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S L Naylor

Publications and source records attributed to S L Naylor.

At least 55 records · Page 3Linked to original sources
PubMed1992

Specific expression of the annexin VIII gene in acute promyelocytic leukemia.

Since the translocation breakpoint t(15;17) (q22;q21) in acute promyelocytic leukemia (APL) occurs within the retinoic acid receptor-alpha (RARA) gene, the expression of many genes normally regulated by RARA may be affected by this translocation. To identify genes that may be aberrantly expressed in APL, a subtraction cDNA library of an APL patient with t(15;17) was constructed. A cDNA, pRD1, specifically expressed in APL was identified. DNA sequence analysis of pRD1 showed that this gene is similar to the DNA sequence of annexin VIII, a gene which encodes a vascular anticoagulant. The annexin VIII gene was assigned to chromosome 10, which indicates that specific expression of this gene in APL is not directly involved in the t(15;17) breakpoint region. We have analyzed the expression of annexin VIII gene in nine t(15;17)-positive APL patients and one APL patient with a chromosome 17q-abnormality. We found that all APL samples expressed high levels of the annexin VIII gene. Expression of the annexin VIII gene in all other leukemias, including acute myelogenous leukemia, chronic myelogenous leukemia, chronic lymphocytic leukemia, and acute lymphoblastic leukemia, was undetectable, except in one patient with acute myelogenous leukemia in which a very low level of expression was detected. Annexin VIII is highly expressed in the APL cell line, NB4. Its expression was significantly reduced after 8 hours of all-trans retinoic acid (ATRA) treatment, whereas the expression of RARA increased several-fold within 4 hours postinduction. Thus, increased expression of RARA preceded the downregulation of annexin VIII after ATRA induction, suggesting an inverse relationship between RARA and annexin VIII expression. Since increased expression of the fusion transcript was seen after ATRA induction and an APL without a t(15;17) translocation expressed high levels of annexin VIII, it appears that increased expression of annexin VIII in APL is not related to the fusion transcript. Therefore, dysregulation of the RARA gene may be related to the overexpression of annexin VIII in APL.

Amino Acid Sequence↗
PubMed1992

New chromosomal mapping assignments for argininosuccinate synthetase pseudogene 1, interferon-beta 3 gene, and the diazepam binding inhibitor gene.

Argininosuccinate synthetase pseudogene 1 (ASSP1), interferon-beta 3 (IFNB3) gene, and diazepam binding inhibitor (DBI) gene have previously been mapped to human chromosome 2. Their nucleotide sequences, recorded in the GENBANK data base, were used to generate DNA primers to amplify specific sequences using the polymerase chain reaction (PCR). These primers failed to amplify DNA sequences when used to analyze microcell hybrid clones containing human chromosome 2. In order to map these genes, a panel of somatic cell hybrids was analyzed by PCR with these primer sets. The results of these experiments place ASSP1 sequences on human chromosome 6, IFNB3 on human chromosome 8, and DBI on human chromosome 6.

Argininosuccinate Synthase↗
PubMed1991

Mouse platelet-derived growth factor receptor alpha gene is deleted in W19H and patch mutations on chromosome 5.

The mouse W19H mutation is an x-ray-induced deletion of more than 2 centimorgans on chromosome 5 encompassing the white spotting mutation W (encoded by the Kit protooncogene), patch (Ph), and recessive lethal (l) loci. The platelet-derived growth factor receptor alpha gene (PDGFRA) like Kit encodes a transmembrane receptor tyrosine kinase. By using mouse-Chinese hamster somatic cell hybrids and haplotype analysis in interspecific backcross mice, mouse Pdgfra was mapped to chromosome 5 in tight linkage with Kit. Hybridization of a PDGFRA probe to DNAs from W19H/ + heterozygous mice and patch heterozygous mice, and their wild-type littermates, demonstrated deletion of Pdgfra. Pulsed-field gel electrophoresis indicated that Kit and Pdgfra are linked on a 630-kilobase Mlu I DNA fragment. Thus the W19H deletion removes at least two receptor tyrosine kinases and the results suggest Pdgfra as a candidate for the Ph locus.

Animals↗
PubMed1991

PCR primers for human chromosomes: reagents for the rapid analysis of somatic cell hybrids.

