A novel therapeutic vaccine of mouse GM-CSF surface modified MB49 cells against metastatic bladder cancer

Depth of invasion to the bladder wall as a prognostic factor and its association with circulating cell-free DNA levels in patients with muscle-invasive bladder cancer

Background

Radical cystectomy (RC) is the standard surgical treatment for patients with muscle-invasive bladder cancer, but the prognosis is not favorable, and new prognostic factors need to be discovered. We investigated the potential of depth of invasion (DOI) as a prognostic factor in patients with muscle-invasive bladder cancer who underwent RC. Furthermore, we examined the association between preoperative levels of circulating cell-free DNA and DOI.

Materials and methods

We retrospectively reviewed patients who underwent RC between January 2007 and December 2017; those who received neoadjuvant chemotherapy were excluded. Depth of invasion was measured using hematoxylin-eosin-stained RC specimens.

Results

Of the 121 patients selected, 41 (33.9%) were eligible for analysis. The median follow-up period was 14 months and mean DOI was 17 mm (range, 2-75 mm). Long DOI (>17 mm) was significantly associated with shorter progression-free survival (hazard ratio, 14.5; 95% confidence interval, 3.9-53.97, p < 0.0001) and cancer-specific survival (hazard ratio, 18.97; 95% confidence interval, 4.04-88.99, p = 0.0002) compared with short DOI. Multivariate analysis revealed that DOI was an independent risk factor for cancer-specific survival. The levels of circulating cell-free DNA were significantly higher in patients with a longer DOI than in those with short DOI (65 vs. 20 ng/mL, respectively; p = 0.028).

Conclusions

Depth of invasion predicted with levels of circulating cell-free DNA and thus could be a useful prognostic factor.

Establishment of an optimized orthotopic bladder cancer model in mice

BACKGROUND

Bladder cancer (BC) is one of the most common malignancies of the genitourinary system. Animal models offer an important tool to explore tumour initiation, progression, and therapeutic mechanisms. Our aim is to construct an optimized orthotopic BC model which is predictable, reproducible, and convenient.

METHODS

The optimized orthotopic BC model was constructed in male C57BL/6 mice utilizing microsyringes to inoculate them with a murine BC cell line (MB49). Anesthetised mice were inoculated with an MB49 cell suspension (10 µL) at approximately 5 × 10⁶/mL. The whole process of modelling was observed and monitored every 3 days for 21 days utilizing HE staining and transabdominal ultrasonography (TUS).

RESULTS

In this study, the model showed excellent success rates for tumour formation (96.67%) and metastatic rate (89.66%). Compared to the control group (sham operation), mice in the modelling group had serous cachexia, visible haematuresis and weight loss (all P < 0.05). The lungs, liver, ureter and kidneys were found to have tumour metastasis. Moreover, the average survival time (19.73 ± 1.69 d) of modelling mice was significantly shorter than that of the control mice (P < 0.05), which remained alive.

CONCLUSION

Our study established a method using microsyringes to inject murine BC cells into the bladder wall, creating a stable transplantable BC model in mice.

Sequential administration of anti-PD-1 and anti-Tim-3 combined with an SA-GM-CSF-anchored vaccine overcomes adaptive immune resistance to reject established bladder cancer

Program death receptor-1 (PD-1) and T-cell immunoglobulin and mucin domain-containing protein-3 (Tim-3) play an important role in tumor immune evasion. PD-1 blockade could produce an effective anti-tumor effect but the response rate was low due to lacking of tumor infiltrating lymphocytes (TILs) and existing of other negative regulatory pathways. Streptavidin(SA)-GM-CSF surface-anchored tumor cells vaccine could induce specific anti-tumor immune response. However, this vaccine failed to induce regression of established tumor because it also up-regulated PD-1 expression on tumor cells dependent on IFNγ and up-regulated PD-1/Tim-3 expression on CD8⁺ TILs. Subsets of CD8⁺ TILs assay showed that PD-1 expression was closely associated with CD8⁺ TILs exhaustion, and Tim-3 expression was closely correlated with secretion function but not proliferation of CD8⁺ TILs. Sequential administration of anti-PD-1 and anti-Tim-3 could further improve the efficacy of SA-GM-CSF-anchored vaccine therapy, and tumor regression was noted in over 50%. This triple therapy improves the specific cytotoxic activity and decreased the apoptosis of CD8⁺ TILs. These findings indicated that this triple therapy could induce a more robust anti-tumor immune response.

