Autochthonous male urothelial carcinoma immune competent model: from induction to BCG transurethral treatment.

OBJECTIVE: To describe a new animal model of autochthonous urothelial cancer (UC) accessible by transurethral catheter in males, from induction to treatment. Seven-week-old male Fischer 344 rats were used. The first 10 animals were used to overcome and standardize the technical challenges of safe transurethral catheterization of male rats. The remaining 14 animals underwent intravesical N-Methyl-Nitrosourea (MNU) instillation for UC induction, of which six were randomized to undergo intravesical BCG treatment. The stretched male rat urethra travels 35 mm in a tortuous "S" shaped trajectory with a 180° angle behind the pubic bone, safely traversed by a 20G 36" 0.8 mm epidural catheter in a stretched, straightened urethra inserted after anterior dilation of the penile urethra with a 24G IV catheter. Histopathologic analysis of the urinary bladder demonstrated Stage pT1, pTa, and pTis lesions in the 8 controls, all with increased cell proliferation by Ki-67 expression and no pT1 or pTis in the animals 6 treated with BCG. This pioneering study describes an autochthonous, effective, and accessible transurethral animal model of immune-competent UC in males, and may help with understanding of the biology, immunology, and treatment of UC, which predominates in males.

Boosting bladder cancer treatment by intravesical nitazoxanide and bacillus calmette-guérin association.

PURPOSE: Nitazoxanide (NTZ) has shown a promising antitumoral effect, the current study compared the anti-neoplastic effects of intravesical NTZ and BCG plus NTZ in NMIBC animal model. METHODS: 30 rats, Fisher 344 were instilled with 4 intravesical doses of 1.5 mg/kg of N-methyl-N-nitrosourea (MNU) every 15 days for BC induction. The animals were divided into 3 groups (Group BCG 106 UFC - 1 mg of BCG; Group NTZ - 300 mg/kg of NTZ; Group NTZ + BCG - simultaneous treatment of BCG and NTZ) and received weekly intravesical treatment for 6 consecutive weeks. Animals were submitted to ultrasound imaging and euthanasia, their bladders were collected and histopathological, immunohistochemical tests (ki67 e c-Myc) and Western Blotting (PI3K, mTOR, and p-4E-BP) were performed. RESULTS: Histopathological tests showed 66.67%, 62.5% and 37.5% incidence of BC in animals treated with BCG, NTZ, and NTZ + BCG, respectively. Nuclear positivity for ki-67 in BC animals were 12.4% (IC 10.1-14.6%), 13.2% (IC 10.5-15.9%) and 8.8% (IC 6.0-11.6%) in BCG, NTZ and NTZ + BCG group, respectively (p = 0.063). Between animals with carcinoma, c-Myc strong positive was 40.10% in NTZ, 32.2% in BCG and 19.90% in the NTZ + BCG group (p < 0.001). Blotting has shown mTOR (p = 0.0473) and PI3K inhibition (p = 0.0349) in the presence of BCG, added to 4-EBP inhibition in the presence of NTZ (p = 0.0004). CONCLUSIONS: Results show the possible synergy between the gold standard BC treatment BCG and NTZ, in which multiple targets inhibition such as c-Myc and downstream mTOR, p-4E-BP and PI3K might play a role.

Carcinogenesis and Bacillus Calmette-Guérin (BCG) Intravesical Treatment of Non-Muscle-Invasive Bladder Cancer under Tryptophan and Thymine Supplementation.

PURPOSE: Evaluate tryptophan and thymine (TT) impact on carcinogenesis and intravesical BCG bladder cancer treatment. METHODS: After identification of TT in vitro inhibitory effect in multiple cancer cell cultures, bladder cancer animal model was induced by MNU intravesical instillations and randomized into four groups: Control (n = 9), BCG (n = 9), TT (n = 7), and BCG + TT (n = 8). BCG groups received intravesical 106 CFU BCG in 0.2 ml saline for 6 consecutive weeks and TT groups received 1 g/kg (1:1) of TT via daily gavage. After 15 wk of protocol, animals were euthanized and the urinary bladders submitted to histopathology, immunohistochemistry, and Western blotting. RESULTS: Urothelial cancer was identified in 100%, 85.7%, 44.5%, and 37.5% of Control, TT, BCG, and BCG + TT groups, respectively. Cell proliferation marked by nuclear Ki-67 was higher in the Control compared to animals in the other groups (P = 0.03). BCG, TT, and BCG + TT groups showed proliferative cell decline and TLR4/5 labeling increase in the urothelium. BCG decreased the urothelial VEGF labeling, even in TT association. CONCLUSION: TT inhibit urothelial carcinogenesis and potentiate the intravesical BCG in the treatment of bladder cancer by reducing cell proliferation and activating TLRs.