High NF-κB and STAT3 activity in human urothelial carcinoma: a pilot study

Environmental exposure to microcystin-LR increases the risks of urinary bladder proliferation and carcinogenesis: Evidence from case control, animal, and in vitro studies

To date, no reported studies have explored the impacts of microcystin-LR (MC-LR) on bladder tissues, and even the occurrence of bladder cancer. The current study explores the role of MC-LR in the development of bladder cancer through human observation and experimental research. In the population study, the odds ratio of bladder cancer for MC-LR was 6.073 (95 % CI, 2.117-17.422) after adjusting interference confounders. MC-LR is mainly located in the nucleus of epithelial cells in bladder cancer tissues instead of normal tissues. A positive association was observed between MC-LR and advanced tumor stage in serum and tissues. The animal study confirmed that prolonged MC-LR treatment promoted the bladder cancer phenotype accompanied by urinary bladder proliferation. In vitro, we indicated that MC-LR activated the PI3K/AKT/GSK3β/Cyclin D1 and JAK2/STAT3/Bcl2 signaling pathways to induce the growth of SV-HUC-1 cells. Moreover, MC-LR promoted the angiogenesis of SV-HUC-1 cells through PI3K/AKT/mTOR/HIF-1α/VEGF pathway. Our study provided the first evidence that prolonged MC-LR treatment increases the incidence of bladder cancer from human investigations, mice models, and in vitro studies, implying the profound importance of the investigation of MC-LR for public health.

Paeonol Suppresses Proliferation and Motility of Non-Small-Cell Lung Cancer Cells by Disrupting STAT3/NF-κB Signaling

Background: Targeting inflammatory microenvironment is a promising anti-tumor strategy. Paeonol is a phenolic compound with effective anti-inflammatory and anti-tumor properties. However, the effects of paeonol on non-small cell carcinoma (NSCLC) have not been fully investigated. Here, we evaluated the effects of paeonol on proliferation and metastasis of NSCLC and elucidated the underlying mechanisms.

Methods: The effects of paeonol on inflammatory cytokines were determined by cell proliferation and ELISA assays. Assays of wound healing, single cell migration and perforation invasion were used to evaluate migration and invasion of NSCLC cells. Expression of marker proteins in epithelial-mesenchymal transition (EMT) and matrix metalloproteinase (MMP) family enzymes were detected by Western blot assays. Nude mouse A549 cells transplantation tumor model was used to study the anti-lung cancer effects of paeonol in vivo. TUNEL stanining were used to detect the apoptosis of tumor cells in A549 lung cancer mice, and Ki67 analysis was used to detect the proliferation of tumor cells in A549 lung cancer mice. Immunohistochemistry was used to detect the effects of paeonol on signaling molecules in tumor tissues.

Results: Paeonol inhibited A549 cancer cell migration and invasion in vitro. Paeonol inhibited secreaion of inflammatory cytokines in A549 cells, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and transforming growth factor (TGF)-β. Paeonol altered the expression of marker proteins involved in EMT and MMP family enzymes. In addition, paeonol inhibited the transcriptional activity of nuclear factor-κB (NF-κB) and phosphorylation of signal transducers and activators of transcription 3 (STAT3). Paeonol inhibited the growth of A549 cells transplanted tumors in nude mice.

Conclusion: Paeonol potently inhibited NSCLC cell growth, migration and invasion associated with disruption of STAT3 and NF-κB pathways, suggesting that it could be a promising anti-metastatic candidate for tumor chemotherapy.

Targeting Stat3 signaling impairs the progression of bladder cancer in a mouse model

Bladder cancer is the fourth most commonly diagnosed malignancy in men worldwide and has one of the highest recurrence rates of all cancers. This cancer type is unique because chronic inflammation caused by Schistosoma haematobium can cause bladder cancer, while inflammation induced by Bacillus Calmette Guerin is the therapeutic cornerstone for this cancer type. Activation of proinflammatory IL-6/Stat3 axis promotes the development of different cancers by acting on cancer cells as well as by modulating cancer microenvironment. Using a genetic and pharmacological approach in a mouse model, we demonstrated the importance of IL-6 and Stat3 signaling in bladder cancer. Our findings show that pharmacological inhibition of Stat3 with WP1066 effectively delays progression and invasiveness of bladder cancer in N-butyl-N-(4-hydroxybutyl) nitrosamine-induced mouse model. Moreover, either IL-6 blockade or Stat3 inhibition sensitized bladder cancer to anti-PD-L1 immune therapy. Taken together, our study demonstrates an important role of IL-6/Stat3 signaling in bladder cancer and creates a rationale for testing the therapeutic potential of Stat3 inhibitors in human MIBC both alone or in combination with anti-PD-L1 and anti-IL-6 therapy.

