Light-scattering-induced retardation as a high-sensitivity image contrast revealing collagen fibers.

Retardation induced by media can be used as an image contrast to depict the cumulative birefringent features and local variations of the sample, respectively. It is commonly assumed that the retardation is induced by the light propagation; however, the light scattering would generate the retardation as well. In our work, the scattering-induced retardation as a high-sensitivity image contrast for revealing collagen fibers is presented. First, it is shown that the retardation induced by fiber scattering is equal to π when modeled as cylinders. Using the data for the chicken breast and the palm measured by the polarization-sensitive optical coherence tomography system as an example, the scattering-induced retardation is calculated. The measured value of π is in complete agreement with the theory, and the corresponding retardation per unit distance is two orders of magnitude greater than the light-propagation-induced retardation, demonstrating its predominant role on the overall retardation and providing a possibility for highly sensitive displays. Compared with the accumulated retardation image and the differential retardation image, the scattering-induced retardation images could exhibit sharper fiber structures even in deeper regions. This work might be helpful for the early diagnosis of collagen-related diseases.

Circular RNA circLOC101928570 suppresses systemic lupus erythematosus progression by targeting the miR-150-5p/c-myb axis.

BACKGROUND: Accumulating evidence supports the implication of circular RNAs (circRNAs) in systemic lupus erythematosus (SLE). However, little is known about the detailed mechanisms and roles of circRNAs in the pathogenesis of SLE. METHODS: Quantitative real-time PCR was used to determine the levels of circLOC101928570 and miR-150-5p in peripheral blood mononuclear cells of SLE. Overexpression and knockdown experiments were conducted to assess the effects of circLOC101928570. Fluorescence in situ hybridization, RNA immunoprecipitation, luciferase reporter assays, Western blot, flow cytometry analysis and enzyme-linked immunosorbent assay were used to investigate the molecular mechanisms underlying the function of circLOC101928570. RESULTS: The results showed that the level of circLOC101928570 was significantly downregulated in SLE and correlated with the systemic lupus erythematosus disease activity index. Functionally, circLOC101928570 acted as a miR-150-5p sponge to relieve the repressive effect on its target c-myb, which modulates the activation of immune inflammatory responses. CircLOC101928570 knockdown enhanced apoptosis. Moreover, circLOC101928570 promoted the transcriptional level of IL2RA by directly regulating the miR-150-5p/c-myb axis. CONCLUSION: Overall, our findings demonstrated that circLOC101928570 played a critical role in SLE. The downregulation of circLOC101928570 suppressed SLE progression through the miR-150-5p/c-myb/IL2RA axis. Our findings identified that circLOC101928570 serves as a potential biomarker for the diagnosis and therapy of SLE.

Long noncoding RNA ITGB2-AS1 promotes growth and metastasis through miR-4319/RAF1 axis in pancreatic ductal adenocarcinoma.

Long noncoding RNA (lncRNA) has been considered as potentially critical regulators in pancreatic ductal adenocarcinoma (PDAC). In this study, we prospectively investigate the effect and mechanism of lncRNA integrin subunit beta 2-anti-sense RNA 1 (ITGB2-AS1) on regulation of PDAC progression. The expression of ITGB2-AS1 and its target were analyzed by quantitative real-time polymerase chain reaction and in situ hybridization. 3-(4,5-Dimethylthiazol-z-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, wound healing, and transwell assays were used to investigate the influence of ITGB2-AS1 on cell proliferation, cell cycle, migration, and invasion, respectively. The interaction between ITGB2-AS1 and its target was determined via luciferase activity assay and RNA immunoprecipitation. The subcutaneous xenotransplanted tumor model was established and employed to detect the tumorigenic function of ITGB2-AS1, which was evaluated by western blot analysis, immunohistochemistry, and hematoxylin and eosin staining. The results showed that ITGB2-AS1 was elevated in both PDAC tumor tissues and cell lines, predicting a poor prognosis in PDAC patients. Knocking down of ITGB2-AS1 suppressed PDAC cell proliferation, invasion, and migration but induced cell apoptosis in vitro. Moreover, ITGB2-AS1 could target and inhibit the expression of miR-4319 and miR-4319-targeted and -suppressed serine/threonine kinase RAF1. ITGB2-AS1 promoted PDAC progression via inhibition of miR-4319. Interference of ITGB2-AS1 could suppress in vivo tumorigenic ability of PDAC via downregulation of RAF1. In conclusion, ITGB2-AS1 promoted PDAC progression via sponging miR-4319 to upregulate RAF1, suggesting the potential therapeutic target ability of ITGB2-AS1 in PDAC.

