Open Access

Ling Hai, Dirk C. Hoffmann, Robin J. Wagener, Daniel D. Azorin, David Hausmann, Ruifan Xie, Magnus-Carsten Huppertz, Julien Hiblot, Philipp Sievers, Sophie Heuer, Jakob Ito, Gina Cebulla, Alexandros Kourtesakis, Leon D. Kaulen, Miriam Ratliff, Henriette Mandelbaum, Erik Jung, Ammar Jabali, Sandra Horschitz, Kati J. Ernst, Denise Reibold, Uwe Warnken, Varun Venkataramani, Rainer Will, Mario L. Suvà, Christel Herold-Mende, Felix Sahm, Frank Winkler, Matthias Schlesner, Wolfgang Wick, Tobias Kessler

• Tumor microtubes (TMs) connect glioma cells to a network with considerable relevance for tumor progression and therapy resistance. However, the determination of TM-interconnectivity in individual tumors is challenging and the impact on patient survival unresolved. Here, we establish a connectivity signature from single-cell RNA-sequenced (scRNA-Seq) xenografted primary glioblastoma (GB) cells using a dye uptake methodology, and validate it with recording of cellular calcium epochs and clinical correlations. Astrocyte-like and mesenchymal-like GB cells have the highest connectivity signature scores in scRNA-sequenced patient-derived xenografts and patient samples. In large GB cohorts, TM-network connectivity correlates with the mesenchymal subtype and dismal patient survival. CHI3L1 gene expression serves as a robust molecular marker of connectivity and functionally influences TM networks. The connectivity signature allows insights into brain tumor biology, provides a proof-of-principleTumor microtubes (TMs) connect glioma cells to a network with considerable relevance for tumor progression and therapy resistance. However, the determination of TM-interconnectivity in individual tumors is challenging and the impact on patient survival unresolved. Here, we establish a connectivity signature from single-cell RNA-sequenced (scRNA-Seq) xenografted primary glioblastoma (GB) cells using a dye uptake methodology, and validate it with recording of cellular calcium epochs and clinical correlations. Astrocyte-like and mesenchymal-like GB cells have the highest connectivity signature scores in scRNA-sequenced patient-derived xenografts and patient samples. In large GB cohorts, TM-network connectivity correlates with the mesenchymal subtype and dismal patient survival. CHI3L1 gene expression serves as a robust molecular marker of connectivity and functionally influences TM networks. The connectivity signature allows insights into brain tumor biology, provides a proof-of-principle that tumor cell TM-connectivity is relevant for patients’ prognosis, and serves as a robust prognostic biomarker.…