Reduced chondroitin sulfate content prevents diabetic neuropathy through transforming growth factor-ß signaling suppression.

Diabetic neuropathy (DN) is a major complication of diabetes mellitus. Chondroitin sulfate (CS) is one of the most important extracellular matrix components and is known to interact with various diffusible factors; however, its role in DN pathology has not been examined. Therefore, we generated CSGalNAc-T1 knockout (T1KO) mice, in which CS levels were reduced. We demonstrated that diabetic T1KO mice were much more resistant to DN than diabetic wild-type (WT) mice. We also found that interactions between pericytes and vascular endothelial cells were more stable in T1KO mice. Among the RNA-seq results, we focused on the transforming growth factor ß signaling pathway and found that the phosphorylation of Smad2/3 was less upregulated in T1KO mice than in WT mice under hyperglycemic conditions. Taken together, a reduction in CS level attenuates DN progression, indicating that CS is an important factor in DN pathogenesis.

A MAP1B-cortactin-Tks5 axis regulates TNBC invasion and tumorigenesis.

The microtubule-associated protein MAP1B has been implicated in axonal growth and brain development. We found that MAP1B is highly expressed in the most aggressive and deadliest breast cancer subtype, triple-negative breast cancer (TNBC), but not in other subtypes. Expression of MAP1B was found to be highly correlated with poor prognosis. Depletion of MAP1B in TNBC cells impairs cell migration and invasion concomitant with a defect in tumorigenesis. We found that MAP1B interacts with key components for invadopodia formation, cortactin, and Tks5, the latter of which is a PtdIns(3,4)P2-binding and scaffold protein that localizes to invadopodia. We also found that Tks5 associates with microtubules and supports the association between MAP1B and α-tubulin. In accordance with their interaction, depletion of MAP1B leads to Tks5 destabilization, leading to its degradation via the autophagic pathway. Collectively, these findings suggest that MAP1B is a convergence point of the cytoskeleton to promote malignancy in TNBC and thereby a potential diagnostic and therapeutic target for TNBC.

CD40 is expressed in the subsets of endothelial cells undergoing partial endothelial-mesenchymal transition in tumor microenvironment.

Tumor progression and metastasis are regulated by endothelial cells undergoing endothelial-mesenchymal transition (EndoMT), a cellular differentiation process in which endothelial cells lose their properties and differentiate into mesenchymal cells. The cells undergoing EndoMT differentiate through a spectrum of intermediate phases, suggesting that some cells remain in a partial EndoMT state and exhibit an endothelial/mesenchymal phenotype. However, detailed analysis of partial EndoMT has been hampered by the lack of specific markers. Transforming growth factor-ß (TGF-ß) plays a central role in the induction of EndoMT. Here, we showed that inhibition of TGF-ß signaling suppressed EndoMT in a human oral cancer cell xenograft mouse model. By using genetic labeling of endothelial cell lineage, we also established a novel EndoMT reporter cell system, the EndoMT reporter endothelial cells (EMRECs), which allow visualization of sequential changes during TGF-ß-induced EndoMT. Using EMRECs, we characterized the gene profiles of multiple EndoMT stages and identified CD40 as a novel partial EndoMT-specific marker. CD40 expression was upregulated in the cells undergoing partial EndoMT, but decreased in the full EndoMT cells. Furthermore, single-cell RNA sequencing analysis of human tumors revealed that CD40 expression was enriched in the population of cells expressing both endothelial and mesenchymal cell markers. Moreover, decreased expression of CD40 in EMRECs enhanced TGF-ß-induced EndoMT, suggesting that CD40 expressed during partial EndoMT inhibits transition to full EndoMT. The present findings provide a better understanding of the mechanisms underlying TGF-ß-induced EndoMT and will facilitate the development of novel therapeutic strategies targeting EndoMT-driven cancer progression and metastasis.

Roles of TGF-ß signals in tumor microenvironment via regulation of the formation and plasticity of vascular system.

