Identification of Hirsutine as an anti-metastatic phytochemical by targeting NF-κB activation

  • Authors:
    • Chenghua Lou
    • Kei Takahashi
    • Tatsuro Irimura
    • Ikuo Saiki
    • Yoshihiro Hayakawa
  • View Affiliations

  • Published online on: August 27, 2014     https://doi.org/10.3892/ijo.2014.2624
  • Pages: 2085-2091
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Abstract

Nuclear factor-κB (NF-κB) activation has been implicated not only in carcinogenesis but also in cancer cell invasion and metastatic process; therefore, targeting the NF-κB pathway is an attractive strategy for controlling meta­stasis. Amongst 56 chemically defined compounds derived from natural products, we have identified a new phytochemical compound Hirsutine, which strongly suppresses NF-κB activity in murine 4T1 breast cancer cells. In accordance with the NF-κB inhibition, Hirsutine reduced the metastatic potential of 4T1 cells, as seen in the inhibition of the migration and invasion capacity of 4T1 cells. Hirsutine further inhibited the constitutive expression of MMP-2 and MMP-9 in 4T1 cells, and reduced the in vivo lung metastatic potential of 4T1 cells in the experimental model. Given that the migration of human breast cancer cells was also inhibited, our present study implies that Hirsutine is an attractive phytochemical compound for reducing metastasis potential of cancer cells by regulating tumor-promoting NF-κB activity.

Introduction

Breast cancer is the most frequently diagnosed cancer and is therefore the leading cause of cancer death in women worldwide (1). While marked progress has been made in the treatment of breast cancer, such as hormonal therapy for estrogen receptor and/or progesterone receptor-positive tumors, other targeted therapies for selected subgroups of patients, such as HER2-positive cancers, have also been successfully developed. Despite these advances, the mortality rate is still high in breast cancer patients, mainly due to metastasis spread (2); therefore the development of metastasis-targeted therapy for breast cancer is clinically important.

Phytochemicals from natural products are a promising source for the development of novel cancer therapeutics. Because of their potential effectiveness and low toxicity profiles (3), many phytochemicals have been successful in clinical development of many diseases (4,5). Nuclear factor-κB (NF-κB), defined as a multi-functional transcription factor, is widely involved in a variety of physiological and pathological processes (6). It has been widely recognized that NF-κB plays a critical role in the initiation, promotion and progression of certain types of cancers through its ability to upregulate genes responsible for cell survival, invasion, angiogenesis and metastasis (712). Consequently, the NF-κB pathway is regarded as a potential new drug target in cancer metastasis and progression (1315).

In this study, we screened 56 phytochemical compounds for their inhibitory activity in NF-κB. Hirsutine was found to be a prominent NF-κB inhibitor and significantly inhibited the metastatic potential of murine 4T1 breast cancer cells both in vitro and in vivo. Since Hirsutine further reduced the metastatic potential of human breast cancer cells, it is an attractive lead compound targeting metastasis and the progression of breast cancer.

Materials and methods

Reagents

All the compounds (in DMSO) shown in Table I were provided by the Cooperative Research Project I of the Institute of Natural Medicine, University of Toyama, Japan. Antibody against MMP-9 or β-actin was obtained from Santa Cruz Biotechnology (Santa Cruz, CA, USA). Mouse TNF-α was purchased from Jena Bioscience GmbH (Jena, Germany). Hirsutine was purchased from Wako Pure Chemical Industries, Ltd. (Osaka, Japan). pGL4.50 [luc2P/CMV-RE/Hygro] and pGL4.32 [luc2P/NF-κB-RE/Hygro] vector and D-Luciferin were obtained from Promega (Sunnyvale, CA, USA). Lipofectamine 2000 was purchased from Invitrogen (Carlsbad, CA, USA). Hygromycin B was obtained from Nacalai Tesque (Kyoto, Japan).

Table I

Natural compounds.

Table I

Natural compounds.

