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CHEMOSENSITIZING EFFECT OF SPHINGOSINE KINASE-1 INHIBITION IN PROSTATE CANCER CELL AND ANIMAL MODELS
819 PACLITAXEL ENCAPSULATED IN CATIONIC LIPOSOME’S: A NEW OPTION FOR NEOVASCULAR TARGETING FOR THE TREATMENT OF PROSTATE CANCER Trojan L.1, Bode C.1, Weiss C.2, Kraenzlin B., Michaelis U.4, Teifel M.5, Alken P.1, Michel M.S.1
820 CHEMOSENSITIZING EFFECT OF SPHINGOSINE KINASE-1 INHIBITION IN PROSTATE CANCER CELL AND ANIMAL MODELS Pchejetski D.1, Doumerc N.2, Golzio M.1, Naymark M., Teissie J.1, Kohama T.4, Waxmann J., Malavaud B.2, Cuvillier O.1 1
University Hospital Mannheim, Dept. of Urology, Mannheim, Germany, 2University Hospital Mannheim, Dept. of Medical Biometrics and Statistics, Mannheim, Germany, University Hospital Mannheim, Medical Research Centre, Mannheim, Germany, 4MediGene AG, Martinsried, Germany, 5Zentaris AG, Frankfurt am Main, Germany 1
Introduction & Objectives: Neovascular targeting is an established approach for the therapy of prostate cancer (PCa). Cationic liposome’s have been shown to be absorbed by immature vascular endothelial cells due to negative electric charge RI WKHLU RXWHU FHOO PHPEUDQH :H DLPHG WR HYDOXDWH WKH DQWLWXPRXUDO HᚑFDF\ RI Paclitaxel encapsulated in cationic liposome’s for the treatment of PCa. Material & Methods: Tumours were generated by subcutaneous injection of 106 MatLu tumour cells into the right hind leg of 21 male Copenhagen rats. After tumour growth, the animals were treated by an i.v. infusion with either 5% glucose (Gl), Paclitaxel (Pax), cationic liposome’s (CL) or Paclitaxel encapsulated in cationic liposome’s (MBT-0206) on days 12,14,16 and 19. Results: (DFK DQLPDO GHYHORSHG D VXEFXWDQHRXV WXPRXU ZLWK QR VLJQLᚏFDQW GLᚎHUHQFHVLQWXPRXUYROXPHEHWZHHQWKHIRXUJURXSV7KHWULDOVWDUWHGZLWKDQLPDOVಬ ZHLJKWRIsJRQGD\ZKLFKGHFOLQHGVLJQLᚏFDQWO\XQGHUWUHDWPHQWLQWKH 3D[ s J DQGLQWKH0%7 s J JURXSRQGD\2QWKHODVW GD\RIWUHDWPHQWDQLPDOVWUHDWHGZLWK0%7KDGWKHVLJQLᚏFDQWO\ORZHVWWXPRXU YROXPHVZLWK sFPYV3D[ sFP YV&/ sFP YV*/ sFP 7KHTXDQWLᚏFDWLRQRI09'VKRZHGWKHORZHVWFRXQWIRU0%7 WUHDWHG WXPRXUV sYHVVHOVPP IROORZHG E\ */ sYHVVHOV PP 3D[ s YHVVHOVPP DQG&/ sYHVVHOVPP Conclusions: 7KH GDWD FRQᚏUPV WKDW QHRYDVFXODU WDUJHWLQJ ZLWK 0%7 LV D promising new method for the treatment of PCa by reducing the primary tumour PDVVDQGGHPRQVWUDWLQJEHQHᚏWVLQWKHVXSSUHVVLRQRIDQJLRJHQHVLVLQFRPSDULVRQ with the conventional treatment.
