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Mariotto E, Viola G, Zanon C, Aveic S. A BAG's life: Every connection matters in cancer. Pharmacol Ther 2020; 209:107498. [PMID: 32001313 DOI: 10.1016/j.pharmthera.2020.107498] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/17/2020] [Indexed: 12/30/2022]
Abstract
The members of the BCL-2 associated athanogene (BAG) family participate in the regulation of a variety of interrelated physiological processes, such as autophagy, apoptosis, and protein homeostasis. Under normal circumstances, the six BAG members described in mammals (BAG1-6) principally assist the 70 kDa heat-shock protein (HSP70) in protein folding; however, their role as oncogenes is becoming increasingly evident. Deregulation of the BAG multigene family has been associated with cell transformation, tumor recurrence, and drug resistance. In addition to BAG overexpression, BAG members are also involved in many oncogenic protein-protein interactions (PPIs). As such, either the inhibition of overloading BAGs or of specific BAG-client protein interactions could have paramount therapeutic value. In this review, we will examine the role of each BAG family member in different malignancies, focusing on their modular structure, which enables interaction with a variety of proteins to exert their pro-tumorigenic role. Lastly, critical remarks on the unmet needs for proposing effective BAG inhibitors will be pointed out.
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Affiliation(s)
- Elena Mariotto
- Department of Woman's and Child's Health, University of Padova, Via Giustiniani 2, 35127 Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35128 Padova, Italy.
| | - Giampietro Viola
- Department of Woman's and Child's Health, University of Padova, Via Giustiniani 2, 35127 Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35128 Padova, Italy
| | - Carlo Zanon
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35128 Padova, Italy
| | - Sanja Aveic
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35128 Padova, Italy
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Vora HH, Mehta SV, Shah KN, Brahmbhatt BV, Desai NS, Shukla SN, Shah PM. Cytoplasmic Localization of BAG-1 in Leukoplakia and Carcinoma of the Tongue: Correlation with p53 and C-Erbb2 in Carcinoma. Int J Biol Markers 2018; 22:100-7. [PMID: 17549665 DOI: 10.1177/172460080702200203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background The present study evaluated the clinical significance of BAG-1, an antiapoptotic protein, in leukoplakia and carcinoma of the tongue. Methods BAG-1 expression was evaluated by immunohistochemistry in paraffin-embedded tissues of leukoplakia (n=25) and carcinoma of the tongue (n=61). Results Cytoplasmic expression was predominantly seen in 80% and 70% of patients with leukoplakia and carcinoma, respectively. BAG-1 expression was found to be significantly lower in tobacco users than in non-tobacco users. BAG-1 expression in tobacco-using leukoplakia and carcinoma patients was compared by grouping the carcinoma patients according to lymph node status and disease stage. Carcinoma patients with tumor-positive lymph nodes had significantly lower BAG-1 expression than patients with negative lymph nodes and leukoplakia. Further, a trend towards an inverse correlation was observed with p53 and c-erbB2. In univariate and multivariate survival analysis, patient subgroups with 2+ or 3+ marker positivity (BAG-1 negativity, p53 and c-erbB2 positivity) had a reduced overall survival compared with patient subgroups with 1+ marker positivity or negativity. Conclusion BAG-1 negativity in association with p53 and c-erbB2 positivity identified a subgroup of tongue cancer patients with an aggressive phenotype. Hence, an antiapoptotic protein, BAG-1, was found to be down-regulated in chewing-tobacco-mediated tongue carcinogenesis.
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Affiliation(s)
- H H Vora
- Immunohistochemistry Division, The Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India.
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Kun D, Xiang-Lin C, Ming Z, Qi L. Chlamydia inhibit host cell apoptosis by inducing Bag-1 via the MAPK/ERK survival pathway. Apoptosis 2014; 18:1083-92. [PMID: 23708800 DOI: 10.1007/s10495-013-0865-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Chlamydia are obligate intracellular bacteria that frequently cause human disease. Host cells infected with Chlamydia are profoundly resistant to diverse apoptotic stimuli. The inhibition of apoptosis is thought to be an important immune escape mechanism allowing Chlamydia to productively complete their obligate intracellular growth cycle. Chlamydial antiapoptotic activity involves activation of the MAPK/ERK survival pathway. However, the molecular mechanisms are not well understood. Here we show that Bag-1 is up-regulated in Chlamydia-infected cells. U0126 and GW5074 suppress the induction of Bag-1 by Chlamydia, implying that Chlamydia may up-regulate Bag-1 via the MAPK/ERK survival pathway. Overexpression of Bag-1 is sufficient to protect against apoptosis, while depletion of Bag-1 suppresses the antiapoptotic effect of Chlamydia. The data indicate Chlamydia may up-regulate Bag-1 through the MAPK/ERK survival pathway to suppress apoptosis.
