VEGF and angiopoietin signaling in tumor angiogenesis and metastasis

Effects of cholecalciferol supplementation on serum angiogenic biomarkers in breast cancer patients treated with tamoxifen: A controlled randomized clinical trial

OBJECTIVE

The aim of this study was to investigate the effects of cholecalciferol supplementation on serum levels of angiogenic parameters in patients with breast cancer (BC) who were treated with tamoxifen.

METHODS

This was a pilot-based, randomized, triple-blind, placebo-controlled clinical trial with 52 patients with BC randomly assigned to either an intervention group receiving weekly 50 000 IU cholecalciferol or a placebo group for 8 wk. At baseline and at end of study, serum levels of angiogenic growth factors such as vascular endothelial growth factor (VEGF)-A, angiopoietin (Ang)-2, hypoxia-inducible factor (Hif)-1, and high-sensitivity C-reactive protein were measured by enzyme-linked immunosorbent assay. Every 4 wk, a completed 3-d, 24-h dietary record and daily sunlight exposure checklist were collected and anthropometric variables were measured.

RESULTS

The ultimate number of participants in each arm was 22 for analyses. For premenopausal women, cholecalciferol supplementation resulted in a significant decrease in serum levels of Ang-2 and VEGF-A after 8 wk of treatment (P < 0.05). In the absence of vascular invasion, supplementation led to a significant decrease in Ang-2 levels compared with the placebo group (P < 0.05). Supplementation caused significant increases in Hif-1 in patients diagnosed with the infiltration of tumors into vascular or lymphatic vessels (P < 0.05).

CONCLUSION

Cholecalciferol supplementation achieved sufficient efficacy among patients with BC taking tamoxifen and could be effective in the reduction of angiogenic biomarkers particularly dependent on the infiltration status of the tumor to vessels. Further studies with larger subgroups should be investigated.

2, 3-Dihydro-3β-methoxy Withaferin-A Lacks Anti-Metastasis Potency: Bioinformatics and Experimental Evidences

Withaferin-A is a withanolide, predominantly present in Ashwagandha (Withania somnifera). It has been shown to possess anticancer activity in a variety of human cancer cells in vitro and in vivo. Molecular mechanism of such cytotoxicity has not yet been completely understood. Withaferin-A and Withanone were earlier shown to activate p53 tumor suppressor and oxidative stress pathways in cancer cells. 2,3-dihydro-3β-methoxy analogue of Withaferin-A (3βmWi-A) was shown to lack cytotoxicity and well tolerated at higher concentrations. It, on the other hand, protected normal cells against oxidative, chemical and UV stresses through induction of anti-stress and pro-survival signaling. We, in the present study, investigated the effect of Wi-A and 3βmWi-A on cell migration and metastasis signaling. Whereas Wi-A binds to vimentin and heterogeneous nuclear ribonucleoprotein K (hnRNP-K) with high efficacy and downregulates its effector proteins, MMPs and VEGF, involved in cancer cell metastasis, 3βmWi-A was ineffective. Consistently, Wi-A, and not 3βmWi-A, caused reduction in cytoskeleton proteins (Vimentin, N-Cadherin) and active protease (u-PA) that are essential for three key steps of cancer cell metastasis (EMT, increase in cell migration and invasion).

Mapping actionable pathways and mutations in brain tumours using targeted RNA next generation sequencing

Many biology-based precision drugs are available that neutralize aberrant molecular pathways in cancer. Molecular heterogeneity and the lack of reliable companion diagnostic biomarkers for many drugs makes targeted treatment of cancer inaccurate for many individuals. Identifying actionable hyperactive biological pathways in individual cancers may improve this situation.

To achieve this we applied a novel targeted RNA next generation sequencing (t/RNA-NGS) technique to surgically obtained glioma tissues. The test combines mutation detection with analysis of biological pathway activities that are involved in tumour behavior in many cancer types (e.g. tyrosine kinase signaling, angiogenesis signaling, immune response, metabolism), via quantitative measurement of transcript levels and splice variants of hundreds of genes. We here present proof of concept that the technique, which uses molecular inversion probes, generates a histology-independent molecular diagnosis and identifies classifiers that are strongly associated with conventional histopathology diagnoses and even with patient prognosis. The test not only confirmed known glioma-associated molecular aberrations but also identified aberrant expression levels of actionable genes and mutations that have so far been considered not to be associated with glioma, opening up the possibility of drug repurposing for individual patients. Its cost-effectiveness makes t/RNA-NGS to an attractive instrument to aid oncologists in therapy decision making.

PDHA1 Gene Knockout In Human Esophageal Squamous Cancer Cells Resulted In Greater Warburg Effect And Aggressive Features In Vitro And In Vivo

Background

One of the remarkable metabolic characteristics of cancer cells is that they prefer glycolysis rather than oxidative phosphorylation (OXPHOS). Pyruvate dehydrogenase E1 alpha subunit (PDHA1) is an important prerequisite for OXPHOS. Our previous studies have shown that low level of PDHA1 protein expression in esophageal squamous cell cancer (ESCC) was correlated with poor prognosis. However, the effect of PDHA1 inhibition on metabolism and biological behavior of esophageal cancer cells remains unclear.

Methods And Results

In this study, a KYSE450 PDHA1 knockout (KO) cell line of esophageal cancer was established by CRISPR/Cas9 technology. Then, the glycose metabolism, cell proliferation and migration abilities, chemotherapeutic tolerance and angiogenesis of the PDHA1 KO cells were investigated in vitro and in vivo. In the PDHA1 KO cells, the glycolysis and the consumption of glucose and glutamine were significantly enhanced, while the OXPHOS was significantly suppressed, implying Warburg effect in the PDHA1 KO cells. Furthermore, it was also proved in vitro experiments that the PDHA1 KO cell obtained proliferation advantage, as well as significantly greater chemotherapy tolerance and migration ability. Xenograft experiments discovered not only larger tumors but also increased angiogenesis in the PDHA1 KO cell group.

Conclusion

Inhibition of PDHA1 gene expression in human ESCC leads to metabolic reprogramming of Warburg effect and increased malignancies. Targeting ESCC metabolic reprogramming may become a potential therapeutic target.

Long non-coding RNA MALAT1 promotes angiogenesis and immunosuppressive properties of HCC cells by sponging miR-140

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer in adults. Previous studies in our laboratory found that long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was upregulated in HCC cells, which could affect the metastasis and invasion of HCC. However, the underlying mechanism remains unknown. Herein, we studied the interaction between MALAT1 and miR-140 on the regulation of angiogenesis and immunosuppressive properties. We revealed that the expression of MALAT1 and VEGF-A was significantly increased in HCC cells. Knockdown of MALAT1 in HCC cells suppressed the production of VEGF-A, impaired the angiogenesis of HUVECs, and facilitated the polarization of macrophage toward the M1 subset. Mechanistically, the interaction between MALAT1 and miR-140 or between miR-140 and VEGF-A was confirmed by multiple assays. Besides, a negative correlation between MALAT1 and miR-140 was found in HCC tissues. Furthermore, miR-140 inhibition significantly increased VEGF-A expression, promoted angiogenesis of HUVECs, and redirected the polarization of macrophages toward the M2 subset. In addition, in vivo studies also verified the regulatory network of the MALAT1/miR-140 axis on VEGF-A in HCC progression. In summary, this study revealed the mechanism that MALAT1 worked as a putative HCC promotor via inhibiting miR-140. Therefore, targeting MALAT1 or miR-140 might alleviate the progression of HCC in the future.

Metabolic Regulation of Macrophage Polarization in Cancer

Macrophages act as scavengers, modulating the immune response against pathogens and maintaining tissue homeostasis. Metabolism governs macrophage differentiation, polarization, mobilization, and the ability to mount an effective antitumor response. However, in cancer, the tumor microenvironment (TME) can actively reprogram macrophage metabolism either by direct exchange of metabolites or through cytokines and other signaling mediators. Thus, metabolic reprogramming holds potential for modulating macrophages and developing new therapeutic approaches. In this review, we provide an overview of macrophage metabolism as it relates to macrophage function and plasticity in cancer.

