Antiangiogenic Activity of 2-Deoxy-D-Glucose

During tumor angiogenesis, endothelial cells (ECs) are engaged in a number of energy consuming biological processes, such as proliferation, migration, and capillary formation. Since glucose uptake and metabolism are increased to meet this energy need, the effects of the glycolytic inhibitor 2-deoxy-D-glucose (2-DG) on in vitro and in vivo angiogenesis were investigated.In cell culture, 2-DG inhibited EC growth, induced cytotoxicity, blocked migration, and inhibited actively forming but not established endothelial capillaries. Surprisingly, 2-DG was a better inhibitor of these EC properties than two more efficacious glycolytic inhibitors, 2-fluorodeoxy-D-glucose and oxamate. As an alternative to a glycolytic inhibitory mechanism, we considered 2-DG's ability to interfere with endothelial N-linked glycosylation. 2-DG's effects were reversed by mannose, an N-linked glycosylation precursor, and at relevant concentrations 2-DG also inhibited synthesis of the lipid linked oligosaccharide (LLO) N-glycosylation donor in a mannose-reversible manner. Inhibition of LLO synthesis activated the unfolded protein response (UPR), which resulted in induction of GADD153/CHOP and EC apoptosis (TUNEL assay). Thus, 2-DG's effects on ECs appeared primarily due to inhibition of LLOs synthesis, not glycolysis. 2-DG was then evaluated in two mouse models, inhibiting angiogenesis in both the matrigel plug assay and the LH(BETA)T(AG) transgenic retinoblastoma model.In conclusion, 2-DG inhibits endothelial cell angiogenesis in vitro and in vivo, at concentrations below those affecting tumor cells directly, most likely by interfering with N-linked glycosylation rather than glycolysis. Our data underscore the importance of glucose metabolism on neovascularization, and demonstrate a novel approach for anti-angiogenic strategies

A retrospective study of neoadjuvant FOLFIRINOX in unresectable or borderline-resectable locally advanced pancreatic adenocarcinoma

BACKGROUND: 5-fluorouracil, leucovorin, irinotecan and oxaliplatin (FOLFIRINOX) is superior to gemcitabine in patients with metastatic pancreatic cancer who have a good performance status. We investigated this combination as neoadjuvant therapy for locally advanced pancreatic cancer (LAPC). METHODS: In this retrospective series, we included patients with unresectable LAPC who received neoadjuvant FOLFIRINOX with growth factor support. The primary analysis endpoint was R0 resection rate. RESULTS: Eighteen treatment-naïve patients with unresectable or borderline resectable LAPC were treated with neoadjuvant FOLFIRINOX. The median age was 57.5 years and all had ECOG PS of 0 or 1. Eleven (61 %) had tumors in the head of the pancreas and 9 (50 %) had biliary stents placed prior to chemotherapy. A total of 146 cycles were administered with a median of 8 cycles (range 3-17) per patient. At maximum response or tolerability, 7 (39 %) were converted to resectability by radiological criteria; 5 had R0 resections, 1 had an R1 resection, and 1 had unresectable disease. Among the 11 patients who remained unresectable after FOLFIRINOX, 3 went on to have R0 resections after combined chemoradiotherapy, giving an overall R0 resection rate of 44 % (95 % CI 22–69 %). After a median follow-up of 13.4 months, the 1-year progression-free survival was 83 % (95 % CI 59-96 %) and the 1-year overall survival was 100 % (95 % CI 85-100 %). Grade 3/4 chemotherapy-related toxicities were neutropenia (22 %), neutropenic fever (17 %), thrombocytopenia (11 %), fatigue (11 %), and diarrhea (11 %). Common grade 1/2 toxicities were neutropenia (33 %), anemia (72 %), thrombocytopenia (44 %), fatigue (78 %), nausea (50 %), diarrhea (33 %) and neuropathy (33 %). CONCLUSIONS: FOLFIRINOX followed by chemoradiotherapy is feasible as neoadjuvant therapy in patients with unresectable LAPC. The R0 resection rate of 44 % in this population is promising. Further studies are warranted

