Search Results (152)

Over the past three turbulent decades, research has profoundly reshaped our understanding of chronic Toxoplasma gondii infection—traditionally regarded as harmless in immunocompetent individuals—unveiling its surprising impact on human health, performance, and behavior. This review emphasizes the effects of chronic Toxoplasma infection on physical and mental health, cognitive performance, and behavioral changes, highlighting key findings from studies investigating these domains, with a particular focus on both ultimate and proximate mechanisms underlying the observed effects. To this end, the primary focus will be on human studies; however, animal model studies will also be thoroughly considered when necessary and appropriate, to provide context and additional important information. Research demonstrates that chronic Toxoplasma infection may contribute to a broad spectrum of physical health issues. Ecological studies have revealed correlations between toxoplasmosis prevalence and increased morbidity and mortality from various conditions, including cardiovascular diseases, neurological disorders, and certain cancers. Large-scale cross-sectional studies have further shown that infected individuals report a higher incidence of numerous health complaints and diagnosed diseases, suggesting a significant impact on overall physical well-being. In addition to physical health, lifelong Toxoplasma infection (subclinical toxoplasmosis) has been implicated in cognitive impairments and behavioral changes. Studies have reported associations between infection and poorer performance in areas such as reaction time, processing speed, working memory, and executive function. Many of these behavioral changes likely relate to worsened health and a shift towards a “fast life history strategy.” These cognitive deficits can have significant implications for daily functioning and performance. Furthermore, the role of Toxoplasma infection in the development or exacerbation of mental health disorders has been extensively investigated. Meta-analyses, ecological studies, and large-scale observational studies have demonstrated associations between Toxoplasma infection and an increased risk of disorders such as schizophrenia and obsessive–compulsive disorder. While the precise mechanisms underlying these associations remain under investigation, research suggests that neuroinflammation and alterations in neurotransmitter systems are likely to play a role. Far from being harmless, subclinical toxoplasmosis is increasingly recognized as a hidden factor influencing human health, behavior, and cognitive performance—with implications that extend well beyond the individual to public health at large. Further research is warranted to elucidate the complex interplay between Toxoplasma infection, host physiology, and the development of various physical, cognitive, behavioral, and mental health conditions. Full article

Isoforms of prostate transmembrane protein, androgen induced 1 (PMEPA1), are regulated either by TGF-beta or AR activation and provide negative loop-regulation of these signaling pathways. High levels of PMEPA1 protein have been observed in various tumor types, including prostate, bladder, colorectal cancers, and glioblastoma. Direct oncogenic role of PMEPA1 in hepatocellular carcinoma has been recently shown on an animal model. New studies also indicate an upregulation of PMEPA1 in tumor-associated immune and stromal cells; however, its specific role in tumor stromal cells remains largely unexplored. In our previous research, we developed a cancer-stroma sphere (CSS) model that integrates tumor cells with mesenchymal stem cells (MSCs). Evaluations of chemotherapy and CAR-T therapies on CSSs have demonstrated that this model closely mimics in vivo data regarding cytotoxicity and adverse effects of therapy. In the present study, we reveal that PMEPA1 is significantly overexpressed in MSCs within the CSS. Moreover, this overexpression has been induced under short-term co-culture conditions. Among the five isoforms of PMEPA1, PMEPA1a and PMEPA1b isoforms have been detected in MSCs. These findings underscore the potential role of PMEPA1 in the tumor microenvironment modulation by MSCs. Full article

Large-animal models are playing a pivotal role in bridging the translational research gap. Positron emission tomography (PET) imaging is preferred in disease research involving large-animal models. Its ability to non-invasively monitor metabolic activity, receptor–ligand interactions, and pharmacokinetics in real time makes PET imaging an essential tool for evaluating therapeutic efficacy and advancing the development of targeted treatments. This review focuses on recent advancements in dedicated large-animal PET scanners, the utilization of large-animal models for simulating human diseases, and their applications in PET studies. It specifically highlights the critical role of PET imaging in facilitating the development of more effective and safer treatments for infections, chronic heart disease, diabetes, cancer, central nervous system disorders, and addiction, emphasizing its importance in the translational research landscape. Full article