The contribution of dietary and plasma folate and cobalamin to levels of angiopoietin-1, angiopoietin-2 and Tie-2 receptors depend on vascular endothelial growth factor status of primary breast cancer patients

The aim of this study was to determine the association of dietary folate and cobalamin with plasma levels of Angiopoietins (ANG), vascular endothelial growth factor-C (VEGF-C) and tyrosine kinase receptor-2 (Tie-2) of primary breast cancer patients. Women (n = 177), aged 30 to 75 years diagnosed with breast cancer were recruited from an ongoing case series study. Dietary intake of nutrients was estimated by using a validated food frequency questionnaire. Enzyme-linked immunosorbent assay was applied to measure biomarkers. MCF-7 cell cultures were supplemented with folic acid (0–40 μM) for 24 h to measure cell viability and fold change of expression by the real-time reverse transcriptase-polymerase chain reaction. Structural equation modeling was applied to analyze the structural relationships between the measured variables of nutrients and Angiopoietins. Dietary intake of folate and cobalamin showed a significant inverse correlation with plasma ANG-1 and ANG-2 (P < 0.05), particularly in subjects with estrogen-receptor positive tumors or low plasma VEGF-C. Plasma folate was positively associated with the ratio of ANG-1/ANG-2 (P < 0.05). Residual intake levels of total cobalamin were inversely associated with plasma ANG-1 when plasma stratum of VEGF-C was high (P < 0.05). Structural equation modeling identified a significant inverse contribution of folate profiles on the latent variable of Angiopoietins (coefficient β = −0.99, P < 0.05). Folic acid treatment resulted in dose-dependent down-regulations on ANGPT1 and ANGPT1/ANGPT2 ratio but VEGF and ANGPT2/VEGF were upregulated at folic acid >20 μM. Studying the contributing role of dietary folate to pro-angiogenic biomarkers in breast cancer patients can infer the preventive role of folate in the ANGs/VEGF-C-dependent cascade of tumor metastasis. By contrast, high concentrations of folic acid in vitro supported VEGF-C-dependent ANGPT2 overexpression might potentiate micro-lymphatic vessel development to support malignant cell dissemination.

6'-Sialylgalactose inhibits vascular endothelial growth factor receptor 2-mediated angiogenesis

Angiogenesis should be precisely regulated because disordered neovascularization is involved in the aggravation of multiple diseases. The vascular endothelial growth factor (VEGF)-A/VEGF receptor 2 (VEGFR-2) axis is crucial for controlling angiogenic responses in vascular endothelial cells (ECs). Therefore, inactivating VEGFR-2 signaling may effectively suppress aberrant angiogenesis and alleviate related symptoms. In this study, we performed virtual screening, identified the synthetic disaccharide 6′-sialylgalactose (6SG) as a potent VEGFR-2-binding compound and verified its high binding affinity by Biacore assay. 6SG effectively suppressed VEGF-A-induced VEGFR-2 phosphorylation and subsequent in vitro angiogenesis in HUVECs without inducing cytotoxicity. 6SG also inhibited VEGF-A-induced extracellular-regulated kinase (ERK)/Akt activation and actin stress fiber formation in HUVECs. We demonstrated that 6SG inhibited retinal angiogenesis in a mouse model of retinopathy of prematurity and tumor angiogenesis in a xenograft mouse model. Our results suggest a potential therapeutic benefit of 6SG in inhibiting angiogenesis in proangiogenic diseases, such as retinopathy and cancer.

Therapy based on a synthetic molecule can block abnormal blood vessel formation, limiting the progression of diabetic eye conditions and tumor growth in mice. The growth of new blood vessels from existing vessels, called angiogenesis, is critical to wound healing and embryonic development. The main angiogenesis signalling pathway involves growth factors, including one called VEGFR-2. Disruption to this pathway plays a significant part in the development of multiple diseases. A South Korean team led by Ki-Tae Ha at Pusan National University, Yangsan, and Young Jun Koh at Dongguk University, Seoul, identified and trialed a synthetic disaccharide capable of binding to and limiting the activity of VEGFR-2 during faulty signaling. Trials on mice with the diabetic eye condition retinopathy, and mice with implanted tumors, showed that the compound inhibited excessive angiogenesis and limited disease progression.

Primary tumor-secreted VEGF induces vascular hyperpermeability in premetastatic lung via the occludin phosphorylation/ubiquitination pathway

Primary tumor can induce the formation of premetastatic niche. The hyperpermeability of the vessels in the premetastatic niche is the first step in the development of metastasis. However, the cellular and molecular mechanisms of vascular hyperpermeability remain to be elucidated. In this study, 4T1 breast cells were injected into the breasts of mice to establish a tumor model. Our results showed that primary tumors induced hyperpermeability of the vessels in the premetastatic lung. Subsequent studies showed that the level of vascular endothelial growth factor (VEGF) was elevated in the tumor-bearing mice serum and the levels of tight junction (TJ) proteins occludin and ZO-1 were decreased in the premetastatic lung. In vitro studies demonstrated that VEGF increased the permeability of dextran and decreased the levels of occludin and ZO-1 in human umbilical vein endothelial cells. Moreover, the hyperpermeability of vessels and the degradation of occludin was blocked by bevacizumab. Overexpression of occludin alleviated the VEGF-induced hyperpermeability. Further investigations revealed that VEGF-induced occludin phosphorylation at Ser-490 and ubiquitination. Finally, we showed that VEGF accelerated the process of occludin degradation through the ubiquitin-proteasome system. In conclusion, primary tumor-secrete VEGF induce the occludin phosphorylation/ubiquitination and downregulation, resulting in the disruption of TJs and hyperpermeability of vessels in premetastatic lung. The occludin phosphorylation/ubiquitination pathway may be the mechanism of VEGF-induced vascular hyperpermeability in the lung premetastatic niche.

Bifunctional liposomes reduce the chemotherapy resistance of doxorubicin induced by reactive oxygen species

Doxorubicin (DOX) liposome is a widely used nano-medicine for colorectal cancer treatment. However, doxorubicin therapy increases the level of reactive oxygen species (ROS) in tumor cells, such as hydrogen peroxide (H₂O₂), which can stabilize hypoxia-inducible-factor-1α (HIF-1α). In a tumor hypoxic microenvironment, HIF-1 can up-regulate tumor-resistance related proteins, including P-glycoprotein (P-gp), glucose transporter 1 (GLUT-1), and matrix metalloproteinase 9 (MMP-9), leading to tumor tolerance to chemotherapy. The functional inhibition of HIF-1 can overcome this resistance and enhance the efficacy of tumor therapy. Here, we encapsulated one of the most effective HIF-1 inhibitors, acriflavine (ACF), and DOX in liposomes (DOX-ACF@Lipo) to construct bifunctional liposomes. ACF and DOX, released from DOX-ACF@Lipo, could effectively suppress the function of HIF-1 and the process of DNA replication, respectively. Consequently, the bifunctional liposome has great potential to be applied in clinics to overcome chemotherapy resistance induced by hypoxia.

Molecular mechanistic insights: The emerging role of SOXF transcription factors in tumorigenesis and development

Over the last decade, the development and progress of next-generation sequencers incorporated with classical biochemical analyses have drastically produced novel insights into transcription factors, including Sry-like high-mobility group box (SOX) factors. In addition to their primary functions in binding to and activating specific downstream genes, transcription factors also participate in the dedifferentiation or direct reprogramming of somatic cells to undifferentiated cells or specific lineage cells. Since the discovery of SOX factors, members of the SOXF (SOX7, SOX17, and SOX18) family have been identified to play broad roles, especially with regard to cardiovascular development. More recently, SOXF factors have been recognized as crucial players in determining the cell fate and in the regulation of cancer cells. Here, we provide an overview of research on the mechanism by which SOXF factors regulate development and cancer, and discuss their potential as new targets for cancer drugs while offering insight into novel mechanistic transcriptional regulation during cell lineage commitment.

