Evidence Of Weight Loss Research Articles

A growth-differentiation factor 15 receptor agonist in randomized placebo-controlled trials in healthy or obese persons.

Growth Differentiation Factor 15 (GDF15), a divergent member of the TGF-β superfamily, signals via the hindbrain glial-derived neurotrophic factor receptor alpha-like and rearranged during transfection receptor co-receptor (GFRAL-RET) complex. In nonclinical species, GDF15 is a potent anorexigen leading to substantial weight loss. MBL949 is a half-life extended recombinant human GDF15 dimer. MBL949 was evaluated in multiple nonclinical species and then in humans in two randomized and placebo-controlled clinical trials. In the Phase 1 first-in-human, single ascending dose trial MBL949 or placebo was injected subcutaneously to overweight and obese healthy volunteers (n=65) at doses ranging from 0.03 to 20 mg. In Phase 2, MBL949 or placebo was administered subcutaneously every other week for a total of 8 doses to obese participants (n=126) in five different dose regimens predicted to be efficacious based on data from the Phase 1 trial. In nonclinical species, MBL949 was generally safe and effective with reduced food intake and body weight in mice, rats, dogs, and monkeys. Weight loss was primarily from reduced fat, and metabolic endpoints improved. A single ascending dose study in overweight or obese healthy adults demonstrated mean terminal half-life of 18-22 days, and evidence of weight loss at the higher doses. In the Phase 2, weight loss was minimal following biweekly dosing of MBL949 for 14 weeks. MBL949 was safe and generally tolerated in humans over the dose range tested, adverse events of the gastrointestinal system were the most frequent observed. The prolonged half-life of MBL949 supports biweekly dosing in patients. MBL949 had an acceptable safety profile. The robust weight loss observed in nonclinical species did not translate to weight loss efficacy in humans. ClinicalTrials.gov NCT05199090.

Evidence of weight loss in junior female judo athletes affects their development

Evidence of weight loss in junior female judo athletes affects their development

Do people with type 2 diabetes find continuous and intermittent low-energy diets for weight loss and diabetes remission acceptable?

The Manchester Intermittent versus Daily Diet App Study (MIDDAS) tested the feasibility and potential efficacy of two remotely delivered low-energy diet (LED) programmes (800 kcal/day) to support weight loss and remission of type 2 diabetes: continuous [CLED] (8 weeks of daily LED) and intermittent [ILED] (2 days of LED/week for 28 weeks). Understanding participant experiences can help us to understand the acceptability of LED programmes to people with type 2 diabetes, informing future programme development and implementation. Twenty participants (10 CLED; 10 ILED) took part in interviews conducted at the end of the active weight loss phase (CLED week 12, ILED week 28). Interviews were transcribed and analysed thematically using the template analysis approach, with an a priori focus on acceptability. Four themes are presented: prospective acceptability, intervention coherence and perceived effectiveness, opportunity costs and self-efficacy. Both remotely supported CLED and ILED interventions appeared acceptable to participants. CLED participants found the rapid initial weight loss phase comparatively easy and highly motivating but expressed more concerns around weight maintenance. ILED participants found the more gradual weight loss initially frustrating but expressed greater confidence in their longer-term adherence. The importance of continued individualised support from healthcare professionals was emphasised, and evidence of weight loss and improvement in other medical markers through monitoring via the mobile phone app was useful. Different approaches to remotely delivered LEDs appear acceptable; therefore asking patients which approach may be more acceptable to them may be a useful way to offer individualised and tailored support.

