Antidiabetic with antilipidemic and antioxidant effects of flindersine by enhanced glucose uptake through GLUT4 translocation and PPARγ agonism in type 2 diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Medicinal plants have been used by the people of developing countries to treat various diseases. WHO also recommends the use of medicines from plants source. In that, diabetes also one of the diseases that have been treated traditionally by several people all over the world. In India, Toddalia asiatica (L.) Lam. (Rutaceae) is also a medicinal plant used traditionally for the treatment of diabetes in Ayurveda. Moreover, T. asiatica is also used in a polyherbal formulation to treat diabetes. AIM OF THE STUDY: This study examined the antidiabetic with antilipidemic and antioxidant effects of flindersine isolated from T. asiatica leaves. MATERIALS AND METHODS: Diabetes was induced in Wistar rats by feeding a high-fat diet (HFD) for 15 days and injecting a single dose of 40 mg/kg b. wt. of Streptozotocin (STZ). Five days post-injection, the grouped diabetic rats were treated with 20 and 40 mg/kg of flindersine. RESULTS: Flindersine resulted in a clear decline of blood glucose levels during 28 days of treatment in two different doses. Flindersine also significantly (P ≤ 0.05; P ≤ 0.005) reduced the body weight gain, plasma insulin concentration, urea, creatinine, total cholesterol (TC), triglycerides (TG) and free fatty acids (FFA) levels and significantly increased (P ≤ 0.05; P ≤ 0.005) the total protein level, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities compared to the standard drug, pioglitazone. Additionally, flindersine restored the glucose transporter protein 4 (GLUT4), adenosine monophosphate protein kinase (AMPK) and peroxisome proliferator-activated receptor γ (PPARγ) expressions in adipose tissues and skeletal muscles. CONCLUSION: It has been found that flindersine has potent antilipidemic and antidiabetic activities by improving insulin sensitivity by enhancing the phosphorylation of AMPK, GLUT4 translocation, and PPARγ agonism on adipose tissue and skeletal muscles of diabetic rats.

Balasubramide derivative 3C attenuates atherosclerosis in apolipoprotein E-deficient mice: role of AMPK-STAT1-STING signaling pathway.

We previously reported the neuroprotective effects of (+)-balasubramide derived compound 3C, but its action on atherosclerosis in vivo remains unknown. The study was designed to investigate the potential effects of 3C on atherogenesis and explore the possible underlying mechanisms. 3C ameliorated high-fat diet-induced body weight gain, hyperlipidemia, and atherosclerotic plaque burden in apolipoprotein E-deficient (ApoE-/-) mice after 10 weeks of treatment. 3C suppressed the expression of genes involved in triglyceride synthesis in liver. 3C prevented aortic inflammation as evidenced by reduction of adhesive molecule levels and macrophage infiltration. Mechanistic studies revealed that activation of AMP-activated protein kinase (AMPK) is central to the athero-protective effects of 3C. Increased AMPK activity by 3C resulted in suppressing interferon-γ (IFN-γ) induced activation of signal transducer and activator of transcription-1 (STAT1) and stimulator of interferon genes (STING) signaling pathways and downstream pro-inflammatory markers. Moreover, 3C inhibited ox-LDL triggered lipid accumulation and IFN-γ induced phenotypic switch toward M1 macrophage in RAW 264.7 cells. Our present data suggest that 3C prevents atherosclerosis via pleiotropic effects, including amelioration of lipid profiles, vascular inflammation and macrophage pro-inflammatory phenotype. 3C has the potential to be developed as a promising drug for atherosclerosis and related cardiovascular disease.

Dolutegravir and pregnancy outcomes in women on antiretroviral therapy in Brazil: a retrospective national cohort study.

