Human Bladder Cancer Cell Lines Research Articles

Abstract 3743: Neutrophil extracellular traps and their implication with radioresistance in muscle invasive bladder cancer

Abstract PURPOSE: Radiotherapy modifies diverse components of the tumor microenvironment and inflammation plays a pivotal role in modulating radiation responsiveness of tumors. Neutrophils are one of the first-line responders during the acute phase of inflammation and are increasingly being recognized as drivers of tumor progression. One mechanism by which neutrophils play a role in tumor progression is through the formation of neutrophil extracellular traps (NETs). NETs are web-like structures expelled by the neutrophil composed of DNA studded with various proteins. Initially, this was described as a mechanism of antimicrobial defense but lately NETs have been associated with a variety of adverse effects, such as pathogenesis of autoimmune diseases, surgical stress, tumor progression, and metastasis. Recent studies show that the protein High Mobility Group Box-1 (HMGB1), a key player in radioresistance can in fact promote NETs. Importantly, the impact of NETs has not yet been explored in the context of radiation, so we sought to explore this further. METHODS: In vitro: a) Human neutrophils isolated from healthy donors were stimulated with 50ng of rHMGB1 for 4 hours. NETs were quantified through Sytox green fluorescence. b) Neutrophils were co-cultured with irradiated or non-irradiated conditioned media from UM-UC3 human bladder cancer cell line in combination with glycyrrhizin (GLZ), a natural inhibitor of HMGB1. In vivo: Murine bladder cancer cell line (MB49) was subcutaneously implanted into flanks of C57BL/6 and NETosis deficient PAD4-/- mice. Tumors were irradiated (2x5Gy) using the XRAD Smart Irradiator. Intraperitoneal injections of GLZ were used to modulate HMGB1 and intramuscular injections of DNAse were used to deplete NETs. Tumor volumes were measured using a digital caliper till endpoint. RESULTS: Our in vitro results demonstrate incubation of neutrophils with 50ng rHMGB1 significantly induced NETs formation compared to controls (p<0.0001) and this was reversed through addition of GLZ (p<0.0001). Similarly, co-culture of neutrophils with irradiated MB49 conditioned media induced NETs formation (p=0.01) and this effect was reversed with GLZ (p=0.009). Our in vivo results demonstrate that NETosis deficient mice treated with an HMGB1 inhibitor significantly improves response to radiation therapy. PAD4-/- mice treated with GLZ showed delayed tumor growth kinetics (p=0.023) and increased overall survival post radiation (p=0.0231) compared to all other irradiated arms: C57BL/6, PAD4-/-, C57BL/6 + DNAse and C57BL/6 + GLZ. Similarly, C57BL/6 mice treated with DNAse and GLZ also showed a delay in tumor growth kinetics post radiation (p<0.0001). CONCLUSION: NETs may induce radioresistance through interactions with HMGB1. Highlighting the role of HMGB1 in NET formation will provide valuable information on the responses that occur in the tumor microenvironment post radiation therapy. Citation Format: Surashri Shinde-Jadhav, Jose Joao Mansure, Roni Rayes, Mina Ayoub, Jonathan Spicer, Wassim Kassouf. Neutrophil extracellular traps and their implication with radioresistance in muscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3743.

Amentoflavone Induces Apoptosis and Reduces Expression of Anti-apoptotic and Metastasis-associated Proteins in Bladder Cancer.

Amentoflavone has been shown to be effective against a variety of cancer cells, but its role in bladder cancer remains unclear. Thus, the aim of this study is to evaluate whether amentoflavone may induce toxicity effect of bladder cancer. Herein, we evaluated amentoflavone effects in a human bladder cancer cell line TSGH8301 in vitro. Amentoflavone caused significant cytotoxicity in TSGH8301 cells at a concentration as low as 200 μM. FAS/FASL-dependent extrinsic apoptosis and mitochondria-dependent intrinsic apoptosis were observed in amentoflavone-treated cells in a dose-dependent manner. Levels of several proapoptotic proteins, such as FAS, FAS-ligand and BAX (B-cell lymphoma 2 associated X) were increased following amentoflavone treatment. Meanwhile, anti-apoptotic MCL-1 (myeloid cell leukemia sequence 1) and cellular FLICE-inhibitory protein (C-FLIP) protein levels were reduced. Additionally, angiogenesis and proliferation-related proteins, including matrix metalloproteinase (MMP)-2, -9, vascular endothelial growth factor (VEGF), urokinase-type plasminogen actvator (uPA) and cyclin D1 were diminished by amentoflavone. Amentoflavone induced toxicity of bladder cancer by inhibiting tumor progression and inducing apoptosis signaling transduction.

