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Purpose Although YAP1 and TAZ are believed to be equivalent downstream effectors of the Hippo pathway, differential expression of YAP1 or TAZ suggests distinct functions during cancer progression. The exact role of YAP1 and TAZ in esophageal cancer, the 6th leading cancer-related mortality in the world, remains elusive. Methods Following single or double manipulation of YAP1 or TAZ expression, we subjected these manipulated cells to proliferation, migration, invasion, and xenograft tumorigenesis assays. We used RT-qPCR and Western blotting to examine their expression in the manipulated cells with or without inhibition of transcription or translation. We also examined the impact of YAP1 or TAZ deregulation on clinical outcome of esophageal cancer patients from the TCGA database. Results We found that YAP1 functions as a tumor suppressor whereas TAZ exerts pro-tumor functions in esophageal cancer cells. We also found a significant increase in TAZ mRNA expression upon YAP1 depletion, but not vice versa, despite the downregulation of CTGF and CYR61, shared targets of YAP1 and TAZ, in xenografted tissue cells. In addition to transcriptional regulation, YAP1-mediated TAZ expression was found to occur via protein synthesis. Restored TAZ expression mitigated YAP1-mediated suppression of cellular behavior. By contrast, TAZ silencing reduced the promoting effect exerted by YAP1 depletion on cellular behaviors. The observed anti-tumor function of YAP1 was further supported by a better overall survival among esophageal cancer patients with a high YAP1 expression. Conclusion From our data we conclude that YAP1 functions as a suppressor and negatively regulates pro-tumor TAZ expression via transcriptional and translational control in esophageal cancer.

Purpose: Accumulating evidence indicates that factors secreted by cancer epithelial cells shape the tumor microenvironment to promote cancer invasion and metastasis. Recent studies also shed light on alterations of Rab small GTPase–mediated exocytosis in tumorigenesis. However, the mechanisms for Rab-mediated exocytosis in tumor microenvironment remain elusive. We aimed to investigate the interplay between Rab37-mediated exocytosis and tumor microenvironment, focusing on endothelial cell motility and angiogenesis.Experimental Design: We performed fluorescence IHC for Rab37, thrombospondin-1 (TSP1, an antiangiogenesis factor), and angiogenesis marker CD31 in 183 surgically resected esophageal squamous cell carcinoma (ESCC) patient samples. Cell migration, invasion, angiogenesis, and tumor metastasis were measured.Results: ESCC patients with low expression of Rab37 or TSP1 significantly correlated with high CD31 expression and were associated with worse progression-free survival. The multivariate Cox regression analysis showed that concordant low expression of both Rab37 and TSP1 was an independent prognostic factor of ESCC patients. Rab37-mediated exocytosis of TSP1 led to the inhibition of neovasculature in vitro and in vivo. Secreted TSP1 from cancer cells with Rab37 exocytic function inhibited the p-FAK/p-paxillin/p-ERK migration signaling in both cancer epithelial cells and their surrounding endothelial cells. Dysfunction of Rab37 or loss of TSP1 abrogated the suppressive effects on angiogenesis and metastasis.Conclusions: Our findings suggest that Rab37-mediated TSP1 secretion in cancer cells suppresses metastasis and angiogenesis via a cross-talk with endothelial cells and reveal a novel component of the vesicular exocytic machinery in tumor microenvironment and tumor progression. Dysregulation of Rab37/TSP1 axis has clinical implications for prognosis prediction. Clin Cancer Res; 23(9); 2335–45. ©2016 AACR.

Time-lapse movie of TIRF images of EV-CE81T cells expressing GFP-tagged TSP1.

Time-lapse movie of TIRF images of Rab37-CE81T cells expressing GFP-tagged TSP1.

Supplementary Materials, Figures 1-7, Table 1 from A Novel Sialyltransferase Inhibitor Suppresses FAK/Paxillin Signaling and Cancer Angiogenesis and Metastasis Pathways

Oral cancer is one of the most common cancers worldwide and ranks fourth for the mortality rate of cancers in males in Taiwan. The oral microbiota is the microbial community in the oral cavity, which is essential for maintaining oral health, but the relationship between oral tumorigenesis and the oral microbiota remains to be clarified. This study evaluated the effect of microbiome dysbiosis on oral carcinogenesis in mice, and the impact of the microbiome and its metabolic pathways on regulating oral carcinogenesis. We found that antibiotics treatment decreases carcinogen-induced oral epithelial malignant transformation. Microbiome analysis based on 16S rRNA gene sequencing revealed that the species richness of fecal specimens was significantly reduced in antibiotic-treated mice, while that in the salivary specimens was not decreased accordingly. Differences in bacterial composition, including

A Gram-stain-negative or -positive, strictly anaerobic, non-spore-forming and pleomorphic bacterium (designated 14-104T) was isolated from the saliva sample of a patient with oral squamous cell carcinoma. It was an acid-tolerant neutralophilic mesophile, growing at between 20 and 40 °C (with optimum growth at 30 °C) and pH between pH 3.0 and 7.0 (with optimum growth at pH 6.0–7.0). It contained anteiso-C15 : 0 and C15 : 0 as the major fatty acids. The genome size of strain 14-104T was 2.98 Mbp, and the G+C content was 39.6 mol%. It shared Phocaeicola abscessus CCUG 55929T. Reconstruction of phylogenetic and phylogenomic trees revealed that strain 14-104T and P. abscessus CCUG 55929T were clustered as a distinct clade without any other terminal node. The phylogenetic and phylogenomic analyses along with physiological and chemotaxonomic data indicated that strain 14-104T represents a novel species in the genus Phocaeicola , for which the name Phocaeicola oris sp. nov. is proposed. The type strain is 14-104T (=BCRC 81305T= NBRC 115041T).

Background: The malignant transformation of oral potentially malignant disorders (OPMDs) is a potential cause of oral cancers. However, epidemiological studies on malignant transformation of OPMDs are lacking. The present study is aimed to investigate the percentage of OPMD in the oral mucosal screening database and the malignant transformation (%) across different regions of Taiwan. Methods: We determined the cases of malignant transformation of OPMD to oral cancers during the 2-year follow-up by the oral mucosal screening database and the cancer registry database contained in the National Health Insurance Research Database. Patients with oral cancer history before OPMD diagnosis were excluded from the study. We collected data including clinical diagnosis, biopsy result, follow-up, and place of residence of the patient. The most widely used definition from the Council for Economic Planning and Development in Taiwan was used in this study for the classification into Southern, Northern, Eastern, and Western Taiwan regions. Differences in the malignant transformation (%) and ranking between regions were evaluated using analysis of variance test. Results: Chiayi city located in Southern Taiwan has the highest percentage of OPMD in oral screening citizen. The percentage of OPMD in the oral mucosal screening database was highest in Southern Taiwan and lowest in Eastern Taiwan; however, the malignant transformation (%) was highest in the Eastern Taiwan and lowest in Northern Taiwan. Conclusion: Dentists and otolaryngologists in Southern Taiwan, especially Chiayi city, should be cautious when screening the patient because of the high percentage of OPMD in oral mucosal screening database. The percentage of OPMD in the oral mucosal screening database and the malignant transformation (%) are different among the different regions in Taiwan. Further research is needed to clarify the reasons for the different malignant transformation (%) between regions.

