Expression of Human Chromosome 2 Ornithine Decarboxylase Gene in Ornithine Decarboxylase-deficient Chinese Hamster Ovary Cells

Jer Tsong Hsieh, Mitchell F. Denning, Shawn M. Heidel, Ajit K. Verma

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6 Scopus citations


Ornithine decarboxylase (ODQ belongs to a multigene family and some of these may very well be nonfunctional (pseudogenes). We isolated an ODC gene from a human chromosome 2-specific library and transfected the gene into ODC-deficient Chinese hamster ovary cells to directly demonstrate that this ODC gene is functional and ODC is essential for cell proliferation. After screening 2.5 x 10s plaques using a human ODC complementary DNA probe, a typical clone with a 5.4-kilobase insert was isolated and then cloned into the Hindlll site of the pGem-1 vector. One (phODC 2B1) of these clones containing a 5.4-kilobase ODC gene insert was identified. Restriction enzyme analysis and partial sequencing data revealed that phODC 2B1 contained the full length protein-coding sequences but lacked first exon and 3′-polyadenylation sequences. Primer extension analysis indicated that human ODC mRNA has homologous sequences with the ODC gene from human chromosome 2. To determine that the chromosome 2 ODC gene is functional, ODC-deficient Chinese hamster ovary cells were transfected with the ODC expression vector (phSV2Bl-neo) and several G418-resistant transfectants were isolated which expressed 70- to 400-fold more ODC activity than parental or wild-type Chinese hamster ovary cells. Furthermore, these stable transfectants exhibited a higher growth rate than wild-type cells. These results indicate that the ODC gene from human chromosome 2 encodes functional ODC protein, and ODC (and its product putrescine) is required for cell growth.

Original languageEnglish (US)
Pages (from-to)2239-2244
Number of pages6
JournalCancer research
Issue number8
StatePublished - Apr 15 1990


ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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