Before discussion about cancer treatment, we need to review about pathogenesis of the disease.
The Cell Cycle
G1 and G2 (gap 1 and gap 2) are characterized by protein and RNA synthesis, but no DNA synthesis. S (synthesis) is the period of DNA synthesis. M (mitosis) is the period when the nucleus and then the rest of the cell divides.
Genetic abnormalities found in cancer typically affect two general classes of genes.
Cancer-promoting oncogenes are often activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments.
Tumor suppressor genes are often inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.
There are also many factors involve in cancer pathogenesis.
What is the Checkpoint?
The checkpoints are surveillance mechanism and quality control of the genome to maintain genomic integrity. Checkpoint failure often causes mutations and genomic arrangements resulting in genetic instability. Genetic instability is a major factor of birth defects and in the development of many diseases, most notably cancer.
Cells are constantly under the stress of intrinsic and extrinsic agents that cause DNA damage or interference with DNA replication. To cope with these assaults, cells are equipped with DNA maintenance checkpoints to arrest cell cycle and facilitate DNA repair pathways.
lindsay said,
October 3, 2008 @ 7:20 pm
kewl
............ said,
October 6, 2008 @ 7:00 pm
not much
Anonymous said,
October 12, 2008 @ 5:50 am
this is stupid F$%@ biology
courtney said,
October 22, 2008 @ 10:52 pm
ummm and this is supposed to make sence to me how?
courtney said,
October 22, 2008 @ 10:53 pm
ummm and this is supposed to make sense to me how?
Daniel said,
October 29, 2008 @ 5:16 am
Yeah this makes perfect sense. All those that don’t get it either aren’t really interested in learning about cancer or simply expected a one sentence explanation with an illustration using primary colors.
If you don’t get it, I’d be happy to explain it to you @ daniel.lafayette@yahoo.com
ria said,
October 31, 2008 @ 4:30 am
simple and well explained..descriptive diagrams..
chimgee said,
November 25, 2008 @ 5:27 am
hi. i am mongolia.
jam said,
April 26, 2010 @ 2:59 pm
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John Schiavone said,
March 5, 2009 @ 2:34 pm
very very intersting it heled me a lot
Mariam Malik said,
May 15, 2009 @ 8:20 pm
I found this really useful and informative, it was a great summary. Thanks
Ben said,
May 18, 2009 @ 8:53 pm
I am designing a web-site on anti-cancer treatments as part of my level 1
chemistry degree at the university of sheffield and was wondering if i could
use the picture of radiation causing a mutation on your website.
Thankyou for your time
Ben Ombler
vinod said,
June 21, 2009 @ 4:54 am
i liked it..especially the description about cell cycle..
esmail said,
July 21, 2009 @ 12:26 am
these is very simple and unuseful despite thanks
cecil said,
December 14, 2009 @ 3:11 am
we like it………
the description is very nice!!!!!
stranger said,
December 23, 2009 @ 3:09 am
keep my love
sarimah said,
December 18, 2011 @ 1:00 pm
can i know the details about pathogenesis of cancer???