scholarly journals Sensitivity to cytotoxic agents of the EMT6 tumour in vivo: tumour volume versus in vitro plating. 1. Cyclophosphamide

1977 ◽  
Vol 35 (2) ◽  
pp. 208-217 ◽  
Author(s):  
P R Twentyman
Keyword(s):  
Tumour Volume ◽  
Cytotoxic Agents ◽  
Volume Versus

scholarly journals The activity of superoxide-dismutase in animal cell culture CHO-K1 after treatment with fullerenol and mytomicine C

2009 ◽  
Vol 63 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Visnja Bogdanovic ◽  
Marija Slavic ◽  
Jasminka Mrdjanovic ◽  
Slavica Solajic ◽  
Aleksandar Djordjevic
Keyword(s):  
Superoxide Dismutase ◽  
Mammalian Cells ◽  
Animal Cell ◽  
Water Soluble ◽  
Cytotoxic Agents ◽  
Antioxidant Defenses ◽  
Free Radical Scavengers ◽  
Sod Activity

Eukaryotic cell survives in predominantly reduced conditions. Homeostasis of cellular redox system is an imperative of cell surviving and its normal metabolism. ROS are well recognized for playing a dual role as both deleterious and beneficial species, since they can be either harmful or beneficial to living systems. These species are mutagenic compounds known to lead to DNA damage, favor cell transformation, and contribute to the development of a variety of malignant diseases. All the effects of oxidants are influenced by the cellular antioxidant defenses. This multilayer system consists of low molecular weight components and several antioxidant enzymes. Superoxide dismutases (SODs) are the only enzymes dismuting superoxide radicals. Mitomycin C, a cross-linking agent, demonstrated genotoxicity in all in vitro and in vivo test systems in mammalian cells and animals. Water-soluble fullerenes are well known as cytotoxic agents for many cell lines in vitro. At the other side, fullerenols are good free radical scavengers and antioxidants both in vitro and in vivo. This paper investigates the effects of fullerenol on survival and fullerenol/ /mytomicine (MMC) treatment on superoxide-dismutase (SOD) activity in CHO-K1 cells. Samples were treated 3 and 24 h with fullerenol (C60(OH)24) at concentration range 0.01-0.5 mg/mL and survival was monitored with dye exclusion test (DET). The activity of total SOD was estimated in samples treated with chosen concentrations of fullerenol and MMC (0.5 and 0.1 mg/mL) after 3 and 24 h of cell incubation. Increasing of C60(OH)24 concentration leads to decreasing of percent of surviving cells 3 and 24 h after incubation. The activity of total SOD enhanced with higher concentration of fullerenol, while decreased in the highest concentration at both experimental points. In samples treated with MMC, as well as in samples treated with fullerenol (0.0625 mg/mL) + MMC was noticed boost in total SOD activity in comparison with controls. Treatment with fullerenol decreased SOD activity in rest of samples treated with MMC. Decreased activity of superoxide-dismutase in almost all samples treated with fullerenol and MMC might be contributed to antioxidative properties of fullerenol. Increased enzyme level at concentration of 0.0625 mg/mL may be due to its prooxidative activity.

Hybrid Antibodies in Cancer Diagnosis and Therapy

1989 ◽  
Vol 4 (3) ◽  
pp. 131-134 ◽  
Author(s):  
S. Ménard ◽  
S. Canevari ◽  
M.I. Colnaghi
Keyword(s):  
Tumor Cell ◽  
Cancer Diagnosis ◽  
Cytotoxic T Cells ◽  
Lymphocyte Activation ◽  
Cytotoxic Agents ◽  
Toxic Agent ◽  
In Vivo Models ◽  
Promising Tool

Monoclonal Antibodies (Mabs) represent a promising tool for cancer diagnosis and theraphy. Administration of MAbs alone or conjugated to cytotoxic agents has been attempted but has significant limitations. Another potentially effective approach is the use of bispecific or bifunctional antibodies where the capacity to recognize the tumor cell and the toxic agent or lymphocyte activation molecule are united in one MAb. The hybrid molecule can be produced by chemical linkage between the two parentalantibodies, or alternatively by a biological approach that consists in the fusion of the two selected hybridomas. In the resulting quadroma cell the hybridoma immunoglobulin chains recombine randomly to form the bifunctional MAb. In different in vitro and in vivo models, bifunctional MAbs against tumor and CDS at nanomolar concentration has been shown to promote tumor cell killing by cytotoxic T cells. Specific localization of chemotherapeutic drugs in xenografted tumors has been demonstrated in mice pretreated with hybrid MAbs. The advantages of the hybrid MAb approach are that it should reduce the MAb biodistribution problem and that it involves no chemical manipulation between the functional agent and the MAb molecules.

