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

Abstract

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.

Acknowledgments

The authors would like to thank involved institutions and also thank Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas (CPQBA) of UNICAMP for providing the tumor cell lines.

Disclosure statement

None declared.

Ethics Committee Approval number 4582-1/2017.

Author Contributions

M.V.O. and G.D.: Data collection, data analysis, manuscript writing.

H.B.A., I.G.A.K., A.C.C.S., G.Z.R., K.L.F., and M.C.B.L.: Data analysis, manuscript editing.

L.O.R.: Study design, fund acquisition, data analysis, manuscript writing, supervision.

Funding

This work was supported by CNPq Research Productivity, Brazil [grant No. 304747/2018-1 (Reis LO)].