| Abstract
Background: Considering the complex nature of gastrointestinal cancer,
different methods including surgery, radiotherapy, and chemotherapy are
considered for the treatment. Novel strategies including silencing of oncogenes
using safe delivery systems could be considered as a novel approach in colorectal
cancer treatment. The aim of this study was to investigate the silencing effect of
high mobility group A2 (HMGA2) small interfering RNA (siRNA)–loaded
nanoliposomes on gastrointestinal cancers.
Methods: The siRNA‐lipoplexes were prepared using dioleoyl trimethylammonium propane (DOTAP)/cholesterol (Chol)/1, 2‐dioleoyl‐sn‐glycero‐3‐phosphoethanolamine (DOPE) through the freeze‐drying of a monophase solution
method. The size, polydispersity index (PDI), and zeta‐potential of nanoliposomes
were determined using Zetasizer analyzer. The morphology of the nanoliposomes
was determined by transmission electron microscopy (TEM). The agarose gel‐
retardation assay was carried out to confirm the loading of siRNAs into liposome.
The silencing of the HMGA2 in cancer cells was evaluated by quantitative reverse‐
transcription polymerase chain reaction (qRT‐PCR). The effect of liposomes on cell
cytotoxicity was studied by MTT assay. The inhibitory effect of siRNA‐loaded
liposomes was evaluated by a wound‐healing assay. The apoptosis induction was
investigated via the annexin V/propidium iodide assay.
Results: The size, PDI, and zeta‐potential of the prepared liposomes were found
to be 350 nm, 0.67, and 86.3 mV, respectively. They were spherical in shape and
could efficiently associate with siRNA. The results of gene silencing showed that
the optimum condition of HMGA2 silencing was 80 pmol HMGA2 and 24 hours
after treatment in each cancer cell lines. MTT assays indicated that silencing of
HMGA2 in optimal condition could reduce the viability of the cancer cells more
than 60% in the three cell lines. The result of the apoptosis assay showed more
than 50% of the cell deaths related to the apoptosis in all three cell lines. The gene
expression evaluation confirmed that apoptosis was induced via the intrinsic
pathway inducing both caspase‐3 and ‐9 expressions. Also, the reduction in Bcl2
J Cell Biochem. 2018;1-10. wileyonlinelibrary.com/journal/jcb © 2018 Wiley Periodicals, Inc. | 1
expression confirmed the activation apoptosis pathway in the treated cancer cells.
The wound‐healing assay showed the suppression of cancer cell migration after
treatment with the prepared nanoliposomes.
Conclusion: The results of this study showed the HMGA2 siRNA‐loaded
nanoliposomes could be effective in the treatment of gastrointestinal cancers. |