Standard Therapeutic Agents Research Articles

Screening of a library of traditional Chinese medicines to identify compounds and extracts which inhibit Toxoplasma gondii growth.

Toxoplasma gondii can cause severe encephalitis in immunocompromised patients. Although pyrimethamine and sulphadiazine have been standard therapeutic agents for the treatment of acute toxoplasmosis, they have toxic side effects. Therefore, there is a need to identify new drugs that are less toxic. Some traditional Chinese medicines (TCMs) have shown good efficacy in controlling T. gondii replication in mouse models. Here, we screened a natural product library comprising TCMs with the aim of identifying compounds and extracts with anti-toxoplasmosis activities. We found several hit compounds and extracts that could be candidates for new drugs against T. gondii infection.

Docosahexaenoic acid suppresses migration of triple-negative breast cancer cell through targeting metastasis-related genes and microRNA under normoxic and hypoxic conditions.

There is insufficient evidence with respect to the effect of the standard anticancer therapeutic agents as well as common dietary supplements on the expression of such genes and microRNAs (miRNAs). Therefore, this study was aimed to study the effect of applying linoleic acid (LA) and docosahexaenoic acid (DHA) fatty acids alone or combined with Taxol on the expression of the matrix metalloproteinase (MMP)-9, MMP-2, vimentin, and talin2 genes, tumor-suppressor miR-194 and, onco-miR-106b in triple-negative breast cancer cell line, known as MDA-MB-231. MDA-MB-231 as metastatic breast cancer cell line was cultured and treated using 0.3 μM Taxol, 100 μM DHA, and 50 μM LA for 24 hours, alone or combined with Taxol under the normoxic and hypoxic conditions. Cells were harvested, after RNA extraction and complementary DNA synthesis, analysis of the expression levels of the studied genes and miRNAs was done through the use of the quantitative real-time polymerase chain reaction (qRT-PCR). Wound healing assay and Western blot analysis were also performed for confirmation. The results of qRT-PCR showed that treating the MDA-MB-231 cells with DHA caused an increase in the miR-194 expression and a decrease in the miR-106b expression, leading to the downregulation of the MMP-2 and MMP-9, and vimentin, and upregulation of the talin2 under the normoxic and hypoxic conditions. The results of the wound healing scratch assay revealed that the administration of the DHA and the DHA-Taxol combination caused the repression of cell migration in comparison with the control groups under the normoxic and hypoxic conditions. The results of the Western blot analysis demonstrated that DHA and the DHA-Taxol combination caused an increase in the expression of the talin2 protein rather than the control cells under both normoxic and hypoxic conditions. This study showed that DHA has significant antimetastatic effects against the triple-negative breast cancer cells. DHA could serve as a promising supplementation for suppressing the breast cancer cell migration, especially under the hypoxic condition.

Role of GOLPH3 and TPX2 in Neuroblastoma DNA Damage Response and Cell Resistance to Chemotherapy.

Neuroblastoma (NB) is an aggressive, relapse-prone infancy tumor of the sympathetic nervous system and is the leading cause of death among preschool age diseases, so the search for novel therapeutic targets is crucial. Golgi phosphoprotein 3 (GOLPH3) has been reported to be involved in the development, and in the DNA damage response, of various human cancers. Golgi dispersal is a common feature of DNA damage response in mammalian cells. Understanding how cells react to DNA damage is essential in order to recognize the systems used to escape from elimination. We induced DNA damage in two human neuroblastoma cell lines by curcumin. The exposure of neuroblastoma cells to curcumin induced: (a) up-regulation of GOLPH3+ cells; (b) augmentation of double-strand breaks; (c) Golgi fragmentation and dispersal throughout the cytoplasm; (d) increase of apoptosis and autophagy; (e) increased expression of TPX2 oncoprotein, able to repair DNA damage. Primary neuroblastoma samples analysis confirmed these observations. Our findings suggest that GOLPH3 expression levels may represent a clinical marker of neuroblastoma patients’ responsiveness to DNA damaging therapies—and of possible resistance to them. Novel molecules able to interfere with GOLPH3 and TPX2 pathways may have therapeutic benefits when used in combination with standard DNA damaging therapeutic agents in neuroblastoma

OXACILLIN RESISTANT STAPHYLOCOCCUS AUREUS FROM DIVERSE SOURCES IN NNEWI NIGERIA: SUSCEPTIBILITY TO VANCOMYCIN, LINEZOLID, TEICOPLANIN AND MEDICINAL PLANT EXTRACTS

