Cancer

Question 1

What is cancer

Answer 1

Name of diseases in which abnormal cells divide in an accel/uncontrolled manner and have potential to invade other tissues

Question 2

How are cancers organized

Answer 2

Tissue of origin and mutational status

Question 3

Benign

Answer 3

Non-cancerous. Tumors can grow larger but lack ability to spread to neighboring tissues. Can still have bad health effects. Ex moles

Question 4

Malignant cancer

Answer 4

Cells can divide uncontrollably and abnormally fast. Can also invade neighbor tissues. Cancerous

Question 5

Metastasis

Answer 5

Spread of cancer from one tissue to another

Question 6

6 hallmarks of cancer

Answer 6

• sustaining proliferative signaling
• evading growth suppressor
• activating invasion and metastasis
• enabling replicative immortality
• inducing angiogenesis
• resisting cell death

Question 7

Apoptosis

Answer 7

Where a cell suffers some sort of damage and undergoes programmed cell death

Question 8

Cancer cell evasion of apoptosis

Answer 8

Allows damaged cells to replicate. Genetic factors may be involved. P53 tumor suppression gene.

Question 9

Self sufficiency in growth signals: normal vs cancer cells

Answer 9

Normal- req external GF in order to grow and proliferate

Cancer- dont require external growth signals to proliferate. If they do- can produce growth factors on their own

Question 10

Insensitivity to anti growth signals

Normal v cancer

Answer 10

Normal- proliferation regulated and kept under control by anti growth signals

Cancer- insensitive to anti-growth signals

Evident even in vitro

Question 11

Tissue invasion and mets

How cancer does this

Answer 11

Tumors send “pioneer cells” to invade adjacent tissues. Must 1st interact normally w existing local cells, then recruit cells from local tissue to make new tumors

Question 12

Limitless replicative potential

Normal cells

Answer 12

Can only divide a certain number of times before they die. Telomere length determines division times. Shortens after each division, telomerase maintains them

Question 13

Limitless replicative potential

Cancer cells

Answer 13

Can divide indefinitely even when p up DNA error due to inc in cell division

P53 tumor suppressor gene plays a role in limiting replication, turned off in cancer

Question 14

Sustained angiogenesis

Role in Tumor

Answer 14

Tumor needs blood supply to grow in size and spread. Angiogenesis also provides tumor w o2 and nutrients

Question 15

Tumor suppressor

Answer 15

A gene that protects a cell from becoming cancerous. Generally loss of function mutations cause these cells to be susceptible to becoming cancerous

Question 16

Oncogene

Answer 16

Gene that puts a cell on the path to becoming cancerous. Begin as proto-oncogenes which have a regular physiologic function in the cell (r/t proliferation and differentiation). Begin to overexpress.

Question 17

Tumor suppressor ex: p53

Answer 17

Classic role to prevent cells w dna damage from dividing. “Guardian of genome.” 50% of cancers have p53 mutations.

Question 18

Two hit hypothesis

Answer 18

Why tumor suppressor genes become insufficient to prevent cancer. Both alleles for tumor suppressor gene need mutations for gene to lose function. Germline v somatic. Goes for majority of these genes (but not all)

Question 19

Conventional cancer therapy

Answer 19

Radiotherapy
Surgery
Chemotherapy

Question 20

Interfering w dna synthesis

Process

Answer 20

Folate must be taken up by cell and reduced to FH2 then FH4 by dihydrofolate reductase in order to produce nucleosides

Question 21

How methotrexate works

Answer 21

Higher affinity for dihydrofolate reductase than does FH2. Prevents its reduction to FH4

Question 22

Monoclonal antibodies

Answer 22

Block growth signals and stop new blood vessels from forming

Question 23

New targeted therapies

Answer 23

Hormone therapy
Monoclonal antibodies
Tyrosine kinase inhibitors

Question 24

Tyrosine kinase

Answer 24

Enzyme that removes a phosphate from ATP and attaches it to a protein, onto a tyrosine amino acid

Addition of a kinase starts a signal cascade that can lead to proliferation

Question 25

Tyrosine kinase inhibitors do what

Answer 25

Prevent phosphorylation of tyrosine kinase target

Question 26

BCR abl
Known as what

Occurs when what

Assoc w what

Answer 26

Philadelphia chromosome/translocation

When chromosome 22 has a specific translocation w chromosome 9, results in fusion gene known as bcr abl

Chronic myelogenous leukemia

Question 27

Bcr abl
Contains what

Mutated form

Answer 27

A portion that codes for a tyrosine kinase

Tyrosine kinase is always signaling

Question 28

Not all hyper proliferation caused by what, can also be caused by

What wouldn’t work

Answer 28

Mutated EGFR.
Mutated downstream effectors of EGFR

Cetuximab