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1.
Cell Death Dis ; 9(10): 952, 2018 09 20.
Article in English | MEDLINE | ID: mdl-30237496

ABSTRACT

Chronic pancreatitis (CP) is described as a progressive fibro-inflammatory disorder of the exocrine disease, which eventually leads to damage of the gland. Excessive activation of pancreatic stellate cells (PSCs) is a critical participant in the initiation of CP. Autophagy is involved in multiple degeneration and inflammation in acute pancreatitis and CP. In our study, we report that retinoblastoma coiled coil protein 1 (RB1CC1) expression and the autophagic level are elevated in activated PSCs. RB1CC1 is positively correlated with pancreatic fibrogenesis in tissues and plasma of CP patients. Knockdown of RB1CC1 restrains alpha smooth muscle actin (α-SMA) and collagen expressions, and autophagy in activated PSCs in vitro. Furthermore, we show that RB1CC1 induces PSC activation via binding to ULK1 promoter and the direct interaction with ULK1 protein. These suppress ULK1 expression and its kinase activity. In mice, knockdown of RB1CC1 blocks autophagy and then inhibits the pancreatic duct ligation-induced pancreatic fibrosis. Consequently, our study highlights that RB1CC1-mediated autophagy is a key event for the activation of PSCs. Inhibition of RB1CC1 alleviates autophagy, which plays a critical role in anti-fibrotic activation in PSCs and CP progression. RB1CC1 could be a novel strategy for the treatment of pancreatic fibrosis.


Subject(s)
Autophagy/physiology , Intracellular Signaling Peptides and Proteins/metabolism , Pancreas/metabolism , Pancreas/pathology , Pancreatic Stellate Cells/cytology , Pancreatic Stellate Cells/metabolism , Pancreatitis, Chronic/metabolism , Pancreatitis, Chronic/pathology , Protein-Tyrosine Kinases/metabolism , Animals , Autophagy/genetics , Autophagy-Related Proteins , Blotting, Western , Cells, Cultured , Electrophoretic Mobility Shift Assay , Fibrosis/metabolism , Fibrosis/pathology , Fluorescent Antibody Technique , Humans , Immunohistochemistry , Intracellular Signaling Peptides and Proteins/genetics , Male , Mice , Mice, Inbred C57BL , Pancreatitis, Chronic/genetics , Protein-Tyrosine Kinases/genetics
2.
Oncol Lett ; 15(1): 940-946, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29399156

ABSTRACT

Piwi-interacting RNAs (piRNAs/piRs) are small non-coding RNAs that can serve important roles in genome stability by silencing transposable genetic elements. piR651, one of these novel piRNAs, regulates a number of biological functions, as well as carcinogenesis. Previous studies have reported that piR651 is overexpressed in human gastric cancer tissues and in several cancer cell lines, including non-small cell lung cancer (NSCLC) cell lines. However, the role of piRNAs in carcinogenesis has not been clearly defined. In the present study, a small interfering RNA inhibitor of piR651 was transfected into the NSCLC A549 and HCC827 cell lines to evaluate the effect of piR651 on cell growth. The association between piR651 expression and apoptosis was evaluated by flow cytometry and western blot analysis. Wound-healing and Transwell migration and invasion assays were used to determine the effect of piR651 on the migration and invasion of NSCLC cell lines. The results revealed that inhibition of piR651 inhibited cell proliferation and significantly increased the apoptotic rate compared with the negative control (NC), as well as altering the expression of apoptosis-associated proteins. There were fewer migrating and invading cells in the piR651-inhibited group than in the NC group in the Transwell assays. Furthermore, in the wound-healing assay, the wound remained wider in the piR651 inhibitor group, suggesting decreased cell migration compared with that in the NC group. The results of the present study demonstrate that piR651 potentially regulates NSCLC tumorigenic behavior by inhibiting cell proliferation, migration and invasion and by inducing apoptosis. Therefore, piR651 is a potential cancer diagnosis marker.

3.
Oncotarget ; 7(44): 71773-71781, 2016 Nov 01.
Article in English | MEDLINE | ID: mdl-27708234

ABSTRACT

Long intergenic non-protein coding RNA, p53 induced transcript (Linc-pint) is a long noncoding RNA (lncRNA) that regulates tumor cell viability and proliferation. We used qRT-PCR and RNA FISH analysis to evaluate Linc-pint levels in the plasma and tumor tissues of pancreatic cancer (PCa) patients. Our data demonstrate that Linc-pint expression is lower in plasma samples from PCa patients than from healthy individuals, and indicate that plasma Linc-pint levels are more sensitive than CA19-9 for detecting PCa. Our data also show that Linc-pint levels are lower in PCa tumors than in adjacent tissues, carcinoma of the ampulla of Vater (CAV) and cholangiocarcinoma (CCA), and suggest that Linc-pint could be used for distinguishing the cause of malignant obstructive jaundice. Low plasma Linc-pint levels correlate with tumor recurrence, while low tumor Linc-pint levels correlate with poor prognosis for PCa patients after pancreatectomy. These results thus indicate that low plasma Linc-pint expression could serve as a minimally invasive biomarker for early PCa detection, and that low Linc-pint levels in PCa tumors could be used for predicting patient prognosis.


