Telomeres are repetitive DNA sequences at the ends of chromosomes that protect them from deterioration during cell division. Telomeres shorten each time a cell divides, acting as a biological clock. When telomeres become too short, cells can no longer divide and become senescent. Telomerase is an enzyme that adds telomeric repeats to chromosome ends, counteracting shortening and allowing cells to avoid senescence. Cancer cells express high levels of telomerase, allowing them to divide indefinitely. Drugs are being developed to inhibit telomerase as a cancer treatment, though they can also damage telomeres in normal cells. Future research aims to specifically target the telomerase expression in cancer cells.

1. TELOMERES AND
TELOMERASE
By
Muhammad
Aqib Hanif

2. What are telomeres?
 Repetitive DNA sequences at the ends
of all human chromosomes, TTAGGG
 Shoelaces like structure with hard cap
at end
 Do not contain genes
 Importance for replication and
duplication during cell division

3. WHY WE NEED TELOMERES?

4. TELOMERE FUNCTION
Telomeres are also thought to be the "clock" that regulates how many times an
individual cell can divide. Telomeric sequences shorten each time the DNA
replicates

5. TELOMERE AND
AGING
Telomere cause aging by causing
cell senescence

6. To support telomere with aging
researcher looked at
Progeria
 A disease that ages a young so rapidly
that they die in their teen
Developed mouse cells with
defective telomerase

7. “
”
Alpha lipid age defiant telomere
serum
MAKE THE SKIN
 SKIN IS FIRMER, SMOOTHER AND MORE YOUTHFUL
LOOKING
 MADE IN NEW ZEALAND

8. What is telomerase?
 Telomerase is a ribonucleoprotein enzyme
complex (a cellular reverse transcriptase) that
has been referred to as a cellular
immortalizing enzyme.
 It stabilizes telomere length by adding
hexameric (TTAGGG) repeats onto the
telomeric ends of the chromosomes, thus
compensating for the erosion of telomeres
that occurs in its absence.
 High telomerase activity exists in germ
cells, stem cells, epidermal skin cells,
follicular hair cells, and cancer cells.

9. Telomerase provide the pathway for
cancer
 Some cells are immortal
because their telomerase
is switched on
 Cancer cells do not age
because they produce
telomerase, which keeps
the telomere intact.

10. Visual Example
 The blue dish was treated to produce
active telomerase and is still dividing
 The other dish of normal cells of the
same age has stopped dividing

11. Telomerase and cancer
 Thus, clinical telomerase
research is currently focused
on the development of
methods for the accurate
diagnosis of cancer and on
novel anti-telomerase cancer
therapeutics
 Certain drugs are used for this
purpose

12. Genetic link
 The telomerase control gene has been
mapped to 3p21 (chromosome 3, the p
(short) arm, locus 21)
 Although the gene for telomerase is present
in all cells, hTRT is present only in immortal
cells, where it serves to fuse the repeating
sequences of DNA to the chromosomes,
thereby lengthening the telomeres.

13. Treatment of cancer
 Certain drugs are available that
used as anti-telomerase for cancer
cells that inhibit the binding sites of
telomerase to bind with DNA
 But these drugs can also damage
telomeres activity in normal cells
so some side-effects also available
like
 Blood toxicity
 Immune toxicity
 Skin toxicity

14. The future of telomere and telomerase
research
 Target the cancer cells by the
way to their telomerase
expression leaving normal cells
unharmed
 Oncolytic viruses.