Lara‐Velazquez, Montserrat

Abstract Stroke thrombi are heterogeneous; their composition influences their mechanical properties, including stiffness, elasticity, and adhesiveness, which in turn affect their response to therapy. Systemic characterization of the thrombi components could help select therapeutic techniques and anticipate outcomes. We conducted a systematic review and meta-analysis to evaluate associations between thrombi composition and angiographic and functional outcomes in acute ischemic stroke (AIS). Up to May 2025, relevant studies were sourced from four databases: PubMed, Web of Science, Scopus, and Embase. We included cohort studies whose populations are patients with AIS in relation to thrombi composition. Thirty-six studies involving 5,462 patients matched our eligibility criteria. Angiographic success (Thrombolysis in Cerebral Infarction ≥ 2b/3) did not differ significantly between red blood cell (RBC)-rich and fibrin-rich thrombi (risk ratio [RR] 1.02, 95% confidence interval [CI] 0.85–1.22; p = 0.84; I 2 = 63.8%; very low certainty). However, thrombi from patients with good angiographic outcomes had a significantly higher RBC content compared to patients with poor outcomes (mean difference = 7.22%, 95% CI 3.31–11.13; p < 0.001; low certainty). No significant difference was observed between RBC-rich and fibrin-rich thrombi regarding functional independence at 90 days (modified Rankin Scale 0–2) (RR = 1.22, 95% CI 0.73–2.05; p = 0.31; low certainty). While RBC-rich thrombi are associated with more favorable angiographic performance, thrombus composition alone does not predict functional outcomes. Stroke outcomes remain multifactorial, dominated by time to reperfusion, collateral circulation, and baseline severity. Preinterventional assessment of clot composition via imaging or biomarkers may support individualized therapy but should complement, not replace, other prognostic determinants.

Abstract Introduction: Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. The interaction of GBM with the lateral ventricles (LVs) has a significant effect on patient outcome, where LV-proximal GBM results in increased distal recurrence, increased stem cell marker expression, and decreased overall survival compared to LV-distal counterparts. Though the reason for this is unknown, it may be due in part to interaction of GBM with the subventricular zone (SVZ), the largest neurogenic niche. The SVZ contains populations of neural stem cells (NSCs) throughout life that produce many proteins supporting stem cell growth and maintenance. The goal of this project is to identify a bidirectional signaling axis between GBM cells and NSCs and determine its contribution to GBM malignancy. Methods: In vitro, patient-derived GBM brain tumor initiating cells (BTICs) were co-cultured with human fetal NSCs for 48 hours. Both BTICs and NSCs were analyzed for levels of viability, proliferation, migration, and the expression of malignancy-associated factors at a gene and protein level. A method for unbiased cell-specific proteomic labeling was established in vitro by cloning L274G-mutated methionyl tRNA synthetase (MetRS*) into a lentivirus with puromycin resistance. In vivo, Nestin-Cre-ERT2 mice were crossed with the STOPflox R26-MetRS line to establish a tamoxifen-inducible model to label NSC proteins. Results: BTICs co-cultured with NSCs showed increased viability, proliferation, and migration compared to controls. NSCs showed decreased proliferation and increased migration when co-cultured with BTICs. Both show increased levels of malignancy-associated genes and proteins including osteopontin, vimentin, tenascin C, and PDGFA upon co-culture. MetRS*-labeled cells successfully incorporate azide-labeled methionine analog in a cell-specific manner, and labeled proteins are able to be isolated for future proteomic analysis. In vivo, tamoxifen successfully induces the expression of MetRS* and GFP. Conclusion: We have determined that there is a bidirectional signaling axis between NSCs and BTICs that contributes to proliferation, migration, and malignancy-associated factors in GBM. Future studies looking at proteomic changes in both GBM and NSCs using the MetRS* labeling are needed to fully characterize the interaction between these cells in vitro and in vivo to identify new therapeutic targets for LV-associated GBM. Citation Format: Emily S. Norton, Lauren A. Whaley, Anna Carrano, Natanael Zarco, Montserrat A. Lara-Velazquez, Alfredo Quinones-Hinojosa, Hugo Guerrero-Cazares. Exploring the malignancy-promoting interaction between neural stem cells and lateral ventricle-associated glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3073.

Abstract Background Glioblastomas (GBMs) are the main primary brain tumors in adults with almost 100% recurrence rate. Patients with lateral ventricle proximal GBMs (LV-GBMs) exhibit worse survival compared to distal locations for unknown reasons. One hypothesis is the proximity of these tumors to the cerebrospinal fluid (CSF) and its chemical cues that can regulate cellular phenotype. We therefore investigated the role of CSF on GBM gene expression and the role of a CSF-induced gene, SERPINA3, in GBM malignancy in vitro and in vivo. Methods We utilized human CSF and GBM brain tumor-initiating cells (BTICs). We determined the impact of SERPINA3 expression in glioma patients using The Cancer Genome Atlas (TCGA) database. SERPINA3 expression changes were evaluated at mRNA and protein levels. The effects of knockdown (KD) and overexpression (OE) of SERPINA3 on cell migration, viability and cell proliferation were evaluated. Stem cell characteristics on KD cells were evaluated by differentiation and colony formation experiments. Tumor growth was studied by intracranial and flank injections. Results GBM-CSF increased BTIC migration accompanied by upregulation of the SERPINA3 gene. In patient samples and TCGA data, we observed SERPINA3 to correlate directly with brain tumor grade and indirectly with GBM patient survival. SERPINA3 KD induced a decrease in cell proliferation, migration, invasion, and stem cell characteristics, while SERPINA3 OE increased cell migration. In vivo, SERPINA3 KD BTICs showed increased survival in a murine model. Conclusions SERPINA3 plays a key role in GBM malignancy and its inhibition results in a better outcome using GBM preclinical models.

