Oncogenesis
- Chemical Signalling and Cancer
Tumor
-
Benign (self contained)
-
Malignant (migratory, prone to seeding
tumors at other sites)
Hypertrophy - hypertrophic cells; hyperplastic
tissue
Neoplasia - new, often irregular, growth
or tissue
Protooncogenes = Normal gene precursors
of oncogenes
I
V
Mutational Agents
I
V
Oncogenes = Gene associated with abnormal
cell growth
Oncogene Product = Expressed protein
coded by an oncogene
Mutagens
-
Radiation, Chemical
- tend to be small changes, insertions, deletions, or base changes
-
Chromosome Rearrangements
(in meiosis) - can be large changes, deletions, inversions
-
Viral Rearrangement
- viruses can become lysogenic and excise and carry genes or foreign
promoter DNA to subsequent cellular hosts where these insert into nonhomologous
sites and are expressed in a non-regulated or inappropriately regulated
fashion, often leading to oncogenesis via disruption of the normal events
of the cell cycle or cell cycle regulatory points.