Abstract
The mammalian target of rapamycin (mTOR) and its substrates S6K1 and S6K2 regulate cell growth, proliferation, and metabolism through translational control. RPS6KB1 (S6K1) and RPS6KB2 (S6K2) are situated in the commonly amplified 17q21–23 and 11q13 regions. S6K1 amplification and protein overexpression have earlier been associated with a worse outcome in breast cancer, but information regarding S6K2 is scarce. The aim of this study was to evaluate the prognostic and treatment predictive relevance of S6K1/S6K2 gene amplification, as well as S6K2 protein expression in breast cancer. S6K1/S6K2 gene copy number was determined by real-time PCR in 207 stage II breast tumors and S6K2 protein expression was investigated by immunohistochemistry in 792 node-negative breast cancers. S6K1 amplification/gain was detected in 10.7%/21.4% and S6K2 amplification/gain in 4.3%/21.3% of the tumors. S6K2 protein was detected in the nucleus (38%) and cytoplasm (76%) of the tumor cells. S6K1 amplification was significantly associated with HER2 gene amplification and protein expression. S6K2 amplification correlated significantly with high S6K2 mRNA levels, ER+ status and CCND1 amplification. S6K1 and S6K2 gene amplification was associated with a worse prognosis independent of HER2 and CCND1. S6K2 gain and nuclear S6K2 expression was related to an improved benefit from tamoxifen among patients with ER+, respectively ER+/PgR+ tumors. In the ER+/PgR− subgroup, nuclear S6K2 rather indicated decreased tamoxifen responsiveness. S6K1 amplification predicted reduced benefit from radiotherapy. This is the first study showing that S6K2 amplification and overexpression, like S6K1 amplification, have prognostic and treatment predictive significance in breast cancer.
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References
Ma XM, Blenis J (2009) Molecular mechanisms of mTOR-mediated translational control. Nat Rev Mol Cell Biol 10:307–318
Guertin DA, Sabatini DM (2007) Defining the role of mTOR in cancer. Cancer Cell 12:9–22
Perez-Tenorio G, Alkhori L, Olsson B, Waltersson MA, Nordenskjöld B, Rutqvist LE, Skoog L, Stål O (2007) PIK3CA mutations and PTEN loss correlate with similar prognostic factors and are not mutually exclusive in breast cancer. Clin Cancer Res 13:3577–3584
Saal LH, Holm K, Maurer M, Memeo L, Su T, Wang X, Yu JS, Malmström PO, Mansukhani M, Enoksson J, Hibshoosh H, Borg Å, Parsons R (2005) PIK3CA mutations correlate with hormone receptors, node metastasis, and ERBB2, and are mutually exclusive with PTEN loss in human breast carcinoma. Cancer Res 65:2554–2559
Samuels Y, Wang Z, Bardelli A, Silliman N, Ptak J, Szabo S, Yan H, Gazdar A, Powell SM, Riggins GJ, Willson JK, Markowitz S, Kinzler KW, Vogelstein B, Velculescu VE (2004) High frequency of mutations of the PIK3CA gene in human cancers. Science 304:554
Bärlund M, Boulay A, Rudloff J, Ye J, Zumstein-Mecker S, O’Reilly T, Evans DB, Chen S, Lane HA (2005) Dual inhibition of mTOR and estrogen receptor signaling in vitro induces cell death in models of breast cancer. Clin Cancer Res 11:5319–5328
Kurokawa H, Arteaga CL (2003) ErbB (HER) receptors can abrogate antiestrogen action in human breast cancer by multiple signaling mechanisms. Clin Cancer Res 9:511S–515S
Schiff R, Massarweh SA, Shou J, Bharwani L, Mohsin SK, Osborne CK (2004) Cross-talk between estrogen receptor and growth factor pathways as a molecular target for overcoming endocrine resistance. Clin Cancer Res 10:331S–336S