BACKGROUND: Dolutegravir has been widely available in Brazil since 2017. Following the signal that infants born to women with dolutegravir exposure at conception in Botswana had a higher risk of neural tube defects (NTDs), public health leaders initiated a national investigation to evaluate periconception dolutegravir exposure among all pregnant Brazilian women with HIV and its potential association with risk of NTDs, stillbirth, or miscarriage before 22 weeks (also called spontaneous abortion). METHODS: In this retrospective, observational, national, cohort study, we identified all women with pregnancies and possible dolutegravir exposure within 8 weeks of estimated date of conception between Jan 1, 2017, and May 31, 2018, and approximately 3:1 matched pregnant women exposed to efavirenz between Jan 1, 2015, and May 31, 2018, using the Brazilian antiretroviral therapy database. We did detailed chart reviews for identified women. The primary outcomes were NTD and a composite measure of NTD, stillbirth, or miscarriage. NTD incidences were calculated with 95% CI. The composite outcome was examined with logistic regression using propensity score matching weights to balance confounders. FINDINGS: Of 1427 included women, 382 were exposed to dolutegravir within 8 weeks of estimated date of conception. During pregnancy, 183 (48%) of 382 dolutegravir-exposed and 465 (44%) of 1045 efavirenz-exposed women received folic acid supplementation. There were 1452 birth outcomes. There were no NTDs in either dolutegravir-exposed (0, 95% CI 0-0·0010) or efavirenz-exposed groups (0, 95% CI 0-0·0036). There were 23 (6%) stillbirths or miscarriages in 384 dolutegravir-exposed fetuses and 28 (3%) in the 1068 efavirenz-exposed fetuses (p=0·0037). Logistic regression models did not consistently indicate an association between dolutegravir exposure and risk of stillbirths or miscarriages. After study closure, two confirmed NTD outcomes in fetuses with periconception dolutegravir exposure were reported to public health officials. An updated estimate of NTD incidence incorporating these cases and the estimated number of additional dolutegravir-exposed pregnancies between Jan 1, 2015 and Feb 28, 2019, is 0·0018 (95% CI 0·0005-0·0067). INTERPRETATION: Neither dolutegravir nor efavirenz exposure was associated with NTDs in our national cohort; incidence of NTDs is probably well under 1% in dolutegravir-exposed HIV-positive women but still slightly above HIV-uninfected women (0·06%) in Brazil. FUNDING: The Brazilian Ministry of Health and the United States' National Institutes of Health.

A TLR7/8 Agonist-Including DOEPC-Based Cationic Liposome Formulation Mediates Its Adjuvanticity Through the Sustained Recruitment of Highly Activated Monocytes in a Type I IFN-Independent but NF-κB-Dependent Manner.

Novel adjuvants, such as Toll-like receptors (TLRs) agonists, are needed for the development of new formulations able to circumvent limitations of current vaccines. Among TLRs, TLR7/8 agonists represent promising candidates, as they are well described to enhance antigen-specific antibody responses and skew immunity toward T helper (TH) 1 responses. We find here that the incorporation of the synthetic TLR7/8 ligand 3M-052 in a cationic DOEPC-based liposome formulation shifts immunity toward TH1 responses and elicits strong and long-lasting germinal center and follicular T helper cell responses in adult mice. This reflects the prolonged recruitment of innate cells toward the site of immunization and homing of activated antigen-loaded monocytes and monocyte-derived dendritic cells toward draining lymph nodes. We further show that this adjuvanticity is independent of type I IFN but NF-κB-dependent. Overall, our data identify TLR7/8 agonists incorporated in liposomes as promising and effective adjuvants to enhance TH1 and germinal center responses.

Successful use of once-daily high-dose darunavir and dolutegravir in multidrug-resistant HIV.

WHAT IS KNOWN AND OBJECTIVE?: Antiretroviral (ARV) resistance may result during periods of consistently poor adherence. We report the successful use of a novel once-daily (QD) ARV regimen in a patient with multidrug-resistant (MDR) HIV. CASE SUMMARY: Once-daily darunavir 1200 mg/ritonavir 100 mg, dolutegravir and emtricitabine/tenofovir alafenamide was initiated with directly observed therapy. With the assistance of therapeutic drug monitoring, dolutegravir dosing was increased to 150 mg daily. The patient maintained virologic suppression for 18 months. WHAT IS NEW AND CONCLUSIONS?: In this case, QD darunavir/ritonavir achieved similar trough concentrations to twice daily dosing with dolutegravir dose titration necessitated and resulted in HIV virologic control.

MIDD0301 - A first-in-class anti-inflammatory asthma drug targets GABAA receptors without causing systemic immune suppression.