Subject(s)
Biomarkers, Tumor/analysis , Pancreatic Neoplasms/diagnosis , RNA, Long Noncoding/analysis , Adult , Aged , CA-19-9 Antigen/blood , Female , Humans , Male , Middle Aged , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Prognosis , RNA, Long Noncoding/blood
4.
Sci Rep ; 6: 32167, 2016 08 30.
Article in English | MEDLINE | ID: mdl-27571770

ABSTRACT

A synthetic monoketone analog of curcumin, termed 3, 5-bis (2-flurobenzylidene) piperidin-4-one (EF24), has been reported to inhibit the growth of a variety of cancer cells both in vitro and in vivo. However, whether EF24 has anticancer effects on cholangiocarcinoma (CCA) cells and the mechanisms remain to be investigated. The aim of our study was to evaluate the molecular mechanisms underlying the anticancer effects of EF24 on CCA tumor growth and metastasis. Cell proliferation, apoptosis, migration, invasion, tumorigenesis and metastasis were examined. EF24 exhibited time- and dose-dependent inhibitory effects on HuCCT-1, TFK-1 and HuH28 human CCA cell lines. EF24 inhibited CCA cell proliferation, migration, and induced G2/M phase arrest. EF24 induced cell apoptosis along with negative regulation of NF-κB- X-linked inhibitor of apoptosis protein (XIAP) signaling pathway. XIAP inhibition by lentivirus mediated RNA interference enhanced EF24-induced apoptosis, while XIAP overexpression reduced it in CCA cells. In vivo, EF24 significantly suppressed the growth of CCA tumor xenografts and tumor metastasis while displaying low toxicity levels. Our findings indicate that EF24 is a potent antitumor agent that inhibits tumor growth and metastasis by inhibiting NF-κB dependent signaling pathways. EF24 may represent a novel approach for CCA treatment.


Subject(s)
Benzylidene Compounds/pharmacology , Cholangiocarcinoma/drug therapy , G2 Phase Cell Cycle Checkpoints/drug effects , M Phase Cell Cycle Checkpoints/drug effects , NF-kappa B/metabolism , Neoplasm Proteins/metabolism , Piperidones/pharmacology , Signal Transduction/drug effects , Apoptosis/drug effects , Apoptosis/genetics , Cell Line, Tumor , Cell Movement/drug effects , Cell Movement/genetics , Cholangiocarcinoma/genetics , Cholangiocarcinoma/metabolism , Cholangiocarcinoma/pathology , G2 Phase Cell Cycle Checkpoints/genetics , Humans , M Phase Cell Cycle Checkpoints/genetics , NF-kappa B/genetics , Neoplasm Metastasis , Neoplasm Proteins/genetics , Signal Transduction/genetics
5.
Mol Cancer Ther ; 15(9): 2232-43, 2016 09.
Article in English | MEDLINE | ID: mdl-27371730

ABSTRACT

Recently, pancreatic ductal adenocarcinoma (PDAC) has emerged as one of the most aggressive malignant tumors with the worst prognosis. Previous studies have demonstrated that long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is increased in pancreatic cancer and is identified as a diagnostic biomarker. Nonetheless, the molecular mechanism of elevated MALAT1 levels and tumor aggressiveness remains unknown. In this study, MALAT1 was found to be highly expressed in PDAC tissues, and elevated expression was associated with poorer prognoses. In addition, MALAT1 was positively linearly correlated with the expression of LC3B mRNA. Furthermore, several molecules involved in cellular autophagic flux were modulated following the downregulation of MALAT1, including LC3, P62, and LAMP-2. Mechanistically, we found that MALAT1 interacted with RNA binding protein HuR, and silencing of MALAT1 greatly enhanced the posttranscriptional regulation of TIA-1 and had further effects on inhibiting autophagy. MALAT1 was speculated to regulate tumorigenesis via HuR-TIA-1-mediated autophagic activation. Hence, we investigated the biological properties of MALAT1 in terms of tumor proliferation and metastasis by promoting autophagy in vitro In brief, these data demonstrate that MALAT1 could facilitate the advanced progression of tumors in vivo Our study highlights the new roles of MALAT1 on protumorigenic functioning and anticancer therapy via activating autophagy in pancreatic cancer. Mol Cancer Ther; 15(9); 2232-43. ©2016 AACR.


