Expression of placental alkaline phosphatase in epithelial ovarian tumours

The expression of placental alkaline phosphatase in 116 ovarian epithelial tumours was examined in formalin-fixed tissues used for routine histopathologic examination. In the total material, 51% of the tumours displayed positive immunoreactivity, as described by the monoclonal anti-placental alkaline phosphatase antibody C2, with similar incidence (46-67%) in the four major groups of the adenocarcinomas, i.e., serous, mucinous, endometrioid and mesonephric tumours. By use of a histochemical staining index the mucinous and mesonephric tumours demonstrated a more intense staining (2.1 and 2.6) compared to the serous and endometrioid tumours (0.9 and 1.5). The relevance of the findings is discussed in relation to the use of monoclonal antibody technologies for radioimmunolocalization and radioimmunotherapy.     

Occurrence of malignant non-germ cell components in primary mediastinal germ cell tumours.

METHODS: Thirty-five patients with primary mediastinal germ cell tumours (PMGCT) underwent primary thoracotomy in a 30-year period (1965-1994). Of the 35 patients, 12 had benign teratomas, five pure seminomas and 18 non-seminomatous germ cell tumours. RESULTS: Out of 18 non-seminomatous germ cell tumours, 14 comprised more than one malignant component. In two cases malignant teratomas had an additional malignant non-germ cell component: one a mixed sarcomatous component and the other a neuroendocrinal component. There were different methods of treatment between 1965 and 1994. All but one of patients with seminomas survived for 5 years. Among 18 patients with malignant PMGCT, all but two died within 5 years (mean survival rate was 15 months). CONCLUSIONS: When planning treatment of patients with malignant PMGCT we have to take into account the fact that malignant non-germ-cell components may occur. In this circumstances, surgical resection after initial chemotherapy is recommended.     

An immunohistological study of testicular germ cell tumours using two different monoclonal antibodies against placental alkaline phosphatase.

Using two monoclonal antibodies directed against placental alkaline phosphatase (H17E2 and D20L) the immunohistological staining of testicular germ cell tumours was compared with that of a wide range of normal and malignant tissues. All seminomas and malignant teratomas tested gave strong positive labelling with H17E2 but were either negative or only patchily positive with D20L. Neither antibody gave any positive reaction on the normal tissues tested. All other malignancies were negative with both antibodies apart from two cases of ovarian and one case of endometrical cancer (strongly stained by H17E2) and three cases of colonic carcinoma (weakly and patchily stained by both H17E2 and D20L). This indicates that germ cell neoplasms generally express a form of placental alkaline phosphatase recognised by antibody H17E2.     

The occurrence of human placental alkaline phosphatase (PLAP) in extracts of normal, benign and malignant tissues of the female genital tract

In addition to its presence in extracts of carcinomatous tissues from the vulva, endometrium and ovary, PLAP can also be found in tissue extracts of benign conditions of the endometrium and myometrium. We detected slightly elevated levels of PLAP in patients with myoma, raised levels in 2/2 patients with endometrial polyps and high values in 2/2 patients with glandulocystic hyperplasia. Moreover, normal endometrium and fragments of normal Fallopian tube also contained fairly high amounts of endogenous PLAP. These results have important implications with regard to the possible use of PLAP as a tumour marker or of anti-PLAP monoclonal antibodies in radioimmunolocalization or radioimmunotherapy.     

Identification of testicular atypical germ cells by an immunohistochemical technique for placental alkaline phosphatase

The identification of atypical testicular germ cells is often difficult by by routine histologic examination. By immunohistochemical detection of placental alkaline phosphatase (PLAP) and by periodic acid Schiff staining of glycogen, atypical germ cells were easily identified in testicular samples. Forty-one fetal and adult testes were used for a preliminary study, and 121 testes from infants and adults with either cryptorchidism or germ cell tumors were studied for the presence of atypical germ cells. Two types of clear germ cells were differentiated histochemically, and one with PLAP-positive cell surfaces and glycogen-rich cytoplasm was considered to be atypical. The alkaline phosphatase of atypical germ cells appeared to be similar to that found in a few germ cells of early fetal testes. The atypical germ cells seemed to be multi-potential malignant cells capable of developing not only into seminoma but also into other germ cell tumors. Only in yolk sac tumor of infants were the atypical germ cells absent from tumor-adjacent seminiferous tubules.     

