Oncogenesis
MechanismActionExample
Growth Promotion
Overexpression of growth factor receptors (such as epidermal growth factor, or EGF) making cells more sensitive to growth stimulic-erb-B2
Increased growth factor signal transduction by an oncogene that lacks the GTPase activity that limits GTP induction of cytoplasmic kinases that drive cell growthras
Overexpression of a gene product by stimulation from an oncogene (such as ras)c-sis
Lack of normal gene regulation through translocation of a gene where it is controlled by surrounding genes to a place where it is no longer inhibitedc-abl
Binding of oncogene product to the nucleus with DNA transcriptional activation to promote entry into the cell cyclec-myc
Loss of Tumor Suppressor Gene Function
Loss of normal growth inhibitionBRCA-1
Lack of regulation of cell adhesion with loss of growth control through cell interactionAPC
Loss of down-regulation of growth promoting signal transductionNF-1
Loss of regulation of cell cycle activation through sequestation of transcriptional factorsRb
Loss of regulation of cell cycle activation through lack of inhibition of cell proliferation that allows DNA repairp53
Limitation of ApoptosisOverexpression of gene, activated by translocation, prevents apoptosisbcl-2