LncRNA differentiation antagonizing non-protein coding RNA promotes proliferation and invasion through regulating miR-135a/NLRP37 axis in pancreatic cancer.

Background It is well-known that long-chain non-coding RNA (LncRNA) plays an important role in the development of tumor. DANCR, which is one crucial part of the lncRNA family, has been shown to be involved in the invasion of various tumors. However, its molecular mechanism in pancreatic cancer remains unknown. Methods qRT-PCR was used to detect the expression of DANCR, miR-135a mRNA in pancreatic cancer tissues or cells. E-cadherin and NLRP3 protein levels were measured by Western Blot. CCK-8, cell scratch, and transwell assays were applied to detect the proliferation and invasion of pancreatic cancer cells. Bioinformatical analysis and luciferase assay were performed to explore the relationship among DANCR, miR-135a and NLRP3. Results In pancreatic cancer, DANCR was up-regulated while miR-135a was down-regulated. The over-expression of DANCR promoted the proliferation and invasion of pancreatic cancer cells. A negative relationship was found between DANCR and miR-135a expression. Moreover, we found that miR-135a reversed the effects of DANCR in the promoting of pancreatic cancer cells, which was achieved by regulating the downstream protein of NLRP3. The correlations among DANCR, miR-135a and NLRP3 were confirmed in animal experiments. Conclusion DANCR promoted proliferation and invasion through the regulating of miR-135a / NLRP3 axis in pancreatic cancer cell. Our results suggest that DANCR may be a potential target for the therapy of pancreatic cancer.

Reciprocal loop of hypoxia-inducible factor-1α (HIF-1α) and metastasis-associated protein 2 (MTA2) contributes to the progression of pancreatic carcinoma by suppressing E-cadherin transcription.

Metastasis-associated protein 2 (MTA2) is overexpressed in certain malignancies, and plays important roles in tumour metastasis and progression. The present study highlights the function of MTA2 in pancreatic carcinoma through its role as a deacetylator of hypoxia-inducible factor-1α (HIF-1α) and a cotranscriptional factor for E-cadherin expression. We found that overexpression of MTA2 promoted, and knockdown of MTA2 inhibited, the invasion and proliferation of pancreatic carcinoma cells both in vitro and in xenograft models in vivo. We also found that MTA2 is transcriptionally upregulated by HIF-1α through a hypoxia response element (HRE) of the MTA2 promoter in response to hypoxia. Reciprocally, MTA2 deacetylates HIF-1α and enhances its stability through interacting with histone deacetylase 1 (HDAC1). Consequently, HIF-1α recruits MTA2 and HDAC1 to the HRE of the E-cadherin promoter, by which E-cadherin transcription is repressed. In agreement with these experimental results, MTA2 is positively associated with HIF-1α, but inversely correlated with E-cadherin, in pancreatic carcinoma samples. Moreover, data from The Cancer Genome Atlas on 172 pancreatic carcinomas indicate an association between high expression of MTA2 and short overall survival. Taken together, our study identifies MTA2 as a critical hub and potential therapeutic target to inhibit the progression and metastasis of pancreatic carcinoma. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Impact of age on survival of patients with pancreatic cancer after surgery: Analysis of SEER data.

