STMND1 is a phylogenetically ancient stathmin which localizes to motile cilia and exhibits nuclear translocation that is inhibited when soluble tubulin concentration increases

Stathmins are small, unstructured proteins that bind tubulin dimers and are implicated in several human diseases, but whose function remains unknown. We characterized a new stathmin, STMND1 (Stathmin Domain Containing 1) as the human representative of an ancient subfamily. STMND1 features a N-terminal myristoylated and palmitoylated motif which directs it to membranes and a tubulin-binding stathmin-like domain (SLD) that contains an internal nuclear localization signal. Biochemistry and proximity labeling showed that STMND1 binds tubulin, and live imaging showed that tubulin binding inhibits translocation from cellular membranes to the nucleus. STMND1 is highly expressed in multiciliated epithelial cells, where it localizes to motile cilia. Overexpression in a model system increased the length of primary cilia. Our study suggests that the most ancient stathmins have cilium-related functions that involve sensing soluble tubulin.

Systematic characterization of antibody-drug conjugate targets in central nervous system tumors

BACKGROUND

Antibody-drug conjugates (ADCs) enhance the specificity of cytotoxic drugs by directing them to cells expressing target antigens. Multiple ADCs are FDA-approved for solid and hematologic malignancies, including those expressing HER2, TROP2, and NECTIN4. Recently, an ADC targeting HER2 (Trastuzumab-Deruxtecan) increased survival and reduced growth of brain metastases in treatment-refractory metastatic breast cancer, even in tumors with low HER2 expression. Thus, low-level expression of ADC targets may be sufficient for treatment responsiveness. However, ADC target expression is poorly characterized in many central nervous system (CNS) tumors.

METHODS

We analyzed publicly available RNA-sequencing and proteomic data from the children's brain tumor network (N = 188 tumors) and gene-expression-omnibus RNA-expression datasets (N = 356) to evaluate expression of 14 potential ADC targets that are FDA-approved or under investigation in solid cancers. We also used immunohistochemistry to measure the levels of HER2, HER3, NECTIN4, TROP2, CLDN6, CLDN18.2, and CD276/B7-H3 protein in glioblastoma, oligodendroglioma, meningioma, ependymoma, pilocytic astrocytoma, medulloblastoma, atypical teratoid/rhabdoid tumor (AT/RT), adamantinomatous craniopharyngioma (ACP), papillary craniopharyngioma (PCP), and primary CNS lymphoma (N = 575).

RESULTS

Pan-CNS analysis showed subtype-specific expression of ADC target proteins. Most tumors expressed HER3, B7-H3, and NECTIN4. Ependymomas strongly expressed HER2, while meningiomas showed weak-moderate HER2 expression. ACP and PCP strongly expressed B7-H3, with TROP2 expression in whorled ACP epithelium. AT/RT strongly expressed CLDN6. Glioblastoma showed little subtype-specific marker expression, suggesting a need for further target development.

CONCLUSIONS

CNS tumors exhibit subtype-specific expression of ADC targets including several FDA-approved for other indications. Clinical trials of ADCs in CNS tumors may therefore be warranted.

2D and 3D multiplexed subcellular profiling of nuclear instability in human cancer

Nuclear atypia, including altered nuclear size, contour, and chromatin organization, is ubiquitous in cancer cells. Atypical primary nuclei and micronuclei can rupture during interphase; however, the frequency, causes, and consequences of nuclear rupture are unknown in most cancers. We demonstrate that nuclear envelope rupture is surprisingly common in many human cancers, particularly glioblastoma. Using highly-multiplexed 2D and super-resolution 3D-imaging of glioblastoma tissues and patient-derived xenografts and cells, we link primary nuclear rupture with reduced lamin A/C and micronuclear rupture with reduced lamin B1. Moreover, ruptured glioblastoma cells activate cGAS-STING-signaling involved in innate immunity. We observe that local patterning of cell states influences tumor spatial organization and is linked to both lamin expression and rupture frequency, with neural-progenitor-cell-like states exhibiting the lowest lamin A/C levels and greatest susceptibility to primary nuclear rupture. Our study reveals that nuclear instability is a core feature of cancer, and links nuclear integrity, cell state, and immune signaling.

High-plex immunofluorescence imaging and traditional histology of the same tissue section for discovering image-based biomarkers

Precision medicine is critically dependent on better methods for diagnosing and staging disease and predicting drug response. Histopathology using hematoxylin and eosin (H&E)-stained tissue (not genomics) remains the primary diagnostic method in cancer. Recently developed highly multiplexed tissue imaging methods promise to enhance research studies and clinical practice with precise, spatially resolved single-cell data. Here, we describe the 'Orion' platform for collecting H&E and high-plex immunofluorescence images from the same cells in a whole-slide format suitable for diagnosis. Using a retrospective cohort of 74 colorectal cancer resections, we show that immunofluorescence and H&E images provide human experts and machine learning algorithms with complementary information that can be used to generate interpretable, multiplexed image-based models predictive of progression-free survival. Combining models of immune infiltration and tumor-intrinsic features achieves a 10- to 20-fold discrimination between rapid and slow (or no) progression, demonstrating the ability of multimodal tissue imaging to generate high-performance biomarkers.

Lymphocyte networks are dynamic cellular communities in the immunoregulatory landscape of lung adenocarcinoma

Lymphocytes are key for immune surveillance of tumors, but our understanding of the spatial organization and physical interactions that facilitate lymphocyte anti-cancer functions is limited. We used multiplexed imaging, quantitative spatial analysis, and machine learning to create high-definition maps of lung tumors from a Kras/Trp53-mutant mouse model and human resections. Networks of interacting lymphocytes ("lymphonets") emerged as a distinctive feature of the anti-cancer immune response. Lymphonets nucleated from small T cell clusters and incorporated B cells with increasing size. CXCR3-mediated trafficking modulated lymphonet size and number, but T cell antigen expression directed intratumoral localization. Lymphonets preferentially harbored TCF1+ PD-1+ progenitor CD8+ T cells involved in responses to immune checkpoint blockade (ICB) therapy. Upon treatment of mice with ICB or an antigen-targeted vaccine, lymphonets retained progenitor and gained cytotoxic CD8+ T cell populations, likely via progenitor differentiation. These data show that lymphonets create a spatial environment supportive of CD8+ T cell anti-tumor responses.

