Rational Molecular Design of a Fluorescent Probe for Selectively Sensing Human Cytochrome P450 2D6.

Cytochrome P450 2D6 (CYP2D6) is a key enzyme that mediates the metabolism of various drugs and endogenous substances in humans. However, its biological role in drug-drug interactions especially mechanism-based inactivation (MBI), and various diseases remains poorly understood, owing to the lack of molecular tools suitable for selectively monitoring CYP2D6 in complex biological systems. Herein, using a tailored molecular strategy, we developed a fluorescent probe BDPM for CYP2D6. BDPM exhibits excellent specificity and imaging capability for CYP2D6, making it suitable for the real-time monitoring of endogenous CYP2D6 activity in living bio-samples. Therefore, our tailored strategy proved useful for constructing the highly selective and enzyme-activated fluorescent probes. BDPM as a molecular tool to explore the critical roles of CYP2D6 in the pathogenesis of diseases, high-throughput screening of inhibitors and intensive investigation of CYP2D6-induced MBI in natural systems.

Resveratrol Enhances Temozolomide Efficacy in Glioblastoma Cells through Downregulated MGMT and Negative Regulators-Related STAT3 Inactivation.

Chemoresistance blunts the efficacy of temozolomide (TMZ) in the treatment of glioblastoma (GBM). Elevated levels of O6-methylguanine-DNA methyltransferase (MGMT) and activation of signal transducer and of transcription 3 (STAT3) have been reported to correlate with GBM resistance to alkylator chemotherapy. Resveratrol (Res) inhibits tumor growth and improves drug chemosensitivity by targeting STAT3 signaling. Whether the combined therapy of TMZ and Res could enhance chemosensitivity against GBM cells and the underlying molecular mechanism remains to be determined. In this study, Res was found to effectively improve chemosensitivities of different GBM cells to TMZ, which was evaluated by CCK-8, flow cytometry, and cell migration assay. The combined use of Res and TMZ downregulated STAT3 activity and STAT3-regulated gene products, thus inhibited cell proliferation and migration, as well as induced apoptosis, accompanied by increased levels of its negative regulators: PIAS3, SHP1, SHP2, and SOCS3. More importantly, a combination therapy of Res and TMZ reversed TMZ resistance of LN428 cells, which could be related to decreased MGMT and STAT3 levels. Furthermore, the JAK2-specific inhibitor AG490 was used to demonstrate that a reduced MGMT level was mediated by STAT3 inactivation. Taken together, Res inhibited STAT3 signaling through modulation of PIAS3, SHP1, SHP2, and SOCS3, thereby attenuating tumor growth and increasing sensitivity to TMZ. Therefore, Res is an ideal candidate to be used in TMZ combined chemotherapy for GBM.

Jade material in vitro and in vivo: A study on the anti-inflammatory and repair efficacy of jade material on the skin.

OBJECTIVE: The biological safety of natural jade materials and assembled jade-activated materials on cells and their anti-inflammatory and damage repair functions, as well as the repair function on sensitive skin, were studied utilizing in vitro cell biology and in vivo. METHODS: Human skin fibroblasts were used as model cells to conduct cytotoxicity experiments in vitro, and the effects on the expression of inflammatory factors and growth factor-related genes in fibroblasts were explored. The gene expression values of inflammatory factors IL-1, IL-6, TNF-α and cytokines epidermal growth factors, fibroblast growth factors and COL1A1 in fibroblasts were measured by polymerase chain reaction test. Thirty women with sensitive skin were selected to apply a mask containing jade extract three times a week. After two weeks, non-invasive measures related to skin sensitivity were tested. RESULTS: We confirmed the presence of anti-inflammatory effects in both jade materials, with the effects of the assembled activated jade material being superior to that of the natural jade material. Jade extracts significantly increased the gene expressions of EGF, FGF and COL1A1 in HDF. The results of the in vivo study showed that the mask containing jade extract could significantly increase the skin hydration and decrease the rate of transepidermal water loss and skin lactic acid sting test scores after two weeks of use. Subjective evaluations confirmed improvements in skin dryness, smoothness and fineness. No new sensitization occurred in subjects, and the product was non-irritating. No adverse skin reactions were observed during the test. CONCLUSIONS: The jade materials were able to downregulate the expression of inflammatory factor genes, up-regulate the expression of growth factor genes, and improve the anti-inflammation and repair ability of skin. Furthermore, the test results of participants with sensitive skin after using the mask containing jade extract showed that the mask has repairing ability.

