Expression of RCAS1 in Female Genital Organs

The effect of tumor-associated protein RCAS1 gene silencing on blood pressure and urinary protein excretion in pregnant mouse: a pilot study

OBJECTIVE

The level of tumor-associated receptor-binding cancer antigen that is expressed on SiSo cells (RCAS1) is decreased significantly in preeclamptic pregnancies. We hypothesized that RCAS1 protein gene silencing might affect blood pressure and proteinuria in pregnant mice.

STUDY DESIGN

On postcoital day 7.5, pregnant imprinting control region mice were subjected to the transfer of small interfering RNA (siRNA) against RCAS1 protein into the uterine cavity with the use of a hemagglutinating virus Japan envelope. Scramble siRNA was used as a negative control. Blood pressure and urine albumin/creatinine measurements were performed. The effect of the transferred siRNA was examined in uterine samples on postcoital day 8.5 with the use of Western blotting and immunohistochemistry analyses.

RESULTS

In the RCAS1 siRNA group, blood pressure significantly raised on postcoital days 9.5, 10.5, 11.5, and 15.5, whereas urine albumin/creatinine ratio was significantly increased on postcoital day 9.5

CONCLUSION

Our results suggest the importance of RCAS1 protein in the pathophysiologic condition of preeclampsia.

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 human tumor-associated antigen RCAS1 in pregnancies complicated by pre-eclampsia

The human tumor-associated antigen RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is considered to play a role in the escape of tumor cells from immune surveillance and, at the same time, participates in the inhibition of the maternal immune response during pregnancy. The aim of our study was to investigate the expression of tumor-associated RCAS1 protein in the placenta and amniotic membranes and to assess and compare its concentration in amniotic fluid, maternal and cord blood sera in pregnancies complicated by pre-eclampsia. Samples were obtained from women with pre-eclampsia (N=9), pre-eclampsia with IUGR (N=4), normotensive IUGR (N=7) and healthy term controls (N=25) after delivery. Placentas were studied by immunohistochemistry, Western blot analysis and real-time (RT)-PCR. For assessment of RCAS1 protein concentrations in biological fluids, ELISA was performed. RCAS1 mRNA expression in the placentas of pre-eclamptic patients was significantly lower than in controls (p<0.01). The maternal blood serum RCAS1 protein concentration in the pre-eclampsia cases was also significantly lower than in controls (p=0.0207). The other study groups did not differ significantly. This study reveals the possible role of the RCAS1 protein in the development of pre-eclampsia through an immunological pathway.

RCAS1 decidual immunoreactivity in severe pre-eclampsia: immune cell presence and activity

PROBLEM

Pre-eclampsia seems to be related to the disturbance of immune tolerance regulation during pregnancy. Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) decidual level alterations were concomitant with changes in immune cell number and activity in decidua. As decidual immunomodulating activity participates in the development of immune tolerance during pregnancy, we aimed to evaluate the immunoreactivity level of decidual RCAS1 with respect to the presence and activity of immune cells.

METHOD OF STUDY

RCAS1, CD3, CD56, CD69, and CD25 immunoreactivity was assessed by immunohistochemistry in 30 decidual samples derived from patients with severe pre-eclampsia (sPE) and from a healthy control group.

RESULTS

RCAS1 immunoreactivity was statistically significantly higher in decidual tissue samples derived from patients with sPE tissue than in those derived from healthy patients in whom elective cesarean section at term was performed. A statistically significantly lower number of CD56(+) and CD3(+) cells and lower immunoreactivity level of CD69 were found in patients with sPE compared with those from the control group.

CONCLUSION

The limited immune cells infiltration in decidua during sPE is associated with increase in RCAS1 decidual level.

Analysis of metallothionein, RCAS1 immunoreactivity regarding immune cell concentration in the endometrium and tubal mucosa in ectopic pregnancy during the course of tubal rupture

INTRODUCTION

Tubal rupture seems to be linked to a disturbance in maternal immune response and trophoblast cell invasion. The immunomodulating activity of endometrial cells is necessary for the coexistence of activated immune cells and endometrial cells. RCAS1 and metallothionein (MT) participate in this process.

