Cancer biology Lecture 3

Question 1

Define neoplasia

Answer 1

the new growth. The characterised by the abnormal and continuous growth cells no longer subject to the homoeostatic controls that maintain the appropriate number of cells

Question 2

Describe how cancer is formed

Answer 2

• Cell with mutation
• Divides to form hyperplasia
• Builds up further to form Dysplasia
• Becomes an in situ cancer
• It then may migrate and become an invasive cancer

Question 3

Some causes of cancer

Answer 3

Hereditary/genetic
Environmental and occupational factors
Age
Lifestyle
Diet (alcohol and smoking)
Viruses and bacteria
Radiation

Question 4

Describe how HPV causes cervical cancer

Answer 4

• HPV infects cervix through micro-abrasions
• HPV infection is of the cycling cells, causing them to replicate its DNA
• These cells undergo cell cycle de-regulation via E6/E7 viral proteins which degrade p53/Rb respectively
• Causes inhibition of apoptosis, genetic changes etc.

Question 5

Explain the cellular basis of neoplasia

Answer 5

A cell with a beneficial mutation may continue to divide until a collection of identical cells or clone is formed. Cells from this clone may acquire new genetic or epigenetic changes which further enhance their growth and survival

Question 6

Describe colonic polyps

Answer 6

2 types of adeomas : tubular and vilious
Tubular : lower incidence of developing cancer - look like tubles
Vilious: higher incidence of developing cancer

Once a tumour is established, it will give rise to multiple sub clones with differing properties. This is called tumours heterogeneity

Question 7

Describe the 2 types of neoplasms

Answer 7

Benign and malignant

Benign: non-invasive - well define borders, well differentiated, regular nuclei

Malignant: invasive/metastatic, irregular borders, poorly differentiated, irregular, larger nuclei, more frequent and abnormal mitoses.