The aim of this study was to investigate certain genes for their suita
bility as molecular markers for detection of breast carcinoma cells us
ing the reverse transcriptase-polymerase chain reaction (RT-PCR). RNA
was prepared from MCF-7 breast carcinoma cells and peripheral blood le
ucocytes of healthy female volunteers. This RNA was screened for mRNA
of MUC1, cytokeratin 19 (CK19) and CD44 (exons 8-11) by RT-PCR and the
results validated by Southern blots. Variable degrees of expression o
f MUC1 and CD44 (exons 8-11) were detected in normal peripheral blood,
rendering these genes non-specific for epithelial cells and therefore
unsuitable for use as markers to detect breast carcinoma cells. Altho
ugh CK19 mRNA was apparently specific, it was deemed unsuitable for us
e as a marker of breast cancer cells in light of its limited sensitivi
ty. Furthermore, an attempt at using nested primers to increase sensit
ivity resulted in CK19 mRNA being detected after two amplification rou
nds in blood from healthy volunteers.