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Biomedical subjects

M Blick

Publications and source records attributed to M Blick.

At least 37 records · Page 2Linked to original sources
PubMed1988

Reduction to homozygosity at the SIS/PDGF-2 locus in human mesenchymal tumors.

Enhanced expression of the human SIS/PDGF-2 gene has been reported in a number of human cell lines, sarcomas, and glioblastomas. We have analyzed the SIS/PDGF-2 gene for structural alterations in fresh human tumors. DNA samples from 79 patients with solid tumors (63 mesenchymal tumors, 12 lung carcinomas, 4 breast carcinomas) were examined and compared with DNA samples from 50 leukemia patients and 14 unrelated individuals without malignant neoplasms. When DNA samples were digested with a HindIII restriction endonuclease, Southern blot analysis demonstrated two distinct bands (21kb and 18kb) after hybridization to the SIS/PDGF-2 gene probe. A pedigree analysis of a 43-member family indicated that these allelic variants segregated in a Mendelian fashion. There was, however, tumor specific allele loss in 18% of the mesenchymal tumors analyzed, which may indicate a common etiology for this tumor type.

Cell Line↗
PubMed1988

Multiple restriction fragment length polymorphisms of the human epidermal growth factor receptor gene.

We have examined the epidermal growth factor (EGF) receptor gene for structural alterations in fresh human tumors. DNA samples from 92 patients with solid tumors (lung cancer, 37; breast cancer, 24; head and neck cancer, 17; other tumors, 14) were analyzed and compared with those from 22 leukemia patients and 14 individuals without malignant neoplasms. When DNA samples were digested with HindIII restriction endonuclease, Southern blot analysis demonstrated 3 distinct polymorphic bands (9.8, 11, and 12 kilobases) after hybridization to the HER-A64-1 probe and another 2 distinct polymorphic bands (4.9 and 5.2 kilobases) after hybridization to the HER-A64-3 probe. Pedigree analysis of 43 members of a single family and comparative analysis of tumor and normal DNA samples from the same patients demonstrated that the variations in fragment size observed were due to 2 independent restriction fragment length polymorphisms in the region of the EGF receptor gene. Amplification of the EGF receptor gene was detected in 3 cases of breast cancer, but not in other tumors studied. We conclude that the human EGF receptor gene has multiple restriction fragment length polymorphisms and that in fresh human tumor samples rearrangement and amplification of the gene occur infrequently, if ever, within the region encompassed by the 2 complementary DNA probes used.

Alleles↗
PubMed1988

Association of the Epstein-Barr virus with lymphoepithelioma of the thymus.

A 30-year-old woman with the histologic diagnosis of lymphoepithelioma of the thymus is reported on. Investigation of Epstein-Barr serology showed evidence of infection, and Southern blot analysis showed the presence of the viral genome in the tumor specimen. The patient achieved complete remission after treatment with combination chemotherapy, autologous bone marrow transplant, and radiotherapy. These findings suggest that lymphoepithelioma of the thymus may have a viral pathogenesis similar to that of nasopharyngeal carcinoma.

Adult↗
PubMed1988

Amplified and overexpressed epidermal growth factor receptor gene in uncultured primary human breast carcinoma.

We analyzed the epidermal growth factor receptor gene using a complementary DNA probe of the epidermal growth factor receptor gene in 21 uncultured primary breast carcinomas and found that the gene was amplified in three of these tumors. We further demonstrated by immunohistochemistry using a monoclonal antibody to the epidermal growth factor receptor that the receptor protein product of this gene was overexpressed and displayed elevated kinase activity. Our data indicate that one of the molecular mechanisms for overexpression of epidermal growth factor receptor in human breast cancer is epidermal growth factor receptor gene amplification without rearrangement in a subset of tumors.

Adult↗
PubMed1988

Significance and correlations of molecular analysis results in patients with Philadelphia chromosome-negative chronic myelogenous leukemia and chronic myelomonocytic leukemia.