Secondary osteonecrosis (ON) is a common complication in paediatric cancer survivors. Combining multipotent mesenchymal stromal cells (MSCs) with core decompression surgery halts disease progression and stimulates bone regeneration. However, the success of advanced therapy medicinal products (ATMPs) requires versatile “off-the-shelf” tissue engineering products (TEPs). This study evaluated the safety and efficacy of TEPs loaded with allogeneic MSCs from Wharton’s jelly (WJ-MSCs) in a large-animal model of bone regeneration to support a paediatric investigational plan for ON patients. WJ-MSC-laden fibrin-based hydrogels combined with a synthetic bone substitute (PRO-DENSE^TM) were tested in 16 juvenile sheep (8 males and 8 females) distributed in four experimental groups. Each animal received four cylindrical bone defects in the femoral and tibial epiphyses and was assessed at 6 and 12 weeks. Safety was confirmed, and bone regeneration was observed across all groups. A combination of WJ-MSCs with PRO-DENSE^TM led to improved histological scores, osteogenesis, and construct integration. Trabecular bone volume also increased more in cellular groups over time. However, effects were inconsistent across groups, reflecting the variability seen in clinical trials and highlighting the significant impact of factors such as immunogenetic compatibility, MSC batch potency, and interaction with the recipient’s microenvironment on the therapeutic effectiveness and successful clinical translation of allogeneic ATMPs. Full article

Spatially fractionated radiotherapy (SFRT) offers a promising approach for debulking large tumors by delivering high-dose radiation to a fraction of the tumor volume. However, the complex tumor microenvironment necessitates models beyond traditional 2D cultures and resource-intensive animal studies for SFRT investigations. Three-dimensional (3D) scaffold-based models with an adequate cross-sectional area have emerged as uniquely suited platforms to bridge this gap, by providing a more realistic platform for GRID-based SFRT research. In this study, we employed a 3D co-culture scaffold model to dissect the contributions of the radiation-induced bystander effect, abscopal effect, and immune system response on clonogenic survival following GRID irradiation. MDA-MB-231 breast cancer cells were seeded on commercial 3D scaffolds and irradiated at a 20 Gy peak dose using lead grids with three- and six-hole patterns, exposing ~12.8% and 25.7% of the scaffold area, respectively. An assessment of reproductive cell survival revealed a significant bystander effect, as the survival was notably lower than predicted based solely on the directly irradiated fraction. Evidence of an abscopal effect was observed by culturing non-irradiated cells in media exposed to GRID irradiation. Furthermore, a co-culture with allogeneic peripheral blood mononuclear cells (PBMCs) modulated clonogenic survival, with an additive effect observed when combined with SFRT. These findings underscore the presence of a bystander effect in GRID radiotherapy and indicate an abscopal immune component, particularly with the three-hole GRID configuration. This study established the utility of in vitro 3D co-culture scaffolds as an effective model system for elucidating complex SFRT-mediated biological responses. Full article

Esophageal cancer (EC) is the eighth leading cause of cancer-related deaths globally, largely due to its late-stage diagnosis and aggressive progression. Esophagectomy remains the primary treatment, typically requiring organ-based reconstruction techniques such as gastric pull-up or colonic interposition. However, these reconstruction methods often lead to severe complications, significantly reducing the quality of life of patients. To address these limitations, tissue engineering has emerged as a promising alternative, offering bioengineered patch-type and tubular-type scaffolds designed to restore both structural integrity and functional regeneration. Recent advancements in three-dimensional (3D) biofabrication—including 3D bioprinting, electrospinning, and other cutting-edge techniques—have facilitated the development of patient-specific constructs with improved biocompatibility. Despite significant advancements, critical challenges persist in achieving mechanical durability, multilayered cellular organization, and physiological resilience post-transplantation. Ongoing research continues to address these limitations and enhance clinical applicability. Therefore, this review aims to examine recent advancements in esophageal tissue engineering, with a focus on key biofabrication techniques, preclinical animal models, and the major translational challenges that must be addressed for successful clinical application. Full article

