In Vitro and in Vivo Study of a Photostable Quinone Compound with Enhanced Therapeutic Efficacy against Chagas Disease.

Chagas disease, a neglected tropical disease caused by the protozoan Trypanosoma cruzi poses a significant health challenge in rural areas of Latin America. The current pharmacological options exhibit notable side effects, demand prolonged administration, and display limited efficacy. Consequently, there is an urgent need to develop drugs that are safe and clinically effective. Previously, we identified a quinone compound (designated as compound 2) with potent antiprotozoal activity, based on the chemical structure of komaroviquinone, a natural product renowned for its antitrypanosomal effects. However, compound 2 was demonstrated considerably unstable to light. In this study, we elucidated the structure of the light-induced degradation products of compound 2 and probed the correlation between the quinone ring's substituents and its susceptibility to light. Our findings led to the discovery of quinones with significantly enhanced light stability, some of which exhibiting antitrypanosomal activity. The most promising compound was evaluated for drug efficacy in a mouse model of Chagas disease, revealing where a notable reduction in blood parasitemia.

Dihydrotanshinone I exhibits antitumor effects via ß-catenin downregulation in papillary thyroid cancer cell lines.

Thyroid cancer is the most common endocrine carcinoma and, among its different subtypes, the papillary subtype (PTC) is the most frequent. Generally, PTCs are well differentiated, but a minor percentage of PTCs are characterized by a worse prognosis and more aggressive behavior. Phytochemicals, naturally found in plant products, represent a heterogeneous group of bioactive compounds that can interfere with cell proliferation and the regulation of the cell cycle, taking part in multiple signaling pathways that are often disrupted in tumor initiation, proliferation, and progression. In this work, we focused on 15,16-dihydrotanshinone I (DHT), a tanshinone isolated from Salvia miltiorrhiza Bunge (Danshen). We first evaluated DHT biological effect on PTC cells regarding cell viability, colony formation ability, and migration capacity. All of these parameters were downregulated by DHT treatment. We then investigated gene expression changes after DHT treatment by performing RNA-seq. The analysis revealed that DHT significantly reduced the Wnt signaling pathway, which plays a role in various diseases, including cancer. Finally, we demonstrate that DHT treatment decreases protein levels of ß-catenin, a final effector of canonical Wnt signaling pathway. Overall, our data suggest a possible use of this nutraceutical as an adjuvant in the treatment of aggressive papillary thyroid carcinoma.

Aromatic amine antioxidants (AAs) and p-phenylenediamines-quinones (PPD-Qs) in e-waste recycling industry park: Occupational exposure and liver X receptors (LXRs) disruption potential.

Recently, evidence of aromatic amine antioxidants (AAs) existence in the dust of the electronic waste (e-waste) dismantling area has been exposed. However, there are limited studies investigating occupational exposure and toxicity associated with AAs and their transformation products (p-phenylenediamines-quinones, i.e., PPD-Qs). In this study, 115 dust and 42 hand wipe samples collected from an e-waste recycling industrial park in central China were analyzed for 19 AAs and 6 PPD-Qs. Notably, the median concentration of ∑6PPD-Qs (1,110 ng/g and 1,970 ng/m2) was significantly higher (p < 0.05, Mann-Whitney U test) than that of ∑6PPDs (147 ng/g and 34.0 ng/m2) in dust and hand wipes. Among the detected analytes, 4-phenylaminodiphenylamine quinone (DPPD-Q) (median: 781 ng/g) and 1,4-Bis(2-naphthylamino) benzene quinone (DNPD-Q) (median: 156 ng/g), were particularly prominent, which were first detected in the e-waste dismantling area. Occupational exposure assessments and nuclear receptor interference ability, conducted through estimated daily intake (EDI) and molecular docking analysis, respectively, indicated significant occupational exposure to PPD-Qs and suggested prioritized Liver X receptors (LXRs) disruption potential of PPDs and PPD-Qs. The study provides the first evidence of considerable levels of AAs and PPD-Qs in the e-waste-related hand wipe samples and underscores the importance of assessing occupational exposure and associated toxicity effects.

Hydroxysafflor yellow A induced ferroptosis of Osteosarcoma cancer cells by HIF-1α/HK2 and SLC7A11 pathway.

