Curcumin Inhibits Tumor Growth and Angiogenesis in an Orthotopic Mouse Model of Human Pancreatic Cancer

Hindawi Publishing CorporationBioMed Research InternationalVolume 2013 Article ID 810423 8 pageshttpdxdoiorg1011552013810423

Research ArticleCurcumin Inhibits Tumor Growth and Angiogenesis in anOrthotopic Mouse Model of Human Pancreatic Cancer

Sabrina Bimonte1 Antonio Barbieri1 Giuseppe Palma12 Antonio Luciano1

Domenica Rea1 and Claudio Arra1

1 Istituto Nazionale per lo Studio e la Cura dei Tumori ldquoFondazione G Pascalerdquo IRCCS Via Mariano Semmola 80131 Naples Italy2 Istituto di Endocrinologia e Oncologia Sperimentale del Consiglio Nazionale delle RicercheDipartimento di Biologia e Patologia Cellulare e Molecolare ldquoL Califanordquo Universita degli Studi di Napoli ldquoFederico IIrdquoVia Pansini 5 80131 Napoli Italy

Correspondence should be addressed to Sabrina Bimonte sbimonteistitutotumorinait

Received 25 July 2013 Revised 7 October 2013 Accepted 8 October 2013

Academic Editor Monica Fedele

Copyright copy 2013 Sabrina Bimonte et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Pancreatic cancer is a malignant neoplasm originating from transformed cells arising in tissues forming the pancreas The bestchemotherapeutic agent used to treat pancreatic cancer is the gemcitabine However gemcitabine treatment is associated withmany side effects Thus novel strategies involving less toxic agents for treatment of pancreatic cancer are necessary Curcumin isone such agent that inhibits the proliferation and angiogenesis of a wide variety of tumor cells through themodulation of many cellsignalling pathways In this study we investigated whether curcumin plays antitumor effects in MIA PaCa-2 cells In vitro studiesshowed that curcumin inhibits the proliferation and enhances apoptosis ofMIA PaCa-2 cells To test whether the antitumor activityof curcumin is also observed in vivo we generated an orthotopic mouse model of pancreatic cancer by injection of MIA PaCa-2cells in nudemiceWe placedmice on diet containing curcumin at 06 for 6 weeks In these treatedmice tumors were smaller withrespect to controls and showed a downregulation of the transcription nuclear factor NF-120581B and NF-120581B-regulated gene productsOverall our data indicate that curcumin has a great potential in treatment of human pancreatic cancer through the modulation ofNF-120581B pathway

1 Introduction

Pancreatic cancer is a malignant neoplasm originating fromtransformed cells arising in tissues forming the pancreasand it is now the fourth most common cause of cancer-related deaths in the United States and the eighth worldwide[1] This pathology leads to an aggressive local invasionand early metastases and is poorly responsive to treatmentwith chemotherapy [2] At present gemcitabine is the bestchemotherapeutic agent available for treatment of pancreaticcancer However it is noted that patients with this cancertreated with gemcitabine showed several side effects anddeveloped drug resistance over time [3] In order to bypassthese problems novel strategies involving less toxic agentsthat can sensitize pancreatic cancer cells to chemotherapyare necessary Curcumin a component of the spice turmeric

(Curcuma longa) is one such agent and is not toxic tohumans [4] It has been used for thousands years in Orientas a healing agent for variety of illnesses Many studiesprovided evidence that curcumin is an agent with stronginflammatory properties and strong therapeutic potentialagainst many variety of cancer Curcumin inhibits the cellsurvival proliferation and angiogenesis of a wide variety oftumor cells through themodulation of various cell signallingpathways which involve transcription factor protein kinasesgrowth factor and other enzymes In particular it has beendemonstrated that curcumin modulates the activation ofthe transcription factor nuclear factor-120581B (NF-120581B) whichin turn plays a role in the growth and chemoresistance ofpancreatic cancer [5 6] It has been showed that NF-120581Bpromotes pancreatic growth by inhibiting apoptosis [7ndash9]Additionally it has been demonstrated that NF-120581B plays also

2 BioMed Research International

several roles in angiogenesis [10] migration and invasionof pancreatic cells [11] Curcumin has also been shown tosuppress angiogenesis in vivo [12ndash14] In vitro and in vivostudies have already demonstrated that curcumin inhibits thegrowth of human pancreatic cancer cells [15 16] Previouslyit has been demonstrated that curcumin can potentiatesthe antitumor activity of gemcitabine in pancreatic cells bydownregulating NF-120581B-regulated gene products [17]

In this study we assessed the antitumor activities ofcurcumin in human pancreatic cancer cell line and MIAPaCa-2 cells by in vitro and in vivo experiments In vitrodata allowed us to demonstrate that curcumin inhibited theproliferation and enhanced the apoptosis of MIA PaCa-2cells In vivo by generation of an orthotopic mouse modelof pancreatic cancer we showed that tumours from miceinjected withMIA PaCa-2 cells and placed on diet containingcurcumin at 06 for 6 weeks were smaller than thoseobserved in controls We also showed a down regulation ofthe NF-120581B-regulated gene products (cyclin D VEGF MMP-9 and IKK120572120573) Overall our data indicate that curcumin hasa great potential in treatment of human pancreatic cancerthrough the modulation of NF-120581B pathway