scholarly journals Investigation of Newly Prepared Biodegradable 32P-chromic Phosphate-polylactide-co-glycolide Seeds and Their Therapeutic Response Evaluation for Glioma Brachytherapy

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Guoqiang Shao ◽  
Yuebing Wang ◽  
Xianzhong Liu ◽  
Meili Zhao ◽  
Jinhua Song ◽  
...  
Keyword(s):  
Therapeutic Effect ◽  
Tumour Volume ◽  
High Dose Rate ◽  
High Dose ◽  
Therapeutic Area ◽  
Response Evaluation ◽  
Early Evaluation ◽  
Biodistribution Studies

32P high-dose rate brachytherapy allows high-dose radiation delivery to target lesions with less damage to adjacent tissues. The early evaluation of its therapeutic effect on tumours is vital for the optimization of treatment regimes. The most commonly used 32P-CP colloid tends to leak with blind therapeutic area after intratumour injection. We prepared 32P-chromic phosphate-polylactide-co-glycolide (32P-CP-PLGA) seeds with biodegradable PLGA as a framework and investigated their characteristics in vitro and in vivo. We also evaluated the therapeutic effect of 32P-CP-PLGA brachytherapy for glioma with the integrin αvβ3-targeted radiotracer 68Ga-3PRGD2. 32P-CP-PLGA seeds (seed group, SG, 185 MBq) and 32P-CP colloid (colloid group, CG, 18.5 MBq) were implanted or injected into human glioma xenografts in nude mice. Scanning electron microscopy (SEM) of the seeds, micro-SPECT imaging, and biodistribution studies were performed at different time points. The tumour volume was measured using a caliper, and 68Ga-3PRGD2 micro-PET-CT imaging was performed to evaluate the therapeutic effect after 32P intratumour administration. The delayed release of 32P-CP was observed with biodegradation of vehicle PLGA. Intratumoural effective half-life of 32P-CP in the SG (13.3±0.3) d was longer than that in the CG (10.4±0.3) d (P<0.05), with liver appearance in the CG on SPECT. A radioactivity gradient developed inside the tumour in the SG, as confirmed by micro-SPECT and SEM. Tumour uptake of 68Ga-3PRGD2 displayed a significant increase on day 0.5 in the SG and decreased earlier (on day 2) than the volume reduction (on day 8). Thus, 32P-CP-PLGA seeds, controlling the release of entrapped 32P-CP particles, are promising for glioma brachytherapy, and 68Ga-3PRGD2 imaging shows potential for early response evaluation of 32P-CP-PLGA seeds brachytherapy.

scholarly journals CXCR4 inhibitor AMD3100 disrupts the interaction of multiple myeloma cells with the bone marrow microenvironment and enhances their sensitivity to therapy

Blood ◽  
2009 ◽  
Vol 113 (18) ◽  
pp. 4341-4351 ◽  
Author(s):  
Abdel Kareem Azab ◽  
Judith M. Runnels ◽  
Costas Pitsillides ◽  
Anne-Sophie Moreau ◽  
Feda Azab ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Therapeutic Agents ◽  
Cytotoxic Agents ◽  
Parp Cleavage ◽  
Hematopoietic Stem ◽  
Akt Phosphorylation ◽  
Enhanced Sensitivity

Abstract The interaction of multiple myeloma (MM) cells with their microenvironment in the bone marrow (BM) provides a protective environment and resistance to therapeutic agents. We hypothesized that disruption of the interaction of MM cells with their BM milieu would lead to their sensitization to therapeutic agents such as bortezomib, melphalan, doxorubicin, and dexamethasone. We report that the CXCR4 inhibitor AMD3100 induces disruption of the interaction of MM cells with the BM reflected by mobilization of MM cells into the circulation in vivo, with kinetics that differed from that of hematopoietic stem cells. AMD3100 enhanced sensitivity of MM cell to multiple therapeutic agents in vitro by disrupting adhesion of MM cells to bone marrow stromal cells (BMSCs). Moreover, AMD3100 increased mobilization of MM cells to the circulation in vivo, increased the ratio of apoptotic circulating MM cells, and enhanced the tumor reduction induced by bortezomib. Mechanistically, AMD3100 significantly inhibited Akt phosphorylation and enhanced poly(ADP-ribose) polymerase (PARP) cleavage as a result of bortezomib, in the presence of BMSCs in coculture. These experiments provide a proof of concept for the use of agents that disrupt interaction with the microenvironment for enhancement of efficacy of cytotoxic agents in cancer therapy.

