Genetic Model Research Articles

The evolutionary cost of homophily: Social stratification facilitates stable variant coexistence and increased rates of evolution in host-associated pathogens.

Coexistence of multiple strains of a pathogen in a host population can present significant challenges to vaccine development or treatment efficacy. Here we discuss a novel mechanism that can increase rates of long-lived strain polymorphism, rooted in the presence of social structure in a host population. We show that social preference of interaction, in conjunction with differences in immunity between host subgroups, can exert varying selection pressure on pathogen strains, creating a balancing mechanism that supports stable viral coexistence, independent of other known mechanisms. We use population genetic models to study rates of pathogen heterozygosity as a function of population size, host population composition, mutant strain fitness differences and host social preferences of interaction. We also show that even small periodic epochs of host population stratification can lead to elevated strain coexistence. These results are robust to varying social preferences of interaction, overall differences in strain fitnesses, and spatial heterogeneity in host population composition. Our results highlight the role of host population social stratification in increasing rates of pathogen strain diversity, with effects that should be considered when designing policies or treatments with a long-term view of curbing pathogen evolution.

Time-domain inversion of random dynamic loads on offshore platforms based on optimized ensemble learning

This paper presents an optimized ensemble learning method tailored for the field of dynamic load identification. The approach utilizes finite element simulation data to train the ensemble learning model and subsequently employs actual measured response data for load inversion. The key feature of this method lies in leveraging ensemble learning to address the inversion problem when the load is unknown, eliminating the need for solving model parameters directly, and directly constructing an inverse model between the response and external load. By employing three ensemble learning models (Extra Trees, AdaBoost, Light GBM) for load inversion, both Extra Trees and AdaBoost yielded an MSE of 0.09, confirming the feasibility of the method. Furthermore, we evaluated its load inversion performance across different measurement points and machine learning models, as well as its effectiveness in frequency domain inversion. These findings hold significant implications for practical engineering applications.

Genetic contributions to body mass index over adolescence and its associations with adult weight gain: a 25-year follow-up study of Finnish twins.

High body mass index (BMI) in adolescence is a strong predictor of adult obesity. However, the nature of this association is unclear. We investigated how adolescent BMI is associated with adult weight change using longitudinal data from ages 11.5 to 37 years and examined the genetic factors behind these associations. The study cohort consisted of 1400 Finnish twin individuals (40% males) with 494 complete twin pairs who reported their body mass index (BMI) at five ages: 11.5, 14, 17.5, 24, and 37 years. BMI trajectories (defined as BMI changes (i.e., slope) and BMI at baseline age (i.e., intercept)) were calculated in adulthood (from 17.5 to 37 years of age) using linear mixed-effects models. Polygenic Risk Scores of BMI (PRSBMI) and genetic twin models were utilised to analyse the role of genetic factors underlying BMI trajectories and their associations with BMI at 11.5 and 14 years of age. Mean BMI increased in adulthood (4.06 kg/m2 in men and 3.39 kg/m2 in women). The BMI changes correlated with BMI at the baseline age of 17.5 years (i.e. intercept) (r = 0.24 in men and r = 0.35 in women) as well as with BMI in adolescence (11.5 and 14 years of age). Genetic factors contributed to the BMI changes during adulthood (correlation with PRSBMI r = 0.25 in men and r = 0.27 in women; heritability estimates 0.63 and 0.64 respectively) as well as to their correlations with BMI at the baseline age (rA = 0.5 in men and 0.54 in women) and BMI during adolescence (at 11.5 and 14 years of age) (rA = 0.63-0.64). We found that genetic factors play a role in BMI change in adulthood, and part of this genetic component overlaps with the genetics of BMI in adolescence. Genetic predisposition to high BMI in adolescence is also related to adult weight gain.

Efficiency of MALDI-TOF MS at identifying and discriminating immature stages of cimex lectularius and cimex hemipterus bed bugs

