Pekka Leinonen
University of Helsinki
10 Papers
117 Citations
Pekka Leinonen is an academic researcher from University of Helsinki. The author has contributed to research in topics: Ornithine decarboxylase & Heparin. The author has an hindex of 8, co-authored 10 publications.
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Papers
Human myeloma cells acquire resistance to difluoromethylornithine by amplification of ornithine decarboxylase gene.
TL;DR: A selection of cultured human IgG-myeloma cells (Sultan cell line) capable of growing in the presence of up to 3 mM-DFMO resulted in one of the few gene amplifications described in cultured human cells.
Hypomethylation of ornithine decarboxylase gene and erb-A1 oncogene in human chronic lymphatic leukemia.
TL;DR: The methylation state of CCGG sites in and around the human ornithine decarboxylase gene, oncogenes c-myc and erb-A1, and actin genes were determined in human malignant leucocytes from patients with acute and chronic myeloid leukemia, chronic lymphatic leukemia, polycythemia vera, and multiple myeloma by means of isoschizomeric restriction endonuclease analysis.
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Mouse and human ornithine decarboxylase genes. Methylation polymorphism and amplification.
Leena Alhonen-Hongisto,Pekka Leinonen,Riitta Sinervirta,Raija Laine,R. Winqvist,Kari Alitalo,Olli A. Jänne,Juhani Jänne +7 more
TL;DR: The use of two restriction endonucleases, the cleavage site for both of which contains a CG sequence and which only cleave when cytosine is unmethylated indicated that ODC genes in the lymphocytic leukaemia cells were much less methylated than those in the normal leucocytes or in the Sultan cells.
Human myeloma cells acquire resistance to difluoromethylornithine without overproducing ornithine decarboxylase.
TL;DR: An exposure of a human myeloma cell line to 2-difluoromethylornithine the mechanism-based inhibitor of ornithine decarboxylase resulted in a selection of tumor cells readily growing in the presence of 4 mM difluorspiral, a concentration that swiftly halted the growth of the parental cells.
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Chronic exposure to dexamethasone induces hypomethylation of ornithine decarboxylase genes in a human myeloma cell line.
TL;DR: In cells adapted to grow in the presence of micromolar concentrations of dexamethasone, ODC activity was fully comparable to that in the parental cells, and hypomethylation within and/or around ODC genes was associated with a 2–4‐fold enhancement of accumulation of ODC mRNA.
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