Stimulation der Granulopoese mit hämatopoetischen Wachstumsfaktoren

Die therapieinduzierte Neutropenie kann mit den Kolonie stimulierenden Faktoren (CSF) der Granulopoese (G-CSF und GM-CSF) vermieden,abgemildert oder in ihrer Zeitdauer verkürzt werden. Die CSF erm?glichen die Mobilisation h?matopoetischer Stammzellen in das Blut und deren Sammlung für die Transplantation nach Hochdosistherapie.Diese Faktoren sind daher essenziell in der Supportivtherapie maligner Erkranklungen. Der Arbeitskreis Supportivma?nahmen in der Onkologie (ASO) der Deutschen Krebsgesellschaft hat Richtlinien zur Therapie mit den Kolonie stimulierenden Faktoren entwickelt, die unterschiedlichen klinischen Situationen angepasst sind. Der vollst?ndige Text wurde 12/2001 in “Der Onkologe” publiziert [23], er ist auch auf der Homepage des ASO unter http://www.onkosupport.de zu finden [24]. Prof.Dr. H. Link H?matologie, Internistische Onkologie, Endokrinologie, Medizinische Klinik I, Westpfalz-Klinikum Kaiserslautern, Akademisches Lehrkrankenhaus der Johannes-Gutenberg-Universit?t Mainz, 67653 Kaiserslautern, E-Mail: hlink@westpfalz-klinikum.de     

Involvement of E-cadherin and beta-catenin in germ cell tumours and in normal male fetal germ cell development

Intercellular contacts, mediated by E-cadherin, are essential for germ cell migration and maturation. Furthermore, it has been suggested that decrease or loss of E-cadherin correlates with tumour progression and invasive behaviour. beta-catenin is involved in a number of different processes, including cell--cell interaction when bound to cadherins, and determination of cell fate in pluripotent cells when activated via the Wnt signal-transduction pathway. To shed more light on the role of these factors in normal fetal germ cell development and the pathogenesis of germ cell tumours (GCTs), the present study investigated the presence and localization of E-cadherin and beta-catenin by immunohistochemistry. E-cadherin was only weakly expressed in or absent from fetal germ cells of the second and third trimesters, and was not expressed in carcinoma in situ/intratubular germ cell neoplasia unclassified (CIS/ITGCNU) and gonadoblastoma, the precursor of an invasive GCT in dysgenetic gonads. In GCTs, it was generally not expressed in seminoma and dysgerminoma, but was found in the vast majority of non-seminoma cells. beta-catenin was found in the cytoplasm of fetal germ cells at all gestational ages and in spermatogenesis in post-pubertal testes. It was also present in CIS/ITGCNU and gonadoblastoma. Whereas seminomas and dysgerminoma were negative, non-seminoma cells were frequently found to express beta-catenin. Expression of both factors therefore reflects the degree of differentiation of these tumours. No differences for either E-cadherin or beta-catenin were observed between samples of tumours resistant or sensitive to chemotherapy, and E-cadherin expression did not correlate with vascular invasion. E-cadherin and beta-catenin therefore play a role in both normal and malignant germ cell development and differentiation that warrants further investigation, but they seem to be of limited value as predictive or prognostic factors in GCTs.     

Differentiation and development of human female germ cells during prenatal gonadogenesis: an immunohistochemical study

BACKGROUND: In the development of the human ovary, the second trimester includes the transition from oogonial replication to primordial follicle formation. The present study was carried out to assess differentiation and proliferation of germ cells in a series of female gonads from 19 fetuses from the second and third trimester, and two neonates. METHODS: Using immunohistochemistry, the following markers were studied: placental/germ-like cell alkaline phosphatases (PLAP), the marker of pluripotency OCT3/4, the proliferation marker Ki-67, beta-catenin and E-cadherin, the stem cell factor receptor c-KIT, and VASA, a protein specific for the germ cell lineage. RESULTS: PLAP and OCT3/4 were seen during oogenesis, but not in germ cells engaged in folliculogenesis. A similar pattern was observed for Ki-67. Loss of pluripotency occurs once oocytes engage in follicle formation, suggesting a role of cell-cell interactions in the process of germ cell maturation. VASA, c-KIT, beta-catenin and E-cadherin were found in germ cells at all developmental stages of oogenesis and folliculogenesis. CONCLUSIONS: Immunohistochemically, two groups of germ cells can be distinguished. Germ cells that are predominantly found in the cortical region of the ovary before weeks 22-24 of gestation, showing an immature phenotype, are mitotically active, and express OCT3/4, a marker of pluripotency. On the other hand, germ cells undergoing folliculogenesis have lost their pluripotent potential and no longer proliferate.     

