Ezrin's role in gastric cancer progression: Implications for immune microenvironment modulation and therapeutic potential.

At present, surgical resection is the most effective method for the treatment of gastric cancer. However, death caused by inoperable metastasis is still very common, despite research in this area. The mechanisms underlying the occurrence, development, and metastasis of gastric cancer are not fully understood. Ezrin, a plasma membrane-microfilament junction participates in a variety of cellular activities and is closely related to tumorigenesis and development. Few studies have explored the relationship between the tumor immune microenvironment and ezrin expression in gastric cancer. In this study, we used proteomic techniques to analyze the differentially expressed proteins between the gastric cancer cell lines MKN-45 and HGC-27 and screened ezrin as the target protein. We collected patient information from The TCGA and GEO databases, and the results showed that ezrin was positively correlated with adverse clinical features. We further explored the relationship between ezrin expression levels, immune microenvironment, and genomic changes. We found that ezrin was involved in immune regulation and genomic instability in gastric cancer. When the expression of ezrin is high, immune cell infiltration also increases. We also predicted that ezrin is closely related to immunotherapy and chemosensitivity. Single-cell transcriptome data showed that the ezrin gene was mainly expressed in B cells and epithelial cells, and the expression of EZR in these epithelial cells was positively correlated with the epithelial-mesenchymal transformation pathway and Pi3k-AKT pathway score. Through functional verification of the stably transfected cell line constructed by lentivirus, the results of the liver metastasis model in nude mice suggested that high expression of ezrin leads to the formation of more metastatic foci. In summary, our results clarify the prognostic, immunological, and therapeutic value of ezrin in gastric cancer and provide a theoretical basis for more accurate treatment.

Neutrophil extracellular traps induced by the hypoxic microenvironment in gastric cancer augment tumour growth.

BACKGROUND: Inflammation-related predisposition to cancer plays an essential role in cancer progression and is associated with poor prognosis. A hypoxic microenvironment and neutrophil infiltration are commonly present in solid tumours, including gastric cancer (GC). Neutrophil extracellular traps (NETs) have also been demonstrated in the tumour immune microenvironment (TIME), but how NETs affect GC progression remains unknown. Here, we investigated the role of NET formation in the TIME and further explored the underlying mechanism of NETs in GC tumour growth. METHODS: Hypoxia-induced factor-1α (HIF-1α), citrulline histone 3 (citH3) and CD66b expression in tumour and adjacent nontumor tissue samples was evaluated by western blotting, immunofluorescence and immunohistochemical staining. The expression of neutrophil-attracting chemokines in GC cells and their hypoxic-CM was measured by qRT‒PCR and ELISA. Neutrophil migration under hypoxic conditions was evaluated by a Transwell assay. Pathway activation in neutrophils in a hypoxic microenvironment were analysed by western blotting. NET formation was measured in vitro by immunofluorescence staining. The protumour effect of NETs on GC cells was identified by Transwell, wound healing and cell proliferation assays. In vivo, an lipopolysaccharide (LPS)-induced NET model and subcutaneous tumour model were established in BALB/c nude mice to explore the mechanism of NETs in tumour growth. RESULTS: GC generates a hypoxic microenvironment that recruits neutrophils and induces NET formation. High mobility group box 1 (HMGB1) was translocated to the cytoplasm from the nucleus of GC cells in the hypoxic microenvironment and mediated the formation of NETs via the toll-like receptor 4 (TLR4)/p38 MAPK signalling pathway in neutrophils. HMGB1/TLR4/p38 MAPK pathway inhibition abrogated hypoxia-induced neutrophil activation and NET formation. NETs directly induced GC cell invasion and migration but not proliferation and accelerated the augmentation of GC growth by increasing angiogenesis. This rapid tumour growth was abolished by treatment with the NET inhibitor deoxyribonuclease I (DNase I) or a p38 MAPK signalling pathway inhibitor. CONCLUSIONS: Hypoxia triggers an inflammatory response and NET formation in the GC TIME to augment tumour growth. Targeting NETs with DNase I or HMGB1/TLR4/p38 MAPK pathway inhibitors is a potential therapeutic strategy to inhibit GC progression. Video Abstract.

