The Expression And Significance Of P73, MMP-7 And PTEN In Human Oral Lichen Planus And Human Squamous Cell Carcinoma

Background and objectivesOral lichen planus(OLP) was an un-normal cornification mucosa disease with chronic shallow inflammation, which can happen only in oral mucosa or skin, also can happen both in oral mucosa and skin. The attack rate of OLP was about 0.51% and its carcinogenesis rate was 0.4% to 6.25%.The World Health Organization (WHO) had regarded OLP as precancerous condition. Oral Squamous Cell Carcinoma(OSCC) was the commentest malignant carcinoma in the oral cavity, in which constituted above 80%,and constituted 3%～5% in the whole body.Molecular biology research indicated that the cancer progression correlate with the activation of oncogene and the loss of function in tumor suppressor, the degradation of adhesive attraction in cancer cells and substrates, the destroy of basement and basement membrane collogen constituent all profited to the processes of cancer invasion and metastases. Matrix metalloproteinases (MMP) was an enzyme which could degrade extracellular matrix (ECM), and MMP-7 was the smallest member, it was capable of degrading almost all extracellular matrix(ECM) including basement membrane and the degradation of basement membrane mean the invasion and metastases of the cancer. p73, as the new member of p53 family, was regarded as a tumor suppressor in its function of inducing cell cycle blockage and apoptosis, but in many studies we found that p73 highly expressed in cancer tissue which reminded that p73 may be a mimic mutant of p53, which could imitate p53 to work in cells, and made p53 out of action,resulted in cell canceration, played a part in the development of tumor. PTEN is the first gene we found which had phosphatase activation, its high expression could inhibit the growth of the tumor. At present, few studies on the expression of p73, MMP-7and PTEN in OLP and OSCC was known. This research immunohistochemically studied the expression of p73,MMP-7 and PTEN protein in normal oral mucosa,OLP and OSCC of varying grades, to investigate their possible roles in carcinogenesis of oral mucosa and their possible clinical significances.MethodsOne hundred and one cases of formalin-fixed,Paraffin-embedded specimens from oral mucosa lesions were obtained from the pathology archive files of the Department of Pathology in the First Affiliated Hospital of zhengzhou University and the biopsy and operation in the department of Stomatology. These specimens included 46 cases of OLP (erosive-type 20 cases, non-erosive type 26 cases) and 42 cases of OSCC. The specimens of OSCC were pathologically classified as 20 of gradeⅠ,15 of gradeⅡand 7 of gradeⅢ.13 cases of specimens from normal oral mucosa were taken as control. Immunohistochemical detection for p73,MMP-7 and PTEN protein were carried out for all specimens. Calculated the positive cell countings of p73,MMP-7 and PTEN. All dates were statistically analysed.Results1.There are 4 cases normal oral mucosa in 13(positive rate 30.8%)display positive expressionof p73;19 cases non-erosive type OLP in 26 (73.1%)display positive expression of p73;17 cases erosive type OLP in 20(85%)display positive expression of p73; all of 42 cases OSCC display positive expression. Compared with the normal mucosa and OLP, its expression of p73 exist significant difference.2.The positive rate of MMP-7 protein in normal oral mucosa,non-erosive OLP,erosive OLP,OSCCⅠ,OSCCⅡand OSCCⅢwere 30.8%,53.8%,60%,75 %,80%,85.7%. From normal oral mucosa,OLP to OSCC, its expression increased gradually. The expression of each group all have difference (P<0.05)3. There are 12 cases normal oral mucosa in 13(positive rate 92.3%)PTEN protein display positive expression;23 cases non-erosive type OLP in 26 (88.5%)display positive expression; 17 cases erosive type OLP in 20(85%)display positive expression; 16 cases OSCCⅠin 20(80%) display positive expression;positive rate in OSCCⅡis 73.3% and in OSCCⅢis 57.1%.The difference in different grade all have statistically significance (P<0.05)Conclusion1. The positive rate of expression of p73 increased significantly in the two type of OLP and each grade of OSCC, and all of OSCC specimens presented positive expression, which elucidate P73 play an important role in the OSCC processes.2. The expression of MMP-7 in the two type of OLP and each grade of OSCC obviously higher than normal oral mucosa,which remind that MMP-7 may correlate with the processes of OSCC, and might be a predictable index to detect OSCC.3. PTEN protein present highly expression in normal oral mucosa, its positive rate of expression decrease obviously as the malignancy extent of OSCC augment, which also mean the up grade of absence rate of expression, remind that PTEN might contributed to the OSCC processes.