OBJECTIF: L'innocuité du jade naturel, et des substances assemblées activées par le jade, sur les cellules, leurs effets anti-inflammatoire et réparateur, ainsi que leur action réparatrice sur les peaux sensibles ont été étudiés au moyen de la biologie cellulaire in vitro et in vivo. MÉTHODES: Des fibroblastes de peau humaine (HDF - Human Dermal Fibrolasts) ont été utilisés comme cellules modèles pour réaliser des tests de cytotoxicité in vitro, et les effets sur l'expression des facteurs inflammatoires et des gènes associés aux facteurs de croissance dans les fibroblastes ont été étudiés. Les valeurs de l'expression génique des facteurs inflammatoires IL-1, IL-6, TNF-α, des facteurs de croissance épidermique des cytokines (EGF - Epidermal Growth Factor), des facteurs de croissance des fibroblastes (FGF - Fibroblast Growth Factor), et du COL1A1 (Gène Collagen, type I, alpha 1) dans les fibroblastes ont été mesurées au moyen d'un test de réaction en chaîne par polymérase. Trente femmes présentant une peau sensible ont été sélectionnées pour appliquer un masque contenant de l'extrait de jade trois fois par semaine. Au bout de deux semaines, des mesures non invasives de la sensibilité de la peau ont été réalisées. RÉSULTATS: Nous confirmons la présence d'effets anti-inflammatoires pour les deux substances, avec de meilleurs résultats pour la substance assemblée activée par le jade comparé à ceux du jade naturel. Les extraits de jade ont significativement augmenté l'expression de l'EGF, du FGF, et du COL1A1 dans les HDF. Les résultats de l'étude in vivo ont révélé que le masque contenant de l'extrait de jade pouvait améliorer significativement l'hydratation de la peau, réduire le pourcentage de perte en eau trans-épidermique et améliorer les résultats du test de piqûre d'acide lactique (LAST - Lactic Acid Sting Test) de la peau après deux semaines d'utilisation. Les évaluations subjectives ont confirmé des améliorations de la sécheresse cutanée, de la douceur et de la finesse du grain de la peau. Aucune nouvelle sensibilisation n'est apparue chez les sujets, et le produit s'est avéré non-irritant. De même, aucune réaction cutanée indésirable n'a été observée pendant le test. CONCLUSIONS: Le jade a été capable de réguler à la baisse l'expression des gènes associés aux facteurs inflammatoires, de réguler à la hausse l'expression des gènes associés aux facteurs de croissance, et d'améliorer les capacités anti-inflammatoire et réparatrice de la peau. De plus, après utilisation du masque contenant de l'extrait de jade, les résultats des tests chez les participantes ayant une peau sensible ont démontré que ce masque avait une capacité réparatrice.

Endothelial Pannexin 1 Channels Control Inflammation by Regulating Intracellular Calcium.

The proinflammatory cytokine IL-1ß is a significant risk factor in cardiovascular disease that can be targeted to reduce major cardiovascular events. IL-1ß expression and release are tightly controlled by changes in intracellular Ca2+ ([Ca2+]i), which has been associated with ATP release and purinergic signaling. Despite this, the mechanisms that regulate these changes have not been identified. The pannexin 1 (Panx1) channels have canonically been implicated in ATP release, especially during inflammation. We examined Panx1 in human umbilical vein endothelial cells following treatment with the proinflammatory cytokine TNF-α. Analysis by whole transcriptome sequencing and immunoblot identified a dramatic increase in Panx1 mRNA and protein expression that is regulated in an NF-κB-dependent manner. Furthermore, genetic inhibition of Panx1 reduced the expression and release of IL-1ß. We initially hypothesized that increased Panx1-mediated ATP release acted in a paracrine fashion to control cytokine expression. However, our data demonstrate that IL-1ß expression was not altered after direct ATP stimulation in human umbilical vein endothelial cells. Because Panx1 forms a large pore channel, we hypothesized it may permit Ca2+ diffusion into the cell to regulate IL-1ß. High-throughput flow cytometric analysis demonstrated that TNF-α treatments lead to elevated [Ca2+]i, corresponding with Panx1 membrane localization. Genetic or pharmacological inhibition of Panx1 reduced TNF-α-associated increases in [Ca2+]i, blocked phosphorylation of the NF-κB-p65 protein, and reduced IL-1ß transcription. Taken together, the data in our study provide the first evidence, to our knowledge, that [Ca2+]i regulation via the Panx1 channel induces a feed-forward effect on NF-κB to regulate IL-1ß synthesis and release in endothelium during inflammation.

