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Updated: Jul 9, 2026
Profiling of Estrogen-regulated MicroRNAs in Breast Cancer Cells
Published on: February 21, 2014
Evaluation of oestrogen receptor expression in breast cancer by quantification of mRNA
P Potemski1, E Pluciennik, A K Bednarek
1Department of Chemotherapy, Medical University of Lodz, Copernicus Memorial Hospital, Lodz, Poland. piotrpo@mp.pl
Aims:
cDNA microarrays have subclassified breast carcinomas into molecular subtypes with oestrogen receptor-alpha (ER) gene expression as a main marker. The aim was to compare ER expression in 97 patients with operable breast cancer estimated by real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR) and by routine immunohistochemistry, and to determine which method was reliable for molecular subtyping in relation to basal-type keratins and HER2 gene expression.
Methods And Results:
Frozen tumour samples were analysed by real-time RT-PCR for the expression of ER, HER2, keratin 5 and keratin 17 genes. In a group of 27 tumours with a low level of ER mRNA (<1.00), there were eight ER+ cases as assessed by immunohistochemistry, and of 70 cases with a high level of ER mRNA (>or=1.00), 26 were ER- by immunohistochemistry (P = 0.003). Lack of prognostic relevance of ER mRNA level was demonstrated, whereas assessment by immunohistochemistry was related to clinical outcome. Expression of basal keratins and HER2 genes differed significantly between ER+ and ER- tumours based on immunohistochemistry, but not on mRNA level.
Conclusions:
These results throw doubt on the assessment of ER mRNA as a key factor in the molecular distinction between breast tumours.