Background:  Methicillin (Oxacillin)-resistant S. aureus (MRSA or ORSA) remains a major public health concern. This concern has raised the need to continually monitor the susceptibility profile of local MRSA isolates to standard anti-MRSA therapeutic agents. Objective: To isolate MRSA from diverse sources in our locality and to determine their susceptibility to Vancomycin, Linezolid, Teicoplanin, and to extracts of Parkia biglobosa and Vanda roxburgii – medicinal plants commonly used in the treatment of wound sepsis in our locality.  Method: A total of 34 raw meat samples were randomly collected from butchers in Nnewi main market. Other samples collected included: water samples from the market supplies, nasal swabs from 15 butchers, nasal and oral swabs from 8 pet dogs, and surface swab from ten local currency notes. The samples were screened for ORSA. Inhibitory concentrations of Oxacillin to isolates were compared with those of other anti-MRSA agents and to medicinal plants extracts. Results: Results showed that 27 (79%) of meat samples yielded ORSA. The recovery rates of ORSA from other samples were as follows: pet dogs 7(88%), butchers 4 (27%), local currency notes 4(40%), and water supplies 1(50%). Thirteen (34%) of ORSA were of a classic phenotype (MIC ? 16 µg/ml). Linezolid MIC ranged from 0.015 – 4µg/ml, while Vancomycin ranged from 0.06 – 4µg/ml. All isolates (100%) were susceptible to teicoplanin. The MIC of the medicinal plant extracts ranged from 0.098 – 6.25mg/ml. Conclusion: Results suggests that plants could be a valuable source of anti-MRSA drugs and that, pet animals, currency notes, and raw meat, could expose to risk of acquiring ORSA.

Role of bone marrow adipocytes in leukemia and chemotherapy challenges.

Adipose tissue (AT) is an extramedullary reservoir of normal hematopoietic stem cells (HSCs). Adipocytes prevent the production of normal HSCs via secretion of inflammatory factors, and adipocyte-derived free fatty acids may contribute to the development and progression of leukemia via providing energy for leukemic cells. In addition, adipocytes are able to metabolize and inactivate therapeutic agents, reducing the concentrations of active drugs in adipocyte-rich microenvironments. The aim of this study was to detect the role of adipocytes in the progression and treatment of leukemia. Relevant literature was identified through a PubMed search (2000-2018) of English-language papers using the following terms: leukemia, adipocyte, leukemic stem cell, chemotherapy, and bone marrow. Findings suggest the striking interplay between leukemic cells and adipocytes to create a unique microenvironment supporting the metabolic demands and survival of leukemic cells. Based on these findings, targeting lipid metabolism of leukemic cells and adipocytes in combination with standard therapeutic agents might present novel treatment options.

Rate of all infection for ustekinumab versus standard oral systemic therapeutic agents (acitretin, cyclosporine, or methotrexate) in the management of psoriasis: A report from the RADAR (Research on Adverse Drug events And Reports) project

Rate of all infection for ustekinumab versus standard oral systemic therapeutic agents (acitretin, cyclosporine, or methotrexate) in the management of psoriasis: A report from the RADAR (Research on Adverse Drug events And Reports) project

Mathematical models of cytotoxic effects in endpoint tumor cell line assays: critical assessment of the application of a single parametric value as a standard criterion to quantify the dose-response effects and new unexplored proposal formats.

The development of convenient tools for describing and quantifying the effects of standard and novel therapeutic agents is essential for the research community, to perform more precise evaluations. Although mathematical models and quantification criteria have been exchanged in the last decade between different fields of study, there are relevant methodologies that lack proper mathematical descriptions and standard criteria to quantify their responses. Therefore, part of the relevant information that can be drawn from the experimental results obtained and the quantification of its statistical reliability are lost. Despite its relevance, there is not a standard form for the in vitro endpoint tumor cell lines' assays (TCLA) that enables the evaluation of the cytotoxic dose-response effects of anti-tumor drugs. The analysis of all the specific problems associated with the diverse nature of the available TCLA used is unfeasible. However, since most TCLA share the main objectives and similar operative requirements, we have chosen the sulforhodamine B (SRB) colorimetric assay for cytotoxicity screening of tumor cell lines as an experimental case study. In this work, the common biological and practical non-linear dose-response mathematical models are tested against experimental data and, following several statistical analyses, the model based on the Weibull distribution was confirmed as the convenient approximation to test the cytotoxic effectiveness of anti-tumor compounds. Then, the advantages and disadvantages of all the different parametric criteria derived from the model, which enable the quantification of the dose-response drug-effects, are extensively discussed. Therefore, model and standard criteria for easily performing the comparisons between different compounds are established. The advantages include a simple application, provision of parametric estimations that characterize the response as standard criteria, economization of experimental effort and enabling rigorous comparisons among the effects of different compounds and experimental approaches. In all experimental data fitted, the calculated parameters were always statistically significant, the equations proved to be consistent and the correlation coefficient of determination was, in most of the cases, higher than 0.98.

