Healthy SD rats were randomly divided into 3 groups as sham operation (group A), ICH (group B), and HBO2 (group C). The behavioral change and angiogenesis in brain tissue of rats in each group were observed. The protein expression of PCNA, vWF, HIF1-α, and VEGF in rat brain was measured by immunohistochemistry, while the mRNA expression level of HIF1-α and VEGF was determined using quantitative real-time PCR. This study has investigated the effect of HBO2 on intracephalic angiogenesis in rats with intracerebral hemorrhage (ICH). There were significant differences in behavior score between HBO2 and ICH groups at 14, 21, and 28 days. A large number of vessel-like structures and microvessels were observed in perihematomal brain tissues in HBO2 group. There were significant differences in HIF1-α and VEGF protein and HIF1-α mRNA level between HBO2 and ICH groups at 14, 21, and 28 days; at 7, 14, 21, and 28 days, the differences in PCNA and vWF protein expression between the 2 groups were statistically significant. At 21 and 28 days, the expression levels of VEGF mRNA in the 2 groups differed significantly from each other. Our results indicate that HBO2 can significantly promote the expression of HIF1-α and VEGF at both mRNA and protein levels in rats with ICH, increase the protein expression of both PCNA and vWF, promote the formation of new blood vessels, and promote the recovery of behavioral ability, hence resulting in a rapid rehabilitation.

Obesity is a major contributor to the development of steatohepatitis and fibrosis from nonalcoholic fatty liver disease (NAFLD). Hypoxia aggravates progression of NAFLD. In mice on high-fat diet (HFD), hepatic steatosis leads to liver tissue hypoxia, evidenced by accumulation of hypoxia inducible factor-1-alpha (HIF-1α), which is a central regulator of the global response to hypoxia. Hepatocyte cell signaling is an important factor in hepatic fibrogenesis. We here hypothesize that HIF-1α knockout in hepatocyte may protect against liver fibrosis. We first found that HFD led to 80% more hepatic collagen deposition than Hif1a^-/- hep mice, which was confirmed by a-SMA staining of liver tissue. Body weight and liver weight were similar between groups. We then found the increasing HIF1a expression and decreasing PTEN expression in the mice on HFD and in PA-treated HepG2 cells. Finally, we found that HIF1 mediated PTEN/nfkb-p65 pathway plays an important role in the development of NAFLD to liver fibrosis. Collectively, these results identify a novel HIF1a/PTEN/NF-κ Bp65 signaling pathway in NAFLD, which could be targeted for the therapy.

Facioscapulohumeral muscular dystrophy (FSHD) is an incurable disease, characterized by skeletal muscle weakness and wasting. Genetically, FSHD is characterized by contraction or hypomethylation of repeat D4Z4 units on chromosome 4, which causes aberrant expression of the transcription factor DUX4 from the last repeat. Many genes have been implicated in FSHD pathophysiology, but an integrated molecular model is currently lacking. We developed a novel differential network methodology, Interactome Sparsification and Rewiring (InSpiRe), which detects network rewiring between phenotypes by integrating gene expression data with known protein interactions. Using InSpiRe, we performed a meta-analysis of multiple microarray datasets from FSHD muscle biopsies, then removed secondary rewiring using non-FSHD datasets, to construct a unified network of rewired interactions. Our analysis identified β-catenin as the main coordinator of FSHD-associated protein interaction signalling, with pathways including canonical Wnt, HIF1-α and TNF-α clearly perturbed. To detect transcriptional changes directly elicited by DUX4, gene expression profiling was performed using microarrays on murine myoblasts. This revealed that DUX4 significantly modified expression of the genes in our FSHD network. Furthermore, we experimentally confirmed that Wnt/β-catenin signalling is affected by DUX4 in murine myoblasts. Thus, we provide the first unified molecular map of FSHD signalling, capable of uncovering pathomechanisms and guiding therapeutic development.