Tumor cells evolve in tumor microenvironment composed of multiple cell types. Among these, endothelial cells (ECs) are the major players in tumor angiogenesis, which is a driver of tumor progression and metastasis. Increasing evidence suggests that ECs also contribute to tumor progression and metastasis as they modify their phenotypes to differentiate into mesenchymal cells through a process known as endothelial-mesenchymal transition (EndoMT). This plasticity of ECs is mediated by various cytokines, including transforming growth factor-ß (TGF-ß), and modulated by other stimuli depending on the cellular contexts. Recent lines of evidence have shown that EndoMT is involved in various steps of tumor progression, including tumor angiogenesis, intravasation and extravasation of cancer cells, formation of cancer-associated fibroblasts, and cancer therapy resistance. In this review, we summarize current updates on EndoMT, highlight the roles of EndoMT in tumor progression and metastasis, and underline targeting EndoMT as a potential therapeutic strategy.

An analysis modality for vascular structures combining tissue-clearing technology and topological data analysis.

The blood and lymphatic vasculature networks are not yet fully understood even in mouse because of the inherent limitations of imaging systems and quantification methods. This study aims to evaluate the usefulness of the tissue-clearing technology for visualizing blood and lymphatic vessels in adult mouse. Clear, unobstructed brain/body imaging cocktails and computational analysis (CUBIC) enables us to capture the high-resolution 3D images of organ- or area-specific vascular structures. To evaluate these 3D structural images, signals are first classified from the original captured images by machine learning at pixel base. Then, these classified target signals are subjected to topological data analysis and non-homogeneous Poisson process model to extract geometric features. Consequently, the structural difference of vasculatures is successfully evaluated in mouse disease models. In conclusion, this study demonstrates the utility of CUBIC for analysis of vascular structures and presents its feasibility as an analysis modality in combination with 3D images and mathematical frameworks.

Dose-response relationship of pulmonary disorders by inhalation exposure to cross-linked water-soluble acrylic acid polymers in F344 rats.

BACKGROUND: In Japan, six workers handling cross-linked water-soluble acrylic acid polymer (CWAAP) at a chemical plant suffered from lung diseases, including fibrosis, interstitial pneumonia, emphysema, and pneumothorax. We recently demonstrated that inhalation of CWAAP-A, one type of CWAAP, causes pulmonary disorders in rats. It is important to investigate dose-response relationships and recoverability from exposure to CWAAPs for establishing occupational health guidelines, such as setting threshold limit value for CWAAPs in the workplace. METHODS: Male and female F344 rats were exposed to 0.3, 1, 3, or 10 mg/m3 CWAAP-A for 6 h/day, 5 days/week for 13 weeks using a whole-body inhalation exposure system. At 1 h, 4 weeks, and 13 weeks after the last exposure the rats were euthanized and blood, bronchoalveolar lavage fluid, and all tissues including lungs and mediastinal lymph nodes were collected and subjected to biological and histopathological analyses. In a second experiment, male rats were pre-treated with clodronate liposome or polymorphonuclear leukocyte-neutralizing antibody to deplete macrophages or neutrophils, respectively, and exposed to CWAAP-A for 6 h/day for 2 days. RESULTS: CWAAP-A exposure damaged only the alveoli. The lowest observed adverse effect concentration (LOAEC) was 1 mg/m3 and the no observed adverse effect concentration (NOAEC) was 0.3 mg/m3. Rats of both sexes were able to recover from the tissue damage caused by 13 weeks exposure to 1 mg/m3 CWAAP-A. In contrast, tissue damage caused by exposure to 3 and 10 mg/m3 was irreversible due to the development of interstitial lung lesions. There was a gender difference in the recovery from CWAAP-A induced pulmonary disorders, with females recovering less than males. Finally, acute lung effects caused by CWAAP-A were significantly reduced by depletion of alveolar macrophages. CONCLUSIONS: Pulmonary damage caused by inhalation exposure to CWAAP-A was dose-dependent, specific to the lung and lymph nodes, and acute lung damage was ameliorated by depleting macrophages in the lungs. CWAAP-A had both a LOAEC and a NOAEC, and tissue damage caused by exposure to 1 mg/m3 CWAAP-A was reversible: recovery in female rats was less than for males. These findings indicate that concentration limits for CWAAPs in the workplace can be determined.