Clinical experience in a 46-year-old male patient with tuberculous meningitis: Case Report

Introduction: Tuberculosis (TB) is one of the most common cause of death from a single infectious agent. Tuberculosis is primarily a disease of the lungs, but it can also affect other parts of the body and cause extrapulmonary tuberculosis (EPTB). Approximately 5 % of all cases of EPTB are tuberculous meningitis (TMB), caused by the spread of Mycobacterium tuberculosis in the meninges and cerebrospinal fluid (CSF). MTB is the most devastating form of tuberculosis and continues to cause high morbidity and mortality, with approximately 50 % of patients dying or suffering neurological sequelae and complications. The aim of the present study is to learn more about the etiologic, clinical and diagnostic presentation of this pathology. Case report: we present a 46-year-old male patient who reports productive cough of approximately 9 months of evolution with presence of diaphoresis, no evidence of weight loss, 15 days ago the patient reported cough accompanied by hemoptysis, reason for which he went to the nearest health center. His evolution was torpid and his tuberculosis was complicated to tuberculous meningitis where compatible signs and symptoms were evidenced, and immediate treatment was started with isoniazid, rifampicin, pyrazinamide, ethambutol and later four months with isoniazid and rifampicin. Conclusions: the rapid diagnosis of MTB requires an understanding and a joint analysis of the clinical, radiological and laboratory findings of our infected and uninfected patients and the evaluation of prognoses

Primary Isolated Breast Lymphoma Presenting as Primary Breast Cancer with 18F-FDG PET/CT.

A 40-year-old woman with a palpable mass lesion in her right breast suggested as breast cancer was admitted to 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) unit for the metabolic characterization of the lesion and for the staging of the disease. The patient had no fever and no evidence of weight loss or night sweats. 18F-FDG PET/CT revealed an isolated solid mass lesion with increased 18F-FDG uptake in the upper outer quadrant of the right breast and increased 18F-FDG uptake in the lymph nodes of the right axilla suspected as primary breast cancer and its local lymph node metastasis. There was no other pathological 18F-FDG uptake in the whole body. Excisional biopsy histopathology revealed diffuse large B-cell non-Hodgkin lymphoma.

Role of cholecystokinin in satiation: a systematic review and meta-analysis.

The aim of this review was to examine: (1) the ability of cholecystokinin (CCK) or analogues of CCK to influence satiation and changes in body weight generally and (2) the efficacy of CCK in influencing satiation and eating behaviour specifically at physiological levels of dosing. A systematic review of the literature was performed following the PRISMA 2020 guidelines in five electronic databases investigating the effect of exogenous CCK or analogues on satiation and body weight. A meta-analysis of studies that infused CCK and measured satiation via changes in food/energy intake was also conducted. A total of 1054 studies were found using the search terms which were reduced to fifteen studies suitable for inclusion. Of the twelve studies measuring the effect on the weight of food ingested or energy intake, eleven showed a decrease. An analogue of CCK which can be administered orally failed to produce any weight loss at 24 weeks. The meta-analysis found the effect of CCK on satiation dosed at physiological levels was significant with a standardised mean difference of 0·57 (95 % CI 0·30, 0·85, P < 0·0001). By comparison, CCK dosed at higher, pharmacological levels also had a significant effect with a standardised mean difference of 0·91 (95 % CI 0·46, 1·36, P < 0·0001). Eight of the ten studies in the meta-analysis combined CCK infusion with some means to facilitate stomach distension. The present review found evidence that at both physiological and pharmacological levels of dosing CCK has a significant effect on satiation but no evidence for weight loss over the long term.

Patient perceptions and understanding of obesity related endometrial cancer

Obesity is the greatest risk factor for endometrial cancer. There is often a lack of recognition amongst patients about this risk. Evidence for weight-loss in the management of endometrial cancer is emerging. This was questionnaire-based study, that examined opinions and attitudes of patients with endometrial cancer and obesity towards obesity as a risk factor for cancer as well as examining their willingness to engage in weight loss interventions as an alternative treatment to endometrial cancer. This survey was conducted in a gynaeoncology out-patient department in Ireland. A total of 45/50 (90%) of questionnaires were completed. The majority of the patients questioned (86.7%; 39/45) agreed that obesity is a disease. Just over half of the cohort (53.3%; 24/45) believed that obesity can cause cancer. Over one-third, 39.9% (18/45) either disagreed or strongly disagreed that obesity is a risk factor for endometrial cancer while 35.5% (16/45) agreed or strongly agreed. Two-thirds (66.6%; 30/45) knew that the greatest amount of weight could be lost through metabolic surgery. Over three-quarters (82.1%; 37/45) of patients surveyed would be willing to engage in a combination of treatments in order to achieve weight-loss should it be proven to have a role in the management of endometrial cancer. This study demonstrates a need for patient education regarding the strong relationship between obesity and endometrial cancer risk. Patients are willing to consider weight loss interventions if they were proven to be as safe and effective as pelvic surgery in the management of endometrial cancer.

