Synthetic Genistein Research Articles

BIO 300: A Prophylactic Radiation Countermeasure for Acute Radiation Syndrome.

Exposure to high doses of ionizing radiation can result in hematopoietic acute radiation syndrome. Currently, there is no radiation medical countermeasure approved by the U.S. FDA which can be used before radiation exposure to protect exposed individuals. Here we aimed to evaluate the therapeutic potential of an aqueous suspension of synthetic genistein nanoparticles (BIO 300) as a radioprotectant in a pilot efficacy study using a nonhuman primate model of total body irradiation. Eight rhesus macaques were divided into two groups; four received vehicle and four received BIO 300 Injectable Suspension 24 h before 5.8 Gy total-body irradiation. Survival, blood cell counts, blood chemistry, and clinical parameters were monitored over the 60 days of the study. Tissues were collected at necropsy 60 days post-irradiation or from animals that met unscheduled euthanasia criteria and subjected to histopathological analysis. Tissues analyzed included the duodenum, jejunum, ileum, sternum, lung, heart, liver, kidney, spleen, gut-associated lymphoid tissue, and urinary bladder. In this pilot study, all BIO 300 Injectable Suspension treated animals survived to day 60, while only 50% of the vehicle-treated animals survived. We found that BIO 300 Injectable Suspension did not mediate an improvement in blood cell counts (e.g., neutrophils, platelets, white blood cells). However, BIO 300 Injectable Suspension treated animals had a lower incidence of fever and febrile neutropenia, were able to better maintain their body weight post radiation exposure, and exhibited less anemia and faster recovery from anemia. Histopathological analysis revealed that BIO 300-treated animals had less irradiation-induced damage to the sternum and other tissues compared to vehicle controls. BIO 300's mechanism of action is complex and protection against irradiation is attainable without much improvement in the complete blood count (CBC) profile. BIO 300's mechanism for radioprotection involves multiple biological pathways and systems.

Multicenter Phase 1b/2a Clinical Trial of Radioprotectant BIO 300 Oral Suspension for Patients With Non-Small Cell Lung Cancer Receiving Concurrent Chemoradiotherapy

Radiation therapy is part of the standard treatment regimen for non-small cell lung cancer (NSCLC). Although radiation therapy is an effective tool to manage NSCLC, it can be associated with significant dose-limiting toxicities. These toxicities can lead to treatment interruption or early termination and worsening clinical outcomes in addition to reductions in patient quality of life. Based on preclinical efficacy for radioprotection of normal tissues, we evaluated the clinical utility of BIO 300 Oral Suspension (BIO 300; synthetic genistein nanosuspension) in patients with NSCLC. In this multicenter, open-label, single-arm, ascending dose phase 1b/2a study, patients were enrolled with newly diagnosed stage II-IV NSCLC planned for 60 to 70/1.8-2.0 Gy radiation therapy and concurrent weekly paclitaxel/carboplatin. Oral BIO 300 (cohort 1, 500 mg/d; cohort 2, 1000 mg/d; cohort 3, 1500 mg/d) was self-administered once daily starting 2 to 7 days before initiating concurrent chemoradiotherapy and continued until the end of radiation therapy. The primary endpoint was acute dose-limiting toxicities attributable to BIO 300. Secondary outcomes included pharmacokinetics, pharmacodynamics, overall toxicity profile, quality of life, local response rate, and survival. Twenty-one participants were enrolled. No dose-limiting toxicities were reported. BIO 300 dosing did not alter chemotherapy pharmacokinetics. Adverse events were not dose-dependent, and those attributable to BIO 300 (n=11) were all mild to moderate in severity (grade 1, n=9; grade 2, n=2) and predominantly gastrointestinal (n=7). A dose-dependent decrease in serum transforming growth factor β1 levels was observed across cohorts. Based on safety analysis, the maximum tolerated dose of BIO 300 was not met. Patient-reported quality of life and weight were largely stable throughout the study period. No patient had progression as their best overall response, and a 65% tumor response rate was achieved (20% complete response rate). The low toxicity rates, along with the pharmacodynamic results and tumor response rates, support further investigation of BIO 300 as an effective radioprotector.

