Comparative identification of Ca～(2+) channel expression in INS-1 and rat pancreatic β cells

AIM： To identify and compare the profile of Ca^2＋ channel subunit expression in INS-1 and rat pancreatic β cells.METHODS： The rat insulin-secreting INS-1 cell line was cultured in RPMI-1640 with Wistar rats employed as islet donors. Ca^2＋ channel subunit expression in INS-1 and isolated rat β cells were examined by reverse transcription polymerase chain reaction （RT-PCR）. Absolute real-time quantitative PCR was performed in a Bio-Rad iQ5 Gradient Real Time PCR system and the data analyzed using an iQ5 system to identify the expression level of the Ca^2＋ channel subunits. RESULTS： In INS-1 cells, the L-type Ca^2＋ channel 1C subunit had the highest expression level and the TPRM2 subunit had the second highest expression. In rat β cells, the TPRC4β subunit expression was dominant and the expression of the L-type lC subunit exceeded the 1D subunit expression about two-fold. This result agreed with other studies, confirming the important role of the L-type lC subunit in insulinsecreting cells, and suggested that non-voltage-operated Ca^2＋ channels may have an important role in biphasic insulin secretion. CONCLUSION： Twelve major Ca^2＋ channel subunit types were identified in INS-1 and rat β cells and significant differences were observed in the expression of certain subunits between these cells.

Meiotic nuclear divisions 1 suppresses the proliferation and invasion of pancreatic cancer cells via regulating H2A.X variant histone

Introduction:Among all malignant tumors of the digestive system,pancreatic carcinoma exhibits the highest mortality rate.Currently,prevention and effective treatment are urgent issues that need to be addressed.Methods:The study focused on meiotic nuclear divisions 1(MND1),integrating data from the Gene Expression Profiling Interactive Analysis(GEPIA)database with prognostic survival analysis.Simultaneously,experiments at cellular level were employed to demonstrate the effect of MND1 on the proliferation and migration of PC.The small-molecule inhibitor of MND1 was used to suppress the migration of PC cells by knocking down MND1 using small interfering RNA(siRNA)in Patu-8988 and Panc1 cell lines.Results:The results of Cell Counting Kit-8 indicated that the suppression of MND1 resulted in a decrease in cell proliferation.Wound healing and Transwell assays revealed that MND1 knockdown reduced cell migration and invasion.Flow cytometry revealed that inhibiting MND1 hindered the cell cycle.Furthermore,MND1 could stimulate the proliferation,migration,and invasion of Patu-8988 and Panc1 cells by increasing the expression of MND1.Notably,MND1 had a positive effect on H2AFX expression in PC cells.Elevated MND1 expression suggests the low overall survival rate of individuals diagnosed with PC.Conclusion:These findings suggest that MND1 has the potential to be a gene with the ability to accurately diagnose and treat PC.

Human bone marrow mesenchymal stem cell-derived exosomes loaded with gemcitabine inhibit pancreatic cancer cell proliferation by enhancing apoptosis

BACKGROUND Pancreatic cancer remains one of the most lethal malignancies,and has limited effective treatment.Gemcitabine(GEM),a chemotherapeutic agent,is commonly used for clinical treatment of pancreatic cancer,but it has characteristics of low drug delivery efficiency and significant side effects.The study tested the hypothesis that human bone marrow mesenchymal stem cell(MSC)-derived exosomes loaded with GEM(Exo-GEM)would have a higher cytotoxicity against human pancreatic cancer cells by enhancing their apoptosis.AIM To investigate the cytotoxicity of MSC-derived Exo-GEM against pancreatic cancer cells in vitro.METHODS Exosomes were isolated from MSCs and characterized by transmission electron microscopy and nanoparticle tracking analysis.Exo-GEM through electroporation,sonication,or incubation,and the loading efficiency was evaluated.The cytotoxicity of Exo-GEM or GEM alone against human pancreatic cancer Panc-1 and MiaPaca-2 cells was assessed by MTT and flow cytometry assays.RESULTS The isolated exosomes had an average size of 76.7 nm.The encapsulation efficacy and loading efficiency of GEM by electroporation and sonication were similar and significantly better than incubation.The cytotoxicity of Exo-GEM against pancreatic cancer cells was stronger than free GEM and treatment with 0.02μM Exo-GEM significantly reduced the viability of both Panc-1 and MiaPaca-2 cells.Moreover,Exo-GEM enhanced the frequency of GEMinduced apoptosis in both cell lines.CONCLUSION Human bone marrow MSC-derived Exo-GEM have a potent cytotoxicity against human pancreatic cancer cells by enhancing their apoptosis,offering a promising drug delivery system for improving therapeutic outcomes.

