The Existence And Action Of Wnt1 Signaling Pathway In Renal Clear Cell Carcinoma

Part One The expression and action of Wntl protein in renal clear cell carcinomaSubject To study the expression and action of Wntl protein in renal clear cell carcinoma(RCCC).Method Wntl,β-catenin,VEGF and Cyclin T1 proteins in RCCC were investigated by immunohistochemical method.The association between Wntl and the other proteins,as well as the association between the Wntl and tumors' clinical features,were analyzed.Result Wntl was positively stained in all the 40 cases of RCCC,in which 20 cases(50%) showed strong positive staining.Wntl expression was significantly stronger in poorly differentiated(Fuhrman 3-4) or advanced(TNMⅢ-Ⅳ) RCCC(P=0.009,0.02 respectively).Wntl expression showed negative association with patients' gender,age or tumor size.In 40 cases of RCCC,15 cases(37.5%) showed absence ofβ-catenin expression at cytomembrane.36 cases(90%) showed positiveβ-catenin expression in cytoplasm in which 18 cases(45%) showed strong positive expression.The rate of cases with negative membraneβ-catenin staining was much higher in tumors staged TNMⅢ-Ⅳ,when compared with the rate in tumors stagedⅠ-Ⅱ(53.3%vs 16.0%,P=0.014).All these three cases,in which inferior caval vein tumor embolus,inferior caval vein tumor embolus coupled with renal hilar lymph node involving or distant metastasis appeared,were investigated in tumors with negative membrane[3-catenin staining,which showed some relation betweenβ-catenin's membrane staining and tumor stage or tumor metastasis.Wntl expression associated with bothβ-catenin's cytoplamic accumulation and membrane absence(P=0.012,0.024 respectively).Both Wntl andβ-catenin's cytoplasmic accumulation had positive association with VEGF expression in RCCC (P=0.012,0.015 respectively).Cyclin T1 expressed stronger in RCCC(P=0.028). Cyclin T1 expression had a positive assosiation with tumor grade(P＜0.05,r=0.352), and had negative relations with gender,age,tumor size or tumor stage(P＞0.05). Higher Cyclin T1 expression was detected in tumor tissue with higherβ-catenin or higher Wntl level(P=0.001,0.015,respectively). Conclusions Wnt1,which existed in cytoplasm,expressed commonly in RCCC,and could take part in tumorigenesis or tumor's development.Wntl might interrupt the membranous localization ofβ-catenin in RCCC,which attenuated cells' adhesion. The over expressed Wntl protein could induce the cytoplasmic accumulation ofβ-catenin and thereby activate the downstream signals.VEGF and Cyclin T1 should be positively regulated by Wntl/β-catenin and may participate in RCCC's genesis.Part Two Wntl's regulation toβ-catenin on protein's level in renal clear cell carcinomaSubject To study the Wntl's regulation to 15 -catenin on the protein's level in renal clear cell carcinoma.Method Wntl andβ-catenin protein was quantitatively detected in 8 cases of RCCC and 2 cases of normal kidney tissue by western blot method.The association between Wnt 1 and tumor grade or tumor stage was analyzed.Result In 2 cases of normal kidney tissue,the average expression of Wntl was 1.05, while in 8 RCCCs,the number is 1.92,which was significantly higher(P＜0.05).In 6 RCCCs which were Fuhrman graded 2,Wntl expression was higher in the 2 cases with higher stage,while in 6 RCCCs which were staged I,Wntl was higher in the 2 cases with higher tumor grade.In 2 cases of normal kidney tissue,the average expression ofβcatenin was 1.07,while in 8 RCCCs,the number is 2.43,which was also significantly higher(P＜0.01).There was no significant association between Wntl andβ-catenin's protein total amount by Searman's rank correlation test(P＞0.05). Conclusion Wntl expressed stronger in RCCC.The increased total protein ofβ-catenin in RCCC,when coupled with distribution disorder,became the major two factors of protein's accumulation in cytoplasm.In RCCC,Wntl may elevate the protein level of-catenin in cytoplasm primarily by effecing its localization. Part Three The regulatin of Wnt1 andβ-catenin' s mRNA level in renal clear cell carcinomaSubject To study the reason and mechanism of Wntl's activating on mRNA's transcription level.Method Wntl and 13-catenin's mRNA were detected in 5 cases of RCCCs and in their matched normal kidney tissue by RT-PCR method.The association between these two mRNAs and the tumors' clinical features were analyzed.Result RCCC showed higher Wntl mRNA level than the matched normal tissue in all 5 cases(P＜0.05).The lowest Wntl level appeared in the RCCC with lower grade and lower stage,while the highest Wntl level appeared in the RCCC with higher grade and higher stage.The difference ofβ-catenin's mRNA between RCCC and normal kidney was quiet(P＞0.05).There was no association between Wntl andβ-catenin's mRNA(P＞0.05).Result The Wntl activating also existed on the mRNA level.There was no apparent activation ofβ-catenin on the mRNA level.Wntl expression should regulationβ-catenin in the downstreams of mRNA.