Analysis of gene mutations in three cases of dermatofibrosarcoma protuberans (DFSP): ordinary DFSP, DFSP with fibrosarcomatous lesion (DFSP-FS) and lung metastasis of DFSP-FS.
BACKGROUND
Fusion of the collagen type I alpha 1 (COL1A1) gene with the platelet-derived growth factor B-chain (PDGFB) gene has been pointed out in dermatofibrosarcoma protuberans (DFSP). Various exons of the COL1A1 gene have been shown to be involved in the fusion with exon 2 of the PDGFB gene.


OBJECTIVE
We studied the breakpoints of the COL1A1 gene using the tumor specimens from three patients with DFSP.


METHODS
Reverse transcriptase-polymerase chain reaction (PCR) was performed using cultured DFSP tumor cells or frozen tissue. Nucleotide sequence analysis was carried out using the PCR products to identify the breakpoints.


RESULTS
Cases 1, 2 and 3 were diagnosed as ordinary DFSP, DFSP with fibrosarcomatous lesion (DFSP-FS) and lung metastasis of DFSP-FS, respectively. The COL1A1-PDGFB fusion transcripts were detected from the tumor specimens. Sequence analysis revealed that the ends of exons 42, 29 and 38 in the COL1A1 gene were fused with the start of exon 2 in the PDGFB gene in case 1, 2 and 3, respectively.


CONCLUSIONS
This study identified a novel COL1A1 breakpoint, namely, exon 42 of the COL1A1 gene. Detection of the aberrant fusion transcript seems to be useful at differential diagnosis both in primary and metastatic lesions.
Saeki
Hidehisa
H
Department of Dermatology, Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8655, Japan. saeki-der@h.u-tokyo.ac.jp
Hoashi
Toshihiko
T
Tada
Yayoi
Y
Ashida
Ryuichi
R
Kuwano
Yoshihiro
Y
Le Pavoux
Andre
A
Tsunemi
Yuichiro
Y
Shikada
Junichiro
J
Torii
Hideshi
H
Kawabata
Yasuhiro
Y
Kikuchi
Kanako
K
Tamada
Yasuhiko
Y
Matsumoto
Yoshinari
Y
Tamaki
Kunihiko
K
D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D024042:Collagen Type I / Q000235:genetics*; D000090602:Collagen Type I, alpha 1 Chain; D018223:Dermatofibrosarcoma / Q000235:genetics* / Q000556:secondary; D005091:Exons; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D020574:Proto-Oncogene Proteins c-sis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology; D014407:Tumor Cells, Cultured
C000716127:COL1A1 protein, human; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D020574:Proto-Oncogene Proteins c-sis