The influence of gemcitabine on the CD4/CD8 ratio in patients with solid tumours

Gemcitabine (dFdC) is a novel pyrimidine antimetabolite with documented antineoplastic activity against metastatic non-small cell lung cancer (NSCL), pancreatic carcinoma, ovarian and breast cancer. The side effects of gemcitabine are generally mild; severe infections are reported in less than Ilo of patients. In contrast, other new nucleoside analogues such as the purine antimetabolite fludarabine lead to a significant alteration of the CD4/CD8 lymphocyte ratio associated with an increased risk for opportunistic infections. This study investigates the effect of gemcitabine on different lymphocyte subsets during consecutive applications. 16 patients with solid rumours (3 non-small cell lung cancer, 3 pancreas, 3 testicular, 2 breast, ovarian germ-cell, 1 ovarian, 1 small cell lung, 1 gastric cancer, 1 carcinoma of unknown primary); 15 patients were previously treated, received at least 3 applications of gemcitabine (1,000 mg/m(2) as a 30 min infusion, at days 1, 8, 15; q 4 weeks). Lymphocytes surface antigens were analysed by standard technique flow cytometry prior to every infusion. The median number of leukocytes before therapy was 7823/mu l, with lymphocytes 875/mu l, including 68% T-cells (CD3(+)), 9% B-cells (CD19(+); CD20(+)) and 15% NK-cells (CD56(+); CD16(+); CD3(-)), the CD4/CD8 ratio was 1.7. After gemcitabine therapy the median number of leukocytes was 5136/mu l, with lymphocytes 1012/mu l, including 77% T-cells, 8% B-cells and 10% NK-cells and a CD4/CD8 ratio of 2.2. Severe complications or opportunistic infections were not seen in these 16 patients. No significant change of CD4/CD8 ratios and NK-ccll numbers was seen in our patients with solid tumours during weekly treatment with gemcitabine. A severely increased risk for opportunistic infections following treatment with the new antimetabolite gemcitabine appears unlikely.     

Antitumor-activity and toxicity of continuous-infusion versus bolus administration of bleomycin in 2 heterotransplanted human testicular cancer cell-lines

The continuous infusion of the glycopeptide antibiotic cytotoxic agent bleomycin in comparison to bolus application has been postulated to be associated with increased antitumour activity and decreased toxicity, particularly pulmonary fibrosis. In the treatment of patients with testicular cancer, bleomycin is an essential agent and is currently used in continuous infusion and bolus application schedules in cisplatin-based combination therapy regimens. The current study addresses the antitumour activity and general toxicity of bleomycin given as continuous intraperitoneal infusion versus bolus application in human testicular cancer cell lines heterotransplanted into nude mice. Maximally tolerated doses for each administration route, defined as being the LD20 were applied (8.7 or 17.5 mg/kg days 1-7 continuous intraperitoneal infusion via osmotic mini pump or 40 mg/kg intraperitoneal bolus application on days 1, 5, 9). Bleomycin demonstrated antitumour efficacy at all concentrations used in comparison to untreated controls. There was no significant difference in antitumour activity between continuous or bolus application of bleomycin when the same cumulative doses were compared. Neither was there any difference with respect to bleomycin toxicity with 11 +/- 4 or 12 +/- 5% losses of body weight for continuous infusion regimens compared to 13 +/- 3% for bolus application. In a small subgroup of mice histological examination of the lungs demonstrated no signs of pulmonary fibrosis. In summary, using an established testicular cancer xenograft model in nude mice bolus application of bleomycin was as active as continuous infusion of this drug with no apparent difference in overall toxicity. Current standard treatment regimens using bolus application of bleomycin should not be altered without necessary reasons. Bleomycin pulmonary toxicity needs to be studied in clinical trials taking into account possible drug interactions in combination chemotherapy regimens and additional risk factors for pulmonary toxicity.     

Molecular determinants of treatment response in human germ cell tumors.