PURPOSE: Several investigators have documented a rearrangement of the breakpoint cluster region (bcr) in selected patients with a morphologic diagnosis of chronic myelogenous leukemia (CML) but no abnormality of the Philadelphia chromosome (Ph) by cytogenetic studies. Our intention was to systematically investigate the incidence of the bcr rearrangement in such patients, and to correlate the findings with patient characteristics, response to therapy (especially alpha interferon treatment), and overall prognosis. PATIENTS AND METHODS: Molecular analysis studies were performed in 40 patients with Ph-negative CML (23 patients) and myelomonocytic leukemia (CMML; 17 patients). RESULTS: Rearrangement of the breakpoint cluster region (bcr) was detected in 11 of the 23 patients with Ph-negative CML (48 percent), indicating the presence of the abnormal molecular events in Ph-positive CML without documentation of the Ph cytogenetic abnormality. None of the 17 patients with CMML had the bcr rearrangement. Patients with Ph-negative CML and the bcr rearrangement had characteristics similar to those of patients with Ph-positive disease. These included a younger age, higher white blood cell counts, a higher incidence of thrombocytosis and basophilia, and a lower occurrence of thrombocytopenia. The leukocyte alkaline phosphatase score was not a helpful distinguishing feature. Among 21 patients receiving alpha interferon-based regimens, response to therapy was significantly better among patients with Ph-negative disease and the bcr rearrangement (seven of seven, 100 percent), compared with those without the bcr rearrangement (one of six, 17 percent), or patients with CMML (two of eight, 25 percent) (p less than 0.01). At this time of follow-up, only one of the 11 patients with Ph-negative CML and the bcr rearrangement had died from complications of allogeneic bone marrow transplantation, compared with three deaths among the 12 patients with Ph-negative CML and no bcr rearrangement, and 11 deaths among the 19 patients with CMML. CONCLUSION: We conclude that molecular studies help in better understanding the nosology of Ph-negative CML, and define a subgroup of patients with clinical, therapeutic, and prognostic correlations similar to those of patients with Ph-positive CML.

Adolescent↗
PubMed1988

Philadelphia-negative chronic myelogenous leukemia with breakpoint cluster region rearrangement: molecular analysis, clinical characteristics, and response to therapy.

We have detected rearrangement in the breakpoint cluster region (bcr) on chromosome 22 in cells derived from seven chronic myelogenous leukemia (CML) patients who had no cytogenetic evidence of a chromosome abnormality. These Philadelphia (Ph)-negative, bcr rearrangement-positive CML patients had clinical features and laboratory parameters that bore a strong resemblance to those of Ph-positive CML; all patients have shown a favorable response to hydroxyurea, busulphan, or alpha interferon (IFN-alpha) therapy. In one patient, because of the deletion of distal 3' sequences, detection of bcr rearrangement required a large probe that recognized proximal 5' sequences. Cells obtained from five patients were studied by Northern blotting and showed an aberrant 8 kilobase (kb) mRNA indistinguishable from the bcr-abl transcript that is felt to be a pathogenetic factor in Ph-positive CML. In three patients with a normal karyotype, bcr rearrangement was detected at the time of hematologic remission, and represented the only evidence for persistent malignancy. Our results suggest that: (1) the presence of bcr rearrangement in CML is associated with clinical features of Ph-positive disease, even in the absence of the Ph chromosome; (2) deletions occur within bcr and necessitate the use of probes covering both 5' and 3' DNA segments for accurate diagnosis; (3) molecular analysis may provide a useful approach to the follow-up of leukemia therapy in some patients; and (4) these patients respond to hydroxyurea, busulphan, and IFN-alpha therapy.

Adolescent↗
PubMed1988

A phase I trial of intravenously-administered recombinant tumor necrosis factor-alpha in cancer patients.

We report a phase I clinical investigation of 30-minute and four-hour intravenous (IV) infusions of recombinant tumor necrosis factor (rTNF)-alpha. Thirty-nine patients with disseminated cancer received escalating doses of rTNF-alpha for five consecutive days every 2 weeks for a total duration of 8 weeks. Dose escalations followed a modified Fibonacci scale with a minimum of four patients entered at each dose level: 5, 10, 25, 50, 75, 100, 150, 200, and 250 micrograms/m2/d. Toxicities consisted mainly of constitutional symptoms including fever, chills, headache, and fatigue, increasing in severity with dose escalation. No significant differences in dose-limiting toxicities were seen between the two rates of IV infusion. The maximum tolerated dose (MTD) was 200 micrograms/m2 with dose limiting toxicity being constitutional symptoms and hypotension. Hematologic changes included median decrease in both granulocyte and platelet counts of 38% and 41%, respectively (range, 16% to 85%), although clinically significant granulocytopenia and thrombocytopenia were not observed. Hematological parameters returned to baseline within 72 hours after rTNF-alpha was stopped. rTNF-alpha induced changes in lipid metabolism were manifested by median fasting triglyceride elevations above baseline (median, 103 micrograms/dL) of 157% (range, 16% to 389%) after five days of therapy with doses greater than 75 micrograms/m2, associated with a median increase in very-low-density lipoprotein (VLDL) of 80%. Serum rTNF peak levels exceeding 10 ng/mL were observed 30 minutes following rTNF-alpha infusions at MTD dose. Twelve of 34 patients had no change in their evaluable disease for a median duration of 18 weeks (range, 8 to 30 weeks), and 22 patients showed progressive disease. This study forms the framework for phase II trials of IV administered rTNF-alpha.

