Mdm2 mRNA expression in salivary gland tumour cell lines

Background: Murine double minute 2 (mdm2) is a cellular protooncogene, which, in conditions of overexpression or amplification, is capable of inactivating the functions of p53, leading to tumorigenesis. Immunoexpression of mdm2 in salivary gland tumours was previously found; however, it was necessary to find out if mdm2 was overexpressed. The aim of this study was to analyse the mRNA expression of mdm2 in salivary gland neoplasms and to correlate it to immunoexpression of p53 and p21 proteins. Methods: Specimens of different salivary gland neoplasms were obtained from surgical resections, and cell lineages derived from these tissues were established. RNA extraction was performed and mRNA expression was investigated using reverse transcription‐polymerase chain reaction (RT‐PCR). Cellular expression of p53 and p21 proteins was investigated by immunofluorescence technique. Results: Increased expression of mdm2 was found in the majority of cell lines analysed. Conclusions: Comparing all results, we postulated that overexpression of mdm2 is related to the tumorigenesis and/or tumour progression of salivary gland neoplasms.