Hollow Fiber Assay Research Articles

Evaluation of temocillin efficacy against KPC-2-producing Klebsiella pneumoniae isolates in a hollow-fibre infection model.

Temocillin is an old antimicrobial that is resistant to hydrolysis by ESBLs but has variable activity against carbapenemase-producing Enterobacteriaceae. The current EUCAST susceptibility breakpoints for Enterobacterales are set at ≤16 mg/L (susceptible with increased exposure) based on a dose of 2 g q8h, but there is limited information on the efficacy of this dose against temocillin-susceptible carbapenemase-producing Klebsiella pneumoniae isolates. To evaluate the efficacy of this dose using a hollow-fibre infection model (HFIM) against six KPC-2-producing clinical isolates of K. pneumoniae. The isolates were characterized by WGS and temocillin susceptibility was determined using standard and high inoculum temocillin. Mutant frequencies were estimated and temocillin activity was tested in time-kill assays and in the HFIM. At standard conditions, three of the isolates were classified as susceptible (MIC ≤ 16 mg/L) and three as resistant (MIC > 16 mg/L). The HFIM was performed over 3 days to mimic human-like pharmacokinetics of 2 g q8h. Bacterial counts were performed by plating on Mueller-Hinton agar (MHA) and MHA containing 64 mg/L temocillin to detect resistant subpopulations. All isolates showed a reduction in bacterial population of at least 3 log cfu/mL within the first 8 h of simulated treatment in the hollow-fibre assay. Regrowth was observed for the three resistant isolates and one of the susceptible ones. The MIC value for these isolates was higher by at least two dilutions compared with their initial values. These data suggest that an optimized pharmacokinetic regimen may be of clinical interest for the treatment of KPC-2-producing K. pneumoniae susceptible to temocillin. These data showed activity of temocillin against KPC-2-producing K. pneumoniae susceptible to temocillin; however, a dose of 2g q8h administered over 30 min may be inadequate to prevent the emergence of resistant variants.

Probing the Cytotoxic Signaling Induced by Eupenifeldin in Ovarian Cancer Models.

High-grade serous ovarian cancer (HGSOC) is the most common and lethal ovarian cancer histotype. Lack of early detection methods, limited therapeutic agents, and low 5-year survival rate reflect the urgent need to develop new therapies. Eupenifeldin, a bistropolone, originally isolated from Eupenicillium brefeldianum, is a cytotoxic fungal metabolite. In three HSGOC cell lines (OVCAR3, OVCAR5, OVCAR8), eupenifeldin was found to have an IC50 value less than 10 nM, while 10 times higher concentrations were required for cytotoxicity in nontumorigenic fallopian tube secretory epithelial cell lines (FTSEC). An in vivo hollow fiber assay showed significant cytotoxicity in OVCAR3. Eupenifeldin significantly increased Annexin V staining in OVCAR3 and -8, but not OVCAR5. Eupenifeldin activated caspases 3/7 in OVCAR3, OVCAR5, and OVCAR8; however, cleaved PARP was only detected in OVCAR3. Quantitative proteomics performed on OVCAR3 implicated ferroptosis as the most enriched cell death pathway. However, validation experiments did not support ferroptosis as part of the cytotoxic mechanism of eupenifeldin. Autophagic flux and LC3B puncta assays found that eupenifeldin displayed weak autophagic induction in OVCAR3. Inhibition of autophagy by cotreatment with bafilomycin reduced the toxicity of eupenifeldin, supporting the idea that induction of autophagy contributes to the cytotoxic mechanism of eupenifeldin.

Urolithin A: A promising selective estrogen receptor modulator and 27-hydroxycholesterol attenuator in breast cancer.

