Cyclin D1 amplification and p16(MTS1/CDK4I) deletion correlate with poor prognosis in head and neck tumors.
OBJECTIVE
Cyclin D1, a cell cycle regulator localized to chromosome 11q13, is amplified in several human tumors including head and neck squamous cell carcinoma (HNSCC). Amplification and/or overexpression of cyclin D1 have been correlated to a poor prognosis. Deletion of the p16 gene, localized to 9p21, has also been observed in a significant proportion of HNSCC. The p16 gene regulates cyclin D1-CDK4 activity and prevents retinoblastoma tumor suppressor gene phosphorylation, thereby downregulating cellular proliferation. Detection of cyclin D1 amplification and p16 deletion using a simple and sensitive method will be valuable for the development of effective treatment modalities for head and neck cancer.


METHODS
We have used fluorescence in situ hybridization (FISH) to study cyclin D1 amplification and p16 gene deletion in head and neck tumors. Both single- and dual-color FISH were performed.


METHODS
Paraffin-embedded tissues from 103 patients with HNSCC were analyzed using genomic DNA probes for cyclin D1 and p16. Dual-color FISH was performed with chromosome 11 or 9 centromeric probes as a control. Twenty-eight of these samples were analyzed for p16 expression by immunohistochemistry.


RESULTS
Cyclin D1 amplification was observed in 30% (31/103) of patients, and p16 deletion in 52% (54/103). Lack of p16 expression was observed in 64% (18/28) of patients. There was a good correlation between the deletion of p16 sequences and the loss of p16 expression (P = .008). Amplification of cyclin D1 had a statistically significant association with recurrence, distant metastasis, and survival at 36 months. There was a significant association between p16 deletion and the development of distant metastases. Cyclin D1 amplification and p16 deletion together correlated with recurrence, distant metastasis, and survival.


CONCLUSIONS
We demonstrate that FISH is a simple and sensitive method for detecting cyclin D1 amplification and p16 deletion in head and neck cancer. Our results suggest that these two genetic aberrations together portend a poorer outcome than either of the abnormalities alone in head and neck cancer.
Namazie
Ali
A
Division of Head and Neck Surgery, University of California Los Angeles School of Medicine, USA.
Alavi
Sassan
S
Olopade
Olufunmilayo I
OI
Pauletti
Giovanni
G
Aghamohammadi
Neema
N
Aghamohammadi
M
M
Gornbein
Jeffrey A
JA
Calcaterra
Thomas C
TC
Slamon
Dennis J
DJ
Wang
Marilene B
MB
Srivatsan
Eri S
ES
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism; D016009:Chi-Square Distribution; D019938:Cyclin D1 / Q000235:genetics* / Q000378:metabolism; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005784:Gene Amplification; D017353:Gene Deletion; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis
D014408:Biomarkers, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16; D019938:Cyclin D1