Subject(s)
Autophagy/genetics , Gene Expression Regulation, Neoplastic , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , RNA, Long Noncoding/genetics , Animals , Cell Line, Tumor , Cell Proliferation , Disease Models, Animal , ELAV-Like Protein 1/genetics , Female , Gene Silencing , Humans , Mice , Neoplasm Metastasis , Pancreatic Neoplasms/mortality , Poly(A)-Binding Proteins/genetics , Prognosis , RNA Interference , T-Cell Intracellular Antigen-1 , Xenograft Model Antitumor Assays
6.
PLoS One ; 11(4): e0154483, 2016.
Article in English | MEDLINE | ID: mdl-27115738

ABSTRACT

Acute pancreatitis (AP) is an inflammatory disease mediated by damage to acinar cells and pancreatic inflammation. In patients with AP, subsequent systemic inflammatory responses and multiple organs dysfunction commonly occur. Interactions between cytokines and oxidative stress greatly contribute to the amplification of uncontrolled inflammatory responses. Molecular hydrogen (H2) is a potent free radical scavenger that not only ameliorates oxidative stress but also lowers cytokine levels. The aim of the present study was to investigate the protective effects of H2 gas on AP both in vitro and in vivo. For the in vitro assessment, AR42J cells were treated with cerulein and then incubated in H2-rich or normal medium for 24 h, and for the in vivo experiment, AP was induced through a retrograde infusion of 5% sodium taurocholate into the pancreatobiliary duct (0.1 mL/100 g body weight). Wistar rats were treated with inhaled air or 2% H2 gas and sacrificed 12 h following the induction of pancreatitis. Specimens were collected and processed to measure the amylase and lipase activity levels; the myeloperoxidase activity and production levels; the cytokine mRNA expression levels; the 8-hydroxydeoxyguanosine, malondialdehyde, and glutathione levels; and the cell survival rate. Histological examinations and immunohistochemical analyses were then conducted. The results revealed significant reductions in inflammation and oxidative stress both in vitro and in vivo. Furthermore, the beneficial effects of H2 gas were associated with reductions in AR42J cell and pancreatic tissue damage. In conclusion, our results suggest that H2 gas is capable of ameliorating damage to the pancreas and AR42J cells and that H2 exerts protective effects both in vitro and in vivo on subjects with AP. Thus, the results obtained indicate that this gas may represent a novel therapy agent in the management of AP.


Subject(s)
Ceruletide/adverse effects , Hydrogen/administration & dosage , Oxidative Stress/drug effects , Pancreatitis/drug therapy , Taurocholic Acid/adverse effects , Amylases/metabolism , Animals , Cell Line , Cell Survival/drug effects , Cytokines/genetics , Disease Models, Animal , Gene Expression Regulation/drug effects , Hydrogen/pharmacology , Lipase/metabolism , Male , Mice , Pancreatitis/chemically induced , Pancreatitis/enzymology , Rats
7.
Int Urol Nephrol ; 48(2): 175-81, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26560472

ABSTRACT

OBJECTIVES: We investigated the possible involvement of multidrug resistance protein 1 P-glycoprotein (MDR1 P-gp) in the oxalate-induced redistribution of phosphatidylserine in renal epithelial cell membranes. METHODS: Real-time PCR and western blotting were used to examine MDR1 expression in Madin-Darby canine kidney cells at the mRNA and protein levels, respectively, whereas surface-expressed phosphatidylserine was detected by the annexin V-binding assay. RESULTS: Oxalate treatment resulted in increased synthesis of MDR1, which resulted in phosphatidylserine (PS) externalization in the renal epithelial cell membrane. Treatment with the MDR1 inhibitor PSC833 significantly attenuated phosphatidylserine externalization. Transfection of the human MDR1 gene into renal epithelial cells significantly increased PS externalization. CONCLUSIONS: To our knowledge, this study is the first to show that oxalate increases the synthesis of MDR1 P-gp, which plays a key role in hyperoxaluria-promoted calcium oxalate urolithiasis by facilitating phosphatidylserine redistribution in renal epithelial cells.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Gene Expression Regulation , Nephrolithiasis/genetics , Oxalates/adverse effects , Phosphatidylserines/metabolism , RNA, Messenger/genetics , Urothelium/metabolism , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Animals , Blotting, Western , Cell Membrane/metabolism , Cell Membrane/pathology , Cells, Cultured , Cyclosporins/pharmacology , Dogs , Drug Resistance, Multiple , Flow Cytometry , Humans , Nephrolithiasis/drug therapy , Nephrolithiasis/metabolism , Phosphatidylserines/antagonists & inhibitors , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Urothelium/drug effects , Urothelium/pathology
8.
Inflammation ; 39(2): 651-62, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26627481

ABSTRACT

Artesunate, a derivative of artemisinin, has anti-inflammatory properties and exerts protective roles in sepsis. Heme oxygense-1 (HO-1) inhibits the inflammatory response through reduction of proinflammatory cytokines and leukocyte influx into tissues. The present study investigated the effects of artesunate on HO-1 and septic lung injury. Cecal ligation and puncture (CLP) was employed to induce septic lung injury. Mice pretreated with artesunate (AS) (15 mg/kg) exhibited decreased sepsis-induced mortality and lung injury and alleviated lung pathological changes and neutrophil infiltration. In addition, AS lowered the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the serum and bronchoalveolar lavage fluid (BALF) and inhibited cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase isoform (iNOS) expression and NF-κB activation in lung tissue. In addition, AS enhanced NF-E2-related factor-2 (Nrf2) activation and HO-1 expression and enzymatic activity in lung tissue. However, the protective effects of AS on sepsis-induced lung injury were eliminated by ZnPP IX, an HO-1 competitive inhibitor. Therefore, AS plays protective roles in septic lung injury related to the upregulation of HO-1. These findings suggest an effective and applicable treatment to sepsis-induced lung injury and provide new insights into the molecular mechanisms and actions of AS.


