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M Pfreundschuh

Publications and source records attributed to M Pfreundschuh.

At least 109 records · Page 6Linked to original sources
PubMed1996

N-ras genes are not mutated in Hodgkin and Reed-Sternberg cells: results from single cell polymerase chain-reaction examinations.

Ras mutations play an important role in many human tumors. They usually occur at only three codons (12, 13 and 61) of the three ras gene family members and lead to altered proteins resulting in a constitutively activated downstream signal cascade. We have examined the N-ras gene status in Hodgkin's disease (HD). Little is known about the pathogenetic events leading to malignant phenotype in HD. Since Hodgkin and Reed-Sternberg (H and RD) cells comprise only a minority of the cellular infiltrate in HD-lymph nodes, molecular studies concerning the status of oncogenes have been difficult to perform and have yielded conflicting results. We have established a single cell PCR assay for N-ras analysis and have examined H and RS cells from 12 cases of HD by PCR amplification and direct sequencing. None of the single H and RS cells examined carried N-ras mutations at either codons 12/13 or 61. Therefore, N-ras mutations are not involved in the pathogenesis of HD.

Adult↗
PubMed1996

[High-grade non-Hodgkin lymphoma: diagnosis and therapy].

High grade non-Hodgkin's lymphomas comprise a group of heterogenous disorders of the lymphatic system with aggressive clinical behaviour. Extranodal disease manifestations are common, especially in immunocompromised patients [e.g. AIDS]. High-grade NHL are chemo- and radiosensitive. Anthracyclin-containing chemotherapy regimens have led to a significant improvement in prognosis. The CHOP-regime, consisting of doxorubicin, cyclophosphamide, oncovin and prednisolon, is the standard therapy that should be given outside of clinical trials. Age, bad performance status, elevated serum-LDH, presence of more than one extranodal manifestation and disease stage III or IV have been defined as clinically relevant prognostic factors. Current treatment strategies include dose intensification by interval shortening and dose escalation as well as high-dose chemotherapy, followed by autologous stem cell rescue. Patients receiving these experimental therapies should be treated within multicenter clinical trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Human neoplasms elicit multiple specific immune responses in the autologous host.

Expression of cDNA libraries from human melanoma, renal cancer, astrocytoma, and Hodgkin disease in Escherichia coli and screening for clones reactive with high-titer IgG antibodies in autologous patient serum lead to the discovery of at least four antigens with a restricted expression pattern in each tumor. Besides antigens known to elicit T-cell responses, such as MAGE-1 and tyrosinase, numerous additional antigens that were overexpressed or specifically expressed in tumors of the same type were identified. Sequence analyses suggest that many of these molecules, besides being the target of a specific immune response, might be of relevance for tumor growth. Antibodies to a given antigen were usually confined to patients with the same tumor type. The unexpected frequency of human tumor antigens, which can be readily defined at the molecular level by the serological analysis of autologous tumor cDNA expression cloning, indicates that human neoplasms elicit multiple specific immune responses in the autologous host and provides diagnostic and therapeutic approaches to human cancer.

Antibodies, Neoplasm↗
PubMed1995

[Ki-ras mutation as a molecular tumor marker for carcinoma of the pancreas].

More than 90% of tumours of the pancreas have mutations on codon 12 of the Ki-ras oncogene. Cellular DNA from pancreatic secretions and fine-needle biopsies, obtained from 69 patients (41 men, 28 women), were amplified by the polymerase chain reaction (PCR) to demonstrate this characteristic marker. All these patients had undergone endoscopic retrograde pancreatography for suspected pancreatitis or carcinoma of the pancreas. Two different methods were developed to demonstrate the mutations. With the aid of one of these methods, enrichment PCR with analysis of the restriction fragment length (FL), mutations on codon 12 of the Ki-ras gene were demonstrated in unstimulated pancreatic secretions of 29 of 33 patients with pancreatic carcinoma. All eleven fine-needle biopsies that had been cytologically examined showed the tumour-specific mutation. After direct sequencing of enrichment PCR a codon 12 mutation was demonstrated in pancreatic secretion from 21 of 24 patients and with the single strand conformation polymorphism analysis in 17 of 33 patients. In two of these 33 patients two different Ki-ras mutations were discovered. No mutations were found in acute inflammations or stone disease, while in five patients with chronic pancreatitis mutations were demonstrated only in those two patients in whom histological examination had revealed precancerous mucinous hyperplasia. This investigation indicates that codon 12 mutations of the Ki-ras gene, found after PCR in pancreatic secretion and biopsies, constitute a sensitive and specific tumour marker whose clinical value is being assessed.

