Zika virus (ZIKV) has recently caused a pandemic disease, and many cases of ZIKV infection in pregnant women resulted in abortion, stillbirth, deaths and congenital defects including microcephaly, which now has been proposed as ZIKV congenital syndrome. This study aimed to investigate the in situ immune response profile and mechanisms of neuronal cell damage in fatal Zika microcephaly cases. Brain tissue samples were collected from 15 cases, including 10 microcephalic ZIKV-positive neonates with fatal outcome and five neonatal control flavivirus-negative neonates that died due to other causes, but with preserved central nervous system (CNS) architecture. In microcephaly cases, the histopathological features of the tissue samples were characterized in three CNS areas (meninges, perivascular space, and parenchyma). The changes found were mainly calcification, necrosis, neuronophagy, gliosis, microglial nodules, and inflammatory infiltration of mononuclear cells. The in situ immune response against ZIKV in the CNS of newborns is complex. Despite the predominant expression of Th2 cytokines, other cytokines such as Th1, Th17, Treg, Th9, and Th22 are involved to a lesser extent, but are still likely to participate in the immunopathogenic mechanisms of neural disease in fatal cases of microcephaly caused by ZIKV.

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In situ immune response and mechanisms of cell damage in central nervous system of fatal cases microcephaly by Zika virus

BackgroundZika virus (ZIKV) has been linked to central nervous system malformations in fetuses. To characterize the spectrum of ZIKV disease in pregnant women and infants, we followed patients in Rio de Janeiro to describe clinical manifestations in mothers and repercussions of acute ZIKV infection in infants. MethodsWe enrolled pregnant women in whom a rash had developed within the previous 5 days and tested blood and urine specimens for ZIKV by reverse-transcriptase–polymerase-chain-reaction assays. We followed women prospectively to obtain data on pregnancy and infant outcomes. ResultsA total of 345 women were enrolled from September 2015 through May 2016; of these, 182 women (53%) tested positive for ZIKV in blood, urine, or both. The timing of acute ZIKV infection ranged from 6 to 39 weeks of gestation. Predominant maternal clinical features included a pruritic descending macular or maculopapular rash, arthralgias, conjunctival injection, and headache; 27% had fever (short-term and low-grade). By Jul...

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Zika Virus Infection in Pregnant Women in Rio de Janeiro - Preliminary Report.

Summary The Zika virus has spread rapidly in the Americas since its first identification in Brazil in early 2015. Prenatal Zika virus infection has been linked to adverse pregnancy and birth outcomes, most notably microcephaly and other serious brain anomalies. To determine whether Zika virus infection during pregnancy causes these adverse outcomes, we evaluated available data using criteria that have been proposed for the assessment of potential teratogens. On the basis of this review, we conclude that a causal relationship exists between prenatal Zika virus infection and microcephaly and other serious brain anomalies. Evidence that was used to support this causal relationship included Zika virus infection at times during prenatal development that were consistent with the defects observed; a specific, rare phenotype involving microcephaly and associated brain anomalies in fetuses or infants with presumed or confirmed congenital Zika virus infection; and data that strongly support biologic plausibility, including the identification of Zika virus in the brain tissue of affected fetuses and infants. Given the recognition of this causal relationship, we need to intensify our efforts toward the prevention of adverse outcomes caused by congenital Zika virus infection. However, many questions that are critical to our prevention efforts remain, including the spectrum of defects caused by prenatal Zika virus infection, the degree of relative and absolute risks of adverse outcomes among fetuses whose mothers were infected at different times during pregnancy, and factors that might affect a woman’s risk of adverse pregnancy or birth outcomes. Addressing these questions will improve our ability to reduce the burden of the effects of Zika virus infection during pregnancy.

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Zika Virus and Birth Defects — Reviewing the Evidence for Causality

Brain-Region-Specific Organoids Using Mini-bioreactors for Modeling ZIKV Exposure

