Comparative in-Vitro Evaluation of the Myeloid Toxicity of Pentostatin and the Novel PNP-Inhibitor Forodesine.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3766-3766
Author(s):  
Mario Schubert ◽  
Christian Wallenwein ◽  
Larissa Pietsch ◽  
Dan Ran ◽  
Isabel Taubert ◽  
...  

Abstract Abstract 3766 Poster Board III-702 Inhibitors of the purine metabolism show promising results in the treatment of lymphatic malignancies due to their suppressive effects on lymphogenesis. Their first representative, Pentostatin (Pento), an inhibitor of the deoxyadenosine deaminase, has been in clinical use for several decades. However, early clinical trials with higher dose ranges of the drug reported unforseen severe myelotoxic effects. Recently, Forodesine (Foro), a novel inhibitor of the nucleoside phosphorylase (PNP) has been introduced and is currently deployed in clinical phase I/II trials for the treatment of acute lymphatic leukemia (ALL). In order to systematically evaluate the myelotoxic effects of Pento and Foro, we have now examined their influence on the proliferation and differentiation of primitive and lineage committed hematopoietic progenitor cells (HPCs). In vitro dose/effect-curves for Foro, Pento, and Cytarabine (AraC) were generated for the leukemic cell line jurkat by 48 hours of co-incubation with the compounds. Adequate cytotoxic effects, measured in the XTT assay and by flow cytometric analysis, were observed in clinically relevant dose ranges. For the following studies, an equivalent IC60 dose of each chemotherapeutic agent was selected and CD34+ HPCs from either bone marrow, mobilized peripheral blood, or umbilical cord blood were incubated with the compounds for 48 hours. Subsequently, the rate of vital cells was determined by flow cytometry after stainig with Annexin-V and Propidium Iodide. Compared to the untreated control, the lowest amount of vital CD34+ cells was found in AraC-treated samples (30%); Foro and Pento yielded more vital cells (66% vs 61%). The combination of Foro and Pento unexpectedly had the least toxic effect on CD34+ cells (72%; n=5; p<0.05). Cells from those primary cultures were harvested and short- and long term in vitro assays for colony forming units were performed to evaluate the compounds' toxicity on primitive and lineage committed HPCs. The frequency of primitive myeloic progenitors (LTC-IC) was 2.3% in the untreated samples and diminished after treatment with AraC (1.2%) and Pento (1.9%) but surprisingly significantly increased after Foro-treatment (2.7%); the combination of Foro and Pento resulted in a LTC-IC frequency of 2.3% (p<0.01; n=5) suggesting that Foro may have attenuated the myelotoxicity of Pento. Similar effects of Foro were also observed in the short term colony forming assays where Foro seemed to have a protective effect on multipotent GEMM-progenitors: colony count increased 1.3-fold in comparison to the control; AraC yielded only 0.1-fold, Pento 0.8-fold and the combination of Pento and Foro reached 0.9-fold of the control (p<0.05; n=15). In summary, the novel PNP-inhibitor Forodesine has not only proven to have a low in vitro toxicity on lineage committed HPCs but, surprisingly, the frequency of primitive myeloic progenitors (LTC-IC) increased; clinical studies should therefore be performed to evaluate whether Forodesine, while adding to the therapeutic efficiency, may attenuate adverse effects in combination with other chemotherapeutic agents, such as Pentostatin. Disclosures: Schubert: Mundipharma Int. LTD: Research Funding.

2021 ◽  
Vol 22 (5) ◽  
pp. 2731
Author(s):  
Piotr Garnuszek ◽  
Urszula Karczmarczyk ◽  
Michał Maurin ◽  
Arkadiusz Sikora ◽  
Jolanta Zaborniak ◽  
...  