Abstract A16: Establishment and characterization of CCGL007, a novel human chronic lymphocytic leukemia cell line

Abstract Chronic lymphocytic leukemia (CLL) is a monoclonal disorder characterized by a progressive accumulation of functionally incompetent lymphocytes. However, lack of immortalized cell line representative of the CLL disease has hampered a full understanding of disease pathogenesis and development of novel therapeutic agents for treatment. There were very few representative CLL cell lines are available now. To this end, we have tested different culture condition with addition of growth factor supplements to generate CLL cell lines from highly purified peripheral blood B cells of CLL patients. Recently, we have successfully established a new CLL cell line, named CCGL007. CCGL007 cells grow as suspension in liquid culture. Surface marker analysis with a panel of monoclonal antibodies revealed that CCGL007 cell line expresses B cell markers. The chromosomal, immunophenotypic, molecular biologic characteristics, and in vivo tumorigenesis potential of CCGL007 is under investigation. We have used this cell model to test the efficacy of selected standard chemotherapy drugs and new therapeutic agents, such as ibrutinib and several novel in-house BTK inhibitors, against CLL cell growth, and CCGL007 represents as a suitable preclinical model for testing pharmacological agents. Citation Format: Ching-Chuan Kuo, Chih-Cheng Chen, Chih-Hsiang Huang, Lin Li-Mei. Establishment and characterization of CCGL007, a novel human chronic lymphocytic leukemia cell line. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr A16.

RNA Polymerase I Inhibition with CX-5461 As a Novel Strategy to Target MYC in Multiple Myeloma

Background: The role of dysregulation of the proto-oncogene MYC in both early and late myeloma progression events is well established. Among key MYC -downstream targets is upregulation of ribosomal biogenesis, resulting in increased protein translational capacity and biomass accumulation that is characteristic of neoplastic cells. Thus, given the relationship between myeloma pathobiology, MYC dysregulation, and ribosomal biogenesis, we hypothesized that selective targeting of ribosomal RNA (rRNA) transcription with the small molecule RNA polymerase (pol) I inhibitor CX-5461 (Senhwa Biosciences) may represent a novel therapeutic strategy in myeloma.Methods: Studies with CX-5461 were performed in human myeloma cell lines, isogenic p53 wild-type (wt) and knock-out (KO) p53 cells generated using sequence-specific zinc-finger nucleases, drug-resistant cell lines, primary patient samples, and myeloma murine xenograft models using NOD-SCID IL2Rgnull mice.Results: CX-5461 treatment of p53 wt (MM1.S, MOLP-8) and p53 mutant (U266, RPMI-8226) myeloma cell lines demonstrated a time- and dose-dependent decrease in cell proliferation with a median inhibitory concentration (IC50) at nM levels after 72 hours. A corresponding increase in cleaved-PARP, cleaved caspase-9, and cleaved caspase-3 expression was seen on Western blot as well as increased Annexin V staining on flow cytometry analysis, although this was more pronounced in p53 wt versus mutant cell lines. CX-5461 also retained activity in a panel of cell lines resistant to standard myeloma therapeutic agents (bortezomib, carfilzomib, lenalidomide, and doxorubicin) and in primary patient samples, including a heavily pretreated relapsed/refractory patient and a de novo plasma cell leukemia patient with del 17p. In vivo studies using a systemic isogenic MM1.S p53 wt and KO myeloma murine xenograft model demonstrated significant improvement in median overall survival in the CX-5461-treated p53 wt cohort (41 days vs. not reached, P .05), although outcomes were more modest in the p53 KO cohort with only a trend towards improved survival (P.1) in the drug-treated mice.To probe the p53-independent effects of CX-5461, gene expression profiling and gene set enrichment analysis was performed on isogenic MM1.S and MOLP-8 p53 wt and KO myeloma cell lines treated with CX-5461 or vehicle. These results suggested downregulation of MYC downstream targets as one p53-independent effect of RNA pol I inhibition. qPCR and Western blot studies revealed rapid downregulation of MYC at the transcript level within 1-hour of CX-5461 treatment followed by decreases in MYC protein levels.Previous studies have suggested ribosomal biogenesis is tightly controlled by an auto-regulatory feedback mechanism in which ribosomal proteins such as RPL5 and RPL11 can bind to the 3'UTR of MYC mRNA and facilitate its degradation through the RNA-induced silencing complex (RISC). Because RNA pol I inhibition is known to induce a nucleolar stress response and increase the availability of free ribosomal proteins, RISC-mediated degradation of MYC mRNA was explored as one possible mechanism of CX-5461-mediated MYC downregulation. Indeed, treatment with CX-5461 led to increased pull-down of RPL5 when immunoprecipitated with the RISC subunit TAR (HIV-1) RNA Binding Protein 2 (TARBP2) compared to vehicle-treated controls, and RNA immunoprecipitation assays with the catalytic RISC subunit, Argonaute 2 (AGO2), demonstrated enrichment of MYC mRNA with CX-5461 treatment. These results suggest that CX-5461 may induce degradation of MYC through the cooperative binding of ribosomal proteins, RISC subunits, and MYC mRNA.Finally, to evaluate the role of MYC expression and ribosomal biogenesis in relation to CX-5461 sensitivity, MYC was overexpressed in the H1112 myeloma cell line, which at baseline does not harbor a MYC translocation. MYC overexpression in H1112pCDH-myc cells led to increased basal pre-rRNA transcript levels compared to H1112pCDH cells, and furthermore, led to enhanced sensitivity to CX-5461.Conclusion: RNA pol I inhibition by CX-5461 is a promising target in myeloma therapy, with downregulation of MYC representing one mechanism of action. Moreover, increased MYC expression enhances sensitivity to CX-5461, providing rationale for the clinical translation of CX-5461 for the treatment of myeloma and other MYC-driven cancers. DisclosuresO'Brien:Senhwa Biosciences, Inc.: Employment. Keats:Translational Genomic Research Institute: Employment. Orlowski:Bristol-Myers Squibb: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Spectrum Pharmaceuticals: Research Funding; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Acetylon: Membership on an entity's Board of Directors or advisory committees; Onyx Pharmaceuticals: Consultancy, Research Funding; Millennium Pharmaceuticals: Consultancy, Research Funding; Forma Therapeutics: Consultancy; Genentech: Consultancy; BioTheryX, Inc.: Membership on an entity's Board of Directors or advisory committees; Array BioPharma: Consultancy, Research Funding.

