Table of Contents
Leukemia Research and Treatment
Volume 2012, Article ID 861301, 9 pages
http://dx.doi.org/10.1155/2012/861301
Research Article

Mycophenolic Acid Overcomes Imatinib and Nilotinib Resistance of Chronic Myeloid Leukemia Cells by Apoptosis or a Senescent-Like Cell Cycle Arrest

1Laboratoire Hématopoïèse Leucémique et Cibles Thérapeutiques, INSERM U1035, Université Bordeaux Ségalen, 146 Rue Léo Saignat Bat TP 4e étage, 33076 Bordeaux, France
2IRSET, EA 4427 SERAIC, Université Rennes-1, 2 Avenue du Professeur Léon Bernard, 35043 Rennes, France
3IBGC, UMR CNRS 5095, Université Bordeaux Ségalen, 1 Rue Camille Saint Saëns, 33077 Bordeaux, France

Received 30 September 2011; Accepted 16 November 2011

Academic Editor: Judith E. Karp

Copyright © 2012 Claire Drullion et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Supplementary Material

Figure 1: Inhibition of K562 cell proliferation by MPA K562-S, K562-R and K562-RN cells (2.105/ml) (2.105/ml) were grown in the presence of vehicle only, MPA (3μg/ml) or incubated with guanosine (200 μM) and MPA (3 μg/ml) for 3 days. At day 3, cell proliferation was measured by counting cells using trypan blue exclusion assay. Cell viability from triplicate counting is expressed as the mean of 7 independent experiments (A).

Figure 2: MPA induced nuclear foci in K562 cells K562 cells were grown in the presence of vehicle only or MPA (3 μg/ml) for 3 days. K562 cells (5.104) were fixed in PFA and then permeabilized with triton X-100 (0.1%) for 5 min at room temperature. After one wash in PBS, slides were incubated in the presence of Dapi (1 μg/ml) for 5 min at room temperature. After washes, cells were visualized under an inverted microscope. Pictures were acquired and analyzed using the NIS Nikon software.

Figure 3: MPA-induced autophagy is limiting death K562-S, K562-R and K562-RN cells were grown in the presence of vehicle only, MPA (3 μg/ml) or incubated with 3-methyl adenine (3-MA, 2.5 mM), chloroquine (CQ, 25 μM) and MPA (3 μg/ml) for 3 days. K562 cells (5.104) were incubated for 15 min in the presence of annexin-V and propidium iodide. Samples were analyzed for annexin-V and PI positive cells by flow cytometry. Results show the % of annexin V-labelled cells (A, n = 5). K562 cells (105) were fixed in PFA and then incubated overnight in a 96 wells plate in the presence of X-Gal (1mg/ml) at 37°C as described in Figure 3. SA-β-gal positive cells were quantified by counting 102 cells on three separate fields for each condition. Results show the mean of six independent experiments. (B, n= 6).

Figure 4: Inhibition of CD34 cell proliferation by MPA Primary CD34 cells isolated from blood samples of CML patients responding to imatinib were grown in the presence of vehicle only, imatinib 1 μM or MPA 3 μg/ml for 3 days. Cell morphology was observed upon treatment at day 3 (A) or used for detection of SA-β-gal positive cells (B).

Figure 5: CD34 cells of TKI sensitive CML patient respond to imatinib by apoptosis but addition of MPA did not increase the apoptotic response (A). In contrast, CD34 cells from TKI- resistant patient did not respond to imatinib as suspected but achieved apoptosis in response to MPA. The response of CD34 CML cells to MPA is partially reverted by guanosine addition (B) even for the highestMPA concentration required to reach the optimal apoptotic response C).

  1. Supplementary Material