30 Clinical Examples of Cancer Drivers Flashcards
(44 cards)
Name 2 oncogenes and the FORM of leukemia that they drive
MYC - Burkitt’s lymphoma (AGGRESSIVE)
Bcl2 - Follicular lymphoma (indolent)
What are the PRECURSORS of oncogenes?
What is their function?
PROTO-oncogenes drive growth + differentiation
Upon mutation of proto-oncogenes to form oncogenes, what cellular changes can oncogenes DRIVE?
HyperACTIVE protein
More EXPRESSION of normal protein
Name 5 genetic changes that can cause conversion of a proto- to an ONCOGENE
- CODING seq mutation
- Gene AMPLFICATION
- Rearrangements (FUSION protein)
- Rearrangements (near strong PROMOTER)
- KO neg feedback
Effects of:
- CODING seq mutation
- Gene AMPLFICATION
- Rearrangements (FUSION protein)
- Rearrangements (near strong PROMOTER)
- KO neg feedback
- HYPERactive protein (normal amount)
- EXCESS expression (normal protein)
- HYPERactive protein (normal amount)
- EXCESS expression (normal protein)
- EXCESS expression (normal protein)
Secondary immune organs are the SITES of _____
ANTIGEN-driven replication + maturation
Where does B-cell production begin?
What happens?
Haematopoietic SCs develop into NAIVE B-cells
Define NAIVE B-cells
BCR has no exposure to antigens yet
Where do naive B-cells go for maturation?
What happens?
Lymph nodes
= BCR on naive cells EXPOSED to antigens in follicles
The exposure of BCRs to antigens, and subsequent maturation is called
Transformation
Describe the morphology of LNs before vs after antigen-exposure
BEFORE antigen-exposure = SMALL primary follicles
AFTER antigen-exposure = LARGE secondary follicles
“Transformation” is AKA
Germical Centre reaction
At the germinal centre, what are the 2 “populations” of cells, and how do they differ?
LIGHT zone = proliferating MATURE B-cells
DARK zone = DYING weak-binding cells
What events occur in the BONE MARROW and LNs to promote Ig gene-rearrangements?
Bone marrow
= VDJ recombination to create UNIQUE BCRs
Lymph nodes (upon antigen-exposure)
= POINT MUT in V/D/J genes
= Different CLASSES of Ig formed
What is a “dangerous” aspect of Ig gene-rearrangements
Forms many DSBs and REPAIR of these
What kind of DSB-repair ERROR occurs?
Reciprocal Balanced Transition (no DNA lost)
What kind of recombination specifically occurs in Burkitts and Follicular lymphoma?
Burkitts = recombination of IGH promoter + MYC
= t(8;14)
Follicular = recombination of IGH promoter + Bcl2
= t(14;18)
What chr is the IGH promoter on?
14
How are such FUSIONS detected?
FISH
Effects of MYC as an oncogene?
What hallmarks does it control?
Controls all cancer hallmarks except 1 (MILESSEGII)
*Metastasis - dec cell adhesion
*Insensitive to anti-growth - immortalised cells have inc telomerase activity
*Limitless growth potential
*
*Self-sufficient growth - glycolysis+glutaminolysis to support BIOMASS synthesis
*Sustained angiogenesis
- Energetics dysregulation
- Genome instability
- Immune evasion
- Inflammation
What hallmark does MYC NOT control?
APOPTOSIS is maintained normally
Describe the HISTOLOGY of Burkitt’s lymphoma cells
- many LARGE BLASTS
- dark BLUE cytoplasm
- OPEN chromatin
- can REPLACE LN structure
- Smear + DYING celsl common
What immune cell type is COMMON in Burkitt’s ?
Why?
Macrophages - phagocytic for apoptotic cells
What molecular MARKER is 100% expressed in Burkitt’s cells? What does it suggest?
Ki67 = proliferation cycling marker