Most oral squamous cell carcinoma (OSCC) tumors arise from oral premalignant lesions. Oral submucous fibrosis (OSF), usually occurring in male chewers of betel quid, is a premalignant stromal disease characterized by a high malignant transformation rate and high prevalence. Although a relationship between the inhabited microbiome and carcinogenesis has been proposed, no detailed information regarding the oral microbiome of patients with OSF exists; the changes of the salivary microbiome during cancer formation remain unclear. This study compared the salivary microbiomes of male patients with OSCC and a predisposing OSF background (OSCC-OSF group) and those with OSF only (OSF group). The results of high-throughput sequencing of the bacterial 16S rRNA gene indicated that OSF-related carcinogenesis and smoking status significantly contributed to phylogenetic composition variations in the salivary microbiome, leading to considerable reductions in species richness and phylogenetic diversity. The microbiome profile of OSF-related malignancy was associated with increased microbial stochastic fluctuation, which dominated the salivary microbiome assembly and caused species co-occurrence network collapse. Artificial intelligence selection algorithms consistently identified 5 key species in the OSCC-OSF group: Porphyromonas catoniae, Prevotella multisaccharivorax, Prevotella sp. HMT-300, Mitsuokella sp. HMT-131, and Treponema sp. HMT-927. Robust accuracy in predicting oral carcinogenesis was obtained with our exploratory and validation data sets. In functional analysis, the microbiome of the OSCC-OSF group had greater potential for S-adenosyl-l-methionine and norspermidine synthesis but lower potential for l-ornithine and pyrimidine deoxyribonucleotide synthesis and formaldehyde metabolism. These findings indicated that the salivary microbiome plays important roles in modulating microbial metabolites during oral carcinogenesis. In conclusion, our results provided new insights into salivary microbiome alterations during the malignant transformation of OSF.

We utilized the Longitudinal Health Insurance Database which was stemmed from the Taiwan's National Health Insurance Research Database to conduct a retrospective cohort study investigating the risk of becoming dialysis dependent after receiving intravitreal anti-vascular endothelial growth factor (VEGF) agents for retinal diseases. Patients newly receiving intravitreal ranibizumab or aflibercept from 2000 to 2017 for age-related macular degeneration, polypoidal choroidal vasculopathy, diabetic macular edema, retinal vein occlusions, or myopic choroid neovascularization were included as the study group, and patients with same retinal diseases but did not receive intravitreal anti-VEGFs served as controls extracted by age- and sex-matched (1:4) and further propensity score matching (PSM). Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the risk of dialysis. A cohort of 2447 anti-VEGF users and 2447 controls by PSM were evaluated. Higher dialysis risks were observed among patients newly receiving anti-VEGF agents compared to controls (adjusted HR: 1.849; 95% CI: 1.378-2.482) in the PSM cohort. For subgroup analysis, patients newly receiving anti-VEGF treatment for diabetic macular edema had significant risk (adjusted HR: 1.834; 95% CI: 1.448-2.324) of becoming dialysis-dependent, while patients in other subgroups demonstrated similar risks as the controls. In conclusion, intravitreal anti-VEGF agents might increase the risk of becoming dialysis-dependent, especially in patients who are treated for diabetic macular edema.

Long non-coding RNAs (lncRNAs), encoding noncoding transcripts greater than 200 nucleotides, are multifunctional regulator of gene expression and play vital roles in various biological processes. Urothelial cancer-associated 1 (UCA1) is one such molecule and found to be dysregulated in the development of several cancer types, including those in bladder, colon, stomach, lung and breast. One previous study showed that an upregulation of UCA1 expression profile in hypopharyngeal cancer tissues relative to their adjacent normal counterparts significantly negated overall survival among these cancer patients. However, the molecular mechanism whereby UCA1 played any role in HPC, a subtype of head and neck cancer and often detected in advanced stages, remains elusive. In this report, we showed that ectopic UCA1 expression promoted cell migration and invasion while reducing cell proliferation. The increase of migration and invasion was accompanied by partial epithelial mesenchymal transition. By contrast, UCA1 depletion had the opposite effect. In addition to the presence of UCA1 in the culture medium (CM) and a stimulatory effect of CM derived from UCA1-OE cells on cell migration and invasion, we found a predominant nuclear localization of UCA1 in HPC cells. PTBP3, a RNA-binding protein, was identified as a novel interacting partner of UCA1 by RNA pulldown and mass spectrometry. PTBP3 silencing significantly reduced UCA1 mRNA expression, suggesting a regulatory role in UCA1 stability. While mapping the interacting domains between UCA1 and PTBP3, we are also in the process of identifying the involvement of UCA1-PTBP3 axis in hypopharyngeal carcinogenesis. We hope to validate if UCA1 can serve as a novel therapeutic target against or diagnostic marker for hypopharyngeal cancer. Citation Format: Li-Wha Wu. The cell- and non-cell autonomous actions of UCA1 dysregulation in hypopharyngeal cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3754.

Oral cancer is one of the leading causes of cancer death, which are mostly preceded by oral potentially malignant disorders (OPMDs). Taiwanese government launched a free oral cancer screening program. The aim of this study was to analyze the malignant transformation rate of OPMDs. This study was based on national-wide oral screening databases. 3,362,232 people were enrolled. Patients clinically diagnosed with leukoplakia, erythroplakia, oral submucosal fibrosis (OSF), oral verrucous hyperplasia (OVH), and oral lichen planus (OLP), from 2010 to 2013, were identified. We followed up OPMD patients in cancer registry databases to analyze the malignant transformation rate. The malignant transformation rates from the highest to the lowest were: OVH > OSF > erythroplakia > OLP > leukoplakia. The malignant transformation rate was 24.55, 12.76, 9.75, 4.23, and 0.60 per 1000 person-years in the OVH, OSF, erythroplakia, leukoplakia, and comparison cohort. The hazard ratio was 8.19 times higher in the OPMD group compared with comparison cohort group, after age and habit adjustment. Female patients with OPMDs had a high risk of malignant transformation. Nationwide screening is very important for early diagnosis. OVH had the highest malignant transformation possibility. Female OPMD patients are a rare but have a relatively high malignant transformation rate.

Background: The association between microbiome and host disease has been documented in oral cancer, one of the leading cancers worldwide. Huge efforts are made to use the profile of oral microbiome and distinct signature species as markers to distinguish oral cancer patients from healthy individuals. The previous results, however, remain inconclusive. The assembly mechanisms of oral microbiome and their response to changes in oral carcinogenesis also have not been characterized. Here, using 16S rRNA gene amplicon sequencing and in-silico function prediction approaches, we analyzed the saliva microbiome in cohorts of orally healthy, oral verrucous hyperplasia, and oral cancer at taxon and function levels, and compared their corresponding predictive performance of oral cancer using machine learning algorithms.Results: Analyses of diversity and phylogenetic profiles of bacterial communities in saliva showed that microbiome dysbiosis was significantly linked to oral health status. As oral health deteriorated, the number of core species (>75% prevalence) as a percentage of overall species richness declined. In line with the null model-based analysis, taxonomic and functional assemblies of saliva microbiomes were primarily governed by the stochastic processes. Correspondingly, the quantitative assessment of partitioned beta-diversity suggested extremely high species turnover but low function turnover, revealing a functional redundancy of the oral ecosystem. Functional beta-diversity in salvia microbiome shifted from turnover to nestedness during carcinogenesis of oral verrucous hyperplasia, but this pattern was not observed at the taxon level. Moreover, using both taxon and function data as training features for machine learning-aided prediction on host health status supports a superior predictive performance when using functional profiling. Similar results were also obtained and validated using publicly accessible data.Conclusions: Our results suggest that altered oral bacterial communities are highly associated with carcinogenesis of oral verrucous hyperplasia. Partly owing to high taxonomic turnover and stochastic assembly processes of the oral ecosystem, discovering oral microbial consortia as universal biomarkers for oral cancer may prove difficult and arduous. Functional profiles are relatively stable and evolve a nestedness pattern during oral carcinogenesis, serving as a new benchmark to study the interplay of the oral microbiome and host health in the future.

