Sollars Flashcards
Core UNIVERSAL properties of cancer (4)
Uncontrolled proliferation, Immortalization, Protection from anti-proliferative signals, Protection from apoptosis
Uncontrolled proliferation
- autocrine growth and stimulation present
- no contact inhibition (anchorage dependence)
Immortalization
Normal cells, except stem cells, have a finite number of cell divisions they are cable of
Protection from anti-proliferative signals
- differentiation is prevented
- cancer cells do not exhibit density-dependent inhibition
Protection from apoptosis
-normal cells respond to programed cell death signals when necessary, cancer cells do not
Core Properties of Solid Tumors (2)
- Angiogenesis
- Invasion and metastasis
normalization hypothesis
hit w/ high dose of chemo during cancers normalization phase (stage after receiving a low dose of chemo)
Emerging Properties of Cancer (2)
- deregulation of cellular energetics
- evasion mechanisms for the immune system
Enabling Properties of Cancer (2)
- genome instability and mutation
- tumor-promoting inflammation
dedifferentiation
cancer cells in a given tissue revert to characteristics and morphology of precursor cells
Guardians of genome/ Gatekeepers
Tumor suppressors and DNA repair mechanisms
first mutation cancer usually aquires
uncontrolled cellular proliferation
Is cancer monoclonal or polyclonal?
Monoclonal (same X chormosome inactivated/ G6PD test/ Kappa:lamda light chain ratio test)
multi-hit hypothesis
accounts for increasing incidence of cancer with increasing age.
Oncogenes require how many hits to fuck shit up?
Only one hit
Tumor suppressors require how many hits to fuck shit up?
TWO hits. Both copies of the tumor must be non-functional in order to contribute to cancer progression.
Oncogenes have stimulatory effect on cells usually through gain of function mutations with result of: Name a few
- conferring sustained cellular proliferation
- advancement of cell cycle progression
- decreased requirement for growth factors
- promotion of metastasis
- protection from apoptosis
Proto-oncogenes
normal (functional alleles)
Genes whose products normally negatively regulate cell proliferation, promote apoptosis, or maintain homeostatic growth and differentiation potential.
Tumor suppressor genes
Proto-oncogene conversion: deletion or point mutation in DNA results in what? Example?
- Hyperactivity
- Example: Ras
Proto-oncogene conversion: gene amplification in DNA results in what? Examples?
- over-expression
- Examples: Myc and ErbB
Proto-oncogene conversion: chromosomal rearrangement in DNA (due to genomic instability) associated with a novel promotor results in what? Examples?
Over-expression
Examples: Bcl2 and Myc
Proto-oncogene conversion: chromosomal rearrangement in DNA (due to genomic instability) associated with a new coding region results in what? Examples?
Novel product
Examples: BRC/ABL, PBX, PBL/RAR-alpha
Loss of heterozygosity
Tissue surrounding the tumor is heterozygous for Tumor Suppressors while the actual tumor tissue is homozygous
Tumor Suppressor: RB1
cell cycle control
Tumor Suppressor: TP53
p53, cell cycle
Tumor Suppressor: BRCA1
double stranded break repair
Tumor Suppressor: NF1
GTPase activator
RB1 familial tumor suppressor disorder
Retinoblastoma
TP53 familial tumor suppressor disorder
Li-Fraumeni Syndrome
BRCA1 familial tumor suppressor disorder
Familial breast cancer
NF1 familial tumor suppressor disorder
Neurofibromatosis
Sporadic / somatic disorders
patients must acquire both hits during a life time. Do not inherit a nonfunctional Tumor Suppressor gene like seen in familial.
RBI sporadic (somatic) tumor suppressor disorder
small cell lung carcinoma