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Affiliation(s)
- Du Kun
- Department of Clinical Laboratory, The First Affiliated Hospital of Yangtze University, 434000, Jingzhou, Hubei, China.
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Co-overexpression of Bag-1 and heat shock protein 70 in human epidermal squamous cell carcinoma: Bag-1-mediated resistance to 5-fluorouracil-induced apoptosis. Br J Cancer 2011; 104:1459-71. [PMID: 21522149 PMCID: PMC3101929 DOI: 10.1038/bjc.2011.111] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background: The aim was to determine whether Bcl-2-associated athanogene-1 (Bag-1) and/or its binding protein heat shock protein-70 (Hsp70) exhibit deregulated expression in epidermal squamous cell carcinoma (SCC) and whether Bag-1 confers apoptosis resistance. Method: Immunohistochemistry for Bag-1 and Hsp70 was performed on 60 epidermal SCC and 10 normal skin samples. The epidermal SCC cell line SCC-13 was treated with 5-fluorouracil (5-FU) after Bag-1 knockdown to determine whether high Bag-1 levels contribute to growth and/or apoptosis resistance. Results: Normal epithelium expressed primarily nuclear Bag-1. Most tumours showed reduced nuclear Bag-1 staining, but a subset exhibited strong Bag-1 staining, with cytoplasmic Bag-1 staining intensity correlating with cytoplasmic Hsp70 staining intensity (rs=0.462; P<0.001) and less differentiation (P<0.001). Bag-1 knockdown resulted in markedly reduced SCC-13 cell yield, increased spontaneous apoptosis and enhanced sensitivity to 5-FU-induced apoptosis. Apoptosis induced by 5-FU in the Bag-1-knockdown cells was significantly greater than the additive apoptotic effect of 5-FU or Bag-1 knockdown alone. Conclusions: Overexpression of Bag-1 and Hsp70 in poorly differentiated SCC may confer both enhanced tumour cell growth and apoptosis resistance. Bag-1 may contribute to the resistance of more advanced epidermal SCC to chemotherapy.
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Coutinho-Camillo CM, Lourenço SV, Nishimoto IN, Kowalski LP, Soares FA. Expression of Bcl-2 family proteins and association with clinicopathological characteristics of oral squamous cell carcinoma. Histopathology 2010; 57:304-16. [PMID: 20716171 DOI: 10.1111/j.1365-2559.2010.03621.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To characterize the expression of proteins that inhibit (Bcl-2, Bcl-x, Bcl-xL, Bcl-2-related protein A1, BAG-1) or promote (Bak, Bax, Bim/Bod, Bim-Long, Bad, Bid, PUMA) apoptosis and determine possible correlations between the expression of these proteins and clinicopathological features of oral squamous cell carcinoma (OSCC). METHODS AND RESULTS Two-hundred and twenty-nine cases of OSCC, arranged in a tissue microarray, were immunohistochemically analysed. The results demonstrated that the absence of vascular invasion was associated with increased expression of Bak, Bax, Bcl-xL, Bcl-2-related protein and PUMA. Increased expression of Bim/Bod and BAG-1 was associated with the presence of perineural infiltration. An increase in Bid and Bim-Long expression was associated with moderately to well-differentiated tumours. Increased expression of the Bcl-2-related protein and PUMA was associated with tumours occurring in the floor of mouth and increased expression of PUMA was also associated with recurrence of the tumour. Multivariate Cox analysis demonstrated that PUMA and Bim-Long were independent factors in prognosis of OSCC. CONCLUSIONS Our results showed the involvement of the Bcl-2 family of proteins in OSCC tumorigenesis and suggest that the expression of apoptotic molecules might be used as a prognostic indicator for OSCC.
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BAG-1 enhances cell-cell adhesion, reduces proliferation and induces chaperone-independent suppression of hepatocyte growth factor-induced epidermal keratinocyte migration. Exp Cell Res 2010; 316:2042-60. [PMID: 20430025 DOI: 10.1016/j.yexcr.2010.04.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 03/31/2010] [Accepted: 04/19/2010] [Indexed: 11/20/2022]
Abstract
Cell motility is important in maintaining tissue homeostasis, facilitating epithelial wound repair and in tumour formation and progression. The aim of this study was to determine whether BAG-1 isoforms regulate epidermal cell migration in in vitro models of wound healing. In the human epidermal cell line HaCaT, endogenous BAG-1 is primarily nuclear and increases with confluence. Both transient and stable p36-Bag-1 overexpression resulted in increased cellular cohesion. Stable transfection of either of the three human BAG-1 isoforms p36-Bag-1 (BAG-1S), p46-Bag-1 (BAG-1M) and p50-Bag-1 (BAG-1L) inhibited growth and wound closure in serum-containing medium. However, in response to hepatocyte growth factor (HGF) in serum-free medium, BAG-1S/M reduced communal motility and colony scattering, but BAG-1L did not. In the presence of HGF, p36-Bag-1 transfectants retained proliferative response to HGF with no change in ERK1/2 activation. However, the cells retained E-cadherin localisation at cell-cell junctions and exhibited pronounced cortical actin. Point mutations in the BAG domain showed that BAG-1 inhibition of motility is independent of its function as a chaperone regulator. These findings are the first to suggest that BAG-1 plays a role in regulating cell-cell adhesion and suggest an important function in epidermal cohesion.