Subject(s)
Acute Lung Injury/prevention & control , Anti-Inflammatory Agents/pharmacology , Artemisinins/therapeutic use , Enzyme Activation/drug effects , Heme Oxygenase-1/metabolism , Neutrophil Infiltration/drug effects , Sepsis/drug therapy , Acute Lung Injury/metabolism , Animals , Artesunate , Bronchoalveolar Lavage Fluid/chemistry , Cecum/surgery , Cyclooxygenase 2/biosynthesis , Heme Oxygenase-1/antagonists & inhibitors , Interleukin-6/blood , Interleukin-6/metabolism , Lung/pathology , Male , Mice , NF-E2-Related Factor 2/metabolism , NF-kappa B/metabolism , Nitric Oxide Synthase Type II/biosynthesis , Protoporphyrins/pharmacology , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/blood , Tumor Necrosis Factor-alpha/metabolism
9.
Int Immunopharmacol ; 20(1): 24-32, 2014 May.
Article in English | MEDLINE | ID: mdl-24583148

ABSTRACT

NLRP3 inflammasome activation contributes to acute lung injury (ALI), accelerating caspase-1 maturation, and resulting in IL-1ß and IL-18 over-production. Heme oxygenase-1 (HO-1) plays a protective role in ALI. This study investigated the effect of hemin (a potent HO-1 inducer) on NLRP3 inflammasome in sepsis-induced ALI. The sepsis model of cecal ligation and puncture (CLP) was used in C57BL6 mice. In vivo induction and suppression of HO-1 were performed by pretreatment with hemin and zinc protoporphyrin IX (ZnPP, a HO-1 competitive inhibitor) respectively. CLP triggered significant pulmonary damage, neutrophil infiltration, increased levels of IL-1ß and IL-18, and edema formation in the lung. Hemin pretreatment exerted inhibitory effect on lung injury and attenuated IL-1ß and IL-18 secretion in serum and lung tissue. In lung tissues, hemin down-regulated mRNA and protein levels of NLRP3, ASC and caspase-1. Moreover, hemin reduced malondialdehyde and reactive oxygen species production, and inhibited NF-κB and NLRP3 inflammasome activity. Meanwhile, hemin significantly increased HO-1 mRNA and protein expression and HO-1 enzymatic activity. In contrast, no significant differences were observed between the CLP and ZnPP groups. Our study suggests that hemin-inhibited NLRP3 inflammasome activation involved HO-1, reducing IL-1ß and IL-18 secretion and limiting the inflammatory response.


Subject(s)
Acute Lung Injury/immunology , Carrier Proteins/immunology , Hemin/pharmacology , Inflammasomes/immunology , Sepsis/immunology , Acute Lung Injury/etiology , Acute Lung Injury/pathology , Animals , Apoptosis Regulatory Proteins/genetics , CARD Signaling Adaptor Proteins , Carrier Proteins/genetics , Caspase 1/genetics , Heme Oxygenase-1/immunology , Interleukin-18/blood , Interleukin-18/immunology , Interleukin-1beta/blood , Interleukin-1beta/immunology , Lung/drug effects , Lung/immunology , Lung/pathology , Male , Malondialdehyde/immunology , Membrane Proteins/immunology , Mice, Inbred C57BL , NF-kappa B/immunology , NLR Family, Pyrin Domain-Containing 3 Protein , Peroxidase/immunology , RNA, Messenger/metabolism , Reactive Oxygen Species/immunology , Sepsis/complications , Sepsis/pathology
10.
J Exp Clin Cancer Res ; 33: 8, 2014 Jan 18.
Article in English | MEDLINE | ID: mdl-24438216

