The cell cycle

You have probably read a lot about how various chemotherapy drugs only work at specific times during the cells life cycle. 
If you have found this page you are here because you are one of the many people who really want to dig deep and understand more about how lymphoma and cancer in general works. Thus you want to know more about the whole business of the cell life cycle, what it is, how it works it where chemotherapy can disrupt it.

Click the image below for a very good over view of the cycles and where chemotherapy comes into play. Just remember that not all chemotherapy drugs are cell cycle specific. Most chemotherapy regimens combine drugs of various kinds to use the cell cycle and to overcome the cell cycle. 

Here is a general description of each of those phases.

G0 Phase

This is the dormancy phase when the cell is not really doing anything at all. This is a very common phase for most mammalian cells. Cells that are permanently in the G0 phase are called postmitotic cells.

G1 Phase

The G1 phase is a period in the cell cycle during interphase, between mitosis and the S phase. For many cells, this phase is the major period of cell growth during its lifespan.

It Consists of four subphases:

Competence (G1a) 

Entry (G1b) 

Progression (G1c) 

Assembly (G1d)

S Phase

S phase, during which the DNA is replicated, where S stands for the Synthesis of DNA.

G2 Phase

G2 phase is the second growth phase, also the preparation phase for the M phase or mitosis and cytokinesis, the actual division of the cell into two daughter cells.

M Phase

The Mitotic or division phase.

The cell cycle stops at several checkpoints and can only proceed if certain conditions are met, for example, if the cell has reached a certain diameter. Some cells, such as neurons, never divide once they become locked in a G0 phase.

Additional information about the cell cycle can be found at Wikipedia, the on-line encyclopaedia.

http://en.wikipedia.org/wiki/Cell_cycle