Study on the Cytotoxic Microstructure of Titanium Dioxide Nanoparticles by X-Ray Phase-Contrast CT Imaging.

To address the problem of microstructural analysis of titania nanoparticles with high cytotoxicity, the authors propose X-ray phase-comparative CT imaging studies. In this method, the HE-stained section samples were compared with the X-ray phase-contrast CT imaging microscopic images, and 3D texture analysis was used to observe the changes in the preparation of hepatocyte microstructures in the two groups. The results show that X-ray phase-contrast CT imaging microscopic images and their larger image size are closely related to HE staining images, and X-ray phase-contrast CT microscopic images can observe important data of hepatocytes from multiple angles. The ship skeleton extraction method based on the endpoint limit also has advantages over traditional algorithms in extraction accuracy and can provide more 3D feature files, confirming the growth and transformation of normal hepatocytes into hepatocyte cytotoxic microstructures. The distribution effect of using the ensemble process is better than the simple 2D feature set and 3D feature set, and the overall accuracy is improved; the result distribution of the tree determination and random forest methods is also better than that of the support vector machine method. The experimental results show that the X-ray phase-contrast CT images can highlight the 2D and 3D imaging features of the hepatotoxic microstructure of TiO2 nanoparticles and provide data for quantitative analysis.

Scanning Probe Microscopy Bone Marrow Determination of Steogenic Differentiation of Mesenchymal Stem Cells.

To address the question of determining the osteogenic differentiation of mesenchymal stem cells, the bone marrow studies were performed using probe microscopy. All adherent bone marrow was used to isolate the bone marrow mesenchymal stem cells and expanded and purified in vitro. Its morphology under an inverted microscope was observed. We used Zuogui Pills to differentiate the separation methods. Alcian blue staining, modified calcium cobalt alkaline phosphatase staining, and neuron-specific enolase immunohistochemical staining were performed. The experimental results are shown below. The morphology of the isolated and purified cells was analyzed with an inverted microscope, and the isolated and purified cells were analyzed with Zuogui Pill. Alcian blue staining, modified calcium cobalt alkaline phosphatase staining, and neuron-specific enolase immunohistochemical staining confirmed that the cells differentiated into cartilage and osteoblasts, and the cell structure and morphology were similar to those of the bone marrow mesenchymal stem cells. The results showed that the adherent mode of cells obtained from the whole bone marrow was the rat bone marrow mesenchymal stem cells, and the Zuogui Pills could induce multidirectional differences in the bone marrow mesenchymal stem cells.

Immunomodulating Therapy by Picibanil-based Imiquimod and Virotherapy for Advanced Uterine Cancer after Laparoscopic Surgery.

This is a case report of a uterine cancer with the International Federation of Gynecology and Obstetrics staging 3c2 with the initial clinical presentation of postmenopausal vaginal bleeding in August 2015. Endometrium biopsy showed invasive nests of poorly differentiated grade 3 endometrioid adenocarcinoma. The patient received robotic surgery including total hysterectomy, bilateral salpingo-oophorectomy, bilateral pelvic lymph node dissection, para-aortic lymph node dissection, and washing cytology. The final pathology showed an endometrioid carcinoma with myometrium invasion up to 85% and para-aortic and pelvic lymph nodes invasion. The patient received six courses of adjuvant chemotherapy (paclitaxel and carboplatin) with concurrent chemoradiotherapy after the surgery. Later, immunotherapy with Picibanil (OK-432) and interleukin-2 (IL-2) was given, and cancer did not recur for 34 months until tumor recurrence at the liver dome and bilateral lung was noted by positron-emission tomography scan in July 2018. The patient received laparoscopic surgery for intra-abdominal tumor excision in December 2018, and the tumor found extended to the right diaphragm, liver surface, omentum, bilateral flank to pelvic peritoneum, Douglas pouch, and upper rectum. We continued the immunotherapy with OK-432, IL-2, Aldara cream (imiquimod), and later on, virotherapy (human papillomavirus vaccine). The immune risk profiles showed T-cells' proliferation and alteration of the Th1/Th2 activation after immunotherapy and virotherapy. Proctectomy with colon-anal anastomosis and cytoreduction surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) (doxorubicin and paclitaxel) was performed in January 2019. After the surgery, the patient received chemotherapy (topotecan, paclitaxel, lipodox, and carboplatin) and continued the immunotherapy. The immune risk profiles showed CD4, CD4/CD8 increase after HIPEC and immunotherapy. The patient continued the therapy until May 2020.