ABSTRACT

BACKGROUND: c-Jun NH2-terminal kinases (JNKs) are strongly activated by a stressful cellular environment, such as chemotherapy and oxidative stress. Autophagy is a protein-degradation system in which double-membrane vacuoles called autophagosomes are formed. The autophagy-related gene Beclin 1 plays a key role in this process. We previously found that autophagy was induced by dihydroartemisinin (DHA) in pancreatic cancer cells. However, little is known about the complex relationship between ROS, JNK activation, autophagy induction, and Beclin 1 expression. METHODS: Cell viability and CCK-8 assays were carried out to determine the cell proliferation; small interfering RNAs (siRNAs) were used to knockdown c-Jun NH2-terminal kinases (JNK1/2) genes; western blot was performed to detect the protein expression of LC3, JNK, Beclin 1, caspase 3 and ß-actin; production of intracellular ROS was analyzed using FACS flow cytometry; autophagy induction was confirmed by electron microscopy. RESULTS: In the present study, we explored the role of DHA and Beclin 1 expression in autophagy. DHA-treated cells showed autophagy characteristics, and DHA also activated the JNK pathway and up-regulated the expression of Beclin 1. Conversely, blocking JNK signaling inhibited Beclin 1 up-regulation. JNK activation was found to primarily depend on reactive oxygen species (ROS) resulting from the DHA treatment. Moreover, JNK pathway inhibition and Beclin 1 silencing prevented the induction of DHA-induced autophagy. CONCLUSIONS: These results suggest that the induction of autophagy by DHA is required for JNK-mediated Beclin 1 expression.


Subject(s)
Antineoplastic Agents/pharmacology , Artemisinins/pharmacology , Autophagy , JNK Mitogen-Activated Protein Kinases/metabolism , Apoptosis , Apoptosis Regulatory Proteins/metabolism , Beclin-1 , Caspase 3/metabolism , Cell Line, Tumor , Drug Screening Assays, Antitumor , Enzyme Activation , Humans , Membrane Proteins/metabolism , Pancreatic Neoplasms , Phosphorylation , Protein Processing, Post-Translational/drug effects , Reactive Oxygen Species/metabolism
11.
Autophagy ; 9(3): 272-7, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23343748

ABSTRACT

T1D (type 1 diabetes) is an autoimmune disease characterized by lymphocytic infiltration, or inflammation in pancreatic islets called 'insulitis.' Comparatively speaking, T2D (type 2 diabetes) is traditionally characterized by insulin resistance and islet ß cell dysfunction; however, a number of studies have clearly demonstrated that chronic tissue inflammation is a key contributing factor to T2D. The NLR (Nod-like receptor) family of innate immune cell sensors such as the NLRP3 inflammasome are implicated in leading to CASP1 activation and subsequent IL1B (interleukin 1, ß) and IL18 secretion in T2D. Recent developments reveal a crucial role for the autophagy pathway under conditions of oxidative stress and inflammation. Increasingly, research on autophagy has begun to focus on its role in interacting with inflammatory processes, and thereby how it potentially affects the outcome of disease progression. In this review, we explore the pathophysiological pathways associated with oxidative stress and inflammation in T2D. We also explore how autophagy influences glucose homeostasis by modulating the inflammatory response. We will provide here a perspective on the current research between autophagy, inflammation and T2D.


Subject(s)
Autophagy , Diabetes Mellitus, Type 1/physiopathology , Diabetes Mellitus, Type 2/physiopathology , Inflammation/physiopathology , Oxidative Stress , Animals , Carrier Proteins/metabolism , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 2/metabolism , Humans , Insulin Resistance , Insulin-Secreting Cells/cytology , Insulin-Secreting Cells/pathology , NLR Family, Pyrin Domain-Containing 3 Protein , Obesity/physiopathology
12.
Oncol Lett ; 4(6): 1315-1320, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23205129

ABSTRACT

Fibrosarcoma is a malignant soft tissue tumor of mesenchymal origin. Despite advances in medical and surgical treatment, patient survival rates have remained poor. According to the cancer stem cell hypothesis, tumors are comprised of heterogeneous cell populations that have different roles in tumor formation and growth. Cancer stem cells are a small cell subpopulation that exhibits stem-like properties to gain aggressiveness and recurrence. These cells have been identified in a variety of cancerous tumors, but not in human fibrosarcoma. In this study, we observed that HT1080 cells and primary fibrosarcoma cells formed spheres and showed higher self-renewal capacity, invasiveness and drug resistance compared with their adherent counterparts. Moreover, we demonstrated that the cells showed higher expression of the embryonic stem cell-related genes Nanog, Oct3/4, Sox2, Sox10 and their encoding proteins, as well as greater tumorigenic capacity in nude mice. In conclusion, our data suggest the presence of a stem-like cell population in human fibrosarcoma tumors, which provides more evidence for the cancer stem cell hypothesis and assistance in designing new therapeutic strategies against human fibrosarcoma.

13.
PLoS One ; 7(5): e37222, 2012.
Article in English | MEDLINE | ID: mdl-22666346

ABSTRACT

BACKGROUND: Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has recently shown antitumor activity in various cancer cells. Apo2 ligand or tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) is regarded as a promising anticancer agent, but chemoresistance affects its efficacy as a treatment strategy. Apoptosis induced by the combination of DHA and Apo2L/TRAIL has not been well documented, and the mechanisms involved remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that DHA enhances the efficacy of Apo2L/TRAIL for the treatment of pancreatic cancer. We found that combined therapy using DHA and Apo2L/TRAIL significantly enhanced apoptosis in BxPC-3 and PANC-1 cells compared with single-agent treatment in vitro. The effect of DHA was mediated through the generation of reactive oxygen species, the induction of death receptor 5 (DR5) and the modulation of apoptosis-related proteins. However, N-acetyl cysteine significantly reduced the enhanced apoptosis observed with the combination of DHA and Apo2L/TRAIL. In addition, knockdown of DR5 by small interfering RNA also significantly reduced the amount of apoptosis induced by DHA and Apo2L/TRAIL. CONCLUSIONS/SIGNIFICANCE: These results suggest that DHA enhances Apo2L/TRAIL-mediated apoptosis in human pancreatic cancer cells through reactive oxygen species-mediated up-regulation of DR5.


