Expression of cdk6 in head and neck squamous cell carcinoma.
OBJECTIVE
Cdk6 is a key regulator during the G1/S cell cycle transition. Aberrant expression of cdk6 protein has been observed in many cancer types. However, little is known about the expression of cdk6 in head and neck squamous cell carcinoma (HNSCC) and its clinical significance. This study evaluated the expression of cdk6 in HNSCC and analyzed the relationship between cdk6 expression and clinicopathological parameters of HNSCC.


METHODS
Expression of cdk6 was immunohistochemically investigated in 98 HNSCCs. Nuclear and cytoplasmic positive cells were counted separately. Data were presented as the percentage of positive cells. The correlation between the percentage of positive cells and clinicopathological factors was determined.


RESULTS
Nuclear and cytoplasmic staining for cdk6 were detected in 91 cases and 97 cases, respectively. A significant correlation was found only between the percentage of nuclear positive cells and T classification (p value = 0.0410). Tumors with high nuclear cdk6-positive cells showed a linear trend toward advanced tumor status (p value = 0.0064).


CONCLUSIONS
Cdk6 was highly expressed in HNSCC. Tumors with high nuclear cdk6 expression tended to have advanced tumor status. These results suggest that cdk6 plays a vital role in HNSCC and is involved in tumor progression of this cancer.


CONCLUSIONS
An increased nuclear cdk6 expression is an unfavorable factor for HNSCC. Cdk6 may serve as a therapeutic target in this cancer.
Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Mahidol University, Yothi Street, Bangkok, 10400, Thailand. spoomsawat@yahoo.com.
Sopee
S
Poomsawat
Department of Oral Biology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
Sirima
S
Sanguansin
Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Mahidol University, Yothi Street, Bangkok, 10400, Thailand.
Jirapa
J
Punyasingh
Department of Surgery, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Paisarn
P
Vejchapipat
Army Institute of Pathology, Pramongkutklao Hospital, Bangkok, Thailand.
Phaibul
P
Punyarit
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D051361:Cyclin-Dependent Kinase 6 / Q000378:metabolism*; D005260:Female; D006258:Head and Neck Neoplasms / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012307:Risk Factors
C495911:CDK6 protein, human; D051361:Cyclin-Dependent Kinase 6
Cdk6; Head and neck; Immunohistochemistry; Squamous cell carcinoma