Athymic nude mice as an experimental model for cancer treatment

Ultrasound-mediated drug-free theranostics for treatment of prostate cancer

Lipid-shelled nanobubbles (NBs) can be visualized and activated using noninvasive ultrasound (US) stimulation, leading to significant bioeffects. Prior work demonstrates that active targeting of NBs to prostate-specific membrane antigen (PSMA) overexpressed in prostate cancer (PCa) results in enhanced cellular internalization and prolongs NB retention with persistent, cancer-cell specific acoustic activity. In this work, we hypothesized that tumor-accumulated PSMA-NBs combined with low frequency unfocused therapeutic US (TUS) will lead to selective damage and induce a specific therapeutic effect in PSMA-expressing tumors compared to PSMA-negative tumors. We observed that the internalized NBs and cellular compartments were disrupted after the PSMA-NB + TUS (targeted NB therapy or TNT) application, yet treated cells remained intact and viable. In vivo, PSMA-expressing tumors in mice receiving TNT treatment demonstrated a significantly greater extent of apoptosis (78.4 ± 9.3 %, p < 0.01) compared to controls. TNT treatment significantly inhibited the PSMA expressing tumor growth and increased median survival time by 103 %, p < 0.001). A significant reduction in tumor progression compared to untreated control was also seen in an orthotopic rabbit PCa model. Results demonstrate that cavitation of PSMA-NBs internalized via receptor-mediated endocytosis into target PCa cells using unfocused ultrasound results in significant, tumor-specific bioeffects. The effects, while not lethal to PSMA-expressing cancer cells in vitro, result in significant in vivo reduction in tumor progression in two models of PCa. While the mechanism of action of these effects is yet unclear, it is likely related to a locally-induced immune response, opening the door to future investigations in this area.

Antitumor Immunity Mediated by Photodynamic Therapy Using Injectable Chitosan Hydrogels for Intratumoral and Sustained Drug Delivery

Photodynamic therapy (PDT) is an anticancer therapy with proven efficacy; however, its application is often limited by prolonged skin photosensitivity and solubility issues associated with the phototherapeutic agents. Injectable hydrogels which can effectively provide intratumoral delivery of photosensitizers with sustained release are attracting increased interest for photodynamic cancer therapies. However, most of the hydrogels for PDT applications are based on systems with high complexity, and often, preclinical validation is not provided. Herein, we provide a simple and reliable pH-sensitive hydrogel formulation that presents appropriate rheological properties for intratumoral injection. For this, Temoporfin (m-THPC), which is one of the most potent clinical photosensitizers, was chemically modified to introduce functional groups that act as cross-linkers in the formation of chitosan-based hydrogels. The introduction of -COOH groups resulted in a water-soluble derivative, named PS2, that was the most promising candidate. Although PS2 was not internalized by the target cells, its extracellular activation caused effective damage to the cancer cells, which was likely mediated by lipid peroxidation. The injection of the hydrogel containing PS2 in the tumors was monitored by high-frequency ultrasounds and in vivo fluorescence imaging which confirmed the sustained release of PS2 for at least 72 h. Following local administration, light exposure was conducted one (single irradiation protocol) or three (multiple irradiation protocols) times. The latter delivered the best therapeutic outcomes, which included complete tumor regression and systemic anticancer immune responses. Immunological memory was induced as ∼75% of the mice cured with our strategy rejected a second rechallenge with live cancer cells. Additionally, the failure of PDT to treat immunocompromised mice bearing tumors reinforces the relevance of the host immune system. Finally, our strategy promotes anticancer immune responses that lead to the abscopal protection against distant metastases.

Characterization of the gut microbiome in an osteosarcoma mouse model

Compelling evidence has mounted surrounding the relationship between the gut microbiome and many intestinal and extraintestinal cancers. Few studies exist investigating the relationship between the gut microbiome and sarcoma. We hypothesize that the presence of distant osteosarcoma induces change to the profile of flora within the mouse. Twelve mice were used for this experiment: six were sedated and received an injection of human osteosarcoma cells into the flank, while six served as controls. Baseline stool and weight were collected. Tumor size and mouse weight were recorded weekly, and stool samples were collected and stored. Fecal microbiomes of the mice were profiled by 16S rRNA gene sequencing and analyzed for alpha diversity, relative abundances of microbial taxa, and abundance of specific bacteria at different time points. Alpha diversity was increased in the osteosarcoma group compared with the control group. The family Lachnospiraceae had the second strongest negative net average change in relative abundance over time in the osteosarcoma group whereas it had a positive net average change in the control group. An increased Firmicutes/Bacteroidota (F/B) ratio was observed in the osteosarcoma group relative to the control mice. These differences suggest that there may be an interplay between the gut microbiome and osteosarcoma. Clinical significance: Due to the paucity of literature available, our work can support novel research on this relationship and the development of new, personalized treatments for osteosarcoma.

Characterization of novel, severely immunodeficient PrkdcΔex57/Δex57 mice

Severely immunodeficient mice are useful for understanding the pathogenesis of certain tumors and for developing therapeutic agents for such tumors. In addition, engraftment of these mice with human hematopoietic cells can yield information that helps us understand the in vivo molecular mechanisms underlying actual human viral infections. In our present research, we discovered a novel, severely immunodeficient strain of mice having a mutation in exon 57 of the Prkdc gene (PrkdcΔex57/Δex57) in an inbred colony of B10.S/SgSlc mice. Those PrkdcΔex57/Δex57 mice showed thymic hypoplasia and lack of mature T cells and B cells in peripheral lymphoid tissues, resulting in very low levels of production of serum immunoglobulins. In addition, those mice were highly susceptible to influenza viruses due to the lack of acquired immune cells. On the other hand, since they had sufficient numbers of NK cells, they rejected tumor transplants, similarly to Prkdc+/+ mice. Next, we generated Foxn1nu/nuPrkdcΔex57/Δex57Il2rg-/- (NPG) mice on the BALB/cSlc background, which lack all lymphocytes such as T cells, B cells and innate lymphoid cells, including NK cells. As expected, these mice were able to undergo engraftment of human tumor cell lines. These findings suggest that PrkdcΔex57/Δex57 mice will be useful as a novel model of immunodeficiency, while NPG mice will be useful for xenografting of various malignancies.

Establishment of head and neck squamous cell carcinoma mouse models for cetuximab resistance and sensitivity

Aim: Acquired resistance to the targeted agent cetuximab poses a significant challenge in finding effective anti-cancer treatments for head and neck squamous cell carcinoma (HNSCC). To accurately study novel combination treatments, suitable preclinical mouse models for cetuximab resistance are key yet currently limited. This study aimed to optimize an acquired cetuximab-resistant mouse model, with preservation of the innate immunity, ensuring intact antibody-dependent cellular cytotoxicity (ADCC) functionality. Methods: Cetuximab-sensitive and acquired-resistant HNSCC cell lines, generated in vitro, were subcutaneously engrafted in Rag2 knock-out (KO), BALB/c Nude and CB17 Scid mice with/without Matrigel or Geltrex. Once tumor growth was established, mice were intraperitoneally injected twice a week with cetuximab for a maximum of 3 weeks. In addition, immunohistochemistry was used to evaluate the tumor and its microenvironment. Results: Despite several adjustments in cell number, cell lines and the addition of Matrigel, Rag2 KO and BALB/C Nude mice proved to be unsuitable for xenografting our HNSCC cell lines. Durable tumor growth of resistant SC263-R cells could be induced in CB17 Scid mice. However, these cells had lost their resistance phenotype in vivo. Immunohistochemistry revealed a high infiltration of macrophages in cetuximab-treated SC263-R tumors. FaDu-S and FaDu-R cells successfully engrafted into CB17 Scid mice and maintained their sensitivity/resistance to cetuximab. Conclusion: We have established in vivo HNSCC mouse models with intact ADCC functionality for cetuximab resistance and sensitivity using the FaDu-R and FaDu-S cell lines, respectively. These models serve as valuable tools for investigating cetuximab resistance mechanisms and exploring novel drug combination strategies.

Melatonin Modulates the SIRT1-Related Pathways via Transdermal Cryopass-Laser Administration in Prostate Tumor Xenograft

Melatonin displays antitumor activity in several types of malignancies; however, the best delivery route and the underlying mechanisms are still unclear. Alternative non-invasive delivery route based on transdermal administration of melatonin by cryopass-laser treatment demonstrated efficiency in reducing the progression of LNCaP prostate tumor cells xenografted into nude mice by impairing the biochemical pathways affecting redox balance. Here, we investigated the impact of transdermal melatonin on the tumor dimension, microenvironment structure, and SIRT1-modulated pathways. Two groups (vehicle cryopass-laser and melatonin cryopass-laser) were treated for 6 weeks (3 treatments per week), and the tumors collected were analyzed for hematoxylin eosin staining, sirius red, and SIRT1 modulated proteins such as PGC-1α, PPARγ, and NFkB. Melatonin in addition to simple laser treatment was able to boost the antitumor cancer activity impairing the tumor microenvironment, increasing the collagen structure around the tumor, and modulating the altered SIRT1 pathways. Transdermal application is effective, safe, and feasible in humans as well, and the significance of these findings necessitates further studies on the antitumor mechanisms exerted by melatonin.