Immunotherapy in Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a chemotherapy-resistant disease, and current molecularly targeted therapies offer limited clinical benefit but no cures. The observation that RCC is immunogenic led to immune-based strategies for the treatment of this disease. Immunotherapy with high-dose IL-2 can induce long-term, complete responses in a small percentage of patients. IFN has been used as an immune intervention as well but with much less success than IL-2. Currently IFN is used only in combination with the anti-VEGF monoclonal antibody bevacizumab. Further investigation of novel immune interventions in RCC is ongoing with promising results. Dendritic cell vaccines have been tested in single-arm clinical trials suggesting improved survival when added to standard anti-angiogenic therapy. Monoclonal antibodies against PD-1 and PD-L1, novel immune targets, have shown promising response in phase I trials. Peptide vaccines have shown efficacy in phase II trials as well. Phase III trials to test these immune interventions are currently ongoing and have the potential to bring new, effective treatment options for patients with advanced RCC

Targeting tumor vasculature through oncolytic virotherapy: recent advances

The oncolytic virotherapy field has made significant advances in the last decade, with a rapidly increasing number of early- and late-stage clinical trials, some of them showing safety and promising therapeutic efficacy. Targeting tumor vasculature by oncolytic viruses (OVs) is an attractive strategy that offers several advantages over nontargeted viruses, including improved tumor viral entry, direct antivascular effects, and enhanced antitumor efficacy. Current understanding of the biological mechanisms of tumor neovascularization, novel vascular targets, and mechanisms of resistance has allowed the development of oncolytic viral vectors designed to target tumor neovessels. While some OVs (such as vaccinia and vesicular stomatitis virus) can intrinsically target tumor vasculature and induce vascular disruption, the majority of reported vascular-targeted viruses are the result of genetic manipulation of their viral genomes. Such strategies include transcriptional or transductional endothelial targeting, “armed” viruses able to downregulate angiogenic factors, or to express antiangiogenic molecules. The above strategies have shown preclinical safety and improved antitumor efficacy, either alone, or in combination with standard or targeted agents. This review focuses on the recent efforts toward the development of vascular-targeted OVs for cancer treatment and provides a translational/clinical perspective into the future development of new generation biological agents for human cancers

Abstract 5657: uPAR-mediated endothelial targeting facilitates endothelial to tumor cell transfer of oncolytic measles virus: In vitro and in vivo studies

Abstract The tumor endothelium constitutes a barrier to the efficient delivery of viral and non-viral therapeutic agents into tumor cells after systemic administration. Because endothelial cells are easily accessible after intravenous administration of a therapeutic agent, oncolytic viruses that target tumor endothelium may have the advantage of circumventing this problem since they may bind to endothelial cells, replicate in them, and facilitate viral entry into tumor tissue. The urokinase plasminogen receptor (uPAR) is over-expressed in tumor endothelium and plays a critical role in tumor neovascularization. The goal of this study is to demonstrate the ability of an oncolytic measles virus redirected against uPAR (MV-uPA) to infect endothelial cells in vitro and to target tumor vasculature in vivo. We engineered and rescued recombinant oncolytic measles viruses fully retargeted against human (MV-huPA) or murine (MV-muPA) urokinase receptor. A dual targeting measles virus (MV-un-muPA, targeting human cancer cells via CD46 and murine tissues via murine uPAR) was generated by displaying murine ATF of uPA into the C-terminus of the unmodified MV-H glycoprotein of MV-Edm genome, and then rescued. The specific dual species targeting virus offers the unique opportunity to investigate the ability of a virus to target tumor angiogenesis (via murine uPAR) and deliver the infection to tumor cells (via CD46) in vivo. Stimulation of human (HUVEC, HMVEC-L and HMVEC-D) and murine (MS1) endothelial cells by serum and growth factors was associated with upregulation of uPAR expression, as compared to non-stimulated ECs, while levels of CD46 -the natural receptor for non-retargeted oncolytic MV-were not changed. Upregulation of uPAR was associated with higher infection efficiency of ECs by the species specific MV-uPA compared to non-targeted MV-GFP. Human endothelial (EC)-to-human tumor cell (TC) viral transfer in vitro was demonstrated by co-culture experiments between MV-huPA infected ECs expressing GFP and uninfected, RFP expressing breast cancer cells (MDA-MB-231, MDA-MB-436, MCF-7) and identification of yellow fluorescent syncytia. MV-un-muPA efficiently infected mouse ECs (MS1) and human cancer cells. Importantly, MS-1 cells infected with MV-un-muPA successfully transferred the virus to human TCs. Intravenous administration of MV-un-muPA to mice bearing human breast tumors (MDA-MB-231) was associated with targeting of murine tumor vasculature (via murine uPAR), higher viral protein (MV-N) in tumor tissues, and a trend to better survival, compared with single targeted (CD46) control virus, In conclusion, our results demonstrated that tumor endothelial uPAR targeting by MV-uPA facilitates endothelial-to tumor cell viral transfer in vitro, and viral entry into tumor tissues in vivo by targeting angiogenic endothelium. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5657. doi:1538-7445.AM2012-5657</jats:p