Lower extremity venous insufficiency (VI) is a complication of pregnancy. The potential association of this venous disease with structural damage of the placenta has not been described. We analyzed the pattern of histopathologic lesions and the gene and protein expression of HIF1-α and apoptosis regulatory proteins. A prospective study was carried out on placenta samples from 43 women with pregnancy-associated VI and 24 age-matched pregnant healthy controls (HCs). Women with VI showed a significant increase in the number of villi (150.77 ± 42.55 VI versus 122.13 ± 27.74 HC) and in syncytial knots compared with those found in the placentas from HCs (67.15 ± 31.08 VI versus 42.49 ± 17.36 HC), and an increase in the number of bridges (32.40 ± 2.67 VI versus 22.73 ± 2.37 HC; P < .05). The mean number of syncytial nodes per villus is 1.37 ± 0.90 in the VI group and 0.49 ± 0.58 in the HC group (P < .001). Significant increases in the expression of Bax and caspase-3 and caspase-9 in the placentas from women with VI were observed compared with those found in HC. The expression of HIF-1α at both the messenger RNA and protein levels was also significantly increased in the placentas from women with VI. Our study demonstrates that placentas from women with pregnancy-associated VI show structural remodeling, with an increase in the number of villi and syncytial knots and enhanced apoptotic cellular death. Interestingly, this placental damage is associated with an increased expression of hypoxia-triggered molecular pathways, such as HIF-1α.

OBJECTIVE

The present study assessed the functions of the transcription factor hypoxia-inducible factor (HIF) in sensory neurons in models of acute, inflammatory, ischemic, and neuropathic pain. The alpha subunit, HIF1α, was specifically deleted in neurons of the dorsal root ganglia by mating HIF1α(fl/fl) mice with SNScre mice.

RESULTS

SNS-HIF1α(-/-) mice were more sensitive to noxious heat and cold pain stimulation than were HIF1α(fl/fl) control mice. They also showed heightened first-phase nociceptive responses in the formalin and capsaicin tests with increased numbers of cFos-positive neurons in the dorsal horn, and intensified hyperalgesia in early phases after paw inflammation and hind limb ischemia/reperfusion. The behavioral cold and heat pain hypersensitivity was explained by increased calcium fluxes after transient receptor potential channel activation in primary sensory neurons of SNS-HIF1α(-/-) mice and lowered electrical activation thresholds of sensory fibers. SNS-HIF1α(-/-) mice however, developed less neuropathic pain after sciatic nerve injury, which was associated with an abrogation of HIF1-mediated gene up-regulation.

METHODS

The results suggest that HIF1α is protective in terms of acute heat and cold pain but in case of ongoing activation in injured neurons, it may promote the development of neuropathic pain.

CONCLUSIONS

The duality of HIF1 in pain regulation may have an impact on the side effects of drugs targeting HIF1, which are being developed, for example, as anticancer agents. Specifically, in patients with cancer neuropathy, however, temporary HIF1 inhibition might provide a welcome combination of growth and pain reduction.

Cobalt chloride has been used as a hypoxia mimetic because it stabilizes hypoxia inducible factor-1α (HIF1-α) and activates gene transcription through a hypoxia responsive element (HRE). However, differences between hypoxia and hypoxia mimetic cobalt chloride in gene regulation remain elusive. Expression of ferritin, the major iron storage protein, is regulated at the transcriptional and posttranscriptional levels through DNA and RNA regulatory elements. Here we demonstrate that hypoxia and cobalt chloride regulate ferritin heavy chain (ferritin H) expression by two distinct mechanisms. Both hypoxia and cobalt chloride increased HIF1-α but a putative HRE in the human ferritin H gene was not activated. Instead, cobalt chloride but not hypoxia activated ferritin H transcription through an antioxidant responsive element (ARE), to which Nrf2 was recruited. Intriguingly, cobalt chloride downregulated ferritin H protein expression while it upregulated other ARE-regulated antioxidant genes in K562 cells. Further characterization demonstrated that cobalt chloride increased interaction between iron regulatory proteins (IRP1 and IRP2) and iron responsive element (IRE) in the 5'UTR of ferritin H mRNA, resulting in translational block of the accumulated ferritin H mRNA. In contrast, hypoxia had marginal effect on ferritin H transcription but increased its translation through decreased IRP1-IRE interaction. These results suggest that hypoxia and hypoxia mimetic cobalt chloride employ distinct regulatory mechanisms through the interplay between DNA and mRNA elements at the transcriptional and post-transcriptional levels.