Over the last two decades, an increase in bed bug infestations has been observed worldwide. Although their definitive role as vectors of infectious agents has not yet been demonstrated, bed bugs have a direct effect on human health through dermatological reactions to their bites and psychological disorders linked to domestic infestations. In this study, the effectiveness of using MALDI-TOF MS to correctly identify these two bed bug species at immature stages was assessed, as well as it effectiveness as discriminating between the immature stages (IS) of C. lectularius and C. hemipterus and their associated developmental stages. A total of 305 specimens were subjected to MALDI-TOF MS analysis, including 153 C. lectularius (28 eggs and 25 nymphs per stage from IS1 to IS5) and 152 C. hemipterus (27 eggs and 25 nymphs per stage from IS1 to IS5). ). MALDI-TOF MS analysis enabled us to obtain 84.97% (130/153) of high-quality MS spectra in terms of reproducibility and profile intensity. Twenty-four spectra including two per stage, from egg to IS5, and per bed bug species - were added to our in-house MS reference arthropod spectra database. All specimens were correctly identified at the species level, independently of the developmental stage, with log score values (LSVs) ranging from 1.75 to 2.79 (mean = 2.29 ± 0.12) and 1.81 to 2.71 (mean = 2.37 ± 0.03) for C. lectularius and C. hemipterus, respectively. MALDI-TOF MS correctly classified 53,33% (104/195) of the Cimex at the correct immature stage. Conversely, an accurate comparison of the profiles with a Genetic Algorithm model underlined that grouping the immature stages in two groups, early (IS1-IS2) and late (IS3-IS4-IS5), made it possible to obtain a cross validation (CV) and recognition capability (RC) greater than 92% and 94%, respectively, for both species. This study holds great promise for the management of bed bug infestations.

Vagal stimulation ameliorates murine colitis by regulating SUMOylation.

Inflammatory bowel diseases (IBDs) are chronic debilitating conditions without cure, the etiologies of which are unknown, that shorten the lifespans of 7 million patients worldwide by nearly 10%. Here, we found that decreased autonomic parasympathetic tone resulted in increased IBD susceptibility and mortality in mouse models of disease. Conversely, vagal stimulation restored neuromodulation and ameliorated colitis by inhibiting the posttranslational modification SUMOylation through a mechanism independent of the canonical interleukin-10/α7 nicotinic cholinergic vagal pathway. Colonic biopsies from patients with IBDs and mouse models showed an increase in small ubiquitin-like modifier (SUMO)2 and SUMO3 during active disease. In global genetic knockout mouse models, the deletion of Sumo3 protected against development of colitis and delayed onset of disease, whereas deletion of Sumo1 halted the progression of colitis. Bone marrow transplants from Sumo1-knockout (KO) but not Sumo3-KO mice into wild-type mice conferred protection against development of colitis. Electric stimulation of the cervical vagus nerve before the induction of colitis inhibited SUMOylation and delayed the onset of colitis in Sumo1-KO mice and resulted in milder symptoms in Sumo3-KO mice. Treatment with TAK-981, a first-in-class inhibitor of the SUMO-activating enzyme, ameliorated disease in three murine models of IBD and reduced intestinal permeability and bacterial translocation in a severe model of the disease, suggesting the potential to reduce progression to sepsis. These results reveal a pathway of vagal neuromodulation that reprograms endogenous stress-adaptive responses through inhibition of SUMOylation and suggest SUMOylation as a therapeutic target for IBD.

Association of HLA-G Expression, Its Genetic Variants and Related Neuro-Immunomodulation with Characteristics of Bladder Carcinoma.

Human leukocyte antigen G (HLA-G) is an immune checkpoint molecule with immunosuppressive and anti-inflammatory activities. It belongs to class I non-classical major histocompatibility complex molecules and has been upregulated in various cancer types. In bladder cancer (BC) tumors, the association of HLA-G with cancer progression has to be explained. A total of 89 BC patients and 74 control subjects were genotyped for the HLA-G 14 bp ins/del polymorphism. In urine cell samples, HLA-G mRNA expression was analyzed using real-time PCR. Soluble HLA-G (sHLA-G) serum levels were measured by ELISA. The associations between the HLA-G 14 bp ins/del polymorphism, HLA-G mRNA expression, and/or sHLA-G levels and selected variables including tumor grade, disease stage, body mass index, and heart rate variability (HRV) parameters were evaluated. The protective HLA-G 14 bp ins/ins genotype under the recessive genetic model was associated with lower HLA-G mRNA expression in the BC group (p = 0.049). Significantly higher HLA-G mRNA expression was detected in patients with pT2 + pT3 as compared to those with pTa + pT1 stages (p = 0.0436). Furthermore, higher HLA-G mRNA expression was observed in high-grade muscle-infiltrating BC (MIBC) than in the low-grade non-MIBC group (p = 0.0365). Patients with a level of sHLA-G above 29 U/mL had shorter disease-free survival than patients with lower sHLA-G levels. Furthermore, the opposite HRV correlations with sHLA-G levels in BC patients as compared to controls probably reflect the different roles of HLA-G in health and cancer. Our results suggest the impact of the HLA-G 14 bp ins/del variant, HLA-G expression, and autonomic nervous system imbalance on advanced stages of BC.