Background Deep burn wounds have a high tendency to form hypertrophic scars. Previously, we found that angiogenin promoted neovascularization during deep burn wound healing. However, the association between angiogenin and scar formation is unclear. Methods We obtained human burn scar tissues from patients who underwent scar surgery and examined the role of angiogenin in scar tissues and determined its effects in scar fibroblasts and on transforming growth factor β1 (TGF-β1) secretion. Results Our results showed an inverse correlation between angiogenin expression and scar severity. Next, we examined the effects of angiogenin in scar fibroblasts. We found that angiogenin was persistently expressed in human scar fibroblasts and that angiogenin expression significantly increased with time in the culture medium of scar fibroblasts. Treatment of scar fibroblasts with recombinant angiogenin significantly decreased their proliferation and TGF-β1 secretion. Moreover, angiogenin inhibited TGF-β1-mediated Smad2 signaling pathway. Conclusion Our data suggest a negative role of angiogenin in fibroblast proliferation via TGF-β1-mediated Smad2 signaling pathway.

BACKGROUND Burn blister fluid contains several angiogenic factors to promote wound neovascularization. In our previous study, we found that deep partial-thickness burn (DPTB) wounds showed higher expression levels of angiogenin to enhance vascularization compared with superficial partial-thickness burn wounds. Neovascularization is a complex process that involves an interaction between circulating angiogenic cells and mediators. We hypothesized that in addition to angiogenic factors burn blisters may contain specific cell types. The aim of the present study was to characterize the specific cells present in burn blisters. METHODS Twenty-four burn blister fluid samples were obtained with informed consent from patients with superficial partial-thickness burn (n = 16) or DPTB (n = 8) wounds. Blister cells were isolated from individual intact blisters and characterized with flow cytometry analysis using CD14, CD34, vascular endothelial growth factor receptor 2, and CD133 markers. CD14 and CD34 blister cells were also isolated using a magnetic-activated cell sorting system to examine their potential for endothelial differentiation. Angiogenin levels in the burn blister fluids were evaluated with enzyme-linked immunosorbent assay. RESULTS CD14 cells were the most highly represented cell type in the burn fluids of both groups, although a significantly greater percentage of CD14 cells were observed in DPTB fluids. CD14 blister cells had a higher potency to differentiate into functional endothelial cells as compared with CD34 cells. The proportion of CD14 cells gradually increased after burn injury. In contrast to CD14 cells, angiogenin showed the highest expression levels at day 1 postburn. With regard to burn wound neovascularization, angiogenin expression was partially correlated with CD14 blister cells in the burn fluids. CONCLUSIONS We provide the first report on the characterization of blister cells in burn fluids. Our data suggest that CD14 blister cells may play a role in burn wound neovascularization. Measurement of CD14 blister cells serves as a possible tool for assessing burn wound status.

Purpose: Accumulating evidence indicates that factors secreted by cancer epithelial cells shape the tumor microenvironment to promote cancer invasion and metastasis. Recent studies also shed light on alterations of Rab small GTPase–mediated exocytosis in tumorigenesis. However, the mechanisms for Rab-mediated exocytosis in tumor microenvironment remain elusive. We aimed to investigate the interplay between Rab37-mediated exocytosis and tumor microenvironment, focusing on endothelial cell motility and angiogenesis. Experimental Design: We performed fluorescence IHC for Rab37, thrombospondin-1 (TSP1, an antiangiogenesis factor), and angiogenesis marker CD31 in 183 surgically resected esophageal squamous cell carcinoma (ESCC) patient samples. Cell migration, invasion, angiogenesis, and tumor metastasis were measured. Results: ESCC patients with low expression of Rab37 or TSP1 significantly correlated with high CD31 expression and were associated with worse progression-free survival. The multivariate Cox regression analysis showed that concordant low expression of both Rab37 and TSP1 was an independent prognostic factor of ESCC patients. Rab37-mediated exocytosis of TSP1 led to the inhibition of neovasculature in vitro and in vivo. Secreted TSP1 from cancer cells with Rab37 exocytic function inhibited the p-FAK/p-paxillin/p-ERK migration signaling in both cancer epithelial cells and their surrounding endothelial cells. Dysfunction of Rab37 or loss of TSP1 abrogated the suppressive effects on angiogenesis and metastasis. Conclusions: Our findings suggest that Rab37-mediated TSP1 secretion in cancer cells suppresses metastasis and angiogenesis via a cross-talk with endothelial cells and reveal a novel component of the vesicular exocytic machinery in tumor microenvironment and tumor progression. Dysregulation of Rab37/TSP1 axis has clinical implications for prognosis prediction. Clin Cancer Res; 23(9); 2335–45. ©2016 AACR.

Ethnopharmacological relevance The Chinese herbal medicine Qing-Dai (also known as Indigo naturalis) extracted from indigo-bearing plants including Baphicacanthus cusia (Ness) Bremek was previously reported to exhibit anti-psoriatic effects in topical treatment. TH17 was later established as a key player in the pathogenesis of psoriasis. We investigated the anti-TH17 effect of Indigo naturalis and its active compounds. The aim of this study is to evaluate the toxicity of Indigo naturalis (IN) and its derivatives on five cell types involved in psoriasis, and to study the anti-inflammatory mechanism for the toxicity. Materials and methods Following the fingerprint and quantity analysis of indirubin, indigo, and tryptanthrin in IN extract, we used MTS kits to measure the anti-proliferative effect of IN and three active compounds on five different cell types identified in psoriatic lesions. Quantitative RT-PCR analysis was used to measure the expression of various genes identified in the activated keratinocytes and TH17 polarized gene expression in RORγt-expressing T cells. Results We showed that IN differentially inhibited the proliferation of keratinocytes and endothelial cells but not monocytes, fibroblasts nor Jurkat T cells. Among three active compounds identified in IN, tryptanthrin was the most potent compound to reduce their proliferation. In addition to differentially reducing IL6 and IL8 expression, both IN and tryptanthrin also potently decreased the expression of anti-microbial S100A9 peptide, CCL20 chemokine, IL1B and TNFA cytokines, independent of NF-κB-p65-activation. Their attenuating effect was also detected on the expression of signature cytokines or chemokines induced during RORγT-induced TH17 polarization. Conclusions We were the first to confirm a direct anti-TH17 effect of both IN herbal extract and tryptanthrin.

