OBJECTIVE

To observe the inhibitory effects of puerarin on angiopoiesis of endometriotic tissue, and to explore the regulatory effects of puerarin on tumor-related gene expression of endometriosis.

METHODS

The regulatory effects of puerarin on endometriotic angiopoiesis and tumor-related gene expression were observed by using a chicken chorioallantoic membrane model and gene array method.

RESULTS

Chicken chorioallantoic membrane experiment indicated that puerarin obviously inhibited endometriotic vesiculation and angiopoiesis. The area of blood vessels was significantly reduced as compared with the untreated group (P<0.05). The expressions of oncogenes and genes related to adhesion, invasion, and apoptosis, including ERBB2, ETS2, FOS, S100A4, TEK, TERT, NFKBIA, CDH1, CD44, ITGA6, NCAM1, MMP1, FLT1, AKT1, BCL2L and BIRC5 genes, were obviously higher, while the expressions of the anti-oncogenes, anti-apoptosis genes and anti-invasion genes, including KAI1, KISS1, SERPINB5, TNFRSF25, TNFRSF1A, TNFRSF6 and SERPINB2, were significantly lower in eutopic endometrial tissue from patients with endometriosis than those from endometriosis-free women. The expressions of oncogenes (ERBB2, ETS2, FOS), apoptosis gene (BCL2L1), cyclin-dependent kinases (CDK4, CDC25A), and growth factor and receptors (HGF, FGFR2, TGFBR) were significantly enhanced, while the expressions of the anti-oncogenes (KAI1, SERPINB5), apoptosis genes (BAD and TNF) and cyclin-dependent kinase inhibiting factor (CDKN2A) were obviously reduced in ectopic tissue as compared with those in eutopic tissue from patients with endometriosis. Puerarin significantly enhanced the gene expressions in endometriotic stromal cells, including BAD, BAX, CASP8, CASP9, TNFRSF6, CDKN1B, CDKN2A, IFNA1 and IFNB1, and reduced the gene expressions of FOS, CHEK2, SRC, ITGB5, MMP9, PDGFA and NFKBIA.

CONCLUSIONS

The tumor-related gene expression has significant differences in eutopic endometrial tissue between patients with endometriosis and endometriosis-free women, and between ectopic and eutopic tissues from patients with endometriosis. Puerarin can reduce angiopoiesis, regulate tumor-related gene expression and facilitate apoptosis in endometriotic tissue.

The human placenta nourishes and protects the developing foetus whilst influencing maternal physiology for fetal advantage. It expresses several members of the vascular endothelial growth factor (VEGF) family including the pro-angiogenic/pro-permeability VEGF-A165a isoform, the anti-angiogenic VEGF-A165b, placental growth factor (PIGF) and their receptors, VEGFR1 and VEGFR2. Alterations in the ratio of these factors during gestation and in complicated pregnancies have been reported; however, the impact of this on feto-placental endothelial barrier integrity is unknown. The present study investigated the interplay of these factors on junctional occupancy of VE-cadherin and macromolecular leakage in human endothelial monolayers and the perfused placental microvascular bed. Whilst VEGF-A165a (50 ng/ml) increased endothelial monolayer albumin permeability (P<0.0001), equimolar concentrations of VEGF-A165b (P>0.05) or PlGF (P>0.05) did not. Moreover, VEGF-A165b (100 ng/ml; P<0.001) but not PlGF (100 ng/ml; P>0.05) inhibited VEGF-A165a-induced permeability when added singly. PlGF abolished the VEGF-A165b-induced reduction in VEGF-A165a-mediated permeability (P>0.05); PlGF was found to compete with VEGF-A165b for binding to Flt-1 at equimolar affinity. Junctional occupancy of VE-cadherin matched alterations in permeability. In the perfused microvascular bed, VEGF-A165b did not induce microvascular leakage but inhibited and reversed VEGF-A165a-induced loss of junctional VE-cadherin and tracer leakage. These results indicate that the anti-angiogenic VEGF-A165b isoform does not increase permeability in human placental microvessels or HUVEC primary cells and can interrupt VEGF-A165a-induced permeability. Moreover, the interplay of these isoforms with PIGF (and s-flt1) suggests that the ratio of these three factors may be important in determining the placental and endothelial barrier in normal and complicated pregnancies.

