| Background and objects:Advanced ovarian cancer is a kind of gynecological tumor with high motality rate[1]. Although a variety of diagnostic and therapeutic methods are constantly improving, there is no significant improvement in the prognosis of ovarian cancer, with a 5-year survival rate of 40%[2]. The research of tumor heterogeneity has become a hot spot in the research of ovarian cancer. Tumor heterogeneity refers to a monoclonal state of a tumor gradually transformed into a multi clone state during the growth process of the tumor and the tumor cells present molecular or genetic changes. It has been found that the interaction between ovarian cancer cells and the tumor microenvironment plays an important role in the progression, immunosuppression, metastases and recurrence of ovarian cancer[3-5]. Tumor-associated macrophages (TAMs) are important components of tumor microenvironment, which may influence the progression of ovarian cancer and function as immunostimulating or immunosuppressing cells. On the other hand, exosomes of ovarian cancer cells, which carries plenty of protein, mRNA and microRNA, influence the tumor microenvironment, thus relate with the growth, invasion and metastasis of ovarian cancer[6]. Therefore, we intend to perform the experiments to initially explore the interaction between tumor-associated macrophages and ovarian cancer rumor heterogeneity, hoping to find out a new target in the diagnosis and treatment of ovarian cancer. Thin endometrium refers to the endometrial thickness is inadequate when the dominant follicle is mature, which may be caused by intrauterine operations or inflammation. Thin endometrium often related to reduced fertility and estrogen treatment is a commonly used treatment.Methods:1. Centrifugation was used for the isolation and purification of exosomes of ovarian cancer cell lines (ES2, SKOV3, A2780, A2780-L, A2780-H); Western blotting was performed when identifying the specific markers of exosomes and transmission electron microscope was used for the observation of exosome morphology;2. Monocyte derived cell line (THP-1) was induced to differentiate into macrophages. Exosomes isolated from the supernatant of ovarian cancer cell line was added to the culture medium of macrophages. The phagocytosis of exosomes by macrophages was observed by confocal microscope.3. Exosomes derived from varian cancer cell lines were added to the culture media of macrophages and was tested by flow cytometry for CD68 and CD 163. The changes of phenotype of macrophages were analyzed. Macrophages induced by exosomes and ovarian cancer cells were co-cultured to observe effects of macrophages on the biological behavior of ovarian cancer cells.4. Tissue microarrays of advanced ovarian cancer foci, Intraperitoneal implant lesions and recurrent lesions were analyzed by immunohistochemical staining, to identify the relationship between the number as well as the phenotype distribution of TAMs and prognosis of ovarian cancer.5. The clinical records of patients with thin endometrium who had undergone estrogen treatment were collected. Factors related to the treatment effect and the reproduction outcome were analyzed.Results:1. All of the five kinds of ovarian cancer cell lines were observed to secrete exosomes with typical structure, which expressed the specific markers of exosomes;2. Phagocytosis of exosomes derived from ovarian cancer by macrophages was observed in vitro;3. Exosomes derived from ovarian cancer cell lines induced the M2 phenotype of macrophages. macrophages induced by exosomes could promote the proliferation, migration and invasion of ovarian cancer cells. Besides, the chemo-sensitivity of ES2 cells was reduce after co-cultured with TAMs;4. The density of TAMs (especially M2 macrophages) in ovarian cancer tissue was related to the stage, the differentiation of tumors. Higher density of M2 macrophages was associated with less sensitivity to chemotherapeutic drugs. In ovarian cancer primary foci, higher density of M2 macrophages was related to worse prognosis.5. Estrogen treatment was effective in 92.1% of all the patients.The treatment effect was related to the endometrial thickness before the treatment and the treatment duration (P<0.05). The assisted reproductive outcome after the treatment was related to the quality of embryos transferred (P<0.05).Conclusion:Exosomes derived from could change the phenotype of TAMs and therefore create a microenvironment which promotes the growth, progression, and drug-resistance of ovarian cancer. The density of M2 macrophages in ovarian cancer tissue was related to the stage, differentiation and sensitivity of tumor, and may serve as a predictive factor of the prognosis. The treatment effect of estrogen treatment on thin endometrium was related to the endometrial thickness before treatment and the treatment duration. The reproductive outcome was related to the quality of embryos transferred. |