CNRS, Sphingolipids and Cancer Research Lab, Institut de Pharmacology et de Biology Structural, UMR5089, Toulouse, France, 2CHU Rangueil, Dept. RI 8URORJ\ HW 7UDQVSODQWDWLRQ 5«QDOH 7RXORXVH )UDQFH Imperial College London, Imperial College London, London, United Kingdom, 4Daiichi Sankyo Co. Ltd., Daiichi Sankyo Co. Ltd., Tokyo, Japan Introduction & Objectives: We have previously reported (Pchejetski et al., Cancer Res., 65, 2005, 11667-11675) that - in prostate cancer - inhibition of the oncogenic sphingosine kinase-1/sphingosine 1-phosphate (SphK1/S1P) pathway is a key element in chemotherapy-induced apoptosis. Material & Methods: 3& FXOWXUH 6SKLQJRVLQH NLQDVH DFWLYLW\ DQG expression – orthotopic prostate cancer model in mude mice. Results: Here we show that selective pharmacological inhibition of SphK1 WULJJHUVDSRSWRVLVLQ/1&D3DQG3&SURVWDWHFDQFHUFHOOVDQHᚎHFWWKDWLV reversed by SphK1 enforced expression. More importantly, we demonstrate IRU WKH ᚏUVW WLPH WKDW WKH XSUHJXODWLRQ RI WKH 6SK.63 SDWKZD\ SOD\V a crucial role in the resistance of prostate cancer cells to chemotherapy. ,PSRUWDQWO\SKDUPDFRORJLFDO6SK.LQKLELWLRQZLWKWKH%FFRPSRXQGRU VL51$DJDLQVW6SK.ERWKVHQVLWL]H/1&D3DQG3&FHOOVWRGRFHWD[HODQG camptothecin respectively. In an orthotopically xenotransplanted nude mouse PRGHOVFDPSWRWKHFLQDQG%FDORQHGLVSOD\DOLPLWHGHᚎHFWRQWXPRU JURZWKLQ3&FHOOVZKHUHDVLQFRPELQDWLRQWKHUHLVDV\QHUJ\RIHᚎHFWRQ WXPRUVL]HZLWKDVLJQLᚏFDQWLQFUHDVHLQWKHFHUDPLGH63VSKLQJROLSLGUDWLR Conclusions: To conclude, our study highlights the notion that drugs VSHFLᚏFDOO\GHVLJQHGWRLQKLELW6SK.FRXOGSURYLGHDPHDQVRIHQKDQFLQJ WKH HᚎHFWV RI FRQYHQWLRQDO WUHDWPHQW WKURXJK WKH SURVXUYLYDO DQWLDSRSWRWLF SphK1/S1P pathway.
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SORAFENIB INHIBITS THE DEVELOPMENT OF PROSTATE CANCER IN TRAMP MICE DIFFERENTIALLY AFFECTING ENDOTHELIAL AND PERICYTE GROWTH DURING TUMOUR ANGIOGENESIS
EFFECTS OF DOCETAXEL AND NOVEL TITANOCENE ANALOGUES ON CELL DEATH IN PROSTATE CANCER FOLLOWING DOWNREGULATION OF ID-1 AND THE IAPS
Bono A.V.1, Montironi R.2, Cosciani-Cunico S.1, Musiani P., Liberatore M., Iezzi M.
