The role of E-cadherin/catenin complex in laryngeal cancer.

In this review the role of the epithelial E-cadherin/catenin complex in cases of laryngeal cancer is discussed. Cancer of the larynx remains the second most common head and neck malignancy. The E-cadherin/catenin complex expression is abnormal in laryngeal squamous cell carcinomas. Loss or reduction of E-cadherin expression is especially observed in supraglottic larynx cancer in relation with poor histological differentiation and/or lymph nodes metastases. Controversial results in some studies regarding the role of the E-cadherin/catenin complex in various anatomical parts of the larynx have been reported. Further studies are needed to establish the importance of the E-cadherin/catenin complex as a potential biomarker in laryngeal cancer diagnosis and prognosis.

Expression patterns of cyclins D1, E in laryngeal epithelial lesions: correlation with other cell cycle regulators (p53, pRb, Ki-67 and PCNA) and clinicopathological features.

The expression of cell-cycle progression molecules cyclin D1 and cyclin E were immunohistochemically examined in a series of 64 squamous cell invasive carcinomas of the larynx, 10 in situ carcinomas, 34 cases of dysplasia, 11 papillomas and 23 cases of keratosis. The results of their expression were compared with two cell-cycle implicated tumor suppressor proteins p53 and pRb as well as with two proliferation associated indices PCNA and Ki-67 in an attempt to elucidate their potential role in the pathogenesis and progression of these lesions. Nuclear staining for cyclin D1 and E (>5% positive cells) was observed in 19% and 39.7% of the laryngeal carcinomas, respectively. Significantly elevated levels of cyclin D1 and E in invasive laryngeal carcinomas compared with in situ carcinomas were revealed (p=0.045 and p=0.0003, respectively). High levels of cyclin D1 and E expression were correlated with increased Ki-67 score (p=0.037 and 0.017 respectively). A significant positive correlation between cyclin D1 and E was also detected in carcinomas (p=0.018). Decreased levels of cyclins D1 and E in the group of in situ carcinomas compared with those of dysplastic cases and papillomas were also observed. In the dysplastic lesions cyclin D1 expression was correlated with pRb expression (p=0.02). In the cases of keratosis cyclins D1 and E expression were correlated with pRb (p=0.002 and p=0.036, respectively), while cyclin D1 was associated with PCNA (p=0.008) and Ki-67 score (p=0.009). The prognostic significance of cyclins D1, E in determining the risk of recurrence and overall survival with both univariate (long-rang test) and multivariate (Cox regression) methods of analysis showed no statistically significant differences. We conclude that the expression of cyclins D1 and E in squamous cell carcinomas of the larynx does not seem to have a prognostic significance. In addition, their expression may be involved in the development of laryngeal lesions, implicated in cell proliferation, with other cell cycle related proteins, probably by different molecular pathways.