Programmed Cell Death Protein Ligand-1 Silencing with Polyethylenimine-Dermatan Sulfate Complex for Dual Inhibition of Melanoma Growth

Gijung Kwak, Dongkyu Kim, Gi Hoon Nam, Sun Young Wang, In San Kim, Sun Hwa Kim, Ick Chan Kwon, Yoon Yeo

Research output: Contribution to journalArticlepeer-review

84 Citations (Scopus)


Programmed cell death protein-1 (PD-1) is a prominent immune checkpoint receptor interacting with its ligand, programmed cell death protein ligand-1 (PD-L1, B7-H1). The PD-1/PD-L1 interaction induces functional exhaustion of tumor-reactive cytotoxic T cells and, thus, interferes with antitumor T-cell immunity. In addition, PD-1/PD-L1 interaction promotes tumorigenesis via the mTOR signaling pathway in a group of cancers including melanoma. Based on the dual functions of PD-1/PD-L1 interactions in tumor progression, we hypothesize that siRNA targeting PD-L1 (siPD-L1) will suppress melanoma growth, acting on both immune checkpoint and intrinsic tumorigenesis pathways. We tested this hypothesis by delivering siPD-L1 with a polymeric carrier ("pd") consisting of disulfide-cross-linked polyethylenimine (CLPEI) and dermatan sulfate (DS), which we previously found to have a specific interaction with CD146-positive B16F10 melanoma cells. The siPD-L1/pd suppressed the expression of PD-L1 in the interferon-γ (IFN-γ)-challenged B16F10 melanoma cells in a cell-type dependent manner and attenuated the expression of tumor-specific genes in B16F10 cells. siPD-L1/pd suppressed the B16F10 melanoma growth in C57BL/6 immune-competent mice with increased tumor-specific immunity. siPD-L1/pd also suppressed melanoma growth in immune-compromised nude mice. Both animals showed a positive correlation between PD-L1 and p-S6k (a marker of mTOR pathway activation) expression in tumors. These results indicate that the siPD-L1/pd complex attenuates melanoma growth in both T-cell-dependent and independent mechanisms.

Original languageEnglish
Pages (from-to)10135-10146
Number of pages12
JournalACS nano
Issue number10
Publication statusPublished - 2017 Oct 24

Bibliographical note

Funding Information:
The authors acknowledge the support of NSF DMR-1056997, NIH R01 CA199663, NIH R01 EB017791, and the Intramural Research Program (Global RNAi Carrier Initiative) of KIST.

Publisher Copyright:
© 2017 American Chemical Society.


  • B16F10 melanoma
  • PD-L1
  • immune checkpoint blockade
  • mTOR pathway
  • polyelectrolyte carrier
  • siRNA delivery

ASJC Scopus subject areas

  • General Materials Science
  • General Engineering
  • General Physics and Astronomy


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