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Biomedical subjects

B Jandrig

Publications and source records attributed to B Jandrig.

At least 19 recordsLinked to original sources
PubMed2004

Detection of cell-free nucleic acids in bronchial lavage fluid supernatants from patients with lung cancer.

The aim of this study was to determine whether nucleic acids are detectable in cell-free bronchial lavage supernatants, and whether it is possible to find alterations in this DNA and RNA of genes known to be present in lung tumour cells. DNA was isolated from cell-free lavage supernatants from 30 and RNA from 25 lung cancer patients. The DNA was examined for microsatellite alterations (MA) and the RNA analysed for the expression of seven tumour-associated genes. Intact DNA and mRNA could be isolated from all cell-free bronchial lavage supernatants. MA were found in lavage supernatants of 12/30 patients and in lavage cells of 6/30 patients. Altogether alterations were found in 14/30 patients. Analyses of tumour-associated gene expression showed positive results, with at least one marker in the lavage supernatants of all 25 patients. Thus, we could demonstrate, for the first time, that it is possible to isolate intact DNA and RNA from cell-free bronchial lavage supernatants. Their quantity and quality is sufficient for further amplification by polymerase chain reaction (PCR)/reverse transcriptase (RT)-PCR. Altogether, tumour-associated changes were detected in DNA samples from 47% of the patients and in RNA samples from all of the patients analysed.

Aged↗
PubMed2004

Detection of tumor-specific mRNA in cell-free bronchial lavage supernatant in patients with lung cancer.

Bronchoscopy is a standard procedure in the workup of patients with suspicious pulmonary lesions. We wondered whether it is possible to isolate malignancy-associated mRNA from cell-free lavage supernatant. Extracellular mRNA from cell-free lavage supernatant of 25 patients with lung cancer (23 with non-small cell lung cancer, 2 with small cell lung cancer) was isolated, reverse-transcribed, and amplified by reverse transcriptase polymerase chain reaction. The quantity and quality of the isolated RNA were checked after cDNA synthesis by amplification with beta-actin-specific primers. Afterwards, a panel of eight genes known to be expressed in lung tumors was used for the detection of tumor-associated mRNA expression in lavage supernatant and serum. mRNA coding for beta-actin could be isolated from lavage supernatant of all 25 patients. In addition, the expression of at least one tumor-associated gene was detectable in all patients. These results show that intact mRNA can be isolated from cell-free lavage supernatant and that its quantity and quality are sufficient for the detection of tumor-associated gene expression alterations. This may open new possibilities for the diagnosis of lung cancer.

Actins↗
PubMed2002

Polyomavirus infection in hamsters and trichoepitheliomas/cutaneous adnexal tumours.

Multiple skin nodules, with histological features of adnexal tumours consistent with trichoepithelioma, were observed on the head and trunk of Syrian hamsters. Skin biopsies from 20 hamsters from five different colonies were affected, and two of the affected hamsters also had lymphoma. Two owners reported that 16 of 70 hamsters and 50 of 100 hamsters in their colonies had similar skin lesions. These tumours have previously been associated in laboratory colonies with hamster polyomavirus (HaPV) infection. Examination of skin tissues by electron microscopy failed to reveal intranuclear virus particles. Using recombinant major capsid protein VP1 of HaPV, VP1-specific antibodies were detected in sera from 12 of 12 affected hamsters and in four of four unaffected in-contact hamsters, by ELISA. The ELISA data were verified by immunoblot analysis. Eleven of 13 serum samples contained antibodies which reacted with at least one recombinant structural HaPV protein (VP2), including samples from three in-contact unaffected hamsters. Nine of the 11 anti-VP2-positive samples also reacted with recombinant VP3 of HaPV, and six reacted with VP1. Amplification by PCR and sequencing detected VP1 -encoding sequences showing a high degree of homology with HaPV. The findings suggest a possible infection by HaPV or a HaPV-like virus and it is likely that such an infection was enzootic within the affected colonies.