27-hydroxycholesterol (27-HC) is an oxysterol that acts as an endogenous selective estrogen receptor modulator (SERM), and its adverse effects on breast cancer via the estrogen receptor (ER) have provided new insights into the pathology of cholesterol-linked breast cancer. Our earlier in vitro experiments showed that the methanolic extract of pomegranate could exhibit SERM properties and compete with 27-HC. The major constituents of pomegranate are ellagitannins and ellagic acid, which are converted into urolithins by the colonic microbiota. In recent years, urolithins, especially urolithin A (UA) and urolithin B (UB), have been reported to have a plethora of advantageous effects, including antiproliferative and estrogenic activities. In this study, we attempted to determine the potential of urolithins in antagonizing and counteracting the adverse effects of 27-HC in breast cancer cells. Our findings suggested that UA had an antiproliferative capacity and attenuated the proliferative effects of 27-HC, resulting in subsequent loss of membrane potential and apoptosis in breast cancer cells. Further, UA induced estrogen response element (ERE) transcriptional activity and modulated estrogen-responsive genes, exhibiting a SERM-like response concerning receptor binding. Our in vivo hollow fiber assay results showed a loss of cell viability in breast cancer cells upon UA consumption, as well as a reduction in 27-HC-induced proliferative activity. Additionally, it was shown that UA did not induce uterine proliferation or alter blood biochemical parameters. Based on these findings, we can conclude that UA has the potential to act as a potent estrogen receptor alpha (ERα) modulator and 27-HC antagonist. UA is safe to consume and is very well tolerated. This study further opens up the potential of UA as ER modulator and its benefits in estrogen-dependent tissues.

Unveiling the Power of Anticancer Drug Screening: A Clinical Case Study Comparing the Effectiveness of Hollow Fiber Assay Microtube Array Membrane (MTAM-HFA) in Breast Cancer Patients.

Breast cancer is a severe public health problem, and early treatment with powerful anticancer drugs is critical for success. The researchers investigated the clinical results of a novel screening tool termed Microtube Array Membrane Hollow Fiber Assay (MTAM-HFA) in breast cancer patients in this clinical investigation. In all trial participants, the MTAM-HFA was utilized to identify active medicines for the treatment of breast cancer. The MTAM-HFA was shown to be extremely useful in predicting patient response to anticancer medication therapy in this study. Furthermore, the substantial association between the MTAM-HFA screening outcome and the clinical outcome of the respective patients emphasizes the promise of this unique screening technology in discovering effective anticancer medication combinations for the treatment of breast cancer. These findings indicate that the MTAM-HFA has clinical significance and might be a valuable tool in the development of tailored therapy for cancer care. This study provides helpful information for physicians and scientists working on breast cancer therapy research. The potential benefits of employing MTAM-HFA to find accurate therapies for breast cancer patients might lead to enhanced personalized medicine approaches to cancer care, resulting in better patient outcomes. Overall, the MTAM-HFA screening approach has the potential to revolutionize customized cancer therapy, providing hope to both patients and physicians.

Antitumor activity of triazine mimic antibiotics for DNA-binding implications (impressive activity in vitro against a variety of tumor types in the NCI-60 screen): NSC 710607 to fight HCT-116 human colon carcinoma cell lines in vivo using the hollow fiber assay and xenograft mouse models.

Successful clinical applications of DNA-directed selective cytotoxic agents disrupt the vital replication/transcription processes and ultimately lead to cancer cell death. This study aimed to examine the growth screen of two lead triazine compounds in a number of cell lines and xenografts and to develop anticancer agents with noncovalent binding affinity bringing fewer side effects. The NCI initial hollow fiber test was performed using an established procedure. The cytostatic and cytocidal capacities of the test compounds were assessed by evaluating cytotoxicity by simply performing a standard cellular viability assay. The nude mouse human tumor xenograft system was used as an in vivo model. More sensitive drug with sub-micromolar activity met the interdisciplinary criteria for testing and was referred to evaluations in subcutaneous colorectal carcinoma HCT-116 human tumor xenografted into nude mice. Principal findings of the study: total cytostasis, almost nontoxic schedules, specific working hypotheses, strong rationale for the potential use, and important general implications (relevance to human biology). NSC 710607 displayed in vivo better than Cisplatin and 5-fluorouracil abilities to significantly decrease tumor growth. Cell proliferation can be reduced or stopped in vivo in view of the xenograft results. The mimic molecule behaves as DNA-binding antitumor antibiotics with great potential as general anticancer agents and deserves further trials. NSC 710607 represents the result of a design strategy with outstanding potential. This study also identifies the prognostic significance and is likely to translate to other species or systems.