ADMET Investigations On A Synthetic Derivative Of Genistein, And Molecular Docking Experiments Targeting Estrogen Receptor-α (ER-α) In The Pancreas

The main goal of the current research was to perform ADMET and molecular docking studies for a synthetic genistein derivative that can imitate Estrogen and function as an endocrine disruptor, activating the ER receptor on beta-cells in the pancreas to release insulin. The created molecule was molecularly docked using the online molecular docking research tool Dockthor. NGL viewer, an online program for viewing Dockthor data, displayed the docking experiment results. The 2D legend-protein interactions were estimated with BIOVIA Discovery Studio Visualizer. Estrogen-Receptor Alpha was the targeted target, while Compound-A was employed as the legend. In this study, we created a synthetic derivative of genistein, an analogue of Estrogen in terms of ER-α receptor binding. We used molecular docking to evaluate the affinity of compound-A binding to the ER-α and its 2D interactions and Ramachandran plots. We then ran ADMET experiments on the molecule, which revealed a substantial relationship with the molecule's Estrogen Receptor binding capabilities, as well as scores for absorption, distribution, metabolism, excretion, and toxicity.

The Radioprotectant, BIO 300, Protects the Lungs from Total-Body Irradiation Injury in C57L/J Mice.

Acute exposure to high dose radiation can cause acute radiation syndrome (ARS), a potentially life-threatening illness. Individuals that survive ARS are at risk of developing the delayed effects of acute radiation exposure, with the lungs being particularly susceptible (DEARE-lung). For individuals at risk of radiation exposure, there are no Food and Drug Administration-approved medical countermeasures (MCMs) for prophylactic or post-exposure use that can prevent or mitigate DEARE-lung. BIO 300 is a novel formulation of synthetic genistein that has been extensively studied as a prophylactic MCM for the hematopoietic subsyndrome of ARS (H-ARS). Here, we used a C57L/J mouse model of total-body irradiation (TBI) to investigate whether prophylactic administration of BIO 300 is able to prevent animals from developing DEARE-lung. Oral and parenteral formulations of BIO 300 administered prior to TBI were compared against standard of care, PEGfilgrastim, administered shortly after radiation exposure, and the combination of oral BIO 300 administered prior to TBI and with PEGfilgrastim administered post-exposure. All animals were exposed to 7.75 Gy cobalt-60 gamma-radiation and the primary endpoint was lung histopathology at 180 days post-TBI. Animals treated with BIO 300 had a significant reduction in the incidence of interstitial lung inflammation compared to vehicle groups for both the oral (0% vs. 47%) and parenteral (13% vs. 44%) routes of administration. Similar results were obtained for the incidence and severity of pulmonary fibrosis in animals treated with oral BIO 300 (incidence, 47% vs. 100% and mean severity score, 0.53 vs. 1.3) and parenteral BIO 300 (incidence, 63% vs. 100% and mean severity score, 0.69 vs. 1.7). PEGfilgrastim alone had no significant effect in reducing the incidence of inflammation or fibrosis compared to vehicle. The combination of oral BIO 300 and PEGfilgrastim significantly reduced the incidence of interstitial inflammation (13% vs. 46%) and the severity of pulmonary fibrosis (mean severity score, 0.93 vs. 1.6). Results in the C57L/J mice were compared to those in CD2F1 mice, which are less prone to lung injury following total-body irradiation. Taken together, these studies indicate that BIO 300 is a promising MCM that is able to prophylactically protect against DEARE-lung.

Interspecies Comparison and Radiation Effect on Pharmacokinetics of BIO 300, a Nanosuspension of Genistein, after Different Routes of Administration in Mice and Non-Human Primates.