No.Compound
1Galangin
2 Galangin-7-glucoside
3 6-Hydroxygalangin-7-glucoside
4Scutellarin
5Resveratrol
6Artemisine
7Acoinitine
8Albiflorin
9Alisol A
10Alisol B
11Alkannin
12Amygdalin
13Arbutin
14Astragaloside IV
15Atractylenolide III
16Aucubin
17Baicalein
18Baicalin
19Barbaloin
20Bergenin
21Catalpol
22E-Cinnamic acid
23Cinobufagin
24Cinobufotalin
25Corydaline
26Curcumin
27 Dehydrocostuslactone
28 Dimethylesculetin
29 Eleutheroside-B
30Epihesperidin
31Ergosterol
32β-Eudesmol
33E-Ferulic acid
34Geniposide
35Geniposidic acid
36 Gentiopicroside
37Ginsenoside Rc
38Ginsenoside Rd
39Glabridin
40Glycyrrhizic acid
41Hirsutine
42Icariin
43Isofraxidine
44Ligustilide
45Loganin
46Magnolol
47Mesaconitine
48Naringin
49Paeonol
50Palmatine chloride
51 S-Perilladelhyde
52Puerarin
53 Rhynchophylline
54Sinomenine
55Swertiamarin
56Wogonin
Cells

Mouse mammary carcinoma 4T1 cells were maintained in RPMI-1640 medium (Nissui, Tokyo, Japan) supplemented with 10% bovine serum. MDA-MB-231 and MDA-MB-468 human breast cancer cell lines were maintained in Dulbecco’s modified Eagle’s medium (DMEM; Nissui) supplemented with 10% bovine serum. To establish the luciferase gene expressing 4T1 cells (4T1-luc or 4T1-NFκB-luc), and 4T1 cells (5×105/well) were seeded in a 6-well plate and pGL4.50 or pGL4.32 vector was transfected using Lipofectamine 2000. The cells were selected with Hygromycin B (100 μg/ml) and cloned by limiting dilution.

NF-κB luciferase reporter assay

For the detection of luciferase activity, cells were stimulated with or without TNF-α (10 ng/ml) in the screening experiments. Briefly, for screening experiments without stimulation, 4T1-NFκB-luc cells in exponential growth were placed at a final concentration of 2×104 cells/well in a 96-well plate. After 3-h incubation, the cells were treated with compounds or with the vehicle (vehicle control, 0.5% DMSO) for 24 h. Then 20 μl of luciferin (900 μg/ml) was added, and the plates were incubated for another 30 min. Luciferase activity was measured by the Glomax multi detection system (Promega). For the experiments with TNF-α (10 ng/ml) stimulation, 4T1-NFκB-luc cells (2×104 cells/well) were placed in a 96-well plate for 12 h. After incubation, the cells were treated with compounds and TNF-α (10 ng/ml) for 12 h. Then luciferin was added and luciferase activity was measured.

Cell viability assay

Viability of cells was assessed using a WST-1 Cell Counting kit (Wako Pure Chemical Industries). The experimental conditions for cell viability were similar to the previous luciferase reporter assay. Twenty-four hours after treatment with compounds, 10 μl WST-1 reagent was added and incubated for another 2 h (37°C, 5% CO2). The absorbance at 450 nm was measured using a microplate reader.

In vitro wound healing assay

4T1-NFκB-luc cells were plated in a 24-well plate at a concentration of (1×105 cells/well) and allowed to form a confluent monolayer for 24 h. The monolayer was then scratched with a sterile pipette tip (1,000 μl), washed with medium to remove floated and detached cells, and photographed (time 0 h). Cells were successively treated in medium in the presence of different concentrations of Hirsutine (12.5 and 25 μM) along with the vehicle DMSO for 24 h. Scratched areas were photographed (magnification, ×40) at 0 h and then again 24 h later to assess the degree of wound healing. The percentage of wound closure was estimated by the following equation: wound closure % = 1 − (wound area at t24/wound area at t0) × 100%, where t24 is the time after wounding and t0 is the time immediately after wounding.

Haptotaxis and hapto-invasion assay

The filters of a Transwell cell culture insert (8 μm pore size; Whatman Japan KK, Tokyo, Japan) were pre-coated with fibronectin (Iwaki, Tokyo, Japan, 1.25 μg/filter) on the lower surfaces. For the hapto-invasion assay, the upper surface of the filters was coated with Matrigel (Becton-Dickinson, Bedford, MA, 1 μg/filter). Cells were pre-incubated with or without Hirsutine (25 μM) for 24 h. After trypsinization, cells in 0.1% (v/v) BSA medium (1.5×104) were placed in the upper chamber of Transwells. After the subsequent incubation at 37°C, the residual cells were removed from the upper surface of the membrane and the migrated cells on the lower surface of the membrane were fixed in 100% methanol and stained with hematoxylin and eosin. Migration was determined by counting the cells with a microscope at ×100 magnification. Five visual fields were chosen randomly and the average number of migrating cells in the five fields was taken for each group.

