Abstract

A cell cycle (C.C.) is an operation that consists of a progression of phases to prepare the cell for dividing, the main 2 parts of the cycle are composed of interphase which involves gap 1 (G1) a phase when the cell increases in size, synthesis (S) a phase in which DNA copies and gap 2 (G2) a phase that make the cell ready to divide, while the second one is mitosis (M) start with prophase and end to cytokinesis to create a new 2 cells. Between one cycle and another the cell enters a silent or sleep-like condition called cellular quiescence and for regulating the transition of cycle phases there are regulatory proteins called cyclins and cyclins-dependent kinase also there are checkpoints for preventing cells from progressing into the following phase. Apoptosis is a normal cell death trigger spontaneously under physiological and pathological stimuli and it has a correlation with the cell cycle in some morphological features like condense of chromatin and others. Some compounds share double effects on both cell cycle and apoptosis like growth factors (GFs) which enhance cell progression and inhibit apoptosis. At the same time, tumor suppressor proteins, proto-oncogenes, and retinoblastoma tumor suppressors have the opposite effects of GFs on both conditions.

Key words: apoptosis, cell cycle, interphase, growth factors, proto-oncogenes.