scholarly journals Role of mitochondrial glucocorticoid receptor in glucocorticoid-induced apoptosis

2006 ◽  
Vol 203 (1) ◽  
pp. 189-201 ◽  
Author(s):  
Ronit Vogt Sionov ◽  
Orly Cohen ◽  
Shlomit Kfir ◽  
Yael Zilberman ◽  
Eitan Yefenof

The mechanisms by which glucocorticoid receptor (GR) mediates glucocorticoid (GC)-induced apoptosis are unknown. We studied the role of mitochondrial GR in this process. Dexamethasone induces GR translocation to the mitochondria in GC-sensitive, but not in GC-resistant, T cell lines. In contrast, nuclear GR translocation occurs in all cell types. Thymic epithelial cells, which cause apoptosis of the PD1.6 T cell line in a GR-dependent manner, induce GR translocation to the mitochondria, but not to the nucleus, suggesting a role for mitochondrial GR in eliciting apoptosis. This hypothesis is corroborated by the finding that a GR variant exclusively expressed in the mitochondria elicits apoptosis of several cancer cell lines. A putative mitochondrial localization signal was defined to amino acids 558–580 of human GR, which lies within the NH2-terminal part of the ligand-binding domain. Altogether, our data show that mitochondrial and nuclear translocations of GR are differentially regulated, and that mitochondrial GR translocation correlates with susceptibility to GC-induced apoptosis.

APOPTOSIS ◽  
1997 ◽  
Vol 2 (6) ◽  
pp. 501-509 ◽  
Author(s):  
I. Vitté-Mony ◽  
R. G. Korneluk ◽  
R. G. Korneluk ◽  
F. Diaz-Mitoma ◽  
F. Diaz-Mitoma

Blood ◽  
2006 ◽  
Vol 109 (8) ◽  
pp. 3325-3332 ◽  
Author(s):  
Anders Woetmann ◽  
Paola Lovato ◽  
Karsten W. Eriksen ◽  
Thorbjørn Krejsgaard ◽  
Tord Labuda ◽  
...  

AbstractBacterial toxins including staphylococcal enterotoxins (SEs) have been implicated in the pathogenesis of cutaneous T-cell lymphomas (CTCLs). Here, we investigate SE-mediated interactions between nonmalignant T cells and malignant T-cell lines established from skin and blood of CTCL patients. The malignant CTCL cells express MHC class II molecules that are high-affinity receptors for SE. Although treatment with SE has no direct effect on the growth of the malignant CTCL cells, the SE-treated CTCL cells induce vigorous proliferation of the SE-responsive nonmalignant T cells. In turn, the nonmalignant T cells enhance proliferation of the malignant cells in an SE- and MHC class II–dependent manner. Furthermore, SE and, in addition, alloantigen presentation by malignant CTCL cells to irradiated nonmalignant CD4+ T-cell lines also enhance proliferation of the malignant cells. The growth-promoting effect depends on direct cell-cell contact and soluble factors such as interleukin-2. In conclusion, we demonstrate that SE triggers a bidirectional cross talk between nonmalignant T cells and malignant CTCL cells that promotes growth of the malignant cells. This represents a novel mechanism by which infections with SE-producing bacteria may contribute to pathogenesis of CTCL.


1997 ◽  
pp. 105-117 ◽  
Author(s):  
Edoardo Alesse ◽  
Luisa Di Marzio ◽  
Paola Roncaioli ◽  
Francesca Zazzeroni ◽  
Adriano Angelucci ◽  
...  

2015 ◽  
Vol 23 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Jan Kroon ◽  
Martin Puhr ◽  
Jeroen T Buijs ◽  
Geertje van der Horst ◽  
Daniëlle M Hemmer ◽  
...  