Activity of RX-3117, an oral antimetabolite nucleoside, in patients with pancreatic cancer: Preliminary results of stage 1 of the phase 1a/2b

445 Background: RX-3117 is an oral smallmolecule antimetabolite, cyclopentyl pyrimidyl nucleoside that is activated by uridine cytidine kinase 2. RX-3117 has shown efficacy in xenograft models of gemcitabine resistant pancreatic, bladder and colorectal cancer. Data from stage 1 of the Phase 1b/2a clinical study of RX3117 as a single agent in subjects with metastatic pancreatic cancer is described below. Methods: Stage 1 of the Phase 1b/2a study (NCT02030067) is designed to evaluate safety, tolerability and efficacy following treatment with 700 mg administered orally once-daily for 5 consecutive days with 2 days off per week for 3 weeks with 1 week off in each 4 week cycle in a 2-stage Simon design. Eligible subjects (aged ≥ 18 years) were those with relapsed/refractory metastatic pancreatic cancer. The primary endpoint is a ≥ 20% (2 out of 10 subjects) rate of progression free survival (PFS) benefit (i.e., proportion of subjects with stable disease for at least 4 months) and/or a 10% (1 of 10 subjects) with a partial response rate or better. Results: As of Sep 2016, 8 out of 10 subjects have been enrolled (4 females, 4 males), the mean age was 70 years, ECOG performance status was 1 and 5 subjects had received more than 4 prior therapies. Two subjects met the primary endpoint of stable disease with a duration of 140-168 days at the time of this submission. The most frequent adverse events were moderate to severe anemia, mild to moderate fatigue, abdominal pain and diarrhea. Conclusions: This ongoing trial shows an early efficacy signal where RX-3117 is active against advanced pancreatic cancer. As the primary endpoint has been achieved, the study will now move to stage 2 where an additional 40 subjects with advanced pancreatic cancer will be enrolled. Clinical trial information: NCT02030067

Antiangiogenic property of human thrombin

Using protein chromatography, we purified and identified human prothrombin from human plasma as antiangiogenic. Prothrombin significantly inhibited endothelial cell tube formation in vitro at 10 microg/ml. Importantly, it also inhibited bFGF-induced angiogenesis in Matrigel-plug assays performed in mice. The proteolytic activity of thrombin appeared to be critical for the antiangiogenic activity of prothrombin. For example, thrombin exhibited inhibitory effects on endothelial cell tube formation in vitro at 10 U/ml. Addition of lepirudin, a specific inhibitor of thrombin, completely blocked prothrombin's and thrombin's antiangiogenic effects in vitro. We also assessed the importance of thrombin receptors in angiogenesis. Using small peptides that activate different protease-activated receptors (PARs), we showed that activation of PAR-1 led to inhibition of endothelial cell tube formation in vitro and bFGF-induced angiogenesis in vivo. Collectively, our data suggest that thrombin's proteolytic activity can be antiangiogenic