Abstract
Somatic mutations of isocitrate dehydrogenase (IDH) 1 and IDH2 occur in gliomas, acute myeloid leukemia, and cartilaginous tumors. Somatic mosaic IDH1/2 mutations are also reported in Ollier disease and Maffucci syndrome, which are characterized by multiple central cartilaginous tumors. Although IDH1/2 mutation analysis against osteosarcoma has been performed in several studies, no IDH1/2 mutation has been reported. Herein, we newly report the IDH2‐R172S mutation in three of 12 (25%) osteosarcoma patients, which was detected by direct DNA sequencing. No monoclonal antibody (mAb) has been reported against IDH2‐R172S mutation. However, we demonstrate that the IDH2‐R172S peptide was recognized by our established multi‐specific anti‐mutated IDH1/2 mAb, MsMab‐1, in enzyme‐linked immunosorbent assay. Western blot analysis revealed that MsMab‐1 reacts with PA tag combined recombinant proteins of IDH2‐R172S. Furthermore, MsMab‐1 stained IDH2‐R172S‐expressing osteosarcoma tissues in immunohistochemistry. The MsMab‐1 stained nine of 32 (28.1%) osteosarcomas in a tissue microarray. This report is the first describing IDH2 mutations in osteosarcoma, which can be detected by MsMab‐1 mAb. Taken together, these results show that MsMab‐1 can be anticipated for use in immunohistochemical determination of IDH1/2 mutation‐bearing osteosarcoma.
Abstract
Somatic mutations of isocitrate dehydrogenase (IDH) 1 and IDH2 occur in gliomas, acute myeloid leukemia, and cartilaginous tumors. Somatic mosaic IDH1/2 mutations are also reported in Ollier disease and Maffucci syndrome, which are characterized by multiple central cartilaginous tumors. Although IDH1/2 mutation analysis against osteosarcoma has been performed in several studies, no IDH1/2 mutation has been reported. Herein, we newly report the IDH2‐R172S mutation in three of 12 (25%) osteosarcoma patients, which was detected by direct DNA sequencing. No monoclonal antibody (mAb) has been reported against IDH2‐R172S mutation. However, we demonstrate that the IDH2‐R172S peptide was recognized by our established multi‐specific anti‐mutated IDH1/2 mAb, MsMab‐1, in enzyme‐linked immunosorbent assay. Western blot analysis revealed that MsMab‐1 reacts with PA tag combined recombinant proteins of IDH2‐R172S. Furthermore, MsMab‐1 stained IDH2‐R172S‐expressing osteosarcoma tissues in immunohistochemistry. The MsMab‐1 stained nine of 32 (28.1%) osteosarcomas in a tissue microarray. This report is the first describing IDH2 mutations in osteosarcoma, which can be detected by MsMab‐1 mAb. Taken together, these results show that MsMab‐1 can be anticipated for use in immunohistochemical determination of IDH1/2 mutation‐bearing osteosarcoma.