L13 - Anti-cancer 1: Identifying targets

Question 1

What is neoplasia?

Answer 1

new growth

can be benign or malignant

Question 2

What do neoplasms result from?

Answer 2

multiple, irreversible changes in cells

Question 3

What added potential do malignant neoplasms have over benign neoplasms?

Answer 3

invade and metastasise other tissues - enter blood stream via capillaries

Question 4

What is stroma?

Answer 4

fibroblasts & other molecules that pack tissues

Question 5

features of benign neoplasms?

Answer 5

non-invasive
localised
slow growth
close histological resemblance to original tissue

Question 6

Features of malignant neoplasms?

Answer 6

invasive
local & distant spread
rapid growth
variable histological resemblance to original tissue

Question 7

Where do adenocarcinomas arise from?

Answer 7

epithelial cells that line ducts e.g. lung, pancreass, breast

Question 8

Where do squamous cell carcinomas arise from?

Answer 8

epithelial cells that provide protective surfaces e.g. skin, cervix

Question 9

What 2 things are most responsible for lethal consequences of malignant tumours?

Answer 9

invasion

metastasis

Question 10

What is angiogenesis?

Answer 10

cancer cells produce own stroma including NEW BLOOD VESSELS in response to LOW OXYGEN (hypoxia)

Question 11

Can tumours produce new lymphatic vessels?

Answer 11

YES - lymphagiogenesis

Question 12

compare characteristics of normal and transformed cells?

Answer 12

look at huge table in lecture

Question 13

what are the 4 major cellular processes affected in cancer development?

Answer 13

CELL CYCLE

REDUCED APOPOTOSIS

IMPAIRED CELL ADHESION (metastasis)

ANGIOGENESIS

Question 14

What are the 6 hallmarks of cancer?

Answer 14

Evading apoptosis

self-sufficiency in growth signals

insensitivity to anti-growth signals

Tissue invasion & metastasis

Limitless replicative potential

Sustained angiogenesis

Question 15

How can anti-cancer drugs target the cell cycle?

Answer 15

enzymes involved in mediating checkpoints e.g. G1, G2 can be targets

Question 16

4 examples of mutations occurring in cancer?

Answer 16

point mutations e.g. Ras

amplification

deletions

chromosomal rearrangements e.g. translocations

Question 17

3 major types of GENES/PROTEINS involved in cancer?

Answer 17

Oncogenes

Tumour suppressor genes

DNA repair genes

Question 18

What is the overactivity mutation in cancer?

Answer 18

single mutation event creating oncogene

Question 19

What is the under-activity mutation in cancer?

Answer 19

2 MUTATION events in tumour suppressor gene - eliminate function

Question 20

What do the 2 types of mutations in cancer-causing genes result in?

Answer 20

STIMULATE CELL PROLIFERATION

Question 21

What are proto-oncogenes?

Answer 21

normal function in cells, but can be MUTATED to oncogenes

Question 22

What are the functions of proto-oncogenes?

Answer 22

growth factors

growth factor receptors

signal transudcers

nuclear proto-oncogenes & transcription factors

Question 23

How are genes involved in DNA replication error repair involved in cancer?

Answer 23

normally detect error and make genome stable - help protect from atmospheric radiation

loss of enzyme = mutations and genome instability

Question 24

How can DNA repair enzymes be lost?

Answer 24

mutation and epigenetics (modifications to chromation and histones)

Question 25

What DNA repair enzyme is mutated in 50% of HNPCC cases?

Answer 25

MSH2

Question 26

What are the 3 stages of colon cancer?

Answer 26

small adenoma
large adenoma
carcinoma

Question 27

What percentage of colon cancer is Inherited?

Answer 27

10-15%

Question 28

What can make the chance of inherited colon cancer higher?

Answer 28

if inherit tumour suppressor gene already with 1 mutation - only need 1 other mutation to inactivate gene function

Question 29

What are 2 tumour suppressor genes lost in colon cancer?

Answer 29

DCC and p53

Question 30

What are genes often involved in tumours with mutations?

Answer 30

look at big table on slide