PD-1 Blockade Overcomes Adaptive Immune Resistance in Treatment with Anchored-GM-CSF Bladder Cancer Cells Vaccine

Purpose: To investigate whether PD-L1 mediated adaptive resistance could occur in treatment with Anchored-GM-CSF vaccine and whether PD-1 blockade combined with Anchored-GM-CSF vaccine could induce a greater anti-tumor immune response than either immunotherapy alone. Materials and Methods: After establishing long-established subcutaneous metastasis bladder cancer models, mice were treated with Anchored-GM-CSF vaccine and/or anti-PD-1 antibody. T-lymphocyte-cytotoxicity, flow cytometric analysis, immunohistochemical, immunofluorescence staining, CD8⁺ -T cell apoptosis and enzyme-linked immunosorbent assays were performed to evaluate the efficacy of combination therapy with anchored-GM-CSF vaccine and PD-1 blockade and to explore the related mechanism. Results: Anchored-GM-CSF vaccine could significantly increase the number of mature DCs and up-regulate PD-L1 expression dependent on IFN-γ released from CD8⁺ T cells. Anchored-GM-CSF vaccine combined with anti-PD-1 antibody could effectively inhibit tumor growth and even cause regression of the established tumor. More CD4⁺ and CD8⁺ T cells appeared at tumor sites and in peripheral blood in the combination therapy group than in the control groups. Splenocytes from mice of the combination therapy group exhibited the most potent cytotoxicity to MB49 cells. Apoptotic assays showed that PD-1 blockade could significantly reduce CD8⁺ T cells apoptosis. Conclusions: Anchored-GM-CSF vaccines and anti-PD-1 antibodies have synergistic effects in metastatic bladder cancer treatment. PD-1 blockade can overcome immune resistance in treatment with the Anchored-GM-CSF vaccine, while Anchored-GM-CSF vaccine can enhance the efficacy of PD-1 blockade therapy.

Colony-stimulating factors detected in tumor cells and voided urine are potential prognostic markers for patients with muscle-invasive bladder cancer undergoing radical cystectomy

Background

The clinical use of macrophage colony-stimulating factor, granulocyte colony-stimulating factor (G-CSF), and granulocyte macrophage colony-stimulating factor (GM-CSF) has improved the safety of cytotoxic chemotherapy. However, the overexpression of these CSFs in cancers has been reported to be associated with a poor prognosis in various malignancies. We evaluated the potential of CSF expression as a predictor of clinical outcome in patients with muscle-invasive bladder cancer (MIBC).

Methods

Consecutive patients (n=58) with MIBC who underwent radical cystectomy (RC) were included in this retrospective study. Treatment-naïve tumor specimens obtained by initial transurethral resection of bladder tumors prior to RC were immunostained with antibodies against macrophage colony-stimulating factor, G-CSF, and GM-CSF. We compared the clinicopathological variables and survival between these groups. Baseline levels of CSFs in the serum and voided urine were quantified using an enzyme-linked immunosorbent assay and compared with the expression of CSFs in the tumor lesions.

Results

Low expression of GM-CSF in the tumor cells was significantly correlated with a pathological T4 category (vs T2–3; P=0.02). In univariate survival analysis, high G-CSF and low GM-CSF expression in the tumor lesion were associated with poor outcomes. Furthermore, Cox proportional regression analysis revealed that high G-CSF and low GM-CSF expression in the tumor were independent predictors of shorter recurrence-free survival, cancer-specific survival, and overall survival. The levels of CSFs in voided urine were associated with the expression of CSFs in the tumor lesions.

Conclusion

GM-CSF and G-CSF expression in the tumor lesions obtained by initial transurethral resection are independent predictors of poor outcome in MIBC after RC. Levels of G-CSF and GM-CSF in urine before treatment could be useful in prognostication.

