Overexpression of CyclinD1 and underexpression of p16 correlate with lymph node metastases in laryngeal squamous cell carcinoma in Chinese patients

Abstract

CyclinD1 and p16 are involved in the regulation of G1 checkpoint and may play an important role in the tumorgenesis of laryngeal squamous cell carcinoma (LSCC). Previous studies have examined the level of expression of cyclinD1 or p16 in LSCC but no such information is available for their relation and their correlation with lymph node metastasis in Chinese patients. A total of 58 patients underwent surgical resection of laryngeal tumours in the Department of Otolaryngology, Qilu Hospital Shandong University between January 2001 and December 2002. All pathologic specimens were available for immunohistochemical study using antibodies against cyclinD1 and p16. Compared with normal epithelium, expression of CyclinD1 in the LSCC was significantly higher (62.1% vs. 10.0%, P < 0.05), expression of p16 was significantly lower (48.3% vs. 90.0%, P < 0.05); CyclinD1 expression in LSCC was up-regulated in TNM classification (r (s) = 0.409, P < 0.05) as well as with cervical lymph node metastases (r (s) = 0.294, P < 0.05); p16 expression in LSCC was down-regulated with cervical lymph node metastases (r (s) = -0.275, P < 0.05); negative significant correlation between p16 immunostaining and CyclinD1 was observed in LSCC (r (s) = -0.331, P < 0.05). There was a negative correlation between CyclinD1 expression and p16 expression in LSCC. The over-expression of CyclinD1 and the under-expression of p16 may play a significant role in the incidence and development of LSCC and may be important indicators for cervical lymph node metastases in Chinese patients of LSCC.