Activation of ERK1/2 and cyclin D1 expression in oral tongue squamous cell carcinomas: relationship between clinicopathological appearances and cell proliferation.
We report an immunohistochemical investigation of the expression of activated extracellular signal-regulated kinase (ERK1/2) and cyclin D1 protein in both oral tongue squamous cell carcinomas (OTSCCs) and normal tongue epithelium. The expression of Ki-67 labeling index (LI) was also examined in order to evaluate cell proliferation activity. The expression of activated ERK1/2, cyclin D1 protein and Ki-67 LI were significantly stronger in OTSCCs than in normal oral mucosa (P<0.05). Both over-expression of activated ERK1/2 and positive expression of Ki-67 in OTSCCs were significantly associated with a moderately or poorly differentiated grade of carcinoma (P<0.05). Cyclin D1 immunostaining showed statistically significant association with both lymph node metastasis (P<0.05) and a tumor thickness >5mm (P<0.05). Over-expression of activated ERK1/2 was positively correlated with cyclin D1 protein expression (P<0.05, r=0.624) and cell proliferation-related indexes Ki-67 (P<0.05, r=0.723). Our results suggest that over-expression of activated ERK1/2 and cyclin D1 protein are involved in oral tongue carcinogenesis, and that activation of ERK1/2 might be related to cell cycle regulation and cell proliferation in OTSCCs.
Department of Bioengineering, School of Sciences, Graduate School, Northeast University, PR China. wanglihong523@yahoo.com.cn
Lihong
L
Wang
Tingjiao
T
Liu
Mai
M
Nishioka
Rodelio L
RL
Aguirre
Swe Swe
SS
Win
Norihiko
N
Okada
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000473:pathology; D018797:Cell Cycle Proteins / Q000378:metabolism; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000096:biosynthesis*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007564:Japan; D019394:Ki-67 Antigen / Q000378:metabolism; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D019950:Mitogen-Activated Protein Kinase 1 / Q000096:biosynthesis; D048052:Mitogen-Activated Protein Kinase 3 / Q000096:biosynthesis; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D014062:Tongue Neoplasms / Q000201:enzymology* / Q000473:pathology
D018797:Cell Cycle Proteins; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D019938:Cyclin D1; D048049:Extracellular Signal-Regulated MAP Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3