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Frontiers in Immunology 2023Murine syngeneic tumor models have been used extensively for cancer research for several decades and have been instrumental in driving the discovery and development of...
Murine syngeneic tumor models have been used extensively for cancer research for several decades and have been instrumental in driving the discovery and development of cancer immunotherapies. These tumor models are very simplistic cancer models, but recent reports have, however, indicated that the different inoculated cancer cell lines can lead to the formation of unique tumor microenvironments (TMEs). To gain more knowledge from studies based on syngeneic tumor models, it is essential to obtain an in-depth understanding of the cellular and molecular composition of the TME in the different models. Additionally, other parameters that are important for cancer progression, such as collagen content and mechanical tissue stiffness across syngeneic tumor models have not previously been reported. Here, we compare the TME of tumors derived from six common syngeneic tumor models. Using flow cytometry and transcriptomic analyses, we show that strikingly unique TMEs are formed by the different cancer cell lines. The differences are reflected as changes in abundance and phenotype of myeloid, lymphoid, and stromal cells in the tumors. Gene expression analyses support the different cellular composition of the TMEs and indicate that distinct immunosuppressive mechanisms are employed depending on the tumor model. Cancer-associated fibroblasts (CAFs) also acquire very different phenotypes across the tumor models. These differences include differential expression of genes encoding extracellular matrix (ECM) proteins, matrix metalloproteinases (MMPs), and immunosuppressive factors. The gene expression profiles suggest that CAFs can contribute to the formation of an immunosuppressive TME, and flow cytometry analyses show increased PD-L1 expression by CAFs in the immunogenic tumor models, MC38 and CT26. Comparison with CAF subsets identified in other studies shows that CAFs are skewed towards specific subsets depending on the model. In athymic mice lacking tumor-infiltrating cytotoxic T cells, CAFs express lower levels of PD-L1 and lower levels of fibroblast activation markers. Our data underscores that CAFs can be involved in the formation of an immunosuppressive TME.
Topics: Animals; Mice; B7-H1 Antigen; Cancer-Associated Fibroblasts; Tumor Microenvironment; Extracellular Matrix Proteins; Immunosuppressive Agents; Mice, Nude; Phenotype; Neoplasms
PubMed: 38259467
DOI: 10.3389/fimmu.2023.1320614 -
ACS Nano Jul 2021Tumor trafficking of liposomes is routinely monitored via fluorescence microscopy and imaging. To investigate whether an accumulation of liposomes depends on the type of...
Tumor trafficking of liposomes is routinely monitored via fluorescence microscopy and imaging. To investigate whether an accumulation of liposomes depends on the type of fluorescent label, we prepared PEGylated liposomes dual-labeled with indocarbocyanine lipids (ICLs: DiD or DiI) and fluorescent phospholipids (FPLs: Cy3-DSPE or Cy5-DSPE) with similar cyanine headgroups but different spectra. Using confocal microscopy and imaging, we compared tumor extravasation and accumulation of ICLs and FPLs. After systemic injection in a syngeneic mouse model of 4T1 breast cancer, ICLs and FPLs initially colocalized in tumor blood vessels and perivascular space. At later time points, ICLs spread over a significantly larger tumor area and accumulated in tumor macrophages, whereas FPLs were mostly restricted to the vasculature with limited extravascular signal. This phenomenon was independent of liposomal composition and ICL/FPL type and was also observed in syngeneic intracranial GL261 glioma and LY2 head and neck cancer models. The dual-labeled liposomes were stable in plasma and delivered both dyes to tumors at early time points. Notably, while the level of ICLs increased over time, FPLs gradually disappeared from tumors and other organs , likely due to degradation of the phospholipid. These findings demonstrate that trafficking and stability of the label is of critical importance when assessing extravasation and accumulation of nanocarriers in tumors and other organs by fluorescence microscopy and imaging.
Topics: Mice; Animals; Liposomes; Microscopy, Fluorescence; Phospholipids; Glioma; Microscopy, Confocal; Fluorescent Dyes
PubMed: 34197075
DOI: 10.1021/acsnano.1c02982 -
Surgery Oct 2022The adipose stromal vascular fraction contains abundant mesenchymal stem cells and is utilized for cell therapy of male stress urinary incontinence. The purpose of this...
BACKGROUND
The adipose stromal vascular fraction contains abundant mesenchymal stem cells and is utilized for cell therapy of male stress urinary incontinence. The purpose of this paper was to explore the effect of local transplantation of the stromal vascular fraction on improvement of damaged anal sphincter function.