Genomic variants associated with type 2 diabetes mellitus among Filipinos.

Type 2 diabetes mellitus leads to debilitating complications that affect the quality of life of many Filipinos. Genetic variability contributes to 30% to 70% of T2DM risk. Determining genomic variants related to type 2 diabetes mellitus susceptibility can lead to early detection to prevent complications. However, interethnic variability in risk and genetic susceptibility exists. This study aimed to identify variants associated with type 2 diabetes mellitus among Filipinos using a case-control design frequency matched for age and sex. A comparison was made between 66 unrelated Filipino adults with type 2 diabetes mellitus and 121 without. Genotyping was done using a candidate gene approach on genetic variants of type 2 diabetes mellitus and its complications involving allelic association and genotypic association studies with correction for multiple testing. Nine (9) significant variants, mostly involved in glucose and energy metabolism, associated with type 2 diabetes mellitus in Filipinos were found. Notably, a CDKAL1 variant (rs7766070) confers the highest level of risk while rs7119 (HMG20A) and rs708272 (CETP) have high risk allele frequencies in this population at 0.77 and 0.66, respectively, making them potentially good markers for type 2 diabetes mellitus screening. The data generated can be valuable in developing genetic risk prediction models for type 2 diabetes mellitus to diagnose and prevent the condition among Filipinos.

Heat stress on dairy cattle

Climate change significantly impacts the production, health, welfare, and survival of farm animals. The prolonged heat stress is a major concern in tropical and subtropical regions. Heat tolerance enables livestock to maintain thermal balance under extreme climatic conditions, thus ensuring productivity and animal welfare. There is a feasibility of genetic selection for heat tolerance to improve production and reproduction traits. This genetic selection may provide enduring advantages in maintaining productive and reproductive performances as heat stress is a heritable trait. To identify and integrate traits associated with thermal tolerance into breeding programs, it is imperative to have a robust animal performance records and meteorological data. Temperature humidity index (THI) is a widely used biomarker for assessing heat stress in dairy cows, as it combines air temperature and relative humidity. In regions with sparse weather station coverage, NASA POWER satellite data is a viable alternative for obtaining meteorological information to calculate THI and evaluate heat stress impacts. There are multiple models for calculating THI and those focusing on humidity being more effective in humid climates. Genetic models, particularly reaction norm models based on random regressions, were introduced for estimating genetic parameters for heat tolerance in cattle. These models help to understand genotype-environment interactions and non-linear relationship between THI and milk yield reduction. The continued genetic selection for milk production without considering heat tolerance traits increases susceptibility to heat stress, emphasizing a need for comprehensive selection objectives. This review underscores the importance of incorporating heat tolerance traits into genetic selection for dairy cattle and highlights various biomarkers and genetic models used to estimate heat tolerance. Incorporating these traits into breeding goals is essential to improve thermotolerance while maintaining productivity, bolstering resilience of cattle to climate change.

AAV-mediated Gene Therapy for Hereditary Deafness: Progress and Perspectives.

Hereditary deafness is the most prevalent sensory deficit disorder, with over 100 identified deafness-related genes. Clinical treatment options are currently limited to external devices like hearing aids and cochlear implants. Gene therapy has shown promising results in various genetic disorders and has emerged as a potential treatment for hereditary deafness. It has successfully restored hearing function in >20 types of genetic deafness model mice and can almost completely cure patients with hereditary autosomal recessvie deafness 9 (DFNB9) caused by the OTOFERLIN (OTOF) mutation, thus serving as a translational paradigm for gene therapy for other forms of genetic deafness. However, due to the complexity of the inner ear structure, the diverse nature of deafness genes, and variations in transduction efficiency among different types of inner ear cells targeted by adeno-associated virus (AAV), precision gene therapy approaches are required for different genetic forms of deafness. This review provides a comprehensive overview of gene therapy for hereditary deafness, including preclinical studies and recent research advancements in this field as well as challenges associated with AAV-mediated gene therapy.

Extracellular domains of CATSPERε are essential for CatSper assembly during development and activity modulation in sperm capacitation.

