Clinical significance of RCAS1 as a biomarker of uterine cancer

Clinical Applicability of Tissue Polypeptide Antigen and CA-125 in Gynecological Malignancies

BACKGROUND

Nowadays there still is no sufficient screening tool for ovarian and uterine cancer.

OBJECTIVE

The current study aimed to investigate whether cancer antigen 125 (CA-125), tissue polypeptide antigen (TPA) or the combination of both markers are able to act as screening tools for ovarian or uterine cancer.

METHODS

A total of 275 blood samples from different cohorts (ovarian cancer, uterine cancer, benign control group) were prospectively drawn and analyzed.

RESULTS

Established biomarkers TPA and CA-125 showed elevated serum concentrations in patients with malignant tumors as compared to healthy women and women with benign diseases. In ROC curve analyses, both biomarkers were well able to discriminate between malignant and healthy, benign or overall non-malignant cases in the whole sample, with AUCs of 0.842 and above. While TPA was the best diagnostic marker in patients with uterine cancer, CA 125 was the best in patients with ovarian cancer.

CONCLUSIONS

TPA and CA-125 both showed promising results for the detection of gynecologic malignancies. The combination of CA-125 and TPA did not improve sensitivity in comparison to single markers.

High post-treatment serum soluble receptor-binding cancer antigen expressed on SiSo cells (sRCAS1) levels is associated with poor survival of patients with cervical cancer

AIM

Receptor-binding cancer antigen expressed on SiSo cells (sRCAS1) is responsible for induction of selective immunosuppression. In addition, preclinical studies have shown that sRCAS1 levels may reflect cancer aggressiveness. The main aim of our study was to analyze pre- and post-treatment levels of sRCAS1 in the sera of patients treated for cervical cancer and to evaluate whether the levels change during treatment and their impact on patient prognosis.

METHODS

The study included 49 patients suffering from cervical cancer. The early stage cervical cancer patients (14) were treated surgically, while the advanced stage patients (35) underwent radiochemotherapy. Serum sRCAS1 levels were evaluated both before and after intervention with the use of the ELISA method.

RESULTS

We have found that median serum sRCAS1 levels of patients before intervention were not significantly different from the levels assessed after intervention. There were also no differences when pre- and post-treatment levels were compared within the group of early and of advanced stage patients. Serum sRCAS1 levels were not influenced by either the histopathological type of the tumor or the methods of treatment. High post-intervention sRCAS1 levels indicated shortened OS when compared to low sRCAS1 levels. Neither pre-intervention sRCAS1 levels nor the alteration in sRCAS1 levels during treatment were associated with patient prognosis. In multivariate analysis, post-treatment sRCAS1 levels and clinical stage of cervical cancer remained as independent predictors of survival.

CONCLUSION

High post-treatment serum sRCAS1 level in cervical cancer patients seems to be a negative prognostic factor for patient overall survival.

Breast cancer, placenta and pregnancy

BACKGROUND

Breast cancer is one of the most frequently diagnosed malignancies during pregnancy. Tumours often present characteristics of high malignancy and are hormone receptor negative/HER2 positive or triple negative. In general, pregnancy, including the postpartum period, is associated with a transiently increased risk of developing breast cancer but followed by a long-lasting protective period. Placental metastases are very rare and, thus far, breast cancer metastases in the foetal compartment have not been described. To discuss these apparently contradictory observations, this narrative review resumes immunological and hormonal alterations during pregnancy potentially affecting breast cancer risk as well as tumour growth and behaviour.

OBSERVATIONS

Upregulation of breast cancer-associated genes involved in immunological and reproductive processes has been observed in parous women and is potentially responsible for a transiently increased risk in pregnancy. In contrast, maternal immunisation and immunoglobulin production against antigens expressed on trophoblast cells, such as specific glycosylation patterns of mucin-1 or RCAS1-associated truncated glycans, seem to prevent breast cancer development in later years. Animal and human studies indicate that T cells are involved in these processes. Several placenta-derived factors, especially kisspeptin, have direct anti-tumour effects. The pregnancy-related increase of estrogen, progesterone, and other hormones influence growth and characteristics of breast cancer while the role of further placenta-secreted factors is still controversially discussed.

CONCLUSION

Several factors and cells are involved in altered breast cancer risk during and after pregnancy and have potential for developing novel treatment strategies in future.

