Therapeutic Target Research Articles

Elafibranor alleviates alcohol-related liver fibrosis by restoring intestinal barrier function

We discuss the article by Koizumi et al published in the World Journal of Gastroenterology . Our focus is on the therapeutic targets for fibrosis associated with alcohol-related liver disease (ALD) and the mechanism of action of elafibranor (EFN), a dual agonist of peroxisome proliferator-activated receptor α (PPARα) and peroxisome PPAR δ (PPARδ). EFN is currently in phase III clinical trials for the treatment of metabolic dysfunction-associated fatty liver disease and primary biliary cholangitis. ALD progresses from alcoholic fatty liver to alcoholic steatohepatitis (ASH), with chronic ASH eventually leading to fibrosis, cirrhosis, and, in some cases, hepatocellular carcinoma. The pathogenesis of ALD is driven by hepatic steatosis, oxidative stress, and acetaldehyde toxicity. Alcohol consumption disrupts lipid metabolism by inactivating PPARα, exacerbating the progression of ALD. EFN primarily activates PPARα, promoting lipolysis and β-oxidation in ethanol-stimulated HepG2 cells, which significantly reduces hepatic steatosis, apoptosis, and fibrosis in an ALD mouse model. Additionally, alcohol disrupts the gut-liver axis at several interconnected levels, contributing to a proinflammatory environment in the liver. EFN helps alleviate intestinal hyperpermeability by restoring tight junction protein expression and autophagy, inhibiting apoptosis and inflammatory responses, and enhancing intestinal barrier function through PPARδ activation.

Repetitive transcranial magnetic stimulation enhanced by neuronavigation in the treatment of depressive disorder and schizophrenia

This editorial assesses the advancements in neuronavigation enhanced repetitive transcranial magnetic stimulation for depressive disorder and schizophrenia treatment. Conventional repetitive transcranial magnetic stimulation faces challenges due to the intricacies of brain anatomy and patient variability. Neuronavigation offers innovative solutions by integrating neuroimaging with three-dimensional localization to pinpoint brain regions and refine therapeutic targeting. This systematic review of recent literature underscores the enhanced efficacy of neuronavigation in improving treatment outcomes for these disorders. This editorial highlights the pivotal role of neuronavigation in advancing psychiatric care.

Review of Thymic Peptides and Hormones: From Their Properties to Clinical Application

Abstract Background The thymus is the main lymphoid organ that regulates the functions of the immune system, protecting against pathogens, tumors, antigens, and mediators of tissue damage. It produces a family of hormone-like peptides that can modulate physiological processes such as stimulation or suppression of immune responses, angiogenesis, and wound healing. Objective This review aims to comprehensively characterize the properties of thymic peptides and their clinical applications. Methodology This article discusses the structure, biological properties, mechanism of action, and therapeutic applications of the most important thymic hormones (thymosin alpha 1, thymosin beta-4, thymulin, and thymopoietin), as well as preparations that are purified thymic extracts. Results Thymic peptides and extracts act in multiple manners on the immune system: they stimulate the differentiation and maturation of T cells, regulate the activity of natural killer cells and dendritic cells, and induce the release of proinflammatory cytokines, and their immunomodulatory effects have been confirmed in numerous clinical studies. An important feature of thymus preparations is their therapeutic safety—even long-term use does not cause side effects. Conclusions A wide range of therapeutic uses, i.e., from defensive and immunomodulatory tasks to participation in tissue regeneration processes, has led to the use of thymic peptides in the treatment of neoplastic diseases, viral infections, autoimmune diseases or immunodeficiencies. Further investigation of the mechanisms of action of thymic peptides may contribute to the discovery of new therapeutic targets.

Thrombospondin 1 Mediates Autophagy Upon Inhibition of the Rho-Associated Protein Kinase Inhibitor

Age-related macular degeneration (AMD) is a degenerative eye disease leading to central vision loss and is characterized by dysregulated autophagy of the retinal pigment epithelium (RPE) layer. Recent studies have suggested that rho-associated protein kinase (ROCK) inhibitors may enhance autophagy in neurodegenerative diseases and promote the survival of RPE cells. This study investigated the effect of ROCK inhibitors on autophagy gene expression and autophagic vacuole formation in a human RPE (ARPE-19) cell line. The highly selective and potent ROCK inhibitor Y-39983 enhanced the expression of autophagy genes in ARPE-19 cells and increased autophagic vacuole formation. A proteomic analysis using mass spectrometry was performed to further characterize the effects of ROCK inhibition at the protein level. Y-39983 downregulated thrombospondin-1 (THBS1), and suppression of THBS1 in ARPE-19 cells resulted in an increase in autophagic vacuole formation. Our data showed that ROCK inhibitor-induced autophagy was mediated by THBS1 downregulation. We identified ROCK and THBS1 as potential novel therapeutic targets in AMD.