A systematic review of exercise protocols applied to athymic mice in tumor-related experiments

Athymic mice are unable to produce T-cells and are then characterized as immunodeficient. This characteristic makes these animals ideal for tumor biology and xenograft research. New non-pharmacological therapeutics are required owing to the exponential increase in global oncology costs over the last 10 years and the high cancer mortality rate. In this sense, physical exercise is regarded as a relevant component of cancer treatment. However, the scientific community lacks information regarding the effect of manipulating training variables on cancer in humans, and experiments with athymic mice. Therefore, this systematic review aimed to address the exercise protocols used in tumor-related experiments using athymic mice. The PubMed, Web of Science, and Scopus databases were searched without restrictions on published data. A combination of key terms such as athymic mice, nude mice, physical activity, physical exercise, and training was used. The database search retrieved 852 studies (PubMed, 245; Web of Science, 390; and Scopus, 217). After title, abstract, and full-text screening, 10 articles were eligible. Based on the included studies, this report highlights the considerable divergences in the training variables adopted for this animal model. No studies have reported the determination of a physiological marker for intensity individualization. Future studies are recommended to explore whether invasive procedures can result in pathogenic infections in athymic mice. Moreover, time-consuming tests cannot be applied to experiments with specific characteristics such as tumor implantation. In summary, non-invasive, low-cost, and time-saving approaches can suppress these limitations and improve the welfare of these animals during experiments.

AXL-initiated paracrine activation of pSTAT3 enhances mesenchymal and vasculogenic supportive features of tumor-associated macrophages

Tumor-associated macrophages (TAMs) are integral to the development of complex tumor microenvironments (TMEs) and can execute disparate cellular programs in response to extracellular cues. However, upstream signaling processes underpinning this phenotypic plasticity remain to be elucidated. Here, we report that concordant AXL-STAT3 signaling in TAMs is triggered by lung cancer cells or cancer-associated fibroblasts in the cytokine milieu. This paracrine action drives TAM differentiation toward a tumor-promoting "M2-like" phenotype with upregulation of CD163 and putative mesenchymal markers, contributing to TAM heterogeneity and diverse cellular functions. One of the upregulated markers, CD44, mediated by AXL-IL-11-pSTAT3 signaling cascade, enhances macrophage ability to interact with endothelial cells and facilitate formation of primitive vascular networks. We also found that AXL-STAT3 inhibition can impede the recruitment of TAMs in a xenograft mouse model, thereby suppressing tumor growth. These findings suggest the potential application of AXL-STAT3-related markers to quantitatively assess metastatic potential and inform therapeutic strategies in lung cancer.

An overview of mouse models of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has become a severe burden on global health due to its high morbidity and mortality rates. However, effective treatments for HCC are limited. The lack of suitable preclinical models may contribute to a major failure of drug development for HCC. Here, we overview several well-established mouse models of HCC, including genetically engineered mice, chemically-induced models, implantation models, and humanized mice. Immunotherapy studies of HCC have been a hot topic. Therefore, we will introduce the application of mouse models of HCC in immunotherapy. This is followed by a discussion of some other models of HCC-related liver diseases, including non-alcoholic fatty liver disease (NAFLD), hepatitis B and C virus infection, and liver fibrosis and cirrhosis. Together these provide researchers with a current overview of the mouse models of HCC and assist in the application of appropriate models for their research.

Cell-specific crosstalk proteomics reveals cathepsin B signaling as a driver of glioblastoma malignancy near the subventricular zone

Glioblastoma (GBM) is the most prevalent and aggressive malignant primary brain tumor. GBM proximal to the lateral ventricles (LVs) is more aggressive, potentially due to subventricular zone (SVZ) contact. Despite this, crosstalk between GBM and neural stem/progenitor cells (NSC/NPCs) is not well understood. Using cell-specific proteomics, we show that LV-proximal GBM prevents neuronal maturation of NSCs through induction of senescence. Additionally, GBM brain tumor initiating cells (BTICs) increase expression of CTSB upon interaction with NPCs. Lentiviral knockdown and recombinant protein experiments reveal both cell-intrinsic and soluble CTSB promote malignancy-associated phenotypes in BTICs. Soluble CTSB stalls neuronal maturation in NPCs while promoting senescence, providing a link between LV-tumor proximity and neurogenesis disruption. Finally, we show LV-proximal CTSB upregulation in patients, showing the relevance of this crosstalk in human GBM biology. These results demonstrate the value of proteomic analysis in tumor microenvironment research and provide direction for new therapeutic strategies in GBM.

Highlights

Periventricular GBM is more malignant and disrupts neurogenesis in a rodent model.Cell-specific proteomics elucidates tumor-promoting crosstalk between GBM and NPCs.NPCs induce upregulated CTSB expression in GBM, promoting tumor progression.GBM stalls neurogenesis and promotes NPC senescence via CTSB.

The protection of CoronaVac against the infection of wild-type SARS-CoV-2 (WH-09) or Omicron variant in nude-hACE2 mice

BACKGROUND

Immunocompromised individuals have an increased risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe outcomes, but we pay less attention to these people. Athymic nude mice are a murine strain with a spontaneous deficiency of the Foxn1 gene, which can result in thymic degeneration or its absence, leading to immunosuppression and a decrease in the number of T cells, and are widely used in preclinical evaluations of disease in immunocompromised populations.

METHODS

We investigated the protection of the coronavirus disease 2019 (COVID-19) inactivated vaccine (CoronaVac) against the infection of wild-type SARS-CoV-2 (WH-09) or Omicron variant utilizing a hybrid-type nude-hACE2 mouse model.

RESULTS

Compared with nude-hACE2/W mice, the viral load in the brain and lung tissue of nude-hACE2 mice (nude-hACE2/WV) infected with WH-09 after vaccination significantly decreased, and the histopathological changes were also reduced. The viral load in the brain and lung tissue of nude-hACE2 mice (nude-hACE2/OV) infected with the Omicron variant after vaccination was lower than that in nude-hACE2/O, but histopathological symptoms did not improve significantly.

CONCLUSION

CoronaVac provides some protection against infection of both WH-09 and the Omicron variant in the nude-hACE2 mice. Our findings aimed to provide a reference for vaccination against SARS-CoV-2 in immunocompromised populations.

Monocytes educated by cancer-associated fibroblasts secrete exosomal miR-181a to activate AKT signaling in breast cancer cells

BACKGROUND

Cancer-associated fibroblasts (CAFs), one of the major components of the tumor stroma, contribute to an immunosuppressive tumor microenvironment (TME) through the induction and functional polarization of protumoral macrophages. We have herein investigated the contribution of CAFs to monocyte recruitment and macrophage polarization. We also sought to identify a possible paracrine mechanism by which CAF-educated monocytes affect breast cancer (BC) cell progression.

METHODS

Monocytes were educated by primary CAFs and normal fibroblast (NF); the phenotypic alterations of CAF- or NF-educated monocytes were measured by flow cytometry. Exosomes isolated from the cultured conditioned media of the educated monocytes were characterized. An in vivo experiment using a subcutaneous transplantation tumor model in athymic nude mice was conducted to uncover the effect of exosomes derived from CAF- or NF-educated monocytes on breast tumor growth. Gain- and loss-of-function experiments were performed to explore the role of miR-181a in BC progression with the involvement of the AKT signaling pathway. Western blotting, enzyme-linked immunosorbent assay, RT-qPCR, flow cytometry staining, migration assay, immunohistochemical staining, and bioinformatics analysis were performed to reveal the underlying mechanisms.

RESULTS

We illustrated that primary CAFs recruited monocytes and established pro-tumoral M2 macrophages. CAF may also differentiate human monocyte THP-1 cells into anti-inflammatory M2 macrophages. Besides, we revealed that CAFs increased reactive oxygen species (ROS) generation in THP-1 monocytes, as differentiating into M2 macrophages requires a level of ROS for proper polarization. Importantly, T-cell proliferation was suppressed by CAF-educated monocytes and their exosomes, resulting in an immunosuppressive TME. Interestingly, CAF-activated, polarized monocytes lost their tumoricidal abilities, and their derived exosomes promoted BC cell proliferation and migration. In turn, CAF-educated monocyte exosomes exhibited a significant promoting effect on BC tumorigenicity in vivo. Of clinical significance, we observed that up-regulation of circulating miR-181a in BC was positively correlated with tumor aggressiveness and found a high level of this miRNA in CAF-educated monocytes and their exosomes. We further clarified that the pro-oncogenic effect of CAF-educated monocytes may depend in part on the exosomal transfer of miR-181a through modulating the PTEN/Akt signaling axis in BC cells.

CONCLUSIONS

Our findings established a connection between tumor stromal communication and tumor progression and demonstrated an inductive function for CAF-educated monocytes in BC cell progression. We also proposed a supporting model in which exosomal transfer of miR-181a from CAF-educated monocytes activates AKT signaling by regulating PTEN in BC cells.

