Downregulation Of COX-2 Research Articles

The Effect of PSD-93 Deficiency on the Expression of Early Inflammatory Cytokines Induced by Ischemic Brain Injury.

The aim of the study was to explore the effect of PSD-93 deficiency on the expression of early inflammatory cytokines induced by cerebral ischemia/reperfusion injury. Ten- to twelve-week-old male PSD-93 knockout (PSD-93 KO) mice (C57BL/6 genetic background) and wild-type (WT) littermates were randomly divided into sham and ischemia/reperfusion (I/R) group. The focal cerebral I/R model was established by middle cerebral artery occlusion (MCAO) suture method. RT-PCR was used to detect the mRNA expression of IL-6, IL-10, Cox-2, iNOS, and TNF-α4h following reperfusion. Infarct volume at different time points after I/R was analyzed using 2,3,5-triphenyl tetrazolium staining, and neurological damage score (neurological severity scores, NSS) was used to evaluate the effect of PSD-93 gene knockout on the MCAO-induced neurological injury. In WT mice, early I/R injury led to the increase in the mRNA expression of proinflammatory cytokines IL-6, Cox-2, iNOS, and TNF-α that coincided with the decrease in the expression of anti-inflammatory cytokine IL-10, as compared to the sham group (P<0.05). This effect was markedly attenuated by depleting PSD-93 levels by gene knockout. As compared to sham group, in PSD-93 KO mice I/R4h led to downregulation of Cox-2 and iNOS expression, and increase in the mRNA levels of IL-10 (P<0.05). In addition, following MCAO, PSD-93 KO mice exhibited improved NSS and reduced infarct volumes, as compared with WT animals. PSD-93 knockout may play a neuroprotective role by mediating the early release of inflammatory cytokines induced by cerebral ischemia.

Berberine Inhibits Invasion and Metastasis of Colorectal Cancer Cells via COX-2/PGE2 Mediated JAK2/STAT3 Signaling Pathway.

Berberin, extracted from Chinese herbal medicine Coptis chinensis, has been found to have anti-tumor activities. However, the underlying mechanisms have not been fully elucidated. Our current study demonstrated that berberin inhibited the in vitro and in vivo growth, migration/invasion of CRC cells, via attenuating the expression levels of COX-2/PGE2, following by reducing the phosphorylation of JAK2 and STAT3, as well as the MMP-2/-9 expression. We further clarified that an increase of COX-2/PGE2 expression offset the repressive activity of Berberin on JAK2/STAT3 signaling, and a JAK2 inhibitor AZD1480 blocked the effect of COX-2/PGE2 on MMP-2/-9 expression. In summary, Berberin inhibited CRC invasion and metastasis via down-regulation of COX-2/PGE2- JAK2/STAT3 signaling pathway.

Gastroprotective potential of Buddleja scordioides Kunth Scrophulariaceae infusions; effects into the modulation of antioxidant enzymes and inflammation markers in an in vivo model

Ethnopharmacological relevanceA common plant used to treat several gastric disorders is Buddleja scordioides Kunth, commonly known as salvilla. Aim of the studyTo detect inflammatory markers, in order to evaluate the gastroprotective potential of salvilla infusions, as this could have beneficial impact on the population exposed to gastric ulcers and colitis. Materials and methodsThe present work attempted infusions were prepared with B. scordioides (1% w/w) lyophilized and stored. Total phenolic content and GC–MS analysis were performed. Wistar rats were divided into five groups (n=8), a negative vehicle control, an indomethacin group, and three experimental groups, named preventive, curative, and suppressive. All rats were sacrificed under deep ether anesthesia (6h) after the last oral administration of indomethacin/infusion. The rat stomachs were promptly excised, weighed, and chilled in ice-cold and 0.9% NaCl. Histological analysis, nitrites quantification and immunodetection assays were done. ResultsB. scordioides infusions markedly reduced the visible hemorrhagic lesions induced by indomethacin in rat stomachs, also showed down-regulation of COX2, IL-8 and TNFα and up-regulation of COX-1 with a moderate down-regulation of NFkB and lower amount of nitrites. However, this behavior was dependent on the treatment, showing most down-regulation of COX-2, TNFα and IL-8 in the curative treatment; more down-regulation of NF-kB in the preventive treatment; and more up-regulation of COX-1 for the suppressor and preventive treatments. ConclusionThe anti-inflammatory potential of B. scordioides infusions could be related with the presence of polyphenols as quercetin in the infusion and how this one is consumed.

