New agents for bladder cancer

Melatonin and urological cancers: a new therapeutic approach

Urological cancers are responsible for thousands of cancer-related deaths around the world. Despite all developments in therapeutic approaches for cancer therapy, the absence of efficient treatments is a critical and vital problematic issue for physicians and researchers. Furthermore, routine medical therapies contribute to several undesirable adverse events for patients, reducing life quality and survival time. Therefore, many attempts are needed to explore potent alternative or complementary treatments for great outcomes. Melatonin has multiple beneficial potential effects, including anticancer properties. Melatonin in combination with chemoradiation therapy or even alone could suppress urological cancers through affecting essential cellular pathways. This review discusses current evidence reporting the beneficial effect of melatonin in urological malignancies, including prostate cancer, bladder cancer, and renal cancer.

Silencing of CARMA3 inhibits bladder cancer cell migration and invasion via deactivating β-catenin signaling pathway

Background

Bladder cancer (BC) is the ninth most common cancer and the fourteenth leading death worldwide. CARD-containing MAGUK 3 (CARMA3) protein is a novel scaffold protein known to activate NF-κB pathway and is overexpressed in BC tissues.

Purpose

The objective of this study was to identify how CARMA3 affects the metastasis of BC cells via the β-catenin signaling pathway.

Materials and methods

In the present study, 5637 and T24 BC cells with stable low expression of CARMA3 were established, and their migratory and invasive capabilities were further evaluated by wound-healing and transwell assay. The activity and expression of β-catenin were determined by Luciferase assay and immunofluoresence staining. The mRNA and protein expression levels of CARMA3, matrix metallopeptidase (MMP) 9 and MMP2 were detected by quantitative real-time PCR (qRT-PCR) and Western blot analysis. The nude mouse tumor xenograft model was established for in vivo study.

Results

By comparison to the control cells, CARMA3-silenced cells acquired a less aggressive phenotype: decreased migration and invasion. More importantly, we confirmed that CARM3 knockdown could inhibit β-catenin mRNA and protein expression and activity, and reduce the expression and/or activity of matrix metallopeptidase (MMP) 9, MMP2 and C-myc. Also, CARM3 silencing increased E-cadherin expression and attenuated the expression of β-catenin. Moreover, we demonstrated that β-catenin overexpression reversed the inhibiting effect of CARMA3 silencing on cell invasion and migration. Furthermore, our study illustrated that knockdown of CARMA3 suppressed BC cells xenograft tumor growth in nude mice.

Conclusion

We demonstrated that CARMA3 contributes to the malignant phenotype of BC cells at least by activating β-catenin signaling pathway, and it may serve as a therapeutic target for clinic treatment in BC.

Biological/pathological functions of the CXCL12/CXCR4/CXCR7 axes in the pathogenesis of bladder cancer

CXC chemokine ligand 12 (CXCL12) is an important member of the CXC subfamily of chemokines, and has been extensively studied in various human body organs and systems, both in physiological and clinical states. Ligation of CXCL12 to CXCR4 and CXCR7 as its receptors on peripheral immune cells gives rise to pleiotropic activities. CXCL12 itself is a highly effective chemoattractant which conservatively attracts lymphocytes and monocytes, whereas there exists no evidence to show attraction for neutrophils. CXCL12 regulates inflammation, neo-vascularization, metastasis, and tumor growth, phenomena which are all pivotally involved in cancer development and further metastasis. Generation and secretion of CXCL12 by stromal cells facilitate attraction of cancer cells, acting through its cognate receptor, CXCR4, which is expressed by both hematopoietic and non-hematopoietic tumor cells. CXCR4 stimulates tumor progression by different mechanisms and is required for metastatic spread to organs where CXCL12 is expressed, thereby allowing tumor cells to access cellular niches, such as the marrow, which favor tumor cell survival and proliferation. It has also been demonstrated that CXCL12 binds to another seven-transmembrane G-protein receptor or G-protein-coupled receptor, namely CXCR7. These studies indicated critical roles for CXCR4 and CXCR7 mediation of tumor metastasis in several types of cancers, suggesting their contributions as biomarkers of tumor behavior as well as potential therapeutic targets. Furthermore, CXCL12 itself has the capability to stimulate survival and growth of neoplastic cells in a paracrine fashion. CXCL12 is a supportive chemokine for tumor neovascularization via attracting endothelial cells to the tumor microenvironment. It has been suggested that elevated protein and mRNA levels of CXCL12/CXCR4/CXCR7 are associated with human bladder cancer (BC). Taken together, mounting evidence suggests a role for CXCR4, CXCR7, and their ligand CXCL12 during the genesis of BC and its further development. However, a better understanding is still required before exploring CXCL12/CXCR4/CXCR7 targeting in the clinic.

