Aim: To quantify ER variants/isoforms for women with breast cancer in Taiwan, an area with remarkably low breast cancer rates, but with an early onset and poor prognosis.
Methods: Real-time PCR technology was exploited to quantify mRNAs of ERalpha, ERalphaE3Delta, ERalphaE5Delta, ERalphaE7Delta and ERbeta, in 49 breast cancer and paired adjacent normal tissues. Clinical parameters were assembled and tested for assocation with the ER expression.
Results: Comparison of cancer and matched normal samples showed significantly decreased ERbeta (p < 0.001) in cancer tissues, and constant amounts of ERalpha and their variants. The results revealed significantly lower ERalphaE7Delta/ERalpha (p = 0.030) and ERbeta/ERalpha (p = 0.035) ratios in patients with lymph node (LN) metastasis than in those without LN metastasis.
Conclusion: Our data suggests that ERalphaE7Delta and ERbeta may regulate ERalpha in normal human breast tissue.