2 Materials and Methods

21 Materials Curcumin (EE)-17-bis (4-Hydroxy-3-methoxyphenyl)-16-heptadiene-35-dione Diferuloylmeth-ane Diferulylmethane Natural Yellow 3 used for in vitroexperiments was obtained from Sigma Aldrich (PiscatawayNJ) The following polyclonal antibodies cyclin D1 MMP-9and monoclonal antibodies against VEGF were obtainedfrom Santa Cruz Biotechnology (Santa Cruz CA) Anti-IKK120572 and anti-IKK120573 antibodies were kindly provided byImgenex (San Diego CA) The liquid DAB+ SubstrateChromogen System-HRP used for immunocytochemistrywas obtained from DakoCytomation (Carpinteria CA)Penicillin streptomycin RPMI 1640 and fetal bovine serum(FBS) were obtained from Invitrogen (Grand Island NY)Tris glycine NaCl SDS and bovine serum albumin (BSA)were obtained from Sigma Chemical (St Louis MO)Complete feed for mice with curcumin 06 (AIN-93G) waspurchased by Mucedola (Settimo Milanese Italy)

22 Cell Lines The pancreatic cancer cell line MIA PaCa-2transfected with red fluorescent protein (RPF) and MPanc-96 cells was a kind gift from Professor Turco (University ofFisciano Italy) Panc-1 cells were obtained from the Amer-ican Type Culture Collection (Manassas VA) All cell lineswere cultured in RPMI 1640 supplemented with 10FBS100 unitsmL penicillin and 100120583gmL streptomycin

23 Proliferation Assay The effect of curcumin on cellproliferation was determined by using TACS 3-(45-dimeth-ylthiazol-2-yl)-25-diphenyltetrazolium bromide (MTT) cellproliferation assay (Trevigen Githersburg) The cells (2000per well) were incubated with or without curcumin intriplicate in a 96-well plate and then incubated for 2 4 and6 days at 37∘C A MTT solution was added to each welland incubated for 2 h at 37∘C An extraction buffer (20

SDS and 50 dimethylformamide) was added and the cellswere incubated overnight at 37∘C The absorbance of thecell suspension was measured at 570 nm using a microplatereader (DAS Technologies Chantilly VA) This experimentwas repeated twice and the statistical analysis was performedto obtain the final values

24 Wound-Healing Assay MIA PaCa-2 cells were seededat the density of 40 times 103 cells per well into a 6-multiwellplate and cultured in RPMI 1640medium supplemented with1 FBS At the time of confluence cells were incubated inthe absence or presence of curcumin (50120583M) for 48 h aftera slit made horizontally with a white tip at the center of eachconfluent well Cell invasion on the slit of the confluent wellwas assessed at 0 24 and 48 hours in each condition by lightmicroscopy

25 In Vitro Apoptosis Assay by Flow Cytometry Cells werewashed and suspended in 05mL of PBS and 1 ALmLYO-PRO-1 and propidium iodide was added Cells wereincubated for 30min on ice and analyzed by flow cytometry(FACScan Becton Dickinson Franklin Lakes NJ) by mea-surements of fluorescence emission at 530 and 575 nm

The apoptotic cells were stained with the green fluores-cent dye YO-PRO-1 while necrotic cells were stained withpropidium iodide The apoptotic fraction was obtained bydividing the number of apoptotic cells by the total numberof cells (minimumof 104 cells) Data were analyzed using CellQuest software (BectonDickinson) All datawere reproducedat least thrice in independent experiments

26 Transfection of Small Interfering RNA MIA PaCa cells in96-well plates were grown to 50 confluence and transfectedwith double-stranded siRNA for relAp65 (form of NF-120581B)target sequence (Sense 51015840 CCAUCAACUAUGAUGAGUUdTdT 31015840 Antisense 31015840 dGdTGGUAGUUGAUACUACUCAA51015840) or with a siRNAnonspecific control (Ambion Austin TXcat n461) in serum-free medium without antibiotic supple-ments using Hiperfect Transfection Reagent (Qiagen Inc)Cells were incubated under these conditions for 48 h andsilencing was then confirmed by western blotting analysis

27 NF-120581B Activation in Cell and Tumor Samples To assessNF-120581B activation we performed electrophoresis mobilityshift assays (EMSA) on isolated nuclei frompancreatic cancertumor and cell samples as described previously [17 18]Briefly nuclear extracts prepared frompancreatic cancer cells(1 times 106mL) and tumor samples were incubated with 32P-end-labeled 45-mer double-stranded NF-120581B oligonucleotide(4 120583g of protein with 16 fmol of DNA) from the HIVlong terminal repeat (51015840 -TTGTTACAAGGGACTTTCCG-CTGGGGACTTTCCAGGGAGGCGTGG-31015840 indicates NF-120581B-binding sites) for 15min at 37∘C The resulting DNA-protein complex was separated from free oligonucleotide on66 native polyacrylamide gels A double-stranded mutantoligonucleotide (51015840 -TTGTTACAACTCACTTTCCGCTG-CTCACTTTCCAGGGAGGCGTGG-31015840) was used to exam-ine the specificity of binding of NF-120581B to the DNAThe driedgels were visualized and radioactive bands were quantitated

BioMed Research International 3

using Phosphor Imager (Molecular Dynamics SunnyvaleCA) using Image Quant software

28 Mice Sixteen eight-week-old female upstream to Foxn1mice were purchased by Harlan San Pietro al Natisone and(Italy) Mice were housed five for cage in the standard micePlexiglas cages and maintained on a 12 h light 12 h darkcycle (lights on at 700 am) in a temperature-controlled room(22 plusmn 2∘C) and with food and water ad libitum at all timesThe experimental protocols were in compliance with theEuropean Communities Council directive (86609EEC)

