[Studies of the deletion and expression of cytokeratin 13 gene in laryngeal squamous cell carcinoma].

In order to investigate the role of Cytokeratin 13(CK13) gene in laryngeal carcinogenesis, we detected the deletion of CK13 gene through LOH analysis indirectly at DNA level using 5 STR primers within and near CK13 gene in 72 cases of laryngeal squamous cell carcinoma, then detected the differential expression between 16 cases of paired normal and cancerous tissue by Northern blot, and performed immunohistochemistry using well characterized monoclonal antibody against CK13 in squamous cell carcinoma of different stages. We found that all of the microsatellite loci exist LOH, and the LOH frequencies were 18.03%, 28.13%, 27.42%, 39.68% and 34.85% at D17S1964E, D17S2092, D17S791, D17S1665 and D17S808 respectively. The LOH+ cases accounted for 77.78% (56/72), and the frequencies of LOH were not related to the type of laryngeal carcinoma and the lymphoid metastasis; but significantly related to the differentiation, P < 0.05. CK13 gene is expressed significantly higher in 16 cases of normal tissues than in paired cancerous tissues, and the immunostain revealed that CK13 was expressed in normal laryngeal squamous cell or high differentiation stage, and its expression decreased or disappeared in poor ones, P < 0.01. CK13 gene might play an important role in the laryngeal carcinogenesis, acting as a novel tumor suppressor gene, and may be relevant to laryngeal squamous cell carcinoma diagnosis and prognosis. Further research will contribute to conform it.