While reshaping their microenvironment, tumors are also capable of influencing systemic processes including myeloid cell production. Therefore, the tumor-induced myeloid cells, such as myeloid-derived suppressor cells (MDSCs), which are characterized with pro-cancer properties, became another target in order to increase the success of the therapy. This study evaluated the capacity of a novel dendrimeric drug delivery platform to eliminate tumor-induced myeloid cells. As described in a previous study by our research group, the anti-Flt1 antibody-conjugated polyethylene glycol (PEG)-cored poly(amidoamine) (PAMAM) dendrimers improved the efficacy of gemcitabine against pancreatic cancer. Here, the biodistribution studies showed that these dendrimeric structures accumulated in the compartments that became rich in myeloid cells in the pancreatic tumor-bearing mice. When gemcitabine was loaded into the dendrimer complexes, the number of myeloid cells was significantly reduced while the percentage distribution of granulocytic and monocytic myeloid cells was not always significantly altered. The CD11b+Ly6G-Ly6C+ monocytes were more severely affected by the treatments than CD11b+Ly6G+Ly6C+ granulocytes. Immune infiltration levels in the tumor tissue were also altered. Myeloid cells in the spleen and F4/80+ macrophages of the liver were protected. The compartments, such as the liver and the bone marrow, which are known to have high vascular endothelial growth factor (VEGF)-Flt1 pathway activity, were particularly targeted by gemcitabine when delivered through anti-Flt1 antibody-conjugated PAMAM dendrimers. In conclusion, chemotherapeutic agents complexed with dendrimers not only improve anticancer efficacy, but they also assist in the elimination of the tumor-induced myeloid cells.

The present study was conducted to demonstrate of the immunohistochemical localization of vascular endothelial growth factor (VEGF) and its receptors (flt1/fms, flk1/KDR and flt4) as well as vascular endothelial growth inhibitor (VEGI) and to determine the correlation of VEGF and its receptors and VEGI with serum sex steroids (estrogen and progesterone) in the bovine uterus during the sexual cycle. The stage of the estrous cycle in 30 Holstein cattle was assessed based on the gross and histological appearance of the ovaries and uterus and on blood steroid hormone levels. Tissue samples obtained from the uterus were fixed in 10% formaldehyde for routine histological processing. During both follicular and luteal phases, positive cytoplasmic and membrane staining was achieved for VEGF and its receptors (flt1/fms, flk1/KDR and flt4) as well as VEGI in the luminal and glandular epithelial cells, the connective tissue and smooth muscle cells, and the vascular endothelial cells and smooth muscle cells in the uterus. The intensity, proportional and total scores determined for VEGF and its receptors (flt1/fms and flt4) as well as VEGI were greater in the luminal and glandular epithelial cells compared to the connective tissue and smooth muscle cells (P < 0.05). Furthermore, the number and intensity of the flk1/KDR positive cells were greater among the connective tissue cells compared to the luminal and glandular epithelial cells (P < 0.05). As a result, it was determined that the expression of VEGF and its receptors as well as VEGI in the bovine uterus during the follicular and luteal phases varied with different cell types. This suggests that depending on the stage of the sexual cycle, these factors may mediate the establishment of an appropriate environment for the nutritional supply and implantation of the embryo primarily due to the stimulation of angiogenesis but also through the increase in the secretory activity of the epithelial cells in the uterus. Furthermore, this indicates that ovarian steroid hormones play a significant role in regulating the expression of VEGF and its receptors as well as VEGI.

Polymorphisms in the vascular endothelial growth factor (VEGF)/angiogenesis pathway have been implicated previously in cancer risk, prognosis and response to therapy including in esophageal adenocarcinoma. Prior esophageal adenocarcinoma studies focused on using candidate polymorphisms, limiting the discovery of novel polymorphisms. Here, we applied the tagSNP (single nucleotide polymorphism) approach to identify new VEGF pathway polymorphisms associated with esophageal adenocarcinoma prognosis and validated them in an independent cohort of esophageal adenocarcinoma patients. In 231 esophageal adenocarcinoma patients of all stages/treatment plans, 58 genetic polymorphisms (18 KDR, 7 VEGFA and 33 FLT1) selected through tagging and assessment of predicted function were genotyped. Cox-proportional hazard models adjusted for important socio-demographic and clinico-pathological factors were applied to assess the association of genetic polymorphisms with overall survival (OS) and progression-free survival (PFS). Significantly associated polymorphisms were then validated in an independent cohort of 137 esophageal adenocarcinoma patients. Among the 231 discovery cohort patients, 86% were male, median diagnosis age was 64 years, 34% were metastatic at diagnosis and median OS and PFS were 20 and 12 months, respectively. KDR rs17709898 was found significantly associated with PFS (adjusted hazard ratio, aHR = 0.69, 95% confidence interval (CI): 0.53-0.90; P = 5.9E-3). FLT1 rs3794405 and rs678714 were significantly associated with OS (aHR = 1.44, 95% CI: 1.04-1.99; P = 0.03 and aHR = 1.50, 95% CI: 1.01-2.24; P = 0.045, respectively). No VEGFA polymorphisms were found significantly associated with either outcome. Upon validation, FLT1 rs3794405 remained strongly associated with OS (aHR = 1.59, 95% CI: 1.04-2.44; P = 0.03). FLT1 rs3794405 is significantly associated with OS in esophageal adenocarcinoma, whereby each variant allele confers a 45-60% increased risk of mortality. Validation and evaluation of this association in other cancer sites are warranted.