Dowling C.M.1&XᚎH61, Gill C.1, Tacke M.2, Fitzpatrick J.M., Watson R.W.G.1
1 University of Brescia, Dept. of Urology, Brescia, Italy, 2Technical University of Marche Region, Dept. of Pathology, Ancona, Italy, University of Chieti, Aging Research Centre, Chieti, Italy
1
Introduction & Objectives: 6RUDIHQLE %$< LV D SRWHQW LQKLELWRU RI ERWK F5DI DQG E5DIDQGRWKHUVHULQHWKUHRQLQHNLQDVHVDQGRIUHFHSWRUW\URVLQHNLQDVHV 9(*)5)LWHWF ,W WKXVLQKLELWVWXPRXUJURZWKGLUHFWO\WKURXJKLWVHᚎHFWVRQFDQFHUFHOOVDQGLQGLUHFWO\E\SUHYHQWLQJ neoangiogenesis. It is active against some human tumour: renal cell carcinoma, melanoma, and hepatocellular carcinoma and a series of clinical trials is ongoing in other tumours and in prostate cancer. TRAMP mice are an useful model to study prostate cancer as they spontaneously GHYHORS+*3,1DQGVXEVHTXHQWO\DGHQRFDUFLQRPD $'& DQGSRRUO\GLᚎHUHQWLDWHGFDUFLQRPD 3'& LQWKHSURVWDWH7KHDLPRIWKLVH[SHULPHQWZDVWRVWXG\WKHHᚎHFWVRI6RUDIHQLELQDJURXS of TRAMP mice. Material & Methods: Forty TRAMP mice were randomly assigned to a treatment or a control groups. Treatment consisted of oral daily dose Sorafenib 90 mg from tenth to twenty-sixth weeks RI DJH 7KHQ WKH DQLPDOV ZHUH VDFULᚏFHG WKH SURVWDWHV GLVVHFWHG HPEHGGHG LQ SDUDᚑQ DQG VWXGLHGZLWK VWDQGDUG+(LPPXQRVWDLQLQJIRU&'DQG&'IRUHQGRWKHOLDOFHOOV1*DQG ˞60$IRUSHULF\WHVDQG3&1$WRHYLGHQFHSUROLIHUDWLQJFHOOV Results: In the control group the distribution of prostate tissues areas was as follows: 12% normal tissue, 28% HGPIN, 60% ADC. In six animals foci of PDC was also detected. In the Sorafenib WUHDWHGJURXSWKHGLVWULEXWLRQZDV QRUPDOWLVVXH+*3,1DQGDGHQRFDUFLQRPD Moreover in the treated group HGPIN was more stumpy and less twisted and the adenocarcinoma IRFLGLGQRWFRPSOHWHO\ᚏOOWKHOXPLQD(SLWKHOLDOFHOOSUROLIHUDWLRQ 3&1$ ZDVOHVVSURQRXQFHG In four treated animals foci of PDC smaller in comparison with those seen in the untreated animals were seen. The treated animals also displayed more necrotic areas associated with a less evident cell proliferation and a greater number of apoptotic cells and the vascular network was less developed and the blood supply predominantly due to the enlarged blood vessels in the periductal connective tissue. In PDC of treated mice the vascular network consisted of a reduced QXPEHURIODUJHSRRUO\EUDQFKHGYHVVHOV9HVVHOFRXQWDVVHVVHGE\LPDJHDQDO\VLVFRQᚏUPHG WKDW6RUDIHQLEVLJQLᚏFDQWO\UHGXFHGWKHQXPEHURIYHVVHOVLQ+*3,1$'&DQG3'& Conclusions: In this preliminary study, Sorafenib was apparently able to reduce the incidence of HGPIN and ADC in a less extent of PDC of the prostate in TRAMP mice. In the treated animals VLJQLᚏFDQWHᚎHFWVRQWKHWXPRXUYDVFXODWXUHZHUHDOVRVHHQ7KHUHIRUHWKHGUXJVHHPVWRKDYH a noticeable activity on this prostate cancer model and further studies, such the investigation on WKHHᚎHFWVRIFRPELQHGWUHDWPHQWZLWKVXEVWDQFHVLQWHUIHULQJZLWKGLᚎHUHQWFRPSRQHQWVRIWKH angiogenic process are advisable.
