0.1% RGN-259 (Thymosin ß4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial.

We determined the efficacy and safety of 0.1% RGN-259 ophthalmic solution (containing the regenerative protein thymosin ß4) in promoting the healing of persistent epithelial defects in patients with Stages 2 and 3 neurotrophic keratopathy. Complete healing occurred after 4 weeks in 6 of the 10 RGN-259-treated subjects and in 1 of the 8 placebo-treated subjects ( = 0.

Thymosin β4 and the anti-fibrotic switch.

Wound healing involves a rapid response to the injury by circulating cells, followed by inflammation with an influx of inflammatory cells that release various factors. Soon after, cellular proliferation begins to replace the damaged cells and extracellular matrix, and then tissue remodeling restores normal tissue function. Various factors can lead to pathological wound healing when excessive and irreversible connective tissue/extracellular matrix deposition occurs, resulting in fibrosis.

Hematogenous metastasis and tumor dormancy as concepts or dogma? The continuum of vessel co-option and angiotropic extravascular migratory metastasis as an alternative.

It has been accepted for many years that tumor cells spread the circulation to distant sites. The latency period between treatment and tumor recurrence has been attributed to dormant cells in distant organs that emerge and grow as metastatic tumors. These processes are accepted with an incomplete demonstration of their existence.

Monitoring Angiotropic Extravascular Migratory Metastasis In Vitro.

The mechanism of cancer cell migration from the primary tumor toward secondary sites is not fully understood. In addition to intravascular cellular migration, angiotropic extravascular migratory metastasis (EVMM) has been recognized as a metastatic pathway involving tumor cells crawling along the abluminal vascular surface to distant sites. A very simple in vitro 3D assay is described here, which is based on a previous in vitro angiogenesis assay.

Matrigel: history/background, uses, and future applications.

Basement membranes are thin sheets of extracellular matrix with many diverse roles in the body. Those in normal tissue are also highly insoluble and resist attempts to extract and characterize their components. A mouse tumor, the EHS tumor, has provided large amounts of basement membrane material, which has facilitated the structural and functional characterization of its components.

Purinergic Signaling Involvement in Thymosin β4-mediated Corneal Epithelial Cell Migration.

: This study aimed to determine the effect of thymosin beta 4 (Tβ4) on human corneal epithelial cell migration and the downstream signaling pathways. Tβ4 has a role in tissue development, cell migration, inflammation, and wound healing. A previous study showed that Tβ4 directly binds to F0-F1 ATP synthase.

Angiotropism, pericytic mimicry and extravascular migratory metastasis: an embryogenesis-derived program of tumor spread.

Intravascular dissemination of tumor cells is the accepted mechanism of cancer metastasis. However, the phenomenon of angiotropism, pericyte mimicry (PM), and extravascular migratory metastasis (EVMM) has questioned the concept that tumor cells metastasize exclusively via circulation within vascular channels. This new paradigm of cancer spread and metastasis suggests that metastatic cells employ embryonic mechanisms for attachment to the abluminal surfaces of blood vessels (angiotropism) and spread via continuous migration, competing with and replacing pericytes, i.

Thymosin β4: potential to treat epidermolysis bullosa and other severe dermal injuries.

Thymosin β4 is a naturally-occurring regenerative protein present in almost all cells and body fluids, including wound fluid. In multiple preclinical injury models, it promotes dermal repair and tissue regeneration. Thymosin β4 acts by increasing keratinocyte/epithelial cell migration, angiogenesis, and cell survival, and by decreasing inflammation, apoptosis, and scarring.

RGN-259 (thymosin β4) improves clinically important dry eye efficacies in comparison with prescription drugs in a dry eye model.

This study evaluated the clinical activity of RGN-259 (thymosin β4) in comparison with cyclosporine A (CsA), diquafosol (DQS), and lifitegrast (LFA) in a murine model of dry eye. The model was NOD.B10-H2 mice in a 30-40% humidified environment together with daily scopolamine hydrobromide injections for 10 days.

