[Inhibited effects of exogenous caveolin-1 on the growth of laryngeal squamous cell carcinoma cell line Hep-2, experiments in vitro and in vivo].
OBJECTIVE
To study the effect of exogenous caveolin-1 on the growth of laryngeal squamous cell carcinoma and its mechanisms.


METHODS
Eukaryotic expression vectors containing human caveolin-1 gene were transfected into Hep-2 cell line, the positive clones with high expression of caveolin-1 were identified by fluorescence quantitative real time reverse transcriptase-polymerase chain reaction and Western Blot. Cell proliferation viability was tested by methyl thiazolyl tetrazolium assay, the protein expression of epidermal growth factor receptor (EGFR), P-EGFR, extracellular signal-regulated kinase 1, 2 (Erk1, 2), P-Erkl, 2 and caveolin-1 were detected by Western Blot. The combination of caveolin-1 and EGFR were studied by immunoprecipitation and Western Blot. The in vivo antitumor activity of caveolin-1 was tested in Hep-2 xenograft tumor models in athymic nude mice, and the protein expressions of P-EGFR, P-Erk1, 2 and caveolin-1 were examined by immunohistochemistry.


RESULTS
Three of caveolin-1 stably transfected Hep-2 cell clones were established. MTT assay showed that the proliferation of caveolin-1 overexpression Hep-2 cell clones decreased significantly comparing with the control. Immunoprecipitation and western Blot showed that caveolin-1 and EGFR were combined in Hep-2 cell line. Comparing with the parental cell line and cells transfected with control vector, there were the lower phosphorylation of EGFR and Erk1, 2 in the caveolin-1 overexpression Hep-2 cell clones. In the xenograft tumor models in nude mice, caveolin-1 overexpression Hep-2 cell clones showed the slower growth, smaller tumor size and the lower phosphorylation of EGFR and Erk1, 2.


CONCLUSIONS
Overexpression of caveolin-1 inhibits growth of Hep-2 cell line in vitro and in vivo, arresting EGFR-MAPK signal pathway may involve in its mechanism.
Gu
Dong-Hua
DH
Department of Pathology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Li
Hua
H
Wang
Zhen
Z
Chen
Qi
Q
Zhu
Hong-Guang
HG
D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D051242:Caveolin 1 / Q000494:pharmacology*; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000378:metabolism; D006801:Humans; D007822:Laryngeal Neoplasms / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
D051242:Caveolin 1; D066246:ErbB Receptors; D020929:Mitogen-Activated Protein Kinase Kinases