PET/TC con FAPI: procedimiento y revisión de la evidencia en oncología / PET/CT FAPI: Procedure and evidence review in oncology

Las neoplasias se componen de células malignas tumorales que se encuentran rodeadas de diversos elementos celulares no tumorales, que conforman el microambiente o estroma tumoral. La evidencia sobre la importancia este último no ha parado de crecer en los últimos años ya que desempeña un papel necesario para la proliferación celular, la invasión tisular, la angiogénesis y la migración celular. El paradigma es la familia de los nuevos radiofármacos inhibidores de la proteína de activación de fibroblastos (FAPI) que nos muestran la densidad de dicha proteína (FAP) que se encuentra sobreexpresada en la membrana celular de los fibroblastos activados asociados al cáncer (CAF), y su presencia está relacionada con un mal pronóstico. En este documento de formación continuada se incluye el procedimiento para la realización de la tomografía por emisión de positrones/tomografía computarizada (PET/TC) con FAPI, la biodistribución y las potenciales aplicaciones clínicas en oncología publicadas hasta el momento. (AU)

Neoplasms are composed of malignant tumour cells, which are surrounded by other non-tumour cellular elements, what has been defined as the microenvironment or tumour stroma. Evidence on the importance of the tumour microenvironment has not stopped growing in recent years. It plays a central role for cell proliferation, tissue invasion, angiogenesis and cell migration. The paradigm is the family of new FAPI radiopharmaceuticals that show us the density of the fibroblast activation protein (FAP) that is overexpressed in the cell membrane of activated cancer-associated fibroblasts (CAF), and its presence is related to poor prognosis. The paradigm is the family of new FAPI radiopharmaceuticals, which represents the density of activated fibroblasts associated with cancer. This educational document includes the procedure for performing PET/CT FAPI, biodistribution and the main potentially clinical applications in oncology to date. (AU)

The Correlation between VEGF and CD34 Protein Marker and Pyogenic Granuloma.

BACKGROUND: A typical non-neoplastic connective tissue proliferations called a pyogenic granuloma. A vascular adhesion molecule used to assess angiogenesis is the CD34 marker. The primary memberof a family of growth factors, VEGF helps in generating and maintaining the lymphatic and blood circulation systems. OBJECTIVE: The aim of the study was to know the correlation between VEGF and CD34 protein marker and pyogenic granuloma. METHODS: Thirty-one formalin fixed paraffin embedded (FFPE) blocks were taken from female pyogenic granuloma patients ranging in age from 29 to 70. The IHC was used to identify VEGF and CD34 expression in the cytoplasm of the cells. RESULTS: Seventeenout of 31 patients had VEGF positive expression. Twenty-sixout of 31 had CD34 positive expression and 5 with no expression (negative expression). Brown-stained cytoplasm showed high VEGF and CD34 expression, whereas blue stained cytoplasm showed no VEGF and CD34 expression in these cells. CONCLUSIONS: The results suggest the role of suchbiomarkers in the oral pyogenic granuloma pathogenesis, and it appears that CD34 and VEGF are valuable biomarkers in evaluating vascular and inflammatory diseases like pyogenic granuloma.

USP7 inhibitors suppress tumour neoangiogenesis and promote synergy with immune checkpoint inhibitors by downregulating fibroblast VEGF.

BACKGROUND: Understanding how to modulate the microenvironment of tumors that are resistant to immune checkpoint inhibitors represents a major challenge in oncology.Here we investigate the ability of USP7 inhibitors to reprogram the tumor microenvironment (TME) by inhibiting secretion of vascular endothelial growth factor (VEGF) from fibroblasts. METHODS: To understand the role played by USP7 in the TME, we systematically evaluated the effects of potent, selective USP7 inhibitors on co-cultures comprising components of the TME, using human primary cells. We also evaluated the effects of USP7 inhibition on tumor growth inhibition in syngeneic models when dosed in combination with immune checkpoint inhibitors (ICIs). RESULTS: Abrogation of VEGF secretion from fibroblasts in response to USP7 inhibition resulted in inhibition of tumor neoangiogenesis and increased tumor recruitment of CD8-positive T-lymphocytes, leading to significantly improved sensitivity to immune checkpoint inhibitors. In syngeneic models, treatment with USP7 inhibitors led to striking tumor responses resulting in significantly improved survival. CONCLUSIONS: USP7-mediated reprograming of the TME is not linked to its previously characterized role in modulating MDM2 but does require p53 and UHRF1 in addition to the well-characterized VEGF transcription factor, HIF-1α. This represents a function of USP7 that is unique to fibroblasts, and which is not observed in cancer cells or other components of the TME. Given the potential for USP7 inhibitors to transform "immune desert" tumors into "immune responsive" tumors, this paves the way for a novel therapeutic strategy combining USP7 inhibitors with immune checkpoint inhibitors (ICIs).

Transmembrane Protein TMEM230, Regulator of Glial Cell Vascular Mimicry and Endothelial Cell Angiogenesis in High-Grade Heterogeneous Infiltrating Gliomas and Glioblastoma.

High-grade gliomas (HGGs) and glioblastoma multiforme (GBM) are characterized by a heterogeneous and aggressive population of tissue-infiltrating cells that promote both destructive tissue remodeling and aberrant vascularization of the brain. The formation of defective and permeable blood vessels and microchannels and destructive tissue remodeling prevent efficient vascular delivery of pharmacological agents to tumor cells and are the significant reason why therapeutic chemotherapy and immunotherapy intervention are primarily ineffective. Vessel-forming endothelial cells and microchannel-forming glial cells that recapitulate vascular mimicry have both infiltration and destructive remodeling tissue capacities. The transmembrane protein TMEM230 (C20orf30) is a master regulator of infiltration, sprouting of endothelial cells, and microchannel formation of glial and phagocytic cells. A high level of TMEM230 expression was identified in patients with HGG, GBM, and U87-MG cells. In this study, we identified candidate genes and molecular pathways that support that aberrantly elevated levels of TMEM230 play an important role in regulating genes associated with the initial stages of cell infiltration and blood vessel and microchannel (also referred to as tumor microtubule) formation in the progression from low-grade to high-grade gliomas. As TMEM230 regulates infiltration, vascularization, and tissue destruction capacities of diverse cell types in the brain, TMEM230 is a promising cancer target for heterogeneous HGG tumors.

Peritumor Mucosa in Advanced Laryngeal Carcinoma Exhibits an Aberrant Proangiogenic Signature Distinctive from the Expression Pattern in Adjacent Tumor Tissue.

The field cancerization theory is an important paradigm in head and neck carcinoma as its oncological repercussions affect treatment outcomes in diverse ways. The aim of this study is to assess the possible interconnection between peritumor mucosa and the process of tumor neoangiogenesis. Sixty patients with advanced laryngeal carcinoma were enrolled in this study. The majority of patients express a canonical HIF-upregulated proangiogenic signature with almost complete predominancy of HIF-1α overexpression and normal expression levels of the HIF-2α isoform. Remarkably, more than 60% of the whole cohort also exhibited an HIF-upregulated proangiogenic signature in the peritumoral benign mucosa. Additionally, the latter subgroup had a distinctly shifted phenotype towards HIF-2α upregulation compared to the one in tumor tissue, i.e., a tendency towards an HIF switch is observed in contrast to the dominated by HIF-1α tumor phenotype. ETS-1 displays stable and identical significant overexpression in both the proangiogenic phenotypes present in tumor and peritumoral mucosa. In the current study, we report for the first time the existence of an abnormal proangiogenic expression profile present in the peritumoral mucosa in advanced laryngeal carcinoma when compared to paired distant laryngeal mucosa. Moreover, we describe a specific phenotype of this proangiogenic signature that is significantly different from the one present in tumor tissue as we delineate both phenotypes, quantitively and qualitatively. This finding is cancer heterogeneity, per se, which extends beyond the "classical" borders of the malignancy, and it is proof of a strong interconnection between field cancerization and one of the classical hallmarks of cancer-the process of tumor neoangiogenesis.

DPY19L3 promotes vasculogenic mimicry by its C-mannosyltransferase activity.