Genetically diverse mouse platform to xenograft cancer cells

The lack of genetically diverse preclinical animal models in basic biology and efficacy testing has been cited as a potential cause of failure in clinical trials. We developed and characterized five diverse RAG1 null mouse strains as models that allow xenografts to grow. In these strains, we characterized the growth of breast cancer, leukemia and glioma cell lines. We found a wide range of growth characteristics that were far more dependent on strain than tumor type. For the breast cancer cell line, we characterized the spectrum of xenograft/tumor growth at structural, histological, cellular and molecular levels across each strain, and found that each strain captures unique structural components of the stroma. Furthermore, we showed that the increase in tumor-infiltrating myeloid CD45+ cells and the amount of circulating cytokine IL-6 and chemokine KC (also known as CXCL1) is associated with a higher tumor size in different strains. This resource is available to study established human xenografts, as well as difficult-to-xenograft tumors and growth of hematopoietic stems cells, and to decipher the role of myeloid cells in the development of spontaneous cancers.

Mcm2 hypomorph leads to acute leukemia or hematopoietic stem cell failure, dependent on genetic context

Minichromosome maintenance proteins (Mcm2-7) form a hexameric complex that unwinds DNA ahead of a replicative fork. The deficiency of Mcm proteins leads to replicative stress and consequent genomic instability. Mice with a germline insertion of a Cre cassette into the 3'UTR of the Mcm2 gene (designated Mcm2Cre ) have decreased Mcm2 expression and invariably develop precursor T-cell lymphoblastic leukemia/lymphoma (pre-T LBL), due to 100-1000 kb deletions involving important tumor suppressor genes. To determine whether mice that were protected from pre-T LBL would develop non-T-cell malignancies, we used two approaches. Mice engrafted with Mcm2Cre/Cre Lin- Sca-1+ Kit+ hematopoietic stem/progenitor cells did not develop hematologic malignancy; however, these mice died of hematopoietic stem cell failure by 6 months of age. Placing the Mcm2Cre allele onto an athymic nu/nu background completely prevented pre-T LBL and extended survival of these mice three-fold (median 296.5 vs. 80.5 days). Ultimately, most Mcm2Cre/Cre ;nu/nu mice developed B-cell precursor acute lymphoblastic leukemia (BCP-ALL). We identified recurrent deletions of 100-1000 kb that involved genes known or suspected to be involved in BCP-ALL, including Pax5, Nf1, Ikzf3, and Bcor. Moreover, whole-exome sequencing identified recurrent mutations of genes known to be involved in BCP-ALL progression, such as Jak1/Jak3, Ptpn11, and Kras. These findings demonstrate that an Mcm2Cre/Cre hypomorph can induce hematopoietic dysfunction via hematopoietic stem cell failure as well as a "deletor" phenotype affecting known or suspected tumor suppressor genes.

Assessment of antitumor activity of BP-C1, a platinum-based anticancer agent with a lignin-derived polymeric ligand, in autochthonous induced and spontaneous carcinogenesis rodent models

BACKGROUND

A standard approach to study the anticancer activity of novel drugs is their testing in animals with inoculated tumors, which has some limitations. An alternative is the use of spontaneous or carcinogen-induced tumor models as they have better translation potential. The carcinogen-induced and transgenic tumor models were used to assess the antitumor activity of BP-C1, a platinum-containing drug with lignin-derived polymeric ligand.

METHODS

We used female Swiss-H-derived mice and Wistar female rats to induce autochthonous tumors via exposure to benzo[a]pyrene and 1,2-dimethylhydrazine, respectively. Additionally, transgenic HER-2/neu FVB/N female mice, prone to the development of spontaneous mammary carcinomas, were used.

RESULTS

Antitumor activity of BP-C1 was observed in soft tissue sarcomas, induced by benzo[a]pyrene. The animals treated with BP-C1 exhibited more stabilizations and therapy responses compared to placebo controls. The efficacy of BP-C1 was somewhat reduced compared to cyclophosphamide; however, their combination resulted in an enhanced antitumor effect. For the 1,2-dimethylhydrazine-induced rat colon cancer model, BP-C1 reduced tumor multiplicity by 21-41 %. For mammary adenocarcinomas in HER-2/neu FVB/N mice, short-termed complete responses were observed in the BP-C1 groups with a frequency of 12-13 %, while complete responses were absent in the placebo group.

CONCLUSION

The results acquired indicated a wide spectrum of antitumor activity of BP-C1.

Validity of the peak velocity to detect physical training improvements in athymic mice

This study comprises two complementary experiments with athymic Balb/c (Nu/Nu) mice. In experiment 1, the aim was to verify the reproducibility of the peak velocity (V_Peak) determined from the incremental test. The second experiment aimed to assess the V_Peak sensitivity to prescribe and detect modulations of the physical training in athymic nude mice. Sixteen mice were submitted to two incremental treadmill tests separated by 48-h (Experiment 1). The test consisted of an initial warm-up of 5 minutes. Subsequently, animals initiated the tests at 8 m min⁻¹ with increments of 2 m min⁻¹ every 3 minutes. The V_Peak was determined as the highest velocity attained during the protocol. In experiment 2, these animals were randomly allocated to an exercise group (EG) or a control group (CG). The training protocol consisted of 30-min of treadmill running at 70% of the V_Peak five times a week for 4 weeks. High indexes of reproducibility were obtained for V_Peak (Test = 19.7 ± 3.6 m min⁻¹; Retest = 19.2 ± 3.4 m min⁻¹; p = 0.171; effect size = 0.142; r = 0.90). Animals from the EG had a significant increase of V_Peak (Before = 18.4 ± 2.7 m min⁻¹; After = 24.2 ± 6.0 m min⁻¹; p = 0.023). Conversely, a significant decrease was observed for the CG (Before = 21.1 ± 3.9 m min⁻¹; After = 15.9 ± 2.7 m min⁻¹; p = 0.038). The V_Peak is a valid parameter for exercise prescription in studies involving athymic nude mice.

A Micro-Immunotherapy Sequential Medicine MIM-seq Displays Immunomodulatory Effects on Human Macrophages and Anti-Tumor Properties towards In Vitro 2D and 3D Models of Colon Carcinoma and in an In Vivo Subcutaneous Xenograft Colon Carcinoma Model

In this study, the immunomodulatory effects of a sequential micro-immunotherapy medicine, referred as MIM-seq, were appraised in human primary M1 and M2 macrophages, in which the secretion of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, IL-12, IL-23, and tumor necrosis factor (TNF)-alpha, was inhibited. In addition, the potential anti-proliferative effects of MIM-seq on tumor cells was assessed in three models of colorectal cancer (CRC): an in vitro two-dimensions (2D) model of HCT-116 cells, an in vitro tri-dimensional (3D) model of spheroids, and an in vivo model of subcutaneous xenografted mice. In these models, MIM-seq displayed anti-proliferative effects when compared with the vehicle. In vivo, the tumor growth was slightly reduced in MIM-seq-treated animals. Moreover, MIM-seq could slightly reduce the growth of our spheroid models, especially under serum-deprivation. When MIM-seq was combined with two well-known anti-cancerogenic agents, either resveratrol or etoposide, MIM-seq could even further reduce the spheroid’s volume, pointing up the need to further assess whether MIM-seq could be beneficial for CRC patients as an adjuvant therapy. Altogether, these data suggest that MIM-seq could have anti-tumor properties against CRC and an immunomodulatory effect towards the mediators of inflammation, whose systemic dysregulation is considered to be a poor prognosis for patients.

Structural and Functional Thymic Biomarkers Are Involved in the Pathogenesis of Thymic Epithelial Tumors: An Overview

The normal human thymus originates from the third branchial cleft as two paired anlages that descend into the thorax and fuse on the midline of the anterior–superior mediastinum. Alongside the epithelial and lymphoid components, different types of lymphoid accessory cells, stromal mesenchymal and endothelial cells migrate to, or develop in, the thymus. After reaching maximum development during early postnatal life, the human thymus decreases in size and lymphocyte output drops with age. However, thymic immunological functions persist, although they deteriorate progressively. Several major techniques were fundamental to increasing the knowledge of thymic development and function during embryogenesis, postnatal and adult life; these include immunohistochemistry, immunofluorescence, flow cytometry, in vitro colony assays, transplantation in mice models, fetal organ cultures (FTOC), re-aggregated thymic organ cultures (RTOC), and whole-organ thymic scaffolds. The thymic morphological and functional characterization, first performed in the mouse, was then extended to humans. The purpose of this overview is to provide a report on selected structural and functional biomarkers of thymic epithelial cells (TEC) involved in thymus development and lymphoid cell maturation, and on the historical aspects of their characterization, with particular attention being paid to biomarkers also involved in Thymic Epithelial Tumor (TET) pathogenesis. Moreover, a short overview of targeted therapies in TET, based on currently available experimental and clinical data and on potential future advances will be proposed.