Epigenetic Alterations in Post-Traumatic Stress Disorder: Comprehensive Review of Molecular Markers

Background: Post-traumatic stress disorder (PTSD) can occur after a traumatic event. PTSD is characterized by nightmares, flashbacks and avoidance of stressors. It currently affects 2–8% of the population, with military personnel particularly susceptible. Studies show that environmental stressors can induce various epigenetic changes that shape the PTSD phenotype. Despite the significant impact of epigenetic factors on PTSD symptoms and susceptibility, they have not been widely discussed in the literature. This review focuses on describing epigenetic mechanisms in PTSD, especially DNA methylation, chromatin regulation, and noncoding RNA. Summary: The article includes relevant studies published from 2013 to 2023, excluding non-English-language studies or studies with insufficient data. This review investigated gene methylation changes in association with PTSD, including those related to the hypothalamic-pituitary-adrenal axis, brain-derived neurotrophic factor, neurotransmitters, and immune system functioning, as well as the role of histones and regulatory noncoding RNAs. Key Messages: Epigenetic alterations play a crucial role in shaping PTSD susceptibility, symptomatology, and long-term outcomes, highlighting their potential as important markers and therapeutic targets. Understanding these alterations can aid in developing clinical strategies to better predict, prevent, and treat PTSD. However, further large-scale longitudinal studies are needed to establish the temporal relationship between epigenetic changes and the onset of PTSD, as well as to classify other potential epigenetic mechanisms.

Human umbilical cord mesenchymal stem cells small extracellular vesicles-derived miR-370-3p inhibits cervical precancerous lesions by targeting DHCR24

Abstract Background Cervical cancer is often caused by persistent high-risk human papillomavirus (HPV) infection, causing precancerous lesions. Human umbilical cord mesenchymal stem cells-derived small extracellular vesicles (hucMSC-sEV) exhibit diverse effects on tumors. This study investigates hucMSC-sEV, the impact and mechanisms on HPV-positive cervical precancerous lesion cells to provide new treatment insights. Materials and Methods We previously obtained hucMSC and hucMSC-sEV. In vitro experiments evaluated hucMSC-sEV effects on the proliferation and migration of S12 cells (derived from cervical precancerous lesions). Bioinformatics identified key microRNA components, and their impact on S12 cell proliferation and migration was investigated. The target gene of the microRNA component was predicted and confirmed via bioinformatics and dual-luciferase reporter assays. Lentiviral systems overexpressed target gene in S12 cells to examine the effects on microRNA impacts. SH-42 inhibitor was used to investigate target gene treatment potential. Immunohistochemistry assessed target gene expression in cervical precancerous lesions tissue. Results hucMSC-sEV significantly inhibited S12 cell proliferation and migration. Bioinformatics identified miR-370-3p as an effective cargo, which also suppressed S12 cell proliferation and migration. miR-370-3p was confirmed targeting DHCR24 (24-Dehydrocholesterol Reductase). DHCR24 overexpression reversed miR-370-3p’s inhibitory effects, while SH-42 counteracted DHCR24 overexpression’s promoting effects. Clinical specimen analysis supported these findings, demonstrating a positive correlation between DHCR24 protein expression and cervical precancerous lesions’ progression. Conclusions hucMSC-sEV inhibits S12 cell proliferation and migration, mediated by miR-370-3p targeting DHCR24 to regulate cellular cholesterol content. DHCR24 inhibition reduces the cholesterol level and cell functions, suggesting its potential as a therapeutic target in cervical precancerous lesions.

