Molecular biology of laryngeal squamous cell carcinoma.

Some of the mechanisms involved in neoplastic transformation and progression of laryngeal squamous cell carcinoma (LSCC) are discussed. Although tumor suppressor inactivation of p53 and p16 is common in these tumors (about 50% each), oncogenic activation is less well characterized. Cyclin D1 and epidermal growth factor receptor amplification have been reported in one-third and one-quarter of LSCCs, respectively, both related to advanced stages, whereas c-myc could be amplified in 13% of cases although without associated overexpression. The role of ras in LSCC is, at most, exceptional, and the role of human papillomavirus infection in these neoplasms could have been largely overestimated. The AIS (amplified in squamous carcinoma) gene has been recently proposed as the main oncogenic target in head and neck squamous carcinomas and is a promising line of investigation. This, along with the link that exists between p53 and INK4 suppressor pathways through ARF and MDM-2, and the role of the universal cdk inhibitors (the Cip/Kip family) in these neoplasms deserve further investigation. Not forgotten are the mechanisms leading to cell immortalization and invasive capabilities acquisition, some of which are also briefly described.