Paclitaxelisapotentanticanceragentknowntopromotemicrotubule(MT) assembly,inhibitMTdepolymerization,andchangeMTdynamicsrequiredformitosisandcellproliferation.

IC50:4nM(MT)

Paclitaxelat0.1,0.5,and1μMreducestheproliferationandsurvivalofCCRF-HSB-2cellsinadose-dependentfashionandthattheIC₅₀valueoftaxolisabout0.25μM^[1].Paclitaxeldirectlyassociateswiththeendoplasmicreticulumtostimulatethereleaseofcalciumintothecytosol,contributingtotheinductionofapoptosis^[2].

InaSCIDmousexenograftmodel,lowdosemetronomicPaclitaxeltreatmentdecreaseslungdisseminationofEGI-1cellswithoutsignificantlyaffectingtheirlocaltumorgrowth^[3].Lowdosesofpaclitaxelpromotlivermetastasisinmousexenografts,whichcorrelatswithchangesinestrogenmetabolisminthehostliver^[4].Paclitaxel(2mg/kgpertreatment,blackcircles)inducesmechanicalhypersensitivityintheglabrousskinofthehindpaw^[5].

• [1].ParkSJ,etal.Taxolinducescaspase-10-dependentapoptosis.JBiolChem.2004Dec3;279(49):51057-67.Epub2004Sep27.

  [2].PanZ,etal.PaclitaxelattenuatesBcl-2resistancetoapoptosisinbreastcancercellsthroughanendoplasmicreticulum-mediatedcalciumreleaseinadosagedependentmanner.BiochemBiophysResCommun.2013Feb13.pii:S0006-291X(13)00259-3.

  [3].CadamuroM,etal.LowdosepaclitaxelreducesS100A4nuclearimporttoinhibitinvasionandhematogenousmetastasisofcholangiocarcinoma.CancerRes.2016Jun21.

  [4].LiQ,etal.Lowdosesofpaclitaxelenhancelivermetastasisofbreastcancercellsinthemousemodel.FEBSJ.2016Jun16.

  [5].YilmazE,etal.Sensoryneuronsubpopulation-specificdysregulationofintracellularcalciuminaratmodelofchemotherapy-inducedperipheralneuropathy.Neuroscience.2015Aug6;300:210-8.

  [6].JingC,etal.Lenvatinibenhancestheantitumoreffectsofpaclitaxelinanaplasticthyroidcancer.AmJCancerRes.2017Apr1;7(4):903-912.

Todeterminewhichcaspasesareinvolvedinapoptosisinducedbytaxol,caspase-3inhibitor(DEVD-CHO),caspase-6inhibitor(Z-VEID-FMK),caspase-8inhibitor(Z-IETD-FMKorIETD-CHO),caspase-9inhibitors(Z-LEHD-FMKorLEHD-CHO),andcaspase-10inhibitor(Z-AEVD-FMK)areused.Thesecaspaseinhibitorsaredissolvedindimethylsulfoxide(Me₂SO);thefinalconcentrationofMe₂SOis0.1%.Cells(5×10⁵)arepreincubatedinthepresenceorabsenceof100μM eachoftheseinhibitorsfor3hat37°Cthentreatedwithorwithout0.1,0.5,and1μM Paclitaxelfor48handprocessedforannexinVbindingassay.MCEhasnotindependentlyconfirmedtheaccuracyofthesemethods.Theyareforreferenceonly.

1×10⁴cellsareplatedin100μLofthegrowthmediuminthepresenceorabsenceofincreasingconcentrations(0.1-1μM)oftaxolin96-wellplatesandculturedat37°Cin5%CO₂for12-48h.Thecellsarethenincubatedwith25μLofMTT(5mg/mL)at37°Cfor4h.Afterdissolvingthecrystalswith0.04 N HClinisopropanol,theplatesarereadinamicroplatereaderat570nm.Theconcentrationofdrugthatinhibitscellsurvivalby50%(IC₅₀)isdeterminedfromcellsurvivalplots.MCEhasnotindependentlyconfirmedtheaccuracyofthesemethods.Theyareforreferenceonly.