BACKGROUND: To explore the impact of age on all-cause death and cancer-specific death in patients with pancreatic duct adenocarcinoma (PDAC) undergoing surgery. MATERIALS AND METHODS: Individuals with PDAC undergoing surgery between 2004 and 2013 (N = 11,138) were retrospectively studied from the Surveillance, Epidemiology, and End Results (SEER) cancer registry database. The impact of age on all-cause death and cancer-specific death was assessed using Cox regression model and competing risk model respectively. RESULTS: Multivariate Cox regression analysis indicated that the risks of all-cause death increased with age: hazard ratios (95% confidence interval, 95%CI) were 1.10 (1.04-1.17), 1.31 (1.23-1.38), 1.47 (1.35-1.61) for groups 61-70 years, 71-80 years, and >80 years, respectively, compared with ≤60 years. Multivariate competing risk analysis indicated that the risk of cancer-specific death was similar between patients ≤60 years and 61-70 years (subhazard ratio 0.93; 95% confidence interval 0.87-1.00), but decreased in patients 71-80 years (subhazard ratio 0.84; 95%CI 0.79-0.90) and >80 years (subhazard ratio 0.76; 95%CI 0.68-0.85). CONCLUSION: Age at diagnosis appeared to be an independent predictor of prognosis, with reverse impacts on all-cause death and cancer-specific death.

Up-regulation of glycolysis promotes the stemness and EMT phenotypes in gemcitabine-resistant pancreatic cancer cells.

Cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT)-type cells are considered as underlying causes of chemoresistance, tumour recurrence and metastasis in pancreatic cancer. We aimed to describe the mechanisms - particularly glycolysis - involved in the regulation of the CSC and EMT phenotypes. We used a gemcitabine-resistant (GR) Patu8988 cell line, which exhibited clear CSC and EMT phenotypes and showed reliance on glycolysis. Inhibition of glycolysis using 2-deoxy-D-glucose (2-DG) significantly enhanced the cytotoxicity of gemcitabine and inhibited the CSC and EMT phenotypes in GR cells both in vitro and in vivo. Intriguingly, the use of the reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) restored the CSC and EMT phenotypes. H2 O2 produced changes similar to those of 2-DG, indicating that ROS were involved in the acquired cancer stemness and EMT phenotypes of GR cells. Moreover, doublecortin-like kinase 1 (DCLK1), a pancreatic CSC marker, was highly expressed and regulated the stemness and EMT phenotypes in GR cell. Both 2-DG and H2 O2 treatment suppressed DCLK1 expression, which was also rescued by NAC. Together, these findings revealed that glycolysis promotes the expression of DCLK1 and maintains the CSC and EMT phenotypes via maintenance of low ROS levels in chemoresistant GR cells. The glycolysis-ROS-DCLK1 pathway may be potential targets for reversing the malignant behaviour of pancreatic cancer.

Serum calcium as an indicator of persistent organ failure in acute pancreatitis.

AIM: Decreased level of serum calcium was commonly seen in critical illness. Hypocalcemia was significantly more frequent in patients with severe form of acute pancreatitis (AP), and a negative correlation was observed between endotoxemia and serum calcium in AP. AP patients with persistent organ failure (POF) show an extremely high mortality. The association underlying calcium and POF in AP has not been characterized. METHODS: We conducted a retrospective cohort study of adult patients who presented within 72hours from symptom onset of AP at our center between January 2014 and May 2015. Demographic parameters on admission, organ failure assessment, laboratory data and in-hospital mortality were compared between patients with and without POF. Uni-and multi-variate logistic regression analyses were utilized to evaluated the predictive ability of serum calcium. RESULTS: A total of 128 consecutive AP patients, including 29 with POF, were included. Compared to patients without POF, patients with POF showed a significantly lower value of serum calcium on admission (2.11±0.46 vs. 1.55±0.36mmol/L, P<0.001). After multivariate logistic analysis, serum calcium remained an independent risk factor for POF (Hazard ratio 0.21, 95% confident interval: 0.08-0.58; P=0.002). A calcium value of 1.97mmol/L predicted POF with an area under the curve (AUC) of 0.888, a sensitivity with 89.7% and specificity with 74.8%, respectively. CONCLUSION: Our results indicate that serum calcium on admission is independently associated with POF in AP and may serve as a potential prognostic factor.