Identification of new cancer stem cell markers and signaling pathways in HER‑2‑positive breast cancer by transcriptome sequencing

Human epidermal growth factor receptor (HER)‑2‑positive breast cancer accounts for ~25% of all breast cancer cases, has a high propensity for relapse, metastasis and drug resistance, and is associated with a poor prognosis. Therefore, it is necessary to develop more effective therapeutic targets for the treatment of HER‑2‑positive breast cancer. CD44+/CD24‑/low is currently the most commonly used marker for breast cancer stem cells (CSCs), which are considered the main cause of drug resistance, relapse and metastasis. In the present study, the ratio of CD44+/CD24‑/low cells was almost zero in SK‑BR‑3 cells; however, it was >90% in MDA‑MB‑231 cells, as determined by flow cytometry. Since SK‑BR‑3 and MDA‑MB‑231 cells both exhibit a strong propensity for invasion and migration, it was hypothesized that there may be other markers of CSCs in SK‑BR‑3 cells. Therefore, transcriptome sequencing was performed for SK‑BR‑3 and MDA‑MB‑231 cells. It was observed that several leukocyte differentiation antigens and other CSC markers were significantly more highly expressed in SK‑BR‑3 cells. Furthermore, the expression of aldehyde dehydrogenase (ALDH)1A3, CD164 and epithelial cell adhesion molecule (EpCAM) was higher in SK‑BR‑3 cells compared with in other subtypes of breast cell lines, as determined by reverse transcription‑polymerase chain reaction and western blot analysis. In addition, the expression levels of ALDH1A3, ALDH3B2 and EpCAM were higher in HER‑2‑positive breast cancer compared with in paracancerous tissues and other subtypes of breast cancer, as determined by immunohistochemistry. The expression of β‑catenin in the Wnt signaling pathway was lower in SK‑BR‑3 cells compared with in MDA‑MB‑231 cells, which may be used as a prognostic indicator for breast cancer. These findings may help identify novel CSC markers and therapeutic targets for HER‑2‑positive breast cancer.

Is there any potential anticancer effect of raloxifene and fluoxetine on DMBA-induced rat breast cancer?

Breast cancer is the most common cancer among women in the world and the incidence is increasing alarmingly. It was aimed to determine the effect of raloxifene (RAL) and fluoxetine (FLX) on selected parameters in 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma. Thirty-two female Wistar albino rats were assorted into four groups: DMBA (group I), DMBA+RAL (group II), DMBA+FLX (group III), and DMBA+RAL+FLX (group IV). Mammary tissue vascular endothelial growth factor (VEGF), macrophage colony-stimulating factor (M-CSF), matrix metalloproteinase-9 (MMP-9), and tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) levels were determined by the enzyme-linked immunosorbent assay method. The tissue VEGF levels were lower in group IV compared with DMBA group. Decreased M-CSF levels were observed in all therapeutic groups rather than the DMBA group, but the most effective decrease was found in group IV. Compared with the DMBA group, MMP-9 levels were statistically significantly decreased in group II and group IV. However, TIMP-1 levels were higher in the whole therapeutic groups rather than the DMBA group and the most effective increase was observed in group IV. Results of the present study suggest that combined therapy of RAL with FLX might lead to a better outcome targeting breast tumor.

PinX1 represses renal cancer angiogenesis via the mir-125a-3p/VEGF signaling pathway

BACKGROUND

PIN2/TRF1-interacting telomerase inhibitor 1 (PinX1) is a tumor suppressor in various tumors. However, the molecular mechanism underlying PinX1's role in cancer development and progression remains unclear. In this study, we aimed to uncover the new molecular mechanism and role of PinX1 in renal cell carcinoma (RCC) progression.

METHODS

We used miRNA microarray to detect the different expressed miRNAs upon PinX1 knockdown. Chromatin immunoprecipitation and Luciferase reporter assays were taken to identify the molecular mechanism of PinX1 in regulating mir-125-3p. In situ hybridization was performed to analyze the expression of mir-125a-3p in RCC using tissue microarray. The correlations between the mir-125a-3p expression level and clinicopathological features were evaluated using the χ² test. The role and molecular mechanism of PinX1 in RCC angiogenesis were investigated through a series of in vitro and in vivo experiments.

RESULTS

In this study, we discovered a new molecular mechanism of PinX1, in which PinX1 transcriptionally activated mir-125a-3p expression, thereby inhibiting the expression of vascular endothelial growth factor (VEGF), which is the target gene of mir-125a-3p. PinX1 also repressed tumor angiogenesis by increasing the mir-125a-3p expression in renal cancer. Moreover, the loss of mir-125a-3p expression was manifested in patients with RCC, and low miR-125a-3p levels correlated with poor survival of these patients.

CONCLUSIONS

PinX1 represses renal cancer angiogenesis through mir-125a-3p/VEGF signal pathway. The miR-125a-3p may be a candidate clinical prognostic marker and a novel therapeutic target in RCC.

Targeted transcriptional profiling of the tumor microenvironment reveals lymphocyte exclusion and vascular dysfunction in metastatic osteosarcoma

Osteosarcoma (OS) is the most common bone tumor in pediatric and adolescent/young adult patients yet little is known about the microenvironment that supports this aggressive disease. We have used targeted gene expression profiling and immunohistochemistry to characterize the microenvironment of metastatic and non-metastatic OS specimens from pediatric patients exhibiting poor histologic response to chemotherapy. Our results indicate that metastatic specimens exhibit lymphocyte exclusion as T cells are confined to the periphery of the pulmonary lesions. Furthermore, our data provides evidence of vascular dysfunction in metastatic OS indicated by increased expression of VEGFA, an increased ANGPT2:ANGPT1 gene expression ratio, and decreased expression of SELE, the gene encoding the adhesion molecule E-selectin. Moreover, correlation analyses show an inverse relationship between lymphocyte abundance and markers of vascular dysfunction exclusively in the metastatic specimens. Together, our data shows that the non-metastatic OS specimens demonstrate increased expression of various immunotherapeutic targets in comparison metastatic specimens and identifies vascular dysfunction and lymphocyte exclusion as important processes for therapeutic intervention in metastatic disease.

Expression profiles of VEGF-A, VEGF-D and VEGFR1 are higher in distant metastases than in matched primary high grade epithelial ovarian cancer

Background

In many malignancies including ovarian cancer, different angiogenic factors have been related to poor prognosis. However, data on their relations to each other or importance as a prognostic factor in ovarian cancer is missing. Therefore, we investigated the expressions of VEGF-A, VEGF-C, and VEGF-D, and the receptors VEGFR1, VEGFR2, and VEGFR3 in patients with malignant epithelial ovarian neoplasms. We further compared expression levels between primary tumors and related distant omental metastases.

Methods

This study included 86 patients with malignant ovarian epithelial tumors and 16 related distant metastases. Angiogenic factor expression was evaluated using immunohistochemistry (n = 102) and qRT-PCR (n = 29).

Results

Compared to primary high grade serous ovarian tumors, the related omental metastases showed higher expressions of VEGF-A (p = 0.022), VEGF-D (p = 0.010), and VEGFR1 (p = 0.046). In univariate survival analysis, low epithelial expression of VEGF-A in primary tumors was associated with poor prognosis (p = 0.024), and short progression-free survival was associated with high VEGF-C (p = 0.034) and low VEGFR3 (p = 0.002). The relative expressions of VEGF-D, VEGFR1, VEGFR2, and VEGFR3 mRNA determined by qRT-PCR analyses were significantly correlated with the immunohistochemically detected levels of these proteins in primary high grade serous ovarian cancer and metastases (p = 0.004, p = 0.009, p = 0.015, and p = 0.018, respectively).