C-mannosylation is a post-translational modification that occurs intracellularly in the endoplasmic reticulum. In humans, biosynthesis of C-mannosylation in proteins containing thrombospondin type 1 repeat is catalyzed by the DPY19 family; nonetheless, biological functions of protein C-mannosylation are not yet fully understood, especially in tumor progression. Vasculogenic mimicry (VM) is the formation of fluid-conducting channels by highly invasive and genetically deregulated tumor cells, enabling the tumors to form matrix-embedded vasculogenic structures, containing plasma and blood cells to meet the metabolic demands of rapidly growing tumors. In this study, we focused on DPY19L3, a C-mannosyltransferase, and aimed to unravel its role in VM. Knockout of DPY19L3 inhibited the formation of VM in HT1080 human fibrosarcoma cells. Re-expression of wild-type DPY19L3 recovered VM formation; however, DPY19L3 isoform2, an enzymatic activity-defect mutant, did not restore it, suggesting that the C-mannosyltransferase activity of DPY19L3 is crucial to its function. Furthermore, the knockdown of DPY19L3 in MDA-MB-231 breast cancer cells hindered its network formation ability. Altogether, our findings suggest that DPY19L3 is required for VM formation and stipulate the relevance of C-mannosylation in oncogenesis.

Distinct Pathways of Macular Atrophy in Type 3 Macular Neovascularization Associated With AMD.

Purpose: To explore the occurrence of macular atrophy (MA) in eyes with age-related macular degeneration (AMD)-associated Type 3 macular neovascularization (MNV) treated with anti-vascular endothelial growth factor (anti-VEGF) therapy. Importantly, we aimed at describing the existence of separate pathways leading to MA. Methods: We analyzed 41 participants (41 eyes) with treatment-naïve Type 3 MNV who were followed up for a duration of 12 months after beginning the anti-VEGF therapy. At the one-year follow-up visit, optical coherence tomography (OCT) scans were reviewed for the presence of MA. MA regions of interest (ROIs) were selected and traced back to their original dominant baseline lesion (i.e., precursor) through previous serially captured OCT scans. Baseline lesions included precursors associated with the development and exudation of MNV and causes external to the neovascularization itself. Results: At the one-year follow-up visit, MA was graded to be present in 38 (92.7%) out of 41 eyes. These 78 MA ROIs were divided into two subgroups according to the precursor lesion, yielding a group of 53 MA lesions with precursors associated with the development and exudation of MNV (i.e., MA caused by physical harm from Type 3 neovessels, collapse of a serous pigment epithelium detachment, and fibrosis) and 25 MA regions with precursors external to the neovascularization itself (i.e., MA caused by drusen or subretinal drusenoid deposits). Conclusions: Eyes with Type 3 MNV are commonly complicated by MA and precursors of MA include causes associated with the development and exudation of MNV, as well as lesions unrelated to the neovascularization process itself.

BAP31 Promotes Angiogenesis via Galectin-3 Upregulation in Neuroblastoma.

Neuroblastoma (NB) is one of the highly vascularized childhood solid tumors, and understanding the molecular mechanisms underlying angiogenesis in NB is crucial for developing effective therapeutic strategies. B-cell receptor-associated protein 31 (BAP31) has been implicated in tumor progression, but its role in angiogenesis remains unexplored. This study investigated BAP31 modulation of pro-angiogenic factors in SH-SY5Y NB cells. Through protein overexpression, knockdown, antibody blocking, and quantification experiments, we demonstrated that overexpression of BAP31 led to increased levels of vascular endothelial growth factor A (VEGFA) and Galectin-3 (GAL-3), which are known to promote angiogenesis. Conditioned medium derived from BAP31-overexpressing neuroblastoma cells stimulated migration and tube formation in endothelial cells, indicating its pro-angiogenic properties. Also, we demonstrated that BAP31 enhances capillary tube formation by regulating hypoxia-inducible factor 1 alpha (HIF-1α) and its downstream target, GAL-3. Furthermore, GAL-3 downstream proteins, Jagged 1 and VEGF receptor 2 (VEGFR2), were up-regulated, and blocking GAL-3 partially inhibited the BAP31-induced tube formation. These findings suggest that BAP31 promotes angiogenesis in NB by modulating GAL-3 and VEGF signaling, thereby shaping the tumor microenvironment. This study provides novel insights into the pro-angiogenic role of BAP31 in NB.

