A critical analysis of the tumour immunosurveillance controversy for 3-MCA-induced sarcomas

Abstract

The cancer immunoediting hypothesis has gained significant footing over the past decade as a result of work performed using sarcomas induced by 3-methylcholanthrene (3-MCA) in mice. Despite the progress made by several groups in establishing evidence for the three phases of immunoediting (elimination, equilibrium and escape), there continues to be active controversy on the nature of interaction between spontaneously formed tumour cells and the immune system during the early phases of tumourigenesis. At the root of this controversy is conflicting and unresolved evidence spanning back to the 1970s regarding the incidence and frequency of 3-MCA-induced sarcomas in immunocompetent mice as compared to immunodeficient mice. In this mini review we provide a critical analysis of both sides of this controversy.

Figure 1

Tumour incidence was plotted for three doses of 3-MCA from the data in Table 1. Strains of mice and routes of injection are not distinguished in this figure. Furthermore, all immunodeficient knockout mouse models displayed in Table 1 are lumped together as ‘immunodeficient’ in this figure. Error bars are ±s.e.m.