BIO 300, a suspension of synthetic genistein nanoparticles, is being developed for mitigating the delayed effects of acute radiation exposure (DEARE). The purpose of the current study was to characterize the pharmacokinetic (PK) profile of BIO 300 administered as an oral or parenteral formulation 24 h after sham-irradiation, total-body irradiation (TBI) with 2.5-5.0% bone marrow sparing (TBI/BMx), or in nonirradiated sex-matched C57BL/6J mice and non-human primates (NHP). C57BL/6J mice were randomized to the following arms in two consecutive studies: sham-TBI [400 mg/kg, oral gavage (OG)], TBI/BM2.5 (400 mg/kg, OG), sham-TBI [200 mg/kg, subcutaneous (SC) injection], TBI/BM2.5 (200 mg/kg, SC), sham-TBI (100 mg/kg, SC), or nonirradiated [200 mg/kg, intramuscular (IM) injection]. The PK profile was also established in NHP exposed to TBI/BM5.0 (100 mg/kg, BID, OG). Genistein-aglycone serum concentrations were measured in all groups using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. The PK profile demonstrates 11% and 19% reductions in Cmax and AUC0-inf, respectively, among mice administered 400 mg/kg, OG, after TBI/BM2.5 compared to the sham-TBI control arm. Administration of 200 mg/kg SC in mice exposed to TBI/BM2.5 showed a 53% increase in AUC0-inf but a 28% reduction in Cmax compared to the sham-TBI mice. The relative bioavailability of the OG route compared to the SC and IM routes in mice was 9% and 7%, respectively. After the OG route, the dose-normalized AUC0-inf was 13.37 (ng.h/mL)/(mg/kg) in TBI/BM2.5 mice compared to 6.95 (ng.h/mL)/(mg/kg) in TBI/BM5.0 NHPs. Linear regression of apparent clearances and weights of mice and NHPs yielded an allometric coefficient of 1.06. Based on these data, the effect of TBI/BMx on BIO 300 PK is considered minimal. Future studies should use SC and IM routes to maximize drug exposure when administered postirradiation. The allometric coefficient is useful in predicting therapeutic drug dose regimens across species for drug approval under the FDA animal rule.

Development of Genistein Synthesis for Use as a Certified Reference Material

Introduction. The use of certified reference materials (CRMs) ensures metrological traceability and comparability of analysis results performed in different laboratories, by different analysts, at different times. Genistein is a promising substance with a wide spectrum of pharmacological action. genistein is widely used in dietary supplements. Development of regulatory documents for CRM of genistein will ensure the quality of drugs and dietary supplements.Aim. Aim of our study is to improve of the ways of synthesis and determination of spectrum characteristics of genistein for the certification of CRM.Materials and methods. We used synthetic genistein, (Ph.D. V. Yu. Kovtun SPC "Pharmzashchita") (sample № 1) and genistein synthesized and studied at the departments of pharmaceutical chemistry and chemical technology of medicinal substances SPCPU (sample № 2). Infrared spectra of genistein samples were collected on an FSM 1201 infrared Fourier spectrometer (OOO Infraspek, Russia) via KBr pellets technique. All the spectra were collected in the 4000–500 cm−1 range. The NMR (1H and 13C) measurements were performed with a BrukerAvance III NMR spectrometer (400 and 100 MHz) (Bruker, Germany) in DMSO-d6 solvent. Raman spectra were recorded by an ORTES-785TRS-2700 analytical Raman scattering system at a laser power of 100 mW (OPTEC JSC, Russia). Laser interaction time was 5, 10, 20 and 60 seconds. The results were processed using the software "BWSpec 4.10_4", USA. GC-MS was performed on an Agilent Technologies 7890A gas chromatograph (Agilent Technologies, USA) with a 7693 autoinjector and a Hewlett Packard 5975C mass selective detector.Results and discussion. The synthesis was carried out according to the developer's method. The stage "removal of the alkyl protection" has been improved. The spectra of the synthesis intermediate of genistein (biochanin A) correspond to the literature data. Samples of genistein were investigated by methods: MC and NMR 13С, 1Н. The structure of the investigated substance was confirmed; Raman and IR spectroscopy showed that the spectra of the samples do not differ from each other and there are no additional signals.Conclusion. The spectrum characteristics of samples of genistein were obtained by NMR, IR and Raman spectroscopy, which will be used in the regulatory documentation for CRM of genistein. All of this will make it possible to control the quality of medicines based on it and to identify substandard dietary supplements.

Microbiome study in irradiated mice treated with BIO 300, a promising radiation countermeasure