Early Unguided Human Brain Organoid Neurovascular Niche Modeling into the Permissive Chick Embryo Chorioallantoic Membrane.

Engrafting organoids into vascularized tissues in model animals, such as the immunodeficient mouse or chick embryo chorioallantoic membrane (CAM), has proven efficient for neovascularization modeling. The CAM is a richly vascularized extraembryonic membrane, which shows limited immunoreactivity, thus becoming an excellent hosting model for human origin cell transplants. This paper describes the strategy to engraft human brain organoids differentiated at multiple maturation stages into the CAM. The cellular composition of brain organoids changes with time, reflecting the milestones of human brain development. We grafted brain organoids at relevant maturation stages: neuroepithelial expansion (18 DIV), early neurogenesis (60 DIV), and early gliogenesis (180 DIV) into the CAM of embryonic day (E)7 chicken embryos. Engrafted brain organoids were harvested 5 days later and their histological features were analyzed. No histological signs of neovascularization in the grafted organoids or abnormal blood vessels adjacent to the graftings were detected. Moreover, remarkable changes were observed in the cellular composition of the grafted organoids, namely, an increase in the number of glial fibrillary acidic protein-positive-reactive astrocytes. However, the cytoarchitectural changes were dependent on the organoid maturation stage. Altogether, these results suggest that brain organoids can grow in the CAM, and they show differences in the cytoarchitecture depending on their maturation stage at grafting.

Molecular Basis of Angiogenesis and its Application.

Angiogenesis, the development of new blood vessels, is a fundamental physiological process. In addition, angiogenesis plays a key role in the pathogenesis of several disorders, including cancer and eye disorders such as diabetic retinopathy and age-related macular degeneration (AMD). However, identifying the regulators of angiogenesis proved challenging. Numerous factors that stimulated angiogenesis in various bioassays were identified, but their pathophysiological role remained unclear. In 1989, we reported the isolation and cloning of vascular endothelial growth factor (VEGF, VEGF-A) as an endothelial cell-specific mitogen and angiogenic factor. The tyrosine kinases Flt-1 (VEGFR-1) and KDR (VEGFR-2) were subsequently identified as VEGF receptors. Loss of a single vegfa allele results in defective vascularization and embryonic lethality in mice, emphasizing the essential role of VEGF in the development of blood vessels. Subsequently, we reported that anti-VEGF monoclonal antibodies block growth and neovascularization in tumor models. These findings paved the way for the clinical development of a humanized anti-VEGF antibody and other VEGF inhibitors for cancer therapy. To date, several VEGF inhibitors represent standard of care for colorectal cancer and other difficult to treat malignancies. VEGF is also implicated in intraocular neovascularization associated with retinal disorders as well as neovascular AMD. Our group developed a humanized anti-VEGF-A antibody fragment (ranibizumab) for the treatment of wet AMD. Ranibizumab not only maintained but also improved visual acuity and has been approved worldwide for the treatment of wet AMD and other neovascular disorders. Other VEGF inhibitors, including bevacizumab and aflibercept, have also resulted in significant clinical benefits. Today anti-VEGF drugs represent the most effective therapy for intraocular neovascularization. Current research addresses the need to reduce the frequency of intravitreal injections as well the identification of additional pro-angiogenic pathways that could result in improving therapeutic outcomes.

Group XIV C-type lectins: emerging targets in tumor angiogenesis.