Molecular inhibition of prostaglandin E2 with GW627368X: Therapeutic potential and preclinical safety assessment in mouse sarcoma model

Prostaglandin E2, the major COX-2 product, acts via 4 functionally distinct prostanoid receptors, EP(1–4). PGE-2, through its receptors, feeds back to positively increase COX-2 expression augmenting its own synthesis thereby driving angiogenesis, while suppressing apoptosis and innate immunity. In addition to the well characterized PGE2/EP4/cAMP/PKA/CREB, EP4 activation increases GSK3 phosphorylation via PI3K and Akt consequently reducing β-catenin phosphorylation. EP4 induces angiogenesis by enhancing VEGF production via ERK activation. These effects of EP4 are asserted either directly or via EGFR transactivation depending on the type of cancer. In view of the safety concerns regarding long term use of COX-2 inhibitors and to find more effective alternatives, we evaluated the potential of EP4 prostanoid receptor as a target for treating cancer progression using a highly selective EP4 antagonist, 4-(4,9-diethoxy-1,3-dihydro-1-oxo-2H-benz[f]isoindol-2-yl)-N-(phenylsulfonyl)-benzeneacetamide. Oral administration of GW627368X showed significant tumor regression characterized by tumor reduction and induction of apoptosis. Reduction in prostaglandin E2 synthesis also led to reduced level of VEGF in plasma. Regulation of multiple pathways downstream of EP4 was evident by down regulation of COX-2, p-Akt, p-MAPK and p-EGFR. Considering wide distribution of the EP4 prostanoid receptor in major organs and the array of physiological processes it contributes to, the safety profile of the drug was analyzed. No major organ toxicity, immunosupression, behavioral change or change in blood parameters attributable to the drug was observed. The results assert the significance of EP4 prostanoid receptor as a therapeutic target as well as the safety of EP4 blockade by GW627368X.

Protective effects of dendrosomal curcumin on an animal metastatic breast tumor

Curcumin has been shown to inhibit migration and invasion of cancer angiogenesis via interacting with key regulatory molecules like NF-κB. Rapidly metabolized and conjugated in the liver, curcumin has the limited systemic bioavailability. Previous results have shown a new light of potential biocompatibility, biodegradability, as well as anti-cancer effects of dendrosomal curcumin (DNC) in biological systems. The present study aims to deliberate the protective effects of DNC on metastatic breast tumor in vitro and in vivo. After the dosing procedure, twenty-seven female mice were divided into 40 and 80mg/kg groups of DNC, along with a control group to investigate the anti-metastatic effects of DNC on mammary tumor-bearing mice. In vitro results showed that the different concentrations of DNC reduced the migration and the adhesion of 4T1 cells after 24h (P<0.05). Under the dosing procedure, DNC was safe at 80mg/kg and lower doses. The treated DNC animals had a higher survival rate and lower metastatic signs (14%) compared to control (100%) (P<0.05). The metastatic tumors were more common in control mice than the treated groups in the lung, the liver and the sternum tissues. Animals treated with DNC had smaller tumor volume in comparison with control group (P<0.05). Final mean tumor volume reached to approximately 1.11, 0.31 and 0.27cm3 in the control, and 40 and 80mg/kg DNC groups, respectively (P<0.05). Furthermore, suppression of NF-κB expression by DNC led to down-regulation of VEGF, COX-2, and MMP-9 expressions in the breast tumor, the lung, the brain, the spleen and the liver tissues (P<0.05). These outcomes indicate that dendrosomal curcumin has a chemoprotective effect on the breast cancer metastasis through suppression of NF-κB and its regulated gene products.

