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Biomedical subjects

C Wiltschke

Publications and source records attributed to C Wiltschke.

At least 37 records · Page 2Linked to original sources
PubMed1999

Inhibition of proliferation and induction of apoptosis in soft tissue sarcoma cells by interferon-alpha and retinoids.

Uncontrolled proliferation and a defect of apoptosis constitute crucial elements in the development and progression of tumours. Among many other biological response modifiers known to influence these mechanisms, the efficacy of retinoids and interferons in the treatment of various malignant entities is currently matter of discussion. In the present study, we have investigated the effects of 9-cis-retinoic acid (9cRA), 13-cis-retinoic acid (13cRA), all-trans-retinoic acid (tRA) and interferon-alpha on proliferation and apoptosis of human soft tissue sarcoma (STS) cell lines HTB-82 (rhabdomyosarcoma), HTB-91 (fibrosarcoma), HTB-92 (liposarcoma), HTB-93 (synovial sarcoma) and HTB-94 (chondrosarcoma) in relation to p53 genotype as well as p53 expression. HTB-91, HTB-92 and HTB-94 STS cells exhibited mutant p53, whereas wild-type p53 was found in HTB-93 STS cells, and a normal p53 status in HTB-82 STS cells, carrying a silent point mutation only. Interferon-alpha, irrespective of p53 status, inhibited the proliferation of all five cell lines dose- and time-dependently. Similarly, 9cRA, 13cRA and tRA decreased the proliferation of HTB-82 and HTB-93 STS cells, whereas the proliferation of p53-mutated HTB-91, HTB-92 and HTB-94 STS cells remained unchanged. Furthermore, only 9cRA and tRA were capable of inducing apoptosis in HTB-82 and HTB-93 STS cells, whereas HTB-91, HTB-92 and HTB-94 STS cells did not undergo apoptosis under the influence of 9cRA or tRA. Retinoic acid receptor (RAR)-alpha and RAR-beta mRNA were not detectable by Northern blot analysis in the five STS cell lines, whereas mRNA for the universal retinoic acid receptor, RAR-gamma, was expressed in all STS cell lines indicating that retinoid resistance was not associated with a lack of RAR expression. Apoptosis was not induced by interferon-alpha or 13cRA in any of the five STS cell lines tested. Our results indicate that within the panel of tested STS cell lines, inhibition of proliferation and induction of apoptosis result from different mechanisms which differ in their dependence upon the presence of intact p53.

Apoptosis↗
PubMed1998

Paclitaxel and carboplatin in patients with metastatic urothelial cancer: results of a phase II trial.

The present phase II trial was undertaken to assess the efficacy and toxicity of a combination of paclitaxel and carboplatin as first-line chemotherapy in patients with metastatic transitional cell carcinoma of the urothelium. Twenty patients (age range 50-79 years; inclusion criteria: WHO performance status 0-2, no previous cytotoxic treatment) with metastatic transitional cell carcinoma of the urothelium were recruited and received cytotoxic treatment with paclitaxel at a dosage of 175 mg m(-2) administered over a 3-h infusion and carboplatin given at an AUC of 5 mg ml(-1) min (according to creatinine clearance) administered every 21 days. A total of 65% of patients achieved remissions (CR+PR), with CR occurring in 40% of patients. A further 15% of patients experienced stable disease. Remissions occurred after 2.4 +/- 0.8 (mean +/- standard deviation; range two to four) treatment cycles. The mean duration of responses (CR+PR) was 8.5 +/- 5.5 months. After a mean observation period of 11.4 +/- 4.8 months, 16 patients (80%) are alive. Toxicity included alopecia of WHO grade 3 in all patients, leucopenia of WHO grades 1 and 2 in ten patients, grade 3 in eight and grade 4 in two patients and, finally, severe thrombocytopenia grade 3 in only three patients. Non-haematological toxicity consisted of polyneuropathy of WHO grade 1 in 13 patients and grade 2 in five patients. We thus conclude that a combination of paclitaxel and carboplatin at the given dosage and schedule constitutes an active, well-tolerated first-line cytotoxic treatment for patients with metastatic urothelial cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Soluble HER-2/neu neutralizes biologic effects of anti-HER-2/neu antibody on breast cancer cells in vitro.

