Pyrrolo-1,5-benzoxazepines: a new class of apoptotic agents

2001 ◽  
Vol 29 (6) ◽  
pp. 704-706 ◽  
Author(s):  
D. M. Zisterer ◽  
M. M. McGee ◽  
G. Campiani ◽  
A. Ramunno ◽  
C. Fattorusso ◽  
...  
Keyword(s):  
Cellular Response ◽  
Caspase 3 ◽  
Signal Transduction Pathway ◽  
Benzodiazepine Receptor ◽  
Cell Types ◽  
Dependent Manner ◽  
Apoptotic Pathway ◽  
Leukaemia Cell Line ◽  
Apoptotic Activity ◽  
Induced Apoptosis

Some members of a series of novel pyrrolo-1,5-benzoxazepines (PBOXs) potently induce apoptosis in a number of human cancerous cell lines including HL-60 cells and the drug-resistant chronic myelogenous leukaemia cell line, K562. The apoptotic induction seems to be independent of the mitochondrial peripheral-type benzodiazepine receptor (PBR), which binds these PBOXs with high affinity, due to a lack of correlation between their affinities for the receptor and their apoptotic potencies and their high apoptotic activity in PBR-deficient cells. PBOX-6, a potent member of the series, induces a transient activation of c-Jun N-terminal kinase (JNK) in a dose-dependent manner, which correlates with induction of apoptosis. Expression of a cytoplasmic inhibitor of the JNK signal transduction pathway, Jip-1, prevents JNK activity and significantly reduces the extent of apoptosis induced by PBOX-6. This demonstrates the requirement for JNK in the cellular response to this apoptotic agent. In addition, PBOX-6 activates caspase-3-like proteases in K562 and HL-60 cells. The caspase-3 inhibitor, Z-Asp-Glu-Val-Asp-fluoromethylketone (z-DEVD-fmk), blocks caspase-3-like protease activity in both cell types but only prevents PBOX-6-induced apoptosis in HL-60 cells, suggesting that the requirement for caspase-3-like proteases in the apoptotic pathway is dependent on the cell type.

188 CALBINDIN-D28k IS INVOLVED IN THE APOPTOTIC PATHWAY AND PLAYS A ROLE AS AN ANTIAPOPTOTIC GENE IN HYDROGEN PEROXIDE-INDUCED CELL DEATH OF HUMAN ENDOMETRIAL ISHIKAWA CELLS

2011 ◽  
Vol 23 (1) ◽  
pp. 195
Author(s):  
S.-H. Hyun ◽  
E.-M. Jung ◽  
E.-B. Jeung
Keyword(s):  
Cell Death ◽  
Calcium Binding ◽  
Caspase 3 ◽  
Dependent Manner ◽  
Apoptotic Pathway ◽  
P53 Expression ◽  
Ishikawa Cells ◽  
Calbindin D28k ◽  
Antiapoptotic Gene ◽  
Induced Apoptosis

Calbindin-D28k (CaBP-28k), a calcium-binding protein, buffers intracellular Ca2+ and eventually has antiapoptosis properties in neuron, osteoblast, and male germ cells. Although endometrial cancer is the most common invasive gynecological malignancy, CaBP-28k expression in apoptosis signalling is poorly understood. In this study, we investigated whether CaBP-28k expression is regulated by H2O2-induced apoptosis signalling in human endometrial Ishikawa cells. Ishikawa cells were treated with H2O2 in a dose-dependent manner (0, 0.25, 0.5, 1.0, 1.5, 2 mM) and a time-dependent manner (0, 15, 30, 60, 90, 120 min). The protein expressions of Bax, p53, and caspase 3 were determined by Western blot analysis. Treatment of Ishikawa cells with H2O2 induced an increase in Bax and p53 expression at the translational level at 1 mM for 1 h. Interestingly, overexpression of CaBP-28k caused a decrease in Bax, p53, and caspase 3 on H2O2-induced apoptosis in the Ishikawa cells. These results suggest that expression of CaBP-28k blocked up-regulation of apoptotic gene expression. In addition, knockdown of CaBP-28k expression using a small inhibitory RNA resulted in an elevation of H2O2-induced cell death and a increase in Bax, p53, and caspase 3 in H2O2-induced apoptosis, whereas cell survival was increased in overexpressing CaBP-28k cells, providing additional evidence that the induction of CaBP-28k expression may be associated with survival signalling during H2O2-mediated oxidative cell death. Taken together, these results imply that CaBP-28k expression is involved in the apoptotic pathway and may play a role as an antiapoptotic gene in the human endometrial Ishikawa cells.

