Skip to main content
Article thumbnail
Location of Repository

Heat shock protein-90-alpha, a prolactin-STAT5 target gene identified in breast cancer cells, is involved in apoptosis regulation

By Christian Perotti, Ruixuan Liu, Christine T. Parusel, Nadine Böcher, Jörg Schultz, Peer Bork, Edith Pfitzner, Bernd Groner and Carrie S. Shemanko

Abstract

Introduction The prolactin-Janus-kinase-2-signal transducer and activator of transcription-5 (JAK2-STAT5) pathway is essential for the development and functional differentiation of the mammary gland. The pathway also has important roles in mammary tumourigenesis. Prolactin regulated target genes are not yet well defined in tumour cells, and we undertook, to the best of our knowledge, the first large genetic screen of breast cancer cells treated with or without exogenous prolactin. We hypothesise that the identification of these genes should yield insights into the mechanisms by which prolactin participates in cancer formation or progression, and possibly how it regulates normal mammary gland development. Methods We used subtractive hybridisation to identify a number of prolactin-regulated genes in the human mammary carcinoma cell line SKBR3. Northern blotting analysis and luciferase assays identified the gene encoding heat shock protein 90-alpha (HSP90A) as a prolactin-JAK2-STAT5 target gene, whose function was characterised using apoptosis assays. Results We identified a number of new prolactin-regulated genes in breast cancer cells. Focusing on HSP90A, we determined that prolactin increased HSP90A mRNA in cancerous human breast SKBR3 cells and that STAT5B preferentially activated the HSP90A promoter in reporter gene assays. Both prolactin and its downstream protein effector, HSP90α, promote survival, as shown by apoptosis assays and by the addition of the HSP90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), in both untransformed HC11 mammary epithelial cells and SKBR3 breast cancer cells. The constitutive expression of HSP90A, however, sensitised differentiated HC11 cells to starvation-induced wild-type p53-independent apoptosis. Interestingly, in SKBR3 breast cancer cells, HSP90α promoted survival in the presence of serum but appeared to have little effect during starvation. Conclusions In addition to identifying new prolactin-regulated genes in breast cancer cells, we found that prolactin-JAK2-STAT5 induces expression of the HSP90A gene, which encodes the master chaperone of cancer. This identifies one mechanism by which prolactin contributes to breast cancer. Increased expression of HSP90A in breast cancer is correlated with increased cell survival and poor prognosis and HSP90α inhibitors are being tested in clinical trials as a breast cancer treatment. Our results also indicate that HSP90α promotes survival depending on the cellular conditions and state of cellular transformation

Topics: ddc:610
Year: 2009
OAI identifier: oai:publikationen.ub.uni-frankfurt.de:5635

