Breast cancer drugs perturb fundamental vascular functions of endothelial cells by attenuating protein S-nitrosylation

Nitric Oxide and Tumors: From Small-Molecule Donor to Combination Therapy

As an important endogenous signaling molecule, nitric oxide (NO) is involved in various physiological and pathological activities in living organisms. It is proved that NO plays a critical role in tumor therapy, while the extremely short half-life and nonspecific distribution of NO greatly limit its further clinical applications. Thus, the past few decades have witnessed the progress made in conquering these shortcomings, including developing innovative NO donors, especially smart and multimodal nanoplatforms. These platforms can precisely control the spatiotemporal distribution of therapeutic agents in the organism, which make big differences in tumor treatment. Here current NO therapeutic mechanisms for cancer, NO donors from small molecules to smart-responsive nanodrug delivery platforms, and NO-based combination therapy are comprehensively reviewed, emphasizing outstanding breakthroughs in these fields and hoping to bring new insights into NO-based tumor treatments.

Involvement of nitrosative stress cytotoxicity induced by CdTe quantum dots in human vascular endothelial cells

Quantum dots (QDs) are new types of fluorescent nanomaterials which can be utilized as ideal agents for intracellular tracking, drug delivery, biomedical imaging and diagnosis. It is urgent to understand their potential toxicity and the interactions with the toxin-susceptible vascular system, especially vascular endothelial cells. In this study, we intended to explore whether the cytotoxicity of CdTe (cadmium telluride) QDs was partly induced by nitrosative stress in vascular endothelial cells. Our results showed that the intracellular amount of CdTe QDs was gradually increased in a dose- and time-dependent manner, and a concentration-dependent decrease in viability were observed when incubated with CdTe QDs of 20-80 nM. The peroxynitrite level was significantly up-regulated by QDs treatment, which indicated the nitrosative stress was activated. Furthermore, nitrotyrosine level was increased after 24 hr CdTe QDs exposure in a dose-dependent manner, which suggested that CdTe QDs-induced nitrosative stress was associated with tyrosine nitration in EA.hy926. In addition, CdTe QDs induced EA.hy926 apoptosis, and the percentage of cells with low Δψm was increased after CdTe QDs treatment, indicating the mitochondrion depolarization was induced. The increased ROS fluorescence was observed in a QDs dose-dependent manner, which suggested that the oxidative stress was also involved in the CdTe QDs-induced endothelial cytotoxicity. Our work provided experimental evidence into QDs toxicity and potential vascular risks induced by nitrosative stress for the future applications of QDs.