Neoplasia Part 4, UTHSC Fall 2022 D2 Pathology
Resisting Cell Death or Evasion of Programmed Cell Death
- Cell death by apoptosis as a protective response to several pathologic conditions that
might contribute to malignancy if the cells remained viable.
- Biochemical pathways leading to apoptosis
- Cancer cells present mutations in the genes that regulate apoptosis
What three interrelated factors are critical to the immortality of cancer cells?
- Self-renewal
- Evasion of senescence
- Evasion of mitotic crisis
A single cell can
Replicate itself, or differentiate into many cell types
what are the two hypotheses for cancer formation from a stem cell
1. multiple mutations of a stem cell cause it to become a cancer stem cell, leading to
tumor progression
2. stem cells differentiate into a mature cell, then p53 is mutated which turns it into a
cancer stem cell, leading to tumor progression
Telomere
A region of repetitive nucleotide sequences at each end of a chromosome
Telomere Shortening and Aging
as cells replication some of the repetitive sequence in the telomere is cut off. Over years
this eventually causes the breakdown of cellular DNA and aging effects
how do cancer cells overcome the Mitotic Catastrophe Caused by Telomere
Shortening?
they reactive their telomerase, which adds more length to their telomeres, extending
their life
Angiogenesis
the process of vessel sprout from previously existing capillaries
how do tumors create angiogenesis?
tumors release specific factors capable of stimulating the growth of blood vessels
what did Dr. Judah Folkman (1933-2008) show?
even if a solid tumor possesses all the genetic aberrations that are required for
malignant transformation, it cannot enlarge beyond 1 to 2 mm in diameter unless it has
the capacity to induce angiogenesis
what triggers angiogenesis?
hypoxia
what growth factor is transcribed to fascilitate angiogenesis?
VEGF
what controls angiogenesis?
a balance between angiogenesis promoters and inhibitors
T/F Early in tumor development, most human tumors do not induce angiogenesis
True
vascular quiescence stage
early stage of cancer where tumors do not induce angiogenesis
what terminates the vascular quiescence stage?
angiogenic switch
Resisting Cell Death or Evasion of Programmed Cell Death
- Cell death by apoptosis as a protective response to several pathologic conditions that
might contribute to malignancy if the cells remained viable.
- Biochemical pathways leading to apoptosis
- Cancer cells present mutations in the genes that regulate apoptosis
What three interrelated factors are critical to the immortality of cancer cells?
- Self-renewal
- Evasion of senescence
- Evasion of mitotic crisis
A single cell can
Replicate itself, or differentiate into many cell types
what are the two hypotheses for cancer formation from a stem cell
1. multiple mutations of a stem cell cause it to become a cancer stem cell, leading to
tumor progression
2. stem cells differentiate into a mature cell, then p53 is mutated which turns it into a
cancer stem cell, leading to tumor progression
Telomere
A region of repetitive nucleotide sequences at each end of a chromosome
Telomere Shortening and Aging
as cells replication some of the repetitive sequence in the telomere is cut off. Over years
this eventually causes the breakdown of cellular DNA and aging effects
how do cancer cells overcome the Mitotic Catastrophe Caused by Telomere
Shortening?
they reactive their telomerase, which adds more length to their telomeres, extending
their life
Angiogenesis
the process of vessel sprout from previously existing capillaries
how do tumors create angiogenesis?
tumors release specific factors capable of stimulating the growth of blood vessels
what did Dr. Judah Folkman (1933-2008) show?
even if a solid tumor possesses all the genetic aberrations that are required for
malignant transformation, it cannot enlarge beyond 1 to 2 mm in diameter unless it has
the capacity to induce angiogenesis
what triggers angiogenesis?
hypoxia
what growth factor is transcribed to fascilitate angiogenesis?
VEGF
what controls angiogenesis?
a balance between angiogenesis promoters and inhibitors
T/F Early in tumor development, most human tumors do not induce angiogenesis
True
vascular quiescence stage
early stage of cancer where tumors do not induce angiogenesis
what terminates the vascular quiescence stage?
angiogenic switch