Rapid analysis of somatic cell hybrids can be facilitated by using the polymerase chain reaction (PCR) to assay for genes assigned to specific human chromosomes. We describe PCR primer pairs for genes on the short and long arms of the 22 autosomes and the X chromosome. Some of the primers were designed from the 3' untranslated region of cDNA sequences, whereas others were derived from genomic sequence. Each primer set was tested for its specificity and mapped to a chromosome by screening a somatic cell hybrid panel. Two of the primer pairs (APOC2 and G6PD) detect CA dinucleotide repeat polymorphisms.

Base Sequence↗
PubMed1991

cDNAs encoding members of a family of proteins related to human sterol carrier protein 2 and assignment of the gene to human chromosome 1 p21----pter.

Sterol carrier protein 2 (SCP2) is believed to play a key role in intracellular lipid movement. Here we report the cloning and nucleotide sequences of cDNAs encoding SCP2-related proteins of 58.85 kD and 30.8 kD and the assignment of the SCP2 gene to human chromosome 1 p21-pter. The SCP2-related proteins share common deduced carboxyl amino acid sequences with SCP2 and the cDNAs have a common 3' untranslated nucleotide sequence. The mRNAs encoding these proteins increased in a coordinate fashion as human placental cytotrophoblasts differentiated into syncytiotrophoblasts in culture. Our observations document the existence of a family of related proteins encoded by the human SCP2 gene.

Amino Acid Sequence↗
PubMed1991

Use of the single strand conformation polymorphism technique and PCR to detect p53 gene mutations in small cell lung cancer.

Recent studies have suggested that the p53 oncoprotein might function normally as a tumor suppressor. Mutations in highly conserved regions of the p53 gene have been observed in numerous types of tumors and tumor cell lines. To detect in a more sensitive manner p53 gene mutations in small cell lung cancer (SCLC) we utilized the single strand conformation polymorphism (SSCP) technique of Orita et al., (1989). Using PCR primers for the most highly conserved regions of the p53 gene, including exons 4-9, we have identified p53 mutations in 5 of 9 small cell lung cancer (SCLC) tumor DNA samples and in 1 SCLC cell line. None of the mutations seen in tumor DNA samples were present in normal DNA from the same patients, indicating that mutation of the p53 gene in these tumors was a somatic event. Of the six mutations observed, two were found in exon 7, three were found in the region encompassing exons 8 and 9, and one was found in the region encompassing exons 5 and 6. Nucleotide sequencing of one of the exon 7 mutations and one of the exon 8-9 mutations indicated that each was a C to T transition. In SCLC-6 the mutation resulted in substitution of serine for proline at amino acid 278 and in SCLC-4 substitution of tryptophan for arginine at amino acid 248, both nonconservative amino acid substitutions. Both of these changes are in regions of the p53 gene where mutations have been observed in other tumors. Two additional mutations were observed in SCLC cell lines using conventional PCR techniques. One of these is a mutation which results in altered splicing of the p53 pre-mRNA.

Amino Acid Sequence↗
PubMed1990

Altered structure and expression of the human retinoblastoma susceptibility gene in small cell lung cancer.

Karyotypic and molecular genetic evidence has indicated that deletion or rearrangement of both chromosomes 3 and 13 may be important in the pathology of human small cell lung cancer (SCLC). The retinoblastoma susceptibility gene, RB, on chromosome 13 band q14, has previously been shown to be altered in SCLC [J. W. Harbour et al., Science (Wash. DC), 241: 353-357, 1988; J. Yokota et al., Oncogene, 3: 471-475, 1988]. Our studies of 26 SCLC tumor and normal DNA samples indicate that 6 of 6 patients whose normal cell DNA was heterozygous for an RB restriction fragment length polymorphism have lost one of the two alleles in their tumor DNA. Consistent with other studies, we find 2 of 26 tumors with homozygous deletions within the RB gene. Of 13 SCLC cell lines examined, only 3 expressed greater than trace amounts of RB mRNA. RB protein was detected in 2 of 14 SCLC cell lines examined, unlike the results of Yokota et al. (Oncogene, 3: 471-475, 1988) which showed no RB protein in any of the 9 cell lines they examined. Only unphosphorylated RB protein was detected in SCLC cell line H209, suggesting that the RB protein may be inactivated by a novel mechanism in this cell line. These data suggest that inactivation of the RB gene is a frequent if not universal event in SCLC.

