The over-expression of miRNA-17-92 significantly enhanced survival of Z138c cells after different doses of radiation. Z138c-TMP2 or Z138c-miRNA-17-92 cells were cultured for different days after receiving 0 (A), 2 (B), 3 (C), or 4 (D) Gy X-ray irradiation. Data have been presented as mean ± s.d. (N = 5). One representative of three experiments has been shown. *P < 0.05, **P < 0.01 or ***P < 0.001 as compared among the identical groups.