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TILE COUNCIL FOR TOBACCO RESEARCH-U.S.A., INC. 900 •1•1LIRI) AVENUE NEW YORK. N.Y. 10022 Memorandum To: Dr. J.F.Glenn and Staff From: D.H.Ford Re: Site visit with Dr. S. Naylor, University of Texas Health Science Center. San Antonio, Texas. Feb.16, 1990. Grant No. 1620BR1 entitled "Transcribed sequences in small cell lung carcinoma." Goals: To determine the role of the tumor protein TP 53 in relation to the development of SCLC. Previous work on investigating oncogene fms expression has been dropped because it was determined that the r-fms clones obtained from Clonetech were in fact a cloning artifact. Results: A major thrust of the Naylor laboratory is directed toward mapping the gene sequences on chromosomes, including in particular chromosome 3 in relation to SCLC. Recent evidence indicates,however, that this cancer probably also involves deletions on chromosomes 13 and 17 (specifically the gene for TP53) as well as on 3. Dr. Naylor notes that 3 gene sequences are present in a SCLC line (H128) which are not, however, expressed. One gene (DNFL15S2) has a different methylation pattern in this line. Further, she-has found a so-called 'house-keeping gene' for'beta-galactosidase which she feels might also not be expressed in the H128 cell line. If it does not, she plans to attempt to activate it as well as the othei non-expressed genes with 5-azacytidine. Dr. Naylor has also obtained evidence that the RB1 gene associated with retinoblastoma does not express its protein (ppllOrb) in a majority of the SCLC cases she has examined. Thus, she is now attempting to determine if the protein is aberrant.and is initiating studies to sequence the cDNA for the protein to determine if the protein is normal or whether the gene is defective. Hopefully, this will help determine if the RB1 gene is universally involved with SCLC. To facilitate this study, she is utilizing the PCR (polyamine change reaction), starting with mRNA from the tissue to make single strand cDNA in large amounts very quickly using polymerase. She plans to insert specific cDNAs (ie. for RB1) by transfection into plasmids which will be inserted into SCLC cells to determine if the deletions lost from chromosome 3,13 or 17 can be replaced by this or other insertions. Tumor protein 53 is known to be involved in tumor formation and appears to be a tumor suppressor. The gene for TP53 is located on chromosome 17, the site of allele loss in many SCLC tumors. Thus, she is undertaking to characterize the mutations which may occur at this gene site to determine what the relationship might be in SCLC cell lines which have no mRNA for TP53 or an aberrant form. Comment: It now seems clear from Naylor's work and that of others that SCLC probably involves deletions or mutations on 3 chromosomes: 3,13 and 17. From what I heard at a one day meeting she had organized on the mapping of genes on chromosome 3, I would gather that her work is amongst that of the leaders in this area. Despite the difficulties inherant in this type of investigation, she appears to be making excel3ent progress in studies relevant to the interests of CTR. DHF THE COUNCIL FOR TOBACCO RESEARCH-U.S.A., INC. 900 11IIRD AVENUE f NEW YORK. N.Y. 10022 Memorandum To: Dr. J.F.Glenn and Staff From: D.H.Ford Re: Site visit with Dr. J. Polak and S. Bloom, Hammersmith •T _ _ _ - - 1 T _ - - 3 - - L+AT /• T A AT T f l -L. .v r 1 1) 1 O Q O