Cancer biology exam 1 2025
Questions and Answers
What is cancer? - ANSWER✔✔-Cancer is an aberration of normal development. Cancer
cells exhibit behaviors found in normal cells during development and differentiation,
but they behave independently and don't "obey" controls - that's the only difference
between them and normal cells.
Cells become highly organized into different compartments at some point in life. Cancer
develops through gradual changes in cell morphology and properties. Cells go from
tightly adhered -> not as tightly adhered and now overlapping boundaries ->
"carcinoma" -> "cancer"
Tumor vs. Carcinoma vs. Cancer - ANSWER✔✔-"tumor" is just an abnormal growth of
solid tissue.
"carcinoma" is cancer of the epithelia - it is benign because it hasn't metastasized yet.
"cancer" is invasive, cells have disrespected boarder and can now enter bloodstream - it
is malignant.
,Metastasis - ANSWER✔✔-The development of secondary malignant growths at a
distance from the primary site. Not what kills you! What kills you is the lack of function
of normal cells. The route of the pulmonary system determines the tendency of primary
tumors to affect certain other tissues.
Properties of cancer cells - ANSWER✔✔-1. Cancer cells are "immortalized" -
2. Cancer cells do not form differentiated tissues
3. Cancer cells escape apoptosis
4. Cancer cells are invasive
Explain how cancer cells are "immortalized" - ANSWER✔✔-Most normal cells have a
limited potential to divide - telomere shortening will drive cells into senescence. Cancer
cells are similar to stem cells in that they can divide indefinitely, but stem cells are
under tight control and their daughter cells are already partially differentiated. Cancer
cells have no control and their daughter cells have the same potential.
Explain what it means to say cancer cells do not form differentiated tissues -
ANSWER✔✔-Cancer cells' daughter cells posses the same potential as they, to continue
dividing indefinitely without differentiation, or the possibility of reaching senescence.
Cancer is clonal - they are identical cells derived from the same cell.
Explain what it means to say cancer cells escape apoptosis - ANSWER✔✔-Normal cells
may undergo apoptosis a) as part of a developmental program or b) when cells become
, "dangerous" (such as DNA damage). Cancer cells receive the same signals, they just
don't listen to them.
Explain what it means to say cancer cells are invasive - ANSWER✔✔-Cancer cells do
not obey their boundaries and will invade into surrounding tissue. Normal cells can be
invasive at the right time and place - such as a wbc chasing and engulfing a bacteria.
Cancer cells are clonal - ANSWER✔✔-The cells all come from one common ancestor.
One mutation may allow further mutations to take place - this microevolution is needed
for cancer cells to survive.
What causes cancer? - ANSWER✔✔-Cancer is an accumulation of mutations. The main
component of formation is mutations in somatic cells, but you need more than one
thing to go wrong in order to cause cancer.
- random mutations (mistakes in the assembly line)
- inherited mutations (pre-disposition)
- viral infections, i.e. HPV
- environmental factors (chemical or physical), i.e. smoking, UV radiation
1st evidence for environmental effects on cancer? - ANSWER✔✔-Skin cancer in
chimney sweeps - baths helped.
Lead to the discovery of carcinogens.
Questions and Answers
What is cancer? - ANSWER✔✔-Cancer is an aberration of normal development. Cancer
cells exhibit behaviors found in normal cells during development and differentiation,
but they behave independently and don't "obey" controls - that's the only difference
between them and normal cells.
Cells become highly organized into different compartments at some point in life. Cancer
develops through gradual changes in cell morphology and properties. Cells go from
tightly adhered -> not as tightly adhered and now overlapping boundaries ->
"carcinoma" -> "cancer"
Tumor vs. Carcinoma vs. Cancer - ANSWER✔✔-"tumor" is just an abnormal growth of
solid tissue.
"carcinoma" is cancer of the epithelia - it is benign because it hasn't metastasized yet.
"cancer" is invasive, cells have disrespected boarder and can now enter bloodstream - it
is malignant.
,Metastasis - ANSWER✔✔-The development of secondary malignant growths at a
distance from the primary site. Not what kills you! What kills you is the lack of function
of normal cells. The route of the pulmonary system determines the tendency of primary
tumors to affect certain other tissues.
Properties of cancer cells - ANSWER✔✔-1. Cancer cells are "immortalized" -
2. Cancer cells do not form differentiated tissues
3. Cancer cells escape apoptosis
4. Cancer cells are invasive
Explain how cancer cells are "immortalized" - ANSWER✔✔-Most normal cells have a
limited potential to divide - telomere shortening will drive cells into senescence. Cancer
cells are similar to stem cells in that they can divide indefinitely, but stem cells are
under tight control and their daughter cells are already partially differentiated. Cancer
cells have no control and their daughter cells have the same potential.
Explain what it means to say cancer cells do not form differentiated tissues -
ANSWER✔✔-Cancer cells' daughter cells posses the same potential as they, to continue
dividing indefinitely without differentiation, or the possibility of reaching senescence.
Cancer is clonal - they are identical cells derived from the same cell.
Explain what it means to say cancer cells escape apoptosis - ANSWER✔✔-Normal cells
may undergo apoptosis a) as part of a developmental program or b) when cells become
, "dangerous" (such as DNA damage). Cancer cells receive the same signals, they just
don't listen to them.
Explain what it means to say cancer cells are invasive - ANSWER✔✔-Cancer cells do
not obey their boundaries and will invade into surrounding tissue. Normal cells can be
invasive at the right time and place - such as a wbc chasing and engulfing a bacteria.
Cancer cells are clonal - ANSWER✔✔-The cells all come from one common ancestor.
One mutation may allow further mutations to take place - this microevolution is needed
for cancer cells to survive.
What causes cancer? - ANSWER✔✔-Cancer is an accumulation of mutations. The main
component of formation is mutations in somatic cells, but you need more than one
thing to go wrong in order to cause cancer.
- random mutations (mistakes in the assembly line)
- inherited mutations (pre-disposition)
- viral infections, i.e. HPV
- environmental factors (chemical or physical), i.e. smoking, UV radiation
1st evidence for environmental effects on cancer? - ANSWER✔✔-Skin cancer in
chimney sweeps - baths helped.
Lead to the discovery of carcinogens.
