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.
Mantesso
Andrea
A
Department of Oral Pathology, School of Dentistry, University of São Paulo, Av. Lineu Prestes 2227, Cidade Universitária, CEP 05508-900, São Paulo, SP, Brazil. amantesso@hotmail.com
Loducca
Silvia Vanessa Lourenço
SV
Bendit
Israel
I
Garicochea
Bernardo
B
Nunes
Fabio Daumas
FD
de Araújo
Vera Cavalcanti
VC
D008949:Adenoma, Pleomorphic / Q000378:metabolism; D002277:Carcinoma / Q000378:metabolism; D003528:Carcinoma, Adenoid Cystic / Q000378:metabolism; D045744:Cell Line, Tumor / Q000378:metabolism; D006801:Humans; D009208:Myoepithelioma / Q000378:metabolism; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D051736:Proto-Oncogene Proteins c-mdm2; D016283:Proto-Oncogene Proteins p21(ras) / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D012468:Salivary Gland Neoplasms / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis
D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)