Chapter 12 



THE METABOLISM OF THE CANCER CELL' 

 A. Clark Griffin 



I. INTRODUCTION 



A metabolic or compositional j)attern, unigue forjthe^mal ignant cell, h as notbeerx 

 firmly establishecL. Nevertheless, we must recognize that cancer cells do differ in 

 certain fundamental aspects from normal cells. Such differences may occur at the 

 metabolic level or the differences may exist at higher levels of cellular activity. 

 The many classes of_tumors_appear_tC)^ be remarkably cons tajit in their overa ll 

 metabolic patterns. At this time, however, there is insufficient evidence to assume 

 that this general pattern is specific for tumors. There is increasing evidence that 

 the biosynthetic pathways involving amino acid, protein and nucleic acid for- 

 mation, as well as the energy forming reactions, are common for normal and 

 malignant cells. Certainly, quantitative differences do exist and in many instances 

 it has been observed that tumors rely to a large extent on a certain metabolic 

 sequence or pathway for a given function. This same pathway may also be present 

 in normal tissues but operative under normal circumstances to a limited extent. 

 Generally, these quantitative differences provide the basis for the present approach 

 to the chemotherapy of cancer. The chances for success in this area would be in- 

 creased if some unique metabolic feature of cancerous cells could be discovered. 

 Every effort has been extended in order to provide the reader with a review of 

 the studies made on the metabolism and composition of cancerous tissues. These 

 findings obviously must be compared with the normal tissue patterns. The selec- 

 tion of a normal pattern for comparison has presented many difficulties since each 

 normal tissue possesses more or less characteristic features. Also, the normal values 

 are dependent upon species, strain, age, sex, nutritional status and many other 

 factors. Malignant tissues may also vary in their metabolic or compositional 

 patterns depending upon the homogeneity of sample, extent of necrosis and other 

 factors. In general, comparisons have to be made on the basis of the normal or 

 the cancerous "ranges". The advent of such powerful techniques as sequential 

 and preferential blocking in JVeurospora and other organisms, chromatography, 



^ The author acknowledges with sincere thanks the invaluable assistance of M. A. O'Neal 

 in the editorial preparation of this Chapter and Mrs. Beth B. Rafferty in the typing and 

 assembly of the manuscript. Also, the author wishes to thank Dr Van R. Potter for the 

 opportunity to use his valuable charts in this Chapter. 



Literature p. gig 