We report a 28-day repeat dose immunotoxicity evaluation of investigational drug MIDD0301, a novel oral asthma drug candidate that targets gamma amino butyric acid type A receptors (GABAA R) in the lung. The study design employed oral administration of mice twice daily throughout the study period with 100 mg/kg MIDD0301 mixed in peanut butter. Compound dosing did not reveal signs of general toxicity as determined by animal weight, organ weight or haematology. Peanut butter plus test drug (in addition to ad libitum standard rodent chow) did not affect weight gain in the adult mice, in contrast to weight loss in 5 mg/kg prednisone-treated mice. Spleen and thymus weights were unchanged in MIDD0301-treated mice, but prednisone significantly reduced the weight of those organs over the 28-day dosing. Similarly, no differences in spleen or thymus histology were observed following MIDD0301 treatment, but prednisone treatment induced morphological changes in the spleen. The number of small intestine Peyer's patches was not affected by MIDD0301 treatment, an important factor for orally administered drugs. Circulating lymphocyte, monocyte and granulocyte numbers were unchanged in the MIDD0301-treated animals, whereas differential lymphocyte numbers were reduced in prednisone-treated animals. MIDD0301 treatment did not alter IgG antibody responses to dinitrophenyl following dinitrophenyl-keyhole limpet haemocyanin immunization, indicating that systemic humoral immune function was not affected. Taken together, these studies show that repeated daily administration of MIDD0301 is safe and not associated with adverse immunotoxicological effects in mice.

Gepotidacin for the Treatment of Uncomplicated Urogenital Gonorrhea: A Phase 2, Randomized, Dose-Ranging, Single-Oral Dose Evaluation.

Background: In this phase 2 study, we evaluated the efficacy and safety of oral gepotidacin, a novel triazaacenaphthylene bacterial type II topoisomerase inhibitor, for the treatment of uncomplicated urogenital gonorrhea. Methods: Adult participants with suspected urogenital gonorrhea were enrolled and completed baseline (day 1) and test-of-cure (days 4-8) visits. Pretreatment and posttreatment urogenital swabs were collected for Neisseria gonorrhoeae (NG) culture and susceptibility testing. Pharyngeal and rectal swab specimens were collected if there were known exposures. Participants were stratified by gender and randomized 1:1 to receive a 1500-mg or 3000-mg single oral dose of gepotidacin. Results: The microbiologically evaluable population consisted of 69 participants, with NG isolated from 69 (100%) urogenital, 2 (3%) pharyngeal, and 3 (4%) rectal specimens. Microbiological eradication of NG was achieved by 97%, 95%, and 96% of participants (lower 1-sided exact 95% confidence interval bound, 85.1%, 84.7%, and 89.1%, respectively) for the 1500-mg, 3000-mg, and combined dose groups, respectively. Microbiological cure was achieved in 66/69 (96%) urogenital infections. All 3 failures were NG isolates that demonstrated the highest observed gepotidacin minimum inhibitory concentration of 1 µg/mL and a common gene mutation. At the pharyngeal and rectal sites, 1/2 and 3/3 NG isolates, respectively, demonstrated microbiological cure. There were no treatment-limiting adverse events for either dose. Conclusions: This study demonstrated that single, oral doses of gepotidacin were ≥95% effective for bacterial eradication of NG in adult participants with uncomplicated urogenital gonorrhea. Clinical Trials Registration: NCT02294682.

Creation of a long-acting nanoformulated dolutegravir.

Potent antiretroviral activities and a barrier to viral resistance characterize the human immunodeficiency virus type one (HIV-1) integrase strand transfer inhibitor dolutegravir (DTG). Herein, a long-acting parenteral DTG was created through chemical modification to improve treatment outcomes. A hydrophobic and lipophilic modified DTG prodrug is encapsulated into poloxamer nanoformulations (NMDTG) and characterized by size, shape, polydispersity, and stability. Retained intracytoplasmic NMDTG particles release drug from macrophages and attenuate viral replication and spread of virus to CD4+ T cells. Pharmacokinetic tests in Balb/cJ mice show blood DTG levels at, or above, its inhibitory concentration90 of 64 ng/mL for 56 days, and tissue DTG levels for 28 days. NMDTG protects humanized mice from parenteral challenge of the HIV-1ADA strain for two weeks. These results are a first step towards producing a long-acting DTG for human use by affecting drug apparent half-life, cell and tissue drug penetration, and antiretroviral potency.

Development of an oral once-weekly drug delivery system for HIV antiretroviral therapy.

