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2-deoxy-D-glucose toxicity and transport in human multidrug-resistant KB carcinoma cell lines
Abstract:
It is shown that a series of colchicine-selected multidrug-resistant (MDR) human KB carcinoma cell lines displayed increasing 2-deoxy-D-glucose collateral sensitivity, which correlated with increasing multidrug resistance. The relative resistance of MDR cell lines to 2-deoxy-D-glucose was reduced to 0.73 (KB-8-5), 0.3 (KB-8-5-11) and 0.2 (KB-C1) when compared with parental KB-3-1 (1.0). 2-Deoxy-D-glucose accumulation was found to be reduced in the MDR cell lines in a manner that correlated with 2-deoxy-D-glucose collateral sensitivity. At 30 min 2-deoxy-D-glucose accumulation was reduced to 0.61 (KB-8-5), 0.41 (KB-8-5-11) and 0.22 (KB-C1) relative to KB-3-1 uptake (1.0). The efflux of 2-deoxy-D-glucose was not significantly different between resistant and sensitive cell lines. Analysis of 2-deoxy-D-glucose uptake kinetics, by initial rate measurements, showed alterations in K(t) and J(max) for MDR when compared with KB-3-l cells. The levels of GLUT-1 facilitative transporter were found to be reduced significantly in the MDR cell lines in total cell homogenate and plasma membrane fractions by using Western blot analysis. Changes in the plasma membrane level of GLUT-1 correlated with 2-deoxy-D-glucose toxicity and uptake for MDR cell lines, where relative GLUT-i levels were reduced to 0.71 (KB-8-5), 0.43 (KB-8-5-1 1) and 0.27 (KB-Cl) relative to KB-31(1.0). It is concluded that the response of human KB MDR cells to 2-deoxy-D-glucose involved alterations in the level and activity of the facilitative glucose transporter, GLUT-1, in a manner that is associated with the degree of multidrug resistance.
Insights
Multidrug-resistant (MDR) cancer cells show increased sensitivity to 2-deoxy-D-glucose, linked to reduced levels of the GLUT-1 glucose transporter. This suggests GLUT-1 alterations are key in MDR cell responses.
Area of Science:
- Cell Biology
- Cancer Research
- Molecular Pharmacology
Background:
- Multidrug resistance (MDR) is a major challenge in cancer chemotherapy.
- Colateral sensitivity, where resistant cells become sensitive to other drugs, is an emerging therapeutic concept.
- 2-deoxy-D-glucose (2-DG) is a glucose analog that can be used to study glucose metabolism.
Purpose of the Study:
- To investigate the relationship between multidrug resistance and collateral sensitivity to 2-deoxy-D-glucose in human KB carcinoma cell lines.
- To elucidate the role of the GLUT-1 glucose transporter in this observed collateral sensitivity.
Main Methods:
- Development of colchicine-selected multidrug-resistant (MDR) human KB carcinoma cell lines.
- Assessment of 2-deoxy-D-glucose resistance and accumulation in parental and MDR cell lines.
- Analysis of 2-deoxy-D-glucose uptake kinetics.
- Quantification of GLUT-1 transporter levels using Western blot analysis.
Main Results:
- MDR cell lines exhibited increasing collateral sensitivity to 2-deoxy-D-glucose, correlating with increased drug resistance.
- 2-deoxy-D-glucose accumulation and uptake were reduced in MDR cells, inversely correlating with collateral sensitivity.
- Significantly reduced levels of the GLUT-1 facilitative transporter were observed in MDR cell lines, correlating with 2-DG toxicity and uptake.
Conclusions:
- The response of human KB MDR cells to 2-deoxy-D-glucose is associated with alterations in the level and activity of the GLUT-1 glucose transporter.
- Reduced GLUT-1 expression and function contribute to the collateral sensitivity observed in multidrug-resistant cancer cells.