Metastatic pancreatic and lung cancer patient in complete remission following immunotherapy: A case report and review of literature

BACKGROUND Metastatic pancreatic ductal adenocarcinoma(PDAC)is a lethal malignancy with dispiriting survival data.Immunotherapy is a promising approach to many cancer types,but achieves poor outcomes in advanced PDAC due to its immunosuppressive tumor microenvironment.We describe a case of metastatic PDAC effectively treated with pembrolizumab.CASE SUMMARY We report the case of a 67-year-old woman with unresectable locally advanced PDAC,treated with gemcitabine plus nab-paclitaxel followed by radiotherapy plus capecitabine.At nine months,pancreatic tumor progression was observed at the level of the hepatic hilum with the appearance of a new pulmonary nodule suggestive of a second primary,confirmed by left lung biopsy.Systemic immunotherapy was then initiated with pembrolizumab,an immune checkpoint inhibitor targeting programmed cell death protein-1 that covers the two tumor types.The patient showed a complete metabolic response that was maintained throughout the treatment.The patient continues to be disease-free at 5.6 years since the start of immunotherapy.CONCLUSION These results suggest that the administration of pembrolizumab after chemoradiotherapy has a beneficial effect in patients with metastatic PDAC.To our knowledge,this is the first reported case of a patient with metastatic PDAC and metastatic lung cancer showing such a long-lasting complete response after pembrolizumab treatment without curative surgery.Further studies are required to determine biomarkers that identify PDAC patients most likely to benefit from this immunotherapy.

Circulating tumor cells in pancreatic cancer:The prognostic impact in surgical patients

Pancreatic cancer is associated with a poor prognosis,even in the early stages,mainly due to metastatic progression.New diagnostic techniques that predict unfavorable outcomes are needed in order to improve treatment strategies.Circulating tumor cells(CTCs)are showing promising results as a predictive biomarker for various tumors.In this editorial we comment on the article by Zhang et al,who published the first systematic review and meta-analysis evaluating the prognostic value of CTCs as biomarkers in early-stage pancreatic cancer patients undergoing surgery.CTCs were detected in peripheral or central venous system blood,before or during surgery.Positive CTCs showed a correlation with decreased overall survival and decreased relapse-free,disease-free and progression-free survival in this meta-analysis.However,the heterogeneity was significant.The authors suggest that this result was related to the separation methods used between studies,but other differences such as the margin status or the neoadjuvant and adjuvant treatments used are also important to consider.CTCs may be a potential prognostic biomarker in pancreatic cancer patients,but it is necessary to compare and standardize the platforms used to isolate CTCs,to compare different biomarkers from liquid biopsy and to determine the impact on prognosis when therapeutic changes are made based on CTCs levels.

Circulating tumor cells as prognostic marker in pancreatic cancer

In this editorial we comment on the article by Zhang et al published in the recent issue of the World Journal of Clinical Oncology.Pancreatic cancer is the fourth most common cause of cancer-related mortality and has the lowest survival rate among all solid cancers.It causes 227000 deaths annually worldwide,and the 5-year survival rate is very low due to early metastasis,which is 4.6%.Cancer survival increases with better knowledge of risk factors and early and accurate diagnosis.Circulating tumor cells(CTCs)are tumor cells that intravasate from the primary tumor or metastasis foci into the peripheral blood circulation system spontan-eously or during surgical operations.Detection of CTC in blood is promising for early diagnosis.In addition,studies have associated high CTC levels with a more advanced stage,and more intensive treatments should be considered in cases with high CTC.In tumors that are considered radiologically resectable,it may be of critical importance in detecting occult metastases and preventing unnecessary surgeries.

