B9 Week 6

Question 1

Side effects of radiotherapy

Answer 1

Sore and pink skin, intestinal discomfort, fertility issues

Question 2

Microsatellite instability

Answer 2

Prescence of alternate sized repetitive DNA sequences not present in corresponding germline DNA

Question 3

Endogenous mutations of p53

Answer 3

Methylation and deamination of the CpG site

Question 4

Microsatellite instabilityfeatures

Answer 4

Right sided, poorly differentiated, chromosomal diploidy, lymphocytic infiltration, better prognosis when adjusted for stage

Question 5

Late side effects of radiotherapy

Answer 5

Fibrosis, hair loss, dryness, lymphaedema

Question 6

Small kinase inhibitors

Answer 6

Inhibit EGFR tyrosine kinase on the cyptoplasmic side

Question 7

Xeroderma pigmentosum

Answer 7

Caused by mutation in nucleotide excision repair enzymes

Question 8

Effect of aflatoxin

Answer 8

Addition of epoxide group which causes DNA damage by liver cancer tp p53 in the codon 249 due to metabolism by cytochrome P450

Question 9

Location of alkyl lesions

Answer 9

O6-methylguanine

Question 10

Endogenous cancer causes

Answer 10

Oxygen, water, reactive metabolic intermediates

Question 11

Cancers linked to EGFR

Answer 11

Anal cancer, glioblastoma, squamous cell lung carcinoma, epithelial tumours of the head and neck

Question 12

Effect of EGFR inhibitors

Answer 12

Papulopustular rash across the face and neck

Question 13

HNPCC

Answer 13

Colorectal cancer which is inherited caused by a microsatellite instability which has no polyps. There is an early onset and it increases risk of further colorectal cancers

Question 14

Non -homologous joining

Answer 14

Repair for double stranded DNA break where there is rejoining of two broken ends with the loss of some information.

Question 15

Xerostomia

Answer 15

Oral dryness with decreased saliva production due to radiotherapy or chemotherapy

Question 16

Effect of pyramidine dimers

Answer 16

Prevents base pairings which lead to mutations

Question 17

Cause of familial adenomatous colorectal cancer

Answer 17

Mutation in APC which is a caretaker protein that downregulates beta catenin along with AXIN for the control of Wrt cell proliferation. Results in the formation of polyps due to hyperproliferation of bowel cells

Question 18

Sporadic colorectal cancer

Answer 18

Occurs due to accumulation of mutations part of the aging proces. This leads to chromosomal instability or microsatellite instabliity.

Question 19

How do immune checkpoint inhibitors work?

Answer 19

Monoclonal antibodies attach to CTL-4 on malignant tumours and prevent activity of immune suppression

Question 20

Pyramidine dimers

Answer 20

Lesions from cytosine or thymine base due to photochemical reactions

Question 21

Neoadjuvant

Answer 21

Given before primary treatment to shrink the tumour

Question 22

Direct reversal

Answer 22

Used for alkylation damage with a transfer to cysteseine residue

Question 23

Curative chemotherapy for…

Answer 23

Acute leukaemia, Hodgin’s lymphoma, Non-Hodgkin’s lymphoma, small cell lung cancer

Question 24

Which protein accumulates in DNA damage?

Answer 24

p53

Question 25

Neoadjuvant can be used for..

Answer 25

Bladder, breast cancerk, head and neck, oesophageal

Question 26

Which organs are affected in chemotherapy?

Answer 26

Lungs, heart, CNS, endocrine system and skin

Question 27

How does radiotherapy work?

Answer 27

Photon displaces electron and the electron causes DNA damage

Question 28

Cause of HNPCC

Answer 28

DNA mismatch repair genes hMSH2 and hMLH1

Question 29

Glutathione

Answer 29

Reducing agent which reverses radical formation before cell damage occurs such as with aflatoxin

Question 30

Primary drug resistance

Answer 30

On first dosage, there is no response to treatment

Question 31

Secondary drug resistance

Answer 31

Resistance develops to drug over the course of treatment

Question 32

DNA mismatch errors

Answer 32

Errors in DNA replication which results in mismatching alternating DNA sequences to corresponding germline DNA

Question 33

Log-kill hypothesis

Answer 33

Relationship of number of tumour cells to chemotherapy dose in order to determine diagnosis time, treatment and survival

Question 34

Stereotactic radiotherapy

Answer 34

Curative treatment for non-small cell lung cancer and small tumours

Question 35

Cancers caused by exogenous p53 mutation

Answer 35

Skin cancer, liver cancer, lung cancer

Question 36

What causes AP sites to spontaneously appear?

Answer 36

Reactive oxygen species

Question 37

Somatic evolution

Answer 37

Accumulation of mutations which is an important part of the aging process

Question 38

What causes resistance to EGFR inhibitors?

Answer 38

T980 mutation, MET oncogene

Question 39

How do angiogenesis inhibitors work?

Answer 39

Antibodies, tyrosine kinase inhibitors

Question 40

O-6 methylguanine transferase

Answer 40

Causes direct reversal of alkylation damage from modified base to cystosine residue

Question 41

Aflatoxin

Answer 41

Found in moulds on decaying vegetation