Emerging roles of inflammation-mediated endothelial-mesenchymal transition in health and disease.

Endothelial-mesenchymal transition (EndoMT), a cellular differentiation process in which endothelial cells (ECs) lose their properties and differentiate into mesenchymal cells, has been observed not only during development but also in various pathological states in adults, including cancer progression and organ/tissue fibrosis. Transforming growth factor-ß (TGF-ß), an inflammation-related cytokine, has been shown to play central roles in the induction of EndoMT. TGF-ß induces EndoMT by regulating the expression of various transcription factors, signaling molecules, and cellular components that confer ECs with mesenchymal characteristics. However, TGF-ß by itself is not necessarily sufficient to induce EndoMT to promote the progression of EndoMT-related diseases to a refractory extent. In addition to TGF-ß, additional activation by other inflammatory factors is often required to stabilize the progression of EndoMT. Since recent lines of evidence indicate that inflammatory signaling molecules act as enhancers of EndoMT, we summarize the roles of inflammatory factors in the induction of EndoMT and related diseases. We hope that this review will help to develop therapeutic strategies for EndoMT-related diseases by targeting inflammation-mediated EndoMT.

Construction of transplantable artificial vascular tissue based on adipose tissue-derived mesenchymal stromal cells by a cell coating and cryopreservation technique.

Prevascularized artificial three-dimensional (3D) tissues are effective biomaterials for regenerative medicine. We have previously established a scaffold-free 3D artificial vascular tissue from normal human dermal fibroblasts (NHDFs) and umbilical vein-derived endothelial cells (HUVECs) by layer-by-layer cell coating technique. In this study, we constructed an artificial vascular tissue constructed by human adipose tissue-derived stromal cells (hASCs) and HUVECs (ASCVT) by a modified technique with cryopreservation. ASCVT showed a higher thickness with more dense vascular networks than the 3D tissue based on NHDFs. Correspondingly, 3D-cultured ASCs showed higher expression of several angiogenesis-related factors, including vascular endothelial growth factor-A and hepatic growth factor, compared to that of NHDFs. Moreover, perivascular cells in ASCVT were detected by pericyte markers, suggesting the differentiation of hASCs into pericyte-like cells. Subcutaneous transplantation of ASCVTs to nude mice resulted in an engraftment with anastomosis of host's vascular structures at 2 weeks after operation. In the engrafted tissue, the vascular network was surrounded by mural-like structure-forming hASCs, in which some parts developed to form vein-like structures at 4 weeks, suggesting the generation of functional vessel networks. These results demonstrated that cryopreserved human cells, including hASCs, could be used directly to construct the artificial transplantable tissue for regenerative medicine.

Isolation and characterisation of lymphatic endothelial cells from lung tissues affected by lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare pulmonary disease characterised by the proliferation of smooth muscle-like cells (LAM cells), and an abundance of lymphatic vessels in LAM lesions. Studies reported that vascular endothelial growth factor-D (VEGF-D) secreted by LAM cells contributes to LAM-associated lymphangiogenesis, however, the precise mechanisms of lymphangiogenesis and characteristics of lymphatic endothelial cells (LECs) in LAM lesions have not yet been elucidated. In this study, human primary-cultured LECs were obtained both from LAM-affected lung tissues (LAM-LECs) and normal lung tissues (control LECs) using fluorescence-activated cell sorting (FACS). We found that LAM-LECs had significantly higher ability of proliferation and migration compared to control LECs. VEGF-D significantly promoted migration of LECs but not proliferation of LECs in vitro. cDNA microarray and FACS analysis revealed the expression of vascular endothelial growth factor receptor (VEGFR)-3 and integrin α9 were elevated in LAM-LECs. Inhibition of VEGFR-3 suppressed proliferation and migration of LECs, and blockade of integrin α9 reduced VEGF-D-induced migration of LECs. Our data uncovered the distinct features of LAM-associated LECs, increased proliferation and migration, which may be due to higher expression of VEGFR-3 and integrin α9. Furthermore, we also found VEGF-D/VEGFR-3 and VEGF-D/ integrin α9 signaling play an important role in LAM-associated lymphangiogenesis.