Animals↗
PubMed2001

Identification of a recurrent BRCA1 mutation in German breast-cancer and/or ovarian-cancer families.

Specific BRCA1 mutations have been reported to be common within particular populations. We have investigated German breast- and/or ovarian-cancer families and detected a recurrent carboxy-terminal BRCA1 mutation, 5622C > T, using PCR-based restriction assay and haplotype analysis. Unrelated families carrying this BRCA1 mutation shared two different disease-associated haplotypes, indicating two independent mutation events.

Breast Neoplasms↗
PubMed2001

Detection of amplifiable messenger RNA in the serum of patients with lung cancer.

Recently, in addition to the detection of circulating tumor cells in peripheral blood of patients with solid tumors, the presence of free circulating nucleic acids in the plasma and serum has also been described. We have focused on the possibility of isolating and amplifying intact extracellular, tumor-related mRNA from the plasma/serum of patients with lung cancer. For this purpose, we established several RT-PCR-based amplification systems for the detection of a panel of five different genes. The expression of these genes was either shown to be restricted to lung tissue or associated with malignancy. We examined two small groups of 18 patients with lung cancer before and during chemotherapy, respectively. The message for beta-actin (control for integrity of the RNA) was detected in all of the analyzed sera from the control group and patients with lung cancer. Analysis of CK-19 expression was positive in the majority of tumor patients, but positive results were also shown in all of the control sera. The expression of MAGE-2 and TTF-1 genes was not observed in any of the patients in either the lymphocyte preparations or serum samples. Expression of the PGP 9.5 gene was observed in the cells of all 18 patients, but mRNA in the serum was only detectable in one case. The hnRNP-B1 mRNA was detectable in 14/18 sera, and Her2/neu-specific mRNA could be amplified from the serum of 7/18 patients. Combining the last two markers, we were able to detect all patients with a malignant lung tumor.

Actins↗
PubMed2000

Formation of immunogenic virus-like particles by inserting epitopes into surface-exposed regions of hamster polyomavirus major capsid protein.

We generated highly immunogenic virus-like particles that are based on the capsid protein VP1 of the hamster polyomavirus (HaPV-VP1) and harbor inserted foreign epitopes. The HaPV-VP1 regions spanning amino acids 81-88 (position 1), 222/223 (2), 244-246 (3), and 289-294 (4) were predicted to be surface exposed. An epitope of the pre-S1 region of the hepatitis B virus (designated S1; amino acid sequence DPAFR) was introduced into the predicted positions of VP1. All VP1/S1 fusion proteins were expressed in yeast and generated virus-like particles. Immunoassays using the S1-specific monoclonal antibody MA18/7 and immunization of C57Bl6 mice with different VP1/S1 constructs showed a pronounced reactivity and a strong S1-specific antibody response for particles carrying the insert in position 1, 2, 1+2, and 1+3. Our results suggest that HaPV-VP1 represents a highly flexible carrier moiety for the insertion of foreign sequences offering a broad range of potential uses, especially in vaccine development.

Amino Acid Sequence↗
PubMed2000

Suppression of tumorigenicity in breast cancer cells by the microfilament protein profilin 1.

Differential display screening was used to reveal differential gene expression between the tumorigenic breast cancer cell line CAL51 and nontumorigenic microcell hybrids obtained after transfer of human chromosome 17 into CAL51. The human profilin 1 (PFN1) gene was found overexpressed in the microcell hybrid clones compared with the parental line, which displayed a low profilin 1 level. A comparison between several different tumorigenic breast cancer cell lines with nontumorigenic lines showed consistently lower profilin 1 levels in the tumor cells. Transfection of PFN1 cDNA into CAL51 cells raised the profilin 1 level, had a prominent effect on cell growth, cytoskeletal organization and spreading, and suppressed tumorigenicity of the stable, PFN1-overexpressing cell clones in nude mice. Immunohistochemical analysis revealed intermediate and low levels of profilin 1 in different human breast cancers. These results suggest profilin 1 as a suppressor of the tumorigenic phenotype of breast cancer cells.

