23 research outputs found
Routing cancer immunology and immunotherapy from the lab to the clinic 4-5 th March 2014, Center for Applied Medical Research and University Clinic, Pamplona, Spain
New approaches to generate effective anticancer responses by either inducing immune responses or inhibiting immunosuppression are under development to improve efficacy in patients. On March 4-5th, 2014, a symposium was held in Pamplona, Spain, to report the new strategies showing preclinical and clinical results regarding translational research efforts on the topic. Participants interacted through oral presentations of 15 speakers and further discussions on topics that included novel therapeutic agents for cancer immunotherapy, viral vectors and interferon-based approaches, experimental tumor imaging and immunostimulatory monoclonal antibodies. Promising agents to target cancer cells and therapeutic approaches that are under translation from bench to patients were presented
Edelfosine lipid nanoparticles overcome MDR in K-562 leukemia cells by caspaseindependent mechanism
The anti-tumor ether lipid edelfosine is the prototype of a novel generation of promising
anticancer drugs that has been shown to be an effective anti-tumor agent in numerous
malignancies. However, several cancer types display resistance to different anti-tumor
compounds due to multi-drug resistance (MDR), which is a major drawback in anticancer
therapy.
The leukemic cell line K-562 shows resistance to edelfosine, which can be overcome by the
use of nanotechnology. The present paper describes the rate and mechanism of
internalization of free and nano-encapsulated edelfosine. The molecular mechanisms
underlying this cell death is described in the present paper by characterization of several
molecules implied in the apoptotic and autophagic pathways (PARP, LC3IIB, Caspases-3, -
9 and -7) and the pattern of expression is compared with cell induction in a sensitive cell
line HL-60.
The results showed different internalization patterns in both cells. Clathrin and lipid raftmediated
endocytosis were observable in edelfosine uptake whereas these mechanism were
not visible in the uptake of lipid nanoparticles which might suffer phagocytosis and
macropinocytosis. Both treatments endorsed caspase-mediated apoptosis in HL-60 cells but
this cell death was not observed in K-562 cells. Moreover, an important increase in
autophagic vesicles was visible in K-562 cells. Thus, this mechanism might be implicated
in the overcoming of K-562 resistance to the treatment by lipid nanoparticles
Efficacy of edelfosine lipid nanoparticles in breast cancer cells
Breast cancer is a heterogeneous group of neoplasms predominantly originating in the terminal duct lobular units. It represents the leading cause of cancer death in women and the survival frequencies for patients at advanced stages of the disease remain low. New treatment options need to be researched to improve these rates. The anti-tumor ether lipid edelfosine (ET) is the prototype of a novel generation of promising anticancer drugs. However, it presents several drawbacks for its use in cancer therapy, including gastrointestinal and hemolytic toxicity and low oral bioavailability. To overcome these obstacles, ET was encapsulated in Precirol ATO 5 lipid nanoparticles (ET-LN), and its anti-tumor potential was in vitro tested in breast cancer. The formulated ET-LN were more effective in inhibiting cell proliferation and notably decreased cell viability, showing that the cytotoxic effect of ET was considerably enhanced when ET was encapsulated. In addition, ET and ET-LN were able to promote cell cycle arrest at G1 phase. Moreover, although both treatments provoked an apoptotic effect in a time-dependent manner, such anti-tumor effects were noticeably improved with ET-LN treatment. Therefore, our results indicate that encapsulating ET in LN played an essential role in improving the efficacy of the drug
Cytokines in clinical cancer immunotherapy
