A Study On Expression Of Caspase-3,Bcl-2,P53 And C-myc In Human Oral Lichen Planus And Human Oral Squamous Cell Carcinoma

[Background and objectives] Oral lichen planus(OLP) is a disease occurred at skin and mucosa, which can happen only in oral mucosa or skin, also can both happen in oral mucosa and skin. OLP is a chronic non-inflammation disease, which happened mostly at the surface of mucosa and/or skin. It is a hot dispute whether OLP is a precancerous disease. But ever since Bettmann reported that OLP could been turned into cancer in 1905, it had reported that the carcinogenesis rate was 0. 4%~10%. So, in 1972, the World Health Organization (WHO) regarded OLP as precancerous condition by the conception of the precancerous condition. Oral squamous cell carcinoma (OSCC) is the commonest malignant carcinoma in the oral cavity, and the carcinogenesis is generally considered as a multistep process. Many researches found carcinogenesis is related to cell apoptosis. The cell apoptosis and cell multiplication have a relationwhich modulates the quantity and stability of the cells in body. The multiplication velocity of cells accelerates or dead velocity decreases would lead to the quantity of the cell in body accelerate many carcinomas happened because the imbalance between multiplication and dead velocity. Carcinogenesis is dependent on the degree of the imbalance.Some researches have found out the functions of Caspase~3 in the cell apoptosis: It could be activated by the members of Caspase family by means of Fas-induced dead signal means. After that, it can lyse the key constructive protein which led to cell apoptosis. Researches found, compared with normal tissue, the positive staining rates decrease in the tumor tissue. P63 is a anti-cancer gene. Researches found out that wild type P53 protein could inhibit carcinogenesis. But mutations of PM produced mutant type P53 protein which lost the function of anti-cancer. Bcl-2 gene was an important antiapoptotic gene and its product had been demonstrated to prevent apoptosis that was induced by many mechanisms. C-myc was a cell early stage reaction gene which could increase cell multification or induce cell apoptosis. After the activation of C-myc, if there were enough growth factors, which would enable cell to multify, or lead to cell apoptosis. This research immunohistochemically studied the expressions of Caspase-3, P53 , bcl-3 and Omyc protein in evasive OLP, non-erosive OLP and OSCC, and it investigated these factors' function in the process of OLP turning into cancer. So we could find a new way to cure OLP and prevent the occurrence of OSCC.[Methods] There were ninety-one cases of formalin-fixed, paraffin-embedded oral mucosa lesion specimens from the pathological archives of the Department of Pathology of the First Affiliated Hospital of Zhengzhou University. These specimens included 45 cases of OLP (23 cases of erosive OLP group and 22 cases of non-erosive OLP group) and 46 cases of OSCC. 15 cases of specimens from oral normal mucosa were takenas control. Imraunohistochemical detection for Caspase-3, P53, Bcl-2 and C-myc protein were carried out for all specimens and positive rates of expressions were calculated. All date were analysed statistically. [Results]1. Expressions of Caspase-3 protein in oral normal mucosa, OLP and OSCC group: Most controls showed Caspase-3 positive staining (93. 33%, 14/15). The positive rates of Caspase-3 protein in erosive OLP group and non- erosive OLP were 65. 21%(15/23) and 77. 27% (17/22) respectively, and there was no significant difference between them (P>0. 05). And the positive rate of Caspase-3 protein in OSCC was 47. 83% (22/46), which implied the decrease of Caspase-3 protein was important in the occurrence and development of OLP and OSCC, but there was not a major factor in OLP turning into cancer.2. Expressions of Bcl-2 protein in oral normal mucosa, OLP and OSCC group: Few cells of normal controls showed Bcl-2 positive staining (<0. 05). The positive rates of Bcl-2 protein in erosive OLP group and non-erosive OLP were 43. 48% (10/23) and 18. 18% (4/22) respectively. There was a significant difference between them (P<0.