Hemin reduces cellular sensitivity to imatinib and anthracyclins via Nrf2

Tadashi Nagai, Satoru Kikuchi, Ken Ohmine, Takuji Miyoshi, Makiko Nakamura, Takahito Kondo, Kazumichi Furuyama, Norio Komatsu, Keiya Ozawa

研究成果: Article査読

22 被引用数 (Scopus)


Heme plays an important biomodulating role in various cell functions. In this study, we examined the effects of hemin on cellular sensitivity to imatinib and other anti-leukemia reagents. Hemin treatment of human BCR/ABL-positive KCL22 leukemia cells increased IC50 values of imatinib, that is, the drug resistance, in a dose-dependent manner without any change in the BCR/ABL kinase activity. Imatinib-induced apoptosis was also suppressed by hemin treatment in KCL22 cells. Hemin treatment increased the activity of γ-glutamylcysteine synthetase (γ-GCS) light subunit gene promoter, which contains a Maf recognition element (MARE). Protein levels of γ-GCS and heme oxygenase-1 (HO-1), two MARE-containing genes, were also increased after hemin treatment. Knockdown of Nrf2 expression by RNA interference largely abolished the effect of hemin on imatinib-treated cells, suggesting that Nrf2 recognition of MARE is essential for the hemin-mediated protective effect. Similar to hemin, treatment of cells with δ-aminolevulinic acid (δ-ALA), the obligatory heme precursor, also increased IC50 values of imatinib. In contrast, inhibition of cellular heme synthesis by succinylacetone increased the sensitivity of cells to imatinib in two imatinib-resistant cell lines, KCL22/SR and KU812/SR. Hemin treatment also decreased the sensitivity of cells to four anthracyclins, daunorubicin, idarubicin, doxorubicin, and mitoxantrone, in BCR/ABL-negative leukemia U937 and THP-1 cells, as well as in KCL22 cells. These findings thus indicate that cellular heme level plays an important role in determining the sensitivity of cells to imatinib and certain other anti-leukemia drugs and that the effect of heme may be mediated via its ability to upregulate Nrf2 activity.

ジャーナルJournal of Cellular Biochemistry
出版ステータスPublished - 2008 5月 15

ASJC Scopus subject areas

  • 生化学
  • 分子生物学
  • 細胞生物学


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