Intro to Cancer Biology

Question 1

What properties define cancerous cells?

Answer 1

1. They reproduce in defiance of the normal restraints on cell growth and division
2. They invade and colonize territories normally reserved for other cells.

Question 2

What does the term hyperplasia mean?

Answer 2

Hyperplasia is a state in which normal cells are over proliferated.

Question 3

What does the term metaplasia mean?

Answer 3

Metaplasia is a state in which normal appearing cells are locatred in the wrong place, usually an adjacent cell layer.

Question 4

What does the term dysplasia mean?

Answer 4

Dysplasia is an abnormal growth process that produces tissue in which proper cell and tissue organisation have been disrupted.

Question 5

What is neoplasia?

Answer 5

Neoplasia is an abnormal type of tissue growth in which cells proliferate in an uncontrolled manner. This leads to a continual increase in the number of dividing cells

Question 6

What is a proliferating mass of abnormal cells called?

Answer 6

Tumour or neoplasm

Question 7

What is the difference between benign and malignant tumours?

Answer 7

Benign tumours can grow in a confined local area.

Malignant tumours can invade surrounding tissues, invade the bloodstream amd spread to distant parts of the body via a process called metastasis.

Question 8

What is the process of metastasis?

Answer 8

Metastasis is the ability of a malignant tumour to spread to distant parts of the body and cause cancer in regions not connected to the original tumour site.

Question 9

What term describes the ability of malignant tumours to spread around the body from the primary tumour site to another location not directly connected to it?

Answer 9

Metastasis

Question 10

What are ademonas/polyps/warts?

Answer 10

These are larger growths of dysplastic cells

(cells that appear abnormal and have disrupted cell and tissue organisation)

Question 11

What is a cancer cell?

Answer 11

A cancer cell…

• divides continuously and inappropriately
• no longer maintains its original function
• some cancer cells must be able to spread to other sites

Question 12

Why is cancer not a single disease?

Answer 12

Cancers in different tissues are treated very differently and involved many different biological processes.

Question 13

What features characterise cancer?

Answer 13

Proliferation (inappropriate growth without signals)

Immortality (avoiding senescence and telomere shortening)

Avoiding Cell Death (do not undergo apoptosis)

Angiogenesis (new growth of blood vessels)

Metastasis (must be able to escape orginal tissue layer)

Question 14

What is immortality important for the development of cancer?

Answer 14

Immortality

• the cancer must grow for long enough to kill the host
• must avoid senescence- all cells divide for a finite period usually due to telomere shortening
• the cancer must avoid stresses that cause senescence

Question 15

Why is avoiding cell death important for the development of cancer?

Answer 15

Cancers must avoid apoptosis in order to continue proliferating and spreading around the body.

• Cancer cells can violate cell cycle checkpoints and withstand cytotoxic agents.
• The loss of p53 assist in evasion of apoptosis.

Question 16

Why is angiogenesis important for the development of cancer?

Answer 16

Angiogenesis (the production of new blood vessels) is important to provide oxygen and nutrients for the developing tumour. Byproducts of metabolism must also be removed via the blood stream. A steady supply of blood vessesl feeds the tumour.

Question 17

Why are sequential mutation important for the development of cancer?

Answer 17

Sequential mutations can give clones of cells a growth advantage.

Each mutation may confer a selective advantage. Subsequent mutations take a neoplasm/stage close to becoming cancerous.

Question 18

How can an individual mutation eventually lead to tumour formation?

Answer 18

• Mutations destabilise the genome making subsequent mutations more likely.
• In most tumours the first mutation event is one that affects the protection of the cell from damage.
• This leads to an increased likelihood of further mutation events.
• The machinery that normally repairs damage becomes faulty and damaged cells can proliferate unchecked.