Abstract 5064: Sirt6 is a novel tumor suppressor in human urothelial cancer and activated by methysticin

Abstract Sirtuin 6 (SIRT6) plays an important role in longevity, metabolism, DNA-repair, and inflammatory response. In human urothelial cancer, a high level of SIRT6 expression predicts a better survival for patients. We found that overexpression of SIRT6 in human muscle-invasive bladder cancer cell line J82 reduced cell migration and invasion, but didn’t reduce the in vitro cell growth. Kava is a traditional psychotropic beverage made from the rhizomes of Piper methysticum G. Forst. Previous epidemiological studies have shown an inverse relationship between cancer incidence and kava consumption in South Pacific Island Nations. We have shown that Methysticin, a major kavalactone in the Kava plant, inhibits the growth, migration and invasion of bladder cancer lines. However, these anti-cancer activities of Methysticin are attenuated in cells with low expression of SIRT6, expression of enzymatically mutant SIRT6 or SIRT6 knockout, which suggested that the anti-cancer activities of Methysticin are at least in part dependent on SIRT6 expression. Molecular modelling indicates that Methysticin docks into the site next to a loop near the acetylated peptide substrate binding site of SIRT6. The Cellular Thermal Shift Assay (CETSA, an in vivo assay) demonstrated that Methysticin significantly decreased heat-induced protein degradation of SIRT6. Treatment of J82 cells with Methysticin also resulted in a dose-dependent reduction of H3K18 acetylation. Taken together, these results suggest that Methysticin acts a novel SIRT6 activator for its anti-bladder activity. Further studies have demonstrated that Methysticin activates the TBK1/IRF3/STING pathway by increasing the protein expression of TBK1 and the phosphorylation of TBK1 and STING, which suggest that Methysticin may be able to enhance anti-tumor immunity. Therefore, our results support further investigation of Methylation for bladder cancer prevention. Note: This abstract was not presented at the meeting. Citation Format: DongJun Fu, Noriko N. Yokoyama, Mattew Tippin, Xiaolin Zi. Sirt6 is a novel tumor suppressor in human urothelial cancer and activated by methysticin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5064.

Lentiviral vector-mediated gene transfer combined with cisplatin enhances tumor suppression in human bladder cancer cell lines

Abstract Purpose Non-muscle invasive bladder cancer (NMIBC) shows high rates of recurrence and frequently progresses to more advanced stages, such as muscle invasive bladder cancer (MIBC). Repetition of treatment and recurrence are serious burdens and cause severe reduction in the quality of life (QOL) of patients. Thus, a novel therapeutic strategy without high burdens on the patients is an urgent requirement. Consequently, we evaluated tumor growth inhibition in bladder cancer cell lines using a combination of cisplatin (CDDP), one of the prevailing anticancer drugs to treat bladder cancer, and lentiviral vector-mediated gene transfer, where the vector is known to have minimal cytotoxicity. Methods Lentiviral vector with tumor suppressor genes including p53, p16, and phosphatase and tensin homology (PTEN) were infected to human bladder cancer cell lines, UMUC3 and T24, followed by CDDP treatment. Results The transduction of the p53, p16, or PTEN gene was equivalent to the antitumor efficacy of CDDP against bladder cancer cells. Furthermore, lentiviral vector-mediated transduction of tumor suppressive genes in combination with CDDP showed superior antitumor effects relative to individual treatment strategies with the vector or CDDP alone. Conclusion Lentiviral vector-mediated gene transduction is a promising alternative to the existing therapy in treating bladder cancer. The current protocol of CDDP-based chemotherapy may be replaced in the future. Moreover, the combination of gene therapy and chemotherapy may be an effective treatment for bladder cancer.

CD47-Targeted Near-Infrared Photoimmunotherapy for Human Bladder Cancer.