Eur Urol Suppl 2008;7(3):276
Conway Institute of Biomolecular & Biomedical Research, School of Medicine & Medical Sciences, Dublin, Ireland, 2UCD, School of Chemistry & Chemical Biology, Dublin, Ireland, Mater Misericordiae Hospital, Dept. of Surgery, Dublin, Ireland Introduction & Objectives: Docetaxel is the standard treatment strategy for androgenindependent metastatic prostate cancer, but only provides a short survival advantage. This indicates a need to both increase the sensitivity of cancer cells to docetaxel and to identify QHZ FKHPRWKHUDSHXWLF RSWLRQV ,G LQKLELWRU RI GLᚎHUHQWLDWLRQ LV RYHU H[SUHVVHG LQ PDQ\ KXPDQ FDQFHUV DQG SURYLGHV SURWHFWLRQ DJDLQVW 71)˞ LQGXFHG DSRSWRVLV LQ SURVWDWH FDQFHU cells. Id-1 is associated with resistance to JNK-induced apoptosis and may represent a target for manipulation. The IAPs (Inhibitors of Apoptosis Proteins) are a family of proteins which are upregulated in androgen-independent prostate cancer. Novel Titanocene Analogues which are synthesised and modulated by the School of Chemistry and Chemical Biology have shown promising cytotoxic activity against a range of tumour types and may be utilised in the triggering of apoptosis in prostate cancer. To investigate if down-regulation of Id-1 and the IAPs in androgenindependent prostate cancer cells will increase their sensitivity to apoptosis when treated with docetaxel and novel titanocene analogues, mediated by an increase in JNK activity. Material & Methods: 3&FHOOVZHUHFXOWXUHGLQVXSSOHPHQWHG530,PHGLXPFRQWDLQLQJ fetal bovine serum (FBS). Serum depleted cells were cultured in medium containing 1% FBS. 3&FHOOVZHUHDVVHVVHGIRUDSRSWRVLVDQGYLDELOLW\XVLQJSURSLGLXPLRGLGH'1$VWDLQLQJE\ᚐRZ cytometry following treatment with docetaxel and the titanocene analogues. Total protein was LVRODWHGIURP3&FHOOVXVLQJ13LVRODWLRQVROXWLRQDQGVDPSOHVZHUHUXQRQ6'6 polyacrylamide gel, and electrophoretically transferred to Immobilon P (Millipore) to determine Id-1, IAP and JNK expression. Id-1 and the IAPs were down-regulated using siRNA. Results: Docetaxel and the novel titanocene analogues induced apoptosis and JNK SKRVKRU\ODWLRQLQDWLPHDQGGRVHGHSHQGHQWPDQQHULQ3&FHOOV'LUHFW VL51$ DQGLQGLUHFW (serum depletion) down-regulation of Id-1 expression increased apoptotic susceptibility to titanocene- induced apoptosis, however not to docetaxel. Triple IAP knockdown (cIAP-1, cIAP-2 and xIAP) resulted in an increased sensitivity to apoptosis induced by the titanocene analogues but not with docetaxel. Conclusions: Novel titanocene analogues induce apoptosis in androgen-independent prostate cancer cells and appear to do this independently of the JNK pathway. Down-regulation of Id-1 and the IAPs may be potential targets to increase sensitivity of androgen-independent prostate cancer to these novel titanocence analogues.
820 CHEMOSENSITIZING EFFECT OF SPHINGOSINE KINASE-1 INHIBITION IN PROSTATE CANCER CELL AND ANIMAL MODELS Pchejetski D.1, Doumerc N.2, Golzio M.1, Naymark M., Teissie J.1, Kohama T.4, Waxmann J., Malavaud B.2, Cuvillier O.1 1
University Hospital Mannheim, Dept. of Urology, Mannheim, Germany, 2University Hospital Mannheim, Dept. of Medical Biometrics and Statistics, Mannheim, Germany, University Hospital Mannheim, Medical Research Centre, Mannheim, Germany, 4MediGene AG, Martinsried, Germany, 5Zentaris AG, Frankfurt am Main, Germany 1