C-C motif chemokine receptor-2 blockade ameliorates pulmonary hypertension in rats and synergizes with a pulmonary vasodilator

Abstract Aims We investigated whether the disruption of C-C motif chemokine receptor (CCR) 2 may attenuate the development of pulmonary arterial hypertension (PAH) in any rat models with the reversal of the associated pro-inflammatory state and vascular dysfunction, and synergize with a conventional pulmonary vasodilator. Methods and Results Using Ccr2(-/-) rats generated by CRISPR/Cas9, we investigated pulmonary hypertension (PH) in Ccr2(+/+) or Ccr2(-/-) rats treated with monocrotaline (MCT), SU5416/hypoxia (SuHx) and chronic hypoxia (CH). Ccr2(-/-) decreased the right ventricular systolic pressure, an index of right ventricular hypertrophy and mortality rate, and reversed increased expression of inflammatory cytokines/chemokines (interleukin-6, tumor necrosis factor-α, C-C motif chemokine receptor (CCL)-2, interleukin-1β, transforming growth factor-β) in rats 3weeks after MCT injection, but not in SuHx or CH models. Consistently, Ccr2(-/-) decreased indices of pulmonary vascular diseases (PVD) and perivascular macrophage infiltration, as well as reversed impaired bone morphogenetic protein receptor type 2 signaling, increased endothelial apoptosis and impaired nitric oxide signaling and decreased phosphodiesterase-5 (PDE5) expression in lungs in MCT-treated rats. Gene expression of receptors for prostaglandin I2 and endothelin was not changed by Ccr2(-/-) in MCT-treated rats. In cultured pulmonary arterial smooth muscle cells (PASMCs), Ccr2(-/-) suppressed CCL2-induced hyperproliferation and dedifferentiation as well as reversed CCL2-induced decrease in PDE5 expression. The whole-genome RNA sequencing analysis identified differentially expressed genes in CCL2-stimulated Ccr2(-/-) PASMCs, which are related to regulation of cellular differentiation and contraction. Based on studies in rats and cultured PASMCs, we investigated whether a PDE5 inhibitor, tadalafil, synergizes with Ccr2(-/-). Tadalafil administration ameliorated PH and PVDs in MCT-treated Ccr2(-/-) rats but not in Ccr2(+/+) rats. Tadalafil further improved survival in MCT-treated Ccr2(-/-) rats. Conclusion The present findings demonstrated that CCR2 disruption ameliorated PAH in MCT-treated rats, which was associated with the reversal of dysregulated inflammatory pathways and vascular dysfunction and synergized with tadalafil. These findings suggest that CCR2 may be a therapeutic target in intractable PAH patients with a certain CCR2-related inflammatory phenotype and refractory to conventional pulmonary vasodilators.

Genetics of C-peptide and Age at Diagnosis in Type 1 Diabetes

Identified genetic loci for C-peptide and age at diagnosis (AAD) in individuals with type 1 diabetes (T1D) explain only a small proportion of their variation. Here, we aimed to perform large metagenome-wide association studies (GWAS) of C-peptide and AAD in T1D; and to identify the HLA allele/haplotypes associated with C-peptide and AAD. 7,252 and 7,923 European individuals with T1D were included in C-peptide and AAD GWAS, respectively. HLA-DQB1*06:02 which is strongly protective against T1D was associated with higher C-peptide. HLA-DQB1*03:02, HLADRB1*03:01 and HLA-A*24:02 which increase T1D risk were independently associated with younger AAD. HLA-DR3-DR4 haplotype combination, the strongest T1D susceptibility factor, was associated with younger AAD. Outside HLA region, rs115673528 on Chr5 (GABRG2) was associated with C-peptide, and an indel, rs111970692, on Chr15 within CTSH, a known T1D locus, was associated with AAD. Genetically predicted CTSH expression, methylation and protein levels were associated with AAD; Mendelian randomization analysis suggested that higher levels of procathepsin H reduce AAD. In conclusion, some HLA allele/haplotypes associated with T1D also contribute to variability of C-peptide and AAD. Outside HLA, T1D loci are generally not associated with C-peptide or AAD. CTSH could be a potential therapeutic target to delay development/progression of type 1 diabetes.