Adult↗
PubMed1988

Clinical evaluation of a DNA probe assay for the Philadelphia (Ph1) translocation in chronic myelogenous leukemia.

We report the clinical evaluation of an improved DNA probe assay for the characteristic genetic marker of human CML, observed by cytogenetics and designated the Philadelphia chromosome (Ph1). The Ph1 chromosome results from the fusion of c-abl proto-oncogene sequences from chromosome 9 to phl gene sequence on chromosome 22. (The phl gene is often referred to as bcr. However, for clarity we prefer to reserve the designation "bcr" for the region within the phl gene in which translocation breakpoints have been found to occur. We also find it useful to distinguish between two such regions in phl, bcr-210 and bcr-190, named after the 210- and 190-kDa phl/abl fusion proteins resulting from translocations with breakpoints in the respective regions. We refer to the corresponding chromosomal translocations as Ph1(bcr-210) and Ph1(bcr-190).) DNA, extracted from peripheral blood (PB) or bone marrow (BM) and digested with restriction endonuclease BglII, is hybridized with a probe (phl/bcr-3) spanning a breakpoint cluster region within phl. Rearrangements are revealed by the presence of one or two novel junction fragments. Clinical specimens from leukemic patients with active disease were compared by cytogenetic and DNA probe analysis at seven centers in the United States and Europe. The probe assay identified the phl rearrangement in 190 of 191 cases of Ph1-positive CML, as well as in 12 of 27 clinically diagnosed CML specimens lacking a typical Ph1 chromosome. DNA rearrangements also were seen in two of six cases of Ph1-positive ALL. No false positive results were obtained among 93 non-leukemic controls. Mixing experiments showed that the DNA probe assay can detect as few as 1% leukemic cells in a specimen. A preliminary study of CML patients in remission after allogeneic BM transplantation revealed a small fraction of residual Ph1-positive leukemic cells in a significant number of such patients.

Blotting, Southern↗
PubMed1988

Suppression of c-myc and c-myb expression in myeloid cell lines treated with recombinant tumor necrosis factor-alpha.

Proto-oncogenes are thought to be involved in cellular differentiation and proliferation. Tumor necrosis factors (TNFs) are specific cytokines that have cytostatic and cytotoxic effects in vitro against a wide range of human tumor cells. We have previously demonstrated that recombinant TNFs (rTNFs) have an antiproliferative effect on certain human leukemic cell lines (HL-60, KBM3, KBM5) and no effect on others (K562). To study the possible role of the c-myc and c-myb oncogenes in this antiproliferative effect of TNF, we examined their expression in cell lines HL-60, KBM3, KBM5, and K562 before and after incubation with rTNF-alpha. Expression of c-myc and c-myb was elevated in all cell lines prior to incubation with rTNF-alpha. In the sensitive cell lines HL-60, KBM5, and KBM3 expression of c-myc and c-myb decreased rapidly 8-, 16-, and 4-fold, respectively, by 24 hr. K562 cells, insensitive to rTNF-alpha, exhibited no change in c-myc or c-myb expression over 24 hr. These studies demonstrated that down-regulation of c-myc and c-myb expression were associated with antiproliferative effects of rTNF-alpha on these cell lines.

Cell Line↗
PubMed1988

Aberrant expression of the K-ras proto-oncogene in B-cell malignancies.

