Tumor cell-derived spermidine promotes a pro-tumorigenic immune microenvironment in glioblastoma via CD8+ T cell inhibition.

The glioblastoma (GBM) microenvironment is enriched in immunosuppressive factors that potently interfere with the function of cytotoxic T lymphocytes. Cancer cells can directly impact the immune system, but the mechanisms driving these interactions are not completely clear. Here we demonstrate that the polyamine metabolite spermidine (SPD) is elevated in the GBM tumor microenvironment.

Intestinal stem cells enhance local mucosal immunity through apoptotic body phagocytosis.

Modulation of immune tone at mucosal surfaces is critical to maintain homeostasis while facilitating the handling of emerging threats. One dynamic component of immune modulation is the phagocytosis and clearance of apoptotic bodies known as efferocytosis that inhibits inflammation by promoting its resolution. Here, we evaluated the effects of apoptotic body phagocytosis by intestinal epithelial stem and progenitor cells (ISCs).

Bubble reachers and uncivil discourse in polarized online public sphere.

Early optimism saw possibilities for social media to renew democratic discourse, marked by hopes for individuals from diverse backgrounds to find opportunities to learn from and interact with others different from themselves. This optimism quickly waned as social media seemed to breed ideological homophily marked by "filter bubbles" or "echo chambers." A typical response to the sense of fragmentation has been to encourage exposure to more cross-partisan sources of information.

Androgen loss weakens anti-tumor immunity and accelerates brain tumor growth.

Many cancers, including glioblastoma (GBM), have a male-biased sex difference in incidence and outcome. The underlying reasons for this sex bias are unclear but likely involve differences in tumor cell state and immune response. This effect is further amplified by sex hormones, including androgens, which have been shown to inhibit anti-tumor T cell immunity.

Cancer stem cell hypothesis 2.0 in glioblastoma: Where are we now and where are we going?

Over the past 2 decades, the cancer stem cell (CSC) hypothesis has provided insight into many malignant tumors, including glioblastoma (GBM). Cancer stem cells have been identified in patient-derived tumors and in some mouse models, allowing for a deeper understanding of cellular and molecular mechanisms underlying GBM growth and therapeutic resistance. The CSC hypothesis has been the cornerstone of cellular heterogeneity, providing a conceptual and technical framework to explain this longstanding phenotype in GBM.

Should I stay or should I go? Transsulfuration influences invasion and growth in glioblastoma.

A major challenge in treating patients with glioblastoma is the inability to eliminate highly invasive cells with chemotherapy, radiation, or surgical resection. As cancer cells face the issue of replicating or invading neighboring tissue, they rewire their metabolism in a concerted effort to support necessary cellular processes and account for altered nutrient abundance. In this issue of the JCI, Garcia et al.

Homeostatic iron regulatory protein drives glioblastoma growth via tumor cell-intrinsic and sex-specific responses.

Background: Glioblastoma (GBM) displays alterations in iron that drive proliferation and tumor growth. Iron regulation is complex and involves many regulatory mechanisms, including the homeostatic iron regulator () gene, which encodes the homeostatic iron regulatory protein. While is upregulated in GBM and correlates with poor survival outcomes, the function of HFE in GBM remains unclear.

Tumor cell-derived spermidine promotes a pro-tumorigenic immune microenvironment in glioblastoma via CD8+ T cell inhibition.

The glioblastoma microenvironment is enriched in immunosuppressive factors that potently interfere with the function of cytotoxic T lymphocytes. Cancer cells can directly impact the immune system, but the mechanisms driving these interactions are not completely clear. Here we demonstrate that the polyamine metabolite spermidine is elevated in the glioblastoma tumor microenvironment.

Metaorganismal choline metabolism shapes olfactory perception.

Microbes living in the intestine can regulate key signaling processes in the central nervous system that directly impact brain health. This gut-brain signaling axis is partially mediated by microbe-host-dependent immune regulation, gut-innervating neuronal communication, and endocrine-like small molecule metabolites that originate from bacteria to ultimately cross the blood-brain barrier. Given the mounting evidence of gut-brain crosstalk, a new therapeutic approach of "psychobiotics" has emerged, whereby strategies designed to primarily modify the gut microbiome have been shown to improve mental health or slow neurodegenerative diseases.