CA125 and placental alkaline phosphatase as serum tumor markers in epithelial ovarian carcinoma.

Placental alkaline phosphatase (PLAP) was measured by an immunoradiometric assay using the monoclonal antibody C2 (PLAP-C2). Serum samples of 135 patients with epithelial ovarian cancer were analyzed, and the results were compared with CA125 levels. CA125 and PLAP-C2 were elevated in 85 and 43% of the patients, respectively. Only 1 patient with normal CA125 and evidence of disease at the time of sampling had an elevated PLAP-C2. Fifty-three patients with measurable tumor were followed longitudinally during chemotherapy. Correct correlation with disease evolution was observed in 95% of the patients for CA125 and in 59% for PLAP-C2. The PLAP-C2 assay did not add significantly to the predictive value of CA125 in the diagnosis and follow-up of epithelial ovarian cancer.     

Monoclonal antibody assay of serum placental alkaline phosphatase in the monitoring of testicular tumours

A monoclonal antibody (H17E2) recognising both placental alkaline phosphatase (PLAP) and testicular PLAP-like alkaline phosphatase was incorporated in a solid phase immunoassay. This was used to measure levels of PLAP in 257 sera from 148 patients with germ cell neoplasms of the testis. High levels of PLAP were found in all patients with active seminomas (mean 0.85 O.D.) compared to those in clinical remission (mean 0.20 O.D.) (P less than 0.0001). More importantly, changing levels of PLAP correlated with the course of disease in 79 samples from 33 patients with seminoma (P less than 0.0001). Elevated PLAP levels were also noted in patients in remission who were smokers (mean 0.32 O.D.) compared to non-smokers (mean 0.15 O.D.) (P less than 0.001). These data demonstrate that determination of PLAP levels using this sensitive immunoassay is an important new adjunct in the monitoring of the response to treatment in patients with seminoma.     

Serum marker potential of placental alkaline phosphatase-like activity in testicular germ cell tumours evaluated by H17E2 monoclonal antibody assay

A monoclonal antibody (H17E2) was used in a solid-phase localisation of enzyme activity (ILEA) assay to evaluate placental-like alkaline phosphatase (PLAP) as a serum marker of testicular germ cell tumours. Single or repeated assays were performed on 213 normal blood donor and a smaller number of term pregnancy and testicular cancer sera. The detection limit of PLAP by this system was 0.14 O.D. units equivalent to 0.04iul-1. Of 50 patients with established metastatic disease tested before treatment, 88% of 16 with seminoma, 54% of 13 with mixed seminoma and malignant teratoma and 33% of 21 with malignant teratoma had serum PLAP greater than 0.2 O.D. units. This compared to an incidence of 2% in non-smokers and of 29% in smokers who had been free of disease for more than 12 months. In 15 of 22 successfully treated patients, pre-treatment serum PLAP exceeded 0.2 O.D. units (mean 0.69 O.D.) and varying (53-97%) reductions in the initial levels occurred with treatment. These results with monoclonal antibody ILEA assay suggest that measurement of PLAP levels will be useful in the management of patients with germ cell tumours, particularly seminoma.     

An assessment of combined tumour markers in patients with seminoma: placental alkaline phosphatase (PLAP), lactate dehydrogenase (LD) and beta human chorionic gonadotrophin (beta HCG).

We have assessed the tumour markers placental alkaline phosphatase (PLAP), lactate dehydrogenase (LD), and human chorionic gonadotrophin (beta HCG) using 2,000 serum samples from 286 patients with seminoma. The ROC curves show that no one marker performs adequately for the detection of disease either at initial staging or during follow-up. We used a Markov model heuristically to devise strategies, in which marker results were assessed in combination, which might be useful in clinical practice. We found that the best strategy was to consider a test result abnormal only if either the beta HCG was greater than 6 Ul-1 or the LD was greater than 400 U l-1 and the PLAP level was greater than 60 U l-1. This will detect about 50% of patients with disease and the false-positive rate is 2%. In practical terms this means that PLAP need only be estimated in patients whose beta HCG is less than 6 IU l-1 and whose LD is greater than 400 U l-1.     

Demonstration of placental alkaline phosphatase in human breast cancer.