Osteosarcoma is a very serious primary bone cancer with a high death rate and a dismal prognosis. Since there is no permanent therapy for this condition, it is necessary to develop a cure. Therefore, this investigation was carried out to assess the impacts and biological functions of hydroxysafflor yellow A (HYSA) in osteosarcoma cell lines (MG63). In this investigational study, MG63 cells were utilized. Microarray experiments, quantitative polymerase chain reaction (qPCR), immunofluorescent staining, extracellular acidification rate (ECAR), oxygen consumption rate (OCR), glucose consumption, lactate production, and ATP levels, proliferation assay, 5-Ethynyl-2'-deoxyuridine (EDU) staining, and Western blot were performed. In MG63 cells, HYSA lowered cell proliferation and metastasis rates, suppressed EDU cell number, and enhanced caspase-3/9 activity levels. HYSA reduced the Warburg effect and induced ferroptosis (FPT) in MG63 cells. Inhibiting ferroptosis diminished HYSA's anti-cancer activities in MG63 cells. The stimulation of the HIF-1α/SLC7A11 pathway decreased HYSA's anti-cancer activities in MG63 cells. HIF-1α is one target spot for HYSA in a model of osteosarcoma cancer (OC). HYSA altered HIF-1α's thermophoretic activity; following binding with HYSA, HIF-1α's melting point increased from ~55°C to ~60°C. HYSA significantly enhanced the thermal stability of exogenous WT HIF-1α while not affecting Mut HIF-1α, suggesting that ARG-311, GLY-312, GLN-347, and GLN-387 may be involved in the interaction between HIF-1α and HYSA. Conclusively, our study revealed that HYSA induced FPT and reduced the Warburg effect of OC through mitochondrial damage by HIF-1α/HK2/SLC7A11 pathway. HYSA is a possible therapeutic option for OC or other cancers.

Mitochondrial quinone redox states as a marker of mitochondrial metabolism.

Mitochondrial and thus cellular energetics are highly regulated both thermodynamically and kinetically. Cellular energetics is of prime importance in the regulation of cellular functions since it provides ATP for their accomplishment. However, cellular energetics is not only about ATP production but also about the ability to re-oxidize reduced coenzymes at a proper rate, such that the cellular redox potential remains at a level compatible with enzymatic reactions. However, this parameter is not only difficult to assess due to its dual compartmentation (mitochondrial and cytosolic) but also because it is well known that most NADH in the cells is bound to the enzymes. In this paper, we investigated the potential relevance of mitochondrial quinones redox state as a marker of mitochondrial metabolism and more particularly mitochondrial redox state. We were able to show that Q2 is an appropriate redox mediator to assess the mitochondrial quinone redox states. On isolated mitochondria, the mitochondrial quinone redox states depend on the mitochondrial substrate and the mitochondrial energetic state (phosphorylating or not phosphorylating). Last but not least, we show that the quinones redox state response allows to better understand the Krebs cycle functioning and respiratory substrates oxidation. Taken together, our results suggest that the quinones redox state is an excellent marker of mitochondrial metabolism.

Evaluation of 6-PPD quinone toxicity on lung of male BALB/c mice by quantitative proteomics.

N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6-PPDQ), a transformation product of tyre-derived 6-PPD, has been frequently detected in different environments. After 6-PPDQ exposure, we here aimed to examine dynamic lung bioaccumulation, lung injury, and the underlying molecular basis in male BALB/c mice. After single injection at concentration of 4 mg/kg, 6-PPDQ remained in lung up to day 28, and higher level of 6-PPDQ bioaccumulation in lung was observed after repeated injection. Severe inflammation was observed in lung after both single and repeated 6-PPDQ injection as indicated by changes of inflammatory cytokines (TNF-α, IL-6 and IL-10). Sirius red staining and hydroxyproline content analysis indicated that repeated rather than single 6-PPDQ injection induced fibrosis in lung. Repeated 6-PPDQ injection also severely impaired lung function in mice by influencing chord compliance (Cchord) and enhanced pause (Penh). Proteomes analysis was further carried out to identify molecular targets of 6-PPDQ after repeated injection, which was confirmed by transcriptional expression analysis and immunohistochemistry staining. Alterations in Ripk1, Fadd, Il-6st, and Il-16 expressions were identified to be associated with inflammation induction of lung after repeated 6-PPDQ injection. Alteration in Smad2 expression was identified to be associated with fibrosis formation in lung of 6-PPDQ exposed mice. Therefore, long-term and repeated 6-PPDQ exposure potentially resulted in inflammation and fibrosis in lung by affecting certain molecular signals in mammals. Our results suggested several aspects of lung injury caused by 6-PPDQ and provide the underlying molecular basis. These observations implied the possible risks of long-term 6-PPDQ exposure to human health.