Plasma miRNAs Effectively Distinguish Patients With Pancreatic Cancer From Controls: A Multicenter Study.

OBJECTIVES: To identify plasma microRNA (miRNA) markers of pancreatic cancer (PC). BACKGROUND: Accurate pretreatment diagnosis of PC remains challenging, whether plasma miRNAs could be used as biomarkers in PC remains unknown. METHODS: In this multiphase multicenter study, peripheral blood samples were obtained preoperatively in 3 phases: the discovery phase [7 patients with PC, 6 patients with chronic pancreatitis (CP), and 5 healthy volunteers (N)], the preliminary validation phase (29 patients with PC, 16 patients with CP, and 31 N), and the large sample validation phase (156 patients with PC, 65 N, 57 patients with CP, 27 patients with pancreatic neuroendocrine tumors, and 58 patients with other pancreatic tumors). The diagnostic values of the miRNAs were assessed and compared with cancer antigen 19-9 (CA19-9). RESULTS: The discovery phase demonstrated that 29 miRNAs were dysregulated in the patients with PC compared with the controls. In the preliminary validation phase, 13 miRNAs were shown to be dysregulated in the patients with PC and were selected for validation in a multicenter trial. MiR-486-5p exhibited diagnostic value in discriminating patients with PC from normal subjects or patients with CP, with area under the curve values of 0.861 and 0.707, respectively. MiR-938 exhibited diagnostic value in differentiating patients with PC from those with CP, pancreatic neuroendocrine tumors, and patients with other pancreatic tumors, with area under the curve values of 0.693, 0.660, and 0.618, respectively. In addition, we demonstrated that the value of miR-486-5p in discriminating patients with PC from normal subjects or patients with CP was comparable with that of CA19-9 (P = 0.602 and P = 0.230). CONCLUSIONS: This study identified several plasma miRNAs potentially suitable for distinguishing patients with PC from normal subjects or patients with other pancreatic tumors.

PARP-1 mediates LPS-induced HMGB1 release by macrophages through regulation of HMGB1 acetylation.

The high-mobility group box protein 1 (HMGB1) is increasingly recognized as an important inflammatory mediator. In some cases, the release of HMGB1 is regulated by poly(ADP-ribose) polymerase-1 (PARP-1), but the mechanism is still unclear. In this study, we report that PARP-1 activation contributes to LPS-induced PARylation of HMGB1, but the PARylation of HMGB1 is insufficient to direct its migration from the nucleus to the cytoplasm; PARP-1 regulates the translocation of HMGB1 to the cytoplasm through upregulating the acetylation of HMGB1. In mouse bone marrow-derived macrophages, genetic and pharmacological inhibition of PARP-1 suppressed LPS-induced translocation and release of HMGB1. Increased PARylation was accompanied with the nucleus-to-cytoplasm translocation and release of HMGB1 upon LPS exposure, but PARylated HMGB1 was located at the nucleus, unlike acetylated HMGB1 localized at the cytoplasm in an import assay. PARP inhibitor and PARP-1 depletion decreased the activity ratio of histone acetyltransferases to histone deacetylases that elevated after LPS stimulation and impaired LPS-induced acetylation of HMGB1. In addition, PARylation of HMGB1 facilitates its acetylation in an in vitro enzymatic reaction. Furthermore, reactive oxygen species scavenger (N-acetyl-l-cysteine) and the ERK inhibitor (FR180204) impaired LPS-induced PARP activation and HMGB1 release. Our findings suggest that PARP-1 regulates LPS-induced acetylation of HMGB1 in two ways: PARylating HMGB1 to facilitate the latter acetylation and increasing the activity ratio of histone acetyltransferases to histone deacetylases. These studies revealed a new mechanism of PARP-1 in regulating the inflammatory response to endotoxin.

