Pathology Intro To Cancer Flashcards
(37 cards)
Proto-oncogenes
Gene involved in normal cell growth
Oncogene
Mutated proto-oncogene that could lead to cancer
Tumor suppressor genes
Can synthesize growth factors to increase proliforation
Cell growth pathway 1
Signal, GF binds to pathway, activates cytoplasmic signaling of transducing proteins to nucleus
Cell growth pathway 2
Activated transcription factors (DNA) transcripts growth promoters and regulators
Signal transducing proteins - RAS
RAS - activated by tyrosine kinase activity
Encodes for protein to bind to GDP/GTP
Inactive ras binds GDP
Signal transducing proteins PI3
PI3 kinase - AKT signaling
Activated for GF binding & TKA
Common mutation for canine mammary tumors
Transcription factor Myc
Activates many gene expression in cell growth, can upregulate expression of telomerase, can reprogram somatic cells
Common in lymphoma & prostate carcinoma
RB protein
Inhibits cell proliferation
RB protein mechanism
Binds & inhibits transcription factors, prevents cells from G1->S phase
Mutated rb is common in canine hemangiosarcoma & osteosarcoma
Tumor suppressor genes & common cancers
APC - colorectal cancer
PTEN - histiocytic sarcoma
(E-Cadherin, CDKN2A)
P53 - function & common cancer
Tumor suppressor - check point
canine melanoma
What protein signals for intrinsic apoptosis?
Bcl-2 -> cytochrome C
What protein signals for extrinsic apoptosis?
FLIP, FasL, Fas, FADD
Steps for successful metastasis (4)
Invade extracellular matrix
Disseminate through vessels
Locate distant site of tissue
Successfully grow/proliferate
Function of vascular dissemination & homing
Tumor cells aggregating with tumor cells, platelets & coagulation factors to reduce systemic stress on tumor cells
Types of tumor antigens (5)
Viral coded proteins
Mutated proteins
Differentiation antigens
Excessive amts of normal proteins
Cancer/testis antigens
Source of tumor antigens (5)
Viral coded - products of genes of oncogenic viruses
Mutated - altered forms of normal proteins
Differentiation antigens - proteins associated w specific stages of cell differentiation
Excessive proteins - over production of normal cell protein
Cancer antigens - unknown function
Cytotoxic t lymphocytes
Presence is marker for better prognosis, can respond to new antigens (abnormal)
Natural killer cells
Recognize lack of MHC I or stress induced proteins expressed on cell surface
M1 (macrophage)
Pro-inflammatory/anti tumor
Immunoediting
How cancer reduces immune response, reduces MHC expression & antigen neg variants
Immunosuppression: targeting Th1 & macro
TGFb & IL-10 suppress immune, target tumor cells, suppress Th1, convert T cells
Immune suppression- reduction
Evade immune system, remove growth suppressors, ROS (genetic damage)