The efficacy of antiretroviral therapy is significantly compromised by medication non-adherence. Long-acting enteral systems that can ease the burden of daily adherence have not yet been developed. Here we describe an oral dosage form composed of distinct drug-polymer matrices which achieved week-long systemic drug levels of the antiretrovirals dolutegravir, rilpivirine and cabotegravir in a pig. Simulations of viral dynamics and patient adherence patterns indicate that such systems would significantly reduce therapeutic failures and epidemiological modelling suggests that using such an intervention prophylactically could avert hundreds of thousands of new HIV cases. In sum, weekly administration of long-acting antiretrovirals via a novel oral dosage form is a promising intervention to help control the HIV epidemic worldwide.

Synthesis of novel trifluoromethyl-substituted spiro-[chromeno[4,3-d]pyrimidine-5,1'-cycloalkanes], and evaluation of their analgesic effects in a mouse pain model.

Herein we report the synthesis of twelve 2,5-substituted 4-(trifluoromethyl)-spirochromeno[4,3-d]pyrimidines (7-10), as well as an evaluation of their analgesic effect in a mouse pain model. The nine new chromeno[4,3-d]pyrimidines (7-9) were synthesized from the cyclocondensation reactions of three 2,2,2-trifluoro-1-(4-methoxyspiro[chromene-2,1'-cycloalkane]-3-yl)ethanones (3) containing 5-, 6- and 7-membered spirocycloalkanes, with some well-known amidine salts (4-6) [NH2CR(NH)]-in which R=Me, Ph, and NH2-at yields of 60-95%. Subsequently, three new 2-(pyrrol-1-yl)-4-(trifluoromethyl)-chromeno[4,3-d]pyrimidines (10) were obtained through a Clauson-Kaas reaction between the respective 2-(amino)-4-(trifluoromethyl)-chromeno[4,3-d]pyrimidines (9) and 2,5-dimethoxy-tetrahydrofuran. The analgesic evaluation showed that these 4-(trifluoromethyl)chromeno[4,3-d]pyrimidines (100mg/kg, p.o.) and Ketoprofen (100mg/kg, p.o.) significantly reduced capsaicin-induced spontaneous nociception. Moreover, the 2-pyrrolyl-spirocyclohexane derivative 10b (100 and 300mg/kg, p.o.) had an anti-allodynic effect comparable to Ketoprofen (100 and 300mg/kg, p.o.) in the arthritic pain model, without causing locomotor alterations in the mice. These results suggest that the compound 10b is a promising molecule for new analgesic drugs in the treatment of pathological pain, such as in arthritis.

Evaluation of the impact of multivalent metal ions on the permeation behavior of Dolutegravir sodium.

Interactions between active pharmaceutical ingredients (APIs) and polyvalent cations are an important factor within drug absorption in the gastrointestinal tract. Dolutegravir sodium, as a second-generation integrase stand transfer inhibitor for the treatment of HIV was investigated regarding chelation with Al(3+), Ca(2+), Fe(3+), Mg(2+ )and Zn(2+) ions at three different molar ratios. Furthermore, the influence of drug-ion chelates on the permeability of the drug across two intestinal membrane models was analyzed. For this purpose, Caco-2 monolayer model and Ussing chamber technique utilizing freshly excited rat intestinal mucosa were chosen and a buffer system without additional Mg(2+) and Ca(2+) ions was tested regarding cell detachment. The addition of polyvalent cations in an equal molar ratio to the drug solution decreased the dissolved drug by at least 11%. An increased multivalent cation concentration in a ratio of 1:10 afforded an API drop in the solution of at least 88% with the exception of Mg(2+). In particular, Dolutegravir sodium was chelated with iron ions to nearly 100%. Overall, the higher the amount of metal ions in the solution, the lower was the detected amount of the drug. The permeation experiments across the Caco-2 monolayer and the rat intestinal mucosa pointed out that the addition of AlCl3, CaCl2 and ZnCl2 in a molar ratio of 10:1 to the drug led to significantly decreased drug permeation. According to these results the co-administration of Al(3+), Ca(2+ )or Zn(2+ )as well as of supplementary medications containing these polyvalent ions is in case of oral Dolutegravir delivery not recommended.

The preclinical discovery and development of dolutegravir for the treatment of HIV.

