Clinical characteristics and prognostic risk factors of candidemia in non-neutropenic patients: a retrospective cohort study.

This study aimed to determine the clinical characteristics and the prognostic risk factors in non-neutropenic patients with candidemia. Data were retrospectively collected through the medical record information system. Non-neutropenic patients with candidemia were relatively aged, with a more than one-third rate of in-hospitalization mortality. In multivariate analysis, APACHE II score (adjusted odds ratio [aOR], 1.138; 95% confidence interval [CI], 1.067-1.213), septic shock (aOR, 5.704; 95% CI, 2.639-12.326) and RRT (aOR, 16.152; 95% CI, 2.628-99.275) (all P < 0.01) were independent related with non-survivors. In conclusion, non-neutropenic patients with candidemia have a high in-hospitalization mortality, and APACHE II, septic shock, and RRT are independently factors.

Loss of Activin Receptor Type 1B Accelerates Development of Intraductal Papillary Mucinous Neoplasms in Mice With Activated KRAS.

BACKGROUND & AIMS: Activin, a member of the transforming growth factor-ß (TGFB) family, might be involved in pancreatic tumorigenesis, similar to other members of the TGFB family. Human pancreatic ductal adenocarcinomas contain somatic mutations in the activin A receptor type IB (ACVR1B) gene, indicating that ACVR1B could be a suppressor of pancreatic tumorigenesis. METHODS: We disrupted Acvr1b specifically in pancreata of mice (Acvr1b(flox/flox);Pdx1-Cre mice) and crossed them with LSL-KRAS(G12D) mice, which express an activated form of KRAS and develop spontaneous pancreatic tumors. The resulting Acvr1b(flox/flox);LSL-KRAS(G12D);Pdx1-Cre mice were monitored; pancreatic tissues were collected and analyzed by histology and immunohistochemical analyses. We also analyzed p16(flox/flox);LSL-Kras(G12D);Pdx1-Cre mice and Cre-negative littermates (controls). Genomic DNA, total RNA, and protein were isolated from mouse tissues and primary pancreatic tumor cell lines and analyzed by reverse-transcription polymerase chain reaction, sequencing, and immunoblot analyses. Human intraductal papillary mucinous neoplasm (IPMN) specimens were analyzed by immunohistochemistry. RESULTS: Loss of ACVR1B from pancreata of mice increased the proliferation of pancreatic epithelial cells, led to formation of acinar to ductal metaplasia, and induced focal inflammatory changes compared with control mice. Disruption of Acvr1b in LSL-KRAS(G12D);Pdx1-Cre mice accelerated the growth of pancreatic IPMNs compared with LSL-KRAS(G12D);Pdx1-Cre mice, but did not alter growth of pancreatic intraepithelial neoplasias. We associated perinuclear localization of the activated NOTCH4 intracellular domain to the apical cytoplasm of neoplastic cells with the expansion of IPMN lesions in Acvr1b(flox/flox);LSL-KRAS(G12D);Pdx1-Cre mice. Loss of the gene that encodes p16 (Cdkn2a) was required for progression of IPMNs to pancreatic ductal adenocarcinomas in Acvr1b(flox/flox);LSL-Kras(G12D);Pdx1-Cre mice. We also observed progressive loss of p16 in human IPMNs of increasing grades. CONCLUSIONS: Loss of ACVR1B accelerates growth of mutant KRAS-induced pancreatic IPMNs in mice; this process appears to involve NOTCH4 and loss of p16. ACVR1B suppresses early stages of pancreatic tumorigenesis; the activin signaling pathway therefore might be a therapeutic target for pancreatic cancer.

[Effect of metoclopramide on capsule endoscopy examination: a randomized study].

