Study Set Content:
Species strain, tissue specificity
Nongenotoxic
first stage of the cancer process • process that is defined as a stable, heritable change
INITIATION
this stage is a rapid, irreversible process that results in a carcinogen-induced mutational event
INITIATION
chemical and physical agents that interact with cellular components at this stage are referred to as
initiators or initiating agents
s lead to genetic changes including mutations and deletions
initiating agents
Normal cell
Initiated cell
Focal lesion
Cancer
FATE OF INITIATED CELLS:
➢ Remain in a () non-dividing state
➢ May possess mutations incompatible with viability or normal function and be deleted through () mechanisms
➢ May undergo cell division resulting in the () of the initiated cell
static, apoptotic, proliferation
Second stage of the carcinogenesis process involves the selective clonal expansion of initiated cells to produce a preneoplastic lesion
Promotion
Tumor promoters are both exogenous and endogenous agents that operate at this stage and act through several mechanisms involving gene expression changes that result in sustained cell proliferation
Promotion
Tumor promoters generally show organ-specific effects, e.g., a tumor promoter of the liver, such as ()l, will not function as a tumor promoter in the skin or other tissues.
phenobarbital
Process involves the conversion of benign preneoplastic lesions into neoplastic cancer
Progression
DNA modification Mutation
INITIATION
No direct DNA modification
Nongenotoxic
No direct mutation
Promotion
Genotoxic
Initiation
One cell division necessary to lock-in mutation
Initiation
Multiple cell divisions necessary
Promotion
DNA modification
Genotoxic event
Progression