ASK1 suppresses NK cell-mediated intravascular tumor cell clearance in lung metastasis.

Tumor metastasis is the leading cause of death worldwide and involves an extremely complex process composed of multiple steps. Our previous study demonstrated that apoptosis signal-regulating kinase 1 (ASK1) deficiency in mice attenuates tumor metastasis in an experimental lung metastasis model. However, the steps of tumor metastasis regulated by ASK1 remain unclear. Here, we showed that ASK1 deficiency in mice promotes natural killer (NK) cell-mediated intravascular tumor cell clearance in the initial hours of metastasis. In response to tumor inoculation, ASK1 deficiency upregulated immune response-related genes, including interferon-gamma (IFNγ). We also revealed that NK cells are required for these anti-metastatic phenotypes. ASK1 deficiency augmented cytokine production chemoattractive to NK cells possibly through induction of the ligand for NKG2D, a key activating receptor of NK cells, leading to further recruitment of NK cells into the lung. These results indicate that ASK1 negatively regulates NK cell-dependent anti-tumor immunity and that ASK1-targeted therapy can provide a new tool for cancer immunotherapy to overcome tumor metastasis.

Targeting all transforming growth factor-ß isoforms with an Fc chimeric receptor impairs tumor growth and angiogenesis of oral squamous cell cancer.

Tumor progression is governed by various growth factors and cytokines in the tumor microenvironment (TME). Among these, transforming growth factor-ß (TGF-ß) is secreted by various cell types residing in the TME and promotes tumor progression by inducing the epithelial-to-mesenchymal transition (EMT) of cancer cells and tumor angiogenesis. TGF-ß comprises three isoforms, TGF-ß1, -ß2, and -ß3, and transduces intracellular signals via TGF-ß type I receptor (TßRI) and TGF-ß type II receptor (TßRII). For the purpose of designing ligand traps that reduce oncogenic signaling in the TME, chimeric proteins comprising the ligand-interacting ectodomains of receptors fused with the Fc portion of immunoglobulin are often used. For example, chimeric soluble TßRII (TßRII-Fc) has been developed as an effective therapeutic strategy for targeting TGF-ß ligands, but several lines of evidence indicate that TßRII-Fc more effectively traps TGF-ß1 and TGF-ß3 than TGF-ß2, whose expression is elevated in multiple cancer types. In the present study, we developed a chimeric TGF-ß receptor containing both TßRI and TßRII (TßRI-TßRII-Fc) and found that TßRI-TßRII-Fc trapped all TGF-ß isoforms, leading to inhibition of both the TGF-ß signal and TGF-ß-induced EMT of oral cancer cells, whereas TßRII-Fc failed to trap TGF-ß2. Furthermore, we found that TßRI-TßRII-Fc suppresses tumor growth and angiogenesis more effectively than TßRII-Fc in a subcutaneous xenograft model of oral cancer cells with high TGF-ß expression. These results suggest that TßRI-TßRII-Fc may be a promising tool for targeting all TGF-ß isoforms in the TME.

Peptide-2 from mouse myostatin precursor protein alleviates muscle wasting in cancer-associated cachexia.