Microtube Array Membrane Hollow Fiber Assay (MTAM-HFA)-An Accurate and Rapid Potential Companion Diagnostic and Pharmacological Interrogation Solution for Cancer Immunotherapy (PD-1/PD-L1).

Immunotherapy is one of the most promising forms of cancer treatment. In particular, immune checkpoint blockers (ICBs) represent some of the leading candidates which many drug developers have heavily invested in. During pre-clinical development and prior to human clinical trials, animal tests are a critical component for determining the safety and efficacy of newly developed ICBs for cancer treatment. In this study, we strive to demonstrate the feasibility of using hollow fiber assay microtube array membrane (MTAM-HFA) in the screening of anti-cancer ICBs. The MTAM-HFA process was carried out by encapsulating peripheral blood mononuclear cells (PBMCs) and the target cancer cells (cell lines or primary cells) and subcutaneously implanting them into Balb/C mice. At predetermined time points combination regimens of PD-1/PD-L1+ were administered accordingly and at a predetermined time point, the MTAMs were retrieved, and cell viability assays were carried out. The outcomes of the MTAM-HFA were compared against the clinical outcome of patients. Clinical comparison demonstrated excellent correlation between the screening outcome of MTAM-HFA of PD-1/PD-L1+ combination therapy and the clinical outcome of the lung cancer patients. Basic cell studies revealed that the utilization of MTAM-HFA in PD-1/PD-L1+ combination therapy revealed enhanced T-cell activity upon the administration of the PD-1/PD-L1 drug; thereby resulting in the reduction of tumor cell viability by up to 70%, and the cytotoxic effects by 82%. The outcome was echoed in the in vivo cell studies. This suggested that the MTAM-HFA system is suitable for use in PD-1/PD-L1+ screening and the accuracy, rapidity and cost effectiveness made it extremely suitable for application as a companion diagnostic system in both personalized medicine for cancer treatment and could potentially be applied to screen for candidate compounds in the development of next generation PD-1/PD-L1+ combination therapies.

Anti-varicella zoster virus and related anti-inflammation effects of ethanolic extract of Elaeocarpus sylvestris

Ethnopharmacological relevanceElaeocarpus sylvestris var. ellipticus (ES), a plant that grows in Taiwan, Japan, and Jeju Island in Korea. ES root bark, known as “sanduyoung,” has long been used in traditional oriental medicine. ES is also traditionally used to treat anxiety, asthma, arthritis, stress, depression, palpitation, nerve pain, epilepsy, migraine, hypertension, liver diseases, diabetes, and malaria. However, lack of efficacy and mechanism studies on ES. Aim of the studyIn the present study, we aim to investigate the VZV-antiviral efficacy, pain suppression, and the anti-inflammatory and antipyretic effects of ES. Methodsand methods: Inhibition of VZV was evaluated by hollow fiber assays. Analgesic and antipyretic experiments were conducted using ICR mice and SD Rats, and anti-inflammatory experiments were conducted using Raw264.7 cells. ResultsTo evaluate the efficacy of ESE against VZV, we conducted antiviral tests. ESE inhibited cell death by disrupting virus and gene expression related to invasion and replication. In addition, ESE suppressed the pain response as measured by writhing and formalin tests and suppressed LPS-induced inflammatory fever. Further, ESE inhibited the phosphorylation of IκB and NF-κB in LPS-induced Raw264.7 cells and expression of COX-2, iNOS, IL-1β, IL-6, and TNF-α. ConclusionE. sylvestris shows potential as a source of medicine. ESE had a direct effect on VZV and an inhibitory effect on the pain and inflammation caused by VZV infection.

Preclinical Anticancer Activity of an Electron-Deficient Organoruthenium(II) Complex.

