Purpose: Tumor hypoxia underlies treatment failure and yields a more aggressive, invasive, and metastatic cancer phenotype. TH-302 is a 2-nitroimidazole triggered hypoxia-activated prodrug of the cytotoxin bromo-isophosphoramide mustard (Br-IPM). The purpose of this study is to characterize the antitumor activity of TH-302 and investigate its selective targeting of the hypoxic cells in human tumor xenograft models.Experimental Design: Antitumor efficacy was assessed by tumor growth kinetics or by clonogenic survival of isolated cells after tumor excision. Hypoxic fractions (HF) were determined by immunohistochemistry and morphometrics of pimonidazole staining. Tumor hypoxia levels were manipulated by exposing animals to different oxygen concentration breathing conditions. The localization and kinetics of TH-302 induced DNA damage was determined by gH2AX immunohistochemistry.Results: TH-302 antitumor activity was dose-dependent and correlated with total drug exposure. Correlation was found between antitumor activity and tumor HF across 11 xenograft models. Tumorbearing animals breathing 95% O 2 exhibited attenuated TH-302 efficacy, with whereas those breathing 10% O 2 exhibited enhanced TH-302 efficacy, both compared with air (21% O 2 ) breathing. TH-302 treatment resulted in a reduction in the volume of the HF 48 hours after dosing and a corresponding increase in the necrotic fraction. TH-302 induced DNA damage as measured by gH2AX was initially only present in the hypoxic regions and then radiated to the entire tumor in a time-dependent manner, consistent with TH-302 having a "bystander effect."Conclusions: The results show that TH-302 has broad antitumor activity and selectively targets hypoxic tumor tissues. Clin Cancer Res; 18(3); 758-70. Ó2011 AACR.
Matrine has shown therapeutic and/or adjuvant therapeutic effects on the treatment of some patients with breast cancer. However, its mechanisms of action are largely unknown. To disclose the mechanisms, we investigated in vitro and ex vivo effects of matrine on the cancer cells. Our results confirmed that matrine significantly suppressed the proliferation of highly-metastatic human breast cancer MDA-MB-231 cell line. Matrine displayed synergistic effects with existing anticancer agents celecoxib (the inhibitor of cyclooxygenase-2), trichostatin A (the histone deacetylase inhibitor) and rosiglitazone against the proliferation and VEGF excretions in MDA-MB-231 cells. Matrine induced the apoptosis and cell cycle arrest by reducing the ratios of Bcl-2/Bax protein and mRNA levels in the cancer cells. Matrine significantly reduced the invasion, MMP-9/MMP-2 activation, Akt phosphorylation, nuclear factor jB p-65 expression and DNA binding activity, and mRNA levels of MMP-9, MMP-2, EGF and VEGFR1 in MDA-MB-231 cells. Collectively, our results suggest that matrine inhibits the cancer cell proliferation and invasion via EGF/ VEGF-VEGFR1-Akt-NF-jB signaling pathway.
BackgroundBladder cancer is a common serious disease around the world. Long noncoding RNAs (lncRNAs) have been demonstrated to participate in the development and progression of various cancers, including bladder cancer. The aim of this study was to investigate the effects of lncRNA taurine upregulated gene 1 (TUG1) on proliferation and apoptosis in bladder cancer cell lines and the underlying mechanism.MethodsThe levels of TUG1 were detected by quantitative real time polymerase chain reaction (qRT-PCR) in bladder cancer tissues and cells. The mRNA and protein levels of zinc finger E-box binding homeobox 2 (ZEB2) were measured by qRT-PCR and Western blot analysis, respectively. The functional targets of TUG1 were predicted by online softwares and confirmed by luciferase reporter assay. The effects of TUG1 on cell proliferation and apoptosis were examined by MTT and apoptosis assay, respectively. The expression levels of β-catenin, cyclinD1, and c-Myc in T24 cells were determined by Western blot analysis.ResultsThe levels of TUG1 and ZEB2 were significantly increased in bladder cancer tissues and cells. Knockdown of either TUG1 or ZEB2 inhibited proliferation and induced apoptosis in bladder cancer cells. Interestingly, ZEB2 overexpression reversed the effects of TUG1 knockdown on cell proliferation and apoptosis. Moreover, ZEB2 was verified as a direct target of miR-142 and miR-142 could specially bind to TUG1. In addition, downregulation of TUG1 inhibited the Wnt/β-catenin pathway by regulating ZEB2 expression in bladder cancer cells.ConclusionDownregulation of TUG1 expression inhibited proliferation and induced apoptosis in bladder cancer cells by targeting ZEB2 mediated by miR-142 through the inactivation of Wnt/β-catenin pathway.
Cultural content has been examined in consumer adoption of new products, whereas the relationship between enduring cultural beliefs and adoption remains unexplored. In this study, proactive superstitious behaviors (e.g., carrying a lucky charm) and passive superstitious beliefs (e.g., belief in fate) were empirically tested as antecedents of consumer novelty seeking (CNS) and consumer independent judgment making (CIJM). The results suggest that proactive superstitious beliefs positively influence CNS, whereas passive beliefs negatively influence CNS. Only passive superstitious beliefs positively influence CIJM. Results also suggest that previous superstition scales are incomplete and fail to reflect contemporary thinking about superstitious beliefs.
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