Subject(s)
Apoptosis/drug effects , Artemisinins/pharmacology , Pancreatic Neoplasms/pathology , Reactive Oxygen Species/metabolism , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , TNF-Related Apoptosis-Inducing Ligand/metabolism , Up-Regulation/drug effects , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Receptors, TNF-Related Apoptosis-Inducing Ligand/genetics
14.
Autophagy ; 8(2): 158-64, 2012 Feb 01.
Article in English | MEDLINE | ID: mdl-22258092

ABSTRACT

In pancreatic ß-cells, the endoplasmic reticulum (ER) is the crucial site for insulin biosynthesis, as this is where the protein-folding machinery for secretory proteins is localized. Perturbations to ER function of the ß-cell, such as those caused by high levels of free fatty acid and insulin resistance, can lead to an imbalance in protein homeostasis and ER stress, which has been recognized as an important mechanism for type 2 diabetes. Macroautophagy (hereafter referred to as autophagy) is activated as a novel signaling pathway in response to ER stress. In this review, we outline the mechanism of ER stress-mediated ß-cell death and focus on the role of autophagy in ameliorating ER stress. The development of drugs to take advantage of the potential protective effect of autophagy in ER stress, such as glucagon like peptide-1, will be a promising avenue of investigation.


Subject(s)
Autophagy , Endoplasmic Reticulum Stress , Insulin-Secreting Cells/pathology , Animals , Apoptosis , Diabetes Mellitus, Type 2/pathology , Diabetes Mellitus, Type 2/therapy , Humans , Insulin-Secreting Cells/metabolism , Models, Biological
15.
J Cancer Res Clin Oncol ; 138(5): 785-97, 2012 May.
Article in English | MEDLINE | ID: mdl-22270965

ABSTRACT

PURPOSE: Pancreatic cancer is an aggressive malignancy, which generally develops resistance to chemotherapy. Agents that are safe and can sensitize cancer to chemotherapy are urgently needed. Escin, a natural mixture of triterpene saponins isolated from Aesculus wilsonii Rehd, has been demonstrated to possess anti-cancer activity both in vitro and in vivo. The anti-cancer activity of escin could be, in part, due to the inactivation of nuclear factor-κB (NF-κB). In contrast, chemotherapy including gemcitabine could activate NF-κB and lead to chemoresistance. Here, for the first time, we investigated whether escin, via the inactivation of NF-κB, would potentiate the antitumor activity of gemcitabine in pancreatic cancer. METHODS: Cell viability and proliferation, apoptosis, NF-κB activity and the expression of NF-κB-linked genes were all examined in vitro. The antitumor effect of escin with or without gemcitabine in pancreatic cancer was also assessed using BxPC-3 xenografts subcutaneously established in BALB/c nude mice. RESULTS: Escin not only potentiated the proliferation-inhibiting and apoptosis-inducing effect of gemcitabine in both BxPC-3 and PANC-1 cell lines in vitro, but also dramatically enhanced its suppressive effect on tumor growth in nude mice. The mechanism is at least partially due to the inhibition of NF-κB activity and consequent inhibition of c-Myc, COX-2, Cyclin D1, Survivin, Bcl-2 and Bcl-xL, and the activation of caspase-3. CONCLUSION: These data suggest that escin, via inactivation of NF-κB, could potentiate the efficacy of gemcitabine in combating pancreatic cancer, which could be a novel and potentially important therapeutic approach for the treatment for pancreatic cancer.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma/drug therapy , Deoxycytidine/analogs & derivatives , Escin/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , NF-kappa B/physiology , Pancreatic Neoplasms/drug therapy , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Carcinoma/genetics , Carcinoma/pathology , Deoxycytidine/administration & dosage , Deoxycytidine/pharmacology , Down-Regulation/drug effects , Down-Regulation/genetics , Drug Synergism , Escin/administration & dosage , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Models, Biological , NF-kappa B/genetics , NF-kappa B/metabolism , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Tumor Cells, Cultured , Xenograft Model Antitumor Assays , Gemcitabine
16.
PLoS One ; 6(8): e23752, 2011.
Article in English | MEDLINE | ID: mdl-21887310

