H. Dotzlaw et al., The human orphan receptor PXR messenger RNA is expressed in both normal and neoplastic breast tissue, CLIN CANC R, 5(8), 1999, pp. 2103-2107
The expression of PXR mRNA and a variant PXR mRNA, deleted in 111 nucleotid
es in the ligand-binding domain, was detected by reverse transcription-PCR
amplification in both normal and neoplastic human breast tissues, The level
of PXR mRNA did not differ between breast tumors and their adjacent matche
d normal breast tissues. However, the expression of PXR mRNA did vary among
breast tumors. A statistically significant inverse relationship was found
between the level of PXR mRNA expression and estrogen receptor (ER) status,
as defined by ligand binding analysis, The level of PXR mRNA expression in
ER + tumors (median = 22.4, n = 15) was significantly lower (P = 0.04) tha
n the level of PXR mRNA expression in ER-tumors (median = 46.7, n = 15). No
relationship with progesterone receptor status was found. These data raise
the possibility that PXR has a role in human breast tissues.