OBJECTIVE: To investigate the effect of metoclopramide on capsule endoscopy (CE) examination. METHODS: Total 116 patients referred for CE were randomized into two groups with 58 patients in each group. In treatment group patients received 10 mg metoclopramide intramuscular injection after swallowing the capsule and in control group no metoclopramide was administered. The gastric transit time, small bowel transit time, complete endoscopy rate were observed in both groups. RESULTS: The CE examination was completed in 51 patients of treatment group (87.9%) and 48 of control group (84.2%). Mean gastric transit time was (32.45 ± 29.63) min in treatment group and (45.81 ± 40.01)min in control group, there was significant difference between two groups (P<0.05). Mean small bowel transit time was (252.69 ± 113.29) min in treatment group and (258.75 ± 83.83) min in control group, there was no significant difference between two groups (P>0.05). CONCLUSION: Metoclopramide may reduces gastric transit time, but not effect small bowel transit time,which suggests that it might increase the likelihood of complete small-bowel examination in patients undergoing capsule endoscopy.

ADP-ribosylation factor like 7 (ARL7) interacts with alpha-tubulin and modulates intracellular vesicular transport.

ADP-ribosylation factor (ARF) like 7 (ARL7, also named ARL4C) is a member of ARL family and recent studies showed that it is involved in the AI-dependent cholesterol secretion process. Yet its biological function remains largely unknown. Using a MALDI-TOF/MS analysis, we identified alpha-tubulin interacted with ARL7. The interaction was confirmed by GST pull-down assay and co-immunoprecipitation in renal carcinoma cell 786-O in which we found the endogenous ARL7 is expressed. This is the second ARL member found interacting with tubulin after ARL8. In addition, ARL7Q72L, a GTP-binding form, promoted the transferrin transport from early endosome to recycling endosome significantly. The above data suggested that ARL7 might modulate the intracellular vesicular transport via interaction with microtubules.

Selective inhibition of cyclooxygenase-2 suppresses the growth of pancreatic cancer cells in vitro and in vivo.

Cyclooxygenase-2 (COX-2), a prostaglandin synthetase, is involved in development of certain tumors. We therefore analyzed COX-2 expression in pancreatic cancer tissues (53 samples) and Panc-1 human pancreatic cancer cells by immunohistochemistry, RT-PCR and western-blotting analyses. Also, immunohistochemistry of proliferating cell nuclear antigen (PCNA) was performed. We found expression of COX-2 was dramatically upregulated in 36 of 53 cases (67.9%) and the expression of COX-2 was associated with the diameter (> 3 cm) of the tumors (p < 0.05), but not with the age, gender, tumor location, differentiation, lymph-node metastases and TNM stage. The positivity rate of PCNA expression in the pancreatic cancer cells of the COX-2 positive group (32.88 +/- 13.26%) was significantly higher than that in the COX-2 negative group (24.56 +/- 11.51%) (p < 0.05). Then we investigated the effect of selective inhibitors of COX-2 (NS398 and celecoxib) on proliferation of Panc-1 cells by 3-(4,5 dimethyl-2-thiazolyl)-2.5-diphenyl-2H-tetrazolium bromide (MTT) assay. Either NS398 or celecoxib suppressed proliferation of Panc-1 cells dose-dependently in vitro. Furthermore, Panc-1 cells were implanted into nude mice, and celecoxib was administrated orally with feed. The volume of the tumor xenografted into nude mice was decreased by 51.6% in the celecoxib group (p < 0.01). In conclusion, the increased expression of COX-2 may be responsible for rapid proliferation of pancreatic cancer, and specific inhibition of COX-2 suppresses proliferation of Panc-1 cells in vitro and in nude mice. The selective inhibitor of COX-2 may be an effectual agent for pancreatic cancer chemoprevention.

Multiple Lymphomatous Polyposis of the Intestine with Ileocecal Intussusception Due to Mantle Cell Lymphoma: A Case Report of a 34-Year-Old Man.

BACKGROUND Multiple lymphomatous polyposis of the gastrointestinal tract can be associated with the B-cell lymphoma variant, mantle cell lymphoma, with most cases having been described in patients who are more than 50 years-of-age. A rare case of multiple lymphomatous polyposis due to mantle cell lymphoma is reported in a 34-year-old man. CASE REPORT A 34-year-old man presented with paroxysmal abdominal pain followed by spontaneous remission, which had been previously diagnosed as gastritis. An episode of ileocecal intussusception occurred, which was confirmed on imaging studies. The diagnosis of multiple lymphomatous polyposis due to mantle cell lymphoma was confirmed following ileocecal resection and histopathology. The patient refused to receive chemotherapy following surgery. Currently, at two-year follow-up, no further abnormality has been found. A review of the literature has shown the importance of endoscopic evaluation in the diagnosis of lymphomatous polyposis. CONCLUSIONS Multiple lymphomatous polyposis due to mantle cell lymphoma has rarely been described in young patients under the age of 50 years. Gastrointestinal endoscopic examination is important for the early diagnosis of multiple lymphomatous polyposis.

