Vienna, Austria

ESTRO 2023

Session Item

Tumour radiobiology
Poster (Digital)
Primary stem cell enriched sarcoma cell lines for radiobiological investigations
Franziska Eckert, Austria


Primary stem cell enriched sarcoma cell lines for radiobiological investigations

Franziska Eckert1,2, Janina Palm2, Katrin Ganser2, Jonas Kolbenschlag3, Saskia Sachsenmaier4, Hans Boesmueller5, Vlatko Potkrajcic2

1Medical University Vienna, AKH, Comprehensive Cancer Center, Department of Radiation Oncology, Vienna, Austria; 2University Hospital Tuebingen, Department of Radiation Oncology, Tuebingen, Germany; 3University Hospital Tuebingen, BG Unfallklinik, Department of Plastic and Reconstructive Surgery, Tuebingen, Germany; 4University Hospital Tuebingen, Department of Orthopedic Surgery, Tuebingen, Germany; 5University Hospital Tuebingen, Department of Pathology, Tuebingen, Germany

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Purpose or Objective

High risk adult type soft tissue sarcoma are treated with multimodal concepts including surgery, radiotherapy and chemotherapy in selected cases. The prognosis is mainly limited by distant metastases, mainly in the lungs. In order to develop personalized treatment strategies (possibly including immunotherapeutic strategies) primary stem cell enriched cell lines were established in a prospective project and characterized in vitro.

Material and Methods

Two established soft tissue sarcoma cell lines (SWS782, SWS 982, ATCC) were examined. In addition, as part of a prospective translational project, tissue samples of 11 soft tissue sarcomas were collected to establish stem-cell enriched cell cultures. mRNA abundances of different stem cell markers were characterised in four cell lines. Im-munogenic cell death marker HMGB1 was measured after in vitro irradiation by ELISA. CD276 as a possible target for immunotherapy was measured by flow cytometry.


Of the eleven collected samples, stem-cell enriched cultures could be established in six cases (one dedifferentiated liposarcoma, two myxoid liposarcoma, one alveolar soft tissue sarcoma, two NOS sarcoma). For one cell line, tu-mor cell content was confirmed by MDM2 amplification also detected by pathology in the tumor tissue of a dedif-ferentiated liposarcoma. Stem cell marker profiles differed between the cell lines. NGFR was detected in all tested cell lines, ALDH1A3 in three cell lines. HMGB1 concentrations was higher in supernatant of primary stem cell en-riched cell lines compared to ATCC cell lines. After irradiation with 16 Gy three of four cell lines showed a signifi-cant increase of HMGB1 in supernatant compared to unirradiated controls, one cell line showed a non-significant increase. CD276 surface abundance was evaluated in SWS872 and showed the highest increase 48h after irradia-tion. Increase was radiation-dose dependent reaching statistical significance after irradiation with 16 Gy.


Stem-cell enriched cell lines could be established for six of eleven tumor samples of different histologic subtypes. The cell lines differed in their mRNA abundances of stem cell markers. All tested cell lines showed signs of immu-nogenic cell death (HMGB1 in supernatant) after high doses of in vitro irradiation and CD276 expression. As CD276 has been described as an immunotherapy target in pediatric sarcomas and might also be a candidate in adult type soft tissue sarcoma. As the surface abundance was increased after irradiation, combination therapies might be worth investigating.