Citations

Human islet amyloid polypeptide (IAPP) is a 37-residue peptide that is co-secreted with insulin by the β-cell and might be involved in the pathogenesis of non-insulin-dependent diabetes mellitus. We developed an improved assay in vitrobased on the fluorescence of bound thioflavin T to study factors affecting amyloidogenesis. Monomeric IAPP formed amyloid fibrils, as detected by increased fluorescence and by electron microscopy. Fluorimetric analysis revealed that the initial rate of amyloid formation was: (1) proportional to the peptide monomer concentration, (2) maximal at pH 9.5, (3) maximal at 200 mM KCl, and (4) proportional to temperature from 4 to 37 °C. We found that 5-fold and 10-fold molar excesses of proinsulin inhibited fibril formation by 39% and 59% respectively. Insulin was somewhat more potent with 5-fold and 10-fold molar excesses inhibiting fibril formation by 69% and 73% respectively, whereas C-peptide had no effect at these concentrations. Thus at physiological ratios of IAPP to insulin, insulin and proinsulin, but not C-peptide, can retard amyloidogenesis. Because insulin resistance or hyperglycaemia increase the IAPP-to-insulin ratio, increased intracellular IAPP compared with insulin expression in genetically predisposed individuals might contribute to intracellular amyloid formation, β-cell death and the genesis of non-insulin-dependent diabetes mellitus.

Abstract Bowel obstruction is common sequelae of advanced ovarian cancer. Reports suggest that from 5.5 percent to 51 percent of ovarian cancer patients with Stage III or Stage IV disease develop a malignant bowel obstruction. During the course of the disease, one-third of all ovarian cancer patients also will develop pleural effusions, and three-quarters of these contain malignant cells. Such complications adversely affect both survival and quality of life. Our murine primary patient ovarian cancer intraperitoneal tumorgrafts (Avatars) maintain high fidelity of genetic aberrations from the original patient tumor, thus representing a clinically relevant model system. Expression microarray data of Avatars with preferential metastasis to the bowel has revealed upregulation of IGF2. To determine if IGF2 overexpression was sufficient for metastasis, four patient Avatars were transfected with IGF2/Gluc. In order to minimize the potential for genetic drift sometimes seen with in vitro culture, pre-transplantation tumors were minced and incubated with lentiviruses (Control vector or IGF-2/Gluc expression vector) ex-in vivo for a short time (2 hours), then directly transplanted intraperitoneally into immunodeficient mice (five or six mice in each Avatar model). Total 32 animals were used in this study. Stable transfection and overexpression of human IGF-2 was achieved and maintained after three passages as determined by ELISA on tumor tissue lysates. Only one out of 32 mice did not engraft tumor after three months, and tumor taking rate was 96.875%, similar to our previous passage successful rate at 98% and indicate that our ex-in vivo transfection method and overexpression of human IGF-2 did not substantially affect the tumor taking rate. By using Xenogen IVIS200 imaging system (Xenogen Corp.), pleural fluid was observed in all the Avatar mice with tumors overexpressing IGF-2 or not, and the retrieved pleural fluids were positive for malignant cells. However higher pleural nodules forming rate was more common in mice with IGF-2 overexpressing tumors 77% (n=9) vs 40% (n=6). In model PH003/IGF-2, the tumor had 100% bowel metastasis (n=9) compare to 60% in the control group (n=6). Taken together, our Avatar models not only effectively recapitulate ovarian cancer abdominal peritoneum metastasis, but also can mimic advanced ovarian cancer with malignant pleural fluid. The IGF-2 overexpression enhanced metastatic potential relative to control tumor. These results also indicate that the ex-in vivo transfection method developed in this study may be a viable approach for biological research and therapies. This work is funded by the Mayo Ovarian SPORE (CA136393). Citation Format: Xiaonan Hou, Marc A Becker, Saravut J Weroha, Kristina A Butler, Suzanne M Greiner, Paul Haluksa. Overexpression of IGF-2 in primary patient ovarian cancer tumorgrafts increases bowel and thoracic metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1196. doi:10.1158/1538-7445.AM2014-1196