Nutritional recommendations for gout: An update from clinical epidemiology.

To present the evidence for nutritional lifestyle changes recommended for gout patients; an explicit focus will be on the evidence for weight loss in overweight gout patients based on a recent systematic review and to describe methodological details for an upcoming weight loss trial. We did a pragmatic but systematic search in MEDLINE for current guidelines that had made an attempt to make nutritional recommendations for gout. The quality of the evidence for the nutritional recommendations was evaluated based on the guidelines' own ratings and converted into a common simple version based on the GRADE system. The recently published systematic review on weight loss for gout, was based on six databases from which longitudinal studies that had quantified the effects following weight loss were included. The internal validity was assessed with the ROBINS-I tool and the quality of the evidence was assessed with the GRADE approach. Based on the results of the systematic review, a trial was designed, adhering to the principles of evidence based research. We included 17 guidelines. Most guidelines recommend avoiding or limiting alcohol intake (15; i.e. 88%), lose weight if relevant (12; 71%), and reduce fructose intake (11; 65%). The majority of the evidence for the nutritional recommendations was rated Moderate/Low or Very Low quality. Our recent systematic review on weight loss included 10 studies and found that the available evidence indicates beneficial effects of weight loss for overweight and obese gout patients, but the evidence is of low to moderate quality. As a consequence, researchers from the Parker Institute are launching a randomized trial to explore the short-term effects related to a diet-induced weight loss in obese gout patients. The nutritional recommendations for gout are generally based on low quality evidence. In terms of weight loss as a management strategy, the available evidence is in favor of weight loss for overweight/obese gout patients. However, since the current evidence consists of only a few studies (mostly observational) of low methodological quality, the Parker Institute are now initiating a rigorous exploratory randomized trial. Similar efforts are needed for other nutritional management strategies for gout.

CoMET: a protocol for a randomised controlled trial of co-commencement of METformin as an adjunctive treatment to attenuate weight gain and metabolic syndrome in patients with schizophrenia newly commenced on clozapine

IntroductionClozapine, while effective in treatment refractory schizophrenia, is associated with significant weight gain, heart disease and increased risk of type 2 diabetes mellitus (T2DM). Although there is evidence for weight...

Re-engineering the Immune Response to Metastatic Cancer: Antibody-Recruiting Small Molecules Targeting the Urokinase Receptor.

Developing selective strategies to treat metastatic cancers remains a significant challenge. Herein, we report the first antibody-recruiting small molecule (ARM) that is capable of recognizing the urokinase-type plasminogen activator receptor (uPAR), a uniquely overexpressed cancer cell-surface marker, and facilitating the immune-mediated destruction of cancer cells. A co-crystal structure of the ARM-U2/uPAR complex was obtained, representing the first crystal structure of uPAR complexed with a non-peptide ligand. Finally, we demonstrated that ARM-U2 substantially suppresses tumor growth in vivo with no evidence of weight loss, unlike the standard-of-care agent doxorubicin. This work underscores the promise of antibody-recruiting molecules as immunotherapeutics for treating cancer.

Re‐engineering the Immune Response to Metastatic Cancer: Antibody‐Recruiting Small Molecules Targeting the Urokinase Receptor

AbstractDeveloping selective strategies to treat metastatic cancers remains a significant challenge. Herein, we report the first antibody‐recruiting small molecule (ARM) that is capable of recognizing the urokinase‐type plasminogen activator receptor (uPAR), a uniquely overexpressed cancer cell‐surface marker, and facilitating the immune‐mediated destruction of cancer cells. A co‐crystal structure of the ARM‐U2/uPAR complex was obtained, representing the first crystal structure of uPAR complexed with a non‐peptide ligand. Finally, we demonstrated that ARM‐U2 substantially suppresses tumor growth in vivo with no evidence of weight loss, unlike the standard‐of‐care agent doxorubicin. This work underscores the promise of antibody‐recruiting molecules as immunotherapeutics for treating cancer.