Gelatin zymography

Subconfluent monolayers of 4T1-NFκB-luc cells (5×104/well) pretreated for 24 h with Hirsutine (12.5 and 25 μM) were cultured for another 24 h in serum-free RPMI-1640. After incubation, cell-free supernatants were collected and mixed with sample buffer containing 2% SDS (without 2-mercaptoethalnol) and incubated at 37°C for 20 min. Comparative gelatin zymography was performed on 10% SDS-PAGE with 0.1% gelatin. Samples were electrophoresed at 10 mA for 4–5 h at 4°C. Gels were washed with buffer containing 2.5% Triton X-100 and 0.01 M Tris-HCl for 2 h at 4°C and then washed with 0.01 M Tris-HCl for 40 min at room temperature. Gels were incubated in buffer containing 0.05 M Tris-HCl, 0.5 mM CaCl2 and 1 μM ZnCl2 for 48 h at 37°C. After incubation, gels were stained with Coomassie Brilliant Blue for 6 h and destained with 5% acetic acid and 10% methanol. The bands were scanned by an image scanner and quantified by Image J software.

Western blot analysis

4T1-NFκB-luc cells were treated with Hirsutine for 24 h. Treated cells were collected, washed with phosphate-buffered saline (PBS), and lysed in lysis buffer [25 mM HEPES (pH 7.7), 0.3 M NaCl, 1.5 mM MgCl2, 0.2 mM EDTA, 0.1% Triton X-100, 20 mM b-glycerophosphate, 0.1 mM sodium orthovanadate, 0.5 mM phenylemethylsulfonyl fluoride (PMSF), 1 mM dithiothreitol, 10 mg/ml aprotinin and 10 mg/ml leupeptin]. The cell lysates were separated by 10% SDS-PAGE and transferred to PVDF membranes using a glycine transfer buffer [192 mM glycine, 25 mM Tris-HCl (pH 8.8) and 20% (v/v) methanol]. After blocking with Block Ace for 4 h at room temperature, the membrane was incubated overnight with primary antibodies, and then for 60 min with secondary antibodies. Primary antibodies were used at a dilution of 1:1,000. The secondary antibodies (horseradish peroxidase-conjugated goat anti-mouse IgG) were used at a dilution of 1:2,000 and visualized with an enhanced chemiluminescence system (Amersham Biosciences).

Experimental lung metastasis model

Female BALB/c mice were purchased from Japan SLC, Inc. (Hamamatsu, Japan) and maintained in a temperature-controlled, pathogen-free room. All animals were handled according to the approved protocols and guidelines of the Animal Committee of Toyama University (A2012INM-6). For the experimental metastasis model, 4T1-luc cells were inoculated intravenously (i.v., 5×105) with or without pre-treatment with Magnolol or Hirsutine (24 h, 25 μM). For lung metastasis imaging, mice were injected with D-luciferin 7 days after tumor inoculation, then the lungs were removed to measure luminescence using in vivo imaging system (IVIS Lumina II; Caliper Life Sciences, MA, USA).

Statistical analysis

All the data are expressed as the mean ± SD of at least two or three independent experiments unless otherwise stated. Statistical significance was analyzed using Student’s t-test. P<0.05 was considered significant.

Results

Hirsutine inhibits NF-κB activation in metastatic 4T1 breast cancer cells

In order to identify novel anti-metastatic drug candidates targeting inflammatory signals in cancer cells, we first screened our library of natural product-derived compounds using murine 4T1 breast cancer cells stably expressing NF-κB luciferase reporter (4T1-NFκB-luc cells). 4T1-NFκB-luc cells were incubated with a series of natural product-derived compounds (Table I) for 24 h and luminescence was measured to determine NF-κB activity. To discriminate whether the inhibition of NF-κB activity is related to the reduction of cell viability, all tested compounds were measured for their direct cytotoxicity on 4T1-NFκB-luc cells in parallel with the luciferase reporter assays. As summarized in Fig. 1, 4 out of 56 compounds (resveratrol, curcumin, magnolol, Hirsutine) significantly suppressed NF-κB activity in 4T1-NFκB-luc cells (>80%) with relatively little effect on cell viability (<50%). While the pharmacological effect of resveratrol (1618), curcumin (19,20) and magnolol (2131), in NF-κB inhibition has been previously recognized, there is almost no information of Hirsutine on its effect on NF-κB inhibition in cancer cells; therefore, we decided to further explore the potential of Hirsutine as novel anti-metastatic drug candidate targeting inflammatory signals in cancer cells.

