Discovery and Optimization of N-Substituted 2-(4-pyridinyl)thiazole carboxamides against Tumor Growth through Regulating Angiogenesis Signaling Pathways

Antiangiogenic activity of the penicillin derivative TAP7f in melanoma

Previously , we demonstrated that the non-antibiotic penicillin derivative TAP7f inhibited melanoma metastasis in vitro and in vivo through the downregulation of β-catenin and integrin αVβ3. As angiogenesis is required for tumor growth and metastasis, we decided to explore the possible antiangiogenic effect of TAP7f. We found that TAP7f inhibited proliferation, migration, tube formation, and actin cytoskeleton organization of human endothelial cells. In a gel plug assay, an in vivo model for angiogenesis, TAP7f also blocked vascular formation induced by fibroblast growth factor 2. Furthermore, when murine B16-F10 melanoma cells pre-treated with TAP7f were injected intradermally in mice, we observed a decrease in the number and thickness of the capillaries surrounding the tumor. Additionally, TAP7f downregulated vascular endothelial growth factor (VEGF) and platelet-derived growth factor-B (PDGF-B) expression in B16-F10 cells and VEGF receptor expression in HMEC-1 endothelial cells. When the antitumor effect of TAP7f was studied in C57BL/6 J mice challenged with B16-F10 melanoma cells, a significant reduction of tumor growth was observed. Furthermore, a decreased expression of VEGF, PDGF-B, and the endothelial cell marker CD34 was observed in tumors from TAP7f-treated mice. Together, our results suggest that the antiangiogenic activity of TAP7f contributes to its antitumor and antimetastatic action and positions this penicillin derivative as an alternative or complementary agent for the treatment of melanoma. KEY MESSAGES: • TAP7f inhibits proliferation, migration, tube formation, and actin cytoskeleton organization of endothelial cells. • TAP7f downregulates VEGF receptor expression in endothelial cells. • TAP7f downregulates VEGF and PDGF expression in melanoma cells. • TAP7f inhibits angiogenesis in vivo.

Polyphenol Oxidase as a Promising Alternative Therapeutic Agent for Cancer Therapy

Cancers have always been the most difficult to fight, the treatment of cancer is still not considered. Thus, exploring new anticancer drugs is still imminent. Traditional Chinese medicine has played an important role in the treatment of cancer. Polyphenol oxidase (PPO) extracted from Edible mushroom has many related reports on its characteristics, but its role in cancer treatment is still unclear. This study aims to investigate the effects of PPO extracted from Edible mushroom on the proliferation, migration, invasion, and apoptosis of cancer cells in vitro and explore the therapeutic effects of PPO on tumors in vivo. A cell counting kit-8 (CCK8) assay was used to detect the effect of PPO on the proliferation of cancer cells. The effect of PPO on cancer cell migration ability was detected by scratch test. The effect of PPO on the invasion ability of cancer cells was detected by a transwell assay. The effect of PPO on the apoptosis of cancer cells was detected by flow cytometry. Female BALB/c mice (18-25 g, 6-8 weeks) were used for in vivo experiments. The experiments were divided into control group, model group, low-dose group (25 mg/kg), and high-dose group (50 mg/kg). In vitro, PPO extracted from Edible mushroom significantly inhibited the proliferation, migration, and invasion capability of breast cancer cell 4T1, lung cancer cell A549, and prostate cancer cell C4-2, and significantly promoted the apoptosis of 4T1, A549, and C4-2. In vivo experiments showed PPO inhibitory effect on tumor growth. Collectively, the edible fungus extract PPO could play an effective role in treating various cancers, and it may potentially be a promising agent for treating cancers.

A Review of the Structure-Activity Relationship of Natural and Synthetic Antimetastatic Compounds

There are innumerable anticancer compounds derived from either natural or synthetic origins. Many of these compounds have been further developed through structural modifications to not only inhibit cancer cell growth but also to exert an antimetastatic effect. This is achieved by attaching different substituents to generate different structure—activity relationships. This review highlights the effectiveness of different functional groups known to have antimigration and antiproliferation activities, such as fluoro, methoxy, methyl, amino, hydroxy, nitro, bromo, chloro, methylamino, ethoxy, carbonyl, iodo, and trifluoromethyl groups. Additionally, the positioning of these functional groups plays an important role in their anticancer activities, which was evident in one of our studies comparing analogues of a natural compound. Thus, this review suggests future recommendations for the design and development of improved anticancer drugs with higher efficacy.

Alkaloid extract of Corydalis yanhusuo inhibits angiogenesis via targeting vascular endothelial growth factor receptor signaling

Background

Corydalis yanhusuo W.T. Wang (YHS) is a well-known Chinese flowering herbal plant commonly used for centuries in functional food and traditional Chinese medicine. In the present study, we have identified and characterized a novel inhibitor of vascular endothelial growth factor receptor 2 (VEGFR2) with low toxicity, alkaloid extract of YHS, which suppressed angiogenesis that plays a fundamental role in a wide spectrum of physiological functions and pathological processes.