Heparin inhibits the inflammatory response induced by LPS and HMGB1 by blocking the binding of HMGB1 to the surface of macrophages.

High mobility group box 1 protein (HMGB1), a nuclear non-histone DNA-binding protein, is secreted extracellularly during inflammation and is a late mediator of inflammatory responses. The pro-inflammatory activity of recombinant HMGB1 proteins is dependent upon the formation of complexes with other mediators, such as lipopolysaccharide (LPS). This study investigated the influence of heparin on LPS+HMGB1-mediated inflammatory responses in cultured macrophages and a murine sepsis model. HMGB1 promoted the phosphorylation of p38 and ERK1/2. HMGB1 enhanced the induction of the pro-inflammatory cytokine, TNF-α, by LPS in macrophages. Heparin blocked the binding of HMGB1 to the surface of macrophages, and suppressed the phosphorylation of p38 and ERK1/2, but not JNK; TNF-α secretion was also decreased. However, heparin alone did not affect LPS-induced production of TNF-α. Heparin reduced lethality in mice exposed to LPS+HMGB1. To conclude, heparin inhibited LPS-induced HMGB1-amplified inflammatory responses by blocking HMGB1 binding to macrophage surfaces. Heparin could be used therapeutically as an effective inhibitor of HMGB1-associated inflammation.

MicroRNA-217 functions as a prognosis predictor and inhibits colorectal cancer cell proliferation and invasion via an AEG-1 dependent mechanism.

BACKGROUND: Recent studies have indicated the possible function of miR-217 in tumorigenesis. However, the roles of miR-217 in colorectal cancer (CRC) are still largely unknown. METHODS: We examined the expression of miR-217 and AEG-1 in 50 CRC tissues and the corresponding noncancerous tissues by qRT-PCR. The clinical significance of miR-217 was analyzed. CRC cell lines with miR-217 upregulation and AEG-1 silencing were established and the effects on tumor growth in vitro and in vivo were assessed. Dual-luciferase reporter gene assays were also performed to investigate the interaction between miR-217 and AEG-1. RESULTS: Our data demonstrated that miR-217 was significantly downregulated in 50 pairs of colorectal cancer tissues. MiR-217 expression levels were closely correlated with tumor differentiation. Moreover, decreased miR-217 expression was also associated with shorter overall survival of CRC patients. MiR-217 overexpression significantly inhibited proliferation, colony formation and invasiveness of CRC cells by promoting apoptosis and G0/G1 phase arrest. Interestingly, ectopic miR-217 expression decreased AEG-1 expression and repressed luciferase reporter activity associated with the AEG-1 3'-untranslated region (UTR). AEG-1 silencing resulted in similar biological behavior changes to those associated with miR-217 overexpression. Finally, in a nude mouse xenografted tumor model, miR-217 overexpression significantly suppressed CRC cell growth. CONCLUSIONS: Our findings suggest that miR-217 has considerable value as a prognostic marker and potential therapeutic target in CRC.

Can pretreatment serum calcium level predict the efficacy of methotrexate in the treatment of severe plaque psoriasis?

BACKGROUND: The efficacy of methotrexate (MTX) varies in the treatment of psoriasis. OBJECTIVE: We sought to identify an indicator from routine pretreatment tests to predict MTX efficacy in the treatment of psoriasis. METHODS: In a retrospective analysis of 77 psoriatic patients, the correlation between MTX efficacy and pretreatment routine test results was analyzed with Spearman correlation. The potential risks were further evaluated with a linear regression model. Receiver operating characteristic analysis was performed to examine the effectiveness of serum total calcium (tCa) to predict the effect of MTX on psoriasis. The highest Youden index was used to determine the cutoff point, with which the positive and negative predictive values were calculated. Synergistic effects of MTX and calcium on keratinocyte growth and psoriasis-like mouse model were also investigated. RESULTS: The pretreatment tCa level exhibited the closest association with MTX efficacy. The relative psoriasis improvement with tCa was 61.07% (95% confidence interval, 42.85-79.29; P < .001) and better improvements were observed in patients with higher tCa (r = 0.588; P < .002). MTX inhibited keratinocyte growth, which was enhanced synergistically by calcium. In a psoriasis-like mouse model, MTX strongly inhibited epidermis proliferation in the high-calcium group. LIMITATIONS: One limitation of our study is the relatively small sample size. CONCLUSION: Pretreatment tCa level has the highest correlation with MTX efficacy, which might be useful in predicting beneficial treatment results in psoriasis. Larger studies are required to confirm our findings.

