This book comprises the lectures presented at the workshop Modified Nuc1eosides and Cancer held from 28 September to 2 October, 1981 in Freiburg, West Germany. The workshop was organized by Gisela Nass and sponsored by the Deutsche Forschungsgemeinschaft. The purpose of the workshop was to cover the varied analytical methods for quantitative and qualitative determination of modified nucleosides and their metabolism including bio synthesis, all in relation to the function of these compounds in the origin and growth of cancer cells. The potential signi ficance of measuring modified nucleosides in body fluids for tumor diagnosis in humans received particular attention. Various fields of research which have previously been segregat ed are thus unified in this volume. Emphasis was also placed on the fact that modified nucleosides are constituents of the genetic material, the desoxyribonucleic acid, on the one hand, and of the transfer ribonucleic acids on the other hand, with the latter macromolecules participating not only in the translation of genetic information into protein, but also in many regulatory processes in all single- and multi- , cellular organisms including man.

Inhalt
Organization and Expression of tRNA Genes in Drosophila Melanogaster.- Chemical Nature, Properties, Location, and Physiological and Pathological Variations of Modified Nucleosides intRNAs.- Session I. Modified Nucleosides in Situ in Tumors and Transformed Cells of Cell Culture.- InDNA.- Formation and Removal of Methylated Nucleosides in Nucleic Acids of Mammalian Cells.- Structural Modifications and Repair of DNA in Neuro-Oncogenesis by N-Ethyl-N-nitrosourea.- Role of Extent and Persistence of DNA Modifications in Chemical Carcinogenesis by Aromatic Amines.- Can DNA Methylation Regulate Gene Expression?.- In tRNA.- tRNA Alterations in Cancer.- Tumor-Specific tRNA Modifications in Mouse Plasmacytomas and Other Tumors.- Alterations in Post-Transcriptional Modification of the Y Base in Phenylalanine tRNA from Tumor Cells.- Why Is Tumor tRNA Hypomodified with Respect to QNucleoside?.- The Effects of Growth Factors on tRNALys Modification.- Perturbation of the Mitochondrial Lysine tRNA Population by Virus-Induced Transformation or Stress of Mammalian Cells: Functional Properties and Nucleotide Sequence of a Mitochondrially Associated Lysine tRNA.- Involvement of tRNA in Retrovirus Expression: Biological Implications of Reverse Transcriptase-Primer tRNA Interactions.- Session II. Biosynthesis and Degradation of Modified Nucleosides in Cancer Cells.- DNA-Specific Enzymes.- Enzymatic Methylation of Chicken Erythrocyte DNA Modified by Two Carcinogens, 2-(N-Acetoxyacetylamino)Fluorene and Methylnitrosourea.- Inhibition of DNA Methylation by 5-Azacytidine.- Alteration of Enzymatic DNA Methylation by Chemical Carcinogens.- tRNA-Specific Enzymes.- Ethionine-Induced Alterations of tRNA Metabolism.- Processing of tRNA Is Accomplished by a High-Molecular-Weight Enzyme Complex.- Alteration of tRNA Modification in Eukaryotes: Causes and Consequences.- Effects of Cortisol on tRNA Methylase Activities in Rat Mammary Carcinoma.- An Approach to Inhibition of Viral Replication: Inhibition of mRNA Methylation.- Specific Effects of 5-Fluoropyrimidines and 5-Azapyrimidines on Modification of the 5 Position of Pyrimidines, in Particular the Synthesis of 5-Methyluracil and 5-Methylcytosine in Nucleic Acids.- Session III. Modified Nucleosides: Type and Concentration in Body Fluids and Relevance for Cancer Therapy of Tumor-Bearing Individuals.- New Applications of Urinary Nucleoside Markers.- Multivariate Analysis of Urinary RNA Catabolites in Malignancies: Cross-Sectional and Longitudinal Studies.- Evaluation of Carcinoembryonic Antigen, Tissue Polypeptide Antigen, Placental Alkaline Phosphatase, and Modified Nucleosides as Biological Markers in Malignant Lymphomas.- Quantitative High-performance Liquid Chromatography Analysis of Modified Nucleosides in Physiological Fluids, tRNA,and DNA.- Modified Nucleosides in Body Fluids of Tumor-Bearing Patients.- Increasing Urinary Levels of Modified Nucleosides and Bases During Tumor Development in Mice.- Comparison of Urinary Modified Nucleosides and Bases in Rats with Hepatomas and Nephroblastomas.- Characterization and Analysis of Oncofetal tRNA and Its Possible Application for Cancer Diagnosis and Therapy.- Excretion of Polyamines by Children with Leukemia During Chemotherapy.- Subject lndex.