Molecular Beacon‐based Fluorescence Magnetic Nanoprobes for Tumor‐related HSP90 mRNA In‐suit Detection and Imaging

Abstract

Heat shock proteins (HSPs) are a group of molecular chaperones that help proteins folding to their native conformation, protect cells from stressful environments. However, certain HSPs are overexpressed by malignant cells to survive under various therapies, inhibited cancer cells from senescence, apoptosis, stabilized lysosome membrane and promoted autophagy. Therefore, real‐time detection of the expression level of HSPs in living cells is required for both clinical cancer diagnosis application and oncology research to have a better understanding in anti‐apoptosis mechanism of malignant cells. Recently, delivery of molecular beacons that detect tumor‐related genes into cancer cells via nanocarriers shows promising results in the field of nanomedical diagnostics. In this study, uniformly sized and shaped superparamagnetic iron oxide nanocubes (SPIONCs) were synthesized by thermal decomposition and transferred into the aqueous phase via surface exchange with DMSA. G4 PAMAM dendrimer and Pluronic‐P123 were successively linked on SPIONCs‐DMSA in order to increase positive charge meanwhile reduce cytotoxicity. High specificity and sensitivity molecular beacon that targeting HSP90α mRNA was designed and synthesized and was condensed on PAMAM‐functionalized SPIONCs to form nanoprobes. TEM, XRD, TGA, ξ‐potential, DLS, VSM, fluorescence spectroscopy, agarose gel electrophoresis were carried out to characterize the morphology, composition, and properties of the nanoprobes. The mean diameter of as‐synthesized SPIONCs is 11 nm and increased to 100 nm after forming nanoprobes, which is stable in both water and culture media. Proliferation and hemolysis assays of the nanoprobes show low cytotoxicity and good hemocompatibility. LSCM confirmed that after 24h incubation with cells, the nanoprobes were uptake efficiently and located inside lysosome, and successfully escaped to the cytoplasm after 48h incubation. More importantly, the fluorescence of nanoprobes was observed significantly only in the HSP90 overexpressed MDA‐MB‐231 cells, instead of HSP90 low‐expressed MCF‐10A cells, which literally “highlights” a difference between normal and malignant cells, therefore provides a promising nanoplatform for real‐time gene expression level analysis and imaging in living cells.Support or Funding InformationWe would like to thank the financial supports, in whole or in part, by the National Natural Science Foundation of China (31470959, 81671821, 81471785), the Basic Research Program of Sichuan Science and Technology (2017JY0019, 2017JY0217), and the Fundamental Research Funds for the Central Universities (ZYGX2016Z001) for financial supports.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.