Experimental Study On Enhancement Of Fibronectin Mediated Bacillus Camette-Guerin Attachment To Bladder Wall

Department of UrologyCollege of medicine, Zhejiang UniversityPostgraduate: Ding GuoqingTutor: Professor Shen ZhoujunIntroductionBladder transitional cell carcinoma (BTCC) is the most common cancer of genitourinary tract in our country. Although approximately 70% to 75% of patients with BTCC are superficial at initial presentation, the recurrence and progression of tumor lesion are very frequent after surgical resection. Adjuvant intravesical Bacillus Camette-Guerin (BCG) installation has been proven efficacious in the treatment and prophylaxis of superficial papillary bladder tumors and carcinoma in situ of the bladder. But the mechanism by which BCG exerts an antineoplastic effect is not fully understood and there are also about 20% patients who can抰 take advantage of BCG therapy. Recent evidences have suggested that BCG binding to fibronectin (FN) exposed on disrupted urothelial surfaces is required for the antitumor effect to be expressed. And the initial investigation showed that fibronectin-mediated BCG attachment to bladder6mucosa can be modulated by drugs influencing the coagulation pathways. Unfortunately, there are no advanced investigation being reported.Objective:To investigate whether intravesical installation of fibrin clot stabilizer epsilon-aminocaproic acid (EACA) or aminomethylbenzoic acid (PAMBA) and different injures (incision, cryocautery as well as electrocautery) can enhance fibronectin-mediated BCG attachment to bladder wall by experimental study.Materials and Methods:1.Culture and radiolabeling of BCG: 600mg lyophulized BCG was cultured for 24 hours in BCG medium at 37~C in 5% Co2. 800 p Ci [3H]Thymidine was added to the BCG and incubated for continue 72 hours. Then bacteria were washed twice in PBS and resuspended in 30m1 normal saline.2.Rabbits and injuries: Thirty rabbits were meanly divided into five groups (Group A, B, C, D, and E) and the bladder mucosa of every rabbit was injured by electrocautery (current: 5OMA, 4 seconds, area: 1cm2), cryocautery (nitrogen at ?960C, 4 seconds, area:lcm2) and incision (1cm incision, submucosa depth) on left lateral wall, right lateral wall and posterior wall respectively.3.Drugs intravesical installation. Different drugs were installed into bladders of every group.Group A: PBS (5ml) intravesical installation for7 浙江大学硕士学位论文 2．shours；Gro叩B:smlPBSImr叫eslcallnstallatlonfor30mln帆esthen lml radforabeled BCG('H－BCG,with4ml normal satin小nstailation for 2 hours； Gro呷 C,Gro叩 D:ibrin clot st劝ilizers EACA(500m吵g) or PAMBA(25mg／kg)installation for 30 mins then lml'H－BCG for 2 hours；Gro叩 E:ibrln clot讪ibitor heparin(1250叭g)installation for 30 mins then lml 3H,BCG installation for 2 hours． 4．砌mPlestQ切n．AfterdrugsIntraveslcallnstallatlontfeatmem,every imured bladder wall and non－lrpured wall(anterior wall ofbladder)were surgically removed(the size of every sample was cm In diameter)and igested in sml ZN NaOH solution at 37c for 24 hours．Then lml of every sample was added 7ml solmlllatlon cocktail and the quantity of BCGadherence was determlnedby liquid sclntlllatlon counter． 5．Statistical anthels:All data。re analyZed with SPSS software package．Differences between gro叩s were examlnedusing Wllcoxon Mann and Whltneytest．An alpha level ofs％was considered Statist1CClly SlgfilfiCCt． R"uh: l．The level OfBCG attachment to iryured bladder wall was smppecantly hhoer伯an that Onion－iryured wall．The mean levels of BCG att。hment 扣1＊q8叨N劝众r＊dk幻幻mem对盯y＊d18 pp打woca成盯y＊dIs＊肛e very significantly higher than those ofnon－lq＂red bladder walls...