Near-infrared photoimmunotherapy (NIR-PIT) is a localized molecular cancer therapy combining a photosensitizer-conjugated mAb and light energy. CD47 is an innate immune checkpoint widely expressed on bladder cancer cells, but absent from luminal normal urothelium. Targeting CD47 for NIR-PIT has the potential to selectively induce cancer cell death and minimize damage to normal urothelium. The cytotoxic effect of NIR-PIT with anti-CD47-IR700 was investigated in human bladder cancer cell lines and primary human bladder cancer cells derived from fresh surgical samples. Phagocytosis assays were performed to evaluate macrophage activity after NIR-PIT. Anti-CD47-IR700 was administered to murine xenograft tumor models of human bladder cancer for in vivo molecular imaging and NIR-PIT. Cytotoxicity in cell lines and primary bladder cancer cells significantly increased in a light-dose-dependent manner with CD47-targeted NIR-PIT. Phagocytosis of cancer cells significantly increased with NIR-PIT compared with antibody alone (P = 0.0002). In vivo fluorescence intensity of anti-CD47-IR700 in tumors reached a peak 24-hour postinjection and was detectable for at least 14 days. After a single round of CD47-targeted NIR-PIT, treated animals showed significantly slower tumor growth compared with controls (P < 0.0001). Repeated CD47-targeted NIR-PIT treatment further slowed tumor growth (P = 0.0104) and improved survival compared with controls. CD47-targeted NIR-PIT increased direct cancer cell death and phagocytosis resulting in inhibited tumor growth and improved survival in a murine xenograft model of human bladder cancer.

Let-7i inhibits proliferation and migration of bladder cancer cells by targeting HMGA1

BackgroundLet-7 is one of the earliest discovered microRNAs(miRNAs) and has been reported to be down-regulated in multiple malignant tumors. The effects and molecular mechanisms of let-7i in bladder cancer are still unclear. This study was to investigate the effects and potential mechanisms of let-7i on bladder cancer cells.MethodsTotal RNA was extracted from bladder cancer cell lines. The expression levels of let-7i and HMGA1 were examined by quantitative real-time PCR. Cell viability was detected using the CCK-8 and colony formation assays, while transwell and wound healing assays were used to evaluate migration ability. Luciferase reporter assay and western blot were used to confirm the target gene of let-7i.ResultsCompared with the SV-40 immortalized human uroepithelial cell line (SV-HUC-1), bladder cancer cell lines T24 and 5637 had low levels of let-7i expression, but high levels of high mobility group protein A1 (HMGA1) expression. Transfection of cell lines T24 and 5637 with let-7i mimic suppressed cell proliferation and migration. Luciferase reporter assay confirmed HMGA1 may be one of the target genes of let-7i-5p. Protein and mRNA expression of HMGA1 was significantly downregulated in let-7i mimic transfected cell lines T24 and 5637.ConclusionsUp-regulation of let-7i suppressed proliferation and migration of the human bladder cancer cell lines T24 and 5637 by targeting HMGA1. These findings suggest that let-7i might be considered as a novel therapeutic target for bladder cancer.

Increased miR-323a induces bladder cancer cell apoptosis by suppressing c-Met.

The current study aimed to evaluate the expression and role of miR-323a in the progression of bladder cancer (BC), thereby providing a theoretical basis and potential therapy methods for BC patients. Our data showed that miR-323a levels were significantly reduced in BC tissues compared with those of non-cancerous tissues. Meanwhile, miR-323a was significantly decreased in human BC cell lines (T24, J82, TCCSUP, RT-112) than that in human normal bladder epithelial cell line SV-HUC-1. Furthermore, inhibition of miR-323a markedly enhanced the migration and invasive capacity of T24 and TCCSUP cells. Moreover, overexpression of miR-323a significantly prompted the apoptosis of BC cells. Dual luciferase reporter assay and western blot analysis confirmed that c-Met was a target gene of miR-323a. More importantly, upregulation of c-Met significantly prompted BC cell proliferation mainly as a result of the enhanced level of phosphorylation of AKT. This effect could be abolished when c-Met was silenced in BC cells. In summary, reduced miR-323a expression in BC contributed to enhanced BC cell proliferation and migration mainly by targeting c-Met.

Characterization of Histone Deacetylase Expression Within In Vitro and In Vivo Bladder Cancer Model Systems.

