Sex steroid receptor status. A) Both estrogen and progesterone receptors mRNA are detected by RT-PCR but the signal for PR-A is very weak and protein is not detected by Western blot analysis. Ishikawa cell line was used as a positive control for PRA-B antibody. Data shown are representative of results obtained from three independent assays. MTT proliferation assay was conducted to verify the functionality of these receptors in EN-1078D cell line: B) 24 hours of exposure to 17β-oestradiol increases cell growth and C) a significant increase in proliferation was observed after 48 hours of exposure to 10-6M for progesterone (p < 0.05). Data shown are representative of results obtained from three independent assays.