3D Whole-Brain Imaging Approaches to Study Brain Tumors

Interplay Between Schwann Cells and Peripheral Cancers: Mechanisms and Therapeutic Targets in Cancer Progression

Cancer, a leading global health concern, is characterized by uncontrolled proliferation of cells, high invasion into surrounding tissues, and eventual metastasis to distant organs. The complexity of cancer is further amplified by diverse cellular components within the tumor microenvironment (TME), encompassing both cancerous and non-cancerous cells that fuel tumorigenesis and progression. Schwann cells (SCs), the main glial cells of the peripheral nervous system, have emerged as crucial components within the TME in cancer development. Here, we summarize the multifaceted roles of SCs in tumor growth, epithelial-mesenchymal transition, perineural invasion, and chemotherapy resistance. This review focuses on the effects of SCs on eight distinct peripheral cancer types, particularly pancreatic, lung, and colorectal cancers, along with cancer-related pain, one of the most common symptoms that affect quality of life and prognosis in cancer patients. Furthermore, we emphasize the therapeutic potential of SCs by delving into advanced technologies and clinical strategies related to SCs, which make us advocate for further research to elucidate the events and molecular mechanisms underlying the SC-cancer relationship. Translating these insights into clinical applications may offer new hope for improved cancer management and patient outcomes.

Recent advances in 3D printing applications for CNS tumours

Three-dimensional printing (3DP) has emerged as a transformative technology in the field of central nervous system (CNS) tumours, offering innovative advancements in various aspects of diagnosis, treatment and education. By precisely replicating the microenvironment of CNS tumours, modelling tumour vascularisation, and capturing genetic heterogeneity, 3DP enables the development of targeted therapies and personalised treatment strategies. The technology has markedly enhanced preoperative planning and intraoperative guidance, providing highly accurate, patient-specific models that improve tumour localisation, facilitate tailored surgical planning, and offer superior visualisation of complex anatomical structures. Furthermore, 3DP has revolutionised education and training for neurosurgeons, trainees, and patients by delivering realistic simulations that enhance surgical skills and decision-making. Despite its transformative potential, the widespread adoption of 3DP faces challenges, including material biocompatibility issues, high costs, and technical limitations. Furthermore, the ethical and regulatory landscape for 3DP in clinical practice requires further development. This review concludes that while 3DP offers significant promise for advancing CNS tumour treatment, ongoing research is essential to address these challenges and optimising its clinical impact.

Application of fluorescence micro-optical sectioning tomography in the cerebrovasculature and applicable vascular labeling methods

Fluorescence micro-optical sectioning tomography (fMOST) is a three-dimensional (3d) imaging method at the mesoscopic level. The whole-brain of mice can be imaged at a high resolution of 0.32 × 0.32 × 1.00 μm3. It is useful for revealing the fine morphology of intact organ tissue, even for positioning the single vessel connected with a complicated vascular network across different brain regions in the whole mouse brain. Featuring its 3d visualization of whole-brain cross-scale connections, fMOST has a vast potential to decipher brain function and diseases. This article begins with the background of fMOST technology including a widespread 3D imaging methods comparison and the basic technical principal illustration, followed by the application of fMOST in cerebrovascular research and relevant vascular labeling techniques applicable to different scenarios.

Revealing the three-dimensional murine brain microstructure by contrast-enhanced computed tomography

To improve our understanding of the brain microstructure, high-resolution 3D imaging is used to complement classical 2D histological assessment techniques. X-ray computed tomography allows high-resolution 3D imaging, but requires methods for enhancing contrast of soft tissues. Applying contrast-enhancing staining agents (CESAs) ameliorates the X-ray attenuating properties of soft tissue constituents and is referred to as contrast-enhanced computed tomography (CECT). Despite the large number of chemical compounds that have successfully been applied as CESAs for imaging brain, they are often toxic for the researcher, destructive for the tissue and without proper characterization of affinity mechanisms. We evaluated two sets of chemically related CESAs (organic, iodinated: Hexabrix and CA4+ and inorganic polyoxometalates: 1:2 hafnium-substituted Wells-Dawson phosphotungstate and Preyssler anion), for CECT imaging of healthy murine hemispheres. We then selected the CESA (Hexabrix) that provided the highest contrast between gray and white matter and applied it to a cuprizone-induced demyelination model. Differences in the penetration rate, effect on tissue integrity and affinity for tissue constituents have been observed for the evaluated CESAs. Cuprizone-induced demyelination could be visualized and quantified after Hexabrix staining. Four new non-toxic and non-destructive CESAs to the field of brain CECT imaging were introduced. The added value of CECT was shown by successfully applying it to a cuprizone-induced demyelination model. This research will prove to be crucial for further development of CESAs for ex vivo brain CECT and 3D histopathology.

Combined whole-organ imaging at single-cell resolution and immunohistochemical analysis of prostate cancer and its liver and brain metastases

Early steps of cancer initiation and metastasis, while critical for understanding disease mechanisms, are difficult to visualize and study. Here, we describe an approach to study the processes of initiation, progression, and metastasis of prostate cancer (PC) in a genetically engineered RapidCaP mouse model, which combines whole-organ imaging by serial two-photon tomography (STPT) and post hoc thick-section immunofluorescent (IF) analysis. STPT enables the detection of single tumor-initiating cells within the entire prostate, and consequent IF analysis reveals a transition from normal to transformed epithelial tissue and cell escape from the tumor focus. STPT imaging of the liver and brain reveal the distribution of multiple metastatic foci in the liver and an early-stage metastatic cell invasion in the brain. This imaging and data analysis pipeline can be readily applied to other mouse models of cancer, offering a highly versatile whole-organ platform to study in situ mechanisms of cancer initiation and progression.

Scientists have long known that tumors are initiated by few cells. The detection of these cells with high resolution is a challenge due to the microscopic dimensions of organs. Taranda et al. use STP tomography combined with traditional histology to describe these events in prostate cancer and its metastasis.