C-type lectins, distinguished by a C-type lectin binding domain (CTLD), are an evolutionarily conserved superfamily of glycoproteins that are implicated in a broad range of physiologic processes. The group XIV subfamily of CTLDs are comprised of CD93, CD248/endosialin, CLEC14a, and thrombomodulin/CD141, and have important roles in creating and maintaining blood vessels, organizing extracellular matrix, and balancing pro- and anti-coagulative processes. As such, dysregulation in the expression and downstream signaling pathways of these proteins often lead to clinically relevant pathology. Recently, group XIV CTLDs have been shown to play significant roles in cancer progression, namely tumor angiogenesis and metastatic dissemination. Interest in therapeutically targeting tumor vasculature is increasing and the search for novel angiogenic targets is ongoing. Group XIV CTLDs have emerged as key moderators of tumor angiogenesis and metastasis, thus offering substantial therapeutic promise for the clinic. Herein, we review our current knowledge of group XIV CTLDs, discuss each's role in malignancy and associated potential therapeutic avenues, briefly discuss group XIV CTLDs in the context of two other relevant lectin families, and offer future direction in further elucidating mechanisms by which these proteins function and facilitate tumor growth.

CD93 maintains endothelial barrier function and limits metastatic dissemination.

Compromised vascular integrity facilitates extravasation of cancer cells and promotes metastatic dissemination. CD93 has emerged as a target for antiangiogenic therapy, but its importance for vascular integrity in metastatic cancers has not been evaluated. Here, we demonstrate that CD93 participates in maintaining the endothelial barrier and reducing metastatic dissemination. Primary melanoma growth was hampered in CD93-/- mice, but metastatic dissemination was increased and associated with disruption of adherens and tight junctions in tumor endothelial cells and elevated expression of matrix metalloprotease 9 at the metastatic site. CD93 directly interacted with vascular endothelial growth factor receptor 2 (VEGFR2) and its absence led to VEGF-induced hyperphosphorylation of VEGFR2 in endothelial cells. Antagonistic anti-VEGFR2 antibody therapy rescued endothelial barrier function and reduced the metastatic burden in CD93-/- mice to wild-type levels. These findings reveal a key role of CD93 in maintaining vascular integrity, which has implications for pathological angiogenesis and endothelial barrier function in metastatic cancer.

Endothelial cells in tumor microenvironment: insights and perspectives.

The tumor microenvironment is a highly complex and dynamic mixture of cell types, including tumor, immune and endothelial cells (ECs), soluble factors (cytokines, chemokines, and growth factors), blood vessels and extracellular matrix. Within this complex network, ECs are not only relevant for controlling blood fluidity and permeability, and orchestrating tumor angiogenesis but also for regulating the antitumor immune response. Lining the luminal side of vessels, ECs check the passage of molecules into the tumor compartment, regulate cellular transmigration, and interact with both circulating pathogens and innate and adaptive immune cells. Thus, they represent a first-line defense system that participates in immune responses. Tumor-associated ECs are involved in T cell priming, activation, and proliferation by acting as semi-professional antigen presenting cells. Thus, targeting ECs may assist in improving antitumor immune cell functions. Moreover, tumor-associated ECs contribute to the development at the tumor site of tertiary lymphoid structures, which have recently been associated with enhanced response to immune checkpoint inhibitors (ICI). When compared to normal ECs, tumor-associated ECs are abnormal in terms of phenotype, genetic expression profile, and functions. They are characterized by high proliferative potential and the ability to activate immunosuppressive mechanisms that support tumor progression and metastatic dissemination. A complete phenotypic and functional characterization of tumor-associated ECs could be helpful to clarify their complex role within the tumor microenvironment and to identify EC specific drug targets to improve cancer therapy. The emerging therapeutic strategies based on the combination of anti-angiogenic treatments with immunotherapy strategies, including ICI, CAR T cells and bispecific antibodies aim to impact both ECs and immune cells to block angiogenesis and at the same time to increase recruitment and activation of effector cells within the tumor.

Emodin suppresses alkali burn-induced corneal inflammation and neovascularization by the vascular endothelial growth factor receptor 2 signaling pathway.