To further determine the specificity of Hirsutine in its inhibition of NF-κB activation, 4T1-NFκB-luc cells were treated with different doses of Hirsutine to evaluate their effect on NF-κB reporter activity and cell viability. Hirsutine specifically inhibited NF-κB activation of 4T1 cells at a concentration that did not largely affect cell viability (Fig. 2A and C) and further inhibited NF-κB activation even in the presence of TNF-α stimulation in 4T1 cells (Fig. 2B and C). Collectively, the presented results strongly support that Hirsutine is a potent inhibitor of NF-κB in metastatic 4T1 breast cancer cells.

Hirsutine reduces metastatic potential of 4T1 cells

We next examined the effect of Hirsutine on the metastatic potential of 4T1 cells accordaning to the inhibition of NF-κB. As shown in Fig. 3, Hirsutine showed dose-dependent inhibition of the cell migration of 4T1 cells, as determined by the wound closure assay. In addition, pre-treatment with Hirsutine inhibited 4T1 cell haptotaxis (Fig. 4A) towards fibronectin in the Transwell chamber assay. Furthermore, Hirsutine pre-treatment showed significant inhibition of the invasion activity of 4T1 cells (Fig. 4B). In order to determine whether the inhibitory effect of Hirsutine on cellular invasion was relative to the proteolytic activity of 4T1 cells, we employed the gelatin zymography assay to examine the effect of Hirsutine treatment on the production of MMP-2 and MMP-9 in 4T1 cells. As shown in Fig. 5, Hirsutine-treated 4T1 cells showed a reduction in the activity of both MMP-2 and MMP-9 (Fig. 5A and C). We further confirmed that the cytoplasmic expression of MMP-9 was also reduced in Hirsutine-treated 4T1 cells as evaluated by western blotting (Fig. 5B). Collectively, these results clearly indicate that Hirsutine reduces the metastatic potential of 4T1 cells in vitro by regulating cellular migration or invasion in accordance with the inhibitory activity of NF-κB activation. We then tested the therapeutic potential of Hirsutine in breast cancer using an in vivo animal model. In an experimental lung metastasis model of 4T1 breast cancer, we found that pre-treatment with Hirsutine inhibited the metastatic lung colonization of 4T1 cells (Fig. 6).

Hirsutine reduces the migration of human breast cancer cells in vitro

To further explore the clinical relevance of our findings, we tested the effect of Hirsutine on human breast cancer cell lines MDA-MB-231 and MDA-MB-468. Similar to our observation in murine 4T1 cells, both Magnolol and Hirsutine inhibited the haptotaxis of MDA-MB-231 or MDA-MB-468 cells (Fig. 7) at a non-cytotoxic dose (data not shown) implying the efficacy of the compounds in human breast cancer cells in vitro.

Discussion

Activation of NF-κB has been observed in many cancers, including breast cancer, melanoma, lung cancer and various types of other cancers (3234). It is known that NF-κB activation has not only been implicated in carcinogenesis (35,36) but also in cancer cell invasion and the metastatic process (3740); therefore, targeting the NF-κB-mediated inflammatory signaling pathway is an attractive strategy for controlling metastasis. Amongst 56 chemically defined phytochemicals derived from natural products, we identified a new compound, Hirsutine, that strongly suppressed NF-κB activity in 4T1 breast cancer cells. In accordance with the NF-κB inhibition, Hirsutine reduced the metastatic potential of 4T1 cells, as seen in their inhibition of the migration and invasion of 4T1 cells. Importantly, Hirsutine showed anti-metastasis activity against 4T1 breast cancer cells in vivo and therefore could be useful as a lead compound for cancer therapy.