Conclusions

The expressions of VEGF receptors and their ligands significantly differed between malignant ovarian tumors and paired distant metastases. VEGF-A, VEGF-D, and VEGFR1 protein expressions seem to be higher in distant metastases than in the primary high grade serous ovarian cancer lesions.

Increased angiogenesis by the rotational muscle flap is crucial for nerve regeneration

Background

The gold standard surgical treatment of nerve injury includes direct repair, nerve graft, and neurolysis. The underlying effects (either beneficial or detrimental) of angiogenesis during nerve regeneration by rotational muscle flap have not yet determined. We assess the neurological outcome and angiogenesis of nerve injury following a rotational muscle flap.

Methods

We retrospectively analyzed the outcome of the patients with severe radial nerve injury by neurolysis and rotational muscle flap; we also mimicked the clinical situation by nerve crush followed by rotational muscle flap in animals to assess associated angiogenesis factor expression.

Results

Twenty-three out of 25 (92%) cases of severe radial nerve injury underwent neurolysis assisted by muscle flap rotation and eventually reached their preinjury neurological outcome. In the animal study, both FITC–dextran and Dil infusion showed a remarkably increased vascular structure in the crushed nerve integrated by the muscle flap and abolished by Avastin injection. The rotational muscle flap significantly increased angiogenesis factor expression, and this was attenuated by Avastin injection. The increased angiogenesis factor expression paralleled the improvement seen in neurobehavioral and electrophysiological studies as well as the significant expression of nerve regeneration markers and the restoration of denervated muscle morphology.

Conclusion

Based on the clinical and animal data analysis, we conclude that muscle flap rotation provides a platform for angiogenesis in the acceleration of nerve regeneration. It appears that the muscle flap rotation augmented the nerve regeneration process which may be beneficial for nerve repair in clinical application.

Cooperatively Responsive Peptide Nanotherapeutic that Regulates Angiopoietin Receptor Tie2 Activity in Tumor Microenvironment To Prevent Breast Tumor Relapse after Chemotherapy

Expressed in macrophages and endothelial cells, the receptor for angiopoietin, tyrosine kinase with immunoglobulin and epidermal growth factor homology-2 (Tie2), is required for the reconstruction of blood vessels in tumor recurrence after chemotherapy. Thus, small therapeutic peptides that target and block Tie2 activity are promising as a therapeutic for the prevention of tumor relapse after chemotherapy. However, such small peptides often have low bioavailability, undergo rapid enzymatic degradation, and exhibit a short circulation half-life, making them ineffective in cancer therapy. Herein, we designed a dual-responsive amphiphilic peptide (mPEG₁₀₀₀-K(DEAP)-AAN-NLLMAAS) to modify the small peptide T4 (NLLMAAS) as a Tie2 inhibitor, endowing it with the ability to endure in circulation and specifically target tumor tissue. The ultimate nanoformulation (P-T4) releases T4 in response to the combination of the acidic tumor microenvironment and the presence of legumain, which is commonly overexpressed in tumor tissue. Compared with free T4, P-T4 decreases vessel density significantly (free T4: 2.44 ± 1.20%, P-T4: 0.90 ± 0.75%), delays tumor regrowth after chemotherapy (free T4: 43.2 ± 11.8%, P-T4: 63.6 ± 13.9%), and reduces distant metastasis formation (free T4: 4.50 ± 2.40%, P-T4: 0.67 ± 0.32%). These effects of P-T4 are produced by the local blockage of Tie2 signals in Tie2-positive macrophages and endothelial cells. In addition to describing a potential strategy to enhance circulation half-life and the accumulation of an active peptide at tumor sites, our approach exemplifies the successful targeting of multiple cell types that overexpress a key molecule in conditions associated with tumors.

Discovery of chalcone-modified estradiol analogs as antitumour agents that Inhibit tumour angiogenesis and epithelial to mesenchymal transition

Angiogenesis plays an essential role in tumourigenesis and tumour progression, and anti-angiogenesis therapies have shown promising antitumour effects in solid tumours. 2-Methoxyestradiol (2ME2), an endogenous metabolite of estradiol, has been regarded as a potential antitumour agent mainly targeting angiogenesis. Here we synthesized a novel series of chalcones based on 2-methoxyestradiol and evaluated their potential activities against tumours. Compound 11e was demonstrated to have potent antiangiogenic activity. Further studies showed that 11e suppressed tumour growth in human breast cancer (MCF-7) xenograft models without obvious side effects. Evaluation of the mechanism revealed that 11e targeted the epithelial to mesenchymal transition (EMT) process in MCF-7 cells and inhibited HUVEC migration and then contributed to hindrance of angiogenesis. Thus, 11e may be a promising antitumour agent with excellent efficacy and low toxicity.

Antisense Oligonucleotides Targeting Angiogenic Factors as Potential Cancer Therapeutics

Cancer is one of the leading causes of death worldwide, and conventional cancer therapies such as surgery, chemotherapy, and radiotherapy do not address the underlying molecular pathologies, leading to inadequate treatment and tumor recurrence. Angiogenic factors, such as EGF, PDGF, bFGF, TGF-β, TGF-α, VEGF, endoglin, and angiopoietins, play important roles in regulating tumor development and metastasis, and they serve as potential targets for developing cancer therapeutics. Nucleic acid-based therapeutic strategies have received significant attention in the last two decades, and antisense oligonucleotide-mediated intervention is a prominent therapeutic approach for targeted manipulation of gene expression. Clinical benefits of antisense oligonucleotides have been recognized by the U.S. Food and Drug Administration, with full or conditional approval of Vitravene, Kynamro, Exondys51, and Spinraza. Herein we review the scope of antisense oligonucleotides that target angiogenic factors toward tackling solid cancers.

Regulation of Blood and Lymphatic Vessels by Immune Cells in Tumors and Metastasis

Research over the last decades has provided strong evidence for the pivotal role of the tumor-associated blood and lymphatic vasculature in supporting immunoevasion and in subverting T cell-mediated immunosurveillance. Conversely, tumor blood and lymphatic vessel growth is in part regulated by the immune system, with infiltrating innate as well as adaptive immune cells providing both immunosuppressive and various angiogenic signals. Thus, tumor angiogenesis and escape of immunosurveillance are two cancer hallmarks that are tightly linked and interregulated by cell constituents from compartments secreting both chemokines and cytokines. In this review, we discuss the implication and regulation of innate and adaptive immune cells in regulating blood and lymphatic angiogenesis in tumor progression and metastases. Moreover, we also highlight novel therapeutic approaches that target the tumor vasculature as well as the immune compartment to sustain and improve therapeutic efficacy in cancer.

Anti-angiogenic isoform of vascular endothelial growth factor-A in cardiovascular and renal disease

Accumulating evidence suggests that pathologic interactions between the heart and the kidney can contribute to the progressive dysfunction of both organs. Recently, there has been an increase in the prevalence of cardiovascular disease (CVD) and chronic kidney disease (CKD) due to increasing obesity rates. It has been reported that obesity causes various heart and renal disorders and appears to accelerate their progression. Vascular endothelial growth factor-A (VEGF-A) is a major regulator of angiogenesis and vessel permeability, and is associated with CVD and CKD. It is now recognized that alternative VEGF-A gene splicing generates VEGF-A isoforms that differ in their biological actions. Proximal splicing that includes an exon 8a sequence results in pro-angiogenic VEGF-A₁₆₅a, whereas distal splicing inclusive of exon 8b yields the anti-angiogenic isoform of VEGF-A (VEGF-A₁₆₅b). This review highlights several recent preclinical and clinical studies on the role of VEGF-A₁₆₅b in CVD and CKD as a novel function of VEGF-A. This review also discusses potential therapeutic approaches of the use of VEGF-A in clinical settings as a potential circulating biomarker for CVD and CKD.