Cyclooxygenase-2 induces angiogenesis in pancreatic cancer mediated by prostaglandin E2.

The purpose of the present study was to elucidate the effects of cyclooxygenase 2 (COX-2) on the expression of vascular endothelial growth factor (VEGF) and prostaglandin E2 (PGE2) in pancreatic cancer in vitro and in vivo, and to clarify the potential mechanism of COX-2-induced angiogenesis of pancreatic cancer. The study analysis was conducted in the pancreatic cancer PC-3 cell line. The expression of COX-2 and VEGF in human pancreatic cancer tissue was analyzed by immunohistochemistry. Angiogenesis was detected using immunohistochemistry with anti-collagen IV antibodies, and was calculated according to the microvascular density (MVD). In vitro analysis was performed using ELISA or radioimmunoassay (RIA). The effect of exogenous PGE2 on the downregulation of VEGF by Celebrex was also assessed. In vivo analysis was performed using western blotting or RIA. Concurrently, MVD was also investigated in nude mice using immunohistochemistry with anti-collagen IV antibodies. COX-2 was overexpressed in pancreatic cancer tissues, with an overall positive rate of 87.5%. There was a positive association between the expression of COX-2 and MVD. The in vitro study indicated that Celebrex suppressed the expression of VEGF and PGE2 in PC-3 cells in a dose- and time-dependent manner, while exogenous PGE2 rescued the expression of VEGF, which was suppressed by Celebrex, in a dose-dependent manner. The in vivo study revealed that the administration of Celebrex to xenograft nude mice significantly inhibited the expression of VEGF and PGE2. These data provide evidence that PGE2 may be an important mediator between COX-2 and VEGF expression in the process of angiogenesis in pancreatic cancer.

Downregulation of GEP100 Improved the Growth Inhibition Effect of Erlotinib Through Modulating Mesenchymal Epithelial Transition Process in Pancreatic Cancer.

OBJECTIVE: The epidermal growth factor receptor is overexpressed in the majority of pancreatic cancer. Epidermal growth factor receptor tyrosine kinase inhibitor erlotinib was approved to treat patients combining with gemcitabine. However, the sensitivity is low. Here, we try to reveal the regulatory role of guanine nucleotide exchange protein 100 (GEP100) in erlotinib sensitivity. METHODS: We investigated the correlation between GEP100 expression and sensitivity to erlotinib in different pancreatic cancer cell lines, followed by examination of the effect of GEP100 on erlotinib sensitivity by establishing the stable knocked-down cell line. The expression level of epithelial mesenchymal transition-related protein was examined by Western blot, and the regulatory mechanism was investigated by short hairpin RNA. Xenograft experiment was also performed in nude mice. RESULTS: We identified a significant correlation between sensitivity to erlotinib and expression of GEP100. GEP100 downregulation increased its sensitivity to erlotinib. E-cadherin short hairpin RNA treatment inhibited this sensitivity. Immunohistochemical staining showed a mutual exclusive expression pattern of GEP100 and E-cadherin in human pancreatic cancer tissues. Xenograft showed that downregulation of GEP100 enhanced the growth inhibition of erlotinib in nude mice. CONCLUSIONS: Our results suggested that GEP100 and E-cadherin have the predictive value for responsiveness to erlotinib in pancreatic cancer.

Effect of emodin on pancreatic fibrosis in rats.