Cytokines are soluble proteins that mediate cell-to-cell communication. Based on the discovery of the potent anti-tumour activities of several pro-inflammatory cytokines in animal models, clinical research led to the approval of recombinant interferon-alpha and interleukin-2 for the treatment of several malignancies, even if efficacy was only modest. These early milestones in immunotherapy have been followed by the recent addition to clinical practice of antibodies that inhibit immune checkpoints, as well as chimeric antigen receptor T cells. A renewed interest in the anti-tumour properties of cytokines has led to an exponential increase in the number of clinical trials that explore the safety and efficacy of cytokine-based drugs, not only as single agents, but also in combination with other immunomodulatory drugs. These second-generation drugs under clinical development include known molecules with novel mechanisms of action, new targets, and fusion proteins that increase half-life and target cytokine activity to the tumour microenvironment or to the desired effector immune cells. In addition, the detrimental activity of immunosuppressive cytokines can be blocked by antagonistic antibodies, small molecules, cytokine traps or siRNAs. In this review, we provide an overview of the novel trends in the cytokine immunotherapy field that are yielding therapeutic agents for clinical trials
Repurposing infectious disease vaccines for intratumoral immunotherapy
Intratumoral delivery of viruses and virus-associated molecular patterns can achieve antitumor effects that are largely mediated by the elicitation or potentiation of immune responses against the malignancy. Attenuated vaccines are approved and marketed as good manufactiring practice (GMP)-manufactured agents whose administration might be able to induce such effects. Recent reports in mouse transplantable tumor models indicate that the rotavirus, influenza and yellow fever vaccines can be especially suitable to elicit powerful antitumor immunity against cancer following intratumoral administration. These results highlight that intratumoral anti-infectious vaccines can turn cold tumors into hot, and underscore the key role played by virus-induced type I interferon pathways to overcome resistance to immune checkpoint-targeted antibodies
Cancer immunotherapy with immunomodulatory anti-CD137 and anti-PD-1 monoclonal antibodies requires Batf3-dependent dendritic cells
Weak and ineffective antitumor cytotoxic T lymphocyte (CTL) responses can be rescued by immunomodulatory mAbs targeting PD-1 or CD137. Using Batf3â/â mice, which are defective for cross-presentation of cell-associated antigens, we show that BATF3-dependent dendritic cells (DC) are essential for the response to therapy with anti-CD137 or antiâPD-1 mAbs. Batf3â/â mice failed to prime an endogenous CTL-mediated immune response toward tumor-associated antigens, including neoantigens. As a result, the immunomodulatory mAbs could not amplify any therapeutically functional immune response in these mice. Moreover, administration of systemic sFLT3L and local poly-ICLC enhanced DC-mediated cross-priming and synergized with antiâCD137- and antiâPD-1âmediated immunostimulation in tumor therapy against B16-ovalbuminâderived melanomas, whereas this function was lost in Batf3â/â mice. These experiments show that cross-priming of tumor antigens by FLT3L- and BATF3-dependent DCs is crucial to the efficacy of immunostimulatory mAbs and represents a very attractive point of intervention to enhance their clinical antitumor effects
LMO2 expression reflects the different stages of blast maturation and genetic features in B-cell acute lymphoblastic leukemia and predicts clinical outcome
BACKGROUND: LMO2 is highly expressed at the most immature stages of lymphopoiesis. In T-lymphocytes, aberrant LMO2 expression beyond those stages leads to T-cell acute lymphoblastic leukemia, while in B cells LMO2 is also expressed in germinal center lymphocytes and diffuse large B-cell lymphomas, where it predicts better clinical outcome. The implication of LMO2 in B-cell acute lymphoblastic leukemia must still be explored.
DESIGN AND METHODS: We measured LMO2 expression by real time RT-PCR in 247 acute lymphoblastic leukemia patient samples with cytogenetic data (144 of them also with survival and immunophenotypical data) and in normal hematopoietic and lymphoid cells.
RESULTS: B-cell acute lymphoblastic leukemia cases expressed variable levels of LMO2 depending on immunophenotypical and cytogenetic features. Thus, the most immature subtype, pro-B cells, displayed three-fold higher LMO2 expression than pre-B cells, common-CD10+ or mature subtypes. Additionally, cases with TEL-AML1 or MLL rearrangements exhibited two-fold higher LMO2 expression compared to cases with BCR-ABL rearrangements or hyperdyploid karyotype. Clinically, high LMO2 expression correlated with better overall survival in adult patients (5-year survival rate 64.8% (42.5%-87.1%) vs. 25.8% (10.9%-40.7%), P= 0.001) and constituted a favorable independent prognostic factor in B-ALL with normal karyotype: 5-year survival rate 80.3% (66.4%-94.2%) vs. 63.0% (46.1%-79.9%) (P= 0.043).
