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I Wieland

Publications and source records attributed to I Wieland.

23 records · Page 2Linked to original sources
PubMed1992

Isolation of DNA sequences deleted in lung cancer by genomic difference cloning.

To identify DNA sequences that are deleted in human lung cancer, genomic subtraction hybridization was used to construct plasmid libraries that are enriched for DNA sequences deleted in the small cell lung carcinoma cell line SK-LC-17. The clones of the libraries contained predominantly single copy sequences, allowing direct screening of normal and tumor DNA by genomic Southern blotting. Of 150 clones tested, three independent clones (del-27, del-118, and del-109) were identified that specifically hybridized with normal human DNA but not with tumor DNA from the cell line SK-LC-17. The corresponding DNA sequences are localized on human chromosomes 5, 8, and X/Y. The DNA regions identified by del-109 and del-118 were also found to be deleted in several other lung carcinoma cell lines. Moreover, del-118 was deleted in a freshly isolated lymph node metastasis of a human lung adenocarcinoma. It is therefore reasonable to speculate that the identified clones are derived from independent genetic loci encoding potential tumor suppressor genes.

Base Sequence↗
PubMed1990

A method for difference cloning: gene amplification following subtractive hybridization.

We describe a procedure for genomic difference cloning, a method for isolating sequences present in one genomic DNA population ("tester") that is absent in another ("driver"). By subtractive hybridization, a large excess of driver is used to remove sequences common to a biotinylated tester, enriching the "target" sequences that are unique to the tester. After repeated subtractive hybridization cycles, tester is separated from driver by avidin/biotin affinity chromatography, and single-stranded target is amplified by the polymerase chain reaction, rendering it double-stranded and clonable. We model two situations: the gain of sequences that result from infection with a pathogen and the loss of sequences that result from a large hemizygous deletion. We obtain 100- to 700-fold enrichment of target sequences.

Bacteriophage lambda↗
PubMed1986

Reversion of the transformed phenotype of B16 mouse melanoma: involvement of an 83 kd cell surface glycoprotein in specific growth inhibition.

Treating B16 mouse melanoma cells with monoclonal antibody NORM-2 reduces cell growth in tissue culture, agar, and syngeneic mice. We show that the NORM-2 antibody recognizes an integral 83 kd glycoprotein that is mobile in the plane of the plasma membrane of B16 melanoma cells. Expression of the glycoprotein is reduced under conditions that inhibit B16 growth, such as low serum, high cell density, and addition of transforming growth factor-beta. The glycoprotein reappears during S phase, when growth-arrested cells are restimulated. The NORM-2 antigen appears to be involved in growth regulation of B16 melanoma cells both in vitro and in vivo.

Animals↗
PubMed1985

Monoclonal antibodies NORM-1 and NORM-2 induce more normal behavior of tumor cells in vitro and reduce tumor growth in vivo.

In this study, large numbers of hybridomas (produced by syngeneic immunization with B16 mouse melanoma and fusion with NS-1 myeloma cells) were screened for the production of antibodies that affected morphology and growth of animal and human tumor cells in vitro. Two such antibodies, NORM-1 and NORM-2 (both IgG2a), inhibited the growth of B16 melanoma cells in soft agar and increased the serum requirements of tumor cells in tissue culture. Antibody NORM-2 also inhibited the growth of SV40-transformed 3T3 cells in agar and caused them to deposit more fibronectin into extracellular matrix. These antibodies thus seem to induce a more normal behavior of tumor cells in vitro. In vivo both antibodies reduced the number of growing lung tumors of B16 melanoma in C57BL/6 mice by 70%-90% when injected 3 days after the tumor cells. By immunoprecipitation of 35S-methionine-labeled cell extracts, NORM-2 antibody recognized a 59 kd protein in B16 mouse and in A375 human melanoma cells but not in 3T3 fibroblasts.

Animals↗