Garcinia cambogia: Evidence for weight loss, lipid-lowering effects

G. cambogia and HCA The active ingredient in G. cambogia, hydroxycitric acid (HCA), is a competitive inhibitor of adenosine triphosphate citrate lyase, a key enzyme in the synthesis of fatty acids, cholesterol, and triglycerides. HCA is thought to improve the body’s ability to break down fat, increase satiety, and increase high-density lipoprotein cholesterol. These effects may improve exercise tolerance, decrease fat storage, and improve lipids.4 Many G. cambogia products exist, with each containing different HCA concentrations. For weight loss, an extract containing 50% HCA, 1,000 mg three times daily or 500 mg four times daily, has been used. A mild adverse effect pro le has been established, including headache, nausea, upper respiratory tract symptoms, and gastrointestinal symptoms.4 In 2009, FDA warned patients about the risk of liver toxicity with the dietary supplement Hydroxycut, which contained G. cambogia at the time. However, FDA was unable to determine if G. cambogia was the true cause of the events or if they were attributable to other ingredients.5

Abstract 4279: A new class of immunomodulators derivatized from the Tat protein of HIV-1 in a murine breast cancer model

Abstract Introduction: Immunotherapies such as immune checkpoint inhibitors have had limited success in treating breast cancers. We observed that women with HIV infection and even AIDS have an unusually low incidence of breast cancer. The Tat protein of HIV-1 modulates innate immunity through activation of antigen presenting cells (APCs), and thus could be the reason for this finding. A Tat protein derivative designed to eliminate elements contributing to HIV-1 mediated immunosuppression was expressed as a recombinant protein in E. coli and found to stimulate monocytes to differentiate into antigen presenting cells. This protein, designated PIN-2, was tested in the syngeneic 4T1 murine breast cancer model, a poorly immunogenic and invasive triple negative breast cancer (TNBC) cell line. Methods: In vitro activity of PIN-2 was confirmed using a human monocyte activation assay that determined cell surface expression of CD80 and CD86 by flow cytometry after 72h of incubation with PIN-2, compared with controls. BALB/c mice were implanted orthotopically in the mammary fat pad with 10000 4T1 cells (ATCC No. CRL-2593). Treatment was initiated 7 days after implantation. Mice were administered 100ng PIN-2 intravenously 3x/week for 3 weeks. Tumors were measured 2x/week starting 12 days after implantation using a standard caliper method. Mice were sacrificed 29 days after implantation and examined macroscopically for spontaneous pulmonary metastases. Results: PIN-2 significantly increased human monocyte cell surface expression of costimulatory molecules CD80 and CD86 in vitro at concentrations as low as 30ng/mL culture compared to the negative control (P&amp;lt;0.01). The activation was dose dependent. In vivo, PIN-2 treatment reduced tumor volume to less than 60% of the tumor volume of untreated mice 29 days after tumor implantation (686 mm3 tumor size in placebo vs. 407mm3 in treated mice, p&amp;lt;0.01). Moreover, PIN-2 significantly inhibited the development of spontaneous 4T1 lung metastases (p&amp;lt; 0.05 when compared to placebo). Preliminary examination indicates that 90% of the mice in the control group had visible nodules on the surface of the lungs. Macroscopically visible metastases were reduced to only 50% of the PIN-2 treated mice. There was no evidence of weight loss or apparent toxicity by PIN-2. Conclusion: PIN-2 stimulates cell surface expression of costimulatory molecules that serve as markers for activated antigen presenting cells and are essential for cytotoxic T-cell activation. It reduces primary and metastatic tumor burden in an orthotopic murine model of TNBC. These data suggest that PIN-2 functions as an innate immune agonist to facilitate adaptive anti-tumor immune responses in a poorly immunogenic model of breast cancer. Moreover, PIN-2 appears to be well tolerated, supporting further evaluation of PINS in human breast cancer clinical trials. Citation Format: Christoph M. Hotz-Behofsits, Sophie J. Hanscom, Joshua B. Goldberg, Colin B. Bier. A new class of immunomodulators derivatized from the Tat protein of HIV-1 in a murine breast cancer model. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4279. doi:10.1158/1538-7445.AM2015-4279

