Biochemistry, Test 3, Quarter 2, Lecture 3

Front 1

What is the scientific term for cancer?

Back 1

neoplasia

Front 2

What is neoplasia?

Back 2

the process by which normal controlling mechanisms regulate cell growth and differentiation are impaired

Front 3

Name the 2 properties that cancers have in common

Back 3

1) divide and reproduce in an uninhibited fashion
2) invade and colonize other tissues

Front 4

Describe the properties exhibited benign tumors

Back 4

unrestrained growth

Front 5

Describe the properties exhibited by malignant tumors

Back 5

unrestrained growth and the ability to travel to other tissues

Front 6

What is metastases?

Back 6

to traveling of a cancer to a foreign tissue

Front 7

How are cancers classified?

Back 7

based on the tissue of origin

Front 8

Name the 2 broad classes of cancers

Back 8

carcinomas and sarcomas

Front 9

Where do carcinomas originate?

Back 9

epithelial cells

Front 10

Where do sarcomas originate?

Back 10

in the connective tissue, vasculature, muscle

Front 11

What are leukemias?

Back 11

cancer of the blood cells

Front 12

Which type of cancer is more frequent: sarcomas or carcinomas?

Back 12

carcinomas

Front 13

What is the most frequently diagnosed carcinoma?

Back 13

lung cancer

Front 14

What is the nomenclature used for a benign epithelial cancer? For a malignant epithelial cancer?

Back 14

Benign: adenoma
Malignant: adenocarcinoma

Front 15

What is the nomenclature used for a benign cartilage cancer? For a malignant cartilage cancer?

Back 15

Benign: chondroma
Malignant: chondrosarcoma

Front 16

At the basic level, what is the cause for cancer?

Back 16

multiple genetic mutations of a single cell

Front 17

What is an example that exemplifies the monoclonal mutation concept of cancer?

Back 17

tumors in females (x-inactivation) in which tumors express EITHER maternal or paternal X, but not both like the rest of the body.

Front 18

Describe some evidence that supports the multiple-hit hypothesis

Back 18

incidence of cancer would not increase with age. You would be expected to undergo a single mutation at any stage in the life cycle

Front 19

What is the multiple-hit hypothesis of cancer?

Back 19

multiple mutations within a single cell are required for a cancer to occur

Front 20

Compare the mutation requirements between animals and humans to develop cancer

Back 20

animals can develop cancer more rapidly because they don't require as many hits (perhaps due to the smaller number of genes)

Front 21

How many hits (speculated) are required for a human cell to develop cancer?

Back 21

5

Front 22

What is dysplasia?

Back 22

cells are dividing in places other than the basal layer

Front 23

What is a mutagen?

Back 23

a mutation-causing agent

Front 24

What is a carcinogen?

Back 24

a cancer-causing agent

Front 25

Relate mutagens and carcinogens

Back 25

Has been contended that any mutagen should be labeled a carcinogen because its quicker and less expensive to identify mutagens than carcinogens

Front 26

What is the most commonly used mutagenicity test?

Back 26

the Ames Test

Front 27

Describe the process of the Ames Test

Back 27

1) Add a chemical/bacteria/rat liver supernatant
2) reverse mutation (reduce background)
3) count colonies which will index the level of mutagenicity

Front 28

What is a method of catching false negatives in the Ames test?

Back 28

add rat liver supernatant because they can convert non-carcinogenic compound to carcinogenic compounds

Front 29

What is the function of the rat liver supernatant extract?

Back 29

provides a metabolic basis (which some carcinogenic compounds need)

Front 30

Describe the role of cytochrome P450's in the development of cancer

Back 30

Typically used to make substances more water soluble for excretion (by hydroxylation), however, this can also make them more electrophilic and readily bound to macromolecules inducing a point mutation or deletion

Front 31

What is an indirect carcinogen?

Back 31

a carcinogen which require metabolic activation

Front 32

What is a direct carcinogen?

Back 32

a carcinogen which does not require metabolic activation

Front 33

Describe the relationship between a promoter and an initiator in the development of cancer

Back 33

sometimes even multiple mutations of a cell will not cause cancer. These cells may require an "initiator" which is a single mutagenic occurrence that will make the promoter develop into cancer

Front 34

How can repeated wounding lead to cancer?

Back 34

Constantly wounding of cells and resulting frequent cell proliferation

Front 35

What is a promotor

Back 35

chemical or physical agents which stimulate cell proliferation

Front 36

What is an initiator?

Back 36

a mutagenic agent

Front 37

What is the best understood example of a tumor promoter?

Back 37

phorbol esters

Front 38

How do phorbol esters act as promoters?

Back 38

They bind to a receptor (protein kinase C) which mimics the action of binding to DAG and stimulates activation via phosphorylation

Front 39

Name some common examples of promoters

Back 39

cigarette smoke, estrogens, bile acids, viral infections, high fat diet

Front 40

Describe the concept of viral carcinogenesis

Back 40

States that although a small percentage of viruses have been associated with cancers, most of the time, viruses simply "wound" the cell leading to cancers decades down the road

Front 41

How many hits (speculated) are required for a human cell to develop cancer?

Back 41

5

Front 42

What is dysplasia?

Back 42

cells are dividing in places other than the basal layer

Front 43

What is a mutagen?

Back 43

a mutation-causing agent

Front 44

What is a carcinogen?

Back 44

a cancer-causing agent

Front 45

Relate mutagens and carcinogens

Back 45

Has been contended that any mutagen should be labeled a carcinogen because its quicker and less expensive to identify mutagens than carcinogens

Front 46

What is the most commonly used mutagenicity test?

Back 46

the Ames Test

Front 47

Describe the process of the Ames Test

Back 47

1) Add a chemical/bacteria/rat liver supernatant
2) reverse mutation (reduce background)
3) count colonies which will index the level of mutagenicity

Front 48

What is a method of catching false negatives in the Ames test?

Back 48

add rat liver supernatant because they can convert non-carcinogenic compound to carcinogenic compounds

Front 49

What is the function of the rat liver supernatant extract?

Back 49

provides a metabolic basis (which some carcinogenic compounds need)

Front 50

Describe the role of cytochrome P450's in the development of cancer

Back 50

Typically used to make substances more water soluble for excretion (by hydroxylation), however, this can also make them more electrophilic and readily bound to macromolecules inducing a point mutation or deletion

Front 51

What type of cancer is papillomavirus associated with?

Back 51

carcinoma of the uterine cervix

Front 52

What type of cancer is hepatitis-B associated with?

Back 52

liver cancer

Front 53

What type of cancer is associated with Epstein-Barr virus?

Back 53

Burkitt's lymphoma

Front 54

What type of cancer is associated with human t-cell leukemia virus type-1

Back 54

adult t-cell leukemia

Front 55

What type of cancer is associated with HIV

Back 55

Kaposi's sarcoma