Coenzyme Q0 Enhances Ultraviolet B-Induced Apoptosis in Human Estrogen Receptor-Positive Breast (MCF-7) Cancer Cells

The Impact of Light Wavelength and Darkness on Metabolite Profiling of Korean Ginseng: Evaluating Its Anti-Cancer Potential against MCF-7 and BV-2 Cell Lines

Korean ginseng is a source of functional foods and medicines; however, its productivity is hindered by abiotic stress factors, such as light. This study investigated the impacts of darkness and different light wavelengths on the metabolomics and anti-cancer activity of ginseng extracts. Hydroponically-grown Korean ginseng was shifted to a light-emitting diodes (LEDs) chamber for blue-LED and darkness treatments, while white fluorescent (FL) light treatment was the control. MCF-7 breast cancer and lipopolysaccharide (LPS)-induced BV-2 microglial cells were used to determine chemo-preventive and neuroprotective potential. Overall, 53 significant primary metabolites were detected in the treated samples. The levels of ginsenosides Rb1, Rb2, Rc, Rd, and Re, as well as organic and amino acids, were significantly higher in the dark treatment, followed by blue-LED treatment and the FL control. The dark-treated ginseng extract significantly induced apoptotic signaling in MCF-7 cells and dose-dependently inhibited the NF-κB and MAP kinase pathways in LPS-induced BV-2 cells. Short-term dark treatment increased the content of Rd, Rc, Rb1, Rb2, and Re ginsenosides in ginseng extracts, which promoted apoptosis of MCF-7 cells and inhibition of the MAP kinase pathway in BV-2 microglial cells. These results indicate that the dark treatment might be effective in improving the pharmacological potential of ginseng.

In vitro and in vivo anti-tumor activity of Coenzyme Q0 against TWIST1-overexpressing HNSCC cells: ROS-mediated inhibition of EMT/metastasis and autophagy/apoptosis induction

HNSCC (Head and Heck Squamous Cell Carcinoma) is a reasonably prevalent cancer with a high mortality rate. In this study, we tried to examine the anti-metastasis and apoptosis/autophagy actions of Coenzyme Q₀ (CoQ₀, 2,3-dimethoxy-5-methyl-1,4-benzoquinone), a derivative of Antrodia camphorata in HNCC TWIST1 overexpressing (FaDu-TWIST1) cells as well as in vivo tumor xenograft mice model. Using fluorescence based cellular assays, western blot and nude mice tumor xenografts, we determined that CoQ₀ effectively reduced cell viability and displayed rapid morphological changes in FaDu-TWIST1 cells compared to FaDu cells. Non/sub-cytotoxic concentrations of CoQ₀ treatment reduces the cell migration by downregulating TWIST1 and upregulating E-cadherin. Apoptosis produced by CoQ₀ was mostly related with caspase-3 activation, PARP cleavage, and VDAC-1 expression. The FaDu-TWIST1 cells treated with CoQ₀ exhibits autophagy-mediated LC3-II accumulation and acidic vesicular organelles (AVOs) formation. Pre-treatment with 3-MA and CoQ effectively prevented CoQ₀-induced cell death and CoQ₀-triggered autophagy in FaDu-TWIST cells as a death mechanism. CoQ₀ induces ROS production in FaDu-TWIST1 cells and NAC pre-treatment significantly reduces anti-metastasis, apoptosis, and autophagy. Likewise, ROS-mediated AKT inhibition regulates CoQ₀-induced apoptosis/autophagy in FaDu-TWIST1 cells. In vivo studies exhibit, CoQ₀ effectively delays and reduces the tumor incidence and burden in FaDu-TWIST1-xenografted nude mice. Current findings display, CoQ₀ exhibits a novel anti-cancer mechanism hence, it might be appropriate for anticancer therapy, and a new potent drug for HNSCC.

