1.
Anti-VEGF Mediated Immunomodulatory Role of Phytochemicals: Scientific Exposition for Plausible HCC Treatment.
Kumar, AR, Devan, AR, Nair, B, Nath, LR
Current drug targets. 2021;(11):1288-1316
Abstract
Hepatocellular carcinoma (HCC) is one of the most common solid tumours and the second leading cause of cancer-related mortality worldwide. Advanced-recurrent HCC often requires a systemic drug therapy where multi tyrosine kinase inhibitor, Sorafenib represents the first-line therapy option. But it exhibited very limited survival benefit and tumour response due to the early emergence of drug resistance and drug-related adverse effect. Immunotherapy approaches now being widely studied as an effective alternative treatment for HCC. Several immune checkpoint inhibitors (ICI), such as Nivolumab and Pembrolizumab, are approved as monotherapy in sorafenib-resistant HCC patients. But, the existence of a plethora of immunosuppressive signals in the tumour microenvironment often leads to unsuccessful immunotherapies. In this context, combinatorial immunotherapies are getting much acceptance as a way to improve therapeutic outcomes by blocking immunosuppressive signals in the tumour microenvironment (TME). The combination of Vascular Endothelial Growth Factor (VEGF) inhibitors with ICI resulted in significant synergistic effects in various preclinical and clinical studies. However, the adverse effects associated with current synthetic VEGF inhibitors limit its clinical utility. In this review, we have summarized the potential of phytochemicals, especially the category of flavonoids, alkaloids, glycosides, terpenoids, and coumarin, as the available-affordable-safe-effective repositories of VEGF inhibitors. Their possibilities as an alternative for synthetic VEGF inhibitors by synergistic combination with ICI are reviewed, thereby enhancing patient compliance and survival rates. This review highlights the demand for a detailed investigation of the plausible role of plant-based anti-angiogenic-immunotherapy combination against HCC.
2.
Targeting Angiopoietin in Retinal Vascular Diseases: A Literature Review and Summary of Clinical Trials Involving Faricimab.
Khan, M, Aziz, AA, Shafi, NA, Abbas, T, Khanani, AM
Cells. 2020;(8)
Abstract
This review summarizes the latest findings in the literature of Angiopoietin-2 (Ang-2), Tyrosine-protein kinase receptor (Tie-2) complex, and faricimab along with their involvement for the treatment of retinal vascular diseases in various clinical trials. In ischemic diseases, such as diabetic retinopathy, Ang-2 is upregulated, deactivating Tie-2, resulting in vascular leakage, pericyte loss, and inflammation. Recombinant Angiopeotin-1 (Ang-1), Ang-2-blocking molecules, and inhibitors of vascular endothelial protein tyrosine phosphatase (VE-PTP) decrease inflammation-associated vascular leakage, showing therapeutic effects in diabetes, atherosclerosis, and ocular neovascular diseases. In addition, novel studies show that angiopoietin-like proteins may play an important role in cellular metabolism leading to retinal vascular diseases. Current therapeutic focus combines Ang-Tie targeted drugs with other anti-angiogenic or immune therapies. Clinical studies have identified faricimab, a novel bispecific antibody designed for intravitreal use, to simultaneously bind and neutralize Ang-2 and VEGF-A for treatment of diabetic eye disease. By targeting both Ang-2 and vascular endothelial growth factor-A (VEGF-A), faricimab displays an improved and sustained efficacy over longer treatment intervals, delivering superior vision outcomes for patients with diabetic macular edema and reducing the treatment burden for patients with neovascular age-related macular degeneration and diabetic macular edema. Phase 2 results have produced promising outcomes with regard to efficacy and durability. Faricimab is currently being evaluated in global Phase 3 studies.
3.
Human lung-resident macrophages express CB1 and CB2 receptors whose activation inhibits the release of angiogenic and lymphangiogenic factors.
Staiano, RI, Loffredo, S, Borriello, F, Iannotti, FA, Piscitelli, F, Orlando, P, Secondo, A, Granata, F, Lepore, MT, Fiorelli, A, et al
Journal of leukocyte biology. 2016;(4):531-40
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Abstract
Macrophages are pivotal effector cells in immune responses and tissue remodeling by producing a wide spectrum of mediators, including angiogenic and lymphangiogenic factors. Activation of cannabinoid receptor types 1 and 2 has been suggested as a new strategy to modulate angiogenesis in vitro and in vivo. We investigated whether human lung-resident macrophages express a complete endocannabinoid system by assessing their production of endocannabinoids and expression of cannabinoid receptors. Unstimulated human lung macrophage produce 2-arachidonoylglycerol,N-arachidonoyl-ethanolamine,N-palmitoyl-ethanolamine, and N-oleoyl-ethanolamine. On LPS stimulation, human lung macrophages selectively synthesize 2-arachidonoylglycerol in a calcium-dependent manner. Human lung macrophages express cannabinoid receptor types 1 and 2, and their activation induces ERK1/2 phosphorylation and reactive oxygen species generation. Cannabinoid receptor activation by the specific synthetic agonists ACEA and JWH-133 (but not the endogenous agonist 2-arachidonoylglycerol) markedly inhibits LPS-induced production of vascular endothelial growth factor-A, vascular endothelial growth factor-C, and angiopoietins and modestly affects IL-6 secretion. No significant modulation of TNF-α or IL-8/CXCL8 release was observed. The production of vascular endothelial growth factor-A by human monocyte-derived macrophages is not modulated by activation of cannabinoid receptor types 1 and 2. Given the prominent role of macrophage-assisted vascular remodeling in many tumors, we identified the expression of cannabinoid receptors in lung cancer-associated macrophages. Our results demonstrate that cannabinoid receptor activation selectively inhibits the release of angiogenic and lymphangiogenic factors from human lung macrophage but not from monocyte-derived macrophages. Activation of cannabinoid receptors on tissue-resident macrophages might be a novel strategy to modulate macrophage-assisted vascular remodeling in cancer and chronic inflammation.