Expression of nm23H1 and MMP2 in laryngeal carcinoma and its role in aggressiveness of the tumour and node metastasis

Abstract

EnAbstract Introduction Squamous cell carcinomas of the head and neck are known for their aggressive growth and propensity to metastasize. The invasion is facilitated by matrix metalloproteinases (MMPs). The overexpression of many MMPs is positively associated with tumour metastasis. The nm23H1 gene has been implicated as a suppressor gene and reduced expression of its gene product has been observed in patients with positive lymph node metastasis. Objective The aim of this study was to examine the degree of expression of both MMP2 and nm23H1 proteins in 24 patients with primary laryngeal carcinoma using immunohistochemical technique and also to correlate the results with the clinical, radiological and histopathological data, in order to evaluate their role in predicting the local spread and lymph node metastasis. Patients and methods This study included 24 patients with primary laryngeal carcinoma involving various regions of the larynx and was carried out at the Department of Otolaryngology, Ain Shams University Hospitals. The laryngeal and nodal specimens were examined histopathologically and immunohistochemical analysis was carried out for the nm23H1 and MMP2 proteins. Results There was a significant correlation between MMP2 expression and the site of the tumour, as a drastic reduction in MMP2 expression was mainly associated with glottic carcinoma (P<0.05). The tumour stages were associated with an increase in MMP2 expression, but this was not statistically significant (P=0.07). However, the presence of lymph node metastasis was significantly related to the overexpression of MMP2 (P<0.05). As regards nm23H1, a statistically significant correlation was found between nm23H1 expression and the tumour stage (P<0.05). Moreover, the presence of lymph node metastasis was significantly correlated to the loss of nm23H1 expression and vice versa (P<0.05). However, the correlation between the expression levels of MMP2 and nm23H1 was found to be statistically insignificant (P>0.05). Conclusion The increased expression of MMP2 was related to the occurrence of nodal metastasis of the tumour and also to the tumour sites characterized by frequent metastasis (supraglottic and transglottic). In contrast, nm23H1 expression was inversely related to the advancement of the tumour stage and the nodal metastatic state.