Hydroxy-Safflower Yellow A Mitigates Vascular Remodeling in Rat Pulmonary Arterial Hypertension.

Purpose: The underlying causes of pulmonary arterial hypertension (PAH) often remain obscure. Addressing PAH with effective treatments presents a formidable challenge. Studies have shown that Hydroxysafflor yellow A (HSYA) has a potential role in PAH, While the mechanism underlies its protective role is still unclear. The study was conducted to investigate the potential mechanisms of the protective effects of HSYA. Methods: Using databases such as PharmMapper and GeneCards, we identified active components of HSYA and associated PAH targets, pinpointed intersecting genes, and constructed a protein-protein interaction (PPI) network. Core targets were singled out using Cytoscape for the development of a model illustrating drug-component-target-disease interactions. Intersection targets underwent analysis for Gene Ontology (GO) functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Selected components were then modeled for target interaction using Autodock and Pymol. In vivo validation in a monocrotaline-induced PAH (MCT-PAH) animal model was utilized to substantiate the predictions made by network pharmacology. Results: We associated HSYA with 113 targets, and PAH with 1737 targets, identifying 34 mutual targets for treatment by HSYA. HSYA predominantly affects 9 core targets. Molecular docking unveiled hydrogen bond interactions between HSYA and several PAH-related proteins such as ANXA5, EGFR, SRC, PPARG, PGR, and ESR1. Conclusion: Utilizing network pharmacology and molecular docking approaches, we investigated potential targets and relevant human disease pathways implicating HSYA in PAH therapy, such as the chemical carcinogenesis receptor activation pathway and the cancer pathway. Our findings were corroborated by the efficacious use of HSYA in an MCT-induced rat PAH model, confirming its therapeutic potential.

High-contrast NIR fluorescent probes for selective detection of NQO1 in breast cancer.

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a potential biomarker for breast cancer (BC) diagnosis and prognosis. However, existing fluorescent probes for NQO1 detection have limitations such as short emission wavelength, weak fluorescence response, or large background interference. Here, we developed two novel near-infrared (NIR) fluorescent probes, DCl-Q and DCl2-Q, that selectively detect NQO1 activity in BC cells and tissues. They consist of a trimethyl-locked quinone as the recognition group and a donor-π-acceptor structure with halogen atoms as the reporter group. They exhibit strong fluorescence emission at around 660 nm upon binding to NQO1. We demonstrated that they can distinguish BC cells with different NQO1 expression levels and image endogenous NQO1 in tumor-bearing mice. Our probes provide a convenient and highly sensitive tool for BC diagnosis and prognosis based on NQO1 detection.