Animals↗
PubMed2000

Detection of microsatellite alterations in the DNA isolated from tumor cells and from plasma DNA of patients with lung cancer.

In this paper, we show that the same panel of three microsatellite markers is useful for the detection of alterations in the DNA of tumor cells and plasma from patients diagnosed with SCLC and NSCLC. In 31% of the SCLC patients, we detected a microsatellite alteration(s) or LOH in at least one locus. In the group of patients diagnosed with NSCLC, a microsatellite alteration or LOH was detected in at least one locus in 33% of the patients. In all but 2 patients, the identical alteration observed in the DNA from tumor cells was also detected in the DNA isolated from blood plasma. This work confirms the results described by other groups and it extends the diagnostic possibilities of finding tumor cell-specific DNA alterations also in the DNA freely circulating in plasma and serum of patients with cancer.

Adult↗
PubMed1999

Capsid protein-encoding genes of hamster polyomavirus and properties of the viral capsid.

On the basis of its genome organization the hamster polyomavirus (HaPV) is closely related to the murine polyomavirus Py. But HaPV infection, in contrast to Py infection, gives rise to two different tumor types; depending on the hamster strain used for infection, HaPV induces either epitheliomas or lymphomas. Although the HaPV virions were shown to be similar to those of Py and SV40, more precise information about the structure and protein composition of the HaPV capsid was still missing. Here we describe the primary structure of the capsid protein-encoding HaPV genes and the structure and protein composition of the HaPV capsid. Virions isolated from epitheliomas in HaPV-infected hamsters were shown by electron microscopy to be spherical particles with the typical icosahedral structure of polyomaviruses. However, in contrast to the capsids of SV40 and Py, a T = 7 laevo symmetry of HaPV capsids was observed. Separation of HaPV virions in SDS polyacrylamide gels and Western blotting with VP1-specific antisera identified VP1 as the major capsid protein species corresponding in its molecular weight to the predicted value of 41.8 kDa. Because of the presence of two potential translational initiation sites in the VP1 gene, the N-terminal amino acid sequence of virion VP1 was determined and found to start at the second initiation site. The amino acid homologies of HaPV capsid proteins shared with Py varied between 65.5% (VP1), 45.4% (VP3) and 44.6% (VP2), whereas the homologies to the relevant proteins of other polyomaviruses were found to range between 49.6-57.9% for VP1 and 28.9-41% for VP2/VP3.

Amino Acid Sequence↗
PubMed1999

Yeast cells allow high-level expression and formation of polyomavirus-like particles.

Polyomavirus-derived virus-like particles (VLPs) have been described as potential carriers for encapsidation of nucleic acids in gene therapy. Although VLPs can be generated in E. coli or insect cells, the yeast expression system should be advantageous as it is well established for the biotechnological generation of products for human use, especially because they are free of toxins hazardous for humans. We selected the yeast Saccharomyces cerevisiae for expression of the major capsid protein VP1 of a non-human polyomavirus, the hamster polyomavirus (HaPV). Two entire HaPV VP1-coding sequences, starting with the authentic and a second upstream ATG, respectively, were subcloned and expressed to high levels in Saccharomyces cerevisiae. The expressed VP1 assembled spontaneously into VLPs with a structure resembling that of the native HaPV capsid. Determination of the subcellular localization revealed a nuclear localization of some particles formed by the N-terminally extended VP1, whereas particles formed by the authentic VP1 were found mainly in the cytoplasmic compartment.

Animals↗
PubMed1999

Estradiol receptor and prognostic parameters of human breast cancer.