29 Generation of Orthotopic MouseModel of Pancreatic Can-cer and Experimental Protocol RFP-transfectedMIA PaCa-2cells were harvested from subconfluent cultures after a briefexposure to 025 trypsin Trypsinization was stopped withmedium containing 10FBS The cells were washed once inserum-freemediumand suspended in PBSOnly suspensionsconsisting of single cells with gt90 viability were usedfor the injections A total of 16 female Foxn1 nunu micewere used in this experiment and maintained in a barrierfacility on HEPA-filtered racks Animals were individuallyidentified using numbered ear tags All experiments wereconducted in a biological laminar flow hood and all surgicalprocedures were conducted with strict adherence to aseptictechnique The mice were anesthetized with avertin solutioninjected intraperitoneally according to their weight Thenmice were prepped with 10 povidone-iodine on the leftflank and draped in a sterile fashion A longitudinal medianlaparotomy with a xiphopubic incision was made and thetail of the pancreas is exteriorized gently A suspension of5 times 10

5 MIA PaCa 2-RFP cells in 25 120583L of PBS 1Xmousewas injected into the tail of the pancreas by using a 29-gaugeneedle and a calibrated push button-controlled dispensingdevice (Becton Dickinson Franklin Lakes NJ) To preventleakage the injection point was dubbed with sterile cottonOnce haemostasis was confirmed the tail of the pancreaswas returned into the abdomen and the abdominal woundwas closed in a single layer using interrupted 5-0 silk sutures(US Surgical Norwalk CT) and skin staples After 2 weekof implantation mice were randomized into the followingtreatment groups (119899 = 6) on the basis of fluorescentarea measured by MacroFluo imaging (a) untreated miceplaced in normal died (b) curcumin treated mice placedin diet containing curcumin at 06 Tumor volumes weremonitored once a week by using MacroFluo and LAS V37software Leica Microsystems srl (Switzerland Ltd) Beforeimaging mice were anesthetized with Avertin solution Ateach imaging time point the real-time determination oftumor burden was performed by quantifying fluorescentsurface area Graph depicts tumor area means at 35 weeksafter tumor cells injection Therapy was continued for 4weeks and animals were sacrificed 2 weeks later Primarytumors in the pancreas were excised and the final tumorvolume was measured as 119881 = 231205871199033 where 119903 is themean of the three dimensions (length width and depth)Statistical analysis was performed to detect the final tumorvolumes (paired t-test) by Graph Pad Prisme 50 Half of thetumor tissue was formalin fixed and paraffin embedded for

immunohistochemistry and routine HampE stainingThe otherhalf was snap frozen in liquid nitrogen and stored at minus80∘CHampE staining confirmed the presence of tumor(s) in eachpancreas

210 Preparation of Nuclear Extract from Tumor SamplesPancreatic tumor tissues (75ndash100mgmouse) from controland experimentalmicewere prepared as previously described[17] The supernatant (nuclear extract) was collected andstored at minus70∘C until use Protein concentration was deter-mined by the Bradford protein assay with BSA as thestandard

211 Immunohistochemical Analysis for VEGF and COX-2 inTumor Tissue Pancreatic cancer tumor samples from controland treated mice were embedded in paraffin and fixed withparaformaldehyde After being washed in PBS the slideswere blocked with protein block solution (DakoCytoma-tion) for 20min and then incubated overnight with mousemonoclonal antihuman VEGF and anti-COX-2 antibodies(1 60 and 1 80 resp) After the incubation the slides werewashed and then incubated with biotinylated link universalantiserum followed by horseradish peroxidase-streptavidinconjugate (LSAB + kit) The slides were rinsed and colorwas developed using 331015840-diaminobenzidine hydrochlorideas a chromogen Finally sections were rinsed in distilledwater counterstained with haematoxylin and mounted withDPX mounting medium for evaluation Pictures were cap-tured with a Photometrics CoolSNAP color camera (NikonLewisville TX) and MetaMorph version 465 software (Uni-versal Imaging Downingtown PA)

212 Western Blot Analysis Pancreatic tumor tissues (75ndash100mgmouse) from control and experimental mice wereminced and incubated with ice for 1 h in 05mL of ice-coldLysis Buffer (10mMTris ph 80 130mMNacl 1 Triton X-100 10mMNaF 10mM sodium phosphate 10mM sodiumpyrophosphate 2 120583gmL aprotinin 2 120583gmL leupeptin and2 120583gmL pepstatin) The minced tissue was Homogenizedusing a Dounce homogenizer and centrifuged at 16000timesgat 4∘C for 10min Western blotting analysis was performedas described previously [17] 120573-Actin was used as loadingcontrol

3 Results

31 Curcumin Inhibits Proliferation and Enhanced Apoptosisof Pancreatic Cancer Cells In Vitro We first determinedwhether curcumin inhibits the proliferation of human pan-creatic cancer cells by performing in vitro assays on MPanc-96 Panc-1 and MIA PaCa-2 cells Wound healing assaydemonstrated that curcumin (50 120583M) inhibits the prolifer-ation of pancreatic cancer cell lines at 48 h (Figures 1(a)ndash1(f)) These results were also confirmed by MTT assay(Figure 1(g)) In order to asses if curcumin enhances theapoptosis in pancreatic cancer cells we also performed invitro apoptosis assay by flow cytometry Our results showedthat the percentage of apoptosis of MIA PaCa-2 cells treated


with curcumin was higher with respect to controls and toMPanc-96 and Panc-1 cells (Figure 1(h)) Since the effects ofcurcuminweremore evident inMIAPaCa-2 cells we selectedthis pancreatic cancer cell line for further experiments It hasbeen demonstrated that curcumin modulates the activationof the transcription factor nuclear factor-120581B (NF-120581B) for thisreason we performed a nuclear NF-120581B DNA binding assayon MIA PaCA-2 cells treated with curcumin and controlsand we demonstrated that curcumin downregulated NF-120581B activation in MIA PaCa-2 cells (Figure 1(i)) To test thehypothesis that inhibition of NF-120581B would increase the sen-sitivity ofMIA PaCa-2 cells to curcumin-mediated apoptosiswe used small interfering RNA (siRNA) to knock downp65relA (a form of NF-120581B) Silencing was confirmed byreporter assays as well as western blotting (data not shown)Next we transiently silenced expression of p65relA in MIAPaCa-2 cells and examined the effects on the apoptosis aloneand in presence of curcuminWe demonstrated that silencingof NF-120581B is not able to potentiate the apoptotic effects ofcurcumin on MIA PaCa-2 cells (Figure 1(j))