Ruthenium compounds have been shown to be promising alternatives to platinum(II) drugs. However, their clinical success depends on achieving mechanisms of action that overcome Pt-resistance mechanisms. Electron-deficient organoruthenium complexes are an understudied class of compounds that exhibit unusual reactivity in solution and might offer novel anticancer mechanisms of action. Here, we evaluate the in vitro and in vivo anticancer properties of the electron-deficient organoruthenium complex [(p-cymene)Ru(maleonitriledithiolate)]. This compound is found to be highly cytotoxic: 5 to 60 times more potent than cisplatin towards ovarian (A2780 and A2780cisR), colon (HCT116 p53+/+ and HCT116 p53-/-), and non-small cell lung H460 cancer cell lines. It shows no cross-resistance and is equally cytotoxic to both A2780 and A2780cisR cell lines. Furthermore, unlike cisplatin, the remarkable in vitro antiproliferative activity of this compound appears to be p53-independent. In vivo evaluation in the hollow-fibre assay across a panel of cancer cell types and subcutaneous H460 non-small cell lung cancer xenograft model hints at the activity of the complex. Although the impressive in vitro data are not fully corroborated by the in vivo follow-up, this work is the first preclinical study of electron-deficient half-sandwich complexes and highlights their promise as anticancer drug candidates.

Multioside, an active ingredient from adonis amurensis, displays anti-cancer activity through autophagosome formation

BackgroundAdonis amurensis Regel & Radde, commonly found in East Asia, has been traditionally used to treat cardiac insufficiency and edema. Although this plant extract has been shown to regulate cell growth and neovascularization, the anti-cancer mechanism of A. amurensis has not been fully investigated. PurposeIn this study, we aimed to examine the anti-cancer activity of A. amurensis and identify its underlying mechanism. MethodsThe growth of cancer cells was evaluated by MTT and hollow fiber assays. A cancer xenograft nude mouse model was used to assess the anti-cancer activities in vivo. Autophagic activity was measured by the detection of autophagosome formation and by performing a monodansylcadaverine (MDC) assay. ResultA. amurensis extract showed potent anti-cancer activity both in vitro and in vivo. Importantly, the treatment of cancer cells with A. amurensis extract dramatically increased the formation of autophagosomes and was involved in the activation of multiple signaling components including AKT, ERK, and MAPK. Furthermore, we isolated an active ingredient, Multioside, which exhibited strong anti-cancer activity through autophagy. ConclusionA. amurensis displays anti-cancer activity that is mediated by the activation of autophagy, suggesting that A. amurensis could be a useful therapeutic anti-cancer agent.

Abstract 2253: Rapid personalized selection of immune checkpoint blockage agent combinational treatment for an adenocarcinoma patient

Abstract The combination of immune checkpoint blockage (ICB) agent and chemotherapy for cancer treatment is gaining lots of attention lately. However, there is no clear biomarker or index for such treatment, particularly after tumor gaining resistance to ICI. In this study, an improved hollow fiber assay (HFA) was utilized based upon a novel substrate of microtube array membrane (MTAM) to test the possible patient response towards the combined treatment of immunotherapy and chemotherapy. In this case study, biopsy of a stage 4 adenocarcinoma (cT2N3M1b) patient, with the disease progression after a durable response to prior pemetrexed and Nivolumab, was retrieved and treated with enzyme for a homogenous cell suspension. Pieces of MTAM preloaded with 106 of cancer cell along with patient’s peripheral blood mononuclear cell (PBMC) were implanted subcutaneously in bulb C mice. These mice were grouped and subjected to two different ICB combinational treatments (1) Nivolumab with Paclitaxel and (2) Nivolumab with Pemetrexed. 10 days later MTAMs were explanted and cancer cells were subject to MTT assay for their viability. The results of two treatments clearly demonstrated the better efficacy of Nivolumab and Paclitaxel towards this patient cancer cells. Clinically, CT images taken before and after a two-month treatment show positive response towards the combinational treatment of Nivolumab and Paclitaxel. This case study suggests a rapid clinical regiment prediction/selection of ICB combinational treatment is possible in two weeks using MTAM/HFA and provides reasonable evident for the corresponding treatment. Citation Format: Kang-Yun Lee, Chien-Chung Chen, Won-Ting Huang. Rapid personalized selection of immune checkpoint blockage agent combinational treatment for an adenocarcinoma patient [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2253.

Cyclosporine A sensitizes lung cancer cells to crizotinib through inhibition of the Ca2+/calcineurin/Erk pathway.

