Signal Transduction in Cancer Metastasis

Cancerremainstobeoneofthemostdevastatingdiseasesworldwidesincelong ago. Thepoorprognosisofcancerislargelyduetometastasis. Metastasisisoften depictedasamultistageprocessinwhichmalignantcellsspreadfromtheprimary locustodistantorgansviacirculation. Whereasgeneticalterationsweresuggested tobeessentialfortransformationofprimarytumorcellsintometastaticphenotype, epigeneticeventsareequallyimportant,whichmaybetriggeredbymetastaticf- torswhereverintheprimarytumorlocus,bloodcirculationandthesecondaryloci. Signaltransductionsinitiatedbythemetastaticfactorsareresponsibleformediating themolecularandcellularprocessesleadingtometastasis. Blockadeoftherelevant molecularpathwaysisoneofthemosteffectivestrategiesforpreventionoftumor metastasis. Clinicaltrialsareunderwaywithpromisingoutcome. Inthisbook, wetakecomprehensive review inregard withthisexciting eld ofcancerresearch. Chapter1takesabriefoverviewofrecentlyidenti edsignal mechanismsforeachstepoftumormetastasisincludingtheinitiationstage,intra- sation,anti-anoikisinbloodcirculation,homing,extravasationand nalsurvivalin themetastaticsite. Chapter2makesacompletedreviewforthemolecularandcel- lareventsinvolvedininitiationofmetastasis.Especially,thesignalingmechanisms formediatingtumorprogressioninducedbysomeimportantmetastaticfactorsare described. InChapters3and4,thecentralrolesofMAPKanditsdownstreameff- torsMAPKAPKplayineachstepoftumormetastasisarewelldelineated. Chapter5 furtherdescribesdetailedlyabouthowGrb2andotheradaptorproteins,upstreamof MAPK cascade, contribute tometastasis. InChapter 6, therole ofreactive o- genspecies(ROS)intumorprogressionarehighlighted. Moreover,thepotential contribution of ROS to cross talk between major signaling cascades that lead to sustainedMAPKactivationareproposedinChapter7. Chapter8takesaninsight intothesignalingmechanismsfordynamictraf ckingandturnoveroffocalad- sionproteinsinregulationoftractionandretractionforces,whichareneededfor celllocomotionandinvasion. Chapter9describestheinvolvementofNotchsign- ingpathwaywhichisnotonlyessentialforembryonicdevelopmentbutalsoplays importantroleintumorprogression. Chapter10reviewedtherecentlyidenti ed cancer- and metastasis-initiating cells involved in tumor progression. Especially, signal pathways that are frequently deregulated in cancer stem/progenitor cells v vi Preface duringcancerprogressionarehighlighted.Chapter11describestheroleoflipid rafts, a special component within membrane lipid domain, in signal transd- tion triggered by growth factor receptors leading to tumor metastasis. Finally, Chapters12,Chapters13,andChapters14presentthesignalingpathwaysresp- sibleformetastaticprogressionofspeci ctumorsincludingovariancancer,uveal melanomaandhepatoma,respectively. WethankallthecontributorsofeveryChapterinthebookincludingJia-RuWu, Chi-TanHu,LaureVoisin,StephanieDuhamel,SylvainMeloche,AlexeyShiryaev, MarijkeVanGhelue,UgoMoens,AlessioGiubellino,PraveenR. Arany,Moulay A. Alaoui-Jamali, Krikor Bijian, Panagiota Toliopoulos, Pingyu Zhang, Pa