Zika Virus Infects Human Cortical Neural Progenitors and Attenuates Their Growth

A 52-year-old man without comorbidities was admitted to our gastroenterology department after he collapsed while on the toilet and noticed passage of bright red blood per rectum. On clinical examination he appeared to be healthy. Only mild abdominal pain was noticed. He was normotensive but with mild tachycardia (111/min). Laboratory analysis was unremarkable except for normocytic anemia (hemoglobin 78g/L). He deniedmedicine consumption. In order to exclude upper gastrointestinal bleeding, esophagogastroduodenoscopy was performed during which no clinically relevant findings were reported. Colonoscopy was attempted with a gastroscope and without previous purge. Fresh blood with numerous coagula was found in the rectum (▶Fig. 1 a), while the mucosa between the sigmoid andmid-transverse colon was covered with old blood (▶Fig. 1b). The cecum was not reached. The rectum was carefully re-examined and, after cleansing, a 10-mm 0-Isp polyp was discovered at 12 cm from the anal verge (▶Fig. 2 a). Active oozing of venous-type bleeding was observed from the tip of the polyp. Resection using a hot snare without submucosal injection was performed (▶Fig. 2b) and the postpolypectomy defect was closed with two hemoclips (▶Fig. 2 c, ▶Video 1). After an uneventful 24 hours of observation, the patient was discharged home. Histology analysis revealed an 8×6×5mm lobular capillary hemangioma with erosion on the mucosal surface. Also known as pyogenic granuloma, lobular capillary hemangiomas are most common in nasal mucosa and skin [1], and are very rare in the small and large intestine [2]. The typical presentation is gastrointestinal bleeding with or without anemia or abdominal pain. Massive bleeding is rare, although historical literature describes cases of death from exsanguination [3]. We have described a case of massive bleeding from a small polypoid rectal lobular capillary hemangioma in a previously healthy man, which was successfully removed by snare polypectomy with electrocautery.

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Severe rectal bleeding caused by a small polypoid lobular capillary hemangioma.

Nerve sheath tumors (NSTs) are characterized by neoplastic proliferation of Schwann cells, perineurial cells, endoneurial and/or epineurial fibroblasts. Diagnosis of NST is often challenging, particularly in distinguishing malignant NST (MNST) from other soft tissue sarcomas, or sometimes between low-grade MNST and benign NST. Recent studies in human pathology have demonstrated loss of trimethylation at lysine 27 of histone 3 (H3K27me3) in a subset of MNSTs using immunohistochemistry. Loss of H3K27me3 expression is rare in other high-grade sarcomas and also appears to be useful in distinguishing benign and low-grade MNSTs from high-grade subsets. In our retrospective study, we performed H3K27me3 immunohistochemistry in 68 canine tumors previously diagnosed as NST. We detected loss of H3K27me3 expression in 25% (n = 17) of all canine NST, including one neurofibroma, whereas 49% (n = 33) of tumors had mosaic loss of expression and 26% (n = 18) retained expression. No statistically significant differences were found between H3K27me3 expression, histopathological features of tumors, and their immunoreactivity for Sox10, claudin-1, GFAP, and Ki67. Because the classification of canine NST is not yet fully established and its correlation with the prognosis and clinical course of the disease is lacking, prospective studies with possible genetic analyses are needed to assess the true diagnostic value of H3K27me3 loss in canine NST.

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Loss of H3K27me3 expression in canine nerve sheath tumors


 
 
 Intratumoral heterogeneity plays an important role in glioblastoma (GB) resistance to standard therapy consisting of irradiation and chemotherapy with temozolomide (TMZ). However, classical in vitro GB models fail to represent the complex cellular composition of tumors in vivo, which hinders relevant examination of GB therapeutic response. To overcome these limitations, we studied the effects of irradiation and TMZ in a novel patient-derived organoid model.
 
 
 
 We established a patient-derived GB organoid model by a protocol recently published by Jacob et al. Original tumor tissue and tissue-derived organoids were compared by immunofluorescence staining of selected cell type markers and qPCR analysis of expression levels of a panel of selected target genes, including 15 genes defining GB subtypes. To analyze GB therapeutic response, organoids from 11 patients were exposed to a single dose of irradiation (10 Gy), one-week treatment with TMZ (50 µM) or their combination. The effects of therapy were assessed by viability and invasion assays. Expression levels of a number of genes related to GB subtypes, epithelial-mesenchymal transition, stemness, DNA damage responses, cell cycle, cytokines, and cell markers of the tumor microenvironment (TME) were compared between treated organoids and untreated controls. In addition, the heterogeneity of the TME and its responses to treatment were investigated by spatially resolved transcriptomics with in situ sequencing (ISS) methodology.
 
 
 
 Organoids recapitulate inter-patient variability and reflect the cellular composition and gene expression levels of the tumor tissue from which they were derived. GB stem cells and differentiated cancer cells are present in organoids along with various cells of the TME, e.g., macrophages and microglia, lymphocytes, and endothelial cells. Irradiation and TMZ showed no significant effects on organoid viability and invasion. However, some target genes were differentially expressed in the treated organoids, such as E3 ubiquitin-protein ligase MDM2 and cyclin-dependent kinase inhibitor 1A (CDKN1A). To our knowledge, we are the first to apply spatially resolved transcriptomics (ISS) to formalin-fixed, paraffin-embedded sections of (un)treated GB organoids. Our results elucidate the role of the TME in GB therapeutic response and shed light on potential mechanism underlying GB therapy resistance.
 
