Connexin43 functions as a non-canonical phenotypic stability factor in promoting hybrid Epithelial/Mesenchymal phenotype in glioblastoma cells

Anushka Mondal; Sanchari Saha; Adrish Ghosh; Justin D Lathia; Jayasri Das Sarma

doi:10.1016/j.tranon.2025.102463

Connexin43 functions as a non-canonical phenotypic stability factor in promoting hybrid Epithelial/Mesenchymal phenotype in glioblastoma cells

Transl Oncol. 2025 Jun 30:59:102463. doi: 10.1016/j.tranon.2025.102463. Online ahead of print.

Authors

Anushka Mondal¹, Sanchari Saha¹, Adrish Ghosh¹, Justin D Lathia², Jayasri Das Sarma³

Affiliations

¹ Department of Biological Sciences, Indian Institute of Science Education and Research-Kolkata, Mohanpur, West Bengal 741246, India.
² Lerner Research Institute, Cleveland Clinic, Cleveland, USA.
³ Department of Biological Sciences, Indian Institute of Science Education and Research-Kolkata, Mohanpur, West Bengal 741246, India; Department of ophthalmologist, Adjunct Associate Professor, University of Pennsylvania, Philadelphia, USA. Electronic address: dassarmaj@iiserkol.ac.in.

PMID: 40591997
DOI: 10.1016/j.tranon.2025.102463

Abstract

Glioblastoma (GBM) is a highly malignant and aggressive brain tumor with patients typically experiencing a median survival of 15-18 months after diagnosis. Gap junction protein Connexin43 (Cx43) plays a crucial role in GBM by having both tumor-suppressing and tumor-promoting roles. Here, we identify a critical tumor-promoting role of Cx43 in GBM by functioning as a non-canonical phenotypic stability factor and driving partial EMT, which enhances the acquisition of stemness properties in the cells. Using high-grade mouse astrocytoma cell lines, we found that CT2A cells had higher Cx43 gap junction assembly as compared to KR158 cells. The increased Cx43 assembly in CT2A cells activates the NF-κB signaling pathway, promoting a hybrid E/M phenotype and thereby enhancing self-renewal properties. CT2A cells also exhibited collective cell migration, a characteristic feature of hybrid E/M phenotype, stress resistance, and proliferative properties. To verify Cx43's role in NF-κB pathway activation, DBT and DBT-Erp-29 cells (with higher Cx43 expression) were studied, showing increased NF-κB activation in DBT-Erp-29 cells. Interestingly, KR158 cells formed longer tunneling nanotubes to expedite alternative cellular communication due to reduced gap junctional intercellular communication (GJIC). These results offer valuable insights into targeting Cx43-mediated signaling pathways due to the potential tumor-promoting role of Cx43.

Keywords: Cancer stem cells; Connexin43; Glioblastoma; Hybrid E/M phenotype; Partial EMT.