Abstract Glioblastoma (GBM), also known as grade IV astrocytoma, is the most common and devastating primary cancer of the central nervous system in adults. Despite the most advanced therapeutic strategies combining surgery, chemotherapy, and radiation, survival expectancy of GBM patients averages 14 months, with a recurrence rate of almost 100%. Remarkably, tumor location has great implications in the prognosis of GBM. Approximately 50-60% of GBM tumors infiltrates or contacts the subventricular zone (SVZ). These patients have significantly worse outcomes, in terms of median overall survival, time to progression and reoccurrence. The reason for the worse prognosis of SVZ-infiltrating tumors is unknown. The SVZ is the largest neurogenic niche in the adult brain, here the differentiation and migration of SVZ cells is regulated by direct contact with the cerebrospinal fluid (CSF). We suggest that CSF contribute to enhance GBM malignant characteristics in SVZ-infiltrating tumors. This study evaluated the impact of CSF exposure on GBM cells proliferation, migration in vitro and in vivo, as well as changes in gene expression profile. We demonstrated that CSF affects the malignancy of GBM cells by increasing their ability to proliferate and migrate. GBM cells stimulated with cancer CSF, non-cancer CSF, or control conditions at different time points (24-72 hrs) were evaluated for viability (by Alamar Blue assay) and proliferation rate (Ki67+ immunostaining), as well as for migratory capabilities (by means of transwell assay and time-lapse microscopy). We recapitulated these CSF effects in vivo using an in vivo model in which both female and male nude mice were implanted with GBM cells in suspension with human cancer or non-cancer CSF in an hydrogel as vehicle (n=8 mice per group). Tumor growth was followed via IVIS imaging and then studied by measuring tumor area on H&E slides and immunohistochemistry staining for Ki67, 21 days after tumor implantation. Animals receiving cancer CSF presented with greater tumor size and Ki67 proliferation index. To further dissect the mechanisms behind these observations, we performed a transcriptome analysis of CSF-treated GBM cells. At the molecular level we observed that cancer CSF induced changes in pathways regulating apoptosis, survival, integrins signaling, angiogenesis, glucose metabolism and response to inflammatory stimuli, all of which might be responsible for the increase in GBM malignancy. Taken together, this study provides direct evidence that CSF is an important player in determining tumor growth and invasion through the activation of complex gene expression patterns characteristic of a malignant phenotype. Understanding the interaction of brain tumors and CSF may lead to new therapeutic strategies that will target the CSF components in GBM patients. Citation Format: Anna Carrano, Jordan Phillipps, Montserrat Lara-Velazquez, Natanael Zarco, Paola Suarez-Meade, Kaisorn Chaichana, Alfredo Quinones-Hinojosa, Yan Asmann, Hugo Guerrero-Cázares. The role of human cerebrospinal fluid in glioblastoma malignancy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1574.

Abstract Glioblastoma (GBM) is the most aggressive of all the brain tumors with a median patient survival less than 15 months. Despite of surgical resection, radiotherapy, and chemotherapy, recurrence rate is almost 100%. A great percentage of GBM tumors (~60%) infiltrate and contact the ventricular-subventricular zone (V-SVZ). Interestingly, these tumors are the most aggressive, and invariably lead to higher distal recurrence rates, shorter time to tumor progression, and lower overall survival of the patient. The reason for this role of V-SVZ-proximity on the outcome of GBM patients is unknown. We suggest that a potential explanation is the interaction of GBM with the V-SVZ. This region is the largest neurogenic niche in the adult brain where neural stem cells (NSCs) give rise to newborn neuroblasts that migrate toward the olfactory bulb. In GBM there is a cell subpopulation called brain tumor stem cells (BTSCs) with NSCs-like characteristics, but with added potential for tumor initiation, recurrence and invasiveness. Tumor microenvironment plays an important role in migration and invasion process. In the present work, we used the total exosome isolation kit to purify Extracellular Vesicles (EVs) from human primary cultures of BTSCs. We determined that BTSCs-derived EVs contain specific information that is transfer to primary cultures of human Neural Progenitors Cells (NPCs) modulating their proliferation rate, cell viability, and migration. In addition, we identify that NPCs taken up BTSCs-derived EVs and significantly increase the expression levels of stemness-related genes such as Nestin, Nanog, and Sox2, suggesting that a phenotypic transdifferentiation is being carry out. These results support our hypothesis that GBM modulate the tumor microenvironment close to the V-SVZ by releasing EVs that target cellular components in this region and promote their phenotypic transformation, highlighting that NPCs biology changes in the context of tumor environment.

