cancers and regulation

Question 1

Describe how alterations to tumour suppressor genes can lead to the
development of tumours

Answer 1

1. Increased methylation of tumour suppressor genes
2. Mutation in tumour suppressor genes
3. Tumour suppressor genes are not transcribed
4. Results in uncontrollable cell division;

Question 2

Explain how increased methylation could lead to cancer.

Answer 2

Methyl groups added to both copies of a tumour suppressor gene;
The transcription of tumour suppressor genes is inhibited;
Leading to uncontrolled cell division.

Question 3

Explain how the methylation of tumour suppressor genes can lead to
cancer.

Answer 3

Methylation prevents transcription of gene;
Protein not produced that causes apoptosis;
No control of mitosis.

Question 4

MM is caused by a faulty receptor protein in cell-surface membranes.
Cells in MM tumours can be destroyed by the immune system.
Suggest why they can be destroyed by the immune system.

Answer 4

Faulty protein recognised as an antigen
T cells will bind to faulty protein
T cells will stimulate clonal selection of B cells
release of antibodies against faulty protein.

Question 5

for and against gene therapy

Answer 5

no destruction of stem cells
no rejection as made from humans own cells
long term effect unknown
virus can causes side effects