Significance of the antiangiogenic mechanisms of thalidomide in the therapy of diabetic retinopathy

Thalidomide interaction with inflammation in idiopathic pulmonary fibrosis

The "Thalidomide tragedy" is a landmark in the history of the pharmaceutical industry. Despite limited clinical trials, there is a continuous effort to investigate thalidomide as a drug for cancer and inflammatory diseases such as rheumatoid arthritis, lepromatous leprosy, and COVID-19. This review focuses on the possibilities of targeting inflammation by repurposing thalidomide for the treatment of idiopathic pulmonary fibrosis (IPF). Articles were searched from the Scopus database, sorted, and selected articles were reviewed. The content includes the proven mechanisms of action of thalidomide relevant to IPF. Inflammation, oxidative stress, and epigenetic mechanisms are major pathogenic factors in IPF. Transforming growth factor-β (TGF-β) is the major biomarker of IPF. Thalidomide is an effective anti-inflammatory drug in inhibiting TGF-β, interleukins (IL-6 and IL-1β), and tumour necrosis factor-α (TNF-α). Thalidomide binds cereblon, a process that is involved in the proposed mechanism in specific cancers such as breast cancer, colon cancer, multiple myeloma, and lung cancer. Cereblon is involved in activating AMP-activated protein kinase (AMPK)-TGF-β/Smad signalling, thereby attenuating fibrosis. The past few years have witnessed an improvement in the identification of biomarkers and diagnostic technologies in respiratory diseases, partly because of the COVID-19 pandemic. Hence, investment in clinical trials with a systematic plan can help repurpose thalidomide for pulmonary fibrosis.

hsa-mir-(4328, 4422, 548z and -628-5p) in diabetic retinopathy: diagnosis, prediction and linking a new therapeutic target

AIMS

Growing evidence suggests that microRNAs (miRNAs) are crucial in controlling how diabetic retinopathy (DR) develops. We intend to mine miRNAs with diagnostic and predictive value for DR and to investigate new drug therapeutic targets.

METHODS

After performing a differential analysis on the miRNA and mRNA datasets for DR and neovascularization (NEO), miRNA-mRNA networks were created. Combine the results of enrichment analysis, Protein-Protein Interaction Networks (PPI), and Cytoscape to identify key miRNAs. DrugBank was used to find drugs that interacted with transcription factors (TF) predicted by TransmiR. Finally, whole blood and clinical data were collected from 58 patients with type 2 diabetes mellitus (T2DM), and RT-qPCR, logistic analysis, and ROC were used to verify the value of key miRNAs.

RESULTS

Differential analysis indicated the presence of genes and miRNAs that co-regulate DR and NEO. Enrichment analysis showed that key genes are inextricably linked to neovascularization. Combining the results of PPI and Cytoscape identified four key miRNAs, namely hsa-mir-(4328, 4422, 548z and -628-5p). RT-qPCR, logistic, and ROC results showed that decreased expression levels of hsa-mir-(4328, 4422, 548z and -628-5p) signal the risk of evolution to DR in T2DM patients. Finally, we constructed a TF-miRNA network to find the 15 TFs and the 35 drugs that interact with these TFs.

CONCLUSION

hsa-mir-(4328, 4422, 548z and -628-5p) in whole blood are protective factors for DR as novel biomarkers for diagnosis and prediction. In addition, our research provides new drug directions for the treatment of DR, such as Diosmin, Atorvastatin, and so on.

Thalidomide Mitigates Apoptosis via Endoplasmic Reticulum Stress in Diabetic Nephropathy

BACKGROUND

Previous studies have shown that endoplasmic reticulum (ER) stress is related to the apoptosis in the development of diabetic nephropathy (DN) and thalidomide (Thd) has renal-protective effects by suppressing inflammation and proliferation of MCs in DN. However, the effect of Thd on the apoptosis of MCs in DN remains largely unclear. The present research is designed to explore the effect of Thd on apoptosis in DN and the related mechanisms.

OBJECTIVE

The study is designed to examine the effect and mechanism of Thd on apoptosis in type 2 diabetic mice and high glucose (HG)-induced MCs.

METHOD

We first evaluated the ER stress markers and apoptosis-related proteins with the treatment of Thd in type 2 diabetic mice and MCs in vitro under HG conditions. MTT assay was used to assess cell viability. Additionally, we evaluated the effect of Thd treatment upon MC apoptosis through flow cytometry. Real-time polymerase chain reaction (RT-PCR) and Western blot were performed to evaluate genes and protein expression related to ER stress and apoptosis.