PTPN9 induces cell apoptosis by mitigating the activation of Stat3 and acts as a tumor suppressor in colorectal cancer.

BACKGROUND: Accumulating evidence has shown that protein tyrosine phosphatases (PTPs) are involved in regulating the transduction of many signaling pathways and play important roles in modulating the progression of some cancers, but the functions of PTPs in cancers have not been well elucidated until now. Here, we aimed to identify the roles of protein tyrosine phosphatase nonreceptor type 9 (PTPN9), a cytoplasmic PTP, in the development of colorectal cancer and elucidate the regulatory mechanism involved. MATERIALS AND METHODS: Cell viability assessment, colony formation assay, caspase-3 and caspase-9 activity assay, real-time PCR, and Western blot analysis were applied. RESULTS: Our results showed that PTPN9 expression was frequently downregulated in colorectal cancer tissues compared with adjacent normal tissues. Overexpression of PTPN9 mitigated cell growth and colony formation and induced cell apoptosis in colorectal cancer. Conversely, PTPN9 knockdown promoted cell growth and survival. Moreover, PTPN9 negatively regulated the activation of Stat3 and depressed its nuclear translocation in colorectal cancer. The effects of PTPN9 knockdown on cell apoptosis were attenuated by inhibition of the Stat3 pathway. CONCLUSION: These results indicate that PTPN9 inhibits cell growth and survival by repressing the activation of Stat3 in colorectal cancer, which suggests an important underlying mechanism of regulating cell growth and provides a novel candidate therapeutic target for colorectal cancer.

ILK promotes cell proliferation in breast cancer cells by activating the PI3K/Akt pathway.

Breast cancer is a very common malignant tumor, whose incidence ranks the first among various types of cancer in women worldwide. An important hallmark of cancer is the activation of oncogenes, which lead to overgrowth of cancer cells. Therefore, it is necessary to identify the critical genes involved in regulating the progression of breast cancer and elucidate the corresponding molecular mechanisms. The present study demonstrated that integrin­linked kinase (ILK) overexpression promoted cell proliferation and growth in MCF­7 cells, while ILK knockdown led to growth arrest in MDA­MB­231 cells. In addition, activation of the phosphoinositide 3­kinase (PI3K)/Akt pathway was positively regulated by ILK, suggesting that the regulatory effects of ILK on cell growth and proliferation may be at least in part mediated by PI3K/Akt signaling. These results indicated that ILK promoted cell proliferation and growth in breast cancer cells through activation of the PI3K/Akt pathway, suggesting that ILK may be considered to be a potential therapeutic target for the therapy of breast cancer in the future.

Activation of CXCL12/CXCR4 renders colorectal cancer cells less sensitive to radiotherapy via up-regulating the expression of survivin.

Colorectal cancer is the most common malignancy of the gastrointestinal tract. Surgical treatment combined with radiotherapy is the main treatment course for colorectal cancer; nevertheless, radio-resistance is commonly encountered during the treatment course and seriously influences the therapeutic efficacy. We tested the hypothesis that the CXCL12/CXCR4 axis is closely related to radiotherapy sensitivity in colorectal cancer cells. Here, we found that the decrease in cell viability and the increase in cell death induced by radiotherapy were attenuated by CXCL12 treatment, and the inhibition of CXCR4 promoted colorectal cancer cells to be more sensitive to radiotherapy. We also examined the critical roles of CXCL12/CXCR4 in cell survival and found that radiotherapy induced Bax expression and facilitated the activity of caspase-3 and caspase-9, which were reversed by CXCL12 treatment. Cell apoptosis was enhanced by the inhibition of CXCR4 under radiotherapy conditions. Furthermore, treatment with CXCL12 resulted in an increased expression of survivin, and the inhibitory roles of CXCL12 in radiotherapy-induced apoptosis were mitigated by survivin knockdown. These results indicate that CXCL12/CXCR4 protects colorectal cancer cells against radiotherapy via survivin, implying an important underlying mechanism of resistance to radiotherapy during colorectal cancer therapy.