Heterocellular Contact Can Dictate Arterial Function.

RATIONALE: Resistance arteries and conduit arteries rely on different relative contributions of endothelial-derived hyperpolarization versus nitric oxide to achieve dilatory heterocellular signaling. Anatomically, resistance arteries use myoendothelial junctions (MEJs), endothelial cell projections that make contact with smooth muscle cells. Conduit arteries have very few to no MEJs. OBJECTIVE: Determine if the presence of MEJs in conduit arteries can alter heterocellular signaling. METHODS AND RESULTS: We previously demonstrated that PAI-1 (plasminogen activator inhibitor-1) can regulate formation of MEJs. Thus, we applied pluronic gel containing PAI-1 directly to conduit arteries (carotid arteries) to determine if this could induce formation of MEJs. We found a significant increase in endothelial cell projections resembling MEJs that correlated with increased biocytin dye transfer from endothelial cells to smooth muscle cells. Next, we used pressure myography to investigate whether these structural changes were accompanied by a functional change in vasodilatory signaling. Interestingly, PAI-1-treated carotids underwent a switch from a conduit to resistance artery vasodilatory profile via diminished nitric oxide signaling and increased endothelial-derived hyperpolarization signaling in response to the endothelium-dependent agonists acetylcholine and NS309. After PAI-1 application, we also found a significant increase in carotid expression of endothelial alpha globin, a protein predominantly expressed in resistance arteries. Carotids from mice with PAI-1, but lacking alpha globin (Hba1-/-), demonstrated that l-nitro-arginine methyl ester, an inhibitor of nitric oxide signaling, was able to prevent arterial relaxation. CONCLUSIONS: The presence or absence of MEJs is an important determinant for influencing heterocellular communication in the arterial wall. In particular, alpha globin expression, induced within newly formed endothelial cell projections, may influence the balance between endothelial-derived hyperpolarization and nitric oxide-mediated vasodilation.

Pannexin 1 channels in renin-expressing cells influence renin secretion and blood pressure homeostasis.

Kidney function and blood pressure homeostasis are regulated by purinergic signaling mechanisms. These autocrine/paracrine signaling pathways are initiated by the release of cellular ATP, which influences kidney hemodynamics and steady-state renin secretion from juxtaglomerular cells. However, the mechanism responsible for ATP release that supports tonic inputs to juxtaglomerular cells and regulates renin secretion remains unclear. Pannexin 1 (Panx1) channels localize to both afferent arterioles and juxtaglomerular cells and provide a transmembrane conduit for ATP release and ion permeability in the kidney and the vasculature. We hypothesized that Panx1 channels in renin-expressing cells regulate renin secretion in vivo. Using a renin cell-specific Panx1 knockout model, we found that male Panx1 deficient mice exhibiting a heightened activation of the renin-angiotensin-aldosterone system have markedly increased plasma renin and aldosterone concentrations, and elevated mean arterial pressure with altered peripheral hemodynamics. Following ovariectomy, female mice mirrored the male phenotype. Furthermore, constitutive Panx1 channel activity was observed in As4.1 renin-secreting cells, whereby Panx1 knockdown reduced extracellular ATP accumulation, lowered basal intracellular calcium concentrations and recapitulated a hyper-secretory renin phenotype. Moreover, in response to stress stimuli that lower blood pressure, Panx1-deficient mice exhibited aberrant "renin recruitment" as evidenced by reactivation of renin expression in pre-glomerular arteriolar smooth muscle cells. Thus, renin-cell Panx1 channels suppress renin secretion and influence adaptive renin responses when blood pressure homeostasis is threatened.

