BSI Lecture 27-28 Mechanisms of Cancer

Question 1

____ cells reproduce in defiance of normal restraints and invade other tissues or territories normally reserved for other cells

Answer 1

Cancer

Question 2

T or F? Majority of cancers initiated by genetic aberration

Answer 2

True

Question 3

Several ________ are required to cause cancer.

Answer 3

Mutations

Question 4

These arise from epithelial cells

Answer 4

Carcinomas

Question 5

These arise from connective and muscle cells

Answer 5

Sarcomas

Question 6

These arise from hemopoietic cells

Answer 6

Leukemias

Question 7

tumors that are self-limiting in their growth and not invasive are ________

Answer 7

Benign

Question 8

tending to infiltrate, metastasize and terminate fatally are ________

Answer 8

Malignant

Question 9

To change from benign to malignant is ______

Answer 9

Transformation

Question 10

A mutated proto-oncogene usually involved with controlling cell proliferation is a(n) ______

Answer 10

Oncogene

Question 11

Oncogene will contribute to ______. These refer to normal or mutated genes that stimulate the cell cycle.

Answer 11

Tumorigenesis

Question 12

What is the opposite of oncogene?

Answer 12

Tumor supressor gene

Question 13

Normal gene that can be converted into a cancer- promoting oncogene by mutation is a _______-_______-

Answer 13

Proto-oncogene

Question 14

____-_________ gene refers to the wild type form of the gene.

Answer 14

Proto-oncogene

Question 15

Conversion of proto-oncogene to oncogene is called _________

Answer 15

Activation

Question 16

Gene that normally functions to suppress tumorigenesis

Answer 16

Tumor supressor gene

Question 17

T or F? For tumor suppressor gene, loss of function mutation enhances susceptibility to cancer

Answer 17

True

Question 18

T or F? Tumor suppressor genes need loss of function of one allele

Answer 18

False, both alleles

Question 19

T or F? Most cancers arise from a single normal cell.

Answer 19

False, abnormal

Question 20

Evolution of a tumor cell: _________ or _______ _______ gives replicative advantage over other cells

Answer 20

Abnormality; genetic defect

Question 21

T or F? Tumor cells follows rules of mutation and natural selection that govern evolution.

Answer 21

True

Question 22

Evolution of a Tumor cells: as advantaged cell divides, another mutation may occur giving even more advantage for ______ and ________

Answer 22

survival; proliferation

Question 23

Offspring of a well-adapted cell will divide the fastest eventually taking over the tumor becoming the _______ ______ in developing tumor

Answer 23

dominant clone

Question 24

What is a dominant clone?

Answer 24

It is the dominant version of the tumor cells

Question 25

Tumor evolution takes many years to develop a progeny of cells that have the number and appropriate mutations that make it a ______ cancer

Answer 25

malignant

Question 26

T or F? Invade refers to invading underlining tissues

Answer 26

True

Question 27

____ means the cancer has spread to another location in the body.

Answer 27

Metastasize

Question 28

T or F? Cancer cells only require one mutation to invade and spread.

Answer 28

False

Question 29

T or F? Oncogene only require mutation in one of the allele.

Answer 29

True

Question 30

DNA acquires mutations at a fast rate than normal is ______ _______

Answer 30

Genetic instability

Question 31

Oncogene require a ______ of function mutation.

Answer 31

gain

Question 32

Defective DNA repair systems or inability to maintain integrity of chromosomes is an example of _____ ______

Answer 32

Genetic instability

Question 33

Mutation in some gene responsible for genomic stability is an example of ______ ______

Answer 33

Genetic instability

Question 34

T or F? Genetic instability allows for slower accumulation of mutation.

Answer 34

False, more rapid

Question 35

How can cancer sustain proliferative (stimulating cell to divide when its not suppose to)?

Answer 35

1) increase the number of growth factor receptors 2) Mutant receptors that transmit signals without growth factors 3) Mutation in signaling proteins that are normally activated by GF

Question 36

Cancer can evade growth suppressors by causing what to happen?

Answer 36

1. Mutations in tumor suppressor genes (egp53, Rb) | 2. Cell cycle not halted when supposed to be halted.

Question 37

How can cancer evade apoptosis.

Answer 37

1. Increased expression of anti-apoptotic proteins, such as Bcl-2, XIAP, cFLIP. 2. Decreased expression of pro-apoptotic proteins (such as p53, Fas)

Question 38

Once the telemores shorten to a certain point (usually after 50-70 cell divisions), the cell stops dividing and is considered "________"

Answer 38

Senescent

Question 39

Which cells expresses telomerase?

Answer 39

Stem cells and immune cells

Question 40

How do cancer cells acquire limitless replicative potential?

Answer 40

Cancer cells reactivate telomerase (90% of all tumors have reactivated telomerase) therefore, cancer cells can divide an unlimited number of times (replicative immortality. The 10% that do not reactivate telomerase find an alternative pathway to maintain telomere length)

Question 41

What is the most potent stimulus of angiogenesis?

Answer 41

VEGF

Question 42

Cancer cells secrete high levels of angiogenic molecules inducing ________ of the tumor

Answer 42

Hypervascularization

Question 43

T or F? Gain of function mutations in key genes which are central in cell motility can cause tissue invasion and metastasis?

Answer 43

True

Question 44

T or F? Disruption in adhesive mechanisms that keep cells tethered together can lead to cancer invading the tissue and metastasis.

Answer 44

True

Question 45

A mutation that causes an increase in the activity or amount of a protein is a ______ of function mutation.

Answer 45

Gain

Question 46

A mutation that causes an decrease in the activity or amount of a specific protein is a ______ of function mutation.

Answer 46

Loss

Question 47

Change of one base pair is a _____ ____

Answer 47

Point mutation

Question 48

Removal of one or more base pairs is ______

Answer 48

Deletions

Question 49

Addition of one or more base pairs is _____

Answer 49

Insertions

Question 50

Part of gene recombines with other genes is _______

Answer 50

Translocations

Question 51

Extra copies of particular genes is ______

Answer 51

Amplifications

Question 52

Failure of sister chromatids to separate or one daughter cell will lose a chromosome; the other will gain a chromosome.

Answer 52

Nondisjunction

Question 53

Mutations in MDM2 and ATM will cause indirect activation of ______

Answer 53

p53

Question 54

50% of mutation involves various mutations in ____

Answer 54

p53