32 Curcumin Inhibits the Tumor Growth in OrthotopicMouse Model of Pancreatic Cancer In order to study therole curcumin on the tumor growth in vivo we generateda mouse model of pancreatic cancer by injection of MIAPaCa-2-RFP cells in the pancreas of nude mice Based on theMacroFluo images 2 weeks later of cell injection the micewere randomized into two groups control group (normaldiet) and curcumin group (feed added with 06 curcumin)The treatment with feed added with 06 curcumin wasstarted after the tumor cell implantation and continued for6 weeks We also monitored the body weight of mice twice aweek until the end of treatment No difference was observedbetween the body weight of two groups of animals indicatingthat mice eat normally complete fed with curcumin Micewere sacrificed at the end of treatment The images wereperformed on days 10 17 24 and 31 after the start oftreatment (Figure 2(a))The bioluminescence imaging resultsindicated a gradual increase in tumor volume in the curcumingroup compared with treatment groups The final tumorvolumes on day 35 after the start of treatment showed asignificant decrease in the curcumin group compared withcontrol (Figure 2(b)) These data were also confirmed ontumormeasurements performed at the end of the experimentat autopsy using digital Caliper and calculated using theformula 119881 = 231205871199033 (119899 = 6) (data not shown)

33 Curcumin Inhibits NF-120581B Activation and Down-RegulatesNF-120581B-Regulated Gene Products in Orthotopic PancreaticTumors Since it has been demonstrated that curcuminpotentiates the antitumor activity of gemcitabine in pancre-atic cells by downregulating NF-120581B-regulated gene products[17] we performed DNA binding to detect NF-120581B expres-sion in orthotopic tumor tissue samples from control andtreated mice Our results showed the inhibition of NF-120581Bactivation by curcumin (Figure 3(a) lane 2) Since it hasbeen demonstrated that NF-120581B regulates the expression ofseveral markers involved in proliferation (COX-2 cyclinD1) in invasion (MMP-9) and in angiogenesis (VEGF) we

performed an immunohistochemical analysis and Westernblotting on orthotopic tumor tissue samples from control andtreated mice Immunoistochemical analysis indicates thatin tumors of curcumin-treated group there are significantreductions in the expression of COX-2 and VEGF com-pared with the control group (Figure 3(b)) Western blottinganalysis revealed that curcumin significantly decreased theexpression of all of these molecules compared with thecontrol treatment in pancreatic tumor tissues (Figure 3(c))We finally performed a western blot analysis with IKK120572 andIKK120573 in order to understand how curcumin inhibits NF-120581Bactivation in MIA PaCa-2 cells Our data indicated that thereis a reduced expression of IKK120572 and IKK120573 in tumor of micetreated with curcumin with respect to controls indicatingthat curcumin inhibitsNF-120581B activation through suppressionof IKK (Figure 3(c)) Figure 4 shows a schematic diagramwhich contextualizes the various signalling cascades affectedby curcumin in pancreatic cancer cells Altogether these dataindicate that curcumin inhibits NF-120581B activation and down-regulates NF-120581B-regulated gene products in orthotopic pan-creatic tumors

4 Discussion

Pancreatic cancer is a malignant neoplasm originating fromtransformed cells arising in tissues forming the pancreasGemcitabine is the best chemotherapeutic agent availablefor treatment of pancreatic cancer However it is noted thatpatients with this cancer treated with gemcitabine showedseveral side effects and developed drug resistance over time[3] In order to bypass these problems novel strategiesinvolving less toxic agents that can sensitize pancreatic cancercells to chemotherapy are necessary Curcumin a componentof turmeric (Curcuma longa) is one such agent which inhibitthe cell survival proliferation angiogenesis of a wide varietyof tumor cells through the modulation of various cell sig-nalling pathways It has been demonstrated that curcumin indifferent pancreatic cancer cell lines inhibited proliferationpotentiated the apoptosis induced by gemcitabine and inhib-ited constitutive NF-120581B activation Our aimwas to determinewhether curcumin inhibits the growth and angiogenesis ofMIA PaCa-2 human pancreatic cancer cells in in vitro andin vivo conditions It has been largely demonstrated thatcurcumin is able to suppress the growth of several tumorcell lines including drug-resistant lines It suppresses theexpression of cyclin D1 which is involved in progression ofcell through cell cycle and is deregulated in many tumors[19] Curcumin potentiates the apoptosis in tumor cells byactivation of caspase enzymes and suppresses the activationof many transcription factors involved in tumorigenesis [20]Recently it has been demonstrated that curcumin potentiatesantitumor activity of gemcitabine in an orthotopic modelof pancreatic cancer trough suppression of proliferationangiogenesis NF-120581B and inhibition ofNF-120581B-regulated geneproducts [17] According to published data we demonstratedby in vitro experiments that curcumin inhibits proliferationand enhances apoptosis in MIA PaCa-2 human pancreaticcancer cells In addition to these in vitro results we found


200180160140120100

80604020

0

ControlMIA PaCa-2

Panc-1Mpanc-96

MIA

PaC

a-2

Panc

-1M

panc

-96

1 2 3

Curcumin

48 h

48 h

48 h

(a) (b)

(c) (d)

(e) (f)

(g)

(h)

(i) (j)

