Spatially coordinated RTK-ERK signaling dynamics shape osteosarcoma single-cell drug response in the lung microenvironment
- 1Oregon Health and Science University
Abstract
Purpose: Lung metastases are the primary cause of death in osteosarcoma patients and treatment response often vary due to convergence of genetic and phenotypic influences in the context of a dynamic tumor-host tissue environment. The purpose of this study was to determine how dynamic tumor- and host-driven receptor tyrosine kinase (RTK)-ERK signaling interactions contribute to phenotypic drug response heterogeneity. Experimental Design: Live-cell time-lapse microscopy and data-driven dynamical modeling was used to resolve ERK activity, FOSL1/Fra-1 reporter expression, and spatiotemporal cell fate in living, biosensor-expressing osteosarcoma lung metastases ex vivo following MCL1 inhibitor exposure. RTK inhibitors were then evaluated for their ability to suppress adaptive signaling and enhance MCL1 inhibitor efficacy ex vivo and in vivo. Results: MCL1 inhibition induced extensive tumor-cell death; however, persistent ERKhigh/Fra-1high reporter cells emerged and were enriched at the tumor-lung interface, consistent with adaptive resistance. Experimental and computational approaches revealed that tumor-cell lysis amplified fibroblast growth factor receptor (FGFR)-mediated ERK signaling in neighboring cells, promoting a targetable drug-resistant state marked by adaptive ERK induction, FOSL1/Fra-1 expression, and correlated with upregulation of known drug resistance pathways Nrf2 and HMOX1. Combinatorial inhibition of FGFR with fexagratinib, or broad-spectrum RTK inhibitor, pazopanib, suppressed adaptive ERK activation and enhanced MCL1 inhibitor response resulting in greater efficacy ex vivo and in vivo. Conclusions: Tumor-host and tumor-cell-lysis-induced FGFR-ERK signaling contribute to spatiotemporally heterogeneous adaptive resistance in metastatic osteosarcoma. These data support combinatorial targeting of RTK signaling with cytotoxic or targeted agents as a strategy to block adaptive resistance and improve treatment efficacy.
Related
- Pathological mechanisms of long non-coding RNA FOXD2-AS1 promoting osteosarcoma mediated by the COI-1/OCN/Runx-2 signaling pathway
- PLPP1 inhibits Wnt/β-catenin signaling via enhancing Caveolin-1/β-catenin interaction and is negatively regulated by c-Myc in osteosarcoma
- Biomarker-guided immunotherapy in osteosarcoma: from immune microenvironment profiling to patient stratification and combination strategies.
- The Osteosarcoma Tumor Microenvironment: Supportive of Tumor Progression, Hostile to Immunity, but Therapeutically Targetable.
- Single-cell and bulk transcriptomic characterization of the osteosarcoma microenvironment reveals lineage-specific programs and inflammatory differences associated with metastasis
BibTeX
@misc{makkawi2026spatially,
title = {{Spatially coordinated RTK-ERK signaling dynamics shape osteosarcoma single-cell drug response in the lung microenvironment}},
author = {R. Makkawi and C. Halsey and V. Murthy and E. C. Manalo and H. Cros and X. Yi and J. M. Cartier and M. Chang and M. Flory and K. Guptell and A. Gross and R. D. Roberts and J. Copperman and A. E. Davies},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.30.755770},
url = {https://www.biorxiv.org/content/10.64898/2026.09.30.755770v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Spatially coordinated RTK-ERK signaling dynamics shape osteosarcoma single-cell drug response in the lung microenvironment
AU - R. Makkawi
AU - C. Halsey
AU - V. Murthy
AU - E. C. Manalo
AU - H. Cros
AU - X. Yi
AU - J. M. Cartier
AU - M. Chang
AU - M. Flory
AU - K. Guptell
AU - A. Gross
AU - R. D. Roberts
AU - J. Copperman
AU - A. E. Davies
PY - 2026
DA - 2026/09/30
PB - bioRxiv
DO - 10.64898/2026.09.30.755770
UR - https://www.biorxiv.org/content/10.64898/2026.09.30.755770v1
AB - Purpose: Lung metastases are the primary cause of death in osteosarcoma patients and treatment response often vary due to convergence of genetic and phenotypic influences in the context of a dynamic tumor-host tissue environment. The purpose of this study was to determine how dynamic tumor- and host-driven receptor tyrosine kinase (RTK)-ERK signaling interactions contribute to phenotypic drug response heterogeneity. Experimental Design: Live-cell time-lapse microscopy and data-driven dynamical modeling was used to resolve ERK activity, FOSL1/Fra-1 reporter expression, and spatiotemporal cell fate in living, biosensor-expressing osteosarcoma lung metastases ex vivo following MCL1 inhibitor exposure. RTK inhibitors were then evaluated for their ability to suppress adaptive signaling and enhance MCL1 inhibitor efficacy ex vivo and in vivo. Results: MCL1 inhibition induced extensive tumor-cell death; however, persistent ERKhigh/Fra-1high reporter cells emerged and were enriched at the tumor-lung interface, consistent with adaptive resistance. Experimental and computational approaches revealed that tumor-cell lysis amplified fibroblast growth factor receptor (FGFR)-mediated ERK signaling in neighboring cells, promoting a targetable drug-resistant state marked by adaptive ERK induction, FOSL1/Fra-1 expression, and correlated with upregulation of known drug resistance pathways Nrf2 and HMOX1. Combinatorial inhibition of FGFR with fexagratinib, or broad-spectrum RTK inhibitor, pazopanib, suppressed adaptive ERK activation and enhanced MCL1 inhibitor response resulting in greater efficacy ex vivo and in vivo. Conclusions: Tumor-host and tumor-cell-lysis-induced FGFR-ERK signaling contribute to spatiotemporally heterogeneous adaptive resistance in metastatic osteosarcoma. These data support combinatorial targeting of RTK signaling with cytotoxic or targeted agents as a strategy to block adaptive resistance and improve treatment efficacy.
ER -