Tumor growth is angiogenesis dependent. Angiogenic switch (the acquisition of an angiogenic phenotype) is essential for cervical carcinogenesis. Thrombospondin-1 (TSP-1) is an endogenous angiogenic inhibitor with multiple functional domains and interacting receptors. The disruption of TSP-1 fence (the expression in basal epithelia) occurred concordantly during the transition from low-grade squamous intraepithelial lesion into high-grade squamous intraepithelial lesion. This concordance suggests that TSP-1 plays a role in the regulation of angiogenic switch during cervical carcinogenesis. Tumor vasculature as a therapeutic target offers a paradigm shift for anticancer therapy. Endothelial cells do not appear to acquire resistance during antiangiogenic therapy. Low-and-frequent dose “metronic” chemotherapy is found to be antiangiogenic, which is more effective in targeting tumor endothelia than traditional large, single bolus doses. Meanwhile, the invasion process of cancers is associated with stroma reaction, which is characterized by fibroblasts' activation. In addition to the well-known angiogenesis inhibitor, TSP-1 also has a novel role of blocking activated fibroblasts (myofibroblasts) from invading cancer. Activated fibroblasts during stroma reaction could be used as an efficient drug delivery system to prevent or slow the local growth of cancer cells. Elucidation of the mechanism by which fibroblasts are recruited into cancer stroma could lead to new insights into not only the mechanisms of cancer progression but also strategies for cancer treatment. A better understanding of stromal contributions to cancer progression will likely result in the identification of new therapeutics targeting the stroma.

Oral cancer, a subtype of head and neck cancer, is characterized by increased infiltrating regulatory T cells (Treg); however, the pathological significance of the increase in Tregs in disease prognosis and progression and their underlying mechanism remain unestablished. C‐C motif chemokine ligand 22 (CCL22) has been implicated in the recruitment of Tregs. We used RT‐qPCR to determine CCL22 mRNA expression in clinical specimens and cultured cells. Loss‐of‐function and gain‐of‐function studies were carried out to analyze the effects of CCL22 modulations on cell proliferation, migration, invasion, and tumorigenesis and the mechanism involved in the deregulation of CCL22. In oral cancer specimens, CCL22 mRNA was upregulated. The increase was not only associated with reduced disease‐free survival but also strongly correlated with an increase in FOXP3 mRNA, a master regulator of Treg development and functions. Silencing CCL22 expression reduced cell proliferation, migration, and invasion, whereas ectopic overexpression showed opposite effects. Manipulation of CCL22 expression in cancer cells altered tumorigenesis in both immune‐compromised and ‐competent mice, supporting both autonomous and non‐autonomous actions of CCL22. Release of interleukin 1β (IL‐1β) from cancer‐associated fibroblasts (CAF) induces CCL22 mRNA expression in oral cancer cells by activating transcription factor nuclear factor kappa B (NF‐κB). Our data support a model in which CAF‐derived IL‐1β, CCL22, and its receptor CCR4 foster a protumor environment by promoting cell transformation and Treg infiltration. Intervention of the IL‐1β‐CCL22‐CCR4 signaling axis may offer a novel therapeutic strategy for oral cancer treatment.

The S100A2 protein is an important regulator of keratinocyte differentiation, but its role in wound healing remains unknown. We establish epithelial-specific S100A2 transgenic (TG) mice and study its role in wound repair using punch biopsy wounding assays. In line with the observed increase in proliferation and migration of S100A2-depleted human keratinocytes, mice expressing human S100A2 exhibit delayed cutaneous wound repair. This was accompanied by the reduction of re-epithelialization as well as a slow, attenuated response of Mcp1, Il6, Il1β, Cox2, and Tnf mRNA expression in the early phase. We also observed delayed Vegfa mRNA induction, a delayed enhancement of the Tgfβ1-mediated alpha smooth muscle actin (α-Sma) axis and a differential expression of collagen type 1 and 3. The stress-activated p53 tumor suppressor protein plays an important role in cutaneous wound healing and is an S100A2 inducer. Notably, S100A2 complexes with p53, potentiates p53-mediated transcription and increases p53 expression both transcriptionally and posttranscriptionally. Consistent with a role of p53 in repressing NF-κB-mediated transcriptional activation, S100A2 enhanced p53-mediated promoter suppression of Cox2, an early inducible NF-κB target gene upon wound injury. Our study thus supports a model in which the p53-S100A2 positive feedback loop regulates wound repair process.

S100A9 is a calcium-binding protein with two EF-hands and frequently deregulated in several cancer types, however, with no clear role in oral cancer. In this report, the expression of S100A9 in cancer and adjacent tissues from 79 early-stage oral cancer patients was detected by immunohistochemical staining. Although S100A9 protein was present in both tumor and stromal cells, only the early-stage oral cancer patients with high stromal expression had reduced recurrence-free survival. High stromal S100A9 expression was also significantly associated with non-well differentiation and recurrence. In addition to increasing cell migration and invasion, ectopic S100A9 expression in tumor cells promoted xenograft tumorigenesis as well as the dominant expression of myeloid cell markers and pro-inflammatory IL-6. The expression of S100A9 in one stromal component, monocytes, stimulated the aggressiveness of co-cultured oral cancer cells. We also detected the elevation of serum S100A9 levels in early-stage oral cancer patients of a separate cohort of 73 oral cancer patients. The release of S100A9 protein into extracellular milieu enhanced tumor cell invasion, transendothelial monocyte migration and angiogenic activity. S100A9-mediated release of IL-6 requires the crosstalk of tumor cells with monocytes through the activation of NF-κB and STAT-3. Early-stage oral cancer patients with both high S100A9 expression and high CD68+ immune infiltrates in stroma had shortest recurrence-free survival, suggesting the use of both S100A9 and CD68 as poor prognostic markers for oral cancer. Together, both intracellular and extracellular S100A9 exerts a tumor-promoting action through the activation of oral cancer cells and their associated stroma in oral carcinogenesis.

Growth differentiation factor-10 (GDF10), commonly referred as BMP3b, is a member of the transforming growth factor-β (TGF-β) superfamily. GDF10/BMP3b has been considered as a tumor suppressor, however, little is known about the molecular mechanism of its roles in tumor suppression in oral cancer. Clinical significance of GDF10 downregulation in oral squamous cell carcinoma (OSCC) was evaluated using three independent cohorts of OSCC patients. The molecular mechanisms of GDF10 in the suppression of cell survival, cell migration/invasion and epithelial-mesenchymal transition (EMT) were investigated by using oral cancer cell lines. The present study shows that GDF10 is downregulated during oral carcinogenesis, and GDF10 expression is also an independent risk factor for overall survival of OSCC patients. Overexpression of GDF10 attenuates cell proliferation, transformation, migration/invasion, and EMT. GDF10-inhibited EMT is mediated by ERK signaling but not by typical TGF-β signaling. In addition, overexpression of GDF10 promotes DNA damage-induced apoptosis and sensitizes the response to all-trans retinoic acid (ATRA) and camptothecin (CPT). Intriguingly, the expression of GDF10 is induced by type III TGF-β receptor (TGFBR3) through TGF-β-SMAD2/3 signaling. Our findings suggest that TGFBR3 is an upstream activator of GDF10 expression and they share the same signaling to inhibit EMT and migration/invasion. These results support that GDF10 acts as a hinge to collaborate with TGFBR3 in the transition of EMT-MET program. Taken together, we illustrated the clinical significance and the molecular mechanisms of tumor-suppressive GDF10 in OSCC.

