Practical Applications of a Monoclonal Antibody (NDOG₂) against Placental Alkaline Phosphatase in Ovarian Cancer

Abstract

Summary: A monoclonal antibody (NDOG2) against placental alkaline phosphatase (PLAP) in ovarian cancer has been used in three ways by the Bristol University Department of Obstetrics & Gynaecology. First, in an indirect immunoperoxidase technique, NDOG2 demonstrated positive standing in 64% of 56 ovarian carcinomas as well as in 25% of 44 benign tumours. The majority of these positive tumours were serous cystadenocarcinomas or serous cystadenomas and there was considerable variation in the expression of this antigen from tumour to tumour. NDOG2 was also used as the basis of two serum assays and, when labelled with 123-iodine (1231), in radioimmunoscintigraphy (RIS) to monitor patients' response to therapy. The first serum assay measures the enzymic activity of PLAP and the second recognizes the antigenicity of the molecules. Assay 2 proved more useful in that it predicted the course of the disease in 45% of patients followed up, whereas Assay 1 was only of use in 25% of cases. RIS proved to be a useful imaging technique and was at least as sensitive as conventional imaging techniques. The common causes of false-positive and false-negative results are described. IntroductionOvarian cancer is the most commonly occurring gynaecological malignancy in the United Kingdom (OPCS 1983) and, because of its propensity for intra-abdominal metastasis, presents particular problems in assessing a patient's response to therapy. In addition, it is a cancer that

Expression of Placental Alkaline Phosphatase in Epithelial Ovarian Tumours

“…When these data are compared to the lev els seen in sera from patients with ovarian cancer [11,[21][22][23] an inverse relation be tween tissue and serum levels seems to be present. In the circulation, serous and muci nous adenocarcinomas display significant differences in serum levels, i.e., almost 50% of the patients with serous adenocarcinomas had elevated circulating levels of PLAP.…”

Characterisation of Syncytiotrophoblast Vesicles in Normal Pregnancy and Pre-Eclampsia: Expression of Flt-1 and Endoglin

“…The NDOG2 antibody and its IgG1 control were conjugated to either RPhycoerythrin (RPE) or fluorescein isothiocyanate (FITC) using commercially available conjugation kits (Lightning Link; Innova Biosciences) according to the manufacturer’s instructions and was used to stain MV originating from the syncytiotrophoblast (STB). NDOG2 is a STB specific antibody that recognises placental alkaline phosphatase (PLAP) [33]. Non-STB MV in the preparations were identified using W6/32 conjugated to Alexa 647 (AbD Serotec) which binds to MHC class I, expressed by all cells in the body except STB and erythrocytes.…”

The Immunomodulatory Role of Syncytiotrophoblast Microvesicles

“…Cells were stained with the following fluorescently labelled antibodies CD14-APC (eBiosciences), CD3-PeCy5 (Biolegend), CD19-FITC (Serotech), CD56-Pe-Cy7 and CD16-APC-Cy7 (BD Pharmingen) and NDOG-2-PE or IgG-PE isotype control. NDOG-2 is a trophoblast specific antibody that recognises placental alkaline phosphatase [19] . NDOG-2 or IgG control antibodies were conjugated to phycoerythrin (PE) using a lightning-link kit (Innova Biosciences, Cambridge, UK).…”