The flagellar-specific Ca 2+ channel CatSper is a multiprotein complex that is critical for successful fertilization by controlling the sperm Ca 2+ signaling in space and time. Large extracellular domains (ECDs) of four single-pass transmembrane subunits, CATSPERβ, γ, δ, and ε, form a unique canopy structure over the pore-forming channel. However, the molecular mechanisms of canopy assembly during development and its physiological function in mature sperm remain unknown. Here, using two genetic mouse models and the biochemical isolation of a bioactive CATSPERε fragment, we report that CATSPERε ECDs are essential for assembling the CatSper canopy, and thus the entire channel complex, and for modulating CatSper function for sperm hyperactivation and fertilization. CATSPERε-deficient males are sterile because their sperm fail to develop hyperactivated motility due to the absence of the entire channel. In transgenic mice overexpressing CATSPERε with truncated ECDs in testicular germ cells, truncated CATSPERε is unable to interact with native CatSper subunits and incorporate into the complex, thus failing to rescue the defective sperm hyperactivation and infertility of Catspere -null males. These findings provide insight into the underlying molecular and developmental mechanisms of CatSper complex assembly and how CatSper channels can be modulated in physiological settings and by therapeutic intervention.

Generating snoRNA-guided Programmable 2'- O -methylation.

Small nucleolar RNAs (snoRNAs) are critical in guiding post-transcriptional modifications like 2'- O -methylation (Nm), which play crucial roles in downstream processes such as splicing and translation. This study tests a novel method for Nm validation, addressing a significant gap in modern Nm research, and offers insight into the intricacies of snoRNA-guided Nm. While mapping of Nm modifications has seen significant improvement within the past decade, no major techniques have been able to validate these potential sites. Additionally, many mapping techniques lack consensus among proposed Nm sites, especially on mRNAs. Without a proper validation technique, Nm research lags compared to its peer post-transcriptional modifications. The RNase H-based Nm-VAQ assay used here quantifies 2'- O -methylation at single nucleotide resolution across various RNA species including rRNA, snRNA, and mRNA. Its optimization for mRNA allows for an unprecedented way to study the effects of Nm modifications in low abundance transcripts. Utilizing this, the study also explores the potential of creating synthetic snoRNAs to guide Nm modifications. Exogenous snoRNAs are shown to rescue Nm in genetic knockout models and can be mutated to guide Nm at any location along the target RNA transcript. Preliminary work indicates that synthetic snoRNAs demonstrate the ability to modify luciferase, impacting translation efficiency. Targeting an exon increases mRNA abundance but decreases protein expression, consistent with previous findings on Pxdn mRNA. These findings set the scene for novel understanding of the relationship between snoRNA abundance, 2'- O -methylation efficiency, and Nm's impact on gene expression.

Exosc10 deficiency in the initial segment is dispensable for sperm maturation and male fertility in mice

Summary EXOSC10 is an exosome-associated ribonuclease that degrades and processes a wide range of transcripts in the nucleus. The initial segment (IS) of the epididymis is crucial for sperm transport and maturation in mice by affecting the absorption and secretion that is required for male fertility. However, the role of EXOSC10 ribonuclease-mediated RNA metabolism within the IS in the regulation of gene expression and sperm maturation remains unknown. Herein, we established an Exosc10 conditional knockout (Exosc10 cKO) mouse model by crossing Exosc10 F/F mice with Lcn9-Cre mice which expressed recombinase in the principal cells of IS as early as post-natal day 17. Morphological and histological analyses revealed that Exosc10 cKO males had normal spermatogenesis and development of IS. Moreover, the sperm concentration, morphology, motility, and frequency of acrosome reactions in the cauda epididymides of Exosc10 cKO mice were comparable with those of control mice. Thus, Exosc10 cKO males had normal fertility. Collectively, our genetic mouse model and findings demonstrate that loss of EXOSC10 in the IS of epididymis is dispensable for sperm maturation and male fertility.

Метаболічний синдром: механізми розвитку та експериментальні моделі

Metabolic syndrome is a condition characterized by the presence of insulin resis­tance and the presence of two of the following risk factors: obesity, hyperlipidemia (hypertriglyceridemia, decreased high-density lipoprotein cholesterol), hypertension, or microalbuminuria. The multifactorial nature of metabolic syndrome makes it difficult to create an adequate experimental model that would best represent the entire spectrum of the pathophysiology of this condition. This review aims to summarize current literature data on the pathophysiological mechanisms of metabolic syndrome in the context of the development of insulin resistance, obesity, dyslipidemia, impaired glucose tolerance, and inflammation. The article also summarizes modern approaches to the induction of metabolic syndrome in rodents, among which dietary manipulation, genetic modifications, and the use of pharmaceuticals are the most common. As genetic models of metabolic syndrome, rodents with leptin or leptin receptor deficiency are most often used, in particular leptin-deficient mice (ob/ob), leptin receptor-deficient mice (db/db), Zucker obese rats (ZF), diabetic rats lines Zucker with obesity (ZDF) and others. Pharmaceutical drugs that can be used to induce metabolic syndrome include endogenous glucocorticoids and antipsychotic drugs. Several dietary manipulations are used to induce metabolic syndrome in laboratory animals. In particular, one type of diet or a combination of diets can be used, such as diets high in fructose, sucrose and fat, or a diet characterized by a high content of both fructose and fat or sucrose and fat. Manipulations with the composition of products consumed by experimental animals make it possible to simulate the development of metabolic syndrome, since the diet affects the metabolism of the entire body, and has a regulatory effect on hormones, glucose and lipid metabolism pathways.

