SUMMARY While VEGF-targeted therapies are showing promise, new angiogenesis targets are needed to make additional gains. Here, we show that increased Zeste homologue 2 (EZH2) expression in either tumor cells or in tumor vasculature is predictive of poor clinical outcome. The increase in endothelial EZH2 is a direct result of VEGF stimulation by a paracrine circuit that promotes angiogenesis by methylating and silencing vasohibin1 (VASH1). EZH2 silencing in the tumor-associated endothelial cells inhibited angiogenesis mediated by reactivation of VASH1, and reduced ovarian cancer growth, which is further enhanced in combination with EZH2 silencing in tumor cells. Collectively, these data support the potential for targeting EZH2 as an important therapeutic approach. SIGNIFICANCE In this work, we identify EZH2 as a key regulator of tumor angiogenesis. The increase in endothelial EZH2 is a direct result of VEGF stimulation and indicates the presence of a paracrine circuit that promotes angiogenesis. EZH2 silencing in the tumor-associated endothelial cells using siRNA, packaged in the chitosan delivery system, resulted in significant growth inhibition in an orthotopic ovarian cancer model. EZH2 silencing in tumor endothelial cells resulted in decreased angiogenesis that was mediated by increased levels of the angiogenesis inhibitor, vasohibin1 (VASH1). Combined, these data provide a significant conceptual advance in our understanding of the regulation of angiogenesis in ovarian carcinoma and support the potential for targeting EZH2 as a therapeutic approach.

A novel coumarin-based fluorogenic probe bearing the 2-picolyl unit (1) was developed as a fluorescent chemosensor with high selectivity and suitable affinity in biological systems toward Cu(2+) over other cations tested. The fluorescence on-off mechanism was studied by femtosecond time-resolved fluorescence (TRF) upconversion technique and ab initio calculations. The receptor can be applied to the monitoring of Cu(2+) ion in aqueous solution with a pH span 4-10. To confirm the suitability of 1 for biological applications, we also employed it for the fluorescence detection of the changes of intracellular Cu(2+) in cultured cells. The results indicate that 1 should be useful for the fluorescence microscopic imaging and the study on the biological functions of Cu(2+).

Purpose: This study aimed to develop an Arg-Gly-Asp (RGD) peptide-labeled chitosan nanoparticle (RGD-CH-NP) as a novel tumor targeted delivery system for short interfering RNA (siRNA).Experimental Design: RGD peptide conjugated with chitosan by thiolation reaction was confirmed by proton-NMR (H-NMR). Binding of RGD-CH-NP with ανβ3 integrin was examined by flow cytometry and fluorescence microscopy. Antitumor efficacy was examined in orthotopic mouse models of ovarian carcinoma.Results: We show that RGD-CH-NP loaded with siRNA significantly increased selective intratumoral delivery in orthotopic animal models of ovarian cancer. In addition, we show targeted silencing of multiple growth-promoting genes (POSTN, FAK, and PLXDC1) along with therapeutic efficacy in the SKOV3ip1, HeyA8, and A2780 models using siRNA incorporated into RGD-CH-NP (siRNA/RGD-CH-NP). Furthermore, we show in vivo tumor vascular targeting using RGD-CH-NP by delivering PLXDC1-targeted siRNA into the ανβ3 integrin-positive tumor endothelial cells in the A2780 tumor-bearing mice. This approach resulted in significant inhibition of tumor growth compared with controls.Conclusions: This study shows that RGD-CH-NP is a novel and highly selective delivery system for siRNA with the potential for broad applications in human disease. Clin Cancer Res; 16(15); 3910-22.

Purpose: Surgical stress has been suggested to facilitate the growth of preexisting micrometastases as well as small residual tumor postoperatively. The purpose of this study was to examine the effects of surgical stress on ovarian cancer growth and to determine underlying mechanisms responsible for increased growth. Experimental Design: To mimic the effects of surgery, we did a laparotomy or mastectomy under isoflurane inhalation on athymic nude mice 4 days after i.p. tumor cell injection. Propranolol infusion via Alzet pumps was used to block the influence of sympathetic nervous system activation by surgical stress. Results: In both HeyA8 and SKOV3ip1 models, the mice in the laparotomy and mastectomy groups had significantly greater tumor weight (P < 0.05) and nodules (P < 0.05) compared with anesthesia only controls. There was no increase in tumor weight following surgery in the h-adrenergic receptor^negative RMG-II model. Propranolol completely blocked the effects of surgical stress on tumor growth, indicating a critical role for hadrenergic receptor signaling in mediating the effects of surgical stress on tumor growth. In the HeyA8 and SKOV3ip1 models, surgery significantly increased microvessel density (CD31) and vascular endothelial growth factor expression, which were blocked by propranolol treatment. Conclusion: These results indicate that surgical stress could enhance tumor growth and angiogenesis, and h-blockade might be effective in preventing such effects.

