The predictive value of steroid hormone receptor analysis in breast, endometrial and ovarian cancer

Krüppel-like factor 12 decreases progestin sensitivity in endometrial cancer by inhibiting the progesterone receptor signaling pathway

OBJECTIVE

This study aimed to clarify the mechanism by which Krüppel-like factor 12 (KLF12) affects progesterone sensitivity in endometrial cancer (EC) through the progesterone receptor PGR signaling pathway.

METHODS

The relationship of KLF12 with PGR in EC patients was examined by immunohistochemistry, and the expression of KLF12 and PGR in EC cell lines was detected by real-time PCR and western blotting. Cell proliferation assay, plate clone formation, cell apoptosis assay, and cell cycle analysis were conducted to determine the impact of KLF12 intervention on progesterone therapy. CUT&Tag analysis and the dual-luciferase reporter experiment were used to determine the underlying regulatory effect of KLF12 on the PGR DNA sequence. A subcutaneous xenograft nude mouse model was established to validate the in vivo effect of KLF12 on progesterone sensitivity via PGR expression modulation.

RESULTS

KLF12 demonstrated decreased progesterone sensitivity and a negative correlation with PGR expression in EC tissues. Progesterone sensitivity was increased by KLF12 deficiency through PGR overexpression, a result that could be significantly reversed by PGR downregulation. PGR was identified as a target gene of KLF12, which could directly bind to the PGR promotor region and inhibit its expression.

CONCLUSION

This study is the first to investigate the effect of KLF12 expression on EC cell resistance to progesterone. Our results offer important mechanistic insight into the direct regulation of the PGR promoter region, demonstrating that KLF12 expression strongly suppressed the PGR signaling pathway and, as a result, reduced progesterone sensitivity in EC patients.

An immune competent orthotopic model of endometrial cancer with metastasis

Endometrial cancer is the most common gynecologic malignancy in the U.S. with metastatic disease remaining the major cause of patient death. Therapeutic strategies have remained essentially unchanged for decades. A significant barrier to progression in treatment modalities stems from a lack of clinically applicable in vivo models to accurately mimic endometrial cancer; specifically, ones that form distant metastases and maintain an intact immune system. To address this problem, we have established the first immune competent murine orthotopic tumor model for metastatic endometrial cancer by creating a green fluorescent protein labeled cell line from an endometrial cancer that developed in a Pgr ^cre/+ Pten ^f/f Kras ^G12D genetically engineered mouse. These cancer cells were grafted into the abraded uterine lumen of ovariectomized recipient mice treated with estrogen and subsequently developed local and metastatic endometrial tumors. We noted primary tumor formation in 59% mixed background and 86% of C57BL/6 animals at 4 weeks and distant lung metastases in 78% of mice after 2 months. This immunocompetent orthotopic tumor model closely resembles some human metastatic endometrial cancer, modeling both local metastasis and hematogenous spread to lung and has significant potential to advance the study of endometrial cancer and its metastasis.

Immunohistochemical study of the human 17 beta-hydroxysteroid dehydrogenase and steroid receptors in endometrial adenocarcinoma

17 beta-Hydroxysteroid dehydrogenase (17HSD) and estrogen (ER) and progestin (PR) receptors were analyzed immunohistochemically in tissue specimens of 66 patients with endometrial adenocarcinoma. Plasma steroid concentrations were correlated to immunohistochemical data. 17HSD was detected in 48% of the specimens and was stained in the cytoplasm of epithelial cells. The tissues were characterized by a heterogeneous staining pattern for 17HSD. In some patients, intensively stained epithelial cell clusters were seen, indicating that local factors were responsible for the expression of the protein. Poorly differentiated adenocarcinoma specimens tended to have no 17HSD more frequently than did well or moderately differentiated tissues. ER and PR were detectable in 24% and 28% of patients, respectively, and were localized in the nuclei of epithelial and stromal cells. There was a significant correlation between 17HSD and PR staining and an inverse correlation between plasma progesterone concentrations and 17HSD staining. This is contrary to the data obtained with normal endometrium. The main reason for this inverse relation between endometrial 17HSD staining and plasma progesterone concentrations was that, in some postmenopausal patients with low plasma progesterone concentrations, intense staining for 17HSD was detectable in the endometrial carcinoma specimens. This indicates a major difference in the regulation of 17HSD expression in endometrial adenocarcinomas, compared with normal tissues of premenopausal women.

Immunohistochemical study of the human 17 beta-hydroxysteroid dehydrogenase and steroid receptors in endometrial adenocarcinoma

17 beta-Hydroxysteroid dehydrogenase (17HSD) and estrogen (ER) and progestin (PR) receptors were analyzed immunohistochemically in tissue specimens of 66 patients with endometrial adenocarcinoma. Plasma steroid concentrations were correlated to immunohistochemical data. 17HSD was detected in 48% of the specimens and was stained in the cytoplasm of epithelial cells. The tissues were characterized by a heterogeneous staining pattern for 17HSD. In some patients, intensively stained epithelial cell clusters were seen, indicating that local factors were responsible for the expression of the protein. Poorly differentiated adenocarcinoma specimens tended to have no 17HSD more frequently than did well or moderately differentiated tissues. ER and PR were detectable in 24% and 28% of patients, respectively, and were localized in the nuclei of epithelial and stromal cells. There was a significant correlation between 17HSD and PR staining and an inverse correlation between plasma progesterone concentrations and 17HSD staining. This is contrary to the data obtained with normal endometrium. The main reason for this inverse relation between endometrial 17HSD staining and plasma progesterone concentrations was that, in some postmenopausal patients with low plasma progesterone concentrations, intense staining for 17HSD was detectable in the endometrial carcinoma specimens. This indicates a major difference in the regulation of 17HSD expression in endometrial adenocarcinomas, compared with normal tissues of premenopausal women.