4. INTRODUCTION
DNA
REPLICATION
“The process by which a DNA molecule is duplicated” (MESH, 1968)
Its defined by the National Human Genome Research Institute
as “the process by which a molecule of DNA is duplicated.
When a cell divides, it must first duplicate its genome so that
each daughter cell winds up with a complete set of
chromosomes.”
Takes place during S
phase cell cycle
“The replicated DNA molecules are segregated to the two daughter cells
during a subsequent cell cycle phase called mitosis” (Cox, 2009.)
5. Researches tease apart a pathway certain
cancer cells use to replicate. Medical Express (2016, January 28)
“it's a repetitive DNA sequence that caps the ends of each human chromosome and acts as a barrier,
protecting the genome.”
TELOMERE
Every cell replication, the telomere
gets shorter and the risk for DNA
damage becomes more probably
6. Cancer cells could produce the
Telomerase or use the Alternative
Lengthening of Telomeres pathway (ALT)
to “win” and overcome the progressive
telomere shortening .
7. “In the absence of SMARCAL1, the accumulation of replication
stress at ALT telomeres leads to the formation of DNA double strand
breaks and consequently, drives massive genomic instability,"
Elizabeth Blackburn
Discoverer of
Telomerase
that the replication stress response
protein SMARCAL1 is a key in the
ALT pathway
Identified
The SMARCAL1 protein its
responsible to resolve
chronic replication stress
To mantain TELOMERE
STABILITY
What they discovered...
8. "Identifying new players
regulating the ALT pathway
may lead to the identification of
new targeted therapies for
cancers that currently have
limited treatment options"
9. Student opinion
I think the research is usefull cause it
showed us that cells are capable to develop
“new” ways to get into genomic instability
and thanks to that, now we can target
specific cells process where we can take
part to create alternative and efective
therapies to combat cancers that have
limited treatment options, reducing mortality
and giving people more quality life.
10. A defense protein that causes
cancer EurekAlert (22 january, 2016)
Its a protein that protect us against viral infections modifying
the single straned DNA - viral DNA
Cancer
by the growth of
abnormal cells that
have mutations
is
caused
APOBEC
Researchers have found how APOBEC takes advantage of a
weakness in our DNA replication MUTATIONS
11. They founded that APOBEC can only mutate
single stranded DNA and that in almost
neoplasm, the error was in the lagging strand
compared with the leading strand
“ With this discovery, the scientists
brought the evidence that
APOBEC, opportunistically, takes
advantage of the moment when the
lagging strand remains single”.
WEAKER!
12. The most
important and
protected
genes are
replicated early
and the others
“less” important
genes are
replicated later,
generating a
high rate of
fidelity
APOBEC
Takes part in both early
and late replication, but
being more usually in the
early replication!!!
13. So... this types of mutations induced by APOBEC tend to be more significantly
than other types of mutations
Researchers dont know yet how the process is in right way but they know that
something is wrong because the regions with early replication process should
not stay in a single stranded state but now they discover that sometimes it is not
in that way, resourceful by APOBEC
14. Student opinion
This research I think shows us new data
about others mechanism to generate DNA
mutations and it is very important because it
gives useful information to keep
investigating in what happends into the
cancer cells cycle and which factors may
produce alterations on them, giving the
opportunity to understand better and
probably to develop new genetic therapies.
15. Medical utility
The knowing of the cell cycle and the
DNA replication process it's very
important cause it gives to us keys to
understand pathologies and to know
about the vital and more basic process
that all organism have
16. The genomic mutations and problems in
most of cases are irreversible but in
some cases they could be treated with
genic therapy . Thats the reason why the
molecular process (DNA replication) its
very important, because knowing it, we
could develop new therapies more
efficient or develop new ones in
pathologies that doesnt have one yet
Medical utility
17. Its important to know about the
DNA replication because it gives
information about new possible
cell targets to “attack” to prevent
the development of some
diseases, allowing us to reduce
the risk to having them
Medical utility
18. Discovering new possible ways in
how cells can mutate and replicate
is vital to know how to develop
different options of new treatments
in some pathologies that we dont
even have options to cure or reduce
them
Medical utility
19. Bibliography
MARTINEZ SÁNCHEZ, Lina María. Biología molecular. 2. ed. Medellín: UPB. Fac. de Medicina, 2006.
208 p.
COX, Lynne. Molecular Themes In DNA Replication. The Royal Society Of Chemistry, 2009. 2-8 p.
Niikolaev, S. (2016, January 22). A defense protein that causes cáncer. EurekAlert. Rewieved January
27, 2016 from http://www.eurekalert.org/pub_releases/2016-01/udg-adp012216.php
Digravio, G. (2016, January 28). Researchers tease apart a pathway certain cáncer cells use to
replicate. Medical Xpress. Rewieved January 31, 2016 from http://medicalxpress.com/news/2016-
01-pathway-cancer-cells-replicate.html