Microglial Lyzl4 Facilitates β‐Amyloid Clearance in Alzheimer's Disease

AbstractAlzheimer's Disease (AD) is a neurodegenerative condition characterized by the accumulation and deposition of amyloid‐β (Aβ) aggregates in the brain. Despite a wealth of research on the toxicity of Aβ and its role in synaptic damage, the mechanisms facilitating Aβ clearance are not yet fully understood. However, microglia, the primary immune cells of the central nervous system, are known to maintain homeostasis through the phagocytic clearance of protein aggregates and cellular debris. In this study, RNA sequencing analysis and live cell functional screens are employed to uncover microglial genetic modifiers related to AD. Lyzl4 is identified, which encodes a c‐type lysozyme‐like enzyme primarily localized to microglial lysosomes, as a gene significantly upregulated in AD microglia with aging and propose that Lyzl4 upregulation acts as a positive regulator of Aβ clearance. Furthermore, it is found that Lyzl4 overexpression boosts Aβ clearance both in vitro and in vivo, underscoring its potential for mitigating Aβ burden. These novel insights position Lyzl4 as a promising therapeutic target for Alzheimer's disease, paving the way for further exploration into potential AD treatments.

Metabolomics reveals soluble epoxide hydrolase as a therapeutic target for high-sucrose diet-mediated gut barrier dysfunction

Highsucrose diet (HSD) was reported as a causative factor for multiorgan injuries. The underlying mechanisms and therapeutic strategies remain largely uncharted. In the present study, by using a metabolomics approach, we identified the soluble epoxide hydrolase (sEH) as a therapeutic target for HSD-mediated gut barrier dysfunction. Specifically, 16-week feeding on an HSD caused gut barrier dysfunction, such as colon inflammation and tight junction impairment in a murine model. A metabolomics analysis of mouse colon tissue showed a decrease in the 5(6)-epoxyeicosatrienoic acid [5(6)-EET] level and an increase in soluble epoxide hydrolase, which is related to HSD-mediated injuries to the gut barrier. The mice treated with a chemical inhibitor of sEH and the mice with genetic intervention by intestinal-specific knockout of the sEH gene significantly attenuated HSD-caused intestinal injuries by reducing HSD-mediated colon inflammation and improving the impaired tight junction caused by an HSD. Further, in vitro studies showed that treatment with 5(6)-EET, but not its hydrolytic product 5,6-dihydroxyeicosatrienoic acid (5,6-DiHET), significantly ablated high sucrose-caused intestinal epithelial inflammation and impaired tight junction. Additionally, 5(6)-EET is anti-inflammatory and improves gut epithelial tight junction while 5,6-DiHET cannot do so. This study presents an underlying mechanism of and a therapeutic strategy for the gut barrier dysfunction caused by an HSD.

Advances in the Regulation of Periostin for Osteoarthritic Cartilage Repair Applications

Emerging evidence indicates periostin (POSTN) is upregulated in patients with OA, and studies have shown that it can induce the activation of inflammatory cytokines and catabolic enzymes, making it a potential therapeutic target. Link N (LN) is a peptide fragment derived from the link protein and has been demonstrated as an anabolic-like factor and anti-catabolic and anti-inflammatory factors both in vitro and in vivo. This study aims to determine if LN can regulate POSTN expression and function in OA cartilage. Articular cartilage was recovered from donors undergoing total knee replacements to isolate chondrocytes and prepare osteochondral explants. Cells and explants were treated with POSTN and LN (1 and 100 μg) and measured for changes in POSTN expression and various matrix proteins, catabolic and proinflammatory factors, and signaling. To determine the effects of POSTN expression in vivo, a rabbit OA model was used. Immunoprecipitation and in silico modeling were used to determine peptide/POSTN interactions. Western blotting, PCR, and immunohistochemistry demonstrated that LN decreased POSTN expression both in vitro and in vivo. LN was also able to directly inhibit POSTN signaling in OA chondrocytes. In silico docking suggested the direct interaction of LN with POSTN at residues responsible for its oligomerization. Immunoprecipitation experiments confirmed the direct interaction of LN with POSTN and the destabilization of its oligomerization. This study demonstrates the ability of a peptide, LN, to suppress the overexpression and function of POSTN in OA cartilage.