Identification of Erzhu Jiedu Recipe and its molecular mechanism underlying inhibited human hepatoma cells by UHPLC-Q-Exactive Orbitrap HRMS and network pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Erzhu Jiedu Recipe (EZJDR) is a formula of traditional Chinese medicine (TCM) for treating hepatitis B virus-related hepatocellular carcinoma (HBV-HCC). However, its effective components and the mechanism of action remain unclear. AIM OF THE STUDY: To explain how the active compounds of EZJDR suppress the growth of hepatoma cells. METHODS: UHPLC-Q-Exactive Orbitrap HRMS was used to identify the chemical constituents of EZJDR and their distribution in the serum and liver of mice. Together with experimental investigations, network pharmacology unraveled the molecular mechanism of components of EZJDR underlying the inhibited Hep3B cells. RESULTS: A total of 138 compounds which can be divided into 18 kinds of components (such as sesquiterpenoids, diterpenoids, anthraquinones, flavonoids and so on) were found in the aqueous extract of EZJDR. Of these components, the tricyclic-diterpenoids exhibited a highest exposure in the serum (74.5%) and liver (94.7%) of mice. The network pharmacology revealed that multiple components of EZJDR interacted with key node genes involved in apoptosis, proliferation, migration and metabolism through various signaling pathways, including ligand binding and protein phosphorylation. In vitro experiments demonstrated that 6 tricyclic-diterpenoids, 2 anthraquinones and 1 flavonoid inhibited the viability of Hep3B cells, with IC50 values ranging from 3.81 µM to 37.72 µM. Dihydrotanshinone I had the most potent bioactivity, arresting the S phase of cell cycle and inducing apoptosis. This compound changed the expression of proteins, including Bad, Bax, Bcl-2, Bal-x, caspase3 and catalase, which were associated with mitochondria-mediated apoptotic pathways. Moreover, dihydrotanshinone I increased the levels of p21 proteins, but decreased the phosphorylated p53, suggesting accumulation of p53 protein prevented cell cycle progression of Hep3B cells with damaged DNA. CONCLUSIONS: These results suggested that multiple components of EZJDR-diterpenoid, anthraquinone and flavonoid-could be the effective material for the treatment of HBV-HCC. This research provided valuable insights into the molecular mechanism of action underlying the therapeutic effects of EZJDR.

Discovery of proqodine A derivatives with antitumor activity targeting NAD(P)H: quinone oxidoreductase 1 and nicotinamide phosphoribosyltransferase.

NAD(P)H: quinone oxidoreductase 1 (NQO1) is a flavin protease highly expressed in various cancer cells. NQO1 catalyzes a futile redox cycle in substrates, leading to substantial reactive oxygen species (ROS) production. This ROS generation results in extensive DNA damage and elevated poly (ADP-ribose) polymerase 1 (PARP1)-mediated consumption of nicotinamide adenine dinucleotide (NAD+), ultimately causing cell death. Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD+ salvage synthesis pathway, emerges as a critical target in cancer therapy. The concurrent inhibition of NQO1 and NAMPT triggers hyperactivation of PARP1 and intensive NAD+ depletion. In this study, we designed, synthesized, and assessed a novel series of proqodine A derivatives targeting both NQO1 and NAMPT. Among these, compound T8 demonstrated potent antitumor properties. Specifically, T8 selectively inhibited the proliferation of MCF-7 cells and induced apoptosis through mechanisms dependent on both NQO1 and NAMPT. This discovery offers a promising new molecular entity for advancing anticancer research.

[Development of optical probes with excellent intracellular retention].

Small-molecule based activatable fluorescence probes for detecting specific enzyme activity with high sensitivity can visualize the expression site of marker genes and cancers where the enzyme is highly expressed. However, the enzyme-catalyzed fluorescent hydrolysis product easily leaks out and diffuses from the reaction site, making it difficult to perform long-term tracking and immunohistochemical analysis which needs washing/fixation procedure. Our group have focused on quinone methide chemistry and developed series of activatable fluorescence probes with excellent intracellular retention that are converted to quinone-methide or aza-quinone-methide intermediates upon reaction with enzymes, which are then react with intracellular nucleophiles such as proteins and glutathione to be retained in cells and to exhibit significant increase in fluorescence. Based on this molecular design, we have developed fluorescence probes targeting ß-galactosidase and γ-glutamyltranspeptidase with different colors. We also developed photo-functional probes such as activatable photosensitizers and caged fluorophores. These probes can visualize or kill target enzyme-expressing cells with high selectivity by suppressing the leakage of hydrolysis products from target cells, and fluorescence imaging in combination with immunostaining was possible due to the high tolerance of the obtained fluorescence signal even after washing and fixation.

Brønsted acid- and Ni(II)-catalyzed C-H oxidation/rearrangement of cyclotriveratrylenes (CTVs) to cyclic and acyclic quinones as potential anti-cancer agents.

