Fatemeh Safari
1,2,3*, Solmaz Rahmani Barouji
4, Ali Mohammad Tamaddon
51 Medical Biotechnology Department, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
2 Shiraz University of Medical Sciences, Shiraz, Iran.
3 Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
4 Department of Traditional Medicine, Faculty of Traditional Medicine, University of Medical Sciences, Tabriz, Iran.
5 Center for Pharmaceutical Nanotechnology and Biomaterials, Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.
*Corresponding Author: Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran. Email safarif@tbzmed.ac.ir
Abstract
Purpose: Human telomerase reverse transcriptase (hTERT) plays a
crucial role in tumorigenesis and progression of cancers. Gene silencing of
hTERT by short interfering RNA (siRNA) is considered as a promising strategy
for cancer gene therapy. Various algorithms have been devised for designing a
high efficient siRNA which is a significant issue in the clinical usage. Thereby,
in the present study, the relation of siRNA designing criteria and the gene
silencing efficiency was evaluated.
Methods: The siRNA sequences were designed and characterized by
using on line soft wares. Cationic co-polymer (polyethylene
glycol-g-polyethylene imine (PEG-g-PEI)) was used for the construction of
polyelectrolyte complexes (PECs) containing siRNAs. The cellular uptake of the
PECs was evaluated. The gene silencing efficiency of different siRNA sequences
was investigated and the effect of observing the rational designing on the
functionality of siRNAs was assessed.
Results: The size of PEG-g-PEI siRNA with N/P
(Nitrogen/Phosphate) ratio of 2.5 was 114 ± 0.645 nm. The transfection
efficiency of PECs was desirable (95.5% ± 2.4%.). The results of Real-Time PCR
showed that main sequence (MS) reduced the hTERT expression up to 90% and
control positive sequence (CPS) up to 63%. These findings demonstrated that the
accessibility to the target site has priority than the other criteria such as
sequence preferences and thermodynamic features.
Conclusion: siRNA opens a hopeful window in cancer therapy
which provides a convenient and tolerable therapeutic approach. Thereby, using
the set of criteria and rational algorithms in the designing of siRNA
remarkably affect the gene silencing efficiency.