Alleles↗
PubMed1990

Isolation, characterization, and mapping of a human acid beta-galactosidase cDNA.

A lambda gt11 human testicular cDNA library was screened with degenerate oligonucleotide probe mixtures based on amino acid sequence data generated from cyanogen bromide fragments and tryptic fragments of purified human beta-galactosidase. Six positive clones were identified after screening 2 x 10(6) plaques. The sequences of these six clones were determined and found to be derived from two different cDNAs. The sequence of the longest of these cDNAs is nearly identical to that recently determined by Oshima et al. (1988). It codes for a 76-kD protein and all 11 peptides that were generated from the purified enzyme. The second clone is shorter by 393 bp in the central portion of the coding region. Analysis by Northern blotting revealed the presence of a single mRNA species of 2.45 kb in lymphoblasts and testicular tissue. It is deduced from the amino acid sequence data that proteolytic processing of the precursor form of beta-galactosidase must occur by cleavage in the carboxy-terminal portion of the polypeptide perhaps around amino acid 530 at a uniquely hydrophilic sequence. Using a probe generated from the 3' region of the cDNA, we have mapped the locus coding for human beta-galactosidase to chromosome 3p21-3pter.

Amino Acid Sequence↗
PubMed1990

Structure and variability of human chromosome ends.

Mammalian telomeres are thought to be composed of a tandem array of TTAGGG repeats. To further define the type and arrangement of sequences at the ends of human chromosomes, we developed a direct cloning strategy for telomere-associated DNA. The method involves a telomere enrichment procedure based on the relative lack of restriction endonuclease cutting sites near the ends of human chromosomes. Nineteen (TTAGGG)n-bearing plasmids were isolated, two of which contain additional human sequences proximal to the telomeric repeats. These telomere-flanking sequences detect BAL 31-sensitive loci and thus are located close to chromosome ends. One of the flanking regions is part of a subtelomeric repeat that is present at 10 to 25% of the chromosome ends in the human genome. This sequence is not conserved in rodent DNA and therefore should be a helpful tool for physical characterization of human chromosomes in human-rodent hybrid cell lines; some of the chromosomes that may be analyzed in this manner have been identified, i.e., 7, 16, 17, and 21. The minimal size of the subtelomeric repeat is 4 kilobases (kb); it shows a high frequency of restriction fragment length polymorphisms and undergoes extensive de novo methylation in somatic cells. Distal to the subtelomeric repeat, the chromosomes terminate in a long region (up to 14 kb) that may be entirely composed of TTAGGG repeats. This terminal segment is unusually variable. Although sperm telomeres are 10 to 14 kb long, telomeres in somatic cells are several kilobase pairs shorter and very heterogeneous in length. Additional telomere reduction occurs in primary tumors, indicating that somatic telomeres are unstable and may continuously lose sequences from their termini.

Animals↗
PubMed1990

Localization of mouse melanoma growth stimulatory activity gene (Mgsa) between Afp and Gus on chromosome 5 using interspecific backcross mice.

Melanoma growth stimulatory activity (Mgsa) is a polypeptide mitogen and a possible autocrine growth factor for melanoma and other tumor cells. A restriction fragment length variant of Mgsa was followed in interspecific backcross mic Mgsa was localized between Afp and Gus on mouse chromoson 5, distal to known loci affecting skin pigmentation.

Animals↗
PubMed1990

A single Cys706 to Phe substitution in the retinoblastoma protein causes the loss of binding to SV40 T antigen.

Most naturally occurring mutants of the retinoblastoma (RB) protein contain large deletions or truncations. The small cell lung carcinoma cell line H209 contains a normal-sized but unphosphorylated RB protein (Hensel et al., Cancer Res., 50: 3067-3072, 1990), which fails to form a complex with SV40 T antigen, suggesting that the RB gene of H209 may contain a subtle mutation. To define this mutation, the RB complementary DNA and genomic DNA were sequenced, revealing a point mutation in exon 21 that changed a G to a T. This results in an amino acid substitution of a Phe for Cys706. The mutant RB complementary DNA was used as a template for in vitro transcription and translation to synthesize the mutated protein. The resulting protein failed to bind to SV40 T antigen, demonstrating that a single missense mutation of the RB gene led to the complete inactivation of the ability of the RB protein to bind T antigen.

Amino Acid Sequence↗