Pathophysiological responses to a schistosome infection in a wild population of mourning doves (Zenaida macroura)

The blood trematode Gigantobilharzia huronensis typically infects passerine birds and has not been reported in other orders of wild birds. However, in the summer of 2011 in Tempe, Arizona, USA, mourning doves (Zenaida macroura; order: Columbiformes) were collected with infections of G. huronensis. This is the first report of a natural schistosome infection found in wild populations of doves. We sought to determine if G. huronensis infections alter the general body condition and physiology of doves, a seemingly unlikely host for this parasite. Specifically, we hypothesized that birds infected with schistosomes would exhibit reduced weight as well as increased markers of stress and immune system activation. Adult male mourning doves (n=14) were captured using walk-in style funnel traps. After weighing the birds, blood and mesenteric tissue samples were collected. We measured biomarkers of stress including circulating heat shock proteins (HSPs) 60 and 70, as well as oxidized lipoproteins in schistosome-infected and non-infected birds. Indices of immune system reactivity were assessed using agglutination and lysis assays in addition to determining the leukocyte to erythrocyte ratios and prevalence of hemoparasite infections from blood smears. Schistosome-infected mourning doves had significantly increased oxidative stress and evidence of HSP70 mobilization. There was no evidence for weight loss in schistosome-infected birds nor evidence of significant immune system activation associated with schistosome infection. This may be a reflection of the small sample size available for the study. These findings suggest that schistosome infections have pathological effects in doves, but the lack of mature worms suggests that infected birds in this sampling may not have been suitable hosts for parasite maturation.

Case Report: Moderately Differentiated Ulcerated Gallbladder Squamous Cell Carcinoma

Objectives: To enrich the scant scientific evidence existing on this subject. Rationale: Because of this rarity of information, works like this one are indispensable for the scientific, academic and professional community by dealing with an uncommon theme with unique features. Methodology: This study was done with access to the BIREME database, as well as reviewing the patient’s chart. Case description: woman, 71 years old, morbidly obese with of BMI 42, complaining of pain in the right hypochondrium for ten days, positive Murphy’s sign, but without peritonitis markings. An ultrasonography of the abdomen showed gallstones with wall thickening suggestive of neoplasia. Underwent surgery after clearing the infection. During surgery, discovered the gallbladder was covered by omentum, blocked by the transverse colon and duodenum. Having cleared the adhesions, performed cholecystectomy segmentectomy and the anterior portion of segments IV and V after confirmation of malignancy freezing. The histopathological (HE and immunohistochemistry) of the surgical specimen pointed to ulcerated carcinoma moderately differentiated squamous cells. Discussion: squamous cell carcinomas are rare, thus creating sparse and sometimes diversive literature. Usually diagnosed in advanced stages as in the early stages it is considered to be a silent disease. The patient had typical clinical cholecystitis without evidence of weight loss or palpable bladder, in agreement with the literature, in which case most diagnoses are intraoperative, because of the similarity of the clinical picture. The biological behavior of squamous cell cancer is characterized by rapid growth, early metastatic spread and features local and regional infiltration, which also happened to the patient, described being found intraoperatively covered by omentum gallbladder, blocked by the transverse colon and duodenum, beyond the liver involvement, after confirmation by freezing. Although the patient in question had increased GGT present in their examinations, the involvement of the biliary tract was not evident. Conclusion: The reported case and cited publications lead to the conclusion that its being a rare histological type, and thus without extensive literature, a lot of data such as the actual outcome of these patients and the survival time are underestimated and difficult to locate meaningful data.

