30 Questions
Which of the following statements about oncogenes is true?
Overexpression of an oncogene can lead to cancer
What is the normal function of c-Src?
c-Src is a non-receptor tyrosine kinase
What is the difference between c-Src and v-Src?
v-Srv is missing a stretch of DNA with an important tyrosine residue, while c-Src is not
Which virus led to the discovery of oncogenes?
Tumor Virus
How does activation of c-Src occur?
Binding to cell surface receptors
Which of the following is NOT true about Src and v-Src?
v-Src is missing the Sh2 domain
What is the role of the SH2 domain in the activation of Src?
Binds to its own phospho-tyrosine
Who discovered the Rous Sarcoma Virus (RSV) that induces chicken tumors?
Peyton Rous
What did Varmus and Bishop find about the viral oncogene v-src?
It is derived from the cellular c-src gene
What is the role of GAP in the regulation of Ras activity?
Stimulates GTPase activity of Ras
Which Ras gene mutation is most commonly found in colorectal cancer, lung adenocarcinoma, and pancreatic ductal adenocarcinoma?
K-Ras
Which Ras gene mutation is most commonly found in melanoma, acute myeloid leukemia (AML), and thyroid cancer?
N-Ras
Which Ras gene mutation is most commonly found in head and neck squamous cell carcinoma (HNSCC) and urinary bladder carcinoma?
H-Ras
Which targeted therapy is designed to stimulate the patient's immune system to attack cells expressing EGFRvIII in glioblastomas?
Vaccines
Which receptor tyrosine kinase (RTK) is activated by forming dimers with other members of the EGFR family and can lead to cell proliferation?
Her2/Neu
Which of the following is true about oncogenes and tumor suppressor genes?
Oncogenes are associated with cancer when improperly activated.
What is the main difference between a proto-oncogene and an oncogene?
Proto-oncogenes are associated with cancer when improperly activated, while oncogenes are normal cellular genes.
Which of the following is an example of an oncogene?
Src
What is the function of tumor suppressor genes?
To inactivate or delete oncogenes
Which of the following is an example of a receptor tyrosine kinase that is an oncogene?
Her2/Neu
Which RTK is associated with breast cancer when it is overexpressed or if its gene is amplified?
Her2/Neu
Which drug is a small molecule kinase inhibitor of FGFR and is used to treat some patients with intrahepatic cholangiocarcinoma (iCCA)?
Lytgobi
Which RAF protein is most commonly associated with cancer and frequently mutated in melanoma?
B-Raf
Which gene is altered in some forms of intrahepatic cholangiocarcinoma (iCCA) and can be altered in various ways, including activating mutations, chromosomal translocations, gene fusions, and gene amplifications?
FGFR2
Which isoform of PI3K does Zydelig (idelalisib) target, and for which types of cancer is it approved?
PI3KCA
Which of the following CDK4/6 inhibitors is administered orally and approved for advanced HR-positive Her2 negative breast cancer?
Ibrance (palbociclib)
Which of the following is a CDK4/6 inhibitor given by IV injection and has been approved for small cell lung cancer and other cancers?
Cosela (Trilaciclib)
Which of the following is commonly found in some types of cancers, especially melanoma, and can be regulated by activating mutations?
CDK4 gene amplification
Which of the following is a white blood cell cancer for which Aliqopa (copanlisib) is FDA approved for treatment?
Follicular lymphoma
Which of the following is a common mechanism of CDK4 involvement in cancer?
Gene amplification
Study Notes
Oncogenes
- Oncogenes are genes that have the potential to cause cancer when mutated or expressed at high levels.
- The normal function of c-Src is to regulate cell growth and differentiation.
- c-Src is a proto-oncogene, whereas v-Src is an oncogene that is derived from the Rous Sarcoma Virus (RSV).
- The RSV led to the discovery of oncogenes.
- Activation of c-Src occurs when it is phosphorylated and relocated to the plasma membrane.
Src and v-Src
- The main difference between Src and v-Src is that v-Src is a constitutively active form of Src that is derived from the Rous Sarcoma Virus.
- v-Src is an oncogene that can induce tumors in chickens.
Ras and GAP
- Ras is a G-protein that regulates cell growth and differentiation.
- GAP (GTPase-activating protein) regulates Ras activity by stimulating GTP hydrolysis.
Ras Gene Mutations
- The Ras gene mutation most commonly found in colorectal cancer, lung adenocarcinoma, and pancreatic ductal adenocarcinoma is KRAS.
- The Ras gene mutation most commonly found in melanoma, acute myeloid leukemia (AML), and thyroid cancer is NRAS.
- The Ras gene mutation most commonly found in head and neck squamous cell carcinoma (HNSCC) and urinary bladder carcinoma is HRAS.
Targeted Therapies
- Rindopepimut is a targeted therapy designed to stimulate the patient's immune system to attack cells expressing EGFRvIII in glioblastomas.
- Lapatinib is a receptor tyrosine kinase (RTK) inhibitor that targets EGFR and HER2.
- Neratinib is a RTK inhibitor that targets HER2 and EGFR.
Oncogenes and Tumor Suppressor Genes
- Oncogenes are genes that have the potential to cause cancer when mutated or expressed at high levels.
- Tumor suppressor genes are genes that normally inhibit cell growth and division.
- The main difference between a proto-oncogene and an oncogene is that a proto-oncogene is a normal gene that has the potential to become an oncogene if mutated or overexpressed.
Examples of Oncogenes
- HER2 is an example of an oncogene that is associated with breast cancer when overexpressed or amplified.
- FGFR is an example of an oncogene that is associated with intrahepatic cholangiocarcinoma (iCCA) when mutated or overexpressed.
Ras-MAPK Pathway
- BRAF is a RAF protein that is commonly associated with cancer and frequently mutated in melanoma.
- PIK3CA is a gene that is altered in some forms of intrahepatic cholangiocarcinoma (iCCA) and can be altered in various ways, including activating mutations, chromosomal translocations, gene fusions, and gene amplifications.
Cancer Treatments
- Zydelig (idelalisib) is a small molecule kinase inhibitor of PIK3CA that is approved for some types of cancer.
- Palbociclib is a CDK4/6 inhibitor that is orally administered and approved for advanced HR-positive Her2-negative breast cancer.
- Abemaciclib is a CDK4/6 inhibitor that is orally administered and approved for advanced breast cancer.
- Trilaciclib is a CDK4/6 inhibitor that is given by IV injection and has been approved for small cell lung cancer and other cancers.
- Aliqopa (copanlisib) is a PI3K inhibitor that is approved for the treatment of follicular lymphoma.
- Vismodegib is a Hedgehog pathway inhibitor that is approved for basal cell carcinoma.
Test your knowledge on the biology of cancer with this quiz! Learn about the activation and pathways of Ras in cell growth and proliferation, as well as the prevalence of Ras mutations in human cancers. Explore the different types of Ras genes and their mutation rates.
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