Biomarkers, Tumor↗
PubMed1995

Hodgkin and Reed-Sternberg cells do not carry T-cell receptor gamma gene rearrangements: evidence from single-cell polymerase chain reaction examination.

Hodgkin and Reed-Sternberg (H&RS) cells are generally accepted to be the neoplastic cells of Hodgkin's disease (HD), even though they represent only a minority of the cellular infiltrate in affected tissues. Recent immunologic studies and Southern blot analyses of DNA extracted from whole lymph node tissue favored, but did not convincingly prove a lymphoid origin of H&RS cells. To detect rearrangements of the T-cell receptor gamma chain (TCR gamma) genes at the single-cell level as an indication of early T-cell lymphoid differentiation, we isolated H&RS cells by micromanipulation from cytospin preparations of fresh biopsy material. TCR gamma chain rearrangement was detected by polymerase chain reaction using four "forward primers" that were constructed corresponding to all four V families and two "reverse primers" corresponding to consensus sequences of J segments. Rearrangements of all V families in combination with the different J segments were detected in human peripheral blood and tonsillar T cells. Although rearrangements of TCR gamma chain genes were shown in single cells of 10 of 10 T-cell leukemias, no rearrangement of these genes was found in single H&RS cells from 13 consecutive patients with HD. Our results indicate that H&RS cells from the vast majority of cases are not derived from T cells. This finding may have implications for the pathogenesis of HD and the development of more effective treatment regimens.

Base Sequence↗
PubMed1995

['94 oncology update].

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1995

The role of lymphocyte subsets and adhesion molecules in T cell-dependent cytotoxicity mediated by CD3 and CD28 bispecific monoclonal antibodies.

The cure of human Hodgkin's tumors heterotransplanted into SCID mice can be achieved by two bispecific monoclonal antibodies (Bi-mAb) directed against the tumor-associated CD30 antigen and CD3 and CD28, respectively, and normal peripheral human blood T cells. We investigated the role of lymphocyte subsets and adhesion molecules in this Bi-mAb-mediated cytolysis. CD4+ lymphocytes were the most rapidly expanding subpopulation, but Bi-mAb-directed cytotoxicity was mediated preferentially by CD8+ lymphocytes and effector cells belonging to the CD45RO+ "memory" pool. Blocking of the LFA-1/ICAM-1 or CD2/LFA-3 adhesion pathways by mAb decreased Bi-mAb-mediated cytotoxicity. This was not due to inhibition of aggregate formation between Bi-mAb-coated T lymphocytes and target cells. Cross-linking of LFA-1 or CD2 molecules on lymphocytes prestimulated with Bi-mAb bound to CD3 and CD28 antigen lead to a more pronounced and prolonged rise in the intracellular concentration of free Ca2+. Additional CD2 cross-linking resulted in the tyrosine phosphorylation of distinct proteins. These findings indicate that adhesion molecules play a critical role and function as co-stimulatory signals rather than as cellular contact mediators in CD3 and CD28 Bi-mAb-stimulated T lymphocytes.

Antibodies, Bispecific↗
PubMed1995

The B lymphocyte in rheumatoid arthritis: analysis of rearranged V kappa genes from B cells infiltrating the synovial membrane.

The participation of the humoral immune system in rheumatoid arthritis (RA) is characterized by the production of rheumatoid factors (RF). RF are autoantibodies against the Fc part of IgG which are encoded by diverse germ-line genes. Most of the RF-encoding genes are unmutated, but in RA, a substantial quantity is encoded by somatically mutated genes. In addition, the synovial membranes (SM) of the diseased joints of RA patients are infiltrated by B lymphocytes which form germinal center-like aggregates. To analyze the local immune response, B cell foci from two RA SM were isolated by micromanipulation. From DNA of these foci, the rearranged kappa light chain variable region (V kappa) genes were amplified by polymerase chain reaction (PCR), cloned and sequenced. The amplification of different V kappa-J kappa combinations of different foci suggested oligoclonal expansion of B lymphocytes, which was confirmed by sequence analysis: each PCR product contained members of a single B cell clone. The sequence analysis of 29 different clones revealed rearrangements of diverse V kappa genes. Both frequent representatives of the V kappa 3 and the V kappa 1 family, as well as rarely used genes such as the L10 and B2 genes of the V kappa 2 and V kappa 5 families were found. Of the eleven potentially functional gene rearrangements, eight were significantly mutated, indicating their derivation from antigen-selected B cells. Intraclonal diversity in one of these clones may suggest ongoing mutation in the diseased synovial membrane of patients with RA.