RESULTS

The levels of blood urea BUN, CREA, Urine albumin, and UACR in diabetic mice were significantly reduced after 8 weeks of intervention with Thd. And also, there were upregulated glucose-regulated protein 78 (GRP78), Caspase-12, and downregulated B-cell lymphoma 2 (Bcl-2) in glomeruli of DN mice. In vitro, compared with the HG group, MC apoptosis reduced dramatically with Thd treatment along with upregulation of Bcl-2 and downregulation of Bax. At the same time, ER stress markers GRP78, C/EBP homologous protein (CHOP), and Caspase-12 were also mitigated following the Thd treatment.

CONCLUSION

The present study indicates that Thd might reduce the ER stress in DN via downregulating of GRP78, CHOP, and Caspase12 expression, ultimately mitigating MCs apoptosis.

Recent Advances in the Development of Thalidomide-Related Compounds as Anticancer Drugs

INTRODUCTION

Thalidomide is an old well-known drug that was first used as morning sickness relief in pregnant women before being withdrawn from the market due to its severe side effects on normal fetal development, However, over the last few decades, the interest in this old drug has been renewed because of its efficacy in several important disorders for instance, multiple myeloma, breast cancer, and HIV-related diseases due to its antiangiogenic and immunomodulatory properties. Unfortunately, even in these cases, many aftereffects as deep vein thrombosis, peripheral neuropathy, constipation, somnolence, pyrexia, pain, and teratogenicity have been reported, showing the requirement of careful and monitored use. For this reason, research efforts are geared toward the synthesis and optimization of new thalidomide analogues lacking in toxic effects to erase these limits and improve the pharmacological profile.

AIMS

This review aims to examine the state-of-the-art concerning the current studies on thalidomide and its analogues towards cancer diseases (with few hints regarding the antimicrobial activity), focusing the attention on the possible mechanisms of action involved and the lack of toxicity.

CONCLUSION

In the light of the collected data, thalidomide analogues and their ongoing optimization could lead, in the future, to the realization of a promising therapeutic alternative for cancer-fighting.

Tandem mass tag-based proteomic analysis reveals cathepsin-mediated anti-autophagic and pro-apoptotic effects under proliferative diabetic retinopathy

Proliferative diabetic retinopathy (PDR) is a severe complication of diabetes and can cause blindness. However, the available therapeutic modalities to PDR have unsatisfactory efficacies and incur adverse effects, which is due to the paucity in the understanding of pathogenic mechanisms responsible for the disease. In this study, tandem mass tag labeling technology combined with liquid chromatography and tandem mass spectrometry were utilized to identify differentially expressed proteins in vitreous humor of patients with rhegmatogenous retinal detachment and PDR. The data are available via ProteomeXchange with identifier PXD021788. Afterwards, the downregulated protein expression of Cathepsin B, D, and L was verified in vitreous and serum of another cohort. The gene expression profiling of the 3 cathepsins was confirmed in blood cells of an extra cohort. Furthermore, in high glucose (HG)-treated retinal vascular endothelial cell cultures recapitulating the cathepsin expression patterns, Cathepsin B or D downregulation mediated the HG-induced anti-autophagic and pro-apoptotic effects, thereby may contribute to vascular lesions under hyperglycemia. This study demonstrates previously undescribed expression patterns of cathepsins, reveals a novel cathepsin-involved pathogenic mechanism under PDR, and sheds light on potential therapeutic targets to this debilitating retinal disease.

A drug repositioning success: The repositioned therapeutic applications and mechanisms of action of thalidomide

BACKGROUND

Thalidomide is the most teratogenic human medicine ever marketed and was associated with birth defects in approximately 10,000 children in the 1960s. The pharmacological effects of thalidomide are attributed to its anti-angiogenic, anti-inflammatory and modulatory effect on cytokines principally tumor necrosis factor-α, while the teratogenic effects are linked to two molecular targets, namely cereblon and tubulin. Teratogenicity is the gravest adverse effect of thalidomide depending on the dose and time of exposure. Nonetheless, with System for Thalidomide Education and Prescribing Safety program, the possibility of teratogenicity can be completely avoided. The sensitive period during pregnancy for thalidomide teratogenicity in humans is approximately 20-34 days after fertilization.

METHODS

Relevant articles were identified from Google scholar and PubMed (MEDLINE) using different search strategies.

CONCLUSION

Clinical trials showed that thalidomide has been found effective in the treatment of advanced renal cancer, esophageal cancer, chemotherapy refractory endometrial cancer and pancreatic cancer, which can suggest its future therapeutic potential in cancer treatment. Thalidomide is also used in the treatment of inflammatory skin disorders and has shown promising effect in the treatment of autoimmune disorders and inflammatory bowel disease. Despite thalidomide being a renowned teratogen and neurotoxin, it has been successfully repositioned and FDA approved for the treatment of erythema nodosum leprosum and multiple myeloma under strict control.

Enantioselective sensing of (S)-Thalidomide in blood plasma with a chiral naphthalene diimide derivative

Fast, simple in use and highly effective voltammetric enantiosensor dedicated for determination of thalidomide (TD) enantiomers (especially towards the toxic (S)-enantiomer) in blood plasma is still desirable. Here we have proven that newly synthesized chiral naphthalene diimide (NDI) derivatives are excellent electroactive materials for TD enantiosensors. The recognition process relies on the specific interaction between the chiral NDI receptor and the thalidomide enantiomer of the opposite configuration. This unique specific interaction between (S)-thalidomide and (R)-NDI derivative counterparts, evident in the DPV voltammograms, was confirmed by molecular modeling. The demonstrated voltammetric enantiosensors are characterized by the low detection limit at the level of μg·L^-1, wide analytical range from 5·10^-4 - 10 mg·L^-1, high selectivity and long lifetime. The results of the recovery rates showed a very good degree of accuracy towards the determination of (S)-thalidomide in the blood samples, so it can be successfully used in the analysis of clinical samples.

Comprehensive analysis of angiogenesis-related genes and pathways in early diabetic retinopathy

BACKGROUND

Angiogenesis is an important parameter in the development of diabetic retinopathy (DR), and it is indicative of an early stage evolving into a late phase. Therefore, examining the role of angiogenic factors in early DR is crucial to understanding the mechanism of neovascularization.

METHODS

The present study identified hub genes and pathways associated with angiogenesis in early DR using bioinformatics analysis. Genes from published literature and Gene Expression Omnibus (GEO) were collected and analysed.

RESULTS

We collected 73 genes from 70 published studies in PubMed, which were referred to as DR-related gene set 1 (DRgset1). The gene expression profile of GSE12610 was downloaded, and 578 differentially expressed genes (DEGs) between diabetic and normal samples were identified. DEGs and DRgset1 were further combined to create DR-related gene set 2 (DRgset2). After an enrichment analysis, we identified 12 GO terms and 2 pathways associated with neovascularization in DRgset1, and 8 GO terms and 2 pathways in DRgset2. We found 39 new genes associated with angiogenesis and verified 8 candidate angiogenesis-related genes in DR cells using real-time PCR: PIK3CB, ALDH3A1, ITGA7, FGF23, THBS1, COL1A1, MAPK13, and AIF1. We identified 10 hub genes associated with neovascularization by constructing a protein-protein interaction (PPI) network: TNF, VEGFA, PIK3CB, TGFB1, EDN1, MMP9, TLR4, PDGFB, MMP2, and THBS1.

CONCLUSIONS

The present study analysed angiogenesis-related genes and pathways in early DR in a comprehensive and systematic manner. PIK3CB, ALDH3A1, ITGA7, FGF23, THBS1, COL1A1, MAPK13, and AIF1 may be the candidate genes to further explore the mechanisms of angiogenesis in early DR. TNF, PIK3CB, TGFB1, EDN1, MMP9, TLR4, PDGFB, MMP2, and THBS1 may be new targets for early neovascularization therapy in the future.

Intravitreal thalidomide ameliorates inflammation in a model of experimental uveitis induced by BCG

