van Oosterwijk, Jolieke G2; Meijer, Danielle2; van Ruler, Maayke A J H2; van den Akker, Brendy E W M2; Oosting, Jan2; Krenács, Tibor2; Picci, Piero2; Flanagan, Adrienne M2; Liegl-Atzwanger, Bernadette2; Leithner, Andreas2; Athanasou, Nick2; Daugaard, Søren1; Hogendoorn, Pancras C W2; Bovée, Judith V M G2
1 Patologiafdelingen, Diagnostisk Center, Rigshospitalet, The Capital Region of Denmark2 unknown
The mesenchymal, clear cell, and dedifferentiated chondrosarcoma subtypes are extremely rare, together constituting 10% to 15% of all chondrosarcomas. Their poor prognosis and lack of efficacious treatment emphasizes the need to elucidate the pathways playing a pivotal role in these tumors. We constructed tissue microarrays containing 42 dedifferentiated, 23 clear cell, and 23 mesenchymal chondrosarcomas and performed immunohistochemistry to study the expression of growth plate-signaling molecules and molecules shown to be involved in conventional chondrosarcoma. We observed high expression of SOX-9 and FGFR-3, as well as aberrant cellular localization of heparan sulfate proteoglycans, in all subtypes. TGFβ signaling through p-SMAD2 and PAI-1 was highly active in all chondrosarcoma subtypes, which suggests that TGFβ inhibitors as a possible therapeutic strategy in rare chondrosarcoma subtypes. As in conventional chondrosarcoma, antiapoptotic proteins (Bcl-2, and/or Bcl-xl) were highly expressed in all subtypes. Inhibition with the BH-3 mimetic ABT-737 rendered dedifferentiated chondrosarcoma cell lines sensitive to doxorubicin or cisplatin. Our data indicate that antiapoptotic proteins may play an important role in chemoresistance, suggesting a promising role for targeting Bcl-2 family members in chondrosarcoma treatment, irrespective of the subtype.
American Journal of Pathology, 2013, Vol 182, Issue 4, p. 1347-56