JAK3 inhibitors based on thieno[3,2-d]pyrimidine scaffold: design, synthesis and bioactivity evaluation for the treatment of B-cell lymphoma.

JAK3 is predominantly expressed in hematopoietic cells and has been a promising therapeutic target for the treatment of B-cell lymphoma. In this study, a new class of thieno[3,2-d]pyrimidines harboring acrylamide pharmacophore were synthesized as potent covalent JAK3 inhibitors (IC50 < 10 nM). Among them, 9a and 9 g displayed the strongest inhibitory potency against JAK3 kinase activity, with IC50 values of 1.9 nM and 1.8 nM, respectively. Furthermore, compared with the reference agents, Spebrutinib and Ibrutinib, 9a not only demonstrated enhanced antiproliferative activity against B lymphoma cells, but also showed very weak proliferative inhibition against normal peripheral blood mononuclear cells (PBMCs) at a concentration of 20 µM. Analysis of the mechanism revealed that 9a could induce the obvious apoptosis in B lymphoma cells and prevent JAK3-STAT3 cascade as well as BTK pathway. Taken together, 9a may be served as a potential new JAK3 inhibitor for the treatment of B-cell lymphoma.

Short-term skin reactions following use of N95 respirators and medical masks.

BACKGROUND: In the context of the COVID-19 pandemic, cases of adverse skin reactions related to the wearing of masks have been observed. OBJECTIVES: To analyze the short-term effects of N95 respirators and medical masks, respectively, on skin physiological properties and to report adverse skin reactions caused by the protective equipment. METHODS: This study used a randomized crossover design with repeated measurements. Twenty healthy Chinese volunteers were recruited. Skin parameters were measured on areas covered by the respective masks and on uncovered skin 2 and 4 hours after donning, and 0.5 and 1 hour after removing the masks, including skin hydration, transepidermal water loss (TEWL), erythema, pH, and sebum secretion. Adverse reactions were clinically assessed, and perceived discomfort and non-compliance measured. RESULTS: Skin hydration, TEWL, and pH increased significantly with wearing the protective equipment. Erythema values increased from baseline. Sebum secretion increased both on the covered and uncovered skin with equipment-wearing. There was no significant difference in physiological values between the two types of equipment. More adverse reactions were reported following a N95 mask use than the use of a medical mask, with a higher score of discomfort and non-compliance. CONCLUSIONS: This study demonstrates that skin biophysical characters change as a result of wearing a mask or respirator. N95 respirators were associated with more skin reactions than medical masks.

Postoperative resveratrol administration improves prognosis of rat orthotopic glioblastomas.

BACKGROUND: Although our previous study revealed lumbar punctured resveratrol could remarkably prolong the survival of rats bearing orthotopic glioblastomas, it also suggested the administration did not completely suppress rapid tumour growth. These evidences led us to consider that the prognosis of tumour-bearing rats may be further improved if this treatment is used in combination with neurosurgery. Therefore, we investigated the effectiveness of the combined treatment on rat orthotopic glioblastomas. METHODS: Rat RG2 glioblastoma cells were inoculated into the brains of 36 rats. The rats were subjected to partial tumour removal after they showed symptoms of intracranial hypertension. There were 28 rats that survived the surgery, and these animals were randomly and equally divided into the control group without postoperative treatment and the LP group treated with 100 µl of 300 µM resveratrol via the LP route. Resveratrol was administered 24 h after tumour resection in 3-day intervals, and the animals received 7 treatments. The intracranial tumour sizes, average life span, cell apoptosis and STAT3 signalling were evaluated by multiple experimental approaches in the tumour tissues harvested from both groups. RESULTS: The results showed that 5 of the 14 (35.7%) rats in the LP group remained alive over 60 days without any sign of recurrence. The remaining nine animals had a longer mean postoperative survival time (11.0 ± 2.9 days) than that of the (7.3 + 1.3 days; p < 0.05) control group. The resveratrol-treated tumour tissues showed less Ki67 labelling, widely distributed apoptotic regions, upregulated PIAS3 expression and reduced p-STAT3 nuclear translocation. CONCLUSIONS: This study demonstrates that postoperative resveratrol administration efficiently improves the prognosis of rat advanced orthotopic glioblastoma via inhibition of growth, induction of apoptosis and inactivation of STAT3 signalling. Therefore, this therapeutic approach could be of potential practical value in the management of glioblastomas.