Estradiol receptors are regarded to predict a likely success of hormonal therapeutic efforts and the prognosis of breast cancer patients. But today its prognostic importance is controversial, discussed as either reflecting intrinsic property of the tumor tissue or better therapeutic accessibility of receptor positive tumors. Moreover, the most important clinical prognosticators--tumor size and axillary lymph node involvement do not seem to be related to the estradiol receptor status. In our investigation, the length of disease free interval is similar in estradiol receptor positive and negative patients and in all sites of distant metastases, but it is significantly reduced if more than 4 axillary lymph nodes are involved. Post recurrence survival is significantly longer in estradiol receptor positive than negative patients and also in patients treated by tamoxifen containing therapies. Its length is independent of the number of axillary lymph node metastases and the type of distant metastases, with a tendency to be longer in estradiol receptor positive than negative patients. In addition, the overall survival is longer for estradiol receptor positive than negative patients and becomes reduced with more than 4 axillary lymph node metastases. Frequency of deaths in estradiol receptor positive patients is half that of negative subjects. Furthermore, the length of overall survival is independent on the type of distant metastases, with tendency to be longer in estradiol receptor positive than negative patients. Longest overall survival could be observed for estradiol receptor positive patients who got therapy regimens containing tamoxifen. The weak prognostic advantages of estradiol receptor positive patients are interpreted by estradiol receptors as intrinsic parameters of breast cancer tissue characterizing more its biological behavior than therapeutic accessibility.

Adult↗
PubMed1998

Mammalian protein homologous to VAT-1 of Torpedo californica: isolation from Ehrlich ascites tumor cells, biochemical characterization, and organization of its gene.

Recently, interest has focused on the human gene encoding the putative protein homologous to VAT-1, the major protein of the synaptic vesicles of the electric organ of the Pacific electric ray Torpedo californica, after it has been localized on chromosome locus 17q21 in a region encompassing the breast cancer gene BRCA1. Chromosomal instability in this region is implicated in inherited predisposition for breast and ovarian cancer. Here we describe isolation and biochemical characterization of a mammalian 48 kDa protein homologous to the VAT-1 protein of Torpedo californica. This VAT-1 homolog was isolated from a murine breast cancer cell line (Ehrlich ascites tumor) and identified by sequencing of cleavage peptides. The isolated VAT-1 homolog protein displays an ATPase activity and exists in two isoforms with isoelectric points of 5.7 and 5.8. cDNA was prepared from Ehrlich ascites tumor cells, and the murine VAT-1 homolog sequence was amplified by polymerase chain reaction and partially sequenced. The known part of the murine and the human translated sequences share 97% identity. By Northern blots, the size of the VAT-1 homolog mRNA in both murine and human (T47D) breast cancer cells was determined to be 2.8 kb. Based on the presented data, a modified gene structure of the human VAT-1 homolog with an extended exon 1 is proposed. VAT-1 and the mammalian VAT-1 homolog form a subgroup within the protein superfamily of medium-chain dehydrogenases/reductases.

Adenosine Triphosphatases↗
PubMed1998

[PTEN/MMAC1 is apparently not a relevant tumor suppressor gene in development of hereditary breast carcinoma].

In order to clarify the role of the recently discovered tumour suppressor gene PTEN/MMAC1 in hereditary breast cancer, we screened the DNA from members of 10 families with demonstrated hereditary breast cancer for mutations through direct sequencing. Since we could not find any relevant alterations, although further investigations are necessary, PTEN/MMAC1 seems not to play a relevant role in the genesis of hereditary breast cancer.

Breast Neoplasms↗
PubMed1997

Generation of lymphoma-type variant hamster polyomavirus genomes in hamsters susceptible to lymphoma induction.

