Glucose uptake in the human gastric cancer cell line, MKN28, is increased by insulin stimulation

The expression of the insulin-responsive glucose transporter (GLUT) 4 was s tudied in three histologically different human gastric cancer cell lines, M KN28, MKN45, and STSA, RT-PCR demonstrated GLUT1 and GLUT4 mRNA in all thre e cell lines. MKN28 cells expressed GLUT4 protein mon than MKN45 and STSA c ells by immunohistochemistry. Insulin stimulation of MKN28 cells resulted i n a 22% increase in glucose uptake over that found under basal conditions ( 0.60 +/- 0.05 fmol/cell per min after insulin stimulation versus 0.53 +/- 0 .07 fmol/cell per 3 min at basal). No increase in glucose uptake occurred w ith insulin stimulation in MKN45 or STSA cells. We conclude that the insuli n responsive GLUT4 is expressed in MKN28, MKN45, and STKM1 human gastric ca ncer cell lines, albeit in different amounts. The greater expression of thi s transporter in MKN28 cells is likely responsible for the cell's ability t o increase glucose uptake with insulin stimulation. However, the role playe d by GLUT4 in regulating the amount of glucose uptake would not be large in those human gastric cancer cell lines. (C) 1999 Elsevier Science Ireland L td. All rights reserved.