Diagnostic and Prognostic Utility of Serum Receptor-Binding Cancer Antigen Expressed on SiSo Cells (RCAS1) Levels in Colon Cancer Patients

Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is a human tumor-associated antigen that induces cell-cycle arrest and/or apoptosis in cells bearing the RCAS1 receptor. The aim of the present study was to elucidate the diagnostic and prognostic utility of RCAS1 levels in colon cancer patients. Serum RCAS1 levels were determined using a sandwich enzyme-linked immunosorbent assay in 97 colon cancer patients and 20 healthy individuals. The levels were significantly increased in colon cancer patients compared to healthy individuals (p<0.0001). Increased RCAS1 levels were significantly associated with advanced Dukes’ stage (p=0.0079) and high histopathological tumor grade (p=0.0028). Univariate analysis revealed that colon cancer patients with elevated RCAS1 levels had significantly shorter overall survival times (log-rank test, p=0.027). By multivariate analysis, serum RCAS1 was identified as an independent prognostic factor (Cox regression analysis, p=0.033). In conclusion, colon cancer patients with advanced disease stage and grade and poor prognosis showed elevated serum RCAS1 levels. Assessment of serum RCAS1 levels could therefore be considered as a diagnostic and prognostic marker in colon neoplasia.

Analysis of the intensity of immune cell infiltration and immunoreactivity of RCAS1 in diffuse large B-cell lymphoma of the palatine tonsil and its microenvironment

Non-Hodgkin lymphoma of Waldeyer's ring constitutes a small percentage of cases of palatine tonsil malignancies and its precise etiology remains unknown. RCAS1 (receptor cancer-binding antigen expressed on SiSo cells) has been demonstrated to be associated with poor prognosis, the development of lymph node metastases and participation in tumor microenvironment remodeling. Our aim is to analyze the potential role of RCAS1 expression in the tumor and tumor microenvironment in the development of early-stage palatine tonsil B-cell lymphomas. We selected 20 patients and analyzed tissue samples from the lymphoma and tumor microenvironment of each patient and from a reference group of 20 patients with chronic tonsillitis. The presence of RCAS1 protein immunoreactivity was demonstrated in 65% of the examined tissue samples of diffuse large B-cell lymphoma and in 25% of the analyzed stromata in which it was exhibited by CD68-positive cells identified as macrophages and dispersed throughout the stroma. RCAS1 immunoreactivity in the lymphoma tissue samples remained at a level comparable with that of the reference and was significantly higher in these samples than in those from the stroma. Chronic inflammation of the palatine tonsils thus results in intensive infiltration by various types of immune system cells and in excessive RCAS1 immunoreactivity, both of which confirm the important regulatory role of RCAS1 in the immune response in the mucosa-associated lymphatic tissue of Waldeyer's ring. RCAS1 seems to be involved in creating tumor-induced inflammation in the tumor and its microenvironment.

A disintegrin and metalloproteinase 9 is involved in ectodomain shedding of receptor-binding cancer antigen expressed on SiSo cells

In several human malignancies, the expression of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is associated with aggressive characteristics and poor overall survival. RCAS1 alters the tumor microenvironment by inducing peripheral lymphocyte apoptosis and angiogenesis, while reducing the vimentin-positive cell population. Although proteolytic processing, referred to as "ectodomain shedding," is pivotal for induction of apoptosis by RCAS1, the proteases involved in RCAS1-dependent shedding remain unclear. Here we investigated proteases involved in RCAS1 shedding and the association between tumor protease expression and serum RCAS1 concentration in uterine cancer patients. A disintegrin and metalloproteinase (ADAM) 9 was shown to be involved in the ectodomain shedding of RCAS1. Given the significant correlation between tumor ADAM9 expression and serum RCAS1 concentration in both cervical and endometrial cancer as well as the role for ADAM9 in RCAS1 shedding, further exploration of the regulatory mechanisms by which ADAM9 converts membrane-anchored RCAS1 into its soluble form should aid the development of novel RCAS1-targeting therapeutic strategies to treat human malignancies.

