[Effects of caveolin-1 on biologic behavior of laryngeal squamous cell carcinoma HEp2 cell line GU].
OBJECTIVE
To investigate the effects of caveolin-1 on the biologic behavior of laryngeal squamous cell carcinoma HEp2 cell line in vitro.


METHODS
Eukaryotic expression vector of human caveolin-1 gene was constructed and transfected into HEp2 cells by Lipofectamine. The clones stably overexpressing caveolin-1 were identified by real-time PCR and Western blotting. Cell proliferation viability was tested by MTT assay. Anchorage-independent growth was determined by assaying colony formation in soft agar. Flow cytometry was used to assess the cell cycle and apoptosis. The relative phosphorylation level of EGFR and ERK1/2 were detected by Western blotting. Localization of caveolin-1 and EGFR were studied by laser confocal laser scanning microscopy.


RESULTS
The expression vector of caveolin-1 was constructed and three clones stably overexpressing caveolin-1 were obtained. Comparing with the parental HEp2 cells, the transfected cells exhibited a slower growth rate and formed fewer colonies in soft agar. The results of FACS analysis revealed that overexpression of caveolin-1 resulted in the cell cycle arrest at G0/G1 phase and increased the apoptotic cell fraction. EGFR was found to colocalize with caveolin-1 in transfected cells by confocal laser scanning microscopy and Western blotting results showed that overexpression of caveolin-1 reduced the phosphorylation of EGFR and Erkl/2.


CONCLUSIONS
Overexpression of caveolin-1 suppresses the growth of HEp2 cells and induces apoptosis and inhibition of EGFR-MAPK signaling pathway may be involved in its mechanism.
Gu
Dong-hua
DH
Department of Pathology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Tang
Feng
F
Wang
Zhen
Z
Li
Hua
H
Chen
Qi
Q
Zhu
Hong-guang
HG
D017209:Apoptosis; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D066246:ErbB Receptors / Q000378:metabolism*; D005434:Flow Cytometry; D005822:Genetic Vectors / Q000737:chemistry / Q000235:genetics; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008055:Lipids / Q000737:chemistry; D018613:Microscopy, Confocal; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010766:Phosphorylation; D016133:Polymerase Chain Reaction / Q000379:methods; D015398:Signal Transduction / Q000502:physiology; D014162:Transfection / Q000379:methods
D051242:Caveolin 1; D008055:Lipids; C086724:Lipofectamine; D066246:ErbB Receptors; D048052:Mitogen-Activated Protein Kinase 3