Abstract 4560: Targeting chronic lymphocytic leukemia with p53 deficiency with phenethyl isothiocyanate

Abstract Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the United States and Europe. Despite recent advance in new therapeutic agents that have improved treatment outcomes, CLL remains incurable. CLL patients with loss of p53 due to unfavorable cytogenetic alterations such as chromosome 17p deletion often exhibit more malignant disease phenotype, are resistant to many standard therapeutic agents, and have poor clinical outcomes. Thus, finding effective treatment for CLL with p53 deficiency represents a significant challenge, and development new agents and therapeutic strategies to effectively kill CLL cells with loss of p53 function would have profound clinical implications in CLL treatment. We have recently created a mouse model with Tcl1-Tg:p53-/- genotype that resembles the aggressive human CLL disease with p53 deficiency (17p-deletion). We showed that leukemia cells isolated from this mouse model as well as primary human leukemia cells with 17p deletion isolated from CLL patients are resistant to standard anti-CLL agents. Because p53 plays important roles in regulation of apoptosis and in maintaining mitochondrial function/normal metabolism/redox homeostasis, we hypothesized that a loss of p53 function in CLL with 17p- or p53 mutations would on one hand lead to drug resistance and poor therapeutic response to conventional treatment, and would on the other hand also cause mitochondrial dysfunction and high ROS stress. Our study tested the possibility to use the high oxidative stress as a biochemical basis to effectively target the drug-resistant CLL cells with p53 deletion using redox-modulating strategy in vitro and in vivo. Our results showed that ROS-mediating strategies could overcome drug resistance of CLL cells with p53 deficiency, and was able to effectively eliminate fludarabine-resistant CLL cells using phenethyl isothiocyanate (PEITC), which induced rapid glutathione depletion and caused severe ROS accumulation leading to massive death of CLL cells in culture. Importantly, PEITC also exhibited promising in vivo therapeutic activity in the CLL mouse model as a single agent, leading to a significant prolongation of the mouse survival time. Since PEITC is a natural compound found in vegetables with very low toxicity to normal cells, the results of this study may have important therapeutic implications. Our study suggests that PEITC may potentially be used for clinical treatment of CLL with 17p deletion and improve the outcome of this subpopulation of CLL patients, who would otherwise refractory to standard therapeutics. Citation Format: Jinyun Liu, Gang Chen, Helen Pelicano. Targeting chronic lymphocytic leukemia with p53 deficiency with phenethyl isothiocyanate. [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 4560. doi:10.1158/1538-7445.AM2015-4560

GOLPH3 links the Golgi, DNA damage, and cancer.

GOLPH3 is the first example of an oncogene that functions in secretory trafficking at the Golgi. The discovery of GOLPH3's roles in both cancer and Golgi trafficking raises questions about how GOLPH3 and the Golgi contribute to cancer. Our recent investigation of the regulation of GOLPH3 revealed a surprising response by the Golgi upon DNA damage that is mediated by DNA-PK and GOLPH3. These results provide new insight into the DNA damage response with important implications for understanding the cellular response to standard cancer therapeutic agents.