Tumor innervation is a complex interaction between nerves and cancer cells that consists of axons invading tumors, and its complexity remains largely unknown in humans. Although some retrospective studies have provided important insights into the relationship between nerves and tumors, further knowledge is required about this biological process. Animal experiments have elucidated several molecular and cellular mechanisms of tumor innervation; however, no experimental models currently exist to study interactions between human cancer and nerve cells. Human pluripotent stem cells can differentiate into neurons for research purposes; however, the use of these neurons to study interactions with cancer cells remains largely unexplored. Hence, here we analyze the potential of human pluripotent stem cells to study the interaction of cancer cells and neurons derived from human pluripotent stem cells to unravel the poorly understood mechanisms of human tumor innervation. Full article

Background and Objectives: Animal models are widely used in medical research, but most are limited to small or medium-sized species due to logistical constraints. However, pancreatic cancer research and surgical xenograft models require large animals with anatomical similarities to humans and minimal immune rejection. This study evaluates the feasibility of an operative immunodeficient pig model for patient-derived xenografts. Materials and Methods: During the period of October 2020 and October 2021, four pigs were used to establish a pig model at Seoul National University Bundang Hospital. A conventional pig 40 weeks of age was used. After introduction into the animal laboratory, splenectomy and thymectomy were performed to minimize B-cell and T-cell function. One week after the initial operation, oral immunosuppression was administered. After 4 weeks, human PDAC cells were implanted in the liver and pancreas. After 4 weeks of implant, the pigs were sacrificed, and the operative and pathologic findings were analyzed. Results: All four pigs survived the 9-week experiment. Indwelling venous catheters for drug-level monitoring were attempted but failed. Splenectomy and thymectomy were deemed to be feasible and effective. Oral immunosuppression was acceptable, but the initial dosage was better tolerated at low levels. Out of the four pigs, one pig showed a mass formation at the cell line injection site, demonstrating reactive cell clusters on pathology. Conclusions: This pig model using conventional pigs is a feasible model of immunosuppression. It is necessary to fine-tune the oral immunosuppression dosage and develop methods for the frequent monitoring of immunosuppression levels. Full article

Haematological malignancies comprise a diverse group of life-threatening systemic diseases, including leukaemia, lymphoma, and multiple myeloma. Currently available therapies, including chemotherapy, immunotherapy, and CAR-T cells, are often associated with important side effects and with the development of drug resistance and, consequently, disease relapse. In the last decades, it was largely demonstrated that the tumor microenvironment significantly affects cancer cell proliferation and tumor response to treatment. The development of biomimetic, in vitro models may promote the investigation of the interactions between cancer cells and the tumor microenvironment and may help to better understand the mechanisms leading to drug resistance. Although advanced in vitro models have been largely explored in the field of solid tumors, due to the complex nature of the blood cancer tumor microenvironment, the mimicking of haematological malignancies mostly relies on simpler systems, often limited to two-dimensional cell culture, which intrinsically excludes the microenvironmental niche, or to ethically debated animal models. This review aims at reporting an updated overview of state-of-the-art hematological malignancies 3D in vitro models, emphasizing the key features and limitations of existing systems to inspire further research in this underexplored field. Full article