A new PSMA ligand (PSMA-D4) containing the Glu-CO-Lys pharmacophore connected with a new linker system (L-Trp-4-Amc) and chelator DOTA was developed for radiolabeling with therapeutic radionuclides. Herein we describe the synthesis, radiolabeling, and preliminary biological evaluation of the novel PSMA-D4 ligand. Synthesized PSMA-D4 was characterized using TOF-ESI-MS, NMR, and HPLC methods. The novel compound was subject to molecular modeling with GCP-II to compare its binding mode to analogous reference compounds. The radiolabeling efficiency of PSMA-D4 with 177Lu, 90Y, 47Sc, and 225Ac was chromatographically tested. In vitro studies were carried out in PSMA-positive LNCaP tumor cells membranes. The ex vivo tissue distribution profile of the radioligands and Cerenkov luminescence imaging (CLI) was studied in LNCaP tumor-bearing mice. PSMA-D4 was synthesized in 24% yield and purity >97%. The radio complexes were obtained with high yields (>97%) and molar activity ranging from 0.11 to 17.2 GBq mcmol−1, depending on the radionuclide. In vitro assays confirmed high specific binding and affinity for all radiocomplexes. Biodistribution and imaging studies revealed high accumulation in LNCaP tumor xenografts and rapid clearance of radiocomplexes from blood and non-target tissues. These render PSMA-D4 a promising ligand for targeted therapy of prostate cancer (PCa) metastases.


Vaccines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 13
Author(s):  
Lydia Riepler ◽  
Annika Rössler ◽  
Albert Falch ◽  
André Volland ◽  
Wegene Borena ◽  
...  

Neutralizing antibodies are a major correlate of protection for many viruses including the novel coronavirus SARS-CoV-2. Thus, vaccine candidates should potently induce neutralizing antibodies to render effective protection from infection. A variety of in vitro assays for the detection of SARS-CoV-2 neutralizing antibodies has been described. However, validation of the different assays against each other is important to allow comparison of different studies. Here, we compared four different SARS-CoV-2 neutralization assays using the same set of patient samples. Two assays used replication competent SARS-CoV-2, a focus forming assay and a TCID50-based assay, while the other two assays used replication defective lentiviral or vesicular stomatitis virus (VSV)-based particles pseudotyped with SARS-CoV-2 spike. All assays were robust and produced highly reproducible neutralization titers. Titers of neutralizing antibodies correlated well between the different assays and with the titers of SARS-CoV-2 S-protein binding antibodies detected in an ELISA. Our study showed that commonly used SARS-CoV-2 neutralization assays are robust and that results obtained with different assays are comparable.


2012 ◽  
Vol 32 (10) ◽  
pp. 843-849 ◽  
Author(s):  
Salomon Sand ◽  
Joakim Ringblom ◽  
Helen Håkansson ◽  
Mattias Öberg

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1617
Author(s):  
Rosa Garriga ◽  
Tania Herrero-Continente ◽  
Miguel Palos ◽  
Vicente L. Cebolla ◽  
Jesús Osada ◽  
...  

Carbon nanomaterials have attracted increasing attention in biomedicine recently to be used as drug nanocarriers suitable for medical treatments, due to their large surface area, high cellular internalization and preferential tumor accumulation, that enable these nanomaterials to transport chemotherapeutic agents preferentially to tumor sites, thereby reducing drug toxic side effects. However, there are widespread concerns on the inherent cytotoxicity of carbon nanomaterials, which remains controversial to this day, with studies demonstrating conflicting results. We investigated here in vitro toxicity of various carbon nanomaterials in human epithelial colorectal adenocarcinoma (Caco-2) cells and human breast adenocarcinoma (MCF-7) cells. Carbon nanohorns (CNH), carbon nanotubes (CNT), carbon nanoplatelets (CNP), graphene oxide (GO), reduced graphene oxide (GO) and nanodiamonds (ND) were systematically compared, using Pluronic F-127 dispersant. Cell viability after carbon nanomaterial treatment followed the order CNP < CNH < RGO < CNT < GO < ND, being the effect more pronounced on the more rapidly dividing Caco-2 cells. CNP produced remarkably high reactive oxygen species (ROS) levels. Furthermore, the potential of these materials as nanocarriers in the field of drug delivery of doxorubicin and camptothecin anticancer drugs was also compared. In all cases the carbon nanomaterial/drug complexes resulted in improved anticancer activity compared to that of the free drug, being the efficiency largely dependent of the carbon nanomaterial hydrophobicity and surface chemistry. These fundamental studies are of paramount importance as screening and risk-to-benefit assessment towards the development of smart carbon nanomaterial-based nanocarriers.


