Toxicology Exam I

Two mechanisms which make and unrecognizable mutation become recognizable
- adaptive growth
- restorative growth
Adaptive growth
- when the promotor acts directly on the altered cells causing it ot proliferate
- also called positive selection
Restorative growth
- agent kills surrounding good cells via necrosis
- also called negative selection
- creates space for bad cells to proliferate
Progression
- recognizable tumor migrates
- aided by enzymes
- angiogenesis may occur
angiogenesis

a tumor creates its own blood supply and blood vessels
Non-genotoxic carcinogens
- chemicals that cause cancer but do not act directly on the DNA
- no initiation
- could involve promotors
Mechanisms of Non-genotoxic carcinogens
- increased cell proliferation
- decreased apoptosis
- increased activity of non-cancer cells
- increased oxidative stress
- inhibition of gap junction proteins
Oncogenes come from

proto-oncogenes
proto-oncogenes are
- normal elements in the body
- utilized for norma cell growth
When oncogenes are altered spontaneously or upon exposure to a chemical, they can lead to

unchecked growth
Examples of oncogenes
- C-myc
- FOS
- RAS
Oncoproteins
- protein products of oncogenes
- involved in cancer
- become active kinases
Tumor suppressor genes
- anti-oncogenes
- p53

Author

Rx2013

66531

Card Set

Toxicology Exam I

Description

Dr. Badr's 3rd Lecture

Updated

2011-02-15T22:21:52Z

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