Inhibitive effect of genistein on hypoxia-induced basic fibroblast growth factor expression in human retinal pigment epithelium cells

Cellular Mechanisms of FGF-Stimulated Tissue Repair

Growth factors belonging to the FGF family play important roles in tissue and organ repair after trauma. In this review, I discuss the regulation by FGFs of the aspects of cellular behavior important for reparative processes. In particular, I focus on the FGF-dependent regulation of cell proliferation, cell stemness, de-differentiation, inflammation, angiogenesis, cell senescence, cell death, and the production of proteases. In addition, I review the available literature on the enhancement of FGF expression and secretion in damaged tissues resulting in the increased FGF supply required for tissue repair.

Hypoxia-dependent drivers of melanoma progression

Hypoxia, a condition of low oxygen availability, is a hallmark of tumour microenvironment and promotes cancer progression and resistance to therapy. Many studies reported the essential role of hypoxia in regulating invasiveness, angiogenesis, vasculogenic mimicry and response to therapy in melanoma. Melanoma is an aggressive cancer originating from melanocytes located in the skin (cutaneous melanoma), in the uveal tract of the eye (uveal melanoma) or in mucosal membranes (mucosal melanoma). These three subtypes of melanoma represent distinct neoplasms in terms of biology, epidemiology, aetiology, molecular profile and clinical features.In this review, the latest progress in hypoxia-regulated pathways involved in the development and progression of all melanoma subtypes were discussed. We also summarized current knowledge on preclinical studies with drugs targeting Hypoxia-Inducible Factor-1, angiogenesis or vasculogenic mimicry. Finally, we described available evidence on clinical studies investigating the use of Hypoxia-Inducible Factor-1 inhibitors or antiangiogenic drugs, alone or in combination with other strategies, in metastatic and adjuvant settings of cutaneous, uveal and mucosal melanoma.Hypoxia-Inducible Factor-independent pathways have been also reported to regulate melanoma progression, but this issue is beyond the scope of this review.As evident from the numerous studies discussed in this review, the increasing knowledge of hypoxia-regulated pathways in melanoma progression and the promising results obtained from novel antiangiogenic therapies, could offer new perspectives in clinical practice in order to improve survival outcomes of melanoma patients.

Hypoxia-induced retinal pigment epithelium cell-derived bFGF promotes the migration and angiogenesis of HUVECs through regulating TGF-β1/smad2/3 pathway

Hypoxia promotes the secretion of basic fibroblast growth factor (bFGF) in retinal pigment epithelium (RPE), which plays an important part in retinopathy of prematurity (ROP). This study preliminarily explored the effect of hypoxia-induced RPE-derived bFGF on the biological functions of human umbilical vein endothelial cells (HUVECs). After cell culture in hypoxia conditions, the cell viability, apoptosis, and the expressions of bFGF and vascular endothelial growth factor A (VEGFA) in human RPEs were detected by 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, western blot, RT-qPCR, or ELISA. The HUVECs were transfected with siRNA for bFGF (sibFGF) or transforming growth factor-β1 (TGF-β1) (siTGF-β1) and grown in the supernatant RPE under normoxia conditions or hypoxia conditions to further determine the cell viability, migration, angiogenesis, and the expressions of TGF-β1, p-smad2/3, and smad2/3 in the cells by performing MTT, transwell, tube formation, Western blot, or RT-qPCR. Hypoxia culture decreased the cell viability and promoted the apoptosis as well as the expressions of bFGF and VEGFA in RPEs. In both normoxia and hypoxia conditions, RPE-derived bFGF increased the cell viability, migration, angiogenesis, and the expressions of TGF-β1 and p-smad2/3 in the HUVECs, with hypoxia-induced RPE-derived bFGF showing a stronger effect than bFGF induced by normoxia. However, sibFGF reversed the effects caused by RPE-derived bFGF. Moreover, siTGF-β1 decreased the high cell viability, migration and angiogenesis of HUVECs, and downregulated the expressions of TGF-β1 and phosphorylated (p)-smad2/3 upregulated by hypoxia-induced RPE-derived bFGF. Hypoxia-induced RPE-derived bFGF could promote the migration and angiogenesis of HUVECs through regulating TGF-β1/smad2/3 pathway.

Targeting vasculogenic mimicry by phytochemicals: A potential opportunity for cancer therapy

Vasculogenic mimicry (VM) is regarded as a process where very aggressive cancer cells generate vascular-like patterns without the presence of endothelial cells. It is considered as the main mark of malignant cancer and has pivotal role in cancer metastasis and progression in various types of cancers. On the other hand, resistance to the antiangiogenesis therapies leads to the cancer recurrence. Therefore, development of novel chemotherapies and their combinations is urgently needed for abolition of VM structures and also for better tumor therapy. Hence, identifying compounds that target VM structures might be superior therapeutic factors for cancers treatment and controlling the recurrence and metastasis. In recent times, naturally occurring compounds, especially phytochemicals have obtained great attention due to their safe properties. Phytochemicals are also capable of targeting VM structure and also their main signaling pathways. Consequently, in this review article, we illustrated key signaling pathways in VM, and the phytochemicals that affect these structures including curcumin, genistein, lycorine, luteolin, columbamine, triptolide, Paris polyphylla, dehydroeffusol, jatrorrhizine hydrochloride, grape seed proanthocyanidins, resveratrol, isoxanthohumol, dehydrocurvularine, galiellalactone, oxacyclododecindione, brucine, honokiol, ginsenoside Rg3, and norcantharidin. The recognition of these phytochemicals and their safety profile may lead to new therapeutic agents' development for VM elimination in different types of tumors.

Assessing the anticancer effects associated with food products and/or nutraceuticals using in vitro and in vivo preclinical development-related pharmacological tests

This review is part of a special issue entitled "Role of dietary pattern, foods, nutrients and nutraceuticals in supporting cancer prevention and treatment" and describes a pharmacological strategy to determine the potential contribution of food-related components as anticancer agents against established cancer. Therefore, this review does not relate to chemoprevention, which is analysed in several other reviews in the current special issue, but rather focuses on the following: i) the biological events that currently represent barriers against the treatment of certain types of cancers, primarily metastatic cancers; ii) the in vitro and in vivo pharmacological pre-clinical tests that can be used to analyse the potential anticancer effects of food-related components; and iii) several examples of food-related components with anticancer effects. This review does not represent a catalogue-based listing of food-related components with more or less anticancer activity. By contrast, this review proposes an original pharmacological strategy that researchers can use to analyse the potential anticancer activity of any food-related component-e.g., by considering the crucial characteristics of cancer biological aggressiveness. This review also highlights that cancer patients undergoing chemotherapy should restrict the use of "food complements" without supervision by a medical nutritionist. By contrast, an equilibrated diet that includes the food-related components listed herein would be beneficial for cancer patients who are not undergoing chemotherapy.

Potential of the bioflavonoids in the prevention/treatment of ocular disorders

OBJECTIVES

Flavonoids are a common group of plant polyphenols that give colour and flavour to fruits and vegetables. In recent years, flavonoids have gained importance in the pharmaceutical field through their beneficial effects on human health and are widely available as nutritional supplements. Several pharmacological actions of the bioflavonoids may be useful in the prevention or treatment of ocular diseases responsible for vision loss such as diabetic retinopathy, macular degeneration and cataract. This review aims to summarize the potential therapeutic applications of various bioflavonoids in different ocular diseases and also discusses delivery of these agents to the ocular tissues.

KEY FINDINGS

It is apparent that the flavonoids are capable of acting on various mechanisms or aetiological factors responsible for the development of different sight threatening ocular diseases. From a drug delivery perspective, ocular bioavailability depends on the physicochemical and biopharmaceutical characteristics of the selected flavonoids and very importantly the route of administration.

SUMMARY

The potential therapeutic applications of various bioflavonoids in ocular diseases is reviewed and the delivery of these agents to the ocular tissues is discussed. Whereas oral administration of bioflavonoids may demonstrate some pharmacological activity in the outer sections of the posterior ocular segment, protection of the retinal ganglionic cells in vivo may be limited by this delivery route. Systemic or local administration of these agents may yield much higher and effective concentrations of the parent bioflavonoids in the ocular tissues and at much lower doses.

Effect of Genistein on vasculogenic mimicry formation by human uveal melanoma cells

BACKGROUND

Vasculogenic mimicry (VM) was increasingly recognized as a form of aggressive melanoma acquiring blood supply. Genistein had attracted much attention as a potential anticancer agent. Therefore, we examined the effect of Genistein on VM in human uveal melanoma cells.

METHODS

VM structure was detected by periodic acid-Schiff (PAS) staining for uveal melanoma C918 cells cultured on the three-dimensional type I collagen gels after exposed to Genistein. We used reverse transcription polymerase chain reaction (RT-PCR) and Western Blot analysis to examine the effect of Genistein on vascular endothelial cadherin (VE-cadherin) mRNA and protein expression. The nude mice models of human uveal melanoma C918 cells were established to assess the number of VM using immunohistochemical and PAS double-staining.

RESULTS

Genistein inhibited the survival of C918 cells in vitro. The ectopic model study showed that VM in tumor tissue sections were significantly reduced by Genistein in vivo. In vitro, the VM structure was found in control, 25 and 50 microM Genistein-treatment groups but not in 100 and 200 microM. RT-PCR and Western Blot showed that 100 and 200 microM concentration of Genistein could significantly decrease VE-cadherin mRNA and protein expression of C918 cells compared with control (P < 0.05). However, the 25 and 50 microM Genistein slightly decreased the VE-cadherin level in vitro (P > 0.05).

CONCLUSION

Genistein inhibits VM formation of uveal melanoma cells in vivo and in vitro. One possible underlying molecular mechanism by which Genistein could inhibit VM formation of uveal melanoma is related to down-regulation of VE-cadherin.