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Zheng HC, Xu XY, Xing YN, Wei ZL, Takahashi H, Masuda S, Takano Y. Nuclear or cytoplasmic localization of Bag-1 distinctly correlates with pathologic behavior and outcome of gastric carcinomas. Hum Pathol 2010; 41:724-36. [PMID: 20096920 DOI: 10.1016/j.humpath.2009.10.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 10/15/2009] [Accepted: 10/22/2009] [Indexed: 01/26/2023]
Abstract
Bag-1 is an antiapoptotic protein with its altered expression and localization in malignancies. To clarify the role of Bag-1 in gastric carcinogenesis, its expression was examined by immunohistochemistry and in situ hybridization on a tissue microarray containing gastric carcinomas, adjacent nonneoplastic mucosa (NNM), adenomas, intestinal metaplasia (IM), or gastritis. Gastric carcinoma tissue and cell lines were studied for Bag-1 expression by Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). The results demonstrated that Bag-1 proteins were differentially expressed in the nucleus or cytosol of MKN28, AGS, MKN45, KATO-III, or HGC-27 cell lines, despite similar levels of messenger RNA (mRNA) expression. The Bag-1 mRNA overexpression was detectable in 73.3% of 15 gastric carcinomas without significant difference in its encoding products' levels. The nuclear Bag-1 expression gradually decreased from gastritis, IM, adenoma to carcinoma (P < .05), and negatively correlated with lymphatic invasion or lymph node metastasis, cytoplasmic Bag-1 expression, negative parafibromin expression, and poor prognosis (P < .05). Cytoplasmic Bag-1 was weakly immunoreactive in carcinomas, compared with gastritis (P < .05), and positively associated with invasive depth and poor prognosis of the carcinoma (P < .05). The positive rate of Bag-1 mRNA expression was higher in adjacent IMs than carcinomas or adjacent NNM (P < .05). Bag-1 mRNA was expressed more in carcinomas from female patients than the male counterparts (P < .05). There was a positive correlation of Bag-1 mRNA expression with invasive depth and venous invasion (P < .05). Our study indicated that aberrant expression and subcellular distribution of Bag-1 might play an important role in the malignant transformation of gastric epithelial cells and should be considered as a biomarker for gastric carcinogenesis, subsequent progression, and prognosis.
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Affiliation(s)
- Hua-chuan Zheng
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, China Medical University, Shenyang, 110001 China.
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9
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Wood J, Lee SS, Hague A. Bag-1 proteins in oral squamous cell carcinoma. Oral Oncol 2008; 45:94-102. [PMID: 18804403 DOI: 10.1016/j.oraloncology.2008.07.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 07/17/2008] [Accepted: 07/17/2008] [Indexed: 10/21/2022]
Abstract
Bag-1 is an anti-apoptotic protein that exhibits altered expression in many malignancies, including oral squamous cell carcinoma. The bag-1 gene gives rise to different protein products with different subcellular localisations through alternative translational initiation sites. In oral squamous cell carcinoma, cytoplasmic expression has been associated with metastasis to regional lymph nodes and poor prognosis. In contrast, the longest Bag-1 isoform is nuclear and may regulate differentiation in oral epithelium. In this review, the functions of the three isoforms of Bag-1 expressed in oral epithelial cells are discussed in relation to their contribution to oral carcinogenesis.