AIM: To establish the rats model of chronic fibrosing pancreatitis and to prove the anti-fibrotic effect of emodin in chronic pancreatitis with fibrosis. METHODS: Fifty rats were randomly divided into five groups, 10 rats in each group. Trinitrobenzene sulfonic acid (TNBS) was infused into the pancreatic duct to induce chronic pancreatitis in rats (except for normal group). Emodin-treated rats were fed with different doses of emodin (20, 40 and 80 mg/kg body weight) for 28 d, while normal group and control group received 0.9% sodium chloride solution. Serum levels of hyaluronic acid (HA) and laminin (LN) were determined by radioimmunoassay. Histopathological alterations were studied by optical microscopy. Expression of collagen was also examined while transforming growth factor-beta-1 (TGF-beta(1)) was localized by immunochemistry. RESULTS: In emodin-treated rats, the serum levels of HA and LN were decreased significantly (HA, 62.2 +/- 19.3 microg/L vs 112.7 +/- 26.5 microg/L, P < 0.05; LN 44.3 +/- 10.4 microg/L vs 86.2 +/- 16.5 microg/L, P < 0.05); the degree of fibrosis was ameliorated observably; the expression of collagen in pancreatic tissue was reduced especially in high-dose emodin-treated group (36% +/- 5% vs 42% +/- 6%, P < 0.05); with the increased doses of emodin, the expression of TGF-beta(1) was declined, compared with those in control group. CONCLUSION: Emodin has an anti-fibrotic effect on pancreatic fibrosis in rats. Because of its anti-fibrotic effect, it could be a potential herb for the treatment of chronic pancreatitis.

microRNA-1228⁎ impairs the pro-angiogenic activity of gastric cancer cells by targeting macrophage migration inhibitory factor.

Our previous study has shown that microRNA-1228⁎ (miR-1228⁎) is downregulated in gastric cancer tissues and restoration of its expression retards tumor growth in a gastric cancer xenograft model. In this work, we aimed to explore the role of miR-1228⁎ in gastric cancer cell cycle progression and angiogenesis and to identify its functional target gene(s). It was found that miR-1228⁎ overexpression significantly inhibited the proliferation and colony formation of gastric cancer cells, compared to vector-transfected cells. As determined by propidium iodide staining, overexpression of miR-1228⁎ resulted in an enrichment of G0/G1 phase cells in gastric cancer cells. miR-1228⁎-overexpressing cells showed a significant reduction of vascular endothelial growth factor expression and secretion. Conditioned media from miR-1228⁎-overexpressing cells showed a reduced capacity to promote endothelial cell migration and tube formation. Mechanistically, macrophage migration inhibitory factor (MIF) was identified as a direct target gene of miR-1228⁎. Enforced expression of MIF rescued gastric cancer cells from miR-1228⁎-mediated suppression of proliferation and angiogenesis. In vivo xenograft mouse studies further demonstrated that co-expression of MIF with miR-1228⁎ in gastric cancer cells significantly restored tumor growth and increased microvascular density. Taken together, miR-1228⁎ acts as a negative regulator of gastric cancer growth and angiogenesis through downregulation of MIF. This work suggests miR-1228⁎ as a potential target for anti-angiogenic therapy against gastric cancer.

[Effect of emodin on pancreatic fibrosis: experiment with rats].

