Chain-shattering Pt(IV)-backboned polymeric nanoplatform for efficient CRISPR/Cas9 gene editing to enhance synergistic cancer therapy

CRISPR/Cas9 system has become a promising gene editing tool for cancer treatment. However, development of a simple and effective nanocarrier to incorporate CRISPR/Cas9 system and chemotherapeutic drugs to concurrently tackle the biological safety and packaging capacity of viral vectors and combine gene editing-chemo for cancer therapy still remains challenges. Herein, a chain-shattering Pt(IV)-backboned polymeric nanoplatform is developed for the delivery of EZH2-targeted CRISPR/Cas9 system (NPCSPt/pEZH2) and synergistic treatment of prostate cancer. The pEZH2/Pt(II) could be effectively triggered to unpack/release from NPCSPt/pEZH2 in a chain-shattering manner in cancer cells. The EZH2 gene disruption efficiency could be achieved up to 32.2% of PC-3 cells in vitro and 21.3% of tumor tissues in vivo, leading to effective suppression of EZH2 protein expression. Moreover, significant H3K27me3 downregulation could occur after EZH2 suppression, resulting in a more permissive chromatin structure that increases the accessibility of released Pt(II) to nuclear DNA for enhanced apoptosis. Taken together, substantial proliferation inhibition of prostate cancer cells and further 85.4% growth repression against subcutaneous xenograft tumor could be achieved. This chain-shattering Pt(IV)-backboned polymeric nanoplatform system not only provides a prospective nanocarrier for CRISPR/Cas9 system delivery, but also broadens the potential of combining gene editing-chemo synergistic cancer therapy.

Automated summary

A chain-shattering Pt(IV)-backboned polymeric nanoplatform has been developed for the targeted delivery of EZH2-targeted CRISPR/Cas9 system in prostate cancer treatment, achieving efficient EZH2 gene disruption and significant downregulation of EZH2 protein expression. The system also led to enhanced apoptosis through H3K27me3 downregulation, resulting in substantial inhibition of prostate cancer cell proliferation and growth repression of subcutaneous xenograft tumors. This innovative nanoplatform not only provides a prospective nanocarrier for CRISPR/Cas9 system delivery, but also broadens the potential of combining gene editing-chemo synergistic cancer therapy.