ABCB1 and cancer: To test the ability of NDC to overcome MDR, thus allowing DOX to accumulate in the cell and be trafficked to the nucleus, we chose three independent DOX resistant human cancer cell lines (NCI/ADR [ovarian], PC-3A [prostate] and RPMI8226/Dox [multiple myeloma]) expressing high levels of distinct MDR proteins - MDR1 and MRP1 (Fig. S2a).