Introduction & Objectives: Neovascular targeting is an established approach for the therapy of prostate cancer (PCa). Cationic liposome’s have been shown to be absorbed by immature vascular endothelial cells due to negative electric charge RI WKHLU RXWHU FHOO PHPEUDQH :H DLPHG WR HYDOXDWH WKH DQWLWXPRXUDO HᚑFDF\ RI Paclitaxel encapsulated in cationic liposome’s for the treatment of PCa. Material & Methods: Tumours were generated by subcutaneous injection of 106 MatLu tumour cells into the right hind leg of 21 male Copenhagen rats. After tumour growth, the animals were treated by an i.v. infusion with either 5% glucose (Gl), Paclitaxel (Pax), cationic liposome’s (CL) or Paclitaxel encapsulated in cationic liposome’s (MBT-0206) on days 12,14,16 and 19. Results: (DFK DQLPDO GHYHORSHG D VXEFXWDQHRXV WXPRXU ZLWK QR VLJQLᚏFDQW GLᚎHUHQFHVLQWXPRXUYROXPHEHWZHHQWKHIRXUJURXSV7KHWULDOVWDUWHGZLWKDQLPDOVಬ ZHLJKWRIsJRQGD\ZKLFKGHFOLQHGVLJQLᚏFDQWO\XQGHUWUHDWPHQWLQWKH 3D[ s J DQGLQWKH0%7 s J JURXSRQGD\2QWKHODVW GD\RIWUHDWPHQWDQLPDOVWUHDWHGZLWK0%7KDGWKHVLJQLᚏFDQWO\ORZHVWWXPRXU YROXPHVZLWK sFPYV3D[ sFP YV&/ sFP YV*/ sFP 7KHTXDQWLᚏFDWLRQRI09'VKRZHGWKHORZHVWFRXQWIRU0%7 WUHDWHG WXPRXUV sYHVVHOVPP IROORZHG E\ */ sYHVVHOV PP 3D[ s YHVVHOVPP DQG&/ sYHVVHOVPP Conclusions: 7KH GDWD FRQᚏUPV WKDW QHRYDVFXODU WDUJHWLQJ ZLWK 0%7 LV D promising new method for the treatment of PCa by reducing the primary tumour PDVVDQGGHPRQVWUDWLQJEHQHᚏWVLQWKHVXSSUHVVLRQRIDQJLRJHQHVLVLQFRPSDULVRQ with the conventional treatment.
CNRS, Sphingolipids and Cancer Research Lab, Institut de Pharmacology et de Biology Structural, UMR5089, Toulouse, France, 2CHU Rangueil, Dept. RI 8URORJ\ HW 7UDQVSODQWDWLRQ 5«QDOH 7RXORXVH )UDQFH Imperial College London, Imperial College London, London, United Kingdom, 4Daiichi Sankyo Co. Ltd., Daiichi Sankyo Co. Ltd., Tokyo, Japan Introduction & Objectives: We have previously reported (Pchejetski et al., Cancer Res., 65, 2005, 11667-11675) that - in prostate cancer - inhibition of the oncogenic sphingosine kinase-1/sphingosine 1-phosphate (SphK1/S1P) pathway is a key element in chemotherapy-induced apoptosis. Material & Methods: 3& FXOWXUH 6SKLQJRVLQH NLQDVH DFWLYLW\ DQG expression – orthotopic prostate cancer model in mude mice. Results: Here we show that selective pharmacological inhibition of SphK1 WULJJHUVDSRSWRVLVLQ/1&D3DQG3&SURVWDWHFDQFHUFHOOVDQHᚎHFWWKDWLV reversed by SphK1 enforced expression. More importantly, we demonstrate IRU WKH ᚏUVW WLPH WKDW WKH XSUHJXODWLRQ RI WKH 6SK.63 SDWKZD\ SOD\V a crucial role in the resistance of prostate cancer cells to chemotherapy. ,PSRUWDQWO\SKDUPDFRORJLFDO6SK.LQKLELWLRQZLWKWKH%FFRPSRXQGRU VL51$DJDLQVW6SK.ERWKVHQVLWL]H/1&D3DQG3&FHOOVWRGRFHWD[HODQG camptothecin respectively. In an orthotopically xenotransplanted nude mouse PRGHOVFDPSWRWKHFLQDQG%FDORQHGLVSOD\DOLPLWHGHᚎHFWRQWXPRU JURZWKLQ3&FHOOVZKHUHDVLQFRPELQDWLRQWKHUHLVDV\QHUJ\RIHᚎHFWRQ WXPRUVL]HZLWKDVLJQLᚏFDQWLQFUHDVHLQWKHFHUDPLGH63VSKLQJROLSLGUDWLR Conclusions: To conclude, our study highlights the notion that drugs VSHFLᚏFDOO\GHVLJQHGWRLQKLELW6SK.FRXOGSURYLGHDPHDQVRIHQKDQFLQJ WKH HᚎHFWV RI FRQYHQWLRQDO WUHDWPHQW WKURXJK WKH SURVXUYLYDO DQWLDSRSWRWLF SphK1/S1P pathway.