Hirsutine is one of the major alkaloids in Uncaria species and its cardioprotective (41), antihypertensive and anti-arrhythmic activity has been reported (42). The presented activity of Hirsutine in the inhibition of NF-κB activation and the reduction of the metastatic potential of cancer cells is unexplored. While the underlying mechanisms that account for the multifaceted and differential role of NF-κB in cancer metastasis are presently unknown, the NF-κB-mediated inflammatory signaling pathway is an attractive clinical target for controlling metastasis in humans. Importantly, our present observation is applicable clinically because we observed the inhibitory effect of Hirsutine on NF-κB activation in human breast cancer cell lines as seen in the inhibition of p-65 phosphorylation (data not shown) and further in the inhibition of their migration (Fig. 7). Further studies are still required to determine the exact mechanisms of action of Hirsutine in its anti-metastatic activity by clarifying the potential involvement of other signaling pathways and/or transcriptional factors. Considering that the effective doses of Hirsutine shown in this study were relatively high, we also need to consider either chemical or biological modification of Hirsutine to achieve higher potency. Nevertheless, our current study clearly indicates that Hirsutine could be an attractive lead compound for reducing the metastasis potential of cancer cells by regulating NF-κB tumor-promoting activity.

Acknowledgements

We are grateful to Satoru J. Yokoyama and Hiroaki Sakurai for discussions and colleagues in Saiki Laboratory for generous support. This study was partly supported by Yokoyama Foundation and a Grant-in-aid for the 2012 and 2013 Cooperative Research Project I from the Institute of Natural Medicine, University of Toyama. Chenghua Lou is a graduate student supported by the Campus Asian Program of the University of Toyama.

References

1 

Jemal A, Bray F, Center MM, Ferlay J, Ward E and Forman D: Global cancer statistics. CA Cancer J Clin. 61:69–90. 2011. View Article : Google Scholar

2 

Mann J: Natural products in cancer chemotherapy: past, present and future. Nat Rev Cancer. 2:143–148. 2002. View Article : Google Scholar : PubMed/NCBI

3 

Crowell JA: The chemopreventive agent development research program in the Division of Cancer Prevention of the US National Cancer Institute: an overview. Eur J Cancer. 41:1889–1910. 2005. View Article : Google Scholar : PubMed/NCBI

4 

Cragg GM, Newman DJ and Snader KM: Natural products in drug discovery and development. J Nat Prod. 60:52–60. 1997. View Article : Google Scholar

5 

Harvey AL: Natural products in drug discovery. Drug Discov Today. 13:894–901. 2008. View Article : Google Scholar : PubMed/NCBI

6 

Sha WC: Regulation of immune responses by NF-kappa B/Rel transcription factor. J Exp Med. 187:143–146. 1998. View Article : Google Scholar : PubMed/NCBI

7 

Xiao G and Fu J: NF-κB and cancer: a paradigm of Yin-Yang. Am J Cancer Res. 1:192–221. 2011.

8 

Basseres DS and Baldwin AS: Nuclear factor-kappaB and inhibitor of kappaB kinase pathways in oncogenic initiation and progression. Oncogene. 25:6817–6830. 2006. View Article : Google Scholar : PubMed/NCBI

9 

Bours V, Bonizzi G, Bentires-Alj M, et al: NF-kappaB activation in response to toxical and therapeutical agents: role in inflammation and cancer treatment. Toxicology. 153:27–38. 2000. View Article : Google Scholar : PubMed/NCBI

10 

Huang CY, Fong YC, Lee CY, et al: CCL5 increases lung cancer migration via PI3K, Akt and NF-kappaB pathways. Biochem Pharmacol. 77:794–803. 2009. View Article : Google Scholar : PubMed/NCBI

11 

Nottingham LK, Yan CH, Yang X, et al: Aberrant IKKα and IKKβ cooperatively activate NF-κB and induce EGFR/AP1 signaling to promote survival and migration of head and neck cancer. Oncogene. 33:1135–1147. 2014.

12 

Zhang W, Tan W, Wu X, et al: A NIK-IKKα module expands ErbB2-induced tumor-initiating cells by stimulating nuclear export of p27/Kip1. Cancer Cell. 23:647–659. 2013.

13 

Shaffer AL, Rosenwald A and Staudt LM: Lymphoid malignancies: the dark side of B-cell differentiation. Nat Rev Immunol. 2:920–932. 2002. View Article : Google Scholar : PubMed/NCBI

14 

Panwalkar A, Verstovsek S and Giles F: Nuclear factor-kappaB modulation as a therapeutic approach in hematologic malignancies. Cancer. 100:1578–1589. 2004. View Article : Google Scholar : PubMed/NCBI

15 

Orlowski RZ and Baldwin AS Jr: NF-kappaB as a therapeutic target in cancer. Trends Mol Med. 8:385–389. 2002. View Article : Google Scholar : PubMed/NCBI

16 

Singh NP, Singh UP, Hegde VL, et al: Resveratrol (trans-3,5,4′-trihydroxystilbene) suppresses EL4 tumor growth by induction of apoptosis involving reciprocal regulation of SIRT1 and NF-κB. Mol Nutr Food Res. 55:1207–1218. 2011.