MIA PaCa-2 Panc-1 Mpanc-96

100

80

60

40

20

0

Apop

tosis

cells

()

P lt 00001

Con

trol

MIA

Pac

a-2

NF-120581B

50 13 Fold

MIA PaCa-2

siRN

Ac (minus

)

siRN

Ap65

(minus)

siRN

Ac (+

)

siRN

Ap65

(+)

100

80

60

40

20

0

Apop

tosis

cells

()

+ cu

rcum

in

Medium

Control

Figure 1 Curcumin inhibits proliferation and enhances apoptosis in MIA PaCa-2 cells (a)ndash(f) Wound assay results show suppression ofMIA PaCa-2 cell proliferation induced by curcumin at 48 h (b) With respect to controls The results are the mean of total invaded areas ofthree distinct sections on the slide per 48 h (119875 = 002 Mann-Whitney U test) (g) MTT assay results show a suppression of proliferation inpancreatic cancer cells treatedwith curcumin respect to control cells Data are representative of two independent experiments (119875 valuelt005)(h) In vitro apoptosis assay by flow cytometry indicated that curcumin enhances apoptosis in MIA PaCa-2 cells (i) EMSA results showes thatcurcumin suppresses activation of NF-120581B inMIA PACA-2 cells (j) In vitro apoptosis assay by flow cytometry indicates that silencing of NF-120581Busing siRNA 120581B is not able to potentiate the apoptotic effects of curcumin on MIA PaCa-2 cells


Control Curcumin

(a)

Tumor growth MIA PaCA-22000

1500

1000

500

00 10 17 24 31 35

Days after tumor injection

Curcumin

Volu

me (

mm

3)

lowast

Control

(b)

Figure 2 Curcumin inhibits the tumor growth in orthotopic mousemodel of pancreatic cancer (a)MacroFluo images of fluorescent analysistumor area images control and treated mice (b) Measurements of fluorescence per second depicting tumor volume at different time pointsusingMacrofluo images showed that the final tumor volumes on day 35 after the start of treatment is significantly decreased in the curcumingroup compared with control (119875 = 000393)

that curcumin administrated in mice with diet inhibitstumor growth and angiogenesis in an orthotopic modelof pancreatic cancer as indicated by a decrease in tumorvolume of curcumin-treated mice compared to controls ByEMSA assay we demonstrated that curcumin suppressedconstitutive NF-120581B activation in pancreatic cancer tissuesaccording to previous data [17] Our data also showedthat curcumin inhibited the expression of several importantproteins regulated by NF-120581B in particular we demonstratedthat there is a reduced expression of IKK120572 and IKK120573 intumor ofmice treatedwith curcuminwith respect to controls

indicating that curcumin inhibits NF-120581B activation throughsuppression of IKK in MIA PaCa-2 cells Taken together ourresults showed that that curcumin has antitumor effects inan orthotopic mouse model of human pancreatic cancer byinhibitingNF-120581B and its downstream targets Since curcuminis a very well tolerated in human subjects and is assumedby food our mouse model demonstrated curcumin can beused as an alternative agent to chemotherapy in treatmentof human pancreatic cancer Several in vitro and in vivostudies are on-going in our laboratory in order to test if acombination of curcumin (administrated by diet of loaded by


Con

trol

Curc

umin

NF-120581B

48 1 Fold

(a)

Con

trol

Curc

umin

COX-2 VEGF

80 70

3 4

(b)

Con

trol

Curc

umin

VEGF

Cyclin D1

COX-2

MMP-9

IKK120572

IKK120573

120573-Actin

(c)

Figure 3 Curcumin inhibitsNF-120581B activation and downregulatesNF-120581B-regulated gene products in orthotopic pancreatic tumors (a) EMSAassay performed on orthotopic tumor tissue samples showed the inhibition of NF-120581B by curcumin (b) Immunohistochemical analysisfor nuclear COX-2 and VEGF showed the inhibition of COX-2 and VEGF expression in curcumin-treated group compared to controls(Figure 3(b) lower panels) Percentages indicate the positive staining for the given biomarker (c)Western blot showing that curcumin inhibitsthe expression of NF-120581B-dependent gene products VEGF cyclin D1 MMP-9 COX-2 IKK120572 and IKK120573 in pancreatic tumor tissues Samplesfrom three animals in each group were analysed and representative data are shown 120573-Actin was used as loading control

NF-120581B

Curcumin

Metastasis Proliferation AngiogenesisAntiapoptosis

Figure 4 Molecular targets of curcumin in pancreatic cancer cells

nanoparticles) and gemcitabine can be used as possible andnovel therapeutic schedule for pancreatic cancer

Conflict of Interests

The authors have no other relevant affiliations or financialinterest with any organization or entity No writing assistancewas used in the production of paper

Acknowledgments

The authors thank Massimiliano Spinelli for kindly help inproviding informatics assistance We also thank Dr SoniaPetta for her technical support This work was supportedby the 5x mille and current research programs of InstituteNational of Tumors IRCCS ldquoFoundation G Pascalerdquo NaplesItaly

References

[1] A Jemal R Siegel E Ward et al ldquoCancer statistics 2006rdquo CaA Cancer Journal for Clinicians vol 56 no 2 pp 106ndash130 2006

[2] J P Duffy G Eibl H A Reber and O J Hines ldquoInfluenceof hypoxia and neoangiogenesis on the growth of pancreaticcancerrdquoMolecular Cancer vol 2 article no 12 2003

[3] H A Burris III M J Moore J Andersen et al ldquoImprovementsin survival and clinical benefit with gemcitabine as first-line therapy for patients with advanced pancreas cancer arandomized trialrdquo Journal of Clinical Oncology vol 15 no 6pp 2403ndash2413 1997