Resistance to docetaxel is a major clinical problem in advanced prostate cancer (PCa). Although glucocorticoids (GCs) are frequently used in combination with docetaxel, it is unclear to what extent GCs and their receptor, the glucocorticoid receptor (GR), contribute to the chemotherapy resistance. In this study, we aim to elucidate the role of the GR in docetaxel-resistant PCa in order to improve the current PCa therapies. GR expression was analyzed in a tissue microarray of primary PCa specimens from chemonaive and docetaxel-treated patients, and in cultured PCa cell lines with an acquired docetaxel resistance (PC3-DR, DU145-DR, and 22Rv1-DR). We found a robust overexpression of the GR in primary PCa from docetaxel-treated patients and enhanced GR levels in cultured docetaxel-resistant human PCa cells, indicating a key role of the GR in docetaxel resistance. The capability of the GR antagonists (RU-486 and cyproterone acetate) to revert docetaxel resistance was investigated and revealed significant resensitization of docetaxel-resistant PCa cells for docetaxel treatment in a dose- and time-dependent manner, in which a complete restoration of docetaxel sensitivity was achieved in both androgen receptor (AR)-negative and AR-positive cell lines. Mechanistically, we demonstrated down-regulation of Bcl-xL and Bcl-2 upon GR antagonism, thereby defining potential treatment targets. In conclusion, we describe the involvement of the GR in the acquisition of docetaxel resistance in human PCa. Therapeutic targeting of the GR effectively resensitizes docetaxel-resistant PCa cells. These findings warrant further investigation of the clinical utility of the GR antagonists in the management of patients with advanced and docetaxel-resistant PCa.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3877-3877
Author(s):  
Kensuke Matsumoto ◽  
Koji Murao ◽  
Hitomi Imachi ◽  
Takamasa Nishiuchi ◽  
Hiroaki Ohnishi ◽  
...  

Abstract Adult T-cell leukemia (ATL) is a mature CD4+ T-cell malignancy caused by infection with human T-lymphotrophic virus (HTLV-1) and is associated with a marked hypercalcemia on many patients. Recently, it is proposed that Macrophage inflammatory protein-1α (MIP-1α) is the clinical hallmark of hypercalcemia in ATL, but the regulation of MIP-1α secretion has not been clarified yet. In this study, we examined the effect of calcium on the MIP-1α secretion and cell proliferation of ATL cells, and also the role of the Ca2+/calmodulin (CaM)-dependent protein kinase (CaM-K) cascade in transcriptional activation of MIP-1α. The addition of calcium nitrate to the medium enhanced the secretion of MIP-1α by ATL cell lines (ATN, MT-2, OKM-2T) and the proliferation in a dose dependent manner. The maximum response of MIP-1α secretion was induced at 10.42mM calcium in OKM-2T cells. CaM-KK selective inhibitor STO-609 inhibited the calcium dependent secretion of MIP-1α and proliferation of ATL cell lines. We investigated the effects of CaM-KK/CaM-KIV signaling pathway on MIP-1α promoter activity in OKM-2T. The transfection of CaM-KIV stimulated the MIP-1α promoter activity and the upstream kinase, CaM-KK enhanced the stimulatory effect of CaM-KIV on its activity. Furthermore, mutation of the cAMP response element (CRE) within the MIP-1α promoter significantly reduced the effect of CaM-KIV and calcium, and it wasn’t less enhanced by the addition of calcium nitrate to the medium than the wild type. Our studies have indicated that hypercalcemia enhances MIP-1α secretion and the cell growth in ATL cells, and these mechanisms require the CaM-KK/CaM-KIV cascade. These findings raise the possibility that the inhibitory of CaM-KK/CaM-KIV cascade may be of therapeutic value for ATL.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 11101-11101
Author(s):  
Erica Michelle Stringer ◽  
Maxwell N. Skor ◽  
Gini F. Fleming ◽  
Suzanne D. Conzen

11101 Background: Ovarian cancer is the leading cause of death from gynecologic malignancies. High-grade serous ovarian cancer (HGS-OvCa) is often initially sensitive to platinum-based therapy, but relapse rates remain high. The TCGA recently found that HGS-OvCas have a gene expression and mutational profile similar to that of triple negative breast cancer (TNBC). Previously, our group demonstrated that dexamethasone treatment decreased chemotherapy-induced tumor cell apoptosis in TNBC and HGS-OvCa cell lines. We have also shown that glucocorticoid receptor (GR) activation induces expression of anti-apoptotic genes SGK1 and MKP1/DUSP1 in both HGS-OvCa and TNBC cell lines and in primary human ovarian and TNBC tumors. Methods: We examined glucocorticoid receptor (GR), estrogen receptor (ER), and progesterone receptor (PR) expression in a panel of HGS-OvCa cell lines by Western analysis and qRT-PCR. We also performed apoptosis assays with and without mifepristone, glucocorticoid and/or chemotherapy treatment using IncuCyte live-cell imaging technology in order to measure the effect of GR modulation of chemotherapy sensitivity. Results: HGS-OvCa cell lines (including CAOV3, HeyA8, SKOV3, Monty-1) all had detectable GR expression; HeyA8, SKOV3, and Monty-1 cell lines expressed very low levels of ER-alpha while all other HGS-OvCa cell lines did not express any detectable ER-alpha. Furthermore, none of the HGS-OvCa cell lines tested expressed PR.Apoptosis assays revealed that GR activation significantly inhibited gemcitabine/carboplatin-induced apoptosis in HGS-OvCa cell lines and that mifepristone could reverse this cell survival effect, presumably through GR antagonism. Conclusions: These results suggest that treatment with mifepristone, a GR antagonist, reverses GR-mediated cell survival signaling in HGS-OvCa and increases chemotherapy-induced tumor cell death. To further investigate the role of GR activity in HGS-OvCa, we are currently performing xenograft experiments with chemotherapy +/- mifepristone treatment.


PLoS ONE ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. e29934 ◽  
Author(s):  
Ammar Abou-Kandil ◽  
Rachel Chamias ◽  
Mahmoud Huleihel ◽  
W. T. Godbey ◽  
Mordechai Aboud
Keyword(s):  
T Cell ◽  

2003 ◽  
Vol 77 (24) ◽  
pp. 13433-13438 ◽  
Author(s):  
Graham Simmons ◽  
Andrew J. Rennekamp ◽  
Ning Chai ◽  
Luk H. Vandenberghe ◽  
James L. Riley ◽  
...  

ABSTRACT Folate receptor alpha (FRα) has been described as a factor involved in mediating Ebola virus entry into cells (6). Furthermore, it was suggested that interaction with FRα results in internalization and subsequent viral ingress into the cytoplasm via caveolae (9). Descriptions of cellular receptors for Ebola virus and its entry mechanisms are of fundamental importance, particularly with the advent of vectors bearing Ebola virus glycoprotein (GP) being utilized for gene transfer into cell types such as airway epithelial cells. Thus, the ability of FRα to mediate efficient entry of viral pseudotypes carrying GP was investigated. We identified cell lines and primary cell types such as macrophages that were readily infected by GP pseudotypes despite lacking detectable surface FRα, indicating that this receptor is not essential for Ebola virus infection. Furthermore, we find that T-cell lines stably expressing FRα are not infectible, suggesting that FRα is also not sufficient to mediate entry. T-cell lines lack caveolae, the predominant route of FRα-mediated folate metabolism. However, the coexpression of FRα with caveolin-1, the major structural protein of caveolae, was not able to rescue infectivity in a T-cell line. In addition, other cell types lacking caveolae are fully infectible by GP pseudotypes. Finally, a panel of ligands to and soluble analogues of FRα were unable to inhibit infection on a range of cell lines, questioning the role of FRα as an important factor for Ebola virus entry.


2004 ◽  
Vol 78 (9) ◽  
pp. 4582-4590 ◽  
Author(s):  
Naoki Mori ◽  
Takehiro Matsuda ◽  
Masayuki Tadano ◽  
Takao Kinjo ◽  
Yasuaki Yamada ◽  
...  

ABSTRACT Inhibition of histone deacetylase (HDAC) activity induces growth arrest, differentiation, and, in certain cell types, apoptosis. FR901228, FK228, or depsipeptide, is an HDAC inhibitor effective in T-cell lymphomas. Adult T-cell leukemia (ATL) is caused by human T-cell leukemia virus type 1 (HTLV-1) and remains incurable. We examined whether FR901228 is effective for treatment of ATL by assessing its ability to induce apoptosis of HTLV-1-infected T-cell lines and primary leukemic cells from ATL patients. FR901228 induced apoptosis of Tax-expressing and -unexpressing HTLV-1-infected T-cell lines and selective apoptosis of primary ATL cells, especially those of patients with acute ATL. FR901228 also efficiently reduced the DNA binding of NF-κB and AP-1 in HTLV-1-infected T-cell lines and primary ATL cells and down-regulated the expression of Bcl-xL and cyclin D2, regulated by NF-κB. Although the viral protein Tax is an activator of NF-κB and AP-1, FR901228-induced apoptosis was not associated with reduced expression of Tax. In vivo use of FR901228 partly inhibited the growth of tumors of HTLV-1-infected T cells transplanted subcutaneously in SCID mice. Our results indicated that FR901228 could induce apoptosis of these cells and suppress the expression of NF-κB and AP-1 and suggest that FR901228 could be therapeutically effective in ATL.


2010 ◽  
Vol 34 (1) ◽  
pp. 93-99 ◽  
Author(s):  
Rachel Chamias ◽  
Mahmoud Huleihel ◽  
Mordechai Aboud

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