CSH expression was determined at the mRNA level in breast cancer cell lines (BCC) and primary carcinomas by real-time and conventional PCR and the products verified as CSH1 by sequencing.
Because the placenta produces a wide range of hormones and enzymes (in addition to human chorionic gonadotropin and human placental lactogen), results supporting this hypothesis could open new dimensions to genetic research for diseases beyond breast cancer (including gynecologic tumors and reproductive and pregnancy-related disorders).
These findings are not indicative of the presence of an additional species of bioactive, but not immunoreactive, lactogen in the sera of women with or at high risk of breast cancer.