Effective delivery holds the key to successful in vivo application of therapeutic small interfering RNA (siRNA). In this work, we have developed a universal siRNA carrier consisting of a mesoporous silica nanoparticle (MSNP) functionalized with cyclodextrin-grafted polyethylenimine (CP). CP provides positive charge for loading of siRNA through electrostatic interaction and enables effective endosomal escape of siRNA. Using intravital microscopy we were able to monitor tumor enrichment of CP-MSNP/siRNA particles in live mice bearing orthotopic MDA-MB-231 xenograft tumors. CP-MSNP delivery of siRNA targeting the M2 isoform of the glycolytic enzyme pyruvate kinase (PKM2) resulted in effective knockdown of gene expression in vitro and in vivo. Suppression of PKM2 led to inhibition of tumor cell growth, invasion, and migration.

The interferon (IFN) system is integral to the host response against viruses, and many viruses have developed strategies to overcome its antiviral effects. The effects of hepatitis E virus (HEV), the causative agent of hepatitis E, on IFN signaling have not been investigated primarily because of the nonavailability of an efficient in vitro culture system or small animal models of infection. We report here the generation of A549 cell lines persistently infected with genotype 3 HEV, designated as HEV-A549 cells and the effects HEV has on IFN-a-mediated Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling. Treatment of HEV-A549 cells with 250, 500, and 1000 U/mL of IFN-a for 72 hours showed a dose-dependent reduction in HEV RNA levels by 10%, 20%, and 50%, respectively. IFN-a-stimulated genes coding for the antiviral proteins dsRNA-activated protein kinase (PKR) and 2 0 ,5 0 -oligoadenylate synthetase (2 0 ,5 0 -OAS) were downregulated in IFN-a-treated HEV-A549 cells. HEV infection also prevented IFN-a-induced phosphorylation of STAT1. Regulation of STAT1 by HEV was specific, as phosphorylation of STAT2, tyrosine kinase (Tyk) 2, and Jak1 by IFN-a was unaltered. Additionally, STAT1 levels were markedly increased in HEV-A549 cells compared with naive A549 cells. Acute viral infection of susceptible host cells initiates a type I interferon (IFN) response that is composed predominantly of interferon-a and -b (IFNa/b) signaling through the IFN-a receptor. IFN-a/b receptor binding results in receptor subunit dimerization and activation through tyrosine phosphorylation of two tyrosine kinases of the Janus family, Janus kinase 1(Jak1) and tyrosine kinase 2 (Tyk2), which then phosphorylate signal transducer and activator of transcription (STAT) 1 and STAT2 on a single tyrosine residue, leading to STAT1-STAT2 heterotrimerization with interferon regulatory factor (IRF) 9 followed by nuclear localization.

Eradicating malignant tumors by vaccine-elicited host immunity remains a major medical challenge. To date, correlates of immune protection remain unknown for malignant mesothelioma. In this study, we demonstrated that antigen-specific CD8 þ T-cell immune response correlates with the elimination of malignant mesothelioma by a model PD-1-based DNA vaccine. Unlike the nonprotective tumor antigen WT1-based DNA vaccines, the model vaccine showed complete and long-lasting protection against lethal mesothelioma challenge in immunocompetent BALB/c mice. Furthermore, it remained highly immunogenic in tumor-bearing animals and led to therapeutic cure of preexisting mesothelioma. T-cell depletion and adoptive transfer experiments revealed that vaccine-elicited CD8 þ T cells conferred to the protective efficacy in a dose-dependent way. Also, these CD8

Cancer is a complex disease that usually requires several treatment modalities. Here, we have designed a multifunctional nanotherapeutic system incorporating small interfering RNA (siRNA) and gold nanorods for photothermal therapy. Surface engineered gold nanorods with polyethylenimine were synthesized using a layer-by-layer assembly and siRNA was absorbed on the surface. The siRNA was efficiently delivered into breast cancer cells, resulting in subsequent gene silencing. Cells were then irradiated with near-infrared (NIR) light, causing heat-induced anticancer activity. The combination of gene silencing and photothermal therapy resulted in effective inhibition of cell proliferation.