[Minimal residual disease in bone marrow in patients with Ewing's sarcoma detected by RT-PCR amplification of EWS-FLI-1 fusion gene transcript].
OBJECTIVE
To set up a system for sensitively detecting minimal Ewing's sarcoma cells in bone marrow.


METHODS
Ewing's sarcoma cell line T1 cells were serially diluted with normal bone marrow cells so that the concentration of tumor cells was 10(-3), 10(-4), 10(-5), 10(-6), 10(-7), and 0, respectively. Total RNA was isolated from these samples and cDNA was synthesized. EWS-FLI-1, a fusion gene formed due to chromosome translocation, was amplified with PCR. Bone marrow samples from five patients with Ewing's sarcoma patients with tumor metastasis were examined for EWS-FLI-1 transcript.


RESULTS
T1 cells could be detected when one was present in 10(6) normal bone marrow cells. Thus the sensitivity of detection was 10(-6). A 434 bp EWS-FLI-1 transcript was detected in five Ewing's sarcoma patients examined at the time of diagnosis. After complete remission, EWS-FLI-1 was still positive on RT-PCR in 3 patients, although BM pathological examination was negative in all cases.


CONCLUSIONS
RT-PCR for EWS-FLI-1 is sensitive enough to detect minimal residual Ewing's sarcoma cells in the bone marrow. It can identify residual tumor cells in pathologically negative bone marrow specimens.
Tang
S
S
Department of Pediatrics, PLA General Hospital, Beijing 100853, China.
Huang
D
D
Zhang
X
X
D001854:Bone Marrow Cells / Q000737:chemistry*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009362:Neoplasm Metastasis; D018365:Neoplasm, Residual / Q000175:diagnosis* / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000032:analysis* / Q000235:genetics; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012512:Sarcoma, Ewing / Q000175:diagnosis* / Q000235:genetics; D014157:Transcription Factors / Q000032:analysis* / Q000235:genetics; D014407:Tumor Cells, Cultured
C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors