Allopregnanolone suppresses glioblastoma survival through decreasing DPYSL3 and S100A11 expression

Progesterone boosts abiraterone-driven target and NK cell therapies against glioblastoma

INTRODUCTION

Glioblastoma (GBM) poses a significant challenge in oncology, with median survival times barely extending beyond a year due to resistance to standard therapies like temozolomide (TMZ). This study introduces a novel therapeutic strategy combining progesterone (Prog) and abiraterone (Abi) aimed at enhancing GBM treatment efficacy by modulating the tumor microenvironment and augmenting NK cell-mediated immunity.

METHODS

We employed in vitro and in vivo GBM models to assess the effects of Prog and Abi on cell viability, proliferation, apoptosis, and the immune microenvironment. Techniques included cell viability assays, Glo-caspase 3/7 apoptosis assays, RNA-seq and qPCR for gene expression, Seahorse analysis for mitochondrial function, HPLC-MS for metabolomics analysis, and immune analysis by flow cytometry to quantify NK cell infiltration.

RESULTS

Prog significantly reduced the IC50 of Abi in TMZ-resistant GBM cell, suggesting the enhanced cytotoxicity. Treatment induced greater apoptosis than either agent alone, suppressed tumor growth, and prolonged survival in mouse models. Notably, there was an increase in CD3-/CD19-/CD56+/NK1.1+ NK cell infiltration in treated tumors, indicating a shift towards an anti-tumor immune microenvironment. The combination therapy also resulted in a reduction of MGMT expression and a suppression of mitochondrial respiration and glycolysis in GBM cells.

CONCLUSION

The combination of Prog and Abi represents a promising therapeutic approach for GBM, showing potential in suppressing tumor growth, extending survival, and modulating the immune microenvironment. These findings warrant further exploration into the clinical applicability of this strategy to improve outcomes for GBM patients.

Cancer-cell derived S100A11 promotes macrophage recruitment in ER+ breast cancer

Macrophages are pivotal in driving breast tumor development, progression, and resistance to treatment, particularly in estrogen receptor-positive (ER+) tumors, where they infiltrate the tumor microenvironment (TME) influenced by cancer cell-secreted factors. By analyzing single-cell RNA-sequencing data from 25 ER+ tumors, we elucidated interactions between cancer cells and macrophages, correlating macrophage density with epithelial cancer cell density. We identified that S100A11, a previously unexplored factor in macrophage-cancer crosstalk, predicts high macrophage density and poor outcomes in ER+ tumors. We found that recombinant S100A11 enhances macrophage infiltration and migration in a dose-dependent manner. Additionally, in 3D models, we showed that S100A11 expression levels in ER+ cancer cells predict macrophage infiltration patterns. Neutralizing S100A11 decreased macrophage recruitment, both in cancer cell lines and in a clinically relevant patient-derived organoid model, underscoring its role as a paracrine regulator of cancer-macrophage interactions in the protumorigenic TME. This study offers novel insights into the interplay between macrophages and cancer cells in ER+ breast tumors, highlighting S100A11 as a potential therapeutic target to modulate the macrophage-rich tumor microenvironment.

NCI677397 targeting USP24-mediated induction of lipid peroxidation induces ferroptosis in drug-resistant cancer cells

Cancer represents a profound challenge to healthcare systems and individuals worldwide. The development of multiple drug resistance is a major problem in cancer therapy and can result in progression of the disease. In our previous studies, we developed small-molecule inhibitors targeting ubiquitin-specific peptidase 24 (USP24) to combat drug-resistant lung cancer. Recently, we found that the USP24 inhibitor NCI677397 induced ferroptosis, a type of programmed cell death, in drug-resistant cancer cells by increasing lipid reactive oxygen species (ROS) levels. In the present study, we investigated the molecular mechanisms and found that the targeting of USP24 by NCI677397 increased gene expression of most lipogenesis-related genes, such as acyl-CoA synthetase long-chain family member 4 (ACSL4), and activated autophagy. In addition, the activity of several antioxidant enzymes, such as glutathione peroxidase 4 (GPX4) and dihydrofolate reductase (DHFR), was inhibited by NCI677397 treatment via an increase in protein degradation, thereby inducing lipid ROS production and lipid peroxidation. In summary, we demonstrated that NCI677397 induced a marked increase in lipid ROS levels, subsequently causing lipid peroxidation and leading to the ferroptotic death of drug-resistant cancer cells. Our study provides new insights into the clinical use of USP24 inhibitors as ferroptosis inducers (FINs) to block drug resistance during chemotherapy.