HPV-associated dermatological diseases include benign lesions like cutaneous warts and external genital warts. In addition, HPV infection is associated with the development of epithelial skin cancers, in particular cutaneous squamous cell carcinoma (cSCC). In contrast to anogenital and oropharyngeal cancers caused by mucosal HPV types of genus alpha papillomavirus, cSCC-associated HPV types belong to the genus beta papillomavirus. Currently available HPV vaccines that target mucosal HPV types associated with anogenital cancer and genital warts are type-specific and provide no cross-protection against beta HPV. When implementing vaccination to beta HPV to prevent skin tumors, it must be considered that acquisition of these HPV types occurs early in childhood and that the risk for cSCC increases with growing age and decreasing immune surveillance. Thus, individuals considered for beta HPV vaccination usually have pre-existing infection and are largely immunocompromised. On the other hand, worldwide increasing incidence rates of epithelial skin cancer reflect an urgent need for skin cancer prevention measures. Based on the pathogenic involvement of beta HPV, vaccination may represent a promising prevention strategy. Indeed, various procedures of prophylactic and therapeutic vaccination have been developed, and some of them have shown efficiency in animal models. Thus far, however, none of these vaccine candidates has been approved for application in humans. Full article

Identifying proteins that act in tumor invasiveness and metastasis remains a critical unmet need in our search for effective cancer therapy. Hsp90, an abundant intracellular chaperone protein, plays a key role in maintaining cell homeostasis, and its elevated activity is pivotal in cancer progression. Due to the reliance of cancer cells on Hsp90’s chaperone function to sustain tumor growth and spread, Hsp90 inhibitors have been the subject of numerous clinical trials over the past two decades. However, these efforts have largely been unsuccessful, primarily due to the cellular toxicity caused by pan-Hsp90 inhibitors at doses required for anticancer efficacy. Therefore, novel approaches to target Hsp90 are necessary. An identified subpopulation of Hsp90 located outside cells (eHsp90) may offer a promising alternative as a therapeutic target against cancer. Studies including our own have shown that eHsp90 is released specifically by cancer cells, and eHsp90 has unique interactors and functions extracellularly to promote tumor invasiveness, the initial step in metastasis. Inhibition of eHsp90 has been shown to suppress metastasis in animal models, indicating its therapeutic potential, although the underlying mechanisms remain incompletely understood. Cancer cells modulate the tumor microenvironment (TME) during the invasion, especially the ECM proteins and the state of the ECM is a strong predictor of invasive and metastatic cancer. Given that most of the known eHsp90 clients are ECM proteins or are proteins involved in ECM modulation, ECM remodelling could be the key mechanism through which eHsp90 enhances invasiveness. This review will focus on ECM modulation by eHsp90 as a driver of cancer invasion and metastasis. We will also discuss the potency of inhibiting eHsp90 in inhibiting invasion and metastatic spread in preclinical models and the using circulating Hsp90 patient samples as a biomarker of cancer invasion and metastasis. Full article

Cancer is the most common cause of death in adult dogs. All dogs would benefit from early diagnosis, but there are no specific guidelines regarding the schedule of cancer screening in companion animals. The aim of this study was to retrospectively evaluate the age at diagnosis in Italian oncological canine patients. A total of 14,636 canine histologically confirmed neoplastic cases were coded according to the Vet-ICD-O-canine-1 and stratified by malignancy, sex, neutering status, breed, cephalic index, body size, and tumor type. Differences in age distribution were analyzed and the influence of these variables on the time of first malignancy diagnosis was assessed using an event history analysis model. The median age at diagnosis for benign and malignant tumors was 9 and 10 years, respectively. Intact and purebred dogs were diagnosed earlier, but the median age differed significantly by breed. The earliest age at diagnosis was recorded for lymphomas and mast cell tumors. The model showed an accelerating effect of large size, brachy- and dolichocephaly, and sexual integrity in female dogs on the time of malignancy diagnosis. Our results confirm that a “one-size-fits-all” approach to cancer screening is not accurate in dogs and provide relevant data that may lead to the establishment of breed-based screening schedules. Full article