Hepatocellular carcinoma-derived exosomal miRNA-21 contributes to tumor progression by converting hepatocyte stellate cells to cancer-associated fibroblasts

BACKGROUND

Hepatocellular carcinoma (HCC) remains a global challenge due to its high morbidity and mortality rates as well as poor response to treatment. The communication between tumor-derived elements and stroma plays a critical role in facilitating cancer progression of HCC. Exosomes are small extracellular vesicles (EVs) that are released from the cells upon fusion of multivesicular bodies with the plasma membrane. There is emerging evidence indicating that exosomes play a central role in cell-to-cell communication. Much attention has been paid to exosomes since they are found to transport bioactive proteins, messenger RNA (mRNAs) and microRNA (miRNAs) that can be transferred in active form to adjacent cells or to distant organs. However, the mechanisms underlying such cancer progression remain largely unexplored.

METHODS

Exosomes were isolated by differential ultracentrifugation from conditioned medium of HCC cells and identified by electron microscopy and Western blotting analysis. Hepatic stellate cells (HSCs) were treated with different concentrations of exosomes, and the activation of HSCs was analyzed by Western blotting analysis, wound healing, migration assay, Edu assay, CCK-8 assay and flow cytometry. Moreover, the different miRNA levels of exosomes were tested by real-time quantitative PCR (RT-PCR). The angiogenic ability of activated HSCs was analyzed by qRT-PCR, CCK-8 assay and tube formation assay. In addition, the abnormal lipid metabolism of activated HSCs was analyzed by Western blotting analysis and Oil Red staining. Finally, the relationship between serum exosomal miRNA-21 and prognosis of HCC patients was evaluated.

RESULTS

We showed that HCC cells exhibited a great capacity to convert normal HSCs to cancer-associated fibroblasts (CAFs). Moreover, our data revealed that HCC cells secreted exosomal miRNA-21 that directly targeted PTEN, leading to activation of PDK1/AKT signaling in HSCs. Activated CAFs further promoted cancer progression by secreting angiogenic cytokines, including VEGF, MMP2, MMP9, bFGF and TGF-β. Clinical data indicated that high level of serum exosomal miRNA-21 was correlated with greater activation of CAFs and higher vessel density in HCC patients.

CONCLUSIONS

Intercellular crosstalk between tumor cells and HSCs was mediated by tumor-derived exosomes that controlled progression of HCC. Our findings provided potential targets for prevention and treatment of live cancer.

Prognostic implications of peritumoral vasculature in head and neck cancer

BACKGROUND

There is conflicting evidence regarding the role of peritumoral lymphatic vessel density (LVD) and blood microvessel density (MVD) in the metastasis and prognosis of head and neck squamous cell carcinoma (HNSCC). Existing studies are limited to one or two head and neck subsites and/or small sample sizes. A larger study incorporating multiple sub-sites is needed to address the role of peritumoral LVD and MVD in HNSCC metastasis and prognosis.

METHODS

Tissue samples from 200 HNSCC cases were stained simultaneously using immunohistochemistry (IHC) for markers of peritumoral LVD (lymphatic vessel marker D240) and MVD (blood vessel marker CD31). Of the stained slides, 166 and 167 were evaluable for LVD and MVD, respectively. The results were then correlated with clinicopathologic features and patient outcomes.

RESULTS

Patients with metastatic disease were more likely to have high peritumoral MVD. Through multivariable analyses, MVD was not significantly related to DFS and OS, while low LVD was related to higher risk of disease progression and poor survival.

CONCLUSIONS

Peritumoral MVD was found to be positively associated with metastasis, while LVD was found to be inversely related to both metastasis and progression of HNSCC. These findings may suggest a prognostic role of both peritumoral LVD and MVD in patients with HNSCC.

Residue-level determinants of angiopoietin-2 interactions with its receptor Tie2

We combined computational and experimental methods to interrogate the binding determinants of angiopoietin-2 (Ang2) to its receptor tyrosine kinase (RTK) Tie2-a central signaling system in angiogenesis, inflammation, and tumorigenesis. We used physics-based electrostatic and surface-area calculations to identify the subset of interfacial Ang2 and Tie2 residues that can affect binding directly. Using random and site-directed mutagenesis and yeast surface display (YSD), we validated these predictions and identified additional Ang2 positions that affected receptor binding. We then used burial-based calculations to classify the larger set of Ang2 residues that are buried in the Ang2 core, whose mutations can perturb the Ang2 structure and thereby affect interactions with Tie2 indirectly. Our analysis showed that the Ang2-Tie2 interface is dominated by nonpolar contributions, with only three Ang2 and two Tie2 residues that contribute electrostatically to intermolecular interactions. Individual interfacial residues contributed only moderately to binding, suggesting that engineering of this interface will require multiple mutations to reach major effects. Conversely, substitutions in substantially buried Ang2 residues were more prevalent in our experimental screen, reduced binding substantially, and are therefore more likely to have a deleterious effect that might contribute to oncogenesis. Computational analysis of additional RTK-ligand complexes, c-Kit-SCF and M-CSF-c-FMS, and comparison to previous YSD results, further show the utility of our combined methodology.

Therapeutic targeting of angiogenesis molecular pathways in angiogenesis-dependent diseases

Angiogenesis is a critical step in the progression of almost all human malignancies and some other life-threatening diseases. Anti-angiogenic therapy is a novel and effective approach for treatment of angiogenesis-dependent diseases such as cancer, diabetic retinopathy, and age-related macular degeneration. In this article, we will review the main strategies developed for anti-angiogenic therapies beside their clinical applications, the major challenges, and the latest advances in the development of anti-angiogenesis-based targeted therapies.

Characterisation of a Mouse Model of Breast Cancer with Metabolic Syndrome

BACKGROUND/AIM

Patients with breast cancer and metabolic syndrome have poorer outcomes. We aimed to develop and characterise an apolipoprotein E-null/aromatase knockout (ApoE^-/-/ArKO) mouse model of breast cancer with metabolic syndrome to aid research of the mechanisms behind poor prognosis.

MATERIALS AND METHODS

Wild-type, ApoE^-/- and ApoE^-/-/ArKO mice were orthotopically implanted with EO771 murine breast cancer cells. Tumour growth was monitored and tumours investigated for pathological features such as cancer-associated adipocytes, hypoxia and cancer cell proliferation.

RESULTS

Tumours from ApoE^-/-/ArKO mice were significantly more proliferative than those from wild-type mice (p=0.003), and exhibited reduced expression of insulin-like growth factor binding protein-5 (p=0.002). However, ApoE^-/-/ArKO mice also had a reduced rate of metastasis compared to wild-type and ApoE^-/- mice. Tumour hypoxia and the number of cancer-associated adipocytes did not differ.

CONCLUSION

The ApoE^-/-/ArKO model with EO771 breast cancer provides a novel mouse model to investigate the effects of metabolic syndrome on aspects of breast tumour biology.

Impact of prolonged and early bevacizumab treatment on the overall survival of EGFR-mutant and EGFR-wild type nonsquamous non-small cell lung cancer

BACKGROUND

VEGF plays a key role in tumor angiogenesis and immunosuppression. VEGF-blocking has proven beneficial for EGFR mutant and wild-type nonsquamous non-small cell lung cancer (nonsq-NSCLC); however, the number of cycles and treatment line yielding the optimal benefit are unknown.

METHODS

We retrospectively analyzed the data of 115 patients with advanced/metastatic nonsq-NSCLC administered at least one cycle of bevacizumab. The number of bevacizumab cycles was treated as a time-dependent covariate. Predictors of overall survival (OS) were investigated.

RESULTS

Bevacizumab was used as first-line treatment in 47 (40.9%) patients, with a median of five cycles (range: 1-31). Eastern Cooperative Oncology Group performance status ≥ 2 (hazard ratio [HR] 4.78, 95% confidence interval [CI] 2.68-8.51; P < 0.001), wild-type EGFR (HR 2.61, 95% CI 1.45-4.70; P = 0.001), and bleeding during bevacizumab treatment (HR 3.63, 95% CI 1.77-7.45; P < 0.001) were predictive of poor OS; the number of bevacizumab cycles and first-line administration were not. In the wild-type EGFR subgroup, the number of bevacizumab cycles (≥ 5 vs. 1-4) was associated with a significant OS benefit (HR 0.28, 95% CI 0.08-0.98; P = 0.044); first-line administration also showed an OS benefit (HR 0.48, 95% CI 0.20-1.17; P = 0.105). A significant association between the number of cycles and EGFR status was identified (P = 0.046).

