Serum levels of placental protein 10 (PP10) in women with breast cancer and genital carcinoma and in healthy male and female subjects

Circulating microRNA-101 as a potential biomarker for hepatitis B virus-related hepatocellular carcinoma

Circulating microRNAs (miRNAs) are emerging as promising biomarkers for cancer; however, the significance of circulating miRNAs in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remains largely unknown. Based on our prior observations that miRNA-101 (miR-101) is downregulated by HBV and induces epigenetic modification, we sought to test whether circulating miR-101 may serve as a potential biomarker for HCC. The expression of miR-101 in HCCs and serum was evaluated by real-time polymerase chain reaction. Tissue and serum miR-101 levels were assessed in samples from patients with HBV-related HCC and healthy controls. A potential correlation was also evaluated between miR-101 expression and the clinicopathological features and prognosis of HCC patients. miR-101 was downregulated in HBV-related HCC tissues compared with adjacent noncancerous tissues. Furthermore, the miR-101 levels in these tissues from HCC patients were significantly lower than those in tissues from control subjects. Notably, serum miR-101 levels were found to have an inverse correlation with tissue miR-101 expression levels. The expression of serum miR-101 in patients with HBV-related HCC was significantly higher than that in the healthy controls, and this increase correlated with hepatitis B surface antigen positivity, HBV DNA levels and tumor size. These results indicate that different factors govern the levels of miR-101 in the tissue and serum of HCC patients. Given the marked and consistent increase in serum miR-101 levels in HCC patients, circulating miR-101 may serve as a promising biochemical marker for monitoring the progression of tumor development in HBV-related HCC.

Immunohistochemical and immunoelectron microscopic study of cytochrome P-450 of human fetal livers (P-450HFLa): implications for an onco-feto-placental enzyme

Cytochrome P-450 of human fetal livers (P-450HFLa) was demonstrated by the avidin-biotin immunoperoxidase technique in tissue samples as follows: human fetal organs, adult livers, human and cynomolgus placenta, and gynecologic organs which were obtained from 40 patients with gynecologic malignancies and 32 patients with benign diseases. P-450HFLa was clearly localized in the cytoplasm and membranes of the hepatocytes, and the fact was confirmed by an immunoelectron microscopic examination. In addition, a semiquantitative assay of staining intensity demonstrated that this enzyme tended to decrease with advancing age. These findings suggest that hepatic P-450HFLa synthesis is inversely proportional to age, and that this enzyme is one of the differentiation antigens. P-450HFLa was also detected immunohistochemically in other fetal organs. The present study thus confirms that P-450HFLa is not specific to the liver and is ubiquitous even in the fetus. Marked positive staining for P-450HFLa was demonstrated in villous syncytiotrophoblasts. In contrast, no positive staining was found in the cynomolgus-monkey placenta, unlike the case for many other placental antigens. These findings lead to the tentative conclusion that P-450HFLa is a feto-placental enzyme peculiar to humans. P-450HFLa was demonstrated to occur very frequently in gynecologic malignancies. The mean positivity rate for all gynecologic malignancies was 85%, while the rate was below 25% for benign gynecologic diseases, indicating that P-450HFLa is one of the onco-feto-placental enzymes. The present study thus suggests that this enzyme could be a promising new tumor marker for gynecologic malignancies.

Identity between the placental protein PP10 and the specific plasminogen activator inhibitor of placental type PAI-2

The highly specific plasminogen activator inhibitor of placental type, PAI-2, occurs in the placenta in a low molecular mass form of 46.6 kDa, and in pregnancy plasma in a (possibly glycosylated) high molecular mass form of 60 kDa. Extensive knowledge is available about the functional properties of PAI-2 as a plasminogen activator inhibitor and about its molecular biology and regulation. Of the several placenta proteins (PP) isolated, one of them, PP10, has a molecular mass of 48 kDa and its occurrence in malignancy and in complications during pregnancy has been the topic of a number of studies, though its properties and physiological significance are unknown. The present findings constitute evidence of immunological identity between PP10 and PAI-2. The sections of the amino acid sequence of PP10 analysed here were found to have identical counterparts in the sequence of the low molecular mass form of PA1-2, but in several preparations PP10 was found to occur in an inactive two-chain form due to cleavage of an Arg-Thr bond, the two peptide chains being linked to each other by a disulphide bridge. The cleavage site is identical to that observed in the reaction between PAI-2 and urokinase. The results make it possible to coordinate and correlate the findings of many separate studies and our own observations on PP10 and PAI-2.