STAT3/5 Inhibitors Suppress Proliferation in Bladder Cancer and Enhance Oncolytic Adenovirus Therapy

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.

Tissue Profile of CDK4 and STAT3 as Possible Innovative Therapeutic Targets in Urinary Bladder Cancer

Bladder cancer represents a global health problem. It ranks ninth in worldwide cancer incidence. In Egypt, carcinoma of the bladder is the most prevalent cancer, Bladder cancer has the highest recurrence rate of any malignancy. Certainly, suitable molecular diagnostic markers are required to improve the early detection of bladder cancer and then to prolong survival of patients. The present study was aimed to explore the expression of CDk4 and STAT3 in bladder cancer tissues as prospective for target therapy. Our studied groups showed higher values of CDK4 and STAT3 expression in malignant tissues (SCC andUC collectively) compared to cystitis, however, significantly higher values of CDK4 and STAT3 expression were detected in UC group compared to SCC group. Urothelial carcinomas with papillary patterns showed lower parameters of CDK4 and STAT3 expression compared to the non-papillary variant, with significant differences. Higher grades of UC showed significantly higher parameters of CDK4 and STAT3 expression compared to low grade ones. Muscle invasion increases the level of CDK4 and STAT3 expression parameters, compared to non-muscle invasive UC.

Molecular therapy with derivatives of amino benzoic acid inhibits tumor growth and metastasis in murine models of bladder cancer through inhibition of TNFα/NFΚB and iNOS/NO pathways

Muscle-invasive bladder cancer (MIBC) is an aggressive form of urothelial bladder carcinoma (UBC) with poorer outcomes compared to the non-muscle invasive form (NMIBC). Higher recurrent rates and rapid progression after relapse in UBC is known to be linked with chronic inflammation. Here, the preclinical murine models of NMIBC (MB49) and MIBC (MB49-I) were used to assess the antitumor effects of DAB-1, an anti-inflammatory aminobenzoic acid derivative we have developed in order to target cancer-related inflammation. A subchronic toxicity study on cancer-free mice shown that DAB-1 treatment did not affect normal mouse development or normal function of vital organs. In mice bearing MB49-I tumors, whole body accumulation of the radioconjugate [¹³¹I]DAB-1 was higher than in control mice, the main sites of [¹³¹I]DAB-1 accumulation being the liver (34%), the intestines (21%), and the tumors (18%). In vivo molecular therapy of ectopic and orthotopic tumors indicated that treatment with DAB-1 efficiently inhibited tumor growth, metastasis formation, and mortality rate. The antitumor efficacy of DAB-1 was associated with strong decreased tumor cell proliferation and iNOS expression in tumor tissues and deactivation of macrophages from tumor-bearing mice. Mechanistic investigations revealed that DAB-1 efficiently inhibited i) TNFα/NFΚB and IL6/STAT3 signaling pathways activation; ii) TNFα-induced NO production by decreasing NFΚB transcriptional activation and functional iNOS expression; and iii) cellular proliferation with minimal or no effects on cell mortality or apoptosis. In conclusion, this study provides preclinical and biological/mechanistic data highlighting the potential of DAB-1 as a safe and efficient therapeutic agent for the treatment of patients with NMIBC and MIBC.

Quinalizarin induces ROS‑mediated apoptosis via the MAPK, STAT3 and NF‑κB signaling pathways in human breast cancer cells

