Breast Cancer

Question 1

Describe Oncogenes

Answer 1

• mutated form of normal genes, involved in promoting cell proliferation
• mutation result in dominant gain of function

Question 2

Describe Tumour Suppressor genes

Answer 2

• genes whose normal function
  in regulating proliferation is slow down or stop.
• Mutation results in recessive loss of function

Question 3

Describe DNA repair genes

Answer 3

-detect irregularity in the DNA structure, remove the abnormal DNA and synthesize new normal
sequence DNA

Question 4

What are the 3 breast cancer molecular classifications?

Answer 4

1. Her2
2. Triple negative
3. Luminal

Question 5

What are the 2 categories of DNA Repair ?

Answer 5

1. Direct Damage Reversal
2. Excision of DNA damage

Question 6

What are some forms DNA damafe excision ?

Answer 6

• base excision repair
• mismatch repair
• strand break repair

Question 7

Describe the basic process of DNA Damage excision

Answer 7

• nucleotide segment containing base damage
• double-helix distortion/ mis-repaired bases are replaced by normal nucleotide via DNA polymerase synthesis process

Question 7

Describe Base Excision Repair

Answer 7

• involves DNA-N-glycosylases
• these can recognise a single damaged base & cleave the bond between it & sugar in the DNA

Question 8

Decribe Nucleotide Excision Repair (NER)

Answer 8

• Nicks DNA around damaged base & removes region
• fills with Pol on 3’ ends & attaches 5’ end with ligase

Question 9

What are some specific types of damage that NER can repair ?

Answer 9

• thymine dimers
• chemically modified bases

Question 10

Describe Mismatch Repair System

Answer 10

• proofreading fails = methyl-directed mismatch repair system activated
• found in all specie
• recognises mismatched base pairs, excises incorrect & carries out repair synthesis