CONCLUSION

OS benefit is negatively affected by bleeding events in bevacizumab-treated patients. Prolonged and early introduction of bevacizumab may provide an OS benefit for patients with wild-type EGFR nonsq-NSCLC.

Engineering therapeutic bispecific antibodies using CrossMab technology

Bispecific antibodies have recently gained major interest as they allow novel mechanisms-of-action and/or therapeutic applications that cannot be achieved using conventional IgG-based antibodies. A major issue in engineering IgG-based bispecific antibodies has been to enable the correct association of heavy and light chains resulting in correct assembly of the desired bispecific antibody in sufficient yield. Various approaches have been described during recent years to tackle this challenge. We have developed the so-called CrossMab technology that enforces correct light chain association based on the domain crossover of immunoglobulin domains in the Fab region of the bispecific antibody. This versatile technology allows the generation of different bispecific antibody formats including asymmetric heterodimeric monovalent 1 + 1 bispecific antibodies and asymmetric heterodimeric bispecific antibodies with 2 + 1 valency in combination with approaches enabling Fc-hetermodimerization like knob-into-hole technology as well as the generation of tetravalent symmetric bispecific antibodies with 2 + 2 valency, also known as Tandem-Fab based IgG antibodies, using processes suitable for the large scale production of therapeutic bispecific antibodies. Notably, as of now, at least eight different bispecific antibodies using CrossMab technology entered clinical development, and additional CrossMabs are in late preclinical development. This review provides a summary of the status and progress with the engineering and generation of CrossMab technology based bispecific antibodies as well as their therapeutic application.

pH-Responsive Cross-Linked Low Molecular Weight Polyethylenimine as an Efficient Gene Vector for Delivery of Plasmid DNA Encoding Anti-VEGF-shRNA for Tumor Treatment

RNA interference (RNAi) is a biological process through which gene expression can be inhibited by RNA molecules with high selectivity and specificity, providing a promising tool for tumor treatment. Two types of molecules are often applied to inactivate target gene expression: synthetic double stranded small interfering RNA (siRNA) and plasmid DNA encoding short hairpin RNA (shRNA). Vectors with high transfection efficiency and low toxicity are essential for the delivery of siRNA and shRNA. In this study, TDAPEI, the synthetic derivative of low-molecular-weight polyethylenimine (PEI), was cross-linked with imine bonds by the conjugation of branched PEI (1.8 kDa) and 2,5-thiophenedicarboxaldehyde (TDA). This biodegradable cationic polymer was utilized as the vector for the delivery of plasmid DNA expressing anti-VEGF-shRNA. Compared to PEI (25 kDa), TDAPEI had a better performance since experimental results suggest its higher transfection efficiency as well as lower toxicity both in cell and animal studies. TDAPEI did not stimulate innate immune response, which is a significant factor that should be considered in vector design for gene delivery. All the results suggested that TDAPEI delivering anti-VEGF-shRNA may provide a promising method for tumor treatment.

FOXF1 promotes angiogenesis and accelerates bevacizumab resistance in colorectal cancer by transcriptionally activating VEGFA

Forkhead box F1 (FOXF1) has been recently implicated in the progression and metastasis of lung cancer and breast cancer. However, the biological functions and underlying mechanisms by which FOXF1 regulates the progression of colorectal cancer (CRC) are largely unknown. As shown in our previous study, FOXF1 is upregulated in 182 CRC tissues, and elevated FOXF1 expression is significantly associated with microvessel density and advanced TNM (T = primary tumour; N = regional lymph nodes; M = distant metastasis) stages. In this study, 43 CRC tissues collected from patients who underwent treatment with first-line standard chemotherapeutic regimens in combination with bevacizumab were used to explore the correlation between FOXF1 expression and resistance to bevacizumab. In addition, FOXF1 regulated angiogenesis by inducing the transcription of vascular endothelial growth factor A1 (VEGFA) in vitro and in vivo. Furthermore, upregulation of FOXF1 enhanced bevacizumab resistance in CRC, and inhibition of VEGFA attenuated angiogenesis and bevacizumab resistance in FOXF1-overexpressing CRC cells. These results suggest that FOXF1 plays critical roles in CRC angiogenesis and bevacizumab resistance by inducing VEGFA transcription and that FOXF1 represents a potentially new therapeutic strategy and biomarker for anti-angiogenic therapy against CRC.

In situ construction of nanonetworks from transformable nanoparticles for anti-angiogenic therapy

Tumor metastasis as the most common reason of death from cancer has always been a great challenge in both clinical and scientific research, where angiogenesis plays a necessary role. Herein, we report an extracellularly transformable nanomaterial for in situ construction of defensive networks on interaction with vascular endothelial growth factor (VEGF) for anti-angiogenic therapy of tumor. The fibrous networks exhibit transformation-enhanced accumulation and retention (TEAR) effects (over 72 h), and bind and intercept cell-secreted VEGF over particulate and molecular anti-angiogenic agents with high efficiency, leading to anti-angiogenesis. This study demonstrates that angiogenesis is positively related to tumor growth as well as tumor metastasis; the anti-angiogenic therapy inhibits tumor metastasis with an inhibition rate of 65.9%. In addition, this extracellular strategy of transformation may be utilized to bind huge amounts of cell-secreted biomolecules/factors or receptors on cell surfaces and inhibit their functionalities for cancer therapy.

Apatinib targets both tumor and endothelial cells in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed malignancies worldwide with poor prognosis and tends to be hypervascular. Aberrant expression of the vascular endothelial growth factor 2 (VEGFR‐2) has been implicated in the progression of HCC and represents a valid target for anticancer therapy. Apatinib, a small molecule inhibitor of VEGFR‐2 tyrosine kinase, shows strong antitumor activity in various tumors. This study is designed to evaluate the activity of apatinib on both human umbilical vein vascular endothelial cells (HUVECs) and HCC cell lines (in vitro and in vivo), and also to investigate the characteristics and possible mechanisms underlying these effects by molecular biology methods. Following the results in our study, apatinib inhibited phosphorylation of VEGFR‐2 in HUVECs and blocked in vitro endothelial cell migration and tube formation. Concentration‐dependent antiproliferative effects of apatinib were also observed in all 6 HCC cell lines including SK‐Hep‐1, HepG2, Hep3B, Huh‐7, PLC/PRF/5, SMMC‐7721. Moreover, response to apatinib of HCC cell lines was significantly correlated with VEGFR‐2 expression level. Additionally, apatinib significantly inhibit VEGF‐triggered VEGFR‐2 phosphorylation and activation of downstream signaling molecules such as Akt and ERK1/2 in HCCs. Apatinib can also induce a cell cycle arrest at G2/M phase and promote HCC apoptosis tested in vitro. In vivo data showed that apatinib can effectively inhibit tumor growth, decreased angiogenesis, as well as induced HCC apoptosis (in some tumors), and thus prolonged animal survival in a mouse xenograft model of human HCC. Our findings suggested that apatinib is a highly potent, oral active anti‐angiogenic, and anti‐HCC agent. The results from current study provide a clear biological rationale to evaluate apatinib as a new agent in HCC in clinical setting, especially for the VEGFR‐2 overexpression ones.