Blood ◽  
1997 ◽  
Vol 89 (4) ◽  
pp. 1173-1181 ◽  
Author(s):  
Jaroslaw P. Maciejewski ◽  
Elaine M. Sloand ◽  
Tadatsugu Sato ◽  
Stacie Anderson ◽  
Neal S. Young

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) results from somatic mutations in the PIG-A gene, leading to poor presentation of glycosylphosphatidylinositol (GPI)-anchored surface proteins. PNH frequently occurs in association with suppressed hematopoiesis, including frank aplastic anemia (AA). The relationship between GPI-anchored protein expression and bone marrow (BM) failure is unknown. To assess the hematopoietic defect in PNH, the numbers of CD34+ cells, committed progenitors (primary colony-forming cells [CFCs]), and long-term culture-initiating cells (LTC-ICs; a stem cell surrogate) were measured in BM and peripheral blood (PB) of patients with PNH/AA syndrome or patients with predominantly hemolytic PNH. LTC-IC numbers were extrapolated from secondary CFC numbers after 5 weeks of culture, and clonogenicity of LTC-ICs was determined by limiting dilution assays. When compared with normal volunteers (n = 13), PNH patients (n = 14) showed a 4.7-fold decrease in CD34+ cells and an 8.2-fold decrease in CFCs. LTC-ICs in BM and in PB were decreased 7.3-fold and 50-fold, respectively. Purified CD34+ cells from PNH patients had markedly lower clonogenicity in both primary colony cultures and in the LTC-IC assays. As expected, GPI-anchored proteins were decreased on PB cells of PNH patients. On average, 23% of monocytes were deficient in CD14, and 47% of granulocytes and 58% of platelets lacked CD16 and CD55, respectively. In PNH BM, 27% of CD34+ cells showed abnormal GPI-anchored protein expression when assessed by CD59 expression. To directly measure the colony-forming ability of GPI-anchored protein-deficient CD34+ cells, we separated CD34+ cells from PNH patients for the GPI+ and GPI− phenotype; CD59 expression was chosen as a marker of the PNH phenotype based on high and homogeneous expression on fluorescent staining. CD34+CD59+ and CD34+CD59− cells from PNH/AA patients showed similarly impaired primary and secondary clonogeneic efficiency. The progeny derived from CD34+CD59− cells were both CD59− and CD55−. A very small population of CD34+CD59− cells was also detected in some normal volunteers; after sorting, these CD34+CD59− cells formed normal numbers of colonies, but their progeny showed lower CD59 levels. Our results are consistent with the existence of PIG-A–deficient clones in some normal individuals. In PNH/AA, progenitor and stem cells are decreased in number and function, but the proliferation in vitro is affected similarly in GPI-protein–deficient clones and in phenotypically normal cells. As measured in the in vitro assays, expansion of PIG-A– clones appears not be caused by an intrinsic growth advantage of cells with the PNH phenotype.


Blood ◽  
1991 ◽  
Vol 77 (8) ◽  
pp. 1717-1722 ◽  
Author(s):  
RJ Berenson ◽  
WI Bensinger ◽  
RS Hill ◽  
RG Andrews ◽  
J Garcia-Lopez ◽  
...  

Abstract The CD34 antigen is expressed by 1% to 4% of human and baboon marrow cells, including virtually all hematopoietic progenitors detectable by in vitro assays. Previous work from our laboratory has shown that CD34+ marrow cells can engraft lethally irradiated baboons. Because the CD34 antigen has not been detected on most solid tumors, positive selection of CD34+ cells may be used to provide marrow cells capable of engraftment, but depleted of tumor cells. In seven patients with stage IV breast cancer and two patients with stage IV neuroblastoma, 2.5 to 17.5 x 10(9) marrow cells were separated by immunoadsorption with the anti-CD34 antibody 12–8 and 50 to 260 x 10(6) positively selected cells were recovered that were 64 +/- 16% (range 35% to 92%) CD34+. The patients received 1.0 to 5.2 x 10(6) CD34-enriched cells/kg after marrow ablative therapy. Six patients engrafted, achieving granulocyte counts of greater than 500/mm3 at 34 +/- 10 (range 21 to 47) days and platelets counts of greater than 20,000/mm3 at 46 +/- 14 (range 28 to 66) days posttransplant. Five of these patients showed durable engraftment until the time of death 82 to 386 days posttransplant. One patient failed to sustain engraftment associated with metastatic marrow disease. Three patients died at days 14, 14, and 17 posttransplant, two of whom had evidence of early engraftment. These studies suggest that CD34+ marrow cells are capable of reconstituting hematopoiesis in humans.