 
 
 Patient-derived GB organoids recapitulate the key characteristics and complex composition of patient’s tumor tissue, providing a valuable platform for studies of GB therapeutic response and resistance.


https://academic.oup.com/neuro-oncology/article-pdf/24/Supplement_2/ii30/45691596/noac174.100.pdf

P02.07.B Patient-derived glioblastoma organoids: Elucidating the mechanisms of glioblastoma therapeutic resistance in the context of tumor microenvironment

Here, we present the case of a 28-year-old woman who developed severe and progressive thymoma-associated constrictive bronchiolitis with bronchiectasis, despite undergoing thymectomy The disease was further complicated by radiation-induced organizing pneumonia (RIOP), which developed after adjuvant radiotherapy (RT) for Masaoka stage II thymoma The patient was successfully treated with an urgent lung transplantation (LTx) for irreversible respiratory failure

https://onlinelibrary.wiley.com/doi/pdf/10.1111/1759-7714.13936

Urgent lung transplantation for thymic neoplasm-associated severe constrictive bronchiolitis with bronchiectasis and radiotherapy-induced organizing pneumonia: A case report.


 Introduction: Glioblastoma is resistant to standard treatment, leading to tumor recurrence and early death of patients. Using organoid models, we aim to explore the mechanisms of resistance to cancer therapies and identify novel therapeutic vulnerabilities, including stress protecting melanoma-associated antigens (MAGEs). MAGEs are normally restricted to expression in testis but are abnormally activated in cancer and are associated with therapy resistance.
 Methods: Organoids have been established from fresh tumor biopsies and are stored in Gliobank, a Slovenian collection of patient tumor samples with corresponding clinical data. Organoids were first characterized and compared with the corresponding parental tumor tissue by immunofluorescence and qPCR of selected markers. Organoids were then treated with a combination of irradiation, the chemotherapeutic agent temozolomide and/or a chemokine receptor antagonist, and response to therapy was assessed by immunofluorescence, qPCR, cell viability and invasion assays, multiplex ELISA and proximity ligation assay.
 Results: Organoids recapitulated the gene expression profile of parental glioblastoma tissues, including expression of genes related to cancer stem cells, DNA damage response, cell cycle progression, epithelial- to- mesenchymal transition, and cytokine signaling. In addition, the organoids preserved the cellular composition of the parental glioblastoma tissues, consisting of glioblastoma (stem) cells, macrophages, microglia, lymphocytes, and endothelial cells. Standard treatment decreased viability and invasion of organoids in only 2 of 6 patients, suggesting that organoids recapitulate tumor therapy resistance. The increased expression of MDM2 and CDKN1A in organoids after treatment with irradiation and temozolomide suggests that the p53 pathway and DNA damage response mechanisms may contribute to the therapy resistance. Next, we detected high abundance of secreted cytokines in the culture medium of the organoids, including CXCL12. However, treatment of the organoids with the CXCR4 antagonist Plerixafor, which blocked the interactions between CXCL12 and CXCR4 in the organoids, had no effect on organoid viability and invasion, suggesting resistance of glioblastoma to this immunotherapy. Since high expression of several type I MAGEs correlates with poor prognosis of glioma patients based on TCGA database analysis, we investigate the role of MAGEs in therapy resistance of glioblastoma organoids.
 Conclusions: Patient-derived tumor organoids provide a valuable tool to 1) identify novel therapeutic vulnerabilities in the context of the tumor microenvironment, 2) evaluate the effect of novel candidate treatments including immunotherapy, and 3) discover novel markers of therapy resistance.
 Citation Format: Barbara Breznik, Bernarda Majc, Anamarija Habič, Gloria Krapež, Andrej Porčnik, Jernej Mlakar, Tamara Lah Turnšek, Metka Novak, Klementina Fon Tacer. Glioblastoma patient-derived organoids as a model for discovering novel markers of therapy resistance in the context of tumor microenvironment: potential role of melanoma antigens [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 170.

Abstract 170: Glioblastoma patient-derived organoids as a model for discovering novel markers of therapy resistance in the context of tumor microenvironment: potential role of melanoma antigens

Jernej Mlakar

Papers

Severe rectal bleeding caused by a small polypoid lobular capillary hemangioma.

Loss of H3K27me3 expression in canine nerve sheath tumors

P02.07.B Patient-derived glioblastoma organoids: Elucidating the mechanisms of glioblastoma therapeutic resistance in the context of tumor microenvironment

Urgent lung transplantation for thymic neoplasm-associated severe constrictive bronchiolitis with bronchiectasis and radiotherapy-induced organizing pneumonia: A case report.

Abstract 170: Glioblastoma patient-derived organoids as a model for discovering novel markers of therapy resistance in the context of tumor microenvironment: potential role of melanoma antigens