Tohoku J. Exp. Med., 2004, 204(1)

TJEM Minireview and Hypothesis

Melanoma and the Problem of Malignancy

PATRICK A RILEY

Totteridge Institute for Advanced Studies, London, UK

Of the overt biological properties exhibited by malignant cells two appear to command particular attention; these are (1) the transmigratory ability which empowers these cells to invade surrounding tissues and results in their metastatic and destructive potential, and (2) their ability to evade detection by the immune system of the host. Both of these characteristics may well involve several disparate mechanisms. However, it may be that there are some metabolic features that are common to malignant neoplasms which could go some way to explaining one of these behavioural anomalies. It is proposed that abnormalities of oxidative metabolism of cancer cells, resulting in the generation of reactive oxygen species, are responsible for the inhibition of the functions of vicinal antigen-presenting cells and, thus, the failure of the immune system to recognize tumour-specific antigens likely to be expressed by malignant cells as part of their transmigratory capability.

keywords —— malignancy; carcinogenesis; immune surveillance; Langerhans cells; reactive oxygen species; minipig melanoma

© 2004 Tohoku University Medical Press

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Address for reprints: Patrick A Riley, Totteridge Institute for Advanced Studies, 2 the Grange, Grange Avenue, London N20 8AB, UK.

e-mail: rebc900@ucl.ac.uk