Epigenetic aberrations are prominent in bladder cancer (BC) and contribute to disease pathogenesis. We characterized histone deacetylase (HDAC) expression, a family of deacetylation enzymes, in both in vitro and in vivo BC model systems and analyzed expression data from The Cancer Genome Atlas (TCGA). Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting analysis was used to determine the expression status of Class I and II HDACs in ten human BC cell lines, while qRT-PCR was used to determine HDAC expression in 24 human tumor specimens. The TCGA cohort consists of 408 muscle invasive BC (MIBC) clinical samples and analysis of this data set identified expression of HDAC4 and -9 as being associated with basal–squamous disease. These findings agree with qRT-PCR results identifying increased expression of HDAC4, -7, and -9 in basal BC cell lines (p < 0.05; Kruskal–Wallis test) and in clinical specimens with invasive bladder cancer (not statistically significant). We also observed increased expression in Hdac4, -7, and -9 in commonly used BC mouse models. Here, we identify suitable preclinical model systems for the study of HDACs, and show increased expression of Class IIa HDACs, specifically HDAC4 and HDAC9, in basal BC cell lines and in invasive clinical specimens. These results suggest this class of HDACs may be best suited for targeted inhibition in patients with basal BC.

Dihydrotestosterone increases the risk of bladder cancer in men

Men are at a higher risk of developing bladder cancer than women. Although the urinary bladder is not regarded as an sex organ, it has the potential to respond to androgen signals. The mechanisms responsible for the gender differences remain unexplained. Androgen receptor (AR) after binding with 5α-dihydrotestosteron (DHT) undergoes a conformational change and translocates to nucleus to induce transcriptional regulation of target genes. However androgen/AR signaling can also be activated by interacting with several signaling molecules and exert its non-genomic function. The aim of present study was to explain whether the progression of bladder cancer in men is dependent on androgen/AR signaling. Studies were carried out on human bladder cancer cell lines: HCV29, T24, HT1376 and HTB9. Bladder cancer cells were treated for 48 h with 10 nM DHT or not, with replacement after 24 h. Expression of cell signaling proteins, was analyzed using Western Blot and RT-PCR. Subcellular localization of protein was studied using the ProteoExtract Subcellular Proteome Extraction Kit and Western blot analysis. We showed that DHT treatment significantly increased AR expression in bladder cell line HCV29. We also observed DHT-mediated activation of Akt/GSK-3β signaling pathway which plays a central role in cancer progression. Presented results also show that androgen/AR signaling is implicated in phosphorylation of eIF4E which can promote epithelial–mesenchymal transition (EMT). We indicate that AR plays an essential role in bladder cancer progression in male patients. Therefore, androgen-activated AR signaling is an attractive regulatory target for the inhibition or prevention of bladder cancer incidence in men.

EZH2 inhibition suppresses bladder cancer cell growth and metastasis via the JAK2/STAT3 signaling pathway.

The aim of the current study was to investigate the role of enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) in the progression of bladder cancer. Human bladder cancer tissue samples were analyzed by immunohistochemistry, and the association between the clinicopathological parameters and EZH2 expression was analyzed. The proliferation, apoptosis and migration ability of the human bladder cancer cell lines E-J and 5637 with or without the EZH2 inhibitor UNC1999 was investigated. The effect of UNC1999 was further explored in a xenograft model of nude mice. The in vivo and in vitro expression levels of EZH2, janus kinase 2, signal transducer and activator of transcription 3 and their phosphorylated forms were examined by western blotting. The expression levels of EZH2, JAK2 and STAT3 were increased in bladder cancer tissue compared with normal adjacent tissue. Furthermore, the expression of EZH2 was increased in tumors with a higher TNM Classification of Malignant Tumors stage and histological grade compared with tumors with a lower stage and grade. The human bladder cancer cell lines E-J and 5637 treated with UNC1999 demonstrated reduced cell proliferation, apoptosis and migration compared with cells treated without UNC1999. Additionally, EZH2 may promote the proliferation and migration of bladder cancer via the JAK2/STAT3 pathway. EZH2 may serve an important role in the proliferation and migration of human bladder cancer cells, and may aid in the development of novel treatment strategies for bladder cancer.

Higher Expression of Linc00152 Promotes Bladder Cancer Proliferation and Metastasis by Activating the Wnt/β-Catenin Signaling Pathway.

