Module 14: Cancer Flashcards
(24 cards)
What are the key hallmarks of cancer?
Increased proliferation, signaling defects, apoptosis avoidance, angiogenesis, metastasis, and altered metabolism.
What is the difference between a malignant and a benign tumor?
Malignant tumors invade surrounding tissues and can metastasize, while benign tumors remain localized and do not spread.
Define the following cancer types: carcinoma, sarcoma, lymphoma/leukemia, and melanoma.
Carcinoma: cancers originating from epithelial cells.
Sarcoma: cancers arising from connective tissues (bone, muscle).
Lymphoma/leukemia: cancers of the lymphatic system and blood.
Melanoma: cancers originating from melanocytes (pigment-producing skin cells).
What is the difference between a driver mutation and a passenger mutation?
Driver mutations promote cancer development, while passenger mutations are byproducts with no direct role in cancer progression.
What is a microevolutionary process in cancer?
The gradual accumulation of mutations that provide survival advantages to cancer cells.
What is a tumor suppressor gene?
A gene that prevents uncontrolled cell growth. Its loss of function mutations promote cancer.
What is a proto-oncogene, and how does it become an oncogene?
A proto-oncogene is a normal gene that promotes cell growth. It becomes an oncogene through gain-of-function mutations, such as point mutations, gene amplifications, or chromosomal rearrangements.
What are examples of tumor suppressor genes and oncogenes?
Tumor suppressors: TP53, RB1
Oncogenes: Ras, HER2
What is the role of the retinoblastoma (Rb) protein in cancer?
Rb inhibits the cell cycle by binding E2F. Its mutation leads to uncontrolled cell division.
What is E2F protein?
A transcription factor that promotes DNA replication when released from Rb.
How do BRCA1 and BRCA2 function in cancer prevention?
They repair double-stranded DNA breaks, preventing mutations that can lead to cancer.
What is p53 (TP53), and why is it important?
A key tumor suppressor protein that triggers cell cycle arrest or apoptosis in response to DNA damage.
What is a missense mutation?
A mutation that changes a single amino acid in a protein, potentially activating an oncogene or disabling a tumor suppressor.
What is gene amplification?
An increase in the number of copies of a gene, leading to overexpression of cancer-promoting proteins.
What is chromosomal rearrangement or chimeric gene?
A structural change in chromosomes that can crease a fusion gene with new cancer-promoting functions.
What is a translocation?
A chromosomal abnormality where a segment of one chromosome is transferred to another, potentially activating oncogenes.
What is the role of Ras in cancer?
Ras is a GTPase involved in cell signaling. Mutations make Ras continuously active, promoting cell proliferation.
What are growth factor receptors and mitogens?
Growth factor receptors bind mitogens (molecules that stimulate cell division) to activate cell signaling pathways.
What is the Warburg effect?
Cancer cells preferentially use aerobic glycolysis (fermentation) for energy, even in the presence of oxygen.
How are insulin receptors involved in cancer metabolism?
Insulin receptors enhance glucose uptake, supporting the high metabolic demand of cancer cells.
What is an FDG-PET scan, and how does it detect cancer?
A diagnostic imaging technique that detects glucose uptake in tumors using a radioactive glucose analog.
What is a PARP inhibitor, and how does it work?
A drug that blocks DNA repair in cancer cells with defective BRCA1/BRCA2 genes, leading to cell death. Selectively kills the cells with defective BRCA genes.
What are miRNAs, and how do they relate to cancer?
MicroRNAs regulate gene expression. Their dysregulation can promote cancer by silencing tumor suppressors or activating oncogenes.
What is telomerase, and how does it promote cancer?
Telomerase extends telomeres, enabling cancer cells to divide indefinitely (cellular immortality).