OBJECTIVE: To study the effect of emodin on pancreatic fibrosis and potential mechanism thereof. METHODS: Fifty SD rats were randomly divided into 5 equal groups: normal control group, model control group, low-dose emodin-treated group, mediate-dose emodin-treated group, and high-dose emodin-treated group. The rats of the latter 4 groups underwent infusion of trinitrobenzene sulfonic acid (TNBS) into the pancreatic duct so as to establish models of pancreatic fibrosis. The emodin-treated rats were fed with different doses of emodin (20, 40, and 80 mg/kg body weight), while the normal and model control groups received 0.9% sodium chloride solution instead. Twenty-eight days later the rats were killed, blood samples were collected, and their pancreases were taken out. The serum levels of hyaluronic acid (HA) and laminin (LN) were determined by radioimmunoassay. The histopathological alterations were studied by optical microscopy. The expression of collagen was examined by Van Gieson staining. Western blotting was used to detect the protein expression of transforming growth factor-beta(1) (TGF-beta(1)). RESULTS: (1) The serum level of HA of the low-dose, mediate-dose, and high-dose emodin-treated groups were 87 microg/L +/- 22 microg/L, 78 microg/L +/- 25 microg/L, and 62 microg/L +/- 19 microg/L respectively, all significantly lower than that of the model control group (113 microg/L +/- 27 microg/L, P < 0.05 or < 0.01). The serum levels of laminin in the low-dose, mediate-dose, and high-dose emodin-treated groups were 67 microg/L +/- 14 microg/L, 57 microg/L +/- 12 microg/L, and 44 microg/L +/- 10 microg/L respectively, all significantly lower than that of the model control group (86 microg/L +/- 17 microg/L, P < 0.05 or P < 0.01); (2) The degrees of fibrosis of the emodin-treated groups were obviously ameliorated in comparison with the model control group, the higher the dose of emodin the more improved the pathological changes, especially in the high-dose emodin-treated group (P < 0.05). (3) The percentages of collagen positive cells of the low-dose, mediate-dose, and high-dose emodin-treated groups were 39% +/- 7%, 38% +/- 4%, and 36% +/- 5% respectively, all lower than that of the model control group (42% +/- 6%), with a significant difference between the high-dose emodin-treated group and the model control group (P < 0.05). (4) The protein content of TGF-beta(1) of the low-dose, mediate-dose, and high-dose emodin-treated groups were 44.3% +/- 2.1%, 39.2% +/- 1.8%, and 28.8% +/- 1.6% respectively, all significantly lower than that of the model control group (60.7% +/- 1.7%, all P < 0.05), and the protein content of TGF-beta(1) of the high-dose emodin-treated group was significantly lower than those of the other 2 emodin-treated groups (both P < 0.05). CONCLUSION: Emoidn has an anti-fibrosis effect on pancreatic fibrosis, which maybe related to the content of TGF-beta(1) protein.

Sonic Hedgehog-GLI Family Zinc Finger 1 Signaling Pathway Promotes the Growth and Migration of Pancreatic Cancer Cells by Regulating the Transcription of Eukaryotic Translation Initiation Factor 5A2.

OBJECTIVES: The Hh (hedgehog) signaling pathway is still waiting for further studies because its downstream molecular mechanism remains elusive. Because EIF5A2 (eukaryotic translation initiation factor 5A2) gene was up-regulated upon Gli1 (GLI family zinc finger 1) in pancreatic cancer (PC) cells, we speculated that this pathway might promote tumor progression through regulating EIF5A2. METHODS: We investigated regulation effect of Hh signaling pathway to EIF5A2 gene transcription by Gli1 knockdown or overexpression in PC cell lines first. Then, the regulation mechanism of Gli1 to EIF5A2 gene was studied at transcription level. Finally, we studied cancer-promoting effects of Gli1-dependent EIF5A2 in PC cells. RESULTS: The data showed that Gli1 up-regulated expression of EIF5A2 by promoting transcription via cis-acting elements in PC cells. Moreover, vimentin gene was up-regulated significantly by sonic hedgehog (SHh)/Gli1 expression increasing, and E-cadherin was significantly reduced. The EIF5A2 knockdown partially reversed cell proliferation and migration induced by artificial SHh overexpression and inhibited epithelial mesenchymal transition process in PC cells with SHh overexpression (P < 0.05). CONCLUSIONS: Our data establish a novel transcription mechanism of Gli1 to EIF5A2 gene in cis-regulatory manner in PC cells. Thus, EIF5A2 oncogene effect could be incorporated into cancer-promoting molecular network upon Hh signaling pathway.

Smad4 loss synergizes with TGFα overexpression in promoting pancreatic metaplasia, PanIN development, and fibrosis.