2004 ◽  
Vol 14 (4) ◽  
pp. 607-615 ◽  
Author(s):  
P. Kornblith ◽  
R. L. Ochs ◽  
A. Wells ◽  
M. J. Gabrin ◽  
J. Piwowar ◽  
...  

The treatment of ovarian cancer principally relies on the use of platinum and taxane chemotherapeutic agents. Short-term clinical results have been encouraging, but long-term responses remain limited. In this report, an in vitro assay system that utilizes cells grown from human tumor explants has been used to quantitatively evaluate responses to relevant concentrations of alternative chemotherapeutic agents. The results suggest that there are significant differences in the responses of explant-derived cultured cells to the different agents tested. In an evaluation of 276 primary ovarian cancer specimens, five nonstandard drugs were tested in 51 cases. Of these 51 cases, cyclophosphamide had the highest rate of response at 67%, followed by doxorubicin at 61%, gemcitabine at 49%, etoposide at 48%, and topotecan at 14%. Venn diagrams, representing the in vitro responses to the platins and taxanes, as well as the responses to the nonstandard drugs, illustrate that there clearly are distinct differences among patients in a given population. These data underscore the potential importance of evaluating each patient's response to a number of different drugs to optimize the therapeutic decision-making process.


2000 ◽  
Vol 19 (5) ◽  
pp. 309-317 ◽  
Author(s):  
M I Grant ◽  
K Anderson ◽  
G McKay ◽  
M Wills ◽  
C Henderson ◽  
...  

The liver-specific phenotype of immortalised rat hepato-cytes is not irretrievably lost as they age in culture but can be manipulated by modifying the culture environment. Testosterone metabolism was used to investigate the profile of cytochrome P450 isoenzymes present in two immortalised cell lines, P9 and LQC, and in primary cultures of rat hepatocytes, cultured on collagen films, gels and double gel cultures (sandwich configuration). The extent of testosterone metabolism, and the range of metabolites produced, was increased in immortalised cells by the presence of collagen as a substratum film or gel but survival was poorer and the range of metabolites was reduced in sandwich culture. In contrast, testosterone metabolism was retained in primary hepatocytes in sandwich cultures at a higher level than in collagen film or gel cultures. Expression of alpha class glutathione-S-transferases (GSTs) increased and that of GSTP1 decreased (changes which indicate a recovery of normal liver GST phenotype) when the medium of immortalised cell cultures was supplemented with dimethyl sulph-oxide (DMSO). DMSO also improved ethoxyresorufin 0-deethylation (EROD) and testosterone metabolism in immortalised cells. It also markedly inhibited prolifera-tion, DNA, RNA and protein synthesis. Maximal testosterone metabolism was observed in immortalised cells cultured on collagen gels in the presence of l1o (v/v) DMSO. Development of a protocol for treating immortalised liver cells cultured on collagen gels with DMSO to switch between proliferation and differentiation may provide a convenient system expres-sing the xenobiotic metabolising enzymes required for in vitro toxicity testing.


2019 ◽  
Vol 18 ◽  
pp. 117693511982874 ◽  
Author(s):  
Themis Liolios ◽  
Stavroula Lila Kastora ◽  
Giorgia Colombo

MicroRNAs (miRNAs) are endogenous 22-nucleotide RNAs that can play a fundamental regulatory role in the gene expression of various organisms. Current research suggests that miRNAs can assume pivotal roles in carcinogenesis. In this article, through bioinformatics mining and computational analysis, we determine a single miRNA commonly involved in the development of breast, cervical, endometrial, ovarian, and vulvar cancer, whereas we underline the existence of 7 more miRNAs common in all examined malignancies with the exception of vulvar cancer. Furthermore, we identify their target genes and encoded biological functions. We also analyze common biological processes on which all of the identified miRNAs act and we suggest a potential mechanism of action. In addition, we analyze exclusive miRNAs among the examined malignancies and bioinformatically explore their functionality. Collectively, our data can be employed in in vitro assays as a stepping stone in the identification of a universal machinery that is derailed in female malignancies, whereas exclusive miRNAs may be employed as putative targets for future chemotherapeutic agents or cancer-specific biomarkers.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3808-3808
Author(s):  
Daisuke Araki ◽  
Diogo M. Magnani ◽  
Zhirui Wang ◽  
Richard H. Smith ◽  
Andre Larochelle

