Oncology - Sheet1 Flashcards
Epidemiology of Cancer
Epidemiology of cancer
Epstein Barr virus
Burkitts lymphoma
human papillomavirus
cervical cancer
Hepatitis B virus
Liver cancer
Human T-cell lymphotrophic virus
Adult T cell leukemia
Kaposi’s sarcoma- associated herpes virus
Kaposi’s sarcoma
pleomorphis
nucleus becoming more irregular in shape
2 distinctions of malignant tumor
infiltration of surrounding normal tissue and metastasis
Epithelial origin malignant
carcinoma
epithelial originan benign
papilloma, adenoma
mesenchymal origin malignant
sarcoma
mesenchymal origina benign
fibroma, lipoma
hematopoietic origin malignant
lymphoma, leukemia
well differentiated =
benign
undifferentiated =
malignant
carcinoma in situ
pre-invasive cancer. dysplastic changes in full epithelium but no invasion
6 initial cancer hallmarks
growth factor independence, no response to anti-growth, resistance to apoptosis, limitless replicative, recruitment blood, invasion and metastasis
PI3K
kinase involved in intracellular signaling
PI3K function
converts PIP2 to PIP3
What activates PI3K
various receptor tyrosine kinases including EGF
PIP3 function
docking site for plecksrin homology domains. Main function is activation of AKT
Warburg effect
high glycolytic rate in many cancer cells
AKT ajor effect
increases glucose transport and glycolysis = warburg effect
PTEN
antagonist to PIK3, dephosphorylates PIP3
Li-Fraumeni syndrome
only one germ-linke copy of p53 so succeptible to a number of cancers. Loss of Heterozygosity
p53 regulates
p21, GADD45, Bax,puma,noxa, DM2
p21
cyclin/CDK inhibtor. cell cycle arrest
CGADD45
DNA repair pathways protects genome
Bax, Puma, Noxa
pro-apoptotic protein inducing cell death
MDM2
ubiquilates p53, for degredation
ATM, ATR, CHK2
activators of p53
what transcribes MDM2
p53 transcribes it - form of negative feedback inhibition
Two protein classes important in apoptosis
caspases and nucleases
Caspase basic mechanism
use conserved cystein to cleave after aspartate. Makes the CASP part.
Intrinsic apoptotic pathway
cytochrome c binds Apaf-1 recruits initiator procaspase 9
cytochrome c
molecule in mitochondria critical for intrinsic apoptotic pathway
caspase 9 activates
initiator caspase activating 3,6,7 for execution
Cytochrome C release promoters
Bax and Bak
Cytochrome C release inhibit
Bcl-2 inhibits BAK pore formation
BAK function
sits in outer membrane to make pores.
BAX function
when activated goes to BAK and helps make a pore
Extrinsic pathway
Fas receptor activated by FasL. Recruits FADD - procaspases8 or 10 - caspases 3,6,7
Fas receptor
death signaling receptor responding to FasL
FADD
Fas associated death domain protein recruiting initator caspases
Family of death receptors
DR4,5 TNFR1, DR3
hTERT function
can surpress senescence of human cells. it extends and stabilizes chromosomes
breakage fusion bridge cycles
cycles that occur with no telomeres involving DNA damage
VEGF
stimulates EC division, master regulator of antiogenesis. VEGF-A most prominent
VEGF activates
specific receptor tyrosine kinases on ECs
Avastin (bevacizumab)
antibody against VEGF. late stage colon and renal cancer
Sunitinib and sorafenib
small molecule based inhibitors. block VEGFR2
seed and soil concept
cancer will lodge in areas that have appropriate growth factors for it to survive
Avastin problem
successful inhibition of VEGF makes tumor more invasive and metastatic
Cancer Diagnostics
Cancer Diagnostics
philadelphia chromosome
translocation from 22 to 9
philadelphia chromosome encodes
BCR-ABL
BcrABL
has abnormal tyrosine kinase activity
FFPE
formalin fixed paraffin embedded
Imatinib
Prevents ADP bidning to CL enzyme
BRAF mutation
40-60% of melanoma lesions. mutation predicts response to vemurafenib. most common mutation = V600E
BRAF in papillary thryoid carcinoma
benign never have mutation. 40-70 have mutation
BRAF in colorectal
predicts poorer prognosis
Ilumina sequencing
real time sequencing by synthesis
Sequencing read length
nuber of sequential images taken
sequencing read depth
number of DNA fragments sequenced for any position
One test at a time paradigm
only test for utation in cancers where it is signifiant and has a certain rate
bcr abl hallmark
growth-factor independence
Leukemai vs Lymphoblast
Leukemia generally of cells native to marrow. generally more immature cells
acute neoplasm
early undifferentiated state
chronic neoplasm
mature, differentiated states
germinal center B cell markers
CD10+, BCL6+, BCL2-
Mantle B cell markers
CD10-, BCL6-, BCL2+
CD 21 marker
follicular dendritic meshwork
Burkitt lymphoma translocation
t(8:14). overexpress MYC
Follicular lymphoma translocation
t14:18 overexpress BCL2
reason for more B cell NHL
because B cells go through multiple rounds of genetic rearrangement
Small B cell NHLs (3)
SLL/CLL, Follicular lymphoma, marginal zone lymphoma
FL common organ involvement
Spleen and liver. Rarely to bone marrow
FL pathology
centrocytes and centroblasts. follicles close together