INTRODUCTION: Integration of the viral genome into the host cell chromatin is a central step in the replication cycle of HIV. Blocking the viral integrase (IN) enzyme therefore provides an attractive therapeutic strategy, as evidenced by the recent clinical approval of three IN strand transfer inhibitors. Dolutegravir is a therapy that is unique in its ability to evade HIV drug resistance in treatment-naïve patients. AREAS COVERED: This review starts by providing a brief summary of the history of HIV-1 IN inhibitors. The authors follow this with details of the discovery and preclinical and clinical developments of dolutegravir. Finally, the authors provide details of dolutegravir's post-launch including the launch of the combination pill of dolutegravir, abacavir and lamivudine in August 2014. EXPERT OPINION: The launch of raltegravir, the first IN inhibitor from Merck & Co., has created new hopes for the patient. Indeed, pharmaceutical companies have not lost courage by attempting to address the major drawbacks of this first-in-class molecule. And while the drug elvitegravir has been inserted into a four-drug combination pill providing a once-daily dosing alternative, dolutegravir has demonstrated superiority in terms of its efficacy and resistance.

A two-week regimen of high-dose integrase inhibitors does not cause nephrotoxicity in mice.

BACKGROUND: The integrase inhibitors, raltegravir and dolutegravir, are nucleoside reverse transcriptase inhibitor-sparing agents which may be used as part of first-line antiretroviral therapy for HIV. These drugs inhibit creatinine secretion through organic cation transporters, thus elevating serum creatinine without affecting glomerular filtration. We sought to determine whether subtle signs of nephrotoxicity could be observed in mice administered a two-week regimen of high-dose integrase inhibitors. METHODS: C57BL/6 mice were fed standard water (CTRL, n = 6), raltegravir-containing water (40 mg/kg/day, n = 6), or dolutegravir-containing water (2.7 mg/kg/day, n = 6) for two weeks and sacrificed. Endpoints were assessed including urine microalbumin, kidney injury molecule-1 renal tissue gene expression, renal histopathology, serum creatinine, and blood urea nitrogen. RESULTS: The results are NOT consistent with a direct nephrotoxic effect of the integrase inhibitors in mice. Serum creatinine was significantly elevated in raltegravir and dolutegravir mice (p < 0.05) compared to control (raltegravir = 0.25 mg/dl, dolutegravir = 0.30 mg/dl versus CTRL = 0.17 mg/dl). Blood urea nitrogen, cystatin C, and urine microalbumin were unchanged. Kidney injury molecule-1 tissue expression in raltegravir and dolutegravir groups was nonsignificantly elevated compared to control (1.2-fold compared to control). Renal histopathology by periodic acid-Schiff staining failed to reveal glomerular or tubular renal injury in any group. CONCLUSION: These studies are consistent with integrase inhibitors competitively inhibiting creatinine secretion. While no evidence of direct nephrotoxicity was observed after two weeks of high-dose drug administration, additional studies may be performed to understand whether these drugs lead to chronic nephropathy.

Combination therapies prevent the neuropathic, proinflammatory characteristics of bone marrow in streptozotocin-induced diabetic rats.

We previously showed that peripheral neuropathy of the bone marrow was associated with loss of circadian rhythmicity of stem/progenitor cell release into the circulation. Bone marrow neuropathy results in dramatic changes in hematopoiesis that lead to microvascular complications, inflammation, and reduced endothelial repair. This series of events represents early pathogenesis before development of diabetic retinopathy. In this study we characterized early alterations within the bone marrow of streptozotocin (STZ)-induced diabetic rats following treatments that prevent experimental peripheral neuropathy. We asked whether bone marrow neuropathy and the associated bone marrow pathology were reversed with treatments that prevent peripheral neuropathy. Three strategies were tested: inhibition of neutral endopeptidase, inhibition of aldose reductase plus lipoic acid supplementation, and insulin therapy with antioxidants. All strategies prevented loss of nerve conduction velocity resulting from STZ-induced diabetes and corrected the STZ-induced diabetes-associated increase of immunoreactivity of neuropeptide Y, tyrosine hydroxylase, and somatostatin. The treatments also reduced concentrations of interleukin-1ß, granulocyte colony-stimulating factor, and matrix metalloproteinase 2 in STZ-induced diabetic bone marrow supernatant and decreased the expression of NADPH oxidase 2, nitric oxide synthase 2, and nuclear factor-κB1 mRNA in bone marrow progenitor cells. These therapies represent novel approaches to attenuate the diabetic phenotype within the bone marrow and may constitute an important therapeutic strategy for diabetic microvascular complications.

Pharmacological suppression of the Ras/MAPK pathway in thyroid carcinoma cells can provoke opposite effects on cell migration and proliferation: The appearance of yin-yang effects and the need of combinatorial treatments.

