| Abstract: | The aim of the study is to look retrospectively for gene alterations and evaluate apoptosis in rhabdomyosarcomas RMSs from 40 children including 24 patients not previously treated. Histological subtype was botryoid in 1 case, spindle cell in 2 cases, embryonal in 22 cases, alveolar in 10 cases, and undetermined in 5 cases. Gene expression was evaluated immunohistochemically for p53 tumor suppressor gene, MDM2 oncogene, and bcl-2 gene. N-myc amplification was detected by in situ hybridization. Apoptotic cells and bodies were recognized morphologically and stained by 3-OH end labeling. Intranuclear accumulation of p53 protein was obvious 25 of tumor cells in two recurrent embryonal RMSs. Expression of the MDM2 gene was intense 80 of tumor cells in a recurrent and metastatic embryonal RMS. Amplification of the N-myc gene was obvious about 20 of tumor cells in an alveolar RMS metastatic at diagnosis. Expression of the bcl-2 gene was intermediate 25-75 of tumor cells in 26 of cases and high 75 of tumor cells in 10 of cases either embryonal or alveolar. The percentage of tumor cells showing morphologically recognizable apoptosis was 0.2-7.5 mean 2.9 . There was no correlation between apoptosis and histological subtype, bcl-2 expression, or previous treatment. |
