3.8 Apoptosis/Cancer & 3.10 Cancer

Question 1

Define apoptosis

Answer 1

Programmed cell death

Question 2

Apoptosis is needed for

Answer 2

multicellular development

Question 3

What are the 2 ways cells regulate cell death?

Answer 3

Intrinsic and extrinsic pathways

Question 4

Intrinsic signals causing apoptosis

Answer 4

• Deprivation of survival factors
• DNA damage or senscence triggers cell death

Question 5

Extrinsic signals that trigger apoptosis

Answer 5

Activation of death receptors by ligands from outside of cell

Question 6

Purpose of apoptosis

Answer 6

• To sculpt tissues during development (ex: neurons)
• Allow for normal cell turnover (ex: epithelial, immune cells)
• Remove damaged cells

Question 7

What are characteristics of morphological changes due to apoptosis?

Answer 7

• Cell shrinkage
• Chromatin condensation
• Membrane blebbing
• Nuclear fragmentation
• Formation of apoptotic bodies
• No cell lysis

Susan Can’t Bake Nachos For Nick

Question 8

Define caspase

Answer 8

the “hit man” of the cells

Chews everything up

Digests cellular proteins and causes death

Question 9

How does caspase become active

Answer 9

Procaspase (inactive form of caspase) is activated by binding of cytoplasmic cytochrom C

Question 10

Anti-apoptotic family members ___ cytochrome-C release

Answer 10

Inhibit

Question 11

Pro-apoptotic family members ___ cytochrome-C release from mitochondria

Answer 11

Facilitate

Question 12

What are the Bcl-2 family proteins and what are the types within those?

Answer 12

Anti-apoptotic (Bcl-2 and Bcl-XL)

Pro-apoptotic (Bax, Bad, Bim)

Question 13

Steps for caspase activation by cytochrome C release

Answer 13

1. cytochrome C binds to apoptotic protease activating factor 1 (Apaf1)
2. Formation of CARD domain
3. assembly of apoptosome triggered by release of dADP in exchange for dATP
4. activation of procaspase-9
5. caspase-9 cleaves and activates executioner procaspases
6. caspase cascade leading to apoptosis

Question 14

Steps for extrinsic apoptosis

Answer 14

1. ligand on approaching cell binds to death receptors on the doomed cell
2. death receptor gathers caspases with a death domain adaptor
3. caspases become activated
4. cell dies

Question 15

How does a caspase know its supposed to be used for extrinsic apoptosis?

Answer 15

They have death domain adaptor sequences

Question 16

Steps for intrinsic apoptosis

Answer 16

1. apoptotic stimulus
2. cytochrome C release
3. Apaf1 binding
4. caspase activation

Question 17

Describe cancer cells

Answer 17

• Proliferate without restraint
• Ignore signals
• Resistant to apoptotic signals
• Degrade the restraining extracellular matrix

Question 18

Define carcinoma

Answer 18

Cancers arising from epithelial cells

Most common

Question 19

Define sarcomas

Answer 19

Come from CT or muscle cells

Question 20

Define leukemias and lymphomas

Answer 20

Cancers of WBC

Question 21

Cancer is a ___ cell disease from accumulated muations

Answer 21

Stem

Question 22

Each tumor is ___

Answer 22

clonal

Question 23

Define benign tumor

Answer 23

If it stays in its designated tissue

Question 24

Define malignant tumor

Answer 24

It can break out of its niche

Question 25

Define metastatic tumor

Answer 25

It can colonize other tissues/sites Requires a lot of mutations

Question 26

Types of cancer-associated genes

Answer 26

Proto-oncogenes Tumor suppressor genes

Question 27

Define proto-oncogenes

Answer 27

Genes whose proteins promote cell growth or motility and promote tumorogenesis when hyperactivated

Question 28

Define oncogenes

Answer 28

Mutated proto-oncogenes Can cause cancer

Question 29

Define tumor suppressor genes

Answer 29

Protein products limit cell growth or survival and the cell's released from restraint when they're inactivated by mutation

Question 30

Ways cancer genes can be mutated

Answer 30

Point mutation (GOF or LOF) Gene amplification Chromosomal translocation or deletion

Question 31

For tumor cells to escape, they must adopt a more ___ phenotype

Answer 31

Mesenchymal

Question 32

When tumor cells are mesenchymal, it allows them to be

Answer 32

more mobile and have more flexible cytoskeletons

Question 33

What intermediate filaments do you have when changing from epithelial to mesenchymal phenotype?

Answer 33

Change from keratins to _vimentin_

Question 34

What junctions do you have when changing from epithelial to mesenchymal phenotype?

Answer 34

Changing from desmosomes to _focal adhesions (integrins)_

Question 35

Example of EMT

Answer 35

Cleft lip/cleft palate

Question 36

Steps for mammalian palate fusion

Answer 36

1. Adhesion 2. Epithelial-mesenchymal transition (EMT) 3. Apoptosis and mesenchyme confluence

Question 37

Example of growth factors and receptors in oncogenes and tumor suppressors

Answer 37

TGF-alpha EGFR

Question 38

Example of intracellular messengers

Answer 38

RAS

Question 39

Example of cell cycle regulators in oncogenes and tumor suppressors

Answer 39

Cyclin-D1

Question 40

Example of tumor suppressors

Answer 40

P53

Question 41

Example of apoptosis inhibitors

Answer 41

Bcl-2

Question 42

Drugs to treat carcinomas that are DNA synthesis inhibitors

Answer 42

Methotrexate, fluorouracil, cisplatin

Question 43

Drugs to treat carcinomas that are mitotic inhibitors

Answer 43

Taxol (stabilizes microtubules)

Question 44

Specific pathway inhibitor drugs treat \_\_\_

Answer 44

carcinomas

Question 45

Describe squamous cell carcinoma

Answer 45

* All red/red and white patches * Persistent hoarseness and oral ulceration * Unilateral nasal obstruction * Neck mass * Unexplained tooth mobility