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Updated: Aug 4, 2026
Three-Dimensional Bone Extracellular Matrix Model for Osteosarcoma
Published on: April 12, 2019
Modeling phenotypic heterogeneity towards evolutionarily inspired osteosarcoma therapy
Darcy L Welch1,2, Brooke L Fridley3, Ling Cen3
1Adolescent and Young Adult Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.
Abstract:
Osteosarcoma is the most common bone sarcoma in children and young adults. While universally delivered, chemotherapy only benefits roughly half of patients with localized disease. Increasingly, intratumoral heterogeneity is recognized as a source of therapeutic resistance. In this study, we develop and evaluate an in vitro model of osteosarcoma heterogeneity based on phenotype and genotype. Cancer cell populations vary in their environment-specific growth rates and in their sensitivity to chemotherapy. We present the genotypic and phenotypic characterization of an osteosarcoma cell line panel with a focus on co-cultures of the most phenotypically divergent cell lines, 143B and SAOS2. Modest environmental (pH, glutamine) or chemical perturbations dramatically shift the success and composition of cell lines. We demonstrate that in nutrient rich culture conditions 143B outcompetes SAOS2. But, under nutrient deprivation or conventional chemotherapy, SAOS2 growth can be favored in spheroids. Importantly, when the simplest heterogeneity state is evaluated, a two-cell line coculture, perturbations that affect the faster growing cell line have only a modest effect on final spheroid size. Thus the only evaluated therapies to eliminate the spheroids were by switching therapies from a first strike to a second strike. This extensively characterized, widely available system, can be modeled and scaled to allow for improved strategies to anticipate resistance in osteosarcoma due to heterogeneity.
Insights
Intratumoral heterogeneity in osteosarcoma (bone cancer) impacts chemotherapy effectiveness. This study models heterogeneity to reveal how environmental changes and sequential therapies can overcome treatment resistance in patients.
Area of Science:
- Oncology
- Cancer Biology
- Biotechnology
Background:
- Osteosarcoma is the most common bone cancer in pediatric and young adult populations.
- Chemotherapy resistance, often driven by intratumoral heterogeneity, limits treatment efficacy in approximately half of localized osteosarcoma cases.
- Understanding cellular heterogeneity is crucial for developing more effective therapeutic strategies.
Purpose of the Study:
- To develop and characterize an in vitro model of osteosarcoma heterogeneity based on phenotypic and genotypic variations.
- To investigate how environmental and chemical perturbations influence the behavior of co-cultured osteosarcoma cell lines.
- To evaluate therapeutic strategies for overcoming chemoresistance in heterogeneous osteosarcoma models.
Main Methods:
- Genotypic and phenotypic characterization of an osteosarcoma cell line panel, focusing on co-cultures of divergent lines (143B and SAOS2).
- Assessment of cell line competition under varying environmental conditions (e.g., pH, glutamine levels) and chemotherapy exposure.
- Evaluation of spheroid formation and response to single-agent and sequential chemotherapy treatments in a two-cell line co-culture model.
Main Results:
- Environmental factors (pH, glutamine) and chemotherapy significantly altered the composition and success of co-cultured osteosarcoma cell lines.
- Under nutrient-rich conditions, 143B cells outcompeted SAOS2 cells, but SAOS2 dominance was observed in nutrient-deprived or chemotherapy-treated spheroids.
- Sequential chemotherapy, switching from a first-strike to a second-strike agent, was the only evaluated approach effective in eliminating heterogeneous spheroids.
Conclusions:
- The developed in vitro model effectively recapitulates osteosarcoma heterogeneity and its impact on therapeutic response.
- Environmental conditions and cell-cell interactions within heterogeneous populations critically influence treatment outcomes.
- Sequential therapeutic strategies are essential for overcoming chemoresistance mediated by intratumoral heterogeneity in osteosarcoma.