As part of our ongoing search for novel therapeutic structures from microorganism, the chemical examination of marine fungus Phoma sp. resulted in the isolation of ergosterol, ergosterol peroxide (EP), and 9,11-dehydroergosterol peroxide (DEP). The bioassay results demonstrated that the three isolates reduced the viability of various cancer cells, with EP being highest in human lung cancer cell line A549 cells. EP induced caspase-dependent apoptosis through mitochondrial damage in A549 cells. Additionally, EP-induced ROS generation and apoptosis were attenuated by ROS-generating enzymes inhibitors and antioxidant N-acetylcysteine, indicated that ROS played an important role in EP-mediated apoptosis in A549 cells. Furthermore, it was observed that EP induced ROS-dependent autophagy, which attenuated apoptosis in A549 cells. On the other hand, EP reduced the LPS/ATP-induced proliferation and migration of A549 cells through attenuated NLRP3 inflammasome activity. Additionally, EP showed synergistic cytotoxic effect with antitumor drug Sorafenib in A549 cell viability inhibition. Furthermore, Micro-Western Array and Western blot analyses demonstrated that the protein levels of EGFR, HSP27, MEK5, AKT1, mTOR, Smad2, Smad3, TAB1, NF-κB, and HIF1-α decreased, while the levels of p-p38α, p-ERK1/2, p-JNK, fibronectin and p27 increased. Collectively, the results of this study demonstrated that EP might be useful to develop a therapeutic candidate for lung cancer complications.

BACKGROUND

Synergistic transcriptional activation by different stimuli has been reported along with a diverse array of mechanisms, but the full scope of these mechanisms has yet to be elucidated.

RESULTS

We present a detailed investigation of hypoxia-inducible factor (HIF) 1 dependent gene expression in endothelial cells which suggests the importance of crosstalk between the peroxisome proliferator-activated receptor (PPAR) β/δ and HIF signaling axes. A migration assay shows a synergistic interaction between these two stimuli, and we identify angiopoietin-like 4 (ANGPTL4) as a common target gene by using a combination of microarray and ChIP-seq analysis. We profile changes of histone marks at enhancers under hypoxia, PPARβ/δ agonist and dual stimulations and these suggest that the spatial proximity of two response elements is the principal cause of the synergistic transcription induction. A newly developed quantitative chromosome conformation capture assay shows the quantitative change of the frequency of proximity of the two response elements.

CONCLUSIONS

To the best of our knowledge, this is the first report that two different transcription factors cooperate in transcriptional regulation in a synergistic fashion through conformational change of their common target genes.

OBJECTIVE

We set out to characterize the voiding phenotypes of male mice to a water avoidance stress (WAS) protocol and compare the molecular changes with those induced by surgically induced partial bladder outlet obstruction (pBOO).

METHODS

Six-week-old male Swiss Webster mice housed with sibling littermates were individually placed on a platform centered in the middle of a water filled basin for 1 hr daily for 4 weeks. A non stressed cohort of sibling littermates served as controls. Measured end points included voiding frequency, voided volume, bladder mass, and in vivo cystometry. Molecular end points included myosin heavy chain (MHC) isoform distribution by PCR, and nuclear translocation of hypoxia inducible factor (HIF1α) and the nuclear factor of activated T-cells (NFAT) by gel shift assay. These molecular endpoints were compared with samples from male mice undergoing anatomic pBOO.

RESULTS

WAS resulted in increased average voided volumes and bladder mass, and a decrease in voiding frequency (P < 0.05). The slower MHC A isoform was only expressed in the pBOO group that developed severe hypertrophy. Gel shift assays revealed substantial increases in HIF1-α nuclear translocation in the group subjected to pBOO that developed severe hypertrophy but minimal changes in the pBOO group that developed minimal hypertrophy and the swim stress groups.

CONCLUSIONS

The WAS model induces moderate bladder wall hypertrophy in the absence of any surgical manipulation.

Pancreatic stellate cells (PSC) are involved in fibrogenesis and oncogenesis by modulating the extracellular matrix.

OBJECTIVE

To evaluate the effect of cellular stress on PSC activation using a model of normal human pancreatic tissue slices culture preserving the microenvironment.

METHODS

Thin sections (300 μm) of normal human pancreas were cultured under hyperoxia (90% O2) during 72 hours. Viability and morphological analysis were performed at baseline, H24, H48 and H72. Cell differentiation (insulin, trypsin, CA9 and CK7), hypoxia (HIF1-α), apoptosis (caspase-3), proliferation (Ki67), TGF-β expression and PSC activation (smooth muscle actin (SMA), nestin) were assessed using immunostaining, longitudinally. Control experiments were performed under normoxic conditions (21% O2).

