Questions and CORRECT Answers
G1 - CORRECT ANSWER - The first gap, or growth phase, of the cell cycle, consisting of
the portion of interphase before DNA synthesis begins. Cell grows larger and produces ribosome
and proteins.
S - CORRECT ANSWER - All 46 chromosomes are replicated in the cells nucleus
G2 - CORRECT ANSWER - The second gap, or growth phase, of the cell cycle,
consisting of the portion of interphase after DNA synthesis occurs. DNA is condensed into rod
form .
(M) Mitosis - CORRECT ANSWER - Mitosis. Cells physically divides into two daughter
cells, each with its own nucleus and identical chromosomes.
G0 - CORRECT ANSWER - Resting phase and Not succeptible to chemotherapy as it in
not in active cell cycle. Preforming it's programmed function. Will either die or repair DNA.
Cyclin dependent kinases (CDKs) - CORRECT ANSWER - Stimulate the cell to proceed
into the next phase of the cell cycle.
Check points - CORRECT ANSWER - Occur at G1, G2, and Mitosis; uses chemical and
physical signals to monitor the growth of cells. In normal cells if DNA defects are found,
progression through the cell cycle is halted. Errors that cannot be repaired result in cell death
(apoptosis). In cancer cells these check points may be defective resulting in uncontrolled
proliferation.
Apoptosis - CORRECT ANSWER - Natural cell death and removal by phagocytes. Each
normal cell has a limited number of cell divisions. Malignant cells have lost the ability to
undergo apoptosis, resulting in immortalization. Inducing apoptosis to these cells via necrosis is
the goal of cancer treatments.
,Proto-oncogenes - CORRECT ANSWER - normal cellular genes that are important
regulators of normal cellular processes, they promote growth. alterations in the expression of
these cells result in oncogenes
Oncogenes - CORRECT ANSWER - genes that cause cancer by blocking the normal
controls on cell reproduction. Activity of oncogenes produces a constant signal for production in
the cell cycle and cause the cell to grow out of control. MYCN associated with neuroblastoma
Tumor Supressor Gene - CORRECT ANSWER - A gene whose protein product inhibits
cell division, thereby preventing the uncontrolled cell growth that contributes to cancer. If these
genes are damaged or absent, cells lack the appropriate growth inhibiting factors and grow out of
control. P53 gene
p53 - CORRECT ANSWER - tumor suppressor gene. Most often mutated in cancers.
Hallmark of cancer - CORRECT ANSWER - Increase in genetic instability and mutation
rates. Dividing malignant cells rapidly acquire gentic changes , so tumors are similar but not
identical. This means that with variability in cells one chemotherapy agent may not be effective
against all tumor cells.
Hematopoietic stem cell - CORRECT ANSWER - cell in the bone marrow that gives rise
to all types of blood cells (neutrophils, monocytes, lymphocytes, erythrocytes, and platelets).
Lymphoid lineage - CORRECT ANSWER - B cells, T cells, NK cells. B cells from the
bone marrow, T cells from the thymus
myeloid lineage - CORRECT ANSWER - A subset of bone-marrow derived cells
comprising granulocytes, monocytes, and macrophages.
Immune Response - CORRECT ANSWER - The body's defensive reaction to invasion by
bacteria, viral agents, or other foreign substances. May play a role in the prevention of many
cancers.
, 3 layers of the immune response - CORRECT ANSWER - 1) physical barrier (mucous
membranes and skin)
2) innate or nonspecific immune system
3) adaptive or acquired immune system
Physical barrier immune system - CORRECT ANSWER - Skin and mucous membranes.
Interruption of the integrity of these barriers provides a portal of entry for infectious agents.
Innate or passive immunity - CORRECT ANSWER - Rapid, nonspecific response to
invading pathogens. Neutrophils are the first at the site of infection, providing nonspecific
phagocytosis and bacterial ingestion. Possess when we are born.
Adaptive immune system - CORRECT ANSWER - Specific and a delayed/slower
lymphocyte response to specific antigens. T cells and B cells. Page 15
MYCN amplification - CORRECT ANSWER - key risk stratifier for treatment/therapy in
neuroblastoma; technique by which MYCN protein drives cells into the cell cycle; leading to
extra MYCN protein; detected by FISH
I-MIBG - CORRECT ANSWER - Absorbed by tissues containing adrenergic nerves and
us sued in then diagnosis, staging, and follow up of neuroblastoma. It is taken up by an active
tumor, minimizing the false-positive results that may show in a bone scan. After the tracer is
administered, patients are seen 24, 48, and 72 hours for imaging. To protect the thyroid from
radiation exposure, all receive potassium iodine drops 1 day prior and 5-10 days after.
Bone marrow aspirate or biopsy - CORRECT ANSWER - Obtained when Hugh suspicion
of leukemia or lymphoma exists or when a solid tumor may have spread to the bone marrow
lumbar puncture (LP) - CORRECT ANSWER - inserting a needle into the lumbar region
of the spine in order to collect spinal fluid, commonly called a "spinal tap" for suspected
leukemia, NHL, and certain brain tumors to evaluate for malignant cells in the CSF. L3-L4 or
L4-L5