Multiplexed 3D atlas of state transitions and immune interaction in colorectal cancer

Advanced solid cancers are complex assemblies of tumor, immune, and stromal cells characterized by high intratumoral variation. We use highly multiplexed tissue imaging, 3D reconstruction, spatial statistics, and machine learning to identify cell types and states underlying morphological features of known diagnostic and prognostic significance in colorectal cancer. Quantitation of these features in high-plex marker space reveals recurrent transitions from one tumor morphology to the next, some of which are coincident with long-range gradients in the expression of oncogenes and epigenetic regulators. At the tumor invasive margin, where tumor, normal, and immune cells compete, T cell suppression involves multiple cell types and 3D imaging shows that seemingly localized 2D features such as tertiary lymphoid structures are commonly interconnected and have graded molecular properties. Thus, while cancer genetics emphasizes the importance of discrete changes in tumor state, whole-specimen imaging reveals large-scale morphological and molecular gradients analogous to those in developing tissues.

Well-developed Cerebellum in an Ovarian Mature Teratoma From a Pregnant Female

Teratomas are the most common neoplasm of the ovary, comprising over half of all diagnosed tumors in patients under 50. Most lesions are classified as benign mature teratomas and are histologically defined by the presence of mature tissues from one or more of the embryological germ layers: ectoderm, mesoderm, and endoderm. Neuroectodermal derivatives, including glia, neurons, ependymal cells, and meninges are present in a third to half of mature teratomas. Although teratomatous tissue elements are typically arranged in a haphazard fashion, well-developed and organized embryonic organ structures have been rarely reported and often with limited histologic, clinical, or gross characterization. In this report, we describe the case of an ovarian mature cystic teratoma identified in a pregnant female which exhibited remarkably well-developed posterior fossa structures including lobated and foliated cerebellum with appropriate anatomic organization and associated brainstem, ventricular, and meningeal structures.

Copper induces cell death by targeting lipoylated TCA cycle proteins

Copper is an essential cofactor for all organisms, and yet it becomes toxic if concentrations exceed a threshold maintained by evolutionarily conserved homeostatic mechanisms. How excess copper induces cell death, however, is unknown. Here, we show in human cells that copper-dependent, regulated cell death is distinct from known death mechanisms and is dependent on mitochondrial respiration. We show that copper-dependent death occurs by means of direct binding of copper to lipoylated components of the tricarboxylic acid (TCA) cycle. This results in lipoylated protein aggregation and subsequent iron-sulfur cluster protein loss, which leads to proteotoxic stress and ultimately cell death. These findings may explain the need for ancient copper homeostatic mechanisms.

Temporal and spatial topography of cell proliferation in cancer

Proliferation is a fundamental trait of cancer cells, but its properties and spatial organization in tumours are poorly characterized. Here we use highly multiplexed tissue imaging to perform single-cell quantification of cell cycle regulators and then develop robust, multivariate, proliferation metrics. Across diverse cancers, proliferative architecture is organized at two spatial scales: large domains, and smaller niches enriched for specific immune lineages. Some tumour cells express cell cycle regulators in the (canonical) patterns expected of freely growing cells, a phenomenon we refer to as 'cell cycle coherence'. By contrast, the cell cycles of other tumour cell populations are skewed towards specific phases or exhibit non-canonical (incoherent) marker combinations. Coherence varies across space, with changes in oncogene activity and therapeutic intervention, and is associated with aggressive tumour behaviour. Thus, multivariate measures from high-plex tissue images capture clinically significant features of cancer proliferation, a fundamental step in enabling more precise use of anti-cancer therapies.

Scope2Screen: Focus+Context Techniques for Pathology Tumor Assessment in Multivariate Image Data

Inspection of tissues using a light microscope is the primary method of diagnosing many diseases, notably cancer. Highly multiplexed tissue imaging builds on this foundation, enabling the collection of up to 60 channels of molecular information plus cell and tissue morphology using antibody staining. This provides unique insight into disease biology and promises to help with the design of patient-specific therapies. However, a substantial gap remains with respect to visualizing the resulting multivariate image data and effectively supporting pathology workflows in digital environments on screen. We, therefore, developed Scope2Screen, a scalable software system for focus+context exploration and annotation of whole-slide, high-plex, tissue images. Our approach scales to analyzing 100GB images of 109 or more pixels per channel, containing millions of individual cells. A multidisciplinary team of visualization experts, microscopists, and pathologists identified key image exploration and annotation tasks involving finding, magnifying, quantifying, and organizing regions of interest (ROIs) in an intuitive and cohesive manner. Building on a scope-to-screen metaphor, we present interactive lensing techniques that operate at single-cell and tissue levels. Lenses are equipped with task-specific functionality and descriptive statistics, making it possible to analyze image features, cell types, and spatial arrangements (neighborhoods) across image channels and scales. A fast sliding-window search guides users to regions similar to those under the lens; these regions can be analyzed and considered either separately or as part of a larger image collection. A novel snapshot method enables linked lens configurations and image statistics to be saved, restored, and shared with these regions. We validate our designs with domain experts and apply Scope2Screen in two case studies involving lung and colorectal cancers to discover cancer-relevant image features.

Governing health data across changing contexts: A focus group study of citizen's views in England, Iceland, and Sweden

BACKGROUND

The governance structures associated with health data are evolving in response to advances in digital technologies that enable new ways of capturing, using, and sharing different types of data. Increasingly, health data moves between different contexts such as from healthcare to research, or to commerce and marketing. Crossing these contextual boundaries has the potential to violate societal expectations about the appropriate use of health data and diminish public trust. Understanding citizens' views on the acceptability of and preferences for data use in different contexts is essential for developing information governance policies in these new contexts.

METHODS

Focus group design presenting data sharing scenarios in England, Iceland, and Sweden.

RESULTS

Seventy-one participants were recruited. Participants supported the need for data to help understand the observable world, improve medical research, the quality of public services, and to benefit society. However, participants consistently identified the lack of information, transparency and control as barriers to trusting organisations to use data in a way that they considered appropriate. There was considerable support for fair and transparent data sharing practices where all parties benefitted.

CONCLUSION

Data governance policy should involve all stakeholders' perspectives on an ongoing basis, to inform and implement changes to health data sharing practices that accord with stakeholder views. The Findings showed that (1) data should be used for ethical purposes even when there was commercial interest; (2) data subjects and/or public institutions that provide and share data should also receive benefits from the sharing of data; (3) third parties use of data requires greater transparency and accountability than currently exists, (4) there should be greater information provided to empower data subjects.