Uveitis encompasses a heterogeneous and complex group of conditions characterized by intraocular inflammation, frequently affecting young individuals and representing an important cause of irreversible blindness worldwide. Animal models have been critical to understand etiology and pathogenesis of uveitis, being also employed to assess new therapeutic strategies, preceding human studies. However, there is still a need of developing and studying different models, due to the difficulties in recapitulating all forms of human uveitis effectively. Although corticosteroids are usually the first-line therapy for non-infectious uveitis, their long-term use is limited by potentially serious side effects in all possible delivery routes. Thus, thalidomide, a drug with anti-inflammatory and antiangiogenic properties, was investigated in a novel experimental model of uveitis, induced by Mycobacterium bovis Calmette-Guérin Bacillus (BCG), in rabbits. The experimental protocol consisted of two subcutaneous injections of BCG, followed by two intravitreal injections of the same antigen, inducing panuveitis. Animals were treated with a single intravitreal injection of thalidomide suspension or PBS. Clinical manifestations of uveitis improved after intravitreal thalidomide, involving both anterior and posterior segments. Protein content, N-acetyl-b-glucosaminidase (NAG) and myeloperoxidase (MPO) activities were elevated in ocular tissues after disease induction, further decreasing post-treatment with intravitreal thalidomide. This therapeutic response was also confirmed on ocular electrophysiology, as well as histopathology. This experimental model induced panuveitis in rabbits using a low-cost mycobacterial antigen, with intraocular inflammation subsequently improving after treatment. Intravitreal thalidomide may be a potential alternative to treat intraocular inflammation in corticosteroid-sparing therapies.

The Effects of the CXCR4 Antagonist, AMD3465, on Human Retinal Vascular Endothelial Cells (hRVECs) in a High Glucose Model of Diabetic Retinopathy

BACKGROUND High blood glucose levels in diabetes result in retinal angiogenesis, which is the key feature of diabetic retinopathy. This study aimed to investigate the effects of the CXCR4 antagonist, AMD3465, on human retinal vascular endothelial cells (hRVECs) [i]in vitro[/i]. MATERIAL AND METHODS Cell viability and the protein expression levels of CXCR4 and stromal cell-derived factor 1 (SDF-1) were evaluated in high glucose (HG)-treated human retinal vascular endothelial cells (hRVECs). The cell counting kit 8 (CCK-8) assay, the colony formation assay, immunofluorescence, and Western blot were used to investigate the effects of AMD3465 on hRVEC cell viability, colony formation, cell proliferation, and expression of CXCR4 and SDF-1. Cell apoptosis and angiogenesis were assessed by flow cytometry and Western blot. RESULTS Treatment with high glucose reduced the viability of hRVECs and increased the protein expression levels of CXCR4 and SDF-1. Following treatment with AMD3465, the colony formation capacity and cell proliferation in hRVECs increased, and there was a significant reduction in apoptosis rate compared with the untreated cells. AMD3465 significantly reduced the expression of angiogenesis-associated proteins, including ICAM1, VCAM1, VEGF, and AngII. AMD3465 significantly reduced the protein expression levels of TNF-α, IL-1β, NF-κB, and p-p65. CONCLUSIONS The CXCR4 antagonist, AMD3465, reduced apoptosis of HG-treated hRVECs in an [i]in vitro[/i] model of diabetic retinopathy.

Efficacy of Polytetrafluoroethylene/Polylactide-co-glycolide (PTFE/PLGA) Laminate and PTFE/PLGA Laminate Containing Slow-Releasing Thalidomide in Delayed Adjustable Strabismus Surgery in a Rabbit Model

Purpose: To evaluate the efficacy of polytetrafluoroethylene/polylactide-co-glycolide (PTFE/PLGA) laminate containing sustained-release thalidomide for delayed adjustable strabismus surgery. Methods: This is a prospective, masked-observer, controlled study using 50 eyes of 25 rabbits. After superior rectus muscle (SRM) recession, a PTFE/PLGA laminate containing thalidomide (group PT, 20 eyes), PTFE/PLGA laminate alone (group P, 20 eyes), or no barrier (group C, 10 eyes) were applied around the SRM. Delayed adjustment was performed at postoperative 3 or 5 weeks. Adjustability, adjustment lengths, adjustment forces, and degrees of adhesion were evaluated. Results: Both groups PT and P showed significantly better adjustability compared to group C at both 3 weeks (100%, 80%, and 0%, respectively) and 5 weeks (100%, 90%, and 0%, respectively). Between groups PT and P, adjustability, adjustment lengths, and forces were not significantly different at 3 and 5 weeks. Group PT showed a significantly lower grade of adhesion between SRM and sclera (SRM/S) compared to group C at both 3 weeks (p = 0.007) and 5 weeks (p = 0.001, respectively). Group P showed no significant difference in adhesion between SRM/S compared to group C at 3 weeks (p= 0.302) but had a lower grade of adhesion after 5 weeks (p = 0.007). There was no significant difference between groups PT and P at 3 weeks (p= 0.143) and 5 weeks (p= 0.716). Conclusions: PTFE/PLGA laminate containing sustained-release thalidomide was effective in reducing adhesion and allowed delayed adjustment in all eyes. However, PTFE/PLGA laminate alone was also equally effective in reducing adhesion compared to controls.