PURPOSE: Germ cell tumors (GCTs) are highly sensitive to cisplatin-based chemotherapy. This feature is unexplained, as is the intrinsic chemotherapy resistance of mature teratomas and the resistant phenotype of a minority of refractory GCTs. Various cellular pathways may influence the efficacy of chemotherapy. Their impact has not been investigated in a comprehensive study of tumor samples from clinically defined subgroups of GCT patients. EXPERIMENTAL DESIGN: We investigated proteins involved in regulation of apoptosis (p53, BAX, BCL-2, and BCL-X(L)), cell cycle control [p21 and retinoblastoma protein (RB)], and drug export and inactivation [P-glycoprotein, multidrug resistance-associated protein (MRP) 1, MRP2, breast cancer resistance protein, lung resistance protein, metallothionein, and glutathione S-transferase pi] immunohistochemically in samples of unselected GCT patients (n = 20), patients with advanced metastatic disease in continuous remission after first-line chemotherapy (n = 12), and chemotherapy-refractory patients (n = 24). Mature teratoma components (n = 10) within tumor samples from all groups were analyzed separately. The apoptotic index was studied by terminal deoxynucleotidyl transferase-mediated nick end labeling assay. RESULTS: Invasive GCTs of all groups showed a correlation between wild-type p53 and apoptotic index (r(s) = 0.66; P < 0.001). The levels of the antiapoptotic proteins BCL-2 and BCL-X(L) were generally low. p21 was hardly detectable and did not correlate with p53 (r(s) = 0.29; P = 0.07). No significant differences among the three patient groups were identified regarding any of the investigated parameters (all Ps were >0.08), even though only individual samples from chemotherapy-resistant cases showed a strong staining for MRP2 and GSTpi. In contrast to other components, mature teratomas showed an intense p21 and RB staining and were mostly positive for MRP2, lung resistance protein, and GSTpi. CONCLUSIONS: Our results indicate a multifactorial basis for the chemosensitivity of GCTs with lack of transporters for cisplatin, of antiapoptotic BCL-2 family members, of p21 induction by p53, and of RB and an intact apoptotic cascade downstream of p53. These findings suggest a preference for apoptosis over cell cycle arrest after up-regulation of p53. None of the examined parameters offers a general explanation for the chemotherapy-resistant phenotype of refractory tumors. The up-regulation of various factors interfering with chemotherapy efficacy and ability for a p21-induced cell cycle arrest may explain the intrinsic chemotherapy resistance of mature teratomas.     

Antiangiogenic treatment with endostatin inhibits progression of AML in vivo.

Increased vessel density in the bone marrow of patients with acute myeloid leukemia as well as elevated expression of proangiogenic factors by leukemic cells implies a central role of angiogenesis in hematological malignancies. Endostatin (ES), a fragment of collagen XVIII, is an endogenous inhibitor of angiogenesis that has shown therapeutic activity in solid tumors in various preclinical models. Using microencapsulation technology, we studied the therapeutic effect of ES in AML. While ES had no effect on proliferation of M1 murine leukemic cells in vitro, ES producing microbeads significantly inhibited growth of subcutaneous chloromas in SCID mice as compared to controls. In a leukemia model using M1 cells the concomitant treatment of mice with ES microbeads prolonged median survival significantly. Histological analysis revealed a decreased microvessel density and a reduced number of CD31-positive single cells, putatively endothelial progenitor cells, in the bone marrow of treated animals. Taken together, ES has inhibitory effects on neo-angiogenesis in the bone marrow and on progression of leukemia in vivo. These experiments suggest a possible therapeutic role of antiangiogenic gene therapy with ES in AML.     

Rolle der systemischen Therapie ± Radiotherapie beim resektablen Kardia-/Magenkarzinom

Zusammenfassung Die Diskussion um die adjuvante Chemotherapie und adjuvante Radiochemotherapie bei Patienten mit komplett operiertem Magenkarzinom ist in Europa nach wie vor kontrovers. Eine hohe lokoregionale Rezidivrate und Fernmetastasierungsrate nach initial kompletter Resektion eines Magenkarzinoms zeigt deutlich den Bedarf einer effektiven adjuvanten Systemtherapie. Daher wurden in den letzten Jahren innerhalb klinischer Studien verschiedene adjuvante Therapieregimes untersucht, um die Prognose von Patienten mit lokalisiertem resektablem Magenkarzinom zu verbessern. Dabei wurden sowohl die adjuvante alleinige Chemotherapie und alleinige adjuvante Radiation als auch die adjuvante kombinierte Radiochemotherapie eingesetzt.