Novel amino acid-substituted diphenylpyrimidine derivatives as potent BTK inhibitors against B cell lymphoma cell lines.

A new family of diphenylpyrimidine derivatives bearing an amino acid substituent were identified as potent BTK inhibitors. Among them, compound 7b, which features an l-proline substituent, was identified as the strongest BTK inhibitor, with an IC50 of 8.7 nM. Compound 7b also displayed similar activity against B-cell lymphoma cell lines as ibrutinib. Moreover, 7b exhibited low cytotoxic activity against normal PBMC cells. In addition, the acridine orange/ethidium bromide (AO/EB) staining assay, Western blot analysis and flow cytometry analysis also showed its effectiveness in interfering with B-cell lymphoma cell growth. The molecular simulation performance showed that 7b forms additional strong hydrogen bonds with the BTK protein. All these findings provided new clues about the pyrimidine scaffold as an effective BTK inhibitor for the treatment of B-cell lymphoma.

The synthesis of 4-arylamido-2-arylaminoprimidines as potent EGFR T790M/L858R inhibitors for NSCLC.

A series of 4-arylamido-2-arylaminoprimidines bearing acrylamide pharmacophore were synthesized as potent EGFRT790M/L858R inhibitors among which 9c (IC50 = 0.5872 nM), 9d (IC50 = 2.213 nM), or 9h (IC50 = 12.57 nM) showed more potent anti-EGFRT790M/L858R activity compared with AZD-9291 (IC50 = 20.80 nM) and possessed high SI displaying 307.6, 56.5, or 12.5 for EGFRT790M/L858R over the wild-type respectively. 9h also showed pretty good activity against H 1975 cells with an IC50 of 1.664 µM and exhibited low toxicity against the normal HBE cells (IC50 > 20 µΜ). 9h had moderate selectivity for H 1975 over A 431 (SI = 7.0) and the other selected cell lines. Morphological staining results further indicated that 9h could promote apoptosis. Hence, 9h was a promising compound for further investigation as a potential EGFRT790M/L858R inhibitor for the treatment of NSCLC.

Efficacy of protein extracts from medium of Adipose-derived stem cells via microneedles on Asian skin.

OBJECTIVES: To explore efficacy of protein extracts from medium of Adipose-derived stem cells (ADSCs) via microneedles on Asian skin in a double-blind, split-face, randomized, control study. METHODS: Thirty volunteers received the treatment, left-side and right-side of their face were randomly assigned to test side and control side. The protein extracts from medium of ADSCs were applied via microneedles into the test side and ultrapure water was applied into the control side. The only person who knew what was being used by each subject on each side of the face was the therapist. Clinical evaluation including instrument test and self-questionnaire was performed by independent observers before and after the treatment, which lasted for 3 months. RESULTS: All subjects completed the study. Compared to ultrapure water, the protein extracts from medium of ADSCs showed a statistically significant improvement for melanin index, skin brightness, gloss, skin roughness, elasticity, and wrinkles (p < 0.05). More than 70% of the participants described that all wrinkles, firmness, elasticity, hydration, whitening, and radiance were strongly improved in the test side. CONCLUSIONS: Protein extracts from medium of ADSCs presented anti-aging and whitening efficacy via microneedles on Asian skin without skin adverse side.

Comparing the Influence of Five Patch Types on the Result of a 12-Day Cumulative Irritancy Patch Test.

