cDNA microarray containing 41 000 genes-expressed sequence tags, scanning with Agilent G2565AA fluorescence scanner. The Ratio>or=2 and Ratioanalysis software was then used to select the genes of continuing expression in the three different stages of cancer. Meanwhile, RT-PCR was used to confirm the correctness of the results of the gene chip.

RESULTSA total of 5255 differentially expressed genes were detected during the process from normal mucosa to the squamous cell carcinoma, of which 2896 was up-regulated and 2359 down-regulated. There were 22 genes that showed continues abnormal expression through the three different stages of carcinomatous change, including 3 up-regulated, 19 down-regulated. The RT-PCR results of Eaf-2 and Ecg-2 were consistent with the gene chip.

CONCLUSIONSThe development of oral mucosal squamous cell carcinoma involved a number of abnormal genes. The genes showing continues abnormal expression at different stages of carcinomatous change may be the important pathogenetic ones.

9,10-Dimethyl-1,2-benzanthracene ; Animals ; Carcinogens ; Carcinoma, Squamous Cell ; chemically induced ; genetics ; pathology ; Cheek ; Cricetinae ; Female ; Gene Expression Profiling ; Gene Expression Regulation, Enzymologic ; Male ; Mesocricetus ; Mouth Mucosa ; metabolism ; Mouth Neoplasms ; chemically induced ; genetics ; pathology ; Oligonucleotide Array Sequence Analysis ; Precancerous Conditions ; chemically induced ; genetics ; pathology ; RNA, Complementary ; genetics ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction