Histone deacetylase-based dual targeted inhibition in multiple myeloma.

Despite enormous advances in terms of therapeutic strategies, multiple myeloma (MM) still remains an incurable disease with MM patients often becoming resistant to standard treatments. To date, multiple combined and targeted therapies have proven to be more beneficial compared to monotherapy approaches, leading to a decrease in drug resistance and an improvement in median overall survival in patients. Moreover, recent breakthroughs highlighted the relevant role of histone deacetylases (HDACs) in cancer treatment, including MM. Thus, the simultaneous use of HDAC inhibitors with other conventional regimens, such as proteasome inhibitors, is of interest in the field. In this review, we provide a general overview of HDAC-based combination treatments in MM, through a critical presentation of publications from the past few decades related to in vitro and in vivo studies, as well as clinical trials. Furthermore, we discuss the recent introduction of dual-inhibitor entities that could have the same beneficial effects as drug combinations with the advantage of having two or more pharmacophores in one molecular structure. These findings could represent a starting-point for both reducing therapeutic doses and lowering the risk of developing drug resistance.

Resveratrol as a circadian clock modulator: mechanisms of action and therapeutic applications.

In the past decades, resveratrol has gained increasing attention due to its versatile and beneficial properties. This natural polyphenol, commonly present in the human diet, has been shown to induce SIRT1 and to modulate the circadian rhythm at the cellular and organismal levels. The circadian clock is a system regulating behavior and function of the human body, thus playing a crucial role in health maintenance. It is primarily entrained by light-dark cycles; however, other factors such as feeding-fasting, oxygen and temperature cycles play a significant role in its regulation. Chronic circadian misalignment can lead to numerous pathologies, including metabolic disorders, age-related diseases or cancer. Therefore, the use of resveratrol may be a valuable preventive and/or therapeutic strategy for these pathologies. This review summarizes studies that evaluated the modulatory effect of resveratrol on circadian oscillators by focusing on the potential and limitations of resveratrol in biological clock-related disorders.

Antiproliferative activity of compounds isolated from the root bark of Lannea acida in multiple myeloma cell lines.

Lannea acida A. Rich. is a native plant of West Africa used in traditional medicine against diarrhea, dysentery, rheumatism, and women infertility. Eleven compounds were isolated from the dichloromethane root bark extract using various chromatographic techniques. Among those, nine compounds have not been previously reported, i.e. one cardanol derivative, two alkenyl 5-hydroxycyclohex-2-en-1-ones, three alkenyl cyclohex-4-ene-1,3-diols, two alkenyl 7-oxabicyclo[4.1.0]hept-4-en-3-ols, and one alkenyl 4,5-dihydroxycyclohex-2-en-1-one, together with two known cardanols. The structure of the compounds was elucidated using NMR, HRESIMS, ECD, IR, and UV. Their antiproliferative activity was evaluated in three multiple myeloma cell lines: RPMI 8226, MM.1S, and MM.1R. Two compounds showed activity in all cell lines with IC50 values < 5 µM. Further investigations are needed to understand the mechanism of action.

Entinostat-Bortezomib Hybrids against Multiple Myeloma.

Although proteasome inhibitors have emerged as the therapeutic backbone of multiple myeloma treatment, patients often relapse and become drug refractory. The combination between proteasome and histone deacetylase inhibitors has shown to be more efficient compared to monotherapy by enhancing the anti-myeloma activity and improving the patient's lifetime expectancy. Hybrid molecules, combining two drugs/pharmacophores in a single molecular entity, offer improved effectiveness by modulating more than one target and circumventing differences in the pharmacokinetic and pharmacodynamic profiles, which are the main disadvantages of combination therapy. Therefore, eleven histone deacetylase-proteasome inhibitor hybrids were synthesized, combining pharmacophores of entinostat and bortezomib. Compound 3 displayed the strongest antiproliferative activity with an IC50 value of 9.5 nM in the multiple myeloma cells RPMI 8226, 157.7 nM in the same cell line resistant to bortezomib, and 13.1 nM in a 3D spheroid model containing multiple myeloma and mesenchymal stem cells. Moreover, the compound inhibited 33% of histone deacetylase activity when RPMI 8226 cells were treated for 8 h at 10 µM. It also inhibited the proteasome activity with an IC50 value of 23.6 nM.

MALT-1 shortens lifespan by inhibiting autophagy in the intestine of C. elegans.

The caspase-like protease MALT1 promotes immune responses and oncogenesis in mammals by activating the transcription factor NF-κB. MALT1 is remarkably conserved from mammals to simple metazoans devoid of NF-κB homologs, like the nematode C. elegans. To discover more ancient, NF-κB -independent MALT1 functions, we analysed the phenotype of C. elegans upon silencing of MALT-1 expression systemically or in a tissue-specific manner. MALT-1 silencing in the intestine caused a significant increase in life span, whereas intestinal overexpression of MALT-1 shortened life expectancy. Interestingly, MALT-1-deficient animals showed higher constitutive levels of autophagy in the intestine, which were particularly evident in aged or starved nematodes. Silencing of the autophagy regulators ATG-13, BEC-1 or LGG-2, but not the TOR homolog LET-363, reversed lifespan extension caused by MALT-1 deficiency. These findings suggest that MALT-1 limits the lifespan of C. elegans by acting as an inhibitor of an early step of autophagy in the intestine.

Isolation and Structure Elucidation of Compounds from Sesamum alatum and Their Antiproliferative Activity against Multiple Myeloma Cells.

The phytochemical investigation of the dichloromethane root extract of Sesamum alatum led to the isolation of 18 compounds. Among these, compounds 3-8, defined as 9-hydroxy-2,2-dimethyl-2H-benzo[g]chromene-5,10-dione 6-O-ß-d-glucopyranoside (3), (2S,3R)-3,4,7-trihydroxy-2-(3'-methylbut-2'-en-1'-yl)-2,3-dihydro-1H-inden-1-one (4), (Z)-2-(1',4'-dihydroxy-4'-methylpent-2'-en-1'-ylidene)-4,7-dihydroxy-1H-indene-1,3(2H)-dione (5), (S)-2,5,8-trihydroxy-3-(2'-hydroxy-3'-methylbut-3'-en-1'-yl)naphthalene-1,4-dione (6), 6-hydroxy-3-(3'-methylbut-2'-en-1'-yl)-4-oxo-4H-chromene-5-carboxylic acid (7), and (S)-2-(1'-hydroxy-4'-methylpent-3'-en-1'-yl)anthracene-9,10-dione (8), respectively, have not yet been described. Their structures were elucidated based on spectroscopic data analysis, including IR, NMR, HRESIMS and ECD measurements. Additional known compounds, namely, hydroxysesamone (1), anthrasesamone A (2), 2,6-dimethoxy-1,4-benzoquinone (9), syringic acid (10), syringaresinol (11), 2,3-epoxysesamone 8-O-ß-d-glucopyranoside (12), 2,3-diacetylmartinoside (13), 2,3-epoxy-4,5,8-trihydroxy-2-prenyl-1-tetralone (14), ursolic acid (15), chlorosesamone (16), 2,3-epoxysesamone (17), and 2-(4-methyl-3-pentenyl)anthraquinone (18) were isolated. The antiproliferative activity of the compounds was tested against the RPMI 8226 multiple myeloma cell line. When compounds presented an IC50 value <10 µM, they were tested against two other multiple myeloma cell lines, MM.1S and MM.1R. Compound 17 was found to be the most potent, with IC50 values of 0.6, 0.7, and 0.9 µM, respectively, for the three cell lines.

The Multiple Myeloma Landscape: Epigenetics and Non-Coding RNAs.

Despite advances in available treatments, multiple myeloma (MM) remains an incurable disease and represents a challenge in oncohematology. New insights into epigenetic factors contributing to MM development and progression have improved the knowledge surrounding its molecular basis. Beyond classical epigenetic factors, including methylation and acetylation, recent genome analyses have unveiled the importance of non-coding RNAs in MM pathogenesis. Non-coding RNAs have become of interest, as their dysregulation opens the door to new therapeutic approaches. The discovery, in the past years, of molecular techniques, such as CRISPR-Cas, has led to innovative therapies with potential benefits to achieve a better outcome for MM patients. This review summarizes the current knowledge on epigenetics and non-coding RNAs in MM pathogenesis.

Phytochemical Investigation of the Roots of Ipomoea asarifolia and Antiproliferative Activity of the Isolated Compounds against Multiple Myeloma Cells.

Ipomoea asarifolia is a herbaceous plant belonging to the family Convolvulaceae and is native to tropical regions of Africa, America, and Asia. A dichloromethane root extract showed antiproliferative activity against multiple myeloma cells (RPMI 8226). The phytochemical investigation led to the isolation of 15 compounds. Compounds 1-4, named (4S,8S)-1-(furan-3-yl)-9-hydroxy-4,8-dimethylnonane-1,6-dione, isoferulic acid hexadecyl ester, caffeic acid hexadecyl ester, and asarifolin I, respectively, are described for the first time. The structures of these molecules were established from their NMR, UV, IR spectroscopic, and MS data. 4-Hydroxycinnamic acid hexadecyl ester (5), 4-hydroxycinnamic acid octadecyl ester (6), 4-hydroxycinnamic acid eicosyl ester (7), caffeic acid octadecyl ester (8), pescapreins III, IV, XXI, XXIII, XXV, and XXVI (9-14), and stoloniferin III (15) were also isolated. All compounds were tested against a multiple myeloma cell line (RPMI 8226). When their IC50 value was lower than 10 µM, the compounds were also tested against two other multiple myeloma cell lines, MM.1S and MM.1R. Compound 3 was the most potent, with an IC50 value of 3.0 µM against RPMI 8226 cells.

Structure-Activity Relationships of Withanolides as Antiproliferative Agents for Multiple Myeloma: Comparison of Activity in 2D Models and a 3D Coculture Model.

Multiple myeloma (MM) is a hematological cancer in which relapse and resistance are highly frequent. Therefore, alternatives to conventional treatments are necessary. Withaferin A, a withanolide isolated from Withania somnifera, has previously shown promising activity against various MM models. In the present study, structure-activity relationships (SARs) were evaluated using 56 withanolides. The antiproliferative activity was assessed in three MM cell lines and in a 3D MM coculture model to understand the in vitro activity of compounds in models of various complexity. While the results obtained in 2D allowed a quick and simple evaluation of cytotoxicity used for a first selection, the use of the 3D MM coculture model allowed filtering compounds that perform better in a more complex setup. This study shows the importance of the last model as a bridge between 2D and in vivo studies to select the most active compounds and ultimately lead to a reduction of animal use for more sustained in vivo studies. NF-κB inhibition was determined to evaluate if this could be one of the targeted pathways. The most active compounds, withanolide D (2) and 38, should be further evaluated in vivo.

Angiogenesis Analyzer for ImageJ - A comparative morphometric analysis of "Endothelial Tube Formation Assay" and "Fibrin Bead Assay".

Angiogenesis assays based on in vitro capillary-like growth of endothelial cells (EC) are widely used, either to evaluate the effect of anti- and pro-angiogenesis drugs of interest, or to test and compare the functional capacities of various types of EC and progenitor cells. Among the different methods applied to study angiogenesis, the most commonly used is the "Endothelial Tube Formation Assay" (ETFA). In suitable culture conditions, EC form two-dimensional (2D) branched structures that can lead to a meshed pseudo-capillary network. An alternative approach to ETFA is the "Fibrin Bead Assay" (FBA), based on the use of Cytodex 3 microspheres, which promote the growth of 3D capillary-like patterns from coated EC, suitable for high throughput in vitro angiogenesis studies. The analytical evaluation of these two widely used assays still remains challenging in terms of observation method and image analysis. We previously developed the "Angiogenesis Analyzer" for ImageJ (AA), a tool allowing analysis of ETFA-derived images, according to characteristics of the pseudo-capillary networks. In this work, we developed and implemented a new algorithm for AA able to recognize microspheres and to analyze the attached capillary-like structures from the FBA model. Such a method is presented for the first time in fully automated mode and using non-destructive image acquisition. We detailed these two algorithms and used the new AA version to compare both methods (i.e. ETFA and FBA) in their efficiency, accuracy and statistical relevance to model angiogenesis patterns of Human Umbilical Vein EC (HUVEC). Although the two methods do not assess the same biological step, our data suggest that they display specific and complementary information on the angiogenesis processes analysis.

Anti-inflammatory and Quinone Reductase-Inducing Compounds from Beilschmiedia mannii.