Adult↗
PubMed1995

Identification of genetic imbalances in malignant lymphoma using comparative genomic hybridization.

In comparison to leukemias, the clinical relevance of chromosomal aberrations in non-Hodgkin's lymphoma (NHL) is not as well understood. This is primarily due to limitations of chromosomal banding techniques which have been the central methods for cytogenetic analysis. These techniques depend on the availability of fresh tumor tissue and the examination of metaphase cells which may not be representative for the major cell clone in vivo. In contrast, the new technique of comparative genomic hybridization (CGH) allows researchers to obtain a comprehensive view of chromosomal gains and losses by analyzing tumor DNA, which can be prepared from archival tissue samples. Results of CGH studies in three different types of lymphoproliferative disorders are outlined in this paper demonstrating that: (1) in chronic B cell leukemias, chromosomal aberrations are missed by banding analysis in a high proportion of cases, (2) CGH on paraffin-embedded tissue samples can be used for cytogenetic analysis within clinical multicenter trials and (3) DNA amplifications are more frequent in NHL than previously assumed. Thus, it can be expected that CGH will contribute both to the understanding of pathogenetic mechanisms and the identification of clinically relevant chromosome aberrations in NHL.

Chromosome Aberrations↗
PubMed1995

Treatment of heterotransplanted Hodgkin's tumors in SCID mice by a combination of human NK or T cells and bispecific antibodies.

To test the feasibility and efficacy of a new immunotherapeutic approach in Hodgkin's disease, bispecific monoclonal antibodies (BsmAb) were established with specificity for the Hodgkin's-associated CD30 antigen and for CD16 (on NK cells) or CD3 and CD28 (on T lymphocytes), respectively. These BsmAb induced a specific and efficient NK cell or T cell-mediated cytotoxicity in vitro. The treatment of severe combined immunodeficiency (SCID) mice with the NK (anti-CD16/CD30) or T cell (anti-CD3/CD30 and anti-CD28/CD30) activating BsmAb followed by administration of resting human lymphocytes led to complete remission of established heterotransplanted human Hodgkin's tumors. Even disseminated tumors were cured. Studies on the mechanism responsible for tumor destruction revealed that treatment efficacy depended on lymphocyte activation at the tumor site. Localization of human lymphocytes in mice was BsmAb mediated and antigen specific as activated lymphocytes were only detected in CD30+ tumors but not in CD30- colorectal carcinomas co-established as a control in the same animal.

Animals↗
PubMed1995

Further chemotherapy versus low-dose involved-field radiotherapy as consolidation of complete remission after six cycles of alternating chemotherapy in patients with advance Hodgkin's disease. German Hodgkins' Study Group (GHSG).

OBJECTIVE: It was the aim of this prospective randomized multicenter study to compare chemotherapy and radiotherapy as consolidation treatments in patients achieving complete remission (CR) after 6 cycles of doxorubicin-containing chemotherapy in advanced-stage Hodgkin's disease (HD). METHODS: A total of 288 previously untreated patients aged 18-60 years with stage IIIB or IV HD received induction chemotherapy with 3 X (COPP + ABVD). Patients achieving CR were eligible for randomisation to either 20 Gy radiotherapy to initially involved fields (RT-arm) or to an additional 1 X (Copp + ABVD) (CT-arm ). Patients with nodal PR were allocated to more intense radiotherapy (IRT-arm: 20 Gy IF, 40 Gy to persisting tumor). Four patients with persisting organ involvement after induction received salvage chemotherapy. RESULTS: Of 288 patients, 171 (59%) achieved CR after induction chemotherapy. Of these, 100 patients were successfully randomized to RT or CT. In the CT arm relapses were observed on 10 of 49 patients compared with 13 of 51 patients in the RT arm (p = n.s.). Fifty patients refused randomisation and for them a treatment was chosen, and 21 patients refused any further treatment. Of these 21 patients with no consolidation therapy, 9 relapsed, indicating an approximately 3-fold increased relapse risk compared with those receiving either of the consolidation therapies. No relapse was observed in initially involved lung or liver sites. Adverse prognostic factors for freedom from treatment failure and survival were low hemoglobin and large mediastinal mass at initial presentation. CONCLUSIONS: No statistically significant differences in treatment efficacy were detected between 20 Gy IF radiotherapy and 1X (COPP + ABVD) chemotherapy following CR after six cycles of alternating chemotherapy in patients with advanced-stage HD. However, limited observations in a non-randomized cohort indicate that patients without consolidation treatment of CR after 6 cycles of chemotherapy may have an elevated risk of relapse.