Norcantharidin enhances antitumor immunity of GM-CSF prostate cancer cells vaccine by inducing apoptosis of regulatory T cells

Norcantharidin (NCTD) is a promising antitumor drug with low toxicity. It was reported to be able to regulate immunity, but the mechanism is not yet clear. Here we explored whether NCTD could enhance the antitumor immunity induced by prostate cancer cell vaccine. The results of the in vitro study showed that NCTD induced apoptosis and inhibited proliferation of regulatory T cells (Tregs). Mechanistic research showed that NCTD inhibited Akt activation and activated FOXO1 transcription, resulting in a pro‐apoptotic effect. The results of the in vivo study showed that more tumor‐infiltrating Tregs existed within peripheral blood and tumor tissue after treatment with the vaccine. Adding NCTD to vaccine treatment could decrease the number of tumor‐infiltrating Tregs and increase the number of CD4⁺ and CD8⁺ T cells. Combination therapy with NCTD and vaccine was more effective in inhibiting tumor growth than the vaccine alone. In general, this is the first report that NCTD could induce apoptosis of Tregs and enhance the vaccine‐induced immunity.

Silencing of Foxp3 enhances the antitumor efficacy of GM-CSF genetically modified tumor cell vaccine against B16 melanoma

The antitumor response after therapeutic vaccination has a limited effect and seems to be related to the presence of T regulatory cells (Treg), which express the immunoregulatory molecules CTLA4 and Foxp3. The blockage of CTLA4 using antibodies has shown an effective antitumor response conducing to the approval of the human anti-CTLA4 antibody ipilimumab by the US Food and Drug Administration. On the other hand, Foxp3 is crucial for Treg development. For this reason, it is an attractive target for cancer treatment. This study aims to evaluate whether combining therapeutic vaccination with CTLA4 or Foxp3 gene silencing enhances the antitumor response. First, the "in vitro" cell entrance and gene silencing efficacy of two tools, 2'-O-methyl phosphorotioate-modified oligonucleotides (2'-OMe-PS-ASOs) and polypurine reverse Hoogsteen hairpins (PPRHs), were evaluated in EL4 cells and cultured primary lymphocytes. Following B16 tumor transplant, C57BL6 mice were vaccinated with irradiated B16 tumor cells engineered to produce granulocyte-macrophage colony-stimulating factor (GM-CSF) and were intraperitoneally treated with CTLA4 and Foxp3 2'-OMe-PS-ASO before and after vaccination. Tumor growth, mice survival, and CTLA4 and Foxp3 expression in blood cells were measured. The following results were obtained: 1) only 2'-OMe-PS-ASO reached gene silencing efficacy "in vitro"; 2) an improved survival effect was achieved combining both therapeutic vaccine and Foxp3 antisense or CTLA4 antisense oligonucleotides (50% and 20%, respectively); 3) The blood CD4⁺CD25⁺Foxp3⁺ (Treg) and CD4⁺CTLA4⁺ cell counts were higher in mice that developed tumor on the day of sacrifice. Our data showed that tumor cell vaccine combined with Foxp3 or CTLA4 gene silencing can increase the efficacy of therapeutic antitumor vaccination.

Future directions in bladder cancer immunotherapy: towards adaptive immunity

The clinical management of bladder cancer has not changed significantly in several decades. In particular, intravesical bacillus Calmette-Guérin (BCG) immunotherapy has been a mainstay for high-risk nonmuscle invasive bladder cancer since the late 1970s/early 1980s. This is despite the fact that bladder cancer has the highest recurrence rates of any cancer and BCG immunotherapy has not been shown to induce a tumor-specific immune response. We and others have hypothesized that immunotherapies capable of inducing tumor-specific adaptive immunity are needed to impact bladder cancer morbidity and mortality. This article summarizes the preclinical and clinical development of bladder cancer immunotherapies with an emphasis on the last 5 years. Expected progress in the near future is also discussed.

Insight to drug delivery aspects for colorectal cancer

Colorectal cancer (CRC) is the third most common cancer diagnosed worldwide in human beings. Surgery, chemotherapy, radiotherapy and targeted therapies are the conventional four approaches which are currently used for the treatment of CRC. The site specific delivery of chemotherapeutics to their site of action would increase effectiveness with reducing side effects. Targeted oral drug delivery systems based on polysaccharides are being investigated to target and deliver chemotherapeutic and chemopreventive agents directly to colon and rectum. Site-specific drug delivery to colon increases its concentration at the target site, and thus requires a lower dose and hence abridged side effects. Some novel therapies are also briefly discussed in article such as receptor (epidermal growth factor receptor, folate receptor, wheat germ agglutinin, VEGF receptor, hyaluronic acid receptor) based targeting therapy; colon targeted proapoptotic anticancer drug delivery system, gene therapy. Even though good treatment options are available for CRC, the ultimate therapeutic approach is to avert the incidence of CRC. It was also found that CRCs could be prevented by diet and nutrition such as calcium, vitamin D, curcumin, quercetin and fish oil supplements. Immunotherapy and vaccination are used nowadays which are showing better results against CRC.

