Progression of head and neck cancer in an in vitro model.
OBJECTIVE
To identify alterations in angiogenesis and cell cycle regulation as preneoplastic cells progress to cancer in an in vitro model of head and neck tumor progression.


METHODS
Immortal human gingival keratinocyte (IHGK) cells (preneoplastic) were derived from normal oral keratinocytes and were immortalized with human papillomavirus 16. Transformation of IHGK cells with a carcinogen (NNK, 4-[methylnitrosamino]-1-[3-pyridyl]-1-butanone) gave rise to IHGKN cells. We determined the growth rates, cell cycle phase, expression of cell cycle regulators, and expression of vascular endothelial growth factor along with the organotypic features of these cells and compared them with characteristics of head and neck cancer cells.


RESULTS
IHGK and IHGKN cells grown in raft culture were morphologically similar to severe dysplasia and carcinoma, respectively. The proportion of cells in G(0)/G(1) was similar between IHGK and IHGKN. However, the proportion of IHGK cells was 35% greater in S phase as compared with the IHGKN cells, while a greater percentage (40%) of IHGKN cells were in G(2)/M. The expression of the other cell cycle regulators tested was unchanged. IHGK cells secreted less vascular endothelial growth factor on day 1 when compared with IHGKN (50.6 vs 245.6 pg/mL), along with a lower overall production rate (79% vs 133%).


CONCLUSIONS
Transformation of IHGK cells resulted in the activation of vascular endothelial growth factor associated with angiogenesis. Inactivation of the G(1) cell cycle regulation occurred during immortalization and before transformation, and was sustained after carcinogen exposure. These alterations correspond to changes observed in patients with head and neck squamous cell carcinoma. This model can be useful in testing novel therapeutic and preventive strategies.
Yoo
G H
GH
Department of Otolaryngology-Head and Neck Surgery, Wayne State University, 5E University Health Center, 540 E Canfield Ave, Detroit, MI 48201, USA.
Washington
J
J
Piechocki
M
M
Ensley
J
J
Shibuya
T
T
Oda
D
D
Wei
W Z
WZ
D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D018797:Cell Cycle Proteins / Q000032:analysis; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000378:metabolism; D005881:Gingiva / Q000473:pathology; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D015603:Keratinocytes / Q000473:pathology*; D008222:Lymphokines / Q000378:metabolism; D009389:Neovascularization, Pathologic; D020033:Protein Isoforms / Q000378:metabolism; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D018797:Cell Cycle Proteins; D016228:Endothelial Growth Factors; D008222:Lymphokines; D020033:Protein Isoforms; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors