Current status and perspective of antiangiogenic therapy for cancer: urinary cancer

Synergies of Targeting Angiogenesis and Immune Checkpoints in Cancer: From Mechanism to Clinical Applications

BACKGROUND

Angiogenesis marks key progress in the growth, recurrence, and metastasis of various cancers. Antiangiogenic drugs can improve the blood supply and oxygen content of tumors and enhance the effects of chemotherapy and radiotherapy by normalizing tumor blood vessels and microenvironment. The further recent developments of Immune Checkpoint Inhibitors (ICIs) provide significant progress in cancer immunotherapy. The study focused on programmed cell death protein 1 (PD-1) and Cytotoxic T Lymphocyte Antigen 4 (CTLA-4) blockade, reflecting on the evidence of durable responses among various tumor types. The aim of this review was to sum up present evidence and clarify the rationale behind supporting the benefits of combining antiangiogenic drugs with immunotherapy for cancer treatment as well as list the ongoing clinical trials that are being conducted.

METHODS

Using PubMed and Web of Science, published articles have been searched and comprehensively reviewed.

RESULTS

Antiangiogenic agents can trigger antitumor and immunity, and they can also be induced by the immune system. Combining antiangiogenic drugs with immunotherapy may be effective for the treatment of human cancers.

CONCLUSION

It is evidenced that combining angiogenesis inhibitors with immunotherapy has a synergistic effect thus improving the curative effect of both agents.

Prognostic Significance of VEGF after Twenty-Year Follow-up in a Randomized Trial of Fenretinide in Non-Muscle-Invasive Bladder Cancer

Non-muscle-invasive bladder cancer (NMIBC) may progress to muscle-invasive disease, but no effective preventive treatments are available. In addition, no reliable prognostic biomarkers have been identified. We assessed the long-term effect of the oral retinoid fenretinide and the prognostic value of circulating VEGF levels. We updated through the Tumor Registry the vital status of 99 patients with resected Ta/T1 bladder tumors who were recruited in a randomized trial of 2 years of fenretinide or no treatment in 1993-1994. Serum VEGF levels measured at baseline and 12 months were available in a subgroup of 62 patients. After a median of 20.5 years, 54 subjects died, 35 of any cancer and 14 of bladder cancer. Neither overall survival (OS), nor cancer survival (CS) or bladder cancer survival (BCS) was affected by fenretinide (log-rank P ≥ 0.2). DNA aneuploidy in bladder washing was associated with shorter OS (P = 0.02), CS (P = 0.05), and BCS (P = 0.09). Subjects with baseline VEGF levels in the top quintile (≥350 pg/mL) had a significantly shorter OS (P = 0.01), CS (P = 0.02), and BCS (P = 0.008). The trend across quintiles of VEGF was significant for BCS (P = 0.007). Multivariate analyses showed that, in addition to smoking status, VEGF level in the top quintile was an independent prognostic factor for OS (HR = 2.7; 95% CI, 1.1-6.5), CS (HR = 3.3; 95% CI, 1.1-9.4) and BCS (HR = 8.9; 95% CI,1.3-61). Fenretinide did not affect the long-term outcome of patients with NMIBC. High serum VEGF level was a significant predictor of overall and cancer death and may help to identify high-risk subjects who may benefit from a preventive therapy. Cancer Prev Res; 9(6); 437-44. ©2016 AACR.

Anti-angiogenic active immunotherapy: a new approach to cancer treatment

Tumor angiogenesis plays an important role in tumor growth, aggression and metastasis. Many molecules have been demonstrated as positive regulators of angiogenesis, including vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and others. In recent years, significant progress has been made in the research on anti-angiogenic strategies for tumor therapies. In this review, anti-angiogenic active immunotherapies for tumors based on vaccination with xenogeneic homologous molecules and non-xenogeneic homologous molecules are discussed.

Nitroaspirin (NCX-4016), an NO donor, is antiangiogenic through induction of loss of redox-dependent viability and cytoskeletal reorganization in endothelial cells

We recently reported that NCX-4016, a derivative of aspirin containing a nitro moiety that releases nitric oxide (NO) in a sustained fashion in biologic systems, is a potent cytotoxic agent inhibiting the proliferation of cisplatin-resistant human ovarian cancer cells. Therefore, we hypothesize that NCX-4016 possesses antiangiogenic properties. Our study with the bovine lung microvascular endothelial cells (BLMVECs) revealed that NCX-4016 significantly induced the loss of redox-dependent cell viability in a dose- and time-dependent manner, as assayed by the redox-sensitive Alamar blue cell viability assay. Fluorescence microscopy of cells labeled with NO-specific fluorophore (DAF-FM) confirmed that NCX-4016 generated significant levels of intracellular NO. NO donors, including S-nitroso-N-acetylpenicillamine, spermine NONOate, and isosorbide dinitrite, were less effective in causing loss of cell viability. Thiol-protectant, N-acetylcysteine, significantly attenuated the NCX-4016-induced loss of cell viability, suggesting the role of alteration of thiol-redox status therein. NCX-4016 also suppressed oxygen consumption, decreased transendothelial electrical resistance (EC barrier dysfunction), and induced actin cytoskeletal reorganization in BLMVECs. The in vitro assay with human umbilical vein ECs and BLMVECs revealed that NCX-4016, in a dose-dependent manner, significantly inhibited angiogenesis with almost complete inhibition at a 100-microM concentration, suggesting that NCX-4016 can act as an antiangiogenic drug.

Chemo-angiogenic profile of bovine urinary bladder tumors distinguishes urothelial carcinomas from hemangiosarcomas

Angiogenesis and inflammation are two processes regulated by numerous common molecular mechanisms. Inflammation can stimulate angiogenesis, and angiogenesis can facilitate inflammation; both mechanisms have been shown to be involved in carcinogenesis. With this study we sought to gain an understanding of the molecular mechanisms involved in tumor angiogenesis and inflammation in urinary bladder tumors. Tumor specimens were collected at slaughter from Friesian cows chronically exposed to bracken fern. Bracken chronic toxicity is characterized by the presence of multiple mixed tumors in the bladder, being reported throughout the world under the designation of bovine enzootic hematuria. We conducted molecular analyses of angiogenic factors and chemokine production by real-time RT-PCR, and also assessed microvessel density (MVD), microvessel pericyte coverage index (MPI) to reveal mature vessels, the extent of tumor-infiltrating leukocytes (TILk) and tumor cell apoptosis and proliferation in both epithelial and endothelial-derived bovine urinary bladder tumors. We defined a profile of chemokines/chemokine receptors (Mip1beta, CCR1) and angiogenesis-related factors (VEGF, VEGFR2) that allow distinguishing between urothelial carcinomas (epithelial origin) and hemangiosarcomas (endothelial origin). Taken together, our data reveals previously unrecognized paracrine and autocrine chemo-angiogenic loops in the context of bovine urinary bladder tumorigenesis.