Bevacizumab was the first molecular-targeted antiangiogenic therapy approved for the treatment of metastatic colorectal cancer. Until now, there are no predictive biomarkers available to decide the prescription of bevacizumab in patients with colorectal cancer. The purposes of this review were to provide a critical appraisal of the evidence and to identify possible predictive genetic biomarkers. A literature search was performed to identify studies that determine different levels of treatment response between patients stratified according to defined biomarkers. Interesting findings were reported between patients stratified according to rs3025039 and rs833061 polymorphisms of the gene VEGFA, with statistically and clinically significant differences for progression-free survival and overall survival. However, another study conducted in a larger sample does not confirm these previous findings, suggesting that well-designed prospective studies are still needed to achieve conclusive results. FLT1 (or VEGFR1) rs9513070 seems to be an interesting candidate as a predictive biomarker, with differences of more than 10 months in OS between different patients groups. In our opinion, possible interesting biomarker candidates for future research could be the polymorphisms rs833061 and rs3025039 of VEGF-A, rs9513070 or haplotype analysis of FLT1, rs2661280 of RGS5, rs444903 and rs6220 of EGF and Ang-2 or LDH plasma levels.

A yeast artificial chromosome containing the two receptor-type tyrosine kinase genes FLT1 and FLT3 was isolated, analyzed, and compared to a genomic map in order to establish their organization and linkage. FLT1 and FLT3 are physically linked in a head-to-tail configuration and separated by about 150 kb. The region contains three CpG islands. Two of them are likely to correspond to FLT1 and FLT3, whereas the third one is suggestive of another putative, unidentified RTK gene.

We report the synthesis and biological evaluation of 5-substituted 1,4-dihydroindeno[1,2-c]pyrazoles as multitargeted kinase inhibitors. Initial efforts focused on the development of selective KDR inhibitors, while later strategies involved the improvement of potency toward multiple kinase targets. Thus, several compounds were identified as potent KDR, Flt1, Flt3, and c-Kit inhibitors.

Brain arteriovenous malformation (bAVM) is an important risk factor for intracranial hemorrhage. Current therapies are associated with high morbidities. Excessive vascular endothelial growth factor has been implicated in bAVM pathophysiology. Because soluble FLT1 binds to vascular endothelial growth factor with high affinity, we tested intravenous delivery of an adeno-associated viral vector serotype-9 expressing soluble FLT1 (AAV9-sFLT1) to alleviate the bAVM phenotype.

Two mouse models were used. In model 1, bAVM was induced in R26CreER;Eng2f/2f mice through global Eng gene deletion and brain focal angiogenic stimulation; AAV2-sFLT02 (an AAV expressing a shorter form of sFLT1) was injected into the brain at the time of model induction, and AAV9-sFLT1, intravenously injected 8 weeks after. In model 2, SM22αCre;Eng2f/2f mice had a 90% occurrence of spontaneous bAVM at 5 weeks of age and 50% mortality at 6 weeks; AAV9-sFLT1 was intravenously delivered into 4- to 5-week-old mice. Tissue samples were collected 4 weeks after AAV9-sFLT1 delivery.

AAV2-sFLT02 inhibited bAVM formation, and AAV9-sFLT1 reduced abnormal vessels in model 1 (GFP versus sFLT1: 3.66±1.58/200 vessels versus 1.98±1.29, P<0.05). AAV9-sFLT1 reduced the occurrence of bAVM (GFP versus sFLT1: 100% versus 36%) and mortality (GFP versus sFLT1: 57% [12/22 mice] versus 24% [4/19 mice], P<0.05) in model 2. Kidney and liver function did not change significantly. Minor liver inflammation was found in 56% of AAV9-sFLT1-treated model 1 mice.