The efficacy of vildagliptin concomitant with insulin therapy in type 2 diabetic subjects.

BackgroundIn Japan, dipeptidyl peptidase 4 (DPP4) inhibitors have become standard therapeutic agents for type 2 diabetes, and numbers of patients receiving insulin therapy combined with DPP4 inhibitors, which is a highly effective regimen, are increasing.MethodsIn this study, we evaluated the efficacy of vildagliptin administered at the dose of 100 mg twice daily in 57 patients with type 2 diabetes already receiving insulin treatment.ResultsThe 36 patients who simply received add-on vildagliptin showed a 0.6% decrease in HbA1c levels, despite a marked insulin dose reduction, mainly bolus insulin, of approximately 8.3 units. In addition, body mass index exhibited a significant negative correlation with the efficacy of vildagliptin, i.e., ΔHbA1c. On the other hand, the 21 patients switched from 50 mg of sitagliptin to vildagliptin showed HbA1c decreases approaching 0.7%.ConclusionTaking into consideration that twice-daily oral vildagliptin has already been reported to be advantageous in reducing postprandial hyperglycemia, this drug was suggested to be more effective in reducing HbA1c than sitagliptin under conditions in which it is used as a supplement to basal insulin, as in this study.

Targeted Inhibition of the MLL Transcriptional Complex By Proteosome Inhibitors Elicits a High Response Rate in Relapsed/Refractory MLL Rearranged Leukemia

Infants with MLL rearranged (MLLr) acute lymphoblastic leukemia (ALL) have a poor prognosis, with an event free survival of only 23-44%. Whole genome sequencing (WGS) of this subtype has revealed a paucity of cooperating mutations, with an average of 2.2 somatic single nucleotide variations and/or insertions/deletions per case. Despite recent progress in defining the epigenetic alterations that result from the expression of the MLL fusion protein, these insights have only recently begun to be extrapolated into the development of new therapeutic approaches whose benefits have yet to be defined. Thus, there remains an urgent need for the development of alternative approaches to improve outcomes in these patients.To identify compounds that are active in MLLr disease, we established in vitro and in vivo assays to evaluate drug sensitivity of primary infant ALL patient samples. 15 infant MLLr leukemia samples that have previously undergone WGS were xenografted into NOD/SCID/IL2Rγnull (NSG) mice. All samples engrafted and expanded in NSG mice, leading to overt leukemia with a latency of 49 to 276 days. Purification of leukemic blasts from a single moribund mouse yielded on average 108 cells, providing sufficient material to screen large numbers of compounds. In vitro conditions were defined that support growth in 40% of the patient specimens, allowing for a more accurate determination of drug sensitivity. Growth in vitro was associated with early onset of disease in NSG xenografts and younger age at presentation, allowing us to evaluate patient samples that represent aggressive high risk disease. Using this system, we tested bortezomib in addition to 28 other drugs, including standard ALL therapeutic agents as well as targeted kinase inhibitors and inhibitors of epigenetic marks. Three classes of agents were active in this system: anthracyclines, histone deacetylase inhibitors (HDACi), and the proteasome inhibitor bortezomib. In contrast to anthracyclines and HDACi, where IC50 values were on par with those reported in the literature for primary childhood ALL samples, MLLr infant samples required 10-100 fold less bortezomib to induce toxicity.Bortezomib has been shown to mediate responses through several mechanisms, including NFKB inhibition, stabilization of cell cycle regulatory proteins, and induction of apoptosis. Recently, proteasome inhibition has been demonstrated to lead to accumulated MLL fusion protein levels, triggering apoptosis and cell cycle arrest in MLLr cell lines. To determine if NFKB inhibition also plays a role, we evaluated cellular concentrations of the activated NFKB transcription factor, but failed to see decreased levels when MLLr cells were treated with bortezomib. Bortezomib has also been shown to deregulate ubiquitin stores and deplete histone H2B ubiquitination (H2Bub), an epigenetic mark that is linked to histone methylation and expression. Recently, several groups have demonstrated that H2Bub is required for DOT1L activity and HOX gene expression. We therefore evaluated H2Bub levels in bortezomib-treated patient samples and confirmed depletion of this epigenetic mark. Furthermore, patient samples treated with bortezomib downregulated both the MLL gene expression signature and signatures of downstream targets, such as cMYC, demonstrating that the MLL transcriptional program is inhibited in the presence of bortezomib. ChIP-seq is underway to map H2Bub and H3K79 methylation changes genome wide in response to treatment with bortezomib.The HDACi vorinostat and bortezomib have both been evaluated in Phase I and II pediatric leukemia clinical trials. Based on the safety and efficacy from these earlier studies, we treated 6 relapsed/refractory MLLr leukemia patients with a chemotherapy regimen that included mitoxantrone, vorinostat, and bortezomib. 4 patients had a complete response (CR), 1 patient had a partial response (PR) and 1 patient had stable disease for an overall response rate of 5/6 (83%). Clinical trials are in development to assess this combination further for both relapsed MLLr disease as well as newly diagnosed infant ALL. Our data suggests that these three classes of drugs, identified in our laboratory assays, are clinically active thus validating our system. We are now using this platform to proceed with a high throughput drug screen to identify additional compounds for future clinical development. DisclosuresOff Label Use: Vorinostat and Bortezomib for the treatment of pediatric leukemia.