The reciprocal function and regulation of tumor vessels and immune cells offers new therapeutic opportunities in cancer

Tumor angiogenesis and escape of immunosurveillance are two cancer hallmarks that are tightly linked and reciprocally regulated by paracrine signaling cues of cell constituents from both compartments. Formation and remodeling of new blood vessels in tumors is abnormal and facilitates immune evasion. In turn, immune cells in the tumor, specifically in context with an acidic and hypoxic environment, can promote neovascularization. Immunotherapy has emerged as a major therapeutic modality in cancer but is often hampered by the low influx of activated cytotoxic T-cells. On the other hand, anti-angiogenic therapy has been shown to transiently normalize the tumor vasculature and enhance infiltration of T lymphocytes, providing a rationale for a combination of these two therapeutic approaches to sustain and improve therapeutic efficacy in cancer. In this review, we discuss how the tumor vasculature facilitates an immunosuppressive phenotype and vice versa how innate and adaptive immune cells regulate angiogenesis during tumor progression. We further highlight recent results of antiangiogenic immunotherapies in experimental models and the clinic to evaluate the concept that targeting both the tumor vessels and immune cells increases the effectiveness in cancer patients.

Starvation tactics using natural compounds for advanced cancers: pharmacodynamics, clinical efficacy, and predictive biomarkers

The high mortality associated with oncological diseases is mostly due to tumors in advanced stages, and their management is a major challenge in modern oncology. Angiogenesis is a defined hallmark of cancer and predisposes to metastatic invasion and dissemination and is therefore an important druggable target for cancer drug discovery. Recently, because of drug resistance and poor prognosis, new anticancer drugs from natural sources targeting tumor vessels have attracted more attention and have been used in several randomized and controlled clinical trials as therapeutic options. Here, we outline and discuss potential natural compounds as salvage treatment for advanced cancers from recent and ongoing clinical trials and real-world studies. We also discuss predictive biomarkers for patients' selection to optimize the use of these potential anticancer drugs.

Modulation the crosstalk between tumor-associated macrophages and non-small cell lung cancer to inhibit tumor migration and invasion by ginsenoside Rh2

Background

Tumor-associated macrophages (TAMs) play a critical role in modulating the tumor microenvironment and promote tumor metastases. Our studies have demonstrated that ginsenoside Rh2 (G-Rh2), a monomeric compound extracted from ginseng, is a promising anti-tumor agent in lung cancer cells. However, it remains unclear whetherG-Rh2 can modulate the differentiation of TAMs and its interaction with tumor microenvironment. In this study, we investigated how G-Rh2 regulates the phenotype of macrophages and affects the migration of non-small cell lung cancer (NSCLC) cells.

Methods

Murine macrophage-like RAW264.7 cells and human THP-1 monocyte were differentiated into M1 and M2 subsets of macrophages with different cytokines combination, which were further identified by flow cytometry with specific biomarkers. M2 macrophages were sorted out to co-culture with NSCLC cell lines, A549 and H1299. Wound healing assay was performed to examine the cell migration. Expression levels of matrix metalloproteinases 2 and 9 (MMP-2, − 9) and vascular endothelial growth factor-C (VEGF-C) were measured by RT-qPCR and western blot, and the release of VEGF in the supernatant was measured by a VEGF ELISA kit. Finally, modulation of TAMs phenotype and VEGF expression by G-Rh2 was examined in vivo.

Results

We demonstrated that M2 subset of macrophages alternatively differentiated from RAW264.7 or THP-1cells promote migration of NSCLC cells. Further examinations revealed that NSCLC significantly increased the release of VEGF to the media and elevated the expression levels of VEGF at mRNA and protein levels after being co-cultured with M2 macrophages. Similar alterations in MMP-2 and MMP-9 were observed in NSCLC after being co-cultured. Of note,G-Rh2 had a potential to effectively convert M2 phenotype to M1 subset of macrophages. Importantly, G-Rh2 had a preference to decrease the expression levels of VEGF, MMP2, and MMP9 in co-cultured lung cancer cells, over than those in lung cancer cells without co-culturing. Consistently, G-Rh2 reduced M2 macrophage marker CD206 and VEGF expression levels in vivo.

Conclusions

All of these results suggested that M2 subset macrophages drive lung cancer cells with more aggressive phenotypes. G-Rh2 has a potential to convert TAMs from M2 subset to M1 in the microenvironment and prevents lung cancer cell migration, suggesting the therapeutic effects of G-Rh2onlung cancer.

Endothelial lineage-specific interaction of Mycobacterium tuberculosis with the blood and lymphatic systems

Mycobacterium tuberculosis (Mtb) has plagued humanity for tens of thousands of years, yet still remains a threat to human health. Its pathology is largely associated with pulmonary tuberculosis with symptoms including fever, hemoptysis, and chest pain. Mtb, however, also manifests in other extrapulmonary organs, such as the pleura, bones, gastrointestinal tract, central nervous system, and lymph nodes. Compared to the knowledge of pulmonary tuberculosis, extrapulmonary pathologies of Mtb are quite understudied. Lymph node tuberculosis is one of the most common extrapulmonary manifestations of tuberculosis, and presents significant challenges in its diagnosis, management, and treatment due to its elusive etiologies and pathologies. The objective of this review is to overview the current understanding of the tropism and pathogenesis of Mtb in endothelial cells of the extrapulmonary tissues, particularly, in lymph nodes. Lymphatic endothelial cells (LECs) are derived from blood vascular endothelial cells (BECs) during development, and these two types of endothelial cells demonstrate substantial molecular, cellular and genetic similarities. Therefore, systemic comparison of the differential and common responses of BECs vs. LECs to Mtb invasion could provide new insights into its pathogenesis, and may promote new investigations into this deadly disease.

Integrins as therapeutic targets in the organ-specific metastasis of human malignant melanoma

Integrins are a large family of adhesion molecules that mediate cell-cell and cell-extracellular matrix interactions. Among the 24 integrin isoforms, many have been found to be associated with tumor angiogenesis, tumor cell migration and proliferation, and metastasis. Integrins, especially αvβ3, αvβ5 and α5β1, participate in mediating tumor angiogenesis by interacting with the vascular endothelial growth factor and angiopoietin-Tie signaling pathways. Melanoma patients have a poor prognosis when the primary tumor has generated distant metastases, and the melanoma metastatic site is an independent predictor of the survival of these patients. Different integrins on the melanoma cell surface preferentially direct circulating melanoma cells to different organs and promote the development of metastases at specific organ sites. For instance, melanoma cells expressing integrin β3 tend to metastasize to the lungs, whereas those expressing integrin β1 preferentially generate lymph node metastases. Moreover, tumor cell-derived exosomes which contain different integrins may prepare a pre-metastatic niche in specific organs and promote organ-specific metastases. Because of the important role that integrins play in tumor angiogenesis and metastasis, they have become promising targets for the treatment of advanced cancer. In this paper, we review the integrin isoforms responsible for angiogenesis and organ-specific metastasis in malignant melanoma and the inhibitors that have been considered for the future treatment of metastatic disease.

Euterpe oleracea extract inhibits tumorigenesis effect of the chemical carcinogen DMBA in breast experimental cancer

Background

Among the processes involved in the breast tumor microenvironment, angiogenesis and inflammation play a central role, and the main factors of these processes are the vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX-2) and macrophages. Recently, the extract of Euterpe oleracea (açaí), a fruit that is widely found in the Amazon region, already showed antitumorigenic effects in vitro in human breast cancer cell lines. The present study aimed to investigate the effect of açaí on breast cancer using a chemically DMBA (7,12-dimethylbenzanthracene) experimental model.

Methods

One day after initiation of treatment with açaí, mammary carcinogenesis was induced in female Wistar rats using a subcutaneous injection of 25 mg/kg of DMBA in the mammary gland. Forty rats were randomized into two groups: treated with 200 mg/kg of either açaí extract or vehicle, via gastric tube for 16 consecutive weeks. After treatment, the tumor was collected for macroscopic, histological and immunohistochemical (VEGF, vascular endothelial growth factor receptor 2 -VEGFR-2, COX-2 and matrix metalloproteinase -MMP-9) analyses; peritoneal fluid was subjected to flow cytometry (F4–80/MAC-2+) and ELISA immunoassay (VEGF, prostaglandin E₂ -PGE₂ and interleukin-10 -IL-10). Heart, liver and kidney samples were collected for histological analysis.

