Toxicodynamics of Environmental Carcinogenesis

Public Health 280.335 with Trush at Johns Hopkins University

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By: Lauren Burke
Created: 2011-10-14
Size: 45 flashcards
Views: 4

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toxicodynamics

refers to the molecular biochemical and physiological effects of toxicants or their metabolites in biological systems (dose plus target)

what are the causes of cancer

breathing, eating drinking radiation sex doctors parents

what causes carcinogenisis

exogenous
endogenous
and inherited mutations

exogenous

chemicals, radiation, viruses

endogenous

hormones, immune dysfunction

susceptibility

refers to something that has responsiveness and sensitivity

gene environment interaction

the interaction between specific environmental exposures and a specific gene and their subsequent impact on human health

single genes are..

necessary and sufficient for disease (MUST BE INHERITED)

susceptibility gene

alters risk (increases) but is neither necessary nor sufficient for disease causation (Predisposes us to disease if contact with carcinogen)

what is the main historical perpective of environmental carcinogenesis

1775 pott england noted the occurence of soot related cancer in chimney sweeps

what was the first experimental production of tumors in animals?

Ichikawa (application of coal tar to ears of rabbit)

what are physical carcinogenic agents

x rays (ionizing radiation)
uv light
asbestos

what are biological carcinogenic agents

viruses (RNA tumor viruses, and DNA tumor viruses)
bacteria (stomach cancer)

what are chemical carcinogenic agents

inorganic
organic
hormones

what are inorganic carcinogenic agents

arsenic
cadmium
chromium
nickel

what are organic carcinogenic agents

polycyclic aromatic hydrocarbons, heterocyclic amines, aflatoxin, mitrosamineswh

carcinogenesis is..

miltistage

what are the stages to carginogenesis

carcinogen, exposure, initiation, promotion, conversion, progression

a mechanism of chemical carcinogenesis is activation of carcinogents to electrophiles by..

biotransformation

in biotransformation what is the molecular target?

DNA

heterocyclic amines can become carcinogenic to breast colon and prostate by..

cooking meats

different crcinogents attack different..

parts of dna

what are types of DNA repair

base excision repair
nucleotide excision repair

cancer arises from the accumulation of..

genetic damage

what DNA repair defects increase sensitivity to carcinogens?

xeroderma pigmentosum (can't repair UV damage to DNA)
ataxia telangictasis (failure in repair or replication of double strand breaks, caused by radiation)

what is blackfoot disease caused by?

standing in water with arsenic in taiwan

genotoxicty results from..

damage to DNA

mutagenesis

occurrence of point or gene locus mutation, substitution and small deletions or additionsc

clastogenesis

occurrence of chromosomal breaks resulting in gain, loss or rearrangement of pieces of chromosome

aneuploidization

gain or loss of one or more chromosomes (humans have 46 chromosomes)

what are the two main classes of genes that get mutated

gain of function genes
loss of function genes

what are gain of function genes?

proto-oncogenes and oncogenes
(accelerators)

what are loss of function genes?

tumor supressor genes
loss of ability to regulate growth (gene p53) ("brakes")

what is the gene most frequently found to be mutated in human tumores?

p53

epigenetic

in addition to changes in genetic sequence, they are drivers behind epigenetic processes

what are known or suspected drivers of epigenetic processes?

heavy metals, pesticides, diesel eshaust, tobacco smoke. polucyclic aromatic hydrocarbons, hormores, radioactivity, viruses, basic nutrients

what is an epigenetic mechanism for repressing transcription?

methylation

what is multistage carcinogenesis

initiation, promotion, progression

what is initiation

somatic cell mutation in DNA

what is promotion

clonal expansion of initiated cells

what is progression

evolution of neoplastic phenotype (angiogenesis, invasiveness, metastasis) ; malignant

what is prevention

elimination of carcinogenic influences

what is protection

measures designed to interrupt the carcinogenic process without specifc efforts to identify or eliminate carcinogenic influences

About this deck

By: Lauren Burke
Created: 2011-10-14
Size: 45 flashcards
Views: 4

About StudyBlue

“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis