The transformation of a normal cell into one with malignant properties requires the cooperation of a few oncogenic mutations that change cell features and induce complex changes in gene expression patterns.
McMurray and colleagues has shown ( in an article in Nature 2008 vol 453 pp 1112-1115 ) that cell transformation depends upon synergistic modulation of down stream signalling circuitry. Hence maligancy is a highly cooperative process involving synergy at multiple levels of regulation , including gene expression. They show that a large proportion of genes controlled synergistically by loss of function of p53 and Ras activity are critical to the malignant state of murine and human colon cells.
Synergistic control of gene expression by oncogenic mutation is an underlying key to malignancy.
Mind you, this is for colon cells. Maybe other malignancies evolving from other mechanisms behave differently. Time will tell.
McMurray et al 2008, Synergistic response to oncogenic mutations defines gene class critical to cancer phenotype Nature vol 453 pp 1112 = 1115)
- Martin Eastwood