Analysis of gene expression profile induced by EMP-1 in esophageal cancer cells using cDNA Microarray.
OBJECTIVE
To obtain human esophageal cancer cell EC9706 stably expressed epithelial membrane protein-1 (EMP-1) with integrated eukaryotic plasmid harboring the open reading frame (ORF) of human EMP-1, and then to study the mechanism by which EMP-1 exerts its diverse cellular action on cell proliferation and altered gene profile by exploring the effect of EMP-1.


METHODS
The authors first constructed pcDNA3.1/myc-his expression vector harboring the ORF of EMP-1 and then transfected it into human esophageal carcinoma cell line EC9706. The positive clones were analyzed by Western blot and RT-PCR. Moreover, the cell growth curve was observed and the cell cycle was checked by FACS technique. Using cDNA microarray technology, the authors compared the gene expression pattern in positive clones with control. To confirm the gene expression profile, semi-quantitative RT-PCR was carried out for 4 of the randomly picked differentially expressed genes. For those differentially expressed genes, classification was performed according to their function and cellular component.


RESULTS
Human EMP-1 gene can be stably expressed in EC9706 cell line transfected with human EMP-1. The authors found the cell growth decreased, among which S phase was arrested and G1 phase was prolonged in the transfected positive clones. By cDNA microarray analysis, 35 genes showed an over 2.0 fold change in expression level after transfection, with 28 genes being consistently up-regulated and 7 genes being down-regulated. Among the classified genes, almost half of the induced genes (13 out of 28 genes) were related to cell signaling, cell communication and particularly to adhesion.


CONCLUSIONS
Overexpression of human EMP-1 gene can inhibit the proliferation of EC9706 cell with S phase arrested and G1 phase prolonged. The cDNA microarray analysis suggested that EMP-1 may be one of regulators involved in cell signaling, cell communication and adhesion regulators.
Wang
Hai-Tao
HT
National Laboratory of Molecular Oncology, Cancer Institute, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100021, China.
Kong
Jian-Ping
JP
Ding
Fang
F
Wang
Xiu-Qin
XQ
Wang
Ming-Rong
MR
Liu
Lian-Xin
LX
Wu
Min
M
Liu
Zhi-Hua
ZH
D002455:Cell Division / Q000502:physiology; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000473:pathology; D016193:G1 Phase; D020869:Gene Expression Profiling; D006801:Humans; D009363:Neoplasm Proteins; D020411:Oligonucleotide Array Sequence Analysis; D011956:Receptors, Cell Surface / Q000502:physiology*; D016196:S Phase; D014407:Tumor Cells, Cultured
D009363:Neoplasm Proteins; D011956:Receptors, Cell Surface; C097051:epithelial membrane protein-1