A major challenge in tumor therapy is the decrease or even the halting of cell proliferation and migration of cancerous cells. In the present study, we have analyzed the impact of a pharmacological blockade of the PI3K/Akt and MAPK/ERK1/2 signaling pathways on cell migration, proliferation and cell death in three human thyroid tumor cell lines that represent the main types of malignant thyroid carcinomas (B-CPAP, follicular; Cal-62, anaplastic; FTC-133, papillary thyroid carcinoma cells) and in which these pathways are constitutively activated. In general, pharmacological perturbation of PI3/Akt (application of MK-2206) and MEK/ERK1/2 (application of PD0325901 or U0126) signaling led to a cell line and drug-specific decrease in the proliferation and migration potential of thyroid carcinoma cells, although to a varying extent. However, one exception became apparent: in Cal-62 cells inhibition of the MEK/ERK1/2 module increased the migration rate up to 50%. This effect could be prevented by a simultaneous suppression of the PI3/Akt pathway, but also by application of the multiple kinase inhibitor sorafenib, a treatment that did not change the activation state of Akt. Thus, a pharmacological perturbation of canonical signaling pathways in thyroid carcinoma may induce drug-dependent yin-yang effects that are characterized by a simultaneous suppression of one (i.e., proliferation) and the activation of another (i.e., migration) cellular process. The appearance of such phenomena should be taken into account when therapy plans are established.

Simeprevir for the treatment of chronic hepatitis C genotype 1 infection.

Simeprevir is a second-wave hepatitis C virus NS3/4A protease inhibitor that was designed to optimize its antiviral activity, safety, drug-drug interactions, and pharmacokinetic profile. When used to treat patients with hepatitis C virus genotype 1, simeprevir is coadministered with peginterferon and ribavirin for 12 weeks, followed by double therapy with Peg-IFN and ribavirin for an additional 12 or 36 weeks. Phase III studies achieved a sustained virologic response in 80-90% of treatment-naïve patients (International Phase III studies QUEST-1/2: 80/81%; Japanese Phase III trial CONCERTO-1: 89%). Unlike with the first protease inhibitors, telaprevir or boceprevir, used in triple therapy, when using simeprevir the frequency of clinically problematic adverse events such as anemia, rash, and digestive symptoms is almost comparable to that of double therapy. The advent of simeprevir has enabled interferon therapy, which started as monotherapy in early 1990s, to reach its maximum efficacy and arrive at what can be considered its final form at least in genotype 1b.

Preclinical and early clinical evaluation of the oral AKT inhibitor, MK-2206, for the treatment of acute myelogenous leukemia.

PURPOSE: Recent studies suggested that AKT activation might confer poor prognosis in acute myelogenous leukemia (AML), providing the rationale for therapeutic targeting of this signaling pathway. We, therefore, explored the preclinical and clinical anti-AML activity of an oral AKT inhibitor, MK-2206. Experimental Methods: We first studied the effects of MK-2206 in human AML cell lines and primary AML specimens in vitro. Subsequently, we conducted a phase II trial of MK-2206 (200 mg weekly) in adults requiring second salvage therapy for relapsed/refractory AML, and assessed target inhibition via reverse phase protein array (RPPA). RESULTS: In preclinical studies, MK-2206 dose-dependently inhibited growth and induced apoptosis in AML cell lines and primary AML blasts. We then treated 19 patients with MK-2206 but, among 18 evaluable participants, observed only 1 (95% confidence interval, 0%-17%) response (complete remission with incomplete platelet count recovery), leading to early study termination. The most common grade 3/4 drug-related toxicity was a pruritic rash in 6 of 18 patients. Nevertheless, despite the use of MK-2206 at maximum tolerated doses, RPPA analyses indicated only modest decreases in Ser473 AKT (median 28%; range, 12%-45%) and limited inhibition of downstream targets. CONCLUSIONS: Although preclinical activity of MK-2206 can be demonstrated, this inhibitor has insufficient clinical antileukemia activity when given alone at tolerated doses, and alternative approaches to block AKT signaling should be explored.

Preclinical evaluation of AMG 925, a FLT3/CDK4 dual kinase inhibitor for treating acute myeloid leukemia.

