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Source at https://doi.org/10.1016/j.jconrel.2018.11.029. Licensed CC BY-NC-ND 4.0. The effect of poly(2-ethyl-butyl cyanoacrylate) nanoparticles containing the cytotoxic drug cabazitaxel was studied in three breast cancer cell lines and one basal-like patient-derived xenograft model grown in the mammary fat pad of immunodeficient mice. Nanoparticle-encapsulated cabazitaxel had a much better efficacy than similar concentrations of free drug in the basal-like patient-derived xenograft and resulted in complete remission of 6 out of 8 tumors, whereas free drug gave complete remission only with 2 out of 9 tumors. To investigate the different efficacies obtained with nanoparticle-encapsulated versus free cabazitaxel, mass spectrometry quantification of cabazitaxel was performed in mice plasma and selected tissue samples. Nanoparticle-encapsulated drug had a longer circulation time in blood. There was approximately a three times higher drug concentration in tumor tissue 24 h after injection, and two times higher 96 h after injection of nanoparticles with drug compared to the free drug. The tissue biodistribution obtained after 24 h using mass spectrometry analyses correlates well with biodistribution data obtained using IVIS® Spectrum in vivo imaging of nanoparticles labeled with the fluorescent substance NR668, indicating that these data also are representative for the nanoparticle distribution. Furthermore, immunohistochemistry was used to estimate infiltration of macrophages into the tumor tissue following injection of nanoparticle-encapsulated and free cabazitaxel. The higher infiltration of anti-tumorigenic versus pro-tumorigenic macrophages in tumors treated with the nanoparticles might also contribute to the improved effect obtained with the nanoparticle-encapsulated drug. Tumor infiltration of pro-tumorigenic macrophages was four times lower when using nanoparticles containing cabazitaxel than when using particles without drug, and we speculate that the very good therapeutic efficacy obtained with our cabazitaxel-containing particles may be due to their ability to reduce the level of pro-tumorigenic macrophages in the tumor. In summary, encapsulation of cabazitaxel in poly(2-ethyl-butyl cyanoacrylate) nanoparticles seems promising for treatment of breast cancer.

Lipid nanocapsules (LNCs) have proven their efficacy in delivering different drugs to various cancers, but no studies have yet described their uptake mechanisms, paclitaxel (PTX) delivery or resulting cytotoxicity towards breast cancer cells. Herein, we report results concerning cellular uptake of LNCs and cytotoxicity studies of PTX-loaded LNCs (LNCs-PTX) on the three breast cancer cell lines MCF-7, MDA-MB-231 and MDA-MB-468. LNCs-PTX of sizes 50 ± 2 nm, 90 ± 3 nm and 120 ± 4 nm were developed by the phase inversion method. Fluorescence microscopy and flow cytometry were used to observe the uptake of fluorescently labeled LNCs and cellular uptake of LNCs-PTX was measured using HPLC analyses of cell samples. These studies revealed a higher uptake of LNCs-PTX in MDA-MB-468 cells than in the other two cell lines. Moreover, free PTX and LNCs-PTX exhibited a similar pattern of toxicity towards each cell line, but MDA-MB-468 cells appeared to be more sensitive than the other two cell lines, as evaluated by the MTT cytotoxicity assay and a cell proliferation assay based upon [3H]thymidine incorporation. Studies with inhibitors of endocytosis indicate that the cellular uptake is mainly via the Cdc42/GRAF-dependent endocytosis as well as by macropinocytosis, whereas dynamin-dependent processes are not required. Furthermore, our results indicate that endocytosis of LNCs-PTX is important for the toxic effect on cells. Western blot analysis revealed that LNCs-PTX induce cytotoxicity by means of apoptosis in all the three cell lines. Altogether, the results demonstrate that LNCs-PTX exploit different mechanisms of endocytosis in a cell-type dependent manner, and subsequently induce apoptotic cell death in the breast cancer cells here studied. The article also describes biodistribution studies following intravenous injection of fluorescently labeled LNCs in mice.

Source at https://doi.org/10.1002/1878-0261.12319. The tumor microenvironment (TME) may influence both cancer progression and therapeutic response. In breast cancer, particularly in the aggressive triple‐negative/basal‐like subgroup, patient outcome is strongly associated with the tumor's inflammatory profile. Tumor‐associated macrophages (TAMs) are among the most abundant immune cells in the TME, shown to be linked to poor prognosis and therapeutic resistance. In this study, we investigated the effect of the metastasis‐ and inflammation‐associated microenvironmental factor S100A4 on breast cancer cells (BCCs) of different subtypes and explored their further interactions with myeloid cells. We demonstrated that extracellular S100A4 activates BCCs, particularly the basal‐like subtype, to elevate secretion of pro‐inflammatory cytokines. The secreted factors promoted conversion of monocytes to TAM‐like cells that exhibited protumorigenic activities: stimulated epithelial–mesenchymal transition, proliferation, chemoresistance, and motility in cancer cells. In conclusion, we have shown that extracellular S100A4 instigates a tumor‐supportive microenvironment, involving a network of cytokines and TAM‐like cells, which was particularly characteristic for basal‐like BCCs and potentiated their aggressive properties. The S100A4–BCC–TAM interaction cascade could be an important contributor to the aggressive behavior of this subtype and should be further explored for therapeutic targeting.