Programmed cell death 1 inhibitor sintilimab plus concurrent chemoradiotherapy for locally advanced pancreatic adenocarcinoma

BACKGROUND Pancreatic adenocarcinoma,a malignancy that arises in the cells of the pancreas,is a devastating disease with unclear etiology and often poor prognosis.Locally advanced pancreatic cancer,a stage where the tumor has grown significantly but has not yet spread to distant organs,presents unique challenges in treatment.This article aims to discuss the current strategies,challenges,and future directions in the management of locally advanced pancreatic adenocarcinoma(LAPC).AIM To investigate the feasibility and efficacy of programmed cell death 1(PD-1)inhibitor sintilimab plus concurrent chemoradiotherapy for LAPC.METHODS Eligible patients had LAPC,an Eastern cooperative oncology group performance status of 0 or 1,adequate organ and marrow functions,and no prior anticancer therapy.In the observation group,participants received intravenous sintilimab 200 mg once every 3 wk,and received concurrent chemoradiotherapy(concurrent conventional fractionated radiotherapy with doses planning target volume 50.4 Gy and gross tumor volume 60 Gy in 28 fractions and oral S-140 mg/m2 twice daily on days 1-14 of a 21-d cycle and intravenous gemcitabine 1000 mg/m2 on days 1 and 8 of a 21-d cycle for eight cycles until disease progression,death,or unacceptable toxicity).In the control group,participants only received concurrent chemoradiotherapy.From April 2020 to November 2021,64 participants were finally enrolled with 34 in the observation group and 30 in the control group.RESULTS Thirty-four patients completed the scheduled course of chemoradiotherapy,while 32(94.1%)received sintilimab plus concurrent chemoradiotherapy with 2 patients discontinuing sintilimab in the observation group.Thirty patients completed the scheduled course of chemoradiotherapy in the control group.Based on the Response Evaluation Criteria in Solid Tumors guidelines,the analysis of the observation group revealed that a partial response was observed in 11 patients(32.4%),stable disease was evident in 19 patients(55.9%),and 4 patients(11.8%)experienced progressive disease;a partial response was observed in 6(20.0%)patients,stable disease in 18(60%),and progressive disease in 6(20%)in the control group.The major toxic effects were leukopenia and nausea.The incidence of severe adverse events(AEs)(grade 3 or 4)was 26.5%(9/34)in the observation group and 23.3%(7/30)in the control group.There were no treatment-related deaths.The observation group demonstrated a significantly longer median overall survival(22.1 mo compared to 15.8 mo)(P<0.05)and progression-free survival(12.2 mo vs 10.1 mo)(P<0.05)in comparison to the control group.The occurrence of severe AEs did not exhibit a statistically significant difference between the observation group and the control group(P>0.05).CONCLUSION Sintilimab plus concurrent chemoradiotherapy was effective and safe for LAPC patients,and warrants further investigation.

