Hypoxia induced responses are reflected in the stromal proteome of breast cancer

A micro-metabolic rewiring assay for assessing hypoxia-associated cancer metabolic heterogeneity

Cancer metabolism plays an essential role in therapeutic resistance, where significant inter- and intra-tumoral heterogeneity exists. Hypoxia is a prominent driver of metabolic rewiring behaviors and drug responses. Recapitulating the hypoxic landscape in the tumor microenvironment thus offers unique insights into heterogeneity in metabolic rewiring and therapeutic responses, to inform better treatment strategies. There remains a lack of scalable tools that can readily interface with imaging platforms and resolve the heterogeneous behaviors in hypoxia-associated metabolic rewiring. Here we present a micro-metabolic rewiring (μMeRe) assay that provides the scalability and resolution needed to characterize the metabolic rewiring behaviors of different cancer cells in the context of hypoxic solid tumors. Our assay generates hypoxia through cellular metabolism without external gas controls, enabling the characterization of cell-specific intrinsic ability to drive hypoxia and undergo metabolic rewiring. We further developed quantitative metrics that measure the metabolic plasticity through phenotypes and gene expression. As a proof-of-concept, we evaluated the efficacy of a metabolism-targeting strategy in mitigating hypoxia- and metabolic rewiring-induced chemotherapeutic resistance. Our study and the scalable platform thus lay the foundation for designing more effective cancer treatments tailored toward specific metabolic rewiring behaviors.

Tumor Hypoxia: How Conventional Histology Is Reshaped in Breast Carcinoma

Intratumoral hypoxia is common in any form of malignancy initializing focal necrosis or tumor cell adaptation. Hypoxia inducible factor-1-driven reprogramming favors the loss of tumor cell proliferation (quiescence) and partial cellular reversion, induces stemness and/or mesenchymal-like features in the exposed tumor areas. The characteristic hypoxia-driven tumor cell phenotype is principally directed to reduce energy consumption and to enhance survival, but the gained features also contribute to growth advantage and induce the reorganization of the microenvironment and protective mechanisms against external stress. The hypoxia-induced phenotypic changes are at least in part reflected by conventional morphology in breast carcinoma. Intratumoral variability of classical morphological signs, such as the growth pattern, the histological grade, cell proliferation, necrosis, microcalcification, angiogenesis, and the immune cell infiltration is also related with the co-existence of hypoxic areas. Thus, a deeper understanding of hypoxia-activated mechanisms is required. The current paper aims to summarize the major tissue factors involved in the response to hypoxia and their potential contribution to the breast carcinoma phenotype.

Circadian rhythm, hypoxia, and cellular senescence: From molecular mechanisms to targeted strategies

Cellular senescence precipitates a decline in physiological activities and metabolic functions, often accompanied by heightened inflammatory responses, diminished immune function, and impaired tissue and organ performance. Despite extensive research, the mechanisms underpinning cellular senescence remain incompletely elucidated. Emerging evidence implicates circadian rhythm and hypoxia as pivotal factors in cellular senescence. Circadian proteins are central to the molecular mechanism governing circadian rhythm, which regulates homeostasis throughout the body. These proteins mediate responses to hypoxic stress and influence the progression of cellular senescence, with protein Brain and muscle arnt-like 1 (BMAL1 or Arntl) playing a prominent role. Hypoxia-inducible factor-1α (HIF-1α), a key regulator of oxygen homeostasis within the cellular microenvironment, orchestrates the transcription of genes involved in various physiological processes. HIF-1α not only impacts normal circadian rhythm functions but also can induce or inhibit cellular senescence. Notably, HIF-1α may aberrantly interact with BMAL1, forming the HIF-1α-BMAL1 heterodimer, which can instigate multiple physiological dysfunctions. This heterodimer is hypothesized to modulate cellular senescence by affecting the molecular mechanism of circadian rhythm and hypoxia signaling pathways. In this review, we elucidate the intricate relationships among circadian rhythm, hypoxia, and cellular senescence. We synthesize diverse evidence to discuss their underlying mechanisms and identify novel therapeutic targets to address cellular senescence. Additionally, we discuss current challenges and suggest potential directions for future research. This work aims to deepen our understanding of the interplay between circadian rhythm, hypoxia, and cellular senescence, ultimately facilitating the development of therapeutic strategies for aging and related diseases.