Coenzyme Q0 defeats NLRP3-mediated inflammation, EMT/metastasis, and Warburg effects by inhibiting HIF-1α expression in human triple-negative breast cancer cells

Coenzyme Q₀ (CoQ₀) is a derivative quinone from Antrodia camphorata (AC) that exerts anticancer activities. This study examined the anticancer attributes of CoQ₀ (0-4 µM) on inhibited anti-EMT/metastasis and NLRP3 inflammasome, and altered Warburg effects via HIF-1α inhibition in triple-negative breast cancer (MDA-MB-231 and 468) cells. MTT assay, cell migration/invasion assays, Western blotting, immunofluorescence, metabolic reprogramming, and LC-ESI-MS were carried out to assess the therapy potential of CoQ₀. CoQ₀ inhibited HIF-1α expression and suppressed the NLRP3 inflammasome and ASC/caspase-1 expression, followed by downregulation of IL-1β and IL-18 expression in MDA-MB-231 and 468 cells. CoQ₀ ameliorated cancer stem-like markers by decreasing CD44 and increasing CD24 expression. Notably, CoQ₀ modulated EMT by upregulating the epithelial marker E-cadherin and downregulating the mesenchymal marker N-cadherin. CoQ₀ inhibited glucose uptake and lactate accumulation. CoQ₀ also inhibited HIF-1α downstream genes involved in glycolysis, such as HK-2, LDH-A, PDK-1, and PKM-2 enzymes. CoQ₀ decreased extracellular acidification rate (ECAR), glycolysis, glycolytic capacity, and glycolytic reserve in MDA-MB-231 and 468 cells under normoxic and hypoxic (CoCl₂) conditions. CoQ₀ inhibited the glycolytic intermediates lactate, FBP, and 2/3-PG, and PEP levels. CoQ₀ increased oxygen consumption rate (OCR), basal respiration, ATP production, maximal respiration, and spare capacity under normoxic and hypoxic (CoCl₂) conditions. CoQ₀ increased TCA cycle metabolites, such as citrate, isocitrate, and succinate. CoQ0 inhibited aerobic glycolysis and enhanced mitochondrial oxidative phosphorylation in TNBC cells. Under hypoxic conditions, CoQ₀ also mitigated HIF-1α, GLUT1, glycolytic-related (HK-2, LDH-A, and PFK-1), and metastasis-related (E-cadherin, N-cadherin, and MMP-9) protein or mRNA expression in MDA-MB-231 and/or 468 cells. Under LPS/ATP stimulation, CoQ₀ inhibited NLRP3 inflammasome/procaspase-1/IL-18 activation and NFκB/iNOS expression. CoQ₀ also hindered LPS/ATP-stimulated tumor migration and downregulated LPS/ATP-stimulated N-cadherin and MMP-2/-9 expression. The present study revealed that suppression of HIF-1α expression caused by CoQ₀ may contribute to inhibition of NLRP3-mediated inflammation, EMT/metastasis, and Warburg effects of triple-negative breast cancers.

Antrodia camphorata and coenzyme Q0 , a novel quinone derivative of Antrodia camphorata, impede HIF-1α and epithelial-mesenchymal transition/metastasis in human glioblastoma cells

Antrodia camphorata (AC) and Coenzyme Q₀ (CoQ₀ ), a novel quinone derivative of AC, exhibits antitumor activities. The present study evaluated EMT/metastasis inhibition and autophagy induction aspects of AC and CoQ₀ in human glioblastoma (GBM8401) cells. Our findings revealed that AC treatment (0-150 μg/mL) hindered tumor cell proliferation and migration/invasion in GBM8401 cells. Notably, AC treatment inhibited HIF-1α and EMT by upregulating epithelial marker protein E-cadherin while downregulating mesenchymal proteins Twist, Slug, Snail, and β-catenin. There was an appearance of the autophagy markers LC3-II and p62/SQSTM1, while ATG4B was downregulated by AC treatment. We also found that CoQ₀ (0-10 μM) could inhibit migration and invasion in GBM8401 cells. In particular, E-cadherin was elevated and N-cadherin, Vimentin, Twist, Slug, and Snail, were reduced upon CoQ₀ treatment. In addition, MMP-2/-9 expression and Wnt/β-catenin pathways were downregulated. Furthermore, autophagy inhibitors 3-MA or CQ reversed the CoQ₀ -elicited suppression of migration/invasion and metastasis-related proteins (Vimentin, Snail, and β-catenin). Results suggested autophagy-mediated antiEMT and antimetastasis upon CoQ₀ treatment. CoQ₀ inhibited HIF-1α and metastasis in GBM8401 cells under normoxia and hypoxia. HIF-1α knockdown using siRNA accelerated CoQ₀ -inhibited migration. Finally, CoQ₀ exhibited a prolonged survival rate in GBM8401-xenografted mice. Treatment with Antrodia camphorata/CoQ₀ inhibited HIF-1α and EMT/metastasis in glioblastoma.