Effects of ginsenoside Rh2 on growth and migration of pancreatic cancer cells

AIM:To investigate the effects of ginsenoside Rh2 on the human pancreatic cancer cell line Bxpc-3.METHODS:The human pancreatic cancer cell line Bxpc-3 was cultured in vitro and treated with or without ginsenoside Rh2.Growth rates for Bxpc-3 cells were assessed by methyl thiazolyl tetrazolium(MTT) and colony formation assays.Cell cycle changes were analyzed by flow cytometry.Apoptosis was measured by flow cytometry and Hoechst 33258 fluorescence staining.A scratch assay and a Matrigel invasion assay were used to detect cell migration and invasion.Expression of Bax,Bcl-2,survivin,cyclin D1,matrix metalloproteinase(MMP)-2,MMP-9,cleaved caspase-3,caspase-8,and caspase-9 mRNA were determined by reverse transcriptase-polymerase chain reaction(RT-PCR).Bax,Bcl-2,survivin,cyclin D1,cleaved caspase-3,caspase-8 and caspase-9 protein levels were examined by western blotting.Expression of MMP-2 and MMP-9 proteins in culture supernatants were determined by enzymelinked immunosorbent assay(ELISA).RESULTS:Rh2 significantly inhibited Bxpc-3 cell proliferation in a dose-and time-dependent manner,as evaluated by the MTT(P < 0.05) and colony formation assays(P < 0.05).Compared to the control group,Rh2 significantly increased the percentage of Bxpc-3 cells in the G 0 /G 1 phase from 43.32% ± 2.17% to 71.32% ± 1.16%,which was accompanied by a decrease in S phase(from 50.86% ± 1.29% to 28.48% ± 1.18%) and G 2 /M phase(from 5.81% ± 1.19% to 0.20% ± 0.05%) in a dose-dependent manner(P < 0.05),suggesting that Rh2 arrested cell cycle progression at the G 0 /G 1 phase,as measured by flow cytometry.Compared to the control group,cells treated with Rh2 showed significantly higher apoptosis ratios in a dosedependent manner(percentage of early apoptotic cells:from 5.29% ± 2.28% to 38.90% ± 3.42%(F = 56.20,P < 0.05);percentage of late apoptotic cells:from 4.58% ± 1.42% to 36.32% ± 2.73%(F = 86.70,P < 0.05).Rh2 inhibited Bxpc-3 cell migration and invasion,as detected by scratch wound healing assay and Matrigel invasion assay [percentages of scratch wound healing for 12 h,24 h and 48 h(control vs experimental group):37.3% ± 4.8%vs 18.30% ± 1.65%,58.7% ± 3.5% vs 38.00% ± 4.09% and 93.83% ± 4.65% vs 65.50% ± 4.09%,respectively;t = 6.489,t = 6.656 and t = 7.926,respectively,P < 0.05;the number of cells invading at various concentrations(0 μmol/L,35 μmol/L,45 μmol/L and 55 μmol/L):81.10 ± 9.55,46.40 ± 6.95,24.70 ± 6.88 and 8.70 ± 3.34,respectively(F = 502.713,P < 0.05)].RT-PCR,western blotting or ELISA showed that mRNA and protein expression of Bax,cleaved caspase-3 and caspase-9 were upregulated(P < 0.05),while mRNA and protein expression of Bcl-2,survivin,cyclin D1,MMP-2 and MMP-9 were downregulated(P < 0.05).CONCLUSION:Ginsenoside Rh2 inhibits proliferation,migration and invasion and induces apoptosis of the human pancreatic cancer cell line Bxpc-3.

Roles of Smad3 and Smad7 in rat pancreatic stellate cells activated by transforming growth factor-beta 1

BACKGROUND: Pancreatic stellate cells (PSCs) play a major role in promoting pancreatic fibrosis. Transforming growth factor beta 1 (TGF-beta 1) is a critical mediator of this process. This study aimed to determine the expression of the Smad3 and Smad7 genes in the process of PSC activation, and explore the mechanisms of chronic pancreatitis. METHODS: The expressions of Smad3 and Smad7 in PSCs before and after TGF-beta 1 treatment were detected by reverse transcription-polymerase chain reaction and Western blotting analysis. Smad3 expression was detected in PSCs after treatment with 5 ng/ml of TGF-beta 1 for 24 hours. RESULTS: Smad7 expression was decreased in TGF-beta 1 -activated PSCs (P<0.05) in a dose-dependent manner. When TGF-beta 1 concentration reached 10 ng/ml, the expression of p-Smad3, Smad3, and Smad7 was inhibited (P<0.05). CONCLUSIONS: TGF-beta 1 promotes the expression of Smad3 and inhibits the expression of Smad7 during the activation of PSCs. In contrast, high-dose TGF-beta 1 downregulates the expression of Smad3 in completely activated PSCs.

An immortalized rat pancreatic stellate cell line RP-2 as a new cell model for evaluating pancreatic fibrosis,inflammation and immunity

BACKGROUND： Pancreatic stellate cells （PSCs） play a critical role in the pathogenesis of pancreatic fibrosis and have emerging functions as progenitor cells, immune cells or intermediaries in pancreatic exocrine secretion. Increasing evidence has shown that desmin as an exclusive cytoskeleton marker of PSC is only expressed in part of these cells. This study was to establish a desmin-positive PSC cell line and evaluate its actions on pancreatic fibrosis, inflammation and immunity.