This paper describes a simple and practical protocol for the direct synthesis of acyclic and cyclic quinone derivatives via an acid-promoted nickel(II)-catalyzed inner rim C-H oxidation of cyclotriveratrylene (CTV) and its analogues. The cyclic quinone derivatives resulted from trimethoxy-cyclotriveratrylene (TCTV) through C-C bond formation via intramolecular ipso substitution followed by subsequent anionic rearrangement containing stereo-vicinal quaternary centers. The DFT calculations strongly support the experimental findings and reveal the role of Brønsted acids in the C-H bond activation of CTV. All the newly synthesized compounds were screened for their in vitro anti-cancer activity using colorimetric SRB assay analysis. Among them, compounds 3a, 3d, 3h, 4a, 4b, 4c and 4e exhibited moderate anticancer activity against A549, HCT-116, PC-3, MDA-MB-231, HEK-293 and SW620 human cancer cell lines.

Synthetic Biology-based Construction of Unnatural Perylenequinones with Improved Photodynamic Anticancer Activities.

The construction of structural complexity and diversity of natural products is crucial for drug discovery and development. To overcome high dark toxicity and poor photostability of natural photosensitizer perylenequinones (PQs) for photodynamic therapy, herein, we aim to introduce the structural complexity and diversity to biosynthesize the desired unnatural PQs in fungus Cercospora through synthetic biology-based strategy. Thus, we first elucidate the intricate biosynthetic pathways of class B PQs and reveal how the branching enzymes create their structural complexity and diversity from a common ancestor. This enables the rational reprogramming of cercosporin biosynthetic pathway in Cercospora to generate diverse unnatural PQs without chemical modification. Among them, unnatural cercosporin A displays remarkably low dark toxicity and high photostability with retention of great photodynamic anticancer and antimicrobial activities. Moreover, it is found that, unlike cercosporin, unnatural cercosporin A could be selectively accumulated in cancer cells, providing potential targets for drug development. Therefore, this work provides a comprehensive foundation for preparing unnatural products with customized functions through synthetic biology-based strategies, thus facilitating drug discovery pipelines from nature.

Dihydrotanshinone I reduces H9c2 cell damage by regulating AKT and MAPK signaling pathways.

Cardiovascular disease is the deadliest disease in the world. Previous studies have shown that Dihydrotanshinone I (DHT) can improve cardiac function after myocardial injury. This study aimed to observe the protective effect and mechanism of DHT on H9c2 cells by establishing an oxygen-glucose deprivation/reoxygenation (OGD/R) injury model. By constructing OGD/R injury simulation of H9c2 cells in a myocardial injury model, the proliferation of H9c2 cells treated with DHT concentrations of 0.1 µmol/L were not affected at 24, 48, and 72 h. DHT can significantly reduce the apoptosis of H9c2 cells caused by OGD/R. Compared with the OGD/R group, DHT treatment significantly reduced the level of MDA and increased the level of SOD in cells. DHT treatment of cells can significantly reduce the levels of ROS and Superoxide in mitochondria in H9c2 cells caused by OGD/R and H2O2. DHT significantly reduced the phosphorylation levels of P38MAPK and ERK in H9c2 cells induced by OGD/R, and significantly increased the phosphorylation levels of AKT in H9c2 cells. DHT can significantly reduce the oxidative stress damage of H9c2 cells caused by H2O2 and OGD/R, thereby reducing the apoptosis of H9c2 cells. And this may be related to regulating the phosphorylation levels of AKT, ERK, and P38MAPK.

Evidence for cytochrome P450 3A4-mediated metabolic activation of SCO-267.