Thalidomide decreases high glucose-induced extracellular matrix protein synthesis in mesangial cells via the AMPK pathway

A previous study demonstrated the renal-protective effect of thalidomide (Thd) in diabetic nephropathy rats through the activation of the adenosine monophosphate-activated protein kinase (AMPK) and inhibition of the nuclear factor κB (NF-κB)/monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor (TGF)-β1/mothers against decapentaplegic homolog signaling pathways. The association between AMPK inactivation and high glucose (HG)-induced meningeal cell (MC) proliferation and extracellular matrix (ECM) accumulation via NF-κB and TGF-β1 signaling remains unknown. The aim of the current study was to demonstrate the effects of Thd on cell proliferation and ECM expression in HG-cultured MCs and the underlying mechanisms. HG-cultured human MCs were treated with Thd. Cell proliferation was measured by MTT assay and quantification of cell proliferation was based on the measurement of bromodeoxyuridine incorporation. The differences in TGF-β1, fibronectin and MCP-1 protein expression levels were detected via ELISA and western blot analysis. The AMPK signaling pathway was also examined by western blot analysis in MCs. Compound C, an AMPK inhibitor and AICAR (5-aminoimidazole-4-carboxamide 1β-D-ribofuranoside), an AMPK agonist, were used to analyze the functional role of AMPK in MCs. Cell proliferation was significantly decreased in HG-cultured MCs following treatment with high concentrations of Thd (100 and 200 µg/ml) for 24 h compared with the HG-cultured MC group. Thd suppressed the inflammatory processes in HG-induced MCs. These effects were partially mediated through the activation of AMPK and inhibition of the NF-κB/MCP-1 signaling pathways. Taken together, these results suggest that Thd may have therapeutic potential in diabetic renal injury via the AMPK signaling pathway.

Intraperitoneal injection of thalidomide alleviates early osteoarthritis development by suppressing vascular endothelial growth factor expression in mice

Vascular endothelial growth factor (VEGF) is expressed in articular cartilage and increases in expression levels have been associated with the progression of osteoarthritis (OA). Thalidomide is a drug that has been reported to inhibit angiogenesis and reduce VEGF production by downregulating VEGF expression. The objective of the present study was to determine whether intraperitoneal administration of thalidomide may attenuate early OA development in mice. Male C57BL/6 mice (10‑weeks‑old) were randomly assigned into the destabilization of the medial meniscus (Dmm) with thalidomide treatment (Dmm+Th), Dmm and Sham groups equally. An OA model was induced surgically in Dmm+Th and Dmm groups, and mice of the Dmm+Th group were subsequently treated with an intraperitoneal injection of thalidomide (200 mg/kg/day). At 2 and 4 weeks following surgery, the pathological alterations in cartilage samples were assessed qualitatively by hematoxylin and eosin staining and Safranin O/Fast green staining, and quantitatively by the Osteoarthritis Research Society International scoring system. The mRNA expression levels of matrix metalloproteinase‑13 (MMP‑13) and VEGF were measured by reverse transcription‑quantitative polymerase chain reaction. The protein expression levels of MMP‑13 and VEGF were detected by immunofluorescence and immunohistochemistry, respectively. The production of VEGF in serum was evaluated via an ELISA assay. Pathological scores were significantly higher in the Dmm and the Dmm+Th groups than those in the Sham group; however, the Dmm+Th group exhibited markedly less severe pathological changes compared with the Dmm group. Compared with the Sham group, the mRNA and protein expression levels of VEGF and MMP‑13 in the Dmm and the Dmm+Th groups were significantly increased. The Dmm+Th group exhibited significantly decreased expression levels of VEGF and MMP‑13, as well as significantly decreased serum VEGF concentration compared with the Dmm group. Thus, the results of the present study demonstrated that intraperitoneal administration of thalidomide may alleviate the development of early OA by suppressing VEGF expression in mice and may have potential as a novel therapy for the treatment of OA.

Renal-protective effect of thalidomide in streptozotocin-induced diabetic rats through anti-inflammatory pathway

Background

Diabetic nephropathy (DN) is a major microvascular complication in diabetes. An increasing body of evidence has shown that DN is related to chronic inflammation, kidney hypertrophy, and fibrosis. While thalidomide has been shown to have anti-inflammatory and antifibrotic effects, the effects of thalidomide on the pathogenesis of DN are unclear. This study was undertaken to explore whether thalidomide has renal-protective effects in diabetic rats.