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Affiliation(s)
- Jemma Wood
- Department of Oral and Dental Science, University of Bristol, Lower Maudlin Street, Bristol, BS1 2LY, UK
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Higashiyama S, Iwabuki H, Morimoto C, Hieda M, Inoue H, Matsushita N. Membrane-anchored growth factors, the epidermal growth factor family: beyond receptor ligands. Cancer Sci 2008; 99:214-20. [PMID: 18271917 PMCID: PMC11158050 DOI: 10.1111/j.1349-7006.2007.00676.x] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The epidermal growth factor (EGF) family and the EGF receptor (EGFR, ErbB) tyrosine kinase family have been spearheading the studies of signal transduction events that determine cell fate and behavior in vitro and in vivo. The EGFR family and their signaling pathways are giving us tremendous advantages in developing fascinating molecular target strategies for cancer therapy. Currently, two important types of EGFR inhibitors are in clinical use: neutralizing antibodies of EGFR or ErbB2, and synthetic small compounds of tyrosine kinase inhibitors designed for receptors. On the other hand, basic research of the EGF family ligands presents new challenges as membrane-anchored growth factors. All members of the EGF family have important roles in development and diseases and are shed from the plasma membrane by metalloproteases. The ectodomain shedding of the ligands has emerged as a critical component in the functional transactivation of EGFRs in interreceptor cross-talk in response to various shedding stimulants such as G-protein coupled receptor agonists, growth factors, cytokines, and various physicochemical stresses. Among the EGFR-ligands, heparin-binding EGF-like growth factor (HB-EGF) is a prominent ligand in our understanding of the pathophysiological roles of ectodomain shedding in cancer, wound healing, cardiac diseases, etc. Here we focus on ectodomain shedding of the EGF family ligands, especially HB-EGF by disintegrin and metalloproteases, which are not only key events of receptor cross talk, but also novel intercellular signaling by their carboxy-terminal fragments to regulate gene expression directly.
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Affiliation(s)
- Shigeki Higashiyama
- Department of Biochemistry and Molecular Genetics, Center for Regenerative Medicine (CEREM), Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan.
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Dobbyn HC, Hill K, Hamilton TL, Spriggs KA, Pickering BM, Coldwell MJ, de Moor CH, Bushell M, Willis AE. Regulation of BAG-1 IRES-mediated translation following chemotoxic stress. Oncogene 2007; 27:1167-74. [PMID: 17700523 PMCID: PMC2570717 DOI: 10.1038/sj.onc.1210723] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
There are three major isoforms of BAG-1 in mammalian cells, termed BAG-1L (p50), BAG-1M (p46) and BAG-1S (p36) that function as pro-survival proteins and are associated with tumorigenesis and chemoresistance. Initiation of BAG-1 protein synthesis can occur by both cap-dependent and cap-independent mechanisms and it has been shown that synthesis of BAG-1S is dependent upon the presence of an internal ribosome entry segment (IRES) in the 5'-UTR of BAG-1 mRNA. We have shown previously that BAG-1 IRES-meditated initiation of translation requires two trans-acting factors poly (rC) binding protein 1 (PCBP1) and polypyrimidine tract binding protein (PTB) for function. The former protein allows BAG-1 IRES RNA to attain a structure that permits binding of the ribosome, while the latter protein appears to be involved in ribosome recruitment. Here, we show that the BAG-1 IRES maintains synthesis of BAG-1 protein following exposure of cells to the chemotoxic drug vincristine but not to cisplatin and that this is brought about, in part, by the relocalization of PTB and PCBP1 from the nucleus to the cytoplasm.
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Affiliation(s)
- H C Dobbyn
- School of Pharmacy, University of Nottingham, Nottingham, UK
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Lee SS, Crabb SJ, Janghra N, Carlberg C, Williams AC, Cutress RI, Packham G, Hague A. Subcellular localisation of BAG-1 and its regulation of vitamin D receptor-mediated transactivation and involucrin expression in oral keratinocytes: implications for oral carcinogenesis. Exp Cell Res 2007; 313:3222-38. [PMID: 17662274 DOI: 10.1016/j.yexcr.2007.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 06/11/2007] [Accepted: 06/25/2007] [Indexed: 11/20/2022]
Abstract
In oral cancers, cytoplasmic BAG-1 overexpression is a marker of poor prognosis. BAG-1 regulates cellular growth, differentiation and survival through interactions with diverse proteins, including the vitamin D receptor (VDR), a key regulator of keratinocyte growth and differentiation. BAG-1 is expressed ubiquitously in human cells as three major isoforms of 50 kDa (BAG-1L), 46 kDa (BAG-1M) and 36 kDa (BAG-1S) from a single mRNA. In oral keratinocytes BAG-1L, but not BAG-1M and BAG-1S, enhanced VDR transactivation in response to 1alpha,25-dihydroxyvitamin D3. BAG-1L was nucleoplasmic and nucleolar, whereas BAG-1S and BAG-1M were cytoplasmic and nucleoplasmic in localisation. Having identified the nucleolar localisation sequence in BAG-1L, we showed that mutation of this sequence did not prevent BAG-1L from potentiating VDR activity. BAG-1L also potentiated transactivation of known vitamin-D-responsive gene promoters, osteocalcin and 24-hydroxylase, and enhanced VDR-dependent transcription and protein expression of the keratinocyte differentiation marker, involucrin. These results demonstrate endogenous gene regulation by BAG-1L by potentiating nuclear hormone receptor function and suggest a role for BAG-1L in 24-hydroxylase regulation of vitamin D metabolism and the cellular response of oral keratinocytes to 1alpha,25-dihydroxyvitamin D3. By contrast to the cytoplasmic BAG-1 isoforms, BAG-1L may act to suppress tumorigenesis.
