Purpose: Cell cycle dysregulation resulting in expression of antiapoptotic genes and uncontrolled proliferation is a feature of undifferentiated nasopharyngeal carcinoma. The pharmacodynamic effects of seliciclib, a cyclin-dependent kinase (CDK) inhibitor, were studied in patients with nasopharyngeal carcinoma. Experimental Design: Patients with treatment-naI« ve locally advanced nasopharyngeal carcinoma received seliciclib at 800 mg or 400 mg twice daily on days 1 to 3 and 8 to 12. Paired tumor samples obtained at baseline and on day 13 were assessed by light microscopy, immunohistochemistry, and transcriptional profiling using real-time PCR low-density array consisting of a panel of 380 genes related to cell cycle inhibition, apoptosis, signal transduction, and cell proliferation. Results: At 800 mg bd, one patient experienced grade 3 liver toxicity and another had grade 2 vomiting; no significant toxicities were experienced in 13 patients treated at 400 mg bd. Seven of fourteen evaluable patients had clinical evidence of tumor reduction. Some of these responses were associated with increased tumor apoptosis, necrosis, and decreases in plasma EBV DNA posttreatment. Reduced protein expression of Mcl-1, cyclin D1, phosphorylated retinoblastoma protein pRB (T821), and significant transcriptional down-regulation of genes related to cellular proliferation and survival were shown in some patients posttreatment, indicative of cell cycle modulation by seliciclib, more specifically inhibition of cdk2/cyclin E, cdk7/cyclin H, and cdk9/cyclinT. Conclusions: Brief treatment with this regimen of seliciclib in patients with nasopharyngeal carcinoma is tolerable at 400 mg bd and associated with tumor pharmacodynamic changes consistent with cdk inhibition, and warrants further efficacy studies in this tumor.

BackgroundGraphene oxide (GO) has attracted intensive interest in biological and medical fields in recent years due to its unique physical, chemical, and biological properties. In our previous work, we proved that GO could deliver small interfering RNA (siRNA) into cells and downregulate the expression of the desired gene.MethodsThis study investigated the potential of a modified GO nanocarrier for co-delivery of siRNA and doxorubicin (DOX) for enhanced cancer therapy. Fourier transform infrared spectroscopy, laser particle size analyzer, UV-visible spectroscopy, gel electrophoresis retardation, and in vitro release assay were studied.ResultsThe results of real-time polymerase chain reaction revealed that the expression of vascular endothelial growth factor (VEGF) mRNA was decreased 46.84%±3.72% (mean ± SD). Enzyme-linked immunosorbent assay indicated that the expression of VEGF protein was down-regulated to 52.86%±1.10% (mean ± SD) in vitro. In vivo tumor growth assay GO-poly-l-lysine hydrobromide/folic acid (GPF)/DOX/siRNA exhibited gene silencing and tumor inhibition (66.95%±2.35%, mean ± SD) compared with naked siRNA (1.62%±1.47%, mean ± SD) and DOX (33.63%±5.85%, mean ± SD). GPF/DOX/siRNA exhibited no testable cytotoxicity.ConclusionThe results indicated that co-delivery of siRNA and DOX by GPF could be a promising application in tumor clinical therapy.

Graphene oxide (GO) has emerged as a potential drug delivery vector. For siRNA delivery, GO should be modified to endow it with gene delivery ability and targeting effect. However, the cationic materials used previously usually had greater toxicity. In this study, GO was modified with a non-toxicity cationic material (chitosan) and a tumor specific monoclonal antibody (anti-EpCAM) for the delivery of survivin-siRNA (GCE/siRNA). And the vector (GCE) prepared was proved with excellent biosafety and tumor targeting effect. The GCE exhibited superior performance in loading siRNA, maintained stability in different solutions and showed excellent protection effect for survivin-siRNA in vitro . The gene silencing results in vitro showed that the mRNA level and protein level were down-regulated by 48.24% ± 2.50% and 44.12% ± 3.03%, respectively, which was equal with positive control ( P > 0.05). It was also demonstrated that GCE/siRNA had a strong antitumor effect in vitro , which was attributed to the efficient antiproliferation, and migration and invasion inhibition effect of GCE/siRNA. The results in vivo indicated that GCE could accumulate siRNA in tumor tissues. The tumor inhibition rate of GCE/siRNA 54.74% ± 5.51% was significantly higher than control 4.87% ± 8.49%. Moreover, GCE/siRNA showed no toxicity for blood and main organs, suggesting that it is a biosafety carrier for gene delivery. Taken together, this study provides a novel design strategy for gene delivery system and siRNA formulation.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.