N-cadherin Aided in Maintaining the Characteristics of Leukemic Stem Cells.

In our previous study, it has been revealed that N-cadherin(+) and leukemic stem cells (LSCs, CD34(+)/CD38(-)/CD123(+)) could be enriched by chemotherapy because of their resistance to chemotherapy. In this study, we found that N-cadherin mRNA was highly expressed in the bone marrow mononuclear cells (BMMNCs) of patients with t(8;21) translocation. To determine the role of N-cadherin in maintaining LSCs self-renewal and stationary properties, colony-forming assay, cell cycle analysis, and engraftment in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice were used to compare N-cadherin(+) and N-cadherin(-) cells. Both leukemic cell lines KG1a and CD34(+)/CD38(-) BMMNCs derived from acute myeloid leukemia patients were used, and cells were divided into N-cadherin(+) and N-cadherin(-) fraction after sorting by FACS. The results showed that N-cadherin(+) cells had remarkable increased numbers of colonies with cytokines stimulation when compared with the negative control, suggesting a higher proliferative capacity of N-cadherin(+) cells with cytokines stimulation. The results also showed that most cells in N-cadherin(+) fraction stayed in the G(0)-G(1) stage, indicating the involvement of N-cadherin in maintaining the quiescent state of LSCs in niche. The results of engraftment showed that there was a higher proportion of hCD45(+) cells in mice transplanted with N-cadherin(+) cells than N-cadherin(-) cells. In addition, it was obvious that NOD/SCID mice transplanted with N-cadherin(+) cells had a shorter lifetime than the negative control, suggesting that LSCs self-renewal capacity resides predominantly in N-cadherin(+) fraction. In summary, Ncadherin might play an important role in maintaining the self-renewal and stationary properties of LSCs. (C) 2016 Wiley Periodicals, Inc.