Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chemical Carcinogenesis - Coggle Diagram
Chemical Carcinogenesis
Risk Assesment of Carcinogenic Chemical
Regulatory Toxicology
Classification
5 groups
Group 1
Carcinogenic to man, should be forbidden
Epidemiological data
Short Term Testing
Long Term Testing
Group 2A
Probably carcinogenic to man
Animal data
Group 2B
Possibly carcinogenic to man
Animal data
Group 3
Cmpd can't be classified due to lack of sufficient data
Group 4
Proven to be non-carcinogenic for man
Avoidable Chemicals
When positive in genotoxicity studies, no further testing
Non-avoidable chemicals
Carcinogenicity animal studies still needed
How Chemicals cause cancer
Genotoxic Carcinogens
every molecule increases cancer risk
Example
Polycyclic aromatic hydrocarbons
PAHs
Aflatoxin B1
Non-genotoxic carcinogens
a safe level of exposure can be defined
Characteristics
X direct binding of chemical to DNA
X direct damage
X interaction of chemical or metabolite w/ DNA
Yet some chemicals can cause cancer
Example
Reactive Oxygen Species
Dioxins
Asbestos fibers
Mutation and regulation of cell division
What is cancer
Multistep process
Overactivation of positive regulators
Oncogenic
Proto-oncogenes
Genes w/ normal function in regulating cell division
Oncogenes
Transformed genes causing uncontrolled cell division
Inactivation of negative regulator
Inhibition of tumor suppressors
Tumor Suppressor
Gene normally blocks cell cycle progression
in response to DNA damage
No cntrl of cell division of cells w/ damaged DNA