VOL. 4 (1950) BIOCHIMICA ET BIOPHYSICA ACTA 293 



THE BIOCHEMISTRY OF ABNORMALITIES IN CELL DIVISION 



by 



E. BOYLAND 



Chester Beatty Research Institute, Royal Cancer Hospital, London {England) 



Carbohydrates have been considered for a long time to be the fuel of the tissues 

 of the body, but it is only during the last few years that some of the mechanisms 

 whereby the energy from carbohydrate catabolism is utilized have been revealed. 

 Meyerhof has done more than any other biochemist to show how carbohydrate meta- 

 boHsm involves phosphorylation and how the phosphorylated products can yield energy 

 for other biological processes. A remarkable property of living machinery is that it 

 can make, repair and maintain its own working parts. Cancer tissue has a high carbo- 

 hydrate metabolism and a high rate of cell division. The carbohydrate metabolism, 

 partly aerobic and partly anaerobic, yields the energy necessary for cell division and the 

 maintenance of the nuclei which seem to control the processes of cell division. The main 

 constituents of cell nuclei of both normal and cancer cells appear to be proteins and nu- 

 cleic acids, and the carbohydrate metabohsm is possibly merely concerned with pro- 

 duction of high energy phosphate bonds which will yield energy in a form available for 

 synthesis of nucleic acids and possibly of proteins. Inhibition of these processes will 

 stop cell division and so inhibit growth. If the inhibition is such that cell division is 

 impeded but not stopped then the incidence of abnormalities such as damaged chromo- 

 somes, mutations or cancer might be increased. 



Normal cells are not capable of continuous growth. If they continue to receive 

 surplus nourishment after attaining a certain limiting size they divide. If the process 

 of cell division is inhibited, then growth is also inhibited. In the cell division or mitosis 

 in which nuclei and plasmagenes play a dominant role there is exact partitioning of. the 

 chromosome material between the daughter cells. The occurrence of spontaneous chro- 

 mosome abnormahties and mutations shows that chromosomes are not absolutely 

 stable. The induction of changes or mutations by physical and chemical agents indicates 

 that the nuclear material is sensitive and vulnerable to conditions of the environment. 



Perhaps the most sensitive indication of abnormalities of cell division is the occur- 

 rence of mutations, as these are functional manifestations of such abnormalities. If the 

 change of normal cells to cancer cells is a somatic mutation then the fact that an agent 

 is carcinogenic is an indication that it is mutagenic. Actually most of the mutagenic 

 agents which lend themselves to testing have been found to be carcinogenic and many 

 carcinogenic agents have been shown to induce mutations. 



Many of the means which will induce cancer and increase the mutation rate of 

 animals will inhibit the growth of animals or of tumours growing in animals. Such 

 inhibition of growth by carcinogenic hydrocarbons was described by Haddow^. Inhibi- 

 tion of growth in this way may form the basis for therapy of cancer. 



The more complete correlation between the actions we are considering was first 



References p. 300. 