By applying a regulated mechanism to restrict sFLT1 expression to bAVM, AAV9-sFLT1 can potentially be developed into a safer therapy to reduce the bAVM severity.

Cervical cancer (CC) is the fourth commonest cancer in women worldwide. Increasing evidence proves that microRNA (miRNA)-messenger RNA (mRNA) network is involved in CC. In this study, miRNA and mRNA expression profiles were downloaded from The Cancer Genome Atlas (TCGA) database. Differently expressed miRNAs (DE-miRNAs) and mRNAs (DE-mRNAs) were obtained by "Empirical Analysis of Digital Gene Expression Data in R (EdgeR)" package. Then, functional analyses were conducted. With Cytoscape software, a protein-protein interaction (PPI) network was established to identify hub genes that were used for building an miRNA-hub gene network. Next, a prognostic signature based on hub genes was constructed by Cox regression analysis, and its prognostic value was assessed by a nomogram. Finally, the relationship between immune cell infiltration and the three genes in the prognostic model was investigated by using the CIBERSORT algorithm. We screened out 5096 DE-mRNAs and 114 DE-miRNAs between healthy cervical and CC tissues. Then, 102 target DE-mRNAs of upregulated DE-miRNAs and 150 target DE-mRNAs of downregulated DE-miRNAs were obtained. PPI network demonstrated 20 hub nodes with higher connectivity. DE-mRNAs were mostly enriched in pathways in cancer, cell cycle, and proteoglycans in cancer. The miRNA-hub gene network showed that most hub genes could be potentially modulated by miR-200c-3p, miR-23b-3p, and miR-106b-5p. Quantitative real-time PCR proved that 10 miRNAs were downregulated and 6 mRNAs were upregulated markedly in CC tissues. Furthermore, a prognostic signature was established based on enhancer of zeste homolog 2 (EZH2), Fms-related tyrosine kinase 1 (FLT1), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The area under the curve value of the 5-year receiver operating characteristic curve was 0.609. The three genes were also found to be related to the infiltration of six types of immune cells, including dendritic cells, macrophages M0 and M1, mast cells, and monocytes. In conclusion, the development of CC is regulated by the miRNA-mRNA network we proposed in this study.

Keywords: TCGA; bioinformatic analysis; cervical cancer; miRNAs; prognostic value.

Incubation of gradient purified human spermatozoa, which are routinely maintained in media prior to IVF and intracytoplasmic sperm injection (ICSI), induced DNA strand breaks (up to 89 nicks x 10(-3) bp) and chromatin release. Unlike highly dispersed Alu repeat sequences, the centromeric heterochromatin was much less susceptible to endonuclease attack. In addition to chromatin release, the permeability of the sperm membrane was altered as evidenced by reduced accessibility of sperm nuclei to decondensation factors in mouse embryo extracts. Hybridization of cDNA microarrays with DNA released from spermatozoa revealed a consistent hypersensitivity of certain genes to endogenous cleavage including TP53, VHL (tumour suppressors), BRCA1 (breast cancer), NOS1 (neurotransmitter), PECAM1, FLT1 (angiogenesis) and CDKN1C (cell cycle/imprinted). N-tert-butyl hydroxylamine (NTBH), a derivative of the anti-teratogenic alpha-phenyl-N-t-butyl nitrone (PBN) and synthetic superoxide dismutase (SOD)/catalase mimetics inhibited chromatin release and sustained or dissipated relative mitochondrial membrane potential. Together, these results show a link between the hyperactivation of sperm mitochondria and chromosomal damage of specific genes in vitro, and that the potential risk of disruption of paternally contributed genes can be circumvented by antioxidants which are known to target mitochondria.

