Intro to Cancer Flashcards
What is neoplasia?
Pathological process in which a permanent alteration is made to a cell’s growth
What is a neoplasm?
A mass of tissue that is actively and progessively growing due to neoplasia
What are the characteristics of a malignant tumour?
- metastaic
- rapidly multiplying
- invasive
- anaplastic and undifferentiated
What does anaplastic mean?
Cells with poor cellular differentiation, lose morphological mature cell characteristics and orientation wrt each other
Why do childhood cancers often arise?
Due to problems with developmental and differentiation processes
Give an example of a childhood cancer and how it arises
Neuroblastoma arises from failure to differentiate the neural crest
How can childhood neuroblastoma be treated?
High pulse of retionic acid can induce differentiation in neural crest cells
How is the integrity of the cancer genome compromised?
- Chromosomal structure, has translocations or duplications
- Alterations of cellular proteome
- Epigenetic changes
How can aflatoxin B1 cause mutagenesis?
It is metabolised by cytochrome p45 to a chemical which can bind to G residues in DNA
What alterations do cancer cells have to their telomeres?
- Have longer telomeres
- Reactivate telomerase so cells keep dividing
What are the 2 main categories of mutations that can cause cancer?
- gain of function mutation to produce an oncogene
- loss of function mutation to inactivate a tumour suppressor gene
How can translocations and chromosomal alterations cause cancer?
- Generate proteins that have oncogenic activity
- Lead to altered gene expression
Give an example of an oncogenic fusion gene being created
BCR-ABL in chronic myelogenous leukaemia
Give an example of altered gene expression in cancer cells caused by chromosomal alterations
C-Myc in Burkitt’s lymphoma
How can histone modifications cause cancer?
Cancer cells have changes in histone markers and chromatin in a closed state at promoters of tumour suppressor genes so expression is reduced