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
Keyword(s):  
T Cell ◽  
Glucocorticoid Receptor ◽  
Cell Lines ◽  
Cell Types ◽  
Thymic Epithelial Cells ◽  
Dependent Manner ◽  
Localization Signal ◽  
Induced Apoptosis ◽  
T Cell Lines

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.

Identification of apoptotic genes mediating TGF-β/Smad3-induced cell death in intestinal epithelial cells using a genomic approach

2007 ◽  
Vol 292 (1) ◽  
pp. G28-G38 ◽  
Author(s):  
Yanna Cao ◽  
Lu Chen ◽  
Weili Zhang ◽  
Yan Liu ◽  
Harry T. Papaconstantinou ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Intestinal Epithelial ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Genomic Approach ◽  
Apoptotic Genes ◽  
Induced Apoptosis

Transforming growth factor (TGF)-β-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues in vivo. Previously, we have shown that TGF-β inhibits the growth of rat intestinal epithelial (RIE)-1 cells. However, RIE-1 cells are relatively resistant to TGF-β-induced apoptosis due to a low endogenous Smad3-to-Akt ratio. Overexpression of Smad3 sensitizes RIE-1 cells (RIE-1/Smad3) to TGF-β-induced apoptosis by altering the Smad3-to-Akt ratio in favor of apoptosis. In this study, we utilized a genomic approach to identify potential downstream target genes that are regulated by TGF-β/Smad3. Total RNA samples were analyzed using Affymetrix oligonucleotide microarrays. We found that TGF-β regulated 518 probe sets corresponding to its target genes. Interestingly, among the known apoptotic genes included in the microarray analyses, only caspase-3 was induced, which was confirmed by real-time RT-PCR. Furthermore, TGF-β activated caspase-3 through protein cleavage. Upstream of caspase-3, TGF-β induced mitochondrial depolarization, cytochrome c release, and cleavage of caspase-9, which suggests that the intrinsic apoptotic pathway mediates TGF-β-induced apoptosis in RIE-1/Smad3 cells.

Multiple Signal Pathways Involved in Crocetin-Induced Apoptosis in KYSE-150 Cells

Pharmacology ◽  
2019 ◽  
Vol 103 (5-6) ◽  
pp. 263-272 ◽  
Author(s):  
Sheng Li ◽  
Yuhua Qu ◽  
Xiu-Yin Shen ◽  
Ting Ouyang ◽  
Wen-Bin Fu ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Squamous Carcinoma ◽  
Annexin V ◽  
Signal Pathways ◽  
Dependent Manner ◽  
Apoptosis Pathway ◽  
Anticancer Properties ◽  
Multiple Signal ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

Background: Crocetin is a carotenoid extracted from the traditional Chinese medical herb saffron. Previous studies have demonstrated that crocetin possesses anticancer properties that are effective against various cancers. As an extension of our earlier study, the present study explored the underlying mechanisms in crocetin’s anticancer effect on KYSE-150 cells. The phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT), Mitogen-activated protein kinases (MAPK), and p53/p21 signal pathways play an important role in carcinogenesis, progression, and metastasis of carcinoma cells. Thus, we investigated crocetin’s effects on the PI3K/AKT, MAPK, and p53/p21 pathways in esophageal squamous carcinoma cell line KYSE-150 cells. Methods: KYSE-150 cells were treated with various concentrations of crocetin. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltertrazolium bromide assay, Annexin V/PI stain as well as Rh123 stain were used to evaluate the cell viability, apoptosis, and MMP. Western blot was used to detect the expression of PI3K, AKT, ERK1/2, p38, c-Jun NH-terminal kinase (JNK), P53, P21, Bcl-2, Bax, and cleaved caspase-3, which were associated with cell proliferation and apoptosis. Results: Our results showed that crocetin significantly inhibited the proliferation of KYSE-150 cells in a dose- and time-dependent manner. Crocetin also markedly induced cell apoptosis. Furthermore, we have found that crocetin not only inhibited the activation of PI3K/AKT, extracellular signal–regulated kinase-1/2 (ERK1/2), and p38 but also upregulated the p53/p21 level. These regulations ultimately triggered the mitochondrial-mediated apoptosis pathway with an eventual disruption of MMP, increased levels of Bax and cleaved caspase-3, and decreased levels of Bcl-2. Conclusions: These findings suggested that crocetin interfered with multiple signal pathways in KYSE-150 cells. Therefore, this study suggested that crocetin could potentially be used as a therapeutic candidate for the treatment of esophageal cancer.

