Cancer

Question 1

What is cancer?

Answer 1

Arises when normal cells are transformed into malignant ones

Question 2

What marks cancer?

Answer 2

Marked by uncontrolled cell proliferation and resistance to apoptosis

Question 3

What is carcinogenesis?

Answer 3

Generation of cancer
Linked to mutagenesis

Question 4

What is mutagenesis?

Answer 4

Production of a change in DNA sequence

Question 5

What are the histologies of cancer?

Answer 5

Metaplasia, hyperplasia, dysplasia, neoplasia, metastases

Question 6

Describe metaplasia

Answer 6

Change in cell type, can be result of injury, develop into dysplasia
- squamous to columnar epithelium in oesophagus

Question 7

Describe hyperplasia

Answer 7

Increased number of cells, normal cellular appearance, reversible
- benign prostatic hyperplasia

Question 8

Describe dysplasia

Answer 8

increased proliferation
change in nuclei, loss of tissue architecture

Question 9

Describe neoplasia

Answer 9

malignancy, no physiological control, irreversible

Question 10

Describe metastases

Answer 10

spread to different parts in the body

Question 11

What are the hallmarks of cancer?

Answer 11

Capabilities to promote growth of malignancy

Question 12

Give examples of self sufficient growth signals

Answer 12

Constitutively active receptors (EGFR), proteins downstream of growth factor signaling (RAS-RAF-MEK pathway)

Question 13

What is the EGFR pathway?

Answer 13

Epidermal growth factor binds to epidermal growth factor receptor
- stimulates downstream pathway to drive cellular proliferation
- change in gene expression transcription

Question 14

How do cells evade apoptosis?

Answer 14

Resistance through loss of p53 activity or overexpression of anti-apoptotic Bcl2

Question 15

What is Bcl2?

Answer 15

Family of apoptotic inhibit enzymes for apoptosis

Question 16

Why do tumours need blood vessels?

Answer 16

Requirement for tumours to increase significantly in size

Question 17

How do cancer cells bind to new environments?

Answer 17

Cell adhesion molecules (CAMs) and integrins

Question 18

How do cancer cells produce ATP/energy (cancer cell metabolism)?

Answer 18

Malignant cells produce ATP by glycolysis and lactate fermentation

Question 19

What is lactate fermentation in cancer cells?

Answer 19

Lactic acid burn from big tumours

Question 20

Why do cancer cells switch to anaerobic glycolysis?

Answer 20

Tumours are hypoxic: adaptation to lack of oxygen
AKT pathway activation and p53 activation

Question 21

What are the forms of cancer?

Answer 21

Carcinoma, sarcoma, leukaemia, lymphoma, melanoma

Question 22

What is carcinoma?

Answer 22

Originate from epithelial cells

Question 23

What is sarcoma?

Answer 23

Originate in bone and soft tissue (connective tissue), muscle and fibrous tissues

Question 24

What is leukaemia?

Answer 24

Cancers of white blood cells, invasive

Question 25

What is lymphoma?

Answer 25

Malignancy of lymphocytes, lymph nodes

Question 26

What is melanoma?

Answer 26

Originate from melanocytes, skin pigment

Question 27

How are defects inherited?

Answer 27

Defects in cell must be genetic or epigenetic Affect proteins they encode

Question 28

What are the types of mutations?

Answer 28

Inherited, spontaneous, induced

Question 29

Explain inherited mutations

Answer 29

Associated with familial history of cancer - BRCA1 mutations - Lynch syndrome (colorectal)

Question 30

What is aneuploidy in spontaneous mutations?

Answer 30

Change in chromosome number Failure to repair errors in replication

Question 31

Explain induced mutations

Answer 31

Environmental exposures - UV light induces formation of thymine dimers

Question 32

What is an exon?

Answer 32

Region of genome that ends up within an mRNA molecule

Question 33

What is an intron?

Answer 33

Non-coding sequence of RNA transcription

Question 34

What are the two types of genetic change?

Answer 34

Transition and transversion

Question 35

What is transition?

Answer 35

Base is still a purine or still a pyrimidine Guanine -> Adenine Cytosine -> Thymine

Question 36

What is transversions?

Answer 36

Change from purine to pyrimidine or backwards Thymine -> Guanine

Question 37

In what cancer are chromosomal changes common?

Answer 37

Leukamia

Question 38

What genes are mutated in cancer?

Answer 38

Oncogenes, tumour supressor genes

Question 39

What are oncogenes?

Answer 39

Capable of initiating cancer formation when activated Drive abnormal cell proliferation

Question 40

What are tumour suppressor genes?

Answer 40

Suppress abnormal growth and carcinogenesis Implicated in regulation of cell cycle, apoptosis and DNA repair

Question 41

What is the most frequent mutated gene?

Answer 41

TP53 has a crucial role in DNA damage