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Journal of Experimental & Clinical... Mar 2022Impaired p53 function is one of the central molecular features of a tumor cell and even a partial reduction in p53 activity can increase the cancer risk in mice and men....
BACKGROUND
Impaired p53 function is one of the central molecular features of a tumor cell and even a partial reduction in p53 activity can increase the cancer risk in mice and men. From a therapeutic perspective it is noteworthy that tumor cells often become addicted to the absence of p53 providing a rationale for developing p53 reactivating compounds to treat cancer patients. Unfortunately, many of the compounds that are currently undergoing preclinical and clinical testing fail to fully reactivate mutant p53 proteins, raising the crucial question: how much p53 activity is needed to elicit a therapeutic effect?
METHODS
We have genetically modelled partial p53 reactivation using knock-in mice with inducible expression of the p53 variant E177R. This variant has a reduced ability to bind and transactivate target genes and consequently causes moderate cancer susceptibility. We have generated different syngeneically transplanted and autochthonous mouse models of p53-deficient acute myeloid leukemia and B or T cell lymphoma. After cancer manifestation we have activated E177R expression and analyzed the in vivo therapy response by bioluminescence or magnetic resonance imaging. The molecular response was further characterized in vitro by assays for gene expression, proliferation, senescence, differentiation, apoptosis and clonogenic growth.
RESULTS
We report the conceptually intriguing observation that the p53 variant E177R, which promotes de novo leukemia and lymphoma formation, inhibits proliferation and viability, induces immune cell infiltration and triggers cancer regression in vivo when introduced into p53-deficient leukemia and lymphomas. p53-deficient cancer cells proved to be so addicted to the absence of p53 that even the low-level activity of E177R is detrimental to cancer growth.
CONCLUSIONS
The observation that a partial loss-of-function p53 variant promotes tumorigenesis in one setting and induces regression in another, underlines the highly context-specific effects of individual p53 mutants. It further highlights the exquisite sensitivity of cancer cells to even small changes in p53 activity and reveals that changes in activity level are more important than the absolute level. As such, the study encourages ongoing research efforts into mutant p53 reactivating drugs by providing genetic proof-of-principle evidence that incomplete p53 reactivation may suffice to elicit a therapeutic response.
Topics: Apoptosis; Carcinogenesis; Humans; Mutant Proteins; Neoplasms; Tumor Suppressor Protein p53
PubMed: 35232479
DOI: 10.1186/s13046-022-02269-6 -
Vascular Pharmacology Aug 2016Tubulin binding agents (TBAs) are drugs commonly used in cancer therapy as antimitotics. In the last years it has been described that TBAs, like combretastatin A-4...
Tubulin binding agents (TBAs) are drugs commonly used in cancer therapy as antimitotics. In the last years it has been described that TBAs, like combretastatin A-4 (CA-4), present also vascular disrupting activity and among its derivatives we identified three analogues endowed with potent microtubule depolymerizing activity, higher than that of the lead compound. In this paper we have investigated the anti-vascular activity of these derivatives. We tested the anti-angiogenic effects in human umbilical endothelial cells (HUVEC) and in vivo in chick chorioallantoic membrane assay (CAM), and in a syngeneic tumor mouse model. The three molecules, compound 1: 1-(3,4,5-trimethoxyphenyl)-5-(4-ethoxyphenyl)-1H-1,2,4-triazole; compound 2: (1-(3,4,5-trimethoxyphenyl)-5-(4-ethoxyphenyl)-1H-tetrazole, compound-3 (4-amino-2-p-tolylaminothiazol-5-yl)-(3,4,5-trimethoxyphenyl)-methanone) showed a moderate effect on the growth of HUVEC cells at concentrations below 200nM. At lower concentrations (5-20nM), in particular compound 2, they induced inhibition of capillary tube formation, inhibition of endothelial cell migration and affected endothelial cell morphology as demonstrated by the alteration of the microfilaments network. Moreover, they also increased permeability of HUVEC cells in a time dependent manner. In addition, compounds 1 and 3, as well as the reference compound CA-4, inhibited VEGF-induced phosphorylation of VE-cadherin and in addition compound 3 prevented the VEGF-induced phosphorylation of FAK. In CAM assay, both compounds 2 and 3 efficiently counteracted the strong angiogenic response induced by bFGF, even at the lowest concentration used (1pmol/egg). Moreover in a syngenic mouse model, compounds 1-3 after a single i.p. injection (30mg/kg), showed a stronger reduction of microvascular density. Altogether our results identified these derivatives as potential new vascular disrupting agents candidates.