Global and single-cell proteomics view of the co-evolution between neural progenitors and breast cancer cells in a co-culture model

BACKGROUND

Presence of nerves in tumours, by axonogenesis and neurogenesis, is gaining increased attention for its impact on cancer initiation and development, and the new field of cancer neuroscience is emerging. A recent study in prostate cancer suggested that the tumour microenvironment may influence cancer progression by recruitment of Doublecortin (DCX)-expressing neural progenitor cells (NPCs). However, the presence of such cells in human breast tumours has not been comprehensively explored.

METHODS

Here, we investigate the presence of DCX-expressing cells in breast cancer stromal tissue from patients using Imaging Mass Cytometry. Single-cell analysis of 372,468 cells across histopathological images of 107 breast cancers enabled spatial resolution of neural elements in the stromal compartment in correlation with clinicopathological features of these tumours. In parallel, we established a 3D in vitro model mimicking breast cancer neural progenitor-innervation and examined the two cell types as they co-evolved in co-culture by using mass spectrometry-based global proteomics.

FINDINGS

Stromal presence of DCX + cells is associated with tumours of higher histological grade, a basal-like phenotype, and shorter patient survival in tumour tissue from patients with breast cancer. Global proteomics analysis revealed significant changes in the proteomic landscape of both breast cancer cells and neural progenitors in co-culture.

INTERPRETATION

These results support that neural involvement plays an active role in breast cancer and warrants further studies on the relevance of nerve elements for tumour progression.

FUNDING

This work was supported by the Research Council of Norway through its Centre of Excellence funding scheme, project number 223250 (to L.A.A), the Norwegian Cancer Society (to L.A.A. and H.V.), the Regional Health Trust Western Norway (Helse Vest) (to L.A.A.), the Meltzer Research Fund (to H.V.) and the National Institutes of Health (NIH)/NIGMS grant R01 GM132129 (to J.A.P.).

Self-Referenced Au Nanoparticles-Coated Glass Wafers for In Situ SERS Monitoring of Cell Secretion

Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for discrimination of bimolecules in complex systems. However, its practical applications face challenges such as complicated manufacturing procedures and limited scalability of SERS substrates, as well as poor reproducibility during detection which compromises the reliability of SERS-based analysis. In this study, we developed a convenient method for simultaneous fabrication of massive SERS substrates with an internal standard to eliminate the substrate-to-substrate differences. We first synthesized Au@CN@Au nanoparticles (NPs) which contain embedded internal standard molecules with a single characteristic peak in the Raman-silent region, and then deposited the NPs on 6 mm glass wafers in a 96-well plate simply by centrifugation for 3 min. The one-time obtained 96 SERS substrates have excellent intrasubstrate uniformity and intersubstrate repeatability for SERS detection by using the internal standard (relative standard deviation = 10.47%), and were able to detect both charged and neutral molecules (crystal violet and triphenylphosphine) at a concentration of 10-9 M. Importantly, cells can be directly cultured on glass wafers in the 96-well plate, enabling real time monitoring of the secretes and metabolism change in response to external stimulation. We found that the release of nucleic acids, amino acids and lipids by MDA-MB-231 cells significantly increased under hypoxic conditions. Overall, our approach enables fast and large-scale production of Au@CN@Au NPs-coated glass wafers as SERS substrates, which are homogeneous and highly sensitive for monitoring trace changes of biomolecules.