Review of Bioactivity, Isolation, and Identification of Active Compounds from Antrodia cinnamomea

Antrodia cinnamomea is a precious and popular edible and medicinal mushroom. It has attracted increasing attention due to its various and excellent bioactivities, such as hepatoprotection, hypoglycemic, antioxidant, antitumor, anticancer, anti-inflammatory, immunomodulation, and gut microbiota regulation properties. To elucidate its bioactivities and develop novel functional foods or medicines, numerous studies have focused on the isolation and identification of the bioactive compounds of A. cinnamomea. In this review, the recent advances in bioactivity, isolation, purification, and identification methods of active compounds from A. cinnamomea were summarized. The present work is beneficial to the further isolation and discovery of new active compounds from A. cinnamomea.

Coenzyme Q0 Inhibits NLRP3 Inflammasome Activation through Mitophagy Induction in LPS/ATP-Stimulated Macrophages

Coenzyme Q (CoQ) analogs with a variable number of isoprenoid units have exhibited as anti-inflammatory as well as antioxidant molecules. Using novel quinone derivative CoQ₀ (2,3-dimethoxy-5-methyl-1,4-benzoquinone, zero side chain isoprenoid), we studied its molecular activities against LPS/ATP-induced inflammation and redox imbalance in murine RAW264.7 macrophages. CoQ₀'s non- or subcytotoxic concentration suppressed the NLRP3 inflammasome and procaspase-1 activation, followed by downregulation of IL1β expression in LPS/ATP-stimulated RAW264.7 macrophages. Similarly, treatment of CoQ₀ led to LC3-I/II accumulation and p62/SQSTM1 activation. An increase in the Beclin-1/Bcl-2 ratio and a decrease in the expression of phosphorylated PI3K/AKT, p70 S6 kinase, and mTOR showed that autophagy was activated. Besides, CoQ₀ increased Parkin protein to recruit damaged mitochondria and induced mitophagy in LPS/ATP-stimulated RAW264.7 macrophages. CoQ₀ inhibited LPS/ATP-stimulated ROS generation in RAW264.7 macrophages. Notably, when LPS/ATP-stimulated RAW264.7 macrophages were treated with CoQ₀, Mito-TEMPO (a mitochondrial ROS inhibitor), or N-acetylcysteine (NAC, a ROS inhibitor), there was a significant reduction of LPS/ATP-stimulated NLRP3 inflammasome activation and IL1β expression. Interestingly, treatment with CoQ₀ or Mito-TEMPO, but not NAC, significantly increased LPS/ATP-induced LC3-II accumulation indicating that mitophagy plays a key role in the regulation of CoQ₀-inhibited NLRP3 inflammasome activation. Nrf2 knockdown significantly decreased IL1β expression in LPS/ATP-stimulated RAW264.7 macrophages suggesting that CoQ₀ inhibited ROS-mediated NLRP3 inflammasome activation and IL1β expression was suppressed due to the Nrf2 activation. Hence, this study showed that CoQ₀ might be a promising candidate for the therapeutics of inflammatory disorders due to its effective anti-inflammatory as well as antioxidant properties.