Pancreatic stellate cells promote proliferation and invasiveness of human pancreatic cancer cells via galectin-3

AIM: To investigate the role of pancreatic stellate cells (PSCs) and galectin-3 (GAL-3) in the proliferation and infiltration of pancreatic cancer cell line SW1990. METHODS: Human pancreatic cancer cell line SW1990 and PSCs were cultured in vitro . Supernatant fluid of cultured PSCs and SW1990 cells was collected. Expression of GAL-3 in SW1990 cells and PSCs was detected by ELISA, RT-PCR and Western blotting. Proliferation of cultured PSCs and SW1990 cells was measured by 3-(4, 5-methylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Infiltration of SW1990 cells was detected by a cell infiltration kit. RESULTS: SW1990 cells expressed GAL-3 and this was up-regulated by the supernatant fluid of cultured PSCs. PSCs did not express GAL-3. SW1990 cells stimulated proliferation of PSCs via GAL-3. GAL-3 antibody inhibited SW1990 cell proliferation, while the supernatant fluid of PSCs stimulated proliferation of SW1990 cells through interaction with GAL-3 protein. The supernatant fluid of PSCs enhanced the invasiveness of SW1990 cells through interaction with GAL-3. CONCLUSION: GAL-3 and PSCs were involved in the proliferation and infiltration process of pancreatic cancer cells.

Endothelin-1 stimulates contraction and migration of rat pancreatic stellate cells

AIM： To examine the ability of FT-1 to affect the cell functions of PSCs and the underlying molecular mechanisms. METHODS： PSCs were isolated from the pancreas of male Wistar rats after perfusion with collagenase, and cells between passages two and five were used. Expression of ET-1 and FT receptors was assessed by reverse transcription-PCR and immunostaining. Phosphorylation of myosin regulatory light chain （MLC）, extracellular-signal regulated kinase （FRK）, and Akt was examined by Western blotting. Contraction of PSCs was assessed on hydrated collagen lattices. Cell migration was examined using modified Boyden chambers. Ceil proliferation was assessed by measuring the incorporation of 5-bromo-2＇- deoxyuridine. RESULTS： Culture-activated PSCs expressed ETA and ETB receptors, and ET-1. ET-1 induced phosphorylation of NLC and FRK, but not Akt. ET-1 induced contraction and migration, but did not alter proliferation of PSCs. FT-1-induced contraction was inhibited by an ETA receptor antagonist BQ-123 and an ETB receptor antagonist BQ-788, whereas migration was inhibited by BQ-788 but not by BQ-123. A Rho kinase inhibitor Y-27632 abolished both contraction and migration. CONCLUSION： ET-1 induced contraction and migration of PSCs through El receptors and activation of Rho-Rho kinase. ETA and FTB receptors play different roles in the regulation of these cellular functions in response to ET-1.

Activation of JAK-STAT pathway is required for platelet-derived growth factor-induced proliferation of pancreatic stellate cells

AM: To clarify the role of Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway in platelet-derived growth factor (PDGF) induced proliferation in activated pancreatic stellate cells (PSCs). METHODS: PSCs were isolated from rat pancreas tissue, and used in their culture-activated, myofibroblast-like phenotype. STAT-specific binding activity was assessed by electrophoretic mobility shift assay. Activation of Src, JAK2, STAT1, STAT3, and ERK was determined by Western blotting using anti-phosphospecific antibodies. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2'-deoxyuridine. RESULTS: PDGF-BB induced STAT-specific binding activity, and activation of Src, JAK2, STAT1, STAB, and ERK. Ethanol and acetaldehyde at clinically relevant concentrations decreased basal activation of JAK2 and STAT3. PDGF-induced activation of STAT1 and STAT3 was inhibited by a Src inhibitor PP1 and a JAK2 inhibitor AG490, whereas PDGF-induced activation of ERK was inhibited by PP1, and not by AG490. PDGF-induced proliferation was inhibited by PP1 and AG490 as well as by STAT3 antisense oligonucleotide. CONCLUSION: PDGF-BB activated JAK2-STAT pathway via Src-dependent mechanism. Activation of 3AK2-STAT3 pathway, in addition to ERK, may play a role in PDGF-induced proliferation of PSCs.