Inflammation promotes regeneration of injured tissues through poorly understood mechanisms, some of which involve interleukin (IL)-6 family members, the expression of which is elevated in many diseases including inflammatory bowel diseases and colorectal cancer. Here we show in mice and human cells that gp130, a co-receptor for IL-6 cytokines, triggers activation of YAP and Notch, transcriptional regulators that control tissue growth and regeneration, independently of the gp130 effector STAT3. Through YAP and Notch, intestinal gp130 signalling stimulates epithelial cell proliferation, causes aberrant differentiation and confers resistance to mucosal erosion. gp130 associates with the related tyrosine kinases Src and Yes, which are activated on receptor engagement to phosphorylate YAP and induce its stabilization and nuclear translocation. This signalling module is strongly activated upon mucosal injury to promote healing and maintain barrier function.

Rationale: The contribution of bone marrow–borne hematopoietic cells to the ischemic myocardium has been documented. However, a pivotal study reported no evidence of myocardial regeneration from hematopoietic-derived cells. The study did not take into account the possible effect of early injury–induced signaling as the test mice were parabiotically paired to partners immediately after surgery-induced myocardial injury when cross-circulation has not yet developed. Objective: To re-evaluate the role of circulating cells in the injured myocardium. Methods and Results: By combining pulse-chase labeling and parabiosis model, we show that circulating cells derived from the parabiont expressed cardiac-specific markers in the injured myocardium. Genetic fate mapping also revealed that circulating hematopoietic cells acquired cardiac cell fate by means of cell fusion and transdifferentiation. Conclusions: These results suggest that circulating cells participate in cardiomyocyte regeneration in a mouse model of parabiosis when the circulatory system is fully developed before surgery-induced heart injury.

Oral cancer, a subtype of head and neck cancer, has been the 4th leading cause of male cancer death in Taiwan for the past decade. Smoking, alcohol consumption, and betel quid chewing are major risk factors for oral cancer in Taiwan. The crosstalk between immunity and cancer cells can both inhibit and enhance tumor growth and is now classified as a cancer hallmark. The accumulation of regulatory T cells (Tregs) in several tumor types potentially plays a critical role in tumor evasion of immune surveillance. Oral cancer is also characterized by an increase in the number of infiltrating Tregs; however, the significance of the increase on the patient prognosis remains controversial. We found that the expression of CCL22, a chemokine for Treg recruitment, was not only positively with poor prognosis in oral cancer patients but also significantly correlated with that of FOXP3, a master regulator for Treg development and functions, in the same patients. The correlation is also validated in TCGA database analysis of head and neck cancer patients. The depletion of CCL22 expression reduced oral cancer cell proliferation, migration and invasion, suggesting an oncogenic role of CCL22 in oral cancer. Since CCR4 is the receptor for CCL22, we studied the in vitro and in vivo impact of deregulated CCL22-CCR4 signaling axis in oral carcinogenesis. We first confirmed the surface expression of CCR4 in oral cancer cells by flow cytometry. Ectopic CCL22 overexpression increased oral cancer cell migration and invasion without the effect on proliferation. Through injection of CCL22-altered oral cancer cells in both syngeneic and athymic backgrounds, the cell autonomous and non-autonomous actions of CCL22 and the mechanism responsible for the CCL22 deregulation in oral cancer will be discussed. This study will not only further the role of CCL22-CCR4 signaling axis in modulating the crosstalk between oral cancer and its microenvironment but also provide a novel therapeutic strategy for treating oral cancer. Citation Format: Li-Wha Wu. Cell autonomous and non-autonomous actions of CCL22 in oral carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5167.

Osteoarthritis (OA) is a degenerative joint disease characterized by progressive destruction of articular cartilage. Interleukin (IL)-20 is a proinflammatory cytokine involved in the pathogenesis of rheumatoid arthritis. We investigated the role of IL-20 in OA and evaluated whether anti-IL-20 antibody (7E) treatment attenuates disease severity in murine models of surgery-induced OA. Immunohistochemical staining was used to detect IL-20 and its receptors expression in synovial tissue and cartilage from OA patients, and in OA synovial fibroblasts (OASFs) and chondrocytes (OACCs) from rodents with surgery-induced OA. RTQ-PCR and western blotting were used to determine IL-20-regulated OA-associated gene expression in OASFs and OACCs. OA rats and OA mice were treated with 7E. Arthritis severity was determined based on the degree of cartilage damage and the arthritis severity score. We found that IL-20 and its receptors were expressed in OASFs and OACCs. IL-20 induced TNF-α, IL-1β, MMP-1, and MMP-13 expression by activating ERK-1/2 and JNK signals in OASFs. IL-20 not only upregulated MCP-1, IL-6, MMP-1, and MMP-13 expression, but also downregulated aggrecan, type 2 collagen, TGF-β, and BMP-2 expression in OACCs. Arthritis severity was significantly lower in 7E-treated OA rats, and 7E- or MSC-treated OA mice. Therefore, we concluded that IL-20 was involved in the progression and development of OA through inducing proinflammatory cytokines and OA-associated gene expression in OASFs and OACCs. 7E reduced the severity of arthritis in murine models of surgery-induced OA. Our findings provide evidence that IL-20 is a novel target and that 7E is a potential therapeutic agent for OA.

// Yi-Zih Kuo 1 , Wei-Yu Fang 1 , Cheng-Chih Huang 2 , Sen-Tien Tsai 2, 3 , Yi-Ching Wang 4 , Chih-Li Yang 5 , Li-Wha Wu 1, 5, 6 1 Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan, R.O.C 2 Department of Otolaryngology, National Cheng Kung University Hospital, Tainan 70428, Taiwan, R.O.C 3 Department of Radiation Oncology, National Cheng Kung University Hospital, Tainan 70428, Taiwan, R.O.C 4 Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan, R.O.C 5 Institute of Molecular Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan, R.O.C 6 Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, R.O.C. Correspondence to: Li-Wha Wu, email: liwhawu@mail.ncku.edu.tw Sen-Tien Tsai, email: T602511@mail.ncku.edu.tw Keywords: hyaluronan, HAS3, oral cancer, TNF-α, MCP-1 Received: July 20, 2016 Accepted: December 27, 2016 Published: January 17, 2017 ABSTRACT Hyaluronan (HA) is a major extracellular matrix component. However, its role and mediation in oral cancer remains elusive. Hyaluronan synthase 3 (HAS3), involved in pro-inflammatory short chain HA synthesis, was the predominant synthase in oral cancer cells and tissues. HAS3 overexpression significantly increased oral cancer cell migration, invasion and xenograft tumorigenesis accompanied with the increased expression of tumor necrosis factor alpha (TNF-α) and monocyte chemoattractant protein 1 (MCP-1). Conversely, HAS3 depletion abrogated HAS3-mediated stimulation. HAS3 induced oncogenic actions partly through activating EGFR-SRC signaling. HAS3-derived HA release into extracellular milieu enhanced transendothelial monocyte migration and MCP-1 expression, which was attenuated by anti-HAS3 antibodies or a HAS inhibitor, 4-Methylumbelliferone (4-MU). The NF-κB-binding site III at -1692 to -1682 bp upstream from the transcript 1 start site in HAS3 proximal promoter was the most responsive to TNF-α-stimulated transcription. ChIP-qPCR analysis confirmed the highest NF-κB-p65 enrichment on site III. Increased HAS3 mRNA expression was negatively correlated with the overall survival of oral cancer patients. A concomitant increase of TNF-α, a stimulus for HAS3 expression, with HAS3 expression was not only associated with lymph node metastasis but also negated clinical outcome. Together, HAS3 and TNF-α formed an inter-regulation loop to enhance tumorigenesis in oral cancer.

