Background: MicroRNA modulation therapy has shown great promise to treat hepatocellular
carcinoma (HCC), however Efficient tissue-specific and safe delivery remains a major challenge.
Objective: We sought to develop an inorganic-organic hybrid vehicle for the systemic delivery of the
tumor suppressor miR-34a, and to investigate the efficiency of the delivered miR-34a in the treatment
of HCC in vitro and in vivo.
Methods: In the present study, pEGP-miR cloning and expression vector, expressing miR-34a, was
electrostatically bound to polyethyleneimine (PEI), and then loaded onto ZSM-5 zeolite nanoparticles
(ZNP). Qualitative and quantitative assessment of the transfection efficiency of miR-34a construct in
HepG2 cells was applied by GFP screening and qRT-PCR, respectively. The expression of miR-34a
target genes was investigated by qRT-PCR in vitro and in vivo.
Results: ZNP/PEI/miR-34a nano-formulation could efficiently deliver into HepG2 cells with low cytotoxicity,
indicating good biocompatibility of generated nanozeolite. Furthermore, five injected doses
of ZNP/PEI/miR-34a nano-formulation in HCC induced male Balb-c mice, significantly inhibited tumor
growth, and demonstrated improved cell structure, in addition to a significant decrease in alphafetoprotein
level and liver enzymes activities, as compared to the positive control group. Moreover,
injected ZNP/PEI/miR-34a nano-formulation led to a noticeable decrease in the CD44 and c-Myc levels.
Results also showed that ZNP/PEI/miR-34a nano-formulation inhibited several target oncogenes
including AEG-1, and SOX-9, in vitro and in vivo.
Conclusion: Our results suggested that miR-34a is a powerful candidate in HCC treatment and that
AEG-1 and SOX-9 are novel oncotargets of miR-34a in HCC. Results also demonstrated that our
nano-formulation may serve as a candidate approach for miR-34a restoration for HCC therapy, and
generally for safe gene delivery.