Methods

Male Sprague Dawley rats were injected intraperitoneally with 50 mg/kg streptozotocin to induce diabetes. Diabetic rats were treated with thalidomide (200 mg/kg/d) for 8 weeks, and then blood and urine were collected for measurement of renal function-related parameters. Histopathology, immunohistochemistry, enzyme-linked immunosorbent assay, and Western blot analyses were performed to assess renal proinflammatory cytokines, fibrotic protein, and related signaling pathways.

Results

Diabetic rats exhibited obvious renal structural and functional abnormalities, as well as renal inflammation and fibrosis. Compared with diabetic control rats, those treated with thalidomide showed significantly improved histological alterations and biomarkers of renal function, as well as reduced expression of renal inflammatory cytokines, including NF-κB and MCP-1. Furthermore, renal fibrotic proteins, such as TGF-β1, TβRII, TβRI, smad3, collagen IV, and fibronectin were also remarkably suppressed. Treatment with thalidomide markedly stimulated the phosphorylation of AMPKα.

Conclusion

In this study, thalidomide suppressed the inflammatory and fibrotic processes in DN. These effects were partly mediated by the activation of AMPKα, and inhibition of the NF-κB/MCP-1 and TGF-β1/Smad signaling pathways. These results suggest that thalidomide may have therapeutic potential in diabetic renal injury through the anti-inflammatory pathway.

Proposed mechanisms of Terminalia catappa in hyperglycaemia and associated diabetic complications

Objectives

Terminalia catappa has shown potent antidiabetic activity in the past; however, the exact molecular mechanisms by which it acts have not been elucidated. This review aims at exploring several hypotheses which have been proposed to explain its mechanism of action, including reduction in oxidative stress, inflammation, angiogenesis, lipid profile correction and direct hypoglycaemic actions.

Methods

A thorough review of all the articles, research as well as reviews, available regarding the concerned topic was performed. MEDLINE databases were searched using keywords (and their combinations), such as T. catappa, renin oxidative stress, inflammation, angiogenesis, diabetic retinopathy, α-glucosidase and α-amylase, among several others. English-language articles were preferably selected.

Key findings

Apart from metabolic dysfunctions, several hyperglycaemia-induced pathological conditions come into scene as the after-effects of diabetes. These mainly include inflammation, oxidative stress, angiogenesis and lipid profile alteration, which ultimately result in vascular endothelial dysfunction, hepatic steatosis, lipid peroxidation and apoptosis of endothelial, hepatic and neuronal cells. Terminalia catappa effectively attenuates the progression of diabetic retinopathy and shows significant hypoglycaemic actions. The mechanisms behind these effects were explained.

Conclusion

Terminalia catappa may provide an effective natural product to treat hyperglycaemia and prevent subsequent diabetic complications.

Endostatin combined with radiotherapy suppresses vasculogenic mimicry formation through inhibition of epithelial-mesenchymal transition in esophageal cancer

The growth of solid tumors requires angiogenesis to provide oxygen and nutrients and to support cell proliferation. The switch from an avascular to a vascular phenotype is typically related to acceleration of tumor growth. Anti-angiogenic therapy is becoming a very promising way for malignant tumors. Meanwhile, malignant tumor cells themselves were able to develop the formation of cell-lined vessels that contribute to tumor neovascularization and supply the nutrients and oxygen, which is called vasculogenic mimicry (VM). However, the molecular mechanism of VM remains unclear. The purpose of this study was to investigate the efficacy of the novel recombinant human endostatin (rh-Endo) protein combined with radiotherapy on human esophageal squamous cell carcinoma (ESCC) cell lines Eca-109 and TE13. Our results showed that rh-Endo combined with radiotherapy significantly inhibited the proliferation, migration, invasion, and VM of human esophageal cancer cells in a dose-dependent manner; however, it has no direct effect on apoptosis of carcinoma cells, which indicated that rh-Endo combined with radiotherapy significantly changed the microenvironment of esophageal carcinoma, and played an important role in preventing distant metastasis. Our findings suggested that rh-Endo inhibited the metastasis of esophageal cancer and the activation of AKT pathway, and the down-regulation of epithelial-mesenchymal transition (EMT) may be associated with such effect of rh-Endo. These results also supported the bright prospect of rh-Endo combined with radiotherapy for clinical applications in the future.