EB10, an Anti-FLT3 Monoclonal Antibody, Selectively Targets ALL Cell Lines and Primary ALL Blasts without Interfering with Normal Hematopoiesis.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2744-2744 ◽  
Author(s):  
Obdulio Piloto ◽  
Patrick Brown ◽  
Li Li ◽  
Bao Nguyen ◽  
Kyu-Tae Kim ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Lines ◽  
Scid Mice ◽  
Cytotoxic Agents ◽  
Radioactive Isotopes ◽  
Leukemic Cells ◽  
Class Iii ◽  
Antibody Treatment

Abstract The class III receptor tyrosine kinase, FLT3, is expressed by &gt;90% of B-lineage acute lymphoblastic leukemias (ALL) blasts. In addition, it is expressed at extremely high levels in ALL patients with MLL-rearrangements or hyperdiploidy and sometimes mutated in these same patients. In this report, we investigated the effects of EB10, an anti-human FLT3 monoclonal antibody capable of preventing binding of FLT3 ligand (FL), on ALL cell lines and primary cells. In vitro studies, examining the ability of EB10 to inhibit FLT3 activation and downstream signaling in ALL cell lines and primary blasts, yielded variable results. In some cell lines FLT3 phosphorylation was inhibited and with it, downstream activation of pathways involving MAPK, AKT, and STAT5 phosphorylation. However, several cell lines actually exhibited FLT3 activation upon antibody treatment, possibly because of antibody-mediated receptor dimerization, and subsequent activation of downstream pathways. Nevertheless, through antibody-mediated cellular cytotoxicity (ADCC) such an antibody could still prove efficacious against leukemia cells in vivo. In fact, EB10 treatment significantly prolongs survival and/or reduces engraftment of ALL cell lines and primary ALL blasts in NOD/SCID mice. This effect might be even more pronounced in a host that was less immune compromised than are NOD/SCID mice. The leukemic cells surviving EB10 treatment in the mice were characterized by FACS analysis and found to express low levels or no FLT3. In contrast to the reduction in engraftment of human ALL primary blasts, EB10 treatment of NOD/SCID mice did not reduce engraftment of human hematopoietic CD34+ cells. Taken together, these data demonstrate that EB10 is selectively cytotoxic to ALL blasts while having little effect on normal hematopoiesis. Such an antibody, either naked or conjugated to radioactive isotopes or cytotoxic agents, may prove useful in the therapy of infant ALL as well as childhood and adult ALL patients whose blasts typically express FLT3.

FLT3 Immunotherapy Can Eliminate Engraftment of ALL Cells in NOD/SCID Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 869-869
Author(s):  
Obdulio Piloto ◽  
Bao Nguyen ◽  
Patrick Brown ◽  
Kyu-Tae Kim ◽  
David Huso ◽  
...  
Keyword(s):  
Cell Lines ◽  
Scid Mice ◽  
Cytotoxic Agents ◽  
Radioactive Isotopes ◽  
Leukemic Cells ◽  
Pcr Analysis ◽  
Facs Analysis ◽  
Antibody Treatment

Abstract The class III receptor tyrosine kinase, FLT3, is expressed by over 90% of B-lineage acute lymphoblastic leukemias (ALL) blasts. In addition, it is expressed at extremely high levels in ALL patients with MLL-rearrangements or hyperdiploidy and sometimes mutated in these same patients. In this report, we investigated the effects of EB10, an anti-human FLT3 monoclonal antibody capable of preventing binding of FLT3 ligand (FL), on ALL cell lines and primary cells. In vitro studies, examining the ability of EB10 to inhibit FLT3 activation and downstream signaling in ALL cell lines and primary blasts, yielded variable results. In some cell lines FLT3 phosphorylation was inhibited and with it, downstream activation of pathways involving MAPK, AKT, and STAT5 phosphorylation. However, several cell lines actually exhibited FLT3 activation upon antibody treatment, possibly because of antibody-mediated receptor dimerization, and subsequent activation of downstream pathways. Nevertheless, through antibody-mediated cellular cytotoxicity (ADCC) such an antibody could still prove efficacious against leukemia cells in vivo. In fact, EB10 treatment significantly prolongs survival and/or reduces engraftment of several ALL cell lines and some primary ALL samples in NOD/SCID mice, even when EB10 treatment results in FLT3 activation of those cell lines in vitro. Moreover, FACS and PCR analysis of EB10 treated NOD/SCID mice surviving 150 days post leukemic cell injection revealed that FLT3 immunotherapy eliminated leukemic engraftment. The leukemic cells surviving EB10 treatment in the mice were characterized by FACS analysis and found to express lower levels of FLT3. To assess for resistance, cells surviving EB10 treatment were injected into NOD/SCID mice and treated with a single dose of EB10. FACS analysis revealed that these cells remain sensitive to EB10 treatment. Taken together, these data demonstrate that EB10 is cytotoxic to ALL blasts in vivo and EB10 treatment did not select for resistant clones. Such an antibody, either naked or conjugated to radioactive isotopes or cytotoxic agents, may prove useful in the therapy of infant ALL as well as childhood and adult ALL patients whose blasts typically express FLT3.

