Analysis of HPV-Positive and HPV-Negative Head and Neck Squamous Cell Carcinomas and Paired Normal Mucosae Reveals Cyclin D1 Deregulation and Compensatory Effect of Cyclin D2.

Aberrant regulation of the cell cycle is a typical feature of all forms of cancer. In head and neck squamous cell carcinoma (HNSCC), it is often associated with the overexpression of cyclin D1 (). However, it remains unclear how expression changes between tumor and normal tissues and whether human papillomavirus (HPV) affects differential expression. Here, we evaluated the expression of D-type cyclins in a cohort of 94 HNSCC patients of which 82 were subjected to whole genome expression profiling of primary tumors and paired normal mucosa. Comparative analysis of paired samples showed that was upregulated in 18% of HNSCC tumors. Counterintuitively, was downregulated in 23% of carcinomas, more frequently in HPV-positive samples. There was no correlation between the change in D-type cyclin expression and patient survival. Intriguingly, among the tumors with downregulated , one-third showed an increase in cyclin D2 () expression. On the other hand, one-third of tumors with upregulated showed a decrease in . Collectively, we have shown that was frequently downregulated in HNSCC tumors. Furthermore, regardless of the HPV status, our data suggested that a change in expression was alleviated by a compensatory change in expression.