scholarly journals Targeted Delivery of Nanocarrier-Conjugated Doxorubicin to Widen the Therapeutic Window of the Most Active Drug in Lymphoma Therapeutics

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4061-4061
Author(s):  
Artavazd Arumov ◽  
Piumi Y. Liyanage ◽  
Asaad Trabolsi ◽  
Lingxiao Li ◽  
Evan R. Roberts ◽  
...  
Keyword(s):  
Body Weight ◽  
Western Blot ◽  
Tumor Cells ◽  
Cell Lines ◽  
Active Drug ◽  
Tumor Bearing ◽  
Molar Equivalent ◽  
Proof Of Principle

Doxorubicin (Dox) remains the most active drug against aggressive lymphomas, forming the backbone of multiple potentially curative frontline combination regimens. R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone), for example, cures diffuse large B-cell Lymphoma (DLBCL), the most common lymphoid malignancy in the United States, greater than 60% of the time. Patients with relapsed/refractory disease, however, have poor prognosis and require new options. Advances in nanotechnology provide new opportunities to widen therapeutic windows for existing drugs by enhancing delivery to tumor cells and limiting toxicities to non-malignant tissues. Carbon-Nitride Dots (CND) are novel nanocarriers we have developed that can be conjugated with a diverse range of molecules and have an established safe pharmacologic profile. Here, we sought CND-based enhancement of Dox's anti-lymphoma activities. We generated unconjugated CNDs (~3 nm) through a hydrothermal microwave synthesis, followed by carbodiimide cross-linking bioconjugation steps to covalently link Dox and/or transferrin (TF), the protein ligand for the transferrin receptor (TFR). Because TFR is expressed on the cell surface in a range of B-cell lymphomas including DLBCL, we aimed to increase Dox delivery to tumor cells and limit delivery to non-malignant tissues. We probed a cohort of DLBCL cell lines for TFR expression via western blot, followed by baseline viability assays. Unconjugated CNDs showed no toxicity in vitro, while conjugation to Dox alone resulted in potency similar to unconjugated Dox. CND-Dox-TF, however, was 1-2 Log10 more potent than Dox alone (LD50 1.2-48.5 nM vs. 205.5->1000 nM), consistent with enhanced activity due to the entry of the nanocarrier into the cells through the TF-TFR interaction. To create a functional model, we cloned the TFR1 gene into a GFP-lentiviral expression vector. We infected previously tested cell lines with TFR1, confirmed increased TFR expression via western blot, and exposed cells to CND nanocarriers. TFR1-infected cells showed selective disadvantage during CND-Dox-TF treatment compared to uninfected and empty-vector controls, while CND and CND-Dox controls showed no differential effect. After establishing CND-Dox-TF proof of principle in vitro, we next initiated testing in vivo, beginning with maximum-tolerated dose (MTD) finding experiments. We treated three groups of non-tumor-bearing NOD scid gamma (NSG) mice intravenously with a single dose of (1) CND, (2) CND-Dox, and (3) CND-Dox-TF. Maximum dosing of CND-Dox-TF based on solubility in 100 µL PBS was roughly 1:4 molar equivalent to Dox MTD (3.3 mg/kg). This dose of CND-Dox-TF caused decreased body weight to >20% loss from starting dosing and animals had to be sacrificed, with organ pathology pending. Molar equivalent dosing of CND and CND-Dox, however, resulted in no weight loss, demonstrating biologic activity of the TF moiety but unfortunately intolerable toxicity at this initial dose. We then reduced the CND-Dox-TF dose to 1:16 molar equivalent to Dox MTD and repeated dosing to three non-tumor-bearing animals. This resulted in decreased body weight of 10% from starting dose by day 11, followed by a rebound to normal body weight by day 17. This observed body weight fluctuation is similar to what is seen under a 0.75% of Dox MTD. With a dose of 33 mg/kg identified as the MTD of the CND-Dox-TF, we are now proceeding to anti-tumor efficacy experiments in four available PDX models of DLBCL (two each from previously untreated and relapsed/refractory patients). We will compare the MTD of Dox versus the MTD of CND-Dox-TF initially as single agents. We will then compare R-CHOP to "R-nanoCHOP" (replacement of Dox with the MTD of CND-Dox-TF). We hypothesize that both through the TF-TFR interaction and enhanced tumor permeability and retention that are known properties of CNDs, CND-Dox-TF treated mice will have improved anti-lymphoma responses. In sum, we show that a TF ligand conjugated to Dox via our CND nanocarrier significantly increases the anti-lymphoma efficacy of Dox on DLBCL cell lines. Importantly, we also show these novel nanocarrier therapeutic molecules are safe to administer in vivo, and we define MTD for studies moving forward. Proof of principle that CND nanotechnology enhances anti-lymphoma activity of Dox would open the door for many such approaches aimed at a variety of malignancies. Disclosures No relevant conflicts of interest to declare.