Preclinical Evaluation of CAR T Cell Function: In Vitro and In Vivo Models

Immunotherapy using chimeric antigen receptor (CAR) T cells is a rapidly emerging modality that engineers T cells to redirect tumor-specific cytotoxicity. CAR T cells have been well characterized for their efficacy against B cell malignancies, and rigorously studied in other types of tumors. Preclinical evaluation of CAR T cell function, including direct tumor killing, cytokine production, and memory responses, is crucial to the development and optimization of CAR T cell therapies. Such comprehensive examinations are usually performed in different types of models. Model establishment should focus on key challenges in the clinical setting and the capability to generate reliable data to indicate CAR T cell therapeutic potency in the clinic. Further, modeling the interaction between CAR T cells and tumor microenvironment provides additional insight for the future endeavors to enhance efficacy, especially against solid tumors. This review will summarize both in vitro and in vivo models for CAR T cell functional evaluation, including how they have evolved with the needs of CAR T cell research, the information they can provide for preclinical assessment of CAR T cell products, and recent technology advances to test CAR T cells in more clinically relevant models.

Angiogenesis in patient-derived xenografts of odontogenic myxoma

Previously, by employing 3D organotypic tissue culture and patient-derived xenograft (PDX) model, oral myxoma response to a MAPK/MEK inhibitor was observed. Gross examination of the tumour fragments obtained after 55 days of PDX grafting revealed increased capsule vascularization. Microscopic analyses showed blood capillaries intermixed with myxoma cells, but the origin of these capillaries, from mice or humans, was not established. This study aimed to investigate whether the endothelial cells observed in the myxoma PDX model are derived from the mouse or from the primary human tumour. Immunohistochemistry was performed on five tumour fragments from the PDX of myxoma after 55 days of implantation in mice. Immunopositivity for antibodies against human (HLA-ABC) and mouse (H2 Db/H2-D1) major histocompatibility complex class I (MHCI) was assessed in the endothelial cells. The endothelial cells in the PDX fragments revealed a membrane staining for the human MHCI protein in the PDX tumour and adjacent connective tissue capsule, indicating that capillaries were derived from the human tumour fragment. Considering the probable human origin of the endothelial cells from capillary blood vessels in the myxoma PDX, we conclude that this PDX model is an interesting model to study myxoma angiogenesis.

Murine Models of Chronic Viral Infections and Associated Cancers

Viruses are now recognized as bona fide etiologic factors of human cancer. Carcinogenic viruses include Epstein– Barr virus (EBV), high-risk human papillomaviruses (HPVs), hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell leukemia virus type 1 (HTLV-1), human immunodeficiency virus type 1 (HIV-1, indirectly), and several candidate human cancer viruses. It is estimated that 15% of all human tumors worldwide are caused by viruses. Tumor viruses establish long-term persistent infections in humans, and cancer is an accidental side effect of viral replication strategies. Viruses are usually not complete carcinogens, supporting the concept that cancer results from the accumulation of multiple cooperating events, in which human cancer viruses display different, often opposing roles. The laboratory mouse Mus musculus is one of the best in vivo experimental systems for modeling human pathology, including viral infections and cancer. However, mice are unsusceptible to infection with the known carcinogenic viruses. Many murine models were developed to overcome this limitation and to address various aspects of virus-associated carcinogenesis, from tumors resulting from xenografts of human tissues and cells, including cancerous and virus infected, to genetically engineered mice susceptible to viral infections and associated cancer. The review considers the main existing models, analyzes their advantages and drawbacks, describes their applications, outlines the prospects of their further development.

Resident stroma-secreted chemokine CCL2 governs myeloid-derived suppressor cells in the tumor microenvironment

Accumulating evidence has shown that cancer stroma and BM-derived cells (BMDCs) in the tumor microenvironment (TME) play vital roles in tumor progression. However, the mechanism by which oral cancer stroma recruits any particular subset of BMDCs remains largely unknown. Here, we sought to identify the subset of BMDCs that is recruited by cancer stroma. We established a sequential transplantation model in BALB/c nude mice, including (a) BM transplantation of GFP-expressing cells and (b) coxenografting of patient-derived stroma (PDS; 2 cases, designated PDS1 and PDS2) with oral cancer cells (HSC-2). As controls, xenografting was performed with HSC-2 alone or in combination with normal human dermal fibroblasts (HDF). PDS1, PDS2, and HDF all promoted BMDC migration in vitro and recruitment in vivo. Multicolor immunofluorescence revealed that the PDS coxenografts recruited Arginase-1⁺CD11b⁺GR1⁺GFP⁺ cells, which are myeloid-derived suppressor cells (MDSCs), to the TME, whereas the HDF coxenograft did not. Screening using microarrays revealed that PDS1 and PDS2 expressed CCL2 mRNA (encoding C-C motif chemokine ligand 2) at higher levels than did HDF. Indeed, PDS xenografts contained significantly higher proportions of CCL2⁺ stromal cells and CCR2⁺Arginase-1⁺CD11b⁺GR1⁺ MDSCs (as receiver cells) than the HDF coxenograft. Consistently, a CCL2 synthesis inhibitor and a CCR2 antagonist significantly inhibited the PDS-driven migration of BM cells in vitro. Furthermore, i.p. injection of the CCR2 antagonist to the PDS xenograft models significantly reduced the CCR2⁺Arginase-1⁺CD11b⁺GR1⁺ MDSC infiltration to the TME. In conclusion, oral cancer stroma–secreted CCL2 is a key signal for recruiting CCR2⁺ MDSCs from BM to the TME.

Role of Biobanks for Cancer Research and Precision Medicine in Hepatocellular Carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a highly complex and deadly cancer. There is an urgent need for new and effective treatment modalities. Since the primary goal in the management of cancer is to cure and improve survival, personalized therapy can increase survival, reduce mortality rates, and improve quality of life. Biobanks hold potential in leading to breakthroughs in biomedical research and precision medicine (PM). They serve as a biorepository, collecting, processing, storing, and supplying specimens and relevant data for basic, translational, and clinical research.

OBJECTIVE

We aimed to highlight the fundamental role of biobanks, harboring high quality, sustainable collections of patient samples in adequate size and variability, for developing diagnostic, prognostic, and predictive biomarkers to develop and PM approaches in the management of HCC.

METHOD

We obtained information from previously published articles and BBMRI directory.

RESULTS AND CONCLUSION

Biobanking of high-quality biospecimens along with patient clinical information provides a fundamental scientific infrastructure for basic, translational, and clinical research. Biobanks that control and eliminate pre-analytical variability of biospecimens, provide a platform to identify reliable biomarkers for the application of PM. We believe, establishing HCC biobanks will empower to underpin molecular mechanisms of HCC and generate strategies for PM. Thus, first, we will review current therapy approaches in HCC care. Then, we will summarize challenges in HCC management. Lastly, we will focus on the best practices for establishing HCC biobanking to support research, translational medicine in the light of new experimental research conducted with the aim of delivering PM for HCC patients.

Immunodeficiency Accelerates Vitamin A Deficiency

BACKGROUND

Vitamin A deficiency increases susceptibility to infection caused by impaired immune function.

OBJECTIVES

We investigated whether immunodeficiency could facilitate the development of vitamin A deficiency.

METHODS

Vitamin A deficiency was followed in 2 mouse models of immunodeficiency: the athymic nude mouse (nu/nu) and the humoral immunodeficient SENCAR (SENsitive to CARcinogenesis) mouse. Vitamin A deficiency was also monitored in outbred Balb/c and in NIH mice. The monitoring of vitamin A deficiency was done after feeding the mice and their mothers a semisynthetic, vitamin A-deficient diet from birth of the experimental mice. These mice were weaned onto the same deficient diet at 3-4 wk of age, while control groups were fed the same diet containing 3 μg retinoic acid per gram of diet.

RESULTS

The immunodeficient nu/nu and SENCAR mice developed vitamin A deficiency earlier than either the heterozygous nu/+ controls or the Balb/c and NIH strains. In female mice, symptoms included depletion of liver retinol and retinyl palmitate, squamous metaplasia of the uterus, and death. Male mice lost weight more frequently and sooner than female mice, in which mortality generally occurred in the absence of loss of body weight. Pairwise comparisons using Tukey's honest significant difference test of the nu/nu and SENCAR mice versus the Balb/c and NIH mice showed a faster loss of retinol and retinyl palmitate in all pairs (P ≤ 0.0001) except for retinol when comparing nu/nu and NIH strains (P = 0.3383).

CONCLUSIONS

Our findings are consistent with an increased usage of liver retinol and retinyl palmitate in the immunocompromised nu/nu and in the immunodeficient SENCAR mice and suggest that compensatory mechanisms dependent on vitamin A utilization are called upon to rescue immunodeficiency both in the T-cell-deficient phenotype of the nu/nu mice and in the humoral immunodeficient SENCAR mice.