The proto-oncogenes have the capacity for conversion to an oncogene that is capable of inducing or maintaining the transformed state when they are overly expressed or altered by mutation or rearrangement. To study the possible involvement of these genes in the neoplastic transformation of B-cell malignancies, we have analyzed their expression in 18 fresh samples obtained from the peripheral blood of patients with a variety of B-cell malignancies. A high-molecular weight c-k-ras transcript (5.2 kb) was detected in all samples including normal lymphocytes. In contrast, a low-molecular weight c-k-ras transcript (1.2 kb) was not detected in our control normal lymphocytes, but was found in 9 fresh samples. The 1.2 kb c-k-ras transcript was expressed 2-3-fold higher than the 5.2 kb c-k-ras transcript. C-h-ras (2.9 kb, 1.4 kb) was expressed at a low level in 4 and 13 samples, but not in normal lymphocytes. C-myc (2.3 kb) and c-raf (3.8 kb) were expressed in all samples including normal lymphocytes without significant variation in the level of expression. C-fos (2.2 kb) was expressed in 15 samples and normal lymphocytes with a wide range in the level of expression. C-myb (3.7 kb) and c-fes (2.7 kb) were expressed at a low level in 6 and 10 samples, respectively, including normal lymphocytes. C-sis (4.0 kb) was not detected in any sample including normal lymphocytes.

DNA↗
PubMed1988

Analysis of breakpoints within the bcr gene and their correlation with the clinical course of Philadelphia-positive chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) is characterized by a reciprocal translocation between chromosomes 9 and 22. The breakpoints on chromosome 22 are clustered within a 5.8-kilobase (kb) DNA fragment known as the breakpoint cluster region (bcr), which encodes part of a functionally active gene. We analyzed the bcr in DNAs from 108 consecutive, unselected Philadelphia chromosome-positive CML patients by Southern blot and determined five restriction enzyme fragments within which breaks occur on chromosome 22. The exact sublocalization was determined in the DNA of 100 patients. It was found to be within the 5.8-kb in 99 patients and outside the bcr in only one. Within the bcr, most of the breakpoints occurred in fragments 1, 2, and 3. Overall, laboratory and clinical features of CML did not correlate with specific breakpoint fragments, but chronic-phase duration was longer in patients with a breakpoint in fragment 2 of the bcr. Large 3' bcr deletions were found in nine patients but did not influence clinical outcome. DNA from one of six patients analyzed both during chronic phase and blastic crisis showed an additional aberrant fragment, which suggested that a second abnormal clone developed in blastic crisis.

Blast Crisis↗
PubMed1988

Lack of breakpoint cluster region rearrangement in marrow fibroblasts of patients with Philadelphia chromosome-positive chronic myelogenous leukemia.

Involvement of marrow fibroblasts in myeloproliferative disorders such as chronic myelogenous leukemia (CML) is controversial. We examined the blood leukocytes and bone marrow fibroblasts of four patients with Philadelphia chromosome- (Ph1) positive CML for evidence of rearrangement in the breakpoint cluster region (BCR). Fibroblasts were obtained by growing bone marrow in long-term culture, disposing of nonadherent cells, and passaging three times before final trypsinization and analysis. DNA from fibroblasts and peripheral leukocytes was digested with Bg1II, Bc1I, EcoRI, and HindIII restriction endonucleases and hybridized to both 3' and 5' BCR probes. Southern blot analysis of the DNA from the peripheral leukocytes in all four patients demonstrated rearrangement in the BCR. However, analysis of DNA from marrow fibroblasts showed only the normal BCR restriction fragments in all patients. This study demonstrates the absence of the Ph1 -associated molecular events in the fibroblasts of patients with CML. It is consistent with previous studies using G6PD isoenzymes to show polyclonality in CML fibroblasts and with most cytogenetic studies that did not show the Ph1 in these cells. In summary, we present further evidence that involvement of CML fibroblasts is a secondary event in the leukemogenic process.

Bone Marrow Cells↗
PubMed1988

Bcl-1 gene rearrangements in B cell lymphoma.