Apoptotic function of tumor-associated antigen RCAS1 in oral squamous cell carcinoma

Background

Receptor-binding cancer antigen expressed on SiSo cell (RCAS1) is derived from uterine adenocarcinoma and can induce apoptosis in lymphocytes, allowing tumor cells to escape from immune surveillance. RCAS1 is reportedly expressed in a membranous pattern on tumor cell or soluble one in serum of patients. The aim of this study was to investigate expression patterns of RCAS1 and the effect on apoptosis in oral squamous cell carcinoma (OSCC) cell lines.

Methods

In four kinds of OSCC cell lines (HSC-2, HSC-3, SQUU-A, and SQUU-B), RCAS1 mRNAs and proteins were determined by RT-PCR and immunocytochemistry. Membranous RCAS1 was determined by flow cytometry. Culture supernatants were analyzed for detection of soluble RCAS1 by dot blotting and enzyme-linked immunosorbent assay. Apoptotic ability of RCAS1 on the erythroid leukemia cell line K562 with the putative receptor was evaluated by flow cytometry in co-culture with highly metastatic SQUU-B, with knocked-down RCAS1 cells or in a no-cell contact condition.

Results

RCAS1 mRNA and proteins were expressed in all of OSCC cell lines. Membranous pattern were expressed in all cell lines, while soluble pattern was detected in all supernatants. RCAS1 mRNA, membranous and soluble RCAS1 were significantly seen in SQUU-B more than the other 3 cell lines (P < 0.05). K562 apoptosis was induced in co-culture with each of all cell lines, particularly with SQUU-B. Apoptosis was markedly reduced in co-culture with RCAS1 knockdown cells, but was induced in co-culture without cell contract of SQUU-B.

Conlusions

Our study suggests that RCAS1 has an apoptotic function via membranous/soluble expression pattern in OSCC cells. RCAS1 may thus affect tumor escape from immune surveillance in OSCC by inducing apoptosis.

[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.

The analysis of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) immunoreactivity within the microenvironment of the ovarian cancer lesion relative to the applied therapeutic strategy

RCAS1 is involved in generating the suppressive profile of the tumor microenvironment that helps cancer cells evade immune surveillance. The status of the cells surrounding the cancer nest may affect both the progression of the cancer and the development of metastases. In cases of ovarian cancer, a large number of patients do not respond to the applied therapy. The patient’s response to the applied therapy is directly linked to the status of the tumor microenvironment and the intensity of its suppressive profile. We analyzed the immunoreactivity of RCAS1 on the cells present in the ovarian cancer microenvironment in patients with the disease; these cells included macrophages and carcinoma-associated fibroblasts. Later we analyzed the immunoreactivity levels within these cells, taking into consideration the clinical stage of the cancer and the therapeutic strategy applied, such as the number of chemotherapy regiments, primary cytoreductive surgery, or the presence of advanced ascites. In the patients who did not respond to the therapy we observed significantly higher immunoreactivity levels of RCAS1 within the cancer nest than in those patients who did respond; moreover, in the non-responsive patients we found RCAS1 within both macrophages and carcinoma-associated fibroblasts. RCAS1 staining may provide information about the intensity of the immuno-suppressive microenvironment profile found in cases of ovarian cancer and its intensity may directly relate to the clinical outcome of the disease.

Ovarian cancer biomarkers: a focus on genomic and proteomic findings

Among the gynaecological malignancies, ovarian cancer is one of the neoplastic forms with the poorest prognosis and with the bad overall and disease-free survival rates than other gynaecological cancers; several studies, analyzing clinical data and pathological features on ovarian cancers, have focused on the identification of both diagnostic and prognostic markers for applications in clinical practice. High-throughput technologies have accelerated the process of biomarker discovery, but their validity should be still demonstrated by extensive researches on sensibility and sensitivity of ovarian cancer novel biomarkers, determining whether gene profiling and proteomics could help differentiate between patients with metastatic ovarian cancer and primary ovarian carcinomas, and their potential impact on management.

Therefore, considerable interest lies in identifying molecular prognostic biomarkers and protein indicators to guide treatment decisions and clinical follow up; the current state of knowledge about the potential clinical value of gene expression profiling in ovarian cancer is discussed, focusing on three main areas: distinguishing normal ovarian tissue from ovarian tumors, identifying different subtypes of ovarian cancer and identifying cancer likely to be responsive to therapy.

