miR-206 expression is downregulated in cyclin D1 amplified breast tumours

• Amplification in the 11q13 region has been found in around 15% of all breast cancers and is strongly correlated with oestrogen receptor (ER) positive tumours. We have previously found that amplification of at least one of the genes PAK1 or CCND1 is associated with decreased recurrencefree survival among ER+ patients. Other genes in the amplicon might also contribute to this effect and situated close to CCND1 are the FGF-3, -4 and - 19 genes. The FGF-4 protein has been shown to inhibit the expression of the ERα regulator miR-206 in chicken embryo. In this study we analysed 23 tumours with and 27 tumours without previously detected 11q13 amplification to explore if 11q13 amplification is associated with decreased levels of miR-206 and if miR-206 is associated with ER expression. Using real-time PCR, we found that miR-206 expression was inversely correlated to CCND1 and 11q13 amplification (P=0.016 and P=0.022 respectively). Tumours with low miR-206 expression had higher levels of ERα than tumours with intermediate and high expression (P=0.043). We conclude that miR-206 might be an important regulator of the ERα. Our finding that low mir-206 is associated with CCND1 amplification and thereby also FGF-4 amplification points towards the possibility of a miR-206 regulator, FGF-4 or another FGF, present in the amplicon.

Nyckelord

MEDICINE

MEDICIN

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)