Emerging role of ferroptosis in breast cancer: New dawn for overcoming tumor progression

Breast cancer has become a serious threat to women's health. Cancer progression is mainly derived from resistance to apoptosis induced by procedures or therapies. Therefore, new drugs or models that can overcome apoptosis resistance should be identified. Ferroptosis is a recently identified mode of cell death characterized by excess reactive oxygen species-induced lipid peroxidation. Since ferroptosis is distinct from apoptosis, necrosis and autophagy, its induction successfully eliminates cancer cells that are resistant to other modes of cell death. Therefore, ferroptosis may become a new direction around which to design breast cancer treatment. Unfortunately, the complete appearance of ferroptosis in breast cancer has not yet been fully elucidated. Furthermore, whether ferroptosis inducers can be used in combination with traditional anti- breast cancer drugs is still unknown. Moreover, a summary of ferroptosis in breast cancer progression and therapy is currently not available. In this review, we discuss the roles of ferroptosis-associated modulators glutathione, glutathione peroxidase 4, iron, nuclear factor erythroid-2 related factor-2, superoxide dismutases, lipoxygenase and coenzyme Q in breast cancer. Furthermore, we provide evidence that traditional drugs against breast cancer induce ferroptosis, and that ferroptosis inducers eliminate breast cancer cells. Finally, we put forward prospect of using ferroptosis inducers in breast cancer therapy, and predict possible obstacles and corresponding solutions. This review will deepen our understanding of the relationship between ferroptosis and breast cancer, and provide new insights into breast cancer-related therapeutic strategies.

Coenzyme Q0, a novel quinone derivative of Antrodia camphorata, induces ROS-mediated cytotoxic autophagy and apoptosis against human glioblastoma cells in vitro and in vivo

Coenzyme Q0 (CoQ0, 2,3-dimethoxy-5-methyl-1,4-benzoquinone) derived from Antrodia camphorata exerts anticancer activities against breast, melanoma, and ovarian carcinoma. Glioblastoma multiforme is a common tumor affecting the central nervous system. This study explored anticancer properties of CoQ0 on human glioblastoma both in vitro and in vivo, and explained the molecular mechanism behind it. CoQ0 treatment retarded the growth and suppressed colony formation in glioblastoma (U87MG and GBM8401) cells. CoQ0 induced apoptosis by activation of caspase-3, cleavage of PARP, and dysregulation of Bax and Bcl-2 in both cell lines. Annexin V/PI staining indicated CoQ0 mediated necrosis and apoptosis. Interestingly, AVOs were increased trough induction of autophagy by CoQ0, LC3-II accumulation, and p62/SQSTM1 expression, leading to death mechanism. Z-VAD-FMK has no effect on CoQ0-induced autophagy but autophagy inhibition by 3-methyladenine (3-MA)/chloroquine (CQ) led to CoQ0-induced apoptosis. N-acetylcysteine (NAC) inhibited CoQ0-mediated ROS production and diminished CoQ0-induced apoptotic and autophagic cell death. Further, CoQ0 inhibited PI3K/AKT/mTOR signaling pathways. CoQ0 reduced the tumor burden in U87MG and GBM8401 xenografted athymic nude mice and significantly modulated tumor xenograft by inducing apoptosis and autophagy. CoQ0 generated ROS-mediated apoptotic and autophagic cell death for effective glioblastoma treatment.

Effect of antioxidants coenzyme Q10 and β-carotene on the cytotoxicity of vemurafenib against human malignant melanoma