[18F]2-Fluoro-2-deoxy-sorbitol PET Imaging for Quantitative Monitoring of Enhanced Blood-Brain Barrier Permeability Induced by Focused Ultrasound

Focused ultrasound in combination with microbubbles (FUS) provides an effective means to locally enhance the delivery of therapeutics to the brain. Translational and quantitative imaging techniques are needed to noninvasively monitor and optimize the impact of FUS on blood-brain barrier (BBB) permeability in vivo. Positron-emission tomography (PET) imaging using [¹⁸F]2-fluoro-2-deoxy-sorbitol ([¹⁸F]FDS) was evaluated as a small-molecule (paracellular) marker of blood-brain barrier (BBB) integrity. [¹⁸F]FDS was straightforwardly produced from chemical reduction of commercial [¹⁸F]2-deoxy-2-fluoro-D-glucose. [¹⁸F]FDS and the invasive BBB integrity marker Evan’s blue (EB) were i.v. injected in mice after an optimized FUS protocol designed to generate controlled hemispheric BBB disruption. Quantitative determination of the impact of FUS on the BBB permeability was determined using kinetic modeling. A 2.2 ± 0.5-fold higher PET signal (n = 5; p < 0.01) was obtained in the sonicated hemisphere and colocalized with EB staining observed post mortem. FUS significantly increased the blood-to-brain distribution of [¹⁸F]FDS by 2.4 ± 0.8-fold (V_T; p < 0.01). Low variability (=10.1%) of V_T values in the sonicated hemisphere suggests reproducibility of the estimation of BBB permeability and FUS method. [¹⁸F]FDS PET provides a readily available, sensitive and reproducible marker of BBB permeability to noninvasively monitor the extent of BBB disruption induced by FUS in vivo.

Antitumor effect of radiation therapy on orthotopic PDX models of human esophageal adenocarcinoma

As a rule, esophageal adenocarcinoma develops in the lower esophagus. Life expectancy and survival rates depend on the cancer stage and the general health of the patient. Chemoradiotherapy is the most successful treatment approach to this type of cancer. The choice of optimal radiation doses for achieving the best possible therapeutic effect is still a challenge. The aim of this paper was to study effective radiation doses and assess response of human esophageal adenocarcinoma to radiation using a PDX model. The study was conducted in female Balb/c nude mice (n = 25). Fragments of the donor tumor were implanted into the cervical esophagus of immunodeficient mice. Effects of radiation on the obtained orthotopic xenografts were studied after each of 3 irradiation sessions (4, 6, 8, and 10 Gy in each of the experimental groups, respectively). First-passage xenografts reproduced the morphology of the donor tumor. The mean tumor volume differed significantly between the control group and the experimental groups exposed to 6, 8 or 10 Gy (р ≤ 0.01) after each irradiation session. Tumor growth delay was significant after exposure to the total dose of 18 Gy. The further radiation dose increase was ineffective. The reduction of tumor volume in the xenografts was correlated to the increase in the one-time radiation dose. The total dose over 18 Gy produced a detrimental effect on the hematopoietic system and blood biochemistry of the experimental mice.

Safety and Efficacy Evaluation In Vivo of a Cationic Nucleolipid Nanosystem for the Nanodelivery of a Ruthenium(III) Complex with Superior Anticancer Bioactivity

Simple Summary

The availability of selective, effective, and safe anticancer agents is a major challenge in the field of cancer research. As part of a multidisciplinary research project, in recent years our group has proposed an original class of nanomaterials for the delivery of new anticancer drugs based on ruthenium(III) complexes. In cellular models, these nanosystems have been shown to be effective in counteracting growth and proliferation of human breast cancer cells. Compared to conventional metallochemotherapeutics such as platinum-based agents whose clinical practice is associated with serious undesirable effects, ruthenium complexes share improved biochemical profiles making them more selective towards cancer cells and less cytotoxic to healthy cells. Their combination with biocompatible nanocarriers further enhances these promising features, as here showcased by our research carried out in an animal model which underscores the efficacy and safety in vivo of one of our most promising ruthenium-based nanosystems.

Abstract

Selectivity and efficacy towards target cancer cells, as well as biocompatibility, are current challenges of advanced chemotherapy powering the discovery of unconventional metal-based drugs and the search for novel therapeutic approaches. Among second-generation metal-based chemotherapeutics, ruthenium complexes have demonstrated promising anticancer activity coupled to minimal toxicity profiles and peculiar biochemical features. In this context, our research group has recently focused on a bioactive Ru(III) complex—named AziRu—incorporated into a suite of ad hoc designed nucleolipid nanosystems to ensure its chemical stability and delivery. Indeed, we proved that the structure and properties of decorated nucleolipids can have a major impact on the anticancer activity of the ruthenium core. Moving in this direction, here we describe a preclinical study performed by a mouse xenograft model of human breast cancer to establish safety and efficacy in vivo of a cationic Ru(III)-based nucleolipid formulation, named HoThyRu/DOTAP, endowed with superior antiproliferative activity. The results show a remarkable reduction in tumour with no evidence of animal suffering. Blood diagnostics, as well as biochemical analysis in both acute and chronic treated animal groups, demonstrate a good tolerability profile at the therapeutic regimen, with 100% of mice survival and no indication of toxicity. In addition, ruthenium plasma concentration analysis and tissue bioaccumulation were determined via appropriate sampling and ICP-MS analysis. Overall, this study supports both the efficacy of our Ru-containing nanosystem versus a human breast cancer model and its safety in vivo through well-tolerated animal biological responses, envisaging a possible forthcoming use in clinical trials.

Application Route and Immune Status of the Host Determine Safety and Oncolytic Activity of Oncolytic Coxsackievirus B3 Variant PD-H

The coxsackievirus B3 strain PD-0 has been proposed as a new oncolytic virus for the treatment of colorectal carcinoma. Here, we generated a cDNA clone of PD-0 and analyzed the virus PD-H, newly generated from this cDNA, in xenografted and syngenic models of colorectal cancer. Replication and cytotoxic assays revealed that PD-H replicated and lysed colorectal carcinoma cell lines in vitro as well as PD-0. Intratumoral injection of PD-H into subcutaneous DLD-1 tumors in nude mice resulted in strong inhibition of tumor growth and significantly prolonged the survival of the animals, but virus-induced systemic infection was observed in one of the six animals. In a syngenic mouse model of subcutaneously growing Colon-26 tumors, intratumoral administration of PD-H led to a significant reduction of tumor growth, the prolongation of animal survival, the prevention of tumor-induced cachexia, and the elevation of CD3+ and dendritic cells in the tumor microenvironment. No virus-induced side effects were observed. After intraperitoneal application, PD-H induced weak pancreatitis and myocarditis in immunocompetent mice. By equipping the virus with target sites of miR-375, which is specifically expressed in the pancreas, organ infections were prevented. Moreover, employment of this virus in a syngenic mouse model of CT-26 peritoneal carcinomatosis resulted in a significant reduction in tumor growth and an increase in animal survival. The results demonstrate that the immune status of the host, the route of virus application, and the engineering of the virus with target sites of suitable microRNAs are crucial for the use of PD-H as an oncolytic virus.

Tumor Growth Progression in Ectopic and Orthotopic Xenografts from Inflammatory Breast Cancer Cell Lines

Xenografts can grow in immunosuppressed hosts, such as SCID mice, and tumor material can be injected into hosts either ectopically or orthotopically. Choosing the correct model to use is a crucial step in animal research. The aim of this study was to report the differences between ectopic and orthotopic xenografts in tumor progression, metastasis capacity, histological features, and steroid hormone profiles in xenografts from the cIMC (canine inflammatory mammary cancer) cell line IPC-366 and hIBC (human inflammatory breast cancer) cell line SUM149. To achieve this purpose, 40 female mice 6-8 weeks old were inoculated with IPC-366 and SUM149 cells subcutaneously (ectopic models) or into mammary fat pad (orthotopic models). Mice were monitored for tumor progression and appearance of metastases, and generated tumors were analyzed in terms of histological examination and steroid hormone production. The results revealed differences in tumor appearance and percentage of metastasis between ectopic and orthotopic models, which were higher in the ectopic xenografts from both cell lines. However, both models had similar characteristics of tumor progression, histological features, and steroid hormone secretion profiles. We show that the ectopic model can be validated as a good and useful model of tumor development in addition to, not contrary to, the orthotopic model in breast cancer research.

A novel humanized cutaneous lupus erythematosus mouse model mediated by IL-21-induced age-associated B cells

Cutaneous lupus erythematosus (CLE) is a relapsing autoimmune disease, but key elements that drive disease initiation and progression remain elusive. To date, the lack of ideal murine model which resemble human cutaneous lupus makes it extremely challenging for moving mechanistic discoveries and novel therapeutics. Here, we prompt a humanized murine model to develop an inducible rapid-onset murine that performs cutaneous rather than systemic lupus, depending on the successful human immune system reconstruction from active lupus patients and UVB irradiation as for essentially pathogenic triggers. In addition, we demonstrate a newly discovered population of B cell with a unique phenotype, that of the age-associated B cell (ABC, T-bet⁺ CD11b⁺), exhibits B cell clusters in humanized cutaneous lupus. In the response of IL-21 and TLR7/9 signals, recruitment of autoreactive B cells to the position of inflammation with subsequent localized antibody production of IgG2a, IgG2b, IgG3, has the potential to exacerbate ongoing inflammation and thus driving lupus-like autoimmunity in a B-cell-dominant fashion. Overall, our model provides a relevant system for exploring the pathophysiology of cutaneous lupus, a suitable model for drug development, as well as updating a potential role of IL-21 and TLR7/9 to be targeted by biologics.

