Involvement of the Catecholamine Pathway in Glioblastoma Development

Impact of Solute Carrier Transporters in Glioma Pathology: A Comprehensive Review

Solute carriers (SLCs) are essential for brain physiology and homeostasis due to their role in transporting necessary substances across cell membranes. There is an increasing need to further unravel their pathophysiological implications since they have been proposed to play a pivotal role in brain tumor development, progression, and the formation of the tumor microenvironment (TME) through the upregulation and downregulation of various amino acid transporters. Due to their implication in malignancy and tumor progression, SLCs are currently positioned at the center of novel pharmacological targeting strategies and drug development. In this review, we discuss the key structural and functional characteristics of the main SLC family members involved in glioma pathogenesis, along with their potential targeting options to provide new opportunities for CNS drug design and more effective glioma management.

ß-Adrenoreceptors in Human Cancers

Cancer is the leading cause of death and represents a significant economic burden worldwide. The numbers are constantly growing as a result of increasing life expectancy, toxic environmental factors, and adoption of Western lifestyle. Among lifestyle factors, stress and the related signaling pathways have recently been implicated in the development of tumors. Here we present some epidemiological and preclinical data concerning stress-related activation of the ß-adrenoreceptors (ß-ARs), which contributes to the formation, sequential transformation, and migration of different tumor cell types. We focused our survey on research results for breast and lung cancer, melanoma, and gliomas published in the past five years. Based on the converging evidence, we present a conceptual framework of how cancer cells hijack a physiological mechanism involving ß-ARs toward a positive modulation of their own survival. In addition, we also highlight the potential contribution of ß-AR activation to tumorigenesis and metastasis formation. Finally, we outline the antitumor effects of targeting the ß-adrenergic signaling pathways, methods for which primarily include repurposed ß-blocker drugs. However, we also call attention to the emerging (though as yet largely explorative) method of chemogenetics, which has a great potential in suppressing tumor growth either by selectively modulating neuronal cell groups involved in stress responses affecting cancer cells or by directly manipulating specific (e.g., the ß-AR) receptors on a tumor and its microenvironment.

Epigenetic Suppression of the IL-7 Pathway in Progressive Glioblastoma

Background: Immune evasion in glioblastoma (GBM) shields cancer cells from cytotoxic immune response. Methods: We investigated CpG methylation in promoters, genes, and pathways in 22 pairs of formalin-fixed paraffin-embedded sequential (FFPE) GBM using restricted resolution bisulfite sequencing (RRBS) and bioinformatic analyses. Results: Gene ontology revealed hypermethylation in elements of the innate and adaptive immune system when recurrent GBM samples (GBMrec) were compared to control (CG) and primary GBM samples (GBMprim). Higher methylation levels of the IL-7 signaling pathway and response to IL-7 were found in GBMrec suggesting a progressive blockade of the IL-7 driven T cell response in sequential GBM. Analyses of the Cancer Genome Atlas array-based data confirmed hypermethylation of the IL-7 pathway in recurrent compared with primary GBM. We also quantified DNA CpG methylation in promoter and gene regions of the IL-7 ligand and IL-7 α-receptor subunit in individual samples of a large RRBS-based sequential cohort of GBM in a Viennese database and found significantly higher methylation levels in the IL-7 receptor α-subunit in GBMrec compared with GBMprim. Conclusions: This study revealed the progressive suppression of the IL-7 receptor-mediated pathway as a means of immune evasion by GBM and thereby highlighted it as a new treatment target.