Sex Steroid Hormone Receptors in Human Thymoma

Abstract

In this study we examined the immunohistochemical localization of sex steroid receptors for estrogen alpha (ER alpha) and ER beta, progesterone-A (PR-A) and PR-B, and androgen (AR) in human thymoma (n = 132) and correlated these findings with various clinicopathological parameters. We used RT-PCR and real-time PCR to further study the expression of these receptors in 20 thymoma cases. Immunoreactivity for all sex steroid receptors was detected in the nuclei of thymoma epithelial cells. The percentage of immunopositive cases and the H-score values for each receptor (mean +/- SD) were: ER alpha, 66% and 85.8 +/- 80.2; ER beta, 7% and 7.2 +/- 8.7; PR-A, 4% and 2.7 +/- 4.9; PR-B, 49% and 55.8 +/- 68.3; and AR, 15% and 14.1 +/- 11.7, respectively. The results of real-time PCR were consistent with those of immunohistochemistry, especially results for ER alpha, PR-B, and AR. A significant positive correlation was detected between immunoreactivity for ER alpha and PR-B. ER alpha immunoreactivity was inversely correlated with tumor size, clinical stage, WHO classification, and Ki-67 labeling index. In addition, the status of ER alpha immunoreactivity was significantly associated with a better clinical outcome in thymoma patients. Results from our study suggest that estrogens may inhibit thymoma growth via ER alpha, and that ER alpha immunoreactivity may act as a prognostic factor in human thymoma.

Steroid receptor expression in thymomas and thymic carcinomas

“…This result indicates that the high expression of ERa noted in the earlier mentioned study may be because of a cross-reaction with ERb. To the best of our knowledge, there was only 1 report published to date analyzing ERb expression in thymomas, and the expression rate was extremely low (7%) 38 compared with that observed in the current study. This discrepancy may be because of differences in the patient population, source of antibody, dilution, method of antigen retrieval, and scoring system.…”

“…The previous study also demonstrated low expression rates of PgR-A (4%) and AR (15%). 38 These results indicate that PgR-A and AR have low potential as targets for therapy and have little involvement in thymoma and thymic tumorigenesis.…”

“…38 One possible reason for this discrepancy is that because ERa expression was heterogeneously distributed, areas with positive ERa expression could not be easily detected on TMA, which was a tiny area compared with the whole section. Another possible reason is the differences in the specificity and sensitivity of the antibodies used for ERa.…”

GnRH-agonist implants suppress reproductive function and affects ovarian LHR and FSHR expression in prepubertal female cats

“…A mean expression index was calculated to represent the protein expression of LHR or FSHR in each ovarian tissue section from an individual animal [14], [15] and [16].…”

Mitochondrial-Related Gene Expression and Macrophage Signatures in Non-Small Cell Lung Cancer, Including Patients with Emphysema as Co-Morbidity

“…Briefly, 500 cells of interest (tumour or macrophages) were counted, and an H-score was generated by adding the percentage of strongly stained nuclei multiplied by 3, the percentage of moderately stained nuclei multiplied by 2, and the percentage of weakly stained nuclei multiplied by 1, giving a possible score of range of 0-300 [19].…”