Figure 5.

Folate receptor protein and mRNA levels in PyMT and wt breast tissues. Breast tissues dissected from wt FVB/N (wt) or PyMT transgenic female mice (tg) were recovered at the indicated time points and homogenised. Heart (H) and kidney (K) tissues were included as negative and positive controls for FR expression. (A) Reverse transcription–PCR (RT–PCR) was performed with RNA extracted from the indicated tissues using primers targeting murine FR, the MT oncogene and RPLP0, respectively. RPLP0 was used as a control. (B) Immunoblot analysis was performed using antibodies raised against murine FR, or actin. Actin was used as a loading control. The sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) for the FR blot was performed under non-reducing conditions. Two biologically independent RNA extractions were performed and each was subjected to two cDNA synthesis reactions. PCR experiments were repeated four times, and the immonoblot analyses were carried out at least three times with independent protein extractions.