ABSTRACT

BACKGROUND: Epithelial to mesenchymal transition (EMT) induced by hypoxia is one of the critical causes of treatment failure in different types of human cancers. NF-κB is closely involved in the progression of EMT. Compared with HIF-1α, the correlation between NF-κB and EMT during hypoxia has been less studied, and although the phenomenon was observed in the past, the molecular mechanisms involved remained unclear. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α) promotes EMT in pancreatic cancer cells. On molecular or pharmacologic inhibition of NF-κB, hypoxic cells regained expression of E-cadherin, lost expression of N-cadherin, and attenuated their highly invasive and drug-resistant phenotype. Introducing a pcDNA3.0/HIF-1α into pancreatic cancer cells under normoxic conditions heightened NF-κB activity, phenocopying EMT effects produced by hypoxia. Conversely, inhibiting the heightened NF-κB activity in this setting attenuated the EMT phenotype. CONCLUSIONS/SIGNIFICANCE: These results suggest that hypoxia or overexpression of HIF-1α induces the EMT that is largely dependent on NF-κB in pancreatic cancer cells.


Subject(s)
Epithelial-Mesenchymal Transition , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Hypoxia/metabolism , NF-kappa B/physiology , Pancreatic Neoplasms/pathology , Cadherins , Cell Line, Tumor , Gene Expression , Humans , Hypoxia/complications , Hypoxia-Inducible Factor 1, alpha Subunit/administration & dosage , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Pancreatic Neoplasms/metabolism , Phenotype , Tumor Cells, Cultured
17.
J Urol ; 186(3): 1114-20, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21784463

ABSTRACT

PURPOSE: We evaluated the possible involvement of phospholipid transporters and reactive oxygen species in the oxalate induced redistribution of renal epithelial cell phosphatidylserine. MATERIALS AND METHODS: Madin-Darby canine kidney cells were labeled with the fluorescent phospholipid NBD-PS in the inner or outer leaflet of the plasma membrane and then exposed to oxalate in the presence or absence of antioxidant. This probe was tracked using a fluorescent quenching assay to assess the bidirectional transmembrane movement of phosphatidylserine. Surface expressed phosphatidylserine was detected by annexin V binding assay. The cell permeable fluorogenic probe DCFH-DA was used to measure the intracellular reactive oxygen species level. RESULTS: Oxalate produced a time and concentration dependent increase in phosphatidylserine, which may have resulted from impaired aminophospholipid translocase mediated, inward directed phosphatidylserine transport and from enhanced phosphatidylserine outward transport. Adding the antioxidant N-acetyl-L-cysteine significantly attenuated phosphatidylserine externalization by effectively rescuing aminophospholipid translocase activity. CONCLUSIONS: To our knowledge our findings are the first to show that oxalate induced increased reactive oxygen species generation impairs aminophospholipid translocase activity and decreased aminophospholipid translocase activity has a role in hyperoxaluria promoted calcium oxalate urolithiasis by facilitating phosphatidylserine redistribution in renal epithelial cells.


Subject(s)
Calcium Oxalate/metabolism , Epithelial Cells/metabolism , Kidney/cytology , Oxidative Stress , Phospholipid Transfer Proteins/metabolism , Urolithiasis/etiology , Animals , Cells, Cultured , Dogs
18.
Cancer Chemother Pharmacol ; 68(6): 1421-30, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21479633

ABSTRACT

PURPOSE: Dihydroartemisinin (DHA) has recently shown antitumor activity in human pancreatic cancer cells. However, its effect on antiangiogenic activity in pancreatic cancer is unknown, and the mechanism is unclear. This study was aimed to investigate whether DHA would inhibit angiogenesis in human pancreatic cancer. METHODS: Cell viability and proliferation, tube formation of human umbilical vein endothelial cells (HUVECs), nuclear factor (NF)-κB DNA-binding activity, expressions of vascular endothelial growth factor (VEGF), interleukin (IL)-8, cyclooxygenase (COX)-2, and matrix metalloproteinase (MMP)-9 were examined in vitro. The effect of DHA on antiangiogenic activity in pancreatic cancer was also assessed using BxPC-3 xenografts subcutaneously established in BALB/c nude mice. RESULTS: DHA inhibited cell proliferation and tube formation of HUVECs in a time- and dose-dependent manner and also reduced cell viability in pancreatic cancer cells. DHA significantly inhibited NF-κB DNA-binding activity, so as to tremendously decrease the expression of NF-κB-targeted proangiogenic gene products: VEGF, IL-8, COX-2, and MMP-9 in vitro. In vivo studies, DHA remarkably reduced tumor volume, decreased microvessel density, and down-regulated the expression of NF-κB-related proangiogenic gene products. CONCLUSIONS: Inhibition of NF-κB activation is one of the mechanisms that DHA inhibits angiogenesis in human pancreatic cancer. We also suggest that DHA could be developed as a novel agent against pancreatic cancer.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Artemisinins/pharmacology , NF-kappa B/antagonists & inhibitors , Neovascularization, Pathologic/prevention & control , Pancreatic Neoplasms/drug therapy , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Endothelial Cells/drug effects , Humans , Male , Mice , Pancreatic Neoplasms/blood supply
19.
J Gastroenterol Hepatol ; 26(1): 186-93, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21175813