BackgroundThe mammalian gut harbors very complex and diverse microbiota that play an important role in intestinal homeostasis and host health. Exposure to radiation results in dysbiosis of the gut microbiota leading to detrimental pathophysiological changes to the host. To alleviate the effects of irradiation, several candidate countermeasures are under investigation. BIO 300, containing synthetic genistein formulated as an amorphous solid dispersion or as an aqueous suspension of nanoparticles, is a promising candidate under advanced development. The aim of this study was to investigate the effects of BIO 300 on the gut microbiome and metabolome of mice exposed to 60Co gamma-radiation. The gut microbiota and metabolome of control and drug-treated mice exposed to radiation was characterized by bacterial 16S rRNA amplicon sequencing and untargeted metabolomics.ResultsWe found that irradiation altered the Firmicutes/Bacteroidetes ratio and significantly decreased the relative abundance of Lactobacillus, both in BIO 300-treated and control mice; however, the ratio returned to near normal levels in BIO 300-treated mice by day 14 post-irradiation. Concomitantly, we also observed corrective shifts in metabolic pathways that were perturbed after irradiation.ConclusionsOverall, the data presented show that radiation exposure led to a relative depletion of commensals like Lactobacillus leading to an inflammatory metabolic phenotype while the majority of the drug-treated mice showed alleviation of this condition primarily by restoration of normal gut microbiota. These results indicate that the radioprotective effects of BIO 300, at least in part, may involve correction of the host-microbiome metabolic axis.

A novel oral formulation of BIO 300 confers prophylactic radioprotection from acute radiation syndrome in mice

Purpose Exposure to high doses of ionizing radiation can result in hematopoietic acute radiation syndrome (H-ARS) and delayed effects of acute radiation exposure (DEARE). There is no radiation medical countermeasure (MCM) approved by the U.S. Food and Drug Administration which can be used prior to radiation exposure to protect exposed individuals. Different formulations containing synthetic genistein (BIO 300) are being developed to counter the harmful effects of radiation exposure. Materials and methods We investigated the efficacy of a BIO 300 oral powder (OP) formulation as a prophylactic radiation MCM against a lethal dose of cobalt-60 gamma-radiation in CD2F1 male mice while comparing to other formulations of BIO 300 and Neulasta (PEGylated filgrastim), a standard of care drug for H-ARS. Results BIO 300 OP provided significant radioprotection against ionizing radiation in mice when administered twice per day for six days prior to total-body radiation exposure. Its radioprotective efficacy in the murine model was comparable to the efficacy of a single subcutaneous (sc) injection of Neulasta administered after total-body radiation exposure. Conclusions Our results demonstrate that BIO 300 OP, which can be administered orally, is a promising prophylactic radiation countermeasure for H-ARS.

Comparative proteomic analysis of serum from nonhuman primates administered BIO 300: a promising radiation countermeasure

Hematopoietic acute radiation syndrome (H-ARS) and delayed effects of acute radiation exposure (DEARE) are detrimental health effects that occur after exposure to high doses of ionizing radiation. BIO 300, a synthetic genistein nanosuspension, was previously proven safe and effective against H-ARS when administered (via the oral (po) or intramuscular (im) route) prior to exposure to lethal doses of total-body radiation. In this study, we evaluated the proteomic changes in serum of nonhuman primates (NHP) after administering BIO 300 by different routes (po and im). We utilized nanoflow-ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (NanoUPLC-MS/MS) methods for comprehensive global profiling and quantification of serum proteins. The results corroborate previous findings that suggest a very similar metabolic profile following both routes of drug administration. Furthermore, we observed minor alterations in protein levels, 2 hours after drug administration, which relates to the Cmax of BIO 300 for both routes of administration. Taken together, this assessment may provide an insight into the mechanism of radioprotection of BIO 300 and a reasonable illustration of the pharmacodynamics of this radiation countermeasure.

BIO 300, a Nanosuspension of Genistein, Mitigates Radiation-Induced Erectile Dysfunction and Sensitizes Human Prostate Cancer Xenografts to Radiation Therapy

To assess whether BIO 300, a synthetic genistein nanosuspension, improves the therapeutic index in prostate cancer treatment by preventing radiation-induced erectile dysfunction (ED) without reducing tumor radiosensitivity. Male Sprague-Dawley rats were exposed to 25 Gy of 220-kV prostate-confined x-rays. Animals were randomized to receive sham radiation therapy (RT), RT alone, RT with daily BIO 300 at 2 experimental dosing regimens, or RT with daily genistein. Erectile response was evaluated over time. Penile shaft tissue was harvested for histologic analyses. Murine xenograft studies using prostate cancer cell lines determined the effects of BIO 300 dosing on RT efficacy. Prostate-confined RT significantly decreased apomorphine-induced erectile response (P < .05 vs sham RT). Erection frequency in animals receiving prophylactic treatment with BIO 300 starting 3 days before RT was similar to sham controls after RT. Treatment with synthetic genistein did not mitigate loss in erectile frequency. At week 14, post-RT treatment with BIO 300 resulted in significantly higher quality of erectile function compared with both the RT arm and the RT arm receiving genistein starting 3 days before irradiation (P < .05). In hormone-sensitive and insensitive prostate tumor-bearing mice, BIO 300 administration did not negatively affect radiation-induced tumor growth delay. BIO 300 prevents radiation-induced ED, measured by erection frequency, erectile function, and erection quality, when administered 3 days before RT and continued daily for up to 14 weeks. Data also suggest that BIO 300 administered starting 2 hours after RT mitigates radiation-induced ED. Data provide strong nonclinical evidence to support clinical translation of BIO 300 for mitigation of ED while maintaining treatment response to RT.