Abstract 1816: Phenogenomic characterization of immunomodulatory purinergic signaling in glioblastoma

INTRODUCTION: Extracellular purinergic signaling plays critical roles in the regulation of tumor growth and anti-tumor immunity via autocrine/paracrine binding of metabolites to receptors on neoplastic and non-neoplastic populations. Extracellular purine concentrations are principally mediated by the ectonucleotidase enzymes CD39 and CD73, which catabolize ATP to adenosine. Within the tumor microenvironment, neoplastic, immune, and stromal cells expressing these enzymes may co-localize to generate an immunosuppressive adenosine-rich niche. However, the cellular composition, spatial architecture and phenotypic properties of these tumor ecosystems and their relationship to tumor genotype have been poorly characterized.

METHODS: We quantified CD73 expression by immunohistochemistry (IHC) in a cohort of CNS tumors [meningiomas(N=222), gliomas(N=244), ependymomas(N=44), medulloblastomas(N=24), craniopharyngiomas(N=38)]. We used publicly-available single-cell RNA-seq data and 36 marker multiplexed tissue imaging (t-CyCIF) of 139 clinically and genomically annotated glioblastomas to characterize CD39 and CD73 expressing populations, define immune architecture and tumor cell states at single cell resolution, evaluate spatial correlations, and identify markers of clinical outcome. Mass spectrometry imaging (MALDI-MSI) was employed to generate spatially-resolved quantification of purine metabolite levels in glioblastoma resections (N=9).

RESULTS: IHC revealed strong CD73 expression in meningiomas and gliomas. Tumor CD73 expression was associated with poor progression-free-survival in IDH-wildtype glioblastoma (p=0.04). scRNA-seq in glioblastoma revealed that CD73 is predominantly expressed by tumor cell populations, while CD39 is predominantly expressed by monocytic (macrophage, microglial) populations. t-CyCIF showed enrichment of EGFR, Ki-67, and TP53 expression in CD73-high tumor cells at a single cell level independent of genotype, as well as significant spatial correlation between CD73 expression in tumor cells and CD39 expression in macrophages. MALDI-MSI showed significantly greater adenosine concentrations in glioblastomas with high CD73 expression. CD73 expression significantly correlated with EGFR amplification or C-terminal deletion (EGFRvIII or variants), type-II interferon signaling, and PD-L1 expression in glioblastoma.

CONCLUSIONS: Phenogenomic analysis of purinergic signaling in glioblastoma revealed correlations between CD73 expression and genotype, adenosine concentration, and clinical outcome. Spatial analysis revealed interaction between macrophages CD39 expression and tumor cell CD73 expression, suggesting that these populations may interact to suppress anti-tumor immunity. Anti-CD73 therapy may provide therapeutic benefits in glioblastoma by blunting immunosuppressive and oncogenic adenosine signaling.

Citation Format: Shannon Coy, Jia-Ren Lin, Shu Wang, Sylwia Stopka, Rumana Rashid, Jaeho Hwang, Prasidda Khadka, Philipp Euskirchen, Pratiti Bandopadhayay, Patrick Y. Wen, Peter K. Sorger, Nathalie Agar, Keith L. Ligon, Mehdi Touat, Sandro Santagata. Phenogenomic characterization of immunomodulatory purinergic signaling in 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 1816.

Abstract 4: Temporal and spatial topography of cell proliferation in cancer

Uncontrolled cell proliferation is a defining feature of malignancy. Current understanding of proliferation, particularly in humans, derives primarily from studying cells growing rapidly in the non-physiological conditions of cell culture. However, tumors are exceedingly complex admixtures of different cell types and subclonal malignant populations comprising proliferative, non-proliferative, and arrested states that are influenced by physical, metabolic, and molecular conditions. Images of single or small sets of protein markers from fixed tissue samples only provide limited and static views into the nature of these complex states. Here we identify proliferation states and develop a quantitative framework to extract cell cycle dynamics from multiplexed, spatially-resolved tissue images of millions of tumor cells from human cancers and genetically engineered tumors in mice. Across spatial scales, tumors display intrinsic regional variability in proliferation patterns and in the coherence of cell cycle markers in high-dimensional space. Cell cycle dynamics and cell cycle coherence are not solely a function of tumor growth and oncogene expression and rapidly adapt following genetic and therapeutic perturbations. Replacing binary metrics with multivariate traits provides a quantitative framework for extracting multidimensional dynamic information from static images that is broadly applicable to the study of temporal processes within the native architecture of human disease tissues.

Citation Format: Giorgio Gaglia, Sheheryar Kabraji, Danae Argyropoulou, Yang Dai, Johann Bergholz, Shannon Coy, Jia-Ren Lin, Eric P. Winer, Deborah Dillon, Jean J. Zhao, Peter K. Sorger, Sandro Santagata. Temporal and spatial topography of cell proliferation in cancer [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 4.

Abstract 122: Highly multiplexed, spatially-resolved tissue imaging of genetically engineered mouse models of cancer to discover and characterize immune regulators of tumorigenesis

Despite the encouraging success of immunotherapy for certain malignancies, most patients with solid tumors do not yet benefit from such therapies. It is therefore critical that we identify factors dictating responsiveness to immunotherapy by more completely characterizing tumor-immune interactions. Even though immunotherapies are used in humans, in-depth analysis of murine models is essential for a mechanistic understanding of the crosstalk among tumor, immune, and stromal components of the tumor microenvironment (TME): only animal models have the necessary manipulability and reproducibility for causal, mechanistic studies. However, murine modelling must be combined with spatially resolved analytical methods such as highly multiplexed tissue imaging that enable accurate characterization of the TME at a single-cell level. Here we use tissue cyclic immunofluorescence (t-CyCIF) multiplexed imaging to characterize the immune microenvironment of a mouse lung adenocarcinoma model initiated via lentiviral delivery of Cre recombinase into the lungs of KrasLSL-G12D/+;p53fl/fl (KP) mice. Using this new platform, we identify tumor cells and immune cell types (dendritic cells, NK cells, macrophages, B cells, helper T cells, regulator T cells and cytotoxic T cells). We characterize the effects of expressing tumor antigen (i.e., LucOS), of CRISPRa based upregulation of the chemokines (e.g., CXCL10), and of combination immune check point inhibitor treatments (e.g., one-week treatment with anti-PD-1 and anti-CTLA-4 (PC)). Remarkably the total immune composition of the mouse lungs remains relatively unchanged following these perturbations, but there are marked changes in the immune cell localization in tumor nodules, in the number and size of immune cell networks and in the functional activation states of cytotoxic T cells. For example, one week of PC treatment did not affect tumor burden and did not change the extent of immune cell infiltration however, it did drastically change cytotoxic T cell phenotypes with increased effector phenotypes (i.e., GzmB and Perforin expression and proliferation) and decreased exhaustion-like phenotypes (i.e., PD-1 and Tim-3 expression). Lymphocyte networks decreased in number but were closer to tumors. Using high-dimensional protein expression data to characterize GEMM models following in situ genetic or therapeutic perturbation is a powerful new platform to investigate tumor-immune interactions.

