Nm23-H1 regulates the proliferation and differentiation of the human chronic myeloid leukemia K562 cell line: A functional proteomics study

Background: Diet plays an important role in cancer prevention. Apigenin, a flavonoid with thechemical formula C15H10O5, is abundantly present in vegetables. Vegetarian foods containing flavonoids are rich sources of bioactive compounds. Flavonoids have been utilized in herbal treatment. Nanogels are drug delivery systems based on polymers and are used in tissue engineering and for drug delivery. This study was conducted to compare the effects of apigenin and a nanodrug on the viability of the K562 cell line of chronic myeloid leukemia at different durations under laboratory conditions. Materials and Methods: Chitosan was first dissolved in 1% acetic acid, and ethylene dichloride EDC and NHS were added to the solution. Then, the nanodrug was prepared by loading apigenin into stearate–chitosan nanogel (scs nanogel), and its physical and morphological characteristics were evaluated by TEM, DLS, and FTIR. Trypan blue staining, MTT assay, and flow cytometry were used to analyze the effects of various concentrations of apigenin and apigenin-loaded chitosan–stearate nanogel (APG–SCS) at 24, 48, and 72 h after they were applied to the K562 cell line. Results: The diameter of the nanodrug particles was measured using DLS and confirmed by TEM. The K562 cells treated with APG–SCS and with apigenin exhibited significant differences compared with the control (P < 0.05). Apoptosis was detected by flow cytometry. Conclusion: This study showed that the toxic effects of apigenin and the nanodrug improved with increasing concentrations and exposure durations compared to those in the control.The toxic effect of apigenin loaded into the stearate-chitosan nanogel was greater than apigenin, and the toxic effects of both materials were greater compared to the control under laboratory conditions.[GMJ.2018;7:e1008]

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Imatinib-induced apoptosis could be enhanced by Triptolide in Imatinib-resistant chronic myeloid leukemia cell line through down-regulation of HIF-1αand Nrf2

Blood ◽

10.1182/blood.v122.21.4928.4928 ◽

2013 ◽

Vol 122 (21) ◽

pp. 4928-4928

Author(s):

Bing Xu ◽

Feili Chen ◽

Yuejian Liu ◽

Shiyun Wang ◽

Rongwei Li ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Cell Line ◽

K562 Cell ◽

Myeloid Leukemia ◽

Target Genes ◽

Leukemia Cell Line ◽

K562 Cell Line ◽

Down Regulation ◽

G Cells ◽

Induced Apoptosis

Abstract Background The emergence of Imatinib has brought a new era for the treatment of chronic myeloid leukemia. However, resistant to Imatinib might lead to the treatment failure and death of patients. Thus, finding a drug which could enhance the Imatinib-induced apoptosis in vitro could provide the experimental base for the treatment of chronic myeloid leukemia. K562 cell line is a common cell line used in the study of chronic myeloid leukemia while K562/G cell line which is resistant to Imatinib is derived from K562 cell line. Aim This study aims to explore whether low-dose Triptolide(TPL) could enhance the Imatinib-induced apoptosis in K562/G cells and related mechanism. Methods K562/G cells were subjected to different treatments and thereafter MTT assay, flow cytometry and Western blot or RT-PCR were used to determine IC50, apoptotic status and expression of Nrf2, HIF-1α and their target genes. Results Triptolide is highly cytotoxic to K562/G cells in a concentration-dependent manner. To determine the combination effect of TPL and anticancer agents, K562/G cells were exposed to Imatinib(50μM) with or without TPL (25nM) for 24h. The apoptotic cells were determined by PI/Annexin V staining and flow cytometric analysis. Apoptotic ratio of cells treated by Imatinib together with TPL is significantly increased compared to cells treated by Imatinib alone (24.78±1.12 vs. 77.52±7.75, P<0.01). Next, the underlying mechanism was investigated. High expression of Hypoxia-inducible factor-1α (HIF-1α) has been shown to be related with bad clinical outcome in patients while Nrf2 is responsible for chemo-resistanct in cancer cells. Imatinib in combination with TPL could decrease Nrf2 and HIF-1α expression at protein and mRNA levels. Down-stream genes of Nrf2 e.g NQO1, GSR and HO-1 as well as target genes of HIF-1α e.g BNIP3, VEGF and CAIX are also down-regulated at mRNA level. Conclusion TPL could significantly increase the Imatinib-induced apoptotic ratio in K562/G cells through down-regulation of HIF-1α and Nrf2. Disclosures: No relevant conflicts of interest to declare.

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