Mechanism and therapeutic window of a genistein nanosuspension to protect against hematopoietic-acute radiation syndrome.

There are no FDA-approved drugs that can be administered prior to ionizing radiation exposure to prevent hematopoietic-acute radiation syndrome (H-ARS). A suspension of synthetic genistein nanoparticles was previously shown to be an effective radioprotectant against H-ARS when administered prior to exposure to a lethal dose of total body radiation. Here we aimed to determine the time to protection and the duration of protection when the genistein nanosuspension was administered by intramuscular injection, and we also investigated the drug's mechanism of action. A single intramuscular injection of the genistein nanosuspension was an effective radioprotectant when given prophylactically 48 h to 12 h before irradiation, with maximum effectiveness occurring when administered 24 h before. No survival advantage was observed in animals administered only a single dose of drug after irradiation. The dose reduction factor of the genistein nanosuspension was determined by comparing the survival of treated and untreated animals following different doses of total body irradiation. As genistein is a selective estrogen receptor beta agonist, we also explored whether this was a central component of its radioprotective mechanism of action. Mice that received an intramuscular injection of an estrogen receptor antagonist (ICI 182,780) prior to administration of the genistein nanosuspension had significantly lower survival following total body irradiation compared with animals only receiving the nanosuspension (P < 0.01). These data define the time to and duration of radioprotection following a single intramuscular injection of the genistein nanosuspension and identify its likely mechanism of action.

Estrogenicity of the isoflavone genistein pigeon pie seeds (Cajanus cajan L. Mill sp.) on reproductive organs in rat

Genistein is a compound with structures and properties similar to 17β estradiol which can be extracted from pigeon pie. The aim of the study was to identify the genistein profiles of pigeon pie in blood, urine, and feces and their effects on uterine and vaginal tissue structures of rats. Nine female white rats of Sprague Dawley, 6-7 months, weighing 150-180 g, were used and given pigeon pie seed solution for 36 days, genistein profiles were analyzed using HPLC, uterine and vaginal tissue structures were analyzed with HE staining. The results showed that the genistein contained in pigeon pie was lower than that in the synthetic genistein; vaginal epithelials and uterine proliferations were indicated. To conclude, pigeon pie was found to contain genistein which is a potential alternative for a natural estrogen source.

Targeted Metabolomics Identifies Pharmacodynamic Biomarkers for BIO 300 Mitigation of Radiation-Induced Lung Injury.

Biomarkers serve a number of purposes during drug development including defining the natural history of injury/disease, serving as a secondary endpoint or trigger for intervention, and/or aiding in the selection of an effective dose in humans. BIO 300 is a patent-protected pharmaceutical formulation of nanoparticles of synthetic genistein being developed by Humanetics Corporation. The primary goal of this metabolomic discovery experiment was to identify biomarkers that correlate with radiation-induced lung injury and BIO 300 efficacy for mitigating tissue damage based upon the primary endpoint of survival. High-throughput targeted metabolomics of lung tissue from male C57L/J mice exposed to 12.5Gy whole thorax lung irradiation, treated daily with 400mg/kg BIO 300 for either 2weeks or 6weeks starting 24h post radiation exposure, were assayed at 180 d post-radiation to identify potential biomarkers. A panel of lung metabolites that are responsive to radiation and able to distinguish an efficacious treatment schedule of BIO 300 from a non-efficacious treatment schedule in terms of 180 d survival were identified. These metabolites represent potential biomarkers that could be further validated for use in drug development of BIO 300 and in the translation of dose from animal to human.