NOTCH3 promotes malignant progression of bladder cancer by directly regulating SPP1 and activating PI3K/AKT pathway

AbstractThe biological role and precise molecular mechanisms of Notch receptor 3 (NOTCH3) in the malignant progression of bladder cancer (BLCA) remain unclear. In this study, we found that NOTCH3 was significantly upregulated and associated with poor prognosis in BLCA patients. Functional experiments demonstrated that NOTCH3 knockdown inhibited BLCA cell proliferation, migration, invasion and significantly suppressed tumor growth and metastasis in vivo as well. Mechanically, chromatin immunoprecipitation and dual-luciferase reporter assays confirmed that NOTCH3 could promote the transcription of secreted phosphoprotein 1 (SPP1), a potential downstream target gene of NOTCH3, by binding to the CSL elements in the SPP1 promoter. Moreover, we also found that targeting NOTCH3 inhibited BLCA growth and metastasis by suppressing the SPP1-PI3K/AKT axis. Our study highlights the critical role of NOTCH3-SPP1-PI3K/AKT axis in the malignant progression of BLCA, suggesting that NOTCH3 may be a potential therapeutic target for BLCA.

NMI, POLR3G and APIP are the key molecules connecting glaucoma with high intraocular pressure: a clue for early diagnostic biomarker candidates

AIM: To understand the molecular connectivity between the intraocular pressure (IOP) and glaucoma which will provide possible clues for biomarker candidates. METHODS: The current study uncovers the important genes connecting IOP with the core functional modules of glaucoma. An integrated analysis was performed using glaucoma and IOP microarray datasets to screen for differentially expressed genes (DEGs) in both conditions. To the selected DEGs, the protein interaction network was constructed and dissected to determine the core functional clusters of glaucoma. For the clusters, the connectivity of IOP DEGs was determined. Further, enrichment analyses were performed to assess the functional annotation and potential pathways of the crucial clusters. RESULTS: The gene expression analysis of glaucoma and IOP with normal control showed that 408 DEGs (277 glaucoma and 131 IOP genes) were discovered from two GEO datasets. The 290 DEGs of glaucoma were extended to form a network containing 1495 proteins with 9462 edges. Using ClusterONE, the network was dissected to have 12 clusters. Among them, three clusters were linked with three IOP DEGs [N-Myc and STAT Interactor (NMI), POLR3G (RNA Polymerase III Subunit G), and APAF1-interacting protein (APIP)]. In the clusters, ontology analysis revealed that RNA processing and transport, p53 class mediators resulting in cell cycle arrest, cellular response to cytokine stimulus, regulation of phosphorylation, regulation of type I interferon production, DNA deamination, and cellular response to hypoxia were significantly enriched to be implicated in the development of glaucoma. Finally, NMI, POLR3G, and APIP may have roles that were noticed altered in glaucoma and IOP conditions. CONCLUSION: Our findings could help to discover new potential biomarkers, elucidate the underlying pathophysiology, and identify new therapeutic targets for glaucoma.

A dynamical systems model for the total fission rate in Drp1-dependent mitochondrial fission

Mitochondrial hyperfission in response to cellular insult is associated with reduced energy production and programmed cell death. Thus, there is a critical need to understand the molecular mechanisms coordinating and regulating the complex process of mitochondrial fission. We develop a nonlinear dynamical systems model of dynamin related protein one (Drp1)-dependent mitochondrial fission and use it to identify parameters which can regulate the total fission rate (TFR) as a function of time. The TFR defined from a nondimensionalization of the model undergoes a Hopf bifurcation with bifurcation parameter μ = k + M k - where M is the total concentration of mitochondrial fission factor (Mff) and k+ and k− are the association and dissociation rate constants between oligomers on the outer mitochondrial membrane. The variable μ can be thought of as the maximum build rate over the disassembling rate of oligomers. Though the nondimensionalization of the system results in four dimensionless parameters, we found the TFR and the cumulative total fission (TF) depend strongly on only one, μ. Interestingly, the cumulative TF does not monotonically increase as μ increases. Instead it increases with μ to a certain point and then begins to decrease as μ continues to increase. This non-monotone dependence on μ suggests interventions targeting k+, k−, or M may have a non-intuitive impact on the fission mechanism. Thus understanding the impact of regulatory parameters, such as μ, may assist future therapeutic target selection.