Cancer cachexia, characterized by continuous muscle wasting, is a key determinant of cancer-related death; however, there are few medical treatments to combat it. Myostatin (MSTN)/growth differentiation factor 8 (GDF-8), which is a member of the transforming growth factor-ß family, is secreted in an inactivated form noncovalently bound to the prodomain, negatively regulating the skeletal muscle mass. Therefore, inhibition of MSTN signaling is expected to serve as a therapeutic target for intractable muscle wasting diseases. Here, we evaluated the inhibitory effect of peptide-2, an inhibitory core of mouse MSTN prodomain, on MSTN signaling. Peptide-2 selectively suppressed the MSTN signal, although it had no effect on the activin signal. In contrast, peptide-2 slightly inhibited the GDF-11 signaling pathway, which is strongly related to the MSTN signaling pathway. Furthermore, we found that the i.m. injection of peptide-2 to tumor-implanted C57BL/6 mice alleviated muscle wasting in cancer cachexia. Although peptide-2 was unable to improve the loss of heart weight and fat mass when cancer cachexia model mice were injected with it, peptide-2 increased the gastrocnemius muscle weight and muscle cross-sectional area resulted in the enhanced grip strength in cancer cachexia mice. Consequently, the model mice treated with peptide-2 could survive longer than those that did not undergo this treatment. Our results suggest that peptide-2 might be a novel therapeutic candidate to suppress muscle wasting in cancer cachexia.

TNF-α enhances TGF-ß-induced endothelial-to-mesenchymal transition via TGF-ß signal augmentation.

The tumor microenvironment (TME) consists of various components including cancer cells, tumor vessels, cancer-associated fibroblasts (CAFs), and inflammatory cells. These components interact with each other via various cytokines, which often induce tumor progression. Thus, a greater understanding of TME networks is crucial for the development of novel cancer therapies. Many cancer types express high levels of TGF-ß, which induces endothelial-to-mesenchymal transition (EndMT), leading to formation of CAFs. Although we previously reported that CAFs derived from EndMT promoted tumor formation, the molecular mechanisms underlying these interactions remain to be elucidated. Furthermore, tumor-infiltrating inflammatory cells secrete various cytokines, including TNF-α. However, the role of TNF-α in TGF-ß-induced EndMT has not been fully elucidated. Therefore, this study examined the effect of TNF-α on TGF-ß-induced EndMT in human endothelial cells (ECs). Various types of human ECs underwent EndMT in response to TGF-ß and TNF-α, which was accompanied by increased and decreased expression of mesenchymal cell and EC markers, respectively. In addition, treatment of ECs with TGF-ß and TNF-α exhibited sustained activation of Smad2/3 signals, which was presumably induced by elevated expression of TGF-ß type I receptor, TGF-ß2, activin A, and integrin αv, suggesting that TNF-α enhanced TGF-ß-induced EndMT by augmenting TGF-ß family signals. Furthermore, oral squamous cell carcinoma-derived cells underwent epithelial-to-mesenchymal transition (EMT) in response to humoral factors produced by TGF-ß and TNF-α-cultured ECs. This EndMT-driven EMT was blocked by inhibiting the action of TGF-ßs. Collectively, our findings suggest that TNF-α enhances TGF-ß-dependent EndMT, which contributes to tumor progression.

TGF-beta and TNF-alpha cooperatively induce mesenchymal transition of lymphatic endothelial cells via activation of Activin signals.