Development of Membrane-Bound GM-CSF and IL-18 as an Effective Tumor Vaccine

The development of effective adjuvant is the key factor to boost the immunogenicity of tumor cells as a tumor vaccine. In this study, we expressed membrane-bound granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-18 (IL-18) as adjuvants in tumor cells to stimulate immune response. B7 transmembrane domain fused GM-CSF and IL-18 was successfully expressed in the cell membrane and stimulated mouse splenocyte proliferation. Co-expression of GM-CSF and IL-18 reduced tumorigenesis (P<0.05) and enhanced tumor protective efficacy (P<0.05) significantly in comparison with GM-CSF alone. These results indicated that the combination of GM-CSF andIL-18 will enhance the immunogenicity of a cell-based anti-tumor vaccine. This membrane-bound approach can be applied to other cytokines for the development of novel vaccine strategies.

Evaluation of hGM-CSF/hTNFα surface-modified prostate cancer therapeutic vaccine in the huPBL-SCID chimeric mouse model

To validate its efficacy in the context of the human immune system, a novel therapeutic vaccine of hGM-CSF/hTNFα surface-modified PC-3 cells against human prostate cancer was evaluated in the human peripheral blood lymphocytes-severe combined immunodeficiency (huPBL-SCID) chimeric mouse model. The hGM-CSF or/and hTNFα modified vaccines inhibited prostate cancer growth effectively so as to prolong the mouse survival significantly. The splenocytes from the hGM-CSF/hTNFα vaccine-inoculated mice showed the strongest tumor-specific cytotoxicity against PC-3 cells and the highest production of IFNɤ. These features indicated that type 1 protective immune response was induced efficiently against human prostate cancer and further enhanced through synergetic adjuvant effects of hGM-CSF and hTNFα.

A pan-inhibitor of DASH family enzymes induces immune-mediated regression of murine sarcoma and is a potent adjuvant to dendritic cell vaccination and adoptive T-cell therapy

Multimodality therapy consisting of surgery, chemotherapy, and radiation will fail in approximately 40% of patients with pediatric sarcomas and result in substantial long-term morbidity in those who are cured. Immunotherapeutic regimens for the treatment of solid tumors typically generate antigen-specific responses too weak to overcome considerable tumor burden and tumor suppressive mechanisms and are in need of adjuvant assistance. Previous work suggests that inhibitors of DASH (dipeptidyl peptidase IV activity and/or structural homologs) enzymes can mediate tumor regression by immune-mediated mechanisms. Herein, we demonstrate that the DASH inhibitor, ARI-4175, can induce regression and eradication of well-established solid tumors, both as a single agent and as an adjuvant to a dendritic cell (DC) vaccine and adoptive cell therapy (ACT) in mice implanted with the M3-9-M rhabdomyosarcoma cell line. Treatment with effective doses of ARI-4175 correlated with recruitment of myeloid (CD11b) cells, particularly myeloid DCs, to secondary lymphoid tissues and with reduced frequency of intratumoral monocytic (CD11bLy6-CLy6-G) myeloid-derived suppressor cells. In immunocompetent mice, combining ARI-4175 with a DC vaccine or ACT with tumor-primed T cells produced significant improvements in tumor responses against well-established M3-9-M tumors. In M3-9-M-bearing immunodeficient (Rag1) mice, ACT combined with ARI-4175 produced greater tumor responses and significantly improved survival compared with either treatment alone. These studies warrant the clinical investigation of ARI-4175 for treatment of sarcomas and other malignancies, particularly as an adjuvant to tumor vaccines and ACT.

Advances and Prospects in Cancer Immunotherapy

Cancer immunotherapy is a promising and effective treatment modality for patients with cancers. Cytokine, anticytokine, and antibody therapies appear to be effective in treating various forms of cancer. The human papillomavirus vaccine is protective for cervical cancer, and this discovery has paved the way to the development of cancer vaccines for other forms of virus-associated cancers such as liver cancer and Merkel cell carcinoma. Clinical trials have demonstrated that adoptive cell therapy using tumor-infiltrating lymphocytes can induce tumor regression in approximately 75% of metastatic melanoma patients, suggesting the possibility of using similar technique to effectively treat breast, lung, and renal cancers in the near future. Besides, genetically engineered T cells transduced with genes encoding specific T cell receptors and chimeric antigen receptors have been shown effective in the treatment of cancer patients. These studies suggest that combination therapies are superior choices in cancer immunotherapy for patients.