Melanoma is a type of highly invasive skin cancer derived from melanocytes with poor prognosis. Vemurafenib (PLX4032) is a clinically approved targeted therapeutic for BRAF mutant melanoma that has a high therapeutic response rate and significantly prolongs the overall survival time of patients with melanoma. Antioxidants have been widely used as supplements for cancer prevention and for decreasing the side effects of cancer therapy. However, antioxidants can also protect cancer cells from oxidative stress and promote cancer growth and progression. The present study aimed to examine the effect of the antioxidants coenzyme Q10 (CoQ10) and β-carotene on melanoma cell growth and invasiveness and on the cytotoxicity of vemurafenib against both vemurafenib-sensitive (SK-MEL-28) and vemurafenib-resistant (A2058) human malignant melanoma cell lines. MTS assay and wound-healing assay demonstrated that CoQ10 alone significantly reduced the viability and migration of melanoma cells, respectively, and synergistically worked with vemurafenib to decrease the viability and migration of human melanoma cells. In contrast, MTS assay and flow cytometry revealed that β-carotene alone did not affect the viability and apoptosis induction of melanoma cells; however, it inhibited cell migration and invasiveness. Wound-healing and Transwell assay demonstrated that β-carotene alleviated the cytotoxicity of vemurafenib and mitigated the inhibitory effect of vemurafenib on cell migration and invasion. Both CoQ10 and β-carotene protected melanoma cells from undergoing apoptosis induced by vemurafenib. Immunoblotting demonstrated that β-carotene at physiological concentration worked synergistically with vemurafenib to suppress the Ras-Raf-Mek-Erk intracellular signaling pathway. The present study aimed to add to the evidence of the in vitro effects of CoQ10 and β-carotene on the antimelanoma effects of vemurafenib.

Coenzyme Q0 immobilized on Magnetic Nanoparticle: Synthesis and Antitumoral Effect on Saos, MCF7 and Hela Cell Lines

Many attempts in medical community focused on the preparation of anticancer agents. Various Coenzyme Q such as CoQ0 analogs have been reported as anti-inflammatory, anticancer, and antioxidant substances. In this study a novel derivatives of Coenzyme Q as an anticancer agent have been introduced. The prepared magnetic nanoparticle, containing CoQ0 were prepared using common chemical methods and also characterized by means of nuclear magnetic resonance (NMR), fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA), and differential scanning calorimetric (DSC). To evaluate the antiproliferative effects of the nanoparticle, the prepared compound was treated with cell lines such as Hela, MCF-7 and Saos. Moreover, the outcomes were compared with normal fibroblast cell line. These assessments were performed by means of MTT assay. Investigation on the capability of this prepared nanoparticle showed some reliable results including cytotoxicities against MCF7, Saos and Hela cancer cell lines which were illustrated by displaying the morphology of the treated cells using AO/EB dual staining fluorescent technique. Employing simple method for preparation as well as the promising cytotoxic results makes it as a promising candidate for further bioexperiments.

Coenzyme Q0 From Antrodia cinnamomea Exhibits Drug-Resistant Bacteria Eradication and Keratinocyte Inflammation Mitigation to Ameliorate Infected Atopic Dermatitis in Mouse

Atopic dermatitis (AD) is an inflammatory skin disease that is usually accompanied by Staphylococcus aureus infection due to cutaneous barrier-function damage. Benzenoid compounds from Antrodia cinnamomea are known to exhibit antibacterial and anti-inflammatory activities. This study sought to investigate the potential of benzenoids for treating bacteria-infected AD. The compounds were screened against methicillin-resistant S. aureus (MRSA). Coenzyme Q₀ (CoQ₀), a key ingredient in A. cinnamomea, showed the strongest MRSA growth inhibition. We further tested the inhibitory effect of CoQ₀ on planktonic and biofilm MRSA. The work was also performed to explore the potential effectiveness of CoQ₀ on AD using activated keratinocytes and in vivo experimental AD mice as the models. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CoQ₀ against MRSA were 7.81 μg/ml. CoQ₀ was found to eradicate biofilm MRSA efficiently and reduce the biofilm thickness. CoQ₀ killed MRSA by inhibiting DNA polymerase and topoisomerases. A proteomic assay showed that CoQ₀ also reduced the ribosomal proteins. In the anti-inflammation study, CoQ₀ was found to downregulate the expression of interleukin (IL)-6, chemokine (C-C motif) ligand (CCL)5, and CCL17 in HaCaT cells. CoQ₀ at 0.5 μg/ml could recover the filaggrin decreased by HaCaT activation to the normal control. We established a bacteria-infected AD-like model in mice using ovalbumin (OVA) and topically applied MRSA. Topical CoQ₀ delivery lessened the MRSA presence in the AD-like lesions by >90%. The erythema, barrier function, and epidermal thickness of the AD-like wounds were improved by CoQ₀ through the reduction of IL-1β, IL-4, IL-6, IL-10, interferon (IFN)-γ, and by neutrophil infiltration in the lesional skin. CoQ₀ is therefore regarded as effective in mitigating AD symptoms associated with bacterial load.