Terpenoids Isolated From the Shoot of Plectranthus hadiensis Induces Apoptosis in Human Colon Cancer Cells Via the Mitochondria-Dependent Pathway

The plant Plectranthus hadiensis is a rich source of many bioactive phytochemicals, especially terpenoids. The terpenoid fraction was isolated and phytochemical characterization was done using GC-MS. The aim of the present study was to find out the antiproliferative activity and the mechanism of cell death induction by the terpenoid fraction on human colon cancer cells (HCT-15). MTT assay was performed with different concentrations of the fraction (10, 20, and 50 µg/mL) to obtain IC50 value for 24 h to induce cell death. The induction of apoptosis were studied by Hoechst staining, acridine orange/ethidium bromide staining, Comet assay, DNA fragmentation, and caspase-3 activity assays. The mechanism of apoptosis induction was studied by expression analysis of antiapoptotic Bcl-2 and proapoptotic Bax using RT-PCR and also by Western blot analysis of proteins involved in the apoptotic pathway. The terpenoid fraction induced significant morphological changes and DNA fragmentation in the cells. Positive Hoechst staining and acridine orange/ethidium bromide staining indicated apoptosis induction by the fraction. DNA fragmentation, which is a characteristic feature of apoptosis, was also observed. Upregulation of caspase-3 activity and proapoptotic Bax, and the downregulation of antiapoptotic Bcl-2 and COX-2 confirmed that the apoptosis induction was via the mitochondria-dependent pathway.

N-trans-feruloyltyramine inhibits LPS-induced NO and PGE2 production in RAW 264.7 macrophages: Involvement of AP-1 and MAP kinase signalling pathways

Mitogen-activated protein kinase (MAPK) signalling pathway can regulate inflammatory and immune responses. N-trans-feruloyltyramine (FLA) is an active phenylpropanoid compound. It possesses antioxidant, antimicrobial, anti-melanogenesis, and anticancer activities. However, the precise molecular mechanisms underlying FLA modulation of cytokine expression in LPS-stimulated RAW 264.7 macrophages have not been fully investigated. In this study, we examined the mechanisms underlying the immunomodulative effects of FLA isolated from Arcangelisia gusanlung. FLA strongly suppressed mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), but not tumor necrosis factor (TNF)-α, thereby inhibiting the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Furthermore, FLA also inhibited nuclear translocation of activation protein (AP)-1, and simultaneously decreased the expression and phosphorylation of the c-Jun N-terminal kinase (JNK) protein. These results suggest that the anti-inflammatory effects of FLA might be attributed to downregulation of COX-2 and iNOS via suppression of AP-1 and the JNK signalling pathway in RAW 264.7 macrophages.

Tetramethylpyrazine inhibits the proliferation of acute lymphocytic leukemia cell lines via decrease in GSK-3β.

Tetramethylpyrazine (TMP) has been proven to be an anticancer agent in many studies. However, its effectiveness in acute lymphoblastic leukemia (ALL) and its molecular mechanisms are still unclear. The present study aimed to evaluate the effect of TMP against Jurkat and SUP-B15 ALL cell lines and to investigate the possible detailed mechanism of action of TMP. A Cell Counting Kit-8 (CCK-8) assay was employed to examine the proliferation of Jurkat and SUP-B15 cells. Flow cytometric analysis was conducted to detect the cell cycle distribution and apoptotic rate. The expression of total glycogen synthase kinase-3β (GSK-3β), cox-2, survivin, bcl-2 and p27 RNA and protein levels was detected by quantitative real-time PCR and western blot assay, respectively. Additionally, western blot analysis was used to determine the whole-cell and nuclear protein levels of GSK-3β downstream transcription factors, NF-κB (p65) and c-myc. TMP inhibited the proliferation of Jurkat and SUP-B15 cells in a dose- and time-dependent manner, with IC₅₀ values of 120 and 200 µg/ml, respectively at 48 h. TMP induced the apoptosis of Jurkat and SUP-B15 cells and synergistically blocked cell cycle progression at the G0/G1 phase. Cells treated with TMP exhibited significantly attenuated GSK-3β, NF-κB (p65) and c-myc expression, followed by downregulation of bcl-2, cox-2 and survivin and an upregulation of p27. The results showed that TMP induced apoptosis and caused cell cycle arrest in Jurkat and SUP-B15 cells through the downregulation of GSK-3β, which may have further prevented the induced translocation of NF-κB and c-myc from the cytoplasm to the nucleus.