scholarly journals BSCI-12. Inhibition of melanoma brain metastasis by targeting miR-146a

2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii3-iii3
Author(s):  
Jiwei Wang ◽  
Emma Rigg ◽  
Taral R Lunavat ◽  
Wenjing Zhou ◽  
Zichao Feng ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Tumor Cells ◽  
Cell Lines ◽  
Western Blots ◽  
Cell Growth And Migration ◽  
Human Astrocytes ◽  
And Migration ◽  
The Brain

Abstract Background Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released by the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. Materials and Methods miRNAs from exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. Results miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146a in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. Conclusions MiR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.

scholarly journals Identification of Prostaglandin F2 Receptor Negative Regulator (PTGFRN) as an internalizable target in cancer cells for antibody-drug conjugate development

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0246197
Author(s):  
Jorge Marquez ◽  
Jianping Dong ◽  
Chun Dong ◽  
Changsheng Tian ◽  
Ginette Serrero
Keyword(s):  
Flow Cytometry ◽  
Western Blot ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Negative Regulator ◽  
Target Validation ◽  
Antibody Drug

Antibody-drug conjugates (ADC) are effective antibody-based therapeutics for hematopoietic and lymphoid tumors. However, there is need to identify new targets for ADCs, particularly for solid tumors and cancers with unmet needs. From a hybridoma library developed against cancer cells, we selected the mouse monoclonal antibody 33B7, which was able to bind to, and internalize, cancer cell lines. This antibody was used for identification of the target by immunoprecipitation and mass spectrometric analysis, followed by target validation. After target validation, 33B7 binding and target positivity were tested by flow cytometry and western blot analysis in several cancer cell lines. The ability of 33B7 conjugated to saporin to inhibit in vitro proliferation of PTFRN positive cell lines was investigated, as well as the 33B7 ADC in vivo effect on tumor growth in athymic mice. All flow cytometry and in vitro internalization assays were analyzed for statistical significance using a Welsh’s T-test. Animal studies were analyzed using Two-Way Analysis of Variance (ANOVA) utilizing post-hoc Bonferroni analysis, and/or Mixed Effects analysis. The 33B7 cell surface target was identified as Prostaglandin F2 Receptor Negative Regulator (PTGFRN), a transmembrane protein in the Tetraspanin family. This target was confirmed by showing that PTGFRN-expressing cells bound and internalized 33B7, compared to PTGFRN negative cells. Cells able to bind 33B7 were PTGFRN-positive by Western blot analysis. In vitro treatment PTGFRN-positive cancer cell lines with the 33B7-saporin ADC inhibited their proliferation in a dose-dependent fashion. 33B7 conjugated to saporin was also able to block tumor growth in vivo in mouse xenografts when compared to a control ADC. These findings show that screening antibody libraries for internalizing antibodies in cancer cell lines is a good approach to identify new cancer targets for ADC development. These results suggest PTGFRN is a possible therapeutic target via antibody-based approach for certain cancers.

P16.08 Inhibition of melanoma brain metastasis by targeting miR-146a

2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii57-ii57
Author(s):  
J Wang ◽  
E K Rigg ◽  
T R Lunavat ◽  
W Zhou ◽  
Z Feng ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Tumor Cells ◽  
Cell Lines ◽  
Western Blots ◽  
Cell Growth And Migration ◽  
Human Astrocytes ◽  
And Migration ◽  
The Brain

Abstract BACKGROUND Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released from the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. MATERIAL AND METHODS miRNAs in exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. RESULTS miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146 in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. CONCLUSION miR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.