A Benzenoid 4,7-Dimethoxy-5-Methyl-L, 3-Benzodioxole from Antrodia cinnamomea Attenuates Dendritic Cell-Mediated Th2 Allergic Responses

Dendritic cells (DCs) play a critical role in initiating immune responses; however, DCs also induce Th2-related allergic sensitivities. Thus, DCs become a target for therapeutic design in allergic diseases. In this study, we aim to investigate the anti-allergic effect of pure compounds from a medicinal mushroom Antrodia cinnamomea (Ac) on DC-induced allergic responses. We identified a benzenoid compound 4,7-dimethoxy-5-methyl-l,3-benzodioxole (DMB) which may modulate Th2 polarization in bone marrow-derived DCs (BMDCs) and in a murine food allergy model. DMB effectively reduced the Th2 adjuvant cholera toxin (CT)-induced BMDC maturation and cytokine production. In studying the mechanism, DMB blocked the molecular processes involved in Th2 induction, including cAMP activation, IL-33 production, and IRF4/Tim4 upregulation, in CT-activated BMDCs. Furthermore, DMB treatment attenuated the symptoms, clinical scores, and Th2 responses of CT-induced ovalbumin (OVA)-specific food allergy in mice at sensitization stage. These results indicated that DMB could suppress DC function for Th2 polarization and mitigate allergic responses. Thus, DMB may have potential to be a novel agent for preventing or treating food allergy.

Anti-EMT properties of CoQ0 attributed to PI3K/AKT/NFKB/MMP-9 signaling pathway through ROS-mediated apoptosis

Background

Breast cancer is the most prevalent cancer among women. In triple-negative breast cancer (TNBC) cells, a novel quinone derivative, coenzyme Q₀ (CoQ₀), promotes apoptosis and cell-cycle arrest. This study explored the anti-epithelial–mesenchymal transition (EMT) and antimetastatic attributes of CoQ₀ in TNBC (MDA-MB-231).

Methods

Invasion, as well as MTT assays were conducted. Lipofectamine RNAiMAX was used to transfect cells with β-catenin siRNA. Through Western blotting and RT-PCR, the major signaling pathways’ protein expressions were examined, and the biopsied tumor tissues underwent immunohistochemical and hematoxylin and eosin staining as well as Western blotting.

Results

CoQ₀ (0.5–2 μM) hindered tumor migration, invasion, and progression. Additionally, it caused MMP-2/− 9, uPA, uPAR, and VEGF downregulation. Furthermore, in highly metastatic MDA-MB-231 cells, TIMP-1/2 expression was subsequently upregulated and MMP-9 expression was downregulated. In addition, CoQ₀ inhibited metastasis and EMT in TGF-β/TNF-α-stimulated non-tumorigenic MCF-10A cells. Bioluminescence imaging of MDA-MB-231 luciferase–injected live mice demonstrated that CoQ₀ significantly inhibited metastasis of the breast cancer to the lungs and inhibited the development of tumors in MDA-MB-231 xenografted nude mice. Silencing of β-catenin with siRNA stimulated CoQ₀-inhibited EMT. Western blotting as well as histological analysis established that CoQ0 reduced xenografted tumor development because apoptosis induction, cell-cycle inhibition, E-cadherin upregulation, β-catenin downregulation, and metastasis and EMT regulatory protein modulation were observed.

Conclusions

CoQ₀ inhibited the progression of metastasis as well as EMT (in vitro and in vivo). The described approach has potential in treating human breast cancer metastasis.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1196-x) contains supplementary material, which is available to authorized users.

