Abstract
Growth factors and mitogens influence signaling pathways and often induce the activity of p70S6 kinase (p70S6K), which in turn phosphorylates the ribosomal S6 protein (S6). Although recent data are rather conflicting, the overall view suggests that phosphorylated S6 is a regulator of global protein synthesis, cell proliferation, cell size and glucose homeostasis. In the present work, emphasis was given to cell cycle-dependent activation of S6 focusing mainly on human lymphoid and lymphoma cells. Paraffin-embedded human tissue blocks from lymph node and different tumor biopsies as well as in vitro cell lines were investigated by immunohistochemistry, immunocytochemistry, flow cytometry and Western blotting using antibodies directed against phospho-S6, phospho-mTOR, phospho-p70S6K and phospho-Histone H3. To enrich the cell number in different phases of the cell cycle, nocodazole, staurosporine or rapamycin were used in cell cultures. We observed strong phospho-S6 positivity by immunostainings in the dividing lymphoid cells of reactive lymph nodes and in lymphoma cells cultured in vitro. Phospho-S6 protein levels were shown to be elevated throughout mitosis in lymphoma cells; however, the high expression of phospho-S6 in mitotic cells was not a general hallmark of tumor cell types studied so far: phospho-S6-negative mitotic cells were detected in several carcinoma and sarcoma biopsies. These observations may have practical implications as they raise the possibility to consider p70S6K and/or S6 as a potential therapeutic target—besides mTOR—in certain lymphomas and perhaps in clinical immunosuppression.
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Abraham RT, Gibbons JJ (2007) The mammalian target of rapamycin signaling pathway: twist and turns in the road to cancer therapy. Clin Cancer Res 3:3109–3114
Boulay A, Lane HA (2007) The mammalian target of rapamycin kinase and tumor growth inhibition. Recent Results Cancer Res 172:99–124
Chaturvedi D, Poppleton HM, Stringfield T, Barbier A, Patel TB (2006) Subcellular localization and biological actions of activated RSK1 are determined by its interactions with subunits of cyclic AMP-dependent protein kinase. Mol Cell Biol 26:4586–4600
Cho YY, He Z, Zhang Y, Choi HS, Zhu F, Choi BY et al (2005) The p53 protein is a novel substrate of ribosomal S6 kinase 2 and a critical intermediary for ribosomal S6 kinase 2 and histone H3 interaction. Cancer Res 65:3596–3604
Costa LJ (2007) Aspects of mTOR biology and the use of mTOR inhibitors in non-Hodgkin’s lymphoma. Cancer Treat Rev 33:78–84
Craxton A, Otipoby KL, Jiang A, Clark EA (1999) Signal transduction pathways that regulate the fate of B lymphocytes. Adv Immunol 73:79–152
Darzynkiewicz Z, Bruno S, Del Bino G, Gorczyca W, Hotz MA, Lassota P et al (1992) Features of apoptotic cells measured by flow cytometry. Cytometry 13:795–808
Fenton TR, Gout IT (2011) Functions and regulation of the 70 kDa ribosomal S6 kinases. Int J Biochem Cell Biol 43:47–59
Fingar DC, Richardson CJ, Tee AR, Cheatham L, Blenis J (2004) mTOR controls cell cycle progression through its cell growth effectors S6K1 and 4E-BP1/eukaryotic translation initiation factor 4E. Mol Cell Biol 24:200–216
Hayashi M, Fearns C, Eliceiri B, Yang Y, Lee JD (2005) Big Mitogen-activated protein kinase 1/extracellular signal-regulated kinase 5 signaling pathway is essential for tumor-associated angiogenesis. Cancer Res 65:7699–7706
Kim D, Akcakanat A, Singh G, Shama C, Meric-Berstam F (2009) Regulation and localization of ribosomal protein S6 kinase 1 isoforms. Growth Factors 27:12–21
LoPicollo J, Blumenthal GM, Bernstein WB, Dennis PA (2008) Targeting the PI3K/Akt/mTOR pathway: effective combinations and clinical consideration. Drug Resist Updat 11:32–50
Lu Z, Luo RZ, Lu Y, Zhang X, Yu Q, Khare S et al (2008) The tumor suppressor gene ARHI regulates autophagy and tumor dormancy in human ovarian cancer cells. Clin Invest 118:3917–3929
Mamane Y, Petroulakis E, LeBacquer O, Sonenberg N (2006) mTOR, translation initiation and cancer. Oncogene 25:6416–6422
Meyuhas O (2008) Physiological roles of ribosomal protein S6: one of its kind. Int Rev Cell Mol Biol 268:1–37
Nakagawa M, Ohmido N, Ishikawa K, Uchiyama S, Fukui K, Azuma T (2008) Anti-peptide antibodies for examining the conformation, molecular assembly and localization of an intracellular protein S6, in vivo. J Biochem 143:325–332
