Roles of Neutrophils in Glioma and Brain Metastases

Neutrophils, which are the most abundant circulating leukocytes in humans, are the first line of defense against bacterial and fungal infections. Recent studies have reported the role and importance of neutrophils in cancers. Glioma and brain metastases are the most common malignant tumors of the brain. The tumor microenvironment (TME) in the brain is complex and unique owing to the brain-blood barrier or brain-tumor barrier, which may prevent drug penetration and decrease the efficacy of immunotherapy. However, there are limited studies on the correlation between brain cancer and neutrophils. This review discusses the origin and functions of neutrophils. Additionally, the current knowledge on the correlation between neutrophil-to-lymphocyte ratio and prognosis of glioma and brain metastases has been summarized. Furthermore, the implications of tumor-associated neutrophil (TAN) phenotypes and the functions of TANs have been discussed. Finally, the potential effects of various treatments on TANs and the ability of neutrophils to function as a nanocarrier of drugs to the brain TME have been summarized. However, further studies are needed to elucidate the complex interactions between neutrophils, other immune cells, and brain tumor cells.

Curcumae Radix Extract Reduces Beta-Amyloid (Αβ) and Tau Protein Through Increased Mitochondrial Respiration

Background: Neurodegenerative diseases are increasingly being studied owing to the increasing proportion of the aging population. Several potential compounds have been studied to prevent neurodegenerative diseases, one of which is Curcumae Radix that is known to be beneficial for inflammatory conditions, metabolic syndrome, and various types of pain. However, it is not well studied and its influence on energy metabolism in neurodegenerative diseases is unclear. We focused on the relationship between neurodegenerative diseases and energy metabolism through Curcumae Radix extract in an animal model. Methods: Mice were treated with Curcumae Radix extract for 5 weeks orally 5 times in a week (50 mg/kg body weight). Murine delayed brain tumor (DBT) cells were supplemented with Curcumae Radix extract. We monitored the neurodegenerative makers and metabolic indicators using Western blotting and qRT-PCR and then assessed the cellular glycolysis and mitochondrial respiration through metabolic flux assay.Results: Low expression levels of Alzheimer’s disease-related markers were observed after treatment with Curcumae Radix extract. It was determined through the pAMPK/AMPK ratio that the ATP state was sufficient in the cerebrum and brain tumor cells. With this, an increase in glycolysis would be expected as glucose is the main energy source of the brain. However, glycolysis-related genes and the extracellular acidification rate showed that glycolysis decreased. Despite this, basal respiration and ATP production through mitochondrial respiration and increased TCA cycle and OXPHOS-related genes were observed in the Curcumae Radix group. Conclusions: In neurodegenerative diseases involving mitochondrial dysfunction, Curcumae Radix may act as a metabolic modulator of brain health to treat and prevent these diseases.

Autocrine signaling explains the emergence of Allee effects in cancer cell populations

In many human cancers, the rate of cell growth depends crucially on the size of the tumor cell population. Low, zero, or negative growth at low population densities is known as the Allee effect; this effect has been studied extensively in ecology, but so far lacks a good explanation in the cancer setting. Here, we formulate and analyze an individual-based model of cancer, in which cell division rates are increased by the local concentration of an autocrine growth factor produced by the cancer cells themselves. We show, analytically and by simulation, that autocrine signaling suffices to cause both strong and weak Allee effects. Whether low cell densities lead to negative (strong effect) or reduced (weak effect) growth rate depends directly on the ratio of cell death to proliferation, and indirectly on cellular dispersal. Our model is consistent with experimental observations of brain tumor cells grown at different densities. We propose that further studying and quantifying population-wide feedback, impacting cell growth, will be central for advancing our understanding of cancer dynamics and treatment, potentially exploiting Allee effects for therapy.

Dense Hierarchical CNN – A Unified Approach for Brain Tumor Segmentation

Brain tumor segmentation is an essential and challenging task because of the heterogeneous nature of neoplastic tissue in spatial and imaging techniques. Manual segmentation of the tumor in MRI images is prone to error and time-consuming tasks. An efficient segmentation mechanism is vital to the accurate classification and segmentation of tumorous cells. This study presents an efficient hierarchical clustering-based dense CNN approach for accurately classifying and segmenting the brain tumor cells in MRI images. The research focuses on improving the efficiency of the segmentation algorithms by considering the qualitative measures such as the dice score coefficient using quantitative parameters such as mean square error and peak signal to noise ratio. The experimental analysis states the efficacy and prominence of the proposed technique compared to other models are tabulated within the paper.

Mechanisms of Invasion in Glioblastoma: Extracellular Matrix, Ca2+ Signaling, and Glutamate

Glioblastoma (GBM) is the most common and malignant form of primary brain tumor with a median survival time of 14–16 months in GBM patients. Surgical treatment with chemotherapy and radiotherapy may help increase survival by removing GBM from the brain. However, complete surgical resection to eliminate GBM is almost impossible due to its high invasiveness. When GBM cells migrate to the brain, they interact with various cells, including astrocytes, neurons, endothelial cells, and the extracellular matrix (ECM). They can also make their cell body shrink to infiltrate into narrow spaces in the brain; thereby, they can invade regions of the brain and escape from surgery. Brain tumor cells create an appropriate microenvironment for migration and invasion by modifying and degrading the ECM. During those processes, the Ca2+ signaling pathway and other signaling cascades mediated by various ion channels contribute mainly to gene expression, motility, and invasion of GBM cells. Furthermore, GBM cells release glutamate, affecting migration via activation of ionotropic glutamate receptors in an autocrine manner. This review focuses on the cellular mechanisms of glioblastoma invasion and motility related to ECM, Ca2+ signaling, and glutamate. Finally, we discuss possible therapeutic interventions to inhibit invasion by GBM cells.