Deficiency of FABP7 Triggers Premature Neural Differentiation in Idiopathic Normocephalic Autism Organoids

AbstractAutism spectrum disorder (ASD), which is caused by heterogeneous genetic and environmental factors, is characterized by diverse clinical phenotypes linked to distinct pathological mechanisms. ASD individuals with a shared clinical phenotype might contribute to revealing the molecular mechanism underlying ASD progression. Here, it is generated induced pluripotent stem cell (iPSC)‐derived cerebral organoids from normocephalic individuals with ASD in a prospective birth cohort with a shared clinical diagnosis. Multiple cell lines and time series scRNA‐seq combined with a histomorphological analysis revealed premature neural differentiation of neural stem cells (NSCs) and decreased expression of Fatty acid binding protein 7 (FABP7) in ASD organoids. It is subsequently revealed alterations in the phosphorylation levels of Mitogen‐Activated Protein Kinase Kinase 1/2 (MEK1/2), which are downstream of FABP7, and the regulation of the FABP7/MEK pathway reversed improper neural differentiation in the ASD organoids. Moreover, both Fabp7‐knockdown and MEK2‐overexpressing mice exhibited repetitive stereotyped behaviors and social defects relevant to autism. This study reveals the role of the FABP7/MEK pathway in abnormal NSC differentiation in normocephalic individuals with ASD, which might provide a promising therapeutic target for ASD treatment.

Ascorbate peroxidase modulation confirms key role in Leishmania infantum oxidative defence

Abstract Background Ascorbate peroxidase (APX) has emerged as a promising target for chemotherapy because of its absence in humans and crucial role in the antioxidant defence of trypanosomatids. APXs, which are class I haeme-containing enzymes, reduces hydrogen peroxide using ascorbate to produce water and monodehydroascorbate, thereby preventing cell damage caused by H2O2. Methods We aimed to create an APX-knockout L. infantum line using CRISPR/Cas9. Despite unsuccessful attempts at full knockouts, we achieved deletion of chromosomal copies post-APX episomal insertion, yielding LiΔchrAPX::LbAPX parasites. We performed phenotypic characterization to assess the impact of these genetic modifications, which included the determination of APX transcript expression levels using quantitative PCR, drug sensitivity, infectivity, and parasite survival in macrophages. Results Quantitative polymerase chain reaction (PCR) analysis revealed a 10- to 13-fold reduction in APX transcript expression in LiΔchrAPX::LbAPX compared with wild-type (LiWT) and APX-overexpressing (Li::Cas9::LbAPX) parasites, respectively. The episomes in those knockdown parasites remained stable even after 20 drug-free passages in vitro. Li::Cas9::LbAPX parasites showed increased resistance to trivalent antimony (SbIII) and isoniazid, reduced tolerance to H2O2, and unchanged macrophage infectivity compared with LiWT. In contrast, LiΔchrAPX::LbAPX parasites were more sensitive to SbIII and isoniazid, exhibited greater susceptibility to H2O2-induced oxidative stress, and 72 h post-infection, showed fewer infected macrophages and intracellular amastigotes compared with LiWT parasites. Conclusions Our findings hint at the indispensability of APX in L. infantum and raise the possibility of its potential as a therapeutic target for leishmaniasis. Graphical Abstract

Abstract IA016: Vascular control of metastasis

Abstract The molecular analysis of tumor vessel interactions during tumor progression and metastasis has primarily focused on the study of tumor cell-derived angiogenic and lymphangiogenic signals with the purpose to exploit such factors as therapeutic targets. Angiogenic factors activate endothelial cells in nearby blood and lymphatic capillaries to sprout towards the tumor. Tumor angiogenesis thereby not only nourishes the growing tumor, but access to the blood and lymphatic vasculatures enables cells from the primary tumor to enter the circulation to eventually form metastases at distant sites. The complex cellular interactions between tumor cells and endothelial cells have in this context mostly been studied from a tumor cell-centric perspective, i.e., the tumor cells send signals to which endothelial cells merely respond. Yet, the past decade has witnessed a fundamental change of paradigm with the discovery that the vascular endothelium does not just respond to exogenous cytokines but exerts active ’angiocrine’ gatekeeper roles controlling their microenvironment in an instructive manner. We have applied the concepts of angiocrine signaling towards the study of tumor progression and metastasis. Employing novel surgical preclinical metastasis models that better mimic tumor progression and the response to therapy as it occurs in humans, we have molecularly dissected vascular endothelial cells in progressing primary tumors as well as in the pre-metastatic and metastatic niches. These experiments were on the one hand aimed at establishing the systems map of endothelial transcriptomic changes during tumor progression and metastasis and on the other hand to identify and validate novel therapeutic targets. This presentation will review recent advances in the field of tumor microenvironment research and present novel angiocrine signaling mechanisms as promising targets of future mechanism-driven anti-metastatic therapy. Citation Format: Hellmut G. Augustin. Vascular control of 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 IA016.