Materials and methods to achieve electronics intimately integrated on the surfaces of substrates with complex, curvilinear shapes are described. The approach exploits silicon membranes in circuit mesh structures that can be deformed in controlled ways using thin, elastomeric films. Experimental and theoretical studies of the micromechanics of such curvilinear electronics demonstrate the underlying concepts. Electrical measurements illustrate the high yields that can be obtained. The results represent significant experimental and theoretical advances over recently reported concepts for creating hemispherical photodetectors in electronic eye cameras and for using printable silicon nanoribbons/membranes in flexible electronics. The results might provide practical routes to the integration of high performance electronics with biological tissues and other systems of interest for new applications.

Purpose: Resistance to platinum chemotherapy remains a significant problem in ovarian carcinoma. Here, we examined the biological mechanisms and therapeutic potential of targeting a critical platinum resistance gene, ATP7B, using both in vitro and in vivo models. Experimental Design: Expression of ATP7A and ATP7B was examined in ovarian cancer cell lines by real-time reverse transcription-PCR and Western blot analysis. ATP7A and ATP7B gene silencing was achieved with targeted small interfering RNA (siRNA) and its effects on cell viability and DNA adduct formation were examined. For in vivo therapy experiments, siRNA was incorporated into the neutral nanoliposome 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC). Results: ATP7A and ATP7B genes were expressed at higher levels in platinum-resistant cells compared with sensitive cells; however, only differences in ATP7B reached statistical significance. ATP7A gene silencing had no significant effect on the sensitivity of resistant cells to cisplatin, but ATP7B silencing resulted in 2.5-fold reduction of cisplatin IC 50 levels and increased DNA adduct formation in cisplatin-resistant cells (A2780-CP20 and RMG2). Cisplatin was found to bind to the NH 2 -terminal copper-binding domain of ATP7B, which might be a contributing factor to cisplatin resistance. For in vivo therapy experiments, ATP7B siRNA was incorporated into DOPC and was highly effective in reducing tumor growth in combination with cisplatin (70-88% reduction in both models compared with controls). This reduction in tumor growth was accompanied by reduced proliferation, increased tumor cell apoptosis, and reduced angiogenesis. Conclusion: These data provide a new understanding of cisplatin resistance in cancer cells and may have implications for therapeutic reversal of drug resistance.Ovarian cancer has the highest mortality rate among all gynecologic malignancies (1). Following cytoreductive surgery, treatment with paclitaxel and platinum has become a recommended approach for initial chemotherapy (2). Current combination chemotherapy regimens produce complete remission in up to 80% of patients with advanced ovarian cancer. However, despite these initial high response rates, most patients suffer relapse and require treatment with multiple subsequent chemotherapy regimens (3). Successful management of advanced or recurrent gynecologic malignancies is often difficult due to both

Although several prognostic factors are used to predict recurrence and to select adequate candidates for liver transplantation for hepatocellular carcinoma (HCC), these prognostic factors have some clinical limitations. The purpose of this study was to evaluate 18 F-FDG PET as a prognostic factor and to optimize its ability to predict tumor recurrence in liver transplantation for HCC. Methods: The study included a total of 59 HCC patients (45 men and 15 women; mean age 6 SD, 56 6 8 y) who underwent 18 F-FDG PET and subsequent orthotopic liver transplantation. All patients were followed up for more than 1 y (mean, 29 6 17 mo), and recurrence of tumor was monitored. Three PET parameters-maximal standardized uptake value (SUV max ), ratio of tumor SUV max to normal-liver SUV max (T SUVmax /L SUVmax ), and ratio of tumor SUV max to normal-liver mean SUV (T SUVmax / L SUVmean )-were tested as prognostic factors and compared with conventional prognostic factors. Results: Among the 3 parameters tested, T SUVmax /L SUVmax was the most significant in the prediction of tumor recurrence, with a cutoff value of 1.15. In a multivariate analysis of various prognostic factors including T SUVmax /L SUVmax , serum a-fetoprotein, T stage, size of tumor, and vascular invasion of tumor, T SUVmax /L SUVmax was the most significant, and only vascular invasion of tumor had additional significance. According to T SUVmax /L SUVmax , the 1-y recurrencefree survival rate above the cutoff was markedly different from the rate below the cutoff (97% vs. 57%, P , 0.001). Conclusion: In this study, 18 F-FDG PET was an independent and significant predictor of tumor recurrence. In liver transplantation for HCC, 18 F-FDG PET can provide effective information on the prognosis for tumor recurrence and the selection of adequate candidates for liver transplantation.

No abstract