Abstract B023: Regulatory T (Treg) cell contributes to tumor cell dissemination via extracellular matrix (ECM) remodeling, which is driven by TAMs in an IFNg-dependent manner

Abstract Background: The extracellular matrix (ECM) is a highly organized non-cellular network consisting of structural proteins, growth factors, cytokines and other secreted molecules. The ECM is highly dynamic and is a critical player in the regulation of local invasion and metastasis. The ECM network is ever-changing and an important immunosuppressive component of the tumor microenvironment (TME). However, the reciprocal effects of the immune system on the tumor-associated ECM are elusive and largely unexplored. Regulatory T (Treg) cells function to enforce peripheral tolerance and are potent suppressors of tumor immunity. We have previously shown that Treg cells promote tumor growth in murine breast cancer models by favoring alternative activation of tumor-associated macrophages (TAMs) via suppression of IFN-g. Aims: In this work, we sought to assess whether Treg cell-mediated immune suppression is associated with changes in the ECM, and whether those ECM changes functionally impact metastatic dissemination. Further, we assessed the requirement of TAMs and IFN-g in the ECM remodeling. Design Methods: In this study, we used spontaneous and transplantable models of breast cancer susceptible to genetic ablation of Treg cells. We used a combination of histopathological analysis, tumor decellularization, bioengineering 3D-chip modeling, in vivo manipulations and bioinformatic analysis, to evaluate remodeling of the ECM, cancer cell invasive behavior and metastatic dissemination. Results Summary: Treg cell ablation resulted in significant ECM remodeling, with reduced amounts and organization of collagen fibers, and increased amounts of fibronectin and laminin. Tumor cells seeding on Treg cell ablated tumor- derived decellularized ECM matrices results in reduced epithelial-mesenchymal transition (EMT) transcription factors, and profound impairment of collective migration. In vivo, Treg cell ablation in a neo-adjuvant setting followed by primary tumor resection resulted in significant reduction of circulating tumor cells (CTC) and impairment of lung metastatic disease. Importantly, we demonstrated that Treg cell ablation-driven changes in the matrisome correlate with long-term improved survival in a cohort of breast cancer patient samples. Through genetic knock-out models and in-vivo neutralization, we observed that Treg cell-dependent changes in ECM-related phenotypes are dependent on IFN-g-signaling. Single-cell RNA-sequencing (scRNA-seq) of murine breast tumors revealed that the matrisome signature is highly upregulated among TAMs, compared to other TME cell types. Lastly, using conditional genetic knock-out models we show these IFN-g-dependent changes are mostly driven by TAMs. Conclusions: Altogether, we identified a novel metastasis-promoting effect of Treg cells in the breast cancer microenvironment through regulation of ECM dynamics beyond their described effects on primary tumor growth. Citation Format: Ailen D. Garcia-Santillan, Jessanne Y. Lichtenberg, He Shen, Jasmine M Rodriguez, Jonathan Barra, Nicholas M Clark, Wei Du, Leandro M Martinez, Ashley D Hadjis, Taylor Calicchia, Mikhail G Dozmorov, Jose J Bravo-Cordero, Amy L Olex, Priscilla Y Hwang, Paula D Bos. Regulatory T (Treg) cell contributes to tumor cell dissemination via extracellular matrix (ECM) remodeling, which is driven by TAMs in an IFNg-dependent manner [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B023.

