Open AccessA Genomic Profile of Local Immunity in the Melanoma Microenvironment Following Treatment with α Particle-Emitting Ultrasmall Silica Nanoparticles
Author(s) -
Aleksandra M. Urbanska,
Raya Khanin,
Simone Alidori,
Sam Wong,
Bárbara Piffero Mello,
Bryan Aristega Almeida,
Feng Chen,
Kai Ma,
Melik Z. Turker,
Tatyana Korontsvit,
David A. Scheinberg,
Pat Zanzonico,
Ulrich Wiesner,
Michelle S. Bradbury,
Thomas P. Quinn,
Michael R. McDevitt
Publication year - 2020
Publication title -
cancer biotherapy and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 59
eISSN - 1557-8852
pISSN - 1084-9785
DOI - 10.1089/cbr.2019.3150
Subject(s) - melanoma , tumor microenvironment , immune system , cancer research , chemistry , cd8 , cytotoxic t cell , immunology , biology , in vitro , biochemistry
An α particle-emitting nanodrug that is a potent and specific antitumor agent and also prompts significant remodeling of local immunity in the tumor microenvironment (TME) has been developed and may impact the treatment of melanoma. Biocompatible ultrasmall fluorescent core-shell silica nanoparticles (C' dots, diameter ∼6.0 nm) have been engineered to target the melanocortin-1 receptor expressed on melanoma through α melanocyte-stimulating hormone peptides attached to the C' dot surface. Actinium-225 is also bound to the nanoparticle to deliver a densely ionizing dose of high-energy α particles to cancer. Nanodrug pharmacokinetic properties are optimal for targeted radionuclide therapy as they exhibit rapid blood clearance, tumor-specific accumulation, minimal off-target localization, and renal elimination. Potent and specific tumor control, arising from the α particles, was observed in a syngeneic animal model of melanoma. Surprisingly, the C' dot component of this drug initiates a favorable pseudopathogenic response in the TME generating distinct changes in the fractions of naive and activated CD8 T cells, Th1 and regulatory T cells, immature dendritic cells, monocytes, MΦ and M1 macrophages, and activated natural killer cells. Concomitant upregulation of the inflammatory cytokine genome and adaptive immune pathways each describes a macrophage-initiated pseudoresponse to a viral-shaped pathogen. This study suggests that therapeutic α-particle irradiation of melanoma using ultrasmall functionalized core-shell silica nanoparticles potently kills tumor cells, and at the same time initiates a distinct immune response in the TME.