The screening of a series of 11 metastatic breast tumors for the presence of the placental isoenzyme of alkaline phosphatase (EC3.1.3.1) by RIA revealed one strong producer. The alkaline phosphatase of this tumor was characterized with respect to its immunochemical cross-reactivity, inhibition by L-phenylalanine and levamisole, subunit molecular weight (Mr) and isoelectric point (pl) in two-dimensional electrophoresis, and one-dimensional peptide map. In all parameters of the characterization, the tumor alkaline phosphatase, except for subunit molecular weight which was slightly lower (60,000 versus 64,000 for the placental isoenzyme). No strong placental alkaline phosphatase producers were found among 16 primary tumors examined by RIA. The screening of patients' sera for the placental alkaline phosphatase using RIA indicated elevated levels over post-menopausal controls in 20% of the metastatic patients. Only 3% of the primary patients had elevated serum levels. These results suggest that the placental isoenzyme of alkaline phosphatase may be a useful tumor marker for recurrent breast cancer.     

EXPRESSION OF PLACENTAL ALKALINE PHOSPHATASE IN ESOPHAGEAL CANCER CELL LINE Eca109

Placentalalkalinephosph'atase(PLAP)hasbeenshowntobeaoncodevelopmentalgeneproduct,whichismostfrequefltlyproducedbysomehumanmalignanttumorsandtumor-derivedcelllines,suchasovariancancer.cervicalcancerandtesticularcancer."2IthasheretoforenotbeendeportedthatesophagealcancerorcelllineeXPresstheenzyme.Forthisreason,westudieditsexpressionandprednisoloneinductioninesophagealcancercellline,Ecal09.MATERIALSANDMETHODSCellCultureandPrednisoloneTreatmentEca109cellowereobtainedfromDepartmentofCe…     

Outcome of patients with residual germ cell or non-germ cell malignancy after resection of primary mediastinal nonseminomatous germ cell cancer.

PURPOSE: To identify prognostic variables and outcomes in patients with primary mediastinal nonseminomatous germ cell tumor (PMNSGCT) with postchemotherapy resection of persistent cancer. PATIENTS AND METHODS: Forty-seven consecutive patients with residual cancer after resection of PMNSGCT were retrospectively reviewed. Univariate comparisons were performed. RESULTS: At diagnosis, 43 patients had elevated serum tumor markers (STMs), and 20 had extramediastinal disease. At resection, 21 patients had elevated STMs. After resection, 26 patients had germ cell tumors (GCT), 12 had malignant transformation of teratoma with elements of non-GCT, and nine had both GCT and non-GCT. Sixteen of 47 patients continuously have no evidence of disease (NED). This includes eight of 26 patients with GCT histology and two of 12 patients with non-GCT histology. Of 27 patients with mediastinal-only disease at presentation, 14 have continuously NED. Of 20 patients with extramediastinal disease at presentation, two have continuously NED. Seven of 21 patients with elevated STMs at time of resection have continuously NED. Sixteen patients received adjuvant chemotherapy, and seven have continuously NED. Overall, 16 of 47 patients have continuously NED, an additional four patients have NED with further therapy (currently NED), two patients are alive with disease, 23 patients died of disease, and two patients died postoperatively. CONCLUSION: The presence of elevated STMs at resection does not appear to alter outcome if residual disease is completely resected. In this poor-risk patient population, surgical resection of persistent cancer, even in the presence of elevated STMs, can still achieve long-term survival.     

Production of epithelial and mesenchymal tumours with rat liver cells transformed in vitro.

Epithelial-like cells originating from the livers of 10-day and 8-week-old BD rats were established in culture. The cells were treated in vitro for 1 or 4 weeks with dimethylnitrosamine (DMN) or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Although some structural changes were observed in treated cells, it was not possible to score for morphological transformation in vitro. Newborn syngeneic rats were injected with 1.5-2 times 10(6) treated or 1.5-5 times 10(6) control cells at various times up to 38 weeks from the beginning of treatment with the carcinogen. Following the injection of DMN-treated cells, a total of 32 of the 42 injected rat developed tumours, of which 17 were epithelial, 10 carcinosarcomas and 5 fibrosarcomas. Following the injection of the MNNG-treated cells into 61 rats, a total of 30 tumours were observed, including 8 carcinomas, 9 carcinosarcomas and 13 fibroscarcomas. Tumours, mainly of the mesenchymal type, were also observed in rats inoculated with control cells but at a lower frequency. The observation observed in rats inoculated with control cells but at a lower frequency. The observation of mesenchymal tumours is attributed to the presence of a mixed population of epithelial and mesenchymal cells in the orginal culture.     