Amplification and over-expression of the HER-2/neu proto-oncogene are associated with poor prognosis in women with both node-positive and node-negative breast cancer. Therefore, the encoded surface glycoprotein represents an attractive target for cancer immunotherapies. Furthermore, the extracellular domain of HER-2/neu is released from the cell surface by proteolytic cleavage. In the present experiments, we investigated the potential biologic effects of soluble HER-2/neu with particular emphasis on its interaction with anti-HER-2/neu antibodies. A monoclonal antibody specific for the extracellular domain of HER-2/neu dose dependently inhibited the proliferation of highly HER-2/neu-expressing SK-BR-3 and BT-474 breast cancer cells but had no effect on the proliferation of weakly to moderately HER-2/neu-expressing MCF-7, HBL-100 and ZR-75-1 breast cells. Addition of SK-BR-3 or BT-474 cell supernatants with high concentrations of soluble HER-2/neu led to a neutralization of anti-HER-2/neu antibody-mediated inhibition of proliferation due to a binding of soluble HER-2/neu by the antibody, which could be demonstrated by immunoprecipitation. Furthermore, the ability of anti-HER-2/neu antibodies to mediate antibody-dependent cellular cytotoxicity (ADCC) by lymphokine-activated killer cells was assessed. Cytolysis of SK-BR-3 tumor cells was increased significantly in the presence of anti-HER-2/neu antibodies. Similar to the proliferation inhibition, ADCC was neutralized by addition of soluble HER-2/neu-containing supernatants. Our data suggest that tumors rich in HER-2/neu might thus escape certain steps of immunologic control by neutralizing biologic activities of anti HER-2/neu antibodies due to the presence of soluble HER-2/neu.

Antibodies, Monoclonal↗
PubMed1997

Decreased expression of ICAM-1 and its induction by tumor necrosis factor on breast-cancer cells in vitro.

In order to study adhesion-molecule expression and its consequences for cellular recognition, the presence of adhesion molecules ICAM-1, VCAM-1, VLA-4, LFA-1, alpha, LFA-1 beta, LFA-3, beta1-integrin and beta3-integrin was studied on specimens from breast tissue by immunohistochemistry and on cells from breast cell lines propagated in vitro. Breast-cancer tissue and the breast-cancer cell lines MCF-7, SK-BR-3 and ZR-75-1 showed expression of ICAM-1 and VLA-4 significantly lower than that of benign breast cells or normal breast epithelium. Of various cytokines tested, including recombinant human (rh) interleukin-6 (IL-6), rh tumor necrosis factor alpha (TNF-alpha), interleukin 2 (IL-2), granulocyte/macrophage-colony-stimulating-factor (GM-CSF), interferon-alpha (IFN-alpha) and interferon-gamma (IFN-gamma), only TNF was able to re-induce expression of ICAM-1 on cells from MCF-7, SK-BR-3 and ZR-75-1. Further, the ability of either unstimulated or lymphokine-stimulated killer (LAK) cells to recognize and lyse native or TNF-stimulated breast-cancer cells was studied. Whereas neither unstimulated lymphocytes or LAK cells were able to lyse untreated breast-cancer cells deficient for ICAM-1 expression, pre-treatment of tumor cells with TNF led to increased tumor-cell lysis. Anti-ICAM-1 antibodies, and pre-treatment of tumor cells with anti-TNF-receptor antibodies, abrogated these findings, corroborating their specificity. We thus conclude that the defective expression of ICAM-1 in our model might constitute a mechanism by which breast-cancer cells escape immunologic recognition and lysis by appropriate effector cells.

Antibodies↗
PubMed1997

Plasma exchange for treatment of thrombotic thrombocytopenic purpura in critically ill patients.