Abstract 105: Establishment of imaging-based orthotopic tumor models for pharmacological evaluation of anticancer agents

Abstract Since its emergence in the mid 90's, the in vivo bioluminescent imaging (BLI) technology has been widely accepted by academia and pharmaceutical industry for research and pre-clinical drug development. The non-invasiveness and high sensitivity nature of BLI enables tumor lesions to be detectable far before they are palpable, allowing longitudinal tracking of tumors from their early development stages. BLI is particularly advantageous for monitoring systemic and orthotopic tumors that are not accessible by caliper measurement. Current preclinical evaluation of anti-cancer agents relies heavily on subcutaneous xenograft models. However, ectopically developed tumors in the subcutaneous tissue differ drastically in tumor stromata in aspects of cell contents and drug permeability, thus will often poorly predict pharmacological efficacy of the test agents. The notion that orthotopic models can better recapitulate the clinical tumor development and metastasis, thus better predict the clinical outcome of the anticancer drugs has gradually gained acceptance. Towards the development of better mouse models for pre-clinical drug development, we have established over twenty imaging based orthotopic tumor cell lines, including U87MG and AM38 brain tumors, HCT116, LoVo and SW620 colorectal cancers, A549 lung cancer, MSTO-211H mesothelioma, Raji and Namalwa lymphoma, MiaPaca-3 and Panc-1 pancreatic cancer, HepG2 liver cancer, and DU145 prostatic cancer. These tumor cells are extremely bright in luminescence emission, ranging from 1085 to 6397 photons/second/cell, thus allowing very sensitive detection in orthotopic tissues even with a few hundred cells. The tumorigenicity of the luciferase labeled cells has been validated in the pertinent orthotopic models. Evaluation of the responsiveness of some of the models to standard therapeutic agents has been conducted. In the U87MG orthotopic glioma model, we observed tumor regression in mice treated with temozolomide in a 5 mg/kg, po, q2d x 5 regimen. Current study of the orthotopic MSTO-211H mesothelioma model in response to standard clinical treatment drugs, such as pemetrexed, carboplatin and paclitaxel is in progress. It is expected that these imaging based orthotopic models will improve the pre-clinical pharmacological evaluation of anti-cancer agents and therefore better bridge the preclinical to clinical translation. Citation Format: Ning Zhang, Wei Wang, Dan Meng, Jinjin Pan, Jing Jin, Yanxia Fan, Wenhao Jin, Shuo Zhang, Ze Chen, Xueqin Yang, Hongjun Wang. Establishment of imaging-based orthotopic tumor models for pharmacological evaluation of anticancer agents. [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 105. doi:10.1158/1538-7445.AM2014-105

Super-selective intracoronary injection of Rho-kinase inhibitor relieves refractory coronary vasospasms: A case report

Coronary spastic angina (CSA) may become refractory when patients discontinue medication, resume smoking, are overworked, are under mental stress, or are hyperventilation [ [1] Hirano Y. Uehara H. Nakamura H. et al. Diagnosis of vasospastic angina: comparison of hyperventilation and cold-pressor stress echocardiography, hyperventilation and cold-pressor stress coronary angiography, and coronary angiography with intracoronary injection of acetylcholine. Int J Cardiol. 2007 Apr 4; 116: 331-337 Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar ]. Calcium channel blockers (CCBs) are effective standard therapeutic agents for CSA. In some cases, however, a combination of medications such as CCBs, nitrogen, and nicorandil fails to relieve CSA. We report a case of refractory CSA, which was eventually relieved by super-selective intracoronary injection of a Rho-kinase inhibitor, fasudil.

Characterization of the heterozygous glucokinase knockout mouse as a translational disease model for glucose control in type 2 diabetes.