PKIB promotes cell proliferation and the invasion-metastasis cascade through the PI3K/Akt pathway in NSCLC cells.

Lung cancer is one of the most common malignancies in the world, and non-small cell lung cancer (NSCLC) is a major subtype of lung cancer. Overgrowth of tumor cells usually results from the intensive proliferation of cancer cells, but the mechanisms by which the proliferation of cancer cells are promoted are currently unclear. Thus, it is necessary to determine the vital factors involved in regulating the growth of NSCLC. The MTT assay, BrdU assay, western blots, and migration and invasion assays were used in our study. Here, we found that PKIB (cAMP-dependent protein kinase inhibitor-ß), a novel molecular target, was up-regulated in NSCLC tissues compared with the normal tissues adjacent to the tumors. Moreover, overexpression of PKIB promoted cell proliferation and potentiated the invasion and migration in A549 cells, whereas knocking down PKIB gene expression inhibited the proliferation and attenuated the invasive behavior and metastasis in H1299 cells. However, all of these effects of PKIB on cell proliferation and metastasis were reduced by inhibiting the PI3K/Akt pathway. Our results indicate that PKIB promotes cell proliferation and tumorigenesis by activating the PI3K/Akt pathway in NSCLC, implying that this is an important underlying mechanism that affects the progression of NSCLC.

Protective Effects of Hydrogen Gas on Experimental Acute Pancreatitis.

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.

BMP8B mediates the survival of pancreatic cancer cells and regulates the progression of pancreatic cancer.

Pancreatic cancer has become one of the most common types of cancer. It is believed that inhibiting the apoptosis of tumor cells as well as overgrowth of tumor cells accelerate the progression and development of cancer. However, the detailed mechanisms of pancreatic cancer progression remain to be fully elucidated. Although bone morphogenetic protein (BMP) families are crucial mediators in some types of cancer, whether BMP8B is involved in regulating the growth and apoptosis of pancreatic cancer cells and the progression of pancreatic cancer is not clear. In the present study, we found that the expression of BMP8B was downregulated in pancreatic cancer tissue compared with the normal tissue adjacent to the tumors. Moreover, the overexpression of BMP8B inhibited cell growth and promoted activation of caspase-3 and -9, the decrease of mitochondrial membrane potential and cell apoptosis in PANC-1, while silencing the BMP8B gene expression with BMP8B shRNA exerted anti-apoptotic effects and boosted the growth of pancreatic cancer cells in BxPC-3. Therefore, we concluded that BMP8B mediates the survival of pancreatic cancer cells and regulates the progression of pancreatic cancer, making it a potential therapeutic target for pancreatic cancer.

Long-term outcomes of laparoscopic splenectomy versus open splenectomy for idiopathic thrombocytopenic purpura.

The long-term outcomes of laparoscopic splenectomy (LS) versus open splenectomy (OS) in patients with idiopathic thrombocytopenic purpura (ITP) are not known. A retrospective analysis of 73 patients who underwent splenectomy (32 LS and 41 OS) for refractory ITP between April 2003 and June 2012 was conducted. LS was associated with shorter hospital stay (P = 0.01), less blood loss and blood transfusion during surgery, quicker resumption of oral diet (P < 0.0001), and earlier drain removal (P < 0.01). Conversion to OS was required in 4 patients (12.5%). Operation time was significantly longer in LS (P < 0.0001). Deep venous thrombosis (DVT) was observed in 1 patient after LS and in 4 patients after OS (P = 0.52). One patient died from intraperitoneal bleeding after OS, another patient developed pulmonary embolism. Median follow-up of 36 months was performed in LS group (29 of 32, 91%) and of 46 months in OS group (35 of 41, 85%), 25 patients (86%) in LS group and 32 (91%) in OS group reached sustained complete response (P = 0.792). Kaplan-Meier analysis showed that there was no significant difference in the relapse-free survival rate between the groups (P = 0.777). In conclusion, the long-term outcome of laparoscopic splenectomy is not different from that of open splenectomy for patients with ITP.