Melatonin potentiates the antitumor effect of curcumin by inhibiting IKKβ/NF-κB/COX-2 signaling pathway

Curcumin, a natural polyphenolic compound, has commonly been used as a food additive or in many traditional medicine remedies for over 2,000 years in many Asian countries. Melatonin is a hormone secreted from pineal glands of mammals and possesses diverse physiological functions. Both curcumin and melatonin have the effective potential to inhibit proliferation of various types of cancers, but there is no report on their combination for bladder cancer treatment, and the underlying mechanism remains poorly understood. In the present study, we investigated whether the combination of curcumin and melatonin leads to an enhanced inhibition of cell proliferation in bladder cancer cells. Our results showed that the combinational treatment enhanced the repression of nuclear translocation of NF-κB and their binding on COX-2 promoter via inhibiting IKKβ activity, resulting in inhibition of COX-2 expression. In addition, combined treatment with curcumin and melatonin induced cell apoptosis in bladder cancer through enhancing the release of cytochrome c from the mitochondrial intermembrane space into the cytosol. These results, therefore, indicated that melatonin synergized the inhibitory effect of curcumin against the growth of bladder cancer by enhancing the anti-proliferation, anti-migration, and pro-apoptotic activities, and provide strong evidence that combined treatment with curcumin and melatonin might exhibit an effective therapeutic option in bladder cancer therapy.

USP21 promotes cell proliferation and metastasis through suppressing EZH2 ubiquitination in bladder carcinoma

Bladder cancer (BC) is the second most common malignant tumor of the urinary tract in the world. In this study, we found that ubiquitin-specific protease (USP21) was upregulated in BC and the ectopic expression of USP21 was closely associated with tumor size and metastasis. Moreover, patients with higher levels of USP21 had poorer survival rate. Multiple function analysis such as CCK-8, colony formation, wound healing, and transwell analysis indicated that USP21 regulated cell proliferation and metastasis in bladder carcinoma cell lines. We also found that USP21 could facilitate epithelial–mesenchymal transition. As EZH2 has been reported to promote cell metastasis in BC, our work identified that USP21 deubiquitinated EZH2 and stabilized it. Our data demonstrated that USP21 might play a crucial role in regulating BC progression and could provide a potential therapeutic strategy for BC.

Single-cell analyses of transcriptional heterogeneity in squamous cell carcinoma of urinary bladder

Cell-to-cell expression heterogeneity within a single tumor is a common phenotype among various cancer types including squamous cell carcinoma. To further study the fundamentals and importance of heterogeneity of cell functions and its potential mechanisms, we performed single-cell RNA-seq (scRNA-seq) on human squamous cell carcinoma of the bladder (SCCB) and its corresponding physiologically normal epithelia. Extensive differentially expressed genes were uncovered by comparing cancer and normal single cells, which were preferentially enriched in cancer-correlated pathways, such as p53 signaling and bladder cancer pathway. Furthermore, the most diversely expressed genes were particularly enriched in MAPK signaling pathway, such as CACNG4, CACNA1E and CACNA1H, which involve in cancer evolution and heterogeneity formation. Co-expression network and hub-gene analyses revealed several remarkable "hub genes" of each regulatory module. Some of them are cancer related, such as POU2F3, NKD1 and CYP2C8, while LINC00189, GCC2 and OR9Q1 genes are rarely reported in human diseases. The genes within an interesting module are highly correlated with others, which could be treated as potential targets for SCCB patients. Our findings have fundamental implications for SCCB biology and therapeutic strategies.