A simple radioimmunoassay of human placental alkaline phosphatase (Regan isoenzyme) using specific antibody polymers.

Rabbit antiserum against highly purified high-molecular-weight B-variant of human placental alkaline phosphatase (M.W. 200,000) was rendered monospecific by absorption with polymerized pooled male serum proteins; the absorbed antiserum was then polymerized with ethyl chloroformate and used in radioimmunoassay as a stable solid-phase immunoabsorbent. Homogeneous preparation of the enzyme, with a specific activity of 477 mumoles phenol per mg per min, was also obtained by absorbing the chromatographically purified enzyme with polymerized rabbit antiserum directed to whole human serum proteins; the pure enzyme was then labeled with 125-I as the tracer retaining at least 80% of its antigenicity. Only a minute quantity of the polymerized antibody particles is required for each assay in admixture with the labeled and unlabeled enzyme. By adding a small amount of starch-gel particles before low-speed centrifugation, complete phase separation was achieved. The radioimmunoassay could detect 0.4 to 0.8 ng enzyme protein per tube, which is comparable to the sensitivity achieved by enzymic assays. However, radioimmunoassay is advantageous over the enzymic assay in being direct, specific (no interference by the nonplacental-type alkaline posphatase), and capable of detecting both catalytically active and inactive forms of the enzyme. Native variants of placental-type alkaline phosphatase including Regan isoenzyme and Nagao isoenzyme (D-phenotype of normal placental alkaline phosphatase), could thus be directly determined by this procedure in the clinical specimens.     

Precise detection of the germinomatous component of intracranial germ cell tumors of the basal ganglia and thalamus using placental alkaline phosphatase in cerebrospinal fluid

Journal of Neuro-Oncology - The disadvantages of biopsy for lesions in the basal ganglia and thalamus include a risk of various complications, difficulty in selecting the target tissue in some...     

A human gastric choriocarcinoma cell line with human chorionic gonadotropin and placental alkaline phosphatase production.

A gastric choriocarcinoma cell line synthesizing human chorionic gonadotropin (HCG) was established in 1971 by Oboshi et al. and was found to possess human placental alkaline phosphatase. The present paper also deals with the relationship between the cell growth and HCG secretion and with cellular localization of HCG and human placental alkaline phosphatase by cytochemical and ultrastructural methods. This cell line was found to secrete HCG during cellular proliferation, with the maximum secretion in the stationary phase (about 1 muIU/cell/48 hr), and the hormone could be detected in a small proportion of mono- and/or multinuclear cells in both logarithmic and stationary phases. The organ-specific, heat-stable, L-phenylalanine-sensitive, immunoreactive human placental alkaline phosphatase was localized on the cell membrane of many cells. Ultrastructurally, the line consisted mainly of cytotrophoblastic and intermediate cells in the process of syncytial formation, with more or less squamous metaplasia. From these findings it was concluded that the cell line maintained the properties of trophoblastic cells from morphological and functional aspects, i.e., it was a cell line with two distinct marker substances.     

Differential patterns of placental and epithelial cadherin expression in basal cell carcinoma and in the epidermis overlying tumours.

P-cadherin (P-CD) and E-cadherin (E-CD) are expressed by keratinocytes and play an important role in skin morphogenesis. P-CD expression is restricted to the basal layer of normal epidermis, whereas E-CD is expressed in all the living layers. We have previously reported a reduced expression of E-CD in most cases of infiltrative basal cell carcinoma (BCC). In the present work we have investigated by immunohistochemistry the expression of both P-CD and E-CD in a new series of 32 patients with BCC. Most cases of superficial multicentric BCC and some nodular tumours had preserved expression of both cadherins in all tumour cells. The majority of nodular BCCs had partially reduced expression of one or both cadherins with an ordered distribution of cells showing different cadherin staining throughout the tumour mass. A severe reduction of E-CD expression with a disordered distribution of cells with different immunostaining intensity was observed in most specimens of infiltrative BCC. In contrast, P-CD expression was preserved in all cases of infiltrative BCC. These results suggest that P-CD and E-CD play different roles in the growth pattern of BCC. In addition, both anomalous P-CD expression and reduced E-CD expression were frequently observed in the spinous layer of epidermis overlying tumours. This phenomenon was significantly associated with the presence of keratinocytic atypia, which suggests that disturbed cadherin expression could be a marker of premalignant changes and/or hyperproliferative activity in human epidermis.