1. Researchers have discovered a new four-stranded quadruple helix DNA structure called G-quadruplexes that exists in human genomes, particularly in regions rich in guanine. These quadruplexes are more common in rapidly dividing cells like cancer cells. 2. A separate study identified new sites in cells where DNA breaks early in the replication process. These break sites correlate with damage seen in cancers like diffuse large B cell lymphoma. Comparing mouse and human cells, both exhibit similar trends of genome instability at these sites. 3. Discoveries of DNA structures and break sites help understand the origins of diseases and cancer, offering new treatment approaches through stopping replication in cancer cells or addressing instability.

1. 1
Biomolecular News
By Daniel Gallego González
Medicine Student
III Semester

2. 2 FRONT FACE

3. 3 BACK FACE

4. 4 INTRODUCTION
 When living cells divide, each
daughter cell must receive a copy
of the genome, for that reason the
DNA must be replicated.
The DNA replication is a critical
process that can trigger several
disease if it is unsuccessful. For that
reason, this process is studied to
treat pathologies such as cancer.

5. 5 FIRST NOTICE
Cambridge researchers have
published a that four-stranded
‘quadruple helix’ DNA structures
known as G-quadruplexes also
exist within the human genome.
¿WHAT DOES THE “G” MEAN?
 It indicates that the ‘quadruple
helix’ is present in regions of DNA
rich in guanine.

6. 6 FIRST NOTICE
 The research pretends to show
clear links between
concentrations of four-stranded
quadruplexes and the process of
DNA replication.
This quadruplexes are more
likely to occur in genes of cells
that are rapidly dividing,
such as cancer cells.

7. 7 FIRST NOTICE
Professor Shankar “We are seeing links
Balasubramanian from between trapping the
the University of Cambridge's
Department of Chemistry and
quadruplexes with
Cambridge Research Institute: molecules and the ability
to stop cells dividing, which
is hugely exciting”.

8. 8 FIRST NOTICE
1. Antibody proteins that 2. Fluorescence to 3. Could stop carcinogen
detect and bind to mark the antibodies. cells’ proliferation.
G-quadruplexes.
The ‘quadruple helix’ DNA structure may well
be the key to new ways of selectively inhibiting
the proliferation of cancer cells.

9. 9 PERSONAL COMMENT

10. 10
SECOND NOTICE
 Research by scientists at the
National Cancer Institute has
identified a new class of DNA
sites in cells that break early
in the replication process.
This research was headed by
Andre Nussenzweig, chief of
the Laboratory of Genome
Integrity, Center for Cancer
Research, NCI.

11. 11
SECOND NOTICE
Some genes that comprise DNA strands increase the risk
for cancer, induce replication stress, and result in a higher
likelihood of cells acquiring DNA damage, such as breaks.
DNA REPLICATION DNA BREAKS LYMPHOMA
 It was found that these break sites correlate
with damage often seen in B cell cancers, such as
diffuse large B cell lymphoma.

12. 12
SECOND NOTICE
They used the mouse immune
system as a model, isolated
healthy cells, and then monitored
the cells for initiation of DNA
damage in order to understand
how a healthy cell mutated.

13. 13
SECOND NOTICE
 The scientists then
compared the DNA damage
sites in their mouse model
with sites mutated in
human diffuse large B cell
lymphoma tissue samples.
 It was found that both
mouse and human cells
exhibit similar trends
of genome instability.

14. 14
PERSONAL COMMENT
Again, advances in molecular biology allow
us to understand the etiologic origin of many
diseases and offer new alternatives for its
diagnosis and treatment. The B cell cancers, such
as diffuse large B cell lymphoma, had never been
completely understood. For that reason, this
research will help too many people with this
diseases, approaching to a possible cure.

15. 15
MEDICAL BENEFIT
 Genetics and Molecular Biology
provide to Medicine new
alternatives for the treatment
of complicated diseases, which
were believed that had no cure.
 Is very important to study the
DNA replication to understand
the origin and development of
diseases that previously had no
explanation, and therefore
could not be treated.

16. 16
MEDICAL BENEFIT
 The research of the
G-quadruplex DNA
structure, will allow the
trapping of cells with a high
level of replication such as
carcinogen ones, for
stopping and destroying
them, which could be a new
cure for cancer in a
molecular level.

17. 17
MEDICAL BENEFIT
 From this latest research in B
cell cancer, some instability in
specific genetic sequences has
been recognized, giving rise to a
possible genetic intervention
to help people with this
aggressive disease.

18. 18
MEDICAL BENEFIT
 Undoubtedly, the DNA replication is a complicated process
that is vulnerable to several damages.
 There are many diseases that arise from problems in
this cellular process. In order to prevent them, this
kind of investigations are essential to understand the
causes and to get the solutions.

19. 19
REFERENCES
ARTICLES
1. G-quadruplexes also exist within the human genome [Internet].
Cambridge: University of Cambridge; 2013. [Consulted at January
29th, 2013].
2. DNA breaks early in replication process associated with B cell
cancers [Internet]. Bethesda: National Cancer Institute; 2013.
[Consulted at February 29th, 2013].
BIBLIOGRAPHY
1. CLARK, David; PAZDERNIK, Nanette. Molecular Biology. 2. ed.
Oxford: Elsevier Inc, 2013. 274-276 p.
2. KUNDU, Tapas. Epigenetics: Development and disease. Bangalore:
Molecular biology and genetics unit Jawaharlal Nehru Centre for
Advanced Scientific Research. Springer, 2013. 57-58 p.
3. BHAGAVAN, N; CHUNG-EUN, Han. Essentials of Medical
Biochemistry. London: Elsevier Inc, 2011. 294-295 p.

20. 20
By Daniel Gallego González,
Cañón del Chicamocha,
Santander, 2011.