BackgroundRecent studies have demonstrated that Linc00152 is highly expressed in multiple cancer types and its genes show tumor-promoting characteristics. However, the efficacy and biological mechanism of Linc00152 in bladder cancer remains unclear.Material/MethodsWe study investigated the relative expression and promoter methylation of Linc00152 in 126 cases of bladder cancer tissues by qRT-PCR and Bisulfite sequencing PCR. qRT-PCR was used to assess the relative expression of Linc00152 in 4 human bladder cancer cell lines. To explore the biological properties of Linc00152, we performed cell growth and soft-agar colony-formation assays, flow cytometry analyses, wound-healing assay, and Transwell assay. Western blot analysis was used to detect the underlying mechanisms of Linc00152 in bladder cancer.ResultsWe found that Linc00152 was highly expressed in 126 cases of bladder carcinoma tissues (p<0.001) and 4 cell lines (p<0.01), and Linc00152 is more commonly expressed in patients with advanced-stage cancer (p=0.021). Knockdown of Linc00152 by using siRNAs in bladder cancer cell lines (T24 and HT-1197) suppressed cell viability and growth by causing cell cycle arrest and apoptosis (p<0.001), as well as inhibiting cell migration and invasion (p<0.001). In addition, the quantitative RT-PCR and Western blot results suggest that knockdown of Linc00152 reduced Wnt/β-Catenin signaling (p<0.001).ConclusionsThis research shows that Linc00152 is highly expressed in patients with bladder cancer and the possible carcinogenic effect of Linc00152 in bladder cancer occurs through activating the Wnt/β-Catenin signaling pathway, and could be a new biomarker for diagnosis and prevention of this cancer.

Two novel platinum(II) complexes with sorafenib and regorafenib: Synthesis, structural characterization, and evaluation of in vitro antitumor activity

Two new Pt(II) complexes with sorafenib (SRFN) and regorafenib (RGFN), having the general formulae [Pt(SRFN)(DMSO)Cl2] (SRFN-Pt) and [Pt(RGFN)(DMSO)Cl2] (RGFN-Pt), were prepared and characterized by ESI-MS, IR, UV–Vis spectroscopy, elemental analyses, and 1H and 13C NMR, respectively. The anticancer activities of SRFN-Pt and RGFN-Pt were evaluated by MTT assay with NCI-H460 (human non-small cell lung cancer NCI-H460 cell line), SK-OV-3 (ovarian cancer cell line), SK-OV-3/DDP (cisplatin-resistant SK-OV-3 cell line), T-24 (human bladder cancer cell line), HeLa (cervical cancer cell line), A549/DDP (cisplatin-resistant A549/DDP non-small cell lung cancer cell line) cancer cells and in the normal HL-7702 cells. The results suggested that SRFN-Pt and RGFN-Pt were more effective against the A549/DDP tumor cells (IC50 = 1.18 ± 0.15 μM and 0.13 ± 0.03 μM) than SRFN (45.03 ± 0.79 μM), RGFN (40.11 ± 2.15 μM), and cisplatin (97.63 ± 1.06 μM), respectively, and RGFN-Pt was more effective than SRFN-Pt. In addition, SRFN-Pt and RGFN-Pt induced G2/M and S phase arrest. Cytotoxic mechanism studies revealed that SRFN-Pt and RGFN-Pt triggered mitochondria-mediated apoptotic cell death at low concentration. RGFN-Pt exhibited obvious priority on the in vitro antitumor activity than SRFN-Pt, which should be undoubtedly correlated with the key roles of the fluoro substituted groups in the RGFN ligand of RGFN-Pt. The in vitro anti-tumor activity studies suggested that RGFN-Pt pointed to a new direction in developing Pt(II) drugs as anti-cancer agent.

Assessing Radiosensitivity of Bladder Cancer in vitro: A 2D vs. 3D Approach.