OBJECTIVE: Description of diagnostic procedures, treatment modalities and intensive care management of patients with thrombotic thrombocytopenic purpura (TTP). DESIGN: Descriptive study. SETTING: Internal medicine Intensive Care Unit (University Hospital of Vienna). PATIENTS: Six patients (two after allogeneic bone marrow transplantation), treated for 12 episodes of TTP. INTERVENTIONS: Treatment with plasma exchange (fresh frozen plasma, 50-80 ml/kg per day), prednisone (0.75 mg/kg b.i.d.) and, in some cases, vincristine. Supportive therapy as needed. MEASUREMENTS AND RESULTS: Patients were admitted to the ICU because of neurological symptoms with acute onset (42% mild, 58% severe), hemolysis and thrombocytopenia. Additional symptoms were fever (50%), bleeding tendency (50%), acute renal failure (42%) and metabolic derangement (8%). Initial laboratory values showed thrombocytopenia (median 17 G/l), hemolysis (median hemoglobin 10.0 g/dl, lactate dehydrogenase 635 U/l, reticulocyte count 175 G/l) with red cell fragmentation. Coagulation tests were normal. Respiratory assist was needed in six episodes (severe seizures, cardiopulmonary resuscitation). In patients without preexisting hematological abnormality the platelet counts exceeded 100 G/l after 3-8 cycles of plasma exchange. In patients after bone marrow transplantation, the platelet counts never exceeded 40 G/l, but the lactate dehydrogenase levels dropped significantly. The neurological symptoms disappeared in all patients and renal function normalized. One patient died before the initiation of therapy. Three patients relapsed 1-3 times between 2 weeks and 5 months after the last episode. The relapses were associated with symptoms similar to the first episode and responded promptly to plasma therapy. CONCLUSIONS: TTP is a rare, but life-threatening disorder. It needs immediate diagnosis and has a good prognosis after adequate treatment with plasma exchange.

Adult↗
PubMed1995

Natural killer cell activity in long-term survivors of testicular cancer. Influence of cytostatic therapy and initial stage of disease.

BACKGROUND: Patients with testicular cancer can be cured by cisplatin-based chemotherapy in many cases. Thus, concern about possible late toxicities of treatment is warranted. METHODS: In this investigation, the absolute number of natural killer (NK) cells according to their CD56+ phenotype, NK cell activity, and antibody dependent cellular cytotoxicity (ADCC) were investigated in 29 patients with seminomas or nonseminomatous germ cell tumors (NSGCT) a median of 31 months (range, 5-73 months) after termination of chemotherapeutic treatment. RESULTS: No difference in the absolute number of NK cells, NK cell activity, and ADCC was found between patients with testicular cancer after either standard polychemotherapy consisting of bleomycin, etoposide, and cisplatin (BEP) or monotherapy with carboplatin and healthy control subjects. When patients were analyzed further using multivariate analysis, a significant (P < 0.05) detrimental influence of BEP polychemotherapy versus carboplatin monotherapy on NK cell activity was found. Moreover, NK cell activity also depended significantly (P < 0.05) on the time elapsed after chemotherapy was administered, but normalized with time. Because the absolute number of NK cells was not affected, is was assumed that polychemotherapy induced a functional defect. In a subanalysis of patients with NSGCTs, metastases at diagnosis resulted in a significant (p < 0.05) and persistent stimulation of NK cell activity but not of ADCC. CONCLUSION: Cytostatic chemotherapy in patients with testicular cancer did not lead to compromised lytic effector cell function as assessed by NK cell activity and ADCC. However, a short, time-dependent reduction was found that also depended on the intensity of chemotherapeutic treatment. This finding related to the observation of a long-lasting stimulus of NK cell activity by initial metastases in patients with NSGCTs.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1995

Reduced mitogenic stimulation of peripheral blood mononuclear cells as a prognostic parameter for the course of breast cancer: a prospective longitudinal study.