RESULTS

Thirty sections per specimen (n=10) were cultured. Hypoxia pathways were activated by the higher expression of HIF1-α at H48 and H72. Apoptosis was limited with only rare acinar cells expressing of the caspase-3 at 48 and H72 (NS). Morphological analysis showed gradual appearance of acinoductal metaplasia, proven by CK7 expression and ductal phenotype of dedifferentiated acini. Transdifferentiation of PSC was shown by de novo SMA immunochemistry at H24 and H48. Expression of Ki67 index identified significant proliferation of activated PSC (double immunostaining Ki67-SMA) at H48 and H72 (p=0.02). In vitro culture of normal human pancreas thin sections is feasible with optimized cell viability at 72 hours. This model of culture in hyperoxic conditions provides evidences that cellular stress may rapidly induce transactivation of PSC with ducto-acinar metaplasia.

BACKGROUND

Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that regulates the adaptive response to hypoxia in mammalian cells. It consists of a regulatory subunit HIF-1alpha, which accumulates under hypoxic conditions, and a constitutively expressed subunit, HIF-1beta. In this study, we investigated HIF-1alpha naked DNA-induced angiogenesis in a cerebral ischemic model in vivo.

METHODS

We utilized a rat encephalo-myo-synangiosis (EMS) model and inoculated HIF-1alpha DNA into the brain surface or the temporal muscle. We analysed whether HIF-1alpha induced angiogenic factors and collateral circulation.

RESULTS

A histological section treated with HIF-1alpha DNA showed an increased expression of HIF1 a and VEGF with collateral circulation, in comparison with control DNA (p < 0.01). The HIF-1alpha transcription factor is able to promote significant angiogenesis development.

CONCLUSIONS

These results suggest the feasibility of a novel approach for therapeutic collateral circulation of cerebral ischemia in which neovascularization may be achieved indirectly using a transcriptional regulatory strategy.

OBJECTIVE

We tested whether delayed pharmacologic preconditioning elicited by isoflurane is protective in infarct-remodelled hearts.

RESULTS

Male Wistar rats were treated with the preconditioning drug isoflurane 6 weeks after permanent ligation of the left anterior descending coronary artery. Twenty-four and 48 h later, hearts were perfused on the Langendorff system and treated with cyclooxygenase-2 or 12-lipoxygenase inhibitors before exposure to 40 min of ischaemia followed by 90 min of reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining and lactate dehydrogenase release. Cyclooxygenase-2 expression and activity were measured by Western blotting and colorimetric assay. Nuclear translocation of cyclooxygenase-2-inducing transcription factors HIF1alpha, CREB, STAT3, and NFkappaB was determined. Post-infarct, remodelled hearts exhibit alterations in cellular signalling, time course and extent of isoflurane-induced late protection. While remodelled, preconditioned hearts exhibited protection exclusively at 24 h, healthy hearts showed sustained protection for up to 48 h, which correlated with cyclooxygenase-2 protein expression and enzymatic activity. The cyclooxygenase-2 inhibitors celecoxib and NS-398, but not the 12-lipoxygenase inhibitor cinnamyl-3,4-dihydroxycyanocinnamate, abolished delayed protection in both healthy and remodelled hearts, identifying cyclooxygenase-2 as a key mediator of late protection in both models. Isoflurane induced nuclear translocation of HIF1alpha in all hearts, but CREB was exclusively activated in healthy but not remodelled myocardium, which expressed higher levels of the CREB antagonist ICER. Delayed protection by isoflurane in remodelled hearts was more vulnerable to inhibition by celecoxib.

CONCLUSIONS

Isoflurane failed to mobilize cyclooxygenase-2-inducing CREB in ICER-overexpressing, remodelled hearts, which was associated with a shortening of the second window of protection.

BACKGROUND

Heterotopic ossification (HO) frequently causes complications following orthopaedic and trauma surgery and may drastically reduce the postoperative outcome due to pain and joint contracture. Current therapeutic options include NSAID's and local radiation. However, both options of prevention show disadvantages such as delayed fracture healing and impaired ossification as well as other side effects.(9) Our goal was to investigate a novel approach in the prevention of heterotopic ossification by pharmacologically interfering with the molecular signalling pathways involved in this process. Hypoxia leads to numerous effects on a cellular level, one of which is the activation of the transcriptional complex hypoxia-inducible factor (HIF).(19) Among several other actions, the HIF1-α signalling pathway in turn regulates angiogenesis through induction of the expression of vascular endothelial growth factor (VEGF).(21) We hypothesised that by pharmacologically interfering with the HIF-1α signalling pathway, the amount of HO formation may be reduced. Echinomycin is a known inhibitor of HIF-1-alpha and was used in our study with the aim to prevent HO from forming.