This pilot study investigated the feasibility of using magnetic resonance elastography (MRE) for the non-invasive detection and quantification of liver fibrosis in the Oncopig cancer model. Seven 8-week-old Oncopigs underwent alcoholic liver fibrosis induction and serial MRE imaging and liver biopsy at 1, 2, and 3 months post procedure. MRE was utilized to quantify liver stiffness, and liver fibrosis was histologically graded using the METAVIR system. The primary outcome measure was the capability to detect and quantify liver fibrosis using MRE with radiologic–pathologic correlation. Liver fibrosis induction, MRE imaging, and liver biopsy were successfully performed. MRE liver fibrosis was evident in 57% (4/7), 50% (3/6), and 40% (2/5) animal subjects 1, 2, and 3 months after fibrosis induction, with mean liver stiffness of 2.94, 3.25, and 2.91 kPa, respectively. Histological liver fibrosis was noted in 71% (5/7), 100% (5/5), and 100% (5/5) of animal subjects with available tissue samples. There was no significant statistical correlation between the MRE-measured liver stiffness and the METAVIR fibrosis scores. In conclusion, quantifiable liver fibrosis may be induced in the Oncopig. MRE has potential utility in non-invasively detecting liver stiffness in this large-animal preclinical model, though tissue biopsy was more sensitive in demonstrating disease. Full article

Background and Objectives: PIN1 is overexpressed in several human cancers, including prostate cancer, breast cancer, and oral squamous carcinomas. Juglone (J), derived from walnut, was reported to selectively inhibit PIN1 by modifying its sulfhydryl groups. In this study, the potential effects of juglone, also known as PIN1 inhibitor, on oral cancer and carcinogenesis were investigated at the molecular level. Materials and Methods: 4-Nitroquinoline N-oxide (4-NQO) was used to create an oral cancer model in animals. Wistar rats were divided into five groups: Control, NQO, Juglone, NQO+J, and NQO+J*. The control group received the basal diet and tap water throughout the experiment. The NQO group received 4-NQO for 8 weeks in drinking water only. The Juglone group was administered intraperitoneally in a juglone solution for 10 weeks (1 mg/kg/day). The NQO+J group received 4-NQO in drinking water for 8 weeks, starting 1 week after the cessation of 4-NQO treatment. They were then administered intraperitoneally in a juglone solution for 10 weeks. (1 mg/kg/day). NQO+J* group: received 4 NQO for 8 weeks in drinking water and administered intraperitoneally in a juglone solution for 10 weeks (1 mg/kg/day). They were sacrificed at the end of the 22-week experimental period. The tongue tissues of the rats were isolated after the experiment, morphological changes were investigated by histological examinations, and the molecular apoptotic process was investigated by rt-qPCR and western blot. Results: Histological results indicate that tumors are formed in the tongue tissue with 4-NQO, and juglone treatment largely corrects the epithelial changes that developed with 4-NQO. It has been determined that apoptotic factors p53, Bax, and caspases are induced by the effect of juglone, while antiapoptotic factors such as Bcl-2 are suppressed. However, it was observed that the positive effects were more pronounced in rats given juglone together with 4-NQO. Conclusions: The use of PIN1 inhibitors such as juglone in place of existing therapeutic approaches might be a promising and novel approach to the preservation and treatment of oral cancer and carcinogenesis. However, further research is required to investigate the practical application of such inhibitors. Full article

The response of tumors to anti-cancer therapies is defined not only by cell-intrinsic therapy sensitivities but also by local interactions with the tumor microenvironment. Fibroblasts that make tumor stroma have been shown to produce paracrine factors that can strongly reduce the sensitivity of tumor cells to many types of targeted therapies. Moreover, a high stroma/tumor ratio is generally associated with poor survival and reduced therapy responses. However, in contrast to advanced knowledge of the molecular mechanisms responsible for stroma-mediated resistance, its effect on the ability of tumors to escape therapeutic eradication remains poorly understood. To a large extent, this gap of knowledge reflects the challenge of accounting for the spatial aspects of microenvironmental resistance, especially over longer time frames. To address this problem, we integrated spatial inferences of proliferation-death dynamics from an experimental animal model of targeted therapy responses with spatial mathematical modeling. With this approach, we dissected the impact of tumor/stroma distribution, magnitude and distance of stromal effects. While all of the tested parameters affected the ability of tumor cells to resist elimination, spatial patterns of stroma distribution within tumor tissue had a particularly strong impact. Full article