Nano-Targeting of Thyrointegrin αvβ3 Receptor in Solid Tumors and Impact on Radiosensitization

Tetraiodothyroacetic acid is a ligand of thyrointegrin αvβ3, a protein that is highly expressed in various solid tumors and surrounding neovascular regions. Its nano derivative, Nano-diamino-tetrac (NDAT), has anticancer properties in preclinical models, enhances radiosensitivity, and inhibits cancer cell growth in vitro after X-ray irradiation. Using a novel experimental system developed to deliver accurate radiation dose to tumors under sterile conditions, this study establishes NDAT's radiosensitizing effect in SUIT-2 pancreatic cancer and H1299 non-small cell lung carcinoma xenografts in athymic mice for tumor-targeted radiation. In this work, low-melting-point Lipowitz alloy was used to shield normal organs and allow accurate tumor-targeted irradiation. Over a three-week period, mice with SUIT-2 xenografts received daily NDAT treatment at different doses (0, 1, 3, or 10 mg/kg body weight) and tumor-targeted irradiation (1 or 5 Gy). Validation was performed with a test dose of 30 Gy to mice bearing SUIT-2 xenografts and resulted in more than 80% reduction in tumor weight, compared to nonirradiated tumor weight. The results of this work showed that NDAT had a radiosensitizing effect in a dose-dependent manner in decreasing tumor growth and viability. An enhanced anticancer effect of NDAT (1 mg/kg body weight) was observed in mice with H1299 xenografts receiving 5 Gy tumor-targeted irradiation, indicated by decreased tumor weight and increased necrosis, compared to nonirradiated tumors. This technique demonstrated accurate tumor-targeted irradiation with new shielding methodology, and combined with thyrointegrin antagonist NDAT treatment, showed anticancer efficacy in pancreatic cancer and non-small cell lung carcinoma.

Investigating the effects of two novel 4-MMPB analogs as potent lipoxygenase inhibitors for prostate cancer treatment

Background

Lipoxygenases are one of the critical signaling mediators which can be targeted for human prostate cancer (PC) therapy. In this study, 4-methyl-2-(4-methylpiperazinyl)pyrimido[4,5-b]benzothiazine (4-MMPB) and its two analogs, 4-propyl-2-(4-methylpiperazinyl)pyrimido[4,5-b]benzothiazine (4-PMPB) and 4-ethyl-2-(4-methylpiperazinyl)pyrimido[4,5-b]benzothiazine (4-EMPB), were proposed to have anti-tumor properties in prostate cancer.

Methods

After synthesizing the compounds, cytotoxic effects of 4-MMPB and its two analogs against PC-3 cancerous and HDF normal cells were investigated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and then mechanism of cell death was assessed by flow cytometry. Finally, the anti-tumor effects of the mentioned compounds were investigated in an immunocompromised C57BL/6 mouse model.

Results

4-PMPB and 4-EMPB had similar anti-cancer effects on PC-3 cells as compared with 4-MMPB, while they were not effective on normal cells. Moreover, apoptosis and ferroptosis were the main mechanisms of induced cell death in these cancerous cells. Furthermore, in vivo results indicated that both analogs had similar anti-cancer effects as 4-MMPB, leading to delayed tumor growth without any noticeable side effects in weight loss and histological investigations.

Conclusion

Thus, our results suggest that specific targeting of lipoxygenases via 4-MMPB analogs can be considered as a treatment of choice for PC therapy, although it requires further investigations.

Patient-derived xenograft: a developing tool for screening biomarkers and potential therapeutic targets for human esophageal cancers

Esophageal cancer (EC) represents a human malignancy, diagnosed often at the advanced stage of cancer and resulting in high morbidity and mortality. The development of precision medicine allows for the identification of more personalized therapeutic strategies to improve cancer treatment. By implanting primary cancer tissues into immunodeficient mice for expansion, patient-derived xenograft (PDX) models largely maintain similar histological and genetic representations naturally found in patients' tumor cells. PDX models of EC (EC-PDX) provide fine platforms to investigate the tumor microenvironment, tumor genomic heterogeneity, and tumor response to chemoradiotherapy, which are necessary for new drug discovery to combat EC in addition to optimization of current therapeutic strategies for EC. In this review, we summarize the methods used for establishing EC-PDX models and investigate the utilities of EC-PDX in screening predictive biomarkers and potential therapeutic targets. The challenge of this promising research tool is also discussed.

Development of a bispecific immune engager using a recombinant malaria protein

As an immune evasion and survival strategy, the Plasmodium falciparum malaria parasite has evolved a protein named VAR2CSA. This protein mediates sequestration of infected red blood cells in the placenta through the interaction with a unique carbohydrate abundantly and exclusively present in the placenta. Cancer cells were found to share the same expression of this distinct carbohydrate, termed oncofetal chondroitin sulfate on their surface. In this study we have used a protein conjugation system to produce a bispecific immune engager, V-aCD3, based on recombinant VAR2CSA as the cancer targeting moiety and an anti-CD3 single-chain variable fragment linked to a single-chain Fc as the immune engager. Conjugation of these two proteins resulted in a single functional moiety that induced immune mediated killing of a broad range of cancer cells in vitro and facilitated tumor arrest in an orthotopic bladder cancer xenograft model.

Patient-derived xenograft models for the study of benign human neoplasms

Preclinical models are a core feature of translational research, and patient-derived xenograft (PDX) models have increasingly been used with such purpose. PDX involves the transplantation of fresh human tumor samples into immunodeficient mice to overcome immunologic rejection. It is a valuable tool for basic as well as preclinical research, contributing to the establishment of models to characterize the neoplasms to drug screening and to allow the identification of therapeutic targets. The use of these models is justified because they retain the histological and genomic features of the primary tumor. PDX models are well described for malignant neoplasms, for which the advantages are clear and include the development of drug treatments. The establishment of malignant tumors PDX is undeniably important from a medical perspective. However, few studies have used such models for benign neoplasms. The use of PDX for benign neoplasm studies can help to clarify the pathobiology of these diseases, as well as invasion and malignant transformation mechanisms, which from a biological perspective is equally important to the study of malignant tumors. Therefore, the aim of this study is to review the current methodology for PDX model generation and to cover its main applications, focusing on benign neoplasms.

A Systematic Review of the Effects of Equol (Soy Metabolite) on Breast Cancer

Equol is a soy isoflavone metabolite that can be produced by intestinal bacteria. It is lipophilic and resembles natural oestrogens with an affinity to oestrogen receptors. This review is focused on how equol affects breast cancer, as evidenced by in vivo and in vitro studies. Equol is considered chemoprotective in specific endocrine-related pathologies, such as breast cancer, prostate cancer, cardiovascular diseases, and menopausal symptoms. In humans, not everyone can produce equol from gut metabolism. It is postulated that equol producers benefit more than non-equol producers for all the endocrine-related effects. Equol exists in two enantiomers of R-equol and S-equol. Earlier studies, however, did not specify which enantiomer was being used. This review considers equol's type and concentration variations, pathways affected, and its outcome in in vivo and in vitro studies.

Development of the Nude Rabbit Model

Loss-of-function mutations in the forkhead box N1 (FOXN1) gene lead to nude severe combined immunodeficiency, a rare inherited syndrome characterized by athymia, severe T cell immunodeficiency, congenital alopecia, and nail dystrophy. We recently produced FOXN1 mutant nude rabbits (NuRabbits) by using CRISPR-Cas9. Here we report the establishment and maintenance of the NuRabbit colony. NuRabbits, like nude mice, are hairless, lack thymic development, and are immunodeficient. To demonstrate the functional applications of NuRabbits in biomedical research, we show that they can successfully serve as the recipient animals in xenotransplantation experiments using human induced pluripotent stem cells or tissue-engineered blood vessels. Our work presents the NuRabbit as a new member of the immunodeficient animal model family. The relatively large size and long lifespan of NuRabbits offer unique applications in regenerative medicine, cancer research, and the study of a variety of other human conditions, including immunodeficiency.