A missense mutation from arginine to tryptophan at residue 849 in the kinase domain of Tie2 (Tie2-R849W) is commonly identified in familial venous malformations. The mechanistic action of Tie2-R849W variant expression on angiogenic cascades including smooth muscle cell recruitment, however, remains elusive. To avoid confounding factors from endogenous Tie2 expression, Tie2-depleted endothelial cells (ECs) were used to study the effects of ectopic shRNA-resistant Tie2 variant expression, Tie2-WT* and Tie2-R849W*, on vascular cell proliferation, migration, tube formation, and smooth muscle cell (SMC) recruitment. Tie2-R849W* induced STAT1 phosphorylation at Tyr701. Tie2-R849W*-expressing cells had reduced ability to migrate and form tubes on Matrigel than their wildtype counterparts. STAT1 phosphorylation attenuated VEGF-A-induced STAT3 tyrosine phosphorylation in Tie2-R849W*-expressing HUVECs. The induced STAT1 activation also decreased VEGF-A-induced bFGF mRNA expression by competing with activated STAT3 for a direct binding to the consensus STAT-binding site at positions -997 to -989 bp from transcription start site in the bFGF promoter. Depleting STAT1 expression rescued the inability of Tie2-R849W expression to mediate angiogenesis. Moreover, bFGF neutralization or constitutive STAT1 activation, reminiscence of Tie2-R849W* expression, suppressed the smooth muscle cell recruiting ability of endothelial conditioned medium. This work reveals an anti-angiogenic role of STAT1 activation that acts in Tie2-R849W-expressing ECs to impair VEGF-A-mediated STAT3 signaling, bFGF production, and smooth muscle cell recruitment. A balancing activity of STAT1 and STAT3 may be important for Tie2-mediated vascular homeostasis.

Deep partial thickness burn (DPTB) wound fluids have a greater propensity for establishing neovascularization than did superficial partial thickness burn (SPTB) wound fluids in our previous study. To investigate the factors responsible for this activity, cytokine array and enzyme-linked immunosorbent assay were used to perform an expression analysis of angiogenic factors in burn fluid. Although present in approximately equal amounts in both SPTB and DPTB blister fluids from burn patients, angiogenin does appear to be involved in the ability of DPTB blister fluid to promote neovascularization in vitro and in vivo. Angiogenin alone was sufficient to induce endothelial differentiation of circulating angiogenic cells (CAC) without vascular endothelial growth factor A involvement. In addition, angiogenin was positively associated with CAC differentiation in the burn blister fluid. Blocking the effect of angiogenin in burn blister fluids resulted in a significant reduction of endothelial cell proliferation, CAC differentiation, and new blood vessels formation in vivo. Moreover, immunohistochemistry revealed that high angiogenin expression colocalizes with high vascularity in human burn wounds at day 7, further supporting our hypothesis that angiogenin is involved in burn wound neovascularization.

Increased sialyltransferase (ST) activity promotes cancer cell metastasis, and overexpression of cell surface sialic acid correlates with poor prognosis in cancer patients. To seek therapies targeting metastasis for cancer treatment, we developed a novel ST inhibitor, Lith-O-Asp, and investigated its antimetastatic and antiangiogenic effects and mechanisms. We found that cells treated with Lith-O-Asp showed a reduction of activity on various ST enzymes by in vitro and cell-based activity analyses. Lith-O-Asp inhibited migration and invasion abilities in various cancer cell lines and showed inhibitory effect on the angiogenic activity of human umbilical vein endothelial cells. Indeed, Lith-O-Asp treatment consequently delayed cancer cell metastasis in experimental and spontaneous metastasis assays in animal models. Importantly, Lith-O-Asp decreased the sialic acid modification of integrin-β1 and inhibited the expression of phospho-FAK, phospho-paxillin, and the matrix metalloprotease (MMP) 2 and MMP9. Lith-O-Asp attenuated the Rho GTPase activity leading to actin dynamic impairment. In addition, 2DE-MS/MS and immunoblotting analyses showed that Lith-O-Asp altered the protein expression level and phosphorylation status of various proteins involved in crucial metastasis and angiogenesis pathways such as vimentin and ribonuclease/angiogenin inhibitor RNH1. Furthermore, Lith-O-Asp treatment significantly inhibited the invasive ability exerted by ectopic overexpression of various ST enzymes catalyzing α-2,6- or α-2,3-sialylation. Our results provide compelling evidence that the potential pan-ST inhibitor, Lith-O-Asp, suppressed cancer cell metastasis likely by inhibiting FAK/paxillin signaling and expressing antiangiogenesis factors. Lith-O-Asp is worthy for further testing as a novel antimetastasis drug for cancer treatment. Cancer Res; 71(2); 473–83. ©2011 AACR.

Oral Diseases (2011) 17, 283–290 Objective: S100A2, a Ca2+ -binding protein with two EF-hands, is a tumor suppressor in oral cancer. Helix III flanking the C-terminal EF-hand is implicated to participate in the interaction of S100A2 and its target(s). The aim of this study was to examine if the coding sequence polymorphism S100A2_185G>A, leading to the peptide 62 substitution of asparagine (AAC, A allele) for serine (AGC, G allele) in helix III, had modulation effects on S100A-mediated tumor suppression. Subjects and Methods: We sequenced the coding sequence of S100A2 gene in normal oral keratinocytes (NOKs), dysplastic oral keratinocytes (DOKs), eight oral cancer lines, and 54 pairwise oral cancer specimens. We also compared the in vitro anti-tumor effect of wildtype (G allele) and variant (A allele) S100A2 expression using cell proliferation, migration, invasion, and colony formation assays. Results: With the exception of CAL27 and SCC-15 cancer lines being heterozygotes of A and G alleles, the remaining oral cells were homozygotic in G alleles. No alterations of anti-growth, anti-migration, anti-invasion, and anti-colony formation were observed between variant and wildtype cells. Moreover, no minor S100A2_185A allele was detected in 54-pairwise clinical specimens. Conclusion: The coding sequence polymorphism S100A2_185G>A had no regulatory role in S100A2-mediated tumor suppression in oral cancer.