Chan S, Scheulen ME, Johnston S, Mross K, Cardoso F, Dittrich C, Eiermann W, Hess D, Morant R, Semiglazov V, Borner M, Salzberg M, Ostapenko V, Illiger HJ, Behringer D, Bardy-Bouxin N, Boni J, Kong S, Cincotta M, Moore L (2005) Phase II study of temsirolimus (CCI-779), a novel inhibitor of mTOR, in heavily pretreated patients with locally advanced or metastatic breast cancer. J Clin Oncol 23:5314–5322
deGraffenried LA, Friedrichs WE, Russell DH, Donzis EJ, Middleton AK, Silva JM, Roth RA, Hidalgo M (2004) Inhibition of mTOR activity restores tamoxifen response in breast cancer cells with aberrant Akt activity. Clin Cancer Res 10:8059–8067
Baselga J, Semiglazov V, van Dam P, Manikhas A, Bellet M, Mayordomo J, Campone M, Kubista E, Greil R, Bianchi G, Steinseifer J, Molloy B, Tokaji E, Gardner H, Phillips P, Stumm M, Lane HA, Dixon JM, Jonat W, Rugo HS (2009) Phase II randomized study of neoadjuvant everolimus plus letrozole compared with placebo plus letrozole in patients with estrogen receptor-positive breast cancer. J Clin Oncol 27:2630–2637
Park IH, Bachmann R, Shirazi H, Chen J (2002) Regulation of ribosomal S6 kinase 2 by mammalian target of rapamycin. J Biol Chem 277:31423–31429
Jastrzebski K, Hannan KM, Tchoubrieva EB, Hannan RD, Pearson RB (2007) Coordinate regulation of ribosome biogenesis and function by the ribosomal protein S6 kinase, a key mediator of mTOR function. Growth Factors 25:209–226
Lee-Fruman KK, Kuo CJ, Lippincott J, Terada N, Blenis J (1999) Characterization of S6K2, a novel kinase homologous to S6K1. Oncogene 18:5108–5114
Shima H, Pende M, Chen Y, Fumagalli S, Thomas G, Kozma SC (1998) Disruption of the p70(s6k)/p85(s6k) gene reveals a small mouse phenotype and a new functional S6 kinase. EMBO J 17:6649–6659
Montagne J, Stewart MJ, Stocker H, Hafen E, Kozma SC, Thomas G (1999) Drosophila S6 kinase: a regulator of cell size. Science 285:2126–2129
Pende M, Um SH, Mieulet V, Sticker M, Goss VL, Mestan J, Mueller M, Fumagalli S, Kozma SC, Thomas G (2004) S6K1(−/−)/S6K2(−/−) mice exhibit perinatal lethality and rapamycin-sensitive 5′-terminal oligopyrimidine mRNA translation and reveal a mitogen-activated protein kinase-dependent S6 kinase pathway. Mol Cell Biol 24:3112–3124
Lofts FJ, Gullick WJ (1992) c-erbB2 amplification and overexpression in human tumors. Cancer Treat Res 61:161–179
Singleton TP, Strickler JG (1992) Clinical and pathologic significance of the c-erbB-2 (HER-2/neu) oncogene. Pathol Annu 27 Pt 1:165–190
Slamon DJ, Clark GM, Wong SG, Levin WJ, Ullrich A, McGuire WL (1987) Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neu oncogene. Science 235:177–182
Al-Kuraya K, Schraml P, Torhorst J, Tapia C, Zaharieva B, Novotny H, Spichtin H, Maurer R, Mirlacher M, Kochli O, Zuber M, Dieterich H, Mross F, Wilber K, Simon R, Sauter G (2004) Prognostic relevance of gene amplifications and coamplifications in breast cancer. Cancer Res 64:8534–8540
Bostner J, Ahnström Waltersson M, Fornander T, Skoog L, Nordenskjöld B, Stål O (2007) Amplification of CCND1 and PAK1 as predictors of recurrence and tamoxifen resistance in postmenopausal breast cancer. Oncogene 26:6997–7005
Jirström K, Stendahl M, Ryden L, Kronblad A, Bendahl PO, Stål O, Landberg G (2005) Adverse effect of adjuvant tamoxifen in premenopausal breast cancer with cyclin D1 gene amplification. Cancer Res 65:8009–8016