Immunosuppression has been often associated with the course of malignant diseases. In the present study, the proliferation of peripheral blood mononuclear cells (PBMCs) in response to mitogenic stimulation with phytohaemagglutinin (PHA) was assessed prospectively in 90 patients with stage I-III breast cancer. Whereas PHA-induced proliferation of PBMCs derived from patients with breast cancer preoperatively was significantly decreased when compared with data obtained in healthy control individuals (P < 0.001), the degree of the defect in PHA-induced proliferation of PBMCs depended upon the tumour burden as manifested by tumour size and axillary lymph node involvement (P < 0.003 in each case). PHA-induced proliferation of PBMCs dropped significantly in patients who received adjuvant chemotherapy consisting of cyclophosphamide, methotrexate and fluorouracil (CMF) after an observation period of 6 months (P < 0.01), but not in patients under adjuvant treatment with tamoxifen only. After an additional 6 months (i.e. 12 months after surgery), PHA-induced proliferation of PBMCs was similar in patients after adjuvant chemotherapy with CMF and in those receiving continued adjuvant tamoxifen treatment (P > 0.1), but in all patients still significantly decreased as compared with healthy controls (P < 0.001). When data obtained preoperatively and after 12 months were compared, it was found that out of 23 patients whose PBMCs had experienced a drop in their PHA-induced proliferation, 14 (61%) had developed metastatic disease within the subsequent 24 months (i.e. 36 months after surgery). In contrast, out of 59 patients whose PBMCs showed an increase in their PHA-induced proliferation within the first 12 months after surgery, only one (2%) presented with disease progression. We thus conclude that PHA-induced proliferation of PBMCs derived from patients with breast cancer depends upon the tumour load and is a good clinical predictor for the further course of the disease.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

In vivo administration of granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor increases neutrophil oxidative burst activity.

The influence of CSF therapy on the superoxide (O2-) releasing capacity in response to N-formyl-methionyl-leucyl-phenylalanine (FMLP) of neutrophils from 32 patients with testicular cancer receiving high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT) was assessed: 8 patients were treated as control group without CSF therapy, 12 patients received GM-CSF, and 12 patients received G-CSF. To monitor the kinetics of the respiratory burst, leukocytes were collected before initiation of chemotherapy and ABMT, during CSF administration on days 1 and 3 after leukocyte recovery, and 7 days after leukocyte recovery (controls) or 3 days after the end of CSF therapy. Neutrophils from patients who received GM-CSF showed a significantly higher superoxide anion release compared with control patients (p < 0.001). O2- production in these patients was higher than that achieved by in vitro preincubation of neutrophils from control patients. Increased burst activity was seen only during infusion of GM-CSF and returned to pretherapeutic values after the end of GM-CSF administration. A similar but less pronounced increase was seen in patients who received G-CSF. In vitro preincubation of neutrophils from the same patients with GM-CSF, G-CSF, or TNF showed that O2- production by neutrophils from patients receiving GM-CSF could not be further enhanced, whereas O2- production by neutrophils derived from patients receiving G-CSF could be further augmented by TNF but not by GM-CSF. Interestingly, neutrophils from patients treated with GM-CSF but not those with G-CSF therapy retained a higher response to in vitro stimulation with GM-CSF or TNF after the end of CSF administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Marrow Transplantation↗
PubMed1995

Influence of in vivo administration of GM-CSF and G-CSF on monocyte cytotoxicity.