Detection of disseminated pancreatic cells by amplification of cytokeratin-19 with quantitative RT-PCR in blood,bone marrow and peritoneal lavage of pancreatic carcinoma patients

AIM： To evaluate the diagnostic potential of cytokeratin-19 （CK-19） mRNA for the detection of disseminated tumor cells in blood, bone marrow and peritoneal lavage in patients with ductal adenocarcinoma of the pancreas. METHODS： Sixty-eight patients with pancreatic cancer （/7 = 37）, chronic pancreatitis （n = 16）, and non-pancreatic benign surgical diseases （/7 = 15, control group） were included in the study. Venous blood was taken preoperatively, intraoperatively and at postoperative d 1 and 10. Preoperative bone marrow aspirates and peritoneal lavage taken before mobilization of the tumor were analyzed. All samples were evaluated for disseminated tumor cells by CK-19-specific nested-PCR and quantitative fluorogenic RT-PCR. RESULTS： CK-19 mRNA expression was increased in 24 （64%） blood samples and 11 （30%） of the peritoneal lavage samples in the patients with pancreatic cancer. In 15 （40%） of the patients with pancreatic cancer, disseminated tumor cells were detected in venous blood and bone marrow and/or peritoneal lavage. In the peritoneal lavage, the detection rates were correlated with the tumor size and the tumor differentiation. CK-19 levels were increased in pT3/T4 and moderately/poorly differentiated tumors （G2/G3）. Pancreatic cancer patients with at least one CK-19 mRNA-positive sample showed a trend towards shorter survival. Pancreatic cancer patients showed significantly increased detection rates of disseminated tumor cells in blood and peritoneal lavage compared to the controls and the patients with chronic pancreatitis. CONCLUSION： Disseminated tumor cells can be detected in patients with pancreatic ductal adenocarcinorna by CK-19 fluorogenic RT-PCR. In peritoneal lavage, detection rate is correlated with tumor stage and differentiation. In the clinical use, CK-19 is suitable for the distinction between malignant and benign pancreatic disease in combination with other tumor-specific markers.

Green tea polyphenol epigallocatechin-3-gallate blocks PDGF-induced proliferation and migration of rat pancreatic stellate cells

AIM: To clarify the effects of epigallocatechin-3-gallate (EGCG) on the platelet-derived growth factor (PDGF)-BB-induced proliferation and migration of pancreatic stellate cells (PSCs). METHODS: PSCs were isolated from rat pancreas tissue and used in their culture-activated, myofibroblast-like phenotype. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2'-deoxyuridine. Cell migration was assessed using modified Boyden chambers. Cyclin D1, p21waf1, and p27kip1 expression and phosphorylation of PDGF β-receptor, extracellular signal-regulated kinase, and Akt were examined by Western blotting. Activation of phospha-tidylinositol 3-kinase was examined by kinase assay using phosphatidylinositol as a substrate. Cell cycle was assessed by flow cytometry after staining with propidium iodide. RESULTS: EGCG at non-cytotoxic concentrations inhibited PDGF-induced proliferation and migration. This effect was associated with the inhibition of cell cycle progression beyond the G1 phase, decreased cyclin Dl and increased p27kip1 expression. EGCG inhibited tyrosine phosphorylation of PDGF p-receptor and downstream activation of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase/ Akt pathways. CONCLUSION: EGCG inhibited PDGFBB-induced proliferation and migration of PSCs through the inhibition of PDGFmediated signaling pathways.

Trametinib and dactolisib but not regorafenib exert antiproliferative effects on rat pancreatic stellate cells

BACKGROUND： Modulation of the stroma response is considered a promising approach for the treatment of chronic pancreatitis and pancreatic cancer. The aim of this study was to evaluate the effects of three clinically available small molecule kinase inhibitors, regorafenib, trametinib and dactolisib, on effector functions of activated pancreatic stellate cells （PSCs）, which play a key role in pancreatic fibrosis.

Expression of platelet endothelial cell adhesion molecule-1 between pancreatic microcirculation and peripheral circulation in rats with acute edematous pancreatitis

OBJECTIVE: To study the ehanges of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in peripheral circulation anti pancreatic microcirculation in rats with acute edematous pancreatitis (AEP). METHODS: The model of AEP was established with 50 Wistar rats, and the changes of PECAM-1 expression on PMNs from the splenic vein and inferior vena cava were determined by flow cytometry. RESULTS: PECAM-I expression on PMNs showed no significant difference between pancreatic microcirculation and peripheral circulation at AEP2h and AEP4h time points. From the AEP4h to the AEP8h time point, PECAM-1 expression in peripheral circulation was up-regulated, but PECAM-1 expression in pancreatic microcirculation was down-regulated. PECAM-1 expression had a significant difference between pancreatic microcirculation and peripheral circulation at the AEP8h time point (P<0.05). CONCLUSION: PECAM-1 expression on PMNs is in a converse way between pancreatic microcirculation and peripheral circulation in AEP.