Adolescent↗
PubMed1995

Tumor therapy by immune recruitment with bispecific antibodies.

Many strategies for experimental immunotherapy of cancers aim at inducing and expanding tumor-specific cytotoxic T-lymphocytes. One of the most promising approaches uses bispecific monoclonal antibodies (Bi-MAbs) which are able to accumulate and activate human effector cells at the tumor site. Human resting peripheral NK- or T cells targeted by appropriate Bi-MAbs to tumor cells expressing a tumor-associated antigen display multiple signs of activation including proliferation, cytokine secretion, upregulation of cytotoxic peptides and enzymes and induce an efficient tumor cell lysis in vivo. Moreover, tumor-bearing SCID which were treated by effector cell-triggering Bi-MAbs and human peripheral blood lymphocytes had complete regressions of established tumors and most or all animals were cured by human NK-cell or T-cell cytotoxicity, respectively. Local tumor site-specific activation of T-cells was demonstrated, and enhanced granzyme and perforin expression together with the results of inhibition experiments suggest both mechanisms as the major contributors to the cytolytic machinery of Bi-MAb-mediated T-cell cytotoxicity in vivo. The encouraging results of this approach, which is able to cure animals with even advanced disseminated tumors, together with the local site-specific effector cell activation, which suggests minimal side effects, warrant the clinical evaluation of this Bi-MAb approach. As lymphocytes from tumor patients can be adequately activated by the respective Bi-MAbs, the clinical application of Bi-MAbs promises to become a safe, efficient and simple approach which should be readily applicable to the treatment of human malignancies that cannot be cured by standard regimens.

Antibodies, Bispecific↗
PubMed1995

Multiinstitutional home-therapy trial of recombinant human interleukin-2 and interferon alfa-2 in progressive metastatic renal cell carcinoma.

PURPOSE: In a phase II multiinstitutional outpatient trial, patients with progressive metastatic renal cell carcinoma were treated with a combination of subcutaneous (SC) recombinant interleukin-2 (rIL-2) and recombinant interferon alfa-2 (rIFN alpha 2). PATIENTS AND METHODS: One hundred fifty-two patients with metastatic renal cell carcinoma were treated. Treatment courses consisted of SC rIL-2 at 20 x 10(6) IU/m2 three times per week in weeks 1 and 4, and at 5 x 10(6) IU/m2 three times per week in weeks 2, 3, 5, and 6. Additionally, patients received SC rIFN alpha 2 6 x 10(6) U/m2 once per week in weeks 1 and 4, and three times per week in weeks 2, 3, 5, and 6. RESULTS: There were nine (6%) complete responses (CRs) and 29 (19%) partial responses (PRs), for an overall response rate of 25% (95% confidence interval, 19% to 32%). The median duration of responses for CRs and PRs was 16+ and 9 months, respectively. Additionally, 55 patients (36%) had stable disease (SD). Fifty-nine patients (39%) had continued disease progression (PD) despite treatment, or went off study after less than 4 weeks of therapy. The majority of patients treated experienced fever, chills, malaise, nausea, vomiting, and anorexia, side effects that were mostly limited to World Health Organization (WHO) grade 1 and 2. However, one patient developed grade 4 CNS toxicity with extended somnolence. On cessation of therapy, the neurologic symptoms in this patient were fully reversible, with no neurologic deficiency. CONCLUSION: In summary, this multiinstitutional home-therapy setting of SC rIL-2 and SC rIFN alpha 2 in patients with progressive metastatic renal cell carcinoma demonstrated drastically reduced systemic toxicity, while it confirmed the therapeutic efficacy of the low-dose SC immunotherapy combination schedule.

Adult↗
PubMed1994

Detection of immunoglobulin heavy-chain gene rearrangement at the single-cell level in malignant lymphomas: no rearrangement is found in Hodgkin and Reed-Sternberg cells.

Hodgkin and Reed-Sternberg (HRS) cells, the neoplastic cells of Hodgkin's disease (HD), represent only a minority of the cellular infiltrate in affected tissue. Therefore, rearrangements of the immunoglobulin heavy-chain (IgH) gene detected in DNA extracted from an entire Hodgkin's lymph node cannot be attributed to the HRS cells and cannot be used as an argument for the B-cell origin of HRS cells. We developed a new method for the amplification of rearranged DNA of the IgH gene from single cells. Using 6 "forward primers" which were constructed corresponding to consensus sequences of the 6 known families of the IgH variable (V) region (framework region I) and a mix of 2 "reverse primers" corresponding to consensus sequences of the different joining (J) segments, rearrangements of all 6 V-families were detected in human peripheral blood lymphocytes. Rearranged IgH DNA could be amplified from single cells of B-cell lymphoma-cell lines and from 13 patients with B-cell non-Hodgkin's lymphomas. However, analysis of HRS cells isolated from lymph nodes of 13 patients with Hodgkin's disease did not show any rearrangement of the IgH gene locus. These findings, obtained by polymerase chain reaction (PCR) on isolated single HRS cells, contrast with previous studies that used Southern-blot analysis of entire tissues affected by Hodgkin's disease. We conclude that the neoplastic HRS cells in Hodgkin's disease--with the possible exception of the nodular paragranuloma subtype--are probably not derived from B cells.