Recovery of Forearm and Fine Digit Function After Chronic Spinal Cord Injury by Simultaneous Blockade of Inhibitory Matrix Chondroitin Sulfate Proteoglycan Production and the Receptor PTPσ.

Spinal cord injuries (SCI), for which there are limited effective treatments, result in enduring paralysis and hypoesthesia, in part because of the inhibitory microenvironment that develops and limits regeneration/sprouting, especially during chronic stages. Recently, we discovered that targeted enzymatic removal of the inhibitory chondroitin sulfate proteoglycan (CSPG) component of the extracellular and perineuronal net (PNN) matrix via Chondroitinase ABC (ChABC) rapidly restored robust respiratory function to the previously paralyzed hemi-diaphragm after remarkably long times post-injury (up to 1.5 years) following a cervical level 2 lateral hemi-transection.

Sex-Biased T-cell Exhaustion Drives Differential Immune Responses in Glioblastoma.

Unlabelled: Sex differences in glioblastoma (GBM) incidence and outcome are well recognized, and emerging evidence suggests that these extend to genetic/epigenetic and cellular differences, including immune responses. However, the mechanisms driving immunologic sex differences are not fully understood. Here, we demonstrate that T cells play a critical role in driving GBM sex differences.

GAP43-dependent mitochondria transfer from astrocytes enhances glioblastoma tumorigenicity.

The transfer of intact mitochondria between heterogeneous cell types has been confirmed in various settings, including cancer. However, the functional implications of mitochondria transfer on tumor biology are poorly understood. Here we show that mitochondria transfer is a prevalent phenomenon in glioblastoma (GBM), the most frequent and malignant primary brain tumor.

PARP Inhibitors for the Treatment of BRCA1/2-Mutated Metastatic Breast Cancer: A Systematic Review and Meta-analysis.

Background: The PARP inhibitors (PARPis) olaparib and talazoparib are currently approved for the treatment of deleterious germline BRCA1/2-mutated (gBRCA+) metastatic breast cancer (MBC). These approvals were based on improvements in progression-free survival (PFS) observed in two randomized controlled trials (RCTs). Other PARPis, such as veliparib and niraparib, have also been studied.

WDR5 represents a therapeutically exploitable target for cancer stem cells in glioblastoma.

Glioblastomas (GBMs) are heterogeneous, treatment-resistant tumors driven by populations of cancer stem cells (CSCs). However, few molecular mechanisms critical for CSC population maintenance have been exploited for therapeutic development. We developed a spatially resolved loss-of-function screen in GBM patient-derived organoids to identify essential epigenetic regulators in the SOX2-enriched, therapy-resistant niche and identified WDR5 as indispensable for this population.

Distinct Cell Adhesion Signature Defines Glioblastoma Myeloid-Derived Suppressor Cell Subsets.

Unlabelled: In multiple types of cancer, an increased frequency in myeloid-derived suppressor cells (MDSC) is associated with worse outcomes and poor therapeutic response. In the glioblastoma (GBM) microenvironment, monocytic (m) MDSCs represent the predominant subset. However, the molecular basis of mMDSC enrichment in the tumor microenvironment compared with granulocytic (g) MDSCs has yet to be determined.

SerpinB3 drives cancer stem cell survival in glioblastoma.

Despite therapeutic interventions for glioblastoma (GBM), cancer stem cells (CSCs) drive recurrence. The precise mechanisms underlying CSC resistance, namely inhibition of cell death, are unclear. We built on previous observations that the high cell surface expression of junctional adhesion molecule-A drives CSC maintenance and identified downstream signaling networks, including the cysteine protease inhibitor SerpinB3.

VRK1 Is a Synthetic-Lethal Target in VRK2-Deficient Glioblastoma.