Interleukin-21 sustains inflammatory signals that contribute to sporadic colon tumorigenesis.

Interleukin (IL)-21 triggers inflammatory signals that contribute to the growth of neoplastic cells in mouse models of colitis-associated colorectal cancer (CRC). Because most CRCs are sporadic and arise in the absence of overt inflammation we have investigated the role of IL-21 in these tumors in mouse and man. IL-21 was highly expressed in human sporadic CRC and produced mostly by IFN-γ-expressing T-bet/RORγt double-positive CD3+CD8- cells. Stimulation of human CRC cell lines with IL-21 did not directly activate the oncogenic transcription factors STAT3 and NF-kB and did not affect CRC cell proliferation and survival. In contrast, IL-21 modulated the production of protumorigenic factors by human tumor infiltrating T cells. IL-21 was upregulated in the neoplastic areas, as compared with non-tumor mucosa, of Apc(min/+) mice, and genetic ablation of IL-21 in such mice resulted in a marked decrease of both tumor incidence and size. IL-21 deficiency was associated with reduced STAT3/NF-kB activation in both immune cells and neoplastic cells, diminished synthesis of protumorigenic cytokines (that is, IL-17A, IL-22, TNF-α and IL-6), downregulation of COX-2/PGE2 pathway and decreased angiogenesis in the lesions of Apc(min/+) mice. Altogether, data suggest that IL-21 promotes a protumorigenic inflammatory circuit that ultimately sustains the development of sporadic CRC.

Mesenchymal stem cells alleviate airway inflammation and emphysema in COPD through down-regulation of cyclooxygenase-2 via p38 and ERK MAPK pathways.

Bone marrow-derived mesenchymal stem cells (MSCs) have been identified as one possible strategy for the treatment of chronic obstructive pulmonary disease (COPD). Our previous studies have demonstrated that MSC administration has therapeutic potential in airway inflammation and emphysema via a paracrine mechanism. We proposed that MSCs reverse the inflammatory process and restore impaired lung function through their interaction with macrophages. In our study, the rats were exposed to cigarette smoke (CS), followed by the administration of MSCs into the lungs for 5 weeks. Here we show that MSC administration alleviated airway inflammation and emphysema through the down-regulation of cyclooxygenase-2 (COX-2) and COX-2-mediated prostaglandin E2 (PGE2) production, possibly through the effect on alveolar macrophages. In vitro co-culture experiments provided evidence that MSCs down-regulated COX-2/PGE2 in macrophages through inhibition of the activation-associated phosphorylation of p38 MAPK and ERK. Our data suggest that MSCs may relieve airway inflammation and emphysema in CS-exposed rat models, through the inhibition of COX-2/PGE2 in alveolar macrophages, mediated in part by the p38 MAPK and ERK pathways. This study provides a compelling mechanism for MSC treatment in COPD, in addition to its paracrine mechanism.

