Effects of ADAM10 and ADAM17 Inhibitors on Natural Killer Cell Expansion and Antibody-dependent Cellular Cytotoxicity Against Breast Cancer Cells In Vitro.

BACKGROUND/AIM: The inhibition of a disintegrin and metalloproteinase (ADAM) has the potential to become a novel approach for natural killer (NK) cell-based cancer immunotherapy. Thus, the aim of this study was to investigate the influence of ADAM10 and ADAM17 inhibitors on expanded NK cell to enhance antibody-dependent cellular cytotoxicity (ADCC) in breast cancer cell lines. MATERIALS AND METHODS: NK cells were expanded in medium supplemented with an ADAM10 or ADAM17 inhibitor to prevent the shedding of soluble CD16/FcγRIII. The expression level of CD16 and production of interferon-gamma (IFN-γ) was detected by flow cytometry using specific antibodies. ADCC activity of expanded NK cells was estimated in trastuzumab treated breast cancer cell lines such as MCF-7, MDA-MB-231, SKBR3, and BT-474 cells. RESULTS: The ADAM17 inhibitor increased the purity of expanded NK cells to 90% after 14 days at 5 and 10 µM in vitro (p=0.043). However, the expansion rate of NK cells was decreased at 10 µM of the ADAM 17 inhibitor (p=0.043). Inhibition of ADAM10 suppressed the expansion of NK cells, although the NK purity was increased at 1 µM of the inhibitor. The expression of CD16 was significantly increased at 1 and 5 µM of the ADAM17 inhibitor (p=0.046, 0.028, respectively) during the culturing period. Inhibition of ADAM10 reduced the expression of CD16 on NK cells. The cytotoxic activity of the ADAM17 inhibitor treated NK cells against MCF-7 (p=0.039) and BT-474 (p=0.027) cells was significantly elevated. The ADCC activity of NK cells treated with 5 µM of ADAM17 inhibitor was significantly increased against SKBR-3 and BT-474 (p=0.027). Inhibition of ADAM17 increased the production of IFN-γ in expanded NK cells. CONCLUSION: The inhibition of ADAM17 enhanced the purity of expanded NK cells and the ADCC activity of these cells against trastuzumab treated breast cancer cell lines.

Near-Infrared Illumination of Native Tissues for Image-Guided Surgery.

Our initial efforts to prepare tissue-specific near-infrared (NIR) fluorescent compounds generated successful correlation between physicochemical properties and global uptake in major organs after systemic circulation and biodistribution. Herein, we focus on the effects on biodistribution based on modulating electronic influencing moieties from donating to withdrawing moieties at both the heterocyclic site and through meso-substitution of pentamethine cyanine fluorophores. These selected modifications harnessed innate biodistribution pathways through the structure-inherent targeting, resulting in effective imaging of the adrenal glands, pituitary gland, lymph nodes, pancreas, and thyroid and salivary glands. These native-tissue contrast agents will arm surgeons with a powerful and versatile arsenal for intraoperative NIR imaging in real time.

Analysis of early C2C12 myogenesis identifies stably and differentially expressed transcriptional regulators whose knock-down inhibits myoblast differentiation.

Myogenesis is a tightly controlled process involving the transcriptional activation and repression of thousands of genes. Although many components of the transcriptional network regulating the later phases of myogenesis have been identified, relatively few studies have described the transcriptional landscape during the first 24 h, when myoblasts commit to differentiate. Through dense temporal profiling of differentiating C2C12 myoblasts, we identify 193 transcriptional regulators (TRs) whose expression is significantly altered within the first 24 h of myogenesis. A high-content shRNA screen of 77 TRs involving 427 stable lines identified 42 genes whose knockdown significantly inhibits differentiation of C2C12 myoblasts. Of the TRs that were differentially expressed within the first 24 h, over half inhibited differentiation when knocked down, including known regulators of myogenesis (Myod1, Myog, and Myf5), as well as 19 TRs not previously associated with this process. Surprisingly, a similar proportion (55%) of shRNAs targeting TRs whose expression did not change also inhibited C2C12 myogenesis. We further show that a subset of these TRs inhibits myogenesis by downregulating expression of known regulatory and structural proteins. Our findings clearly illustrate that several TRs critical for C2C12 myogenesis are not differentially regulated, suggesting that approaches that focus functional studies on differentially-expressed transcripts will fail to provide a comprehensive view of this complex process.