Suggested articles

Citations

  1. (1997). A: GAS elements: a few nucleotides with a major impact on cytokine-induced gene expression.
  2. (2002). A: HSP90 as a new therapeutic target for cancer therapy: the story unfolds. Expert Opin Biol Ther
  3. (2005). Activated mitofusin 2 signals mitochondrial fusion, interferes with Bax activation, and reduces susceptibility to radical induced depolarization.
  4. (1997). Activation of the prolactin receptor but not the growth hormone receptor is important for induction of mammary tumors in transgenic mice.
  5. (2002). Akt forms an intracellular complex with heat shock protein 90 (Hsp90) and Cdc37 and is destabilized by inhibitors of Hsp90 function.
  6. (2005). AM: HER2/neu increases the expression of Wilms' Tumor 1 (WT1) protein to stimulate Sphase proliferation and inhibit apoptosis in breast cancer cells. Oncogene
  7. (2000). Analysis of prolactin-modulated gene expression profiles during the Nb2 cell cycle using differential screening techniques. Genome Biol
  8. (2002). Ansamycin antibiotics inhibit Akt activation and cyclin D expression in breast cancer cells that overexpress HER2. Oncogene
  9. (1999). Asano G: Expression of hsp90 and cyclin D1 in human breast cancer. Cancer Lett
  10. (2007). Bak regulates mitochondrial morphology and pathology during apoptosis by interacting with mitofusins. Proc Natl Acad Sci USA
  11. (2003). Bax inhibitor-1 is overexpressed in prostate cancer and its specific down-regulation by RNA interference leads to cell death in human prostate carcinoma cells.
  12. (1997). BL: Prolactin induced tyrosine phosphorylation of p59fyn may mediate phosphatidylinositol 3-kinase activation in Nb2 cells.
  13. (2004). Chinnaiyan AM: ONCOMINE: a cancer microarray database and integrated data-mining platform. Neoplasia
  14. (2006). CJ: The genes induced by signal transducer and activators of transcription (STAT)3 and STAT5 in mammary epithelial cells define the roles of these STATs in mammary development. Mol Endocrinol
  15. (1995). Cloning and expression of Stat5 and an additional homologue (Stat5b) involved in prolactin signal transduction in mouse mammary tissue. Proc Natl Acad Sci USA
  16. (2004). Combinatorial attack on multistep oncogenesis by inhibiting the Hsp90 molecular chaperone. Cancer Lett
  17. (2006). Conzen SD: Glucocorticoid receptor activation signals through forkhead transcription factor 3a in breast cancer cells. Mol Endocrinol
  18. (1998). Cook PH: The physical association of multiple molecular chaperone proteins with mutant p53 is altered by geldanamycin, an hsp90-binding agent. Mol Cell Biol
  19. (1982). Correlation between prolactin-receptor interaction, down-regulation of receptors, and stimulation of casein and deoxyribonucleic acid biosynthesis in rabbit mammary gland explants. Endocrinology
  20. (2006). Defining the role of prolactin as an invasion suppressor hormone in breast cancer cells. Cancer Res
  21. (2002). Degradation of HER2 by ansamycins induces growth arrest and apoptosis in cells with HER2 overexpression via a HER3, phosphatidylinositol 3'-kinase-AKT-dependent pathway. Cancer Res
  22. (2004). DG: Functional proteomic screens reveal an essential extracellular role for hsp90 alpha in cancer cell invasiveness. Nat Cell Biol
  23. (2004). Dhanasekaran N: Galpha13 stimulates cell migration through cortactin-interacting protein Hax-1.
  24. (1996). differentiation and survival of HC11 mammary epithelial cells: diverse effects of receptor tyrosine kinaseactivating peptide growth factors.
  25. (1996). DR: Increased heat shock protein 90 (hsp90) expression leads to increased apoptosis in the monoblastoid cell line U937 following induction with TNF-alpha and cycloheximide: a possible role in immunopathology.
  26. (2007). Drugging the cancer chaperone HSP90: combinatorial therapeutic exploitation of oncogene addiction and tumor stress.
  27. (1996). Expression and roles of heat shock proteins in human breast cancer.
  28. (1997). Expression of the prolactin gene in normal and neoplastic human breast tissues and human mammary cell lines: promoter usage and alternative mRNA splicing. Breast Cancer Res Treat
  29. (2003). FJ: A high-affinity conformation of
  30. (2006). GI: Characterization and over-expression of chaperonin tcomplex proteins in colorectal cancer.
  31. Heat shock protein 90: a unique chemotherapeutic target. Semin Oncol 2006, 33:457-465.Available online http://breast-cancer-research.com/content/10/6/R94 Page 17 of 18 (page number not for citation purposes)