METHODS
A rat model of vaginal distension was used as a model of damaged anal sphincter function. The adipose stromal vascular fraction was separated from the inguinal fat of syngeneic green fluorescent protein transgenic rats and delivered into the internal anal sphincter of vaginal distension rats. The maximum resting pressure was evaluated during insertion and withdrawal of the catheter at 4 or 10 days after vaginal distension treatment to estimate anal sphincter function. Green fluorescent protein-transfected human-adipose-derived mesenchymal stem cells were transplanted into the internal anal sphincter of nude rats. Hematoxylin-eosin and Masson trichrome staining were performed to evaluate tissue damage and collagen synthesis. Transplanted cells were identified using a green fluorescent protein antibody and a human-specific antibody. Activation of the transplanted human-ADSC was evaluated by quantitative RT-PCR RESULTS: The mean maximum resting pressure (during catheter withdrawal) of vaginal distension rats was significantly lower than that of control rats, and stromal vascular fraction injection normalized it 4 days after treatment (control: 5.66 ± 0.98, vaginal distension: 4.04 ± 1.28, vaginal distension + stromal vascular fraction: 5.92 ± 1.28 [mmHg, control versus vaginal distension: P = .039; vaginal distension versus vaginal distension + stromal vascular fraction: P = .007]). Histological examination showed that vaginal distension disrupted the internal anal sphincter, and the transplanted syngeneic stromal vascular fraction survived for 10 days. Transplanted xenogeneic human-adipose-derived mesenchymal stem cells survived in the internal anal sphincter of nude rats for 4 and 10 days. Genes related to extracellular remodeling were up-regulated in the transplanted human-adipose-derived mesenchymal stem cells CONCLUSION: Syngeneic and heterotopic transplanted adipose-derived mesenchymal stem cells engrafted in the internal anal sphincter and ameliorated damaged anal sphincter function in a rat model of vaginal distension.
Topics: Anal Canal; Animals; Collagen; Eosine Yellowish-(YS); Female; Green Fluorescent Proteins; Hematoxylin; Humans; Male; Rats; Rats, Nude; Stromal Vascular Fraction
PubMed: 35973873
DOI: 10.1016/j.surg.2022.06.015 -
Frontiers in Oncology 2019Despite tremendous efforts in the last decade to improve treatments, melanoma still represents a major therapeutic challenge and overall survival of patients remains... (Review)
Review
Despite tremendous efforts in the last decade to improve treatments, melanoma still represents a major therapeutic challenge and overall survival of patients remains poor. Therefore, identifying new targets to counteract melanoma is needed. In this scenario, autophagy, the "self-eating" process of the cell, has recently arisen as new potential candidate in melanoma. Alongside its role as a recycling mechanism for dysfunctional and damaged cell components, autophagy also clearly sits at a crossroad with metabolism, thereby orchestrating cell proliferation, bioenergetics and metabolic rewiring, all hallmarks of cancer cells. In this regard, autophagy, both in tumor and host, has been flagged as an essential player in melanomagenesis and progression. To pave the way to a better understanding of such a complex interplay, the use of genetically engineered mouse models (GEMMs), as well as syngeneic mouse models, has been undoubtedly crucial. Herein, we will explore the latest discoveries in the field, with particular focus on the potential of these models in unraveling the contribution of autophagy in melanoma, along with the therapeutic advantages that may arise.
PubMed: 31998652
DOI: 10.3389/fonc.2019.01506 -
Frontiers in Pharmacology 2023Atezolizumab (a PD-L1 inhibitor) has shown remarkable efficacy and tolerability in various cancer types. Despite its efficacy and safety, atezolizumab monotherapy has...
Atezolizumab (a PD-L1 inhibitor) has shown remarkable efficacy and tolerability in various cancer types. Despite its efficacy and safety, atezolizumab monotherapy has limitations, such as acquired resistance and adverse events. Bojungikki-tang (BJIKT) is an herbal decoction widely prescribed in Asian countries and used to treat cancer-related symptoms including fatigue, appetite loss, gastrointestinal disorders, and other side effects from cancer therapy. Due to its immunomodulatory effects, Bojungikki-tang has been investigated as a combined treatment with anticancer agents. We evaluated the potential drug-drug interaction (DDI) between Bojungikki-tang and the anti-PD-L1 antibody based on the Food and Drug Administration (FDA) guidelines. In the study, we conducted an drug-drug interaction study using a syngeneic mouse model of CMT-167 in C57BL/6. We then determined the antibody concentrations to evaluate the pharmacokinetic (PK) drug-drug interaction and measured variable biomarkers related to therapeutic efficacy and immune response. The pharmacodynamic (PD) drug-drug interaction study investigated changes in response between anti-PD-L1 antibody monotherapy and combination therapy. Using the pharmacokinetic and pharmacodynamic data, we conducted a statistical analysis to assess drug-drug interaction potential. In the presence of Bojungikki-tang, the pharmacokinetic characteristics of the anti-PD-L1 antibody were not changed. This study suggested that combination treatment with Bojungikki-tang and atezolizumab is a safe treatment option for non-small cell lung cancer. Clinical studies are warranted to confirm this finding.
