THE EXPRESSION OF P53 AND MDM4 IN ORAL, LARYNGEAL AND CUTANEOUS SQUAMOUS CELL CARCINOMA; A COMPARATIVE STUDY

Background: P53 and MDM4 had been known to have dual mechanism depending on their localization. Nuclear p53 can bind to DNA and activate proapoptotic gene expression; cytoplasmic p53 can trigger transcription-independent apoptosis by directly interacting with Bcl-2 family members. Objectives: The aim of current study to evaluate and compare the expression of P53, MDM4 in oral , laryngeal and cutaneous SCC by microarray(TMA) and to investigate the correlation of expression of these markers with histopathological grading of tumor. Methods: One-hundred twenty paraffin embedded SCC sample of Iraqi patients collected during period 2009-2012, retrieved for TMA construction and the expression of P53 and MDM4 was examined by immunohistochemistry. Results: Data showed males with SCC were more than females ( 63.3%/76 , 36.7%/44). Most cancer types expressed both nuclear and cytoplasmic staining of P53 and MDM4 in different percentage, cutaneous Scc Nuclear/cytoplasm expression of P53 were ( 38.8%/94.6%), laryngeal (55%/90%), oral (36.8%/86.8%). Cutaneous SCC N/Cyt expression of MDM4 were (91.8%/72.9%), laryngeal (91.3%/76.3%), oral (97.5%/62.5%).There is no significant difference in expression of both protein markers and tumor types. Obvious significant correlation showed between tumor grading P53 nuclear expression. Conclusions: P53 and MDM4 were frequently overexpressed in SCC cases and there was a significant correlation between these markers. Nuclear p53 and cytoplasmic MDM4 overexpression can be considered as prognostic factor with tumour grading. High percentage MDM4 overexpression should be considered in their treatment