METHODS

We examined the effect of Echinomycin on HO formation in a murine model where an Achilles tenotomy was performed. This has previously been shown to reliably produce islets of heterotopic ossification within the soft tissue of mouse hind limbs at 10 weeks after surgery. The control group underwent Achilles tenotomy only, whereas the Echinomycin group additionally received Echinomycin subcutaneously. After trial completion, the limbs were harvested and Micro-CT was performed. Heterotopic bone volume was then identified in 3d images and quantified.

RESULTS

We found a highly significant reduction in the bone volume following subcutaneous administration of Echinomycin compared to the control group.

CONCLUSIONS

Although a substantial reduction could be achieved, it was not possible to completely prevent heterotopic ossification from forming. Further studies have yet to be conducted to optimise the results by altering the dosage and duration of administration as well as investigate the mechanism by which Echinomycin led to the reduction of HO formation.

OBJECTIVE

Early-stage oral squamous cell carcinoma (OSCC) treatment is based on anatomic location, clinical TNM staging, and histological grade. It is a heterogeneous disease group. Classification of patients with OSCC by immunohistochemical analysis of established oncoproteins and evaluate disease course was our primary objective. Characterization of stage I OSCC patients in Southwest Finland was our secondary objective.

METHODS

Immunohistochemical analysis of tumor specimens and retrospective analysis of patient data of the patient treated in Turku University Hospital for T1N0M0 OSCC during the years 2000-2004.

METHODS

Paraffin-embedded tumor specimens from 35 OSCC patients were collected and analyzed for HIF-1α, CD44, p16, Ki67, and podoplanin by immunohistochemistry and correlated with clinical findings.

RESULTS

Tumoral CD44 and HIF1-α expression levels, in combination, predicted 5-year disease-free survival. Reduced expression of CD44 and elevated expression of HIF1-α is associated with the lowest probability of disease-free survival compared to the population as a whole (P < .001 in Kaplan-Meier analysis). Patients with grade I tumors demonstrated improved disease-specific survival compared to those with grade II tumors (P = .027). No association was seen between p16 expression, Ki67 labeling index, or podoplanin expression and prognosis in our 35 specimens.

CONCLUSIONS

HIF-1α and CD44 immunohistochemical detection could potentially serve as a prognostic tool in therapy selection for early-stage OSCC.

METHODS

2b.

OBJECTIVE

To investigate the relation of reactive oxygen species (ROS) to hypoxia induced factor 1α (HIF-1α) in gastric ischemia.

METHODS

The animal model of gastric ischemia reperfusion was established by placing an elastic rubber band on the proximal part of the bilateral lower limb for ligature for 3 h and reperfusion for 0, 1, 3, 6, 12 or 24 h. Ischemic post-conditioning, three cycles of 30-s reperfusion and 30-s femoral aortic reocclusion were conducted before reperfusion. Histological and immunohistochemical methods were used to assess the gastric oxidative damage and the expression of HIF1-α in gastric ischemia. The malondialdehyde (MDA) content and superoxide dismutase (SOD), xanthine oxidase (XOD) and myeloperoxidase (MPO) activities were determined by colorimetric assays.

RESULTS

Ischemic post-conditioning can reduce post-ischemic oxidative stress and the expression of HIF-1α of gastric tissue resulting from limb ischemia reperfusion injury. MDA, SOD, XOD and MPO were regarded as indexes for mucosal injuries from ROS, and ROS was found to affect the expression of HIF-1α under gastric ischemic conditions.

CONCLUSIONS

ROS affects HIF-1α expression under gastric ischemic conditions induced by limb ischemia reperfusion injury. Therefore, ROS can regulate HIF-1α expression in gastric ischemia.

Cells exposed to low-oxygen conditions (hypoxia) alter their metabolism to survive. This response, although vital during development and high-altitude survival, is now known to be a major factor in the selection of cells with a transformed metabolic phenotype during tumorigenesis. It is thought that hypoxia-selected cells have increased invasive capacity and resistance to both chemo- and radiotherapies, and therefore represent an attractive target for antitumor therapy. Hypoxia inducible factors (HIFs) are responsible for the majority of gene expression changes under hypoxia, and are themselves controlled by the oxygen-sensing HIF prolyl hydroxylases (PHDs). It was previously shown that mutations in succinate dehydrogenase lead to the inactivation PHDs under normoxic conditions, which can be overcome by treatment with alpha-ketoglutarate derivatives. Given that solid tumors contain large regions of hypoxia, the reactivation of PHDs in these conditions could induce metabolic catastrophe and therefore prove an effective antitumor therapy. In this report we demonstrate that derivatized alpha-ketoglutarate can be used as a strategy for maintaining PHD activity under hypoxia. By increasing intracellular alpha-ketoglutarate and activating PHDs we trigger PHD-dependent reversal of HIF1 activation, and PHD-dependent hypoxic cell death. We also show that derivatized alpha-ketoglutarate can permeate multiple layers of cells, reducing HIF1alpha levels and its target genes in vivo.