AIMS: While overexpression of TGFα has been reported in human pancreatic ductal adenocarcinoma (PDAC), mice with overexpressed TGFα develop premalignant pancreatic acinar-to-ductal metaplasia (ADM) but not PDAC. TGF-ß signaling pathway is pivotal to the development of PDAC and tissue fibrosis. Here we sought to investigate the interplay between TGFα and TGF-ß signaling in pancreatic tumorigenesis and fibrosis, namely via Smad4 inactivation. METHODS: The MT-TGFα mouse was crossed with a new Smad4 conditional knock-out mouse (Smad4flox/flox;p48-Cre or S4) to generate Smad4flox/flox;MT-TGFα;p48-Cre (STP). After TGFα overexpression was induced with zinc sulfate water for eight months, the pancreata of the STP, MT-TGFα, and S4 mice were examined for tumor development and fibrotic responses. PanIN lesions and number of ducts were counted, and proliferation was measured by Ki67 immunohistochemistry (IHC). Qualitative analysis of fibrosis was analyzed by Trichrome Masson and Sirius Red staining, while vimentin was used for quantification. Expression analyses of fibrosis, pancreatitis, or desmoplasia associated markers (α-SMA, Shh, COX-2, Muc6, Col1a1, and Ctgf) were performed by IHC and/or qRT-PCR. RESULTS: Our STP mice exhibited advanced ADM, increased fibrosis, increased numbers of PanIN lesions, overexpression of chronic pancreatitis-related marker Muc6, and elevated expression of desmoplasia-associated marker Col1A1, compared to the MT-TGFα mice. The inactivation of Smad4 in the exocrine compartment was responsible for both the enhanced PanIN formation and fibrosis in the pancreas. The phenotype of the STP mice represents a transient state from ADMs to PanINs, closely mimicking the interface area seen in human chronic pancreatitis associated with PDAC. CONCLUSION: We have documented a novel mouse model, the STP mice, which displayed histologic presentations reminiscent to those of human chronic pancreatitis with signs of early tumorigenesis. The STP mice could be a suitable animal model for interrogating the transition of chronic pancreatitis to pancreatic cancer.

[Inhibition of angiogenesis in pancreatic carcinoma by cyclooxygenase-2 antisense oligodeoxynucleotides].

OBJECTIVE: To investigate the effect of cyclooxygenase-2 antisense oligodeoxynucleotides (COX-2 AS-ODNs) on the angiogenesis in pancreatic carcinoma and to evaluate the intermediary effect of prostaglandin 2 in this process. METHODS: Specific targeting COX-2 AS-ODNs were designed and synthesized, and transfected into the PC3 human pancreatic carcinoma cells cultured in vitro. Fluorescence microscopy was used to observe the PC3 cells 0.12. 24, 40, and 72 hours after the transfection. the second cultured PC3 cells were divided into 5 groups: control group, Lipo group (transfected with Lipofectin only), C1 group (transfected with 1 micro g COX-2 AS-ODN + Lipo/well), C2 group (transfected with 2 micro g COX-2 AS-ODN + Lipo/well), and C3 group (transfected with 3 micro g COX-2 AS-ODN + Lipo/well). RT-PCR was used to observe the expression of COX-2 mRNA in the PC3 cells. The third batch of PC3 cells were transfected with 3 micro g COX-2 AS-ODN + Lipo/well, and the expression of COX-2 mRNA was observed 0, 12, 24, 48, and 72 hours later by RT-PCR. 3 micro g COX-2 AS-ODN + Lipo/bottle and 9 micro g COX-2 AS-ODN + Lipo/bottle were added into the cultured PC3 cells and Western blotting was used to observe the expression of COX-2 protein 24 hours later. 24 chicken eggs were inoculated with PC3 cells into the chorio-allantoic membrane and then divided equally into 5 groups; control group, Lipo group, COX-2 AS-ODN + Lipo group, and COX-2 AS-ODN + Lipo + PGE2 group. Leica microscopy was used to observe the angiogenesis in the transplanted carcinoma. RESULTS: RT-PCR showed that the downregulation of expression of COX-2 mRNA in the PC3 cells with the increase of the COX-2 AS-ODN concentration, peaking at the concentration of 0.2 micro mol/L. The effect of COX-2 AS-ODN was strongest by the 12th hour after transfection and then began to decrease and basically disappeared 48 hours after. Western blotting showed that COX-2 AS-ODN, especially that of the concentration of the expression of 9 micro g/bottle, inhibited the expression of COX-2 AS-ODN. The angiogenesis of the transplanted carcinoma in the eggs was significantly inhibited in the Lipo + COX-2 AS-ODN group, the density of newly generated vessels in the Lipo + COX-2 AS-ODN + PGE2 group was between those of the other 2 groups. CONCLUSION: COX-2 AS-ODN significantly inhibits the angiogenesis in the pancreatic carcinoma. Endogenous COX-2 AS-ODN may play an important role in such a process and PGE2 may play an intermediate role therein.