SCO-267 is a potent G-protein-coupled receptor 40 agonist that is undergoing clinical development for the treatment of type 2 diabetes mellitus. The current work was undertaken to investigate the bioactivation potential of SCO-267 in vitro and in vivo. Three SCO-267-derived glutathione (GSH) conjugates (M1-M3) were found both in rat and human liver microsomal incubations supplemented with GSH and nicotinamide adenine dinucleotide phosphate. Two GSH conjugates (M1-M2) together with two N-acetyl-cysteine conjugates (M4-M5) were detected in the bile of rats receiving SCO-267 at 10 mg/kg. The identified conjugates suggested the generation of quinone-imine and ortho-quinone intermediates. CYP3A4 was demonstrated to primarily catalyze the bioactivation of SCO-267. In addition, SCO-267 concentration-, time-, and NADPH-dependently inactivated CYP3A in human liver microsomes using testosterone as a probe substrate, along with KI and kinact values of 4.91 µM and 0.036 min-1 , respectively. Ketoconazole (a competitive inhibitor of CYP3A) displayed no significant protective effect on SCO-267-induced CYP3A inactivation. However, inclusion of GSH showed significant protection. These findings revealed that SCO-267 undergoes a facile CYP3A4-catalyzed bioactivation with the generation of quinone-imine and ortho-quinone intermediates, which were assumed to be involved in SCO-267 induced CYP3A inactivation. These findings provide further insight into the bioactivation pathways involved in the generation of reactive, potentially toxic metabolites of SCO-267. Further studies are needed to evaluate the influence of SCO-267 metabolism on the safety of this drug in vivo.

Antioxidant and cytotoxic activities of quinones from Cetraria laevigata.

Chemical investigation of the extracts obtained from the red thallus tips from Cetraria laevigata resulted in the isolation of five known quinoid pigments identified by FT-IR, UV, NMR, MS methods and by comparison with literature data (skyrin (1), 3-ethyl-2,7-dihydroxynaphthazarin (2), graciliformin (3), cuculoquinone (4) and islandoquinone (5)). An antioxidant capacity of compounds 1-5 were evaluated and compared with quercetin using a lipid peroxidation inhibitory assay and superoxide radical (SOR), nitric oxide radical (NOR), 1,1-diphenyl-2-picrylhydrazine (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) scavenging assays. Compounds 2, 4 and 5 were far more active: they demonstrated the antioxidant capacity in various test assays with the IC50 values 5-409 µM comparable to the flavonoid quercetin. While, the isolated quinones (1-5) exhibited weak cytotoxicity in human cancer cell line A549 assessed by MTT assay.

Design and synthesis of luotonin A-derived topoisomerase targeting scaffold with potent antitumor effect and low genotoxicity.

Conventional topoisomerase (Topo) inhibitors typically usually exert their cytotoxicity by damaging the DNAs, which exhibit high toxicity and tend to result in secondary carcinogenesis risk. Molecules that have potent topoisomerase inhibitory activity but involve less DNA damage provide more desirable scaffolds for developing novel chemotherapeutic agents. In this work, we broke the rigid pentacyclic system of luotonin A and synthesized thirty-three compounds as potential Topo inhibitors based on the devised molecular motif. Further investigation disclose that two compounds with the highest antiproliferation activity against cancer cells, 5aA and 5dD, had a distinct Topo I inhibitory mechanism different from those of the classic Topo I inhibitors CPT or luteolin, and were able to obviate the obvious cellular DNA damage typically associated with clinically available Topo inhibitors. The animal model experiments demonstrated that even in mice treated with a high dosage of 50 mg/kg 5aA, there were no obvious signs of toxicity or loss of body weight. The tumor growth inhibition (TGI) rate was 54.3 % when 20 mg/kg 5aA was given to the T24 xenograft mouse model, and 5aA targeted the cancer tissue precisely without causing damage to the liver and other major organs.

Hydroxysafflor Yellow A Promotes HaCaT Cell Proliferation and Migration by Regulating HBEGF/EGFR and PI3K/AKT Pathways and Circ_0084443.

