Cell Cycles and Proliferation

Cell cycle is a complex mechanism that governs the cell growth and proliferation. Cell proliferation contributes to the continuity of life by producing cells, replenishing cells which undergone to cellular differentiation to acquired specialized phenotypes (function and morphology) to carry out living mechanism and towards the end-point-cell-death. Cell proliferation is determined by both extracellular signals such as cytokines and mitogen, and intrinsic cellular factors. Interactions of extracellular signals with intrinsic cellular factors trigger the biochemical events of cell proliferation. In the case of acquired immunity, proliferation is the important state after lymphocytes encountered to antigen presentation, and then leads to their effectors functions. Cell cycle regulators control the appropriate entry and progression throughout the cell cycle event. Thus, any cell cycle deregulation will potentially lead to tumourigenesis. (Malumbres and Carnero 2003)

Upon exposure to extracellular signals and activation of intrinsic cellular factors, cells undergo an ordered series o...