Safety and potential efficacy of gemfibrozil as a supportive treatment for children with late infantile neuronal ceroid lipofuscinosis and other lipid storage disorders.

Neuronal Ceroid Lipofuscinosis (NCL), also known as Batten disease, is a group of genetically distinct lysosomal disorders that mainly affect the central nervous system, resulting in progressive motor and cognitive decline primarily in children. Multiple distinct genes involved in the metabolism of lipids have been identified to date with various mutations in this family of diseases. There is no cure for these diseases but some new therapeutic approaches have been tested that offer more hope than the standard palliative care.

Imaging of Angiotropism/Vascular Co-Option in a Murine Model of Brain Melanoma: Implications for Melanoma Progression along Extravascular Pathways.

Angiotropism/pericytic mimicry and vascular co-option involve tumor cell interactions with the abluminal vascular surface. These two phenomena may be closely related. However, investigations of the two processes have developed in an independent fashion and different explanations offered as to their biological nature.

Primary Mechanisms of Thymosin β4 Repair Activity in Dry Eye Disorders and Other Tissue Injuries.

Dry eye disorders are becoming more common due to many causes, including an aging population, increased pollution, and postrefractive surgery. Current treatments include artificial tears; gels; lubricants; tear duct plugs; and anti-inflammatory agents such as steroids, doxycycline, and cyclosporine. For more severe forms of the disease, serum tears and scleral contact lenses are employed.

Advances in the basic and clinical applications of thymosin β4.

Introduction: Thymosin β4 (Tβ4), a multifunctional peptide, has been used successfully in several clinical trials involving tissue repair and regeneration. The review will first update the current information on the common underlying cellular cascades and pathways that are basic to Tβ4's regenerative activity and second, on the current and potential uses of this protein in the clinic.

Areas Covered: Significant advances in our understanding of the actions of Tβ4 have occurred in directing stem cell maturation and in regeneration and repair of injuries.

Thymosin β4 significantly reduces the signs of dryness in a murine controlled adverse environment model of experimental dry eye.

Objective: Dry eye syndrome is a common condition that affects up to 20% of the population aged 45 and older. There are no successful treatments to date. The goal of this research was to determine the efficacy of various doses and the optimal frequency of thymosin β4 (Tβ4) treatment in a murine severe dry eye model.

In vitro microtumors provide a physiologically predictive tool for breast cancer therapeutic screening.

Many anti-cancer drugs fail in human trials despite showing efficacy in preclinical models. It is clear that the in vitro assays involving 2D monoculture do not reflect the complex extracellular matrix, chemical, and cellular microenvironment of the tumor tissue, and this may explain the failure of 2D models to predict clinical efficacy. We first optimized an in vitro microtumor model using a tumor-aligned ECM, a tumor-aligned medium, MCF-7 and MDA-MB-231 breast cancer spheroids, human umbilical vein endothelial cells, and human stromal cells to recapitulate the tissue architecture, chemical environment, and cellular organization of a growing and invading tumor.

Angiotropism, pericytic mimicry and extravascular migratory metastasis in melanoma: an alternative to intravascular cancer dissemination.

For more than 15 years, angiotropism in melanoma has been emphasized as a marker of extravascular migration of tumor cells along the abluminal vascular surface, unveiling an alternative mechanism of tumor spread distinct from intravascular dissemination. This mechanism has been termed extravascular migratory metastasis (EVMM). During EVMM, angiotropic tumor cells migrate in a 'pericytic-like' manner (pericytic mimicry) along the external surfaces of vascular channels, without intravasation.

Matrigel: from discovery and ECM mimicry to assays and models for cancer research.

The basement membrane is an important extracellular matrix that is found in all epithelial and endothelial tissues. It maintains tissue integrity, serves as a barrier to cells and to molecules, separates different tissue types, transduces mechanical signals, and has many biological functions that help to maintain tissue specificity. A well-defined soluble basement membrane extract, termed BME/Matrigel, prepared from an epithelial tumor is similar in content to authentic basement membrane, and forms a hydrogel at 24-37°C.

