Block 4 -- Cancer & Oncogenes Flashcards
What is a carcinoma?
Neoplasia derived from epithelial cells (breast, lung, prostate)
What is sarcoma?
Neoplasia derived from connective or mesenchymal tissue.
What is a glioma?
Neoplasia derived from glia
What is leukemia/lymphoma?
Neoplasia derived from cells of blood & bone marrow
What is the most fatal type of cancer?
lung
What cancer is most common in kids?
Leukemia
What are the hallmarks of cancer?
1) ability to continuously proliferate
2) evade apoptosis/unstable DNA
3) unlimited growth potential
4) independence from growth factors & contact inhibition
5) increased angiogenesis
6) invasiveness (metastasis)
7) altered ability to differentiate
8) evasion of immune system
9) dysregulated metabolism
10) inflammation
What is a proto-oncogene?
Gene that codes for normal proteins involved in cell-cycle progression
What is an oncogene?
The mutation of a proto-oncogene
– no regulation of cell cycle
What is a tumor suppressor gene?
a gene with a protein product that normally inhibits cell division
What are two causes of mutation?
1) environmental insult (DNA damage)
2) genetic insult (loss of DNA repair mechanism)
What mutations are needed (simplified model) to cause cancer?
1) an oncogene is inappropriately expressed or overexpressed
2) inactivation of both alleles of a TSG
Describe cancer as a disease.
1) Polygenic, genetic disease
2) Caused by inability of cell to maintain control of cell cycle
3) Only a few cancers are inherited
Describe the pathway to the formation of cancer?
1) inactivated TSG (proliferation)
2) inactivated DNA repair gene
3) mutation of proto-oncogene –> oncogene
4) more TSG mutations
What is a teratoma?
- tumor derived from pluripotent germ cells
- usually found in ovaries/testicles in kids
- de-differentiated, encapsulated, and defined