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NuRabbit colony is established and available for the research community

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NuRabbits are nude and immunodeficient due to a mutation(s) in the FOXN1 gene

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NuRabbits support iPSC teratoma assay

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NuRabbits support xenotransplant of tissue-engineered blood vessels

Directed evolution of cyclic peptides for inhibition of autophagy

In recent decades it has become increasingly clear that induction of autophagy plays an important role in the development of treatment resistance and dormancy in many cancer types. Unfortunately, chloroquine (CQ) and hydroxychloroquine (HCQ), two autophagy inhibitors in clinical trials, suffer from poor pharmacokinetics and high toxicity at therapeutic dosages. This has prompted intense interest in the development of targeted autophagy inhibitors to re-sensitize disease to treatment with minimal impact on normal tissue. We utilized Scanning Unnatural Protease Resistant (SUPR) mRNA display to develop macrocyclic peptides targeting the autophagy protein LC3. The resulting peptides bound LC3A and LC3B—two essential components of the autophagosome maturation machinery—with mid-nanomolar affinities and disrupted protein–protein interactions (PPIs) between LC3 and its binding partners in vitro. The most promising LC3-binding SUPR peptide accessed the cytosol at low micromolar concentrations as measured by chloroalkane penetration assay (CAPA) and inhibited starvation-mediated GFP-LC3 puncta formation in a concentration-dependent manner. LC3-binding SUPR peptides re-sensitized platinum-resistant ovarian cancer cells to cisplatin treatment and triggered accumulation of the adapter protein p62 suggesting decreased autophagic flux through successful disruption of LC3 PPIs in cell culture. In mouse models of metastatic ovarian cancer, treatment with LC3-binding SUPR peptides and carboplatin resulted in almost complete inhibition of tumor growth after four weeks of treatment. These results indicate that SUPR peptide mRNA display can be used to develop cell-penetrating macrocyclic peptides that target and disrupt the autophagic machinery in vitro and in vivo.

SUPR peptide mRNA display was used to evolve a cell-permeable, macrocyclic peptide for autophagy inhibition.

A pentapeptide enabled AL3810 liposome-based glioma-targeted therapy with immune opsonic effect attenuated

AL3810, a molecular dual inhibitor of the vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR), has earned the permission of phase II clinical trial for tumor treatment by China FDA. As a reversible ATP-competitive inhibitor, AL3810 targets ATP-binding site on intracellular region of VEGFR and FGFR, whereas, AL3810 lacking interplay with extracellular region of receptors rendered deficient blood–brain tumor barrier (BBTB) recognition, poor brain penetration and unsatisfactory anti-glioma efficacy. Integrin αvβ3 overexpressed on capillary endothelial cells of BBTB as well as glioma cells illuminated ligand-modified liposomes for pinpoint spatial delivery into glioma. The widely accepted peptide c(RGDyK)-modified liposome loading AL3810 of multiple dosing caused hypothermia, activated anti-c(RGDyK)-liposome IgG and IgM antibody and pertinent complements C3b and C5b-9, and experienced complement-dependent opsonization. We newly proposed a pentapeptide mn with superb αvβ3-binding affinity and tailored AL3810-loaded mn-modified liposome that afforded impervious blood circulation, targeting ability, and glioma therapeutic expertise as vastly alleviated immune opsonization on the underpinning of the finite antibodies and complements assembly. Stemming from attenuated immunogenicity, peptide mn strengthened liposome functions as a promising nanocarrier platform for molecular targeting agents.

Polymeric Encapsulation of a Ruthenium Polypyridine Complex for Tumor Targeted One- and Two-Photon Photodynamic Therapy

Photodynamic therapy is a medical technique, which is gaining increasing attention to treat various types of cancer. Among the investigated classes of photosensitizers (PSs), the use of Ru(II) polypyridine complexes is gaining momentum. However, the currently investigated compounds generally show poor cancer cell selectivity. As a consequence, high drug doses are needed, which can cause side effects. To overcome this limitation, there is a need for the development of a suitable drug delivery system to increase the amount of PS delivered to the tumor. Herein, we report the encapsulation of a promising Ru(II) polypyridyl complex into polymeric nanoparticles with terminal biotin groups. Thanks to this design, the particles showed much higher selectivity for cancer cells in comparison to noncancerous cells in a 2D monolayer and 3D multicellular tumor spheroid model. As a highlight, upon intravenous injection of an identical amount of the Ru(II) polypyridine complex of the nanoparticle formulation, an improved accumulation inside an adenocarcinomic human alveolar basal epithelial tumor of a mouse up to a factor of 8.7 compared to the Ru complex itself was determined. The nanoparticles were found to have a high phototoxic effect upon one-photon (500 nm) or two-photon (800 nm) excitation with eradication of adenocarcinomic human alveolar basal epithelial tumor inside a mouse model. Overall, this work describes, to the best of our knowledge, the first in vivo study demonstrating the cancer cell selectivity of a very promising Ru(II)-based PDT photosensitizer encapsulated into polymeric nanoparticles with terminal biotin groups.

Anti-tumor efficacy of CKD-516 in combination with radiation in xenograft mouse model of lung squamous cell carcinoma

BACKGROUND

Hypoxic tumors are known to be highly resistant to radiotherapy and cause poor prognosis in non-small cell lung cancer (NSCLC) patients. CKD-516, a novel vascular disrupting agent (VDA), mainly affects blood vessels in the central area of the tumor and blocks tubulin polymerization, thereby destroying the aberrant tumor vasculature with a rapid decrease in blood, resulting in rapid tumor cell death. Therefore, we evaluated the anti-tumor efficacy of CKD-516 in combination with irradiation (IR) and examined tumor necrosis, delayed tumor growth, and expression of proteins involved in hypoxia and angiogenesis in this study.

METHODS

A xenograft mouse model of lung squamous cell carcinoma was established, and the tumor was exposed to IR 5 days per week. CKD-516 was administered with two treatment schedules (day 1 or days 1 and 5) 1 h after IR. After treatment, tumor tissues were stained with hematoxylin and eosin, and pimonidazole. HIF-1α, Glut-1, VEGF, CD31, and Ki-67 expression levels were evaluated using immunohistochemical staining.

RESULTS

Short-term treatment with IR alone and CKD-516 + IR (d1) significantly reduced tumor volume (p = 0.006 and p = 0.048, respectively). Treatment with CKD-516 + IR (d1 and d1, 5) resulted in a marked reduction in the number of blood vessels (p < 0.005). More specifically, CKD-516 + IR (d1) caused the most extensive tumor necrosis, which resulted in a significantly large hypoxic area (p = 0.02) and decreased HIF-1α, Glut-1, VEGF, and Ki-67 expression. Long-term administration of CKD-516 + IR reduced tumor volume and delayed tumor growth. This combination also greatly reduced the number of blood vessels (p = 0.0006) and significantly enhanced tumor necrosis (p = 0.004). CKD-516 + IR significantly increased HIF-1α expression (p = 0.0047), but significantly reduced VEGF expression (p = 0.0046).

CONCLUSIONS

Taken together, our data show that when used in combination, CKD-516 and IR can significantly enhance anti-tumor efficacy compared to monotherapy in lung cancer xenograft mice.

Microwave-assisted synthesis of meso-carboxyalkyl-BODIPYs and an application to fluorescence imaging

In this study, a significantly improved method for the synthesis of modular meso-BODIPY (boron dipyrromethene) derivatives possessing a free carboxylic acid group (which was subsequently coupled to peptides), is disclosed. This method provides a vastly efficient synthetic route with a > threefold higher overall yield than other reports. The resultant meso-BODIPY acid allowed for further easy incorporation into peptides. The meso-BODIPY peptides showed absorption maxima from 495-498 nm and emission maxima from 504-506 nm, molar absorptivity coefficients from 33 383-80 434 M-1 cm-1 and fluorescent quantum yields from 0.508-0.849. The meso-BODIPY-c(RGDyK) peptide was evaluated for plasma stability and (proved to be durable even up to 4 h) was then assessed for its fluorescence imaging applicability in vivo and ex vivo. The optical imaging in vivo was limited due to autofluorescence, however, the ex vivo tissue analysis displayed BODIPY-c(RGDyK) internalization and cancer detection thereby making it a novel tumor-integrin associated fluorescent probe while displaying the lack of interference the dye has on the properties of this ligand to bind the receptor.

Head and neck cancer patient-derived xenograft models - A systematic review

BACKGROUND

Patient-derived xenograft (PDX) involve the direct surgical transfer of fresh human tumor samples to immunodeficient mice. This systematic review aimed to identify publications of head and neck cancer PDX (HNC-PDX) models, describing the main methodological characteristics and outcomes.

METHODS

An electronic search was undertaken in four databases, including publications having used HNC-PDX. Data were analyzed descriptively.

RESULTS

63 articles were yielded. The nude mouse was one most commonly animal model used (38.8 %), and squamous cell carcinoma accounted for the majority of HNC-PDX (80.6 %). Tumors were mostly implanted in the flank (86.3 %), and the latency period ranged from 30 to 401 days. The successful rate ranged from 17 % to 100 %. Different drugs and pathways were identified.

CONCLUSION

HNC-PDX appears to significantly recapitulate the morphology of the original HNC and represents a valuable method in translational research for the assessment of the in vivo effect of novel therapies for HNC.