Lymphatic systems play important roles in the maintenance of fluid homeostasis and undergo anatomical and physiological changes during inflammation and aging. While lymphatic endothelial cells (LECs) undergo mesenchymal transition in response to transforming growth factor-ß (TGF-ß), the molecular mechanisms underlying endothelial-to-mesenchymal transition (EndMT) of LECs remain largely unknown. In this study, we examined the effect of TGF-ß2 and tumor necrosis factor-α (TNF-α), an inflammatory cytokine, on EndMT using human skin-derived lymphatic endothelial cells (HDLECs). TGF-ß2-treated HDLECs showed increased expression of SM22α, a mesenchymal cell marker accompanied by increased cell motility and vascular permeability, suggesting HDLECs to undergo EndMT. Our data also revealed that TNF-α could enhance TGF-ß2-induced EndMT of HDLECs. Furthermore, both cytokines induced the production of Activin A while decreasing the expression of its inhibitory molecule Follistatin, and thus enhancing EndMT. Finally, we demonstrated that human dermal lymphatic vessels underwent EndMT during aging, characterized by double immunostaining for LYVE1 and SM22α. These results suggest that both TGF-ß and TNF-α signals play a central role in EndMT of LECs and could be potential targets for senile edema.

Fibroblast growth factor signals regulate transforming growth factor-ß-induced endothelial-to-myofibroblast transition of tumor endothelial cells via Elk1.

The tumor microenvironment contains various components, including cancer cells, tumor vessels, and cancer-associated fibroblasts, the latter of which are comprised of tumor-promoting myofibroblasts and tumor-suppressing fibroblasts. Multiple lines of evidence indicate that transforming growth factor-ß (TGF-ß) induces the formation of myofibroblasts and other types of mesenchymal (non-myofibroblastic) cells from endothelial cells. Recent reports show that fibroblast growth factor 2 (FGF2) modulates TGF-ß-induced mesenchymal transition of endothelial cells, but the molecular mechanisms behind the signals that control transcriptional networks during the formation of different groups of fibroblasts remain largely unclear. Here, we studied the roles of FGF2 during the regulation of TGF-ß-induced mesenchymal transition of tumor endothelial cells (TECs). We demonstrated that auto/paracrine FGF signals in TECs inhibit TGF-ß-induced endothelial-to-myofibroblast transition (End-MyoT), leading to suppressed formation of contractile myofibroblast cells, but on the other hand can also collaborate with TGF-ß in promoting the formation of active fibroblastic cells which have migratory and proliferative properties. FGF2 modulated TGF-ß-induced formation of myofibroblastic and non-myofibroblastic cells from TECs via transcriptional regulation of various mesenchymal markers and growth factors. Furthermore, we observed that TECs treated with TGF-ß were more competent in promoting in vivo tumor growth than TECs treated with TGF-ß and FGF2. Mechanistically, we showed that Elk1 mediated FGF2-induced inhibition of End-MyoT via inhibition of TGF-ß-induced transcriptional activation of α-smooth muscle actin promoter by myocardin-related transcription factor-A. Our data suggest that TGF-ß and FGF2 oppose and cooperate with each other during the formation of myofibroblastic and non-myofibroblastic cells from TECs, which in turn determines the characteristics of mesenchymal cells in the tumor microenvironment.

Interleukin-13 receptor α2 is a novel marker and potential therapeutic target for human melanoma.

Malignant melanoma is one of the untreatable cancers in which conventional therapeutic strategies, including chemotherapy, are hardly effective. Therefore, identification of novel therapeutic targets involved in melanoma progression is urgently needed for developing effective therapeutic methods. Overexpression of interleukin-13 receptor α2 (IL13Rα2) is observed in several cancer types including glioma and pancreatic cancer. Although IL13Rα2 is implicated in the progression of various types of cancer, its expression and roles in the malignant melanoma have not yet been elucidated. In the present study, we showed that IL13Rα2 was expressed in approximately 7.5% melanoma patients. While IL13Rα2 expression in human melanoma cells decreased their proliferation in vitro, it promoted in vivo tumour growth and angiogenesis in melanoma xenograft mouse model. We also found that the expression of amphiregulin, a member of the epidermal growth factor (EGF) family, was correlated with IL13Rα2 expression in cultured melanoma cells, xenograft tumour tissues and melanoma clinical samples. Furthermore, expression of amphiregulin promoted tumour growth, implicating causal relationship between the expression of IL13Rα2 and amphiregulin. These results suggest that IL13Rα2 enhances tumorigenicity by inducing angiogenesis in malignant melanoma, and serves as a potential therapeutic target of malignant melanoma.