In this elaborate we discuss the use of novel molecules, discovered by proteomics and genomics approaches, as potential protein biomarkers in the management of ovarian cancer, to improve the anticancer therapy for malignant ovarian tumors and to monitor the clinical follow up.

An outlook on ovarian cancer and borderline ovarian tumors: focus on genomic and proteomic findings

Among the gynaecological malignancies, ovarian cancer is one of the neoplastic forms with the poorest prognosis and with the bad overall and disease-free survival rates than other gynaecological cancers. Ovarian tumors can be classified on the basis of the cells of origin in epithelial, stromal and germ cell tumors. Epithelial ovarian tumors display great histological heterogeneity and can be further subdivided into benign, intermediate or borderline, and invasive tumors. Several studies on ovarian tumors, have focused on the identification of both diagnostic and prognostic markers for applications in clinical practice. High-throughput technologies have accelerated the process of biomolecular study and genomic discovery; unfortunately, validity of these should be still demonstrated by extensive researches on sensibility and sensitivity of ovarian cancer novel biomarkers, determining whether gene profiling and proteomics could help differentiate between patients with metastatic ovarian cancer and primary ovarian carcinomas, and their potential impact on management. Therefore, considerable interest lies in identifying molecular and protein biomarkers and indicators to guide treatment decisions and clinical follow up. In this review, the current state of knowledge about the genoproteomic and potential clinical value of gene expression profiling in ovarian cancer and ovarian borderline tumors is discussed, focusing on three main areas: distinguishing normal ovarian tissue from ovarian cancers and borderline tumors, identifying different genotypes of ovarian tissue and identifying proteins linked to cancer or tumor development. By these targets, authors focus on the use of novel molecules, developed on the proteomics and genomics researches, as potential protein biomarkers in the management of ovarian cancer or borderline tumor, overlooking on current state of the art and on future perspectives of researches.

The Involvement of RCAS1 in Creating a Suppressive Tumor Microenvironment in Patients with Salivary Gland Adenocarcinoma

The tumor microenvironment is the tissue that determines the growth and progression of the tumor as well as its ability to initiate metastases. The aim of the present study has been to evaluate the role of RCAS1 in creating the suppressive tumor microenvironment in cases of parotid adenocarcinoma. The tissue samples of salivary gland adenocarcinomas and their stroma and the palatine tonsils which constituted the reference tissue sample group were obtained during routine surgical procedures. The immunoreactivity of RCAS1, CD3, CD25, CD68, CD69, and Foxp3 antigens was then evaluated by using the immunohistochemistry method. The patient’s consent was obtained in each case. A statistically significantly higher RCAS1 immunoreactivity level was found in the adenocarcinoma tissue samples in comparison to that found in the stromal tissue samples. A statistically significantly higher RCAS1 immunoreactivity was also identified in the adenocarcinoma tissue samples derived from patients who had lymph node metastases in comparison to patients without such metastases. Additionally, we observed the presence of RCAS1-positive macrophages in the stromal tissue samples. The infiltration of CD68-positive cells was significantly stronger in the adenocarcinoma and stromal tissue slides than in the reference group tissue slides; moreover, the infiltration was a good deal more prominent in the stromal tissue than in the adenocarcinoma tissue. The CD68 immunoreactivity levels in both the tumor and stromal tissue samples were found to be significantly higher in those patients who had lymph node metastases than in the patients without such metastases. Additionally, the infiltration of CD3- and CD25-positive cells was more prominent in the reference tissue slides than in the adenocarcinoma and stromal tissue slides, and was stronger in the adenocarcinoma tissue than in the stromal tissue. Furthermore, the infiltration of Foxp3-positive cells was seen exclusively in the stroma whereas it was not even detected in the adenocarcinoma tissue. Lastly, the Foxp3-positive cell infiltration was more prominent in the stromal tissue than in the reference group tissue. The present study demonstrates that RCAS1 expression by both tumor cells and tumor-associated macrophages may participate in creating the immunosuppressive microenvironment in parotid gland adenocarcinoma, thus promoting tumor development as well as metastases.

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.