Background: Bladder cancer is the fourth most commonly diagnosed cancer among males worldwide. Current treatment strategies established for bladder cancer mainly consist of cystectomy yet advances in radiation therapy have pointed to the value of organ-preserving strategies in preserving patients' quality of life.Aim: To study and compare the radiosensitivity in two-dimension (2D) and physiologically-relevant three-dimension (3D) in vitro culture of three human bladder cancer cell lines, RT4, T24, and UM-UC-3.Materials and Methods: Clonogenic assay was performed to assess cells' radiosensitivity in 2D. Employing the 3D Matrigel™-based cultures to enrich for cancer stem cells (CSCs) allowed us to assess the survival of this subpopulation of cells via evaluating the number, i.e., sphere forming unit (SFU), and the sizes of cultured spheres, formed from cells exposed to different radiation doses compared to non-irradiated cells.Results: Irradiating cells with increasing radiation doses revealed highest survival rates with RT4 cells in 2D, followed by T24 and UM-UC-3. In 3D, however, UM-UC-3 cells were shown to be the most radio-resistant as evidenced by the number of spheres formed, yet they displayed the least efficient volume reduction/regression (VR), whilst the volume decreased significantly for both RT4 and T24 cells. Sphere VR and sphere ratio (SR) values were then plotted against each other demonstrating a linear correlation between volume and number with RT4 and UM-UC-3 cell lines, but not T24. Lastly, multiple regression model was employed to evaluate the possibility of obtaining a function combining both 3D parameters, SR and VR, with the surviving fraction (SF) in 2D, and showed a linear regression for T24 cells only, with a correlation coefficient of 0.97 for the combined parameters.Conclusion: We were able to radiobiologically characterize 3 human bladder cancer cell lines showing differential effects of radiation between 2D and 3D culture systems, paving the way for achieving better assessment of radiosensitivity of bladder cancer in vitro.

Inhibition of PI3K pathway increases immune infiltrate in muscle-invasive bladder cancer

ABSTRACTAlthough immune checkpoint inhibitors have shown improvement in survival in comparison to chemotherapy in urothelial bladder cancer, many patients still fail to respond to these treatments and actual efforts are made to identify predictive factors of response to immunotherapy. Understanding the tumor-intrinsic molecular basis, like oncogenic pathways conditioning the presence or absence of tumor-infiltrating T cells (TILs), should provide a new rationale for improved anti-tumor immune therapies.In this study, we found that urothelial bladder cancer from human samples bearing PIK3CA gene mutations was significantly associated with lower expression of a defined immune gene signature, compared to unmutated ones. We identified a reduced 10-gene immune gene signature that discriminates muscle-invasive bladder cancer (MIBC) samples according to immune infiltration and PIK3CA mutation. Using a humanized mouse model, we observed that BKM120, a pan-PI3K inhibitor, significantly inhibited the growth of a human bladder cancer cell line bearing a PIK3CA mutation, associated to increased immune cell infiltration (hCD45+). Using qRT-PCR, we also found an increase in the expression of chemokines and immune genes in PIK3CA-mutated tumors from mice treated with BKM120, reflecting an active immune infiltrate in comparison to untreated ones. Moreover, the addition of BKM120 rendered PIK3CA-mutated tumors sensitive to PD-1 blockade. Our results provide a relevant rationale for combination strategies of PI3K inhibitors with immune checkpoint inhibitors to overcome resistance to immune checkpoint inhibitors.

MiR-3687 Overexpression Promotes Bladder Cancer Cell Growth by Inhibiting the Negative Effect of FOXP1 on Cyclin E2 Transcription.

Cyclin E2, a member of the cyclin family, is a key cell cycle-related protein. This protein plays essential roles in cancer progression, and, as such, an inhibitor of cyclin E2 has been approved to treat several types of cancers. Even so, mechanisms underlying how to regulate cyclin E2 expression in cancer remain largely unknown. In the current study, miR-3687 was upregulated in clinical bladder cancer (BC) tumor tissues, The Cancer Genome Atlas (TCGA) database, and human BC cell lines. Inhibition of miR-3687 expression significantly reduced human BC cell proliferation invitro and tumor growth invivo, which coincided with the induction of G0/G1 cell cycle arrest and downregulation of cyclin E2 protein expression. Interestingly, overexpression of cyclin E2 reversed the inhibition of BC proliferation induced by miR-3687. Mechanistic studies suggested that miR-3687 binds to the 3' UTR of foxp1 mRNA, downregulates FOXP1 protein expression, and in turn promotes the transcription of cyclin E2, thereby promoting the growth of BC cells. Collectively, the current study not only establishes a novel regulatory axis of miR-3687/FOXP1 regarding regulation of cyclin E2 expression in BC cells, but also provides strong suggestive evidence that miR-3687 and FOXP1 may be promising targets in therapeutic strategies for human BC.

MicroRNA‑663b downregulation inhibits proliferation and induces apoptosis in bladder cancer cells by targeting TUSC2.

