Cancer Biology

Question 1

What do chromosomes look like in cancer cells?

Answer 1

Missing, extra, incorrectly fused parts, structurally abnormal

Question 2

What is aneuploidy and euploidy?

Answer 2

Euploidy - normal configuration of chromosomes

Aneuploidy - incorrect configuration of chromosomes

Question 3

How can mutations pass from parents to offspring?

Answer 3

Mutations occur in the germ line (sperm and egg)

Question 4

What are tumors?

Answer 4

Clusters of malfunctioning cells

Question 5

What is benign and malignant?

Answer 5

Benign - noninvasive and localized

Malignant - invasive, metastatic

Question 6

What types of tumors are there?

Answer 6

Epithelial - skin
Mesenchymal - connective tissues
Hematopoietic - circulatory and immune systems
Neuroectodermal - nervous system

Question 7

What are the most common types of cancer?

Answer 7

Carcinomas (epithelial)

Question 8

What are the two types of carcinomas?

Answer 8

Squamous cell carcinomas - epithelia form protective cell layers
Adenocarcinomas - secretory epithelia

Question 9

What is hyperplastic, metaplastic, and dysplastic?

Answer 9

Hyperplastic - normal but too many
Metaplastic - displacement of normal cells by cells of a different type
Dysplastic - not normal cell configuration

Question 10

What is metastasis?

Answer 10

Seeding of tumor colonies to different sites in the body; must be invasive, have motility, and adapt to foreign environments

Question 11

What is monoclonal and polyclonal?

Answer 11

Monoclonal - descend from one ancestral cell

Polyclonal - descend from different subpopulation of cells

Question 12

What does carcinogenic mean?

Answer 12

Cancer creating

Question 13

What causes cancer?

Answer 13

Mutations, chemicals, physical agents, heredity, illness

Question 14

What are tumor promoters?

Answer 14

Carcinogens that are nonmutagenic

Question 15

What are commonality of cancer cells?

Answer 15

1. Lack contact inhibition (pile up)
2. Clonal outgrowth with common progenitor
3. Grow in anchorage-independent fashion

Question 16

What viruses have been found to induce cancers?

Answer 16

Rous srcoma virus, papovirus, human adenovirius, herpesvirus, poxvirus

Question 17

What is a protooncogene?

Answer 17

a precursor to an oncogene

Question 18

What is insertional mutagenesis?

Answer 18

Insertion of genomes adjacent to cellular genes in chromosomes activate protooncogenes

Question 19

What is transfection?

Answer 19

Introduce DNA from chemically transformed cells into normal cells

Question 20

What is gene amplification?

Answer 20

Replication of a segment in excess

Question 21

What is translocation?

Answer 21

Movement of one region of a chromosome to another; different transcription factors can cause overexpression

Question 22

How do structural proteins and cancer relate?

Answer 22

When proteins are mutated or structurally altered, they are deregulated causing them to overexpress signals or not produce necessary signals

Question 23

How does cell signaling pathways and cancer relate?

Answer 23

Incorrect cell signaling pathways can either promote cancer or stop from preventing it

Question 24

What is the most common cell signaling molecule altered in cancer cells?

Answer 24

Growth factors

Question 25

What are tumor suppressor genes?

Answer 25

genes that prevent proliferation and division

Question 26

How are tumor suppressor genes turned off?

Answer 26

Both copies need to be turned off; genetic mutation or epigenetic silencing through promoter methylation; loss of heterozygosity, mitotic recombination, loss of region, inappropriate chromosomal segregation, switch of DNA template strand

Question 27

What is the cell cycle?

Answer 27

Precisely programmed series of events that enable a cell to duplicate contents to two daughter cells

Question 28

What makes the cell cycle work?

Answer 28

Cyclin-dependent kinases; changing levels of cyclins; checkpoints control operating to ensure correct method;

Question 29

What is p53?

Answer 29

a transcription factor; induces creation of p21 which creates pro-apoptotic proteins

Question 30

When is p53 typically activated?

Answer 30

When its degradation is blocked:
cell physiologic stress, such as anoxia, damage to the genome, signaling imbalances in the intracellular growth-regulating machinery