Bärlund M, Forozan F, Kononen J, Bubendorf L, Chen Y, Bittner ML, Torhorst J, Haas P, Bucher C, Sauter G, Kallioniemi OP, Kallioniemi A (2000) Detecting activation of ribosomal protein S6 kinase by complementary DNA and tissue microarray analysis. J Natl Cancer Inst 92:1252–1259
van der Hage JA, van den Broek LJ, Legrand C, Clahsen PC, Bosch CJ, Robanus-Maandag EC, van de Velde CJ, van de Vijver MJ (2004) Overexpression of P70 S6 kinase protein is associated with increased risk of locoregional recurrence in node-negative premenopausal early breast cancer patients. Br J Cancer 90:1543–1550
Noh WC, Kim YH, Kim MS, Koh JS, Kim HA, Moon NM, Paik NS (2008) Activation of the mTOR signaling pathway in breast cancer and its correlation with the clinicopathologic variables. Breast Cancer Res Treat 110:477–483
McShane LM, Altman DG, Sauerbrei W, Taube SE, Gion M, Clark GM (2006) REporting recommendations for tumor MARKer prognostic studies (REMARK). Breast Cancer Res Treat 100:229–235
Rutqvist LE, Johansson H (2006) Long-term follow-up of the Stockholm randomized trials of postoperative radiation therapy versus adjuvant chemotherapy among ‘high risk’ pre- and postmenopausal breast cancer patients. Acta Oncol 45:517–527
Rutqvist LE, Johansson H (2007) Long-term follow-up of the randomized Stockholm trial on adjuvant tamoxifen among postmenopausal patients with early stage breast cancer. Acta Oncol 46:133–145
Askmalm MS, Carstensen J, Nordenskjöld B, Olsson B, Rutqvist LE, Skoog L, Stål O (2004) Mutation and accumulation of p53 related to results of adjuvant therapy of postmenopausal breast cancer patients. Acta Oncol 43:235–244
Jansson A, Delander L, Gunnarsson C, Fornander T, Skoog L, Nordenskjöld B, Stål O (2009) Ratio of 17HSD1 to 17HSD2 protein expression predicts the outcome of tamoxifen treatment in postmenopausal breast cancer patients. Clin Cancer Res 15:3610–3616
Sinclair CS, Rowley M, Naderi A, Couch FJ (2003) The 17q23 amplicon and breast cancer. Breast Cancer Res Treat 78:313–322
Couch FJ, Wang XY, Wu GJ, Qian J, Jenkins RB, James CD (1999) Localization of PS6K to chromosomal region 17q23 and determination of its amplification in breast cancer. Cancer Res 59:1408–1411
Albertson DG (2006) Gene amplification in cancer. Trends Genet 22:447–455
Elsheikh S, Green AR, Aleskandarany MA, Grainge M, Paish CE, Lambros MB, Reis-Filho JS, Ellis IO (2008) CCND1 amplification and cyclin D1 expression in breast cancer and their relation with proteomic subgroups and patient outcome. Breast Cancer Res Treat 109:325–335
Letessier A, Sircoulomb F, Ginestier C, Cervera N, Monville F, Gelsi-Boyer V, Esterni B, Geneix J, Finetti P, Zemmour C, Viens P, Charafe-Jauffret E, Jacquemier J, Birnbaum D, Chaffanet M (2006) Frequency, prognostic impact, and subtype association of 8p12, 8q24, 11q13, 12p13, 17q12, and 20q13 amplifications in breast cancers. BMC Cancer 6:245
Lyzogubov V, Khozhaenko Y, Usenko V, Antonjuk S, Ovcharenko G, Tikhonkova I, Filonenko V (2005) Immunohistochemical analysis of Ki-67, PCNA and S6K1/2 expression in human breast cancer. Exp Oncol 27:141–144
Phin S, Kupferwasser D, Lam J, Lee-Fruman KK (2003) Mutational analysis of ribosomal S6 kinase 2 shows differential regulation of its kinase activity from that of ribosomal S6 kinase 1. Biochem J 373:583–591
Massarweh S, Schiff R (2007) Unraveling the mechanisms of endocrine resistance in breast cancer: new therapeutic opportunities. Clin Cancer Res 13:1950–1954