BackgroundCrizotinib has potent anti-tumor activity in patients with advanced MET-amplified non-small cell lung cancer (NSCLC). However, the therapeutic effect is still not satisfying. Thus, developing approaches that improve the efficacy of crizotinib remains a significant challenge.MethodsMET-amplified NSCLC cell lines were treated with crizotinib and cyclosporine A (CsA). Cell viability was determined by MTS assay. The changes of apoptosis, cell cycle and calcineurin-Erk pathways were assessed by western blot. Xenograft mouse model, primary human NSCLC cells and hollow fiber assays were utilized to confirm the effects of CsA.FindingsWe demonstrated that CsA significantly increased the anti-tumor effect of crizotinib on multiple MET-amplified NSCLC cells in vitro and in vivo. Mechanistically, crizotinib treatment led to the activation of Ca2+-calcineurin (CaN)-Kinase suppressor of Ras 2 (KSR2) signaling, resulting in Erk1/2 activation and enhanced survival of cancer cells. CsA effectively blocked CaN-KSR2-Erk1/2 signaling, promoting crizotinib-induced apoptosis and G2/M arrest. Similarly, pharmacologic or genetic inhibition of Erk1/2 also enhanced crizotinib-induced growth inhibition in vitro. Xenograft studies further confirmed that CsA or Erk1/2 inhibitor PD98059 enhanced the anti-cancer activity of crizotinib through inhibition of CaN-Erk1/2 axis. The results were also validated by primary human NSCLC cells in vitro and hollow fiber assays in vivo.InterpretationThis study provides preclinical evidences that combination therapy of CsA and crizotinib is a promising approach for targeted treatment of MET-amplified lung cancer patients.FundThis work was supported by the National Natural Science Foundation of China, the Key Projects of Natural Foundation of Zhejiang Province, the Ten thousand plan youth talent support program of Zhejiang Province, the Zhejiang Natural Sciences Foundation Grant, and the Zhejiang medical innovative discipline construction project-2016.

Electrospun Polylactic Acid (PLLA) Microtube Array Membrane (MTAM)-An Advanced Substrate for Anticancer Drug Screening.

The advent of personalized cancer treatment resulted in the shift from the administration of cytotoxic drugs with broad activity spectrum to a targeted tumor-specific therapy. Aligned to this development, the focus of this study revolved around the application of our novel and patented microtube array membrane (MTAM) in the US National Cancer Institute (NCI) developed an HFA (hollow fiber assay) assay; hereinafter known as MTAM/HFA. Electrospun poly-L-lactic acid (PLLA) MTAM was sterilized and loaded with cell lines/patient derived tumor cells (PDTC) and subcutaneously implanted into the backs of BALB/C mice. Anticancer drugs were administered at the respective time points and the respective MTAMs were retrieved and the viability tumor cells within were quantified with the MTT assay. Results revealed that the MTAMs were excellent culture substrate for various cancer cell lines and PDTCs (patient derived tumor cells). Compared to traditional HFA systems that utilize traditional hollow fibers, MTAM/HFA revealed superior drug sensitivity for a wide range of anticancer drug classes. Additionally, the duration for each test was <14 days; all this while capable of producing similar trend outcome to the current gold-standard xenograft models. These benefits were observed in both the in vitro and in vivo stages, making it a highly practical phenotypic-based solution that could potentially be applied in personalized medicine.

PROSPECTIVE AND RETROSPECTIVE ANIMAL MODEL USED IN THE PHARMACOLOGICAL SCREENING OF ANTI-CANCER DRUG

Cancer is a disease characterized by uncontrolled proliferation of cells that have transformed from the normal cells of the body. The widely used cancer drugs suffers from the drawback of high toxicity not within the reach of a common man. This urgently necessitating the screening of these compounds. This review focuses on the major contributions of preclinical screening models to anticancer drug development over the years till recent times, from the empirical drug screening of cytotoxic agents against uncharacterized tumor models to the target-orientated drug screening of agents with defined mechanisms of action,, a general transition has been observed. The newer approaches to anticancer drug development involve the molecular characterization of models along with an appreciation of the pharmacodynamics and pharmacokinetic properties of compounds [e. g., the US National Cancer Institute (NCI) in vitro 60-cell line panel, hollow fibre assay, and s. c. xenograft]. In vivo tumor models including orthotopic, metastatic, and genetically engineered mouse models are also reviewed. The preclinical screening efforts of the European are also included. In 2015 with the rapid development of cancer modeling in zebrafish, great opportunities exist for chemical screens to find anticancer drug since 1970 the European Organisation for Research and Treatment of Cancer and Cancer Research UK, have been collaborating with the NCI in the acquisition and screening of compounds.

