Fig. 1.

HBXIP up-regulates MDM2 through decreasing miR-18b in breast cancer cells. a The expression of HBXIP, p53, and MDM2 at the level of mRNA was examined by RT-PCR analysis in MCF-7 cells. b The mRNA level of HBXIP and MDM2 was examined by RT-PCR analysis in HCT116 p53^−/− cells. c, d The expression of HBXIP and MDM2 at the levels of mRNA and protein was examined by RT-PCR and Western blot analysis in MCF-7 and LM-MCF-7 cells, respectively. The expression level of miR-18b was detected by real-time PCR analysis in MCF-7 and LM-MCF-7 cells, respectively. e, f The mRNA level of HBXIP and MDM2 was determined by RT-PCR analysis in MCF-7 and LM-MCF-7 cells, respectively. Each experiment was repeated at least three times. Student’s t test; *P < 0.05; **P < 0.01