Patient-derived glioblastoma stem cells transfer mitochondria through tunneling nanotubes in tumor organoids

Abstract

Glioblastoma (GBM) is the most aggressive brain cancer and its relapse after surgery, chemo and radiotherapy appears to be led by GBM stem cells (GSLCs). Also, tumor networking and intercellular communication play a major role in driving GBM therapy-resistance. Tunneling Nanotubes (TNTs), thin membranous open-ended channels connecting distant cells, have been observed in several types of cancer, where they emerge to drive a more malignant phenotype. Here, we investigated whether GBM cells are capable to intercommunicate by TNTs. Two GBM stem-like cells (GSLCs) were obtained from the external and infiltrative zone of one GBM from one patient. We show, for the first time, that both GSLCs, grown in classical 2D culture and in 3D-tumor organoids, formed functional TNTs which allowed mitochondria transfer. In the organoid model, recapitulative of several tumor’s features, we observed the formation of a network between cells constituted of both Tumor Microtubes (TMs), previously observed in vivo, and TNTs. In addition, the two GSLCs exhibited different responses to irradiation in terms of TNT induction and mitochondria transfer, although the correlation with the disease progression and therapy-resistance needs to be further addressed. Thus, TNT-based communication is active in different GSLCs derived from the external tumoral areas associated to GBM relapse, and we propose that they participate together with TMs in tumor networking.

Peering into tunneling nanotubes—The path forward

“…Human glioblastoma tumors implanted into a mouse brain and labeled with an astrocytoma cell GFP reporter form long (> 500 lm) and thick (> 1 lm) connections called Tumor Microtubes (TMs) between glioblastoma cells (Osswald et al, 2015). However, it is not clear whether TMs allow cargo exchange between cells similarly to TNTs (Pinto et al, 2020(Pinto et al, , 2021.…”

Mitochondrial Transfer in Cancer: A Comprehensive Review

“…In general, actin polymerization is paramount for TNT formation, as compounds disrupting actin functions damage TNT integrity [ 48 , 50 , 51 ]. However, some TNTs also contain microtubules and have been shown to be thicker in size [ 40 , 51 ]. The existence of TNTs with or without microtubules suggests that these structures have different biochemical roles.…”

“…Furthermore, in an AML model, cancer cells acquired mitochondria from stromal cells in the tumor microenvironment, thus improving their metabolic function through an increased production of ATP [ 29 ]. Finally, in a patient-derived organoid model using glioblastoma stem cells, mitochondrial transfer occurred between cells in both 2D and 3D cultures, indicating that this phenomenon also occurs in human brain tumors [ 40 ].…”

MICAL2PV suppresses the formation of tunneling nanotubes and modulates mitochondrial trafficking

“…Scale bar: 60 lm. TNT-mediated mitochondrial transfer, we adopted a co-culture assay reported previously (Abounit et al, 2015;Pinto et al, 2021). In this assay, Mito-GFP-labeled shCtr or shM2 cells (as donor cells) were co-cultured with recipient cells expressing cytosolic mCherry at 1:1 ratio either in direct contact or in transwells where cells were separated by a filter (Fig 3D).…”