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Affiliation(s)
- San San Lee
- Department of Oral and Dental Science, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, UK
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Wadle A, Mischo A, Henrich PP, Stenner-Liewen F, Stenner-Lieven F, Scherer C, Imig J, Petersen G, Pfreundschuh M, Renner C. Characterization of Hap/BAG-1 variants as RP1 binding proteins with antiapoptotic activity. Int J Cancer 2005; 117:896-904. [PMID: 15986447 DOI: 10.1002/ijc.21259] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The MAPRE protein family (EB1, RP1, EB2) represents a highly conserved group of proteins that localize preferentially to the plus end of microtubules, both in the nucleus and cytoplasm. In addition, MAPRE family members are characterized by their capability to bind to the C-terminus of the adenomatous polyposis coli (APC) protein and tubulin in order to stabilize microtubules. Apart from the interaction with APC and tubulin, no other direct binding partners are known today. Because the RP1 gene product was identified in activated T cells, we set out to search for new interacting molecules in a yeast 2-hybrid system. We isolated a cDNA variant encoding for the antiapoptotic Hap/BAG-1 protein truncated by 34 amino acids at the C-terminus. In the original Hap/BAG-1 protein, the C-terminal domain is responsible for binding to Bcl-2 and Hsp/Hsc70, which is believed to be the reason for its antiapoptotic activity. Although this putative Hap/BAG-1 variant protein showed no interaction with Bcl-2 or Hsp/Hsc70, it was perfectly able to confer resistance to apoptosis. Subcellular distribution analysis revealed that the Hap/Bag-1 variant protein localized homogenously to the cytoplasm and shuttles into the nucleus in response to stress, a process that could be blocked by RP1 protein overexpression.
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Affiliation(s)
- Andreas Wadle
- Med. Department I, Saarland University Medical School, Homburg, Germany
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Wang WY, Tang HW, Zhang ZP, Han B, Gao YH, Ma FC, Yan QG, Zhao YL. Expression of Bag-1 and Bcl-2 and its significance in gastric cancer. Shijie Huaren Xiaohua Zazhi 2005; 13:1186-1189. [DOI: 10.11569/wcjd.v13.i10.1186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the expression of Bag-1 and Bcl-2 protein and its clinical significance in gastric cancer (GC).
METHODS: Immunohistochemistry was used to detect the expressison of Bag-1 and Bcl-2 protein in 92 patients with gastric cancer and 40 normal tissues as control.
RESULTS: Compared with normal mucosa, Bag-1 and Bcl-2 were over-expressed in gastric cancerous tissues (60.9% vs 7.5%, 72.8% vs 10%, P<0.01). The expression of Bcl-2 protein was significantly correlated with the differentiation degree (rs = 0.513, P<0.05) and the expression of Bag-1 was significantly associated with Bcl-2 level in gastric cancer (rs = 0.522, P<0.01).
CONCLUSION: The over-expression of Bcl-2 leads to uncontrolled growth and unceasingly increases of GC cells by accelerating cell transformation and proliferation. Bag-1 promotes the function of Bcl-2 and co-expression of Bag-1 and Bcl-2 may mean poor prognosis of GC patients.
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Higashiyama S, Nanba D. ADAM-mediated ectodomain shedding of HB-EGF in receptor cross-talk. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1751:110-7. [PMID: 16054021 DOI: 10.1016/j.bbapap.2004.11.009] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2004] [Revised: 11/09/2004] [Accepted: 11/11/2004] [Indexed: 11/29/2022]
Abstract
All ligands of the epidermal growth factor receptor (EGFR) which has important roles in development and disease, are shed from the plasma membrane by metalloproteases. The ectodomain shedding of EGFR ligands has emerged as a critical component in the functional activation of EGFR in the interreceptor cross-talk. Identification of the sheddases for EGFR ligands using mouse embryonic cells lacking candidate sheddases (a disintegrin and metalloprotease; ADAM) has revealed that ADAM10, -12 and -17 are the sheddases of the EGFR ligands in response to various shedding stimulants such as GPCR agonists, growth factors, cytokines, osmotic stress, wounding and phorbol ester. Among the EGFR ligands, heparin-binding EGF-like growth factor (HB-EGF) is a representative ligand to understand the pathophysiological roles of the ectodomain shedding in wound healing, cardiac diseases, etc. Here we focus on the ectodomain shedding of HB-EGF by ADAMs, which is not only a key event of receptor cross-talk but also a novel intercellular signaling by the carboxy-terminal fragment (CTF signal).
