Tumour Development One Flashcards
Difference between mitosis and meiosis
- Mitosis Single cell divides into two genetically identical
- meiosis is 4 gametes with half the n of chromosomes of original cell
Definition of differentiation
Process by which unspecialised cells become specialised for a particular reason
Most radio sensitive and radio resistant stages of cell growth cycle
Late G2 and all phases of mitosis is most radiosensitive
Most radio resistant is late S phase
What are Oncogenes
They code for proteins that encourage cell growth, and if they are mutated, they can divide uncontrollably
What are tumour suppressor genes?
They stop cell growth, but when mutated they allow themselves to grow uncontrollably
What are DNA repair genes?
They repair damaged cells.
What are proto- oncogenes?
Mutations can lead to cell proliferation and promote cell cancer genes
Describe the steps of oncogenes
If they are activated they code of a protein that leads to cell proliferation which leads to an increase in cell numbers and the proliferation switch stays on and leads to a tumour
What is a human cell cycle time
15-120 hours, average 48 hours
What is the tumour doubling time
Time taken to double the cell population, it is double a cell cycle time so 96 hours
Cell Loss factors
Exfoliation
Hypoxia
Metastases
Biologically inadequate
Explain the soil and seed hypothesis
Metastatic cell - seed
Organ environment - soil
Certain tumours will seed certain points, they are specific
Angiogenesis meaning
Enough blood supply for a tumour to continue growing so anti angiogenesis drugs can be used for cancer
