Figure 4.

The RAD51-sensitive MEC1 cell line can be targeted by the RAD51 inhibitor DIDS in vivo. (A) Quantitative RT-PCR of AICDA (AID) and RAD51 of MEC1, K562, and CCRF-SB cells. (B) Flow cytometry of intracellular staining of AID in the aforementioned cell lines. (C) Ex vivo growth of MEC1 B-cells in the presence of different doses of DIDS. (D) MEC1 tumor burden in NRG™ mice after two-week treatment with DIDS as measured by hCD19+ cells in the spleen. Each point represents a mouse (data pooled from 3 experiments). (E) Tumor burden of MEC1 cells and MEC1 cells without AID (AKO) after DIDS treatment (N = 5 to 9 mice). (F) In vivo treatment of AID-/- mice with different concentrations of DIDS, followed by treatment of splenocytes with radiation ex vivo, illustrating the capacity of DIDS to work in combination treatment with IR (N = 5 mice).