Anti-tumor Activity of Saussurea laniceps against Pancreas Adenocarcinoma

The purpose of this study was to confirm the anti-tumor activity of an ethanol extract of Saussurea laniceps against pancreatic tumor and to isolate the active compound from S. laniceps extract. Treatment with S. laniceps extract and hispidulin inhibited proliferation of pancreatic cell lines, such as Capan-1, Capan-2, Panc-1 and S2-013 in a dose-dependent manner using the hollow fiber assay. Hispidulin showed typical hallmarks of apoptotic cell death a significant anti-tumor activity on Capan-2 cells at a dose of 100 mg/kg and 200 mg/kg. S. laniceps has potential cytotoxic and apoptotic effects on human pancreatic carcinoma cells. Its mechanism of action might be associated with the apoptotic cell death through DNA fragmentation.

Abstract A33: The implication of patient derived tumor cell (PDTC) tested/screened with novel microtube array membrane (MTAM)-based hollow fiber assay (HFA).

Abstract Background: Previously we have demonstrated the novel microtube array membrane (MTAM) can serves as an excellent substrate for a rapid, in vivo anti-cancer drug screening assay based on the hollow fiber assay (HFA), with higher cell-drug sensitivity, cell-host interaction, plus the clear angiogenesis, owing to its unique structural characteristics. In current study, the patient derived tumor cells (PDTC) were subjected to MTAM/X based screening platform. Patient derived colon cancer sample was treated and loaded into MTAM, studied first in cell growth and characterization, and later the cell toxicity by several representative cancer drugs, both in vitro and in vivo. The goal of this study is to explore the potential of utilizing MTAM/X with PDX for rapid, reliable, lower cost personalized anti-cancer drug selection platform. Materials and Methods: Nano-porous PLLA MTAMs (npMTAM) were fabricated via a co-axial electrospinning and characterized morphologically first, then mechanical and permeation properties were determined. The nano-porous microstructure was also characterized by porosimeter. PTDC (colon cancer, 0.5 cm3) was obtained surgically and treated with enzyme-containing medium, homogenized before loaded into npMTAM at 105-106 cell per sample. The subcutaneous implantation of these MTAMs were conducted with 4 MTAMs per model (BALB/c) one day before the drug treatment. Regiments used according to the recommended dosage were cisplatin, 5 FU and Erbitux. In vitro and in vivo PDTC growth within MTAM were determined via MTT assay. The in vivo drug cytotoxicity towards PDTC was then determined by MTT in a 9-day period, in the meantime, the supportive results of angiogenesis was characterized via imaging process. Results: Nano-porous PLLA MTAMs were successfully prepared with a tube wall thickness of 2-3 microns and pore size of 100-200 nm. PDTC (colon cancer) was loaded into npMTAM within 2 hours after surgical collection. The in vitro and in vivo growth of PDTC in npMTAM was observed clearly in a two weeks period. Upon the administration of 5 FU, Cisplatin and Erbitux to the test model, cell growth was altered, however in different fashion. 5FU show early cell cytotoxicity, however, loss its inhibition capability afterwards. Erbitux showed no sign of inhibition. Finally greatest inhibition of this particular patient tumor was found with cisplatin. Extent of angiogenesis was found to be in consist with MTT data. The overall time needed to generate the final results is within 2 weeks. Conclusions: Testing PDTC in vivo within npMTAM based assay (PDXiMTAM), we demonstrated the feasibility of in vivo personalized cancer drug selection platform can be achieved in a reasonable time periods of 2 weeks. Selection from a group of four regiments, cisplatin demonstrated its highest cytotoxicity towards this specific tumor. This will be a very practical assay in clinical setting to identify most effective drug at personal level. Our results therefore suggest that such assay could be further developed in timely treatment selection. A double blind, cohort clinical trial of 60 patients with colon cancer is currently ongoing to validate PDXiMTAM. Citation Format: Po-Li Wei, Chia-Shiuan Tseng, Chien-Chung Chen, Chien-Jin Chiu, George Hsiao. The implication of patient derived tumor cell (PDTC) tested/screened with novel microtube array membrane (MTAM)-based hollow fiber assay (HFA).. [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 A33.