Glioblastoma (GBM) is the most common primary intracranial neoplasia, and is characterized by its extremely poor prognosis. Despite maximum surgery, chemotherapy, and radiation, the histological heterogeneity of GBM makes total eradication impossible, due to residual cancer cells invading the parenchyma, which is not otherwise seen in radiographic images. Even with gross total resection, the heterogeneity and the dormant nature of brain tumor initiating cells allow for therapeutic evasion, contributing to its recurrence and malignant progression, and severely impacting survival. Visual delimitation of the tumor’s margins with common surgical techniques is a challenge faced by many surgeons. In an attempt to achieve optimal safe resection, advances in approaches allowing intraoperative analysis of cancer and non-cancer tissue have been developed and applied in humans resulting in improved outcomes. In addition, functional paradigms based on stimulation techniques to map the brain’s electrical activity have optimized glioma resection in eloquent areas such as the Broca’s, Wernike’s and perirolandic areas. In this review, we will elaborate on the current standard therapy for newly diagnosed and recurrent glioblastoma with a focus on surgical approaches. We will describe current technologies used for glioma resection, such as awake craniotomy, fluorescence guided surgery, laser interstitial thermal therapy and intraoperative mass spectrometry. Additionally, we will describe a newly developed tool that has shown promising results in preclinical experiments for brain cancer: optical coherence tomography.

AbstractBackgroundThe CYP11A1 gene encodes the cytochrome P450 side‐chain cleavage enzyme, which is essential for steroid formation. Recessive variants in this gene can lead to impairment of sexual differentiation caused by a complete or partial loss of steroid hormone production. The phenotypic spectrum in affected 46XY males may vary from surgically repairable defects including cryptorchidism and hypospadias to complete feminization of external gonads, accompanied by symptoms of adrenal dysfunction.MethodsWhole‐exome sequencing (WES) of a 12‐year‐old male proband and his parents was performed after a protracted diagnostic odyssey failed to uncover the cause of his primary adrenal insufficiency. Of note, the proband had early symptomatology and corrective surgery for hypospadias, raising suspicion for a disorder of steroidogenesis.ResultsWES identified compound heterozygous variants in CYP11A1 including a novel canonical splice site variant (c.425+1G>A) and a previously reported p.E314K variant, which were consistent with a diagnosis of congenital adrenal insufficiency with partial 46XY sex reversal.ConclusionCongenital adrenal insufficiency with 46XY sex reversal is a rare disorder that is characterized by dysregulation of steroid hormone synthesis, leading to adrenal and gonadal dysfunction. In this report, we describe a patient with adrenal insufficiency, hypospadias, and skin hyperpigmentation who was found to have a novel c.425+1G>A variant in trans with the p.E314K variant in CYP11A1. We performed structural analyses to examine the effect of the p.E314K variant on protein function and show that it falls in the core of the protein may disrupt cholesterol binding in the active site.

Purpose of review The pituitary gland is one of the key components of the endocrine system. Congenital or acquired alterations can mediate destruction of cells in the gland leading to hormonal dysfunction. Even though pharmacological treatment for pituitary disorders is available, exogenous hormone replacement is neither curative nor sustainable. Thus, alternative therapies to optimize management and improve quality of life are desired. Recent findings An alternative modality to re-establish pituitary function is to promote endocrine cell regeneration through stem cells that can be obtained from the pituitary parenchyma or pluripotent cells. Stem cell therapy has been successfully applied to a plethora of other disorders, and is a promising alternative to hormonal supplementation for resumption of normal hormone homeostasis. Summary In this review, we describe the common causes for pituitary deficiencies and the advances in cellular therapy to restore the physiological pituitary function.

Abstract Human neural progenitor cell (NPC) migration within the subventricular zone (SVZ) of the lateral ganglionic eminence is an active process throughout early brain development. The migration of human NPCs from the SVZ to the olfactory bulb during fetal stages resembles what occurs in adult rodents. As the human brain develops during infancy, this migratory stream is drastically reduced in cell number and becomes barely evident in adults. The mechanisms regulating human NPC migration are unknown. The Slit–Robo signaling pathway has been defined as a chemorepulsive cue involved in axon guidance and neuroblast migration in rodents. Slit and Robo proteins expressed in the rodent brain help guide neuroblast migration from the SVZ through the rostral migratory stream to the olfactory bulb. Here, we present the first study on the role that Slit and Robo proteins play in human-derived fetal neural progenitor cell migration (hfNPC). We describe that Robo1 and Robo2 isoforms are expressed in the human fetal SVZ. Furthermore, we demonstrate that Slit2 is able to induce a chemorepellent effect on the migration of hfNPCs derived from the human fetal SVZ. In addition, when Robo1 expression is inhibited, hfNPCs are unable to migrate to the olfactory bulb of mice when injected in the anterior SVZ. Our findings indicate that the migration of human NPCs from the SVZ is partially regulated by the Slit–Robo axis. This pathway could be regulated to direct the migration of NPCs in human endogenous neural cell therapy.