OBJECTIVE: To investigate the effects of emodin on alkali burn-induced corneal inflammation and neovascularization. METHODS: The ability of emodin to target vascular endothelial growth factor receptor 2 (VEGFR2) was predicted by molecular docking. The effects of emodin on the invasion, migration, and proliferation of human umbilical vein endothelial cells (HUVEC) were determined by cell counting kit-8, Transwell, and tube formation assays. Analysis of apoptosis was performed by flow cytometry. CD31 levels were examined by immunofluorescence. The abundance and phosphorylation state of VEGFR2, protein kinase B (Akt), signal transducer and activator of transcription 3 (STAT3), and P38 were examined by immunoblot analysis. Corneal alkali burn was performed on 40 mice. Animals were divided randomly into two groups, and the alkali-burned eyes were then treated with drops of either 10 µM emodin or phosphate buffered saline (PBS) four times a day. Slit-lamp microscopy was used to evaluate inflammation and corneal neovascularization (CNV) in all eyes on Days 0, 7, 10, and 14. The mice were killed humanely 14 d after the alkali burn, and their corneas were removed and preserved at －80 ℃ until histological study or protein extraction. RESULTS: Molecular docking confirmed that emodin was able to target VEGFR2. The findings revealed that emodin decreased the invasion, migration, angiogenesis, and proliferation of HUVEC in a dose-dependent manner. In mice, emodin suppressed corneal inflammatory cell infiltration and inhibited the development of corneal neovascularization induced by alkali burn. Compared to those of the PBS-treated group, lower VEGFR2 expression and CD31 levels were found in the emodin-treated group. Emodin dramatically decreased the expression of VEGFR2, p-VEGFR2, p-Akt, p-STAT3, and p-P38 in VEGF-treated HUVEC. CONCLUSION: This study provides a new avenue for evaluating the molecular mechanisms underlying corneal inflammation and neovascularization. Emodin might be a promising new therapeutic option for corneal alkali burns.

Aflibercept 5+PRN with retinal laser photocoagulation is more effective than retinal laser photocoagulation alone and aflibercept 3+PRN with retinal laser photocoagulation in patients with high-risk proliferative diabetic retinopathy and diabetic macular edema: a 12-month clinical trial.

Objective: This study aimed to investigate and compare the efficacy and safety of retinal laser photocoagulation (PRP) alone, PRP with aflibercept 3+PRN, and PRP with aflibercept 5+PRN in patients with both high-risk proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME). Methods: Overall, 170 patients with high-risk PDR and DME (170 eyes from 170 patients) who visited our ophthalmology clinic from December 2018 to December 2020 were divided into the PRP (n=58), aflibercept 5+PRN with PRP (n=53), and aflibercept 3+PRN with PRP (n= 59) groups. General information, such as age, sex, and eye category, was obtained. Moreover, best-corrected visual acuity (BCVA), baseline central macular foveal thickness (CFT), microaneurysm (MA), area of neovascularization (NV), area of hard exudate (HE), and cytokine levels in atrial fluid before and after treatment, were assessed. The χ2 test was used for comparison between groups for statistical data. Analysis of variance was used for the statistical description of measurement data, independent samples were analyzed using Student's t-test, and Student-Newman-Keuls test was used for group comparisons. Differences were considered statistically significant at P < 0.05. Results: After treatment, no significant improvement in the BCVA (logMAR) of patients in the PRP group was observed. The BCVA (log MAR) decreased from 0.72 ± 0.17 and 0.74 ± 0.17 to 0.50 ± 0.13 and 0.53 ± 0.17 in PRP with aflibercept 5+PRN and PRP with aflibercept 3+PRN groups, respectively, with a statistically significant difference compared to those in the PRP group (P<0.05 in all cases). However, no statistically significant difference was observed between the combined treatment groups (P>0.05). The CFT in the PRP-only group decreased slightly from 361.80 ± 36.70 µm to 353.86 ± 40.88 µm, with no statistically significant difference (P>0.05), whereas the CFT in the aflibercept 5+PRN with PRP and aflibercept 3+PRN with PRP groups decreased from 356.57 ± 37.57 µm and 358.17 ± 44.66 µm to 284.87 ± 31.52 µm and 303.19 ± 37.00 µm, respectively, with statistically significant differences before and after treatment (P<0.05 for both groups). Statistically significant differences were observed in CFT between the three groups after treatment (P<0.05 in all cases). The number of MA (pcs) in the PRP, aflibercept 5+PRN with PRP, and aflibercept 3+PRN with PRP groups decreased from 118.34 ± 27.96, 118.60 ± 33.34, and 116.59 ± 28.95 to 92.95 ± 29.04, 44.60 ± 20.73, and 54.26 ± 25.43, respectively. The two-way comparison of the three groups revealed statistically significant differences in MA (P<0.05 in all cases). In the three groups, NV decreased from 1.00 ± 0.21 mm², 1.01 ± 0.18 mm², and 0.98 ± 0.20 mm² before treatment to 0.49 ± 0.17 mm², 0.31 ± 0.16 mm², and 0.38 ± 0.14 mm², respectively, with statistically significant differences (P<0.05 in all cases). After 12 months of treatment, 13, 18, and 18 patients had reduced HE area in the PRP-only, aflibercept 5+PRN with PRP, and aflibercept 3+PRN with PRP groups, respectively, with statistically significant differences (P<0.05 in all cases). After 12 months of treatment, vascular endothelial growth factor, monocyte chemoattractant protein-1, and glial fibrilliary acidic protein levels (pg/mL) in the aqueous humor decreased in both combined treatment groups compared with that at baseline, with statistically significant differences; however, no significant difference was observed between the two combined treatment groups (P>0.05). Conclusion: Aflibercept 5+PRN combined with PRP was safe and effective in treating patients with high-risk PDR and DME, and was more effective than PRP-only and aflibercept 3+PRN with PRP in improving CFT and MA.

