c-Myc promotes tumor proliferation and anti‑apoptosis by repressing p21 in rhabdomyosarcomas

: v-myc avian myelocytomatosis viral oncogene homolog (c-Myc) is an important member protein of the Myc family that is important in cell cycle progression, apoptosis and tumorigenesis. In the present study, the role of c‑Myc in rhabdomyosarcoma (RMS) was assessed. Firstly, expression of endogenous c‑Myc and cyclin dependent kinase inhibitor 1A (p21) was examined in normal skeletal muscle, RMS specimens and TE671 RMS cells by immunohistochemistry, reverse transcription‑quantitative polymerase chain reaction and western blotting. Furthermore, cell cycle progression and apoptosis were assessed in TE671 RMS cells following treatment with a c‑Myc inhibitor, 10058‑F4. The results demonstrated that c‑Myc was overexpressed in clinical RMS tissues and TE671 cells, with the highest expression observed in the most RMS samples. Expression of p21 protein and apoptosis function were increased following treatment with 10058‑F4, but no difference was observed in cell cycle progression. In conclusion, the present study indicated that c‑Myc promotes RMS development by inhibiting apoptosis through repression of p21 transcription. Further studies will be required to evaluate c‑Myc as a target for RMS clinical treatment.