Metastisis-cancer

Question 0

Why do cells choose one organ over the other to spread to while metastasized?

Answer 0

This is determined by the mechanism theory, which is that the cells will move determined by the blood flow.

Question 1

What are the four most common places metastasized cancers will go?

Answer 1

liver, lungs, bone marrow, and brain

Question 2

What is the seed and soil theory?

Answer 2

cancer cells are like seeds they require certain things in the tissue where they would be allowed to grow.
Seed= tumor cell
soil= new organ site

Question 3

what is the difference between invasion and metastasis?

Answer 3

invasion is when cells move to a neighbor organ

metastasis is when the cancer cells enter either lymph or blood system and spread to a new site.

Question 4

What is the first step in metastasis?

Answer 4

invasion and infiltration of surrounding normal host tissue with penetration of small lymphatic or vascular channels.
invasion of other near by tissue. Then infiltration of lymph or blood system.

Question 5

what is the second major step of metastasis?

Answer 5

Release of neoplastic cells either single cells or small clumps into circulation.
release of cancer cells in blood or lymph system

Question 6

What are steps 3 and 4 of the metastasis?

Answer 6

3) survival of cancer cells in circulation
4) arrest in the capillary beds of distant organs.
cancer cells stop in the vessel where the possible new organ habitat could be.

Question 7

what is step five in metastasis?

Answer 7

Penetration of lymph or blood vessel walls followed by growth of the disseminated tumor cells.
cells get past the lymph or blood vessel wall and enters the new tissue where it then begins to grow.

Question 8

what is intravasation?

Answer 8

when cells move into a blood or lymph vessel.

Question 9

what is extravasation?

Answer 9

when the cells move out of the blood or lymph vessels.

Question 10

Major changes during EMT

Answer 10

changes in adhesive forces between cells (E-cadherin is lost)
cell motility signaling molecules that direct movement of a cell
production of protease to degrade the extracellular matrix

Question 11

What is E-cadherin

Answer 11

This acts as an adhesive to all the surrounding cells. It keeps them together.

Question 12

What is the Rho family and what do they do for the cells?

Answer 12

The Rho family proteins regulate actin formation of the cell and so it controls the cell structure and movment.

Question 13

What is required for a controlled degradation of components of the extracellular matrix?

Answer 13

matrix degrading enzymes

Question 14

What are some matrix degrading enzymes?

Answer 14

Matrix metalloproteinases (MMPs)

Question 15

What is the Matrix metelloproteinases (MMP) job?

Answer 15

to help cancer cells invade the Extra cellular Matrix (ECM)

Question 16

What is the Hayflick Limit?

Answer 16

A scientist Leonard Hayflick explained that most normal cells are mortal because the can only divide a finite number of times.

Question 17

What is the major problem with DNA replication?

Answer 17

Every time DNA is replicated it results in the loss of genetic material at the ends.

Question 18

What are telomeres?

Answer 18

The are protective ends on chromosomes

Question 19

Why do telomeres shorten after going through an S phase?

Answer 19

Each round of DNA replication leaves 50-200 base pairs unreplicated at the en of the 3’

Question 20

What is telomeres repeated sequence?

Answer 20

ttaggg

aatccc

Question 21

What is the purpose of telomeres?

Answer 21

protects the DNA from attack of nucleases

telomeres allow cells to distinguish chromosomes ends from broken DNA

Question 22

How do Eukaryotic cells overcome the problem with not copying the ends of DNA?

Answer 22

eukaryotic cells use the enzyme telomerase, which allows the replication of the 3’ end to be completed. ( acts similar to PCR)

Question 23

What is the telomere theory?

Answer 23

It is saying some cells can live forever as long as they continue to reactivate telomerase.
Cells that cannot reactivate telomerase will stop dividing

Question 24

What is senescence?

Answer 24

The cell stops dividing for ever.!!!!….!!!

Question 25

What is needed for cells to express telomerase?

Answer 25

Early embryonic cells
germ cells
some stem cells but highly controlled

Question 26

What is angiogenesis ?

Answer 26

is the formation of new blood vessels

Question 27

Why is it important for tumor cells to have angiogenesis?

Answer 27

If blood vessels were to grow to the cancer cells they would be supplied with oxygen and nutrients to grow.
Also provides a direct route for cancer cells to metastasize.

Question 28

What are the two most important molecules for angiogenesis?

Answer 28

VEGF- Vascular Endothelial Growth Factor
signals endothelial cells to make new vessels
MMP- Matrix Metalloproteases
this degrades the extra cellular matrix to make room for the new blood vessels.

Question 29

What does VEGF stand for and what does it do?

Answer 29

Vascular Endothelial Growth Factor

signals endothelial cells to make new vessels

Question 30

What does MMP stand for and what does it do?

Answer 30

Matrix Metalloproteases

degrades extracellular matrix to make room for the new blood vessels.

Question 31

What is the purpose of MMP?

Answer 31

to make room for the new blood vessels