This study explored the epigenetic mechanism of FOXK1 in the development of estrogen receptor-positive breast cancer. Various molecular biology techniques were used, including immunoprecipitation, Western blotting, RNA interference, and quantitative PCR. The results demonstrated a clear relationship between FOXK1 and the REST/CoREST complex at the protein level and showed that decreasing FOXK1 expression also reduced the coREST complex. The study provides insight into a potential therapeutic approach for ER+ breast cancer by targeting this interaction.

1. Sebastián Elías Diaz Luna
III Semestre
Universidad Pontificia Bolivariana

2. Breast Cancer
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Breast cancer occurs due to the
uncontrolled multiplication of any cellular
group present. It has the ability to spread
to other tissues, known as metastasis.
Among the most common types of
breast cancer are:
• Infiltrating ductal carcinoma.
• Infiltrating lobular carcinoma.
https://www.cdc.gov/spanish/cancer/breast/basic_info/what-is-breast-cancer.htm

3. FOXK1
FOXK1, derived from forkhead/winged-helix domain transcription factors, has
many functions, with one of the most studied being the regulation of
fasting/inanition; it induces anaerobic glycolysis.
https://omim.org/entry/616302?search=FOXK1&highlight=foxk1
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4. Objective
This study focused on exploring the epigenetic mechanism of FOXK1 in the
development of estrogen receptor-positive (ER+) breast cancer.

5. Materials and methods
Co- inmunoprecipitación
Immunoprecipitation is a laboratory
technique that involves isolating a
protein of interest from a set of
proteins through purification and the
use of antigenic markers.
During the experiment, it was used
to verify the relationship between
FOX4 and the REST/CoREST
complex at the protein level.
Western blotting
Western blotting is a laboratory
technique used for the analysis and
detection of proteins in tissue or
cells, using antigenic markers.
During the experiment, it was used
to analyze the proteins that regulate
the apoptotic pathway present in the
MCF-7 cell culture.

6. Materials and methods
RNA interference
It is an RNA sequence used to
interfere with protein synthesis,
so that a protein is silenced or
its production decreases.
In the experiment, it was used
to decrease the expression of
FOXK1 along with the coREST
complex and observe the short
and long-term effects.
Quantitative polymerase chain
reaction
Technique used in molecular
biology to quantify the amount of
DNA due to its exponential growth.
In the experiment, it was used to
quantitatively describe the amount
of apoptotic genes after RNAi
suppression.

7. Figure 1A
Figure 1B
Figure 2C
Results

8. Results
Figure 3A (2nd chart) Figure 4C

9. Discussion
Author(s) Idea Agree/Disagree
Glass CK, Rosenfeld MG. “The modulation of gene
expression, either activation or
suppression, involves a plethora
of transcription factors, often
supported by a series of
coactivators or corepressors.”
Agree, during the experiment, a
clear relationship between
FOXK1 and the REST/CoREST
complex was demonstrated. Its
mechanisms of action are still
unknown.
Pazin MJ, Kadonaga JT
Rosenfeld MG, Lunyak VV, Glass
CK
Hu X, Lazar MA.
“In particular, transcriptional
repression is characterized by the
recruitment of specific
corepressor complexes,(…)”
Agree, for the experiment, it was
necessary to observe what
happened when FOXK1 was
expressed at a low level; due to
its relationship with the complex,
its expression was also reduced.
Ye F, Dewanjee S, Li Y, et al. “the efficacy of targeting agents
against such tumors remains
limited”
Agree, the limitations of the
experiment state that for the
object of study, only the described
relationship works. There are
countless types of breast cancers.

10. Conclusions
During the experiment, thanks to various molecular biology techniques, the
effects of FOXK1 along with its complex could be observed, allowing for a
therapeutic approach to breast cancer with receptors (ER+). The
quantitative and qualitative interaction was observed, something that is
rarely achieved without the use of these techniques.