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P. Lin et al.
S3E). Interestingly, SFN treatment can decrease the chemotherapeutic effect of Ara-C (0-40 mM) in SKM-1. The IC50 was raised from 1.72 mM to 5.73 mM in SKM-1 by 2.5 mM SFN treatment (P=0.008) (Figure 2E). A similar effect of SFN could also be found in MLLPTD/WT/RUNX1- S291fs (Online Supplementary Figure S3F-H). 1 mM SFN treatment increased the Ara-C IC50 from 0.17 mM to 0.26 mM compared to vehicle treatment (P=0.001) (Online Supplementary Figure S3H).
Re-sensitizing MDS cells to Ara-C treatment in vitro by knockdown of NRF2
Transduction of NRF2 shRNA plasmid in human and mouse MDS cell lines repressed NRF2 mRNA levels by approximately 40-60%, compared with scramble shRNA plasmid transduction (Online Supplementary Figure S4A and B). Immunoblot analysis revealed that NRF2 shRNA robustly reduced the expression of NRF2 protein (Online Supplementary Figure S4C and D). Knockdown of NRF2
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Figure 2. NRF2 inhibitor and activator regulate the sensitivity of myelodysplastic syndrome (MDS) cells to cytarabine (Ara-C) treatment. (A) Ara-C IC50 was signifi- cantly decreased in primary MDS cells treated with the NRF2 inhibitor Luteolin. (B) Luteolin decreased NRF2 protein levels in SKM-1. (C) The NRF2 agonist Sulforaphane increased NRF2 protein levels in SKM-1. (D) Ara-C IC50 was significantly decreased by Luteolin in SKM-1. (E) Ara-C IC50 was significantly increased by Sulforaphane in SKM-1. (F) NRF2 silencing significantly decreased IC50 of Ara-C in SKM-1. (G) NRF2 shRNA enhanced apoptosis induced by Ara-C in SKM-1 cell lines. *P<0.05; **P<0.01; ***P≤0.001. h: hours.
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