Oncogene vs Proto-oncogene...what is the difference?

[Methal]

And how do they relate to viruses/cancer?

[sachin]

An oncogene is a modified gene, or a set of nucleotides that codes for a protein, that increases the malignancy of a tumor cell. Some oncogenes, usually involved in early stages of cancer development, increase the chance that a normal cell develops into a tumor cell, possibly resulting in cancer. New research indicates that small RNAs 21-25 nucleotides in length called miRNAs can control expression of these genes by downregulating them.


A proto-oncogene is a normal gene that can become an oncogene, either after mutation or increased expression. Proto-oncogenes code for proteins that help to regulate cell growth and differentiation. Proto-oncogenes are often involved in signal transduction and execution of mitogenic signals, usually through its protein product. Upon activation, it (or its product) becomes a tumor inducing agent, an oncogene.


Further Check out this:
http://web.indstate.edu/thcme/mwking/oncogene.html
http://web.indstate.edu/thcme/mwking/oncogene.html