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SORAFENIB INHIBITS THE DEVELOPMENT OF PROSTATE CANCER IN TRAMP MICE DIFFERENTIALLY AFFECTING ENDOTHELIAL AND PERICYTE GROWTH DURING TUMOUR ANGIOGENESIS
EFFECTS OF DOCETAXEL AND NOVEL TITANOCENE ANALOGUES ON CELL DEATH IN PROSTATE CANCER FOLLOWING DOWNREGULATION OF ID-1 AND THE IAPS
Bono A.V.1, Montironi R.2, Cosciani-Cunico S.1, Musiani P., Liberatore M., Iezzi M.
Dowling C.M.1&XᚎH61, Gill C.1, Tacke M.2, Fitzpatrick J.M., Watson R.W.G.1
1 University of Brescia, Dept. of Urology, Brescia, Italy, 2Technical University of Marche Region, Dept. of Pathology, Ancona, Italy, University of Chieti, Aging Research Centre, Chieti, Italy
1
Introduction & Objectives: 6RUDIHQLE %$< LV D SRWHQW LQKLELWRU RI ERWK F5DI DQG E5DIDQGRWKHUVHULQHWKUHRQLQHNLQDVHVDQGRIUHFHSWRUW\URVLQHNLQDVHV 9(*)5)LWHWF ,W WKXVLQKLELWVWXPRXUJURZWKGLUHFWO\WKURXJKLWVHᚎHFWVRQFDQFHUFHOOVDQGLQGLUHFWO\E\SUHYHQWLQJ neoangiogenesis. It is active against some human tumour: renal cell carcinoma, melanoma, and hepatocellular carcinoma and a series of clinical trials is ongoing in other tumours and in prostate cancer. TRAMP mice are an useful model to study prostate cancer as they spontaneously GHYHORS+*3,1DQGVXEVHTXHQWO\DGHQRFDUFLQRPD $'& DQGSRRUO\GLᚎHUHQWLDWHGFDUFLQRPD 3'& LQWKHSURVWDWH7KHDLPRIWKLVH[SHULPHQWZDVWRVWXG\WKHHᚎHFWVRI6RUDIHQLELQDJURXS of TRAMP mice. Material & Methods: Forty TRAMP mice were randomly assigned to a treatment or a control groups. Treatment consisted of oral daily dose Sorafenib 90 mg from tenth to twenty-sixth weeks RI DJH 7KHQ WKH DQLPDOV ZHUH VDFULᚏFHG WKH SURVWDWHV GLVVHFWHG HPEHGGHG LQ SDUDᚑQ DQG VWXGLHGZLWK VWDQGDUG+(LPPXQRVWDLQLQJIRU&'DQG&'IRUHQGRWKHOLDOFHOOV1*DQG ˞60$IRUSHULF\WHVDQG3&1$WRHYLGHQFHSUROLIHUDWLQJFHOOV Results: In the control group the distribution of prostate tissues areas was as follows: 12% normal tissue, 28% HGPIN, 60% ADC. In six animals foci of PDC was also detected. In the Sorafenib WUHDWHGJURXSWKHGLVWULEXWLRQZDV QRUPDOWLVVXH+*3,1DQGDGHQRFDUFLQRPD Moreover in the treated group HGPIN was more stumpy and less twisted and the adenocarcinoma IRFLGLGQRWFRPSOHWHO\ᚏOOWKHOXPLQD(SLWKHOLDOFHOOSUROLIHUDWLRQ 3&1$ ZDVOHVVSURQRXQFHG In four treated animals foci of PDC smaller in comparison with those seen in the untreated animals were seen. The treated animals also displayed more necrotic areas associated with a less evident cell proliferation and a greater number of apoptotic cells and the vascular network was less developed and the blood supply predominantly due to the enlarged blood vessels in the periductal connective tissue. In PDC of treated mice the vascular network consisted of a reduced QXPEHURIODUJHSRRUO\EUDQFKHGYHVVHOV9HVVHOFRXQWDVVHVVHGE\LPDJHDQDO\VLVFRQᚏUPHG WKDW6RUDIHQLEVLJQLᚏFDQWO\UHGXFHGWKHQXPEHURIYHVVHOVLQ+*3,1$'&DQG3'& Conclusions: In this preliminary study, Sorafenib was apparently able to reduce the incidence of HGPIN and ADC in a less extent of PDC of the prostate in TRAMP mice. In the treated animals VLJQLᚏFDQWHᚎHFWVRQWKHWXPRXUYDVFXODWXUHZHUHDOVRVHHQ7KHUHIRUHWKHGUXJVHHPVWRKDYH a noticeable activity on this prostate cancer model and further studies, such the investigation on WKHHᚎHFWVRIFRPELQHGWUHDWPHQWZLWKVXEVWDQFHVLQWHUIHULQJZLWKGLᚎHUHQWFRPSRQHQWVRIWKH angiogenic process are advisable.