STAT3 cooperates with the non-canonical NF-κB signaling to regulate pro-labor genes in the human placenta

IntroductionOur recent studies have shown that constitutively activated non-canonical RelB/NF-κB2 (p52) in the human placenta positively regulates the pro-labor genes CRH and COX-2. STAT3 regulates NF-κB2 (p100) processing to active p52, and in turn, nuclear activation of RelB/p52, by directly binding to p100/p52 in a variety of cancer cells. In the current study, we tested the hypothesis that STAT3 is involved in regulation of pro-labor genes by associating with RelB/p52 heterodimers in the human placenta. MethodsWe used a variety of techniques including immunohistochemical staining, gene silencing, ectopic expression, chromatin immunoprecipitation, Western blot, RT-qPCR, and immunofluorescence assays in primary culture of cytotrophoblast and placental tissues. ResultsWe found that knockdown of STAT3 led to down-regulation of both CRH and COX-2 in a dose-dependent manner. By using chromatin immunoprecipitation, we further showed that interaction of RelB with the CRH or COX-2 gene promoters decreased when STAT3 was depleted. Immunofluorescence demonstrated co-localization of STAT3 with RelB or p100/p52 in both the cytoplasm and nucleus of term cytotrophoblasts. DiscussionCollectively, these results suggest that STAT3 constitutes part of the RelB/p52-containing activator complex that positively regulates pro-labor genes in the human placenta.

Oleic acid ameliorates Aβ-induced inflammation by downregulation of COX-2 and iNOS via NFκB signaling pathway

Beta-amyloid peptide (Aβ) damage is one of major potential causes of Alzheimer's disease (AD) and its modulation has emerged as a promising approach to control the onset of AD. In the present study, the effects of oleic acid (OA) against Aβ25–35-stimulated neurotoxicity, inflammatory responses, and further molecular mechanism underlying the neuroprotective properties of OA in PC12 cells were investigated. Pre-treatment of OA significantly decreased Aβ25–35-mediated cytotoxicity by increasing cell viability through the attenuation of intracellular reactive oxygen species (ROS) level and downregulation of pro-apoptotic activated caspase-3, thereby mitigating apoptotic morphological alterations. Improper up-regulation of both cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) by Aβ25–35 was significantly suppressed by preconditioning of OA through repression of the inhibitory unit I-κB degradation, which impedes subsequent nuclear translocation of the functionally active subunit of transcription factor nuclear factor-kappa B (NF-κB). OA noticeably attenuated Aβ25–35-stimulated phosphorylation of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK1/2), and c-Jun-N-terminal kinase (JNK). Taken together, these findings suggest that the mechanisms responsible for anti-apoptotic and anti-inflammatory properties of OA in Aβ25–35-mediated neuronal damage is associated with COX-2 and iNOS downregulation through activation of NF-κB mediated by upstream kinases including JNK, ERK and p38 MAPK.

Cyclooxygenase-2 Silencing for the Treatment of Colitis: A Combined In Vivo Strategy Based on RNA Interference and Engineered Escherichia Coli

Nonpathogenic-invasive Escherichia coli (InvColi) bacteria are suitable for genetic transfer into mammalian cells and may act as a vehicle for RNA Interference (RNAi) in vivo. Cyclooxygenase-2 (COX-2) is overexpressed in ulcerative colitis (UC) and Crohn's disease (CD), two inflammatory conditions of the colon and small intestine grouped as inflammatory bowel disease (IBD). We engineered InvColi strains for anti-COX-2 RNAi (InvColi(shCOX2)), aiming to investigate the in vivo feasibility of a novel COX-2 silencing strategy in a murine model of colitis induced by dextran sulfate sodium (DSS). Enema administrations of InvColi(shCOX2) in DSS-treated mice led to COX-2 downregulation, colonic mucosa preservation, reduced colitis disease activity index (DAI) and increased mice survival. Moreover, DSS/InvColi(shCOX2)-treated mice showed lower levels of circulating pro-inflammatory cytokines and a reduced colitis-associated shift of gut microbiota. Considering its effectiveness and safety, we propose our InvColi(shCOX2) strategy as a promising tool for molecular therapy in intestinal inflammatory diseases.

