EXAMS SCRIPT 2026 QUESTIONS AND ANSWERS
SURE A+
✔✔Cytokines - ✔✔-Secreted by lymphocytes
-Tasked with eliminating the antigen
-Multifunctional subsances having proinflammatory, anti-inflammatory, and regulatory
functions in the immune system
✔✔Cytokines Include.. - ✔✔-Interferons (IFNs)
-Tumor necrosis factors
-Transforming GFs
-Interleukins (IL -1, -2, -3, -4, -6, -8, -10, and -15)
-These cytokines regulate antibody production and the functions of B and T cells as well
as interact with antigen-presenting cells and NKCs
✔✔Benign Tumors - ✔✔-encapsulated and grow in an orderly manner with smooth
edges
-Do not invade neighboring tissue
-DO not metastasize to distant sites
-the cells well differentiated in that they look like the parent cell
✔✔Characteristics of Cancer Cells - ✔✔-Malignant tumors are not encapsulated
-Cell structure is different from parent tissue (no as well differentiated)
,-Cell division is uncontrolled
-Cells are loosely adherent without contact inhibition
-Cells are able to invade neighboring tissue
-Cells can migrate and metastasize to distant sites
-Can stimulate the development of new blood vessels to supply the tumor
(angiogenesis)
✔✔Proto-oncogene - ✔✔-regulate normal cell growth and division
-large family of genes that code for proteins and enzymes that turn on the cell cyle
✔✔Oncogene - ✔✔when mistakes in copies of DNA can occur, if a mutation occurs
next to a proto-oncogene, it can "turn on" and become a ______
✔✔Examples of oncogoenes - ✔✔1. EGFR or Erb-B1 (codes for an epidermal GF
receptor in the receptor-tyrosine kinase family ad is associated with head and neck and
colorectal cancers)
-EGFR inhibitor therapies are known to cause cutaneous reactions
2. Erb-B2 or HER2/neu (codes for an EGFR protein in the tyrosine kinase family and is
associated with some breast cancers)
✔✔Tumor suppressor genes - ✔✔-act like brakes in a car, slowing down or stopping
cell growth and division
-in the presence of malignancies, they bind to DNA with intention of repairing or
activating apoptosis
-for it to be turned on it must be expressed or "opened" in the DNA helix so that it can
be transcribed or copied
✔✔p53 - ✔✔-"sucidie gene"
-activates apoptosis when the cell is damaged beyond repair or too old to function
-more than 50% of solid tumors, the gene is mutated and unable to perform its normal
function
✔✔Growth Signals - ✔✔-cancer cells are able to find their own growth signals making
them self-sufficient
, ✔✔Signal transduction - ✔✔-the communication or passage of a message telling the
cell to do a biologic process, such as make a protein, divide, or make new blood vessels
✔✔Signal transduction steps - ✔✔1. Messages usually sent from outside the cell where
the messenger (ligand) first binds to the cell receptor which extended through the cell
membrane
2. These receptors ae called receptor tyrosine kinases
3. To send the message through the membrane, the receptor often has to join with
another recetor to become active and t autophophorylate
4. This is called dimerization and can be the following:
✔✔Dimerization - ✔✔1. Homodimerization: binding with the same type of receptor, such
as an epidermal GF receptor (EGFR) 1 receptor with another EGFR
2. Heterodimerization: binding with a different kind of receptor, such as EGFR1 binding
with EGFR2
✔✔Protein tyrosine kinases phosphorylates - ✔✔-turned on by giving up a phosphate
molecule
-the message is now send via a "bucket bridage", or passing the message from one
molecule to other signaling molecules until the message gets first into the cell nucleus
-where it is transcribed
✔✔Pathways - ✔✔many pathways and crossalks signaling btw and among the different
pathways, and they all have the power to control cell behavior in one way or another
✔✔mitogen-activating protein kinase (Raf-1/MAPK) pathway - ✔✔-shown to decrease
the benefits of some cancer drugs
-decrease disease-free survival time in some pts
✔✔mammalian target of rapamycin (mTOR) survival pathway - ✔✔-play a role in
resistance to some chemotherapy agents in certain pts by keeping cells that have been
exposed to chemotherapy from undergoing apoptosis
-role in angiogenesis
✔✔phosphoinositide 3-kinases (PI3K) - ✔✔-transduction enzymes that activate Akt,
leading to cell survival, increased cell proliferation, and growith