Relationship between expression of polymorphonuclear leukocyte elastase and renal cell carcinoma

    ZHAO Zhiª²Guang, SHAO Guoª²Xing

    Department of Urology, Tangdu Hospital, Fourth Military Medical University, Xi¬ðan 710038, China

    ¡¾Abstract¡¿ AIM: To study the relationship between the expression of polymorphonuclear leukocyte elastase (PMNE) and renal cell carcinoma (RCC) patients. METHODS: By molecular, immunological and pathological methods, we measured the PMNE expression in the cytoplasmic extracts of 59 renal cell carcinomas, observed the microvascular invasion of RCC cells and sequenced the PMNE promoter gene of RCC. The result of promoter sequencing showed a nucleic acid mutant. The mutated promoter activity was also compared with that of wild type by constructing pGL3/PMNE luciferase expression vector. RESULTS: The PMNE was over expressed in RCC cells (P<0ª±01) and the expression levels of PMNE in the tissue extracts of G3 and G4 were much higher than those in the tissue extracts of G1 and G2(P<0ª±01). The PMNE overª²expression was also detected in the specimen of RCC with microvascular invasion(P<0ª±01). In one case, permutation mutant from A to C in theª²879/ª²716 (TCAA to TCCA) was found. The luciferase expression in K562 cells transfected with mutated PMNE promoter luciferase expression vector was markedly higher than those transfected with wild type PMNE promoter vector. CONCLUSION: PMNE is over expressed in RCC and the level of its expression is closely related with the stage and the invasion ability of the tumor. PMNE promoter gene permutation mutant, ª²879/ª²716TCAA to TCCA, may lead to higher PMNE enzyme activity, which promotes the invasive potential of RCC cells. Our data indicate that PMNE may play an important role in the development of RCC. ......