Citation Format: Giorgio Gaglia, Megan Burger, Claire Ritch, Danae Argyropoulou, Yang Dai, Shannon Coy, Jia-Ren Lin, Peter Sorger, Tyler Jacks, Sandro Santagata. Highly multiplexed, spatially-resolved tissue imaging of genetically engineered mouse models of cancer to discover and characterize immune regulators of tumorigenesis [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 122.

Temporal and spatial topography of cell proliferation in cancer

3122

Background: Tumors are complex ecosystems where exogenous and endogenous cues are integrated to either stimulate or inhibit cancer cell proliferation. However, the nature of these complex cell cycle states, their spatial organization, response to perturbation, and implications for clinical outcomes, are poorly characterized in tumor tissues. Methods: We used multiplexed tissue imaging to develop a robust classifier of proliferation, the multivariate proliferation index (MPI), using 513 unique tumors across five cancer types. Next, we used dimensionality reduction analysis to assess how the patterns of cell cycle protein expression in tumors were altered in response to perturbation. Results: The MPI outperforms single markers, like Ki67, when classifying proliferative index across diverse tumor types and reveals the proliferative architecture of tumors in situ. We find that proliferative and non-proliferative cancer cells are organized across microscopic (cell-to-cell) and macroscopic (tissue-level) scales. Both domains are reshaped by therapy, and local clusters of proliferative and non-proliferative tumor cells preferentially neighbor distinct tumor-infiltrating immune cells. We further phenotyped non-proliferating cancer cells using markers of quiescent cancer cells, cancer stem cells, and dormant cancer cells. We found that these types of non-proliferating cancer cells can occupy distinct regions within the same primary tumor. In high-dimensional marker space, populations of proliferative cancer cells express canonical patterns of cell cycle protein markers, a property we refer to as “cell cycle coherence”. Untreated tumors exist in a continuum of coherence states, ranging from optimal coherence, akin to freely cycling cells in culture, to reduced coherence characterized by either cell cycle polarization or non-canonical marker expression. Coherence can be stereotypically altered by induction and abrogation of mitogen signaling in a HER2-driven model of breast cancer. Cell cycle coherence is modulated by neoadjuvant therapy in patients with localized breast cancer, and coherence is associated with disease-free survival after adjuvant therapy in patients with colorectal cancer, mesothelioma and glioblastoma. Conclusions: The MPI robustly defines proliferating and non-proliferating cells in tissues, with immediate implications for clinical practice and research. The coherence metrics capture the diversity of post-treatment cell cycle states directly in clinical samples, a fundamental step in advancing precision medicine. More broadly, replacing binary metrics with multivariate traits provides a quantitative framework to study temporal processes from fixed static images and to investigate the rich spatial biology of human cancers.

HAND1 and BARX1 Act as Transcriptional and Anatomic Determinants of Malignancy in Gastrointestinal Stromal Tumor

PURPOSE

Gastrointestinal stromal tumor (GIST) arises from interstitial cells of Cajal (ICC) or their precursors, which are present throughout the gastrointestinal tract. Although gastric GIST is commonly indolent and small intestine GIST more aggressive, a molecular understanding of disease behavior would inform therapy decisions in GIST. Although a core transcription factor (TF) network is conserved across GIST, accessory TFs HAND1 and BARX1 are expressed in a disease state-specific pattern. Here, we characterize two divergent transcriptional programs maintained by HAND1 and BARX1, and evaluate their association with clinical outcomes.

EXPERIMENTAL DESIGN

We evaluated RNA sequencing and TF chromatin immunoprecipitation with sequencing in GIST samples and cultured cells for transcriptional programs associated with HAND1 and BARX1. Multiplexed tissue-based cyclic immunofluorescence and IHC evaluated tissue- and cell-level expression of TFs and their association with clinical factors.

RESULTS

We show that HAND1 is expressed in aggressive GIST, modulating KIT and core TF expression and supporting proliferative cellular programs. In contrast, BARX1 is expressed in indolent and micro-GISTs. HAND1 and BARX1 expression were superior predictors of relapse-free survival, as compared with standard risk stratification, and they predict progression-free survival on imatinib. Reflecting the developmental origins of accessory TF programs, HAND1 was expressed solely in small intestine ICCs, whereas BARX1 expression was restricted to gastric ICCs.

CONCLUSIONS

Our results define anatomic and transcriptional determinants of GIST and molecular origins of clinical phenotypes. Assessment of HAND1 and BARX1 expression in GIST may provide prognostic information and improve clinical decisions on the administration of adjuvant therapy.

TAMI-45. PHENOGENOMIC CHARACTERIZATION OF IMMUNOMODULATORY PURINERGIC SIGNALING IN GLIOBLASTOMA

INTRODUCTION

Purinergic signaling plays critical roles in the regulation of tumor growth and anti-tumor immunity via autocrine/paracrine binding of metabolites to receptors on neoplastic and non-neoplastic populations. Extracellular purine concentrations are mediated by the ectonucleotidase enzymes CD39 and CD73, which catabolize ATP to adenosine. Within tumors such as glioblastoma, neoplastic, immune, and stromal cells expressing these enzymes may co-localize to generate immunosuppressive adenosine-rich environments. However, the composition, architecture, and phenotypic properties of these tumor ecosystems and their relationship to tumor genotype are poorly characterized.

METHODS

We quantified CD73 expression by immunohistochemistry in a cohort of CNS tumors [meningiomas(n=222), gliomas(n=244), ependymomas(n=44), medulloblastomas(n=24), and craniopharyngiomas(n=38)]. We used publicly-available single-cell RNA-seq data and 36-marker multiplexed tissue imaging (t-CyCIF) of 139 clinically and genomically annotated glioblastoma resections to characterize CD39 and CD73-expressing populations, define the immune architecture and tumor cell-states at single cell resolution, and identify markers of clinical outcome. We used mass spectrometry imaging (MALDI-MSI) to generate spatially-resolved quantification of purine metabolite levels in glioblastoma resections (n=10).

