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Abstract: Background: Focal adhesion kinase (FAK), a cytoplasmic tyrosine kinase, plays a crucial role in focal adhesion turnover by interfacing between the extracellular space, transmembrane integrins, and actin filaments. Its significance for the progression of several malignancies, including bladder cancer, has been well-documented. However, its precise role and the implications of its inhibition in bladder cancer tissues and urothelial in vitro models has not been fully explored. This study examined FAK expression and function in human bladder cancer biopsies and in vitro bladder cancer models. Materials and methods: Ex vivo analyses were performed using reverse transcription-quantitative PCR (qRT-PCR), western blotting, and immunohistochemistry to compare FAK expression between bladder cancer tissues and adjacent normal tissues. In vitro, FAK expression was assessed in low-grade (LG) human non-invasive papilloma urothelial cell line RT4 for NMIBC (Ta), high-grade (HG) human muscle-invasive cancer urothelial cell line T24 for MIBC (T2) and normal porcine urothelial (NPU) cells using qRT-PCR and western blotting, as well as flow cytometry for the quantification of FAK-positive RT4 and T24 cells. The role of FAK in cancer cell survival was explored in vitro using microRNA (miRNA) to silence FAK expression. Additionally, we used FAK inhibitors PND-1186, PF-573228 and defactinib to investigate the effects of FAK inhibition on normal compared to cancerous bladder urothelial cells. Results: Ex vivo analyses demonstrated significantly higher FAK expression in bladder cancer tissues compared to adjacent normal tissues. Similarly, in vitro analyses showed significantly higher FAK expression in RT4 and T24 cells than NPU cells. Silencing FAK using anti-FAK plasmids led to increased caspase-3-mediated apoptosis of RT4 and T24 cells and growth reduction of stably transfected T24 cells. Importantly, based on cell viability assays, treatment with 100 μM defactinib for 2 hours per day on 3 consecutive days was identified as a clinically relevant regimen. Under this treatment, the viability of differentiated NPU cells remained high at 108.4 ± 17.1%, while the viability of 2-day RT4 and 2-day T24 cells was drastically reduced to 4.1 ± 2.7% and 7.6 ± 2.9%, respectively. Conclusions: To our knowledge, this is the first report demonstrating the role of FAK and its inhibition across both normal and cancerous bladder urothelial models. This study highlights the critical role of FAK in the progression of human bladder cancer and establishes a foundation for exploring FAK inhibition as a potential therapeutic approach in bladder cancer treatment.
Keywords: bladder cancer, defactinib, focal adhesion kinase, human urothelial carcinoma, urothelial cell
Published in DiRROS: 09.12.2025; Views: 199; Downloads: 123
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Abstract: Background. Atezolizumab, a programmed-death ligand-1 (PD-L1) inhibitor, is a novel treatment option for patients with metastatic urothelial cancer (mUC). Clinical prognostic factors, survival outcomes, and the safety of patients with mUC treated with atezolizumab, in a real-world setting, were investigated.Patients and methods. 62 patients with mUC, treated at the Institute of Oncology Ljubljana between May 8th 2018 and Dec 31st 2019, were included. Response rates and immune-related adverse events (irAE) were collected. Progression-free survival and overall survival times were assessed using the Kaplan-Meier method. The Cox propor-tional hazards model was applied to identify the factors affecting survival. Results. Of 62 patients, five (8.1%) have not yet been evaluated and 20 (32%) died prior to the first radiographic evaluation. We observed clinical benefit in 19 (33%), objective response in 12 (21%), and complete response in five (9%) patients. Median overall survival for the whole population was 6.8 (95% CI, 2.6–11.0), for platinum-naïve 8.7 (95% CI: 0.8–16.5), and for the platinum-treated group 6.8 (95% CI, 3.7–10) months. At the 5.8 (0.3–23.1) month median follow-up, the median duration of the response was not reached. IrAE occurred in 20 (32%) patients and seven (11%) of them discontinued the treatment. Multivariate analysis in platinum-treated patients showed that a treatment-free interval of more than six months was prognostic for overall survival (OS). Conclusions. Responses to atezolizumab led to long disease remission in a subset of our patients. The median OS in our real-world population was compromised by a large percentage of patients with poor ECOG performance status (PS). A treatment-free interval from chemotherapy was associated with the longer survival of platinum-treated pa-tients with mUC receiving further atezolizumab.
Keywords: PD-L1 inhibitor, urothelial cancer, bladder, atezolizumab
Published in DiRROS: 23.07.2024; Views: 1081; Downloads: 583
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Abstract: Background. Bladder cancer is the 7th most common cancer in men. About 75% of all bladder cancer are nonmuscle invasive (NMIBC). The golden standard for definite diagnosis and first-line treatment of NMIBC is transurethral resection of bladder tumour (TURB). Historically, the monopolar current was used first, today bipolar current is preferred by most urologists. Following TURB, depending on the tumour grade, additional intravesical chemo- or/and immunotherapy is indicated, in order to prevent recurrence and need for surgical resection. Development of new technologies, molecular and cell biology, enabled scientists to develop organoids % systems of human cells that are cultivated in the laboratory and have characteristics of the tissue from which they were harvested. In the field of urologic cancers, the organoids are used mainly for studying the course of different diseases, however, in the field of bladder cancer the data are scarce. Conclusions. Different currents - monopolar and bipolar, have different effect on urothelium, that is important for oncological results and pathohistological interpretation. Specimens of bladder cancer can be used for preparation of organoids that are further used for studying carcinogenesis. Bladder organoids are step towards personalised medicine, especially for testing effectiveness of chemo-/immunotherapeutics.
Keywords: bladder cancer, transurethral resection of bladder tumour, monopolar/bipolar current, consensus molecular subtype
Published in DiRROS: 12.07.2024; Views: 902; Downloads: 536
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