The influence of colony-stimulating factors (CSFs) on the monocyte functions of 32 patients with refractory testicular cancer receiving high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT) was tested. Eight patients were treated as a control group without CSF therapy, 12 patients received recombinant human granulocyte-macrophage-CSF (rhGM-CSF), and 12 patients received recombinant human granulocyte-CSF (rhG-CSF). For the assessment of monocyte activation induced by CSF expression of major histocompatibility complex (MHC) class I and II antigens, production of tumor necrosis factor (TNF) and monocyte-mediated cytotoxicity against tumor cell targets were chosen. Monocytes from patients with GM-CSF therapy showed a significant increase in MHC class I and II antigen expression as compared to patients without CSF treatment (p < 0.001). A significant increase in the expression of MHC class I was seen in monocytes from patients under G-CSF treatment, whereas no change of class II antigens was noticed. Production of TNF and monocyte-mediated cytotoxicity against U937 tumor cells was significantly increased in monocytes derived from patients receiving GM-CSF, as compared to those from the control group, while no effect was detectable in monocytes from patients with G-CSF therapy. However, after in vitro stimulation with interferon-gamma (IFN-gamma), monocytes derived from GM-CSF as well as from G-CSF treated patients responded with a significantly higher TNF-production and cytotoxicity than monocytes from control patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

[The significance of adhesion molecules in oncology].

Adhesion molecules are membrane proteins responsible for the complex functions of cell adhesion and cellular recognition and are thus of importance in inflammatory as well as neoplastic diseases. Adhesion molecules seem to play a significant role at each level of the metastatic cascade, including the destruction of normal cell-cell as well as cell-substrate cohesion, the penetration of tumor cells into the vascular system and the further spread into distant organs. In this summary an overview of subtypes, structure and function of the major groups of adhesion molecules is given and their possible role in the development, propagation and metastatic spread of malignancies discussed. Cell adhesion and its defects may be of importance in the behaviour of tumor cells and their spread. A better understanding of their function and possible manipulation of their expression, e.g., by cytokines could provide new therapeutic approaches in clinical oncology.

Cell Adhesion↗
PubMed1994

Increased natural killer cell activity correlates with low or negative expression of the HER-2/neu oncogene in patients with breast cancer.

BACKGROUND: Increased expression of the HER-2/neu oncogene in breast cancer correlates with decreased estrogen receptor concentration and seems to be an important prognostic factor. The authors investigated whether there is a correlation between HER-2/neu expression and immunologic parameters representing tumor defense in patients with breast cancer. METHOD: A Western blot analysis was used to investigate HER-2/neu expression, whereas a chromium-release assay using the K562 cell line as target was used to measure natural killer (NK) cell activity. RESULTS: In patients with breast cancer, NK cell activity was significantly higher compared with patients with benign tumors (P = 0.006) or healthy control subjects (P = 0.002). Moreover, 23.3% of patients with breast cancer showed an overexpression of HER-2/neu protein. Within this group of patients, NK cell activity was significantly lower (45.6 +/- 16.1%) compared with the group with no HER-2/neu overexpression (57.3 +/- 11.0%). NK cell activity did not increase in patients with HER-2/neu overexpression. Thus, there was a statistically significant correlation of cytolytic effector cell function with HER-2/neu expression of the tumor (P = 0.003), and HER-2/neu overexpression correlated with a negative estrogen receptor status (P = 0.005). CONCLUSION: These data add further evidence to previous observations from the authors' laboratory that certain tumor characteristics may be associated with reactions of the host with breast cancer.

Breast↗
PubMed1994

Coexpression of HER-2/neu and p53 is associated with a shorter disease-free survival in node-positive breast cancer patients.

Breast cancer tissue was examined for overexpression of HER-2/neu and p53 oncogene proteins. Samples from 105 breast cancer patients were investigated by Western-blot analysis and their relationship to other established markers and clinical outcome was examined. In 21.0% of the cases HER-2/neu was overexpressed, and in 46.7% the p53 protein level was increased. Expression of these two oncogene products was closely correlated. Overexpression of both oncogenes was associated with larger tumour size and negative hormone receptor. The percentage of HER-2/neu and p53 overexpression was higher in node-positive patients, although statistical evaluation was not significant. While overexpression of HER-2/neu as well as p53 in node-positive patients was associated insignificantly with shorter disease-free survival, a significant difference could be documented when the disease-free survival of patients with overexpression of both oncogene proteins was compared to that of patients with no overexpression.

Breast Neoplasms↗