RESULTS

CD73 exhibited strong expression in a subset of gliomas and meningiomas but was typically not expressed in ependymomas or medulloblastomas. CD73 expression correlated with poor progression-free-survival in IDH-wildtype glioblastoma (p=0.04). scRNA-seq and t-CyCIF in glioblastoma showed CD73 expression in tumor cells, and CD39 expression in macrophages and endothelial cells. MALDI-MSI showed significantly greater adenosine concentrations (3.5-fold;p=0.04) in glioblastomas with high CD73 expression. scRNA-seq showed direct correlations between stem-like mRNA expression, proliferation, and CD73 expression in DIPG. CD73 expression significantly correlated with EGFR amplification, interferon signaling, and PD-L1 expression in glioblastoma.

CONCLUSIONS

Phenogenomic analysis of purinergic immunomodulatory signaling revealed significant interplay between CD73 activity and genotype, adenosine concentration, differentiation-state, clinical outcome, and possible interaction between CD39-positive macrophages and CD73-positive neoplastic cells. Anti-CD73 therapy may provide therapeutic benefits in glioblastoma by blunting immunosuppressive and oncogenic adenosine signaling.

An update on the CNS manifestations of neurofibromatosis type 2

Neurofibromatosis type II (NF2) is a tumor predisposition syndrome characterized by the development of distinctive nervous system lesions. NF2 results from loss-of-function alterations in the NF2 gene on chromosome 22, with resultant dysfunction of its protein product merlin. NF2 is most commonly associated with the development of bilateral vestibular schwannomas; however, patients also have a predisposition to development of other tumors including meningiomas, ependymomas, and peripheral, spinal, and cranial nerve schwannomas. Patients may also develop other characteristic manifestations such as ocular lesions, neuropathies, meningioangiomatosis, and glial hamartia. NF2 has a highly variable clinical course, with some patients exhibiting a severe phenotype and development of multiple tumors at an early age, while others may be nearly asymptomatic throughout their lifetime. Despite the high morbidity associated with NF2 in severe cases, management of NF2-associated lesions primarily consists of surgical resection and treatment of symptoms, and there are currently no FDA-approved systemic therapies that address the underlying biology of the syndrome. Refinements to the diagnostic criteria of NF2 have been proposed over time due to increasing understanding of clinical and molecular data. Large-population studies have demonstrated that some features such as the development of gliomas and neurofibromas, currently included as diagnostic criteria, may require further clarification and modification. Meanwhile, burgeoning insights into the molecular biology of NF2 have shed light on the etiology and highly variable severity of the disease and suggested numerous putative molecular targets for therapeutic intervention. Here, we review the clinicopathologic features of NF2, current understanding of the molecular biology of NF2, particularly with regard to central nervous system lesions, ongoing therapeutic studies, and avenues for further research.

Correction to: An update on the CNS manifestations of neurofibromatosis type 2

The article An update on the CNS manifestations of neurofibromatosis type 2, written by Shannon Coy, Rumana Rashid, Anat Stemmer‑Rachamimov and Sandro Santagata, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 04 June 2019 without open access.

Multiplexed immunofluorescence reveals potential PD-1/PD-L1 pathway vulnerabilities in craniopharyngioma

Background

Craniopharyngiomas are neoplasms of the sellar/parasellar region that are classified into adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP) subtypes. Surgical resection of craniopharyngiomas is challenging, and recurrence is common, frequently leading to profound morbidity. BRAF V600E mutations render PCP susceptible to BRAF/MEK inhibitors, but effective targeted therapies are needed for ACP. We explored the feasibility of targeting the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint pathway in ACP and PCP.

Methods

We mapped and quantified PD-L1 and PD-1 expression in ACP and PCP resections using immunohistochemistry, immunofluorescence, and RNA in situ hybridization. We used tissue-based cyclic immunofluorescence to map the spatial distribution of immune cells and characterize cell cycle and signaling pathways in ACP tumor cells which intrinsically express PD-1.

Results

All ACP (15 ± 14% of cells, n = 23, average ± SD) and PCP (35 ± 22% of cells, n = 18) resections expressed PD-L1. In ACP, PD-L1 was predominantly expressed by tumor cells comprising the cyst lining. In PCP, PD-L1 was highly expressed by tumor cells surrounding the stromal fibrovascular cores. ACP also exhibited tumor cell-intrinsic PD-1 expression in whorled epithelial cells with nuclear-localized beta-catenin. These cells exhibited evidence of elevated mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) signaling. Profiling of immune populations in ACP and PCP showed a modest density of CD8+ T cells.

Conclusions

ACP exhibit PD-L1 expression in the tumor cyst lining and intrinsic PD-1 expression in cells proposed to comprise an oncogenic stem-like population. In PCP, proliferative tumor cells express PD-L1 in a continuous band at the stromal-epithelial interface. Targeting PD-L1 and/or PD-1 in both subtypes of craniopharyngioma might therefore be an effective therapeutic strategy.

Neuronal differentiation and cell-cycle programs mediate response to BET-bromodomain inhibition in MYC-driven medulloblastoma

BET-bromodomain inhibition (BETi) has shown pre-clinical promise for MYC-amplified medulloblastoma. However, the mechanisms for its action, and ultimately for resistance, have not been fully defined. Here, using a combination of expression profiling, genome-scale CRISPR/Cas9-mediated loss of function and ORF/cDNA driven rescue screens, and cell-based models of spontaneous resistance, we identify bHLH/homeobox transcription factors and cell-cycle regulators as key genes mediating BETi's response and resistance. Cells that acquire drug tolerance exhibit a more neuronally differentiated cell-state and expression of lineage-specific bHLH/homeobox transcription factors. However, they do not terminally differentiate, maintain expression of CCND2, and continue to cycle through S-phase. Moreover, CDK4/CDK6 inhibition delays acquisition of resistance. Therefore, our data provide insights about the mechanisms underlying BETi effects and the appearance of resistance and support the therapeutic use of combined cell-cycle inhibitors with BETi in MYC-amplified medulloblastoma.

Integrating Genomics Into Neuro-Oncology Clinical Trials and Practice

Important advances in our understanding of the molecular biology of brain tumors have resulted in a rapid evolution in the taxonomy of central nervous system (CNS) tumors, which culminated in the revised 2016 World Health Organization classification of CNS tumors that incorporates an integrated molecular/histologic diagnostic approach. Our expanding understanding of brain tumor genomics and molecular evolution during the disease course has started to impact clinical management. Furthermore, incorporation of genomic information in ongoing and planned neuro-oncology clinical trials is expected to lead to improved outcomes and result in personalized treatment options for patients with CNS malignancies.