Anti-flt1 peptide (GNQWFI, AF) specifically binds to Vascular Endothelial Growth Factor Receptor 1 (VEGFR1), thereby inhibiting the interaction of VEGFR1 with a series of ligands. ES2 (IVRRADRAAVP) can effectively inhibit the proliferation and invasion of endothelial cells and play a key role in anti-angiogenesis. AF and ES2 peptides differ in their activity. To better exploit the advantages of both, we designed a new peptide called ES2-AF (IVRRADRAAVPGGGGGGNQWFI). Hyaluronic acid (HA) is widely used in the pharmaceutical industry because of its biodegradable and high load performance. The HA-specific cell surface receptor CD44 was highly expressed in the tumour site during the anti-tumour study. Therefore, we used HA as a modifier to chemically modify ES2-AF; it was expected that the modified compound would have preferable solubility, stronger targeting, longer half-life, and better anti-angiogenesis effects in vivo. In this study, the anti-proliferative, anti-migration and targeting activities of HA-ES2-AF in vitro were studied by MTT, ELISA, transwell and SPR assays. Meanwhile, the anti-neovascularization activity of HA-ES2-AF in vivo was studied by CAM assay, and the targeting of HA-ES2-AF to tumour tissue was studied by bioimaging techniques. Finally, we also studied the half-life of HA-ES2-AF in vivo. In short, the bioactivity of the new peptide ES2-AF was enhanced to a certain extent, and ES2-AF modified by HA had higher anti-neovascularization activity in vitro and in vivo, had stronger targeting to tumour tissue, and had a significantly prolonged half-life in vivo. These results laid the foundation for its further development into targeting anti-tumour drugs.

BACKGROUND

Cutaneous melanoma displays high morbidity and mortality rates. Isolated limb perfusion with melphalan (Mel) is used for the treatment of non-resectable, locally advanced extremity melanomas. When combined with tumor necrosis factor alpha (TNF-alpha) treatment, the complete response varies between 70% and 90%. The mechanisms underlying the effects of Mel and TNF-alpha are not completely understood. We evaluated the impact of systemic Mel and TNF-alpha administration on tumor growth, analyzed the morphological changes promoted by each treatment, and identified early expressed genes in response to Mel and TNF-alpha treatment, either alone or in combination, in a murine melanoma model.

METHODS

Six- to eight-week-old male mice were subcutaneously inoculated with B16F10 melanoma cells and then intravenously injected with TNF-alpha, melphalan or a combination of both drugs when the tumors reached 1.0 cm(2). Tumor growth was monitored every other day, and histological analysis was performed when the tumors reached 3.0 cm(2). Total RNA was extracted from the resected tumors and submitted to amplification, labeling and hybridization on an oligonucleotide microarray (Fox Chase Cancer Center). Tumor growth and histological parameters were compared using ANOVA. Survival curves were calculated using the Kaplan-Meier method. Two-way ANOVA was used to identify differentially expressed genes among the various treatments, and Dunn's test was used for pair-wise comparisons.

RESULTS

Systemic administration of Mel impaired tumor growth (p<0.001), improved animal survival (p<0.001), and decreased mitotic rate (p=0.049). Treatment with TNF-alpha alone had no impact, neither on tumor growth, nor on survival, but it increased necrosis (p<0.024) and decreased mitotic rates (p=0.001) in the tumors. Combined treatment with Mel and TNF-alpha had similar effects in tumor growth, survival, necrosis and mitotic rate as observed with individual treatments. Moreover, 118 genes were found differentially expressed by microarray analysis and 10% of them were validated by RT- real time PCR. In our model we found that the treatments regulate genes that play important roles in tumorigenesis such as cell adhesion (Pard3, Pecam1, Ilk, and Dlg5), proliferation (Tcfe3 and Polr1e), cell motility (Kifap3, Palld, and Arhgef6), apoptosis (Bcl2l11), and angiogenesis (Flt1 and Ptprj).

CONCLUSIONS

Our data reproduces, in mice, some of the features observed in melanoma patients treated with the combination of Mel and TNF-alpha. The identification of genes with altered expression by these drugs both individually and in combination might help in the understanding of their mechanism of action and, as a consequence, improved strategies that could impact their clinical application.

BACKGROUND

The acute respiratory distress syndrome (ARDS) is one of the main causes of mortality in adults admitted to intensive care units. Previous studies have demonstrated the existence of genetic variants involved in the susceptibility and outcomes of this syndrome. We aimed to identify novel genes implicated in sepsis-induced ARDS susceptibility.

METHODS

We first performed a prioritization of candidate genes by integrating our own genomic data from a transcriptomic study in an animal model of ARDS and from the only published genome-wide association study of ARDS study in humans. Then, we selected single nucleotide polymorphisms (SNPs) from prioritized genes to conduct a case-control discovery association study in patients with sepsis-induced ARDS (n = 225) and population-based controls (n = 899). Finally, we validated our findings in an independent sample of 661 sepsis-induced ARDS cases and 234 at-risk controls.

