Neoplasia: Proto Oncogen Flashcards
Growth factors receptors oncoproteins that are activated by mutations in various cancer
RAS
PI3K
MYC
D cyclins
Signaling nodes that have to the greatest impact on the malignant phenotype
Darwinian selections
Operates immediate downstream from receptor tyrosine kinase
RAS
Apply brakes to RAS activation
GAPs
Same function of PI3K
PTEN
Downstream of RAS
Arms
Important in promoting cancer cell growth
MAPK
PI3K
MAPK
Mitogen activated protein kinase
Normal cells + growth factors
Proliferation
Paracrine action
Cancer cells + growth factors
Autocrine loop
Eg.
PDGF
TGF-a
EGFR
Important pathogenic element in tumors
Autocrine loop
Tyrosine kinase receptor
Extracellular ligand binding domain
Cytoplasmic tyrosine kinase domain
Encodes EGFR (point mutation) Found in a subset of lung adenocarcinoma
ERBB1
Encodes tyrosine kinase family HER2
Breast carcinoma
ERBB2
Gene rearrangement
ALK, EML4
EML4- ALK protein
Encodes yet another receptor tyrosine kinase
Hindi na tumatalab yung ibang gamot dahil dito, lalo na pag advanced na yung cancer.
MET
When RAS mutation are present in tumor
Absent mutations in receptor tyrosine kinase
Tumor activated RAS can completely substitute for
Tyrosine kinase activity
Most common type of abnormality involving proto oncogene
RAS mutations
RAS in humans
HRAS
KRAS
NRAS
This are retrovirus
Mutated RAS
15-20%
RAS 90%
Pancreatic adenocarcinoma
Cholangiocarcinoma
RAS 50%
Colon
Endometrial
Thyroid
RAS 30%
Lung adenocarcinoma
Myeloid leukemia
Excited signal transmitting state RAS bound
GTP
Quiescent state of RAS bound
GDP
During tyrosine kinase growth factors in RAS
GDP to GTP
Prevents uncontrolled RAS activity
GAP
Gain of function on RAS
GTP
Lost of function in RAS
GAP
BRAF
100%
Hairy cell leukemias
BRAF
> 60%
Melanoma
BRAF
80%
Benign novi