path processes

Question 1

infiltration of inflammatory cells during cellular phase of acute response to infection

Answer 1

1. Margination- Neutrophil assumes marginal position within vessel
2. Rolling- Attach to selectins on endothelial cells, roll
3. Adhesion- Integrins on neutrophil surface allow for adhesion
4. Diapedesis (emigration)- dig through using collagenase which digests basement membrane

Question 2

hallmarks of cancer

Answer 2

1. self sufficiency in growth signals
2. resistance to growth stop signals
3. no limit to no. of times cells can divide (cell immortalisation)
4. ability to perform angiogenesis
5. resistance to apoptosis
6. ability to invade + produce metastases

Question 3

4 types of regulatory genes for the cell cycle + examples

Answer 3

Proto-oncogenes- signalling pathways that drive proliferation/ gain of function mutations and are dominant. E.g RAS, BRAF
Tumour supressor genes- Stop cell proliferation/ loss of function mutation and requires 2 hits. E.g Tp53, retinoblastoma gene
Caretaker/DNA repair genes- prevent accumulation of DNA damage. E.g. nucleotide excision repair, mismatch repair, double strand break
Apoptosis regulating genes- regulate apoptosis of cells e.g p53

Question 4

Cell cycle checkpoints

Answer 4

R point: End of G1, involve p53 proteins that arrest cell cycle, initiates DNA repair by increasing p21 which prevents phosphorylation of cyclins- if not then apoptosis

G1/S transition: Checks DNA before replicated, regulated by cyclins and CDKs, C + CDK gives activated CDK

G2/M transition: DNA checked after replication

Question 5

6 hallmarks of cancer

Answer 5

Growth signal producing
Angiogenesis
Metastasis (able to)
Immortality
No apoptosis
Growth stop signal resistant

Question 6

examples of tumour markers

Answer 6

Human chorionic gonadotropin- testicular cancer
alpha fetoprotein- liver cell cancer
calcitonin- medullary carcinoma of thyroid
CA-125- ovarian cancer
prostate-specific antigen- prostate cancer