  32. (2007). Heat shock protein 90: the cancer chaperone.
  33. (2000). Horseman ND: Glycosylation-dependent cell adhesion molecule 1
  34. (2000). Horseman ND: Prolactin gene-disruption arrests mammary gland development and retards T-antigen-induced tumor growth. Oncogene
  35. (2002). Houlgatte R: Gene expression profiles of poor-prognosis primary breast cancer correlate with survival. Hum Mol Genet
  36. (2002). Hsp90 as a capacitor of phenotypic variation.
  37. (2006). Hsp90 inhibitor 17-AAG reduces ErbB2 levels and inhibits proliferation of the trastuzumab resistant breast tumor cell line JIMT-1. Immunol Lett
  38. (2004). Hsp90: an emerging target for breast cancer therapy. Anticancer Drugs
  39. (2007). Hudis CA: Combination of trastuzumab and tanespimycin (17-AAG, KOS-953) is safe and active in trastuzumab-refractory HER-2 overexpressing breast cancer: a phase I dose-escalation study.
  40. (1994). Hynes NE: Growth suppression of normal mammary epithelial cells by wild-type p53. Oncogene
  41. (2003). Inhibition of heat shock protein 90 function down-regulates Akt kinase and sensitizes tumors to Taxol. Cancer Res
  42. (2006). Inhibitors of the HSP90 molecular chaperone: current status. Adv Cancer Res
  43. (2006). Involution: apoptosis and tissue remodelling that convert the mammary gland from milk factory to a quiescent organ. Breast Cancer Res
  44. (2008). Jak2/Stat5 signaling in mammogenesis, breast cancer initiation and progression.
  45. (2007). JF: HS1-associated protein X-1 regulates carcinoma cell migration and invasion via clathrin-mediated endocytosis of integrin alphavbeta6. Cancer Res
  46. (2004). JM: Prolactin acts as a potent survival factor for human breast cancer cell lines.
  47. (2004). KJ: Direct activation of HSP90A transcription by c-Myc contributes to c-Myc-induced transformation.
  48. (2007). Kluger HM: High HSP90 expression is associated with decreased survival in breast cancer. Cancer Res
  49. (2004). L: Inactivation of Stat5 in mouse mammary epithelium during pregnancy reveals distinct functions in cell proliferation, survival, and differentiation. Mol Cell Biol
  50. (2003). LA: Prolactin induces ERalpha-positive and ERalpha-negative mammary cancer in transgenic mice. Oncogene
  51. (2003). LA: The role of prolactin in mammary carcinoma. Endocr Rev
  52. (1998). Lindquist S: Hsp90 as a capacitor for morphological evolution. Nature
  53. (1994). Mammary gland factor (MGF) is a novel member of the cytokine regulated transcription factor gene family and confers the prolactin response. Embo J
  54. (1992). Mammary gland-specific nuclear factor is present in lactating rodent and bovine mammary tissue and composed of a single polypeptide of 89 kDa.
  55. (1995). Miyajima A: A novel cytokine-inducible gene CIS encodes an SH2-containing protein that binds to tyrosinephosphorylated interleukin 3 and erythropoietin receptors. Embo J
  56. (1997). Miyajima A: Molecular cloning of CISH, chromosome assignment to 3p21.3, and analysis of expression in fetal and adult tissues. Cytogenet Cell Genet
  57. (2004). ND: Prolactin and transforming growth factor-beta signaling exert opposing effects on mammary gland morphogenesis, involution, and the Akt-forkhead pathway. Mol Endocrinol
  58. (1995). NE: p53-dependent and p53-independent activation of apoptosis in mammary epithelial cells reveals a survival function of EGF and insulin.
  59. (2003). Neckers L: The heat shock protein 90 inhibitor geldanamycin and the ErbB inhibitor ZD1839 promote rapid PP1 phosphatase-dependent inactivation of AKT in ErbB2 overexpressing breast cancer cells. Cancer Res
  60. (2007). Ormandy CJ: Loss of mammary epithelial prolactin receptor delays tumor formation by reducing cell proliferation in low-grade preinvasive lesions. Oncogene
  61. (2003). Ormandy CJ: The neuropeptide galanin augments lobuloalveolar development.
  62. (2005). Ormandy CJ: Transcriptional changes underlying the secretory activation phase of mammary gland development. Mol Endocrinol
  63. (2000). PA: Induction of bcl-xL expression in mammary epithelial cells is glucocorticoid-dependent but not signal transducer and activator of transcription 5-dependent. Cancer Res
  64. (2003). PA: Investigation of the transcriptional changes underlying functional defects in the mammary glands of prolactin receptor knockout mice. Recent Prog Horm Res
  65. (2008). Prolactin and breast cancer etiology: An epidemiologic perspective.