Effects of the HIF-1α and NF-κB loop on epithelial-mesenchymal transition and chemoresistance induced by hypoxia in pancreatic cancer cells.

Hypoxia is a microenvironmental factor which plays a critical role in tumor development and chemoresistance. Epithelial-to-mesenchymal transition (EMT) induced by hypoxia is one of the critical causes of treatment failure and chemoresistance in different types of human cancers. Stabilization of the hypoxia-inducible factor-1α (HIF-1α) transcription complex, caused by intratumoral hypoxia, promotes tumor progression and chemoresistance. Previous evidence suggests that hypoxia can also activate nuclear factor-κB (NF-κB), a known mediator of EMT, which is accompanied by reduced expression of epithelial marker E-cadherin and enhanced expression of the mesenchymal markers Vimentin and N-cadherin as well as overexpression of various transcription factors of EMT, such as Snail and Twist. Based on this evidence, the present study aimed to investigate whether downregulation of the p65 subunit of NF-κB or HIF-1α by small interfering RNA (siRNA) may reverse the EMT phenotype and inhibit the proliferation and induce the apoptosis of pancreatic cancer cell lines (PANC-1, BxPC3) under hypoxic conditions in vitro and enhance the efficacy of gemcitabine in the treatment of pancreatic cancer. These results provide molecular evidence showing that the activation of the HIF-1α and NF-κB loop is mechanistically linked with the chemoresistance phenotype (EMT phenotype) of pancreatic cancer cells under hypoxic conditions, suggesting that the inactivation of HIF-1α and NF-κB signaling by novel strategies may be a potential targeted therapeutic approach for overcoming EMT and chemoresistance induced by hypoxia.

Inhibition of hydrogen sulfide synthesis provides protection for severe acute pancreatitis rats via apoptosis pathway.

We aimed to investigate the relationship between the synthesis of hydrogen sulfide (H(2)S) and the pancreatic acinar cell apoptosis in severe acute pancreatitis (SAP) rats, as well as analyse the potential apoptotic pathway involved in this process. Sixty rats had been equally divided into four groups: sham, SAP, SAP + sodium hydrosulfide (NaHS) and SAP + DL-propargylglycine (PAG). 24 h after SAP induction, all surviving animals of each group were sacrificed to collect blood and tissue samples for the following measurements: the level of serum H(2)S as well as the levels of tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), H(2)S synthesizing activity, CSE mRNA and protein expression, maleic dialdehyde (MDA) and myeloperoxidase (MPO) activity, the expression of Bax, Bcl-2, caspase-3, -8 and -9, the release of cytochrome c and the activation of nuclear factor-kappa B (NF-κB), ERK1/2, JNK1/2 and p38 in pancreas. Furthermore, in situ detection of cell apoptosis was examined and the severity of pancreatic damage was analyzed by pathological grading and scoring. Results Significant differences in every index except IL-10 had been found between the SAP, NaHS and PAG groups (P < 0.05). Treatment with PAG obviously induced the pancreatic acinar cell apoptosis as well as improved all the pathological changes and inflammatory parameters. In contrast, administration of NaHS significantly attenuated apoptosis in the pancreas and aggravated the severity of pancreatic damage. Moreover, the expressions of caspase-3, -8, -9 and the release of cytochrome c were all increased in the apoptotic cells, and the activity of NF-κB as well as the phosphorylation of ERK1/2, JNK1/2 and p38 decreased accompanying with the reduction of the serum H(2)S level. H(2)S plays a pivotal role in the regulation of pancreatic acinar cell apoptosis in SAP rats. The present results showed that inhibition of H(2)S synthesis provided protection for SAP rats via inducing acinar cell apoptosis. This process acted through both extrinsic and intrinsic apoptotic pathways, and may be regulated by reducing the activity of NF-κB.

Pristimerin causes G1 arrest, induces apoptosis, and enhances the chemosensitivity to gemcitabine in pancreatic cancer cells.