The diagnosis and management of non-alcoholic fatty liver disease: Practice Guideline by the American Association for the Study of Liver Diseases, American College of Gastroenterology, and the American Gastroenterological Association

These recommendations are based on the following: (1) a formal review and analysis of the recently published world literature on the topic [Medline search up to June 2011]; (2) the American College of Physicians’ Manual for Assessing Health Practices and Designing Practice Guidelines; (3) guideline policies of the three societies approving this document; and (4) the experience of the authors and independent reviewers with regards to NAFLD. Intended for use by physicians and allied health professionals, these recommendations suggest preferred approaches to the diagnostic, therapeutic and preventive aspects of care. They are intended to be flexible and adjustable for individual patients. Specific recommendations are evidence-based wherever possible, and when such evidence is not available or inconsistent, recommendations are made based on the consensus opinion of the authors. To best characterize the evidence cited in support of the recommendations, the AASLD Practice Guidelines Committee has adopted the classification used by the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) workgroup with minor modifications (Table 1). The strength of recommendations in the GRADE system is classified as strong (1) or weak (2). The quality of evidence supporting strong or weak recommendations is designated by one of three levels: high (A), moderate (B) or low-quality (C). This is a practice guideline for clinicians rather than a review article and interested readers can refer to several comprehensive reviews published recently.

Reassessment of motor-behavioural test analyses enables the detection of early disease-onset in a transgenic mouse model of amyotrophic lateral sclerosis

As a model for amyotrophic lateral sclerosis (ALS), transgenic hSOD1 G93A mice constitute the standard tool for evaluating future therapeutic strategies. Due to axonal retraction from neuromuscular junctions, the animals suffer from muscle wasting leading to weakness and paralysis of the extremities, which in early stages can be detected by measuring weight loss. Suspecting that underlying mechanisms might yield subtle neuromuscular abnormalities ahead of weight loss onset, we wanted to determine a behavioural test to detect disease onset time earlier. We compared the monitoring of weight with the “forced” examination of grip strength and the investigation of freely behaving animals within an open field. Additionally, we compared two different data analysis methods: (1) two-way ANOVA with Bonferroni correction (2) break point analysis calculating symptom onset time points for each animal. Break point analysis revealed onset times that significantly preceded those obtained by standard two-way ANOVA. Open field analysis of freely moving animals could not give an advantage over weight loss measurements. Grip strength assessment of hindlimbs detected disease onset 36 days before the first evidence of weight loss, providing a maximal treatment window of 84 days on average before the death of male animals. We conclude that grip strength analysis of hindlimbs is a very sensitive and reproducible motor behavioural test, which can even be applied to small cohorts of animals. Combined with break point analysis, it represents the method of choice to detect early disease onset in hSOD1 G93A mice.

A small-molecule inhibitor of D-cyclin transactivation displays preclinical efficacy in myeloma and leukemia via phosphoinositide 3-kinase pathway

AbstractD-cyclins are universally dysregulated in multiple myeloma and frequently overexpressed in leukemia. To better understand the role and impact of dysregulated D-cyclins in hematologic malignancies, we conducted a high-throughput screen for inhibitors of cyclin D2 transactivation and identified 8-ethoxy-2-(4-fluorophenyl)-3-nitro-2H-chromene (S14161), which inhibited the expression of cyclins D1, D2, and D3 and arrested cells at the G0/G1 phase. After D-cyclin suppression, S14161 induced apoptosis in myeloma and leukemia cell lines and primary patient samples preferentially over normal hematopoietic cells. In mouse models of leukemia, S14161 inhibited tumor growth without evidence of weight loss or gross organ toxicity. Mechanistically, S14161 inhibited the activity of phosphoinositide 3-kinase in intact cells and the activity of the phosphoinositide 3-kinases α, β, δ, and γ in a cell-free enzymatic assay. In contrast, it did not inhibit the enzymatic activities of other related kinases, including the mammalian target of rapamycin, the DNA-dependent protein kinase catalytic subunit, and phosphoinositide-dependent kinase-1. Thus, we identified a novel chemical compound that inhibits D-cyclin transactivation via the phosphoinositide 3-kinase/protein kinase B signaling pathway. Given its potent antileukemia and antimyeloma activity and minimal toxicity, S14161 could be developed as a novel agent for blood cancer therapy.

