Inhibited Metastasis and Amplified Chemotherapeutic Effects by Epigene-Transfection Based on a Tumor-Targeting Nanoparticle.

Purpose: Tumor metastasis and drug resistance have always been vital aspects to cancer mortality and prognosis. To compromise metastasis and drug resistance, a nanoparticle IPPD-PHF2 (IR780/PLGA-PEI(Dox)-PHF2) has been engineered to accomplish efficient targeted epigenotherapy forced by PHF2-induced MET (mesenchymal to epithelial transition).

Materials And Methods: IPPD-PHF2 nanoparticle was synthesized and characterized by several analytical techniques. The transfection efficiency of IPP-PHF2 (IR780/PLGA-PEI-PHF2) was compared with PP-PHF2 (PLGA-PEI-PHF2) in vitro by WB and in vivo by IHC, and the cytotoxicity of IPP was compared with Lipo2000 in vitro by CCK8 assay. The inhibition of cancer cell migration caused by PHF2-upregulation was tested by wound healing assay, and the enhanced chemotherapeutic sensitivity was detected by flow cytometry. Tumor-targeting property of IPPD-PHF2 was proved by fluorescent imaging in vivo with MDA-MB-231 tumor-bearing nude mice. Except for fluorescent imaging ability, considerable photoacoustic signals of IPPD-PHF2 at tumor sites were verified. The anti-tumor activity of IPPD-PHF2 was investigated using in vivo human breast cancer MDA-MB-231 cell models.

Results: Tumor-targeting nanoparticle IPPD-PHF2 had an average size of about 319.2 nm, a stable zeta potential at about 38 mV. The encapsulation efficiency of doxorubicin was around 39.28%, and the adsorption capacity of plasmids was about 64.804 μg/mg. Significant up-regulation of PHF2 induced MET and caused reduced migration as well as enhanced chemotherapeutic sensitivity. Either IPPD (IR780/PLGA-PEI(Dox)) or IPP-PHF2 (IR780/PLGA-PEI-PHF2) presented minor therapeutic effects, whereas IPPD-PHF2 specifically accumulated within tumors, showed extraordinary transfection efficiency specifically in tumor sites, acted as inhibitors of metastasis and proliferation, and presented good multimodality imaging potentials in vivo.

Conclusion: IPPD-PHF2 NPs is a promising tool to bring epigenotherapy into a more practical era, and the potential application of harm-free multimodality imaging guidance is of great value.