ABSTRACT

BACKGROUND AND AIM: More and more microRNA (miRNA) are found to be involved in tumor genesis and progress. Arsenic trioxide has been an effective chemotherapeutic drug in cancer therapy for many years. In this study, we aimed to find the miRNA involved in the mechanisms of arsenic trioxide treatment in cancer therapy. METHODS: We detected the expression profile of miRNA by miRNA microarray and quantitative real-time polymerase chain reaction. Cell viability assay, flow cytometry analysis, prediction of miRNA targets, Western blot analysis and luciferase reporter assay were carried out to determine the role of one selected miRNA, namely mir-29a, in affecting the biological behaviors of HepG-2 cells. RESULTS: Among the 677 human miRNA in the microarray, five miRNA were upregulated and four were downregulated in HepG-2 cells treated with arsenic trioxide compared to their controls. If only changes above two folds were considered, four miRNA were identified, namely miR-24, miR-29a, miR-30a and miR-210, which were all upregulated. Among them, miR-29a showed a positive therapeutic effect in liver cancer cells by inhibiting cell growth and inducing cell apoptosis, and PPM1D was confirmed to be the target gene of miR-29a. Furthermore, a synergy effect was detected between miR-29a and arsenic trioxide. CONCLUSIONS: Arsenic trioxide altered miRNA expression profile in HepG-2 cells. Among the altered miRNA, miR-29a seemed to take a role in the mechanism of arsenic trioxide in liver cancer therapy. The synergy effect between miR-29a and arsenic trioxide may offer this drug a new chance in cancer therapy by decreasing its dose and toxic side-effects.


Subject(s)
Antineoplastic Agents/pharmacology , Arsenicals/pharmacology , Carcinoma, Hepatocellular/genetics , Gene Expression Regulation, Neoplastic/drug effects , Liver Neoplasms/genetics , MicroRNAs/metabolism , Oxides/pharmacology , Apoptosis/drug effects , Arsenic Trioxide , Blotting, Western , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Flow Cytometry , Gene Expression Profiling/methods , Genes, Reporter , Hep G2 Cells , Humans , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Oligonucleotide Array Sequence Analysis , Phosphoprotein Phosphatases/genetics , Phosphoprotein Phosphatases/metabolism , Protein Phosphatase 2C , Reverse Transcriptase Polymerase Chain Reaction , Transfection
20.
Zhonghua Wai Ke Za Zhi ; 48(12): 924-8, 2010 Jun 15.
Article in Chinese | MEDLINE | ID: mdl-21055229

ABSTRACT

OBJECTIVE: To study the protective function and pathophysiology of cystathionine gamma-lyase (CSE)/hydrogen sulfide (H(2)S) system in hepatic ischemia-reperfusion injury (HIRI) in rats. METHODS: Wistar rats were randomly distributed into sham group (n = 18), ischemia-reperfusion (IR) group (n = 18), IR + NaHS group (n = 18) and IR + DL-propargylglycine (PAG) group (n = 18). The hepatic IR model was established by Pringle's hepatic vascular occlusion. At each of the indicated time points (1, 3 and 6 hours after IR), the serum levels of H(2)S and the hepatic CSE activity were measured. The serum levels of inflammatory factors, including TNF-α, IL-10 were determined by ELISA methods. The expression of apoptotic protein, TNF-α, in liver tissue was tested by Western blot assay, cell apoptosis was examined by TUNEL and the histological changes were examined in each group. RESULTS: The serum levels of H(2)S and CSE activity were significantly increased in group IR compared with group sham at all indicated time points (P < 0.05). The serum level of inflammatory factors (P < 0.01) and the hepatic expression of TNF-α protein (P < 0.05) were elevated obviously in group IR than that in group sham. Administration of NaHS could reduce the production of inflammatory factors in serum (P < 0.01), inhibit hepatic protein expression of TNF-α (P < 0.05) and attenuate the liver histological scores of IR injury (P < 0.05), whereas PAG aggravated them. CONCLUSION: The endogenous CSE/H(2)S system maybe involved in the pathogenesis of hepatic IR injury, which suggests that CSE/H(2)S system can protect liver from IR injury in rats by intervening in inflammatory reaction, attenuating the injury severity and inhibiting expression of apoptotic protein TNF-α.


Subject(s)
Cystathionine gamma-Lyase/physiology , Hydrogen Sulfide/blood , Liver/blood supply , Reperfusion Injury/physiopathology , Animals , Apoptosis/drug effects , Cystathionine gamma-Lyase/blood , Disease Models, Animal , Interleukin-10/blood , Liver/metabolism , Liver/pathology , Male , Random Allocation , Rats , Rats, Wistar , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Reperfusion Injury/prevention & control , Sulfides/pharmacology , Tumor Necrosis Factor-alpha/metabolism
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