New chondrosarcoma cell lines and mouse models to study the link between chondrogenesis and chemoresistance

Abstract

Chondrosarcomas are cartilage-forming, poorly vascularized tumors. They represent the second malignant primary bone tumor of adults after osteosarcoma, but in contrast to osteosarcoma they are resistant to chemotherapy and radiotherapy, surgical excision remaining the only therapeutic option. Few cell lines and animal models are available, and the mechanisms behind their chemoresistance remain largely unknown. Our goal was to establish new cell lines and animal cancer models from human chondrosarcoma biopsies to study their chemoresistance. Between 2007 and 2012, 10 chondrosarcoma biopsies were collected and used for cell culture and transplantation into nude mice. Only one transplanted biopsy and one injected cell line has engrafted successfully leading to conventional central high-grade chondrosarcoma similar to the original biopsies. In culture, two new stable cell lines were obtained, one from a dedifferentiated and one from a grade III conventional central chondrosarcoma biopsy. Their genetic characterization revealed triploid karyotypes, mutations in IDH1, IDH2, and TP53, deletion in CDKN2A and/or MDM2 amplification. These cell lines expressed mesenchymal membrane markers (CD44, 73, 90, 105) and were able to produce a hyaline cartilaginous matrix when cultured in chondrogenic three-dimensional (3D) pellets. Using a high-throughput quantitative RT-PCR approach, we observed that cell lines cultured in monolayer had lost expression of several genes implicated in cartilage development (COL2A1, COMP, ACAN) but restored their expression in 3D cultures. Chondrosarcoma cells in monolayer were sensitive to several conventional chemotherapeutic agents but became resistant to low doses of mafosfamide or doxorubicin when cultured in 3D pellets, in parallel with an altered nucleic accumulation of the drug. Our results indicate that the cartilaginous matrix produced by chondrosarcoma cells may impair diffusion of several drugs and thus contribute to chemoresistance. Therefore, 3D chondrogenic cell pellets constitute a more relevant model to study chondrosarcoma chemoresistance and may be a valuable alternative to animal experimentations.

Development and characterization of a human three-dimensional chondrosarcoma culture for in vitro drug testing

“…For chondrosarcoma cells, the main methods published are pellets, which use centrifugal force to favor cell-to-cell adhesion at the bottom of a tube [21]. Although this method is simple and rapidly implemented, it may generate shear stress in the cells [22].…”

Osteoblastic and osteoclastic differentiation of human mesenchymal stem cells and monocytes in a miniaturized three-dimensional culture with mineral granules

“…However, this miniaturized 3-D construct may reproduce the microenvironment of tumours with less complexity than animal tissues. Various normal cells and the ECM may be implicated in tumour development or in the drug resistance of tumour cells [38,39]. The present 3-D constructs, where numerous cell types, including tumour cells may be cultured on an abundant osteoid matrix with BCP particles, may help in the development of new oncology drugs and decrease drug failure during clinical testing [7,40,41].…”

5′‐methylschweinfurthin G reduces chondrosarcoma tumor growth

“…This level of cytotoxic sensitivity is similar to human glioblastoma (IC 50 of 34 nM, 48 h of treatment), shown to be the most sensitive tumor line to schweinfurthins . The cartilage‐like extracellular matrix of well‐differentiated human chondrosarcoma cells has been shown to increase resistance to cytotoxicity of chemotherapeutic agents (e.g., mafosfamide, doxorubicin) . The cartilage‐like well‐differentiated LM1 cells cultured in alginate, a system that promoted the extensive accumulation of extracellular matrix, resulted in only a minor increase in resistance to MeSG treatment.…”

“…17 The cartilage-like extracellular matrix of welldifferentiated human chondrosarcoma cells has been shown to increase resistance to cytotoxicity of chemotherapeutic agents (e.g., mafosfamide, doxorubicin). 40 The cartilage-like well-differentiated LM1 cells cultured in alginate, a system that promoted the extensive accumulation of extracellular matrix, resulted in only a minor increase in resistance to MeSG treatment. LM1 cells suspended in alginate had a level of sensitivity in the low nanomolar values range (IC 50 ¼ 62 nM) similar to that of cells lacking their hyaline cartilage-like extracellular matrix.…”