Could pericytic mimicry represent another type of melanoma cell plasticity with embryonic properties?

We hypothesize that the interaction between angiotropic melanoma cells and the abluminal vascular surface can induce or sustain embryonic and/or stem cell migratory properties in these tumor cells. As a result, such angiotropic melanoma cells may migrate along the abluminal vascular surface, demonstrating pericytic mimicry. Through these cellular interactions, melanoma cells may migrate toward secondary sites.

Pilot study on "pericytic mimicry" and potential embryonic/stem cell properties of angiotropic melanoma cells interacting with the abluminal vascular surface.

The interaction of tumor cells with the tumor vasculature is mainly studied for its role in tumor angiogenesis and intravascular metastasis of circulating tumor cells. In addition, a specific interaction of tumor cells with the abluminal surfaces of vessels, or angiotropism, may promote the migration of angiotropic tumor cells along the abluminal vascular surfaces in a pericytic location. This process has been termed extravascular migratory metastasis.

Laminin-111-derived peptides and cancer.

Laminin-111 is a large trimeric basement membrane glycoprotein with many active sites. In particular, four peptides active in tumor malignancy studies have been identified in laminin-111 using a systematic peptide screening method followed by various assays. Two of the peptides (IKVAV and AG73) are found on the α1 chain, one (YIGSR) of the β1 chain and one (C16) on the γ1 chain.

The regenerative peptide thymosin β4 accelerates the rate of dermal healing in preclinical animal models and in patients.

Chronic nonhealing cutaneous wounds are a worldwide problem with no agent able to promote healing. A naturally occurring, endogenous repair molecule, thymosin beta 4 (Tβ4), has many biological activities that promote dermal repair. It is released by platelets at the site of injury and initiates the repair cascade.

Thymosin β4 stabilizes hypoxia-inducible factor-1α protein in an oxygen-independent manner.

The small actin-binding protein thymosin β4 (Tβ4) is understood to stimulate angiogenesis. Previously, we reported that Tβ4 induces angiogenesis by increasing vascular endothelial growth factor (VEGF) expression, but the mechanism underlying how Tβ4 upregulates VEGF expression remain unknown. To identify the mechanism of VEGF induction by Tβ4, we measured VEGF promoter activity and analyzed the effect of Tβ4 on VEGF RNA stability.

Increased initiation and growth of tumor cell lines, cancer stem cells and biopsy material in mice using basement membrane matrix protein (Cultrex or Matrigel) co-injection.

This protocol requires 2-4 h and presents a method for injecting tumor cells, cancer stem cells or dispersed biopsy material into subcutaneous or orthotopic locations within recipient mice. The tumor cells or biopsy are mixed with basement membrane matrix proteins (CultrexBME or Matrigel) at 4 °C and then injected into recipient animals at preferred anatomical sites. Tumor cells can also be co-injected with additional cell types, such as fibroblasts, stromal cells, endothelial cells and so on.

Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications.

Introduction: Thymosin β(4), a low molecular weight, naturally-occurring peptide plays a vital role in the repair and regeneration of injured cells and tissues. After injury, thymosin β(4), is released by platelets, macrophages and many other cell types to protect cells and tissues from further damage and reduce apoptosis, inflammation and microbial growth. Thymosin β(4) binds to actin and promotes cell migration, including the mobilization, migration, and differentiation of stem/progenitor cells, which form new blood vessels and regenerate the tissue.

The potent peptide antagonist to angiogenesis, C16Y, and cisplatin act synergistically in the down-regulation of the Bcl-2/Bax ratio and the induction of apoptosis in human ovarian cancer cells.

Cisplatin is one of the most potent antitumor agents for ovarian cancer, but has also been implicated in normal tissue cytotoxicity. We examined the effect of cisplatin alone and in combination with C16Y, a newly-identified anti-angiogenic peptide from the NH2-terminal domains of the γ-chain of laminin-1, on the modulation of Bcl-2/Bax expression and induction of apoptosis in ovarian cancer cells (OVACAR3). C16Y did not elicit cell death of human umbilical vein endothelial cells (HUVECs).