Abstract Patient conditioning is a critical initial step in hematopoietic stem and progenitor cell (HSPC) transplantation procedures to enable marrow engraftment of infused cells. Preparative regimens have traditionally been achieved by delivering cytotoxic doses of chemotherapeutic agents, with or without radiation. However, these regimens impair host immune function and are associated with significant morbidity. The use of monoclonal antibodies, either alone or conjugated to an internalizing toxin, to target specific antigens on hematopoietic cells has been proposed as a tractable alternative, especially in contexts, such as ex vivo autologous gene therapy, where preservation of immunity is desired. Efficient clearance of marrow has been demonstrated in preclinical models using CD45- or CD117-targeting antibodies conjugated to the plant toxin Saporin. However, this approach still awaits demonstration of long-term safety and efficacy in humans. In this study, we investigated whether toxin-conjugated antibodies targeting the cMPL receptor on HSPCs can provide the basis for a conditioning regimen prior to transplant. Thrombopoietin (TPO) and its receptor cMPL act as primary regulators of HSPC self-renewal and survival. The TPO:cMPL axis also regulates megakaryopoiesis and platelet production but, unlike CD45 and CD117 proteins, cMPL is otherwise not expressed in other blood cell types or in non-hematopoietic tissues. Hence, this approach may uniquely allow effective and specific depletion of host HSCs while sparing most hematopoietic progenitors and mature blood cells. To investigate cMPL as an antigen for targeted depletion of human HSPCs, we produced a recombinant bivalent anti-cMPL single-chain variable fragment (sc(FV) 2) (Orita et al. Blood 2004) fused with diphtheria toxin truncated at residue 390 (DT390) to prevent toxin internalization in off-target cells. We first confirmed the cMPL receptor-dependent cytotoxic effects of the anti-cMPL-DT390 conjugate in a HEK293A cell line engineered to express the human cMPL receptor. We observed marked cellular killing in vitro (IC50 = 21 pM) compared to the cMPL-negative control HEK293A cell line (Fig. A). Next, we assessed anti-cMPL-DT390 for its ability to inhibit growth of human CD34+ cells in vitro. G-CSF mobilized peripheral blood (PB) CD34+ cells were obtained from five healthy individuals. Surface expression of cMPL was compared by flow cytometry in subsets increasingly enriched in cells with long-term repopulating activity, including bulk CD34+, CD34+CD38- and CD34+CD38-CD90+CD45RA-CD49f+ cells. Levels of cMPL expression increased congruently with levels of HSC purity (Fig. B). Consistent with a cMPL dependent cytotoxic effect, increased cellular death was measured in populations expressing higher densities of cMPL receptors (IC50 = 104 nM), suggesting preferential targeting of the most primitive hematopoietic compartment (Fig. C). We then assessed whether anti-cMPL-DT390 could safely target and deplete human HSPCs in vivo in humanized NBSGW immunodeficient mice. At 12 weeks post-transplantation, engrafted animals (mean 19.8% CD45+ cells in PB) received a single maximum tolerated dose of 1.2 mg/kg anti-cMPL-DT390 (n=7) or vehicle control solution (n=7) by tail vein injection. HSPC depletion was assayed by measuring human myeloid (CD45+CD13+) chimerism in the mouse PB after antibody administration. We observed a gradual decline in HSPC activity, as represented by the decreased production of human myeloid cells following administration of anti-cMPL-DT390, peaking at 6 weeks with a 2.6-fold reduction in frequency of human CD45+CD13+ cells compared to untreated animals (p = 0.003) (Fig. D). Overall, our study provides proof-of-concept that bivalent anti-cMPL immunotoxin can effectively target and deplete human HSPCs, and may thus provide a novel nontoxic preparative approach to improve HSPC engraftment in transplantation for genetic and other nonmalignant disorders. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.


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