Pericyte signaling via soluble guanylate cyclase shapes the vascular niche and microenvironment of tumors.

Pericytes and endothelial cells (ECs) constitute the fundamental components of blood vessels. While the role of ECs in tumor angiogenesis and the tumor microenvironment is well appreciated, pericyte function in tumors remains underexplored. In this study, we used pericyte-specific deletion of the nitric oxide (NO) receptor, soluble guanylate cyclase (sGC), to investigate via single-cell RNA sequencing how pericytes influence the vascular niche and the tumor microenvironment. Our findings demonstrate that pericyte sGC deletion disrupts EC-pericyte interactions, impairing Notch-mediated intercellular communication and triggering extensive transcriptomic reprogramming in both pericytes and ECs. These changes further extended their influence to neighboring cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) through paracrine signaling, collectively suppressing tumor growth. Inhibition of pericyte sGC has minimal impact on quiescent vessels but significantly increases the vulnerability of angiogenic tumor vessels to conventional anti-angiogenic therapy. In conclusion, our findings elucidate the role of pericytes in shaping the tumor vascular niche and tumor microenvironment and support pericyte sGC targeting as a promising strategy for improving anti-angiogenic therapy for cancer treatment.

Exosomal hsa_circ_0093884 derived from endothelial progenitor cells promotes therapeutic neovascularization via miR-145/SIRT1 pathway.

Therapeutic neovascularization is a strategy to promote blood vessel growth and improve blood flow, which is critical to tissue repair and regeneration in ischemic diseases. Here, we investigated the role of endothelial progenitor cell - derived exosomes (EPC-Exos) in therapeutic neovascularization and clarified the mechanism of hsa_circ_0093884 in EPC-Exos mediated neovascularization. Injection of EPC-Exos improved mouse ischemic hindlimb perfusion, promoted angiogenesis in Matrigel plugs and mouse skin wound healing. In vitro coculture with EPC-Exos improved HUVEC proliferation, angiogenic and migration ability, while alleviated hypoxia-induced apoptosis. hsa_circ_0093884 was identified from eleven types of circRNA derived from SIRT1 and proved to be enriched in EPC-Exos. Overexpression of hsa_circ_0093884 in EPC-Exos further enhanced the angiogenic capacity, while knockdown of hsa_circ_0093884 abolished the benefits. Mechanistically, EPC-Exos mediated shuttling of hsa_circ_0093884 induced cytoplasmic sponge of miR-145, thereby releasing repression of SIRT1. In vitro co-transfection indicated silence of miR-145 further strengthened the angiogenic effect of hsa_circ_0093884, while overexpression of miR-145 inhibited hsa_circ_0093884 mediated angiogenesis and abolished the beneficial effect of EPC-Exos. Furthermore, in vivo experiments using endothelial specific SIRT1 conditional knockout mice indicated hsa_circ_0093884 overexpressing EPC-Exos failed to promote therapeutic neovascularization in SIRT1cKO mice. Collectively, our results demonstrated that EPC-Exos promoted therapeutic neovascularization through hsa_circ_0093884/miR-145/SIRT1 axis.

