The Liver in Relation to Normal and Malignant Growth: A Review

Abstract

In his presidential address delivered before the British Association on “Some Chemical Aspects of Life” Sir Frederick Gowland Hopkins has lately drawn attention to the significance of chemical structure in cellular activity and has illustrated his theme by descriptions of the specific functions exerted in metabolism by such substances as acetylcholine, thyroxine, adrenalin, insulin and the sex hormones. Of special interest is his mention of the related conception that kindred substances—hormones or vitamins according to their origin—may exert similar specific functions in the promotion of organismal and tissue growth. Authenticated examples of this type of influence are afforded by the action of the vitamin-like substances required for growth promotion in the case of certain micro-organisms (Knight and Fildes, 1933); the stimulation of plant growth by the production of specific auxines, and the influence on body growth exerted in a general and specialised manner respectively by vitamins A and D. It is obvious that this subject is of the utmost importance to all students of the physiology of growth and that the elucidation of such mechanisms is the rational path to their effective control in the case of the normal and the malignant cell alike. It must be pointed out, however, that throughout the literature pertaining to these subjects there exist certain serious misconceptions and ambiguities with regard to nomenclature. These have been the subject of a timely warning in a recent annotation in the columns of the Lancet (2:1226, 1932), from which source one may with profit summarise certain principles of terminology and definition. The first essential observation is that growth in the biological sense presupposes cell division; it follows that a growth-stimulating factor in the true sense must owe its title to its promotive effects on cell multiplication. In addition, these effects must be produced on cell multiplication as a whole, and hot be restricted merely to a single cell lineage or system, unless this restriction is clearly stated. A growth-promoting principle should therefore augment cell division, both normal and malignant. Conversely—and here one may quote the note in question— “an anti-growth principle should inhibit cell division, and if it had this action it might reasonably be expected to inhibit the cell division of a malignant neoplasm. But if this anti-growth factor inhibited cell division, it should have this effect on the active cell divisions going on in normal tissues such as the testis, the epithelium of the intestinal mucous membranes, the spleen and lymphoid tissues, where new lymphocytes are formed, and the skin, to mention only a few of the tissues in which growth— i.e. , the formation of new cells—actively proceeds even in an adult organism. A growth-inhibiting factor should therefore produce lymphopenia, sterility, and lesions in the skin and in the intestinal mucous membranes.”