Positive Selection of Candidate Tumor-Suppressor Genes by Subtractive Hybridization

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 88; no. 7; pp. 2825 - 2829
• Main Authors: Lee, Sam W., Tomasetto, Catherine, Sager, Ruth
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 01-04-1991; National Acad Sciences
• Subjects: 550201 - Biochemistry- Tracer Techniques; ANIMAL TISSUES; ANIMALS; BASIC BIOLOGICAL SCIENCES; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BODY; Breast; Breast Neoplasms - diagnosis; Breast Neoplasms - genetics; calcium-binding protein; Cell growth; Cell Line; Cell lines; Complementary DNA; connexin 26; DAYS LIVING RADIOISOTOPES; DISEASES; DNA; DNA HYBRIDIZATION; DRUGS; ELECTROPHORESIS; ENZYMES; Epithelial cells; EPITHELIUM; Female; FEMALES; Gene Expression Regulation, Neoplastic; Gene Library; Gene Rearrangement; GENE REGULATION; GENE REPRESSORS; GENES; Genes, Tumor Suppressor; GLANDS; GLUTATHIONE; glutathione transferase; Humans; HYBRIDIZATION; ISOTOPES; Kidney Neoplasms - genetics; LIGHT NUCLEI; MAMMALS; MAMMARY GLANDS; MAN; MESSENGER-RNA; MHC class II genes; NEOPLASMS; NUCLEI; Nucleic Acid Hybridization; NUCLEIC ACIDS; NUCLEOPROTEINS; ODD-ODD NUCLEI; ORGANIC COMPOUNDS; ORGANS; PEPTIDES; PHOSPHORUS 32; PHOSPHORUS ISOTOPES; POLYPEPTIDES; PRIMATES; Prognosis; PROTEINS; RADIOISOTOPES; RADIOPROTECTIVE SUBSTANCES; RECOMBINANT DNA; RNA; RNA, Messenger - genetics; TISSUES; TRANSFERASES; Tumor cell line; Tumors; VERTEBRATES; Wilms Tumor - genetics; WOMEN
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.88.7.2825

A positive selection system designed to identify and recover candidate tumor-suppressor genes is described. The system compares mRNA expression of genes from normal and tumor-derived human mammary epithelial cells grown in a special medium that supports similar growth rates of the two cell types. mRNAs uniquely expressed in normal cells are recovered as cDNAs after subtraction with mRNA from tumor cells. Seven different clones, from 0.6 to 4.8 kilobases in transcript size and including both rare and abundunt transcripts, were recovered in the first 23 clones analyzed. Among the isolated clones were genes encoding the gap-junction protein connexin 26, two different keratins, and glutathione-S-transferase π, as well as an unknown gene in the S100 family of small calcium-binding proteins. In principle, tumor-suppressor genes include two classes: class I, in which loss of function results from mutation or deletion of DNA and class II, in which loss of function is from a regulatory block to expression. A class II suppressor gene is assumed to be regulated by a different suppressor gene that lost its function by mutation or deletion. Both classes of tumor-suppressor genes may provide valuable proteins with clinical applications in cancer diagnosis or therapy. Class II suppressors may be especially useful because the normal genes are present and their reexpression may be inducible by drugs or other treatments.