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Effect of nitric oxide on the daunorubicin efflux mechanism in K562 cells
Juliana Costa Curta1, Ana Carolina Rabello de Moraes, Marley Aparecida Licínio
1Departamento de Análises Clínicas, Universidade Federal de Santa Catarina, Campus Trindade, CEP: 88040-900, Florianpolis, SC, Brazil.
Abstract:
NO (nitric oxide) donating drugs have been investigated for their important role in the sensitization of neoplastic cells to chemotherapy drugs. The goal of this work was to investigate the involvement of NO in the resistance of K562 cells to DNR (daunorubicin). Only simultaneous addition of DNR and SNAP (S-nitroso-N-acetyl-dl-penicillamine) caused significant cell death by apoptosis. Combination of the compounds decreased Bcl-2 and survivin, and increased Bax and active-caspase 3 expression. Fluorescence microscope and cytometric analysis showed that DNR and SNAP together caused DNR intracellular accumulation in K562 cells. RT-PCR (reverse transcription-PCR) analysis showed that DNR and SNAP, alone or in association, produced significant decreases in lrp expression. abcc1 gene expression was unaffected by the presence of SNAP, but when treated with DNR there was a small reduction that was intensified by DNR and SNAP in combination. The transport mechanism involved in the resistance to DNR in K562 cells involves ABCC1 and LRP (lung resistance protein) resistance proteins. DNR and SNAP inhibition of the expression of these proteins occurs by distinct mechanisms, and this disrupts the K562 resistance to DNR.
Insights
Nitric oxide (NO) donating drugs, like SNAP, enhance chemotherapy effectiveness. Combining daunorubicin (DNR) with SNAP triggers apoptosis in K562 cancer cells by increasing drug accumulation and reducing resistance proteins.
Area of Science:
- Biochemistry
- Molecular Biology
- Cancer Research
Background:
- Nitric oxide (NO) donating drugs are explored for sensitizing cancer cells to chemotherapy.
- Understanding NO's role in drug resistance is crucial for effective cancer treatment.
Purpose of the Study:
- To investigate the role of nitric oxide (NO) in the resistance of K562 cells to daunorubicin (DNR).
- To evaluate the combined effects of NO donors and DNR on cancer cell apoptosis and drug resistance mechanisms.
Main Methods:
- K562 cells were treated with DNR and SNAP (S-nitroso-N-acetyl-dl-penicillamine).
- Apoptosis was assessed via caspase-3 activation and changes in Bcl-2 family proteins.
- Intracellular DNR accumulation was measured using fluorescence microscopy and flow cytometry.
- Gene expression of resistance proteins (LRP, ABCC1) was analyzed using RT-PCR.
Main Results:
- Simultaneous administration of DNR and SNAP induced significant apoptosis in K562 cells.
- The combination therapy led to decreased Bcl-2 and survivin, and increased Bax and active-caspase 3.
- DNR and SNAP co-treatment enhanced intracellular DNR accumulation and reduced LRP expression.
- Combined treatment also intensified the reduction in ABCC1 gene expression.
Conclusions:
- NO donation, via SNAP, can overcome K562 cell resistance to DNR.
- The synergistic effect involves enhanced DNR uptake and downregulation of key resistance proteins (LRP and ABCC1).
- This strategy holds potential for improving chemotherapy efficacy in resistant cancers.