The global heterozygous glucokinase (GK) knockout (gk(wt/del)) male mouse, fed on a high-fat (60% by energy) diet, has provided a robust and reproducible model of hyperglycaemia. This model could be highly relevant to some facets of human type 2 diabetes (T2D). We aimed to investigate the ability of standard therapeutic agents to lower blood glucose at translational doses, and to explore the glucose-lowering potential of novel glucokinase activators (GKAs) in this model. We measured the ability of insulin, metformin, glipizide, exendin-4 and sitagliptin, after acute or repeat dose administration, to lower free-feeding glucose levels in gk(wt/del) mice. Further, we measured the ability of novel GKAs, GKA23, GKA71 and AZD6370 to control glucose either alone or in combination with some standard agents. A single dose of insulin (1 unit·kg(-1)), metformin (150, 300 mg·kg(-1)), glipizide (0.1, 0.3 mg·kg(-1)), exendin-4 (2, 20 μg·kg(-1)) and GKAs reduced free-feeding glucose levels. Sitagliptin (10 mg·kg(-1)), metformin (300 mg·kg(-1)) and AZD6370 (30, 400 mg·kg(-1)) reduced glucose excursions on repeat dosing. At a supra-therapeutic dose (400 mg·kg(-1)), AZD6370 also lowered basal levels of glucose without inducing hypoglycaemia. Standard glucose-lowering therapeutic agents demonstrated significant acute glucose lowering in male gk(wt/del) mice at doses corresponding to therapeutic free drug levels in man, suggesting the potential of these mice as a translatable model of human T2D. Novel GKAs also lowered glucose in this mouse model.

Analytical criteria to quantify and compare the antioxidant and pro-oxidant capacity in competition assays: The bell protection function

The development of a convenient mathematical application for testing the antioxidant and pro-oxidant potential of standard and novel therapeutic agents is essential for the research community and food industry in order to perform more precise evaluations of products and processes. In this work, a simple non-linear dose–time tool to test the effectiveness of compounds for competitive assays is presented. The model helps to describe accurately the antioxidant and pro-oxidant response as a function of time and dose by two criteria values and allows one to perform easily comparisons of both capacities from different compounds. The quantification procedure developed was applied to two well known in vitro competition assays, the β-carotene and crocin bleaching asymptotic reactions. The dose–time dependency of the response of commercial antioxidants and some expected pro-oxidant compounds was evaluated in this study and the results showed low experimental error. In addition, as an illustrative example of the capabilities of the criteria proposed, the quantification of the combined effect of an antioxidant and a pro-oxidant was analyzed. Afterwards, the model was verified for other relevant competitive methods, using available experimental data from the bibliography. Its application is simple, it provides parametric estimates which characterize the response, and it facilitates rigorous comparisons among the effects of different compounds and experimental approaches. In all experimental data tested, the calculated parameters were always statistically significant (Student's t-test, α=0.05), the equations were consistent (Fisher's F-test) and the goodness of fit coefficient of determination was higher than 0.98.

A time-dose model to quantify the antioxidant responses of the oxidative hemolysis inhibition assay (OxHLIA) and its extension to evaluate other hemolytic effectors.

The development of a convenient mathematical application for testing the antioxidant potential of standard and novel therapeutic agents is essential for the research community to perform evaluations in a more precise form. The in vitro oxidative hemolysis inhibition assay, despite its relevance for in vivo responses, lacks a proper mathematical model to quantify the responses. In this work, a simple nonlinear time-dose tool to test the effectiveness of antioxidant compounds is presented. The model was verified with available experimental data from the bibliography. The model helps to describe accurately the antioxidant response as a function of time and dose allowing comparisons between compounds. Its advantages are a simple application, provision of parametric estimates that characterize the response, simplification of the protocol, economization of experimental effort, and facilitation of rigorous comparisons among the effects of different compounds and experimental approaches. Finally, other effectors that may obstruct or be of interest for the antioxidant determination are also modeled in similar principles. Thus, the basis of more complex multivariable models is provided. In all experimental data fitted, the calculated parameters were always statistically significant, the equations prove to be consistent, and the correlation coefficient of determination was in all cases higher than 0.98.

SL-401, A Targeted Therapy Directed to the Interleukin-3 Receptor Present On Leukemia Blasts and Cancer Stem Cells, Is Active As a Single Agent in Patients with Advanced AML

