As a biomarker for gastric cancer, circPTPN22 regulates the progression of gastric cancer through EMT pathway

1. Alejandro Daniel Páez Sequeda
Juan Camilo Peláez Ortiz
Tercer semestre
Universidad Pontificia Bolivariana

2. GASTRIC CANCER
• Gastric cancer (GC) is a malignant
neoplasm that develops in the
stomach. From the histological
point of view, two types of tumors
are distinguished: intestinal and
diffuse. The first has a frankly
glandular appearance, while the
second is characterized by the
presence of cells that appear
isolated or forming
agglomerations in the mucous or
muscular layer.

3. circPTPN22
CircRNAs are formed by splicing
events after exon or intron
cyclization, and their expression
abundance is high. About one-eighth
of the genes expressed in humans
can produce detectable circRNAs,
and their expression level is more
than ten times of the corresponding
linear messenger RNA (mRNA)
levelproduce.
In relation to this study it has been found
a numBer of miRNAs like, has_miR_659,
has_miR_513a_3p and has_miR_665,
the last one has been proven that
regulates de metástasis of GC by
affecting de EMT pathway

4. OBJECTIVE
Evaluate how biomarker for gastric
cancer, circPTPN22 regulates the
progression of gastric cancer through the
EMT pathway

5. RT-qPCR
Es una ampilifación enzimatica de la presencia
de ADN, se usó la transcripción reversa para
evaluar la expresión proteica desde ARN para
obtener la secuencia de ADN
Fue cuantitativa para obtener datos
específicos sobre la cantidad de expresión
Para detección de:
- E-cad
- N-cad
- Vimetin
- Snail protein
Luego de la regulación
- E-cad: aumento
- Vimetin: disminución

6. Western blots
Se utiliza para determinar la
presencia y cantidad de
antígenos y de anticuerpos
específicos.
Para detección de:
- E-cad
- N-cad
- Vimetin
- Snail protein
Luego de la regulación
- E-cad: aumento
- Vimetin: disminución

7. Plasmid
construction and
cell transfection
La transfección consiste en
introducir material genético
externo en células eucariotas
mediante plásmidos.
Se construyó un plásmido
shRNA para inhibir la expresión
del gen via interferencia RNA.
Se realizó este proceso de
inhibición (knockdown) para
poder hacer la medición con la
rt-qPCR y western blot.
A su vez tiene importancia
como tratamiento.

8. CircRNA sequencing
• Se utiliza la secuenciacion
para determinar el orden de
nucleotidos en una
secuencia de RNA.
• Identificar el punto de la
ciclacion en la secuencia de
CircRNA

9. RESULTADOS

10. RESULTADOS

11. RESULTADOS

12. RESULTADOS

13. DISCUSSION
AUTOR ARGUMENT AGREE/DISAGREE
Deng G. et al. (2020) CircRHOBTB3 may be a new
diagnostic
marker and therapeutic target for GC
Sitarz R, et al. (2018) More than 80% of patients are
diagnosed with advanced stage in the
absence of specific symptoms, with a
low 5-year survival rate of between
10% and 30%
Chen LL, Yang L (2015) Recent studies
have shown that circRNAs are
endogenous closed
non-coding RNAs (ncRNAs). It has a
stable structure,
long half-life, and tumor specificity

14. CONCLUSIONS
1. circPTPN22 is an effective diagnostic and prognostic biomarker of
GC
2. The down-regulation of circPTPN22 expresión could inhibit the
proliferation and metastasis of GC cells by afeccting EMT pathway
3. circRNA sequencing, and RT-qPCR results showed that circPTPN22 is
upregulated in GC tissues