Results

After 16 weeks of induction, the mammary carcinoma was confirmed by macroscopic and histological evaluation. Survival analysis indicates that açaí increased the survival (P = .0002, long-rank test) and reduced the deaths number (P = .0036, Chi-square test). Açaí treatment decreased the number of inflammatory cells and macrophage positive cells (Mac-2 + F4–80+), as well as promoting a reduction in immunostaining of VEGF, VEGFR-2 and COX-2. The açaí group also exhibited lower concentrations of PGE₂, VEGF and IL-10 compared to the control. The histopathological results of the liver and kidneys showed protective effect of açaí, since in the control group, there was an increase in fibrosis, atypical cells and hemorrhagic microenvironment.

Conclusion

The results of this study demonstrated the antiangiogenic and anti-inflammatory potential of açaí, like due to the decreases of the number of activated macrophages, resulting in the inhibition of DMBA carcinogenicity in breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2183-z) contains supplementary material, which is available to authorized users.

Melatonin Inhibits Reactive Oxygen Species-Driven Proliferation, Epithelial-Mesenchymal Transition, and Vasculogenic Mimicry in Oral Cancer

Globally, oral cancer is the most common type of head and neck cancers. Melatonin elicits inhibitory effects on oral cancer; however, the biological function of melatonin and underlying mechanisms remain largely unknown. In this study, we found that melatonin impaired the proliferation and apoptosis resistance of oral cancer cells by inactivating ROS-dependent Akt signaling, involving in downregulation of cyclin D1, PCNA, and Bcl-2 and upregulation of Bax. Melatonin inhibited the migration and invasion of oral cancer cells by repressing ROS-activated Akt signaling, implicating with the reduction of Snail and Vimentin and the enhancement of E-cadherin. Moreover, melatonin hampered vasculogenic mimicry of oral cancer cells through blockage of ROS-activated extracellular-regulated protein kinases (ERKs) and Akt pathways involving the hypoxia-inducible factor 1α. Consistently, melatonin retarded tumorigenesis of oral cancer in vivo. Overall, these findings indicated that melatonin exerts antisurvival, antimotility, and antiangiogenesis effects on oral cancer partly by suppressing ROS-reliant Akt or ERK signaling.

IL-8 associates with a pro-angiogenic and mesenchymal subtype in glioblastoma

Glioblastoma (GBM) is a highly aggressive brain tumor characterized by a high rate of vascularization. However, therapeutic targeting of the vasculature through anti-vascular endothelial growth factor (VEGF) treatment has been disappointing, for which Angiopoietin-2 (Ang-2) upregulation has partly been held accountable. In this study we therefore explored the interplay of Ang-2 and VEGFA and their effect on angiogenesis in GBM, especially in the context of molecular subclasses. In a large patient cohort we identified that especially combined high expression of Ang-2 and VEGFA predicted poor overall survival of GBM patients. The high expression of both factors was also associated with increased IL-8 expression in GBM tissues, but in vitro stimulation with Ang-2 and/or VEGFA did not indicate tumor or endothelial cell-specific IL-8 responses. Glioblastoma stem cells (GSCs) of the mesenchymal (MES) subtype showed dramatically higher expression of IL8 when compared to proneural (PN) GSCs. Secreted IL-8 derived from MES GSCs induced endothelial proliferation and tube formation, and the MES GBMs had increased counts of proliferating endothelial cells. Our results highlight a critical pro-angiogenic role of IL-8 in MES GBMs.

Sox7 promotes high-grade glioma by increasing VEGFR2-mediated vascular abnormality

High-grade glioma (HGG) is highly angiogenic, but antiangiogenic therapy has transient clinical benefit in only a fraction of patients. Vascular regulators of these heterogeneous responses remain undetermined. We found up-regulation of Sox7 and down-regulation of Sox17 in tumor endothelial cells (tECs) in mouse HGG. Sox7 deletion suppressed VEGFR2 expression, vascular abnormality, hypoxia-driven invasion, regulatory T cell infiltration, and tumor growth. Conversely, Sox17 deletion exacerbated these phenotypes by up-regulating Sox7 in tECs. Anti-VEGFR2 antibody treatment delayed tumor growth by normalizing Sox17-deficient abnormal vessels with high Sox7 levels but promoted it by regressing Sox7-deficient vessels, recapitulating variable therapeutic responses to antiangiogenic therapy in HGG patients. Our findings establish that Sox7 promotes tumor growth via vessel abnormalization, and its level determines the therapeutic outcome of VEGFR2 inhibition in HGG. In 189 HGG patients, Sox7 expression was heterogeneous in tumor vessels, and high Sox7 levels correlated with poor survival, early recurrence, and impaired vascular function, emphasizing the clinical relevance of Sox7 in HGG.

A Novel Fusion Antibody Exhibits Antiangiogenic Activity and Stimulates NK Cell-mediated Immune Surveillance Through Fused NKG2D Ligand

A single-chain variable fragment (scFv) targeting vascular endothelial growth factor receptor 2 was previously generated from a phage display library in our laboratory. However, it has shortened half-life and lacks Fc fragment for effector cell recognition. To address these challenges, a ligand of NK-cell receptor NKG2D was fused to the scFv and created a fusion protein scFv-major histocompatibility complex class I-related chain A (MICA), which is expected to recognize tumor cells through the scFv moiety and stimulate NK cells through the MICA. The fusion protein demonstrated specific binding to both vascular endothelial growth factor receptor 2 and NKG2D in protein-based and cell-based assays. In addition, it demonstrated antiangiogenic activities including restraining the proliferation, migration, transwell invasion, and tube formation of human umbilical vein endothelial cells. Furthermore, the fusion protein exhibited significant cytotoxicity on K562, MDA-MB-435, and B16F10 cells and triggered NK92 cell-mediated cytotoxicity on MDA-MB-435 cells by stimulating the release of significant cytokines. The fusion protein targeting strategy, therefore, provides a means to engage lymphocyte effector cells against tumor specific antigen overexpressing tumor cells.

Linc00511 acts as a competing endogenous RNA to regulate VEGFA expression through sponging hsa-miR-29b-3p in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy. Long non-coding RNAs (lncRNAs) are important regulators in pathological processes, yet their potential roles in PDAC are poorly understood. Here, we identify a fundamental role for a novel lincRNA, linc00511, in the progression of PDAC. Linc00511 levels in PDAC tissue specimens and cell lines were examined by quantitative real-time PCR. Corresponding adjacent non-neoplastic tissues were used as controls. The function of linc00511 in PDAC cell lines was determined by RNA interference approach in vitro and in vivo. Fluorescence in situ hybridization (FISH) was used to characterize linc00511 expression in PDAC cells. Insights of the mechanism of competitive endogenous RNAs (ceRNAs) were obtained from bioinformatic analysis, luciferase assays and RIP assays. The association between the linc00511/hsa-miR29b-3p axis and VEGFA was verified by Western blotting assay. Immunohistochemistry was performed to evaluate the expression of VEGFA in PDAC samples. The aberrant up-regulation of linc00511 was detected in PDAC cell lines and patient specimens compared with controls. An increase in linc00511 expression indicates the adverse clinical pathological characteristics and poor prognosis. Functionally, linc00511 depletion in PDAC cells decreased proliferation, migration, invasion and endothelial tube formation. Mechanistically, linc00511 could up-regulate VEGFA via its competing endogenous RNA (ceRNA) activity on hsa-miR-29b-3p. In summary, our results define an important axis controlling proliferation, invasion and tumour angiogenesis in PDAC. Linc00511 is a novel lncRNA that plays a significant regulatory role in the pathogenesis and progression of PDAC. Thus, Linc00511 represents a new prognostic biomarker to predict clinical outcome of PDAC patients after surgery and may serve as a potential therapeutic target for PDAC treatment.