Spatial transcriptomics of gastric cancer brain metastasis reveals atypical vasculature strategies with supportive immune profiles

Background

Gastric cancer brain metastasis (GCBM) represents a rare but highly aggressive malignancy. Metastatic cancer cells are highly heterogeneous and differentially remodels brain vasculature and immune microenvironments, which affects the treatment effectiveness and patient outcome. This study aimed to investigate the spatial interactions among different cell components, especially the vasculature system and the brain microenvironment of GCBM patients.

Methods

We used digital spatial profiling to examine 140 regions composing tumor, immune, and brain tissues from three GCBM patients. Transcriptomic data with spatial information were analyzed for tissue areas related to different blood recruitment strategies. For validation, independent analysis of patient bulk transcriptomic data and in vivo single-cell transcriptomic data were performed.

Results

Angiogenesis and blood vessel co-option co-existed within the same GCBM lesion. Tumors with high epithelial-mesenchymal transition and an enhanced transcriptomic gene signature composed of CTNNB1, SPARC, VIM, SMAD3, SMAD4, TGFB1, TGFB2, and TGFB3 were more prone to adopt blood vessel co-option than angiogenesis. Enriched macrophage infiltration, angiogenic chemokines, and NAMPT were found in angiogenic areas, while increased T cells, T cell activating cytokines, and reduced NAMPT were found in vessel co-option regions. Spatially, angiogenesis was enriched at the tumor edge, which showed higher DMBT1 expression than the tumor center.

Conclusions

This study mapped the orchestrated spatial characteristics of tumor and immunological compositions that support the conventional and atypical vascularization strategies in GCBM. Our data provided molecular insights for more effective combinations of anti-vascular and immune therapies.

Onco-Breastomics: An Eco-Evo-Devo Holistic Approach

Known as a diverse collection of neoplastic diseases, breast cancer (BC) can be hyperbolically characterized as a dynamic pseudo-organ, a living organism able to build a complex, open, hierarchically organized, self-sustainable, and self-renewable tumor system, a population, a species, a local community, a biocenosis, or an evolving dynamical ecosystem (i.e., immune or metabolic ecosystem) that emphasizes both developmental continuity and spatio-temporal change. Moreover, a cancer cell community, also known as an oncobiota, has been described as non-sexually reproducing species, as well as a migratory or invasive species that expresses intelligent behavior, or an endangered or parasite species that fights to survive, to optimize its features inside the host's ecosystem, or that is able to exploit or to disrupt its host circadian cycle for improving the own proliferation and spreading. BC tumorigenesis has also been compared with the early embryo and placenta development that may suggest new strategies for research and therapy. Furthermore, BC has also been characterized as an environmental disease or as an ecological disorder. Many mechanisms of cancer progression have been explained by principles of ecology, developmental biology, and evolutionary paradigms. Many authors have discussed ecological, developmental, and evolutionary strategies for more successful anti-cancer therapies, or for understanding the ecological, developmental, and evolutionary bases of BC exploitable vulnerabilities. Herein, we used the integrated framework of three well known ecological theories: the Bronfenbrenner's theory of human development, the Vannote's River Continuum Concept (RCC), and the Ecological Evolutionary Developmental Biology (Eco-Evo-Devo) theory, to explain and understand several eco-evo-devo-based principles that govern BC progression. Multi-omics fields, taken together as onco-breastomics, offer better opportunities to integrate, analyze, and interpret large amounts of complex heterogeneous data, such as various and big-omics data obtained by multiple investigative modalities, for understanding the eco-evo-devo-based principles that drive BC progression and treatment. These integrative eco-evo-devo theories can help clinicians better diagnose and treat BC, for example, by using non-invasive biomarkers in liquid-biopsies that have emerged from integrated omics-based data that accurately reflect the biomolecular landscape of the primary tumor in order to avoid mutilating preventive surgery, like bilateral mastectomy. From the perspective of preventive, personalized, and participatory medicine, these hypotheses may help patients to think about this disease as a process governed by natural rules, to understand the possible causes of the disease, and to gain control on their own health.