Quinalizarin has been demonstrated to exhibit potent antitumor activities in lung cancer and gastric cancer cells, but currently, little is known regarding its anticancer mechanisms in human breast cancer cells. The aim of the present study was to investigate the apoptotic effects of quinalizarin in MCF-7 cells and to analyze its molecular mechanisms. The MTT assay was used to evaluate the viability of human breast cancer cells that had been treated with quinalizarin and 5-fluorouracil. Flow cytometric analyses and western blotting were used to investigate the effects of quinalizarin on apoptosis and cycle arrest in MCF-7 cells with focus on reactive oxygen species (ROS) production. The results demonstrated that quinalizarin exhibited significant cytotoxic effects on human breast cancer cells in a dose-dependent manner. Accompanying ROS, quinalizarin induced MCF-7 cell mitochondrial-associated apoptosis by regulating mitochondrial-associated apoptosis, and caused cell cycle arrest at the G₂/M phase in a time-dependent manner. Furthermore, quinalizarin can activate p38 kinase and JNK, and inhibit the extracellular signal-regulated kinase, signal transducer and activator of transcription 3 (STAT3) and NF-κB signaling pathways. These effects were blocked by mitogen-activated protein kinase (MAPK) inhibitor and N-acetyl-L-cysteine. The results from the present study suggested that quinalizarin induced G₂/M phase cell cycle arrest and apoptosis in MCF-7 cells through ROS-mediated MAPK, STAT3 and NF-κB signaling pathways. Thus, quinalizarin may be useful for human breast cancer treatment, as well as the treatment of other cancer types.

Differential expression of NF-κB heterodimer RelA/p50 in human urothelial carcinoma

Background

Urothelial carcinoma (UC) is the fifth most common malignancy that accounts for 5% of all cancers. Diagnostic markers that predict UC progressions are inadequate. NF-κB contributes towards disease progression upon constitutive activation in many solid tumors. The nuclear localization of NF-κB indicates increased transcriptional activity while cytoplasmic localization indicates the inactive protein repository that can be utilized readily by a malignant cell. This study delineates the nuclear and cytoplasmic differential expression of NF-κB heterodimers in UC progression.

Methods

The involvement of the NF-κB proteins in UC was analyzed in silico using cytoscape. The expression of NF-κB heterodimers was analyzed by immunohistochemistry.

Results

PINA4MS app in cytoscape revealed over expression of RelA and suppression of NF-κB1 (p50 precursor) in UC whereas the expression of NF-κB target proteins remained unhindered. Immunohistochemical localization showed nuclear RelA/p50 in low grade UC whereas in high grade only RelA expression was observed. Conversely, cytoplasmic expression of RelA/p50 remained extensive across high and low grade UC tissues (p < 0.005). RelA nuclear and cytoplasmic expression (p < 0.005) was directly proportional to the disease progression. In our study, some of the high-grade UC tissues with squamous differentiation and muscle invasion had extensive nuclear p50 localization. The phenomenon of RelA/p50 expression seen increased in low-grade UC than high grade UC might be due to their interaction with other members of NF-κB family of proteins. Thus, NF-κB RelA/p50 differential expression may play a unique role in UC pathogenesis and can serve as a biomarker for diagnosis.

STAT3 expression is a prognostic marker in upper urinary tract urothelial carcinoma

Signal transducer and activator of transcription 3 (STAT3) plays a prominent role in the growth and invasion of several types of solid tumors. In this study, to assess the expression status and prognostic significance of the STAT3 pathway in upper urinary tract urothelial carcinoma (UTUC), we immunohistochemically stained for STAT3 and STAT3 pathway proteins, sphingosine-1-phosphate receptor 1 (S1PR1) and interleukin-6 (IL-6), in a tissue microarray containing 99 UTUC specimens. There were no significant associations between STAT3, S1PR1, or IL-6 expression pattern and tumor grade or pT stage. However, the patients with high STAT3 tumor had a significantly higher risk of both disease progression (p = 0.009) and cancer-specific mortality (p = 0.009), but not with tumors expressing S1PR1 or IL-6. High STAT3 expression in the nucleus was also associated with a significantly higher risk of both disease progression (p = 0.003) and cancer-specific mortality (p = 0.034). Multivariate analysis revealed that high STAT3 expression in the nucleus was significantly associated with cancer-specific survival after adjustment for pathological stage, lymph node involvement, lymphovascular invasion, and tumor grade (HR = 2.136, 95% CI = 1.009–4.767, p = 0.047). Our findings indicated that STAT3 could be a cancer-promoting factor and potentially a significant prognostic factor in UTUC.

RIPK4 promotes bladder urothelial carcinoma cell aggressiveness by upregulating VEGF-A through the NF-κB pathway

BACKGROUND

Constitutively activated nuclear factor kappa B (NF-κB) signalling plays vital roles in bladder urothelial carcinoma (BC) progression. We investigate the effect of receptor-interacting protein kinase 4 (RIPK4) on NF-κB activation and BC progression.

