Project description:Apo2L/TRAIL stimulates cancer-cell death through the proapoptotic receptors DR4 and DR5, but the determinants of tumor susceptibility to this ligand are not fully defined. mRNA expression of the peptidyl O-glycosyl transferase GALNT14 correlated with Apo2L/TRAIL sensitivity in pancreatic carcinoma, non-small cell lung carcinoma and melanoma cell lines (P < 0.00009; n=83), and up to 30% of samples from various human malignancies displayed GALNT14 overexpression. RNA interference of GALNT14 reduced cellular Apo2L/TRAIL sensitivity, whereas overexpression increased responsiveness. Biochemical analysis of DR5 identified several ectodomain O-GalNAc-Gal-Sialic acid structures. Sequence comparison predicted conserved extracellular DR4 and DR5 O-glycosylation sites; progressive mutation of the DR5 sites attenuated apoptosis signaling. O-glycosylation promoted ligand-stimulated clustering of DR4 and DR5, which mediated recruitment and activation of the apoptosis-initiating protease caspase-8. These results uncover a novel link between death receptor O-glycosylation and apoptosis signaling, providing potential predictive biomarkers for Apo2L/TRAIL-based cancer therapy. Keywords: cell type comparison
Project description:Apo2L/TRAIL stimulates cancer-cell death through the proapoptotic receptors DR4 and DR5, but the determinants of tumor susceptibility to this ligand are not fully defined. mRNA expression of the peptidyl O-glycosyl transferase GALNT14 correlated with Apo2L/TRAIL sensitivity in pancreatic carcinoma, non-small cell lung carcinoma and melanoma cell lines (P < 0.00009; n=83), and up to 30% of samples from various human malignancies displayed GALNT14 overexpression. RNA interference of GALNT14 reduced cellular Apo2L/TRAIL sensitivity, whereas overexpression increased responsiveness. Biochemical analysis of DR5 identified several ectodomain O-GalNAc-Gal-Sialic acid structures. Sequence comparison predicted conserved extracellular DR4 and DR5 O-glycosylation sites; progressive mutation of the DR5 sites attenuated apoptosis signaling. O-glycosylation promoted ligand-stimulated clustering of DR4 and DR5, which mediated recruitment and activation of the apoptosis-initiating protease caspase-8. These results uncover a novel link between death receptor O-glycosylation and apoptosis signaling, providing potential predictive biomarkers for Apo2L/TRAIL-based cancer therapy. Experiment Overall Design: Gene expression for untreated cell lines analyzed. Some cell lines have one replicate profile, some two (Samples with 2 CEL files). Normalized data for replicates was averaged. Analysis involved a regularized t-test to identify genes with expression differences between Apo2L sensitive and resistant lines.
Project description:T1 and G1 are the two melanoma cell lines, established from primary tumor (T1) and lymph node metastases (G1) of a 77 years old male patient. While G1 cells were resistant to TRAIL (TNF-related apoptosis-inducing ligand) mediated cell death, T1 cells exhibited a high dose- and time-dependent sensitivity to TRAIL. Cells were treated with or without of two doses (0.2 and 1ug/ml) of TRAIL for 24 h. Gene expression of each sample vs pool was measured. TRAIL-resistant metastatic G1 vs primary TRAIL-sensitive T1 was compared.
Project description:Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to be a potent inducer of apoptosis in various cancer cell lines and primary cancer cells. However, in clinical trials administration of recombinant TRAIL or TRAIL death receptor agonists did not show sufficient efficacy for treatment of tested malignant disorders compared to standard chemotherapy. Acquired resistance of cancer cells to TRAIL and to other “death receptor” ligands may explain not only the inability of TRAIL and TRAIL “death receptor” agonists to achieve the clearance of cancer cells in vivo but also the escape of cancer cells from immune cell – mediated killing. Selective pressure of TRAIL on TRAIL-sensitive Jurkat T-lymphoblastic leukemia cells provided several TRAIL resistant Jurkat cell line clones (TR1, TR2, TR3). Irrespective of molecular changes histone deacetylase inhibitors (HDACi), such as suberoylanilide-hydroxamic acid (SAHA, vorinostat), were able to restore sensitivity of all three TRAIL-resistant clones to TRAIL. Gene expression analysis of TR1 clone treated with SAHA 1microM for 12 hours compared to untreated TR1 clone showed significant decrease in expression of CFLAR/cFLIP (0.71; p=0.006), BIRC5/survivin (0.80; p=0.024) and BID (0.66; p<0.001). Expression of both TRAIL “death” receptors DR4 (1.57; p<0.001) and DR5 (1.47; p=0.002) were significantly increased compared to untreated TR1 cells. The mRNA expression of caspases-2,-3,-8,-9,-10 did not significantly change with the SAHA treatment.