Receptor-binding cancer antigen expressed on SiSo cells induces apoptosis via ectodomain shedding

Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is a secreted antigen that induces apoptosis in putative receptor-expressing cells, including peripheral lymphocytes and natural killer (NK) cells. RCAS1 expression is associated with aggressive characteristics and poor overall survival for 15 different human malignancies. The putative RCAS1 receptor has not been isolated and the mechanism of RCAS1 apoptosis induction remains unclear. This study explores how RCAS1 is involved in apoptosis initiation. The cell lines SiSo and MCF-7, human uterine carcinoma and breast adenocarcinoma, respectively, both express RCAS1, but RCAS1 secretion is undetectable in MCF-7 cells. SiSo and MCF-7 cells were stimulated to induce RCAS1 ectodomain shedding followed by assessment of RCAS1 expression and secretion. Additionally, the RCAS1 putative receptor-expressing human chronic myelogenous leukemia cell line K562 was co-cultured with SiSo, MCF-7, or soluble RCAS1 to follow RCAS1 secretion in apoptosis initiation. RCAS1 secretion was strongly suppressed by inhibitors of metalloproteases, protein kinase C (PKC)-delta, mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase kinase (MEK), epidermal growth factor (EGF), and G-protein-coupled receptor (GPCR). K562 apoptosis could be induced only by co-culturing with SiSo or soluble RCAS1. RCAS1 is thus secreted by ectodomain shedding, which may represent a pivotal step in RCAS1-induced apoptosis initiation.

Predicting the response of advanced cervical and ovarian tumors to therapy

The management of advanced cervical and ovarian cancers remains a significant challenge as many women fail to respond to recommended therapy, resulting in disease progression and ultimately patient death. Because of tumor heterogeneity, it is rare for all cancers of a particular type to respond to a specific therapy; and, as a result, many patients receive treatment from which they derive little or no benefit, leading to increased morbidity and undue costs. A marker that could rapidly predict or forecast disease outcome would clearly be beneficial in allowing the administration of a tailored regime for each patient while reducing toxicity and cost. Traditional prognostic factors of tumor size, grade, and stage are not ideal for predicting patient outcome, whereas the use of in vitro assays to detect chemosensitivity or resistance has not yet translated into routine clinical practice. Similarly, biomarkers and tumor markers vary in their predictive ability. DNA array technology offers great promise in predicting the response to therapy based on gene expression profiles, and can allow for targeted therapies against specific molecular alterations that cause disease. Imaging techniques, particularly those with the ability to characterize biological tissues and provide functional, structural, and molecular information, have the potential to noninvasively integrate physical and metabolic information. These include F-18-fluorodeoxyglucose positron emission tomography, dynamic contrast-enhanced magnetic resonance imaging, and diffusion weighted magnetic resonance imaging, all techniques that attempt to evaluate and predict therapy response and so influence clinical outcome. This review examines different methods of predicting the response to treatment in advanced cervical and ovarian tumors.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to describe why prediction of response to therapy for cervical and ovarian cancers is important, describe obstacles to use of in vitro assays to predict outcomes for therapy for ovarian and cervical cancers, and explain potentially new predictive markers.

The association between RCAS1 expression in laryngeal and pharyngeal cancer and its healthy stroma with cancer relapse

BACKGROUND

The purpose of this study has been to establish the level of RCAS1 - a membrane protein expressed in various cancer cells and able to induce apoptosis of CTLs and NK cells in pharyngeal and laryngeal cancer and its clear surgical margin - with respect to clinicopathological features and to patient's follow up and evaluate its possible role in cancer relapse.

METHODS

A total of 122 tissue samples were obtained: 51 samples from laryngeal and pharyngeal squamous cell carcinoma, 51 samples from the clear surgical margins of these tumors, and 20 tissue samples derived from the healthy mucous membranes of the upper respiratory tract mucosa of patients without cancerous tumors. Patients were observed for a total of 4 years following surgical treatment. The level of RCAS1 expression was assessed by immunohistochemistry and Western blot.

RESULTS

RCAS1 was identified in all laryngeal and pharyngeal carcinomas and in almost all the clear surgical margin samples. The level of RCAS1 expression was significantly higher in the cancerous samples than in the clear surgical margins and was determined to be related to the grade of the cancer and the presence of lymph node metastases. In cases of cancer relapse, significantly higher levels of RCAS1 expression were observed in the clear surgical margins.

CONCLUSION

Selective cytotoxic immune cell suppression concomitant with tumor growth and associated with RCAS1 expression seems to be an important event connected with cancer relapse.