Let-7d increases ovarian cancer cell sensitivity to a genistein analog by targeting c-Myc.

c-Myc is a key oncogenic transcription factor that participates in tumor pathogenesis. In this study, we found that levels of c-Myc mRNA and protein were higher in early ovarian cancer tissues than normal ovary samples. Increased c-Myc levels correlated positively with clinical stage I (Ia+b/Ic) in ovarian cancer patients. Patients with higher nuclear c-Myc expression had shorter overall survival times than patients with low c-Myc expression. Knocking down c-Myc sensitized ovarian cancer cells to 7-difluoromethoxyl-5,4’-di-n-octylgenistein (DFOG), a novel synthetic genistein analogue that suppressed PI3K/AKT signaling in vitro and in vivo. Finally, c-Myc was confirmed to be a direct target of let-7d, and let-7d-induced suppression of c-Myc increased the DFOG-sensitivity of ovarian cancer cells. These results indicate that nuclear c-Myc expression is an unfavorable factor in early ovarian cancer, and that let-7d increases ovarian cancer cell sensitivity to DFOG by suppressing c-Myc and PI3K/AKT signaling.

7-Difluoromethoxyl-5,4'-di-n-octyl genistein inhibits the stem-like characteristics of gastric cancer stem-like cells and reverses the phenotype of epithelial-mesenchymal transition in gastric cancer cells.

7-Difluoromethoxyl-5,4'-di-n-octyl genistein (DFOG), a novel synthetic genistein analogue, exerts anticarcinogenic activity in several types of cancers, including gastric cancer. Accumulating evidence in recent years strongly indicates the existence of cancer stem cells in gastric cancer. The objective of the present study was to investigate whether DFOG inhibits the stemness and reverses the epithelial-mesenchymal transition (EMT) phenotype of gastric cancer stem-like cells (GCSLCs) derived from human gastric cancer SGC-7901 cells and to identify its potential mechanism. Sphere-forming cells (SFCs) from the SGC-7901 cells possessed the properties of GCSLCs. DFOG preferentially inhibited self-renewal, cell migration and cell invasion, and downregulated the expression of stem cell biomarkers in a dose-dependent manner. At the molecular level, these effects were accompanied by the downregulation of forkhead boxM1 (FoxM1). Meanwhile, FoxM1 siRNA transfection was able to synergize the inhibition of expression of FoxM1 and Twist1 induced by DFOG in GCSLCs. In addition, we found that DFOG treatment decreased the expression of N-cadherin and increased the expression of E-cadherin. More importantly, FoxM1 siRNA transfection cooperated with DFOG to suppress the self-renewal capacity, cell migration and cell invasion, and downregulated the expression of CD133, CD44, ALDH1, and also regulated the expression of N-cadherin and E-cadherin. These findings showed that DFOG inhibited the stem-like characteristics of GCSLCs and reversed the EMT phenotype by modulation of FoxM1 and further decreased Twist1 expression. Our results provide a further rationale and experimental basis for using DFOG to improve the efficacy of treatment for patients with gastric cancer.

The cytoprotective effect of the phytoestrogen genistein on tumor cells

In order to determine the cytotoxic or cytoprotective effect of the synthetic isoflavonoid genistein, we studied its effect on HeLa tumor cells, which contain estrogen alpha receptors and do not contain estrogen beta receptors. It was shown that the genistein concentration (IC50 = 0.2 mM) at which the half maximal inhibition of the HeLa cell viability is achieved is ten times higher than the concentrations of tamoxifen and cisplatin, which are reference agents with a cytotoxic effect. At micromolar concentrations (0.1–10 µM) genistein decreased the cytotoxic effects of cisplatin and tamoxifen. We found the reduced Bax mRNA expression and increased Bcl-2 mRNA expression during incubation of the cells with genistein, which also indicates its cytoprotective anti-apoptotic effect. Genistein, even in high concentrations, had no effect on the membrane potential and calcium capacity of isolated mitochondria and did not activate the opening of the Ca2+-induced mitochondrial pore. Thus, the data show a protective effect of the isoflavonoid genistein on tumor cells.