Project description:Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to be a potent inducer of apoptosis in various cancer cell lines and primary cancer cells. However, in clinical trials administration of recombinant TRAIL or TRAIL death receptor agonists did not show sufficient efficacy for treatment of tested malignant disorders compared to standard chemotherapy. Acquired resistance of cancer cells to TRAIL and to other âdeath receptorâ ligands may explain not only the inability of TRAIL and TRAIL âdeath receptorâ agonists to achieve the clearance of cancer cells in vivo but also the escape of cancer cells from immune cell â mediated killing. Selective pressure of TRAIL on TRAIL-sensitive Jurkat T-lymphoblastic leukemia cells provided several TRAIL resistant Jurkat cell line clones (TR1, TR2, TR3). Irrespective of molecular changes histone deacetylase inhibitors (HDACi), such as suberoylanilide-hydroxamic acid (SAHA, vorinostat), were able to restore sensitivity of all three TRAIL-resistant clones to TRAIL. Gene expression analysis of TR1 clone treated with SAHA 1microM for 12 hours compared to untreated TR1 clone showed significant decrease in expression of CFLAR/cFLIP (0.71; p=0.006), BIRC5/survivin (0.80; p=0.024) and BID (0.66; p<0.001). Expression of both TRAIL âdeathâ receptors DR4 (1.57; p<0.001) and DR5 (1.47; p=0.002) were significantly increased compared to untreated TR1 cells. The mRNA expression of caspases-2,-3,-8,-9,-10 did not significantly change with the SAHA treatment. Total cellular RNA was isolated from biologic duplicates of untreated Jurkat cells (WT), TRAIL resistant Jurkat cell clone (TR1) and 1 µM and 0.5 µM suberoylanilide-hydroxamic acid (SAHA, vorinostat) treated TR1 cell clones for 12 hours. Jurkat cell line subclones TR1was established by selective pressure of TRAIL 1000 ng/mL on Jurkat cells over the period of 12 weeks.
Project description:Senescent cells secrete a plethora of factors with potent paracrine signaling capacity. Strikingly, senescence, which acts as a defense against cell transformation, exerts pro-tumorigenic activities through its secretome by promoting numerous tumor-specific features, such as cellular proliferation, epithelial-mesenchymal transition and invasiveness. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has the unique activity of activating cell death exclusively in tumor cells. Given that the senescence-associated secretome supports cell transformation, we asked whether factor(s) of this secretome would establish a program required for the acquisition of TRAIL sensitivity. We found that conditioned media from several types of senescent cells (CMS) efficiently sensitized pre-transformed cells to TRAIL, while the same was not observed with normal or immortalized cells. Dynamic transcription profiling analysis of CMS-exposed pre-transformed cells revealed paracrine autoregulatory loop of senescence-associated secretome factors and a dominant role of CMS-induced MYC. Sensitization to TRAIL coincided with MYC upregulation and massive changes in gene regulation. CMS-induced MYC silenced its target gene CFLAR, encoding the apoptosis inhibitor FLIPL, thus leading to the acquisition of TRAIL sensitivity. Altogether, our results reveal that senescent cell-secreted factors exert a TRAIL sensitizing effect on pre-transformed cells by modulating the expression of MYC and CFLAR. Notably, CMS dose-dependent sensitization to TRAIL was observed with TRAIL-insensitive cancer cells and confirmed in co-culture experiments. Dissection and characterization of TRAIL-sensitizing CMS factors and the associated signaling pathway(s) may provide a mechanistic insight in the acquisition of TRAIL sensitivity and lead to novel concepts for the apoptogenic therapy of pre-malignant and TRAIL-resistant tumors. Pre-transformed BJEL cells were incubated with CMS for 0, 1, 3, 6, 8, 16 or 24 h respectively. Total RNA has been extracted from each time point and used for gene expression analysis (Affymetrix Human Gene 1.0 ST Arrays).