The Humanized Anti-CD40 Monoclonal Antibody, SGN-40, Potentiates Chemotherapy Regimens in NHL Xenograft Models Via Pro-Apoptotic Signaling.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2342-2342 ◽  
Author(s):  
Timothy S. Lewis ◽  
Renee S. McCormick ◽  
Kim Kissler ◽  
Ivan J. Stone ◽  
Mechthild Jonas ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Monoclonal Antibody ◽  
Antitumor Activity ◽  
Family Member ◽  
Cytotoxic Agents ◽  
P53 Family ◽  
Signaling Mechanism ◽  
Xenograft Models

Abstract SGN-40 is a humanized antibody targeting CD40, a TNF receptor family member expressed on normal B cells, non-Hodgkin’s lymphoma (NHL), multiple myeloma, and a variety of carcinomas. Previous studies have shown that SGN-40 triggers proapoptotic signal transduction, mediates effector function (ADCC), and has in vivo antitumor activity in CD40+ lymphoma xenograft models. We now report in vivo efficacy data for SGN-40 in combination with the anti-CD20 monoclonal antibody, rituximab, and approved chemotherapy regimens for the treatment of NHL. The growth of subcutaneous Ramos tumors in SCID mice was delayed following SGN-40 or rituximab treatment. However, the combination of SGN-40 + rituximab (S-R) significantly improved efficacy over either antibody alone. SGN-40 was then tested with ICE (ifosfamide, carboplatin, etoposide) chemotherapy with or without rituximab (S-R-ICE and S-ICE). These studies demonstrated that both S-R-ICE and S-ICE treated mice had lower tumor burden than R-ICE or SGN-40 treated animals. Additionally, the effect of SGN-40 in combination with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy with or without rituximab (S-R-CHOP and S-CHOP) was examined. S-R-CHOP and S-CHOP therapies showed a significant delay in tumor growth compared with R-CHOP or SGN-40 alone. Furthermore, the efficacy observed in S-R-ICE and S-R-CHOP treatments exceeded the S-R combination, suggesting that SGN-40 chemosensitizes lymphoma cells by a signaling mechanism in addition to augmenting ADCC when combined with rituximab. To better understand the chemosensitization effect of SGN-40 in xenograft models, signal transduction events triggered by SGN-40 were examined in vitro. SGN-40 treatment caused the sustained degradation of the BCL-6 protooncogene in several lymphoma cell lines, following prolonged MAP Kinase pathway activation. BCL-6 is implicated in lymphomagenesis of germinal center derived lymphomas, and is proteasomally degraded after phosphorylation by ERK1/2 MAPK. Immunohistochemical analyses of Ramos tumors harvested from mice following treatment with SGN-40 or S-CHOP revealed elevated numbers of apoptotic cells versus untreated tumors. A distinct downregulation of BCL-6 staining in Ramos tumor cells was also observed in SGN-40 and S-CHOP treated animals, correlating with increased cell death. Finally, in some NHL lines SGN-40 upregulated the p53 family member TAp63alpha, a chemo-sensitizing transcription factor capable of inducing apoptosis when overexpressed. When combined with cytotoxic agents, SGN-40 caused a greater induction of TAp63alpha compared with chemotherapy alone, a potential mechanism underlying the improved antitumor activity seen in combination studies. Collectively, these data suggest that SGN-40 signaling occurs at the tumor site, likely contributing directly to tumor cell killing and chemosensitization. These preclinical studies support our earlier work suggesting that addition of SGN-40 to standard therapeutic regimens may improve the outcome for patients with NHL.