Eur Urol Suppl 2008;7(3):276
Conway Institute of Biomolecular & Biomedical Research, School of Medicine & Medical Sciences, Dublin, Ireland, 2UCD, School of Chemistry & Chemical Biology, Dublin, Ireland, Mater Misericordiae Hospital, Dept. of Surgery, Dublin, Ireland Introduction & Objectives: Docetaxel is the standard treatment strategy for androgenindependent metastatic prostate cancer, but only provides a short survival advantage. This indicates a need to both increase the sensitivity of cancer cells to docetaxel and to identify QHZ FKHPRWKHUDSHXWLF RSWLRQV ,G LQKLELWRU RI GLᚎHUHQWLDWLRQ LV RYHU H[SUHVVHG LQ PDQ\ KXPDQ FDQFHUV DQG SURYLGHV SURWHFWLRQ DJDLQVW 71)˞ LQGXFHG DSRSWRVLV LQ SURVWDWH FDQFHU cells. Id-1 is associated with resistance to JNK-induced apoptosis and may represent a target for manipulation. The IAPs (Inhibitors of Apoptosis Proteins) are a family of proteins which are upregulated in androgen-independent prostate cancer. Novel Titanocene Analogues which are synthesised and modulated by the School of Chemistry and Chemical Biology have shown promising cytotoxic activity against a range of tumour types and may be utilised in the triggering of apoptosis in prostate cancer. To investigate if down-regulation of Id-1 and the IAPs in androgenindependent prostate cancer cells will increase their sensitivity to apoptosis when treated with docetaxel and novel titanocene analogues, mediated by an increase in JNK activity. Material & Methods: 3&FHOOVZHUHFXOWXUHGLQVXSSOHPHQWHG530,PHGLXPFRQWDLQLQJ fetal bovine serum (FBS). Serum depleted cells were cultured in medium containing 1% FBS. 3&FHOOVZHUHDVVHVVHGIRUDSRSWRVLVDQGYLDELOLW\XVLQJSURSLGLXPLRGLGH'1$VWDLQLQJE\ᚐRZ cytometry following treatment with docetaxel and the titanocene analogues. Total protein was LVRODWHGIURP3&FHOOVXVLQJ13LVRODWLRQVROXWLRQDQGVDPSOHVZHUHUXQRQ6'6 polyacrylamide gel, and electrophoretically transferred to Immobilon P (Millipore) to determine Id-1, IAP and JNK expression. Id-1 and the IAPs were down-regulated using siRNA. Results: Docetaxel and the novel titanocene analogues induced apoptosis and JNK SKRVKRU\ODWLRQLQDWLPHDQGGRVHGHSHQGHQWPDQQHULQ3&FHOOV'LUHFW VL51$ DQGLQGLUHFW (serum depletion) down-regulation of Id-1 expression increased apoptotic susceptibility to titanocene- induced apoptosis, however not to docetaxel. Triple IAP knockdown (cIAP-1, cIAP-2 and xIAP) resulted in an increased sensitivity to apoptosis induced by the titanocene analogues but not with docetaxel. Conclusions: Novel titanocene analogues induce apoptosis in androgen-independent prostate cancer cells and appear to do this independently of the JNK pathway. Down-regulation of Id-1 and the IAPs may be potential targets to increase sensitivity of androgen-independent prostate cancer to these novel titanocence analogues.