Defibrotide (DF) Targets Tumor-Microenvironmental Interactions and Sensitizes Multiple Myeloma and Solid Tumor Cells to Cytotoxic Chemotherapeutics.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 286-286 ◽  
Author(s):  
Constantine S. Mitsiades ◽  
Cecile Rouleau ◽  
Krishna Menon ◽  
Beverly Teicher ◽  
Massimo Iacobelli ◽  
...  
Keyword(s):  
Stem Cell ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Solid Tumor ◽  
Single Agent ◽  
Conventional Chemotherapy ◽  
Adhesive Properties

Abstract Introduction: Defibrotide (DF) is a polydisperse oligonucleotide with anti-thrombotic, thrombolytic, anti-ischemic, and anti-adhesive properties, which selectively targets the microvasculature and has minimal hemorrhagic risk. DF is an effective treatment for veno-occlusive disease (VOD), an important regimen-related toxicity in stem cell transplantation characterized by endothelial cell injury. DF also augments stem cell mobilization by modulating adhesion in vivo. Because of its cytoprotective effect on the endothelium, we specifically investigated whether DF protects tumor cells from cytotoxic anti-tumor agents. Further, because of its broad anti-adhesive properties, we evaluated whether DF modulates the interaction of MM cells with bone marrow stromal cells (BMSCs), which confers growth, survival and drug resistance in the BM milieu. Methods: In vitro studies in isogenic dexamethasone (Dex)-sensitive and resistant MM cell lines (MM-1S and MM1R, respectively) showed that DF does not attenuate the sensitivity of MM cells to Dex, the proteasome inhibitor bortezomib (PS-341), melphalan (MEL), vinca alkaloids (vincristine, vinblastine), taxanes (paclitaxel) or platinum (cisplatin), but does decrease their sensitivity to doxorubicin. These selective effects in vitro of DF in protecting tumor cells against doxorubicin and modestly sensitizing MM cells to platinum was also confirmed in solid tumor breast (MCF-7) and colon (HT-29) carcinoma cell lines. Although DF had minimal in vitro inhibitory effect on MM or solid tumor cell growth in vitro, it showed in vivo activity as a single agent and enhanced the responsiveness of MM tumors to cytotoxic chemotherapeutics, such as MEL or cyclophosphamide, in human MM xenografts in SCID/NOD mice. The in vivo single-agent activity and chemosensitizing properties of DF, coupled with its lack of major in vitro activity, suggested that DF may not directly target tumor cells, but rather modulate tumor cell interaction with BMSCs. In an ex vivo model of co-culture of primary MM tumor cells with BMSCs (which protects MM cells against conventional chemotherapy), DF alone had a only modest effect on tumor cell viability, but it significantly enhanced MM cell sensitivity to cytotoxic chemotherapy (e.g. MEL), suggesting that a major component of the biological effects of DF may be attributable not to direct targeting of tumor cells, but to modulation of the interactions that tumor cells develop with the local stromal milieu. Conclusion: Our studies show that DF mediates in vivo anti-MM activity by abrogating interactions of MM cells with their BM milieu, thereby enhancing sensitivity and overcoming resistance to conventional chemotherapy. These data support future clinical trials of DF, in combination with both conventional and novel therapies, to improve patient outcome in MM.