Ion Channels and Ionotropic Receptors in Astrocytes: Physiological Functions and Alterations in Alzheimer's Disease and Glioblastoma

The human brain is composed of nearly one hundred billion neurons and an equal number of glial cells, including macroglia, i.e., astrocytes and oligodendrocytes, and microglia, the resident immune cells of the brain. In the last few decades, compelling evidence has revealed that glial cells are far more active and complex than previously thought. In particular, astrocytes, the most abundant glial cell population, not only take part in brain development, metabolism, and defense against pathogens and insults, but they also affect sensory, motor, and cognitive functions by constantly modulating synaptic activity. Not surprisingly, astrocytes are actively involved in neurodegenerative diseases (NDs) and other neurological disorders like brain tumors, in which they rapidly become reactive and mediate neuroinflammation. Reactive astrocytes acquire or lose specific functions that differently modulate disease progression and symptoms, including cognitive impairments. Astrocytes express several types of ion channels, including K+, Na+, and Ca2+ channels, transient receptor potential channels (TRP), aquaporins, mechanoreceptors, and anion channels, whose properties and functions are only partially understood, particularly in small processes that contact synapses. In addition, astrocytes express ionotropic receptors for several neurotransmitters. Here, we provide an extensive and up-to-date review of the roles of ion channels and ionotropic receptors in astrocyte physiology and pathology. As examples of two different brain pathologies, we focus on Alzheimer's disease (AD), one of the most diffuse neurodegenerative disorders, and glioblastoma (GBM), the most common brain tumor. Understanding how ion channels and ionotropic receptors in astrocytes participate in NDs and tumors is necessary for developing new therapeutic tools for these increasingly common neurological conditions.

Allopregnanolone: Metabolism, Mechanisms of Action, and Its Role in Cancer

Allopregnanolone (3α-THP) has been one of the most studied progesterone metabolites for decades. 3α-THP and its synthetic analogs have been evaluated as therapeutic agents for pathologies such as anxiety and depression. Enzymes involved in the metabolism of 3α-THP are expressed in classical and nonclassical steroidogenic tissues. Additionally, due to its chemical structure, 3α-THP presents high affinity and agonist activity for nuclear and membrane receptors of neuroactive steroids and neurotransmitters, such as the Pregnane X Receptor (PXR), membrane progesterone receptors (mPR) and the ionotropic GABA_A receptor, among others. 3α-THP has immunomodulator and antiapoptotic properties. It also induces cell proliferation and migration, all of which are critical processes involved in cancer progression. Recently the study of 3α-THP has indicated that low physiological concentrations of this metabolite induce the progression of several types of cancer, such as breast, ovarian, and glioblastoma, while high concentrations inhibit it. In this review, we explore current knowledge on the metabolism and mechanisms of action of 3α-THP in normal and tumor cells.

Allopregnanolone Promotes Migration and Invasion of Human Glioblastoma Cells through the Protein Tyrosine Kinase c-Src Activation

Glioblastomas (GBs) are the most aggressive and common primary malignant brain tumors. Steroid hormone progesterone (P4) and its neuroactive metabolites, such as allopregnanolone (3α-THP) are synthesized by neural, glial, and malignant GB cells. P4 promotes cellular proliferation, migration, and invasion of human GB cells at physiological concentrations. It has been reported that 3α-THP promotes GB cell proliferation. Here we investigated the effects of 3α-THP on GB cell migration and invasion, the participation of the enzymes involved in its metabolism (AKR1C1-4), and the role of the c-Src kinase in 3α-THP effects in GBs. 3α-THP 100 nM promoted migration and invasion of U251, U87, and LN229 human-derived GB cell lines. We observed that U251, LN229, and T98G cell lines exhibited a higher protein content of AKR1C1-4 than normal human astrocytes. AKR1C1-4 silencing did not modify 3α-THP effects on migration and invasion. 3α-THP activated c-Src protein at 10 min (U251 cells) and 15 min (U87 and LN229 cells). Interestingly, the pharmacological inhibition of c-Src decreases the promoting effects of 3α-THP on cell migration and invasion. Together, these data indicate that 3α-THP promotes GB migration and invasion through c-Src activation.