The quinoxaline di-N-oxide DCQ blocks breast cancer metastasis in vitro and in vivo by targeting the hypoxia inducible factor-1 pathway

Abstract

BackgroundAlthough tumor hypoxia poses challenges against conventional cancer treatments, it provides a therapeutic target for hypoxia-activated drugs. Here, we studied the effect of the hypoxia-activated synthetic quinoxaline di-N-oxide DCQ against breast cancer metastasis and identified the underlying mechanisms.MethodsThe human breast cancer cell lines MCF-7 (p53 wildtype) and MDA-MB-231 (p53 mutant) were treated with DCQ under normoxia or hypoxia. Drug toxicity on non-cancerous MCF-10A breast cells was also determined. In vitro cellular responses were investigated by flow cytometry, transfection, western blotting, ELISA and migration assays. The anti-metastatic effect of DCQ was validated in the MDA-MB-231 xenograft mouse model.ResultsDCQ selectively induced apoptosis in both human breast cancer cells preferentially under hypoxia without affecting the viability of non-cancerous MCF-10A. Cancer cell death was associated with an increase in reactive oxygen species (ROS) independently of p53 and was inhibited by antioxidants. DCQ-induced ROS was associated with DNA damage, the downregulation of hypoxia inducible factor-1 alpha (HIF-1α), and inhibition of vascular endothelial growth factor (VEGF) secretion. In MCF-7, HIF-1α inhibition was partially via p53-activation and was accompanied by a decrease in p-mTOR protein, suggesting interference with HIF-1α translation. In MDA-MB-231, DCQ reduced HIF-1α through proteasomal-dependent degradation mechanisms. HIF-1α inhibition by DCQ blocked VEGF secretion and invasion in MCF-7 and led to the inhibition of TWIST in MDA-MB-231. Consistently, DCQ exhibited robust antitumor activity in MDA-MB-231 breast cancer mouse xenografts, enhanced animal survival, and reduced metastatic dissemination to lungs and liver.ConclusionDCQ is the first hypoxia-activated drug showing anti-metastatic effects against breast cancer, suggesting its potential use for breast cancer therapy.

Selective Hypoxia‐Cytotoxin 7‐Fluoro‐2‐Aminophenazine 5,10‐Dioxide: Toward “Candidate‐to‐Drug” Stage in the Drug‐Development Pipeline

“…In order to avoid this problem SN30000 ( B , Figure ) has been developed and studied in its ability to act as selective hypoxic cytotoxin . In addition, N ‐oxide derivatives belonging to quinoxaline 1,4‐dioxide and phenazine 5,10‐dioxide families have been evaluated mainly as in vitro selective hypoxic cytotoxins and in some cases, for example for quinoxaline 1,4‐dioxides, in vivo studies were done to probe their effectiveness . In reference to synthetic phenazine 5,10‐dioxides some interesting derivatives were identified by us, i. e. derivatives C and 1 (Figure ), which displayed the best in vitro potency, concentration that gives 1% cell survival in hypoxia.…”

Hypnosis and music interventions (HMIs) inactivate HIF-1: A potential curative efficacy for cancers and hypertension

“…Third, the increased activity of HIF-1 is notably associated with higher cancer risk and higher cancer morbidity [19]. However, inhibiting HIF-1 has potent anti-cancer effects [27][28][29], and we therefore collect the relevant evidence demonstrating how HMIs inactivate HIF-1 and benefit cancer treatment.…”

“…For example, quinoxaline di-N-oxide DCQ, apolipoprotein A-I mimetic peptides, digoxin, and resveratrol have shown potential anti-cancer efficacy by inhibiting HIF-1 through different mechanisms [19,20,22,[27][28][29].…”

The role of hypoxia-induced factor 1�� in breast cancer

“…The amount of VEGF and glucose transporter 1 messenger RNA in the cells was also analyzed, which was very low in relative to normality, showing that M410 was directly involved in the transcriptional activity of HIF-1α [45] . DCQ (2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide) contains an N-oxyde portion (present in hypoxia-activated drugs used in cancer treatments) similar to tirapazamine (TPZ) used in treatments against other types of cancer, but inefficient in breast cancer [46] . Similarly to the results with TPZ treatments found in the literature, DCQ induced an increase in p-Akt levels and a reduction in p-mTOR levels suggesting possible anti-translational activity in MCF-7 cells, which would decrease the rates of HIF-1α.…”

“…Similarly to the results with TPZ treatments found in the literature, DCQ induced an increase in p-Akt levels and a reduction in p-mTOR levels suggesting possible anti-translational activity in MCF-7 cells, which would decrease the rates of HIF-1α. DCQ was identified as a promising drug in the treatment of breast cancer because it exhibits pro-apoptotic and antimetastatic features by reducing HIF-1α and the post-HIF-1α gene signaling cascade [46] . Extracellular matrix metalloproteinase inducer (EMMPRIN) glycoprotein, also known as cluster of differentiation 147 (CD147), is a densely glycosylated type I transmembrane glycoprotein, highly expressed in tumors [47] .…”