Mutations in the p16 gene in DMBA-induced pancreatic intraepithelial neoplasia and pancreatic cancer in rats.

BACKGROUND: 7, 12-dimethylbenzanthracene (DMBA)-induced pancreatic intraepithelial neoplasia (PanIN) and pancreatic cancer in rats provide a classic model for uncovering the molecular mechanisms underlying pancreatic cancer. However, this model has not been characterized genetically, and in particular, the major genetic alterations in the p16 gene are unknown. METHODS: Lesions of PanIN and pancreatic cancer were induced with DMBA implantation in 40 rats, and control pancreatic tissue was obtained from 10 age-matched rats without exposure to DMBA. Pancreatic tissue was harvested three months after DMBA implantation and DNA was extracted. Homozygous deletions and point mutations of the p16 (exons 1 and 2) gene were detected by PCR amplification and direct sequencing. RESULTS: DMBA implantation in the 40 rats induced 26 PanINs and 9 carcinomas. The overall frequency of p16 alterations in the pancreatic tissue of these rats was 42.86% (15/35), and the changes were point mutations, not homozygous deletions. p16 mutations were present in 30.77% (8/26) of the rats with PanIN and 77.78% (7/9) of the rats with carcinoma (P<0.05). The increasing incidence of p16 alterations was detected in 20.00% (1/5) of PanIN-1, 28.57% (2/7) of PanIN-2 and 35.71% (5/14) of PanIN-3 lesions. CONCLUSION: Our findings indicated that p16 alteration is a common event in the carcinogenesis of this model and that the mutation pattern is analogous to that of human lesions.

[History of surgical intervention in severe acute pancreatitis treatment].

Severe acute pancreatitis (SAP) is hard to treat for the abrupt onset, critical condition and complicated pathophysiology. Historically, the treatment strategy of SAP hovered between surgical intervention and conservative treatment. At the turn of the 20(th) century, SAP was reported to be cured by surgical intervention in a series cases, which lead to the dominance of surgical intervention in SAP treatment. Subsequently, SAP was documented to respond to nonoperative therapy. A wave of conservatism emerged, and surgical intervention for SAP was rarely practiced for the next 3 decades. However, surgeons refined the indications and considered new approaches for surgical treatment in 1960s because of the poor outcomes of conservation, and surgical interventions was mainly performed at early stage of SAP. However, a series of prospective studies showed that conservative treatment of patients with sterile pancreatic necrosis is superior to surgical intervention, and that delayed intervention provide improved outcomes in 1990s, which changed the treatment concept of SAP again. The modern treatment concept formed during the progression: organ supportive care dominates in the early stage of the disease, and surgical intervention should be performed at late stage with proper indications. Despite the advances in treatment, the morbidity of SAP is still 5%-20%, which suggests the pancreatic surgeons' exploration in the future.

[Surgical treatment of necrotizing pancreatitis: 10-year experience at a single center].

