BSI Lecture 27-28 Mechanisms of Cancer Flashcards

1
Q

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

A

Cancer

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2
Q

T or F? Majority of cancers initiated by genetic aberration

A

True

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3
Q

Several ________ are required to cause cancer.

A

Mutations

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4
Q

These arise from epithelial cells

A

Carcinomas

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5
Q

These arise from connective and muscle cells

A

Sarcomas

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6
Q

These arise from hemopoietic cells

A

Leukemias

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7
Q

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

A

Benign

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8
Q

tending to infiltrate, metastasize and terminate fatally are ________

A

Malignant

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9
Q

To change from benign to malignant is ______

A

Transformation

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10
Q

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

A

Oncogene

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11
Q

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

A

Tumorigenesis

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12
Q

What is the opposite of oncogene?

A

Tumor supressor gene

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13
Q

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

A

Proto-oncogene

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14
Q

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

A

Proto-oncogene

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15
Q

Conversion of proto-oncogene to oncogene is called _________

A

Activation

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16
Q

Gene that normally functions to suppress tumorigenesis

A

Tumor supressor gene

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17
Q

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

A

True

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18
Q

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

A

False, both alleles

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19
Q

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

A

False, abnormal

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20
Q

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

A

Abnormality; genetic defect

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21
Q

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

A

True

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22
Q

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

A

survival; proliferation

23
Q

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

A

dominant clone

24
Q

What is a dominant clone?

A

It is the dominant version of the tumor cells

25
Q

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

A

malignant

26
Q

T or F? Invade refers to invading underlining tissues

A

True

27
Q

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

A

Metastasize

28
Q

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

A

False

29
Q

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

A

True

30
Q

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

A

Genetic instability

31
Q

Oncogene require a ______ of function mutation.

A

gain

32
Q

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

A

Genetic instability

33
Q

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

A

Genetic instability

34
Q

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

A

False, more rapid

35
Q

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

A

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

36
Q

Cancer can evade growth suppressors by causing what to happen?

A
  1. Mutations in tumor suppressor genes (egp53, Rb)

2. Cell cycle not halted when supposed to be halted.

37
Q

How can cancer evade apoptosis.

A
  1. Increased expression of anti-apoptotic proteins, such as Bcl-2, XIAP, cFLIP.
  2. Decreased expression of pro-apoptotic proteins (such as p53, Fas)
38
Q

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

A

Senescent

39
Q

Which cells expresses telomerase?

A

Stem cells and immune cells

40
Q

How do cancer cells acquire limitless replicative potential?

A

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)

41
Q

What is the most potent stimulus of angiogenesis?

A

VEGF

42
Q

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

A

Hypervascularization

43
Q

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

A

True

44
Q

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

A

True

45
Q

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

A

Gain

46
Q

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

A

Loss

47
Q

Change of one base pair is a _____ ____

A

Point mutation

48
Q

Removal of one or more base pairs is ______

A

Deletions

49
Q

Addition of one or more base pairs is _____

A

Insertions

50
Q

Part of gene recombines with other genes is _______

A

Translocations

51
Q

Extra copies of particular genes is ______

A

Amplifications

52
Q

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

A

Nondisjunction

53
Q

Mutations in MDM2 and ATM will cause indirect activation of ______

A

p53

54
Q

50% of mutation involves various mutations in ____

A

p53