Clonal composition of malignant fibrous histiocytoma: analysis by PCR-based assay of the human androgen receptor gene (HUMARA).
Malignant fibrous histiocytoma (MFH), the most common soft-tissue sarcoma, consists mainly of two different cell populations: histiocytelike and fibroblastlike cells. It has been suggested to contain a large amount of reactive histiocytes and fibroblasts hard to distinguish from the tumor cells. In this study, the clonality of MFH was determined by analyzing the patterns of X chromosome inactivation at the human androgen receptor gene (HUMARA) using DNA samples from archival snap-frozen and paraffin-embedded tissues. All the eleven informative female heterozygotes without severe inflammation showed the monoclonal pattern; 8 storiform-pleomorphic (6 distinct, 2 relative monoclonal pattern) and 3 myxoid (3 distinct monoclonal pattern) subtype. Although normal tissue DNA, amplifiable by the polymerase chain reaction, valid for the assay was not available in these cases, statistically at least 5 cases are monoclonal (p = 0.037 <0.05), even when markedly skewed lyonization were to primarily exist in the normal tissue at the highest rate as ever reported (33%). Experiments using the mixture of monoclonal and polyclonal DNA at varying ratios have suggested that a distinct monoclonal pattern is obtained only when the monoclonal component exceeds 80%. Our study demonstrates that most cells that are present in MFH are monoclonal in origin which may be the population of tumor cells.
Department of Pathology, Osaka University Medical School, Osaka, Japan.
M Q
MQ
Fujita
N
N
Hashida
M
M
Shin
H
H
Nakanishi
W
W
Yoshihara
K
K
Aozasa
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002999:Clone Cells; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D005260:Female; D018219:Histiocytoma, Benign Fibrous / Q000235:genetics* / Q000473:pathology / Q000648:ultrastructure*; D006801:Humans; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011944:Receptors, Androgen / Q000235:genetics*
D017931:DNA Primers; D004273:DNA, Neoplasm; D011944:Receptors, Androgen