METHODS

The expression of RIPK4 was examined in 25 cryopreserved paired bladder samples and 112 paraffin BC specimens. In vivo and in vitro assays were performed to validate effect of RIPK4 on NF-κB pathway-mediated BC progression.

RESULTS

High expression of RIPK4 was observed in BC tissues and was an independent predictor for poor overall survival. Up or downregulating the expression of RIPK4 enhanced or inhibited, respectively, the migration and invasion of BC cells in vitro and in vivo. Mechanistically, RIPK4 promoted K63-linked polyubiquitination of tumour necrosis factor receptor-associated factor 2 (TRAF2), receptor-interacting protein (RIP) and NF-κB essential modulator (NEMO). RIPK4 also promoted nuclear localisation of NF-κB-p65, and maintained activation of NF-κB substantially, leading to upregulation of VEGF-A, ultimately promoting BC cell aggressiveness.

CONCLUSIONS

Our data highlighted the molecular aetiology and clinical significance of RIPK4 in BC: upregulation of RIPK4 contributes to NF-κB activation, and upregulates VEGF-A, and BC progression. Targeting RIPK4 might represent a new therapeutic strategy to improve survival for patients with BC.

Paeoniflorin inhibits the growth of bladder carcinoma via deactivation of STAT3

Bladder cancer (BCa) is one of the most common urinary cancers. The present study aims to investigate whether Paeoniflorin (Pae) can exert inhibitory effects on BCa. The results showed that Pae inhibited proliferation of human BCa cell lines in a concentration- and time-dependent manner. Pae and cisplatin (Cis) synergistically inhibited the growth of tumours in RT4-bearing mice. Pae treatment neutralized the body loss induced by Cis. Moreover, Pae induced apoptosis in RT4 cells and increased the activities of caspase3, caspase8 and caspase9. Western blotting and immunohistochemical analysis revealed that the phosphorylated signal transducer and activator of transcription-3 (p-STAT3) level were decreased in Pae-treated RT4 cells and Pae-treated tumour-bearing mice. Furthermore, STAT3 transcriptional target B-cell lymphoma-2 was decreased in Pae-treated RT4 cells. Interestingly, Pae prevented translocation of STAT3 to the nucleus in RT4 cells. Collectively, Pae inhibits the growth of BCa, at least in part, via a STAT3 pathway.

STAT3 inhibition by WP1066 suppresses the growth and invasiveness of bladder cancer cells

Signal transducer and activator of transcription 3 (STAT3) regulates the expression of genes mediating cell survival, proliferation and angiogenesis and is aberrantly activated in various types of malignancies, including bladder cancer. We examined whether it could be a novel therapeutic target for bladder cancer using the STAT3 inhibitor WP1066. In T24 and UMUC-3 bladder cancer cells, 5 µM WP1066 prevented the phosphorylation of STAT3 and 2.5 µM WP1066 decreased cell survival and proliferation significantly (P<0.01). WP1066 also induced apoptosis accompanied by the suppression of the expression of Bcl-2 and Bcl-xL in T24 cells. Moreover, the covered area in a wound and the number of cells invading through a Matrigel chamber decreased significantly (P<0.01) when cells were treated with WP1066. The activities of MMP-2 and MMP-9 were also decreased by treatment with 10 µM WP1066. Our results revealed that using WP1066 to inhibit the STAT3 signaling pathway suppressed the viability and invasiveness of bladder cancer cells effectively and could be a novel therapeutic strategy against bladder cancer.

Chronic inflammation in urothelial bladder cancer

The association between inflammation and cancer has been pointed out in epidemiological and clinical studies, revealing how chronic inflammation may contribute to carcinogenesis in various malignancies. However, the molecular events leading to malignant transformation in a chronically inflamed environment are not fully understood. In urothelial carcinoma of the urinary bladder, inflammation plays a dual role. On the one hand, chronic inflammation is a well-established risk factor for the development of bladder cancer (BC), as seen in Schistosoma haematobium infection. On the other, intravesical therapy by bacillus Calmette-Guérin (BCG), which induces inflammation, offers protection against cancer recurrence. The large variety of pro-inflammatory mediators expressed by BC and immune cells binds to specific receptors which control signalling pathways. These activate transcription of a plethora of downstream factors. This review summarizes recent data regarding inflammation and urothelial carcinoma, with special emphasis on the role the inflammatory response plays in BC recurrence risk and progression.