233b chemical carcinogens Flashcards Preview

heme/onc > 233b chemical carcinogens > Flashcards

Flashcards in 233b chemical carcinogens Deck (20):
1

what % of cancers are environmentally induced + aging? biggest contributors?

85% from environmental carcinogens + aging

environment: #1-diet, #2-tobacco

2

aflatoxins (aspergillus) - organ and cancer?

liver

hepatocellular carcinoma

3

alkylating agents (chemo drugs) - organ and cancer?

blood

leukemia/lymphoma

4

aromatic amines (benzidine, 2-apthylamine) - organ and cancer?

bladder

transitional cell carcinoma

5

arsenic - organs and cancesr?

liver --> angiosarcoma

lung --> lung cancer

skin --> squamous cell carcinoma

6

asbestos - organ and cancer?

lung

bronchogenic carcinoma > mesothelioma

7

carbon tetrachloride - organ and cancer?

liver

centrilobular necrosis, fatty change

8

cigarette smoke - organs and cancer?

bladder --> transitional cell carcinoma

esophagus --> SCC/adenocarcinoma

kidney --> RCC

larynx --> SCC

lung --> SCC and small cell carcinoma

pancreas --> pancreatic adenocarcinoma

9

ethanol - organ and cancer?

liver - HCC

10

ionizing radiation - organ and cancer?

thyroid

papillary thyroid carcinoma

11

nitrosamines (smoked foods) - organ and cancer?

stomach

gastric cancer

12

radon - organ and cancer?

lung

lung cancer (2nd leading cause after smoking)

13

vinyl chloride - organ and cancer?

liver

angiosarcoma

14

polymerase chain reaction - purpose? steps?

amplifies desired fragment of DNA for dx

steps:
1) denature via heat
2) anneal during cooling w/ DNA primers to specific sequence
3) elongation - heat stable DNA polymerase replicates DNA following primers
4) repeat for amplification
5) Agarose gel electrophoresis - PCR products are separated by size (small travels farther) - compare against DNA ladder

15

ames test - purpose? type of test? steps?

in vitro testing for carcinogens

bacterial mutagenesis assay

see if bacteria can grow without histidine (mutation has lead to mutation that allows growth in medium which bacteria doesn't usually grow)

16

unscheduled DNA synthesis (UDS) test AKA
in vitro hepatocyte DNA repair assay - purpose? steps?

test for carcinogens that damage DNA after metabolism

most carcinogens require metabolic activation (use rat hepatocytes) --> test if mutagen can cause DNA damage via measuring of uptake of H3-thymidine which is incorporated during repair process

17

carcinogenesis - stages?

Initiation

Promotion

Progression

18

carcinogenesis - initiation

Initiation - binds DNA (DNA adduct) and causes mutation that isn't repaired in a single cell (failure of DNA repair); permanent; requires initiator which binds DNA and causes mutation

19

carcinogenesis - promotion

Promotion - initiated cell replicates normally and increases # (differentiated benign neoplasia), reversible; Promotors lead to progression (ROS, estradiol, DES, etc) -- weakly carcinogenic on own and doesn't bind DNA, can modify epigenetics

20

carcinogenesis - progression

Progression - additional genetic events --> malignant changes (undifferentiated neoplasia) that is irreversible; examples - inflammation, asbestos, benzene --> attract inflammatory cells