The Monoclonal Antibody nBT062 Conjugated to Cytotoxic Maytansinoids Has Potent and Selective Cytotoxicity against CD138 Positive Multiple Myeloma Cells in Vitro and in Vivo.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1716-1716 ◽  
Author(s):  
Hiroshi Ikeda ◽  
Teru Hideshima ◽  
Robert J. Lutz ◽  
Sonia Vallet ◽  
Samantha Pozzi ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Monoclonal Antibody ◽  
Tumor Cells ◽  
Cell Lines ◽  
Xenograft Model ◽  
Growth Delay ◽  
Selective Cytotoxicity ◽  
Bystander Killing

Abstract CD138 is expressed on differentiated plasma cells and is involved in the development and/or proliferation of multiple myeloma (MM), for which it is a primary diagnostic marker. In this study, we report that immunoconjugates comprised of the murine/human chimeric CD138-specific monoclonal antibody nBT062 conjugated with highly cytotoxic maytansinoid derivatives (nBT062-SMCC-DM1, nBT062-SPDB-DM4 and nBT062-SPP-DM1) showed cytotoxic activity against CD138-positive MM cells both in vitro and in vivo. These agents demonstrated cytotoxicity against OPM1 and RPMI8226 (CD138-positive MM cell lines) in a dose and time-dependent fashion and were also cytotoxic against primary tumor cells from MM patients. Minimal cytotoxicity was noted in CD138-negative cell lines and no activity was observed against peripheral blood mononuclear cells from healthy volunteers, suggesting that CD138-targeting is important for immunoconjugate-mediated cytotoxicity. Examination of the mechanism of action whereby these immunoconjugates induced cytotoxicity in MM cells demonstrated that treatment triggered G2/M cell cycle arrest, followed by apoptosis associated with cleavage of PARP and caspase-3, -8 and -9. Neither interleukin-6 nor insulin-like growth factor-I could overcome the apoptotic effect of these agents. The level of soluble (s)CD138 in the BM plasma from 15 MM patients was evaluated to determine the potential impact of sCD138 on immunoconjugate function. The sCD138 level in BM plasma was found to be significantly lower than that present in MM cell culture supernatants where potent in vitro cytotoxicity was observed, suggesting that sCD138 levels in MM patient BM plasma would not interfere with immunoconjugate activity. Because adhesion to bone marrow stromal cells (BMSCs) triggers cell adhesion mediated drug resistance to conventional therapies, we next examined the effects of the conjugates on MM cell growth in the context of BMSC. Co-culture of MM cells with BMSCs, which protects against dexamethasoneinduced death, had no impact on the cytotoxicity of the immunoconjugates. The in vivo efficacy of these immunoconjugates was also evaluated in SCID mice bearing established CD138-positive MM xenografts and in a SCID-human bone xenograft model of myeloma. Significant tumor growth delay or regressions were observed at immunoconjugate concentrations that were well tolerated in all models tested. The ability of these agents to mediate bystander killing of proximal CD138-negative cells was also evaluated. While nBT062-SPDB-DM4 was inactive against CD138-negative Namalwa cells cultured alone, significant killing of these CD138-negative cells by nBT062-SPDB-DM4 was observed when mixed with CD138-positive OPM2 cells. This bystander killing may contribute to the eradication of MM tumors by disrupting the tumor microenvironment and/or killing CD138-negative MM tumor cells, such as the putative CD138 negative myeloma stem cells. These studies demonstrate strong evidence of in vitro and in vivo selective cytotoxicity of these immunoconjugates and provide the preclinical framework supporting evaluation of nBT062-based immunoconjugates in clinical trials to improve patient outcome in MM.

A Novel Acanthoic Acid Analog NPI-1342 Blocks IκB Kinase-α and Trigger In Vitro and In Vivo cytotoxicity in Multiple Myeloma Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1841-1841
Author(s):  
Dharminder Chauhan ◽  
Ajita V. Singh ◽  
Arghya Ray ◽  
Teru Hideshima ◽  
Paul G. Richardson ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Growth ◽  
Board Of Directors ◽  
Tumor Cells ◽  
Cell Lines ◽  
Inhibitory Effect ◽  
Advisory Committees ◽  
Acid Analog

Abstract Abstract 1841 Introduction: The dimeric Nuclear Factor-kappa B (NF-κB) transcription factor plays a key role during multiple myeloma (MM) cell adhesion-induced cytokine secretion in bone marrow stromal cells, which in turn triggers MM cell growth in a paracrine manner. NF-κB signaling pathway is mediated via canonical (IKK-α/IKK-β/NEMO-P50/65 or NF-κB1) and non-canonical (IKK-α/IKK-α/NIK-p52/RelB or NF-κB2) components. Prior studies have also linked constitutive activation of non-canonical NF-κB pathway to genetic abnormalities/mutation, allowing for an autocrine growth of MM cells. Other recent studies showed that constitutive NF-κB activity in tumor cells from MM patients renders these cells refractory to inhibition by bortezomib; and in fact, that bortezomib induces canonical NF-κB activity. These reports provided the impetus for the development of an agent with ability to modulate canonical and/or non-canonical NF-κB axis, allowing for a more robust and specific inhibition of NF-κB. Recent research and development efforts at Nereus Pharmaceuticals, Inc., have identified a novel small molecule acanthoic acid analog NPI-1342 as a potent NF-κB inhibitor. Here, we examined the effects of NPI-1342 on canonical versus non-canonical NF-κB signaling pathways, as well as its anti-tumor activity against MM cells using both in vitro and in vivo model systems. Methods: We utilized MM.1S, MM.1R, RPMI-8226, U266, KMS12PE, NCI-H929, OCI-MY5, LR5, Dox-40, OPM1, and OPM2 human MM cell lines, as well as purified tumor cells from patients with MM. Cell viability assays were performed using MTT and Trypan blue exclusion assays. Signal transduction pathways were evaluated using immunoblot analysis, ELISA, and enzymology assays. Animal model studies were performed using the SCID-hu model, which recapitulates the human BM milieu in vivo. Results: We first examined the effects of NPI-1342 on lipopolysaccharides (LPS)-induced NF-κB activity. Results showed that NPI-1342 inhibits LPS-stimulated NF-κB activity in vitro, as measured by phosphorylation of IkBa. To determine whether NPI-1342 triggers a differential inhibitory effect on IKKβ versus IKKα, MM.1S MM cells were treated with NPI-1342 for 48 hours, and protein lysates were subjected to kinase activity assays. NPI-1342 blocked IKKα, but not IKKβ or IKKγ phosphorylation. We next assessed whether the inhibitory effect of NPI-1342 on NF-κB activity is associated with cytotoxicity in MM cells. We utilized a panel of MM cell lines: at least five of these have mutations of TRAF3 (MM.1S, MM.1R, DOX40 and U266); one has no known NF-κB mutations (OPM2), and one has amplification of NF-κB1 (OCI-MY5). Treatment of MM cell lines and primary patient (CD138 positive) MM cells for 48 hours significantly decreased their viability (IC50 range 15–20 μM) (P < 0.001; n=3) without affecting the viability of normal peripheral blood mononuclear cells, suggesting selective anti-MM activity and a favorable therapeutic index for NPI-1342. NPI-1342-induced a marked increase in Annexin V+ and PI- apoptotic cell population (P < 0.001, n=3). Mechanistic studies showed that NPI-1342-triggered apoptosis in MM cells is associated with activation of caspase-8, caspase-9, caspase-3, and PARP cleavage. We next examined the in vivo effects of NPI-1342 in human MM xenograft models. For these studies, we utilized the SCID-hu MM model, which recapitulates the human BM milieu in vivo. In this model, MM cells are injected directly into human bone chips implanted subcutaneously in SCID mice, and MM cell growth is assessed by serial measurements of circulating levels of soluble human IL-6R in mouse serum. Treatment of tumor-bearing mice with NPI-1342 (20 mg/kg intraperitoneally, QD1-5 for 2 weeks), but not vehicle alone, significantly inhibits MM tumor growth in these mice (10 mice each group; P = 0.004). The doses of NPI-1342 were well tolerated by the mice, without significant weight loss. Finally, immunostaining of implanted human bone showed robust apoptosis and blockade of NF-κB in mice treated with NPI-1342 versus vehicle alone. Conclusions: We demonstrate the efficacy of a novel small molecule inhibitor of NF-κB NPI-1342 in MM using both in vitro and in vivo models. NPI-1342 blocks NF-κB activity with a preferential inhibitory activity against IKK-α component of NF-κB signaling. Our preclinical studies support evaluation of NPI-1342 as a potential MM therapy. Disclosures: Hideshima: Acetylon: Consultancy. Richardson:Millennium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Palladino:Nereus Pharmaceuticals, Inc: Employment, Equity Ownership. Anderson:Celgene: Consultancy; Millennium: Consultancy; Onyx: Consultancy; Merck: Consultancy; Bristol Myers Squibb: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Acetylon:; Nereus Pharmaceuticals, Inc: Consultancy.

