Developmental expression of alkaline phosphatase genes; reexpression in germ cell tumours and in vitro immortalized germ cells

Human germ cell alkaline phosphatase (GCAP) is developmentally expressed in primordial germ cells and in trace amounts in the testis and thymus. The equivalent mouse isozyme, embryonic alkaline phosphatase (EAP), is similarly expressed in the testis and thymus but also from the 2-cell to blastocyst stage of preimplantation development. EAP has been found to be transiently expressed in M-phase spermatogenic cells in the mouse testis. These alkaline phosphatase isozymes serve as markers of germ cell differentiation and in the management of germ cell tumors. GCAP is expressed in carcinoma-in-situ and seminoma where serum GCAP levels are often elevated and may provide clinically useful information. However, GCAP is a polymorphic enzyme, and monoclonal antibodies to be used in the clinical evaluation of tumor tissues or fluids should be carefully evaluated for their ability to detect all allelic variants of GCAP.     

Low levels of amniotic fluid placental alkaline phosphatase in Down's syndrome

OBJECTIVE: To investigate amniotic fluid placental alkaline phosphatase (PLAP) levels in normal and trisomy 21 pregnancies. DESIGN: Cross sectional study. SETTING: A tertiary referral prenatal diagnostic service. SUBJECTS: Three hundred and eleven women with singleton pregnancies of normal karyotype between 10 and 23 weeks gestation and 31 women with pregnancies associated with trisomy 21 Down's syndrome. OUTCOME MEASURES: PLAP levels were measured by immunoradiometric assay in amniotic fluid obtained by amniocentesis. RESULTS: Amniotic fluid PLAP was detectable from 12 weeks gestation and the median value rose to a peak of 4.57 iu/l at 18 weeks. Pregnancies associated with Down's syndrome had significantly lower levels with a median multiple of median (MoM) of 0.638, (U = 3374, P = 0.0016, 95% CI = 0.50, 0.89). For the 20 women with trisomy 21 pregnancies detected at 16 to 18 weeks, the median MoM was 0.482, (U = 3694, P = 0.0011, 95% CI = 0.37, 0.85). CONCLUSION: These data demonstrates that PLAP levels are reduced in the amniotic fluid of women carrying a fetus with trisomy 21.     

Natural interferon enhances expression of placental alkaline phosphatase in human seminoma xenograft

A 56-year-old female presented with idiopathic hypertrophic cranial pachymeningitis manifesting as headache, hypopituitarism, and diabetes insipidus, mimicking lymphocytic hypophysitis. Five months later, she complained of double vision and unusual right facial sensation. The diagnosis was based on magnetic resonance imaging, angiography, and meningeal biopsy via transsphenoidal surgery, and exclusion of other know causes of pachymeningitis. Despite initial response to steroid treatment, her symptoms recurred repeatedly and she became steroid-dependent. Repetition of short-term steroid pulse therapy restrained the deterioration of her condition. The clinical presentation of idiopathic hypertrophic cranial pachymeningitis is variable, and it may develop with signs of adjacent tissue involvement. Resultant secondary hypophysitis must be differentiated from lymphocytic hypophysitis. Initial steroid therapy is effective in improving symptoms, but should be carefully considered since the natural course of this disease seems to be self-limited.     

Chemotherapy of disseminated germ cell tumors

Current modes and issues of chemotherapy for the patients with disseminated germ cell tumors (GCTs) are described. A review of the literature of prospective randomized trials designed to compare the efficacy and toxicities between induction chemotherapy regimens for patients with either good- or poor-risk disseminated GCTs showed that three cycles of bleomycin, etoposide, and cisplatin (BEP) or four cycles of etoposide and cisplatin (EP) for good-risk GCTs, and four cycles of BEP for poor-risk GCTs, are the most effective regimens even now. A prognostic factor-based staging system can distinguish patients with either good- or poor-risk GCTs, and help make risk-based decisions about therapeutic modes. However, there is a variety of criteria that make intertrial comparison difficult. An internationally accepted prognostic classification of disseminated GCTs reported recently by the International Germ Cell Cancer Collaborative Group will resolve these problems. High-dose chemotherapy (HDCT) with autologous stem cell rescue can cure a relatively small but significant percentage of heavily pretreated patients who are deemed incurable with any other therapeutic strategy. Moreover, HDCT in first-line therapy for patients with poor-risk GCTs is now expected to improve treatment outcome obtained by BEP. Because HDCT has not totally overcome cisplatin-resistance, further investigation should be required.     

Bispecific antibody targeted T cell therapy of ovarian cancer: clinical results and future directions

The high frequency of relapse after induction chemotherapy in advanced ovarian carcinoma patients calls for new therapeutic modalities. Retargeted T cell-mediated lysis can be achieved using the bispecific antibody (BsmAb) OCTR, directed to CD3 on T cells and to the folate receptor on ovarian carcinoma cells. Twenty-eight patients with limited intraperitoneal disease after first-line therapy entered a phase II study. They received two i.p. 5 day cycles of activated PBMC retargeted with OCTR. Despite unfavorable tumor characteristics, 7 of 26 patients (27%) showed complete or partial intraperitoneal responses with strict surgicopathologic evaluation. In most cases, the disease relapsed outside the peritoneal cavity, and in 1 case complete intraperitoneal response was accompanied by progression in retroperitoneal lymph nodes. The morbidity was mild to moderate and transient. Combination of i.v. and i.p. administration of OCTR-retargeted lymphocytes will possibly lead to extraperitoneal cure. Ongoing clinical studies indicate that the i.v. infusion of up to 8 x 10(8) OCTR-retargeted T lymphocytes does not induce a higher toxicity than the i.p. treatment. To avoid PBMC preactivation, new approaches for delivering accessory signals are under investigation. Preliminary results indicate that nonactivated PBMC retargeted by OCTR in the presence of an anti-CD28 monoclonal antibody (mAb) are able to significantly inhibit tumor growth.     

Development of germ cell transplants in mice

Development of spermatogonial transplants was studied by using 5- to 6-wk-old histocompatible mice as cell donors and sterile (W-locus) mice as recipients. Groups of animals transplanted with germ cell suspensions were killed at 10 min, 9 h, 24 h, 1 wk, 1 mo, 2 mo, and 3 mo along with age-matched "start" and "end" W-locus controls. Weight of testes increased significantly at 24 h through 3 mo after germ cell transplantation, suggesting that the infused cells quickly stimulated organ function. Small clones of young spermatocytes were evident at 1 mo and sperm at 2 mo. The percentage of tubular profiles containing active spermatogenesis originating from spermatogonia increased with time (0.8% at 1 mo, 8.9% at 2 mo, and 28.2% at 3 mo). Most transplanted germ cells were eliminated from the seminiferous epithelium through phagocytosis by Sertoli cells that occurred primarily before 1 wk, although some pachytene cells were able to proceed through meiosis by 1 wk. A variety of abnormal features are described that characterize developing spermatogenesis in the transplanted testis. Spermatogenesis improved quantitatively and qualitatively with time although released sperm were frequently engulfed by intratubular macrophages and Sertoli cells. A quantitative analysis of spermatogenesis from transplanted germ cells will serve as a basis for improving spermatogonial transplant efficiency.     

Bispecific monoclonal antibody-mediated targeting of an indium-111-labeled DTPA dimer to primary colorectal tumors: pharmacokinetics, biodistribution, scintigraphy and immune response

Eleven patients with primary colorectal carcinoma tumors (4 +/- 2 cm) were given intravenous injections of 1-10 mg of an anti-CEA, anti-In-DTPA bispecific Fab'-Fab monoclonal antibody, and 2-8 days later, were injected with 1.2-4.2 nmol of an 111In-labeled DTPA dimer (6 mCi). The bispecific antibody exhibited good stability and F(ab)'2-like pharmacokinetics. After injection, the 111In-DTPA dimer distributed in a large volume (88 ml/kg-180 ml/kg) and cleared through the kidneys (mean residence time in the whole body: 9 hr-16 hr). Uptake of 111In by the tumor using this two-step technique (1.8%-17.5% injected dose ID/kg, measured from surgical samples 48 hr after hapten injection) was not found significantly lower than that achieved with our reference 111In-labeled anti-CEA F(ab)'2 1 to 4 days after injection in six patients with similar clinical status (5.5%-30.2% ID/kg). In addition, tumor-to-blood and tumor-to-liver uptake ratios were significantly improved (blood 7.8 versus 4.2, liver 2.8 versus 0.8). As a result, low background images allowed detection of 12 of 13 lesions, 4 hr and 24 hr after hapten injection. However, 7 of 11 patients developed HAMA.     