Nimesulide inhibits the growth of human esophageal carcinoma cells by inactivating the JAK2/STAT3 pathway

Although selective COX-2 inhibitors have cancer-preventive effects and induce apoptosis, the mechanisms underlying these effects are not fully understood. This study investigated the effects of nimesulide, a selective COX-2 inhibitor, on apoptosis and on the JAK/STAT signaling pathway in Eca-109 human esophageal squamous carcinoma cells. The effects and mechanisms of nimesulide on Eca-109 cell growth were studied in culture and in nude mice with Eca-109 xenografts. Cells were cultured with or without nimesulide and/or the JAK2 inhibitor AG490. Cell proliferation was evaluated using the MTT assay, and apoptosis was investigated. COX-2 mRNA expression was measured using reverse transcription polymerase chain reaction, and protein expression was detected by Western blot analysis, immunohistochemistry, and flow cytometry. Nimesulide significantly inhibited Eca-109 cell viability in vitro in a dose- and time-dependent manner (P<0.05). Nimesulide also induced apoptosis, which was accompanied by a significant decrease in the expression of COX-2 and survivin and an increase in caspase-3 expression. Nimesulide downregulated the phosphorylation levels of JAK2 and STAT3, and JAK2 inhibition by AG490 significantly augmented both nimesulide-induced apoptosis and the downregulation of COX-2 and survivin (P<0.05). In vivo, nimesulide inhibited the growth of Eca-109 tumors and the expression of p-JAK2 and p-STAT3. Thus, nimesulide downregulates COX-2 and survivin expression and upregulates caspase-3 expression in Eca-109 cells, by inactivating the JAK2/STAT3 pathway. These effects may mediate nimesulide-induced apoptosis and growth inhibition in Eca-109 cells in vitro and in vivo.

Silencing of COX-2 by RNAi Modulates Epithelial-Mesenchymal Transition in Breast Cancer Cells Partially Dependent on the PGE2Cascade

In order to prove whether downregulation of COX-2 (Cyclooxygenase-2) could modulate the epithelial- mesenchymal transition (EMT) of breast cancer, celecoxib and siRNA were respectively used to inhibit COX-2 function and expression in MDA-MB-231 cells. The EMT reversal effect in the RNAi treated group was better than that of the celecoxib group while there were no obvious differences in the medium PGE2 levels between the two groups. The results show that COX-2 pathways may contribute considerably to EMT of breast cancer cells, partially dependent on the PGE2 cascade. Akt2, ZEB2 and Snail were measured to clarify the underlying mechanisms of COX-2 on EMT; COX-2 may modulate EMT of breast cancer by regulating these factors. This finding may be helpful to elucidate the mechanisms of selective COX-2 inhibitor action in EMT modulation in breast cancer.

Antiangiogenic effects of a novel synthetic curcumin analogue in pancreatic cancer

Hypoxia-inducible factors (HIFs) and NF-κB play essential roles in cancer cell growth and metastasis by promoting angiogenesis. Heat shock protein 90 (Hsp90) serves as a regulator of HIF-1α and NF-κB protein. We hypothesized that curcumin and its analogues EF31 and UBS109 would disrupt angiogenesis in pancreatic cancer (PC) through modulation of HIF-1α and NF-κB. Conditioned medium from MIA PaCa-2 or PANC-1 cells exposed to curcumin and its analogues in vitro significantly impaired angiogenesis in an egg CAM assay and blocked HUVEC tube assembly in comparison to untreated cell medium. In vivo, EF31 and UBS109 blocked the vascularization of subcutaneous matrigel plugs developed by MIA PaCa-2 in mice. Significant inhibition of VEGF, angiopoietin 1, angiopoietin 2, platelet derived growth factor, COX-2, and TGFβ secretion was observed in PC cell lines treated with UBS109, EF31 or curcumin. Treatment with UBS109, EF31 or curcumin inhibited HSP90, NF-κB, and HIF-1α transcription in PC cell lines. UBS109 and EF31 inhibited HSP90 and HIF-1α expression even when elevated due to NF-κB (p65) overexpression. Finally, we demonstrate for the first time that curcumin analogues EF31 and UBS109 induce the downregulation of HIF-1α, Hsp90, COX-2 and VEGF in tumor samples from xenograft models compared to untreated xenografts. Altogether, these results suggest that UBS109 and EF31 are potent curcumin analogues with antiangiogenic activities.