Sonic hedgehog-Gli1 signaling pathway regulates the epithelial mesenchymal transition (EMT) by mediating a new target gene, S100A4, in pancreatic cancer cells.

AIMS: The hedgehog signaling pathway plays an important role in EMT of pancreatic cancer cells, but the precise mechanisms remain elusive. Because S100A4 as a key EMT moleculer marker was found to be upregulated upon Gli1 in pancreatic cancer cells, we focused on the relationship between Shh-Gli1 signals and S100 genes family. METHODS: On the base of cDNA microarray data, we investigated regulating mechanism of Gli1 to some members of S100A genes family in pancreatic cancer cell lines firstly. Then, the regulation of Gli1 to S100A4 gene was studied by molecular biology assays and the pro-metastasis effection of Gli1-dependent S100A4 was investigated in vitro. Finally, the expressions of Shh, Gli1, S100A4 and E-cadherin in pancreatic cancer tissues were studied by using immunohistochemistry assays. RESULTS: Five members of the S100 genes family, S100A2, S100A4, S100A6, S100A11, and S100A14 were found to be downregulated significantly upon Gli1 knockdown. Gli1 enhancer prediction combining with in vitro data demonstrated that Gli1 primarily regulates S100A family members via cis-acting elements. Indeed, the data indicate S100A4 and vimentin genes were upregulated significantly by Shh/Gli1-expression increasing and E-cadherin was significantly reduced at the same time. Migration of PC cells was increased significantly in a dose-dependent manner of Gli1 expression (P<0.05) and siS100A4 significantly reversed the response of PC cells induced by L-Shh transduction (P<0.01). CONCLUSION: Our data establish a novel connection between Shh-Gli1 signaling and S100A4 regulation, which imply that S100A4 might be one of the key factors in EMT mediated by Shh-Gli1 signaling in pancreatic cancer.

Restoration of miR-1228* expression suppresses epithelial-mesenchymal transition in gastric cancer.

Dysregulated miRNAs play critical roles during carcinogenesis and cancer progression. In the present study, the function of miR-1228* in regulating cancer progression was investigated in gastric cancer. Decreased expression of miR-1228* was observed in human gastric cancer tissues comparing to normal tissues. Subsequently, the role of miR-1228* was evaluated in vivo using the tumor xenograft model. In this model, miR-1228* overexpression suppressed xenograft tumor formation. Furthermore, we demonstrated miR-1228* negatively regulated NF-κB activity in SGC-7901 gastric cancer cells and found that CK2A2 was a target of miR-1228*. Upregulation of miR-1228* decreased the expression of mesenchymal markers and increased the epithelial marker E-cadherin, suggesting its potential role in suppressing epithelial-mesenchymal transition. Collectively, these findings provide the first evidence that miR-1228* plays an important role in regulating gastric cancer growth and suggest that selective restoration of miR-1228* might be beneficial for gastric cancer therapy.

K-Ras resides on the Arf6-mediated CIE system and its active type interacted with Arf6T27N.

Ras is known as an oncogene transferring signals from the plasma membrane. Recent studies have demonstrated that plasma membrane was not the unique platform for Ras signaling. Ras could also be endocytosed and transported to different endomembrane compartments, evoking different signal pathways there. It is of great significance to exploit the unique intracellular trafficking features of different Ras isoforms to develop new anti-Ras drugs. ADP-ribosylation factor 6 (Arf6) was known to mediate one of the clathrin-independent endocytosis (CIE) pathways. The role of Arf6 in K-Ras dynamic remains largely unknown. In this study, we showed that K-RasG12V co-localized with Arf6 at the plasma membrane, and entered the tubular endosomes or protrusions induced by cytochalasin D or aluminum fluoride in the same way as H-RasG12V does. A subcellular fractionation experiment demonstrated that Arf6 siRNA treatment reduced the plasma membrane presence of both endogenous Ras isoforms and inhibited the phosphorylation of Erk triggered by EGF. When co-expressed with Arf6Q67L, both isoforms were sequestered into the large phosphatidylinositol 4,5-biphosphate [PI(4,5)P2]-enriched vacuoles. However, when co-expressed with Arf6T27N, K-RasG12V co-localized with Arf6T27N at the tubular endosomes significantly than H-RasG12V. Immunoprecipitation and GST fusion protein pull-down studies found out for the first time that K-RasG12V interacted with Arf6T27N. Swapping mutation study showed that the above difference was due to different C-termini. Our study indicated that Arf6 was involved in the dynamic regulation of both Ras isoforms.

