Hallmarks of Cancer-March 31 2025 (1) (1) Flashcards
(25 cards)
What are the hallmarks of cancer?
- Invasion and metastasis
- Genomic instability
- Sustained proliferative signaling
- Altered metabolism (Warburg effect)
- Resistance to cell death
- Lack of replicative senescence
- Evasion of immune surveillance
- Induction of angiogenesis
Examples of these hallmarks can be found in various cancer types.
What is genomic instability in cancer?
Cancer driving mutations that result in a highly heterogeneous tissue containing diverse genetic landscapes.
This includes mutations in proto-oncogenes and tumor suppressor genes.
What was the purpose of the Pan-Cancer Analysis of Whole Genomes Project (PCAWG)?
To analyze the whole genome of different cancer types through mutational analysis of tumors from 2,658 donors across 37 countries.
It involved over 1300 scientists and clinicians.
What is the Philadelphia chromosome?
A reciprocal translocation between chromosome 9 and chromosome 22 that generates the BCR-ABL gene, providing continuous proliferative signals to CML cells.
Discovered by Dr. Nowell and graduate student Hungerford.
What is the Warburg effect?
Cancer cells preferentially use glycolysis over the Krebs cycle for energy production even in aerobic conditions.
This effect was first described by Otto Warburg.
What happens during apoptosis in cancer cells?
Cancer cells often overexpress BCL2, which inhibits apoptosis by neutralizing pro-apoptotic proteins like BAX.
Apoptosis is a highly regulated physiological process of programmed cell death.
What is the Hayflick limit?
The number of times a normal somatic cell can divide before cell division stops, typically around 50-60 divisions.
This limit is related to telomere shortening.
What is the role of telomerase in cancer cells?
Telomerase reverse-transcriptase (TERT) maintains telomere length, allowing cancer cells to avoid replicative senescence and achieve limitless replication.
This contributes to chromosomal stability in cancer cells.
What is the function of hypoxia-inducible factor-α (HIF-α)?
HIF-α promotes the synthesis and secretion of Vascular endothelial growth factor (VEGF) to stimulate angiogenesis in tumors.
It is activated in response to hypoxic conditions in tumor cores.
What is the significance of VEGF in cancer?
VEGF activates VEGF receptors (VEGFR) on endothelial cells to promote tumor angiogenesis, ensuring sufficient nutrient and oxygen supply.
This is crucial for tumor growth and survival.
True or False: Cancer cells can evade immune surveillance.
True
Cancer cells express PD-L1, which helps them escape detection by cytotoxic T cells.
Fill in the blank: Cancer cells prefer _______ over the Krebs cycle for energy production.
glycolysis
This preference is part of the Warburg effect.
What are the common mutations found in cancer driving mutations?
- Gain of function mutations in proto-oncogenes (e.g., KRAS, B-RAF, MYC)
- Loss of function mutations in tumor suppressor genes (e.g., TP53, PTEN, RB1)
- Loss of function mutations in DNA repair genes (e.g., BRCA1, BRCA2)
These mutations contribute to cancer development and progression.
What are hormone-dependent cancers?
Cancers that rely on hormones for sustained proliferative signaling, such as breast and prostate cancer.
Breast cancer is classified based on hormone receptor expression.
What is the role of androgen in prostate cancer?
Androgens activate the androgen receptor (AR) in prostate cancer cells, providing sustained proliferative signals.
This signaling can become independent in some cancer cells.
What is the relationship between glucose metabolism and cancer imaging?
The high glucose accumulation in cancer cells is utilized in diagnostic imaging techniques like PET scans to visualize tumors.
Radiolabeled glucose is administered to patients for this purpose.
What is the role of VEGF in tumor angiogenesis?
VEGF activates VEGF Receptors (VEGFR) on endothelial cells to promote tumor angiogenesis.
VEGF stands for Vascular Endothelial Growth Factor, which is crucial for new blood vessel formation.
Which receptors do norepinephrine activate to promote tumor angiogenesis?
Adrenergic β2 receptors on endothelial cells.
Norepinephrine is released from sympathetic nerves and plays a role in the tumor microenvironment.
What are pericytes and their function in angiogenesis?
Pericytes are part of blood capillaries that release VEGF and angiopoietin-1 (Ang-1) to promote the survival of endothelial cells.
Angiopoietin-1 is a protein that plays a significant role in blood vessel maturation and stability.
True or False: Norepinephrine is involved in enhancing tumor angiogenesis.
True
Norepinephrine’s action on adrenergic receptors contributes to the angiogenic process in tumors.
Fill in the blank: The tumor microenvironment includes _______ cells, which are involved in angiogenesis.
stromal
Stromal cells include various cell types that provide structural support to the tumor.
Name two factors released by pericytes that promote endothelial cell survival.
- VEGF
- Angiopoietin-1
These factors are essential for the maintenance and stability of blood vessels in tumors.
What is the significance of the tumor microenvironment in cancer biology?
It plays a critical role in supporting tumor growth and angiogenesis through the interaction of cancer cells and stromal cells.
The tumor microenvironment is a complex and dynamic area that influences cancer progression.
What is the primary function of angiopoietin-1 in the context of angiogenesis?
To promote the survival of endothelial cells.
Angiopoietin-1 works alongside VEGF to ensure proper blood vessel formation.
