Fig. 2

In vitro genetic correction and expansion of 2° TD FANCC ^–/– cells. a Diagram depicting the experimental steps of 2° TD in vitro. Tomato-positive HSPC cells were used as carrier cells harboring the LV-GFP-FANCC vector to migrate across the transwell membrane to the bottom chamber for 2° TD on the PD331 cells. b Microscopic imaging of 2° TD by using Tomato HSPC as a carrier and FANCC^–/– PD331 as recipient cells. c Measurement of 2° TD with experimental variables including radiation, DNA damage by MMC, and chemotaxis by SDF-1α. The combination of SDF-1α, radiation, and MMC were also used as different parameters that affect 2° TD directly or indirectly (n = 6; ***p > 0.0001). d Mean florescent intensity (MFI) as a measure of transgene expression. e PCR analysis of LV-GFP-FANCC status. f Expansion of FANCC-corrected 2° TD PD331 cells under MMC selection pressure (n = 3). Con control, GFP green fluorescent protein, HSC hematopoietic stem cell, MMC mitomycin-C, n/s not significant, Ra irradiation, SDF stromal-derived factor