scholarly journals The pan-Bcl-2 inhibitor obatoclax promotes differentiation and apoptosis of acute myeloid leukemia cells

2020 ◽  
Vol 38 (6) ◽  
pp. 1664-1676
Author(s):  
Małgorzata Opydo-Chanek ◽  
Iwona Cichoń ◽  
Agnieszka Rak ◽  
Elżbieta Kołaczkowska ◽  
Lidia Mazur
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Treatment Strategies ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Dependent Manner ◽  
Apoptotic Pathway ◽  
Acute Myeloid Leukemia Cells ◽  
Induced Apoptosis ◽  
Acute Myeloid

Summary One of the key features of acute myeloid leukemia (AML) is the arrest of differentiation at the early progenitor stage of myelopoiesis. Therefore, the identification of new agents that could overcome this differentiation block and force leukemic cells to enter the apoptotic pathway is essential for the development of new treatment strategies in AML. Regarding this, herein we report the pro-differentiation activity of the pan-Bcl-2 inhibitor, obatoclax. Obatoclax promoted differentiation of human AML HL-60 cells and triggered their apoptosis in a dose- and time-dependent manner. Importantly, obatoclax-induced apoptosis was associated with leukemic cell differentiation. Moreover, decreased expression of Bcl-2 protein was observed in obatoclax-treated HL-60 cells. Furthermore, differentiation of these cells was accompanied by the loss of their proliferative capacity, as shown by G0/G1 cell cycle arrest. Taken together, these findings indicate that the anti-AML effects of obatoclax involve not only the induction of apoptosis but also differentiation of leukemic cells. Therefore, obatoclax represents a promising treatment for AML that warrants further exploration.

Mcl-1 is downregulated in cisplatin-induced apoptosis, and proteasome inhibitors restore Mcl-1 and promote survival in renal tubular epithelial cells

2007 ◽  
Vol 292 (6) ◽  
pp. F1710-F1717 ◽  
Author(s):  
Cheng Yang ◽  
Varsha Kaushal ◽  
Sudhir V. Shah ◽  
Gur P. Kaushal
Keyword(s):  
Epithelial Cells ◽  
Cytochrome C ◽  
Caspase 3 ◽  
Proteasome Inhibitors ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Renal Tubular ◽  
Induced Apoptosis

Mcl-1 is an antiapoptotic member of the Bcl-2 family that plays an important role in cell survival. We demonstrate that proteasome-dependent regulation of Mcl-1 plays a critical role in renal tubular epithelial cell injury from cisplatin. Protein levels of Mcl-1 rapidly declined in a time-dependent manner following cisplatin treatment of LLC-PK1cells. However, mRNA levels of Mcl-1 were not altered following cisplatin treatment. Expression of other antiapoptotic members of the Bcl-2 family such as Bcl-2 and BclxL was not affected by cisplatin treatment. Cisplatin-induced loss of Mcl-1 occurs at the same time as the mitochondrial release of cytochrome c, activation of caspase-3, and initiation of apoptosis. Treatment of cells with cycloheximide, a protein synthesis inhibitor, revealed rapid turnover of Mcl-1. In addition, treatment with cycloheximide in the presence or absence of cisplatin demonstrated that cisplatin-induced loss of Mcl-1 results from posttranslational degradation rather than transcriptional inhibition. Overexpression of Mcl-1 protected cells from cisplatin-induced caspase-3 activation and apoptosis. Preincubating cells with the proteasome inhibitor MG-132 or lactacystin not only restored cisplatin-induced loss of Mcl-1 but also resulted in an accumulation of Mcl-1 that exceeded basal levels; however, Bcl-2 and BclxL levels did not change in response to MG-132 or lactacystin. The proteasome inhibitors effectively blocked cisplatin-induced mitochondrial release of cytochrome c, caspase-3 activation, and apoptosis. These studies suggest that proteasome regulation of Mcl-1 is crucial in the cisplatin-induced apoptosis via the mitochondrial apoptotic pathway and that Mcl-1 is an important therapeutic target in cisplatin injury to renal tubular epithelial cells.

scholarly journals Autophagy Inhibition Enhances Apoptosis Induced by Dioscin in Huh7 Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Ming-Ju Hsieh ◽  
Shun-Fa Yang ◽  
Yih-Shou Hsieh ◽  
Tzy-Yen Chen ◽  
Hui-Ling Chiou
Keyword(s):  
Cell Apoptosis ◽  
Caspase 3 ◽  
Natural Food ◽  
Dependent Manner ◽  
Caspase Activation ◽  
Huh7 Cells ◽  
Dependent Cell ◽  
Induced Apoptosis ◽  
Dose Dependent ◽  
Autophagy Inhibition

