TGF-beta 1 mRNA expression in clinical breast cancer and its relationship to ER mRNA expression

Eighty nine primary breast cancers were investigated for the expression of TGF-beta 1 and ER mRNA using PCR of reverse transcribed RNA. PCR products were validated using Southern blots and hybridization with radiolabelled cDNA probes. TGF beta(1) mRNA was found to be expressed in 56/89 (63%) of the breast cancers while ER mRNA was expressed in 23/89 (26%) of the tumours, Using chi-square analysis TGF-beta mRNA expression was found to correlate significantly with ER mRNA expression (p < 0.001), in that virtually all tumours that expressed ER mRNA co-expressed TGF beta(1). In tumours that were ER mRNA negative, TGF beta(1) expression was more variable, These results suggest that during tumour progression, ER expression is lost more frequently than is growth factor expression.