We have isolated and characterized a plasmid (pChug 20.1) that contains the cDNA of a nuclear uracil DNA glycosylase (UDG) gene Isolated from normal human placenta. This cDNA directed the synthesis of a fusion protein (Mr 66,000) that exhibited UDG activity. The enzymatic activity was specific for a uracil-containing polynucleotide substrate and was inhibited by a glycosylase antibody or a (3-galactosidase antibody. Sequence analysis demonstrated an open reading frame that encoded a protein of 335 amino acids of calculated Mr 36,050 and pI 8.7, corresponding to the Mr 37,000 and pI 8.1 of purified human placental UDG. No homology was seen between this cDNA and the UDG of herpes simplex virus, Escherichia coil, and yeast; nor was there homology with the putative human mitochondrial UDG cDNA or with a second human nuclear UDG cDNA. Surprisingly, a search of the GenBank data base revealed that the cDNA of UDG was completely homologous with the 37-kDa subunit of human glyceraldehyde-3-phosphate dehydrogenase. Human erythrocyte glyceraldehyde-3-phosphate dehydrogenase was obtained commercially in its tetrameric form. A 37-kDa subunit was isolated from it and shown to possess UDG activity equivalent to that seen for the purified human placental UDG.The multiple functions of this 37-kDa protein as here and previously reported indicate that it possesses a series of activities, depending on its oligomeric state. Accordingly, mutation(s) in the gene of this multifunctional protein may conceivably result in the diverse cellular phenotypes of Bloom syndrome.Human cells contain two major DNA excision-repair pathways to remove DNA lesions (1). Bulky DNA adducts are eliminated by the nucleotide-excision pathway, whereas most alkylated bases and alterations due to spontaneous damage are removed by the base-excision pathway. DNA glycosylases remove modified bases in the latter pathway by cleaving the base-sugar bond. Uracil present in DNA as a result of utilization of dUTP during DNA synthesis (2) or by deamination of existing cytosine residues (3, 4) is removed by the uracil DNA glycosylase (UDG).In an examination of the molecular mechanisms involved in expression of human nuclear DNA-repair genes, we isolated a normal human placental cDNA that hybrid-selected the mRNA encoding the nuclear UDG (5). Northern (RNA) blot analysis revealed the presence of a 1.6-kilobase (kb) RNA transcript. In this study we report that the nucleotide sequence of this human glycosylase cDNA* and the deduced amino acid sequence of the glycosylase are identical to those reported for the 37-kDa subunit of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (G3PD). This finding reveals an unusual and different biochemical function ofthe monomeric form ofG3PD in normal human cells as that of a UDG that functions in the base-excision repair of DNA.

Conclusions: SBRT salvage of local prostate recurrence in previously irradiated patients appears clinically feasible in this challenging group. It demonstrates favorable PSA and DFS response, typically deferring the need for salvage androgen deprivation therapy or other treatment by over 5 years, with low GU and GI toxicity. Ó 2019 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Abbreviations: ADT Z androgen deprivation therapy; EBRT Z external beam radiation therapy; RT Z radiotherapy; SBRT Z stereotactic body radiation therapy. Volume 106 Number 2 2020Local recurrent prostate cancer SBRT salvage 293

The cell cycle regulation of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH)/uracil DNA glycosylase (UDG) gene was examined in normal human cells. Steady state RNA levels were monitored by Northern blot analysis using a plasmid (pChug 20.1) which contained the 1.3 kb GAPDH/UDG cDNA. The biosynthesis of the 37 kDa GAPDH/UDG protein was determined using an anti-human placental GAPDH/UDG monoclonal antibody to immunoprecipitate the radiolabeled protein. Increases in steady state GAPDH/UDG mRNA levels were cell cycle specific. A biphasic pattern was observed resulting in a 19-fold increase in the amount of GAPDH/UDG mRNA. The biosynthesis of the 37 kDa GAPDH/UDG protein displayed a similar biphasic regulation with a 7-fold increase. Pulse-chase experiments revealed a remarkably short half life of less than 1 hr. for the newly synthesized 37 kDa protein, comparable to that previously documented for a number of oncogenes. GAPDH/UDG mRNA levels were markedly reduced at 24 hr. when DNA synthesis was maximal. These results define the GAPDH/UDG gene as cell cycle regulated with a characteristic temporal sequence of expression in relation to DNA synthesis. The cell cycle synthesis of a labile 37 kDa monomer suggests a possible regulatory function for this multidimensional protein. Further, modulation of the GAPDH/UDG gene in the cell cycle may preclude its use as a reporter gene when the proliferative state of the cell is not kept constant.

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Previous studies indicated that Schwann cells in immature nerves express nerve growth factor (NGF) receptors, and that this expression is down regulated during development but re-induced by Wallerian degeneration. It was also shown that immature Schwann cells are induced to express galactocerebroside and other molecules characteristic of mature Schwann cells by either contact with an axon or treatment with the cyclic adenosine 3',5'-monophosphate (cAMP) analogues dibutyryl cAMP (dbcAMP) and 8-bromo cAMP or the adenylate cyclase activator forskolin. In the present study, NGF receptors on the surface of cultured Schwann cells were demonstrated by binding of an anti-rat NGF receptor monoclonal antibody or of radioiodinated NGF. Treatment of cultured Schwann cells with cAMP analogues or forskolin resulted in a progressive decrease in both immunoreactive NGF receptors and radioiodinated NGF binding. The cultured Schwann cells contained a polyadenylated RNA species homologous with human melanoma NGF receptor mRNA in sequence and size. The amount of this NGF mRNA was lower in cAMP analogue-treated than in untreated Schwann cells.