Ralationship between polymorphisms and diplotypes of HLA-G 3’UTR and fetuses with abnormal chromosomes or unexplained pregnancy loss (UPL)

ObjectivesHuman leukocyte antigen G (HLA-G) plays a crucial role in pregnancy. Pregnancy loss (PL) is caused by a variety of causes, such as fetal chromosomal abnormalities, maternal hypertension and diabetes, immune causes, spontaneous immune diseases, infections, unknown causes, etc. This study reports on the association of fetal HLA-G 3’UTR polymorphisms and diplotypes with chromosomally abnormal fetuses (CAF) or unexplained pregnancy loss (UPL).MethodsA total of 552 specimens were collected and grouped by next-generation sequencing technology (NGS) and fetal survival: UPL (112 cases), CAF (170 cases) and control (258 cases). The polymorphisms of HLA-G 3’UTR in all samples were detected by Sanger sequencing. The genotypes, haplotypes and diplotypes of HLA-G 3’UTR were analyzed. The classification and regression tree (CART) analysis was used to evaluate the role of HLA-G diplotypes in predicting fetal outcomes. The correlations between CAF or UPL and maternal age, paternal age, times of miscarrage, times of delivery were analyzed by logistic regression.ResultsThe frequencies of HLA-G + 2960del/del and + 3035CC genotypes were remarkablly increased in CAF than those in control group. The frequencies of HLA-G + 2960ins/del, + 3010CC, + 3035TC, + 3142GG, + 3187AA in CAF were significantly lower than those in normal fetuses. Through genetic models and logistic regression analysis, the dominant model of HLA-G 3’UTR genotypes [such as + 2960 (OR = 1.27, 95% CI = 1.05–1.54, p = 0.016), + 3010 (OR = 0.78, 95% CI = 0.63–0.97, p = 0.026), + 3035 (OR = 1.22, 95% CI = 1.00–1.49, p = 0.047), + 3142 (OR = 0.76, 95% CI = 0.62–0.95, p = 0.014) and + 3187 (OR = 0.80, 95% CI = 0.65–0.99, p = 0.041)] were dramatically associated with CAF. However, the frequencies of HLA-G + 3010GC, + 3142GC and + 3187AG in fetuses with UPL were memorably decreased than those in normal fetuses. No significant difference was found in the frequencies of HLA-G haplotypes in all groups. However, the frequency of UTR-1 positive specimens in CAF was significantly higher than that in UPL and control group. At the same time, the frequency of UTR-1/UTR-3 diplotypes in CAF was observably higher than that in UPL and control group, while the UTR-1/UTR-7 frequency in UPL was signally lower than that in control group. Multivariate logistic regression analysis indicated that positive HLA-G UTR-1 (OR = 1.8, 95% CI = 1.16–2.81, p = 0.009), times of abortion (OR = 1.23, 95% CI = 1.02–1.50, p = 0.035), and times of delivery (OR = 0.31, 95% CI = 0.20–0.48, p < 0.001) were correlated with CAF.ConclusionsThis study suggests that HLA-G 3’UTR polymorphisms and diplotypes play an important role in the process of successful pregnancy of the embryos with abnormal chromosomes after fertilization. At the same time, Different alleles or diplotypes also affect the development of embryos with UPL.

Abstract C008: New insights from a novel mouse model of synovial sarcoma

Abstract Mouse models are the basis of preclinical and translational research in solid tumors. Multiple methods exist to induce tumor formation in mice, including genetically engineered mouse models, chemotoxic agents, injection of tumor cells, and xenograft approaches. Synovial sarcoma, a rare highly malignant soft-tissue tumor, poses a serious threat to patients due to its aggressive nature and associated high rates of mortality and morbidity. This disease's underlying cause and development remain poorly comprehended, and existing treatment approaches have yielded unsatisfactory outcomes. In the last two decades, numerous effective animal models of soft tissue sarcoma (STS) have been created, primarily utilizing genetically engineered mice and zebrafish, however long latency of tumor development for several months in these models creates a barrier for practical in-vivo experiments for drug testing or manipulating the cellular composition of the tumor microenvironment. In studying cancer immunotherapy, it is important to consider aspects of antitumor immune responses and to produce a model that mimics the complexity of the immune system We have generated a new mouse model of synovial sarcoma of exceptionally fast tumor development. Intramuscular delivery of Cre recombinase protein in mice which drives conditional knockdown in PTEN, stabilization of β-catenin, and formation of fusion oncogenes of SS18-SSX2 was sufficient to initiate high-grade synovial sarcomas with myofibroblastic differentiation in 3 weeks. As immunotherapy is increasingly applied to sarcomas, our mouse model will serve as a great tool for preclinical data. Flow cytometry-based analysis of peripheral blood shows significant changes in immune cell populations as early as five days after Tat-Cre injection and continues throughout the development of synovial sarcoma. These results suggest a significant systemic phenotypic alteration of circulating immune cells, which may impact other major organs in this genetic mouse model of synovial sarcoma. Single- cell RNA sequencing of the CD45+ leukocytes in the tumor microenvironment reveals subsets that may promote tumor progression. Our work promises to significantly enhance our understanding of the pathogenesis of this disease and establish a reliable preclinical platform for devising and assessing therapeutic interventions. Citation Format: Hesham Mohei, Donn Van Deren, Irene S. Molina, Malay Haldar. New insights from a novel mouse model of synovial sarcoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C008.