Previous studies on the therapeutic potential of plant species found in the diet of chimpanzees living in Taï National Park have shown that they could be potential candidates for the search of new molecules useful for humans. Based on the screening of some of these plants, the fruits of Beilschmiedia mannii, whose dichloromethane extract showed cancer chemopreventive properties, were selected. Bioactivity-guided fractionation of the extract resulted in the isolation and identification of two γ-pyrones, including desmethoxydihydromethysticin (1: ), found in a natural source for the first time, and a new congener, beilschmiediapyrone (2: ), as well as five known alkamides (3:  - 7: ). Their structures were established by using nuclear magnetic resonance spectroscopy and mass spectrometry methods. The isolated compounds were evaluated for their cancer chemopreventive potential by using quinone reductase induction and nuclear factor-kappa B inhibition tests in Hepa 1c1c7 and HEK-293/NF-κB-Luc cells, respectively. Among them, compounds 1: and 2: were the most active. The concentrations to double the quinone reductase activity were 7.5 µM for compound 1: and 6.1 µM for compound 2: . Compounds 1: and 2: inhibited nuclear factor-kappa B with IC50 values of 2.1 and 3.4 µM, respectively. These results are promising with regard to cancer chemoprevention, especially because this plant is also used for cooking by the local population around the Taï forest.

Withanolide D Enhances Radiosensitivity of Human Cancer Cells by Inhibiting DNA Damage Non-homologous End Joining Repair Pathway.

Along with surgery and chemotherapy, radiation therapy (RT) is an important modality in cancer treatment, and the development of radiosensitizers is a current key challenge in radiobiology to maximize RT efficiency. In this study, the radiosensitizing effect of a natural compound from the withanolide family, withanolide D (WD), was assessed. Clonogenic assays showed that a 1 h WD pretreatment (0.7 µM) before irradiation decreased the surviving fraction of several cancer cell lines. To determine the mechanisms by which WD achieved its radiosensitizing effect, we then assessed whether WD could promote radiation-induced DNA damages and inhibit double-strand breaks (DSBs) repair in SKOV3 cells. Comet and γH2AX/53BP1 foci formation assays confirmed that DSBs were higher between 1 and 24 h after 2 Gy-irradiation in WD-treated cells compared to vehicle-treated cells, suggesting that WD induced the persistence of radiation-induced DNA damages. Immunoblotting was then performed to investigate protein expression involved in DNA repair pathways. Interestingly, DNA-PKc, ATM, and their phosphorylated forms appeared to be inhibited 24 h post-irradiation in WD-treated samples. XRCC4 expression was also down-regulated while RAD51 expression did not change compared to vehicle-treated cells suggesting that only non-homologous end joining (NHEJ) pathways was inhibited by WD. Mitotic catastrophe (MC) was then investigated in SKOV3, a p53-deficient cell line, to assess the consequence of such inhibition. MC was induced after irradiation and was predominant in WD-treated samples as shown by the few numbers of cells pursuing into anaphase and the increased amount of bipolar metaphasic cells. Together, these data demonstrated that WD could be a promising radiosensitizer candidate for RT by inhibiting NHEJ pathway and promoting MC. Additional studies are required to better understand its efficiency and mechanism of action in more relevant clinical models.

Bioactive metabolites from the leaves of Withania adpressa.

CONTEXT: Withania (Solanaceae) species are known to be a rich source of withanolides, which have shown several biological properties. OBJECTIVE: To identify the compounds responsible for Withania adpressa Coss. antioxidant activity and further test them for their NF-κB inhibition and antiproliferative activity in multiple myeloma cells. MATERIALS AND METHODS: Compounds were obtained from the EtOAc extract of W. adpressa leaves. Structure elucidation was carried out mainly by 1D- and 2D-NMR, and mass spectrometry. Isolated compounds were tested in a dose-response for their in vitro NF-κB inhibition and antiproliferative activity in multiple myeloma cells after 5 and 72 h treatment, respectively. RESULTS: The fractionation resulted in the isolation of a new glycowithanolide named wadpressine (5) together with withanolide F, withaferin A, coagulin L, and nicotiflorin. The latter showed a moderate ability to scavenge free radicals in DPPH (IC50 = 35.3 µM) and NO (IC50 = 41.3 µM) assays. Withanolide F and withaferin A exhibited low µM antiproliferative activity against both multiple myeloma cancer stem cells and RPMI 8226 cells. Furthermore, they inhibited NF-κB activity with IC50 values of 1.2 and 0.047 µM, respectively. The other compounds showed a moderate inhibition of cell proliferation in RPMI 8226 cells, but were inactive against cancer stem cells and did not inhibit NF-κB activity. DISCUSSION AND CONCLUSIONS: One new glycowithanolide and four known compounds were isolated. Biological evaluation data gave further insight on the antitumor potential of withanolides for refractory cancers.

Intranasal administration of resveratrol successfully prevents lung cancer in A/J mice.