Artesunate induces apoptosis of bladder cancer cells by miR-16 regulation of COX-2 expression

Bladder cancer is the most common malignant tumor of the urinary tract and remains one of the major causes of cancer death worldwide. In this study, we investigated the effect and mechanism of Artesunate (ART), a traditional Chinese medicine, on inducing apoptosis of human bladder cancer cells. In vivo antitumor activity was investigated in bladder cancer in rat by subcutaneous injection of different concentration of ART. The effect of ART on growth inhibition and apoptosis of bladder cancer cells was evaluated using dimethylthiazoly-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. Cyclooxygenase-2 (COX-2) and miR-16 expression levels were determined with real-time PCR. The concentrations of prostaglandin E2 (PGE2) in the supernatants of bladder cancer cells were measured with an ELISA kit. The miR-16 inhibitor or mimic were transfected into cells to up- or down-regulate miR-16 expression. ART efficiently inhibited orthotopic tumor growth in the bladder cancer rat, which is accompanied with an increase of miR-16 expression and a decrease of COX-2 expression. In vitro, ART could induce cytotoxicity and apoptosis in bladder cancer cells, but presented a much lighter toxicity effect against normal human urothelial cells. ART significantly increased miR-16 expression and decreased the expression of COX-2 and the production of PGE2. More importantly, down-regulation of miR-16 expression could reverse the effect of ART on apoptosis and COX-2 expression in bladder cells. Moreover, exogenous PGE2 could inhibit apoptosis of bladder cancer cells treated with ART. In conclusion, ART can elicit an anti-tumor effect against bladder cancer by up-regulation of miR-16 expression, which resulted in the decrease of COX-2 expression and PGE2 production. Hence, ART might be an effective drug for the treatment of bladder cancer.

Surveillance of patients with bladder cancer following cystectomy: yield of CT urography

PURPOSE

To determine the yield of CT urography (CTU) in the surveillance of patients with bladder cancer following cystectomy.

MATERIALS AND METHODS

In this IRB-approved, HIPAA-compliant, retrospective study of 5,404 CT urograms performed at our institution between March 2000 and February 2011, 225 CT urograms were performed in 105 patients [79 men, 26 women; mean age 65 years (43-85)] following cystectomy for bladder cancer. Median follow-up after cystectomy was 63 months (range 1-234), median time between cystectomy and CTU was 39 months (range 0-229), median follow-up after CTU was 34 months (range 1-111). CTU examinations were reviewed by two radiologists in consensus and findings were categorized into those related to surgery, locoregional recurrence, metastases, or metachronous upper tract urothelial tumor (UTT).

FINDINGS

Findings were present in 69 (65.7 %) of 105 patients, including findings related to surgery in 60 (57.1 %) patients, locoregional recurrence or metastatic disease in 21 (20 %) patients, and UTT in 3 (2.9 %) patients. Of surgery-related findings, hydronephrosis (23/105, 21.9 %) and parastomal hernia (17/105, 16.2 %) were the most common findings. Visceral metastases (16/105, 15.2 %) and lymph node metastases (13/105, 12.4 %) were the most common manifestations of recurrent disease.

CONCLUSION

CTU findings in the surveillance of patients with bladder cancer after cystectomy are common and include those related to surgery, spread of the disease, and metachronous tumors. Our study supports current published guidelines on the use of CTU in these patients.

Interleukin-11, an interleukin-6-like cytokine, is a promising predictor for bladder cancer prognosis

Numerous studies have suggested that interleukin 11 (IL-11) has roles in human gastric, prostate and bone cancer and endometrial carcinoma. Hence, we evaluated the expression of IL-11 in bladder cancer and the correlation of IL-11 levels and clinico-pathological features. The expression of IL-11 in primary human bladder cell culture, human bladder cancer cell lines, transitional cell carcinoma (TCC) and non-cancerous bladder tissues (NATs) were analyzed by western blotting. Enzyme-linked immunosorbent assay (ELISA) for urinary IL-11 was performed to compare the IL-11 levels in healthy subjects and subjects diagnosed with bladder cancer. Our study suggested that the expression of IL-11 in human bladder cancer cell lines and TCC was downregulated compared with primary human bladder cell culture and matched NATs. We also demonstrated reduced urinary levels of IL-11 in subjects with bladder cancer compared with healthy subjects. Furthermore, we revealed that the levels of IL-11 were associated with tumor grade and stage. The results suggested that reduced levels of IL-11 may play an important role in the carcinogenesis and progression of TCC. They also indicated that IL-11 may be a promising predictor for prognosis of TCC.