Preclinical anticancer effectiveness of a fraction from Casearia sylvestris and its component Casearin X: in vivo and ex vivo methods and microscopy examinations

Ethnopharmacological relevanceCasearia sylvestris (Salicaceae) is found in South America and presents antiulcerogenic, cytotoxic, antimicrobial, anti-inflammatory and antihypertensive activities. Aim of the studyTo assess the in vivo and ex vivo antitumor action of a fraction with casearins (FC) and its main component - Casearin X-isolated from C. sylvestris leaves. Materials and methodsFirstly, Sarcoma 180 bearing Swiss mice were treated with FC and Cas X for 7 days. Secondly, BALB/c nude animals received hollow fibers with colon carcinoma (HCT-116) or glioblastoma (SF-295) cells and were treated with FC for 4 days. On 5th day, proliferation was determined by MTT assay. ResultsFC 10 and 25mg/kg/day i.p. and 50mg/kg/day oral and Cas X 25mg/kg/day i.p. and 50mg/kg/day oral revealed tumor growth inhibition rates of 35.8, 86.2, 53.7, 90.0 and 65.5% and such tumors demonstrated rare mitoses and coagulation necrosis areas. Similarly, FC reduced multiplying of HCT-116 and SF-295 cells when evaluated by the Hollow Fiber Assay (2.5 and 5mg/kg/day i.p. and 25 and 50mg/kg/day oral), with cell growth inhibition rates ranging from 33.3 to 67.4% (p<0.05). Flow cytometry experiments revealed that FC reduced membrane integrity and induced DNA fragmentation and mitochondrial depolarization (p<0.05). ConclusionsFC and Cas X were efficient antitumor substances against murine and human cancer cells and caused reversible morphological changes in liver, kidneys and spleens, emphasizing clerodane diterpenes as an emerging class of anticancer molecules.

Syrbactin Structural Analog TIR-199 Blocks Proteasome Activity and Induces Tumor Cell Death

Multiple myeloma is an aggressive hematopoietic cancer of plasma cells. The recent emergence of three effective FDA-approved proteasome-inhibiting drugs, bortezomib (Velcade®), carfilzomib (Kyprolis®), and ixazomib (Ninlaro®), confirms that proteasome inhibitors are therapeutically useful against neoplastic disease, in particular refractory multiple myeloma and mantle cell lymphoma. This study describes the synthesis, computational affinity assessment, and preclinical evaluation of TIR-199, a natural product-derived syrbactin structural analog. Molecular modeling and simulation suggested that TIR-199 covalently binds each of the three catalytic subunits (β1, β2, and β5) and revealed key interaction sites. In vitro and cell culture-based proteasome activity measurements confirmed that TIR-199 inhibits the proteasome in a dose-dependent manner and induces tumor cell death in multiple myeloma and neuroblastoma cells as well as other cancer types in the NCI-60 cell panel. It is particularly effective against kidney tumor cell lines, with >250-fold higher anti-tumor activities than observed with the natural product syringolin A. In vivo studies in mice revealed a maximum tolerated dose of TIR-199 at 25 mg/kg. The anti-tumor activity of TIR-199 was confirmed in hollow fiber assays in mice. Adverse drug reaction screens in a kidney panel revealed no off-targets of concern. This is the first study to examine the efficacy of a syrbactin in animals. Taken together, the results suggest that TIR-199 is a potent new proteasome inhibitor with promise for further development into a clinical drug for the treatment of multiple myeloma and other forms of cancer.