OBJECTIVE: To investigate the indication, timing and methods of surgery for acute necrotizing pancreatitis. METHODS: There were 5 538 patients with acute pancreatitis (AP) were treated in the Union Hospital, Tongji Medical College from January 2005 to December 2014. Of all AP cases, 2 415 patients with acute necrotizing pancreatitis proved by computed tomography, and 732 patients underwent surgical treatment. Among 732 patients with surgical treatment, 439 (60.0%) were males and two hundreds and ninety-three (40.0%) were females. The median age was 45 years, ranging 20-76 years. Two hundreds and eighty-nine cases were treated with minimally invasive debridement and drainage and 684 cases were treated with open debridement. RESULTS: The cure rate of minimally invasive operation was 16.6% (48/289). The rest of the 241 patients were treated furtherly with open necrosectomy. Among 684 patients with open surgery, 523 patients (76.5%) were infected, and the median time from the onset of symptom to first open operation was 46 d (range 19-205 d). There were 115 patients need to surgery again because of necrotic tissue residual and the reoperation rate was 16.81% (115/684), 684 patients were performed open surgery on average 1.26 times per person. The main postoperative complications were intra-abdominal hemorrhage (37 cases), upper digestive tract fistula (34 cases), colonic fistula (12 cases), gastrointestinal obstruction (29 cases) and pancreatic fistula (83 cases). The overall incidence of complications were 28.5% (195/684). Forty-nine cases died after surgery and the mortality rate was 6.7% (49/732). CONCLUSION: Rational surgical indications and timing of surgical intervention are the key to improve the efficacy of necrotizing pancreatitis, open debridement is still an effective method for necrotizing pancreatitis.

Sirtuin 1 facilitates chemoresistance of pancreatic cancer cells by regulating adaptive response to chemotherapy-induced stress.

Chemotherapy drugs themselves may act as stressors to induce adaptive responses to promote the chemoresistance of cancer cells. Our previous research showed that sirtuin 1 (SIRT1) was overexpressed in pancreatic cancer patients and deregulation of SIRT1 with RNAi could enhance chemosensitivity. Thus, we hypothesized that SIRT1 might facilitate chemoresistance in pancreatic cancer cells through regulating the adaptive response to chemotherapy-induced stress. In the present study, SIRT1 in PANC-1, BXPC-3, and ASPC-1 cells was upregulated after treatment with gemcitabine. Moreover, the decrease in SIRT1 activity with special inhibitor EX527 had a synergic effect on chemotherapy with gemcitabine in PANC-1 and ASPC-1 cell lines, which significantly promoted apoptosis, senescence, and G0 /G1 cycle arrest. Western blot results also showed that SIRT1, acetylated-p53, FOXO3a, and p21 were upregulated after combined treatment, whereas no obvious change was evident in total p53 protein. To further confirm the role of SIRT1 in clinical chemotherapy, SIRT1 was detected in eight pancreatic cancer tissues acquired by endoscopy ultrasonography guided fine needle aspiration biopsy before and after chemotherapy. Compared to before chemotherapy, SIRT1 was significantly increased after treatment with gemcitabine in six cases. Thus, our results indicated a special role for SIRT1 in the regulation of adaptive response to chemotherapy-induced stress, which is involved in chemoresistance. Moreover, it indicates that blocking SIRT1 activity with targeting drugs might be a novel strategy to reverse the chemoresistance of pancreatic cancer.

Valproic acid sensitizes pancreatic cancer cells to natural killer cell-mediated lysis by upregulating MICA and MICB via the PI3K/Akt signaling pathway.

BACKGROUND: Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, is reported to exert anti-tumor effects by upregulating the expression of the natural killer group 2D (NKG2D) ligands on tumor cells; however, the mechanisms vary in different tumor types, and the effect and mechanism of action of VPA in pancreatic cancer cells are unknown. METHODS: The present study evaluated the effect of VPA to susceptibility of pancreatic cancer cells to the NK cell-mediated lysis in vitro and in vivo. Then we investigated the mechanism which the effect of VPA depend on. RESULTS: The lactate dehydrogenase assay (LDH) and xenograft experiment demonstrated that VPA significantly sensitized pancreatic cancer cells to NK cell-mediated lysis in vitro and in vivo. Quantitative real time- polymerase chain reaction (qRT-PCR) and flow cytometry demonstrated that VPA upregulated the mRNA and cell surface expression of the NKG2D ligands major histocompatibility complex class I-related chain A and B (MICA and MICB) in pancreatic cancer cells. Effects of VPA both in vitro and in vivo were significantly attenuated by the PI3K/Akt pathway inhibitor LY294002 or a siRNA targeting PI3K catalytic subunit alpha isoform (PI3KCA). CONCLUSION: VPA enhances the susceptibility of pancreatic cancer cells to NK cell-mediated cytotoxicity both in vitro and in vivo by upregulating the expression of MICA and MICB via a PI3K/Akt signaling pathway-dependent mechanism.