PubMed: 37274110
DOI: 10.3389/fphar.2023.1181263 -
Scientific Reports Feb 2022Hemangiosarcoma (HSA) is a malignant tumor derived from endothelial cells. Tumor-associated macrophages are one of the major components of tumor microenvironment and...
Hemangiosarcoma (HSA) is a malignant tumor derived from endothelial cells. Tumor-associated macrophages are one of the major components of tumor microenvironment and crucial for cancer development. The presence and function of macrophages in HSA have not been studied because there is no syngeneic model for HSA. In this study, we evaluated two mouse HSA cell lines and one immortalized mouse endothelial cell line for their usefulness as syngeneic models for canine HSA. Our results showed that the ISOS-1 cell line developed tumors with similar morphology to canine HSA. ISOS-1 cells highly expressed KDM2B and had similar KDM2B target expression patterns with canine HSA. Moreover, we determined that in both ISOS-1 and canine HSA tumors, macrophages were present as a major constituent of the tumor microenvironment. These macrophages were positive for CD204, an M2 macrophage marker, and express PD-L1, an immune checkpoint molecule. Canine HSA with macrophages expressing PD-L1 had a smaller number of T-cells in tumor tissues than tumors with PD-L1 negative macrophages. ISOS-1-conditioned medium could induce M2 polarization and PD-L1 expression in RAW264.7 mouse macrophage cell line and mouse peritoneal macrophages. These results show that ISOS-1 can be used as a syngenic model for canine HSA and suggest that macrophages play an important role in immune evasion in HSA. Using the syngeneic mouse model for canine HSA, we can further study the role of immune cells in the pathology of HSA.
Topics: Animals; Cell Line, Tumor; Dogs; Hemangiosarcoma; Macrophages; Mice; Splenic Neoplasms; Tumor Escape; Tumor Microenvironment
PubMed: 35136176
DOI: 10.1038/s41598-022-06203-w -
Oncoimmunology 2022Blockade of checkpoint receptors with monoclonal antibodies against CTLA-4, PD-1 and PD-L1 has shown great clinical success in several cancer subtypes, yielding...
A newly discovered PD-L1 B-cell epitope peptide vaccine (PDL1-Vaxx) exhibits potent immune responses and effective anti-tumor immunity in multiple syngeneic mice models and (synergizes) in combination with a dual HER-2 B-cell vaccine (B-Vaxx).
Blockade of checkpoint receptors with monoclonal antibodies against CTLA-4, PD-1 and PD-L1 has shown great clinical success in several cancer subtypes, yielding unprecedented responses albeit a significant number of patients develop resistance and remain refractory. Both PD-1/PD-L1 and HER-2 signaling pathway inhibitors have limited efficacy and exhibits significant toxicities that limit their use. Ongoing clinical studies support the need for rationale combination of immuno-oncology agents to make a significant impact in the lives of cancer patients. We introduce the development of a novel chimeric PD-L1 B-cell peptide epitope vaccine (amino acid 130-147) linked to a "promiscuous" T cell measles virus fusion (MVF) peptide (MVF-PD-L1(130); PDL1-Vaxx) or linked to tetanus toxoid (TT3) TT3-PD-L1 (130) via a linker (GPSL). These vaccine constructs are highly immunogenic and antigenic in several syngeneic animal models. The PD-L1 vaccines elicited high titers of polyclonal antibodies that inhibit tumor growth in multiple syngeneic cancer models, eliciting antibodies of different subtypes IgG1, IgG2a, IgG2b and IgG3, induced PD-1/PD-L1 blockade, decreased proliferation, induced apoptosis and caused ADCC of tumor cells. The PDL1-Vaxx induces similar inhibition of tumor growth versus the standard anti-mouse PD-L1 antibody in both syngeneic BALB/c and C57BL/6J mouse models. The combination of PDL1-Vaxx with HER-2 vaccine B-Vaxx demonstrated synergistic tumor inhibition in D2F2/E2 carcinoma cell line. The anti-PDL1-Vaxx block PD-1/PD-L1 interaction and significantly prolonged anti-tumor responses in multiple syngeneic tumor models. The combination of HER-2 vaccine (B-Vaxx) with either PDL1-Vaxx or PD1-Vaxx demonstrated synergistic tumor inhibition. PDL1-Vaxx is a promising novel safe checkpoint inhibitor vaccine.