Mammalian target of rapamycin (mTOR) is essential in controlling several cellular functions. This pathway is dysregulated in keloid disease (KD). KD is a common fibroproliferative dermal lesion with an ill-defined treatment strategy. KD demonstrates excessive matrix deposition, angiogenesis, and inflammatory cell infiltration. In KD, both total and phosphorylated forms of mTOR and p70(S6K)(Thr421/Ser424) are upregulated. Therefore, the aim of this study was to investigate adenosine triphosphate-competitive inhibitors of mTOR kinase previously unreported in keloid and their comparative efficacy with Rapamycin. Here, we present two mTOR kinase inhibitors, KU-0063794 and KU-0068650, that target both mTORC1 and mTORC2 signaling. Treatment with either KU-0063794 or KU-0068650 resulted in complete suppression of Akt, mTORC1, and mTORC2, and inhibition of keloid cell spreading, proliferation, migration, and invasive properties at a very low concentration (2.5 μmol l(-1)). Both KU-0063794 and KU-0068650 significantly (P<0.05) inhibited cell cycle regulation and HIF1-α expression compared with that achieved with Rapamycin alone. In addition, both compounds induced shrinkage and growth arrest in KD, associated with the inhibition of angiogenesis, induction of apoptosis, and reduction in keloid phenotype-associated markers. In contrast, Rapamycin induced minimal antitumor activity. In conclusion, potent dual mTORC1 and mTORC2 inhibitors display therapeutic potential for the treatment of KD.

The aim of this study was to examine the anti-tumour effects of dual vertical VEGF targeting consisting in the association between bevacizumab, a VEGF-depleting drug, and the VEGF receptor antityrosine kinase AZD2171. Mice bearing human head and neck CAL33 xenografted tumours were treated once daily for 11 d with either vehicle (controls), AZD2171 (2.5mg/kg/day, p.o.), bevacizumab (5mg/kg/day, i.p.) or the bevacizumab-AZD2171 combination. The AZD2171-bevacizumab combination produced additive effects on tumour growth and reduced the number of proliferating cells relative to control. Bevacizumab did not influence tumour vascular necrosis whilst AZD2171 (p=0.01) and the combination (p=0.01) increased it. The number of mature tumour cells decreased significantly with the combination treatment only (p=0.001), which induced the largest increase in the Bax/Bcl2 ratio (up to 25-fold) and a progressive 3-fold decrease in HIF1-alpha expression between 24h and 192h. The present data indicate that there is no redundancy in targeting the same angiogenic pathway with the presently tested clinically applicable drugs. The study provides a strong rationale for future clinical trials.

Fibroblast Growth Factor receptor (FGFR) activity plays crucial roles in tumor growth and patient survival. However, FGF (Fibroblast Growth Factor) signaling as a target for cancer therapy has been under-investigated compared to other receptor tyrosine kinases. Here, we studied the effect of FGFR signaling inhibition on tumor growth, metastasis and lymphangiogenesis by expressing a dominant negative FGFR (FGFR-2DN) in an orthotopic mouse mammary 66c14 carcinoma model. We show that FGFR-2DN-expressing 66c14 cells proliferate in vitro slower than controls. 66c14 tumor outgrowth and lung metastatic foci are reduced in mice implanted with FGFR-2DN-expressing cells, which also exhibited better overall survival. We found 66c14 cells in the lumen of tumor lymphatic vessels and in lymph nodes. FGFR-2DN-expressing tumors exhibited a decrease in VEGFR-3 (Vascular Endothelial Growth Factor Receptor-3) or podoplanin-positive lymphatic vessels, an increase in isolated intratumoral lymphatic endothelial cells and a reduction in VEGF-C (Vascular Endothelial Growth Factor-C) mRNA expression. FGFs may act in an autocrine manner as the inhibition of FGFR signaling in tumor cells suppresses VEGF-C expression in a COX-2 (cyclooxygenase-2) or <em>HIF1</em>-<em>α</em> (hypoxia-inducible factor-1 <em>α</em>) independent manner. FGFs may also act in a paracrine manner on tumor lymphatics by inducing expression of pro-lymphangiogenic molecules such as VEGFR-3, integrin <em>α</em>9, prox1 and netrin-1. Finally, in vitro lymphangiogenesis is impeded in the presence of FGFR-2DN 66c14 cells. These data confirm that both FGF and VEGF signaling are necessary for the maintenance of vascular morphogenesis and provide evidence that targeting FGFR signaling may be an interesting approach to inhibit tumor lymphangiogenesis and metastatic spread.