Topics: Angiogenesis Inducing Agents; Angiogenesis Inhibitors; Animals; Antigens, CD; Bibenzyls; Cadherins; Capillary Permeability; Cardiac Myosins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Shape; Cells, Cultured; Chick Embryo; Chorioallantoic Membrane; Dose-Response Relationship, Drug; Focal Adhesion Kinase 1; Human Umbilical Vein Endothelial Cells; Humans; Melanoma, Experimental; Mice, Inbred C57BL; Myosin Light Chains; Neovascularization, Pathologic; Neovascularization, Physiologic; Phosphorylation; Signal Transduction; Time Factors
PubMed: 27235861
DOI: 10.1016/j.vph.2016.05.006 -
Nature Communications Aug 2020Immunotherapy has emerged as a promising approach to treat cancer, however, its efficacy in highly malignant brain-tumors, glioblastomas (GBM), is limited. Here, we...
Immunotherapy has emerged as a promising approach to treat cancer, however, its efficacy in highly malignant brain-tumors, glioblastomas (GBM), is limited. Here, we generate distinct imageable syngeneic mouse GBM-tumor models and utilize RNA-sequencing, CyTOF and correlative immunohistochemistry to assess immune-profiles in these models. We identify immunologically-inert and -active syngeneic-tumor types and show that inert tumors have an immune-suppressive phenotype with numerous exhausted CD8 T cells and resident macrophages; fewer eosinophils and SiglecF+ macrophages. To mimic the clinical-settings of first line of GBM-treatment, we show that tumor-resection invigorates an anti-tumor response via increasing T cells, activated microglia and SiglecF+ macrophages and decreasing resident macrophages. A comparative CyTOF analysis of resected-tumor samples from GBM-patients and mouse GBM-tumors show stark similarities in one of the mouse GBM-tumors tested. These findings guide informed choices for use of GBM models for immunotherapeutic interventions and offer a potential to facilitate immune-therapies in GBM patients.
Topics: Animals; Brain; Brain Neoplasms; Cell Line, Tumor; Glioblastoma; Humans; Immune Tolerance; Immunophenotyping; Immunotherapy; Isografts; Lymphocytes, Tumor-Infiltrating; Mice; Mice, Inbred C57BL; Neoplasm Transplantation; Neoplasms, Experimental; Tumor Microenvironment
PubMed: 32764562
DOI: 10.1038/s41467-020-17704-5 -
Journal of Oncology Pharmacy Practice :... Oct 2019Graft-versus-host disease has been reported to occur rarely in syngeneic hematopoietic stem cell transplant recipients. Clinical and histological changes consistent with...
Graft-versus-host disease has been reported to occur rarely in syngeneic hematopoietic stem cell transplant recipients. Clinical and histological changes consistent with graft-versus-host disease have been reported to occur in this patient population. We report a case of a 46-year-old Caucasian male with diffuse large B-cell lymphoma in complete remission who underwent a syngeneic hematopoietic stem cell transplant. He was diagnosed with grade III acute skin and gastrointestinal graft-versus-host disease requiring high-dose corticosteroids and immunosuppressive therapy and resulting in a complete response. Syngeneic graft-versus-host disease is an anomaly that needs to be considered as a differential diagnosis of patients experiencing dermatitis, gastroenteritis, or hepatitis after an identical twin hematopoietic stem cell transplant.
Topics: Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Humans; Male; Middle Aged; Remission Induction
PubMed: 30319065
DOI: 10.1177/1078155218805541 -
Advances in Experimental Medicine and... 2020Murine models have become powerful tools in leukemia research for investigating interactions between blast cells niche factors. In the tumor microenvironment, immune... (Review)
Review
Murine models have become powerful tools in leukemia research for investigating interactions between blast cells niche factors. In the tumor microenvironment, immune cells are one of the most important niche factors, capable of mounting dynamic innate or adoptive responses against leukemic cells. Acute myeloid leukemia (AML) is a systemic cancer accompanied by immune disruption. In order to exploit the enhanced activity of immune cells in AML treatment, the use of syngeneic mouse models is necessary. Studies of crosstalk between cancer blast cells and immune cells in syngeneic mouse models are beneficial, as the absence of immune functions in syngeneic models enables focus on cancer-associated immune reactions. Once AML is induced, innate and adoptive immune cells respond differently, ultimately resulting in suppression of the immune cells. Murine AML models are commonly induced by intravenous or subcutaneous injection of C1498 cells. Despite the popularity of murine models, they have not yet resulted in the elucidation of distinct differences in immune cells by the injection method. Here, we investigated the frequency of immune cells and survival rate of mice with AML induced using both injection methods.