Antitumor cell-complex vaccines employing genetically modified tumor cells and fibroblasts

The present study evaluates the immune response mediated by vaccination with cell complexes composed of irradiated B16 tumor cells and mouse fibroblasts genetically modified to produce GM-CSF. The animals were vaccinated with free B16 cells or cell complexes. We employed two gene plasmid constructions: one high producer (pMok) and a low producer (p2F). Tumor transplant was performed by injection of B16 tumor cells. Plasma levels of total IgG and its subtypes were measured by ELISA. Tumor volumes were measured and survival curves were obtained. The study resulted in a cell complex vaccine able to stimulate the immune system to produce specific anti-tumor membrane proteins (TMP) IgG. In the groups vaccinated with cells transfected with the low producer plasmid, IgG production was higher when we used free B16 cell rather than cell complexes. Nonspecific autoimmune response caused by cell complex was not greater than that induced by the tumor cells alone. Groups vaccinated with B16 transfected with low producer plasmid reached a tumor growth delay of 92% (p ≤ 0.01). When vaccinated with cell complex, the best group was that transfected with high producer plasmid, reaching a tumor growth inhibition of 56% (p ≤ 0.05). Significant survival (40%) was only observed in the groups vaccinated with free transfected B16 cells.

A modified method for isolation of bladder cancer stem cells from a MB49 murine cell line

BACKGROUND

The vaccine was efficiently effective against bladder cancer in earlier studies. However, a part of the mouse bladder tumour regrew due to regression after a period of time as the cancer stem cells could not be eliminated. In this study, we showed a modified method for the isolation of MB49 bladder cancer stem cells (MCSCs).

METHODS

Through a comparison of different serum-free culture mediums (SFM), MCSCs were isolated by a combination of the limited dilution method and the optimal SFM method. The characterizations of MCSCs were verified by the fluorescence activated cell sorting, the quantitative polymerase chain reaction, the western blotting, the cell proliferation assay, the soft agar assay, the transwell assay, the resistance to chemotherapy assay and the tumor xenograft formation assay.

RESULTS

The optimal SFM contained a RPMI1640+ epidermal growth factor (20 ng/ml), a basic fibroblast growth factor (20 ng/ml), a leukemia inhibitory factor (20 ng/ml), a B-27 serum-free supplement (20 μl/ml), and a bovine serum albumin (4 μg/ml). MCSCs possessed the high expression of cancer stem cell markers (CD133, CD44, OCT4, NANOG, and ABCG2) and the ability of differentiation. In functional comparisons, MCSCs had higher proliferative abilities, lower susceptibility to chemotherapy, greater migration in vitro, and stronger tumorigenic abilities in vivo.

CONCLUSION

MCSCs displayed specific cancer stem cells properties. Our study showed MCSCs were isolated successfully with a modified method using a combination of limited dilution and SFM methods.

Comparative antitumor effect among GM-CSF, IL-12 and GM-CSF+IL-12 genetically modified tumor cell vaccines

Genetically modified cells have been shown to be one of the most effective cancer vaccine strategies. An evaluation is made of the efficacy of both preventive and therapeutic antitumor vaccines against murine melanoma, using C57BL/6 mice and irradiated B16 tumor cells expressing granulocyte and macrophage colony-stimulating factor (GM-CSF), interleukin-12 (IL-12) or both. Tumor was transplanted by the injection of wild-type B16 cells. Tumor growth and survival were measured to evaluate the efficacy of vaccination. Specific humoral response and immunoglobulin G (IgG) switch were evaluated measuring total IgG and IgG1 and IgG2a subtypes against tumor membrane proteins of B16 cells. In preventive vaccination, all treated groups showed delayed tumor growth. In addition, the group vaccinated to express only GM-CSF achieved 100% animal survival (P<0.005). Vaccination with GM-CSF+IL-12-producing B16 cells yielded lesser results (60% survival, P<0.005). Furthermore, all surviving animals remained disease-free after second tumor implantation 1 year later. The therapeutic vaccination strategies resulted in significantly delayed tumor growth, mainly using B16 cells producing GM-CSF+IL-12 cytokines, with 70% tumor growth inhibition (P<0.001)-although none of the animals reached overall survival. The results obtained suggest that the GM-CSF+IL-12 combination only increases the efficacy of therapeutic vaccines. No differences in classical regulatory T cells were found among the different groups.