Management of malignant germ cell tumors of the ovary

A high sensitive method for detecting the change of microsomal membrane surface oligosaccharides was developed to study the regulatory role of lipid- or peptide-linked mannoside of endoplasmic reticulum in synaptic functions. The binding of concanavalin A to the microsomal membrane surface was measured quantitatively using a microgram-order of rat brain microsomal proteins. The fluorescence polarization of concanavalin A (Con A)-fluorescein isothiocyanate (FITC) conjugate bound to the membrane was analyzed to quantitate the change of binding constant and the number of binding sites. As a control, the non-specific binding of bovine serum albumin-FITC conjugate was measured by the same technique. We measured the change of fluorescence intensity of membrane-bound FITC conjugates by the flow cytometry and found that the intensity of FITC conjugate bound to the membrane increased more than that of free form of the probe. We observed that the alpha-mannosidase-treatment of rat brain microsomes resulted in the increase of binding constant of Con A to the microsomal surface without significant loss of binding sites.     

High-dose chemotherapy with autologous stem cell support in poor-risk germ cell tumors

We propose a simple and fast method of detecting apoptosis using an automated hematology analyzer. Detection is based on cellular optical light scatter properties and demonstration of the membrane fragility which characterizes cells undergoing the process of apoptosis. As part of it's routine leucocyte differential analysis, the Abbott Cell-Dyn 4000 collects multi-angle cellular light scatter data. In addition red fluorescence (FL3) emitted by cells following propidium iodide labeling is collected. This provides quantitation of both the erythroblast count and a leukocyte viability index (WVF). Fresh or cryopreserved peripheral blood cells from 17 B-chronic lymphocytic leukemia (B-CLL) patients were incubated in presence of theophylline, fludarabine or in medium alone. After 36-hrs of culture the percentage of apoptotic cells of the sample was determined from the parameters of the CD 4000 described above and thereafter this was compared with reference methods for estimation of apoptosis. The reference methods used were in situ detection of cell death on slides (TUNEL test) and also flow cytometry (Annexin V). Results showed an excellent correlation between the 3 techniques. This rapid, easy and reliable method of quantifying apoptosis may be very useful means of routinely predicting the response to chemotherapy.     

Synchronous bilateral testis tumor: mixed germ cell and theca cell tumors

Synchronous bilateral testis tumors of different histologic types are rare. All previous cases have demonstrated germ cell tumors on both sides. The simultaneous appearance of a germ cell tumor and a contralateral non-germ cell tumor has not been reported. We herein report a thirty-four-year-old man who presented with a mixed non-seminomatous germ cell tumor of the left testis and theca cell tumor of the right testis.     

