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International Journal of Experimental Diabetes Research
Volume 1 (2000), Issue 3, Pages 211-219
http://dx.doi.org/10.1155/EDR.2000.211

Streptozotocin and Alloxan-based Selection Improves Toxin Resistance of Insulin-Producing RINm Cells

1Diabetes and Obesity Research Laboratory, Felsenstein Medical Research Center of Tel-Aviv University, Petah Tikva, Israel
2Molecular Hepatology Laboratory, Rabin Medical Center and Felsenstein Medical Research Center of Tel-Aviv University, Petah Tikva, Israel
3Gino Stock Dermatophysiology Laboratory, Dana Children Hospital, Sourasky Medical Center, Tel-Aviv, Israel

Accepted 22 December 1999

Copyright © 2000 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The aim of our study was to develop a method for selection of subpopulations of insulin producing RINm cells with higher resistance to beta cell toxins. Cells, resistant to streptozotocin (RINmS) and alloxan (RINmA), were obtained by repeated exposure of parental RINm cells to these two toxins, while the defense capacity, was estimated by the MTT colorimetric method, and [H3]-thymidine incorporation assay. We found that RINmS and RINmA displayed higher resistance to both streptozotocin (STZ) and alloxan (AL) when compared to the parental RINm cells. In contrast, no differences in sensitivity to hydrogen peroxide were found between toxin selected and parental cells. Partial protection from the toxic effect of STZ and AL was obtained only in the parental RINm cells after preincubation of cells with the unmetabolizable 3- O-methyl-glucose. The possibility that GLUT-2 is involved in cell sensitivity to toxins was confirmed by Western blot analysis, which showed higher expression of GLUT-2 in parental RINm compared to RINmS and RINmA cells. In addition to the higher cell defense property evidenced in the selected cells, we also found higher insulin content and insulin secretion in both RINmS and RINmA cells when compared to the parental RINm cells. In conclusion, STZ and AL treatment can be used for selection of cell sub-populations with higher cell defense properties and hormone production. The different GLUT-2 expression in parental and re sistant cells suggest involvement of GLUT-2 in mechanisms of cell response to different toxins.