Abstract B018: Multifaceted pro-metastatic role of IL-17 signaling in modulating the tumor microenvironment of colorectal cancer

Abstract Colorectal cancer (CRC) ranks second in mortality and advanced CRCs are resistant to current immunotherapies and prone to metastasis, which necessitates research into enhancing innate and adaptive anti-cancer immune responses. Chronic inflammation mediated by cytokines like IL6 and notably, IL17 activates the oncogenic pathways in cancer cells, promoting sporadic and inflammatory CRC. What is unknown, is the ability of cytokines to control tumor microenvironment (TME) via cell type specific mechanisms to increase cancer progression, metastasis and/or therapy resistance. Increased levels of IL17A in CRC portends poor prognosis indicating its potential involvement into metastasis. However, the role of IL17 signaling in TME in the process of CRC progression and metastasis remains enigmatic. We utilized different models of CRC progression and metastasis, as well as variety of genetic mice models and therapeutic interventions. First, using a model of colitis-associated cancer we found that “late” IL17A neutralization decreases tumor burden, possibly acting through regulation of ferroptosis, NK cells mediated cytotoxicity, as well as myeloid cells and chemokine network essential for the control of immunosuppressive TME. Next, models of CRC metastasis, including those based on MC38 cells and APTAK cancerous organoids, showed that IL17A neutralization reduces metastasis growth. Also, FACS analysis revealed that IL17A promotes the recruitment of tumor- associated macrophages and other key myeloid subsets into the metastatic liver environment. Further research, using mice with conditional knockout of IL17RC receptor in myeloid cells (Il17rc f/f -LysMCre) or hepatocytes (Il17rc f/f -AlbCre) also showed significance of IL17 signaling activation in CRC metastasis through two distinct mechanisms. Employing different techniques, from FACS, immunohistochemistry, to RNAseq and scRNAseq data analysis, we observed that local hepatic activation of IL17RC signaling recruits neutrophils and reduces infiltration of cytotoxic CD8+T and NK cells to the metastatic niche supporting tumor growth, while myeloid IL17RC signaling reshapes TME, including macrophages and neutrophils, enhancing CRC metastasis. Our research indicates that IL17 signaling plays a multifaceted pathogenic role in CRC progression by operating in at least several cell types, providing new insights into the basic biology of CRC metastasis and potentially illuminating the design and improvement of CRC treatment strategies. Citation Format: Katarzyna Chojnacka, Katrina Mae Reyes, Hana Tomizawa, Sergei Grivennikov. Multifaceted pro-metastatic role of IL-17 signaling in modulating the tumor microenvironment of colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B018.

Abstract PR015: Sepsis-induced inflammation alters natural killer cell-mediated surveillance of liver metastasis