Lung cancer is the most lethal cancer in the world. About 80% of lung cancer deaths are linked to tobacco use. As a complement to tobacco control, efficient chemoprevention strategies are needed to tackle lung cancer epidemic. Resveratrol is one of the most studied natural products, notably for its cancer chemoprevention properties. However, its low oral bioavailability has often limited the translation of in vitro activities to in vivo effects. While oral administration of resveratrol effectively inhibited colorectal carcinogenesis, it failed to protect mice from chemically-induced lung carcinogenesis. Therefore, non-invasive parenteral routes must be considered to bring resveratrol to the lungs. In the present study, intranasal administration of a concentrated formulation proved to be a valid method to expose the lungs to a sufficient amount of resveratrol. This formulation was administered three times a week for 25 weeks to A/J mice having 4-[methyl(nitroso)amino]-1-(3-pyridinyl)-1-butanone-induced lung carcinogenesis. Resveratrol-treated mice showed a 27% decrease in tumour multiplicity, with smaller tumours, resulting in 45% decrease in tumour volume/mouse. In vitro investigations highlighted apoptosis as a potential mechanism of action. This study presents an effective way to overcome resveratrol low oral bioavailability, encouraging a reevaluation of its use in future clinical trials.

NF-κB and Angiogenesis Inhibitors from the Aerial Parts of Chresta martii.

The ethyl acetate extract of the aerial parts of Chresta martii showed significant in vitro NF-κB inhibition. Bioactivity-guided isolation was undertaken using HPLC microfractionation to localize the active compounds. Different zones of the HPLC chromatogram were linked to NF-κB inhibition. In parallel to this HPLC-based activity profiling, HPLC-PDA-ESI-MS and UHPLC-TOF-HRMS were used for the early identification of some of the compounds present in the extract and to get a complete phytochemical overview. The isolation of the compounds was performed by high-speed counter-current chromatography and further semipreparative HPLC. Using this approach, 14 compounds were isolated, two of them being new sesquiterpene lactones. The structures of the isolated compounds were elucidated by spectroscopic methods including UV, ECD, NMR, and HRMS. All isolated compounds were evaluated for their inhibitory activity of NF-κB and angiogenesis, and compound 2 showed promising NF-κB inhibition activity with an IC50 of 0.7 µM. The isolated compounds 1, 2, 5, 7, and 8 caused a significant reduction in angiogenesis when evaluated by an original 3D in vitro angiogenesis assay.

Anti-inflammatory and antiproliferative diterpenoids from Plectranthus scutellarioides.

Chemical investigation of the dichloromethane extract of the aerial parts of Plectranthus scutellarioides led to the isolation and characterization of 10 diterpenoids with an abietane skeleton and one cembrane-type diterpenoid. Among them, six have not yet been described in the literature. Their structures were established by 1D and 2D NMR, UV and IR spectroscopy, and HRESIMS. The relative configuration was determined by Gauge-Independent Atomic Orbital NMR chemical shift calculations supported by the advanced statistical method DP4 plus and further confirmed by electronic circular dichroism. The isolated constituents were evaluated for their in vitro NF-κB inhibitory activity, as well as for their cytotoxic effects in human multiple myeloma cancer stem cells and RPMI 8226 tumor cell line. Coleon O, coleon G, lanugone K and 6-acetylfredericone B showed the highest inhibitory effect against NF-κB, displaying IC50 of 11.2, 11.0, 4.5 and 9.7 µM, respectively. Coleon O exhibited also a significant activity towards human multiple myeloma cancer stem cells and RPMI 8226 cells with IC50 of 9.2 and 8.4 µM, respectively.

HDAC inhibitors: a 2013-2017 patent survey.

INTRODUCTION: Zinc-dependent histone deacetylases (HDAC) inhibitors represent an important class of biologically active compounds with four of them approved by the FDA. A wide range of molecules has been reported for applications in several human diseases. AREAS COVERED: This review covers recent efforts in the synthesis and applications of HDAC inhibitors from 2013-2017. EXPERT OPINION: HDAC inhibitors represent an important class of biologically active compounds for single or combination therapies. The current synthetic methodologies are oriented towards selective HDAC isoforms to achieve better therapeutic effects. Among the recent patents available, most of them focus on HDAC6 selective inhibitors. Beside this search for isoform selectivity, the quest for zinc binding groups with better pharmacokinetic properties and high potency against HDACs only motivates medicinal chemists, as well as the design of inhibitors targeting HDACs and at the same time another biological target. If the major applications are for anticancer activity, one can note the emerging applications in neurological or metabolic disorders or for the stimulation of the immune system.