Abstract A16: Boosting of in vivo hollow fiber assay by using luciferase-labeled tumor cell lines

Abstract In drug development, predicting in vivo inhibitory drug activity from cellular assay data is difficult due to the complexity of the living system, resulting in the sacrifice of many mice in vain. In order to prescreen compounds for their in vivo activity more efficiently, the hollow fiber assay (HFA) was developed in 1995 by Hollingshead et al. The HFA assay allows the simultaneous evaluation of multiple cell lines implanted in separated drug-(but not cell-) permeable fibers within a single mouse. We herein report on the advancement of this technology by use of luciferase-labeled tumor cell lines. The limits of detection are boosted and disturbing (non-labeled) stroma cells attached to the fibers are excluded enabling a clear separation of drug effects on the tumor cells. The effect of Gemcitabine and Paclitaxel on growth of luciferase-labeled MDA-MB-231 and A549 cells in HFA was analyzed by MTT in comparison to luciferase activity analysis. The general findings between both read-outs were comparable. The growth of MDA-MB-231 cells was inhibited by both, Paclitaxel and Gemcitabine, whereas inhibition of A549 cell growth was only observed under Paclitaxel treatment. T/C calculation for the MTT analysis predicted a partial response in all cases. In contrast, the luciferase activity analysis clearly distinguished between a complete response for MDA-MB-231 cell growth when treated with Paclitaxel and Gemcitabine and a partial response for Paclitaxel on A549 cell growth. These results correspond to the in vivo xenograft studies: T/C for Gemcitabine using MDA-MB-231 cells was 2-fold lower (16.2%) than T/C in A549 tumors using Paclitaxel (36.3%). In addition, results are shown applying this technology for up to 42 days instead of the typical 14 days, enhancing the possibility to analyze slow-acting drugs. In summary, the HFA assay for in vivo drug screening with luciferase-labeled tumor cells remarkably increases the power and predictability for drug efficacy in xenograft studies. Citation Format: Cynthia Schaefer-Obodozie, Ulrike Leisegang, Susanne Ruf, Bianca Giesen, Christoph Schaechtele, Holger Weber. Boosting of in vivo hollow fiber assay by using luciferase-labeled tumor cell lines. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A16.

Anticancer Activity and Autophagy Involvement of Self-Assembled Arene–Ruthenium Metallacycles

A suite of six metallacycles (1–6) was generated via coordination-driven self-assembly using the three dicarboxylate-bridged arene–Ru precursors [Ru2(μ-η4-OO∩OO)(η6-p-iPrC6H4Me)2][CF3SO3]2; (OO∩OO = oxalate (A1), 2,5-dihydroxy-1,4-benzoquinonato (dobq) (A2), 5,8-dihydroxy-1,4-naphthoquinonato (donq) (A3); CF3SO3 = triflate) with one of two dipyridyl ligands (L1 and L2). The metallacycles were isolated in excellent yield (86–92%) as triflate salts and characterized by proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) and electrospray ionization–mass spectrometry (ESI-MS) to confirm their structural assignments. Single-crystal X-ray crystal analysis of 1 revealed that two L1 ligands bridged two A1 acceptors to form a rectangular architecture. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was conducted to evaluate the in vitro cytotoxicities relative to two chemotherapeutic agents: namely, cisplatin and doxorubicin. Metallacycles 3 and 6 potently inhibited the growth of HCT-15 human colon and AGS human gastric cancer cells. The hollow fiber (HF) assay was performed to investigate the in vivo antitumor activities of metallacycles 3 and 6. Metallacycle 6 was more effective in inhibiting HCT-15 cells than metallacycle 3 in both in vitro and in vivo studies. Moreover, 3 and 6 induced autophagic activity in HCT-15 cells. These results suggested that the autophagic response elicited by metallacycles 3 and 6 could mediate the anticancer effects observed in human colorectal cancer cells.

A potential oral anticancer drug candidate, Moringa oleifera leaf extract, induces the apoptosis of human hepatocellular carcinoma cells.

It has previously been reported that cold water-extracts of Moringa oleifera leaf have anticancer activity against various human cancer cell lines, including non-small cell lung cancer. In the present study, the anticancer activity of M. oleifera leaf extracts was investigated in human hepatocellular carcinoma HepG2 cells. By the analysis of apoptotic signals, including the induction of caspase or poly(ADP-ribose) polymerase cleavage, and the Annexin V and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays, it was demonstrated that M. oleifera leaf extracts induce the apoptosis of HepG2 cells. In the hollow fiber assay, oral administration of the leaf extracts significantly reduced (44-52%) the proliferation of the HepG2 cells and A549 non-small cell lung cancer cells. These results support the potential of soluble extracts of M. oleifera leaf as orally administered therapeutics for the treatment of human liver and lung cancers.