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Affiliation(s)
- Shigeki Higashiyama
- Division of Biochemistry and Molecular Genetics, Department of Molecular and Cellular Biology, Ehime University School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan.
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Xie X, Clausen OPF, Boysen M. Bag-1 expression as a prognostic factor in tongue squamous cell carcinomas. Laryngoscope 2004; 114:1785-90. [PMID: 15454773 DOI: 10.1097/00005537-200410000-00021] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To investigate the prognostic significance of the antiapoptotic protein Bag-1. In addition, the relationship between Bag-1 expression, other apoptosis-related and proliferative parameters. STUDY DESIGN Eighty-five randomly selected patients with T1 to T4 oral tongue squamous cell carcinomas (SCC) were studied. METHODS Sections from diagnostic, formalin-fixed, paraffin-embedded specimens were stained immunohistochemically to detect Bag-1 protein. RESULTS Bag-1 expression correlated positively with apoptosis-related parameters such as Bcl-2 expression (P =.001) and proliferation-related parameters including Ki-67, mean argyrophilic nucleolar organizer regions (mAgNOR), and the percentage of AgNOR (pAgNOR) (P =.0117, P =.0257, and P =.0008, respectively). Correlation with Bag-1 expression and T classification (P =.0362), N classification (P =.0284), and clinical stage (P =.0117) was also found. In addition, Bag-1 expression was associated with the carbohydrate epitopes H-antigen and Le (P =.0004 and P =.0011, respectively). No correlation was found between Bag-1 expression and p53 accumulation, Bax expression, or apoptotic index (AI). However, a combined score of Bcl-2 and Bag-1 expression was inversely associated with AI (P =.046). Patients with tumors expressing high Bag-1 values had a shortened disease-specific survival time when compared with those with low Bag-1 values (P =.0017). A two-parameter combination between Bag-1 expression and Bax expression or AI, respectively, revealed an enhanced prognostic potential (P <.0001) when compared with single parameters. CONCLUSION Correlation between Bag-1 expression and other biologic variables revealed that Bag-1 might be involved in several biologic processes including apoptosis and cell proliferation. The expression of Bag-1 protein, particularly in combination with Bax expression or AI, respectively, has prognostic value in oral tongue SCC.
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Affiliation(s)
- Xin Xie
- Department of Otolaryngology, Institute for Pathology, Rikshospitalet, University of Oslo, 0027 Oslo, Norway
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Nanba D, Higashiyama S. Dual intracellular signaling by proteolytic cleavage of membrane-anchored heparin-binding EGF-like growth factor. Cytokine Growth Factor Rev 2004; 15:13-9. [PMID: 14746810 DOI: 10.1016/j.cytogfr.2003.10.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Heparin-binding EGF-like growth factor (HB-EGF), a member of the EGF family, is synthesized as a membrane-anchored precursor (proHB-EGF) that is cleaved to release a soluble HB-EGF by specific metalloproteases. Proteolytic cleavage of proHB-EGF yields amino- and carboxy-terminal fragments (HB-EGF and HB-EGF-C). Recent studies indicate that the processing of proHB-EGF is strictly regulated and involved in a variety of biological processes and that not only HB-EGF but also HB-EGF-C functions as a signaling molecule. ProHB-EGF generates dual intracellular signaling molecules by its proteolytic cleavage.
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Affiliation(s)
- Daisuke Nanba
- Department of Medical Biochemistry, Ehime University School of Medicine, Shitsukawa, Shigenobu-cho, Onsen-gun, Ehime 791-0295, Japan
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Yan QG, Shi JG, Huang GS, Zhang CS, Li Q, Hu PZ, Wang WL. In situ quantitative study of BAG-1 and BAD in extrahepatic cholangiocarcinoma. Shijie Huaren Xiaohua Zazhi 2003; 11:1144-1147. [DOI: 10.11569/wcjd.v11.i8.1144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To detect the expression of apoptosis related proteins BAG-1 and BAD and to investigate their functions of apoptosis modulation and relations to tumor differentiation in extrahepatic cholangiocarcinoma.
METHODS Quantitative in situ methods of DAKO EnvisionTM Systems immunohistochemistry in combination with computer-assisted image analysis and apoptotic cells counting were used to observe the expression levels of BAG-1 and BAD and the apoptosis indexes in 42 cases of extrahepatic cholangiocarcinoma.
