The tumor-suppressor gene, WW domain-containing oxidoreductase (WWOX), has been found to be lost in various types of cancers. ROS result as a tightly regulated signaling process for the induction of cell senescence. The aim of this study was to investigate the role of WWOX in the regulation of ROS and cell senescence, which is intriguing in terms of the possible mechanism of WWOX contributing to bladder cancer. In this study, we used the AY-27 rat bladder tumor cell line and F344 orthotopic bladder tumor models to reveal the pro-senescence effects of WWOX and the corresponding underlying mechanism in bladder cancer. WWOX-overexpressing lentivirus (LV-WWOX) remarkably stimulated cellular senescence, including increased senescence-associated secretory phenotype (SASP) formation, enlarged cellular morphology, and induced SA-β-Gal-positive staining. A further mechanism study revealed that the pro-senescence effect of LV-WWOX was dependent on increased intercellular reactive oxygen species (ROS) generation, which subsequently triggered p21/p27. Moreover, LV-WWOX significantly inhibited the tumor size by 30.49% in the F344/AY-27 rat orthotopic model (p < 0.05) by activating cellular senescence. The expression of p21 was significantly enhanced in the orthotopic bladder tumors under WWOX treatment. The orthotopic bladder tumors in the groups of rats verified the effect in vivo. Our study suggests that WWOX, an ROS-dependent senescence-induced gene, could be further studied for its therapeutic implications in bladder cancer.

Multicellular tumor spheroids and tumoroids are considered ideal in vitro models that reflect the features of the tumor microenvironment. Biomimetic components resembling the extracellular matrix form scaffolds to provide structure to 3-dimensional (3D) culture systems, supporting the growth of both spheroids and tumoroids. Although Matrigel has long been used to support 3D culture systems, batch variations, component complexity, and the use of components derived from tumors are complicating factors. To address these issues, we developed the ACD 3D culture system to provide better control and consistency. We evaluated spheroid and tumoroid formation using the ACD 3D culture system, including the assessment of cell viability and cancer marker expression. Under ACD 3D culture conditions, spheroids derived from cancer cell lines exhibited cancer stem cell characteristics, including a sphere-forming size and the expression of stem cell marker genes. The ACD 3D culture system was also able to support patient-derived primary cells and organoid cell cultures, displaying adequate cell growth, appropriate morphology, and resistance to oxaliplatin treatment. These spheroids could also be used for drug screening purposes. In conclusion, the ACD 3D culture system represents an efficient tool for basic cancer research and therapeutic development.

Background/Objectives: Bladder urothelial carcinoma is a frequent malignant tumor of the urinary system, characterized by its high rates of recurrence and resistance to chemotherapy. This study explored the beneficial effects of overexpressing WW domain-containing oxidoreductase (WWOX) in AY-27 cells encapsulated in an injectable gelatin hydrogel for potential therapeutic applications in bladder cancer. Methods: AY-27 cells were genetically transduced with lentiviruses (LV) to overexpress WWOX (LV-WWOX) and subsequently encapsulated in a gelatin hydrogel. The mechanical properties and morphology of the hydrogels were assessed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The therapeutic efficacy of this approach was evaluated using an F344/AY-27 rat orthotopic bladder cancer model, in which the LV-WWOX-hydrogel (H-LV-WWOX) was administered via intravesical instillation. Results: The gelatin hydrogel formulation demonstrated excellent biocompatibility, stability, and controlled release. In a rat orthotopic model, intravesical instillation of H-LV-WWOX significantly enhanced local immune responses, resulting in notable tumor regression. Compared to the sham-treated group, this approach reduced systemic toxicity and improved overall treatment outcomes. The anticancer effect of WWOX can be attributed to its ability to amplify TNF-α-induced reactive oxygen species (ROS) generation. This ROS-mediated pathway leads to enhanced apoptosis and DNA damage in cancer cells, highlighting the potential mechanism through which WWOX exhibits tumor-suppressive activities. Conclusions: These findings support the therapeutic potential of WWOX overexpression in gelatin hydrogels for bladder cancer treatment and warrant further clinical investigation.