Figure 6

Identification of major RARα isoforms in various normal tissues and in breast cancer. Total RNA was extracted from MCF-7 cells, five human breast tumors and normal tissue controls (peripheral blood leukocytes, thymus, spleen and breast) and reverse transcribed into cDNA by RT-PCR. The cDNA fragments were amplified by competitive PCR using forward primers specifically against RARα1 and RARα2 and a common reverse primer. The PCR products were identified by electrophoresis on a 2% agarose gel by ethedium bromide staining. The cDNA for GAPDH was amplified in each sample as an internal control.