Expression And Significance Of Livin And Cleaved Caspase-3 In Condyloma Acuminatum

Background:condyloma acuminatum(CA) is a chronic benign proliferative disease caused by HPV infection, characterized clinically by tachyauxesis, high recurrence rate and transmissibility. HPV infection causes abnormal proliferation and differentiation of KC, which lose there normal function of apoptosis, proliferate excessively and form the papilloma. IAPs(inhibitor of apoptosis proteins) and Caspase(cysteine containing aspartate specific protease) play the most important roles in the regulatory mechanisms of apoptosis. Livin is the newest member of IAPs, it can not only inhibit apoptosis, but also interfere with cell cycle, promote cell proliferation, and resist cytotoxicity mediated by NK cells which is conducive to immune escape of tumor cells. It is closely related with occurrence, development and treatment of tumor, becoming a research hotspot in recent years.The anti-apoptotic effect of Livin is mainly performed through inhibition of Caspase, which are strategic proteins in apoptosis mechanism, and Caspase-3 is the major executor. Caspase-3 is activated by being sheared firstly to active fragments known as cleaved Caspase-3, playing the role as proteolytic enzymes to promot apoptosis. Therefore, the expression levels of cleaved Caspase-3 can broadly reflect the conditions about activity of Caspase-3 and apoptosis.Objective:To detect the expression of Livin and cleaved Caspase-3 in CA and normal skin controls. And to explore the significance of Livin and cleaved Caspase-3, and their correlation in CA.Methods: 1.34 cases diagnosed by clinic and pathology as CA were obtained from the outpatient of the department of Dermatology of QiLu Hospital during March to October 2010. All cases were primary patients without any treatment.15 normal skin controls were obtained from foreskins removed by circumcision.2.The immunohistochemical SP method was applied to detect the expression of Livin and cleaved Caspase-3 in CA and normal skin.3.By using SPSS17.0 statistical analysis software, Comparison of positive rate was tested by Fisher exact test, and Spearman rank correlation coefficient test was used to analyze the correlation between these two proteins. The diference had statistical significance when P<0.05.Results:1.The expression of Livin in normal foreskin and CA.The positive expression of Livin was localized mainly in plasma and few in nucleus of KC,being stained buffy or darkbrown, which was observed in whole epidermal layers, mostly in stratum spinosum and granulosum. There was no positive expression of Livin in normal skins, while the positive expression rate was 82.4% in CA,which was significantly higher than that in normal skin(P<0.01).2.The expression of cleaved Caspase-3 in normal foreskin and CAThe positive expression of cleaved Caspase-3 was localized in both plasma and nucleus of KC, mainly in plasma,being stained buffy or darkbrown, which was observed in whole epidermal layers,mostly in stratum spinosum and granulosum. There was no positive expression of cleaved Caspase-3 in normal skins, while the positive expression rate was 38.2% in CA, which was significantly higher than that in normal skin(P<0.01).3.The correlation between the expression of Livin and cleaved Caspase-3 in CACorrelation analysis of staining intensity of these two proteins showed that the expression of Livin was negatively correlated with cleaved Caspase-3 in CA (r=-5.25,P<0.001).Conclusion:1.Livin and cleaved Caspase-3 were both negatively expressed in normal skin, suggesting that these two proteins may not be involved in differentiation of normal epidermal.2.The positive expression rate for Livin and cleaved Caspase-3 in CA were significantly higher than that in normal skin, suggesting that both may participate in the pathogenesis of CA. KC was infected with HPV, while the expression of Livin was activated, inhibiting apoptosis of KC, to protect the growing environment of HPV. The positive expression of cleaved Caspase-3 implied that Caspase-3 was partly activated, maintaining a certain extent of apoptosis, to clear excessively proliferated KC.3.The expression of Livin was negatively correlated with cleaved Caspase-3 in CA, suggesting that Livin may prevent apoptosis by inhibiting the activation of Caspase-3, and provide HPV with advantages of propagation.