Despite rapid advances in chemotherapy and surgical resection strategies, pancreatic cancer remains the fourth leading cause of cancer related deaths in the United States with a 5-year survival rate of less than 5%. Therefore, novel therapeutic agents for the prevention and treatment of pancreatic cancer are urgently needed. The aim of this study was to investigate the effect of pristimerin, a quinonemethide triterpenoid compound isolated from Celastraceae and Hippocrateaceae, on inhibition of cell proliferation and induction of apoptosis in three pancreatic cancer cells, BxPC-3, PANC-1 and AsPC-1, in both monotherapy and in combination with gemcitabine. Treatment with pristimerin decreased the cell proliferation of all three pancreatic cancer cells in a dose- and time-dependent manner. Treatment of pancreatic cancer cells with pristimerin also resulted in G1-phase arrest which was strongly associated with a marked decrease in the level of cyclins (D1 and E) and cyclin-dependent kinases (cdk2, cdk4 and cdk6 ) with concomitant induction of WAF1/p21 and KIP1/p27. Pristimerin treatment also resulted in apoptotic cell death, cleavage of caspase-3, modulation in the expressions of Bcl-2 family proteins, inhibition of the translocation and DNA-binding activity of NF-κB. In addition, pristimerin potentiated the growth inhibition and apoptosis inducing effects of gemcitabine in all three pancreatic cancer cells, at least in part, by inhibiting constitutive as well as gemcitabine-induced activation of NF-κB in both its DNA-binding activity and transcriptional activity. Taken together, these data provide the first evidence that pristimerin has strong potential for development as a novel agent against pancreatic cancer.

[Experimental study of the function of nuclear factor-κB-dependent epithelial to mesenchymal transition in pancreatic cancer cells under hypoxic conditions].

OBJECTIVE: To investigate the function of nuclear factor (NF)-κB in the epithelial to mesenchymal transition induced by hypoxia in pancreatic cancer cells. METHODS: For cultured pancreatic cancer cells (BxPC-3 and Panc-1) under hypoxic and normoxic conditions, the differences in the morphology were observed by optical microscope. The expression of markers of epithelial and mesenchymal phenotypes, E-cadherin, vimentin and N-cadherin, were determined by Western blot. NF-κB P65 activity was measured by electrophoretic mobility shift assay. Invasion and gemcitabine resistance of pancreatic cancer cells were evaluated in matrigel invasion assay and cell counting kit-8 assay. Both molecular and pharmacologic means of inhibiting NF-κB P65 were used in these hypoxic cells and then the above resulting phenotypes were compared with those of the control-treated cells. RESULTS: After cultured pancreatic cancer cells under hypoxic conditions for 48 h, normoxic cells exhibited a polygonal shape and formed tight clusters of cells, whereas hypoxic cells took on an elongated, fibroblastoid morphology associated with a more highly invasive character and resistance to gemcitabine; hypoxic cells exhibited an suppression of E-cadherin and increase in vimentin and N-cadherin expression. NF-κB P65 activity was elevated in hypoxic cells. On the contrary, on molecular or pharmacologic inhibition of NF-κB P65, hypoxic cells regained expression of E-cadherin, lost expression of N-cadherin, and reversed their highly invasive and drug resistant phenotype. CONCLUSIONS: Pancreatic cancer cells underwent epithelial to mesenchymal transition exposed to hypoxia, exhibited highly invasive and drug resistant phenotype. Inhibition of NF-κB P65 under hypoxic conditions, pancreatic cancer cells regained expression of E-cadherin, lost expression of N-cadherin, and reversed their highly invasive and drug resistant phenotype.

Dihydroartemisinin enhances Apo2L/TRAIL-mediated apoptosis in pancreatic cancer cells via ROS-mediated up-regulation of death receptor 5.

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.

Nuclear factor-κB-dependent epithelial to mesenchymal transition induced by HIF-1α activation in pancreatic cancer cells under hypoxic conditions.

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.

Dihydroartemisinin inhibits angiogenesis in pancreatic cancer by targeting the NF-κB pathway.

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.