[Molecular mechanisms of oncogenic transformation: what's new?].

During the past two years, new molecular targets have been discovered which link cell cycle, cell proliferation and cellular growth. It has become more and more evident that whereas gain-of-function mutations in specific genes can lead to cancer, genomic instability plays also an important role in tumour progression. With examples taken from the recent literature, we describe in this short review crucial findings on the molecular mechanisms controlling cell cycle and proliferation. We illustrate how specific combinations of proto-oncogenes alterations can result in tissue-specific tumours. Finally, impairment of the interactions of a cancer cell with its surrounding neighbours is also shown to participate in the progression toward aggressive phenotypes.