Topics: Amino Acids; Animals; Antibodies, Monoclonal; B7-H1 Antigen; CTLA-4 Antigen; Cancer Vaccines; Epitopes, B-Lymphocyte; Immunity; Immunoglobulin G; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neoplasms; Peptides; Programmed Cell Death 1 Receptor; Tetanus Toxoid; Vaccines, Subunit
PubMed: 36211807
DOI: 10.1080/2162402X.2022.2127691 -
International Journal of Molecular... Apr 2021To fight cancer more efficiently with cell-based immunotherapy, more information about the cells of the immune system and their interaction with cancer cells in vivo is...
To fight cancer more efficiently with cell-based immunotherapy, more information about the cells of the immune system and their interaction with cancer cells in vivo is needed. Therefore paraffin wax embedded primary breast cancers from the syngeneic mouse WAP-T model and from xenografted tumors of breast, colon, melanoma, ovarian, neuroblastoma, pancreatic, prostate, and small cell lung cancer were investigated for the infiltration of immunocompetent cells by immunohistochemistry using antibodies against leukocyte markers. The following markers were used: CD45 as a pan-leukocyte marker, BSA-I as a dendritic cell marker, CD11b as an NK cell marker, and CD68 as a marker for macrophages. The labeled immune cells were attributed to the following locations: adjacent adipose tissue, tumor capsule, intra-tumoral septae, and cancer cells directly. In xenograft tumors, the highest score of CD45 and CD11b positive, NK, and dendritic cells were found in the adjacent adipose tissue, followed by lesser infiltration directly located at the cancer cells themselves. The detected numbers of CD45 positive cells differed between the tumor entities: few infiltrating cells in breast cancer, small cell lung cancer, neuroblastoma, a moderate infiltration in colon cancer, melanoma and ovarian cancer, strongest infiltration in prostate and pancreatic cancer. In the syngeneic tumors, the highest score of CD45 and CD11b positive, NK and dendritic cells were observed in the tumor capsule, followed by a lesser infiltration of the cancer tissue. Our findings argue for paying more attention to investigate how immune-competent cells can reach the tumor cells directly.
Topics: Animals; Breast Neoplasms; Cell Line, Tumor; Colonic Neoplasms; Dendritic Cells; Disease Models, Animal; Female; Heterografts; Humans; Hyperplasia; Immunity, Cellular; Killer Cells, Natural; Lung Neoplasms; Lymphocytes, Tumor-Infiltrating; Macrophages; Mice; Neuroblastoma; Pancreatic Neoplasms; Xenograft Model Antitumor Assays
PubMed: 33921688
DOI: 10.3390/ijms22084213 -
Brain Pathology (Zurich, Switzerland) Mar 2019Prion diseases are progressive neurodegenerative disorders affecting humans and other mammalian species. The term prion, originally put forward to propose the concept... (Review)
Review
Prion diseases are progressive neurodegenerative disorders affecting humans and other mammalian species. The term prion, originally put forward to propose the concept that a protein could be infectious, refers to PrP , a misfolded isoform of the cellular prion protein (PrP ) that represents the pathogenetic hallmark of these disorders. The discovery that other proteins characterized by misfolding and seeded aggregation can spread from cell to cell, similarly to PrP , has increased interest in prion diseases. Among neurodegenerative disorders, however, prion diseases distinguish themselves for the broader phenotypic spectrum, the fastest disease progression and the existence of infectious forms that can be transmitted through the exposure to diseased tissues via ingestion, injection or transplantation. The main clinicopathological phenotypes of human prion disease include Creutzfeldt-Jakob disease, by far the most common, fatal insomnia, variably protease-sensitive prionopathy, and Gerstmann-Sträussler-Scheinker disease. However, clinicopathological manifestations extend even beyond those predicted by this classification. Because of their transmissibility, the phenotypic diversity of prion diseases can also be propagated into syngenic hosts as prion strains with distinct characteristics, such as incubation period, pattern of PrP distribution and regional severity of histopathological changes in the brain. Increasing evidence indicates that different PrP conformers, forming distinct ordered aggregates, encipher the phenotypic variants related to prion strains. In this review, we summarize the most recent advances concerning the histo-molecular pathology of human prion disease focusing on the phenotypic spectrum of the disease including co-pathologies, the characterization of prion strains by experimental transmission and their correlation with the physicochemical properties of PrP aggregates.
Topics: Brain; Cell Line; Cells, Cultured; Creutzfeldt-Jakob Syndrome; Dendritic Spines; Genetic Testing; Hippocampus; Humans; Neurodegenerative Diseases; Neurons; Pathology, Molecular; Phosphorylation; PrPC Proteins; Prion Diseases; Prion Proteins; Prions; Signal Transduction
PubMed: 30588685
DOI: 10.1111/bpa.12695 -
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