Anti-Myeloma Activity of a Novel Free Radical Inducer Rrx-001

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4712-4712 ◽  
Author(s):  
Deepika Sharma Das ◽  
Ze Tian ◽  
Arghya Ray ◽  
Durgadevi Ravillah ◽  
Yan Song ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Clinical Trial ◽  
Drug Resistance ◽  
Board Of Directors ◽  
Tumor Cells ◽  
Cell Lines ◽  
Advisory Committees ◽  
Healthy Donors

Abstract Background and Rationale: Multiple Myeloma (MM) remains incurable despite the advent of novel drugs, highlighting the need for further identification of factors mediating disease progression and resistance. The bone marrow (BM) microenvironment confers growth, survival, and drug resistance in MM cells. Studies to date suggest an important role of BM hypoxia (low oxygenation) in MM cell survival, drug resistance, migration, and metastasis. Therapies targeting the MM cell in its BM milieu under hypoxic conditions may therefore achieve responses in patients resistant to various therapies. Recent studies led to the development of a novel aerospace-industry derived Phase 2 molecule RRx-001 with epigenetic and NO-donating properties. RRx-001 generates reactive oxygen and nitrogen species (RONS), which induces oxidative stress in tumor cells. Importantly, RRx-001 is also a potent vascular disrupting agent, which further provides rationale for utilizing RRx-001 as a therapeutic agent since tumor-associated angiogenesis is a characteristic of MM. A Phase I clinical trial has shown RRx-001 to have antitumor activity in heavily pretreated cancer patients and to be safe and well tolerated with no dose-limiting toxicities (Reid et al. J Clin Oncol 32:5s, 2014 suppl; abstr 2578). Here we examined the anti-MM activity of RRx-001 using in vitro and in vivo models of MM. Materials and methods: MM cell lines, patient MM cells, and peripheral blood mononuclear cells (PBMCs) from normal healthy donors were utilized to assess the anti-MM activity of RRx-001 alone or in combination with other agents. Drug sensitivity, cell viability, apoptosis, and migration assays were performed using WST, MTT, Annexin V staining, and transwell Inserts, respectively. Synergistic/additive anti-MM activity was assessed by isobologram analysisusing “CalcuSyn” software program. Signal transduction pathways were evaluated using immunoblotting. ROS release, nitric oxide generation, and mitochondrial membrane potential was measured as previously described (Chauhan et al., Blood, 2004, 104:2458). In vitro angiogenesis was assessed using matrigel capillary-like tube structure formation assays. DNMT1 activity was measured in protein lysates using EpiQuik DNMT1 assay kit. 5-methyl cytosine levels were analyzed in gDNA samples using methylflash methylated DNA quantification kit from Enzo life sciences; USA. For xenograft mouse model, CB-17 SCID-mice were subcutaneously inoculated with MM.1S cells as previously described (Chauhan et al., Blood, 2010, 115:834). Statistical significance of data was determined using a Student’st test. RRx-001 was obtained from RadioRx Inc., CA, USA; bortezomib, SAHA, and pomalidomide were purchased from Selleck chemicals, USA. Results: Treatment of MM cell lines (MM.1S, MM.1R, RPMI-8226, OPM2, H929, Dox-40 ARP-1, KMS-11, ANBL6.WT, ANBL6.BR, and LR5) and primary patient cells for 24h significantly decreased their viability (IC50 range 1.25nM to 2.5nM) (p < 0.001; n=3) without markedly affecting PBMCs from normal healthy donors, suggesting specific anti-MM activity and a favorable therapeutic index for RRx-001. Tumor cells from 3 of 5 patients were obtained from patients whose disease was progressing while on bortezomib, dexamethasone, and lenalidomide therapies. Moreover, RRx-001 inhibits proliferation of MM cells even in the presence of BM stromal cells. Mechanistic studies show that RRx-001-triggered apoptosis is associated with 1) induction of DNA damage response signaling via ATM/p53/gH2AX axis; 2) activation of caspases mediating both intrinsic and extrinsic apoptotic pathways; 3) increase in oxidative stress through release of ROS and generation of NO; and 4) decrease in DNA methyltransferase (DNMT1) enzymatic activity and global methylation levels. Furthermore, RRx-001 blocked migration of MM cells and angiogenesis. In vivo studies using subcutaneous human MM xenograft models show that RRx-001 is well tolerated and inhibits tumor growth. Finally, combining RRx-001 with bortezomib, SAHA, or pomalidomide induces synergistic anti-MM activity and overcomes drug resistance. Conclusion: Our preclinical studies showing efficacy of RRx-001 in MM disease models provide the framework for clinical trial of RRx-001, either alone or in combination, to improve outcome in relapsed and refractory MM patients. Disclosures Richardson: Oncopeptides AB: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees. Oronsky:RadioRx Inc, : Employment. Scicinski:RadioRx Inc,: Employment. Chauhan:Triphase Accelerator: Consultancy. Anderson:Celgene: Consultancy; Millenium: Consultancy; Onyx: Consultancy; Gilead: Consultancy; Sanofi Aventis: Consultancy; BMS: Consultancy; Oncopep/Acetylon: Equity Ownership.