Project description:Understanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH has recently been implicated in poor clinical outcome in breast cancer, neroblastoma, hepatocellular carcinoma and prostate cancer. In this present study, we focused on the therapeutic benefit of MTDH depletion to restore sensitivity to cell death mediated by a combinatorial therapy of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), which promotes death of cancerous cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells results in sensitization of cells that were previously resistant to cell death mediated by combinatorial treatment with TRAIL and HDAC inhibitor LBH589. MTDH was found to be involved in G2/M checkpoint regulation in response to LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance.Using microarray technology, we identified 57 downstream target genes of MTDH, including Calbindin 1 and Galectin 1, which may contribute to MTDH-mediated resistance to combinatorial TRAIL and HDAC inhibitor targeted therapy. Inhibition of PDK1,AKT phosphorylation and increase Bim expression and XIAP degradation may result in sensitivity to cell death induction in MTDH depleted Hec50co cells by TRAIL and LBH 589 combination treatment. These findings indicate that depletion of MTDH is a potentially novel avenue for effective cancer therapy. The microarray was performed on three biological triplicates as well as three experimental triplictes of stable knockdown and control cells. MTDH was knocked down using a shRNA.
Project description:Understanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH has recently been implicated in poor clinical outcome in breast cancer, neroblastoma, hepatocellular carcinoma and prostate cancer. In this present study, we focused on the therapeutic benefit of MTDH depletion to restore sensitivity to cell death mediated by a combinatorial therapy of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), which promotes death of cancerous cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells results in sensitization of cells that were previously resistant to cell death mediated by combinatorial treatment with TRAIL and HDAC inhibitor LBH589. MTDH was found to be involved in G2/M checkpoint regulation in response to LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance.Using microarray technology, we identified 57 downstream target genes of MTDH, including Calbindin 1 and Galectin 1, which may contribute to MTDH-mediated resistance to combinatorial TRAIL and HDAC inhibitor targeted therapy. Inhibition of PDK1,AKT phosphorylation and increase Bim expression and XIAP degradation may result in sensitivity to cell death induction in MTDH depleted Hec50co cells by TRAIL and LBH 589 combination treatment. These findings indicate that depletion of MTDH is a potentially novel avenue for effective cancer therapy. The microarray was performed on three biological triplicates as well as three experimental triplicates of stable knockdown and control cells. MTDH was knocked down using a shRNA.
Project description:Understanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH has recently been implicated in poor clinical outcome in breast cancer, neroblastoma, hepatocellular carcinoma and prostate cancer. In this present study, we focused on the therapeutic benefit of MTDH depletion to restore sensitivity to cell death mediated by a combinatorial therapy of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), which promotes death of cancerous cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells results in sensitization of cells that were previously resistant to cell death mediated by combinatorial treatment with TRAIL and HDAC inhibitor LBH589. MTDH was found to be involved in G2/M checkpoint regulation in response to LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance.Using microarray technology, we identified 57 downstream target genes of MTDH, including Calbindin 1 and Galectin 1, which may contribute to MTDH-mediated resistance to combinatorial TRAIL and HDAC inhibitor targeted therapy. Inhibition of PDK1,AKT phosphorylation and increase Bim expression and XIAP degradation may result in sensitivity to cell death induction in MTDH depleted Hec50co cells by TRAIL and LBH 589 combination treatment. These findings indicate that depletion of MTDH is a potentially novel avenue for effective cancer therapy.
Project description:Understanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH has recently been implicated in poor clinical outcome in breast cancer, neroblastoma, hepatocellular carcinoma and prostate cancer. In this present study, we focused on the therapeutic benefit of MTDH depletion to restore sensitivity to cell death mediated by a combinatorial therapy of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), which promotes death of cancerous cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells results in sensitization of cells that were previously resistant to cell death mediated by combinatorial treatment with TRAIL and HDAC inhibitor LBH589. MTDH was found to be involved in G2/M checkpoint regulation in response to LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance.Using microarray technology, we identified 57 downstream target genes of MTDH, including Calbindin 1 and Galectin 1, which may contribute to MTDH-mediated resistance to combinatorial TRAIL and HDAC inhibitor targeted therapy. Inhibition of PDK1,AKT phosphorylation and increase Bim expression and XIAP degradation may result in sensitivity to cell death induction in MTDH depleted Hec50co cells by TRAIL and LBH 589 combination treatment. These findings indicate that depletion of MTDH is a potentially novel avenue for effective cancer therapy.