The JAK-STAT signalling pathway regulates cellular processes like cell division, cell death and immune regulation. Dysregulation has been identified in solid tumours and STAT3 activation is a marker for poor outcome. The aim of this study was to explore potential therapeutic strategies by targeting this pathway in bladder cancer (BC). High STAT3 expression was detected in 51.3% from 149 patient specimens with invasive bladder cancer by immunohistochemistry. Protein expression of JAK, STAT and downstream targets were confirmed in 10 cell lines. Effects of the JAK inhibitors Ruxolitinib and BSK-805, and STAT3/5 inhibitors Stattic, Nifuroxazide and SH-4-54 were analysed by cell viability assays, immunoblotting, apoptosis and cell cycle progression. Treatment with STAT3/5 but not JAK1/2 inhibitors reduced survival, levels of phosphorylated STAT3 and Cyclin-D1 and increased apoptosis. Tumour xenografts, using the chicken chorioallantoic membrane (CAM) model responded to Stattic monotherapy. Combination of Stattic with Cisplatin, Docetaxel, Gemcitabine, Paclitaxel and CDK4/6 inhibitors showed additive effects. The combination of Stattic with the oncolytic adenovirus XVir-N-31 increased viral replication and cell lysis. Our results provide evidence that inhibitors against STAT3/5 are promising as novel mono- and combination therapy in bladder cancer.

Bladder cancer is the tenth most common cancer worldwide, where its burden remains a challenge and needs new novel therapies. Several reports indicate expression of CYP4Z1 and CYP1B1 in many tumours. Their expressions are associated with a poor prognosis, and therefore proposed as promising biomarkers or targets for anticancer therapy. By using immunohistochemistry, expression of CYP4Z1 and CYP1B1 was evaluated in a panel of different types of bladder cancer, and the enzymes’ relation to histopathological features were assessed. Results showed an increased expression of CYP4Z1 (54.3%) and CYP1B1 (76.9%) in the majority of bladder cancers compared to weak or lack of expression of both enzymes in normal tissues. CYP4Z1expression was significantly associated with tumour grade and stage where the expression was markedly increased in a high grade and advanced stage of the disease (p < 0.05). Additionally, CYP1B1 expression was also associated with TNM staging (p < 0.05) and its expression was increased in patients with lymph node metastasis. The expression profiles of CYP4Z1 and CYP1B1 suggest that both enzymes have the potential to be biomarkers or targets for novel anticancer therapy for bladder cancer. Nevertheless, further studies are needed to better delineate whether these enzymes are druggable targets.

Background: cervical cancer is one of the most common malignancies in women worldwide and its management remains challenging and complex. As Cytochrome4Z1 (CYP4Z1) is overexpressed in many tumours, its expression in cervical cancer is unknown. Therefore, the present study aimed to evaluate CYP4Z1 expression in cervical cancers. Methods: CYP4Z1 expression was immunohistochemically assessed in 100 cases of cervical cancers along with ten normal cervix tissues, and the enzyme’s relationship to several clinicopathological features and survival was explored. Results: CYP4Z1 was strongly expressed in 55% of cervical cancer patients. Normal cervix samples were negative for CYP4Z1 expression. Importantly, this expression was significantly found in patients with the late stage of the disease, lymph node metastasis, and high tumour invasion (p < 0.05). Interestingly, CYP4Z1 expression was significantly correlated with shorter survival times of cervical cancer patients. Univariate analysis showed that CYP4Z1 expression, tumour stage, lymph node metastasis, and tumour invasion were significantly correlated with patient survival (p < 0.05). The multivariate analysis revealed that only CYP4Z1 expression and tumour stage were significantly correlated with patient survival (p < 0.05). Conclusions: CYP4Z1 expression is associated with cervical cancer patients’ survival and may serve as an independent predictor of poor prognosis in cervical cancer patients.