Effect of cabazitaxel on the growth of human castration-refractory prostate cancer cells in vitro compared to docetaxel and on the anti-tumor properties of the angio-inhibitor PEDF in vivo.

2015 ◽  
Vol 33 (7_suppl) ◽  
pp. 205-205
Author(s):  
Thomas Nelius ◽  
Courtney Jarvis ◽  
Dalia Martinez-Marin ◽  
Stephanie Filleur
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Cell Lines ◽  
In Vitro Cytotoxicity ◽  
In Vivo Studies ◽  
Raw264.7 Macrophages

205 Background: Docetaxel/DTX and cabazitaxel/CBZ have shown promise in the treatment of metastatic Castration-Refractory Prostate Cancer/mCPRC however, comparative studies are missing. Toxicities of these drugs are significant, urging the need to modify taxane regimens. Recently, low-dose metronomic/LDM treatments using conventional chemotherapeutic drugs have shown benefits in CPRC in improving the effect of anti-angiogenic agents. Previously, we have demonstrated that LDM-DTX in combination with PEDF curbs significantly CRPC growth, limits metastases formation and prolongs survival in vivo. In this study, we intended to compare the cytotoxic effect of CBZ and DTX on CRPC cells in vitro and CL1 tumors in vivo. Methods: PC3, DU145 cell lines were from ATCC.CL1 cells were obtained from androgen-deprived LNCaP cells. Cell proliferation was assessed by crystal violet staining and cell cycle analyses. In vitro cytotoxicity assays were performed on CL1 cells/RAW264.7 macrophages co-cultures treated with PEDF and increasing doses of taxanes. For the in vivo studies, CL1 cells were engineered to stably express the DsRed Express protein +/- PEDF. PEDF anti-tumor effects were assessed on s.c. xenografts treated with DTX (5mg/kg ip ev. 4 day) as reference, CBZ (5mg/kg ip ev. 4 days, 1mg/kg for 10 days, 0.5mg/kg q.a.d. and 0.1mg/kg daily) or placebo. Results: CBZ limits cell proliferation with a greater efficacy than DTX in all CRPC cell lines tested. DU145 presented the largest difference. High doses of taxane blocked tumor cells in mitosis, whereas LDM increased the SubG1 population. This effect was significantly higher in DU145 cells treated with CBZ. In vivo, 5mg/kg CBZ delayed tumor growth more efficiently than 5mg/kg DTX. PEDF/5mg/kg CBZ markedly delayed tumor growth compared to all treatments. Finally, engulfment of tumor cells by macrophages was higher in combined treatments suggesting an inflammation-related process. Conclusions: CBZ is more efficient than DTX both in vitro and in vivo.The data also reinforce PEDF as a promising anti-neoplasic agent in combination with LDM taxane chemotherapies.