Down-regulation of Cyclooxygenase-2 by the Carboxyl Tail of the Angiotensin II Type 1 Receptor

The enzyme cyclooxygenase-2 (COX-2) plays an important role in the kidney by up-regulating the production of the vasoconstrictor hormone angiotensin II (AngII), which in turn down-regulates COX-2 expression via activation of the angiotensin II type 1 receptor (AT1) receptor. Chemical inhibition of the catalytic activity of COX-2 is a well-established strategy for treating inflammation but little is known of cellular mechanisms that dispose of the protein itself. Here we show that in addition to its indirect negative feedback on COX-2, AT1 also down-regulates the expression of the COX-2 protein via a pathway that does not involve G-protein or β-arrestin-dependent signaling. Instead, AT1 enhances the ubiquitination and subsequent degradation of the enzyme in the proteasome through elements in its cytosolic carboxyl tail (CT). We find that a mutant receptor that lacks the last 35 amino acids of its CT (Δ324) is devoid of its ability to reduce COX-2, and that expression of the CT sequence alone is sufficient to down-regulate COX-2. Collectively these results propose a new role for AT1 in regulating COX-2 expression in a mechanism that deviates from its canonical signaling pathways. Down-regulation of COX-2 by a short peptide that originates from AT1 may present as a basis for novel therapeutic means of eliminating excess COX-2 protein.

O1-2-3 - Photodynamic Therapy of Human Hepatoma by Photosan-Ii Loaded Hollow Silica Nanoparticles

Background: Nanoparticles have shown higher efficacy in delivering photosensitizers for photodynamic therapy (PDT). Here we reported the comparison of the killing effects of conventional photosensitizer Photosan-II and Photosan-II loaded hollow silica nanoparticles (HSNP) on Huh-7 human hepatoma cells. In addition, we explored the underlying mechanisms of the effects of Photosan-II loaded HSNP in the tumor microenvironment.Methods: Photosan-II was loaded into HSNP by one-step wet chemical-based synthetic route. The cellular viability was determined by MTT assay. Apoptotic and necrotic cells were measured by flow cytometry. Furthermore, Huh-7 xenograft model in nude mouse was established and PDT was administrated when tumor size was 2 mm3.Results: We found that Photosan-II loaded HSNP was more effective to inhibit the proliferation and induce the apoptosis of Huh-7 cells than free Photosan-II. In addition, Photosan-II loaded HSNP was more effective to inhibit the growth of Huh-7 xenograft in nude mice than free Photosan-II. Western blot analysis demonstrated that the expression levels of COX-2, NF-κB, ERK1 were significantly lower in the xenografts from mice treated with Photosan-II loaded HSNP than in those treated with free Photosan-II.Conclusions: Our data suggest that HSNP is a promising vehicle for photodynamic therapy that could increase the photodynamic efficacy of Photosan-II both in vivo and in vitro, and the downregulation of COX-2, NF-κB and ERK1 may account for the higher efficacy of Photosan-II loaded HSNP for hepatoma.

Abstract 1705: Combinatorial therapeutics with targeting head and neck cancer initiating cells using active components from antrodia cinnamomea and conventional chemotherapy