The present study aimed to explore the role and underlying molecular mechanism of microRNA‑663b (miR‑663b) in the tumorigenesis of bladder cancer. The miR‑663b expression in human bladder cancer tissues and cell lines was measured determined reverse transcription‑quantitative polymerase chain reaction. TargetScan was used to predict the potential targets of miR‑663b, and a dual‑luciferase reporter assay was performed to validate tumor suppressor candidate 2 (TUSC2) as a target of miR‑663b. Cell Counting Kit‑8 was used for cell viability analysis, and cell apoptosis was evaluated by flow cytometry. In addition, western blot analysis was performed to detect protein expression in current study. The findings suggested that miR‑663b was upregulated in bladder cancer tissues and cell lines compared with normal tissue and cells. TUSC2 was validated as a direct target of miR‑663b and was negatively regulated by miR‑663b. miR‑663b inhibition significantly reduced the viability of T24 cells, and T24 cell apoptosis was markedly induced. In addition, miR‑663b inhibition enhanced the expression levels of p53 and p21 in T24 cells. Furthermore, the changes caused by miR‑663b inhibitor in T24 cells were eliminated by TUSC2 gene silencing. In conclusion, inhibition of miR‑663b reduced viability and induced apoptosis in bladder cancer cells by targeting TUSC2. These findings provide a promising novel therapeutic target for bladder cancer treatment.

The ERH gene regulates migration and invasion in 5637 and T24 bladder cancer cells

BackgroundThis study aimed to determine whether the enhancer of the rudimentary homolog (ERH) gene regulates cell migration and invasion in human bladder urothelial carcinoma (BUC) T24 cells and the underlying mechanism.MethodsFirst, we knocked down ERH in BUC T24 and 5637 cells by shRNA and then used wound healing cell scratch migration assays, transwell cell migration assays, transwell cell invasion chamber experiments and nude mouse tail vein transfer assays to determine the migration and invasion ability after ERH was knocked down. Moreover, we used gene expression profiling chip analysis and further functional experiments to explore the possible mechanism through which ERH knockdown downregulated metastasis ability in T24 cells.ResultsWound healing cell scratch migration assays, transwell cell migration assays, transwell cell invasion chamber experiments and nude mouse tail vein transfer assays all showed that the metastasis ability was significantly inhibited in human BUC T24 and 5637 cells with ERH knockdown. A gene expression profiling chip analysis in T24 cells showed that the MYC gene may be an important downstream target of the ERH gene, and the functional experiments showed that MYC is a functional target of ERH in BUC T24 cells.ConclusionERH knockdown could inhibit the metastasis of BUC T24 cells in vitro and in vivo. This study further explored the mechanism of the ERH gene in the metastasis of the T24 human bladder cancer cell line and found that ERH may regulate MYC gene expression. The results of this research provide a basis for the clinical application of ERH as a potential target for BUC treatment.

MicroRNA-124-3p suppresses cell migration and invasion by targeting ITGA3 signaling in bladder cancer

A growing body of studies have demonstrated the aberrant expression of microRNAs (miRNAs) contributes to human tumor metastasis. MicroRNA-124-3p (miR-124-3p), which is down-regulated in various cancers, has been found to be involved in several signaling pathways relevant to tumor cell migration and invasion. However, the roles of miR-124-3p in human bladder cancer remain unclear. This study aims to investigate the functional significance of miR-124-3p and to understand how it targets the integrin receptor, and thus affects the progression of human bladder cancer. Clinical specimens from 36 patients and three human bladder cancer cell lines were analyzed for miR-124-3p and integrin α3 (ITGA3) . To investigate the effects of miR-124-3p and ITGA3 on proliferation of bladder cancer cells, the MTT assay, colon-formation assay and flow cytometry were performed. In addition, wound healing assay and transwell assay were carried out to examine the migration and invasion of the bladder cancer cells transfected with miR-124-3p mimics or si-ITGA3. The luciferase reporter assay, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were applied to validate the miR-124-3p directly binding with ITGA3. Finally, western blot was used to examine the expression level of the proteins involved in FAK/PI3K/AKT and FAK/Src signal pathway as well as epithelial-mesenchymal transition (EMT) process. The down-regulation of miR-124-3p and up-regulation of ITGA3 were observed in clinical specimens and bladder cancer cell lines. Overexpression of miR-124-3p or silencing ITGA3 inhibited tumor cell migration and invasion. Luciferase assay confirmed miR-124-3p directly targets ITGA3, and western blot suggested that miR-124-3p plays a crucial role in the EMT and metastasis of human bladder cancer through FAK/PI3K/AKT and FAK/Src signaling mechanism. Also, by targeting ITGA3, miR-124-3p can modulate the expression of N- and E-cadherin, and thus inhibit the EMT. By targeting ITGA3 and downstream FAK/PI3K/AKT and FAK/Src signaling pathways, miR-124-3p suppresses cell migration and invasion in bladder cancer. Our study reasonably speculates that miR-124-3p can be potentially developed as a therapeutic target and prognostic biomarker for bladder cancer.