ADAMTS16 drives epithelial-mesenchymal transition and metastasis through a feedback loop upon TGF-β1 activation in lung adenocarcinoma

AbstractLung adenocarcinoma (LUAD) is the major subtype of lung cancer. The poor prognosis of LUAD patients is attributed primarily to metastasis. ADAMTS16 is a crucial member of the ADAMTS family and is involved in tumor progression. However, its role and regulatory mechanism in LUAD remain unexplored. In this study, ADAMTS16 was identified as a crucial oncogene and survival predictor in LUAD via analyses of public datasets. Clinical specimens and tissue microarrays confirmed the differential expression and prognostic value of ADAMTS16 in LUAD patients. Transcriptome data and in vitro experiments demonstrated that ADAMTS16 was positively associated with epithelial-mesenchymal transition (EMT) and the migration abilities of LUAD cells. Knockdown of ADAMTS16 attenuated lung and pleural metastasis in an animal model. Mechanistically, the results of the enzyme-linked immunosorbent assay (ELISA) and western blot (WB) suggested that ADAMTS16 activated the TGF-β signaling pathway by facilitating the conversion of LAP-TGF-β1 to active TGF-β1. Co-Immunoprecipitation (co-IP) indicated an interaction between ADAMTS16 and LAP-TGF-β1. Inhibition of ADAMTS16 impaired EMT and aggressiveness of LUAD cells, while treatment with recombinant TGF-β1 reversed this inhibition. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays indicated that SOX4 acted as a transcriptional activator of ADAMTS16 and that TGF-β1 regulated the expression of ADAMTS16 by increasing the binding of SOX4 to the promoter of ADAMTS16. Suppressing the TGF-β signaling pathway inhibited ADAMTS16 expression, EMT, and lung metastasis, whereas overexpressing SOX4 reversed this inhibition. Therefore, ADAMTS16 forms a positive feedback loop with the TGF-β1/SOX4 axis to regulate EMT and metastasis, and disruption of this feedback loop inhibits tumor progression. These findings underscore the potential of ADAMTS16 as a prognostic biomarker and therapeutic target in LUAD and offer novel insight into the mechanism of EMT and metastasis.

Abstract C032: The impact of neoadjuvant endocrine therapy (NET) in ER+ breast cancer tumor microenvironment and metastasis

Abstract Breast cancer is the most common cancer in women worldwide and the second leading cause of death. The Estrogen Receptor positive (ER+) subtype constitutes approximately 80% of the yearly 250,000 breast cancer diagnoses in the US. Anti-estrogen endocrine therapy, administered either pre- or post-operatively, is the cornerstone treatment for all stages of breast cancer. Pre- operative or neoadjuvant endocrine therapy (NET) reduces pre-surgical tumor burden, improves surgical outcome, and provides prognostic information. Although the treatment often has a favorable initial response, about 20% of patients eventually develop resistance and recurrent disease, even decades after the primary diagnosis.We hypothesized that resistance in NET is mediated through pro-metastatic changes in the tumor microenvironment affecting either (i) dissemination machinery or (ii) cancer cell phenotype.The main mode of breast cancer hematogenous dissemination to distant sites is through intravasation portals called Tumor Microenvironment of Metastasis (TMEM) doorways. Each TMEM doorway consists of a tumor cell overexpressing the actin-regulatory protein MENA, a Tie2high/ VEGFAhigh macrophage and an endothelial cell, all in direct contact. TMEM doorway activity leads to vascular opening events, during which tumor cells located in areas around TMEM doorways intravasate and disseminate to secondary sites. Therefore, to investigate the impact of NET on cancer cell dissemination, we evaluated its effect on (i) TMEM doorway score (the number of TMEM doorways per tissue area), (ii) TMEM doorway opening, (iii) the number of circulating tumor cells and (iv) the number of disseminated tumor cells. We used the orthotopic MCF7 breast cancer xenograft model grown in NOD/SCID mice and tested two drugs widely used in NET, Fulvestrant (a Selective Estrogen Receptor Degrader) and Tamoxifen (a Selective Estrogen Receptor Modulator). NET did not affect the TMEM doorway score, TMEM doorway activity, the number of CTCs or the number of DTCs. We are now focused on evaluating the effect of NET on the density of cancer cells which are upregulated in programs of invasion, stemness, and dormancy. This “Triple Threat Phenotype (TTP)” gives tumor cells an enhanced ability to disseminate to and colonize distant organs. To this effect we will stain primary MCF7 tumors from NET and vehicle-treated mice for markers of invasiveness (MENA), stemness (SOX9) and dormancy (NR2F1). Detecting any changes in the phenotype of metastatic tumor cells following NET will help us understand underlying mechanisms of endocrine therapy resistance and may lead to new therapeutic targets and improve patient outcomes. Citation Format: Anastasia Aristoteleia Chondronikola, Dimitra Anastasiadou, Aliona Zintiridou, Camille L. Duran, Nicole Barth, Burcu Karadal-Ferrena, Erika Pereira-Zambalde, Lina Ariyan, Suryansh Shukla, George S. Karagiannis, David Entenberg, John S. Condeelis, Maja H. Oktay. The impact of neoadjuvant endocrine therapy (NET) in ER+ breast cancer tumor microenvironment and 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 C032.