CONCLUSIONS: Our data indicate that LMO2 expression depends on the molecular features and the differentiation stage of B-cell acute lymphoblastic leukemia cells. Furthermore, assessment of LMO2 expression in adult patients with a normal karyotype, a group which lacks molecular prognostic factors, could be of clinical relevance
Involvement of miRNAs in the differentiation of human glioblastoma multiforme stem-like cells
Glioblastoma multiforme (GBM)-initiating cells (GICs) represent a tumor subpopulation with neural stem cell-like properties that is responsible for the development, progression and therapeutic resistance of human GBM. We have recently shown that blockade of NFÎșB pathway promotes terminal differentiation and senescence of GICs both in vitro and in vivo, indicating that induction of differentiation may be a potential therapeutic strategy for GBM. MicroRNAs have been implicated in the pathogenesis of GBM, but a high-throughput analysis of their role in GIC differentiation has not been reported. We have established human GIC cell lines that can be efficiently differentiated into cells expressing astrocytic and neuronal lineage markers. Using this in vitro system, a microarray-based high-throughput analysis to determine global expression changes of microRNAs during differentiation of GICs was performed. A number of changes in the levels of microRNAs were detected in differentiating GICs, including over-expression of hsa-miR-21, hsa-miR-29a, hsa-miR-29b, hsa-miR-221 and hsa-miR-222, and down-regulation of hsa-miR-93 and hsa-miR-106a. Functional studies showed that miR-21 over-expression in GICs induced comparable cell differentiation features and targeted SPRY1 mRNA, which encodes for a negative regulator of neural stem-cell differentiation. In addition, miR-221 and miR-222 inhibition in differentiated cells restored the expression of stem cell markers while reducing differentiation markers. Finally, miR-29a and miR-29b targeted MCL1 mRNA in GICs and increased apoptosis. Our study uncovers the microRNA dynamic expression changes occurring during differentiation of GICs, and identifies miR-21 and miR-221/222 as key regulators of this process
Immunotherapeutic effects of intratumoral nanoplexed poly I:C
Poly I:C is a powerful immune adjuvant as a result of its agonist activities on TLR-3, MDA5 and RIG-I. BO-112 is a
nanoplexed formulation of Poly I:C complexed with polyethylenimine that causes tumor cell apoptosis showing
immunogenic cell death features and which upon intratumoral release results in more prominent tumor infiltration
by T lymphocytes. Intratumoral treatment with BO-112 of subcutaneous tumors derived from MC38, 4 T1 and B16-
F10 leads to remarkable local disease control dependent on type-1 interferon and gamma-interferon. Some degree
of control of non-injected tumor lesions following BO-112 intratumoral treatment was found in mice bearing bilateral
B16-OVA melanomas, an activity which was enhanced with co-treatment with systemic anti-CD137 and anti-PD-L1
mAbs. More abundant CD8+ T lymphocytes were found in B16-OVA tumor-draining lymph nodes and in the tumor
microenvironment following intratumoral BO-112 treatment, with enhanced numbers of tumor antigen-specific
cytotoxic T lymphocytes. Genome-wide transcriptome analyses of injected tumor lesions were consistent with a
marked upregulation of the type-I interferon pathway. Inspired by these data, intratumorally delivered BO-112 is
being tested in cancer patients (NCT02828098)
A tumor-targeted trimeric 4-1BB-agonistic antibody induces potent anti-tumor immunity without systemic toxicity
The costimulation of immune cells using first-generation anti-4-1BB monoclonal antibodies (mAbs) has demonstrated anti-tumor activity in human trials. Further clinical development, however, is restricted by significant off-tumor toxicities associated with Fc gamma R interactions. Here, we have designed an Fc-free tumor-targeted 4-1BB-agonistic trimerbody, 1D8(N)/(C)EGa1, consisting of three anti-4-1BB single-chain variable fragments and three anti-EGFR single-domain antibodies positioned in an extended hexagonal conformation around the collagen XVIII homotrimerization domain. The1D8(N)/(C)EGa1 trimerbody demonstrated high-avidity binding to 4-1BB and EGFR and a potent in vitro costimulatory capacity in the presence of EGFR. The trimerbody rapidly accumulates in EGFR-positive tumors and exhibits anti-tumor activity similar to IgG-based 4-1BB-agonistic mAbs. Importantly, treatment with 1D8(N)/(C)EGa1 does not induce systemic inflammatory cytokine production or hepatotoxicity associated with IgG-based 4-1BB agonists. These results implicate Fc gamma R interactions in the 4-1BB-agonist-associated immune abnormalities, and promote the use of the non-canonical antibody presented in this work for safe and effective costimulatory strategies in cancer immunotherapy