RESULTS

Three candidate genes were prioritized: dynein cytoplasmic-2 heavy chain-1, fms-related tyrosine kinase 1 (FLT1), and integrin alpha-1. Of those, a SNP from FLT1 gene (rs9513106) was associated with ARDS in the discovery study, with an odds ratio (OR) for the C allele of 0.76, 95% confidence interval (CI) 0.58-0.98 (p = 0.037). This result was replicated in an independent study (OR = 0.78, 95% CI = 0.62-0.98, p = 0.039), showing consistent direction of effects in a meta-analysis (OR = 0.77, 95% CI = 0.65-0.92, p = 0.003).

CONCLUSIONS

We identified FLT1 as a novel ARDS susceptibility gene and demonstrated that integration of genomic data can be a valid procedure to identify novel susceptibility genes. These results contribute to previous firm associations and functional evidences implicating FLT1 gene in other complex traits that are mechanistically linked, through the key role of endothelium, to the pathophysiology of ARDS.

Tumor microenvironment favors the escape from immunosurveillance by promoting immunosuppression and blunting pro-inflammatory responses. Since most tumor-associated macrophages (TAM) exhibit an M2-like tumor cell growth promoting polarization, we have studied the role of 2G-03NN24 carbosilane dendrimer in M2 macrophage polarization to evaluate the potential application of dendrimers in tumor immunotherapy. We found that the 2G-03NN24 dendrimer decreases LPS-induced IL-10 production from in vitro generated monocyte-derived M2 macrophages, and also switches their gene expression profile towards the acquisition of M1 polarization markers (INHBA, SERPINE1, FLT1, EGLN3 and ALDH1A2) and the loss of M2 polarization-associated markers (EMR1, IGF1, FOLR2 and SLC40A1). Furthermore, 2G-03NN24 dendrimer decreases STAT3 activation. Our results indicate that the 2G-03NN24 dendrimer can be a useful tool for antitumor therapy by virtue of its potential ability to limit the M2-like polarization of TAM.

Copeptin, a marker of arginine vasopressin (AVP) secretion, is elevated throughout human pregnancies complicated by preeclampsia (PE), and AVP infusion throughout gestation is sufficient to induce the major phenotypes of PE in mice. Thus, we hypothesized a role for AVP in the pathogenesis of PE. AVP infusion into pregnant C57BL/6J mice resulted in hypertension, renal glomerular endotheliosis, intrauterine growth restriction, decreased placental growth factor (PGF), altered placental morphology, placental oxidative stress, and placental gene expression consistent with human PE. Interestingly, these changes occurred despite a lack of placental hypoxia or elevations in placental fms-like tyrosine kinase-1 (FLT1). Coinfusion of AVP receptor antagonists and time-restricted infusion of AVP uncovered a mid-gestational role for the AVPR1A receptor in the observed renal pathologies, versus mid- and late-gestational roles for the AVPR2 receptor in the blood pressure and fetal phenotypes. These findings demonstrate that AVP is sufficient to initiate phenotypes of PE in the absence of placental hypoxia, and indicate that AVP may mechanistically (independently, and possibly synergistically with hypoxia) contribute to the development of clinical signs of PE in specific subtypes of human PE. Additionally, they identify divergent and gestational time-specific signaling mechanisms that mediate the development of PE phenotypes in response to AVP.

OBJECTIVE

Formation of a functional vascular system is essential and its formation is a highly regulated process initiated during embryogenesis, which continues to play important roles throughout life in both health and disease. In previous studies, Fzd5 was shown to be critically involved in this process and here we investigated the molecular mechanism by which endothelial loss of this receptor attenuates angiogenesis.

RESULTS

Using short interference RNA-mediated loss-of-function assays, the function and mechanism of signaling via Fzd5 was studied in human endothelial cells (ECs). Our findings indicate that Fzd5 signaling promotes neovessel formation in vitro in a collagen matrix-based 3D co-culture of primary vascular cells. Silencing of Fzd5 reduced EC proliferation, as a result of G0/G1 cell cycle arrest, and decreased cell migration. Furthermore, Fzd5 knockdown resulted in enhanced expression of the factors Angpt2 and Flt1, which are mainly known for their destabilizing effects on the vasculature. In Fzd5-silenced ECs, Angpt2 and Flt1 upregulation was induced by enhanced PKC signaling, without the involvement of canonical Wnt signaling, non-canonical Wnt/Ca2+-mediated activation of NFAT, and non-canonical Wnt/PCP-mediated activation of JNK. We demonstrated that PKC-induced transcription of Angpt2 and Flt1 involved the transcription factor Ets1.