The hamster polyomavirus (HaPV) induces either hair follicle epitheliomas or lymphomas in either Z3 or HaP respectively. Syrian hamsters. In the lymphomas specifically deleted "lymphoma-type" (lt) HaPV genomes are accumulated. In the present study the temporal pattern of generation of HaPV (lt) DNA was investigated in context of the development of lymphomas in neonatally infected HaP hamsters. The generation of HaPV (lt) DNA was first detectable during the postnatal phase of high level replication of viral DNA in hemopoietic organs (at 7 days post infection), thus clearly preceding the development of overt lymphoma. A variety of HaPV (lt) DNA species is generated in lymphoid cells, but usually only one of them is accumulated to high amounts in lymphoma cells. Furthermore, the pattern of HaPV (lt) and wild-type (wt) DNA was studied in normal and tumor tissues of tumor-bearing hamsters as well as in tumor-free hamsters. In tumor-bearing hamsters predominantly HaPV (lt) DNA species were found in the infected tissues, while HaPV (wt) DNA was detected rarely and only in tumor-free tissues. In contrast, in tissues of tumor-free hamsters HaPV (wt) DNA prevailed over HaPV (lt) DNA species.

Animals↗
PubMed1997

Deletion mapping and linkage analysis provide strong indication for the involvement of the human chromosome region 8p12-p22 in breast carcinogenesis.

We have identified a high frequency of loss of heterozygosity (LOH) on the human chromosome region 8p12-p22 in a panel of microdissected familial (86% LOH) and sporadic (74% LOH) breast tumours. The two most frequently deleted regions were defined around marker D8S133 and in a broader centromeric region bounded by markers D8S137 and D8S339. We cannot unequivocally characterize the 8p12-p22 loss as an early or a late event in breast carcinogenesis. In parallel, we have performed linkage analysis in four German breast cancer families. A location score greater than 13.67 corresponding to a LOD score of 2.97 at the marker D8S137 has been obtained. Our results considerably strengthen the evidence for a breast cancer susceptibility gene(s) located on the short arm of the chromosome region at 8p12-p22.

Adult↗
PubMed1997

Steroid hormone receptors and antineoplastic chemotherapy in human breast cancer.

Several clinical and experimental investigations suggest that the action of antineoplastic chemotherapy in premenopausal women influences the menopause. Such hormonal reactions are mediated via specific steroid hormone receptors. Therefore, connections between hormone receptors and antineoplastic chemotherapy can be assumed making possible to predict success of chemotherapy on the basis of receptor status. Nevertheless, clinical experiences and animal and cell culture experiments yielded controversial results. This was related to the predictive value of receptor status as well as to the benefits of combined hormone and chemotherapy treatments in concurrent or sequential form. It is undeniable that a displacing of steroidal ligand from its receptors by the usual antineoplastic drugs does not occur. Furthermore, the receptor levels remain unchanged after a treatment with antineoplastic drugs. Thus, the mechanism of action of chemotherapeutic drugs is not related directly to the presence or absence of steroid hormone receptors. Despite this fact the receptor status in chemotherapeutic regimes seems to be helpful to define low or high risk patients. Influences on the ER de-novo-synthesis, actions related to parameters representing reduced tumor growth rates, down-regulation of the receptor gene expression or via receptor mediated hormonal actions to other genes, like the apoptosis-related gene bcl-2, are thought to be possible mechanisms of action of antineoplastic drugs on steroid hormone receptors. Future investigations should monitor the ratios between exon lacking receptor variants and the wild-type receptor during chemotherapy or the control of a ligand uptake during chemotherapy by means of the positron emission tomography.

Antineoplastic Agents, Hormonal↗
PubMed1996

BRCA1 mutations in German breast-cancer families.

We analyzed germline mutations of the BRCA1 gene in 20 German breast/ovarian-cancer families. BRCA1 mutations co-segregating with breast-cancer susceptibility were identified in 3 of these families. All mutations were found to generate a premature stop codon leading to the synthesis of truncated BRCA1 proteins of different length. Nine polymorphisms were detected in BRCA1, 4 of which have not been described previously. Analysis of familial tumors for LOH revealed that only the disease-related allele of BRCA1 was present.

Adult↗