Download What is a stem cell?

Do Now 8/14/14
1. Describe the relationship between the
nucleus and the ribosomes.
2. What are the 3 phases of interphase?
Describe what occurs during each phase.
3. What are the 4 stages of mitosis? Draw a
picture to represent each stage.
I will be coming around to check your notes.
Cell Cycle, Cancer
& Stem Cells
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
The Cell Cycle
**Orderly set of steps between eukaryotic cell divisions
Why do Cells Divide?
Growth
Reproduction
(in single celled organisms)
Repair
Control of the Cell Cycle
G1 Checkpoint - Check to see if DNA is damaged
G2 Checkpoint - Check to see if DNA is replicated properly
M Checkpoint - spindle assembly checkpoint, check for alignment of
chromosomes
Apoptosis - programmed cell death, if any of the checks fail
Mitosis & Cytokinesis
Mitosis - The division of the nucleus that results in identical
complete copies of chromosmes packaged into two new nuclei
Cytokinesis - The division of the cytoplasm that results in two
daughter cells
Prophase • Metaphase • Anaphase • Telophase
PMAT
“Please make another twin”
Interphase: Resting
Prophase: Chromosomes visible, spindle forms as centrioles move
Metaphase: Chromosomes line up along equator
Anaphase: Chromatids separate
Telophase: Nuclear membrane forms on each side, cytokinesis
begins
**In plant cells, cytokinesis begins when a new cell wall forms between the two
new cells.
**In animal cells, the two new cells pinch and pull apart
The Cell Cycle and Cancer
neoplasm: abnormal growth of cells
benign: non-cancerous
malignant: cancerous
Cancer: cellular growth disorder that results from the mutation of
genes that regulate the cell cycle
Cancer cells
lack differentiation
have abnormal nuclei
form tumors
undergo metastasis & angiogenesis
•
•
•
•
Mitosis produces 2 daughter cells
The two daughter cells contain the exact same number of
chromosomes as the original parent cell
Daughter cells are DIPLOID
HeLa Cells
A HeLa cell (also Hela or hela cell)
is a cell type in an immortal cell
line used in scientific research. It
is the oldest and most commonly
used human cell line.
The line was derived from cervical
cancer cells taken from Henrietta
Lacks, a patient who eventually
died of her cancer on October 4,
1951.
Article on Henrietta
Lacks
1.Name the phases
starting at the top.
1.Name the phase
2.Identify X
3.Identify Y
5. Name the
phase
6. Name the
phase
Introducing stem cells
A life story…
What is a stem cell?
stem cell
SELF-RENEWAL
(copying)
stem cell
DIFFERENTIATION
(specializing)
specialized cell
e.g. muscle cell, nerve cell
What is a stem cell?
Stem cell
SELF-RENEWAL
(copying)
Identical stem cells
Stem cell
DIFFERENTIATION
(specializing)
Specialized cells
Why self-renew AND differentiate?
1 stem cell
1 stem cell
Self renewal - maintains
the stem cell pool
4 specialized cells
Differentiation - replaces dead or damaged
cells throughout your life
Where are stem cells found?
embryonic stem cells
blastocyst - a very early
embryo
tissue stem cells
fetus, baby and throughout life
Types of stem cell:
1) Embryonic stem cells
Embryonic stem (ES) cells:
Where we find them
blastocyst
cells inside
= ‘inner cell mass’
embryonic stem cells taken from
the inner cell mass
outer layer of cells
= ‘trophectoderm’
fluid with nutrients
culture in the lab
to grow more cells
Embryonic stem (ES) cells:
What they can do
differentiation
embryonic stem cells
PLURIPOTENT
all possible types of specialized cells
Embryonic stem (ES) cells:
Challenges
skin
neurons
embryonic stem cells
blood
?
liver
Types of stem cell:
2) Tissue stem cells
Tissue stem cells:
Where we find them
surface of the eye
skin
testicles
brain
breast
intestines (gut)
bone marrow
muscles
Tissue stem cells:
What they can do
blood stem cell
differentiation
found in
bone marrow
MULTIPOTENT
only specialized types of blood cell:
red blood cells, white blood cells,
platelets
Types of stem cell:
3)Induced pluripotent (iPS)
stem cells
Induced pluripotent stem cells (iPS cells)
‘genetic reprogramming’
= add certain genes to the cell
adult cell
induced pluripotent stem (iPS) cell
behaves like an embryonic stem cell
differentiation
culture iPS cells in the lab
Advantage: no need for embryos!
all possible types of
specialized cells
Induced pluripotent stem cells (iPS cells)
genetic reprogramming
pluripotent stem cell
(iPS)
adult cell (skin)
differentiation
Stem cell jargon
Potency
cell
Pluripotent
A measure of how many types of specialized cell a stem
can
make
Can make all types of specialized cells in the body
Embryonic stem cells are pluripotent
Multipotent Can make multiple types of specialized cells, but not all types
Tissue stem cells are multipotent
Stem Cell Experts
• You will be assigned a stem cell topic
• 5 minutes to read the article on your own
• 5 minutes to discuss the main points of
the article
• 3 minutes each to present the main
points to your group members
Stem Cell Articles
http://www.eurostemcell.org/factsheet/embryonic-stem-cellresearch-ethical-dilemma
http://www.eurostemcell.org/factsheet/stem-cell-research-therapytypes-stem-cells-and-their-current-uses
http://www.eurostemcell.org/factsheet/origins-ethics-andembryos-sources-human-embryonic-stem-cells
http://www.eurostemcell.org/factsheet/ethics-and-reprogrammingethical-questions-after-discovery-ips-cells