A Cohort Study of the Natural History of Odontoid Pseudoarthrosis Managed Nonoperatively in Elderly Patients

OBJECTIVE

Although the primary goal of treatment of type II odontoid fracture is bony union, some advocate continued nonsurgical management of minimally symptomatic older patients who have fibrous union or minimal fracture motion. The risk of this strategy is unknown. We reviewed our long-term outcomes after dens nonunion to define the natural history of Type II odontoid fractures in elderly patients managed nonoperatively.

METHODS

A retrospective chart review of 50 consecutive adults aged 65 or older with Type II odontoid fracture initially managed nonsurgically from 1998 to 2012 at a single tertiary care institution was conducted. Particular attention was paid to patients who had orthosis removal despite absent bony fusion. Patients were contacted prospectively by telephone and followed until death, surgical intervention, or last known contact.

RESULTS

Fifty patients initially were managed nonsurgically; of these, 21 (42.0%) proceeded to bony fusion, 3 (6%) underwent delayed surgery for persistent instability, and 26 (52%) had orthosis removal despite the lack of solid arthrodesis on imaging. The last group had a median follow-up of 25 months (range 4-158 months), with 20 of 26 (76.9%) followed until death. Of these patients, 1 patient developed progressive quadriplegia and dysphagia 11 months after initial injury. Compared with patients with spontaneous union, patients with nonunion had shorter life expectancy, despite no significant differences between the groups with respect to age, sex, injury mechanism, radiographic variables, or follow-up duration.

CONCLUSIONS

Orthosis removal despite fracture nonunion may be reasonable in elderly patients with Type II dens fractures.

Correlation of Subjective Hospital Compare Metrics With Objective Outcomes of Cranial Neurosurgical Procedures in New York State

Background

Public reporting is at the forefront of health care reform.

Objective

To investigate whether patient satisfaction as expressed in a public reporting platform correlates with objective outcomes for cranial neurosurgery patients.

Methods

We performed a cohort study involving patients undergoing cranial neurosurgery from 2009 to 2013 who were registered in the Statewide Planning and Research Cooperative System database. This cohort was merged with the corresponding data from the Centers for Medicare and Medicaid Services Hospital Compare website. The association of patient satisfaction metrics with outcomes was examined with the use of a propensity-adjusted regression model.

Results

Overall, 19 591 patients underwent cranial neurosurgery during the study. Using a propensity-adjusted multivariable regression analysis, we demonstrated that hospitals with a greater percentage of patient-assigned "high" scores had decreased mortality (OR, 0.60; 95% CI, 0.53-0.67), rate of discharge to rehabilitation (OR, 0.93; 95% CI, 0.88-0.98), length of stay (adjusted difference, -1.29; 95% CI, -1.46 to -1.13), and hospitalization charges (adjusted difference, -23%; 95% CI, -36% to -9%) after cranial neurosurgery. Similar associations were identified for hospitals with a higher percentage of patients, who would recommend these institutions to others.

Conclusion

In a Centers for Medicare and Medicaid Services Hospital Compare-Statewide Planning and Research Cooperative System merged dataset, we observed an association of higher performance in patient satisfaction measures with decreased mortality, rate of discharge to rehabilitation, hospitalization charges, and length of stay.

Association of Hospital Teaching Status with Neurosurgical Outcomes: An Instrumental Variable Analysis

BACKGROUND

The interpretation of the results of prior studies on the association of hospital teaching status with surgical outcomes is limited by selection bias. We investigated whether undergoing surgical operations in teaching hospitals is associated with improved outcomes.

METHODS

We performed a cohort study of all patients undergoing spine and cranial operations who were registered in the New York Statewide Planning and Research Cooperative System database from 2009 to 2013. We examined the association of teaching status (defined as academic affiliation for the primary analysis) with inpatient case fatality, discharge to a facility, and length of stay (LOS). An instrumental variable analysis was used to control for unmeasured confounding and to simulate the effect of a randomized trial.

RESULTS

During the study period, 186,483 patients underwent surgical operations that met the inclusion criteria. Instrumental variable analysis demonstrated that hospitalization in teaching hospitals was associated with higher rates of case fatality (adjusted difference, 25%; 95% confidence interval [CI], 4%-46%), discharge to a facility (adjusted difference, 5.7%; 95% CI, 4.5%-7.0%), and longer LOS (adjusted difference, 31.4%; 95% CI, 16.0%-46.1%) in comparison with nonteaching hospitals. The same associations were present in propensity score adjusted mixed effects models. These persisted in prespecified subgroups stratified on particular operations and for different definitions of teaching hospitals.

CONCLUSIONS

Using a comprehensive all-payer cohort of surgical patients in New York State, we identified an association of treatment in teaching hospitals with increased case fatality, rate of discharge to rehabilitation, and longer LOS. Further research into the factors contributing to superior outcomes in nonteaching institutions is warranted.

Does the ranking of surgeons in a publicly available online platform correlate with objective outcomes?

OBJECTIVE The accuracy of public reporting in health care, especially from private vendors, remains an issue of debate. The authors investigated the association of the publicly reported physician complication rates in an online platform with real-world adverse outcomes of the same physicians for patients undergoing posterior lumbar fusion. METHODS The authors performed a cohort study involving physicians performing posterior lumbar fusions between 2009 and 2013 who were registered in the Statewide Planning and Research Cooperative System database. This cohort was merged with publicly available data over the same time period from ProPublica, a private company. Mixed-effects multivariable regression models were used to investigate the association of publicly available complication rates with the rate of discharge to a rehabilitation facility, length of stay, mortality, and hospitalization charges for the same surgeons. RESULTS During the selected study period, there were 8,457 patients in New York State who underwent posterior lumbar fusion performed by the 56 surgeons represented in the ProPublica Surgeon Scorecard over the same time period. Using a mixed-effects multivariable regression model, the authors demonstrated that publicly reported physician-level complication rates were not associated with the rate of discharge to a rehabilitation facility (OR 0.97, 95% CI 0.72-1.31), length of stay (adjusted difference -0.1, 95% CI -0.5 to 0.2), mortality (OR 0.87, 95% CI 0.49-1.55), and hospitalization charges (adjusted difference $18,735, 95% CI -$59,177 to $96,647). Similarly, no association was observed when utilizing propensity score-adjusted models, and when restricting the cohort to a predefined subgroup of Medicare patients. CONCLUSIONS After merging a comprehensive all-payer posterior lumbar fusion cohort in New York State with data from the ProPublica Surgeon Scorecard over the same time period, the authors observed no association of publicly available physician complication rates with objective outcomes.

Does the ranking of surgeons in a publicly available online platform correlate with objective outcomes?