Generation of foxn1/Casper Mutant Zebrafish for Allograft and Xenograft of Normal and Malignant Cells

Cell transplantation into immunodeficient recipients is a widely used approach to study stem cell and cancer biology; however, studying cell states post transplantation in vivo is inconvenient in mammals. Here, we generated a foxn1/Casper mutant zebrafish that is transparent and exhibits T cell deficiency. By employing the line for hematopoietic stem cell (HSC) transplantation (HSCT), we could achieve nonconditioned transplantation. Meanwhile, we found that fetal HSCs from 3 days post fertilization zebrafish embryos produce a better transplant outcome in foxn1/Casper mutants, compared with adult HSCs. In addition to HSCT, the foxn1/Casper mutant is feasible for allografts of myelodysplastic syndrome-like and muscle cells, as well as xenografts of medaka muscle cells. In summary, foxn1/Casper mutants permit the nonconditioned engraftment of multiple cell types and visualized characterization of transplanted cells in vivo.

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foxn1/Casper mutant zebrafish permit unconditioned and visualized cell transplantation

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Zebrafish fetal HSCs possess more robust engraftment ability than adult HSCs

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foxn1/Casper mutant zebrafish permit allogeneic MDS-like cell transplantation

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Allograft and xenograft of muscle cells can be monitored in foxn1/Casper mutant zebrafish

Gompertz tracking of the growth trajectories of the human-liver-cancer xenograft-tumors in nude mice

BACKGROUND AND OBJECTIVE

The accurate tracking of the growth trajectories of the human-liver-cancer xenograft-tumors in nude mice is an important prerequisite for the effective use of relevant trial results. Our objective is first to find out whether the Gompertz model can accurately track the growth trajectories of the xenograft-tumors in the non-target control group, Gsk3β knockdown, and c-Myc knockdown groups; secondly, to verify the effect of knocking down Gsk3β or c-Myc on the growth of xenograft-tumors and reveal the mechanism; finally, to demonstrate the 100-day Gompertz growth trajectory, which is a complete growth process with two phases and three stages.

METHODS

The 18 male specific-pathogen-free (SPF) BALB/c nude mice were randomly divided into three groups and different interventions were performed to establish the non-target control, Gsk3β knockdown, and c-Myc knockdown groups. The volumes of the xenograft-tumors were measured from day 14 to day 30 after transplantation. The first 30-days and the whole 100-days of Gompertz growth trajectories of the xenograft-tumors were obtained respectively, and the growth assessment indicators of each group were calculated based on the parameters of the Gompertz model.

RESULTS

1) The Gompertz model can accurately track the growth trajectories of xenograft-tumors in the non-target control, Gsk3β knockdown, and c-Myc knockdown groups; 2) knocking down Gsk3β or c-Myc can inhibit the growth of xenograft-tumors. It is the combined effect of growth-promoting factor, growth inhibitory factor, and the delay of angiogenesis, of which the delay of angiogenesis plays a decisive role; 3) the 100-day Gompertz growth trajectory can provide complete information about the two phases and three stages of xenograft-tumor growth. Therefore, it is strongly recommended that nude mouse trials be extended from 30 days (currently widely accepted) to 100 days.

CONCLUSIONS

The Gompertz model can well reveal the growth pattern of the human-liver-cancer xenograft-tumors in nude mice. Combined with the growth assessment indicators obtained from the Gompertz model parameters, one can further clarify the mechanism that affects the growth of xenograft-tumors. The Gompertz tracking of the growth trajectories of the human-liver-cancer xenograft-tumors in nude mice has broad application prospects in the fields of basic research, drug verification, and clinical treatment, etc.

Anticancer targets and mechanisms of calycosin to treat nasopharyngeal carcinoma

Calycosin is a naturally occurring phytoestrogen, and it has the anti-nasopharyngeal carcinoma (NPC) action played by calycosin. However, the elaborate mechanisms of calycosin treating NPC remain to be unrevealed. In current report, a promising tool of network pharmacology method was used to uncover the anti-NPC targets and therapeutic mechanisms played by calycosin. Furthermore, were conducted to validate the bioinformatic findings in human and preclinical studies. As results, the bioinformatic findings showed the core anti-NPC targets played by calycosin included tumor protein p53 (TP53), mitogen-activated protein kinase 14 (MAPK14), caspase 8 (CASP8), mitogen-activated protein kinase 3 (MAPK3), caspase 3 (CASP3), receptor interacting protein kinase 1 (RIPK1), proto-oncogene c (JUN), and estrogen receptor 1 (ESR1). Concurrently, the top 20 biological processes and top 20 pharmacological pathways of calycosin treating NPC were identified and illustrated. In clinical data, NPC samples showed up-regulated expression of MAPK14, reduced TP53, and CASP8 expressions in comparison with those in non-NPC controls. As revealed in experimental data, calycosin-treated NPC cells resulted in reduced cell survival rate, increased cell apoptosis. In apoptosis-specific staining, calycosin-treated NPC cells exhibited elevated apoptotic cell number. Following the immunostaining assays, the results indicated increased TP53-, CASP8-positive cells, and reduced MAPK14-positive cells in calycosin-treated NPC cells and xenograft tumor sections. Altogether, the bioinformatic findings from network pharmacology reveal all core targets and mechanisms of calycosin treating NPC, and some of bioinformatic findings are identified using human and preclinical experiments. Notably, the screened biotargets may be potentially used to clinically treat NPC.

Generation of knockout rabbits with X-linked severe combined immunodeficiency (X-SCID) using CRISPR/Cas9

Severe immunodeficient mice are widely used to examine human and animal cells behaviour in vivo. However, mice are short-lived and small in size; while large animals require specific large-scale equipment. Rabbits are also commonly employed as experimental models and are larger than mice or rats, easy to handle, and suitable for long-term observational and pre-clinical studies. Herein, we sought to develop and maintain stable strains of rabbits with X-linked severe combined immunodeficiency (X-SCID) via the CRISPR/Cas9 system targeting Il2rg. Consequently, X-SCID rabbits presented immunodeficient phenotypes including the loss of T and B cells and hypoplasia of the thymus. Further, these rabbits exhibited a higher success rate with engraftments upon allogeneic transplantation of skin tissue than did wild type controls. X-SCID rabbits could be stably maintained for a minimum of four generations. These results indicate that X-SCID rabbits are effective animals for use in a non-rodent model of severe immunodeficiency.

EB1-dependent long survival of glioblastoma-grafted mice with the oral tubulin-binder BAL101553 is associated with inhibition of tumor angiogenesis

Glioblastoma (GBM) are aggressive brain tumors with limited treatment options. Cancer stem-like cells (CSLCs) contribute to GBM invasiveness, representing promising targets. BAL101553, a prodrug of BAL27862, is a novel small molecule tubulin-binding agent, promoting tumor cell death through spindle assembly checkpoint activation, which is currently in Phase 1/2a in advanced solid tumor patients including GBM. This study aimed to evaluate long-term daily oral BAL101553 treatment of mice orthotopically grafted with GBM CSLCs (GBM6) according to EB1 expression-level, and to decipher its mechanism of action on GBM stem cells. Oral treatment with BAL101553 for 100 days provoked a large EB1 expression level-dependent survival benefit, together with a decrease in tumor growth and brain invasion. Formation of vascular structures by the fluorescent GBM6-GFP-sh0 cells, mimicking endothelial vascular networks, was observed in the brains of control grafted mice. Following BAL101553 treatment, vessels were no longer detectable, suggesting inhibition of the endothelial trans-differentiation of GBM stem cells. In vitro, BAL27862 treatment resulted in a switch to the endothelial-like phenotype of GBM6 towards an astrocytic phenotype. Moreover, the drug inhibited secretion of VEGF, thus preventing normal endothelial cell migration activated by CSLCs. The decrease in VEGF secretion was confirmed in a human GBM explant following drug treatment. Altogether, our data first confirm the potential of EB1 expression as a response-predictive biomarker of BAL101553 in GBM we previously published and add new insights in BAL101553 long-term action by counteracting CSLCs mediated tumor angiogenesis. Our results strongly support BAL101553 clinical studies in GBM patients.

Mouse Tumor-Bearing Models as Preclinical Study Platforms for Oral Squamous Cell Carcinoma

Preclinical animal models of oral squamous cell carcinoma (OSCC) have been extensively studied in recent years. Investigating the pathogenesis and potential therapeutic strategies of OSCC is required to further progress in this field, and a suitable research animal model that reflects the intricacies of cancer biology is crucial. Of the animal models established for the study of cancers, mouse tumor-bearing models are among the most popular and widely deployed for their high fertility, low cost, and molecular and physiological similarity to humans, as well as the ease of rearing experimental mice. Currently, the different methods of establishing OSCC mouse models can be divided into three categories: chemical carcinogen-induced, transplanted and genetically engineered mouse models. Each of these methods has unique advantages and limitations, and the appropriate application of these techniques in OSCC research deserves our attention. Therefore, this review comprehensively investigates and summarizes the tumorigenesis mechanisms, characteristics, establishment methods, and current applications of OSCC mouse models in published papers. The objective of this review is to provide foundations and considerations for choosing suitable model establishment methods to study the relevant pathogenesis, early diagnosis, and clinical treatment of OSCC.