A 12-day cumulative irritancy patch test is available for predicting skin irritation potential. This study is important to determine the ideal patch type to be used in the irritancy patch test. This study was conducted to determine the cumulative skin irritation potential of five different patch types using predictive patch test techniques. Five types of patches were tested in a 12 day repeated insult test. The patch types were Hill Top Chamber occlusive, Finn Chamber occlusive, Band-Aid semiocclusive, Webril® semiocclusive, and Webril® occlusive. The test materials applied to the patches were cream, lotion, 2% bath cream, and controls of 1% sodium lauryl sulfate (1% SLS), respectively. A dermatologist performed the grading. The test results revealed that with cream, the cumulative scores of Hill Top Chamber occlusive, Finn Chamber occlusive, Band-Aid semiocclusive, Webril® semiocclusive, and Webril® occlusive were 22, 27, 16, 9, and 21, respectively; with lotion, the cumulative scores were 192, 200, 192, 200, and 70, respectively; with 2% bath cream, the cumulative scores were 523, 306, 523, 306, and 506, respectively; with 1% sodium dodecyl sulfate solution, the cumulative scores were 792, 801, 753, 526, and 841, respectively. Comparison of the five different patch types revealed that Webril® semiocclusive had the lowest cumulative irritation scores and incidence of adverse reactions. Comparison of the three test materials revealed that cream was the mildest material with the lowest cumulative irritation scores.

Design, synthesis and biological evaluation of sulfonamide-substituted diphenylpyrimidine derivatives (Sul-DPPYs) as potent focal adhesion kinase (FAK) inhibitors with antitumor activity.

A class of sulfonamide-substituted diphenylpyrimidines (Sul-DPPYs) were synthesized to improve activity against the focal adhesion kinase (FAK). Most of these new Sul-DPPYs displayed moderate activity against the FAK enzyme with IC50 values of less than 100nM; regardless, they could effectively inhibit several classes of refractory cancer cell lines with IC50 values of less than 10µM, including the pancreatic cancer cell lines (AsPC-1, Panc-1 and BxPC-3), the NSCLC-resistant H1975 cell line, and the B lymphocyte cell line (Ramos cells). Results of flow cytometry indicated that inhibitor 7e promoted apoptosis of pancreatic cancer cells in a dose-dependent manner. In addition, it almost completely induced the apoptosis at a concentration of 10µM. Compound 7e may be selected as a potent FAK inhibitor for the treatment of pancreatic cancer.

PP2A as the Main Node of Therapeutic Strategies and Resistance Reversal in Triple-Negative Breast Cancer.

Triple negative breast cancer (TNBC), is defined as a type of tumor lacking the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). The ER, PR and HER2 are usually the molecular therapeutic targets for breast cancers, but they are ineffective for TNBC because of their negative expressions, so chemotherapy is currently the main treatment strategy in TNBC. However, drug resistance remains a major impediment to TNBC chemotherapeutic treatment. Recently, the protein phosphatase 2A (PP2A) has been found to regulate the phosphorylation of some substrates involved in the relevant target of TNBC, such as cell cycle control, DNA damage responses, epidermal growth factor receptor, immune modulation and cell death resistance, which may be the effective therapeutic strategies or influence drug sensitivity to TNBCs. Furthermore, PP2A has also been found that could induce ER re-expression in ER-negative breast cancer cells, and which suggests PP2A could promote the sensitivity of tamoxifen to TNBCs as a resistance reversal agent. In this review, we will summarize the potential therapeutic value of PP2A as the main node in developing targeting agents, disrupting resistance or restoring drug sensitivity in TNBC.

Resveratrol Increases Anti-Proliferative Activity of Bestatin Through Downregulating P-Glycoprotein Expression Via Inhibiting PI3K/Akt/mTOR Pathway in K562/ADR Cells.

Multidrug resistance (MDR) is a major obstacle in the clinical therapy of hematological malignancies. P-glycoprotein (P-gp) overexpression results in reduction of intracellular drug concentration with a consequence that the cytotoxicity of anti-tumor drugs is decreased, which leads to MDR in K562/ADR cells. In this study, we found that resveratrol enhanced the anti-proliferative activity of bestatin in K562/ADR cells. Co-treatment with resveratrol, IC50 values of bestatin in K562/ADR cells significantly decreased and activation of caspase-3 and caspase-8 increased, which indicated that resveratrol potentiated bestatin-induced apoptosis. Resveratrol increased the intracellular concentration of bestatin through inhibiting P-gp function and downregulating P-gp expression at mRNA and protein levels, which increased anti-proliferative activity of bestatin in K562/ADR cells. Resveratrol decreased the phosphorylation of Akt and mTOR but did not affect the phosphorylations of JNK or ERK1/2. These results demonstrated that resveratrol could increase the anti-proliferative activity of bestatin through downregulating P-gp expression via suppressing the PI3K/Akt/mTOR signaling pathway.