Celecoxib Inhibits Proliferation and Induces Apoptosis via Cyclooxygenase-2 Pathway in Human Pancreatic Carcinoma Cells

In order to evaluate the effects and mechanisms of celecoxib in inhibiting proliferation and inducing apoptosis on human pancreatic carcinoma cells, the anti-proliferative effect was measured by using methabenzthiazuron (MTT) assay. Cell cycle and apoptosis were analyzed by using flow cytometry (FCM), and the PGE 2 levels in the supernatant of cultured pancreatic carcinoma cells were quantitated by enzyme-linked immunoabsordent assay (ELISA). Our results showed that celecoxib suppressed the production of PGE 2 and inhibited the growth of JF-305 cells, and the anti-proliferative effect of celecoxib could be abolished by addition of PGE 2. FCM revealed that celecoxib could inhibit proliferation and induce apoptosis by G 1-S cell cycle arrest. It was concluded that cyclooxygenase-2 specific inhibitor celecoxib could inhibit proliferation and induced apoptosis of human pancreatic carcinoma cells via suppression of PGE 2 production in vitro.

Pancreatic β cell regeneration induced by clinical and preclinical agents

Diabetes,one of the most common chronic diseases in the modern world,has pancreaticβcell deficiency as a major part of its pathophysiological mechanism.Pancreatic regeneration is a potential therapeutic strategy for the recovery ofβcell loss.However,endocrine islets have limited regenerative capacity,especially in adult humans.Almost all hypoglycemic drugs can protectβcells by inhibitingβcell apoptosis and dedifferentiation via correction of hyperglycemia and amelioration of the consequent inflammation and oxidative stress.Several agents,including glucagon-like peptide-1 andγ-aminobutyric acid,have been shown to promoteβcell proliferation,which is considered the main source of the regeneratedβcells in adult rodents,but with less clarity in humans.Pancreatic progenitor cells might exist and be activated under particular circumstances.Artemisinins andγ-aminobutyric acid can induceα-to-βcell conversion,although some disputes exist.Intestinal endocrine progenitors can transdeterminate into insulin-producing cells in the gut after FoxO1 deletion,and pharmacological research into FoxO1 inhibition is ongoing.Other cells,including pancreatic acinar cells,can transdifferentiate intoβcells,and clinical and preclinical strategies are currently underway.In this review,we summarize the clinical and preclinical agents used in different approaches forβcell regeneration and make some suggestions regarding future perspectives for clinical application.

Expression of stem cell markers CK-19 and PDX-1mRNA in pancreatic islet samples of different purity from rats

BACKGROUND: Islet stem cells are more or less retained in the procedure of islet isolation and purification, and are transplanted together with islet grafts. Keratoprotein (CK-19) and pancreatic duodenal hox gene 1 (PDX-1) are markers of stem cells. This study was undertaken to examine the expression of these markers in pancreatic islet samples of different purity from rats. METHODS: A total of 30 male Sprague-Dawley rats were randomly assigned to 3 groups to undergo perfusion with V-type collagenase via the pancreatic duct, then the pancreas was excised, diced, shaken, digested and centrifuged to obtain islet sediments. The sediment from group A was not purified, while that from group B was purified with 25% Ficoll-400 and that from group C with 25% and 11% Ficoll-400. RNA was extracted from the different islet samples for reverse transcriptase-polymerase chain reaction (RT-PCR). The expression of the pancreatic stem cell markers CK-19 and PDX-1 was assessed. RESULTS: The purity of islets in samples was (43.6 +/- 6.29)% in group A; (65.3 +/- 4.40)% in group B; and (77.6 +/- 6.36)% in group C (P<0.05). The expression of CK-19 and PDX-1 mRNA was significantly higher in group A than in groups B and C, but group C showed the lowest level of expression. CONCLUSION: The expression of CK-19 and PDX-1 mRNA in islet samples of different purity suggests the presence of stem cells in all islet samples.