Immunohistochemical study of tissue polypeptide antigen (TPA) and cancer antigen 125 (CA125) in the human and cynomolgus monkey placenta, umbilical cord and decidua

Tissue polypeptide antigen (TPA) and cancer antigen 125 (CA125) were studied immunohistochemically by the avidin-biotin immunoperoxidase technique in human and cynomolgus monkey placentae, membranes, umbilical cords and decidua. In early human placentae, TPA was localized mainly in the cell membranes of villous syncytio- and cyto-trophoblast. The cytoplasm of those trophoblastic cells were weakly stained with TPA. The membrane of basal chorionic trophoblast cells was strongly stained with TPA and the cytoplasm stained weakly. In early cynomolgus placentae, similar immunostaining results were obtained. However, the positive stainings for TPA was more marked in the cytoplasm of villous syncytiotrophoblast and basal chorionic trophoblast, and less marked in the cell membrane of villous cytotrophoblast. In early human and cynomolgus placentae, CA125 was not demonstrated immunohistochemically in the villi and basal chorion. In human and cynomolgus term placentae, the villous syncytiotrophoblast and basal and reflected chorionic trophoblast showed similar immunostaining as the early placentae. In addition, TPA was found in the amniotic epithelium in both sorts of placentae. TPA was not detected immunohistochemically in the umbilical cord and decidual cells. While weakly positive stains for CA125 were observed in decidual cells, CA125 was localized mainly in the membrane and cytoplasm of amniotic epithelium in both human and cynomolgus term placentae. TPA and CA125 are thus oncoplacental antigens and the monkey could serve as a model for their investigation.

Placental protein 10: levels in benign and malignant ovarian cyst fluids and pleural exudates

Placental protein 10 (PP10) was measured in benign (n = 47) and malignant (n = 10) ovarian cyst fluids and in pleural fluid specimens from 19 patients with pleural metastases of various carcinomas (n = 15) or infectious pleurisy (n = 4). PP10 was found in 9 out of 18 follicular or luteal cyst fluids (range 2.0-42.0 micrograms/l) and in 24 out of 29 benign ovarian tumours (range 2.6-38.0 micrograms/l). Nine out of ten malignant ovarian cyst fluids contained detectable PP10 (range 4.0-55.2 micrograms/l). PP10 was found in all the pleural fluids from 15 patients with metastatic bronchial, pulmonary, breast or pancreatic carcinomas (range 5.1-100.2 micrograms/l), as well as from four patients with pleurisy (range 5.0-28.6 micrograms/l). Our results indicate that PP10 is tumour-associated, but not tumour-specific.

Placental protein 10 (PP10) in the serum of patients with trophoblastic and nontrophoblastic gynaecological tumours

Serum levels of placental protein 10 (PP10) were measured by radioimmunoassay in patients with trophoblastic (n = 23) and non-trophoblastic (n = 122) gynaecological tumours before, during and after treatment. Elevated levels (greater than 2.0 micrograms/l) were found in 96% of patients with an untreated trophoblastic tumour, and in 22%, 20% and 12% of patients with endometrial, cervical and ovarian carcinoma, respectively. After treatment the levels fell in patients with trophoblastic disease. Although PP10 may be tumour-associated in such cases, it is premature to assume any significance for PP10 as a tumour marker in clinical practice, because changes in serum hCG levels are much more informative.

Biological markers of breast cancer: a review

This review of biological markers of breast carcinoma has summarized a fairly representative series of studies pertaining to endocrine, carcinoembryonic, tissue-associated, serologic, biochemical, and specific tumor markers, with attention to some of the contributions from genetic engineering techniques applied to this research area. It is meant to be a helpful review with two purposes: those involved in research or clinical studies of breast cancer may wish to use this review as a basis for adding additional references in each category and to refer to the references provided for further study, thought, and synthesis of the data, perhaps to stimulate new associations between pertinent facts; those involved in the general scientific or clinical fields may wish to use it as an overview of biological markers pertaining to a particular form of cancer and perhaps this review will permit faster, more easily accessible synthesis of data, and a better understanding of a variety of parameters which are associated with breast cancer diseases.