Cancer signaling and targeted therapies Flashcards
What are the three different types of genes that are important in making a cell cancerous?
Genes that encourage the cell to multiply (oncogenes “accelerators”) –> Stuck accelerator (GOF)
Genes that stop the cell multiplying (tumor suppressor genes “brakes”) –> LOF
Genes that repair other damaged genes (DNA repair genes “mechanic”)
What are the types of mutations and chromosomal rearrangement that yield conversion of proto-oncogenes into oncogenes?
How are they similar and how are they different?
Types of Mutations
Deletion or point mutation in coding sequence –> hyperactive protein made in normal amounts
Regulatory mutations –> normal protein greatly overproduced
Gene amplification –> normal protein greatly overproduced
Chromosome Rearrangement
Nearby regulatory DNA sequences cause normal proteins to be overproduced
OR
fusion to actively transcriptome gene produced hyperactive fusion protein
Similarity: They cause proto-oncogene –> oncogenes
What is the mechanism that could lead to changes in tumor suppressors that can lead to cancer?
A normal cell will undergo a mutation event which will inactivate the tumor suppressor gene. There will be no effect of mutations in one gene.
The second mutation event, which will inactivates second gene copy which will eliminate the tumor suppressor gene, promoting cell transformation
_______________ is the non-targeted therapy to treat cancer.
Side effects:
Not only kills fast-growing cancer cells, but also kills or slows the growths of healthy cells that grow and divide quickly.
Damage to healthy cells many cause: mouth sores, nausea, and hair loss
Chemotherapy
______________ are drugs or other substances that block the growth and spread of cancer by interfering with specific molecules. Sometimes called “precision medicines”
Targeted cancer therpaies
Name of few differences of targeted therapies from standard chemotherapy
Targeted therapies act on specific molecular targets that are associated with cancer, whereas most chemotherapies act on all cells (healthy and cancerous cells)
Targeted therapies are deliberately chosen or design to interact with their targets, chemotherapies were identified because they kill cells.
Targeted therapies are often cytostatic *block tumor cell proliferation) whereas standard chemotherapy agents are cytotoxic (kill tumor cells)
What is the drug form,
the cancer type
molecular targets
and mechanism of action
of Herceptin?
Drug form: Monoclonal antibody
Cancer Type: breast cancer
Molecular Targets: HER2 (Human Epidermal Growth Factor Receptor 2), a protein whose overexpression is associated with higher aggressiveness in many breast cancers
MOA: Herceptin blocks downstream HER2 signaling to inhibit proliferation of signal tumor cells (inactivation)
What is the drug form,
the cancer type
molecular targets
and mechanism of action
of Gleevec?
Drug form: Small molecular inhibitor
Cancer types: Certain types of cancer, especially chronic myelogenous/myeloid leukemia (CML) but also # of other malignancies.
Molecular targets: ABL non-receptor tyrosine kinase
MOA: See image
True or False
Different patients to a particular drug can differ in cancer treatment
True