Extensive research results support the application of herbal medicine or natural food as an augment during therapy for various cancers. However, the effect of dioscin on tumor cells autophagy has not been clearly clarified. In this study, the unique effects of dioscin on autophagy of hepatoma cells were investigated. Results found that dioscin induced caspase-3- and -9-dependent cell apoptosis in a dose-dependent manner. Moreover, inhibition of ERK1/2 phosphorylation significantly abolished the dioscin-induced apoptosis. In addition, dioscin triggered cell autophagy in early stages. With autophagy inhibitors to hinder the autophagy process, dioscin-induced cell apoptosis was significantly enhanced. An inhibition of caspase activation did not affect the dioscin-induced LC3-II protein expression. Based on the results, we believed that while apoptosis was blocked, dioscin-induced autophagy process also diminished in Huh7 cells. In conclusion, this study indicates that dioscin causes autophagy in Huh7 cells and suggests that dioscin has a cytoprotective effect.

scholarly journals Protective Effects of Pretreatment with Quercetin Against Lipopolysaccharide-Induced Apoptosis and the Inhibition of Osteoblast Differentiation via the MAPK and Wnt/β-Catenin Pathways in MC3T3-E1 Cells

2017 ◽  
Vol 43 (4) ◽  
pp. 1547-1561 ◽  
Author(s):  
Chun Guo ◽  
Rui-Juan Yang ◽  
Ke Jang ◽  
Xiao-ling Zhou ◽  
Yu-zhen Liu
Keyword(s):  
Cytochrome C ◽  
Osteoblast Differentiation ◽  
Caspase 3 ◽  
Quantitative Polymerase Chain Reaction ◽  
Bone Diseases ◽  
Cell Counting ◽  
Dependent Manner ◽  
Protective Effects ◽  
Expression Levels ◽  
Induced Apoptosis

Background/Aims: Quercetin, a flavonoid found in onions and other vegetables, has potential inhibitory effects on bone resorption in vivo and in vitro. In our previous study, we found that quercetin treatment reversed lipopolysaccharide (LPS)-induced inhibition of osteoblast differentiation through the mitogen-activated protein kinase (MAPK) pathway in MC3T3-E1 cells. In this study, we investigated the underlying mechanisms of pretreatment with quercetin on apoptosis and the inhibition of osteoblast differentiation in MC3T3-E1 cells induced by LPS. Methods: MC3T3-E1 osteoblasts were treated with quercetin for 2 h; cells were then incubated with LPS in the presence of quercetin for the indicated times. Cell viability was measured using the Cell Counting Kit-8 (CCK-8) assay, and cell apoptosis was evaluated using Hoechst 33258 staining. The mRNA expression levels of osteoblast-specific genes, Bax and caspase-3 were determined by real-time quantitative polymerase chain reaction (qPCR). Protein levels of osteoblast-specific genes, caspase-3, Bax, cytochrome c, Bcl-2, Bcl-XL, phosphorylated MAPKs and Wnt/β-catenin were measured using Western blot assays. The MAPK and Wnt/β-catenin signalling pathways were blocked prior to pretreatment with quercetin. Results: Pretreatment with quercetin significantly restored LPS-suppressed bone mineralization and the mRNA and protein expression levels of osteoblast-specific genes such as Osterix (OSX), runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and osteocalcin (OCN) in a dose-dependent manner. Pretreatment with quercetin also inhibited osteoblast apoptosis, significantly restored the down-regulated expression of Bcl-2 and Bcl-XL and decreased the upregulated expression of caspase-3, Bax, and cytochrome c in MC3T3-E1 cells induced by LPS. Furthermore, pretreatment with quercetin not only decreased the abundance of phosphorylated p38 MAPK and increased the abundance of phosphorylated extracellular signal regulated kinase (ERK), but also triggered the Wnt/β-catenin pathway through enhancing expression of Wnt3 and β-catenin. Pretreatment with MAPK inhibitors or the Wnt/β-catenin inhibitor XAV939 blocked the protective effects of quercetin against LPS-induced apoptosis and the inhibition of osteoblast differentiation. Conclusions: Our findings suggest that pretreatment with quercetin may be a potential drug for preventing abnormal human bone loss induced by LPS in bacteria-induced bone diseases.

scholarly journals The Pyridone-Annelated Isoindigo (5‘-Cl) Induces Apoptosis, Dysregulation of Mitochondria and Formation of ROS in Leukemic HL-60 Cells

