ImmunoClor: Preclinical Evaluation of a Nanoimmunotherapeutic Strategy Based on MAO-A Inhibition for the Treatment of Non-Muscle Invasive Bladder Cancer

• Grant number: 25/14699-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Biological Sciences - Morphology - Anatomy
• Principal Investigator: Wagner José Fávaro
• Grantee: Matheus Mendes Costa
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Non-muscle invasive bladder cancer (NMIBC) is a highly prevalent and morbid urological neoplasm, characterized by frequent recurrence, risk of progression, and therapeutic refractoriness in a substantial subset of patients. Resistance to conventional intravesical therapies, such as Bacillus Calmette-Guérin (BCG), is largely attributed to the immunosuppressive nature of the tumor microenvironment (TME), which is dominated by immune evasion mechanisms mediated by tumor-associated macrophages (TAMs) of the M2 phenotype, overexpression of immune checkpoints (PD-L1, CTLA-4), and suppression of cytotoxic lymphocyte activity. In this context, growing evidence has identified monoamine oxidase A (MAO-A) as a key regulator of tumor-driven immunosuppression by promoting chronic oxidative stress and polarizing TAMs toward an M2 phenotype. Selective inhibition of MAO-A has emerged as a promising strategy to restore antitumor immune competence by reprogramming the TME and enhancing effector immune responses. This project aims to evaluate the therapeutic effects of ImmunoClor, an innovative nanoformulation composed of an inorganic nanocomplex (CIN-1) associated with selective MAO-A inhibition, in an orthotopic murine model of NMIBC induced by N-ethyl-N-nitrosourea (ENU). The investigation is structured into four main methodological axes: (1) histopathological evaluation of bladder tissues following ImmunoClor treatment, with classification of urothelial lesions and their regression; (2) immunohistochemical analysis of biomarkers associated with effector immune response (CD8, CX3CR1, iNOS, IFN-¿) and immunosuppression (PD-L1, CTLA-4, FOXP3, CD163), including calculation of the tumor immune score (IS); (3) immunophenotyping by flow cytometry of immune cell populations in the spleen and inguinal lymph nodes (T lymphocytes, regulatory T cells, NK cells, macrophages, and antigen-presenting cells), with assessment of functional activation and differentiation profile; and (4) comparative analysis of isolated intravesical versus combined intravesical/intraperitoneal administration routes to determine the most effective delivery strategy for modulating the TME and controlling tumor progression. It is expected that ImmunoClor will promote TME reprogramming by reducing the presence of immunosuppressive cells while enhancing effector immune infiltration, resulting in improved histopathological outcomes. The findings from this study may provide a scientific foundation for the development of MAO-A inhibition-based therapeutic strategies in refractory NMIBC, with significant translational potential in clinical nanoimmunotherapy protocols. (AU)