79 TYROSINE KINASE AND MTOR INHIBITION IN RENAL CELL CARCINOMA SPHEROIDS

Abstract

You have accessJournal of UrologyKidney Cancer: Basic Research I1 Apr 201079 TYROSINE KINASE AND MTOR INHIBITION IN RENAL CELL CARCINOMA SPHEROIDS Kai Kraemer, Claudia Mattissek, Daniela Wuttig, Jana Herrmann, Susanne Fuessel, Marc-Oliver Grimm, and Manfred P. Wirth Kai KraemerKai Kraemer More articles by this author , Claudia MattissekClaudia Mattissek More articles by this author , Daniela WuttigDaniela Wuttig More articles by this author , Jana HerrmannJana Herrmann More articles by this author , Susanne FuesselSusanne Fuessel More articles by this author , Marc-Oliver GrimmMarc-Oliver Grimm More articles by this author , and Manfred P. WirthManfred P. Wirth More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.127AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Targeted therapies have become the standard systemic treatment of advanced renal cell carcinoma (RCC). Their effect on angiogenesis is well-known but whether they affect tumor cells directly remains unclear. In this study, direct effects of separate and combined treatments (simultaneously and consecutively) with tyrosine kinase inhibitors and mTOR inhibitors on RCC spheroids were evaluated. METHODS Multicellular spheroids from A498 and 786-O RCC cell lines were used as models for treatments with the tyrosine kinase inhibitor sorafenib or the mTOR inhibitor RAD001. First, the expression of relevant tyrosine kinases and mTOR was confirmed by immunofluorescence and qPCR. During incubation for 8 or 14 days with different concentrations of the inhibitors (dissolved in DMSO), spheroid diameter was measured daily for up to 22 days by microscopy. In addition, apoptosis and cellular viability as well as the inhibitors' influence on the target molecules were assessed. RESULTS The sorafenib targets FLT1, KDR and PDGFRB as well as the RAD001 target mTOR were expressed in tumor spheroids. RAD001 treatment caused a concentration-dependent decrease in spheroid volume after 14 days to 20% (A498) and 30% (786-O) of their initial volume without affecting spheroid's integrity. After treatment, the spheroid volume remained stable (500nM) or increased again (<100nM). No apoptosis was detected following RAD001 treatment. In contrast, sorafenib caused swelling of the spheroids. After 1 week of sorafenib treatment (10μM) the spheroids completely dissolved and massive cell death occurred. The simultaneous application of 500nM RAD001 and 5μM sorafenib also caused disintegration of spheroids being more effective than the consecutive application. Moreover, simultaneous treatment caused the most prominent reduction in spheroid viability to less than 20% of the control. CONCLUSIONS Both inhibitors affect tumor cells directly but the effects differ. While RAD001 decreased spheroid volume sorafenib caused complete disintegration. The simultaneous application of both inhibitors was more effective against RCC spheroids than separate and consecutive treatments. Dresden, Germany© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e33 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kai Kraemer More articles by this author Claudia Mattissek More articles by this author Daniela Wuttig More articles by this author Jana Herrmann More articles by this author Susanne Fuessel More articles by this author Marc-Oliver Grimm More articles by this author Manfred P. Wirth More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...