PPAR\u03b3 activation serves as therapeutic strategy against bladder cancer via inhibiting PI3K-Akt signaling pathway

BackgroundHeterogeneity in bladder cancer results in variable clinical outcomes, posing challenges for clinical management of this malignancy. Recent studies suggest both tumor suppressive and oncogenic role of PPARγ in bladder cancer. The fuction of PPARγ signaling pathway in modulating carcinogenesis is controversial.MethodsThe expression of PPARγ and association with overall survival were analyzed in patients from two cohorts. The effect of PPARγ activation on cell proliferation, cell cycle, and cell apoptosis were determined with the agonists (rosiglitazone and pioglitazone), the inverse agonist (T0070907), and the antagonist (GW9662) in Umuc-3 and 5637 bladder cancer cells. The correlation of PPARγ activation with PI3K-Akt pathway was evaluated with RNA sequencing data from the TCGA cases and 30 human bladder cancer cell lines. The effect of PPARγ activation on tumor growth was validated with subcutaneous tumor models in vivo. The effect of PPARγ activation on PI3K-Akt signaling transduction was determined with multiple assays including immunohistochemistry, flow cytometry, proteomic array, and western blotting.ResultsWe showed that PPARγ was a favorable prognostic factor in patients with bladder cancer. PPARγ activation by rosiglitazone and pioglitazone markedly induced cell cycle G2 arrest and apoptosis in bladder cancer cells, which resulted in inhibition of cell proliferation in vitro and suppression of tumor growth in vivo. The underlying mechanism involved marked inhibition of PI3K-Akt pathway.ConclusionsThis study reported the tumor-suppressive effect of PPARγ agonists in bladder cancer, suggesting that transactivation of PPARγ could be served as a potential strategy for the chemoprevention and therapeutic treatment of bladder cancer.

Development of myeloid-derived suppressor cells (MDSC) targeted therapy for the treatment of cisplatin-resistant bladder cancer.

415 Background: The emergence of immune checkpoint inhibitors (ICI) has brought hope for cure and survival for those suffering from various cancers, including bladder cancer. However, the response rate of ICI monotherapy is modest, and recent reports indicate that myeloid-derived suppressor cells (MDSC) might play a role in the resistant mechanism of ICI. In this study, we assess the effect of chemokine signal on the proliferation of bladder cancer and investigate whether MDSC could be a new target for the treatment of cisplatin-resistant bladder cancer. Methods: We established a cisplatin resistant strain (MB49R) of mice bladder cancer cell line MB49, and examined the alteration of the expression levels of inflammatory chemokines by chemokine array. Next, we isolated MDSCs from spleen and tumor in tumor-bearing mice to examine gene expression levels of chemokine receptors (CXCR2 and CCR2) and immunosuppression genes (Arg-1 and iNOS). Furthermore, we assessed the efficacy of CDDP, α-PD-L1 and chemokine antagonists against the proliferation of tumors in MB49 and MB49R xenograft models. Results: Expression levels of CCL2 and CXCL1/2, which are involved in the migration of MDSC, were significantly increased in the culture supernatant of MB49R compared to those in MB49 cell lines. This result was confirmed by real-time RT-qPCR of tumor extract, and this increase was also observed in human bladder cancer cell lines (T24 and T24R). CXCR2 and CCR2 were highly expressed in PMN-MDSC and M-MDSC, respectively, which were isolated from spleen or tumors in tumor-bearing mice, and gene expression levels of Arg-1 and iNOS were dramatically increased in M-MDSCs from the tumor tissues compared to those from spleen. Also, analysis by flow cytometry revealed that PMN-MDSC dramatically decreased in MB49R compared to parental MB49 tumors, while the proportion of M-MDSC was not changed in MB49R, which indicates that M-MDSC could be a target for the treatment of CDDP resistant bladder cancer. Conclusions: The results in the present study might indicate that the combination treatment with ICI and MDSC-targeting therapy could be an option for the treatment of cisplatin-resistant bladder cancer.