Upper aerodigestive track cancer (UATC) including oral and esophageal cancer is the 3rd leading cause of cancer death in the world. Most of these patients demonstrate compromised immunity systems. Myeloid-derived suppressor cells (MDSCs), a population of cells exerting immunosuppressive effects, can sustain cancer progression by providing a pro-tumor microenvironment through the enhancement of T-cell suppressive factors like arginase 1 (ARG1). MDSCs can subsequently facilitate the development of immunosuppressive regulatory T cells (Tregs). Tumor-associated macrophages (TAMs) produce multiple inflammation modulators and are other key players in tumor microenvironment and divided into M1 and M2 phenotypes with specific expression of different cytokines in each type. Several S100 proteins are recently shown to participate in tumor promotion or suppression through both autocrine and least known receptor-mediated paracrine release. RAGE and TLR4, frequently expressed on immune cells, are two known receptors for S100 proteins. Among many S100 proteins, we previously showed a tumor suppressor role of S100A2 in oral cancer. Whether S100A2 functions as a tumor suppressor in mice and plays any role in regulating these immune cell populations during upper aerodigestive track carcinogenesis remains elusive. Due to lack of S100A2 expression in mice, epithelial-specific human S100A2 transgenic mice and their wildtype littermates were used for tumor induction in upper areodigestive track by the co-treatment of 4NQO and arecoline. Epithelial S100A2 significantly repressed tumor formation in esophagus. To understand the involvement of immune cell recruitment in these mice, flow cytometry and qRT-PCR analyses were used. Among the key molecules associated with MDSCs, Tregs and TAMs, S100A2 preferentially induced tumor macrophage polarization to M1 phenotype with a marginal decrease of Tregs recruitment at 7 month post tumor induction. Together, epithelial S100A2 exerts anti-tumor effect in part through differential impact on immune cell recruitment although more studies are needed to underscore the action mechanism. Citation Format: Li-Wha Wu. Epithelial S100A2 reduced upper aerodigestive track carcinogenesis by immunomodulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3085.

The success of using glycolytic inhibitors for cancer treatment depends on studying the individual role of frequently deregulated glycolytic genes in cancer. This report aims to study the prognostic implication, and determine the cellular role and action mechanism of glycolytic ENO1 overexpression in head and neck cancer. The relationship of ENO1 mRNA expression in 44-pair clinical specimens with patient clinicopathologic characteristics was analysed by semi-quantitative RT-PCR, Kaplan–Meier survival curve and Cox model analyses. Following ectopic ENO1 expression or knockdown, we studied the proliferative, migratory, invasive, colony-forming and tumourigenic abilities of ENO1 -genetically altered cells. DNA microarray analysis was used to identify downstream targets responsible for the ENO1 action in the cells. The expression of ENO1 mRNA was increased in 68% of tumour (T) specimens when compared to their normal (N) counterparts, and positively associated with clinical progression ( p ENO1 expression (T/N ⩾ 2) was frequently observed in the patients with large primary tumours, late clinical stages or advanced neck metastasis. Moreover, high ENO1 patients had significantly poorer clinical outcomes than low expressers (T/N ENO1 expression stimulated cell transformation, invasion and tongue tumour formation. ENO1 knockdown abrogated the stimulation. Suppression of ENO1 -induced proinflammatory CCL20 chemokine expression significantly attenuated its stimulatory effects on cell transformation and invasion. A concordant expression of ENO1 and CCL20 was validated both in ENO1 -expresing cells and in clinical specimens. Together, we demonstrate a prognostic role of ENO1 overexpression in head and neck cancer and ENO1 -mediated promotion of cell transformation and invasion partly via induced CCL20 expression.

The effect of burn blister fluid in neovascularization during burn wound healing is unknown. Burn blister fluid, containing a large amount of chemokines, is thought to play a role in the early stage of neovascularization. This process includes angiogenesis and vasculogenesis. Because of different healing time of burn wounds, we hypothesized that neovascularization in superficial partial thickness burn (SPTB) and deep partial thickness burn (DPTB) wounds were different. The neovasculogenic effects of two different burn blister fluids were also different. We found Day 7 DPTB wounds had a significant increase in blood vessels compared with SPTB wounds by immunohistochemistry. DPTB blister fluid significantly promoted neovascularization via increasing endothelial cell proliferation, and migration and differentiation of circulating angiogenic cells relative to SPTB blister fluids. In the animal study, DPTB blister fluids markedly promoted new blood vessel formation compared with those from SPTB blister fluids using in vivo Matrigel plug assay. These results suggest that DPTB wounds require more new vessel formation than SPTB. Furthermore, the measurement of angiogenic activities in burn blister fluids serves as a possible tool for assessing burn wound status.

This study reports a novel cell co-culture technique using micro-molding in capillaries (MIMIC) technology that was utilized to observe the transmigration conditions of two types of cells with and without fluidic shear stress. Besides, the gap size of co-culture device could achieve shortest and not mixture. Endothelial cells (ECs) and smooth muscle cells (SMCs) were used in our experiment. In addition, concentrations of two cell are 8000 cells/μL (ECs) and 9000 cells/μL (SMCs), respectively, the shear stress is 7 dyne/cm2, and the isolation distance between two types of cell are 50 and 200 μm. It is found that in the smaller culture space (50 μm) condition, ECs and SMCs would induce mutually, which would further make cell migration; in larger culture space (200 μm) condition, no inducing reaction took place between ECs and SMCs. It will have more advantages in bio-manipulation and tissue repair engineering.

Aims Thrombomodulin (TM), a potent anticoagulant, is not detected in quiescent vascular smooth muscle cells (VSMCs). In diseased vessels, VSMC expresses TM, but the mechanisms are unclear. This study examined molecular mechanisms for TM expression in VSMCs. Methods and results Platelet-derived growth factor-BB (PDGF-BB) induced TM expression in cultured human aortic VSMCs. PDGF-induced TM is functional in activating protein C. TM induction was eliminated by inhibitors of Src kinase, phosphatidylinositol 3-kinase (PI3-kinase), and mammalian target of rapamycin (mTOR) and by expressing dominant-negative Akt while expressing active Akt-stimulated TM expression. PDGF-BB activated the TM promoter, and the deletion of a sequence segment −394/−255 drastically reduced TM promoter activity. Transcription factor E26 transformation-specific sequence-1 (Ets-1) was upregulated by PDGF-BB in a PI3-kinase- and mTOR-dependent manner. RNA interference of Ets-1 inhibited PDGF induction of TM, and overexpressing Ets-1 increased TM expression. Chromatin immunoprecipitation and electrophoretic mobility shift assay detected increased Ets-1 binding to the TM promoter after PDGF treatment. Following carotid artery ligation of C57/BL6 mice, PDGF-BB and TM were co-expressed in the media and neointima. Conclusion In VSMCs, PDGF-BB stimulates TM expression that is mainly mediated by Ets-1 via the Src kinase/PI3-kinase/Akt/mTOR signalling pathway. Furthermore, PDGF-BB may regulate TM expression in VSMCs during vascular remodelling.

Summary. Background: Angiostatin, a circulating angiogenic inhibitor, is an internal fragment of plasminogen and consists of several isoforms, K1-3 included. We previously showed that K1-3 was the most potent angiostatin to induce E-selectin mRNA expression. The purpose of this study was to identify the mechanism responsible for K1-3-induced E-selectin expression and investigate the role of E-selectin in the anti-angiogenic action of K1-3. Methods and results: Quantitative real time RT-PCR and Western blotting analyses confirmed a time-dependent increase of E-selectin mRNA and protein induced by K1-3. Subcellular fractionation and immunofluorescence microscopy showed the co-localization of K1-3-induced E-selectin with caveolin 1 (Cav1) in lipid rafts in which E-selectin may behave as a signaling receptor. Promoter-driven reporter assays and site-directed mutagenesis showed that K1-3 induced E-selectin expression via promoter activation and AP1 and Ets-1 binding sites in the proximal E-selectin promoter were required for E-selectin induction. The in vivo binding of both protein complexes to the proximal promoter was confirmed by chromatin immunoprecipitation (ChIP). Although K1-3 induced the activation of ERK1/2 and JNK, only repression of JNK activation attenuated the induction of E-selectin by K1-3. A modulatory role of E-selectin in the anti-angiogenic action of K1-3 was manifested by both overexpression and knockdown of E-selectin followed by cell proliferation assay. Conclusions: We show that K1-3 induced E-selectin expression via AP1 and Ets-1 binding to the proximal E-selectin promoter (−356/+1), which was positively mediated by JNK activation. Our findings also demonstrate E-selectin as a novel target for the anti-angiogenic therapy.