OBJECTIVE The accuracy of public reporting in health care, especially from private vendors, remains an issue of debate. The authors investigated the association of the publicly reported physician complication rates in an online platform with real-world adverse outcomes of the same physicians for patients undergoing posterior lumbar fusion. METHODS The authors performed a cohort study involving physicians performing posterior lumbar fusions between 2009 and 2013 who were registered in the Statewide Planning and Research Cooperative System database. This cohort was merged with publicly available data over the same time period from ProPublica, a private company. Mixed-effects multivariable regression models were used to investigate the association of publicly available complication rates with the rate of discharge to a rehabilitation facility, length of stay, mortality, and hospitalization charges for the same surgeons. RESULTS During the selected study period, there were 8,457 patients in New York State who underwent posterior lumbar fusion performed by the 56 surgeons represented in the ProPublica Surgeon Scorecard over the same time period. Using a mixed-effects multivariable regression model, the authors demonstrated that publicly reported physician-level complication rates were not associated with the rate of discharge to a rehabilitation facility (OR 0.97, 95% CI 0.72-1.31), length of stay (adjusted difference -0.1, 95% CI -0.5 to 0.2), mortality (OR 0.87, 95% CI 0.49-1.55), and hospitalization charges (adjusted difference $18,735, 95% CI -$59,177 to $96,647). Similarly, no association was observed when utilizing propensity score-adjusted models, and when restricting the cohort to a predefined subgroup of Medicare patients. CONCLUSIONS After merging a comprehensive all-payer posterior lumbar fusion cohort in New York State with data from the ProPublica Surgeon Scorecard over the same time period, the authors observed no association of publicly available physician complication rates with objective outcomes.

Comparison of outcomes of patients with inpatient or outpatient onset ischemic stroke

BACKGROUND

Reperfusion times for ischemic stroke occurring in the outpatient setting have improved significantly in recent years. However, quality improvement efforts have largely ignored ischemic stroke occurring in patients hospitalized for unrelated indications.

METHODS

We performed a cohort study involving patients with ischemic stroke (with inpatient or outpatient onset) from 2009 to 2013 who were registered in the Statewide Planning and Research Cooperative System (SPARCS) database. A propensity score-adjusted regression analysis was used to assess the association of location of onset and outcomes. Mixed effects methods were employed to control for clustering at the hospital level.

RESULTS

Of the 176 571 ischemic strokes, 160 157 (90.7%) occurred outside of a hospital and 16 414 (9.3%) occurred in patients hospitalized for unrelated indications. Using a logistic regression model with propensity score adjustment, we demonstrated that inpatient stroke onset was associated with increased inpatient mortality (OR 3.09; 95% CI 2.81 to 3.38), rate of discharge to rehabilitation (OR 2.57; 95% CI 2.37 to 2.79), and length of stay (LOS) (β=11.58; 95% CI 10.73 to 12.42). In addition, it was associated with lower odds (OR 0.69; 95% CI 0.62 to 0.77) of undergoing stroke-related interventions (mechanical thrombectomy and intravenous tissue plasminogen activator) compared with outpatient stroke onset.

CONCLUSIONS

Using a comprehensive all-payer cohort of patients with ischemic stroke in New York State, we identified an association of inpatient stroke onset with fewer stroke-related interventions and increased mortality, rate of discharge to rehabilitation, and LOS.

Surgical Clipping versus Endovascular Intervention for the Treatment of Subarachnoid Hemorrhage Patients in New York State

Object

Randomized trials have demonstrated a survival benefit for endovascular treatment of ruptured cerebral aneurysms. We investigated the association of surgical clipping and endovascular coiling with outcomes in subarachnoid hemorrhage (SAH) patients in a real-world regional cohort.

Methods

We performed a cohort study involving patients with ruptured cerebral aneurysms, who underwent surgical clipping, or endovascular coiling from 2009–2013 and were registered in the Statewide Planning and Research Cooperative System (SPARCS) database. An instrumental variable analysis was used to investigate the association of treatment technique with outcomes.

Results

Of the 4,098 patients undergoing treatment, 2,585 (63.1%) underwent coiling, and 1,513 (36.9%) underwent clipping. Using an instrumental variable analysis, we did not identify a difference in inpatient mortality [marginal effect (ME), -0.56; 95% CI, -1.03 to 0.02], length of stay (LOS) (ME, 1.72; 95% CI, -3.39 to 6.84), or the rate of 30-day readmissions (ME, -0.30; 95% CI, -0.82 to 0.22) between the two treatment techniques for patients with SAH. Clipping was associated with a higher rate of discharge to rehabilitation (ME, 0.63; 95% CI, 0.24 to 1.01). In sensitivity analysis, mixed effect regression, and propensity score adjusted regression models demonstrated identical results.

Conclusions

Using a comprehensive all-payer cohort of patients in New York State presenting with aneurysmal SAH we did not identify an association of treatment method with mortality, LOS or 30-day readmission. Clipping was associated with a higher rate of discharge to rehabilitation.

New York State: Comparison of Treatment Outcomes for Unruptured Cerebral Aneurysms Using an Instrumental Variable Analysis

Background

There is wide regional variation in the predominant treatment for unruptured cerebral aneurysms. We investigated the association of elective surgical clipping and endovascular coiling with mortality, readmission rate, length of stay, and discharge to rehabilitation.

Methods and Results

We performed a cohort study involving patients with unruptured cerebral aneurysms, who underwent surgical clipping or endovascular coiling from 2009 to 2013 and were registered in the Statewide Planning and Research Cooperative System database. An instrumental variable analysis was used to investigate the association of treatment technique with outcomes. Of the 4643 patients undergoing treatment, 3190 (68.7%) underwent coiling, and 1453 (31.3%) underwent clipping. Using an instrumental variable analysis, we did not identify a difference in inpatient mortality (marginal effect, 0.13; 95% CI, −0.30, 0.57), or the rate of 30-day readmission (marginal effect, −1.84; 95% CI −4.06, −0.37) between the 2 treatment techniques for patients with unruptured cerebral aneurysms. Clipping was associated with a higher rate of discharge to rehabilitation (marginal effect, 2.31; 95% CI 0.21, 4.41), and longer length of stay (β, 2.01; 95% CI 0.85, 3.04). In sensitivity analysis, mixed-effect regression, and propensity score, adjusted regression models demonstrated identical results.

Conclusions

Using a comprehensive all-payer cohort of patients in New York State with unruptured cerebral aneurysms, we did not identify an association of treatment method with mortality or 30-day readmission. Clipping was associated with a higher rate of discharge to rehabilitation and longer length of stay.