17 

Kumar A and Sharma SS: NF-kappaB inhibitory action of resveratrol: a probable mechanism of neuroprotection in experimental diabetic neuropathy. Biochem Biophys Res Commun. 394:360–365. 2010. View Article : Google Scholar : PubMed/NCBI

18 

Youn J, Lee JS, Na HK, Kundu JK and Surh YJ: Resveratrol and piceatannol inhibit iNOS expression and NF-kappaB activation in dextran sulfate sodium-induced mouse colitis. Nutr Cancer. 61:847–854. 2009. View Article : Google Scholar : PubMed/NCBI

19 

Chhunchha B, Fatma N, Kubo E, Rai P, Singh SP and Singh DP: Curcumin abates hypoxia-induced oxidative stress based-ER stress-mediated cell death in mouse hippocampal cells (HT22) by controlling Prdx6 and NF-κB regulation. Am J Physiol Cell Physiol. 304:C636–C655. 2013.PubMed/NCBI

20 

Leclercq IA, Farrell GC, Sempoux C, dela Pena A and Horsmans Y: Curcumin inhibits NF-kappaB activation and reduces the severity of experimental steatohepatitis in mice. J Hepatol. 41:926–934. 2004. View Article : Google Scholar : PubMed/NCBI

21 

Lin SY, Chang YT, Liu JD, et al: Molecular mechanisms of apoptosis induced by magnolol in colon and liver cancer cells. Mol Carcinog. 32:73–83. 2001. View Article : Google Scholar : PubMed/NCBI

22 

Ikeda K, Sakai Y and Nagase H: Inhibitory effect of magnolol on tumour metastasis in mice. Phytother Res. 17:933–937. 2003. View Article : Google Scholar : PubMed/NCBI

23 

Yang SE, Hsieh MT, Tsai TH and Hsu SL: Effector mechanism of magnolol-induced apoptosis in human lung squamous carcinoma CH27 cells. Br J Pharmacol. 138:193–201. 2003. View Article : Google Scholar : PubMed/NCBI

24 

Hsu YF, Lee TS, Lin SY, et al: Involvement of Ras/Raf-1/ERK actions in the magnolol-induced upregulation of p21 and cellcycle arrest in colon cancer cells. Mol Carcinog. 46:275–283. 2007. View Article : Google Scholar : PubMed/NCBI

25 

Huang SH, Chen Y, Tung PY, et al: Mechanisms for the magnolol-induced cell death of CGTH W-2 thyroid carcinoma cells. J Cell Biochem. 101:1011–1022. 2007. View Article : Google Scholar : PubMed/NCBI

26 

Lee SJ, Cho YH, Park K, et al: Magnolol elicits activation of the extracellular signal-regulated kinase pathway by inducing p27KIP1-mediated G2/M-phase cell cycle arrest in human urinary bladder cancer 5637 cells. Biochem Pharmacol. 75:2289–2300. 2008. View Article : Google Scholar

27 

Tsai JR, Chong IW, Chen YH, et al: Magnolol induces apoptosis via caspase-independent pathways in non-small cell lung cancer cells. Arch Pharm Res. 37:548–557. 2014. View Article : Google Scholar : PubMed/NCBI

28 

Chen MC, Lee CF, Huang WH and Chou TC: Magnolol suppresses hypoxia-induced angiogenesis via inhibition of HIF-1α/VEGF signaling pathway in human bladder cancer cells. Biochem Pharmacol. 85:1278–1287. 2013.PubMed/NCBI

29 

Rasul A, Yu B, Khan M, et al: Magnolol, a natural compound, induces apoptosis of SGC-7901 human gastric adenocarcinoma cells via the mitochondrial and PI3K/Akt signaling pathways. Int J Oncol. 40:1153–1161. 2012.PubMed/NCBI

30 

Lee J, Jung E, Park J, et al: Anti-inflammatory effects of magnolol and honokiol are mediated through inhibition of the downstream pathway of MEKK-1 in NF-kappaB activation signaling. Planta Med. 71:338–343. 2005. View Article : Google Scholar : PubMed/NCBI