Vasohibin-2 is required for epithelial-mesenchymal transition of ovarian cancer cells by modulating transforming growth factor-ß signaling.

Vasohibin-2 (VASH2) is a homolog of VASH1, an endothelium-derived angiogenesis inhibitor. Vasohibin-2 is mainly expressed in cancer cells, and has been implicated in the progression of cancer by inducing angiogenesis and tumor growth. Although VASH2 has been recently reported to be involved in epithelial-mesenchymal transition (EMT), its precise roles are obscure. The aim of the present study was to clarify the role of VASH2 in the EMT of cancer cells in relation to transforming growth factor-ß (TGF-ß) signaling, which is a major stimulator of EMT. Decreased expression of VASH2 in ovarian cancer cells significantly repressed the expression of TGF-ß type I receptor, namely activin receptor-like kinase 5. Transforming growth factor-ß1-induced phosphorylation of Smad2 and Smad3 was markedly decreased in VASH2 knockdown cells while the expression of Smad2 and Smad3 was unchanged. Accordingly, the responses to TGF-ß1 shown by promoter assay and plasminogen activator inhibitor type 1 expression were significantly attenuated in VASH2 knockdown cells. Furthermore, knockdown of VASH2 in cancer cells abrogated the TGF-ß1-induced reduced expression of epithelial markers including E-cadherin, and the elevated expression of mesenchymal markers including fibronectin, ZEB2, and Snail2, suggesting that endogenous VASH2 is required for TGF-ß1-induced EMT. In accordance with these results, the effects of TGF-ß1 on cell morphology, migration, invasion, and MMP2 expression were also abrogated when VASH2 was knocked down. These results indicate that VASH2 played a significant role in the EMT by modulating the TGF-ß signaling. We propose that VASH2 would be a novel molecular target for the prevention of EMT in cancers.

Dual targeting of vascular endothelial growth factor and bone morphogenetic protein-9/10 impairs tumor growth through inhibition of angiogenesis.

Clinical development of anti-angiogenic agents has been a major landmark in cancer therapy for several types of cancers. Signals mediated by both vascular endothelial growth factor (VEGF) and bone morphogenetic protein (BMP)-9 and 10 have been implicated in tumor angiogenesis. However, previous studies have shown that targeting the individual signals was not sufficiently effective in retarding tumor growth in certain preclinical and clinical conditions. In the present study, we developed a novel decoy chimeric receptor that traps both VEGF and BMP-9/10. Single targeting of either VEGF or BMP-9/10 signals significantly reduced the formation of tumor vessels in a mouse xenograft model of human pancreatic cancer; however, it did not show significant therapeutic effects on tumor growth. In contrast, dual targeting of the angiogenic signals resulted in more significant inhibition of tumor angiogenesis, leading to delay of tumor growth. Our findings suggest that simultaneous blockade of VEGF and BMP-9/10 signals is a promising therapeutic strategy for the cancers that are resistant to anti-VEGF and BMP-9/10 therapies.

Roles of signaling and transcriptional networks in pathological lymphangiogenesis.

Lymphangiogenesis, the generation of new lymphatic vessels, plays important roles in cancer metastasis. Outstanding progress during the past decade has dramatically increased the novel knowledge and insights of the mechanisms underlying the generation of new lymphatic vessels, the roles of transcription factors and lymphangiogenic growth factors during physiological development and pathological processes such as cancer and inflammation. Furthermore, an understanding of the molecular consequences during tumor lymphangiogenesis has provided chances to develop better diagnostic and therapeutic approaches that aim to limit the progression of cancer. In this article, we will explain the current knowledge of how lymphatic function is altered in various pathological conditions including cancer progression.