Yamnik RL, Digilova A, Davis DC, Brodt ZN, Murphy CJ, Holz MK (2009) S6 kinase 1 regulates estrogen receptor alpha in control of breast cancer cell proliferation. J Biol Chem 284:6361–6369
Jiang J, Sarwar N, Peston D, Kulinskaya E, Shousha S, Coombes RC, Ali S (2007) Phosphorylation of estrogen receptor-alpha at Ser167 is indicative of longer disease-free and overall survival in breast cancer patients. Clin Cancer Res 13:5769–5776
Yamashita H, Nishio M, Kobayashi S, Ando Y, Sugiura H, Zhang Z, Hamaguchi M, Mita K, Fujii Y, Iwase H (2005) Phosphorylation of estrogen receptor alpha serine 167 is predictive of response to endocrine therapy and increases postrelapse survival in metastatic breast cancer. Breast Cancer Res 7:R753–R764
Zhou D, Ye JJ, Li Y, Lui K, Chen S (2006) The molecular basis of the interaction between the proline-rich SH3-binding motif of PNRC and estrogen receptor alpha. Nucleic Acids Res 34:5974–5986
Söderlund K, Perez-Tenorio G, Stål O (2005) Activation of the phosphatidylinositol 3-kinase/Akt pathway prevents radiation-induced apoptosis in breast cancer cells. Int J Oncol 26:25–32
Liang K, Lu Y, Jin W, Ang KK, Milas L, Fan Z (2003) Sensitization of breast cancer cells to radiation by trastuzumab. Mol Cancer Ther 2:1113–1120
Söderlund K, Skoog L, Fornander T, Askmalm MS (2007) The BRCA1/BRCA2/Rad51 complex is a prognostic and predictive factor in early breast cancer. Radiother Oncol 84:242–251
Russell JS, Brady K, Burgan WE, Cerra MA, Oswald KA, Camphausen K, Tofilon PJ (2003) Gleevec-mediated inhibition of Rad51 expression and enhancement of tumor cell radiosensitivity. Cancer Res 63:7377–7383
Taki T, Ohnishi T, Yamamoto A, Hiraga S, Arita N, Izumoto S, Hayakawa T, Morita T (1996) Antisense inhibition of the RAD51 enhances radiosensitivity. Biochem Biophys Res Commun 223:434–438
Ohnishi T, Taki T, Hiraga S, Arita N, Morita T (1998) In vitro and in vivo potentiation of radiosensitivity of malignant gliomas by antisense inhibition of the RAD51 gene. Biochem Biophys Res Commun 245:319–324
Stål O, Sullivan S, Wingren S, Skoog L, Rutqvist LE, Carstensen JM, Nordenskjöld B (1995) c-erbB-2 expression and benefit from adjuvant chemotherapy and radiotherapy of breast cancer. Eur J Cancer 31A:2185–2190
Stål O, Perez-Tenorio G, Åkerberg L, Olsson B, Nordenskjöld B, Skoog L, Rutqvist LE (2003) Akt kinases in breast cancer and the results of adjuvant therapy. Breast Cancer Res 5:R37–R44
Gunnarsson C, Ahnström M, Kirschner K, Olsson B, Nordenskjöld B, Rutqvist LE, Skoog L, Stål O (2003) Amplification of HSD17B1 and ERBB2 in primary breast cancer. Oncogene 22:34–40
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This study was supported by grants from the Swedish Cancer Foundation, Swedish Research Council and King Gustaf V Jubilee Fund.
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Gizeh Pérez-Tenorio and Elin Karlsson contributed equally to this work.
An invited commentary to this article can be found at doi:10.1007/s10549-010-1207-2.
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Pérez-Tenorio, G., Karlsson, E., Waltersson, M.A. et al. Clinical potential of the mTOR targets S6K1 and S6K2 in breast cancer. Breast Cancer Res Treat 128, 713–723 (2011). https://doi.org/10.1007/s10549-010-1058-x
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DOI: https://doi.org/10.1007/s10549-010-1058-x