[4] C D Lao M T Ruffin IV D Normolle et al ldquoDose escalationof a curcuminoid formulationrdquo BMC Complementary andAlternative Medicine vol 6 article 10 2006

[5] B B Aggarwal ldquoNuclear factor-120581B the enemy withinrdquo CancerCell vol 6 no 3 pp 203ndash208 2004

[6] A Arlt A Gehrz S Muerkoster et al ldquoRole of NF-120581B andAktPI3K in the resistance of pancreatic carcinoma cell lines


against gemcitabine-induced cell deathrdquo Oncogene vol 22 no21 pp 3243ndash3251 2003

[7] S Liptay C K Weber L Ludwig M Wagner G Adler and RM Schmid ldquoMitogenic and antiapoptotic role of constitutiveNF-120581BRel activity in pancreatic cancerrdquo International Journalof Cancer vol 105 no 6 pp 735ndash746 2003

[8] S Fujioka GM Sclabas C Schmidt et al ldquoFunction of nuclearfactor 120581B in pancreatic cancer metastasisrdquo Clinical CancerResearch vol 9 no 1 pp 346ndash354 2003

[9] F R Greten C K Weber T F Greten et al ldquoStat3 and NF-120581B activation prevents apoptosis in pancreatic carcinogenesisrdquoGastroenterology vol 123 no 6 pp 2052ndash2063 2002

[10] H Q Xiong J L Abbruzzese E Lin LWang L Zheng and KXie ldquoNF-120581B activity blockade impairs the angiogenic potentialof human pancreatic cancer cellsrdquo International Journal ofCancer vol 108 no 2 pp 181ndash188 2004

[11] M Yebra E J Filardo E M Bayna E Kawahara J C Beckerand D A Cheresh ldquoInduction of carcinoma cell migration onvitronectin by NF-120581B-dependent gene expressionrdquo MolecularBiology of the Cell vol 6 no 7 pp 841ndash850 1995

[12] J L Arbiser N Klauber R Rohan et al ldquoCurcumin is an in vivoinhibitor of angiogenesisrdquoMolecular Medicine vol 4 no 6 pp376ndash383 1998

[13] D Thaloor A K Singh G S Sidhu P V Prasad H KKleinman and R K Maheshwari ldquoInhibition of angiogenicdifferentiation of human umbilical vein endothelial cells bycurcuminrdquo Cell Growth and Differentiation vol 9 no 4 pp305ndash312 1998

[14] R Mohan J Sivak P Ashton et al ldquoCurcuminoids inhibit theangiogenic response stimulated by fibroblast growth factor-2including expression of matrix metalloproteinase gelatinase BrdquoJournal of Biological Chemistry vol 275 no 14 pp 10405ndash104122000

[15] L Li B B Aggarwal S Shishodia J Abbruzzese and RKurzrock ldquoNuclear factor-120581B and I120581B are constitutively activein human pancreatic cells and their down-regulation by cur-cumin (Diferuloylmethane) is associated with the suppressionof proliferation and the induction of apoptosisrdquoCancer vol 101no 10 pp 2351ndash2362 2004

[16] L Li F S Braiteh and R Kurzrock ldquoLiposome-encapsulatedcurcumin in vitro and in vivo effects on proliferation apop-tosis signaling and angiogenesisrdquo Cancer vol 104 no 6 pp1322ndash1331 2005

[17] A B Kunnumakkara S Guha S Krishnan P Diagaradjane JGelovani andB B Aggarwal ldquoCurcumin potentiates antitumoractivity of gemcitabine in an orthotopic model of pancreaticcancer through suppression of proliferation angiogenesis andinhibition of nuclear factor-120581B-regulated gene productsrdquo Can-cer Research vol 67 no 8 pp 3853ndash3861 2007

[18] M M Chaturvedi A Mukhopadhyay and B B AggarwalldquoAssay for redox-sensitive transcription factorrdquo Methods inEnzymology vol 319 pp 585ndash602 2000

[19] AMukhopadhyay S Banerjee L J Stafford C XiaM Liu andB B Aggarwal ldquoCurcumin-induced suppression of cell prolif-eration correlates with down-regulation of cyclin D1 expressionand CDK4-mediated retinoblastoma protein phosphorylationrdquoOncogene vol 21 no 57 pp 8852ndash8861 2002

[20] B B Aggarwal A Kumar and A C Bharti ldquoAnticancer poten-tial of curcumin preclinical and clinical studiesrdquo AnticancerResearch vol 23 no 1A pp 363ndash398 2003

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Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom


several roles in angiogenesis [10] migration and invasionof pancreatic cells [11] Curcumin has also been shown tosuppress angiogenesis in vivo [12ndash14] In vitro and in vivostudies have already demonstrated that curcumin inhibits thegrowth of human pancreatic cancer cells [15 16] Previouslyit has been demonstrated that curcumin can potentiatesthe antitumor activity of gemcitabine in pancreatic cells bydownregulating NF-120581B-regulated gene products [17]

In this study we assessed the antitumor activities ofcurcumin in human pancreatic cancer cell line and MIAPaCa-2 cells by in vitro and in vivo experiments In vitrodata allowed us to demonstrate that curcumin inhibited theproliferation and enhanced the apoptosis of MIA PaCa-2cells In vivo by generation of an orthotopic mouse modelof pancreatic cancer we showed that tumours from miceinjected withMIA PaCa-2 cells and placed on diet containingcurcumin at 06 for 6 weeks were smaller than thoseobserved in controls We also showed a down regulation ofthe NF-120581B-regulated gene products (cyclin D VEGF MMP-9 and IKK120572120573) Overall our data indicate that curcumin hasa great potential in treatment of human pancreatic cancerthrough the modulation of NF-120581B pathway

