Neoplasia

Question 1

Neoplasia

Answer 1

Growth of genetically altered cells. Can have no significance or fatal

Question 2

Causes of neoplastic cells

Answer 2

-Inherited
-Chemicals
-Infectious agents
-Physical agents

Question 3

Inherited neoplasia

Answer 3

Germline DNA abnormalities are passed from generations Can cause neoplasia or predisposition of neoplasia

Question 4

Chemical exposure neoplasia

Answer 4

Endogenous or exogenous chemicals act as mutagens or carcinogens

Question 5

Infectious agent neoplasia

Answer 5

Viruses notable cause, Incorporate or activate oncogenes or suppress host responses against neoplastic cells

Question 6

Physical agents neoplasia

Answer 6

Radiation with short wavelengths damage DNA (UV, X rays, gamma rays)

Question 7

DNA damage checkpoints

Answer 7

-G1/S
-S
-G2/M
arrest if damage present

Question 8

DNA replication checkpoint

Answer 8

G2/M. Arrest until replication is complete

Question 9

Spindle checkpoint

Answer 9

M stage. Makes sure chromosomes aligned

Question 10

Morphogenesis checkpoint

Answer 10

G2/M. Arrest when cytoskeletal abnormalities

Question 11

Protooncogenes

Answer 11

Promote cell growth and division

Question 12

Tumor suppressor genes

Answer 12

Inhibit cell growth and division

Question 13

What genes are commonly associated with cell transfromation

Answer 13

-Protooncogenes
-Tumor suppressor genes
-Regulate DNA repair
-Regulate apoptosis

Question 14

Protooncogene examples

Answer 14

-hst and erb genes (growth factors)
-ras gene (signal transducer)
-myc gene, cyclinds and CDK (regulators of the cell cycle)

Question 15

Ways protooncogenes become oncogenes

Answer 15

-Damage to coding sequence and get abnormal protein(oncoprotein)
-Damage from outside of the coding region but dysregulate expression

Question 16

Oncoproteins

Answer 16

No regulatory controls tend to push cell cycle faster and see increased number of abnormal cells

Question 17

Mutated RAS

Answer 17

Lead to permanent activation of pathway even without external signals. Lots of transcription

Question 18

Tumor suppressor gene examples

Answer 18

-Inhibitory cytokines
-Signal transducers and mediators (nf-1 and APC)
-Inhibitory regulators of the cell cycle (p53 and RB)

Question 19

Tumor suppressor genes

Answer 19

Counteract protooncogenes

Question 20

Mutated RB

Answer 20

Tumor suppressor. Blocks movement through the cycle normally. If phosphorylated it will no longer suppress RAS get too much transcription

Question 21

Pathogenesis of tumor suppressor gene

Answer 21

-damage to coding region resulting in abnormal protein
-Damage in non coding region and get dysregulation of protein synthesis

Question 22

Mechanism of mutation to DNA repair genes

Answer 22

-exposure to mutagens
-Mistakes during DNA replication

Question 23

DNA repair genes

Answer 23

Many mistakes are made so mutations are common and are often just fixed. Able to repair because it has two strand and you have a template

Question 24

BRCA1

Answer 24

Repair double stranded breaks. Mutations in this lead to neoplasia due to DNA mutations in dividing cells go up. Can be congenital or acquired

Question 25

Apoptotic genes

Answer 25

Prevent cells with unrepaired DNA damage from replicating. Many are also protooncogenes and tumor suppressor genes. Consist of Bcl-2 gene family

Question 26

Apoptotic gene examples

Answer 26

-p53 uses p21 to cause cell cycle arrest if not repaired it causes apoptosis.

Question 27

Mitochondria and apoptosis

Answer 27

Houses important stimulants for apoptosis. If it gets leaky it releases cytochrome C which sets of the caspases causing apoptosis

Question 28

Transformed cells

Answer 28

Unstable and can lead to more acquired mutations. Sequence of mutations will determine whether it develops into neoplasia. Loos at the pattern

Question 29

Feline mammary carcinoma

Answer 29

HER2

Question 30

Canine mast cells tumors

Answer 30

Kit mutations

Question 31

Canine mammary neoplasia

Answer 31

BRACA 2

Question 32

Bovine leukemia virus associated lymphosarcoma

Answer 32

p53 overexpression

Question 33

p53 and RAS mutations

Answer 33

More common in humans than it is in dogs and cats

Question 34

Other causes of neoplasia

Answer 34

-Non mutagenic stimuli (food etc) alter cell cycle events. Don't alter DNA -Epigenetic heritable changes. Doesn't change DNA may be post-translational