Cell Line 1

ABSTRACT The human methylthioadenosine phosphorylase (MTAP) gene is lo-cated on 9p21 and is frequently homozygously deleted, along withp16 cdkN2a/ARF , in a wide variety of human tumors and human tumor-derived cell lines. The function of MTAP is to salvage methylthioad-enosine, which is produced as a byproduct of polyamine metabolism. Wehave reintroduced MTAP into MCF-7 breast adenocarcinoma cells andhave examined its effect on the tumorigenic properties of these cells.MTAP expression does not affect the growth rate of cells in standardtissue culture conditions but severely inhibits their ability to form coloniesin soft agar or collagen. In addition, MTAP-expressing cells are sup-pressed for tumor formation when implanted into SCID mice. This sup-pression of anchorage-independent growth appears to be because of theenzymatic activity of MTAP, as a protein with a missense mutation in theactive site does not exhibit this phenotype. MTAP expression causes asignificant decrease in intracellular polyamine levels and alters the ratio ofputrescine to total polyamines. Consistent with this observation, the poly-amine biosynthesis inhibitor -difluoromethylornithine inhibits the abilityof MTAP-deficient cells to form colonies in soft agar, whereas addition ofthe polyamine putrescine stimulates colony formation in MTAP-express-ing cells. These results indicate that MTAP has tumor suppressor activityand suggest that its effects may be mediated by altering intracellularpolyamine pools.

[1]  C. Cordon-Cardo,et al.  Methylthioadenosine phosphorylase gene deletions are common in osteosarcoma. , 2002, Clinical cancer research : an official journal of the American Association for Cancer Research.

[2]  D. Kramer,et al.  Effects of Conditional Overexpression of Spermidine/Spermine N 1-Acetyltransferase on Polyamine Pool Dynamics, Cell Growth, and Sensitivity to Polyamine Analogs* , 2000, The Journal of Biological Chemistry.

[3]  M. Prados,et al.  Phase III randomized study of postradiotherapy chemotherapy with alpha-difluoromethylornithine-procarbazine, N-(2-chloroethyl)-N'-cyclohexyl-N-nitrosurea, vincristine (DFMO-PCV) versus PCV for glioblastoma multiforme. , 2000, Clinical cancer research : an official journal of the American Association for Cancer Research.

[4]  B. Tang,et al.  Defects in methylthioadenosine phosphorylase are associated with but not responsible for methionine-dependent tumor cell growth. , 2000, Cancer research.

[5]  A. Yu,et al.  Detection of methylthioadenosine phosphorylase (MTAP) and p16 gene deletion in T cell acute lymphoblastic leukemia by real-time quantitative PCR assay , 2000, Leukemia.

[6]  J. O’Shaughnessy,et al.  α-Difluoromethylornithine as Treatment for Metastatic Breast Cancer Patients , 1999 .

[7]  M. Erion,et al.  The structure of human 5'-deoxy-5'-methylthioadenosine phosphorylase at 1.7 A resolution provides insights into substrate binding and catalysis. , 1999, Structure.

[8]  D. Brat,et al.  Molecular genetic alterations in radiation-induced astrocytomas. , 1999, The American journal of pathology.

[9]  S. Kern,et al.  G1 cell cycle arrest and apoptosis induction by nuclear Smad4/Dpc4: phenotypes reversed by a tumorigenic mutation. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[10]  D. Carson,et al.  Homozygous deletions of methylthioadenosine phosphorylase (MTAP) are more frequent than p16INK4A (CDKN2) homozygous deletions in primary non-small cell lung cancers (NSCLC) , 1998, Oncogene.

[11]  Ken Chen,et al.  The Ink4a Tumor Suppressor Gene Product, p19Arf, Interacts with MDM2 and Neutralizes MDM2's Inhibition of p53 , 1998, Cell.

[12]  W. Cavenee,et al.  Growth suppression of glioma cells by PTEN requires a functional phosphatase catalytic domain. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[13]  M. Schwartz.  Integrins, Oncogenes, and Anchorage Independence , 1997, The Journal of cell biology.

[14]  T G O'Brien,et al.  Ornithine decarboxylase overexpression is a sufficient condition for tumor promotion in mouse skin. , 1997, Cancer research.

[15]  H. Kiyosawa,et al.  Ornithine decarboxylase overexpression in mouse 10T1/2 fibroblasts: cellular transformation and invasion. , 1997, Journal of the National Cancer Institute.

[16]  M. Diccianni,et al.  Frequent deletion in the methylthioadenosine phosphorylase gene in T-cell acute lymphoblastic leukemia: strategies for enzyme-targeted therapy. , 1996, Blood.

[17]  P. Tran,et al.  Genomic cloning of methylthioadenosine phosphorylase: a purine metabolic enzyme deficient in multiple different cancers. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[18]  F. Zindy,et al.  Alternative reading frames of the INK4a tumor suppressor gene encode two unrelated proteins capable of inducing cell cycle arrest , 1995, Cell.

[19]  Kathleen R. Cho,et al.  Frequency of homozygous deletion at p16/CDKN2 in primary human tumours , 1995, Nature Genetics.

[20]  M. Blessing,et al.  Increased frequency of spontaneous skin tumors in transgenic mice which overexpress ornithine decarboxylase. , 1995, Cancer research.

