Amplification and overexpression of the cyclin D1 gene in head and neck squamous cell carcinoma.

Aims-To determine cyclin D1 gene amplification and expression levels in head and neck squamous cell carcinoma (HNSCC) patients.Methods-Total RNA and genomic DNA were isolated from 40 samples of HNSCC tissue and matched normal tissue and were hybridised with a cyclin D1 cDNA probe. Northern and Southern analyses were used to detect mRNA overexpression and cyclin D1 gene amplification, respectively.Results-15 of the 40 HNSCC samples examined (38%) showed cyclin D1 gene amplification. Of these 15 samples, all 13 from which RNA was available showed increased cyclin D1 expression.Conclusions-HNSCC patients with both amplification and overexpression of the cyclin D1 gene are at greater risk than patients who showed no cyclin D1 gene amplification; amplification and over-expression of the cyclin D1 gene may play an important role in the progression of HNSCC and in clinical outcome.