Cancer-cell-phenotype-dependent differential intracellular trafficking of unconjugated quantum dots.

A diverse array of nanoparticles, including quantum dots (QDs), metals, polymers, liposomes, and dendrimers, are being investigated as therapeutics and imaging agents in cancer diseases. However, the role of the cancer-cell phenotype on the uptake and intracellular fate of nanoparticles in cancer cells remains poorly understood. Reported here is that differences in cancer-cell phenotypes can lead to significant differences in intracellular sorting, trafficking, and localization of nanoparticles. Unconjugated anionic QDs demonstrate dramatically different intracellular profiles in three closely related human-prostate-cancer cells used in the investigation: PC3, PC3-flu, and PC3-PSMA. QDs demonstrate punctated intracellular localization throughout the cytoplasm in PC3 cells. In contrast, the nanoparticles localize mainly at a single juxtanuclear location ("dot-of-dots") inside the perinuclear recycling compartment in PC3-PSMA cells, where they co-localize with transferrin and the prostate-specific membrane antigen. The results indicate that nanoparticle sorting and transport is influenced by changes in cancer-cell phenotype and can have significant implications in the design and engineering of nanoscale drug delivery and imaging systems for advanced tumors.