MATERIAL AND METHODS

Tissue samples derived from fallopian tubes and endometrium were collected during one surgical procedure and divided into three groups: unruptured ectopic pregnancy (EP) without bleeding, unruptured EP with hemorrhage into the peritoneal cavity, and ruptured tubal pregnancy. Immunoreactivity of MT, RCAS1, CD56, CD3, CD69 and CD25 were assessed by immunohistochemical methods.

RESULTS

The number of CD3+ and CD56+ cells as well as CD69 antigen immunoreactivity in ruptured tubal mucosa of EP were statistically significantly higher than those measured for unruptured EP without bleeding, while at the same time the number of CD56+ cells in endometrium was statistically significantly lower. The growth of immune cell numbers in tubal mucosa during tubal rupture was not associated with an adequate MT and RCAS1 level.

CONCLUSION

Tubal perforation seems to be linked to a concentration of immune cells and a growth of their activity without an adequate increase of the level of proteins compensating for immune cell response.

RCAS1 decidual immunoreactivity during placental abruption: immune cell presence and activity

PROBLEM

RCAS1 is a protein responsible for the suppression of cytotoxic immune response during gestation. The present study evaluates the immunoreactivity level of RCAS1 with respect to immune cell status during placental abruption (PA) and retained placental tissue (RPT).

METHOD OF STUDY

RCAS1, CD3, CD56, CD69 and CD25 immunoreactivity was assessed by immunohistochemistry in 66 decidual samples derived from PA and from RPT.

RESULTS

RCAS1 immunoreactivity was statistically significantly higher in decidual tissue samples derived from patients with RPT than in those derived from patients with PA. A statistically significantly lower number of CD56(+) and CD3(+) cells and immunoreactivity level of CD69 were found in patients with RPT, compared to those with PA.

CONCLUSION

Placental abruption seems to be associated with excessive accumulation and activity of CD3(+) and CD56(+) cells in decidua, which processes might, in turn, result from an insufficient RCAS1 decidual level.

Clinical significance of RCAS1 as a biomarker of uterine cancer

OBJECTIVES

Expression of RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is associated with prognosis of various malignancies including uterine cancer. Proteolytic cleavage of RCAS1 at extracellular domains (ectodomain shedding) yields soluble RCAS1. Although RCAS1 can induce apoptosis in normal peripheral lymphocytes, its biologic function in cancer patients is unclear. Here, we evaluated serum RCAS1 concentrations to clarify its biologic activity in uterine cancer.

METHODS

Via ELISA, we measured serum RCAS1 concentrations in samples from 54 healthy blood donors and 113 patients-63 with cervical cancer and 50 with endometrial cancer. We also counted the peripheral lymphocyte number. We correlated via statistical means the RCAS1 values with patients' clinicopathologic variables. We assessed inhibition of growth of K562 cells, which express the putative RCAS1 receptor, via WST-1 assay of serum samples to clarify RCAS1's biologic activity.

RESULTS

Uterine cancer patients had significantly higher serum RCAS1 concentrations than did healthy blood donors (P<0.05). Patients with adenocarcinoma had significantly higher RCAS1 concentrations than did those with squamous cell carcinoma (P=0.0340). RCAS1 values were also significantly associated with response to treatment (P<0.001). FasL and TNF-alpha serum concentrations were not significantly different for the different groups, however. The WST-1 assay showed that patients' serum induced K562 cell growth inhibition, but this effect partially recovered after immunodepletion of RCAS1. Peripheral lymphocyte number and serum RCAS1 concentration were inversely related (P=0.0310).

CONCLUSION

RCAS1 may be a biomarker of uterine cancer because of its potential to predict results of uterine cancer treatment and inhibit growth of immune cells.