ORIGINAL ARTICLE: Alterations in RCAS1 Serum Concentration Levels During the Normal Menstrual Cycle and the Lack of Analogical Changes in Ovarian Endometriosis

Regulation of apoptotic pathways during endometriosis: from the molecular basis to the future perspectives

PURPOSE

Endometriosis is defined as the presence of endometrial-like endometrial cells, glands and stroma outside the uterus, causing a strong inflammatory-like microenvironment in the affected tissue. This may provoke a breakdown in the peritoneal cavity homeostasis, with the consequent processes of immune alteration, documented by peripheral mononuclear cells recruitment and secretion of inflammatory cytokines in early phases and of angiogenic and fibrogenic cytokines in the late stages of the disease. Considering the pivotal role of interaction between immune and endometriotic cells, in this paper, we aim to shed light about the role of apoptosis pathways in modulating the fine-regulated peritoneal microenvironment during endometriosis.

METHODS

Narrative overview, synthesizing the findings of literature retrieved from searches of computerized databases.

RESULTS

In normal conditions, endometriotic cells, refluxed through the fallopian tubes into the peritoneal cavity, should be attacked and removed by phagocytes and NK cells. During endometriosis, the breakdown of peritoneal homeostasis causes the failure of scavenging mechanisms, allowing the survival of endometriotic cells. The consequent so-called "immunoescaping" of endometriotic cells could be due, at least in part, to the reduction of apoptotic-mediated pathways previously described.

CONCLUSION

Considering the large amount of evidence retrieved from in vitro as well as in vivo models, the reduced apoptosis of endometriotic cells together with the increased apoptosis of peritoneal fluid mononuclear cells may address the peritoneal homeostasis to a permissive environment for the progression of the disease.

[The involvement of RCAS1 in creating a suppressive tumor microenvironment in patients with pharyngeal squamous cell carcinoma]

INTRODUCTION

Tumor microenvironment makes up the stroma of the neoplasm and is the tissue that determines the growth and progression of the tumor and its ability to create metastases. THE AIM OF THE PRESENT STUDY: has been to evaluate the potential role of RCAS1 protein in creating the suppressive tumor microenvironment in pharyngeal squamous cell carcinomas. The immunoreactivity of RCAS1, CD3, CD25, CD68, CD69 and Foxp3 was assessed in the tissue samples of the tumor, in tumor microenvironment and in the reference samples of palatine tonsils in chronic inflammation.

RESULTS

A statistically significantly higher RCAS1 antigen immunoreactivity was identified in pharyngeal cancer samples than in the stromal samples, the presence of RCAS1 positive macrophages infiltrating the tumor and its stroma was also noticed. The statistically significantly higher RCAS1 antigen immunoreactivity level was identified in the pharyngeal cancer samples in patients with the presence of lymph node metastases in comparison to patients without metastases. The infiltration of CD68 positive cells (macrophages) was significantly higher in the stromal tissue samples than in cancer samples and it was in both, the tumor and the stroma, significantly higher in patients with the presence of lymph node metastases than in patients without metastases. Additionally the presence of CD3 positive TILs was noticed in the tissue of the tumor and in its stroma, the cells were activated, typified by CD69 immunoreactivity which was higher than in the reference samples, and impaired cytotoxicity with low CD25 antigen immunoreactivity. This observation confirmed the presence of selective immune suppression within the tumor and the stroma.

CONCLUSION

RCAS1, an active factor secreted by the tumor and present in its stroma may play an important role in the phenomenon of tumor escape from host immunological surveillance and in creating the immune tolerance for the tumor cells, as well as in the tumor microenvironment remodeling with creating its suppressive profile enabling the further tumor growth and metastases.

Analysis of RCAS1 immunoreactivity within hydatidiform mole cells and decidual cells according to the applied therapeutic strategy: surgery or surgery followed by chemotherapy

INTRODUCTION

Trophoblast cells cooperate with both maternal immune cells and decidual cells to help develop the suppressive microenvironment of the endometrium. The maternal immune response against hydatidiform mole depends on this suppressive endometrial profile. Since RCAS1 is one of the molecular factors participating in the development of the suppressive profile of the endometrium we decided to examine the immunoreactivity of the RCAS1 within both the trophoblast and decidual cells during the development of hydatidiform mole.

METHODS

We analyzed the immunoreactivity of RCAS1 on both trophoblast and decidual cells derived from patients who underwent curettage because of hydatidiform mole. These patients were then divided into two subgroups according to whether or not they required chemotherapy after the surgical procedure.

RESULT

We observed significantly lower immunoreactivity levels of both RCAS1 within the complete molar lesions of the patients on whom surgery alone was performed when compared to the levels found in those for whom surgery was followed by chemotherapy.

