High frequency of fetal cells within a primitive stem cell population in maternal blood.

BACKGROUND: During pregnancy, fetal cells enter the maternal bloodstream resulting in fetal cell microchimerism. The fetal cells persist in the mother for decades and colonize a variety of maternal organs. They are associated with maternal autoimmune diseases and may also participate in tissue repair. The identity of the microchimeric cells is not certain but they must be able to persist long-term and have potential for multitissue differentiation. METHODS AND RESULTS: Here we tested the hypothesis that the fetal microchimeric cells are primitive stem cells, represented by CD34+ adherent cells, which have a wide potential for differentiation. We isolated these stem cells from the blood of pregnant females (n = 25) and detected fetal cells of the correct gender, using fluorescence in situ hybridization, in a high proportion (71% male fetuses and 90% female fetuses; false positive rate 11%, false negative rate 29%) of cases. By RT-PCR, we demonstrated that the cells express Oct-4, Nanog and Rex-1. No fetal cells were detected in the mononuclear or total CD34+ cell populations but high frequencies (mean 11.8%) of fetal cells were detected in the adherent CD34+ cell population. CONCLUSIONS: These results identify adherent CD34+ stem cells as candidate fetal microchimeric cells, which are capable of sustaining the fetal cell population in the long term and have the ability to colonize multiple tissues and organs.

The Tumor-Suppressor Protein OPCML Potentiates Anti-EGFR- and Anti-HER2-Targeted Therapy in HER2-Positive Ovarian and Breast Cancer.

Opioid-binding protein/cell adhesion molecule-like (OPCML) is a tumor-suppressor gene that is frequently inactivated in ovarian cancer and many other cancers by somatic methylation. We have previously shown that OPCML exerts its suppressor function by negatively regulating a spectrum of receptor tyrosine kinases (RTK), such as ErbB2/HER2, FGFR1, and EphA2, thus attenuating their related downstream signaling. The physical interaction of OPCML with this defined group of RTKs is a prerequisite for their downregulation. Overexpression/gene amplification of EGFR and HER2 is a frequent event in multiple cancers, including ovarian and breast cancers. Molecular therapeutics against EGFR/HER2 or EGFR only, such as lapatinib and erlotinib, respectively, were developed to target these receptors, but resistance often occurs in relapsing cancers. Here we show that, though OPCML interacts only with HER2 and not with EGFR, the interaction of OPCML with HER2 disrupts the formation of the HER2-EGFR heterodimer, and this translates into a better response to both lapatinib and erlotinib in HER2-expressing ovarian and breast cancer cell lines. Also, we show that high OPCML expression is associated with better response to lapatinib therapy in breast cancer patients and better survival in HER2-overexpressing ovarian cancer patients, suggesting that OPCML co-therapy could be a valuable sensitizing approach to RTK inhibitors. Mol Cancer Ther; 16(10); 2246-56. ©2017 AACR.

Does fertility treatment increase the risk of uterine cancer? A meta-analysis.

