Human chorionic gonadotrophin-beta transcripts correlate with progesterone receptor values in breast carcinomas

Abstract

The pathophysiological role for the expression of human chorionic gonadotrophin (hCG) in malignant neoplasms is currently speculative. We investigated the overall expression of genes hCG-beta 5, 3, 8 and 7 in breast carcinoma (n=214), fibroadenoma (n=37) and macromastia (n=10) by quantitative reverse transcriptase-PCR. Eighty (37.4%) of the breast cancer samples revealed positive hCG-beta mRNA expression and the mean value was 67. 9 copies per 200 ng total RNA (range: 0-1743; 95% confidence interval (CI) for mean: 44-92). Fibroadenomas had more frequently detected (56.8%) and greater hCG-beta copy numbers (mean 86.9; range: 0-845; 95% CI for mean: 35-138). Macromastia probes yielded no positive hCG-beta mRNA. The hCG-beta mRNA expression was significantly different in the three histological subgroups (P=0. 006). Among breast carcinomas, a positive correlation was detected between hCG-beta mRNA copy numbers and progesterone receptor (PgR) values (P<0.001). No significant differences were seen regarding disease-free (P=0.87) and overall survival (P=0.20) depending on hCG-beta mRNA status. Finally, our findings do not support a role for hCG-beta in malignant transformation of human breast cells and indicate a possible involvement of hCG-beta in benign breast disease. The relationship with PgR expression may suggest that progestins regulate the expression of hCG in breast epithelial cells.