TRIM2 Selectively Regulates Inflammation-Driven Pathological Angiogenesis without Affecting Physiological Hypoxia-Mediated Angiogenesis.

Angiogenesis is a critical physiological response to ischemia but becomes pathological when dysregulated and driven excessively by inflammation. We recently identified a novel angiogenic role for tripartite-motif-containing protein 2 (TRIM2) whereby lentiviral shRNA-mediated TRIM2 knockdown impaired endothelial angiogenic functions in vitro. This study sought to determine whether these effects could be translated in vivo and to determine the molecular mechanisms involved. CRISPR/Cas9-generated Trim2-/- mice that underwent a periarterial collar model of inflammation-induced angiogenesis exhibited significantly less adventitial macrophage infiltration relative to wildtype (WT) littermates, concomitant with decreased mRNA expression of macrophage marker Cd68 and reduced adventitial proliferating neovessels. Mechanistically, TRIM2 knockdown in endothelial cells in vitro attenuated inflammation-driven induction of critical angiogenic mediators, including nuclear HIF-1α, and curbed the phosphorylation of downstream effector eNOS. Conversely, in a hindlimb ischemia model of hypoxia-mediated angiogenesis, there were no differences in blood flow reperfusion to the ischemic hindlimbs of Trim2-/- and WT mice despite a decrease in proliferating neovessels and arterioles. TRIM2 knockdown in vitro attenuated hypoxia-driven induction of nuclear HIF-1α but had no further downstream effects on other angiogenic proteins. Our study has implications for understanding the role of TRIM2 in the regulation of angiogenesis in both pathophysiological contexts.

Zeaxanthin impairs angiogenesis and tumor growth of glioblastoma: An in vitro and in vivo study.

OBJECTIVES: To investigate the therapeutic effects of Zeaxanthin (Zea), one of the oxidized xanthophyll carotenoids belonging to the isoprenoids, on inhibiting the angiogenesis and tumor growth of glioblastoma (GBM) via an in vitro and in vivo study. METHODS: The effects of Zea on the proliferation, adhesion, migration and invasion of human GBM cell lines were detected by cell proliferation assay, cell adhesion assay and Transwell assay. The effect of Zea on angiogenesis was detected by rat aortic ring assay and human umbilical vein endothelial cells (HUVEC) in vitro tube formation assay. The effects of Zea on PARP, Caspase 3 and VEGFR2 phosphorylation as well as VEGFR2's downstream signaling pathway were detected by Western blot. The in vivo human GBM xenograft mouse model was employed to study the therapeutic efficacy of Zea. RESULTS: Zea impaired the proliferation, adhesion, migration and invasion of U87 and U251 cells as well as HUVECs. Rat aortic ring experiments displayed Zea significantly inhibited angiogenesis during VEGF-induced microvascular germination. In vitro and in vivo vascular experiments verified that Zea inhibited VEGF-induced HUVEC proliferation and capillary-like tube formation. Additionally, Zea induced GBM cells apoptosis via increasing the expression of cleaved PARP and Caspase 3. In HUVECs and U251 GBM cells, Zea down-regulated VEGF-induced activation of the VEGFR2 kinase pathway. Meanwhile the expression of p-AKT, p-ERK, p-STAT3 and FAK were all attenuated in U251 cells. Moreover, the effects of Zea on GBM cells proliferation could be blocked by VEGFR2 kinase inhibitor SU5408. These results suggest that Zea may hinder GBM angiogenesis and tumor growth through down-regulating a cascade of oncogenic signaling pathways, both through the inhibition of angiogenesis and the anti-tumor mechanism of a direct cytotoxic effect. Besides, Zea inhibits GBM angiogenesis and tumor growth exemplified through a xenograft mouse model in vivo. CONCLUSION: Zea impairs angiogenesis and tumor growth of GBM both in vitro and in vivo. It can be declared that Zea is a potential valuable anticancer candidate for the future treatment strategy of GBM.