Adenomyosis is an oestrogen-dependent disease caused by a downward extension of the endometrium into the uterine myometrium. Epithelial-mesenchymal transition (EMT) endows cells with migratory and invasive properties and can be induced by oestrogen. We hypothesized that oestrogen-induced EMT is critical in the pathogenesis of adenomyosis. We first investigated whether EMT occurred in adenomyotic lesions and whether it correlated with serum 17β-oestradiol (E2) levels. Immunohistochemistry was performed on adenomyotic lesions and corresponding eutopic endometrium samples from women with adenomyosis. Endometria from women without endometrial disorders were used as a control. In the epithelial component of adenomyotic lesions, vimentin expression was up-regulated and E-cadherin expression was down-regulated compared to the eutopic endometrium, suggesting that EMT occurs in adenomyosis. In adenomyosis, the serum E2 level was negatively correlated with E-cadherin expression in the epithelial components of the eutopic endometrium and adenomyotic lesions, suggesting the involvement of oestrogen-induced EMT in endometrial cells. In oestrogen receptor-positive Ishikawa endometrial epithelial cells, oestrogen induced a morphological change to a fibroblast-like phenotype, a shift from epithelial marker expression to mesenchymal marker expression, increased migration and invasion, and up-regulation of the EMT regulator Slug. Raloxifene, a selective oestrogen receptor modulator, abrogated these effects. To determine the role of oestrogen-induced EMT in the implantation of ectopic endometrium, we xenotransplanted eutopic endometrium or adenomyotic lesions from adenomyosis patients into ovariectomized SCID mice. The implantation of endometrium was oestrogen-dependent and was suppressed by raloxifene. Collectively, these data highlight the crucial role of oestrogen-induced EMT in the development of adenomyosis and suggest that raloxifene may be a potential therapeutic agent for adenomyosis patients.

The interplay between tumor microenvironment and cancer that causes chemoresistance remains unclear. By analyzing public available microarray datasets, we identified that periostin (POSTN) was overexpressed in cancer stroma in epithelial ovarian cancer (EOC) patients. Immunohistochemistry analysis showed overexpression of stromal POSTN is a powerful independent poor prognostic predictor for EOC patients. Furthermore, patients with high levels of stromal POSTN tend to have higher percentage of cisplatin resistance compared to those with low levels of stromal POSTN. Moreover, we found POSTN treatment can induce cisplatin resistant and activate AKT pathway in A2780 cells in vitro. Inhibition of AKT activity by AKT inhibitor MK-2206 abolished POSTN-induced AKT activation and cisplatin resistance in vitro. Taken together, we found high POSTN expression in cancer microenvironment is correlated with poor prognosis in EOC patients and associated with platinum resistance. The effect of POSTN in cancer stroma cells may activate AKT pathway in tumor and AKT inhibitor can be beneficial to augment the efficacy of existing cancer therapeutics.

Adenomyosis is an oestrogen-dependent disease characterized by the invasion of endometrial epithelial cells into the myometrium of uterus, and angiogenesis is thought to be required for the implantation of endometrial glandular tissues during the adenomyotic pathogenesis. In this study, we demonstrate that compared with eutopic endometria, adenomyotic lesions exhibited increased vascularity as detected by sonography. Microscopically, the lesions also exhibited an oestrogen-associated elevation of microvascular density and VEGF expression in endometrial epithelial cells. We previously reported that oestrogen-induced Slug expression was critical for endometrial epithelial–mesenchymal transition and development of adenomyosis. Our present studies demonstrated that estradiol (E2) elicited a Slug-VEGF axis in endometrial epithelial cells, and also induced pro-angiogenic activity in vascular endothelial cells. The antagonizing agents against E2 or VEGF suppressed endothelial cells migration and tubal formation. Animal experiments furthermore confirmed that blockage of E2 or VEGF was efficient to attenuate the implantation of adenomyotic lesions. These results highlight the importance of oestrogen-induced angiogenesis in adenomyosis development and provide a potential strategy for treating adenomyosis through intercepting the E2-Slug-VEGF pathway.

Endometrial stromal tumors are rare uterine tumors (<1%). Four main categories include endometrial stromal nodule, low-grade endometrial stromal sarcoma (LG-ESS), high-grade endometrial stromal sarcoma (HG-ESS), and uterine undifferentiated sarcoma (UUS). This review is a series of articles discussing the uterine sarcomas. LG-ESS, a hormone-dependent tumor harboring chromosomal rearrangement, is an indolent tumor with a favorable prognosis, but characterized by late recurrences even in patients with Stage I disease, suggesting the requirement of a long-term follow-up. Patients with HG-ESS, based on the identification of YWHAE-NUTM2A/B (YWHAE-FAM22A/B) gene fusion, typically present with advanced stage diseases and frequently have recurrences, usually within a few years after initial surgery. UUS is, a high-grade sarcoma, extremely rare, lacking a specific line of differentiation, which is a diagnosis of exclusion (the wastebasket category, which fails to fulfill the morphological and immunohistochemical criteria of translocation-positive ESS). Surgery is the main strategy in the management of uterine sarcoma. Due to rarity, complex biological characteristics, and unknown etiology and risk factors of uterine sarcomas, the role of adjuvant therapy is not clear. Only LG-ESS might respond to progestins or aromatase inhibitors.

Uterine sarcomas account for 3-7% of all uterine cancers. Because of their rarity, unknown etiology, and highly divergent genetic aberration, there is a lack of consensus on risk factors for occurrence and predictive poor outcomes as well as optimal therapeutic choices. Tumor types according to the World Health Organization classification include leiomyosarcoma, endometrial stroma sarcoma, and undifferentiated sarcoma. Staging is done using the 2014 Federation International Gynecology and Obstetrics and 2010 American Joint Committee on Cancer tumor, lymph node, and metastases systems. Tumor grade can be classified based on the French Federation of Cancer Centers Sarcoma Group system or the Broder's system that incorporates tumor differentiation, mitotic count, and tumor necrosis. This review is a series of articles discussing uterine sarcoma, and this is Part I, which focuses on one of the subtypes of uterine sarcomas-uterine leiomyosarcoma. The clinical characteristics, diagnosis, outcome, and recent advances are summarized in this article.