Abstract 3625 Background:SL-401 is a novel biologic targeted therapy, comprised of human IL-3 coupled to a truncated diphtheria toxin payload that inhibits protein synthesis, directed at the interleukin-3 receptor (IL-3R). IL-3R is overexpressed on leukemia blasts and cancer stem cells (CSCs) relative to normal hematopoietic cells. Since SL-401 uniquely targets both the leukemia blasts (tumor bulk) and CSCs, it would be expected to induce tumor regression (anti-tumor bulk effect), as well as inhibit tumor repopulation (anti-CSC effect), thereby improving survival. SL-401 has been evaluated in a Phase 1/2 clinical trial in patients with advanced hematologic cancers. In this study, SL-401 has demonstrated objective clinical responses, including durable complete responses (CRs) and protracted overall survival (OS) in patients with heavily pretreated AML. The current report is a final analysis of the patients with AML or MDS. Study Design:Seventy-eight patients with advanced hematologic cancers, including relapsed or refractory AML (n = 59), de novo AML unfit for chemotherapy (n = 11), high-risk MDS (n = 7), and other (n = 1), were enrolled in a multicenter study. Among the patients with relapsed or refractory AML, the numbers of patients receiving SL-401 as 2nd, 3rd, or >3rd line therapy were 24, 16, and 19, respectively. The median (range) age for AML patients was 65 (7, 84) years. Patients received SL-401 as a 15-minute intravenous infusion in one of two dosing regimens for a single cycle to determine the maximum tolerated dose (MTD) and assess antitumor activity. In Regimen A, 45 patients received doses ranging from 4 to 12.5 μg/kg every other day for up to 6 doses. In Regimen B, 33 patients received doses ranging from 7.1 to 22.1 μg/kg daily for up to 5 doses. Results:A single cycle of SL-401 demonstrated single agent activity in patients with relapsed or refractory AML, including 2 durable CRs of 8 and >25 months duration and 5 partial responses (PRs). OS was also notable among patients who received one cycle of SL-401 as ≥3rd line therapy for AML; the median OS was 3.6 (2.3, 6.1) months. Moreover, at therapeutically relevant doses, defined as the MTD or one or two dose levels below the MTD (9.4, 12.5, or 16.6 μg/kg/day), the median OS among AML patients who received SL-401 as ≥3rdline therapy (n = 16) was 5.6 (2.5, 10.8) months. These OS values compared favorably to historical results of 1.5 months for patients treated with standard chemotherapy.SL-401 was well tolerated. The MTD was not achieved with Regimen A, whereas the MTD for Regimen B was 16.6 μg/kg/day, with manifestations of capillary leak syndrome, including hypoalbuminemia and edema, as the dose-limiting toxicity (DLT) at the 22.1 μg/kg/day dose level. Transient (i.e., lasting ≤2 weeks) transaminase elevations were among the most common ≥Grade 3 AEs. Notably, there was no evidence of treatment-related bone marrow suppression. Conclusion:SL-401 demonstrated single agent anti-tumor activity and was well tolerated in patients with advanced AML. Improved survival was observed among patients who received a single cycle of SL-401 as ≥3rd line treatment, a disease setting in which there is no standard therapy. SL-401 may be an attractive treatment option for these patients given their tendency to be myelosuppressed and therefore are often poor candidates for myelosupressive therapies that have limited benefit on clinical response and survival in this setting.Based on these positive findings, SL-401 will be advanced into a randomized Phase 2b trial to treat patients with AML in the 3rd line setting. Patients will be randomized to treatment with either multiple cycles of SL-401 or physician's choice, which will consist of available standard therapeutic agents. In addition, the efficacy and safety of SL-401-based combination therapy will also be studied in earlier lines of AML given the lack of overlapping toxicities with existing hematologic cancer therapies. Disclosures:Konopleva:Stemline Therapeutics: Research Funding. Cirrito:Stemline Therapeutics: Employment, Equity Ownership, Patents & Royalties. Hoberman:Stemline Therapeutics: Employment, Equity Ownership. Szarek:Stemline Therapeutics: Consultancy, Equity Ownership. Rowinsky:Stemline Therapeutics: Employment, Equity Ownership. Bergstein:Stemline Therapeutics: Employment, Equity Ownership, Patents & Royalties. Frankel:Stemline Therapeutics: Research Funding.

Preclinical Cardiovascular Safety Evaluations of Biologics

Standard therapeutic agents (STA) are usually relatively small and simple molecules, which are synthesized as highly pure and consistent molecules. However, their target specificity can be low so that there is a liability for side effects at non-targeted receptors, enzymes or ion channels. Alternatively, highly specific and targeted small molecules can elicit cardiovascular liabilities due to their target-based effects. As a result of their long existence in pharmaceutical practice, their safety evaluation is fairly well standardized and their potentially promiscuous, non-specific actions mandate broad evaluations. Biologics include a wide variety of products, ranging from relatively small synthesized polypeptides, which are also highly consistent, to very complex products, the composition of which may vary widely between production batches and sources. Biologics are usually highly specific for a single target, so that side effects at other targets are very rare. Their toxicities are more related to immune systems and to infection complications than to cardiovascular repercussions. The standard preclinical cardiac safety evaluations, derived from experience with STA, are frequently not appropriate or warranted for the evaluation of biologics. Indeed, because of the specificity of such biologic products, smaller test batteries than the ones needed for STA may be sufficient. However, because of the potential variability in composition of biologics between production batches and sources, evaluations of such products needs to be performed more frequently than for uniformly produced STA.