Antrodia camphorata inhibits epithelial-to-mesenchymal transition by targeting multiple pathways in triple-negative breast cancers

Antrodia camphorata (AC) exhibits potential for engendering cell-cycle arrest as well as prompting apoptosis and metastasis inhibition in triple-negative breast cancer (TNBC) cells. We performed the current study to explore the anti-epithelial-to-mesenchymal transition (EMT) properties of fermented AC broth in TNBC cells. Our results illustrated that noncytotoxic concentrations of AC (20-60 μg/ml) reversed the morphological changes (fibroblastic-to-epithelial phenotype) as well as the EMT by upregulating the observed E-cadherin expression. Furthermore, we discovered treatment with AC substantially inhibit the Twist expression in human TNBC (MDA-MB-231) cells as well as in those that were transfected with Twist. In addition, we determined AC to decrease the observed Wnt/β-catenin nuclear translocation through a pathway determined to be dependent on GSK3β. Notably, AC treatment consistently inhibited the EMT by downregulating mesenchymal marker proteins like N-cadherin, vimentin, Snail, ZEB-1, and fibronectin; at that same time upregulating epithelial marker proteins like occludin and ZO-1. Bioluminescence imaging that was executed in vivo demonstrated AC substantially suppressed breast cancer metastasis to the lungs. Notably, we found that western blot analysis confirmed that AC decreased lung metastasis as demonstrated by upregulation of E-cadherin expression in biopsied lung tissue. Together with our results support the anti-EMT activity of AC, indicating AC as having the potential for acting as an anticancer agent for the treatment of human TNBC treatment.

CoQ0-induced mitochondrial PTP opening triggers apoptosis via ROS-mediated VDAC1 upregulation in HL-60 leukemia cells and suppresses tumor growth in athymic nude mice/xenografted nude mice

Coenzyme Q (CoQ) analogs with variable numbers of isoprenoid units have been demonstrated as anticancer and antioxidant/pro-oxidant molecules. This study examined the in vitro and in vivo antitumor and apoptosis activities of CoQ₀ (2,3-dimethoxy-5-methyl-1,4-benzoquinone, zero isoprenoid side-chains) through upregulation of the Voltage-dependent anion channel 1 (VDAC1) signaling pathway on human promyelocytic leukemia. CoQ₀ (0-40 μg/mL) treatment significantly reduced HL-60 cell viability, and up-regulated mitochondrial VDAC1 expression. CoQ₀ treatment triggers intracellular ROS generation, calcium release, ΔΨm collapse and PTP opening in HL-60 cells. CoQ₀ treatment induced apoptosis, which was associated with DNA fragmentation, cytochrome c release, caspase-3 and PARP activation, and Bax/Bcl-2 dysregulation. Annexin V-PI staining indicated that CoQ₀ promotes late apoptosis. Furthermore, the blockade of CoQ₀-induced ROS production by antioxidant NAC pretreatment substantially attenuated CoQ₀-induced apoptosis. The activation of p-GSK3β expression, cyclophilin D inhibition, and p53 activation through ROS are involved in CoQ₀-induced HL-60 apoptotic cell death. Notably, ROS-independent p38 activation is involved in CoQ₀-mediated apoptosis in HL-60 cells. In addition, the silencing of VDAC1 also prevented CoQ₀-induced mitochondrial translocation of Bax, activation of caspase-3, and reduction in Bcl-2. Intriguingly, VDAC1 silencing did not prevent ROS production induced by CoQ₀, which in turn indicates that CoQ₀ induced ROS-mediated VDAC1 and then mitochondrial apoptosis in HL-60 cells. In vivo results revealed that CoQ₀ is effective in delaying tumor incidence and reducing the tumor burden in HL-60-xenografted nude mice. Taken together, CoQ₀ could be a promising anticancer agent for the treatment of human promyelocytic leukemia through upregulation of VDAC1 signaling pathways.