BIIC Pathology Lecture 6_ Cancer Pathology and Immunotherapy Flashcards
What are the two main types of oncogenes that are altered in a cancerouse cell?
Receptors that signal transduction cascades or transcription factors are altered to leave them “on” all the time.
What causes the “Philadelphia chromosome”
Gene for the c-ABL tyrosine kinase is translocated from it’s normal location on chromosome 9 to chromosome 22 [t(9:22)], where it fuses with the BCR gene. This results in a constitutivly active BCR-ABL tyrosine kinase gene.
What causes Burkitt Lymphoma?
A [t(8:14)] translocation that puts the MYC gene under the regulation of the immunoglobulin heavy chain gene on chromosome 14. This results in the over expression of MYC.
How do many B cell lymphomas evade Apoptosis?
A [t(14:18)] translocation that moves the immunoglobulin heavey chain gene to the 18th chromosome near BCL2. BCL2 is an anti apoptotic gene. Over expression of BCL2 results the intrinsic pathway of apoptosis becoming inactive.
What are the three ways cancer cells often evade the immune system?
1) loss of the antigenic protein 2) Down regulat MHC class I 3) Produce immunosuppresive cytokines
What are the two main ways cancer cells can down regulate the immune system?
1) Secret cytokines that upregulate CTLA-4 on t cells 2) Upregulate PD-L1 on the surface of cancer cells
How is the immune systems altered to fight cancer?
1) upregulate immune response (things like giving IL-2) 2) Prevent immune suppresion by the tumor
What is a classic check point inhibitor and how does it work?
Ipilimumab. It is a monoclonal antibody against CTLA-4. It binds to CTLA-4 and thus blocks the it from terminating colonial proliferation.
How does CAR-T therapy work?
You take a t cell and insert the gene for an antigen receptor specific for a cancer cell. You then grom a bunch of them and inject them into the patient
Explain how a dendritic cell vaccine works