Abstract C027: The role of Liver Receptor Homolog 1 (LRH-1) in regulating cancer progression by modulating the immune response

Abstract Breast cancer is a significant global health concern, being the second most common type of cancer and the second leading cause of cancer-related deaths among women in the U.S. Metastatic breast cancer is responsible for most of these deaths, and current FDA-approved immunotherapies are effective only for a small subset of patients with PD-L1-positive tumors. Thus, there is a critical need for new therapeutic targets to enhance the immune response against breast cancer. Elevated plasma cholesterol concentrations are associated with poor breast cancer outcomes. Our previous studies indicated that myeloid immune cells are highly sensitive to changes in cholesterol levels and other proteins involved in regulating cholesterol homeostasis. However, the role of Liver Receptor Homolog 1 (LRH-1), a key regulator of cholesterol homeostasis, in myeloid cells is not well understood. Notably, higher expression of LRH-1 mRNA in breast tumors is associated with longer time to recurrence and improved overall survival. Therefore, we aimed to investigate the role of LRH-1 in myeloid immune cells and its impact on breast cancer progression. Initial analysis indicated that LRH-1 is expressed in myeloid cells, with particularly high levels observed in neutrophils. Therefore, we examined how LRH-1 regulates neutrophil functions important to cancer biology, including migration, NETosis, and phagocytosis, as well as its influence through neutrophils on T cells. We found that LRH-1 inhibited neutrophil migration toward cancer cells. Since tumor infiltrating neutrophils are generally associated with poor prognosis, LRH-1 reducing neutrophil migration could indicate a decreased ability of these immune-suppressive cells to infiltrate tumors. Importantly, neutrophils treated with an LRH-1 agonist showed reduced NETosis, while antagonist led to increased NETosis. LRH-1 agonist treatment also significantly reduced neutrophil phagocytosis, whereas an antagonist had no notable effect. Furthermore, T cells exhibited increased expansion when co-cultured with neutrophils treated with an LRH-1 agonist, and reduced proliferation with neutrophils pretreated with an LRH-1 antagonist or inverse agonist, particularly in CD4+ helper T cells and later divisions. Since neutrophils were previously implicated in invoking recurrence from dormant lesions, we evaluated LRH-1 in this context. The treatment of mice harboring dormant D2.0R lesions with an LRH-1 inverse agonist resulted in sooner recurrence and metastatic outgrowth compared to vehicle treated mice. In summary, our findings suggest that LRH-1 plays a crucial role in regulating various neutrophil functions, including migration, NETosis, phagocytosis, and T cell expansion. The ultimate consequence of these regulations are control of dormant mammary cancer lesions. These results highlight LRH-1 as a potential therapeutic target for cancer treatment or prevention of metastatic recurrence. Funding: National Cancer Institute (ERN: R01CA234025) Department of Defense (ERN: BCRP Era of Hope Award) Citation Format: Yu Wang, Bryan Duong, Natalia Krawczynska, Shruti V. Bendre, Claire P. Schane, Erin Weisser, Lara Kockaya, Yifan Fei, Anasuya Das Gupta, Hashni E. Vidana Gamage, Adam T. Nelczyk, Dhanya Pradeep, Erik R. Nelson. The role of Liver Receptor Homolog 1 (LRH-1) in regulating cancer progression by modulating the immune response [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 C027.