RESULTS The expression levels of BAG-1 and BAD were measured with average absorbance (A) derived from the quantitative image analysis. Among 24, 13 and 5 cases of well, moderately and poorly differentiated extrahepatic cholangiocarcinomas, the average A of BAG-1 was respectively 0.068±0.037, 0.112±0.057 and 0.152±0.062, of BAD was respectively 0.079±0.053, 0.138±0.058 and 0.165±0.061, and the apoptotic indexes examined in the hematoxylin-and-eosin-stained specimens were respectively 1.1±0.5, 1.7±0.3 and 3.5±1.3. The expression levels of BAG-1 and BAD and the apoptotic indexes were increased obviously from well, moderately to poorly differentiated extrahepatic cholangiocarcinoma (P<0.05). The expression level of BAD was correlated to the apoptotic indexes (P<0.01).
CONCLUSION Expressions of BAG-1 and BAD and apoptosis indexes were all associated with differentiation of extrahepatic cholangiocarcinoma. BAG-1 and BAD may take part in the apoptosis modulation of the tumor.
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Affiliation(s)
- Qing-Guo Yan
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an 710033, Shaanxi Province, China
| | - Jian-Guo Shi
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an 710033, Shaanxi Province, China
| | - Gao-Sheng Huang
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an 710033, Shaanxi Province, China
| | - Chuan-Shan Zhang
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an 710033, Shaanxi Province, China
| | - Qing Li
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an 710033, Shaanxi Province, China
| | - Pei-Zhen Hu
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an 710033, Shaanxi Province, China
| | - Wen-Liang Wang
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an 710033, Shaanxi Province, China
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Cutress RI, Townsend PA, Sharp A, Maison A, Wood L, Lee R, Brimmell M, Mullee MA, Johnson PWM, Royle GT, Bateman AC, Packham G. The nuclear BAG-1 isoform, BAG-1L, enhances oestrogen-dependent transcription. Oncogene 2003; 22:4973-82. [PMID: 12902980 DOI: 10.1038/sj.onc.1206688] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BAG-1 is a multifunctional protein that interacts with a wide range of cellular targets including heat-shock proteins and some nuclear hormone receptors. BAG-1 exists as three major isoforms, BAG-1L, BAG-1M and BAG-1S. BAG-1L contains a nuclear localization signal, which is not present in the other isoforms, and is predominantly localized in the cell nucleus. Here we have investigated the effects of BAG-1 on function of the oestrogen receptor (ER), a key growth control molecule and target for hormonal therapy in breast cancer. We demonstrate that BAG-1L, but not BAG-1S or BAG-1M, increased oestrogen-dependent transcription in breast cancer cells. BAG-1L interacted with and stimulated the activity of both ER alpha and beta. Although BAG-1L and ERs colocalize to the nucleus, fusing BAG-1S to an heterologous nuclear localization sequence was not sufficient to stimulate transcription. Consistent with an important effect on receptor function, nuclear BAG-1 expression in breast cancers was associated with expression of the progesterone receptor, a transcriptional target of ERalpha, and was associated with improved survival in patients treated with hormonal therapy. These data suggest that BAG-1L is an important determinant of ER function in vitro and in human breast cancer.
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Affiliation(s)
- Ramsey I Cutress
- Cancer Research UK Oncology Unit, Cancer Sciences Division, School of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
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20
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Schliephake H. Prognostic relevance of molecular markers of oral cancer--a review. Int J Oral Maxillofac Surg 2003; 32:233-45. [PMID: 12767868 DOI: 10.1054/ijom.2002.0383] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of the present article was to review the current knowledge on the prognostic value of tumour marker in the treatment of oral squamous cell carcinoma (OSCC). The literature of the past 5 years (1997-August 2002) was screened. One hundred and sixty-nine articles were included in this review, twenty-nine molecular markers of relevance were identified. Tumour markers were allocated to four groups according to their function: (i) Enhancement of Tumour Growth: Cell cycle acceleration and proliferation, (ii) Tumour Suppression and Anti-Tumour Defence: Immune response and apoptosis, (iii) Angiogenesis, (iv) Tumour Invasion and Metastatic Potential: Adhesion molecules and matrix degradation. Data showed that the prognostic relevance of most tumour markers is still not quite clear. Only 12 of 23 reports on the prognostic relevance of markers for cell cycle acceleration and proliferation indicated a significant association with prognosis while 20 of 29 studies on markers for tumour suppression and anti-tumour response showed prognostic relevance. Markers of angiogenesis exhibited only minor importance for the prognosis and treatment of OSCC. Results on markers of tumour invasion and metastatic potential appeared to be too premature for a statement regarding their prognostic value. In general, the location of markers within the tumour and not their quantitative assessment as such is emphasized. Particularly, the analysis of the invasive front of the tumour with regard to the occurrence of molecular markers is supposed to be of great importance for prognostication.