31 

Tse AK, Wan CK, Zhu GY, et al: Magnolol suppresses NF-kappaB activation and NF-kappaB regulated gene expression through inhibition of IkappaB kinase activation. Mol Immunol. 44:2647–2658. 2007. View Article : Google Scholar : PubMed/NCBI

32 

Chua HL, Bhat-Nakshatri P, Clare SE, Morimiya A, Badve S and Nakshatri H: NF-kappaB represses E-cadherin expression and enhances epithelial to mesenchymal transition of mammary epithelial cells: potential involvement of ZEB-1 and ZEB-2. Oncogene. 26:711–724. 2007. View Article : Google Scholar : PubMed/NCBI

33 

Yang J, Pan WH, Clawson GA and Richmond A: Systemic targeting inhibitor of kappaB kinase inhibits melanoma tumor growth. Cancer Res. 67:3127–3134. 2007. View Article : Google Scholar : PubMed/NCBI

34 

Scartozzi M, Bearzi I, Pierantoni C, et al: Nuclear factor-κB tumor expression predicts response and survival in irinotecan-refractory metastatic colorectal cancer treated with cetuximab-irinotecan therapy. J Clin Oncol. 25:3930–3935. 2007.

35 

Keats JJ, Fonseca R, Chesi M, et al: Promiscuous mutations activate the noncanonical NF-kappaB pathway in multiple myeloma. Cancer Cell. 12:131–144. 2007. View Article : Google Scholar : PubMed/NCBI

36 

Annunziata CM, Davis RE, Demchenko Y, et al: Frequent engagement of the classical and alternative NF-kappaB pathways by diverse genetic abnormalities in multiple myeloma. Cancer Cell. 12:115–130. 2007. View Article : Google Scholar : PubMed/NCBI

37 

Yeh CB, Hsieh MJ, Hsieh YH, Chien MH, Chiou HL and Yang SF: Antimetastatic effects of norcantharidin on hepatocellular carcinoma by transcriptional inhibition of MMP-9 through modulation of NF-κB activity. PLoS One. 7:e310552012.PubMed/NCBI

38 

Lin TH, Tan TW, Tsai TH, et al: D-pinitol inhibits prostate cancer metastasis through inhibition of αVβ3 integrin by modulating FAK, c-Src and NF-κB pathways. Int J Mol Sci. 14:9790–9802. 2013.PubMed/NCBI

39 

Chen YY, Lu HF, Hsu SC, et al: Bufalin inhibits migration and invasion in human hepatocellular carcinoma SK-Hep1 cells through the inhibitions of NF-κB and matrix metalloproteinase-2/-9-signaling pathways. Environ Toxicol. Aug 16–2013.(Epub ahead of print).

40 

Yang XC, Wang X, Luo L, et al: RNA interference suppression of A100A4 reduces the growth and metastatic phenotype of human renal cancer cells via NF-κB-dependent MMP-2 and bcl-2 pathway. Eur Rev Med Pharmacol Sci. 17:1669–1680. 2013.PubMed/NCBI

41 

Wu LX, Gu XF, Zhu YC and Zhu YZ: Protective effects of novel single compound, Hirsutine on hypoxic neonatal rat cardiomyocytes. Eur J Pharmacol. 650:290–297. 2011. View Article : Google Scholar : PubMed/NCBI

42 

Horie S, Yano S, Aimi N, Sakai S and Watanabe K: Effects of hirsutine, an antihypertensive indole alkaloid from Uncaria rhynchophylla, on intracellular calcium in rat thoracic aorta. Life Sci. 50:491–498. 1992. View Article : Google Scholar : PubMed/NCBI

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APA
Lou, C., Takahashi, K., Irimura, T., Saiki, I., & Hayakawa, Y. (2014). Identification of Hirsutine as an anti-metastatic phytochemical by targeting NF-κB activation. International Journal of Oncology, 45, 2085-2091. https://doi.org/10.3892/ijo.2014.2624
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Lou, C., Takahashi, K., Irimura, T., Saiki, I., Hayakawa, Y."Identification of Hirsutine as an anti-metastatic phytochemical by targeting NF-κB activation". International Journal of Oncology 45.5 (2014): 2085-2091.
Chicago
Lou, C., Takahashi, K., Irimura, T., Saiki, I., Hayakawa, Y."Identification of Hirsutine as an anti-metastatic phytochemical by targeting NF-κB activation". International Journal of Oncology 45, no. 5 (2014): 2085-2091. https://doi.org/10.3892/ijo.2014.2624