Inhibitor of the CREB Proto-Oncogene Suppresses AML Cell Proliferation and Induces Apoptosis In Vitro and In Vivo

AbstractAbstract 3270The cAMP Response Element Binding Protein, CREB, is a nuclear transcription factor that is critical for cell proliferation, differentiation, and survival in a variety of cell types. We previously demonstrated that CREB is overexpressed in leukemia blasts from greater than 60% of patients with AML. CREB overexpression is also associated with an increased risk of relapse and decreased event free survival in a cohort of AML patients. To understand the role of CREB in leukemogenesis, a transgenic mouse was created by overexpressing CREB under the control of the hMRP8 promoter in Gr-1/Mac-1 + myeloid cells. Bone marrow progenitors from these mice have increased proliferative potential and replating ability. CREB transgenic mice developed myeloproliferative disease after one year, but not acute myeloid leukemia suggesting that CREB is not sufficient to induce complete transformation. Given these results, we hypothesized that CREB could be a potential target for AML therapy. To test this possibility, we knocked down CREB using lentiviral shRNAs in primary mouse hematopoietic stem cells in vitro and in vivo. Downregulation of CREB resulted in significant decrease in myeloid colony numbers in methylcellulose colony assays. However, there was no effect of CREB knockdown in hematopoietic stem cell numbers or long-term engraftment by stem cell transduction and transplantation experiments. In contrast, inhibition of CREB by shRNAs in human myeloid leukemia cells and Ba/F3 cells transduced with T315I mutant BCR-ABL resulted in suppression of growth of leukemia cells in vitro and in NOD-SCID mice. Taken together, these data suggest that CREB preferentially inhibits the growth of leukemia cells without significantly affecting normal hematopoietic stem cell proliferation or function. To target CREB in AML cells, a small molecule, XX-650-23 (MW: 288.3), was developed to inhibit the interaction between CREB and its binding partner, the histone acetyltransferase CBP (CREB Binding Protein). We tested the effects of the drug on AML cell lines Molm-13 and MV-411 in vitro using MTT assays and trypan blue exclusion. The IC50 for both cell lines was between 1–2 micromolar concentration after 72 hours of treatment. Our results also demonstrated that treatment of MV-411 cells with XX-650-23 not only inhibited cell proliferation but also resulted in apoptosis. Treatment of normal human bone marrow progenitors with XX-650-23 had no effect on colony numbers in methylcellulose containing IL-3, IL-6, and Stem Cell Factor up to 10 micromolar concentration. NOD-SCID IL-2Rgamma null (NSG) mice treated with the drug at 10, 15, 17.5, and 20 mg/kg IP once daily for 28 days had no evidence of weight loss or toxicity to organs as measured by peripheral blood counts and chemistries to assess kidney and liver function. We next tested the drug in xenograft models of AML with MV-411 cells (2×106) injected subcutaneously into the flanks of NSG mice. Three groups of 5 mice were treated with either XX-650-23 or vehicle control at 17.5 mg/kg IP daily at the time of injection of MV-411 cells or after the tumors reached a size of 300 mm3. Serum drug concentration 1 hour after first injection was 33 nM. Estimated drug mean residence time was 7.5 hours, and plasma clearance was 9.6 ml/min/kg, assuming complete IP absorption. Our results demonstrated a significant inhibition of tumor growth with treatment of the drug and MV-411 cells at the same time on Day 1. There was also an effect of the drug alone when treated after the tumor reached a size of 300 mm3, although less dramatic. These data suggest that development of a drug that targets CREB is a novel approach to treat AML. We are currently optimizing the treatment of AML cells with XX-650-23 in mice and investigating the downstream signaling pathways to understand the mechanism by which XX-650-23 suppresses proliferation and induces apoptosis of AML cells. Disclosures:Sakamoto:Abbott Laboratories, Inc.: Research Funding; Genentech, Inc.: Research Funding.

The Antihelmintic Flubendazole Inhibits Microtubules through a Mechanism Distinct From Vinca Alkaloids and Displays Preclinical Activity in Leukemia and Myeloma.

