Mica Nanoparticle, STB-HO Eliminates the Human Breast Carcinoma Cells by Regulating the Interaction of Tumor with its Immune Microenvironment

Abstract

Mica, an aluminosilicate mineral, has been proven to possess anti-tumor and immunostimulatory effects. However, its efficacy and mechanisms in treating various types of tumor are less verified and the mechanistic link between anti-tumor and immunostimulatory effects has not been elucidated. We sought to investigate the therapeutic effect of STB-HO (mica nanoparticles) against one of the most prevalent cancers, the breast cancer. STB-HO was orally administered into MCF-7 xenograft model or directly added to culture media and tumor growth was monitored. STB-HO administration exhibited significant suppressive effects on the growth of MCF-7 cells in vivo, whereas STB-HO did not affect the proliferation and apoptosis of MCF-7 cells in vitro. To address this discrepancy between in vivo and in vitro results, we investigated the effects of STB-HO treatment on the interaction of MCF-7 cells with macrophages, dendritic cells (DCs) and natural killer (NK) cells, which constitute the cellular composition of tumor microenvironment. Importantly, STB-HO not only increased the susceptibility of MCF-7 cells to immune cells, but also stimulated the immunocytes to eliminate cancer cells. In conclusion, our study highlights the possible role of STB-HO in the suppression of MCF-7 cell growth via the regulation of interactions between tumor cells and anti-tumor immune cells.

Fraction From Lycium barbarum Polysaccharides Reduces Immunotoxicity and Enhances Antitumor Activity of Doxorubicin in Mice

“… 19 There are several normal methods for NK cell cytolytic activity assay, such as 51 Cr-release assay, 20 MTT assay, 16 and FCM. 15 FCM can detect the status of target cells that are killed by NK cells in a single-cell level, and it was used in our experiment. The results showed that LBP3 restored the cytolytic activity of NK cells to H22 cells in Dox-treated mice.…”

“… 14 The cytotoxicity of natural killer (NK) cells was assayed by FCM as described previously. 15 Briefly, splenocytes were collected and washed twice with precold PBS at 200× g for 5 minutes at 4°C. The erythrocytes were lysed in Red Blood Cell Lysis Buffer for 5 minutes at room temperature, and the cells were washed twice with pre-cold PBS.…”

Human umbilical cord blood-stem cells direct macrophage polarization and block inflammasome activation to alleviate rheumatoid arthritis

“…53 Briefly, MNCs were first isolated from hUCB, followed by the separation of CD14 + monocytes using CD14 microbeads (Miltenyi Biotech, Bergisch Gladbach, Germany). To generate macrophages, monocytes were incubated in six-well cell culture plates at a density of 10 5 cells/cm 2 for 7 days.…”

STB-HO, a novel mica fine particle, inhibits the teratoma-forming ability of human embryonic stem cells after in vivo transplantation

“…In our cancer study, we investigated the therapeutic effect of STB-HO against cancers, particularly breast cancer [ 39 ]. STB-HO treatments exhibited significant suppressive effects on cell growth of MCF-7 breast cancer cell line in a xenotransplantation model, whereas STB-HO did not affect the proliferation and apoptosis of MCF7-cells in cell culture system.…”