Tie2 is an endothelial receptor tyrosine kinase. An amino-acid substitution of tryptophan for arginine at residue 849 (Tie2-R849W) leads to a ligand-independent activation of its kinase activity. This mutation has been associated with familial venous malformations (VMs), manifested by variable thickness or lack of smooth-muscle cells in the veins of patient lesions. The underlying mechanism for Tie2-R849W action in endothelial cells remains elusive. In this study, we used adenoviral infection to differentiate the effects of ectopic Tie2 (wild type, kinase-dead K855A, or constitutively active R849W) expression on endothelial cellular behaviors and Tie2-mediated downstream targets. Ectopic Tie2 reduced endothelial cell proliferation and serum withdrawal-induced apoptosis, while stimulating migration. When comparing R849W with K855A and its wild-type counterpart, a functional tyrosine kinase activity was required only for migration, and constitutively active Tie2-R849W conferred highest resistance to serum-induced apoptosis, but lowest ability to maintain tube-like structures formed on Matrigel. We further demonstrated that Tie2-R849W chronically induced STAT1 tyrosine phosphorylation and the promoter activity of STAT1-responsive IFN-regulatory factor 1 (IRF1). Although STAT1 phosphorylation required JNK and p38MAPK activation, only JNK activation was essential for IRF1 promoter activation by Tie2-R849W. Additional studies are needed to study the role of STAT1 activation in VMs.

Thrombospondin (TSP)-1, a potent angiogenesis inhibitor, has been shown to exert different biological functions on various cell types. Here, we investigate the role of TSP-1 in tumor-stroma reaction, which is mainly characterized by fibroblast activation to create a permissive microenvironment for tumor progression. Immunohistochemistry examinations in the human surgical specimens have shown that a downregulation of TSP-1 during the progression of cervical carcinogenesis was accompanied by an emergence in the upregulation of stroma markers, alpha-smooth muscle actin (alpha-SMA) and desmin. Transfection of SiHa cervical cancer cells with a plasmid expressing the TSP-1 protein exhibited antiangiogenic activity in vitro and resulted in reduced tumor growth in severe combined immunodeficiency (SCID) mice, which was accompanied by a decrease in tumor vascularization and lower expressions of alpha-SMA and desmin than those in the vector controls. Transfection with TSP-1 and purified TSP-1 added to NIH3T3 cells did not alter the protein levels of alpha-SMA and desmin but significantly inhibited matrix metalloprotease-2 activity. Transforming growth factor-beta (TGF-beta), a major factor in the activation of fibroblasts, increased alpha-SMA and desmin expression and the ability of cell migration and invasion in NIH3T3 cells. The increased migration ability and the invasive ability into tumor cluster of TGF-beta-treated NIH3T3 cells were dose dependently inhibited by TSP-1. In contrast, ectopic TSP-1 expression in SiHa cells has little effect on the invasive ability of the NIH3T3 cells. Together, our findings demonstrate a novel role of TSP-1 to inhibit tumor-stroma reaction that could be attributed to the blockage of activated fibroblasts from invading cancer cells.

A novel bioactive polyacetylene compound, 1,2-dihydroxy-5(E)-tridecene-7,9,11-triyne (compound 1), was identified from the Bidens pilosa extract using an ex vivo primary human umbilical vein endothelium cell (HUVEC) bioassay-guided fractionation protocol. Our results demonstrate that compound 1 (at 2.5 microg/mL) possessed significant anti-angiogenic effects, as manifested by an inhibition of HUVEC proliferation, migration, and the formation of tube-like structures in collagen gel. Moreover, compound 1 induced HUVECs to undergo cell death in a concentration- and time-dependent manner. The mechanisms underlying these pharmacological effects include reduced expression of cell cycle mediators such as CDK4, cyclins D1 and A, retinoblastoma (Rb) and vascular endothelial growth factor receptor 1 (VEGFR-1), and promotion of caspase-mediated activation of CDK inhibitors p21(Cip1) and p27(Kip). Moreover, apoptotic induction in HUVECs mediated by compound 1 was found to be in part through overexpression of FasL protein, down-regulation of anti-apoptotic Bcl-2, and activation of caspase-7 and poly(ADP-ribose) polymerase. This study demonstrates the potent anti-angiogenic and apoptotic activities of compound 1, suggesting that phytocompounds such as polyacetylenes deserve more attention regarding their potential as candidates for anti-angiogenic therapeutics.

Amphiregulin (AR), an epidermal growth factor (EGF)-like molecule, is a mitogen for keratinocytes. Squamous cell carcinoma (SCC) is a tumor derived from keratinoctyes. Expression of AR mRNA positively correlated with the clinical progression of 39 oral SCC. Oral SCC line, KB, was used as a model to study if increased expression of AR altered the biological behaviors of SCC cells. Exogenous AR dose-dependently enhanced the proliferation of KB cells expressing EGF receptor 1 (EGFR-1), a major receptor for AR, but little AR. Neutralizing anti-AR antibody significantly reversed the stimulatory effect of exogenous AR on KB cell proliferation. Ectopically expressed AR in stable clones manifested higher abilities to proliferate, migrate and invade Matrigel than vector control. Cyclooxygenase 2 (COX-2), but not metalloprotease 9 (MMP-9) mRNA, was increased in all the AR-expressing stable clones. In summary, AR behaves as a tumor promoter for oral SCC cells partly via increased expression of COX-2.

SummaryThe molecular mechanism mediated by multiple forms of angiostatin via acting on proliferating vascular endothelium remains elusive. To address whether three forms of angiostatin, K1-3, K1-4 or K1-4.5, utilized similar or distinct pathways to mediate anti-angiogenesis, we adopted an adenoviral expression system to express secretable angiostatin molecules for CM collection. The anti-angiogenic activity of K1-3, K1-4 or K1-4.5 was confirmed by using proliferation, migration, tube formation and apoptotic assays of human endothelial cells. These angiostatin molecules at comparable expression level inhibited various in vitro angiogenesis assays with some variations. Furthermore, K1-3, K1-4 or K1-4.5 increased the expression of p53 protein and its downstream effectors, enhanced FasL-mediated signaling pathways, and decreased activation of AKT. At least three different receptors, Fas, integrin αvβ3 and ATP synthase, were involved in the anti-angiogenic action of angiostatin molecules. Besides, the expression of 189 genes at mRNA level was significantly altered by K1-3, K1-4 or K1-4.5. More than 70% of these genes participate in growth, inflammation, apoptosis, migration and extracellular matrix. Taken together, K1-3, K1-4 and K1-4.5, regardless of the number of kringles in the angiostatin molecules, mediated anti-angiogenesis via mostly similar pathways. We are the first to demonstrate the involvement of DAPK1 in the mediation of anti-angiogenesis by angiostatin.