Abstract 1017Poster Board I-39On patent and off-patent drugs with previously unrecognized anti-cancer activity, could be rapidly repurposed for this new indication given their prior toxicity testing. To identify such compounds, we compiled and screened a chemical library for potential anti-leukemia agents. From these screens, we identified the antihelmintic flubendazole that is currently used for the treatment of gastrointestinal and systemic parasites, but has not been evaluated for the treatment of malignancy. To explore its efficacy as an anti-cancer agent, leukemia and myeloma cell lines were treated with increasing concentrations of flubendazole. Seventy-two hours after incubation, cell viability was measured by the MTS assay. Flubendazole reduced cell viability with an LD50 ≤ 1 μM in 8/8 myeloma and 4/6 leukemia cell lines, a concentration that is pharmacologically achievable. Likewise, flubendazole reduced the clonogenic growth of primary AML samples at nanomolar concentrations. Cell death was confirmed by Trypan blue staining. Given the effects in leukemia and myeloma cells lines, we evaluated the effects of flubendazole in mouse models of leukemia and myeloma. Sublethally irradiated SCID mice were injected subcutaneously with OCI-AML2 leukemia or OPM2 myeloma cells. Mice were then treated intraperitoneally with flubendazole (20-50 mg/kg/day – doses more than 10-fold lower than the LD50) or buffer alone. Flubendazole decreased tumor weight and volume in both mouse models up to 5-fold compared to control without evidence of weight loss or gross organ toxicity. Mechanistically, flubendazole inhibited bovine-tubulin polymerization in cell-free assays and disrupted microtubule architecture in intact cells as visualized by confocal microscopy. We demonstrated that flubendazole bound tubulin at the colchicine binding site, a region distinct from where vinca-alkaloids bind. Flubendazole arrested cells in the G2 phase of the cell cycle and increased the number of multi-nucleated cells. We also demonstrated that cell death after flubendazole treatment was related to its ability to inhibit microtubule polymerization by using cell lines with tubulin mutations (gifts from Dr F. Loganzo, Wyeth, Pearl River, NY and Drs. S. Band Horwitz and C. Yang, Albert Einstein College of Medicine, Bronx, NY). Vinca-alkaloids are p-glycoprotein (Pgp) substrates and Pgp over-expression can limit the efficacy of these agents. Therefore, we tested the effects of Pgp over-expression on flubendazole's cytotoxicty. CEM-VBL cells over-expressing Pgp remained fully sensitive to flubendazole, but were over 1000-fold more resistant to vinblastine than wild type CEM cells. Therefore, flubendazole can overcome some forms of vinca-alkaloid resistance. Given that flubendazole binds tubulin at a site distinct from vinca-alkaloids, we evaluated the combination of flubendazole and vinblastine in vitro and in vivo. OCI-AML2 leukemia cells were treated with increasing concentrations of flubendazole and vinblastine. Flubendazole and vinblastine synergistically induced cell death with combination index (CI) values of 0.09, 0.017, 0.003 and 0.001 at the EC 50, 25, 10 and 5, respectively, where CI values <1 are considered synergistic. In contrast, cell death produced by the combination of flubendazole and colchicine was closer to additive with CI values of 0.54, 0.70, 0.897 and 1.07 at EC 50, 25, 10 and 5, respectively. As the combination of flubendazole and vinblastine were synergistic in cell culture, we evaluated the combination in vivo. Mice injected subcutaneously with OCI-AML2 cells were treated with flubendazole (15 mg/kg), vinblastine (0.3 mg/kg) or the combination of the two agents. The combination decreased tumor weight and volume greater than either agent alone without behavioural changes, weight loss, or gross organ toxicity. Similar effects were observed with the in vivo combination of flubendazole and vincristine. Since neurotoxicity is a dose limiting toxicity of vinca-alkaloids such as vincristine, we evaluated the neurotoxicity of flubendazole in mice using the Tail Flick assay. At doses up to 200mg/kg daily of flubendazole, no neurotoxicity was observed. Thus, flubendazole is a novel microtubule inhibitor that displays preclinical activity in leukemia and myeloma. Given its prior safety record when evaluated for the treatment of parasitic disease, flubendazole could be rapidly repurposed for the treatment of hematologic malignancies. Disclosures:Off Label Use: Flubendazole is used to treat gastrointestinal and systemic parasite infections.