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Affiliation(s)
- H Schliephake
- Department of Oral and Maxillofacial Surgery, George Augusta University, Göttingen, Germany
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21
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Niyaz Y, Frenz I, Petersen G, Gehring U. Transcriptional stimulation by the DNA binding protein Hap46/BAG-1M involves hsp70/hsc70 molecular chaperones. Nucleic Acids Res 2003; 31:2209-16. [PMID: 12682371 PMCID: PMC153731 DOI: 10.1093/nar/gkg303] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The hsp70/hsc70-associating protein Hap46 of human origin, also called BAG-1M (Bcl-2-associated athanogene 1), has been characterized previously as a DNA binding protein, which is able to stimulate transcription. By use of in vitro assays we now show that Hap46-mediated transcriptional activation can occur from linearized as well as from supercoiled circular DNA and does not require the presence of a transcription promoter. Accordingly, we observed no preferential binding of Hap46 to overlapping DNA fragments covering the sequence of the cytomegalovirus (CMV) early promoter, thus suggesting non-specific binding. The C-terminal deletion variant Hap46DeltaC47, which is unable to associate with hsp70/hsc70 molecular chaperones, produced greatly diminished effects on transcription, indicating a significant involvement of hsp70/hsc70 chaperones but not an absolute requirement. In contrast, deletion of the acidic hexarepeat region, as in variant Hap46Delta12-62, did not disturb transcriptional stimulation. While full-length Hap46 readily formed complexes with a series of structurally unrelated transcription factors, variant Hap46DeltaC47 proved incapable of doing so. Together these data suggest that transcriptional stimulation is a major biological activity of Hap46 and point to involvement of hsp70/hsc70 molecular chaperones in transcription in concert with Hap46, thus providing a link between hsp70/hsc70 molecular chaperones and components of the transcription machinery.
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Affiliation(s)
- Yilmaz Niyaz
- Molekulare Evolution und Genomik, Im Neuenheimer Feld 230, and Biochemie-Zentrum Heidelberg, D-69120 Heidelberg, Germany
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22
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Townsend PA, Cutress RI, Sharp A, Brimmell M, Packham G. BAG-1: a multifunctional regulator of cell growth and survival. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1603:83-98. [PMID: 12618309 DOI: 10.1016/s0304-419x(03)00002-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BAG-1 is multifunctional protein which interacts with a wide range of cellular targets to regulate growth control pathways important for normal and malignant cells, including apoptosis, signaling, proliferation, transcription and cell motility. Of particular relevance to tumour cells, BAG-1 interacts with the anti-apoptotic BCL-2 protein, various nuclear hormone receptors and the 70 kDa heat shock proteins, Hsc70 and Hsp70. Interaction with chaperones may account for many of the pleiotropic effects associated with BAG-1 overexpression. Recent studies have shown that BAG-1 expression is frequently altered in malignant cells, and BAG-1 expression may have clinical value as a prognostic/predictive marker. This review summarises current understanding of molecular mechanisms of BAG-1 expression and function.
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Affiliation(s)
- Paul A Townsend
- Cancer Research UK Oncology Unit, Cancer Sciences Division, School of Medicine, University of Southampton, Southampton SO16 6YD, UK
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23
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Cutress RI, Townsend PA, Brimmell M, Bateman AC, Hague A, Packham G. BAG-1 expression and function in human cancer. Br J Cancer 2002; 87:834-9. [PMID: 12373595 PMCID: PMC2376178 DOI: 10.1038/sj.bjc.6600538] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2002] [Revised: 07/18/2002] [Accepted: 07/25/2002] [Indexed: 11/09/2022] Open
Abstract
BAG-1 is a multifunctional protein that interacts with a wide range of target molecules to regulate apoptosis, proliferation, transcription, metastasis and motility. Interaction with chaperone molecules may mediate many of the effects of BAG-1. The pathways regulated by BAG-1 play key roles in the development and progression of cancer and determining response to therapy, and there has been considerable interest in determining the clinical significance of BAG-1 expression in malignant cells. There is an emerging picture that BAG-1 expression is frequently altered in a range of human cancers relative to normal cells and a recent report suggests the exciting possibility that BAG-1 expression may have clinical utility as a prognostic marker in early breast cancer. However, other studies of BAG-1 expression in breast cancer and other cancer types have yielded differing results. It is important to view these findings in the context of current knowledge of BAG-1 expression and function. This review summarises recent progress in understanding the clinical significance of BAG-1 expression in cancer in light of our understanding of BAG-1 function.
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Affiliation(s)
- R I Cutress
- Cancer Research UK Oncology Unit, Cancer Sciences Division, Mail Point 824, School of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK.
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