Down-regulation of GEP100 causes increase in E-cadherin levels and inhibits pancreatic cancer cell invasion.

AIMS: Invasion and metastasis are major reasons for pancreatic cancer death and identifying signaling molecules that are specifically used in tumor invasion is of great significance. The purpose of this study was to elucidate the role of GEP100 in pancreatic cancer cell invasion and metastasis and the corresponding molecular mechanism. METHODS: Stable cell lines with GEP100 knocked-down were established by transfecting GEP100 shRNA vector into PaTu8988 cells and selected by puromycin. qRT-PCR and Western blot were performed to detect gene expression. Matrigel-invasion assay was used to detect cancer cell invasion in vitro. Liver metastasis in vivo was determined by splenic injection of indicated cell lines followed by spleen resection. Immunofluorescence study was used to detect the intracellular localization of E-cadherin. RESULTS: We found that the expression level of GEP100 protein was closely related to the invasive ability of a panel of 6 different human pancreatic cancer cell lines. Down-regulation of GEP100 in PaTu8988 cells significantly decreased invasive activity by Matrigel invasion assay, without affecting migration, invasion and viability. The inhibited invasive activity was rescued by over-expression of GEP100 cDNA. In vivo study showed that liver metastasis was significantly decreased in the PaTu8988 cells with GEP100 stably knocked-down. In addition, an epithelial-like morphological change, mimicking a mesenchymal to epithelial transition (MET) was induced by GEP100 down-regulation. The expression of E-cadherin protein was increased 2-3 folds accompanied by its redistribution to the cell-cell contacts, while no obvious changes were observed for E-cadherin mRNA. Unexpectedly, the mRNA of Slug was increased by GEP100 knock-down. CONCLUSION: These findings provided important evidence that GEP100 plays a significant role in pancreatic cancer invasion through regulating the expression of E-cadherin and the process of MET, indicating the possibility of it becoming a potential therapeutic target against pancreatic cancer.

Genome-wide screening reveals an EMT molecular network mediated by Sonic hedgehog-Gli1 signaling in pancreatic cancer cells.

AIMS: The role of sonic hedgehog (SHH) in epithelial mesenchymal transition (EMT) of pancreatic cancer (PC) is known, however, its mechanism is unclear. Because SHH promotes tumor development predominantly through Gli1, we sought to understand its mechanism by identifying Gli1 targets in pancreatic cancer cells. METHODS: First, we investigated invasion, migration, and EMT in PC cells transfected with lentiviral Gli1 interference vectors or SHH over-expression vectors in vitro and in vivo. Next, we determined the target gene profiles of Gli1 in PC cells using cDNA microarray assays. Finally, the primary regulatory networks downstream of SHH-Gli1 signaling in PC cells were studied through functional analyses of these targets. RESULTS: Our results indicate there is decreased E-cadherin expression upon increased expression of SHH/Gli1. Migration of PC cells increased significantly in a dose-dependent manner within 24 hours of Gli1 expression (P<0.05). The ratio of liver metastasis and intrasplenic miniature metastasis increased markedly upon activation of SHH-Gli1 signals in nude mice. Using cDNA microarray, we identified 278 upregulated and 59 downregulated genes upon Gli1 expression in AsPC-1 cells. The data indicate that SHH-Gli1 signals promote EMT by mediating a complex signaling network including TGFß, Ras, Wnt, growth factors, PI3K/AKT, integrins, transmembrane 4 superfamily (TM4SF), and S100A4. CONCLUSION: Our results suggest that targeting the molecular connections established between SHH-Gli1 signaling and EMT could provide effective therapies for PC.