Oncogenicity of LHX2 in pancreatic ductal adenocarcinoma.

The LIM proteins (Lhx1, Lhx2, Lhx3 and Lhx4) have been report to play important roles in human development. The function role of Lhxs have been characterized in various tumor tissues as cancer suppressors or promoters in different can status and types. The aim of present study was to clarify the function role of Lhx proteins in human pancreatic ductal adenocarcinoma (PDA). The gene expression profiles of Lhxs was evaluated using real-time quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) analysis and immunohistochemistry in human PDA tissues compared with normal pancreatic tissues, which identified the gene overexpression of Lhx2 in PDA. Furthermore, we discovered that Lhx2 promoted cancer cell proliferation in vitro/vivo and elevated ß-catenin levels correlated with Lhx2 expression in PDA while the Lhx2 simulated ß-catenin activation was required for LMO1's oncogenic effects. Mechanistically, Lhx2 facilitate TCF4 to bind to ß-catenin and form a stable Lhx2/TCF4/ß-catenin complex and trans-active its downstream target gene. Lhx2 mutations that disrupt the Lhx2-ß-catenin interaction partially prevent its function in tumor cells.

Use of probiotics in the treatment of severe acute pancreatitis: a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Necrotic tissue infection can worsen the prognosis of severe acute pancreatitis (SAP), and probiotics have been shown to be beneficial in reducing the infection rate in animal experiments and primary clinical trials. However, the results of multicenter randomized clinical trials have been contradictory. Our aim in this study was to systematically review and quantitatively analyze all randomized controlled trials with regard to important outcomes in patients with predicted SAP who received probiotics. METHODS: A systematic literature search of the PubMed, Embase and Cochrane Library databases was conducted using specific search terms. Eligible studies were randomized controlled trials that compared the effects of probiotic with placebo treatment in patients with predicted SAP. Mean difference (MD), risk ratio (RR) and 95% confidence interval (95% CI) were calculated using the Mantel-Haenszel fixed- and random-effects models. A meta-analysis on the use of probiotics in the treatment of critically ill patients was also performed to serve as a reference. RESULTS: In this study, 6 trials comprising an aggregate total of 536 patients were analyzed. Significant heterogeneities were observed in the type, dose, treatment duration and clinical effects of probiotics in these trials. Systematic analysis showed that probiotics did not significantly affect the pancreatic infection rate (RR = 1.19, 95% CI = 0.74 to 1.93; P = 0.47), total infections (RR = 1.09, 95% CI = 0.80 to 1.48; P = 0.57), operation rate (RR = 1.42, 95% CI = 0.43 to 3.47; P = 0.71), length of hospital stay (MD = 2.45, 95% CI = -2.71 to 7.60; P = 0.35) or mortality (RR = 0.72, 95% CI = 0.42 to 1.45; P = 0.25). CONCLUSIONS: Probiotics showed neither beneficial nor adverse effects on the clinical outcomes of patients with predicted SAP. However, significant heterogeneity was noted between the trials reviewed with regard to the type, dose and treatment duration of probiotics, which may have contributed to the heterogeneity of the clinical outcomes. The current data are not sufficient to draw a conclusion regarding the effects of probiotics on patients with predicted SAP. Carefully designed clinical trials are needed to validate the effects of particular probiotics given at specific dosages and for specific treatment durations.