Methods

Proliferative ability of human umbilical vascular endothelial cells (HUVECs) was assessed using MTT assay and Ki67 immunofluorescence staining. Migration ability of HUVECs was evaluated by wound healing and transwell assays. In vitro angiogenesis was tested by spheroid sprouting and tube formation assays. In vivo vascularization was examined using Matrigel plug and chick chorioallantoic membrane (CAM) models. Protein expression and phosphorylation levels of VEGFR2, AKT, ERK and STAT3 were determined by Western blot assay.

Results

We demonstrated that alkaloid extract of YHS significantly inhibited a variety of VEGF-induced angiogenesis processes including proliferation, migration, sprouting, and tube formation of HUVECs. Moreover, alkaloid extract of YHS contributed to reduced in vivo neo-vessel formation in Matrigel plugs of mice and CAM models. Further mechanistic studies revealed that alkaloid extract of YHS suppressed VEGF-induced signaling pathway as evaluated by diminished phosphorylation of VEGFR2 and subsequently attenuated its downstream regulators including phospho-ERK1/2, phospho-AKT and phospho-STAT3 levels in HUVECs.

Conclusion

Collectively, these preclinical findings indicate that alkaloid extract of YHS remarkably limits angiogenesis and may serve as a promising anti-angiogenic drug candidate.

Gambogic acid impairs tumor angiogenesis by targeting YAP/STAT3 signaling axis

Angiogenesis is central to a wide range of physiological and pathological processes including wound healing, macular degeneration, and cancer. Excessive or inappropriate vascular supply of tumors is one of the main targets for cancer therapy. Recently, critical and selective transcriptional factors such as yes-associated protein (YAP) that control the expression of angiogenesis factors have gained increasing attention in antiangiogenic therapy. In this study, we have identified and characterized a novel inhibitor of YAP, gambogic acid (GA), which exerted striking antiangiogenic effects both in vitro and in vivo. We demonstrated that GA remarkably inhibited a variety of vascular endothelial growth factor-induced angiogenesis processes including proliferation, migration, sprouting, and tube formation of endothelial cells in vitro. In addition, GA resulted in decreased neo-vessel formation in Matrigel plugs of mice and chick chorioallantoic membrane. More importantly, we showed that GA limited tumor growth via preventing tumor angiogenesis and vascular maturation. Further mechanistic studies illustrated that GA directly targeted YAP/STAT3 signaling axis, which is critical for the transcriptional regulation of a series of angiogenic factors. Taken together, these preclinical findings suggest that GA significantly repressed tumor angiogenesis and may serve as a promising drug candidate against cancer.

Tocilizumab, a Humanized Monoclonal Antibody Against the Interleukin-6 Receptor, Inhibits High Glucose-Induced Vascular Smooth Muscle Cell Migration Through Mitogen-Activated Protein Kinase Signaling Pathways

Rheumatoid arthritis (RA) with diabetes increases the risk of cardiovascular diseases. Interleukin-6 (IL-6) promotes the disease activity of RA and insulin resistance. This study aimed to evaluate the potential effects and molecular mechanisms of IL-6 blocker, tocilizumab, in atherosclerosis with diabetes. Human aortic smooth muscle cells (HASMCs) cultured under hyperglycemic conditions were evaluated for migration, expression of adhesion molecules, and matrix metalloproteinases before and after treatment with tocilizumab. High glucose (HG) significantly increased expression of IL-6, intercellular adhesion molecule (ICAM-1), matrix metalloproteinase-2 & 9, and migration of vascular smooth muscle cells. Tocilizumab suppressed HG-induced expression of ICAM-1, MMP-2, and MMP-9. Pretreatment with tocilizumab also inhibited migration, MAPK signaling, and nuclear translocation of p65-NF-κB in HG-stimulated HASMCs. Our data suggested that tocilizumab may exert an antiatherosclerotic activity in diabetes.

