Punica granatum Extract Inhibits Bladder Cancer Cell Viability, Invasion and Migration through Down-Regulation of HOXD10 Signalling Pathway

Sulforaphane (SFN), an isothiocyanate (ITCs) derived from glucosinolate that is found in cruciferous vegetables, has been reported to exert a promising anticancer effect in a substantial amount of scientific research. However, epidemical studies showed inconsistencies between cruciferous vegetable intake and bladder cancer risk. In this study, human bladder cancer T24 cells were used as in vitro model for revealing the inhibitory effect and its potential mechanism of SFN on cell growth. Here, a low dose of SFN (2.5 µM) was shown to promote cell proliferation (5.18–11.84%) and migration in T24 cells, whilst high doses of SFN (>10 µM) inhibited cell growth significantly. The induction effect of SFN on nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression at both low (2.5 µM) and high dose (10 µM) was characterized by a bell-shaped curve. Nrf2 and glutathione (GSH) might be the underlying mechanism in the effect of SFN on T24 cell growth since Nrf2 siRNA and GSH-depleting agent L-Buthionine-sulfoximine abolished the effect of SFN on cell proliferation. In summary, the inhibitory effect of SFN on bladder cancer cell growth and migration is highly dependent on Nrf2-mediated GSH depletion and following production. These findings suggested that a higher dose of SFN is required for the prevention and treatment of bladder cancer.

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Evaluation of a novel irreversible pan-HER inhibitor in bladder cancer models.

Journal of Clinical Oncology ◽

10.1200/jco.2013.31.6_suppl.253 ◽

2013 ◽

Vol 31 (6_suppl) ◽

pp. 253-253

Author(s):

Petros Grivas ◽

Andreas Karatsinides ◽

Kathleen C. Day ◽

Priya Kunju ◽

Alyssa Paul ◽

...

Keyword(s):

Cell Cycle ◽

Bladder Cancer ◽

Cell Viability ◽

Cell Lines ◽

Cancer Cell ◽

Cancer Cell Lines ◽

Bladder Cancer Cell ◽

Phase Iii ◽

Cytostatic Effect ◽

Cancer Models

253 Background: Human epidermal receptors (HER) are overexpressed and HER signaling is biologically relevant in bladder cancer and may mediate chemotherapy resistance. Dacomitinib is a novel, potent, irreversible pan-HER inhibitor with activity against several solid tumors, currently in a phase III clinical trial in NSCLC. We hypothesized that dacomitinib has antitumor activity in bladder cancer models. Methods: Expression level of EGFR and HER2 protein was measured semi-quantitatively in 8 bladder cancer cell lines. We treated UM-UC-3, UM-UC-6, UM-UC-9 cell lines with dacomitinib (1nM-10uM) for 24-72 hours, and measured cell viability, proliferation, apoptosis, and cell cycle effects. Correlations between dose and cell viability were measured by two-way ANOVA (GraphPad Prism 5.0). We injected age-matched male NOD/SCID mice SC with 1x106 UM-UC-6 and UM-UC-9 cells, respectively, generating xenografts. Mice were randomized and treated with dacomitinib, 6mg/kg p.o. daily, starting 1 day or 1 week after cell injection; controls were treated with vehicle. Mice were monitored daily, weighed weekly, sacrificed at 4 weeks and tumors weighed. Results: In vitro, significant cytostatic effect was noted with as low as 50nM in UM-UC6 cells and 100nM in UM-UC9 cells. UM-UC3 cells did not exhibit cytostatic effect even with 1000nM, corresponding to differential target protein (HER) expression. Dacomitinib (2uM) induced apoptosis (UM-UC-6), and G1 cell cycle arrest in both cell lines. These effects corresponded to dacomitinib-mediated inhibition of EGFR, ERK, AKT phosphorylation. In vivo, xenograft weights in both cell lines were significantly lower in dacomitinib-treated mice vs control (p<0.001), corresponding to pharmacodynamic effects (decreased E-cadherin, p-EGFR, p-ERK, mitotic count). Dacomitinib 6mg/kg p.o. daily resulted in significantly lower tumor weights vs lapatinib 50 mg/kg p.o. daily in UM-UC-9 xenograft model (p=0.0052). Conclusions: Dacomitinib demonstrated single-agent activity in bladder cancer cell lines and xenografts. Induction of apoptosis and G1 phase arrest are the suggested mechanisms for anti-tumor activity. Further investigation of this inhibitor in bladder cancer models is being pursued.

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