Topics: Animals; Disease Models, Animal; Leukemia, Myeloid, Acute; Mice; Tumor Microenvironment
PubMed: 31893439
DOI: 10.1007/978-3-030-34461-0_53 -
Transplantation Apr 2016Although the liver is less immunogenic than other solid organs, most liver transplant recipients receive lifelong immunosuppression. In both experimental models and...
BACKGROUND
Although the liver is less immunogenic than other solid organs, most liver transplant recipients receive lifelong immunosuppression. In both experimental models and clinical transplantation, total lymphoid irradiation (TLI) has been shown to induce allograft tolerance. Our goal was to identify the microRNAs (miRNAs) expressed in tolerant liver allograft recipients in an experimental model of TLI-induced tolerance.
METHODS
To identify the miRNAs associated with TLI-induced tolerance, we examined syngeneic recipients (Lewis→Lewis) and allogeneic recipients (Dark Agouti→Lewis) of orthotropic liver transplants that received posttransplant TLI, allogeneic recipients that were not treated posttransplantation and experienced acute rejection, and native Dark Agouti livers. Quantitative-polymerase chain reaction miRNA array cards were used to profile liver grafts.
RESULTS
We identified 12 miRNAs that were specifically and significantly increased during acute rejection. In early tolerance, 33 miRNAs were altered compared with syngeneic livers, with 80% of the miRNAs increased. In established tolerance, 42 miRNAs were altered. In addition, miR-142-5p and miR-181a demonstrated increased expression in tolerant livers (both early and established tolerance) as compared with syngeneic livers. A principal component analysis of all miRNAs assayed demonstrated a profile in established tolerance that was closely related to that seen in syngeneic livers.
CONCLUSIONS
The miRNA profile of established tolerant allografts is very similar to syngeneic grafts, suggesting tolerance may be a return to an immunological state of quiescence.
Topics: Allografts; Animals; Gene Expression Profiling; Gene Expression Regulation; Graft Rejection; Graft Survival; Immunosenescence; Isografts; Liver; Liver Transplantation; Male; MicroRNAs; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction; Principal Component Analysis; Rats, Inbred Lew; Time Factors; Transplantation Tolerance; Transplantation, Isogeneic
PubMed: 26950716
DOI: 10.1097/TP.0000000000001105 -
Methods in Enzymology 2020Focal radiation therapy has the potential to generate systemic tumor-targeting immune responses so potent as to eradicate anatomically distant, non-irradiated malignant...
Focal radiation therapy has the potential to generate systemic tumor-targeting immune responses so potent as to eradicate anatomically distant, non-irradiated malignant lesions, a phenomenon commonly referred to as "the abscopal response." In cancer patients, bona fide abscopal responses are rare, although the recent introduction of immune checkpoint blockers into the clinical practice has significantly increased their incidence. In rodents, abscopal responses can be conveniently modeled by establishing two, slightly asynchronous and anatomically distant subcutaneous tumors in syngeneic immunocompetent hosts, provided that the therapeutic partners of radiation potentially included in the regimen of choice do not mediate systemic anticancer effects per se. Here, we describe such method to monitor abscopal responses based on mammary carcinoma TSA cells implanted in syngeneic immunocompetent BALB/c mice. With minor variations, the same technique can be conveniently applied to a variety of transplantable mouse tumors.
Topics: Animals; Cell Line, Tumor; Humans; Mice; Mice, Inbred BALB C
PubMed: 32122540
DOI: 10.1016/bs.mie.2019.04.014 -
Journal of Translational Medicine Feb 2019Osteosarcoma (OS) is the most common cancer of bone. Jaw osteosarcoma (JOS) is rare and it differs from other OS in terms of the time of occurrence (two decades later)...
BACKGROUND
Osteosarcoma (OS) is the most common cancer of bone. Jaw osteosarcoma (JOS) is rare and it differs from other OS in terms of the time of occurrence (two decades later) and better survival. The aim of our work was to develop and characterize specific mouse models of JOS.
METHODS
Syngenic and xenogenic models of JOS were developed in mice using mouse (MOS-J) and human (HOS1544) osteosarcoma cell lines, respectively. An orthotopic patient-derived xenograft model (PDX) was also developed from a mandibular biopsy. These models were characterized at the histological and micro-CT imaging levels, as well as in terms of tumor growth and metastatic spread.
