Pharmacological targeting of apelin impairs glioblastoma growth

Glioblastoma are highly aggressive brain tumours that are associated with an extremely poor prognosis. Within these tumours, a subpopulation of highly plastic self-renewing cancer cells exist that retain the ability to expand ex vivo as tumourspheres, induce tumour growth in mice, and have been implicated in radio- and chemo-resistance. Although their identity and fate are regulated by external cues emanating from endothelial cells, the nature of such angiocrine signals remains unknown. Here, we deployed a mass spectrometry proteomic approach to characterise the factors released by brain endothelial cells. We report the identification of the vasoactive peptide apelin as a central regulator for endothelial-mediated maintenance of glioblastoma patient-derived cells with stem-like properties (GSCs). Genetic and pharmacological targeting of apelin cognate receptor APLNR abrogates apelin- and endothelial-mediated expansion of GSCs and suppresses tumour initiation and growth. Functionally, selective competitive antagonists of APLNR were shown to be safe and effective in lengthening the survival of intracranially xenografted mice. Therefore, the APLN/APLNR signalling nexus may operate as a paracrine signal that sustains tumour cell expansion and progression, suggesting that apelin is a druggable factor in glioblastoma.WT107715/Z/15/

Mitochondrial channels: ion fluxes and more.

The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information