CONCLUSIONS

The current study demonstrates a pro-angiogenic role of Fzd5, which was shown to be involved in endothelial tubule formation, cell cycle progression and migration, and partly does so by repression of PKC/Ets1-mediated transcription of Flt1 and Angpt2.

Critical limb ischemia (CLI) represents the most severe form of peripheral arterial disease (PAD) and is the leading cause of non-traumatic amputations in western populations. In recent years, therapeutic angiogenesis has been considered to be a potential treatment option for CLI patients, however the molecular mechanism of ischemia-induced vascularization is still not fully understood. The identification of genetic factors underlying vascular responses to ischemia will improve our understanding of the biological causes of the disease and enhance personalized therapies in the future. In this work, we determined, for the first time, the expression profile of angiogenesis-related genes utilizing unique human material: the popliteal arteries retrieved during lower limb amputation from patients with CLI. Using custom-designed TaqMan Low-Density Array (TLDA) cards we investigated the mRNA level of 90 genes on CLI samples compared to healthy donors. We identified three significantly up-regulated genes in CLI group: matrix metalloproteinase 9 (MMP-9), VE-cadherin (CDH5) and integrin alpha 4 (ITGA4). However, among all investigated genes, only lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) was significantly reduced. In order to verify whether hypoxic conditions occur in popliteal arteries of CLI patients, we validated the transcription level of selected proangiogenic genes by real-time PCR on a larger number of samples. These results showed that the expression of key genes involved in angiogenesis, such as MMP9, HGF, HIF1A, VEGF-A and FLT1 were elevated in patients with CLI. Moreover, the study revealed that the expression of VEGF-A and FLT1 was associated with activation of HIF1A transcription. In conclusion, our data revealed the alteration in the mRNA level of genes involved in matrix remodelling, cell-cell adhesion as well as endothelial cell migration and proliferation in human popliteal arteries.

Background: Soft-tissue sarcomas are a rare group of malignant tumors that usually are treated with surgical excision and radiation therapy, but recently, pazopanib, an oral tyrosine kinase inhibitor, has been used in patients with metastases who do not respond to standard chemotherapy regimens. Based on patients with advanced soft-tissue sarcomas who had received prior chemotherapy, several clinical studies have reported the survival and sensitivity (approximately 5% to 10% sensitive) of patients with soft-tissue sarcomas treated with pazopanib. Recently, next-generation sequencing (NGS) technologies have been used to provide a wide genetic information and to develop personalized medicine in cancer treatment. However, there are few reports and no genetic analyses of patients with soft-tissue sarcomas who had a complete response (CR) to pazopanib.

Questions/purposes: We described the clinicopathologic features of a patient with a rare, advanced soft-tissue sarcoma who achieved a CR to pazopanib treatment. Furthermore, integrative analyses using NGS and arrays were performed to elucidate characteristic alterations, including gene mutations, copy number changes, and protein expression that were associated with response to pazopanib. Additionally, functional analyses consisting of in vitro and in vivo assays were also performed to elucidate whether the identified alterations were associated with oncogenic abilities and drug responses.

Methods: In a sample from a 70-year-old woman with an advanced soft-tissue sarcoma treated for 1 month with 800 mg of oral pazopanib daily, CT scans demonstrated a CR to treatment. To our knowledge, there have been no patients with soft-tissue sarcomas among several clinical trials of pazopanib that have achieved a CR and therefore, our patient is considered to be extremely rare. We performed an integrative analysis including whole-exome sequencing, transcriptome sequencing, and phosphorylation profiling of receptor tyrosine kinases (RTK) using tumor samples from a patient with a CR matched to normal samples. From here on we will refer to this patient as having a CR, although a short term high-grade partial response may be more accurate. These analyses were performed using NGS and the phosphoreceptor tyrosine kinase (phospho-RTK) array. As a validation study, we also performed target sequencing using three samples from patients with long-term stable disease and two samples from patients with progressive disease who responded to pazopanib treatment. In addition, characteristic gene alterations that were identified according to the response to pazopanib in one patient with a CR, in three patients with long-term stable disease, and in 27 patients with high-grade soft-tissue sarcomas with different histologic subtypes and different responses to pazopanib were verified by quantitative real-time polymerase chain reaction. We conducted a focus formation assay to evaluate the transforming activities of these genomic alterations.