scholarly journals Combinations of TLR Ligands: A Promising Approach in Cancer Immunotherapy

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Saskia Stier ◽  
Claudia Maletzki ◽  
Ulrike Klier ◽  
Michael Linnebacher
Keyword(s):  
Tumor Growth ◽  
Tumor Cells ◽  
Cell Lines ◽  
Immune Cells ◽  
Human Lymphocytes ◽  
Growth Control ◽  
Poly I:C ◽  
The Impact

Toll-like receptors (TLRs), a family of pattern recognition receptors recognizing molecules expressed by pathogens, are typically expressed by immune cells. However, several recent studies revealed functional TLR expression also on tumor cells. Their expression is a two-sided coin for tumor cells. Not only tumor-promoting effects of TLR ligands are described but also direct oncopathic and immunostimulatory effects. To clarify TLRs’ role in colorectal cancer (CRC), we tested the impact of the TLR ligands LPS, Poly I:C, R848, and Taxol on primary human CRC cell lines (HROC40, HROC60, and HROC69)in vitroandin vivo(CT26). Taxol, not only a potent tumor-apoptosis-inducing, but also TLR4-activating chemotherapeutic compound, inhibited growth and viability of all cell lines, whereas the remaining TLR ligands had only marginal effects (R848 > LPS > Poly I:C). Combinations of the substances here did not improve the results, whereas antitumoral effects were dramatically boosted when human lymphocytes were added. Here, combining the TLR ligands often diminished antitumoral effects.In vivo, best tumor growth control was achieved by the combination of Taxol and R848. However, when combined with LPS, Taxol accelerated tumor growth. These data generally prove the potential of TLR ligands to control tumor growth and activate immune cells, but they also demonstrate the importance of choosing the right combinations.

scholarly journals Endogenous IL-2 in Cancer Cells: A Marker of Cellular Proliferation

1998 ◽  
Vol 46 (5) ◽  
pp. 603-611 ◽  
Author(s):  
Torsten E. Reichert ◽  
Simon Watkins ◽  
Joanna Stanson ◽  
Jonas T. Johnson ◽  
Theresa L. Whiteside
Keyword(s):  
Cell Cycle ◽  
Tumor Cells ◽  
Cell Lines ◽  
Cellular Proliferation ◽  
Histological Grade ◽  
Interleukin 2 ◽  
Ki 67 ◽  
Human Carcinoma

We have previously demonstrated that interleukin-2 (IL-2) receptors, IL-2 protein, and mRNA for IL-2 are present in human carcinomas in vitro and in vivo. Carcinoma cells synchronized in the G2/M-phase of the cell cycle express significantly more intracytoplasmic IL-2 as well as IL-2R-β and -γ than tumor cells in the G0/G1-phase. Here we evaluated immunohistologically the cell cycle-dependent distribution of the proliferation-associated Ki-67 antigen and expression of the cytokine IL-2 in four different carcinoma cell lines. In addition, 34 tissue samples from patients with squamous cell carcinomas of the head and neck were simultaneously analyzed for Ki-67 and IL-2 expression and the data were correlated to the histological grade of the tumors. All tumor cell lines were shown to express IL-2 in the Golgi complex. The strongest IL-2 expression was seen in tumor cells undergoing mitosis, identified by double staining with the antibody to Ki-67. In the tumor tissue, the highest level of co-expression of IL-2 and Ki-67 was observed in poorly differentiated carcinomas, with a labeling index (LI) of 67.2% for IL-2 and 68.8% for Ki-67. Well-differentiated carcinomas showed a significantly lower expression of both proteins (LI 35.0% for IL-2 and 26.5% for Ki-67). The correlation between the labeling indices was statistically significant ( r = 0.747; p<0.001). These results demonstrate that IL-2 expression in human carcinoma tissues is strongly associated with cell proliferation and significantly correlates with the histological tumor grade.

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