L13 - Anti-cancer 1: Identifying targets Flashcards
What is neoplasia?
new growth
can be benign or malignant
What do neoplasms result from?
multiple, irreversible changes in cells
What added potential do malignant neoplasms have over benign neoplasms?
invade and metastasise other tissues - enter blood stream via capillaries
What is stroma?
fibroblasts & other molecules that pack tissues
features of benign neoplasms?
non-invasive
localised
slow growth
close histological resemblance to original tissue
Features of malignant neoplasms?
invasive
local & distant spread
rapid growth
variable histological resemblance to original tissue
Where do adenocarcinomas arise from?
epithelial cells that line ducts e.g. lung, pancreass, breast
Where do squamous cell carcinomas arise from?
epithelial cells that provide protective surfaces e.g. skin, cervix
What 2 things are most responsible for lethal consequences of malignant tumours?
invasion
metastasis
What is angiogenesis?
cancer cells produce own stroma including NEW BLOOD VESSELS in response to LOW OXYGEN (hypoxia)
Can tumours produce new lymphatic vessels?
YES - lymphagiogenesis
compare characteristics of normal and transformed cells?
look at huge table in lecture
what are the 4 major cellular processes affected in cancer development?
CELL CYCLE
REDUCED APOPOTOSIS
IMPAIRED CELL ADHESION (metastasis)
ANGIOGENESIS
What are the 6 hallmarks of cancer?
Evading apoptosis
self-sufficiency in growth signals
insensitivity to anti-growth signals
Tissue invasion & metastasis
Limitless replicative potential
Sustained angiogenesis
How can anti-cancer drugs target the cell cycle?
enzymes involved in mediating checkpoints e.g. G1, G2 can be targets
4 examples of mutations occurring in cancer?
point mutations e.g. Ras
amplification
deletions
chromosomal rearrangements e.g. translocations
3 major types of GENES/PROTEINS involved in cancer?
Oncogenes
Tumour suppressor genes
DNA repair genes
What is the overactivity mutation in cancer?
single mutation event creating oncogene
What is the under-activity mutation in cancer?
2 MUTATION events in tumour suppressor gene - eliminate function
What do the 2 types of mutations in cancer-causing genes result in?
STIMULATE CELL PROLIFERATION
What are proto-oncogenes?
normal function in cells, but can be MUTATED to oncogenes
What are the functions of proto-oncogenes?
growth factors
growth factor receptors
signal transudcers
nuclear proto-oncogenes & transcription factors
How are genes involved in DNA replication error repair involved in cancer?
normally detect error and make genome stable - help protect from atmospheric radiation
loss of enzyme = mutations and genome instability
How can DNA repair enzymes be lost?
mutation and epigenetics (modifications to chromation and histones)