Direct electrochemical oxidation of Abelson tyrosine-protein kinase 1 and evaluation of its interaction with synthetic substrate, ATP and inhibitors

The electrochemical behaviour of Abelson protein-tyrosine kinase 1 (ABL1) and its interaction with synthetic substrate abltide EAIYAAPFAKKK, ATP, and inhibitors genistein, imatinib mesylate and danusertib were studied by differential pulse voltammetry using a glassy carbon electrode. In neutral electrolytes one oxidation peak due to histidine residues was observed. In acid and basic media the enzyme undergoes conformational modifications which lead to exposure of more electroactive amino acid to the electrode surface facilitating their oxidation. The interaction of ABL1 with the synthetic substrate involves the coiling of abltide around the enzyme which suppresses the oxidation of abltide tyrosine residue and leads the exposure of ABL1 electroactive amino acids to the electrode surface and occurrence of new electrochemical signals. The binding of ATP and ATP-competitive synthetic inhibitors imatinib mesylate, and danusertib results in stable complexes that maintains the symmetry of the enzyme but the electroactive centres of the compounds are hidden inside the binding site, preventing their oxidation. The natural inhibitor genistein is encountered on the outer surface of the enzyme and the electroactive centres are available for oxidation.

Synthetic genistein glycosides inhibiting EGFR phosphorylation enhance the effect of radiation in HCT 116 colon cancer cells.

The need to find new EGFR inhibitors for use in combination with radiotherapy in the treatment of solid tumors has drawn our attention to compounds derived from genistein, a natural isoflavonoid. The antiproliferative potential of synthetic genistein derivatives used alone or in combination with ionizing radiation was evaluated in cancer cell lines using clonogenic assay. EGFR phosphorylation was assessed with western blotting. Genistein derivatives inhibited clonogenic growth of HCT 116 cancer cells additively or synergistically when used in combination with ionizing radiation, and decreased EGFR activation. Our preclinical evaluation of genistein-derived EGFR inhibitors suggests that these compounds are much more potent sensitizers of cells to radiation than the parent isoflavonoid, genistein and indicate that these compounds may be useful in the treatment of colon cancer with radiation therapy.

7-difluoromethoxyl-5,4'-di-n-octyl genistein inhibits ovarian cancer stem cell characteristics through the downregulation of FOXM1.

7-Difluoromethoxyl-5,4′-di-n-octylgenistein (DFOG) is a novel synthetic genistein analogue that possesses anti-cancer activity in a variety of cancers, including ovarian cancer. The objective of the present study was to investigate whether DFOG inhibits the self-renewal capacity of ovarian cancer stem-like cells (OCSLCs) and to identify its potential mechanism of action. It was found that the sphere-forming cells (SFCs) of the SKOV3 cell line exhibited a self-renewal capacity and high tumorigenicity, indicating that they possessed the properties of ovarian cancer stem cells (OCSCs). It was also shown for the first time that DFOG preferentially inhibited proliferation, self-renewal capacity and expression of stem cell markers [cluster of differentiation (CD)133, CD44 and aldehyde dehydrogenase 1 (ALDH1)] in the SFCs derived from the SKOV3 cells. These effects were accompanied by the downregulation of forkhead box M1 (FOXM1) expression. Overexpression of FOXM1 rescued the DFOG-induced downregulation of FOXM1, CD133, CD44 and ALDH1 protein expression. It also inhibited the self-renewal capacity of the SFCs derived from the SKOV3 cells. Thus, DFOG appears to inhibit the characteristics of OCSLCs by downregulating FOXM1 expression.

FOXO3a-mediated suppression of the self-renewal capacity of sphere-forming cells derived from the ovarian cancer SKOV3 cell line by 7-difluoromethoxyl-5,4′-di-n-octyl genistein

Carcinogenesis is predominantly dependent on the cancer stem cells (CSCs) residing or populating within the cancer. We previously demonstrated that the novel synthetic genistein analogue, 7-difluoromethoxyl-5,4'-di-n-octylgenistein (DFOG), induced apoptotic cell death of ovarian and gastric cancer cells. The present study demonstrated that sphere‑forming cells (SFCs) derived from the ovarian cancer cell-line SKOV3 possessed ovarian cancer stem-like cell (OCSLC) properties, including self-renewal and high tumorigenicity. DFOG may be effective in inhibiting the self‑renewal capacity of SFCs derived from the SKOV3 cell line. DFOG decreased the level of phosphorylated FOXO3a protein in SKOV3 cell‑derived SFCs. The inhibition of FOXO3a expression by siRNA significantly attenuated the ability of DFOG to inhibit the self-renewal capacity of SKOV3-derived SFCs. Our results suggested that DFOG has been demonstrated to significantly inhibit the self-renewal capacity of ovarian cancer stem cells (OCSCs) through a mechanism partly dependent on the activation of FOXO3a.