Array comparative genomic hybridization reveals frequent alterations of G1/S checkpoint genes in undifferentiated pleomorphic sarcoma of bone.
Undifferentiated pleomorphic sarcoma of bone (UPSb) is a rare tumor often difficult to differentiate from fibrosarcoma of bone (FSb), diagnostically. We applied array comparative genomic hybridization (array CGH) to screen for genes with potential importance in the tumor and compared the results with alterations seen in FSb. Twenty-two fresh frozen tissue specimens from 20 patients (18 primary tumors and 4 local recurrences) with UPSb were studied. DNA was isolated and hybridized onto Agilent 244K CGH oligoarrays. The hybridization data were analyzed using Agilent DNA Analytics Software. The number of changes ranged from 2 to 168 (average = 66). Losses were most frequently seen at 8p, 9p, 10, 13q, and 18q, and gains at 4q, 5p, 6p, 7p, 8q, 12p, 14q, 17q, 19p, 20q, 22q, and X. Homozygous deletions of CDKN2A, RB1, TP53, and ING1 were seen in 8/20, 7/20, 3/20, and 2/20 cases, respectively. Hypermethylation of both p16(INK4a) and p14(ARF) was found in two cases with loss at CDKN2A. Inactivation either of CDKN2A, RB1, or TP53 was detected in 18/20 cases. One case showed high level gains of CDK4 and MDM2. Frequent gains were seen at MYC, PDGFRA, KIT, and KDR. Immunohistochemical positivity of KIT, PDGFRA, KDR, and PDGFRB was found in 8/14, 5/14, 4/14, and 4/14 cases, respectively. The regions most significantly discriminating between UPSb and FSb included RB1 and MYC. No homozygous deletions of RB1 were found in FSb. In conclusion, our analysis showed the disruption of G1/S checkpoint regulation to be crucial for the oncogenesis of UPSb.
Department of Pathology, Haartman Institute and HUSLAB, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland.
Tarja
T
Niini
Leo
L
Lahti
Francesca
F
Michelacci
Shinsuke
S
Ninomiya
Claudia Maria
CM
Hattinger
Mohamed
M
Guled
Tom
T
Böhling
Piero
P
Picci
Massimo
M
Serra
Sakari
S
Knuutila
D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000235:genetics* / Q000473:pathology; D002648:Child; D055028:Comparative Genomic Hybridization / Q000379:methods*; D056915:DNA Copy Number Variations; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D005260:Female; D005354:Fibrosarcoma / Q000235:genetics / Q000473:pathology; D016193:G1 Phase / Q000235:genetics*; D016161:Genes, Retinoblastoma / Q000235:genetics; D019942:Genes, p16; D016158:Genes, p53 / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000235:genetics* / Q000473:pathology; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000235:genetics; D016196:S Phase / Q000235:genetics*; D013534:Survival; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics; D055815:Young Adult
D004273:DNA, Neoplasm; D019009:Proto-Oncogene Proteins c-kit; D020796:Receptor, Platelet-Derived Growth Factor alpha; D020797:Receptor, Platelet-Derived Growth Factor beta; D040301:Vascular Endothelial Growth Factor Receptor-2