2015 ◽  
Vol 35 (5) ◽  
pp. 1958-1974 ◽  
Author(s):  
Ayman M. Saleh ◽  
Ahmad Aljada ◽  
Mustafa M. El-Abadelah ◽  
Salim S. Sabri ◽  
Jalal A. Zahra ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Molecular Mechanisms ◽  
Reactive Oxygen ◽  
Pyrrolidine Dithiocarbamate ◽  
Nuclear Staining ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Mitochondrial Functions ◽  
Apoptotic Activity ◽  
Induced Apoptosis

Background/Aims: In our quest to develop an isoindigo with improved efficacy and bioavailability, we recently synthesized a series of novel substituted pyridone-annelated isoindigo and evaluated their antiproliferative effects. We identified the compound [(E)-1-(5'-Chloro-2'-oxoindolin-3'-ylidene)-6-ethyl-2,3,6,9-tetrahydro-2,9-dioxo-1H-pyrrolo[3,2-f] quinoline-8-carboxylic acid], abbreviated as 5'-Cl, which shows selective antiproliferative activities against various cancer cell lines mediated through apoptosis. Here we have investigated the molecular mechanisms underlying the apoptotic activity of 5'-Cl in the human promyelocytic leukemia HL-60 cells. Methods: We employed different methods to determine the apoptotic pathways triggered by 5'-Cl in HL-60 cells, using flow cytometry, nuclear staining, caspases activation, mitochondria functioning, generation of reactive oxygen species (ROS) and Western blotting techniques. Results: Low concentrations (1-8 µM) of 5'-Cl inhibited the growth of HL-60 cells in a dose and time-dependent manner. Cytotoxicity of this compound is found to be mediated by a caspase-dependent apoptosis. Also, there were indications of caspase independent apoptosis as z-VAD-FMK failed to fully rescue the cells from 5‘-Cl-induced apoptosis. In addition, the compound triggered generation of Reactive Oxygen Species (ROS), caused depolarization of the mitochondrial inner membrane, decreased the level of cellular ATP, modulated the expression and phosphorylation of Bcl-2 leading to loss of its association with Bax and increased the release of cytochrome c to the cytosol of treated cells. The effects of 5‘-Cl on mitochondria and apoptosis were substantially blocked in the presence of a combination between z-VAD-FMK and either of the ROS scavenger N-acetyl-L-cysteine (NAC) or pyrrolidine dithiocarbamate (PDTC). Conclusion: We demonstrated that the growth inhibitory effects of 5'-Cl in HL-60 cells involve multiple pathways of apoptosis and dysregulation of mitochondrial functions.

scholarly journals Bufalin Inhibits HCT116 Colon Cancer Cells and Its Orthotopic Xenograft Tumor in Mice Model through Genes Related to Apoptotic and PTEN/AKT Pathways

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jie Wang ◽  
Chao Chen ◽  
Shiying Wang ◽  
Yong Zhang ◽  
Peihao Yin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Growth ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Cultured Cells ◽  
Xenograft Model ◽  
Dependent Manner ◽  
Apoptotic Pathway ◽  
Orthotopic Tumor ◽  
Orthotopic Xenograft

Aims. To investigate the anticolorectal cancer (CRC) effects of Bufalin, a bioactive polyhydroxysteroid from Venenum Bufonis, using HCT116 human CRC cell and an established orthotopic xenograft model in mice, and to explore the mechanisms of action.Material and Methods. Cultured HCT116 cells or BALB/c mice with orthotopic tumor were treated by Bufalin (positive control: 5-FU). Cell proliferation, apoptosis, and cycling were determined by MTT, Annexin V/PI staining, and flow cytometry, respectively. In mice, tumor inhibition rate and animal survival were calculated. The expressions of PTEN/phosphate-PTEN, AKT/phosphate-AKT, Bad, Bcl-xl, Bax, or Caspase-3 in cells and/or tumors were determined by Western blot or immunohistochemical staining.Results. Bufalin significantly inhibited cell proliferation and induced cell apoptosis and cycle arrest in a dose/time-dependent manner. In the animal model, Bufalin treatment resulted in significant inhibition of tumor growth and prolonged survival. In the Bufalin-treated cultured cells and/or xenograft tumors, the expressions of PTEN, Bad, Bax, and Caspase-3 were significantly increased, while p-AKT and Bcl-xL significantly decreased.Conclusions. Our results indicate that Bufalin inhibit cell proliferation and orthotopic tumor growth by inducing cell apoptosis through the intrinsic apoptotic pathway, which is of pivotal significance in the identification of an anticancer drug that may synergize with Bufalin.

Sign in / Sign up

Export Citation Format

Share Document