The study aims to investigate whether cytosolic fatty acid-binding protein-4 (FABP4) is involved in angiogenic growth factors- and fatty acid-induced tube formation in first trimester placental trophoblast cells, HTR8/SVneo. We determined the tube formation both at basal as well as stimulated levels in the absence and presence of inhibitors of FABP4 and VEGF signaling pathways. Basal level of tube formation was maximally reduced in the presence of 50 µM of FABP4 inhibitor compared with those by VEGF signaling pathway inhibitors (rapamycin, L-NAME, and p38 MAP kinase inhibitor). Whereas docosahexaenoic acid, 22:6n-3 (DHA)-, and VEGF-induced tube formation was maximally inhibited by p38 MAP kinase inhibitor (63.7 and 34.5%, respectively), however, leptin-induced tube formation was inhibited maximally by FABP4 inhibitor (50.7%). ANGPTL4 and oleic acid (OA)-induced tube formation was not blocked by any of these inhibitors. The FABP4 inhibitor inhibited cell growth stimulated by DHA, leptin, VEGF, and OA (P 0.05) but was not affected by ANGPTL4. VEGF, leptin, and OA also increased FABP4 protein level in these cells, though the uptake of fatty acids by these cells was not affected by the presence of FABP4 inhibitor. Our data demonstrate that FABP4 may be involved in part in the basal level, and stimulated tube formation by VEGF, DHA, and leptin, whereas it has little or no effect in ANGPTL4- and OA-induced tube formation in these cells. Thus, FABP4 may play a differential role in fatty acids and angiogenic growth factors-mediated tube formation in the first trimester trophoblast cells in vitro.

T cell-specific adapter protein (TSAd) encoded by the SH2D2A gene is expressed in activated T cells, NK cells and endothelial cells, but its tissue expression has not yet been mapped. Here, we have defined the specificity of two commercially available anti-TSAd monoclonal reagents using peptide arrays. We found them to bind separate epitopes in the C-terminal part of TSAd. We then used immunohistochemistry to examine TSAd expression in various human lymphoid and non-lymphoid tissues. Immunostaining of adjacent tissue sections revealed that a substantial fraction of CD3-positive cells in normal lymphoid and non-lymphoid tissues expressed TSAd. In particular, essentially all intra-epithelial T cells appeared to coexpress TSAd. In addition, TSAd expression was observed in endothelial cells of dermal microvessels, while it was not detected in endothelial cells of the other tested tissues. This work provides insight into the expression pattern of TSAd in various healthy human tissues.

Background Natural killer (NK) cells have both cytolytic and immunoregulatory functions. We recently described that these cells release the inflammatory cytokines IL-17 and IFN-γ. However, the precise identity of the NK cell subset(s) that secrete these cytokines is not known. Methodology/Principal Findings To isolate the cells secreting IL-17 and IFN-γ, we took advantage of the findings that Th17/Th1 cells express chemokine receptors. Therefore, CD56+NK cells were stained with antibodies against various chemokine receptors and intracellularly with antibodies toward IL-17 and IFN-γ. Consequently, we identified previously unrecognized subset of NK cells generated from normal human peripheral blood after activation with IL-2 but not PMA plus ionomycin. The cells are characterized by the expression of CD56+ and CCR4+, produce IL-17 and IFN-γ and are consequently named NK17/NK1 cells. They also express CD161, NKp30, NKp44, NKp46, NKG2D, CD158, CCL22, IL-2Rβ and the common γ chain but not CD127 or IL-23R. Further, they possess T-bet and RORγt transcription factors. Antibodies to IL-1β, IL-6, IL-21, or TGF-β1 do not inhibit IL-2-induced generation of NK17/NK1 cells, suggesting that IL-2 has the capacity to polarize these cells. Notably, NK17/NK1 cells are abundant in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) without activation, and are generated from the peripheral blood of these patients after activation with IL-2. Conclusions/Significance NK17/NK1 cells identified here have not been previously described in healthy or MS patients. © 2011 Pandya et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.