Abstract Background: Cancer initiating cells (CICs), also termed as Cancer stem cells (CSCs), represent a rare subpopulation of cells, which are responsible for tumor growth. CICs such as head and neck cancer initiating cells (HN-CICs), are often resistant to either radio- or chemotherapy. Therefore, development for drug candidates that target HN-CICs specifically will be effective for future oral cancer therapy. Methods: In this study, we used the in vitro cell-based aldehyde dehydrogenase (ALDH) activity assay system, which has been demonstrated as a CICs marker, to screen for the active purified components from Antrodia Camphorata Mycelia extract (ACME), which can target HN-CICs. Next, the antitumorigenicity of combinatorial treatment with active components from ACME and conventional chemotherapy on HNSCC will be examined in vitro and in vivo. Results: Herein, we first screened for the active components from natural products of ACM significantly down regulate the ALDH activity and CD44 positivity of Head and neck squamous cell carcinoma (HNSCC). Consequently, treatment of YMGKI-2 (analogue of ergosterol), a single and active compound purified from ACME, not only inhibited the ALDH activity but also reduced self-renewal property and expression of stemness genes (Oct-4 and Nanog) in enriched HN-CICs. Moreover, the repressive HN-CICs properties by YMGKI-2 treatment were caused by promoting cell differentiation. Additionally, treatment of YMGKI-2 results in down-regulation of Cox-2 and Src molecular mechanisms which both play important role in CICs. Further, the tumorigenic properties of HNSCC cells were attenuated by YMGKI-2 treatment in vivo. Lastly, combinatorial treatments with YMGKI-2 and standard chemotherapeutic drugs reveal synergistic effects on killing both HN-CICs and non-HN-CICs in vitro and in vivo. Conclusion: Together, our results indicate that YMGKI-2 treatment significantly and selectively abolished the stemness properties and tumorigenicity of HN-CICs. These findings provide a new drug candidate from purified components of ACM as an alternative therapy in combination with conventional chemotherapy treatment modalities for head and neck cancer in the future. Citation Format: Ching-Wen Chang, Jeng-Fan Lo. Combinatorial therapeutics with targeting head and neck cancer initiating cells using active components from antrodia cinnamomea and conventional chemotherapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1705. doi:10.1158/1538-7445.AM2014-1705

Downregulation of COX-2 and CYP 4A signaling by isoliquiritigenin inhibits human breast cancer metastasis through preventing anoikis resistance, migration and invasion

Flavonoids exert extensive in vitro anti-invasive and in vivo anti-metastatic activities. Anoikis resistance occurs at multiple key stages of the metastatic cascade. Here, we demonstrate that isoliquiritigenin (ISL), a flavonoid from Glycyrrhiza glabra, inhibits human breast cancer metastasis by preventing anoikis resistance, migration and invasion through downregulating cyclooxygenase (COX)-2 and cytochrome P450 (CYP) 4A signaling. ISL induced anoikis in MDA-MB-231 and BT-549 human breast cancer cells as evidenced by flow cytometry and the detection of caspase cleavage. Moreover, ISL inhibited the mRNA expression of phospholipase A2, COX-2 and CYP 4A and decreased the secretion of prostaglandin E2 (PGE2) and 20-hydroxyeicosatetraenoic acid (20-HETE) in detached MDA-MB-231 cells. In addition, it decreased the levels of phospho-PI3K (Tyr458), phospho-PDK (Ser241) and phospho-Akt (Thr308). Conversely, the exogenous addition of PGE2, WIT003 (a 20-HETE analog) and an EP4 agonist (CAY10580) or overexpression of constitutively active Akt reversed ISL-induced anoikis. ISL exerted the in vitro anti-migratory and anti-invasive activities, whereas the addition of PGE2, WIT003 and CAY10580 or overexpression of constitutively active Akt reversed the in vitro anti-migratory and anti-invasive activities of ISL in MDA-MB-231 cells. Notably, ISL inhibited the in vivo lung metastasis of MDA-MB-231 cells, together with decreased intratumoral levels of PGE2, 20-HETE and phospho-Akt (Thr308). In conclusion, ISL inhibits breast cancer metastasis by preventing anoikis resistance, migration and invasion via downregulating COX-2 and CYP 4A signaling. It suggests that ISL could be a promising multi-target agent for preventing breast cancer metastasis, and anoikis could represent a novel mechanism through which flavonoids may exert the anti-metastatic activities.