Figure 2.

MicroRNAs-93 and 106a fail to regulate FBXO31 in response to genotoxic stresses. (A) Luciferase activity of FBXO31 3′UTR reporter increased upon treatment of IR. MCF7 cells were transfected with FBXO31 3′UTR luciferase construct, and luciferase activity was measured with and without irradiation. Cells were collected at 4 hours postirradiation. (B–E) Ectopically expressed microRNAs failed to prevent FBXO31 stabilization under genotoxic stresses. MCF7 cells were transfected with indicated miRNAs for 48 hours. The transfected cells were exposed to either IR (B and C) or etoposide treatment (D and E). Whole cell protein extracts were immunoblotted with indicated antibodies. (F and G) MicroRNA levels decreased under stress conditions. MCF7 cells were treated with either IR or Etoposide, total RNA was isolated, and cDNA was prepared followed by real-time RT-PCR.