Expression Of Apoptosis-related Protein Livin And Caspase-3in The Pathogenesis Of Actinic Keratosis

Objective:Actinic keratosis (AK) is the precancerous lesion of the skin, which is caused by a long-term exposure to UV—induced skin cancer. In recent years, more and more research suggests that the disorder of the mechanism of apoptosis may play an important role in tumor occurrence and development process. To investigate the expression of inhibition of apoptosis protein Livin and pro-apoptotic protein Caspase-3by immunohistochemistry in actinic keratosis, exposure parts, non-exposed parts of the normal skin and squamous cell carcinoma (SCC), explore their significance and relationship in squamous cell carcinoma and its precancerous lesion.Methods:The collection of36cases of AK patients and30cases of SCC patients,16cases of normal exposure site and18cases of normal non-exposed parts of skin tissue as controls, were confirmed by HE staining for the AK, the SCC and normal skin tissue. These specimens were divided into four groups: the AK group, the SCC group, the normal exposure and normal non-exposed group, and were examined by EliVisionTM plus Immunohistochemistry. To analyze their possible relationship and significance in skin cancer occurrence and progress. All of the statistics processing was conducted by the SPSS for windows version17.0. The comparisons of rates were analyzed by chi-square test. While the correlations of both factors were examined by the Pearson correlation analysis.Results: 1.The expression of Livin:Livin was stain in the cytoplasm by Immunohistochemistry. The positive rates of Livin protein in16cases of exposure parts of normal skin,18cases of non-exposed parts of normal skin,36cases of actinic keratosis and30cases of squamous cell carcinoma were12.50%,11.11%,61.11%and86.67%respectively. The positive rate of Livin was no significant difference between the group of exposure parts of the normal skin and the group of non-exposed parts of the normal skin (P>0.05). The positive rate of Livin in actinic keratosis group and cutaneous squamous cell carcinoma group was significantly higher than the normal group(including exposure and non-exposed groups),(P<0.05). The positive rate of Livin in actinic keratosis group was significantly higher than the normal group (including exposure and non-exposed groups),(P<0.05). The positive rate of Livin in squamous cell carcinoma group was also higher than the group of actinic keratosis (P<0.05). There was a constantly increasing trend of the livin expression was from normal skin, actinic keratosis group to cutaneous squamous cell carcinoma group.2. The expression of caspase-3:Caspase-3was also stain in the cytoplasm by Immunohistochemistry. The positive rates of Caspase-3protein in16cases of exposure parts of normal skin,18cases of non-exposed parts of normal skin,36cases of actinic keratosis and30cases of squamous cell carcinoma were87.50%,83.33%,52.78%and36.67%respectively. The positive rate of Caspase-3was no significant difference between the group of exposure parts of the normal skin and the group of non-exposed parts of the normal skin (P>0.05). The positive rate of Caspase-3in the normal group(including exposure and non-exposed groups) was significantly higher than actinic keratosis group and cutaneous squamous cell carcinoma group (P<0.05). The positive rate of Caspase-3in the normal group(including exposure and non-exposed site) was significantly higher than actinic keratosis group (P<0.05). The positive rate of Caspase-3in actinic keratosis group was significantly higher than cutaneous squamous cell carcinoma group (P<0.05). There was a constantly decreasing trend of the Caspase-3expression was from normal skin, actinic keratosis group to cutaneous squamous cell carcinoma group.Conclusion:1. The high expression of Livin and the abnormal expression of caspase-3play an important role in the occurrence, development and malignant transformation with precancerous lesions of skin cancer.2. The expression of Livin and Caspase-3was no significant difference between the group of exposure parts and the non-exposed parts of the normal skin.3. The expression rate of Livin shows the trend of gradually increasing and the expression rate of caspase-3shows the continuous decreasing trend from normal skin, skin cancer precursor lesions (actinic keratosis) to squamous cell carcinoma.4. The expression of Livin and Caspase-3was negatively correlated which were involved in the incidence of actinic keratosis and skin squamous cell carcinoma cancer.