CONCLUSION

RCAS1 staining may provide information regarding the intensity of the immunosuppressive microenvironment of both the molar lesion and the endometrium. This information can prove significant in determining the clinical course of hydatidiform mole.

The frequency of CD25+CD4+ and FOXP3+ regulatory T cells in ectopic endometrium and ectopic decidua

BACKGROUND

The presence of regulatory T (Treg) cells in human endometrium is crucial for maintaining immunological homeostasis within the uterus. For this study we decided to evaluate the subpopulations of Treg cells in conditions where a disturbance in the immunological equilibrium in ectopic endometrium and decidua has been observed, such as in cases of ovarian endometriosis (involving local immune cell suppression) and ectopic pregnancy (involving an increase in local immune system activity). We then compared these findings to what we observed in the normal eutopic endometrium of women during the secretory phase of the menstrual cycle (with immune cells under individual control).

METHODS

The endometrium tissue samples evaluated in our study were obtained from 47 women during one of two kinds of laparoscopic procedures. 16 of the women underwent laparoscopies due to Fallopian tube pregnancies (EP), and 16 due to ovarian endometrioma, while 15 women made up a control group. The presence of regulatory T cells in these tissue samples was evaluated by FACS.

RESULTS

In our study, the percentages of FOXP3+ cells within the subpopulation of CD4+ T lymphocytes found in the decidua of the patients treated for Fallopian tube pregnancies were statistically significantly lower than both those observed in the ovarian endometriosis tissue samples and those found in the secretory eutopic endometrium samples of the control group.

CONCLUSION

The disturbance in the immunological equilibrium observed in ectopic endometrium and decidua would seem to be related to the alteration in the Treg cell population that occurs in these ectopic tissues.

Differences in the soluble HLA-G blood serum concentration levels in patients with ovarian cancer and ovarian and deep endometriosis

PROBLEM

The relationship between endometriosis and cancer has been widely discussed in the literature but is still not well clarified. Perhaps significantly, soluble human leukocyte antigen-G (sHLA-G) has been identified in the microenvironment of both ovarian cancer and endometrioma. The aim of this study has been to evaluate the sHLA-G levels in the blood sera of women with deep endometriosis and ovarian endometrioma over the course of the menstrual cycle and to compare to the levels of sHLA-G in the blood sera of women with ovarian cancer.

METHOD OF STUDY

In our study, we examined the blood sera obtained from 123 patients operated on because of ovarian cancer (65 cases), ovarian endometrioma (30 cases), and deep endometriosis (28 cases). We decided to compare the levels of sHLA-G in patients with endometriosis to those found in patients with ovarian cancer with respect to the menstrual cycle phases. The sHLA-G concentration level was measured by enzyme-linked immunosorbent assay kit.

RESULTS

The level of sHLA-G concentration in the blood serum of patients with deep endometriosis fluctuates over the course of the menstrual cycle, and during the proliferative and secretory phases, it remains at a high level comparable to that found in patients with ovarian cancer. By contrast, the level of sHLA-G concentration in the blood serum of patients with ovarian endometrioma fluctuates minimally over the course of the different menstrual cycle phases and, as in patients with ovarian cancer, it remains at high level during the proliferative phase.

CONCLUSION

sHLA-G blood serum concentration levels would seem to provide important information regarding the degree of immune system regulation disturbance in both ectopic endometrial cells and the cancer cell suppressive microenvironment.

RCAS1, MT, and vimentin as potential markers of tumor microenvironment remodeling

A tumor stimulates the remodeling of its microenvironment for its own survival. To protect its own growth and induce angiogenesis, the tumor changes the structure of extracellular matrix and the function of existing cells; it thus chemo-attracts immune system cells altering their function. In our study, we discuss the potential markers of tumor microenvironment remodeling. For instance, RCAS1 is a protein responsible for tumor escape from host immunologic surveillance that additionally seems to be involved in the remodeling of the microenvironment. Another protein, metallothionein, which is both anti-apoptotic and pro-proliferative, is also responsible for modulating the response of immune system cells. Most likely, the expression of this protein by the fibroblasts of tumor microenvironment is related to the remodeled phenotype of these cells because of the tumor influence on cancer-associated fibroblasts. Lastly, vimentin is a protein that would appear to be the marker for the mesenchymal transition of cells from the epithelial phenotype. These cells seem to acquire the mesenchymal phenotype to migrate so that they can facilitate the development of metastases. Interestingly, the expression of vimentin has also been observed in the tumor microenvironment as well and may serve as a marker of a remodeled stroma in the process of facilitating tumor spread.