[21]  O. Olopade,et al.  Construction of a 2.8-megabase yeast artificial chromosome contig and cloning of the human methylthioadenosine phosphorylase gene from the tumor suppressor region on 9p21. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[22]  H. Varmus,et al.  Mutations associated with familial melanoma impair p16INK4 function , 1995, Nature Genetics.

[23]  W. Cavenee,et al.  Replacement of the p16/CDKN2 gene suppresses human glioma cell growth. , 1995, Cancer research.

[24]  A. Iolascon,et al.  5'-Deoxy-5'-methylthioadenosine phosphorylase and p16INK4 deficiency in multiple tumor cell lines. , 1995, Oncogene.

[25]  W. Clark,et al.  Germline p16 mutations in familial melanoma , 1994, Nature Genetics.

[26]  O. Olopade,et al.  Homozygous deletions within chromosomal bands 9p21-22 in bladder cancer. , 1994, Cancer research.

[27]  M. Skolnick,et al.  A cell cycle regulator potentially involved in genesis of many tumor types. , 1994, Science.

[28]  O. Olopade,et al.  Distinct deletions of chromosome 9p associated with melanoma versus glioma, lung cancer, and leukemia. , 1994, Cancer research.

[29]  J A Moshier,et al.  Transformation of NIH/3T3 cells by ornithine decarboxylase overexpression. , 1993, Cancer research.

[30]  O. Garson,et al.  Molecular deletion of 9p sequences in non‐small cell lung cancer and malignant mesothelioma , 1993, Genes, chromosomes & cancer.

[31]  O. Olopade,et al.  Methylthioadenosine phosphorylase deficiency in human non-small cell lung cancers. , 1993, Cancer research.

[32]  L. Andersson,et al.  Ornithine decarboxylase activity is critical for cell transformation , 1992, Nature.

[33]  T. Waltz,et al.  Absence of methylthioadenosine phosphorylase in human gliomas. , 1991, Cancer research.

[34]  R. Myers,et al.  Conversion of 5-S-methyl-5-thio-D-ribose to methionine in Klebsiella pneumoniae. Stable isotope incorporation studies of the terminal enzymatic reactions in the pathway. , 1990, The Journal of biological chemistry.

[35]  E. Furfine,et al.  Intermediates in the conversion of 5'-S-methylthioadenosine to methionine in Klebsiella pneumoniae. , 1988, The Journal of biological chemistry.

[36]  J. Rowley,et al.  Homozygous deletion of the alpha- and beta 1-interferon genes in human leukemia and derived cell lines. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[37]  A. J. Ferro,et al.  The metabolism of 5'-methylthioadenosine and 5-methylthioribose 1-phosphate in Saccharomyces cerevisiae. , 1985, Journal of general microbiology.

[38]  R. Eddy,et al.  Assignment of the gene for methylthioadenosine phosphorylase to human chromosome 9 by mouse-human somatic cell hybridization. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[39]  P. Trackman,et al.  Methionine synthesis from 5'-S-Methylthioadenosine. Resolution of enzyme activities and identification of 1-phospho-5-S methylthioribulose. , 1983, The Journal of biological chemistry.

[40]  N. Kamatani,et al.  Deficiency of methylthioadenosine phosphorylase in human leukemic cells in vivo. , 1982, Blood.

[41]  R. Smith,et al.  5'-Methylthioadenosine metabolism and methionine synthesis in mammalian cells grown in culture. , 1982, Biochemical and biophysical research communications.

[42]  A. J. Ferro,et al.  Utilization by Saccharomyces cerevisiae of 5'-methylthioadenosine as a source of both purine and methionine , 1982, Journal of bacteriology.

[43]  R. Smith,et al.  Identification of 2-keto-4-methylthiobutyrate as an intermediate compound in methionine synthesis from 5'-methylthioadenosine. , 1982, The Journal of biological chemistry.

[44]  P. Trackman,et al.  The metabolism of 1-phospho-5-methylthioribose. , 1981, Biochemical and biophysical research communications.

[45]  N. Kamatani,et al.  Dependence of adenine production upon polyamine synthesis in cultured human lymphoblasts. , 1981, Biochimica et biophysica acta.

[46]  R. Smith,et al.  Methionine synthesis from 5'-methylthioadenosine in rat liver. , 1981, The Journal of biological chemistry.

[47]  T. Savarese,et al.  5'-Methylthioadenosine phosphorylase-L. Substrate activity of 5'-deoxyadenosine with the enzyme from Sarcoma 180 cells. , 1981, Biochemical pharmacology.

[48]  N. Kamatani,et al.  Selective killing of human malignant cell lines deficient in methylthioadenosine phosphorylase, a purine metabolic enzyme. , 1981, Proceedings of the National Academy of Sciences of the United States of America.

[49]  N. Kamatani,et al.  Abnormal regulation of methylthioadenosine and polyamine metabolism in methylthioadenosine phosphorylase-deficient human leukemic cell lines. , 1980, Cancer research.

[50]  J. Toohey.  Methylthioadenosine nucleoside phosphorylase deficiency in methylthio-dependent cancer cells. , 1978, Biochemical and biophysical research communications.

[51]  J. Russo,et al.  Neoplastic transformation of human breast epithelial cells by estrogens and chemical carcinogens , 2002, Environmental and molecular mutagenesis.

[52]  M. F. Naujokas,et al.  Altered cell cycle phase distributions in cultured human carcinoma cells partially depleted of polyamines by treatment with difluoromethylornithine. , 1986, Cancer research.