RESULTS
Homogeneous tumor growth was observed in both the HOS1544 and the MOS-J JOS models by injection of 0.25 × 10 and 0.50 × 10 tumor cells, respectively, at perimandibular sites. Histological characterization of the tumors revealed features consistent with high grade conventional osteosarcoma, and the micro-CT analysis revealed both osteogenic and osteolytic lesions. Early metastasis was encountered at day 14 in the xenogenic model, while there were no metastatic lesions in the syngenic model and in the PDX models.
CONCLUSION
We describe the first animal model of JOS and its potential use for therapeutic applications. This model needs to be compared with the usual long-bone osteosarcoma models to investigate potential differences in the bone microenvironment.
Topics: Animals; Cell Line, Tumor; Cell Proliferation; Female; Humans; Jaw Neoplasms; Lung Neoplasms; Mandible; Mice, Inbred C57BL; Mice, SCID; Osteosarcoma; Tumor Burden; X-Ray Microtomography; Xenograft Model Antitumor Assays
PubMed: 30813941
DOI: 10.1186/s12967-019-1807-5 -
Transplantation May 2020Mechanical and thermal stress has been observed to trigger skin rejection in hand-transplanted patients. This study aims to investigate this phenomenon.
BACKGROUND
Mechanical and thermal stress has been observed to trigger skin rejection in hand-transplanted patients. This study aims to investigate this phenomenon.
METHODS
Syngeneic and allogeneic orthotopic hindlimb transplantations were performed using male rats (Brown Norway to Lewis). Using a specially designed device, standardized mechanical skin irritation at a force of 5 N was applied to the planta pedis of the transplanted limb for 10 days, 4 times daily for 10 minutes. Biopsies, taken on day 10 and after a 5-day observational period, were assessed for macroscopic alterations using a standardized scale, by histopathology and immunohistochemistry, and for inflammatory protein expression using Luminex technology.
RESULTS
Allogeneic animals displayed significant aggravated macroscopic skin alterations compared with naive (P < 0.0001) and syngeneic controls (P = 0.0023). Histopathology showed a trend toward higher rejection/inflammation grades in allogeneic animals compared with syngeneic controls. Minor skin alterations in syngeneic limbs recovered quickly; however, in allogeneic limbs, macroscopic skin alterations were significantly more pronounced (P < 0.0001) 5 days after irritation. Interleukin-1b and interferon-γ levels were upregulated in skin of allogeneic limbs.
CONCLUSIONS
Mechanical skin irritation in vascularized composite allotransplantation can trigger localized skin inflammation consistent with rejection.
Topics: Allografts; Animals; Disease Models, Animal; Graft Rejection; Graft Survival; Hindlimb; Immunosuppressive Agents; Male; Rats; Rats, Inbred BN; Rats, Inbred Lew; Skin; Skin Transplantation; Stress, Mechanical; Vascularized Composite Allotransplantation
PubMed: 31929424
DOI: 10.1097/TP.0000000000003075 -
Comparative Medicine Mar 2017Research in neurooncology traditionally requires appropriate in vivo animal models, on which therapeutic strategies are tested before human trials are designed and... (Comparative Study)
Comparative Study
Research in neurooncology traditionally requires appropriate in vivo animal models, on which therapeutic strategies are tested before human trials are designed and proceed. Several reproducible animal experimental models, in which human physiologic conditions can be mimicked, are available for studying glioblastoma multiforme. In an ideal rat model, the tumor is of glial origin, grows in predictable and reproducible patterns, closely resembles human gliomas histopathologically, and is weakly or nonimmunogenic. In the current study, we used MRI and histopathologic evaluation to compare the most widely used allogeneic rat glioma model, C6-Wistar, with the F98-Fischer syngeneic rat glioma model in terms of percentage tumor growth or regression and growth rate. In vivo MRI demonstrated considerable variation in tumor volume and frequency between the 2 rat models despite the same stereotactic implantation technique. Faster and more reproducible glioma growth occurred in the immunoresponsive environment of the F98-Fischer model, because the immune response is minimized toward syngeneic cells. The marked inability of the C6-Wistar allogeneic system to generate a reproducible model and the episodes of spontaneous tumor regression with this system may have been due to the increased humoral and cellular immune responses after tumor implantation.
Topics: Allografts; Animals; Disease Models, Animal; Glioma; Isografts; Magnetic Resonance Imaging; Rats; Rats, Inbred F344; Rats, Wistar; Reproducibility of Results
PubMed: 28381315
DOI: No ID Found