2 Materials and Methods

21 Materials Curcumin (EE)-17-bis (4-Hydroxy-3-methoxyphenyl)-16-heptadiene-35-dione Diferuloylmeth-ane Diferulylmethane Natural Yellow 3 used for in vitroexperiments was obtained from Sigma Aldrich (PiscatawayNJ) The following polyclonal antibodies cyclin D1 MMP-9and monoclonal antibodies against VEGF were obtainedfrom Santa Cruz Biotechnology (Santa Cruz CA) Anti-IKK120572 and anti-IKK120573 antibodies were kindly provided byImgenex (San Diego CA) The liquid DAB+ SubstrateChromogen System-HRP used for immunocytochemistrywas obtained from DakoCytomation (Carpinteria CA)Penicillin streptomycin RPMI 1640 and fetal bovine serum(FBS) were obtained from Invitrogen (Grand Island NY)Tris glycine NaCl SDS and bovine serum albumin (BSA)were obtained from Sigma Chemical (St Louis MO)Complete feed for mice with curcumin 06 (AIN-93G) waspurchased by Mucedola (Settimo Milanese Italy)

22 Cell Lines The pancreatic cancer cell line MIA PaCa-2transfected with red fluorescent protein (RPF) and MPanc-96 cells was a kind gift from Professor Turco (University ofFisciano Italy) Panc-1 cells were obtained from the Amer-ican Type Culture Collection (Manassas VA) All cell lineswere cultured in RPMI 1640 supplemented with 10FBS100 unitsmL penicillin and 100120583gmL streptomycin

23 Proliferation Assay The effect of curcumin on cellproliferation was determined by using TACS 3-(45-dimeth-ylthiazol-2-yl)-25-diphenyltetrazolium bromide (MTT) cellproliferation assay (Trevigen Githersburg) The cells (2000per well) were incubated with or without curcumin intriplicate in a 96-well plate and then incubated for 2 4 and6 days at 37∘C A MTT solution was added to each welland incubated for 2 h at 37∘C An extraction buffer (20

SDS and 50 dimethylformamide) was added and the cellswere incubated overnight at 37∘C The absorbance of thecell suspension was measured at 570 nm using a microplatereader (DAS Technologies Chantilly VA) This experimentwas repeated twice and the statistical analysis was performedto obtain the final values

24 Wound-Healing Assay MIA PaCa-2 cells were seededat the density of 40 times 103 cells per well into a 6-multiwellplate and cultured in RPMI 1640medium supplemented with1 FBS At the time of confluence cells were incubated inthe absence or presence of curcumin (50120583M) for 48 h aftera slit made horizontally with a white tip at the center of eachconfluent well Cell invasion on the slit of the confluent wellwas assessed at 0 24 and 48 hours in each condition by lightmicroscopy

25 In Vitro Apoptosis Assay by Flow Cytometry Cells werewashed and suspended in 05mL of PBS and 1 ALmLYO-PRO-1 and propidium iodide was added Cells wereincubated for 30min on ice and analyzed by flow cytometry(FACScan Becton Dickinson Franklin Lakes NJ) by mea-surements of fluorescence emission at 530 and 575 nm

The apoptotic cells were stained with the green fluores-cent dye YO-PRO-1 while necrotic cells were stained withpropidium iodide The apoptotic fraction was obtained bydividing the number of apoptotic cells by the total numberof cells (minimumof 104 cells) Data were analyzed using CellQuest software (BectonDickinson) All datawere reproducedat least thrice in independent experiments

26 Transfection of Small Interfering RNA MIA PaCa cells in96-well plates were grown to 50 confluence and transfectedwith double-stranded siRNA for relAp65 (form of NF-120581B)target sequence (Sense 51015840 CCAUCAACUAUGAUGAGUUdTdT 31015840 Antisense 31015840 dGdTGGUAGUUGAUACUACUCAA51015840) or with a siRNAnonspecific control (Ambion Austin TXcat n461) in serum-free medium without antibiotic supple-ments using Hiperfect Transfection Reagent (Qiagen Inc)Cells were incubated under these conditions for 48 h andsilencing was then confirmed by western blotting analysis

27 NF-120581B Activation in Cell and Tumor Samples To assessNF-120581B activation we performed electrophoresis mobilityshift assays (EMSA) on isolated nuclei frompancreatic cancertumor and cell samples as described previously [17 18]Briefly nuclear extracts prepared frompancreatic cancer cells(1 times 106mL) and tumor samples were incubated with 32P-end-labeled 45-mer double-stranded NF-120581B oligonucleotide(4 120583g of protein with 16 fmol of DNA) from the HIVlong terminal repeat (51015840 -TTGTTACAAGGGACTTTCCG-CTGGGGACTTTCCAGGGAGGCGTGG-31015840 indicates NF-120581B-binding sites) for 15min at 37∘C The resulting DNA-protein complex was separated from free oligonucleotide on66 native polyacrylamide gels A double-stranded mutantoligonucleotide (51015840 -TTGTTACAACTCACTTTCCGCTG-CTCACTTTCCAGGGAGGCGTGG-31015840) was used to exam-ine the specificity of binding of NF-120581B to the DNAThe driedgels were visualized and radioactive bands were quantitated










3 Results







4 Discussion



200180160140120100

80604020

0

ControlMIA PaCa-2

Panc-1Mpanc-96

MIA

PaC

a-2

Panc

-1M

panc

-96

1 2 3

Curcumin

48 h

48 h

48 h

(a) (b)

(c) (d)

(e) (f)

(g)

(h)

(i) (j)


100

80

60

40

20

0

Apop

tosis

cells

()

P lt 00001

Con

trol

MIA

Pac

a-2

NF-120581B

50 13 Fold

MIA PaCa-2

siRN

Ac (minus

)

siRN

Ap65

(minus)

siRN

Ac (+

)

siRN

Ap65

(+)