Acute myeloid leukemia (AML) remains a serious unmet medical need. Despite high remission rates with chemotherapy standard-of-care treatment, the disease eventually relapses in a major proportion of patients. Activating Fms-like tyrosine kinase 3 (FLT3) mutations are found in approximately 30% of patients with AML. Targeting FLT3 receptor tyrosine kinase has shown encouraging results in treating FLT3-mutated AML. Responses, however, are not sustained and acquired resistance has been a clinical challenge. Treatment options to overcome resistance are currently the focus of research. We report here the preclinical evaluation of AMG 925, a potent, selective, and bioavailable FLT3/cyclin-dependent kinase 4 (CDK4) dual kinase inhibitor. AMG 925 inhibited AML xenograft tumor growth by 96% to 99% without significant body weight loss. The antitumor activity of AMG 925 correlated with the inhibition of STAT5 and RB phosphorylation, the pharmacodynamic markers for inhibition of FLT3 and CDK4, respectively. In addition, AMG 925 was also found to inhibit FLT3 mutants (e.g., D835Y) that are resistant to the current FLT3 inhibitors (e.g., AC220 and sorafenib). CDK4 is a cyclin D-dependent kinase that plays an essential central role in regulating cell proliferation in response to external growth signals. A critical role of the CDK4-RB pathway in cancer development has been well established. CDK4-specific inhibitors are being developed for treating RB-positive cancer. AMG 925, which combines inhibition of two kinases essential for proliferation and survival of FLT3-mutated AML cells, may improve and prolong clinical responses.

Monascin improves diabetes and dyslipidemia by regulating PPARγ and inhibiting lipogenesis in fructose-rich diet-induced C57BL/6 mice.

Monascin (MS) is a yellow compound isolated from Monascus-fermented products that has pancreatic protective, anti-inflammatory, anti-oxidative, and hypolipidemic activity. We recently found that MS also acts as a peroxisome proliferator-activated receptor-gamma (PPARγ) agonist, thereby promoting insulin sensitivity in C2C12 cells. However, the attenuation of hyperglycemia by MS treatment in vivo remains uncertain. In the present study, both MS and pioglitazone significantly down-regulated blood glucose and hyperinsulinemia in fructose-rich diet (FRD)-induced C57BL/6 mice (8 weeks). In addition, inhibitions of inflammatory factor production, serum dyslipidemia, and hepatic fatty acid accumulation by MS and pioglitazone were attenuated by GW9662 (PPARγ antagonist). These results were mediated by MS-suppressing FRD-elevated lipogenic transcription factors, including sterol regulatory element-binding protein-1c (SREBP-1c), carbohydrate response element-binding protein (ChREBP), PPARγ coactivator-1α (PGC-1α), and PPARγ coactivator-1ß (PGC-1ß). Taken together, de novo lipogenesis results in hyperlipidemia and hyperglycemia by fructose induction thereby leading to diabetes development; we found that MS may inhibit lipogenesis in FRD-induced mice. These findings suggest that MS acts as an antidiabetic agent and thus may have therapeutic potential for prevention of diabetes.

Preclinical evaluation of a novel ATM inhibitor, KU59403, in vitro and in vivo in p53 functional and dysfunctional models of human cancer.

Ataxia telangiectasia mutated (ATM) kinase signals DNA double-strand breaks (DSB) to cell-cycle arrest via p53 and DNA repair. ATM-defective cells are sensitive to DSB-inducing agents, making ATM an attractive target for anticancer chemo- and radiosensitization. KU59403 is an ATM inhibitor with the potency, selectivity, and solubility for advanced preclinical evaluation. KU59403 was not cytotoxic to human cancer cell lines (SW620, LoVo, HCT116, and MDA-MB-231) per se but significantly increased the cytotoxicity of topoisomerase I and II poisons: camptothecin, etoposide, and doxorubicin. Chemo- and radiosensitization by ATM inhibition was not p53-dependent. Following administration to mice, KU59403 distributed to tissues and concentrations exceeding those required for in vitro activity were maintained for at least 4 hours in tumor xenografts. KU59403 significantly enhanced the antitumor activity of topoisomerase poisons in mice bearing human colon cancer xenografts (SW620 and HCT116) at doses that were nontoxic alone and well-tolerated in combination. Chemosensitization was both dose- and schedule-dependent. KU59403 represents a major advance in ATM inhibitor development, being the first compound to show good tissue distribution and significant chemosensitization in in vivo models of human cancer, without major toxicity. KU59403 provides the first proof-of-principle preclinical data to support the future clinical development of ATM inhibitors.