We analyzed 50 B cell lymphoma samples by Southern blot analysis, using the bcl-1 and heavy chain immunoglobulin (JH) probes with two or more restriction endonucleases. All samples showed JH rearrangement, and three samples (two diffuse small lymphocytic lymphomas and one diffuse large cell lymphoma probably transformed from a diffuse small lymphocytic lymphoma) demonstrated rearranged bcl-1 sequences. The three samples showed the t(11;14)(q13;q32) chromosome translocation, and all three contained rearranged JH fragments that comigrated with the rearranged bcl-1 fragment. The breakpoint of the translocation occurred within a 1.6-kb region on chromosome 11 in the three cases. Two of the three patients had primary refractory disease. Two of the three patients had gastrointestinal involvement. Bcl-1 rearrangement may identify an unusual subset of patients with primary refractory disease with gastrointestinal involvement. It may also describe a unique subset of large cell lymphoma patients transformed from diffuse small cell histology.

B-Lymphocytes↗
PubMed1988

Alteration and abnormal expression of the c-myc oncogene in human multiple myeloma.

Structural alterations of the c-myc oncogene in human Burkitt's lymphoma and mouse plasmacytoma suggest that this oncogene is involved in several B cell neoplasms. The possibility of c-myc alterations in human myeloma has not been explored, probably because the low proliferative activity characteristic of this tumor impairs the propagation of representative cell lines for the performance of adequate cytogenetic studies. This report describes alterations in the c-myc locus with concomitant elevated expression of mRNA in the tumor cells of two of 37 patients with multiple myeloma. In one case, somatic cell hybrid studies revealed that the cloned rearranged DNA was entirely derived from chromosome 8, thus indicating a novel mechanism of c-myc activation different from that in Burkitt's lymphoma. Seven other patients exhibited five- to 12-fold overexpression of c-myc RNA when compared with normal marrow cells. Elevated mRNA expression in about one fourth of our patients suggests that the c-myc oncogene has a pathogenetic role in the evolution of multiple myeloma.

Animals↗
PubMed1987

Analysis of the epidermal growth factor receptor gene in fresh human head and neck tumors.

Seventeen fresh uncultured tumors obtained from biopsies of patients with various forms of head and neck cancer and two squamous cell carcinoma cell lines were analyzed for RNA expression and structural alterations of the epidermal growth factor reception gene. We used cDNA probes for the external and the internal domains of the gene. Enhanced mRNA expression was found only in one squamous cell carcinoma cell line, which is known to have high levels of epidermal growth factor receptor. No amplification or structural rearrangement of the epidermal growth factor receptor gene was found.

Adenocarcinoma↗
PubMed1987

Phase I study of recombinant tumor necrosis factor in cancer patients.

Tumor necrosis factor is a cytokine derived from activated macrophages. This agent is cytostatic and cytolytic against transformed human cell lines in vitro and has in vivo activity against a variety of murine tumors. We report a clinical study of the pharmacokinetics, toxicity, and biological activity of i.v. and i.m. administered recombinant human tumor necrosis factor (rTNF). Twenty patients with metastatic cancer were given rTNF in doses ranging from 1 to 200 micrograms/m2 by alternating i.m. and i.v. bolus injections with a minimal intervening period of 72 h. Each patient received a maximum of eight treatments given twice weekly over a 4-week period. With i.v. bolus administration, serum concentrations of rTNF were detected by enzyme-linked immunosorbent assay at doses of 25 micrograms/m2 or greater. The clearance of rTNF in the serum was described by a monoexponential equation with a half-life calculated to be 14-18 min. After i.m. administration, serum concentrations of rTNF were consistently detected by enzyme-linked immunosorbent assay at doses of 150 micrograms/m2 or greater. Peak concentrations were observed within 2 h and rTNF was occasionally detected, at the lower limit of sensitivity of the assay, at 24 h postinjection. rTNF was well tolerated clinically in this dose range, and there was evidence of antitumor effect.

Adult↗
PubMed1987

Molecular characteristics of chronic myelogenous leukemia in blast crisis.

We have studied the expression of c-abl and c-myc in leukemic cells of patients in all clinical phases of chronic myelogenous leukemia. We demonstrate that an aberrant 8-Kb c-abl related transcript is present in the RNA of the leukemic cell from all patients with Ph+ CML and that the loss of both normal chromosome #9 is associated with the loss of the normal c-abl related transcripts. This represents direct evidence that the normal c-abl related transcripts derive from the normal c-abl gene locus on the normal chromosome #9, while the aberrant c-abl related transcript in Ph+ CML derives from the hybrid bcr-abl gene formed as a result of the t(9;22). We further demonstrate that trisomy 8 in some instances is associated with enhanced expression of the c-myc oncogene.

Blast Crisis↗