To establish alternative targeted therapies against triple negative (TN) breast cancer, the energy metabolism and the sensitivity of cell growth, migration, and invasiveness toward metabolic, canonical, and NSAID inhibitors were analyzed in MDA-MB-231 and MDA-MB-468, two TN metastatic breast cancer cell lines, under both normoxia (21% O2) and hypoxia (0.1% O2). For comparative purposes, the analysis was also carried out in the less-metastatic breast MCF-7 cancer cells. Under normoxia, oxidative phosphorylation (OxPhos) was significantly higher (2-times) in MDA-MB-468 than in MDA-MB-231 and MCF-7, whereas their glycolytic fluxes and OxPhos and glycolytic protein contents were all similar. TN cancer cell lines mainly depended on OxPhos (62-75%), whereas MCF-7 cells equally depended on both pathways for ATP supply. Hypoxia for 24 h promoted a significant increase (>20 times) in the glycolytic transcriptional master factor HIF1-α in its target proteins GLUT-1, HKI and II, and LDH-A (2-4 times) as well as in the glycolytic flux (1.3-2 times) vs normoxia in MDA-MB-468, MDA-MB-231, and MCF-7. On the contrary, hypoxia decreased (15-60%) the contents of COXIV, 2OGDH, ND1, and ATP synthase as well as the OxPhos flux (50-75%), correlating with a high mitophagy level in the three cell lines. Under hypoxia, the three cancer cell lines mainly depended on glycolysis (70-80%). Anti-mitochondrial drugs (oligomycin, casiopeina II-gly, and methoxy-TEA) and celecoxib, at doses used to block OxPhos, significantly decreased TN cancer cell proliferation (IC50 = 2-20 μM), migration capacity (10-90%), and invasiveness (25-65%). The present data support the use of mitochondrially targeted inhibitors for the treatment of TN breast carcinoma.

BACKGROUND

A variety of NADPH oxidase (Nox) isoforms including Noxs 1, 2, 4 and 5 catalyze the formation of reactive oxygen species (ROS) in the vascular wall. The Nox2 isoform complex has arguably received the greatest attention in the progression of atherogenesis in animal models. Thus, in the current study we postulated that specific Nox2 oxidase inhibition could reverse or attenuate atherosclerosis in mice fed a high-fat diet.

METHODS

We evaluated the effect of isoform-selective Nox2 assembly inhibitor on the progression and vascularization of atheromatous plaques. Apolipoprotein E-deficient mice (ApoE-/-) were fed a high fat diet for two months and treated over 15 days with Nox2ds-tat or control sequence (scrambled); 10 mg/kg/day, i.p. Mice were sacrificed and superoxide production in arterial tissue was detected by cytochrome C reduction assay and dihydroethidium staining. Plaque development was evaluated and the angiogenic markers VEGF, HIF1-α and visfatin were quantified by real time qRT-PCR. MMP-9 protein release and gelatinolytic activity was determined as a marker for vascularization.

RESULTS

Nox2ds-tat inhibited Nox-derived superoxide determined by cytochrome C in carotid arteries (2.3 ± 0.1 vs 1.7 ± 0.1 O2(•-) nmol/min*mg protein; P < 0.01) and caused a significant regression in atherosclerotic plaques in aorta (66 ± 6 μm(2) vs 37 ± 1 μm(2); scrmb vs. Nox2ds-tat; P < 0.001). Increased VEGF, HIF-1α, MMP-9 and visfatin expression in arterial tissue in response to high-fat diet were significantly attenuated by Nox2ds-tat which in turn impaired both MMP-9 protein expression and activity.

CONCLUSIONS

Given these results, it is quite evident that selective Nox inhibitors can reverse vascular pathology arising with atherosclerosis.