Carbazole-, Aspidofractinine-, and Aspidocarpamine-Type Alkaloids from Pleiocarpa pycnantha.

Three new alkaloids, janetinine (1a), pleiokomenine A (2), and huncaniterine B (3a), and 13 known compounds, pleiomutinine (3b), huncaniterine A (3c), 1-carbomethoxy-ß-carboline (4), evoxanthine (5), deformyltalbotine acid lactone (6), pleiocarpamine (7), N4-methyl-10-hydroxygeissoschizol (8), spegatrine (9), neosarpagine (10), aspidofractinine (11), N1-methylkopsinin (12), pleiocarpine (13), and N1-methylkopsinin- N4-oxide (14), were isolated from the stem bark of Pleiocarpa pycnantha. Janetinine (1a) is a carbazole alkaloid; in pleiokomenine A (2), two aspidofractinine-type alkaloids are bridged by a methylene unit in an unprecedented way, and huncaniterine B (3a) is a pleiocarpamine-aspidofractinine-type dimer. The structures and relative configurations of these compounds were elucidated on the basis of NMR and MS analyses. Their absolute configurations were defined by means of experimental and calculated ECD data, and additionally, the structures of 5 and 13 were determined by single crystal X-ray diffraction. Compounds 1a, 2, 3b, 4, 6, 9, and 12 displayed cancer chemopreventive properties through either quinone reductase induction ( CD = 30.7, 30.2, 29.9, 43.5, and 36.7 µM for 1a, 4, 6, 9, and 12, respectively) and/or NF-κB inhibition with IC50 values of 13.1, 8.4, 9.4, and 8.8 µM for 2, 3b, 6, and 12, respectively.

Lung Cancer Chemopreventive Activity of Patulin Isolated from Penicillium vulpinum.

Lung cancer is the most lethal form of cancer in the world. Its development often involves an overactivation of the nuclear factor kappa B (NF-κB) pathway, leading to increased cell proliferation, survival, mobility, and a decrease in apoptosis. Therefore, NF-κB inhibitors are actively sought after for both cancer chemoprevention and therapy, and fungi represent an interesting unexplored reservoir for such molecules. The aim of the present work was to find naturally occurring lung cancer chemopreventive compounds by investigating the metabolites of Penicillium vulpinum, a fungus that grows naturally on dung. Penicillium vulpinum was cultivated in Potato Dextrose Broth and extracted with ethyl acetate. Bioassay-guided fractionation of this extract was performed by measuring NF-κB activity using a HEK293 cell line transfected with an NF-κB-driven luciferase reporter gene. The mycotoxin patulin was identified as a nanomolar inhibitor of TNF-α-induced NF-κB activity. Immunocytochemistry and Western blot analyses revealed that its mechanism of action involved an inhibition of p65 nuclear translocation and was independent from the NF-κB inhibitor α (IκBα) degradation process. Enhancing its interest in lung cancer chemoprevention, patulin also exhibited antiproliferative, proapoptotic, and antimigration effects on human lung adenocarcinoma cells through inhibition of the Wnt pathway.

A Bivalent Role of Genistein in Sprouting Angiogenesis.

The effects of genistein on angiogenesis remain poorly understood. Some studies claim an antiangiogenic effect and others claim a pro-angiogenic one. Thus, the aim of this study was to determine if genistein may exhibit bivalent angiogenic effects. To address this question, genistein angiogenic modulatory effects were examined using an in vitro 3D angiogenesis model using human umbilical vein endothelial cells. In this model, a bivalent effect of genistein was demonstrated on sprouting angiogenesis, with angiogenic stimulation at low concentrations (0.001 - 1 µM) and inhibition at higher ones (25 - 100 µM). Enhancement of the endothelial tube formation correlated with an increase in human umbilical vein endothelial cell metabolic activity and proliferation. Inhibition of angiogenesis correlated with a decreased metabolic activity, proliferation, and migration. Moreover, high concentrations of genistein influenced human umbilical vein endothelial cell morphology. Expression of genes involved in the angiogenic process in response to genistein was measured to study the mechanism of action. Secretome profiling revealed that angiogenic regulators were modulated with genistein treatment. These results suggested a bivalent effect of genistein on human umbilical vein endothelial cell growth and angiogenesis, and further investigations on the benefit of genistein for cancer chemoprevention, cancer treatment, or pro-angiogenic therapies have to be carefully considered.