  66. (1994). Prolactin induces phosphorylation of Tyr694 of Stat5 (MGF), a prerequisite for DNA binding and induction of transcription.
  67. (2006). Prolactin potentiates transforming growth factor alpha induction of mammary neoplasia in transgenic mice.
  68. (1988). Prolactin regulation of beta-casein gene expression and of a cytosolic 120-kd protein in a cloned mouse mammary epithelial cell line. Embo J
  69. (2006). prolactin-induced mammary gland development. Mol Endocrinol
  70. (2006). Proteomic analysis reveals a novel role for the actin cytoskeleton in vincristine resistant childhood leukemia – an in vivo study. Proteomics
  71. (2005). Quelle FW: Prolactin and heregulin override DNA damage-induced growth arrest and promote phosphatidylinositol-3 kinase-dependent proliferation in breast cancer cells.
  72. (2003). Russo A: STAT proteins: from normal control of cellular events to tumorigenesis.
  73. (1998). S: A sequence of the CIS gene promoter interacts preferentially with two associated STAT5A dimers: a distinct biochemical difference between STAT5A and STAT5B. Mol Cell Biol
  74. (2007). SE: A prospective study of plasma prolactin concentrations and risk of premenopausal and postmenopausal breast cancer.
  75. (2004). SE: Plasma prolactin concentrations and risk of postmenopausal breast cancer. Cancer Res
  76. (2003). Shemanko CS: Comparative proteomic analysis of proliferating and functionally differentiated mammary epithelial cells. Molecular and Cellular Proteomics
  77. (2006). Silva CM: Modulation of signal transducer and activator of transcription 5b activity in breast cancer cells by mutation of tyrosines within the transactivation domain. Mol Endocrinol
  78. (2005). SL: HSP90 and the chaperoning of cancer. Nat Rev Cancer
  79. (2001). SM: Mammary gland involution is delayed by activated Akt in transgenic mice. Mol Endocrinol
  80. (2003). Small interfering RNAmediated reduction in heterogeneous nuclear ribonucleoparticule A1/A2 proteins induces apoptosis in human cancer cells but not in normal mortal cell lines. Cancer Res
  81. (2004). STAT proteins as novel targets for cancer drug discovery. Expert Opin Ther Targets
  82. (2002). Suzuki N: Involvement of human heat shock protein 90 alpha in nicotine-induced apoptosis.
  83. T: IGF-2 is a mediator of prolactin-induced morphogenesis in the breast. Dev Cell
  84. (1999). Tarasenko TN, Telford WG: Spontaneous apoptosis and expression of cell surface heatshock proteins in cultured EL-4 lymphoma cells. Cell Prolif
  85. (2006). Targeting of multiple signalling pathways by heat shock protein 90 molecular chaperone inhibitors. Endocr Relat Cancer
  86. (1999). TE: A human prolactin antagonist, hPRL-G129R, inhibits breast cancer cell proliferation through induction of apoptosis. Clin Cancer Res
  87. (1998). The 90-kDa molecular chaperone family: structure, function, and clinical applications. A comprehensive review. Pharmacol Ther
  88. (2008). Too CK: Prolactin and Estrogen Upregulate Carboxypeptidase-D to Promote Nitric Oxide Production and Survival of MCF-7 Breast Cancer Cells. Endocrinology
  89. Transcription factors, cofactors and target genes mediating prolactin action.
  90. (2000). Tsuruo T: Modulation of Akt kinase activity by binding to Hsp90. Proc Natl Acad Sci USA
  91. (2003). Using gene expression arrays to elucidate transcriptional profiles underlying prolactin function.
  92. (1995). Vonderhaar BK: Prolactin synthesis and secretion by human breast cancer cells. Cancer Res
  93. (2007). W: Geldanamycin destabilizes HER2 tyrosine kinase and suppresses Wnt/beta-catenin signaling in HER2 overexpressing human breast cancer cells. Oncol Rep
  94. (1997). Wild-type p53 is not sufficient for serum starvation-induced apoptosis in cancer cells but accelerates apoptosis in sensitive cells.
  95. (2001). WJ: Activation of Akt (protein kinase B) in mammary epithelium provides a critical cell survival signal required for tumor progression. Mol Cell Biol
  96. (2000). WM: Initiation of DNA fragmentation during apoptosis induces phosphorylation of H2AX histone at serine 139.
  97. (2000). Woenckhaus C: TTC4, a novel candidate tumor suppressor gene at 1p31 is often mutated in malignant melanoma of the skin. Oncogene
  98. (1997). Yoshimura A: CIS, a cytokine inducible SH2 protein, is a target of the JAK-STAT5 pathway and modulates STAT5 activation. Blood

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.