OBJECTIVE: To investigate the effect and possible mechanism of hydroxysafflor yellow A (HSYA) on human immortalized keratinocyte cell proliferation and migration. METHODS: HaCaT cells were treated with HSYA. Cell proliferation was detected by the cell counting kit-8 assay, and cell migration was measured using wound healing assay and Transwell migration assay. The mRNA and protein expression levels of heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF), EGF receptor (EGFR), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR), and hypoxia-inducible factor-1α (HIF-1α) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. Circ_0084443-overexpressing HaCaT cells and empty plasmid HaCaT cells were constructed using the lentiviral stable transfection and treated with HSYA. The expression of circ_0084443 was detected by qRT-PCR. RESULTS: HSYA (800 µmol/L) significantly promoted HaCaT cell proliferation and migration (P<0.05 or P<0.01). It also increased the mRNA and protein expression levels of HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α, and increased the phosphorylation levels of PI3K and AKT (P<0.05 or P<0.01). Furthermore, HSYA promoted HaCaT cell proliferation and migration via the HBEGF/EGFR and PI3K/AKT/mTOR signaling pathways (P<0.01). Circ_0084443 attenuated the mRNA expression levels of HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α (P<0.05). HSYA inhibited the circ_0084443 expression, further antagonized the inhibition of circ_0084443 on HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α, and promoted the proliferation of circ_0084443-overexpressing HaCaT cells (P<0.05 or P<0.01). However, HSYA could not influence the inhibitory effect of circ_0084443 on HaCaT cell migration (P>0.05). CONCLUSION: HSYA played an accelerative role in HaCaT cell proliferation and migration, which may be attributable to activating HBEGF/EGFR and PI3K/AKT signaling pathways, and had a particular inhibitory effect on the keratinocyte negative regulator circ_0084443.

Bridging population pharmacokinetic and semimechanistic absorption modeling of APX3330.

APX3330 ((2E)-2-[(4,5-dimethoxy-2-methyl-3,6-dioxo-1,4-cyclohexadien-1-yl)methylene]-undecanoic acid), a selective inhibitor of APE1/Ref-1, has been investigated in treatment of hepatitis, cancer, diabetic retinopathy, and macular edema. APX3330 is administered orally as a quinone but is rapidly converted to the hydroquinone form. This study describes the pharmacokinetics of APX3330 and explores effect of food on absorption. Total plasma quinone concentrations of APX3330 were obtained following oral administration from studies in healthy Japanese male subjects (single dose-escalation; multiple-dose; food-effect) and patients with cancer patients. Nonlinear mixed effects modeling was performed using Monolix to estimate pharmacokinetic parameters and assess covariate effects. To further evaluate the effect of food on absorption, a semi-physiologic pharmacokinetic model was developed in Gastroplus to delineate effects of food on dissolution and absorption. A two-compartment, first order absorption model with lag time best described plasma concentration-time profiles from 49 healthy Japanese males. Weight was positively correlated with apparent clearance (CL/F) and volume. Administration with food led to an 80% higher lag time. CL/F was 41% higher in the cancer population. The semi-physiologic model indicates a switch from dissolution-rate control of absorption in the fasted-state to gastric emptying rate determining absorption rate in the fed-state. Oral clearance of APX3330 is higher in patients with cancer than healthy Japanese males, possibly due to reduced serum albumin in patients with cancer. Delayed APX3330 absorption with food may be related to higher conversion to the more soluble but less permeable hydroquinone form in the gastrointestinal tract. Future work should address pharmacokinetic differences between APX3330 quinone and hydroquinone forms.

A novel L-shaped ortho-quinone analog as PLK1 inhibitor blocks prostate cancer cells in G2 phase.

Prostate cancer is the most common malignant tumor among men worldwide. Currently, the main treatments are radical prostatectomy, radiotherapy, chemotherapy, and endocrine therapy. However, most of them are poorly effective and induce side effects. Polo-like kinase 1 (PLK1) regulates cell cycle and mitosis. Its inhibitor BI2536 promotes the therapeutic effect of nilotinib in chronic myeloid leukemia, enhances the sensitivity of neural tube cell tumors to radiation therapy and PLK1 silencing enhances the sensitivity of squamous cell carcinoma to cisplatin. Therefore, the aim of this study was to evaluate the effect of the PLK1 inhibitor L-shaped ortho-quinone analog TE6 on prostate cancer. In vitro on prostate cancer cells showed that TE6 inhibited PLK1 protein expression and consequently cell proliferation by blocking the cell cycle at G2 phase. In vivo on a subcutaneous tumor model in nude mice confirmed that TE6 effectively inhibited tumor growth in nude mice, inhibited PLK1 expression and regulated the expression of cell cycle proteins such as p21, p53, CDK1, Cdc25C, and cyclinB1. Thus, PLK1 was identified as the target protein of TE6, these results reveal the critical role of PLK1 in the growth and survival of prostate cancer and point out the ability of TE6 on targeting PLK1, being a potential drug for prostate cancer therapy.