Intro to Cancer

Question 1

Describe the Carcinoma cancer classification

Answer 1

• arise from epithelial cells that cover external & internal surfaces
• lung, breast, colon

Question 2

Describe the Sarcoma cancer classification

Answer 2

• arise from cells of supporting tissues
• bone, cartilage, fat, connective tissue & muscle

Question 3

Describe the Leukaemia & Lymphoma cancer classification

Answer 3

• arise from blood & lymphatic cells
• blood, bone marrow, lymph nodes & other lymphoid organs

Question 4

Briefly describe tumour formation

Answer 4

• uncontrolled proliferation
• disrupted balance between cell division & differentiation

Question 5

What two main gene classes are affected by mutations?

Answer 5

• oncogenes
• tumour suppressor genes

Question 6

Describe Oncogenes

Answer 6

• proto-oncogenes regulate cell growth, proliferation & gene expression
• mutation in a proto-oncogene can give rise to an oncogene
• oncogenes drive unrestrained cell proliferation & confer malignant characteristics to cells
• gain of function mutation

Question 7

How do point mutations affect proto-oncogenes?

Answer 7

• RAS oncogene - codes for abnormal form of RAS protein
• drives progression through S phase of cell cycle

Question 8

Describe Tumour Suppressor Genes

Answer 8

• role = regulate the cell cycle, DNA repair & cell death
• mutation in tumour suppressor gene can disrupt function
• loss of function mutation
• TP53 gene - half of all human cancers have p53 loss of function mutation

Question 9

What affect does p53 have ?

Answer 9

• blocks the replication of damaged or mutated cells