Tumor microenvironment-modulating oncolytic adenovirus combined with GSK-3β inhibitor enhances antitumor immune response against bladder cancer

The duality of GSK-3β in urinary bladder cancer: Tumor suppressor and promoter roles through multiple signaling pathways

Urinary bladder cancer (UBC), the tenth most common cancer globally, is primarily categorized into non-muscle-invasive (NMIBC) and muscle-invasive (MIBC) types. NMIBC has a low risk of metastasis but tends to recur frequently after transurethral resection, whereas MIBC is associated with a higher likelihood of metastasis and poorer prognosis. At diagnosis, roughly 75 % of UBC patients have NMIBC, while the remaining 25 % present with tumor invasion into the bladder's muscle layer. The molecular complexity of UBC has driven research toward identifying subtypes for more personalized treatment approaches. Glycogen synthase kinase-3β (GSK-3β) has emerged as a pivotal regulator in UBC through its dual roles across six key pathways: (1) Wnt/β-catenin regulation (tumor suppression vs oncogenic activation), (2) ER stress responses (apoptosis induction vs cytoprotection), (3) Akt/GSK-3β/β-catenin/c-Myc signaling, (4) PI3K/Akt/mTOR interactions, (5) NF-κB-mediated immune modulation, and (6) Snail1/β-catenin-driven epithelial mesenchymal transition (EMT). Our analysis reveals that GSK-3β's context-dependent functions create both therapeutic opportunities and challenges - while inhibition suppresses tumor growth via β-catenin degradation, it may simultaneously activate NF-κB-mediated oncogenic processes. These paradoxical effects are particularly evident in the tumor microenvironment, where GSK-3β modulation differentially regulates CD8+ T cell function and macrophage polarization. Understanding these complex pathway interactions is crucial for developing precision therapies that exploit GSK-3β's tumor-suppressive roles while mitigating its oncogenic potential.

Enhanced potency of immune checkpoint inhibitors against poorly immunological solid tumors by immune stimulatory oncolytic adenoviruses-mediated remodeling of the tumor microenvironment

Immune checkpoint inhibitor (ICI) have shown promising results against a variety of solid tumors across clinical trials. However, ICI monotherapy is often ineffective in patients with non-immunogenic tumors that exhibit high level of immunosuppression and low level of tumor infiltrating lymphocytes. To address these limitations, we have investigated a combination of ICIs [anti-PD-1 antibody (αPD-1), anti-PD-L1 antibody (αPD-L1), or anti-CTLA-4 antibody (αCTLA-4)] with several different immune stimulatory oncolytic adenoviruses (Ads) expressing different combinations of antitumor cytokines or immune modulatory factors [e.g., (1) interleukin (IL)-12 and granulocyte-macrophage colony-stimulating factor (GM-CSF; RdB/IL12/GMCSF), (2) IL-12 and short hairpin ribonucleic acid (shRNA) targeting vascular endothelial growth factor (RdB/IL12/shVEGF), (3) IL-12 and decorin (RdB/IL12/DCN), (4) GM-CSF, and thymidine kinase (RdB/IL12/GMCSF-TK), or (5) IL-12, GM-CSF, and relaxin (RdB/IL12/GMCSF-RLX)] to overcome tumor-induced immunosuppression. Through comparative evaluation of combination therapy regimens, our findings have identified αPD-1 as the optimal ICI candidate to synergize with different oncolytic Ads to induce potent antitumor immune response against poorly immunological solid tumors.