Pearce LR, Alton GR, Richter DT, Kath JC, Lingardo L, Chapman J, Hwang C, Alessi DR (2010) Characterization of PF-4708671, a novel and highly specific inhibitor of p70 ribosomal S6 kinase (S6K1). Biochem J 431(2):245–255
Pende M, Um SH, Mieulet V, Sticker M, Goss VL, Mestan J et al (2004) S6K1(−/−)/S6K2(−/−) mice exhibit perinatal lethality and rapamycin sensitive 5′ terminal oligopyrimidine mRNAS translation and reveal a mitogen-activated protein kinase dependent S6 kinase pathways. Mol Cell Biol 24:3112–3124
Peterson RT, Schreiber SL (1998) Translation control: connecting mitogens and the ribosome. Curr Biol 8:248–250
Rossi R, Pester JM, McDowell M, Soza S, Montecucco A, Lee-Fruman KK (2007) Identification of S6K2 as a centrosome-located kinase. FEBS Lett 581:4058–4064
Sassone-Corsi P, Mizzen CA, Cheung P, Crosio C, Monaco L, Jaquot S et al (1999) Requirement of Rsk-2 for epidermal growth factor-activated phosphorylation of histone H3. Science 285:886–891
Schmidt T, Whal P, Wüthrich RP, Vogetseder A, Picard N, Kaissling B et al (2007) Immunolocalization of phospho-S6 kinase: a new way to detect mitosis in tissue sections and in cell culture. Histochem Cell Biol 127:123–129
Schouten GJ, Vertegaal AC, Whiteside ST, Israel A, Toebes M, Dorsman JC et al (1997) IkappaB alpha is a target for the mitogen-activated 90 kDa ribosomal S6 kinase. EMBO J 16:3133–3144
Shah OJ, Ghosh S, Hunter T (2003) Mitotic regulation of ribosomal S6 kinase 1 involves Ser/thr, Pro phosphorylation of consensus and non-consensus sites by Cdc2. J Biol Chem 278:16433–16442
Smith JA, Poteet-Smith CE, Malarkey K, Sturgill TW (1999) Identification of an extracellular signal-regulated kinase (ERK) docking site in ribosomal S6 kinase, a sequence critical for activation by ERK in vivo. J Biol Chem 274:2893–2898
Stoeltzing O, Meric-Bernstam F, Ellis LM (2006) Intracellular signaling in tumor and endothelial cells: the expected and, yet again, the unexpected. Cancer Cell 10:89–91
Stolovich M, Tang H, Hornstein E, Levy G, Bae SS, Birnbaum MJ et al (2002) Transduction of growth or mitogenic signals into translational activation of TOP mRNAs is fully reliant on the PI3-kinase mediated pathway, but requires neither S6K nor S6 phosphorylation. Mol Cell Biol 22:8101–8113
Sudakin V, Yen TJ (2007) Targeting mitosis for anti-cancer therapy. BioDrugs 21:225–233
Tang H, Hornstein E, Stolovich M, Levy G, Livingstone M, Templeton D et al (2001) Amino acid-induced translation of TOP mRNAs is fully dependent on PI3-kinase mediated signaling, partly inhibited by rapamycin, and it is independent of S6K1 and S6 phosphorylation. Mol Cell Biol 21:8671–8683
Wang L, Shi WY, Wu ZY, Varna M, Wang AH, Zhou L, Chen L, Shen ZX, Lu H, Zhao WL, Janin A (2010) Cytostatic and anti-angiogenic effects of temsirolimus in refractory mantle cell lymphoma. J Hematol Oncol 3:30–31
Willard FS, Crouch MF (2001) MEK, Erk, and p90RSK are present on mitotic tubulin in Swiss 3T3 cells: a role for MAk kinase pathway in regulating mitotic exit. Cell Signal 13:653–664
Yaba A, Bianchi V, Borini A, Johnson (2008) A putative mitotic checkpoint dependent on mTOR function controls cell proliferation and survival in ovarian granulosa cells. Reprod Sci 15:128–138
Zhao MY, Auerbach A, D’Costa AM et al (2009) Phospho-p70S6K/p85S6K and cdc2/cdk1 are novel targets for diffuse large B-cell lymphoma combination therapy. Clin Cancer Res 15:1708–1720
Zheng B, Shorthouse R, Masek MA, Berry G, Billingham ME, Morris RE (1991) Effects of the new and highly active immunosuppressant, rapamycin, on lymphoid tissues and cells in vivo. Transplant Proc 23:851–855
Acknowledgments
We thank Lajos Berczi, Sándor Paku and Gézáné Csorba (members of our Institute) for discussion and technical assistance. This work was supported by Sebestyén A. and Kopper L. OTKA projects (F048380, K68341, K81624) of the Hungarian Academy of Sciences.
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G. Egervári and Á. Márk contributed equally to this work.
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Egervári, G., Márk, Á., Hajdu, M. et al. Mitotic lymphoma cells are characterized by high expression of phosphorylated ribosomal S6 protein. Histochem Cell Biol 135, 409–417 (2011). https://doi.org/10.1007/s00418-011-0803-5
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DOI: https://doi.org/10.1007/s00418-011-0803-5