100

80

60

40

20

0

Apop

tosis

cells

()

+ cu

rcum

in

Medium

Control



Control Curcumin

(a)


1500

1000

500

00 10 17 24 31 35


Curcumin

Volu

me (

mm

3)

lowast

Control

(b)





Con

trol

Curc

umin

NF-120581B

48 1 Fold

(a)

Con

trol

Curc

umin

COX-2 VEGF

80 70

3 4

(b)

Con

trol

Curc

umin

VEGF

Cyclin D1

COX-2

MMP-9

IKK120572

IKK120573

120573-Actin

(c)


NF-120581B

Curcumin






Acknowledgments


References




























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

























3 Results







4 Discussion



200180160140120100

80604020

0

ControlMIA PaCa-2

Panc-1Mpanc-96

MIA

PaC

a-2

Panc

-1M

panc

-96

1 2 3

Curcumin

48 h

48 h

48 h

(a) (b)

(c) (d)

(e) (f)

(g)

(h)

(i) (j)


100

80

60

40

20

0

Apop

tosis

cells

()

P lt 00001

Con

trol

MIA

Pac

a-2

NF-120581B

50 13 Fold

MIA PaCa-2

siRN

Ac (minus

)

siRN

Ap65

(minus)

siRN

Ac (+

)

siRN

Ap65

(+)

100

80

60

40

20

0

Apop

tosis

cells

()

+ cu

rcum

in

Medium

Control



Control Curcumin

(a)


1500

1000

500

00 10 17 24 31 35


Curcumin

Volu

me (

mm

3)

lowast

Control

(b)





Con

trol

Curc

umin

NF-120581B

48 1 Fold

(a)

Con

trol

Curc

umin

COX-2 VEGF

80 70

3 4

(b)

Con

trol

Curc

umin

VEGF

Cyclin D1

COX-2

MMP-9

IKK120572

IKK120573

120573-Actin

(c)


NF-120581B

Curcumin






Acknowledgments


References




























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of





















4 Discussion



200180160140120100

80604020

0

ControlMIA PaCa-2

Panc-1Mpanc-96

MIA

PaC

a-2

Panc

-1M

panc

-96

1 2 3

Curcumin

48 h

48 h

48 h

(a) (b)

(c) (d)

(e) (f)

(g)

(h)

(i) (j)


100

80

60

40

20

0

Apop

tosis

cells

()

P lt 00001

Con

trol

MIA

Pac

a-2

NF-120581B

50 13 Fold

MIA PaCa-2

siRN

Ac (minus

)

siRN

Ap65

(minus)

siRN

Ac (+

)

siRN

Ap65

(+)

100

80

60

40

20

0

Apop

tosis

cells

()

+ cu

rcum

in

Medium

Control



Control Curcumin

(a)


1500

1000

500

00 10 17 24 31 35


Curcumin

Volu

me (

mm

3)

lowast

Control

(b)





Con

trol

Curc

umin

NF-120581B

48 1 Fold

(a)

Con

trol

Curc

umin

COX-2 VEGF

80 70

3 4

(b)

Con

trol

Curc

umin

VEGF

Cyclin D1

COX-2

MMP-9

IKK120572

IKK120573

120573-Actin

(c)


NF-120581B

Curcumin






Acknowledgments


References




























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

















200180160140120100

80604020

0

ControlMIA PaCa-2

Panc-1Mpanc-96

MIA

PaC

a-2

Panc

-1M

panc

-96

1 2 3

Curcumin

48 h

48 h

48 h

(a) (b)

(c) (d)

(e) (f)

(g)

(h)

(i) (j)


100

80

60

40

20

0

Apop

tosis

cells

()

P lt 00001

Con

trol

MIA

Pac

a-2

NF-120581B

50 13 Fold

MIA PaCa-2

siRN

Ac (minus

)

siRN

Ap65

(minus)

siRN

Ac (+

)

siRN

Ap65

(+)

100

80

60

40

20

0

Apop

tosis

cells

()

+ cu

rcum

in

Medium

Control



Control Curcumin

(a)


1500

1000

500

00 10 17 24 31 35


Curcumin

Volu

me (

mm

3)

lowast

Control

(b)





Con

trol

Curc

umin

NF-120581B

48 1 Fold

(a)

Con

trol

Curc

umin

COX-2 VEGF

80 70

3 4

(b)

Con

trol

Curc

umin

VEGF

Cyclin D1

COX-2

MMP-9

IKK120572

IKK120573

120573-Actin

(c)


NF-120581B

Curcumin






Acknowledgments


References




























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

















Control Curcumin

(a)


1500

1000

500

00 10 17 24 31 35


Curcumin

Volu

me (

mm

3)

lowast

Control

(b)





Con

trol

Curc

umin

NF-120581B

48 1 Fold

(a)

Con

trol

Curc

umin

COX-2 VEGF

80 70

3 4

(b)

Con

trol

Curc

umin

VEGF

Cyclin D1

COX-2

MMP-9

IKK120572

IKK120573

120573-Actin

(c)


NF-120581B

Curcumin






Acknowledgments


References




























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

















Con

trol

Curc

umin

NF-120581B

48 1 Fold

(a)

Con

trol

Curc

umin

COX-2 VEGF

80 70

3 4

(b)

Con

trol

Curc

umin

VEGF

Cyclin D1

COX-2

MMP-9

IKK120572

IKK120573

120573-Actin

(c)


NF-120581B

Curcumin






Acknowledgments


References




























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of





































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of





















of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of
















Documents

Curcumin Inhibits Tumor Growth and Angiogenesis in an Orthotopic Mouse Model of Human Pancreatic Cancer