ag-490 and Urinary-Bladder-Neoplasms

Human urinary bladder cancer is the fifth most common cancer, with a worldwide estimate of about two million patients. Recurrence after complete transurethral prostatic resection is the most important problem in therapy. Combination therapy is a new approach in the treatment of cancers that do not respond to current therapies. These therapies have many advantages over conventional therapies, such as fewer side-effects and greater efficiency. Research efforts using natural compounds for the elimination or growth suppression of the cancer arise from studies on methylsulfonylmethane (MSM). MSM is a natural sulfur compound with no side-effects. AG490 is a tyrosine kinase inhibitor that has been extensively used for inhibiting Jak2 in vitro and in vivo. In our study, the combinatorial effect of these two agents on human bladder cancer cell lines and xenografts was analyzed. We observed that the combination of AG490 and MSM inhibited cancer cell viability and cell migration in vitro. This combination inhibited VEGF mRNA expression in bladder cancer cell lines. In vivo experiments showed that oral administration of AG490 and MSM combination significantly inhibited the growth of tumor xenografts in mice. Our study clearly demonstrates that the predominant effect of this combination is the reduction of signaling molecules including STAT3, STAT5b, IGF-1R, VEGF and VEGF-R2 which are involved in the growth, progression and metastasis of human bladder cancer. The anti-metastatic ability of this drug combination is confirmed using metastatic animal models. Therefore, this combination could have the effect of genesistasis and powerful anticancer effects against bladder cancer.

Topics: Animals; Cell Movement; Cell Survival; Dimethyl Sulfoxide; Gene Expression Regulation, Neoplastic; Humans; Janus Kinase 2; Mice; Receptor, IGF Type 1; RNA, Messenger; Signal Transduction; STAT3 Transcription Factor; STAT5 Transcription Factor; Sulfones; Tyrphostins; Urinary Bladder Neoplasms; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2; Xenograft Model Antitumor Assays

Conventional adjuvant chemotherapies for bladder transitional cell carcinomas (TCCs) may cause strong systemic toxicity and local irritation. Non-toxic resveratrol inhibits TCC cell growth but its feasibility in clinical management of TCCs remains obscure. This study aimed to evaluate the safety and anti-TCC efficacy of resveratrol, using the experimental models closer to the clinical treatment condition. Human TCC EJ cells were exposed to 100 µM, 150 µM and 200 µM resveratrol respectively for 1 hour and 2 hours to mimic intravesical drug instillation and the cell responses were analyzed by multiple experimental approaches. An orthotopic TCC nude mouse model was established by injecting EJ cells into the sub-urothelial layer and used for short-term intravesical resveratrol instillation. The safety of resveratrol instillation was evaluated and compared with that of MCC. The results revealed that 2 h 150 µM or 200 µM resveratrol treatment leaded to remarkable S phase arrest and apoptosis at 72 h time-point, accompanied with attenuated phosphorylation, nuclear translocation and transcription of STAT3, down-regulation of STAT3 downstream genes (survivin, cyclinD1, c-Myc and VEGF) and nuclear translocations of Sirt1 and p53. The importance of STAT3 signaling in cell growth was confirmed by treating EJ cells with JAK2 inhibitor tyrphostin AG490. The efficacy and safety of resveratrol instillation were proved by the findings from nude mouse orthotopic xenograft models, because this treatment caused growth suppression, distinctive apoptosis and STAT3 inactivation of the transplanted tumors without affecting normal urothelium. Our results thus suggest for the first time the practical values of resveratrol as a safe and effective agent in the post-operative treatment of TCCs.

Topics: Active Transport, Cell Nucleus; Analysis of Variance; Animals; Apoptosis; Blotting, Western; Carcinoma, Transitional Cell; Cell Line, Tumor; Cell Proliferation; DNA Primers; Dose-Response Relationship, Drug; Flow Cytometry; Fluorescent Antibody Technique; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Mice; Mice, Nude; Phosphorylation; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; S Phase Cell Cycle Checkpoints; STAT3 Transcription Factor; Stilbenes; Tyrphostins; Urinary Bladder Neoplasms