Lipid accumulation is a driving force in tumor development, as it provides tumor cells with both energy and the building blocks of phospholipids for construction of cell membranes. Aberrant homeostasis of lipid metabolism has been observed in various tumors; however, the molecular mechanism has not been fully elucidated. Methods: Yin yang 1 (YY1) expression in hepatocellular carcinoma (HCC) was analyzed using clinical specimens, and its roles in HCC in lipid metabolism were examined using gain- and loss-of function experiments. The mechanism of YY1 regulation on peroxisome proliferator-activated receptor gamma coactivator-1β (PGC-1β) and its downstream genes medium-chain acyl-CoA dehydrogenase (MCAD) and long-chain acyl-CoA dehydrogenase (LCAD) were investigated using molecular biology and biochemical methods. The role of YY1/ PGC-1β axis in hepatocarcinogenesis was studied using xenograft experiment. Results: This study showed that YY1 suppresses fatty acid β-oxidation, leading to increase of cellular triglyceride level and lipid accumulation in HCC cells, and subsequently induction of the tumorigenesis potential of HCC cells. Molecular mechanistic study revealed that YY1 blocks the expression of PGC-1β, an activator of fatty acid β-oxidation, by directly binding to its promoter; and thus downregulates PGC-1β/MCAD and PGC1-β/LCAD axis. Importantly, we revealed that YY1 inhibition on PGC-1β occurs irrespective of the expression of hypoxia-inducible factor-1α (HIF1-α), enabling it to promote lipid accumulation under both normoxic and hypoxic conditions. Conclusion: Our study reveals the critical role of YY1/PGC-1β axis in HCC cell lipid metabolism, providing novel insight into the molecular mechanisms associated with tumor cell lipid metabolism, and a new perspective regarding the function of YY1 in tumor progression. Thus, our study provides evidences regarding the potential of YY1 as a target for lipid metabolism-based anti-tumor therapy.

In the heart, catecholamine effects occur by activation of beta-adrenergic receptors (β-ARs), mainly the beta 1 (β1-AR) and beta 2 (β2-AR) subtypes, both of which couple to the Gs protein that activates the adenylyl cyclase signaling pathway. The β2-ARs can also couple to the Gi protein that counterbalances the effect of the Gs protein on cyclic adenosine monophosphate production and activates the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway. In several cardiovascular disorders, including heart failure, as well as in aging and in animal models of environmental stress, a reduction in the β1/β2-AR ratio and activation of the β2-AR-Gi-PI3K-Akt signaling pathway have been observed. Recent studies have shown that sirtuins modulate certain organic processes, including the cellular stress response, through activation of the PI3K-Akt signaling pathway and of downstream molecules such as p53, Akt, HIF1-α, and nuclear factor-kappa B. In the heart, SIRT1, SIRT3, and β2-ARs are crucial to the regulation of the cardiomyocyte energy metabolism, oxidative stress, reactive oxygen species production, and autophagy. SIRT1 and the β2-AR-Gi complex also control signaling pathways of cell survival and death. Here, we review the role played by β2-ARs and sirtuins during aging, heart failure, and adaptation to stress, focusing on the putative interplay between the two. That relationship, if proven, merits further investigation in the context of cardiac function and dysfunction.

Here, antitumor mechanism of cinnamaldehyde derivative CB-PIC was elucidated in human SW620 colon cancer cells. CB-PIC significantly exerted cytotoxicity, increased sub-G1 accumulation, and cleaved PARP with apoptotic features, while it enhanced the phosphorylation of AMPK alpha and ACC as well as activated the ERK in hypoxic SW620 cells. Furthermore, CB-PIC suppressed the expression of HIF1 alpha, Akt, and mTOR and activated the AMPK phosphorylation in hypoxic SW620 cells. Conversely, silencing of AMPK α blocked PARP cleavage and ERK activation induced by CB-PIC, while ERK inhibitor PD 98059 attenuated the phosphorylation of AMPK α in hypoxic SW620 cells, implying cross-talk between ERK and AMPK α . Furthermore, cotreatment of CB-PIC and metformin enhanced the inhibition of HIF1 α and Akt/mTOR and the activation of AMPK α and pACC in hypoxic SW620 cells. In addition, CB-PIC suppressed the growth of SW620 cells inoculated in BALB/c athymic nude mice, and immunohistochemistry revealed that CB-PIC treatment attenuated the expression of Ki-67, CD34, and CAIX and increased the expression of pAMPK α in CB-PIC-treated group. Interestingly, CP-PIC showed better antitumor activity in SW620 colon cancer cells under hypoxia than under normoxia, since it may be applied to chemoresistance. Overall, our findings suggest that activation of AMPK α and ERK mediates CB-PIC-induced apoptosis in hypoxic SW620 colon cancer cells.