Abstract A majority of pancreatic ductal adenocarcinoma (PDAC) patients who undergo surgery for primary tumor resection will develop lethal metastases, despite having no evidence of metastasis at the time of their initial diagnosis. Liver metastases constitute nearly half of recurrences detected within the first six months following PDAC resection. Several clinical and experimental studies provide evidence that perioperative inflammation, including infectious complications like sepsis, positively correlates with liver metastasis across several malignancies. Despite these observations, it is still unknown whether there is a causal link between perioperative inflammation and PDAC liver metastasis. To gain mechanistic insight into the regulation of PDAC liver metastasis in the context of perioperative inflammation, we established mouse models that combine experimental PDAC liver metastasis with either the cecal ligation and puncture (CLP) model of polymicrobial sepsis or the lipopolysaccharide (LPS) model of acute sterile endotoxemia. Mice challenged with CLP prior to seeding PDAC cells in the liver had increased metastatic burden at endpoint compared to sham laparotomy controls. In contrast, mice challenged with LPS prior to PDAC cell seeding had reduced metastatic burden at endpoint compared to PBS-injected controls. We hypothesized that these opposing pro- and anti-metastatic effects of CLP and LPS, respectively, were due to qualitatively distinct inflammatory responses elicited in the liver. Our profiling of the host response to either CLP or LPS revealed shared systemic changes, including activation of the acute-phase protein response. However, LPS-associated inflammation uniquely upregulated a distinct set of interferon-regulated genes in the liver important for modifying immune cell activity (i.e., Ccl2, Ccl5, Cxcl9, Cxcl10). Accordingly, immunostaining and flow cytometry of the liver revealed that LPS uniquely increased the abundance of activated natural killer (NK) cells and MPO+ myeloid cells. We utilized Tlr4 -/- mice, which lack the primary receptor for LPS, to determine that the anti-metastatic effect of LPS required a host-facilitated response downstream of TLR4-mediated signaling. Through a series of genetic models and short-term depletion experiments, we determined that NK cells restrict PDAC cell seeding and outgrowth in our experimental liver metastasis model, and that this protective effect is further enhanced by activation of type-I interferon signaling in the host. Our findings confirm prior work identifying NK cell-mediated surveillance of disseminated cancer cells as an important mechanism in protecting against liver metastasis and show sterile endotoxemia and its associated inflammation establish a protective ‘anti-metastatic niche’ marked by enhanced NK cell activity. Further insights into the establishment of this niche may reveal potential therapeutic strategies to reduce the incidence of liver metastasis among resected PDAC patients. Citation Format: Nicole Sivetz, Patrick J. Cunniff, Christopher R. Vakoc, Semir Beyaz, Mikala Egeblad. Sepsis-induced inflammation alters natural killer cell-mediated surveillance of liver metastasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr PR015.

Clinical and Genetic Markers of Vascular Toxicity in Glioblastoma Patients: Insights from NRG Oncology RTOG-0825.

Glioblastoma (GBM) is an aggressive form of brain cancer in which treatment is associated with toxicities that can result in therapy discontinuation or death. This analysis investigated clinical and genetic markers of vascular toxicities in GBM patients during active treatment. 591 Non-Hispanic White GBM patients with clinical data were included in the analysis from NRG RTOG-0825. Genome-wide association studies (GWAS) were performed from genotyped blood samples (N=367) by occurrence of thrombosis or hypertension (grade ≥2). A clinical prediction model was produced for each vascular toxicity. Significant GWAS variants were then added to the clinical model as a single nucleotide polymorphism (SNP) -dose effect variable to produce the final genetic models. Thrombosis and hypertension were experienced by 62 (11%) and 59 (10%) patients, respectively. Patients who experienced hypertension displayed improved survival over those without hypertension (median overall survival: 25.72 vs 15.47 months, p=0.002). The genetic model of thrombosis included corticosteroid use (OR: 7.13, p=0.02), absolute neutrophil count (OR: 1.008, p=0.19), body surface area (OR: 18.87, p=0.0008), and the SNP-dose effect (3 variants; OR: 3.79, p<.0001). The genetic model of hypertension included bevacizumab use (OR: 0.97, p=0.95) and the SNP-dose effect (6 variants; OR: 4.44, p<.0001). In this study, germline variants were superior in predicting hypertension than clinical variables alone. Additionally, corticosteroid use was a considerable risk factor for thrombosis. Future investigations should confirm the hazard of corticosteroid use on thrombosis and the impact of bevacizumab in other malignancies after accounting for the genetic risk of hypertension.

Large deformation simulation of uprooting of trees with complex root system architectures using material point method with embedded truss elements

Abstract Background and aims Urban trees in coastal cities like Hong Kong may suffer from an uprooting failure when subjected to extreme winds. A proper numerical model for tree uprooting simulation can help to select tree species or soil types that better resist uprooting failure. However, modeling tree uprooting is challenging as it is a cross-disciplinary problem involving complex root system architectures (RSAs) and large deformation of both roots and soils. This study aims to develop a hybrid numerical model that combines truss elements and material point method (MPM) to simulate the entire large-deformation uprooting process of trees with complex RSAs. Methods The tree uprooting model is developed by coupling truss elements in finite element method (FEM) with MPM. Laboratory pull-out tests using artificial roots and real root cuttings are adopted to validate the developed model. A comparative study is performed to investigate the difference between using complex and simplified RSAs in tree uprooting simulations. Results The developed model provides consistent predictions of peak load, critical displacement and failure mode when compared with results from laboratory tests. Moreover, the comparative study shows that the uprooting resistance obtained with a complex RSA is higher than that with a simplified RSA. The difference varies with the soil and root mechanical properties. Conclusion The developed hybrid model offers a novel way for simulating an entire tree uprooting process involving large deformations and complex RSAs. The study shows that using a simplified RSA to approximate the complex RSA might result in misleading failure modes.