An ongoing debate over the last two decades has focused on whether fertility treatment in women may lead to an increased risk of developing uterine cancer over a period of time. Uterine cancer (including mainly endometrial carcinoma and the less common uterine sarcoma) is the commonest reproductive tract cancer and the fourth commonest cancer in women in the UK. Our objective was to assess the association between fertility drugs used in the treatment of female infertility (both as an independent therapy and during in vitro fertilization cycles) and the development of uterine cancer. A literature search was performed using Medline, Embase, Cochrane Library and Google Scholar databases for comparative studies until December 2014 to investigate a clinical significance of fertility treatment on the incidence of developing uterine cancer. General and MESH search headings, as well as the 'related articles' function were applied. All comparative studies of 'fertility treatment' versus 'non-fertility treatment' reporting the incidence of uterine cancer as an outcome were included. Uterine cancer incorporated the following terms: uterine cancer, uterine body tumours, uterine sarcomas and endometrial cancers. The primary outcome of interest was the uterine cancer incidence in all 'fertility treatment' versus 'non-fertility treatment' patient groups. Secondary outcomes of interest were: (a) uterine cancer incidence in 'IVF' versus 'non-IVF' patient groups; and (b) uterine cancer incidence according to type of fertility drug used. Odds ratio was the summary statistic. Random-effects modelling, graphical exploration and sensitivity analysis were used to evaluate the consistency of the calculated treatment effect. We included six studies in our final analysis, which comprised 776,224 patients in total. Of these, 103,758 had undergone fertility treatment and 672,466 had not. There was 100% agreement between the two reviewers regarding the data extraction. All the studies contained groups that were comparable in age, although the criteria of reporting age varied. Taking all studies into account, the incidence of uterine cancer was 0.14% (150 of 103,758) in the fertility treatment group and 2.22% (14,918 of 672,466) in the non-fertility treatment group. Using the random-effect model to analyze uterine cancer incidence, this difference was not found to be of statistical significance: OR 0.78 (95% CI, 0.39-1.57). The degree of heterogeneity was high (I(2)=68%). The risk for the development of uterine and in particular endometrial cancer posed by infertility and an unopposed oestrogen state is widely recognized. The present analysis aimed to perceive whether standard fertility drugs were also a risk to future uterine cancer development. The treatment does increase the concentrations of unopposed oestrogen for a short periods of time but if successful leads to fertility. This meta-analysis points to a non-deleterious effect of fertility drugs towards the development of uterine cancer, a conclusion strongly supported by our sub-group analysis.

Use of cyclosporine in uterine transplantation.

Uterine transplantation has been proposed as a possible solution to absolute uterine factor infertility untreatable by any other option. Since the first human attempt in 2000, various teams have tried to clarify which immunosuppressant would be most suitable for protecting the allogeneic uterine graft while posing a minimal risk to the fetus. Cyclosporine A (CsA) is an immunosuppressant widely used by transplant recipients. It is currently being tested as a potential immunosuppressant to be used during UTn. Its effect on the mother and fetus and its influence upon the graft during pregnancy have been of major concern. We review the role of CsA in UTn and its effect on pregnant transplant recipients and their offspring.

The OPCML tumor suppressor functions as a cell surface repressor-adaptor, negatively regulating receptor tyrosine kinases in epithelial ovarian cancer.

UNLABELLED: Epithelial ovarian cancer is the leading cause of death from gynecologic malignancy, and its molecular basis is poorly understood. We previously demonstrated that opioid binding protein cell adhesion molecule (OPCML) was frequently epigenetically inactivated in epithelial ovarian cancers, with tumor suppressor function in vitro and in vivo. Here, we further show the clinical relevance of OPCML and demonstrate that OPCML functions by a novel mechanism in epithelial ovarian cancer cell lines and normal ovarian surface epithelial cells by regulating a specific repertoire of receptor tyrosine kinases: EPHA2, FGFR1, FGFR3, HER2, and HER4. OPCML negatively regulates receptor tyrosine kinases by binding their extracellular domains, altering trafficking via nonclathrin-dependent endocytosis, and promoting their degradation via a polyubiquitination-associated proteasomal mechanism leading to signaling and growth inhibition. Exogenous recombinant OPCML domain 1-3 protein inhibited the cell growth of epithelial ovarian cancers cell in vitro and in vivo in 2 murine ovarian cancer intraperitoneal models that used an identical mechanism. These findings demonstrate a novel mechanism of OPCML-mediated tumor suppression and provide a proof-of-concept for recombinant OPCML protein therapy in epithelial ovarian cancers. SIGNIFICANCE: The OPCML tumor suppressor negatively regulates a specific spectrum of receptor tyrosine kinases in ovarian cancer cells by binding to their extracellular domain and altering trafficking to a nonclathrin, caveolin-1­associated endosomal pathway that results in receptor tyrosine kinase polyubiquitination and proteasomal degradation. Recombinant OPCML domain 1-3 recapitulates this mechanism and may allow for the implementation of an extracellular tumor-suppressor replacement strategy.