Apatinib to enhance chemosensitivity of gastric cancer to paciltaxel and 5-fluorouracil.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15545-e15545
Author(s):  
Xiangdong Cheng ◽  
Zhiyuan Xu ◽  
Jiahui Chen ◽  
Chunli Zhang ◽  
Jianfa Yu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Late Stage ◽  
Zebrafish Embryo ◽  
Xenograft Model ◽  
Cytotoxic Agents ◽  
Pathological Examination ◽  
Conversion Surgery ◽  
Synergistic Interactions

e15545 Background: Patients (pts) with late-stage gastric cancer (GC) have a poor prognosis. Targeted agent combined with chemotherapy is expected to yield clinical benefits. Apatinib, a novel tyrosine kinase inhibitor targeting VEGFR-2, improves outcomes in patients with metastatic GC as a third line of treatment. Hence, we aimed to assess the efficacy and safety of apatinib plus chemotherapy in vivo and in vitro. Methods: The MGC803 cell viability was assessed by CCK-8 assay, and the interactions between apatinib and conventional cytotoxic agents revealed by combined index (CI) values were calculated using Calcusyn 2.0 software. We also used a zebrafish embryo xenograft model to validate the synergistic interactions. Furthermore, 4 pts with late-stage GC were enrolled to receive paclitaxel (PTX)/S1 chemotherapy plus apatinib in conversion surgery. Apatinib was administered 500 mg once a day continuously, PTX 130 mg/m2 was given on day 1, and S-1 was administered at 80 mg/m2for 14 consecutive days, followed by 7 days of rest. Treatment was administered for 3-5 cycles, but the last cycle did not include apatinib. Results: Apatinib showed synergistic interactions with both PTX and 5-Fu in vivo (CIs < 1). The zebrafish embryo xenograft model also demonstrated that addition of 0.25 µg/mL apatinib significantly enhanced the tumor growth inhibition effects of 25 (38.39% vs. 11.77%, P < 0.001) and 50 ng/fish (43.58% vs. 17.88%, P < 0.05) 5-Fu, as well as those of 0.75 ng/fish (53.62% vs. 35.22%, P < 0.001) and 1.5 ng/fish (59.71% vs.46.73%, P < 0.01) PTX. Apatinib plus S1/paclitaxel chemotherapy was well tolerable before surgery. Objective response to preoperative SPA treatment was achieved in all pts. No posteroperative bleeding event or wound-healing complication was observed. No postoperative mortality occurred and morbidity was encountered. Pathological examination showed that all pts had grade Ib pathological response. Conclusions: The experimental data suggested that apatinib improves the efficacy of PTX and 5-Fu both in vitro and in vivo. Clinical evidence showed that combination of PTX/S1 chemotherapy with apatinib has promising efficacy and acceptable safety profile in late-stage GC, especially in the conversion surgery.

Exploration and synthesis of curcumin analogues with improved structural stability both in vitro and in vivo as cytotoxic agents

2009 ◽  
Vol 17 (6) ◽  
pp. 2623-2631 ◽  
Author(s):  
Guang Liang ◽  
Lili Shao ◽  
Yi Wang ◽  
Chengguang Zhao ◽  
Yanhui Chu ◽  
...  
Keyword(s):  
Structural Stability ◽  
Cytotoxic Agents ◽  
Curcumin Analogues

scholarly journals Midkine Mediates Intercellular Crosstalk between Drug-Resistant and Drug-Sensitive Neuroblastoma Cells In Vitro and In Vivo

ISRN Oncology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
Fei Chu ◽  
Jessica A. Naiditch ◽  
Sandra Clark ◽  
Yi-Yong Qiu ◽  
Xin Zheng ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Chemotherapy Resistance ◽  
Neuroblastoma Cells ◽  
Cytotoxic Agents ◽  
Drug Resistant ◽  
Wild Type ◽  
Cytoprotective Effect ◽  
Acquired Drug Resistance

Resistance to cytotoxic agents has long been known to be a major limitation in the treatment of human cancers. Although many mechanisms of drug resistance have been identified, chemotherapies targeting known mechanisms have failed to lead to effective reversal of drug resistance, suggesting that alternative mechanisms remain undiscovered. Previous work identified midkine (MK) as a novel putative survival molecule responsible for cytoprotective signaling between drug-resistant and drug-sensitive neuroblastoma, osteosarcoma and breast carcinoma cells in vitro. In the present study, we provide further in vitro and in vivo studies supporting the role of MK in neuroblastoma cytoprotection. MK overexpressing wild type neuroblastoma cells exhibit a cytoprotective effect on wild type cells when grown in a co-culture system, similar to that seen with doxorubicin resistant cells. siRNA knockdown of MK expression in doxorubicin resistant neuroblastoma and osteosarcoma cells ameliorates this protective effect. Overexpression of MK in wild type neuroblastoma cells leads to acquired drug resistance to doxorubicin and to the related drug etoposide. Mouse studies injecting various ratios of doxorubicin resistant or MK transfected cells with GFP transfected wild type cells confirm this cytoprotective effect in vivo. These findings provide additional evidence for the existence of intercellular cytoprotective signals mediated by MK which contribute to chemotherapy resistance in neuroblastoma.

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