Paclitaxelisdissolvedat25mg/mLin1:1CremophorEL:ethanolandfreshlydiluted1:12.5in0.9%sterilesalinepriortoinjections.

Adult(250-320g)maleSprague-Dawleyratsareusedforallexperiments.Ratsarehousedtwopercageinatemperatureandhumiditycontrolled,ona12h:12hlight:darkschedulewithfoodandwateravailableadlibitum.OneweekfollowingtheDiIinjection,ratsareanesthetizedwithisofluoraneandinjectedintothetailveinwith2mg/kgpaclitaxeloritsvehicle(1:1:23,cremophorEL:ethanol:0.9%saline).Thetailveininjectionisrepeatedthreemoretimeseveryotherdayforatotaloffourinjections.MCEhasnotindependentlyconfirmedtheaccuracyofthesemethods.Theyareforreferenceonly.

• [1].ParkSJ,etal.Taxolinducescaspase-10-dependentapoptosis.JBiolChem.2004Dec3;279(49):51057-67.Epub2004Sep27.

  [2].PanZ,etal.PaclitaxelattenuatesBcl-2resistancetoapoptosisinbreastcancercellsthroughanendoplasmicreticulum-mediatedcalciumreleaseinadosagedependentmanner.BiochemBiophysResCommun.2013Feb13.pii:S0006-291X(13)00259-3.

  [3].CadamuroM,etal.LowdosepaclitaxelreducesS100A4nuclearimporttoinhibitinvasionandhematogenousmetastasisofcholangiocarcinoma.CancerRes.2016Jun21.

  [4].LiQ,etal.Lowdosesofpaclitaxelenhancelivermetastasisofbreastcancercellsinthemousemodel.FEBSJ.2016Jun16.

  [5].YilmazE,etal.Sensoryneuronsubpopulation-specificdysregulationofintracellularcalciuminaratmodelofchemotherapy-inducedperipheralneuropathy.Neuroscience.2015Aug6;300:210-8.

  [6].JingC,etal.Lenvatinibenhancestheantitumoreffectsofpaclitaxelinanaplasticthyroidcancer.AmJCancerRes.2017Apr1;7(4):903-912.

853.91

C₄₇H₅₁NO₁₄

33069-62-4

RoomtemperatureincontinentalUS;mayvaryelsewhere

DMSO:≥31mg/mL;H₂O:<0.1="">

Paclitaxelisdissolvedat20mg/mLinDMSOandfreshlydiluted(1:1-1:200)asasUSPensionwithPBS.
PaclitaxelisdissolvedinDMSO,aliquotedandstoredat-80°Cuntilfurtheruse.ThesamevolumeofDMSOisusedasthevehiclecontrol^[6].

*"<1 mg/ml"="" means="" slightly="" soluble="" or="" insoluble.="" "≥"="" means="" soluble,="" but="" saturation="">

• [1].ParkSJ,etal.Taxolinducescaspase-10-dependentapoptosis.JBiolChem.2004Dec3;279(49):51057-67.Epub2004Sep27.

  [2].PanZ,etal.PaclitaxelattenuatesBcl-2resistancetoapoptosisinbreastcancercellsthroughanendoplasmicreticulum-mediatedcalciumreleaseinadosagedependentmanner.BiochemBiophysResCommun.2013Feb13.pii:S0006-291X(13)00259-3.

  [3].CadamuroM,etal.LowdosepaclitaxelreducesS100A4nuclearimporttoinhibitinvasionandhematogenousmetastasisofcholangiocarcinoma.CancerRes.2016Jun21.

  [4].LiQ,etal.Lowdosesofpaclitaxelenhancelivermetastasisofbreastcancercellsinthemousemodel.FEBSJ.2016Jun16.

  [5].YilmazE,etal.Sensoryneuronsubpopulation-specificdysregulationofintracellularcalciuminaratmodelofchemotherapy-inducedperipheralneuropathy.Neuroscience.2015Aug6;300:210-8.

  [6].JingC,etal.Lenvatinibenhancestheantitumoreffectsofpaclitaxelinanaplasticthyroidcancer.AmJCancerRes.2017Apr1;7(4):903-912.