Immunomodulatory nucleic acids have extraordinary promise for treating disease, yet clinical progress has been limited by a lack of tools to safely increase activity in patients. Immunomodulatory nucleic acids act by agonizing or antagonizing endosomal toll-like receptors (TLR3, TLR7/8, and TLR9), proteins involved in innate immune signaling. Immunomodulatory spherical nucleic acids (SNAs) that stimulate (immunostimulatory, IS-SNA) or regulate (immunoregulatory, IR-SNA) immunity by engaging TLRs have been designed, synthesized, and characterized. Compared with free oligonucleotides, IS-SNAs exhibit up to 80-fold increases in potency, 700-fold higher antibody titers, 400-fold higher cellular responses to a model antigen, and improved treatment of mice with lymphomas. IR-SNAs exhibit up to eightfold increases in potency and 30% greater reduction in fibrosis score in mice with nonalcoholic steatohepatitis (NASH). Given the clinical potential of SNAs due to their potency, defined chemical nature, and good tolerability, SNAs are attractive new modalities for developing immunotherapies.

Metastasis portends a poor prognosis for cancer patients. Primary tumor cells disseminate through the bloodstream before the appearance of detectable metastatic lesions. The analysis of cancer cells in blood-so-called circulating tumor cells (CTCs)-may provide unprecedented opportunities for metastatic risk assessment and investigation. NanoFlares are nanoconstructs that enable livecell detection of intracellular mRNA. NanoFlares, when coupled with flow cytometry, can be used to fluorescently detect genetic markers of CTCs in the context of whole blood. They allow one to detect as few as 100 live cancer cells per mL of blood and subsequently culture those cells. This technique can also be used to detect CTCs in a murine model of metastatic breast cancer. As such, NanoFlares provide, to our knowledge, the first genetic-based approach for detecting, isolating, and characterizing live cancer cells from blood and may provide new opportunities for cancer diagnosis, prognosis, and personalized therapy.cancer metastasis | nanotechnology | diagnostic | mRNA | NanoFlares

There is considerable interest in novel cell imaging tools that avoid the use of fluorescent proteins. One widely used class of such reagents are “pro-fluorescent” biarsenical dyes such as FlAsH, ReAsH, CrAsH, and Cy3As. Despite their utility, biarsenicals are plagued by high background labeling and cytotoxicity, and are challenging to apply in oxidizing cellular locale. Here we demonstrate that [(3-oxospiro[isobenzofuran-1(3H),9′-[9H]xanthene]-3′,6′-diyl)bis(iminomethylene-2,1-phenylene)]bis-(9CI), a rhodamine-derived bisboronic acid (RhoBo) described initially as a monosaccharide sensor, functions as a cell-permeable, turn-on fluorescent sensor for a tetraserine-motifs in recombinant proteins. RhoBo binds peptides or proteins containing Ser-Ser-Pro-Gly-Ser-Ser with affinities in the nanomolar concentration range, and prefers this sequence to simple monosaccharides by >10,000-fold. RhoBo fails to form fluorescent complexes with constituents of the mammalian cell surface, as judged by epifluorescent, confocal, and TIRF microscopy, but fluoresces brightly within the Ser-Ser-Pro-Gly-Ser-Ser-rich cell interior. These results suggest that current efforts to identify optimal serine-rich sequences for RhoBo will allow it to function effectively as a selective small-molecule label for appropriately tagged proteins either upon or within living cells.

Phosphorylation of cortactin downstream of the EGF receptor–Src-Arg kinase cascade triggers maturation of invadopodia, actin-rich protrusions that breast cancer cells use to invade the extracellular matrix. Phosphocortactin recruits Vav2 to invadopodia to activate Rac3 and support actin polymerization, matrix degradation, and invasion.

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