Unlabelled: Synthetic lethality is a genetic interaction that results in cell death when two genetic deficiencies co-occur but not when either deficiency occurs alone, which can be co-opted for cancer therapeutics. Pairs of paralog genes are among the most straightforward potential synthetic-lethal interactions by virtue of their redundant functions. Here, we demonstrate a paralog-based synthetic lethality by targeting vaccinia-related kinase 1 (VRK1) in glioblastoma (GBM) deficient of VRK2, which is silenced by promoter methylation in approximately two thirds of GBM.

Genomic Aberrations in Circulating Tumor DNAs from Palbociclib-Treated Metastatic Breast Cancer Patients Reveal a Novel Resistance Mechanism.

Previously undescribed molecular mechanisms of resistance will emerge with the increased use of cyclin-dependent kinase 4/6 inhibitors in clinical settings. To identify genomic aberrations in circulating tumor DNA associated with treatment resistance in palbociclib-treated metastatic breast cancer (MBC) patients, we collected 35 pre- and post-treatment blood samples from 16 patients with estrogen receptor-positive (ER) MBC, including 9 with inflammatory breast cancer (IBC). Circulating cell-free DNAs (cfDNAs) were isolated for sequencing using a targeted panel of 91 genes.

Duodenal and Biliary Obstruction due to Extrinsic CompressionDuodenal and Biliary Obstruction due to Extrinsic Compression by Recurrent Lobular Breast Carcinoma: A Case Report.

Metastases to the gastrointestinal tract (GIT) from breast carcinoma are rare, detected in approximately <5% of all breast cancer patients. Invasive lobular carcinoma (ILC) is the most common histological type of breast cancer to metastasize to the GIT. We report a case of abdominal recurrence of ILC of the breast causing intra-abdominal contracture leading to extrinsic compression of the duodenum and periampullary biliary tree.

Hydrogen sulfide operates as a glioblastoma suppressor and is lost under high fat diet.

Glioblastoma (GBM) is one of the deadliest and aggressive forms of brain cancer. Environmental and intrinsic factors such as Western Diet and advanced age can function as powerful accelerants to the progression of GBM. Recently, we discovered that pre-clinical GBM models subject to an obesogenic and age-accelerating high fat diet (HFD) presented with hyperaggressive GBM phenotypes, including treatment-refractory cancer stem cell (CSC) enrichment.

Severe consequences of a high-lipid diet include hydrogen sulfide dysfunction and enhanced aggression in glioblastoma.

Glioblastoma (GBM) remains among the deadliest of human malignancies, and the emergence of the cancer stem cell (CSC) phenotype represents a major challenge to durable treatment response. Because the environmental and lifestyle factors that impact CSC populations are not clear, we sought to understand the consequences of diet on CSC enrichment. We evaluated disease progression in mice fed an obesity-inducing high-fat diet (HFD) versus a low-fat, control diet.

Whole-exome sequencing identifies somatic mutations and intratumor heterogeneity in inflammatory breast cancer.

Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. Although it is a rare subtype, IBC is responsible for roughly 10% of breast cancer deaths. In order to obtain a better understanding of the genomic landscape and intratumor heterogeneity (ITH) in IBC, we conducted whole-exome sequencing of 16 tissue samples (12 tumor and four normal samples) from six hormone-receptor-positive IBC patients, analyzed somatic mutations and copy number aberrations, and inferred subclonal structures to demonstrate ITH.

Pretreatment with LCK inhibitors chemosensitizes cisplatin-resistant endometrioid ovarian tumors.

Background: Ovarian cancer is the most fatal gynecologic malignancy in the United States. While chemotherapy is effective in the vast majority of ovarian cancer patients, recurrence and resistance to standard systemic therapy is nearly inevitable. We discovered that activation of the non-receptor tyrosine kinase Lymphocyte Cell-Specific Protein-Tyrosine Kinase (LCK) promoted cisplatin resistance.

Go, cancer stem cell, go! CSCs overcome myelin inhibition to move within white matter pathways.

This scientific commentary refers to ‘Modulation of Nogo receptor 1 expression orchestrates myelin-associated infiltration of glioblastoma’, by Hong (doi:10.1093/brain/awaa408).