B-Lymphocytes↗
PubMed1994

Cure of xenografted human tumors by bispecific monoclonal antibodies and human T cells.

Tumor immunotherapy should increase both the number of T cells that kill the tumor and the likelihood that those cells are activated at the tumor site. Bispecific monoclonal antibodies (Bi-mAbs) were designed that bound to a Hodgkin's tumor-associated antigen (CD30) on the tumor and to either CD3 or CD28 on the T cell. Immunodeficient mice were cured of established human tumors when mice were treated with both the CD3-CD30 and the CD28-CD30 Bi-mAbs and then given human peripheral blood lymphocytes that had been incubated with the CD3-CD30 Bi-mAb and cells that expressed CD30. The enrichment of human T cells within the tumor and the fact that established tumors can be cured may indicate in situ activation of both the T cell receptor and the costimulatory pathway.

Animals↗
PubMed1994

Opposite effects of the CD30 ligand are not due to CD30 mutations: results from cDNA cloning and sequence comparison of the CD30 antigen from different sources.

CD30L, the ligand for the activation antigen CD30, is a member of the tumor necrosis factor family of cytokines. Binding of CD30L to CD30, which is a member of the nerve growth factor/tumor necrosis factor receptor family, induces proliferation in peripheral blood lymphocytes and Hodgkin's derived cell lines with a T-cell phenotype such as HDLM-2 and L540, while cell lines derived from anaplastic large cell lymphomas, such as Karpas 299, undergo cell death. In order to investigate whether mutations of the CD30 antigen are responsible for these opposite effects, we cloned the open reading frame of CD30 cDNAs from the cell lines L540 and Karpas 299 and from peripheral blood lymphocytes by reverse transcriptase polymerase chain reaction. Sequencing of independent plasmid clones revealed that these cells have a silent transition (A-->G) at position 771 of the open reading frame compared to the published sequence derived from the HTLV-1+ cell line HUT-102. As published data have shown that crosslinking of CD30 induces an elevation of cytosolic free calcium ([Ca2+]i) in TCR positive Jurkat cells, we have analysed the effect of crosslinking of CD30 on L540 and Karpas 299 cells. No elevations of [Ca2+]i have been observed in these cell lines after crosslinking of CD30 with HRS-4. We conclude (i) that the different functional effects of CD30 in PBL, L540 and Karpas 299 are not due to differences in the primary structure of the receptor; and (ii) that the different responses observed upon engagement with CD30L for the cell lines L540 and Karpas 299 do not correlate with differences in mobilization of [Ca2+]i after crosslinking of CD30.

Base Sequence↗
PubMed1994

Diagnosis of pancreatic adenocarcinoma by polymerase chain reaction from pancreatic secretions.

As mutations at codon 12 of the Ki-ras oncogene have been shown to occur in 90% of pancreatic adenocarcinomas, a novel strategy for the detection of these mutations in pancreatic secretions obtained at routine endoscopies was developed. Ki-ras DNA was amplified and screened for the presence of mutations at codon 12 with a combination of different rapid, non-radioactive molecular biology techniques. Examination of DNA from cell lines and paraffin-embedded tumour samples was used to establish and test the strategy employed. Pancreatic secretions from 27 patients were examined for the presence of Ki-ras mutations. Mutations at codon 12 were detected in 16/16 secretions from patients with histologically confirmed carcinoma and from one patient with carcinoma of the bile duct. In six patients a mutation identical to the one found in the pancreatic secretions was also demonstrated in paraffin-embedded fine-needle biopsy or surgical samples. Of the remaining ten patients (who had pancreatitis or cholelithiasis) mutations were not found in nine. Ki-ras codon 12 mutation was identified in one of these patients however, and mucous cell hyperplasia of pancreatic ducts was found upon histological examination. These findings establish Ki-ras polymerase chain reaction from pancreatic secretions as a valuable new diagnostic procedure for the demonstration of malignant cells, possibly at an early stage of the disease.

Adenocarcinoma↗