Figure 1

Agarose gel showing expression of mRNA for GIRK1 in human breast cancer cell lines by RT-PCR. The GIRK1 primers amplified a 441-bp fragment whereas the cyclophylin primers amplified a 216 bp fragment. For each cell line, a negative control reaction without M-MLV reverse transcriptase was performed and found to be negative. Lanes 1 & 7, ZR-75-1; Lanes 2 & 8, MCF-7; Lanes 3 & 9, MDA-MB-361; Lanes 4 & 10, MDA-MB-435S; Lanes 5 & 11, MDA-MB-453; Lanes 6 & 12, MDA-MB-468, Lane M, a 100 bp marker. PCR reactions resolved on this gel were in the plateau phase of PCR, therefore concentrations of PCR amplified cDNA samples cannot be compared.