Secondary neoplasms following treatment of malignant germ cell tumors

PURPOSE: The current study investigates the frequency and outcome of secondary malignancies in patients treated for testicular cancer at Hannover University Medical School between 1970 and 1990. PATIENTS AND METHODS: One thousand twenty-five patients with a median follow-up duration of 61 months (range, 12 to 240) were included in the analysis. Follow-up was complete in 1,018 patients (99%). Histology was seminoma in 324 patients (38.7%) and nonseminomatous germ cell tumor in 624 patients (61.3%). At the time of median follow-up, 814 patients (79.9%) were alive. RESULTS: Fourteen patients developed a secondary neoplasm (cumulative incidence, 1.38%; 95% confidence interval [CI], 0.75 to 2.30); 13 patients had solid tumors and one had secondary lymphoblastic leukemia with a t(4; 11) translocation including band 11q23. None of 224 patients on surveillance strategy (with or without retroperitoneal lymph node dissection [RPLND]) developed a second neoplasm, compared with four of 413 patients (0.97%; 95% CI, 0 to 1.9) after cisplatin-based chemotherapy (not significant) and nine of 332 patients (2.7%; 95% CI, 0.9 to 4.5) after radiotherapy (P = .02). The cumulative incidence of a secondary neoplasia of 1.76% (95% CI, 0.97 to 2.94) in patients treated by radiotherapy and/or chemotherapy was significantly higher compared with patients on surveillance protocols (P = .03). Chemotherapy containing standard-dose etoposide did not increase the risk of occurrence of secondary neoplasms. A significantly elevated relative risk of 7.53 (range, 3.4 to 14.3) compared with the male German population was only found for patients treated by radiotherapy. CONCLUSION: Compared with patients who have other curable malignant tumors, an incidence of 1.38 of secondary neoplasms after a median follow-up duration of 61 months is low. The highest risk for secondary neoplasia after treatment of testicular cancer is associated with the use of radiotherapy. Following chemotherapy, no significantly elevated risk was observed. In conclusion, the benefits of curative treatment far outweigh the risk of secondary cancer in patients with malignant germ cell tumors.     

Medical treatment of ovarian malignant germ cell tumors in the adult

Malignant ovarian germ cell tumors are infrequent neoplasms that usually affect young and otherwise healthy females. The outcome of patients has been significantly improved by the introduction of cisplatin-based chemotherapy. After conservative surgery which both establishes the diagnostic and initiates therapy, the postoperative management should be adapted to histological type as well as to tumor stage. In patients with nonseminomatous germ cell tumors, the standard treatment is a combination of bleomycin, etoposide and cisplatin (BEP protocol). The number of cycles to be given is 3 when surgery is optimal, and 4 in patients with residual or metastatic disease. In patients with pure dysgerminomas, 4 cycles of BEP are the optimal treatment for advanced stages. In early stages, the alternative to chemotherapy (3 cycles of BEP) is radiotherapy, typically given to the ipsilateral hemipelvis and para-aortic nodes. Results are satisfactory with a long-term survival rate ranging from 80 to 100%, and a minimal toxicity yielding a reasonable probability of having normal offspring.     

A phase II trial of paclitaxel in refractory germ cell tumors

BACKGROUND: A significant percentage of patients with refractory germ cell tumors will not respond to standard salvage regimens. Thus there is a need for new active agents. Paclitaxel has demonstrated activity against a variety of solid tumors in both laboratory and clinical studies. METHODS: Eighteen patients with refractory germ cell tumors who failed initial cisplatin-based chemotherapy and a maximum of 2 salvage regimens were enrolled into a Phase II trial of paclitaxel at a dose of 170 mg/m2 by intravenous infusion over 24 hours every 21 days without growth factor support. The median age of the patients was 32.5 years (range, 18-49 years). The testis was the primary site of tumor for 13 patients (72%) and the tumor was extragonadal in 5 patients (28%). Six patients (33%) were late recurrences. Twelve patients (67%) had > or = 2 metastatic sites. The median number of previous chemotherapy cycles was six (range, four to nine). Three patients (17%) previously had undergone autologous bone marrow transplantation. RESULTS: Two patients (11%) responded to paclitaxel. Major toxicities were Grade 3-4 neutropenia (55% of patients) and Grade 3-4 neurotoxicity (2 patients). Neutropenic fever occurred in 3 patients (17%). CONCLUSIONS: Paclitaxel demonstrated minimal activity in heavily pretreated patients with multiple, poor risk clinical features. These results in part may be due to the unfavorable characteristics of the patients in the current study, specifically the high percentage of patients with late recurrences and extragonadal primary tumors, both of which are known to respond poorly to salvage therapy. Other trials with different patient populations and doses of paclitaxel reported response rates ranging from 13.3%-26%. The role of paclitaxel in the treatment of patients with refractory germ cell tumors remains to be defined in future studies.