|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1995 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1994 : ¥1,300,000 (Direct Cost : ¥1,300,000)
(1) To evaluate the relationship between differentiation in rhabdomyosarcoma (RMS) cells and expression of muscle regulartory genes, MyoD1 and Myogenin, we induced differentiation of RMS cells by dimethyl sulfoxide (DMSO) and retinoic acid (RA) and assessed the expression of MyoD1 and Myogenin by Northern blot. Although molphological differentiation was induced, no significant alteration was observed in their expression after DMSO and RA treatment. (2) Small round cell tumors, such as RMS,Ewing's sarcoma/primitive neuroectodermal tumor (EWS/PNET), neuroblastoma (NB) and lymphoma are often indistinguishable because of their inmatre morphology. In this study to make accurate and rapid diagnosis of these undifferentiated sarcomas, expression of muscle regulatory genes as well as tumor-specific chimeric transcripts were assessed in 21 cases, in terms of muscle regulatory genes, MyoD1 and Myogenin by Northern blot and chimeric transcripts, EWS-FLI1 and EWS-ERG for EWS/PNET and PAX3-ALV for alveolar RMS by RT-PCR.of 21 cases, 8 cases were diagnosed as RMS by MyoD1 expression, and 5 cases as EWS/PNET by EWS-PLI1 expression. of 8 RMS cases positive for MyoD1, Myogenin expression was observed in 4 cases, while PAX3-ALV in 2 cases. The present results showed RMS and EWS/PNET are distinguishable according to expression of these specific molecular markers. Molecular analysis for expression of myogenic regulatory genes and chimeric transcripts is an useful tool for an accurate and rapid diagnosis of undifferentiated sarcomas. Since there still, however, exist sarcomas of undefined origin, further study needs to be done for molecular analysis. In our series a novel chimeric transcript has been found in the analysis for PAX3-ALV,and is to be characterized for a possibility as a new molecular marker.