792: Role of Oxidative Stress in Tumorigenic Potential of Bladder Cancer Cells

273 Background: Muscle invasive bladder cancer portends a poor long term prognosis. Platinum based therapy is the mainstay of treatment but more effective agents are needed for management of this disease. Heat shock protein 90 (Hsp90) is a ubiquitous protein that has been shown to be overexpressed in tumor cells. It functions as a molecular chaperone responsible for the stability and function of a number of proteins critical to the oncogenic process. 17-(allylamino)-17 demethoxygeldanamycin (17 AAG) is a Hsp90 inhibitor that is currently in phase III trials in several tumor models. The purpose of this study was to evaluate the role of 17 AAG treatment for bladder cancer in vitro. Methods: Seven bladder cancer cell lines representing muscle invasive bladder cancer were treated in the presence and absence of 17 AAG. Both short term and long term treatments were evaluated for their effects on growth, motility and invasion of the cancer cells. Expression of proteins involved in cell growth, survival and metastasis were evaluated with Western blotting. Results: Our data demonstrated that 17 AAG treatment resulted in induction of apoptosis, inhibition of cell cycle progression through inhibition of MAP kinase pathway and cyclin D1 expression. Decreased tumor cell motility and invasion was observed with 17 AAG treatment. Several intracellular signaling pathways involved in cell proliferation, invasion and metastasis were inhibited. Conclusions: Hsp90 inhibition in muscle invasive bladder cancer cells impacts growth, motility and invasiveness by inhibiting numerous intracellular signaling pathways. Taken together, these findings suggest a possible role for Hsp90 inhibitors in bladder cancer tumorigenesis. No significant financial relationships to disclose.

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The role of HIF-1α in regulating NLRP3 inflammasome activation in bladder cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.e17028 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. e17028-e17028 ◽

Cited By ~ 1

Author(s):

Yuan-Ru Chen ◽

Hsin-Chih Yeh ◽

Fang-Yen Chiu ◽

Hsin-En Wu ◽

Huei-Chen Fang ◽

...

Keyword(s):

Bladder Cancer ◽

Urothelial Carcinoma ◽

Cancer Cells ◽

Nlrp3 Inflammasome ◽

Migration And Invasion ◽

Inflammasome Activation ◽

T24 Cells ◽

Nlrp3 Inflammasome Activation ◽

Bladder Cancer Cells

e17028 Background: Bladder cancer is one of the most common malignancies of urinary system with the forth incidence rate and the eighth leading mortality rate in male genitourinary tumors. Hypoxia environment activates the hypoxia‐signalling pathway, principally via hypoxia‐inducible transcription factors (HIF) to activate numerous target genes which mediate embryonic vascularization, metabolism, tumor angiogenesis and the other processes to supply tissues with blood and oxygen. Inflammasomes are multiprotein signal responsible for the maturation of proinflammatory cytokines IL-1β and IL-18 as well as trigger the inflammatory cell pyroptosis. Recent study showed that HIF-1α promotes NLRP3 inflammasome activation in bleomycin-induced acute lung injury. However, the role of HIF1α in regulating the progression of bladder cancer has not been examined so far. The present study aimed to investigate the effect of HIF-1α on NLRP3 inflammasome activation in urothelial carcinoma. Methods: In this research, urothelial carcinoma cell lines were treated with NLRP3 inflammasome inducers, LPS/ATP, to induce NLRP3 inflammasome activation. Results: Our preliminary results showed that both T24 and 5637 bladder cancer cells can be induced NLRP3 inflammasome activation and IL-1β secretion. In addition, hypoxia also induces the secretion of IL-1β in T24 cells. We further investigated the effect of NLRP3 inflammasome activation in modulating EMT-related protein levels, migration and invasion in bladder cancer T24 cells. Our results demonstrated that NLRP3 inflammasome activation promotes tumor growth and metastasis in bladder cancer cells. Furthermore, knockdown of HIF1α reduces both inflammatory response and migratory activity in bladder cancer. Conclusions: Collectively, these results suggest that targeting NLRP3 inflammasome might offer potential to treat hypoxic malignant tumor in bladder carcinoma.

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