Results: In the patient with a CR to pazopanib, we identified several somatic mutations including Fms related receptor tyrosine kinase 1 (FLT1) p.G38S, platelet-derived growth factor receptor alpha (PDGFRA) p.T83S, and platelet-derived growth factor receptor beta (PDGFRB) exon 13 skipping. Amplification at chromosome 12q13-14 encompassing GLI family zinc finger 1 (GLI1) and cyclin-dependent kinase-4 (CDK4) was also detected. Furthermore, an elevated PDGFRB phosphorylation level was observed in the tumor. In target sequencing analyses in five patients, one of three patients with long-term stable disease had 12q13-14 amplification. The mRNA expression of GLI1, CDK4, and pazopanib targets including PDGFRA, PDGFRB, vascular endothelial growth factor receptor (VEGFR)1-3, and stem cell factor receptor (KIT) in samples from the patient with a CR, and 27 patients with high-grade soft-tissue sarcomas was verified. The expression of GLI1 was characteristically increased in the patient with a CR and in those with long-term stable disease relative to other patients with soft-tissue sarcomas. Overexpression of GLI1 showed strong transforming potential in 3T3 cells. Moreover, the overexpression of GLI1 upregulated the expression of the PDGFRB protein and promoted phosphorylation, which was dose-dependently inhibited by pazopanib. However, inhibition of GLI1-induced transformation by pazopanib was limited in the focus formation assay; therefore, mechanisms other than PDGFRB activation may contribute to transformation.

Conclusions: We identified several gene alterations that might be associated with a CR and long-term stable disease in patients who received pazopanib for advanced soft-tissue sarcomas. We therefore believe that this distinct molecular profile warrants further investigation to identify predictive biomarkers of the response to pazopanib.

Clinical relevance: Our findings identify molecular mechanisms that possibly explain the high sensitivity of soft-tissue sarcomas to pazopanib and may lead to the development of predictive biomarkers and novel therapies in patients with this and other types of soft-tissue sarcomas.

SKT11, an important tumor suppressor, is a member of the serine/threonine kinase family and plays a crucial role in tumor invasion and metastasis by activated adenine monophosphate-activated protein kinase (AMPK) and AMPK-related kinase proteins. However, few studies have elaborated its regulations of development and metabolism of cartilage, as well as skeleton. This study was aimed to investigate the role of Stk11-knockout in chondrocyte by bioinformatics analysis. The gene expression profiles for Stk11-knockout and wild-type mice were downloaded from the Gene Expression Omnibus (GEO) database. A total of 1104 differentially expressed genes (DEGs) were identified by Affymetrix Expression Console and Transcriptome Analysis Console (TAC) software, including 560 up-regulated and 544 down-regulated genes. The protein-protein interaction (PPI) networks were built by mapping DEGs into STRING, in which hub genes such as Fos, Pdgfrb, Pdgfra, Flt1/Vegfr1, Smad3, Mapk14, Twist and Aurkb were further identified. For the up-regulated genes, PI3K-AKT signaling pathway and Wnt signaling pathway were two main pathways in the KEGG analysis, and ossification and extracellular matrix organization were involved in the Gene Ontology (GO) analysis. On the other hand, the down-regulated genes were mainly involved in systemic lupus erythematosus and alcoholism pathways, and B cell receptor signaling pathway and immune system process biological processes. MiRNA-9, miRNA-134, miRNA-492, miRNA-224 and miRNA-142-5p were identified as key regulators in the miRNAs-DEG regulatory network. Additionally, OSF2/RUNX2, and NFAT regulated DEGs collectively in the transcription factor regulatory network. The results of RT-PCR verified that the expression of hub genes, transcription factors and miRNAs in our experiment were basically consistent with the microarray hybridization. In this study, we provide an insight into the role of Stk11 in chondrocyte and identify novel genes related to Stk11.

To facilitate efficient oxygen and nutrient delivery, blood vessels in the brain form three-dimensional patterns. However, little is known about how blood vessels develop stereographically in the neocortex and how they control the expansion and differentiation of neural progenitors during neocortical development. We show that highly vascularized and avascular regions are strictly controlled in a spatially and temporally restricted manner and are associated with distinct cell populations. Dividing basal progenitors and oligodendrocyte precursors preferentially contact honeycomb vessels, but dividing apical progenitors are localized in avascular regions without Flt1-positive endothelial cells but directly contact with sprouting neovascular tip cells. Therefore, not all blood vessels are associated equally with neural progenitors. Furthermore, a disruption of normal vascular patterning can induce abnormalities in neural development, whereas the impaired features of neural progenitors influenced angiogenesis patterning. These results indicate that close association between the nervous and vascular systems is essential for neocortex assembly.