Expression Of P53,p63,p73 Protein In Carcinoma Of Tongue And Their Correlation To Clinicopathological Characteristics

Based on the pathological statistics, maxillofacial and oral malignant tumors were almost 8% of the total malignant tumors in our country. Most of them are epidermal origin and squamous cell carcinoma is the most common caner.p53 is a tumor suppressor gene. It is the most common genetic change found in human tumors. In head and neck squamous cell carcinoma(HNSCC) , 40 -50% of the tumors studied have shown a mutation in this gene. Two new members of the p53 gene family, p63 and p73 share considerable structural ho-mologies with the p53, so their transcriptional and apoptotic functions are similar to those of p53. It has been suggested that they may be manifest tumor suppressor gene. However, in contrast to p53 ,p63 and p73 give rise to multiple functionally distinct protein isoforms as a result of alternative splicing and the use of various promoters , their over expression and exceeding rare mutations in a number of tumors contraindicate this hypothesis of tumor suppressor gene. Their roles and the relationship with p53 in tumors need our next investigation.This study will perform immunohistochemistry studies for p53, p63 and p73 protein status to determine their differential expression in carcinoma of tongue as well as their clinicopathological significance.Materials and Methods1. Tissue specimens: A total of 44 tissue speciments were collected from thearchives of 1995 to 2002 in the Department of oral and maxillofacial surgery of The First Affiliated Hospital China Medical University. Among them,41 cases were squamous cell carcinoma which occurred on the lateral border of anterior 2/3 of the tongue and did not receive any chemotherapy or radiotherapy before . Tumor samples were assorted by sex, age, grade, stage and neck lymph node metastasis. 75% were+ + + and below 10% or unstained nuclei were -.(3 ) Statistical analysis. All data were analyzed using the X2 test and Fisher s Exact Test in SPSS11. 5 . P value <0.05 was required for significance.Experimental results1. In normal and hyperplastic epithelia: there were no p53 - positive cells. p63 and p73 staining cells were slight and reduced expression and located on the basal and parabasal layers.2. In 41 carcinomas, the staining positive cells increased in number and intensity for three markers. The staining was diffuse or localized peripheral cells oftumor nests for p63 and p73.3. Statistical analysis of immunohistochemical stainability: The positive expression rate of p63 and p73 protein was significantly higher in carcinomas of tongue(respectively 90.24% and 65. 85% ) than in normal and hyperplastic epi-thelia ( respectively 29.41 % and 17.64% ) ( P < 0.05 ). There was no significant correlation between p63 or p73 protein expression and the different clinico-pathological characteristics ( sex, age, grade stage and neck lymph node matas-tasis). Concordant p63 and p73 expressions were observed in 29 tumors, for p53 and p73 were 19, p53 and p63 were 23. There were no significant correlation each other( P > 0.05). The positive expression rate between p63 and p73 or p53 protein has statistica...