Mechanistic Study of the In Vitro and In Vivo Inhibitory Effects of Protocatechuic Acid and Syringic Acid on VEGF-Induced Angiogenesis

The antiangiogenic activities of two structurally similar phenolics, protocatechuic acid (PA) and syringic acid (SA), were investigated. In vitro study using HUVECs demonstrated that both PA and SA (at 25 μM) significantly ( p < 0.05) inhibited VEGF-induced cell proliferation by 22.68 ± 5.6% and 21.93 ± 2.0%, respectively; cell migration by 50.04 ± 3.3% and 39.72 ± 4.7%, respectively; cell invasion by 44.16 ± 4.23% and 51.90 ± 2.73%, respectively; and cellular ROS generation by 11.48 ± 6.32% and 21.17 ± 9.10%, respectively. Our mechanistic study revealed that PA and SA blocked the VEGFR2-dependent Akt/ MMP2 and ERK pathways in HUVECs. These inhibitory effects were further confirmed by a decrease of endogenous alkaline phosphatase activity for PA and SA (21.47 ± 1.77% and 10.37 ± 1.27%, respectively) and the suppression of subintestinal vessel plexus formation in Tg (fli1a:EGFP) y1-type transgenic zebrafish embryos. PA and SA down-regulated the angiogenesis-related signal transduction pathway of VEGFα-VEGFR2 or Ang2- Tie2 in zebrafish. Moreover, it was also found that PA demonstrated a better inhibition on VEGF-induced migration of HUVEC and zebrafish vasculature. This might be due to the different number of hydroxyl and methoxy substituents possessed by PA and SA. Taken together, these findings indicate that phenolics PA and SA have potent antiangiogenic activities and are potential targets for the design and development of anticancer agents.

Identification of a small-molecule ligand of β-arrestin1 as an inhibitor of stromal fibroblast cell migration accelerated by cancer cells

Stromal fibroblasts, which occupy a major portion of the tumor microenvironment, play an important role in cancer metastasis. Thus, targeting of these fibroblasts activated by cancer cells (carcinoma‐associated fibroblasts; CAFs) might aid in the improved treatment of cancer metastasis. NIH3T3 fibroblasts cocultured with MCF7 cells displayed enhanced migration compared to NIH3T3 fibroblasts cultured alone. We used this system to identify the small‐molecule inhibitors responsible for their enhanced migration, a characteristic of CAFs. We selected β‐arrestin1, which showed high expression in cocultured cells, as a molecular target for such inhibitors. Cofilin, a protein downstream of β‐arrestin1, is activated/dephosphorylated in this condition. The small‐molecule ligands of β‐arrestin1 obtained by chemical array were then examined using a wound healing coculture assay. RKN5755 was identified as a selective inhibitor of activated fibroblasts. RKN5755 inhibited the enhanced migration of fibroblasts cocultured with cancer cells by binding to β‐arrestin1 and interfering with β‐arrestin1‐mediated cofilin signaling pathways. Therefore, these results demonstrate the role of β‐arrestin1 in the activation of fibroblasts and inhibiting this protein by small molecule inhibitor might be a potential therapeutic target for the stromal fibroblast activation (cancer–stroma interaction).

The synthesis and antitumor activity of lithocholic acid and its derivatives

In this paper, a new and concise synthetic route of lithocholic acid (LCA) using commercially available steroid source deoxycholic acid is reported. A series of amide derivatives of LCA were also synthesized and investigated for their activity against the growth of MCF-7 and MCF-7/ADR cells using the sulforhodamine B assay. For MCF-7, the most potent compound 20 showed a 20-fold higher antitumor activity than LCA. For MCF-7/ADR, the most potent compound 24 showed a 22-fold higher antitumor activity than LCA. The transwell migration assay of 20 was evaluated on MDA-MB-231 cells. The colony formation and apoptosis assays of 20 were performed on MCF-7 and MCF-7/ADR cell lines.

Clinical Significance and Effect of lncRNA HOXA11-AS in NSCLC: A Study Based on Bioinformatics, In Vitro and in Vivo Verification

HOXA11 antisense RNA (HOXA11-AS) has been shown to be involved in tumorigenesis and development of different cancers. However, the role of HOXA11-AS in non-small cell lung cancer (NSCLC) remains unclear. In this study, we firstly explored and confirmed the expression of HOXA11-AS in NSCLC tissues and cells. Cytometry, CCK-8, cell scratch, migration, Matrigel invasion and flow cytometry assays were performed to determine the biological impact of HOXA11-AS in vitro. Furthermore, a chick embryo chorioallantoic membrane (CAM) model of NSCLC was constructed to explore the effect of HOXA11-AS on tumorigenicity and angiogenesis in vivo. Additionally, bioinformatics analyses were performed to investigate the prospective pathways of HOXA11-AS co-expressed genes. As results, HOXA11-AS was markedly highly expressed in NSCLC tissues and cells. Furthermore, the proliferation, migration, invasion, tumorigenic and angiogenic ability of NSCLC cells were all inhibited and apoptosis was induced after HOXA11-AS knock-down. HOXA11-AS RNAi also led to cell cycle arrest on G0/G1 or G2/M phase. In addition, the non-small cell lung cancer pathway might be involved in regulating the co-expressed genes of HOXA11-AS in NSCLC. These results indicate that HOXA11-AS plays pivotal roles in NSCLC and it can become a novel therapeutic direction for treating NSCLC.