Background— Oxidative stress may contribute to heart failure (HF) progression. Inhibiting xanthine oxidase in hyperuricemic HF patients may improve outcomes. Methods and Results— We randomly assigned 253 patients with symptomatic HF, left ventricular ejection fraction ≤40%, and serum uric acid levels ≥9.5 mg/dL to receive allopurinol (target dose, 600 mg daily) or placebo in a double-blind, multicenter trial. The primary composite end point at 24 weeks was based on survival, worsening HF, and patient global assessment. Secondary end points included change in quality of life, submaximal exercise capacity, and left ventricular ejection fraction. Uric acid levels were significantly reduced with allopurinol in comparison with placebo (treatment difference, –4.2 [–4.9, –3.5] mg/dL and –3.5 [–4.2, –2.7] mg/dL at 12 and 24 weeks, respectively, both P <0.0001). At 24 weeks, there was no significant difference in clinical status between the allopurinol- and placebo-treated patients (worsened 45% versus 46%, unchanged 42% versus 34%, improved 13% versus 19%, respectively; P =0.68). At 12 and 24 weeks, there was no significant difference in change in Kansas City Cardiomyopathy Questionnaire scores or 6-minute walk distances between the 2 groups. At 24 weeks, left ventricular ejection fraction did not change in either group or between groups. Rash occurred more frequently with allopurinol (10% versus 2%, P =0.01), but there was no difference in serious adverse event rates between the groups (20% versus 15%, P =0.36). Conclusions— In high-risk HF patients with reduced ejection fraction and elevated uric acid levels, xanthine oxidase inhibition with allopurinol failed to improve clinical status, exercise capacity, quality of life, or left ventricular ejection fraction at 24 weeks. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00987415.

BackgroundThere are no effective treatments that slow the progression of neurodegenerative diseases. A major challenge of treatment in neurodegenerative diseases is appropriate delivery of pharmaceuticals into the cerebrospinal fluid (CSF) of affected individuals. Mesenchymal stromal cells (MSCs—either naïve or modified) are a promising therapy in neurodegenerative diseases and may be delivered directly into the CSF where they can reside for months. In this preclinical study, we evaluated the safety of intrathecal autologous MSCs in a rabbit model.Study Design and MethodsAutologous adipose‐derived MSCs (or artificial CSF) were delivered intrathecally, either with single or with repeated injections into the foramen magnum of healthy rabbits and monitored for 4 and 12 weeks, respectively.ResultsRabbits tolerated injections well and no definitive MSC‐related side effects were observed apart from three rabbits that had delayed death secondary to traumatic foramen magnum puncture. Functional assessments and body weights were equivalent between groups. Gross pathology and histology did not reveal any abnormalities or tumor growth. Complete blood count data were normal and there were no differences in CSF interleukin‐6 levels in all groups tested.ConclusionOur data suggest that intrathecal delivery of autologous MSCs is safe in a rabbit model. Data from this study have supported two successful investigational new drug applications to the Food and Drug Administration, resulting in the initiation of two clinical trials using autologous MSCs in amyotrophic lateral sclerosis and multiple system atrophy.

Abstract Purpose: Ovarian cancer has a high recurrence and mortality rate. A barrier to improved outcomes includes a lack of accurate models for preclinical testing of novel therapeutics. Experimental Design: Clinically relevant, patient-derived tumorgraft models were generated from sequential patients and the first 168 engrafted models are described. Fresh ovarian, primary peritoneal, and fallopian tube carcinomas were collected at the time of debulking surgery and injected intraperitoneally into severe combined immunodeficient mice. Results: Tumorgrafts demonstrated a 74% engraftment rate with microscopic fidelity of primary tumor characteristics. Low-passage tumorgrafts also showed comparable genomic aberrations with the corresponding primary tumor and exhibit gene set enrichment of multiple ovarian cancer molecular subtypes, similar to patient tumors. Importantly, each of these tumorgraft models is annotated with clinical data and for those that have been tested, response to platinum chemotherapy correlates with the source patient. Conclusions: Presented herein is the largest known living tumor bank of patient-derived, ovarian tumorgraft models that can be applied to the development of personalized cancer treatment. Clin Cancer Res; 20(5); 1288–97. ©2014 AACR.