Selective identification of hedgehog pathway antagonists by direct analysis of smoothened ciliary translocation

Hedgehog (Hh) signaling promotes tumorigenesis. The accumulation of the membrane protein Smoothened (Smo) within the primary cilium (PC) is a key event in Hh signal transduction, and many pharmacological inhibitors identified to date target Smo's actions. Smo ciliary translocation is inhibited by some pathway antagonists, while others promote ciliary accumulation, an outcome that can lead to a hypersensitive state on renewal of Hh signaling. To identify novel inhibitory compounds acting on the critical mechanistic transition of Smo accumulation, we established a high content screen to directly analyze Smo ciliary translocation. Screening thousands of compounds from annotated libraries of approved drugs and other agents, we identified several new classes of compounds that block Sonic hedgehog-driven Smo localization within the PC. Selective analysis was conducted on two classes of Smo antagonists. One of these, DY131, appears to inhibit Smo signaling through a common binding site shared by previously reported Smo agonists and antagonists. Antagonism by this class of compound is competed by high doses of Smo-binding agonists such as SAG and impaired by a mutation that generates a ligand-independent, oncogenic form of Smo (SmoM2). In contrast, a second antagonist of Smo accumulation within the PC, SMANT, was less sensitive to SAG-mediated competition and inhibited SmoM2 at concentrations similar to those that inhibit wild-type Smo. Our observations identify important differences among Hh antagonists and the potential for development of novel therapeutic approaches against mutant forms of Smo that are resistant to current therapeutic strategies.

In vivo natriuretic peptide reporter assay identifies chemical modifiers of hypertrophic cardiomyopathy signalling

AIMS

Despite increased understanding of the fundamental biology regulating cardiomyocyte hypertrophy and heart failure, it has been challenging to find novel chemical or genetic modifiers of these pathways. Traditional cell-based methods do not model the complexity of an intact cardiovascular system and mammalian models are not readily adaptable to chemical or genetic screens. Our objective was to create an in vivo model suitable for chemical and genetic screens for hypertrophy and heart failure modifiers.

METHODS AND RESULTS

Using the developing zebrafish, we established that the cardiac natriuretic peptide genes (nppa and nppb), known markers of cardiomyocyte hypertrophy and heart failure, were induced in the embryonic heart by pathological cardiac stimuli. This pathological induction was distinct from the developmental regulation of these genes. We created a luciferase-based transgenic reporter line that accurately modelled the pathological induction patterns of the zebrafish nppb gene. Utilizing this reporter line, we were able to show remarkable conservation of pharmacological responses between the larval zebrafish heart and adult mammalian models.

CONCLUSION

By performing a focused screen of chemical agents, we were able to show a distinct response of a genetic model of hypertrophic cardiomyopathy to the histone deacetylase inhibitor, Trichostatin A, and the mitogen-activated protein kinase kinase 1/2 inhibitor, U0126. We believe this in vivo reporter line will offer a unique approach to the identification of novel chemical or genetic regulators of myocardial hypertrophy and heart failure.

Human cardiomyopathy mutations induce myocyte hyperplasia and activate hypertrophic pathways during cardiogenesis in zebrafish

To assess the effects during cardiac development of mutations that cause human cardiomyopathy, we modeled a sarcomeric gene mutation in the embryonic zebrafish. We designed morpholino antisense oligonucleotides targeting the exon 13 splice donor site in the zebrafish cardiac troponin T (tnnt2) gene, in order to precisely recapitulate a human TNNT2 mutation that causes hypertrophic cardiomyopathy (HCM). HCM is a disease characterized by myocardial hypertrophy, myocyte and myofibrillar disarray, as well as an increased risk of sudden death. Similar to humans with HCM, the morphant zebrafish embryos displayed sarcomere disarray and there was a robust induction of myocardial hypertrophic pathways. Microarray analysis uncovered a number of shared transcriptional responses between this zebrafish model and a well-characterized mouse model of HCM. However, in contrast to adult hearts, these embryonic hearts developed cardiomyocyte hyperplasia in response to this genetic perturbation. The re-creation of a human disease-causing TNNT2 splice variant demonstrates that sarcomeric mutations can alter cardiomyocyte biology at the earliest stages of heart development with distinct effects from those observed in adult hearts despite shared transcriptional responses.

Concentrations and total daily output of micronutrients in breast milk of mothers delivering preterm: a longitudinal study

The number of preterm infants fed their own mother's milk appears to be increasing as a result of information suggesting certain benefits over milk from human milk banks or proprietary formulas. It is also apparent that the nutritional requirements of term and preterm infants differ. Thus, the finding of various deficiencies in small preterm infants indicates that studies which examine the nutrient content of milk from mothers who deliver prematurely are important to aid in suggesting appropriate supplementation. In order to provide appropriate recommendations, nutrient content must be assayed during the period of exclusive milk feedings. Accordingly, the concentrations and total daily output of breast milk zinc and copper, and vitamins A, C, and E, were examined in a group of 13 mothers delivering at or before 32 weeks gestation. Collections of a total 24-h output were obtained every 7 days for the first 7 weeks after delivery. Concentrations of all micronutrients were similar to those reported previously during the first 5 weeks of lactation. Most striking, however, was the progressive decline in total output as well as concentration of zinc. After the first 2 weeks of lactation, levels of copper and vitamins A, C, and E were not affected by the duration of lactation. There was substantial variation between mothers in daily output of all the micronutrients. The low output of these micronutrients suggests that some attempt should be made at monitoring the mineral and vitamin status of small preterm infants fed exclusively human milk for the first 3 months of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidermal growth factor in human milk: daily production and diurnal variation during early lactation in mothers delivering at term and at premature gestation

Epidermal growth factor is a polypeptide that stimulates proliferation and differentiation of a variety of cell types, including the developing intestinal epithelium; it is the agent in human milk that induces mitosis in human fibroblast culture. We systematically evaluated the EGF content of milk from 20 women delivering prematurely and from 11 women delivering at term. In preterm mothers, the concentration of EGF was 70 +/- 5 ng/ml (mean +/- SEM), with no significant change during seven weeks of lactation. EGF concentration in milk of term mothers was 68 +/- 19 ng/ml (mean +/- SEM). No diurnal variation in the concentration was found. Total EGF content was closely correlated with the volume of milk expressed, suggesting a passive transport from the circulation. These observations confirm that a substantial amount of EGF is present in human milk and that EGF concentrations are not affected by duration of gestation, time of day, or duration of lactation.