Screening and biological evaluation of a novel STAT3 signaling pathway inhibitor against cancer.

It is now established that the specificity in signaling of signal transducer and activator of transcription 3 (STAT3) is mediated by the SH2 domain of STAT3, which mediates its interaction with the phosphopeptide docking sites displayed by receptors and JAKs, dimerization and subsequent DNA binding. Thus, we aimed to identify and design a class of strong potential small molecular inhibitors of STAT3 for the discovery and development of novel anticancer agents. Several classes of small molecules have been identified as STAT3 inhibitors after structure-based screening of the STAT3 SH2 domain. Next, we detected the activity of these inhibitors using fluorescence polarization (FP) and identified the growth inhibition of DU145 and MDA-MB-468 cells using the CCK-8 assay. Consequently, B9 inhibits the proliferation of tumor cells harboring abnormal activation of STAT3, such as, MDA-MB-468, MDA-MB-231 and DU145. However, there is little inhibition of MCF-7 cells. In addition, The Kd of B9 to STAT3 (I634S/Q635G) is 22.75µM compared to 4.59µM for WT as analyzed by SPR. The phosphorylation of STAT3 in MDA-MB-468 cells was obviously decreased after treatment with B9 at the preconceived concentration of 30µM, as detected using immunoblotting. Here, we evaluated the effect of B9 on the migration of MDA-MB-468 cells. Taken together, our results indicate a novel small molecule that decreases STAT3 activation and function of the STAT3 signaling pathway, thereby inducing an antitumor response in human breast cancer cells harboring constitutively active STAT3.

Endothelial nitric oxide synthase in the microcirculation.

Endothelial nitric oxide synthase (eNOS, NOS3) is responsible for producing nitric oxide (NO)--a key molecule that can directly (or indirectly) act as a vasodilator and anti-inflammatory mediator. In this review, we examine the structural effects of regulation of the eNOS enzyme, including post-translational modifications and subcellular localization. After production, NO diffuses to surrounding cells with a variety of effects. We focus on the physiological role of NO and NO-derived molecules, including microvascular effects on vessel tone and immune response. Regulation of eNOS and NO action is complicated; we address endogenous and exogenous mechanisms of NO regulation with a discussion of pharmacological agents used in clinical and laboratory settings and a proposed role for eNOS in circulating red blood cells.

Discovery of novel nonpeptide allosteric inhibitors interrupting the interaction of CDK2/cyclin A3 by virtual screening and bioassays.

Serine/threonine-specific cyclin-dependent kinases (CDKs) are key regulatory elements in eukaryotic cell cycle progression, and the dysregulation of CDKs has been implicated in cancers. Therefore, CDKs have been identified as anti-cancer targets for the development of small-molecule drugs. In this Letter, virtual screening and biological evaluation were performed to identify novel lead structures that allosterically disrupt the interaction between CDK2 and cyclin A3, which are directed toward a noncatalytic binding pocket of CDK2. Ultimately, B2 was identified as exhibiting superior CDK2/cyclin A3 inhibition activity. In addition, our results indicated that B2 exhibited antiproliferative activities against a broad spectrum of human cancer cell lines. Significantly, B2 certainly interrupted the interaction between CDK2 and cyclin A3 and exhibited a concentration-dependent trend. In summary, our results suggest that B2 is the first effective allosteric chemical small-molecule CDK2 inhibitor to be discovered, and further lead optimization may result in a series of novel anti-CDK2 agents.

miR-92a family and their target genes in tumorigenesis and metastasis.

The miR-92a family, including miR-25, miR-92a-1, miR-92a-2 and miR-363, arises from three different paralog clusters miR-17-92, miR-106a-363, and miR-106b-25 that are highly conservative in the process of evolution, and it was thought as a group of microRNAs (miRNAs) correlated with endothelial cells. Aberrant expression of miR-92a family was detected in multiple cancers, and the disturbance of miR-92a family was related with tumorigenesis and tumor development. In this review, the progress on the relationship between miR-92a family and their target genes and malignant tumors will be summarized.