Effects of two different immunotherapies on triple negative breast cancer in animal model

The ability of immune system to react specifically against tumors inspirited the study of triple negative breast cancer (TNBC) immunotherapies. Sixty spontaneous breast cancer TA2 mice were randomly divided into three groups: GM-CSF group, with therapy of granulocyte-macrophage colony-stimulating factor (GM-CSF) combined with breast cancer stem cells associated antigens and cytosine-phosphorothioate-guanine oligodeoxynucleotides (CpG-ODNs); DC-CIK group, with infusions of dendritic cells/cytokine-induced killer (DC/CIK) cells; and PBS group as controls. After therapy, the cellular immunity of mice in GM-CSF group and DC-CIK group was obviously increased, especially for GM-CSF group (P<0.05), tumor regression was obviously observed in GM-CSF group. The survival rate of mice in GM-CSF group was significantly higher compared to DC-CIK group and PBS group. These results indicated that tumor immunotherapy manifested strong killing activity against TNBC. The therapeutic effect of GM-CSF combined with antigens and CpG was better than DC-CIK cells.

Suppressions of Migration and Invasion by Cantharidin in TSGH-8301 Human Bladder Carcinoma Cells through the Inhibitions of Matrix Metalloproteinase-2/-9 Signaling

Cancer metastasis becomes an initial cause of cancer death in human population. In many cancers, it has been shown that the high levels of matrix metalloproteinase (MMP)-2 and/or MMP-9 are associated with the invasive phenotypes of cancer cells. In this study, we investigated the effects of cantharidin, a derivative of blister beetles which is one of the traditional Chinese medicines, on the adhesion, migration, and invasion of human bladder cancer TSGH-8301 cells. Cantharidin effectively suppressed TSGH-8301 cell adhesion, migration, and invasion in a concentration-dependent manner. Results from Western blotting, RT-PCR, and gelatin zymography assays indicated that cantharidin blocked the protein levels, gene expression (mRNA), and activities of MMP-2 and -9 in TSGH-8301 cells. Cantharidin also significantly suppressed the protein expressions of p-p38 and p-JNK1/2 in TSGH-8301 cells. Taken together, cantharidin was suggested to present antimetastatic potential via suppressing the levels of MMP-2 and MMP-9 expression that might be mediated by targeting the p38 and JNK1/2 MAPKs pathway in TSGH-8301 human bladder cancer cells.

Comparative antitumor effect of preventive versus therapeutic vaccines employing B16 melanoma cells genetically modified to express GM-CSF and B7.2 in a murine model

Cancer vaccines have always been a subject of gene therapy research. One of the most successful approaches has been working with genetically modified tumor cells. In this study, we describe our approach to achieving an immune response against a murine melanoma model, employing B16 tumor cells expressing GM-CSF and B7.2. Wild B16 cells were injected in C57BL6 mice to cause the tumor. Irradiated B16 cells transfected with GM-CSF, B7.2, or both, were processed as a preventive and therapeutic vaccination. Tumor volumes were measured and survival curves were obtained. Blood samples were taken from mice, and IgGs of each treatment group were also measured. The regulatory T cells (Treg) of selected groups were quantified using counts of images taken by confocal microscopy. Results: one hundred percent survival was achieved by preventive vaccination with the group of cells transfected with p2F_GM-CSF. Therapeutic vaccination achieved initial inhibition of tumor growth but did not secure overall survival of the animals. Classical Treg cells did not vary among the different groups in this therapeutic vaccination model.

Inflammatory pathways as promising targets to increase chemotherapy response in bladder cancer

While more and more physicians are choosing chemotherapy for patients with bladder cancer, the current treatment is still far from satisfactory due to low response rate and severe side effects. Emerging evidence indicates that inflammatory microenvironment is involved in the pathogenesis of bladder cancer. Recent studies have also provided ample evidence that chemotherapy response is influenced by activation of major inflammatory mediators, including transcription factors, cytokines, chemokines, and COX-2. We reviewed all published literature addressing the roles of inflammatory microenvironment in bladder cancer and evaluating emerging evidence that inflammatory pathways represent potential therapeutic targets to enhance chemotherapy of bladder cancer.