Cd Se/Zn S quantum dots induce photodynamic effects and cytotoxicity in pancreatic cancer cells

AIM: To investigate the photodynamic effect of Cd Se/Zn S quantum dots(QDs) on pancreatic cancer cells and elucidate the probable mechanisms.METHODS: The pancreatic cancer cell line SW1990 was treated with different concentrations of Cd Se/Zn S QDs(0, 0.5, 1.0, 1.5, 2.0, 2.5 μmol/L), with or without illumination. The viability of SW1990 cells was tested using the Cell Counting Kit-8(CCK-8) assay. The ultrastructural changes of SW1990 cells were observed by transmission electron microscopy. Apoptosis was detected by nuclear staining and flow cytometry(FCM). Reactive oxygen species(ROS) were measured by dichlorofluorescein diacetate via fluorescence microscopy. Expression of Bax, Bcl-2 and caspase-3 was measured by real-time polymerase chain reaction(PCR) and protein immunoblotting 24 h after SW1990 cells were treated with Cd Se/Zn S QDs and illuminated.RESULTS: The CCK-8 assay results showed that both Cd Se/Zn S QDs with and without illumination suppressed SW1990 cell proliferation. Cell viability was significantly lower when illuminated or with a longer incubation time and a higher light dose. Cd Se/Zn S QDs with illumination caused ultrastructural changes in SW1990 cells, such as organelle degeneration and chromatin condensation and aggregation at the periphery of the nucleus. Fluorescence microscopy and FCM showed that Cd Se/Zn S QDs(1.5 μmol/L) with illumination increased SW1990 cell apoptosis(53.2%) and ROS generation compared with no illumination. Real-time PCR showed that expression of Bax and caspase-3 was upregulated and Bcl-2 was downregulated. Immunoblotting results were consistent with real-time PCR results. Inhibition of ROS and apoptosis both attenuated QD-photodynamictherapy-induced cell death.CONCLUSION: Cd Se/Zn S QDs can be used as a photosensitizer to inhibit SW1990 cell proliferation through ROS generation and apoptotic protein expression regulation.

Feasibility and efficacy of endoscopic purse-string suture-assisted closure for mucosal defects induced by endoscopic manipulations

BACKGROUND Large or transmural defects induced by gastrointestinal endoscopic manipulations are difficult to close,although complete closure is recommended for better recovery.Endoscopic purse-string assisted suturing(EPSS)has been used in clinical practice and has proven to be an effective and safe technique for the closure of large mucosal defects.However,details regarding the efficacy of endoscopic pre-purse-string suture(P-EPSS)are unknown,especially that it offers several advantages over conventional EPSS(C-EPSS).AIM To elucidate the outcomes of EPSS-assisted closure in different clinical situations,and evaluate the efficacy of P-EPSS.METHODS This retrospective observational study included a total of 180 patients who underwent closure assisted by P-EPSS(n=63)or C-EPSS(n=117)between July 2014 and June 2020.The P-EPSS and C-EPSS groups were compared and the intergroup differences in aspects such as the lesion size,location,and morphology,incidence of complete closure,intraoperative perforation,and delayed adverse events were evaluated.Data on the features and clinical course of cases with adverse events were collected for further analysis.RESULTS Patients with lesion size larger than 3 cm,lesions located at the fundus of stomach,or submucosal tumors originating from the deep mucosa were more likely to undergo P-EPSS-assisted closure.The P-EPSS group showed a significantly higher proportion of intraoperative perforation(56%vs 17%)and a much shorter procedure time(9.06±6.14 min vs 14.84±7.25 min).Among adverse events,the incidence of delayed perforation(5%vs 4%;P=0.82)and delayed bleeding(3%vs 4%;P=0.96)did not differ significantly between the groups.Multivariate analysis revealed that lesions with incomplete closure[odds ratio(OR)=21.33;95%confidence interval(CI):5.45-83.45;P<0.01]or size greater than 3 cm(OR=3.14;95%CI:1.08-9.18;P=0.039)showed a statistical tendency to result in an increase in delayed adverse events.CONCLUSION The present study revealed that EPSS could achieve secure complete closure of mucosal defect.PEPSS could shorten the procedure and yield complete closure of mucosal defects.Rather than closure-type selection,incomplete closure or lesion size larger than 3 cm were associated with worse outcomes.

Effects of medical adhesives in prevention of complications after endoscopic submucosal dissection

AIM:To evaluate the use of medical adhesive spray in endoscopic submucosal dissection (ESD). METHODS:Patients who underwent ESD between January 2009 and June 2012 (n = 173) were enrolled in the prospective randomized study. Two patients undergoing surgery due to severe intraoperative hemorrhage and failed hemostasis were excluded, and the remaining 171 patients were randomly divided into two groups:group A (medical adhesive group, n = 89) and group B (control group, n = 82). In group A, a medical adhesive spray was evenly applied after routine electrocoagulation and hemostasis using hemostatic clip after ESD. Patients in group B only treated with routine wound management. Intraoperative and postoperative data were collected and compared. RESULTS:In all 171 patients, ESD was successfully completed. There was no significant difference in the average treatment time between groups A and B (59.4 min vs 55.0 min, respectively). The average length of hospital stay was significantly different between group A and B (8.89 d vs 9.90 d, respectively). The incidence of intraoperative perforation was 10.1% in group A and 9.8% in group B, and was not significantly different between the two groups. In all cases, perforations were successfully managed endoscopically and with conservative treatment. The incidence of postoperative delayed bleeding in group A was significantly lower than that in group B (0.00% vs 4.88%, respectively). CONCLUSION:ESD is an effective minimally invasive treatment for gastrointestinal precancerous lesions or early-stage gastrointestinal cancer. Medical adhesive spray is effective in preventing delayed bleeding after ESD, and can thus reduce the average length of hospital stay.

Value of bevacizumab in treatment of colorectal cancer: A meta-analysis

AIM:To assess the efficacy and safety of bevacizumab in the treatment of colorectal cancer.METHODS:All randomized controlled trials of bevacizumab for the treatment of colorectal cancer from January 2003 to June 2013 were collected by searching the Cochrane Library, Pub Med, Chinese National Knowledge Infrastructure and Wanfang databases.The primary endpoint was overall survival(OS), and the secondary endpoints were progression-free survival, overall response rate and adverse events.Two reviewers extracted data independently.Statistical analyses were performed with Stata 12.0.The degree of bias was assessed using funnel plots for the effect size of OS at the primary endpoint.RESULTS:Following the inclusion criteria and exclusion criteria, ten studies comprising 6977 cases were finally included, of which nine were considered to be of high quality(4-7 points) and one of low quality(1-3 points).Our meta-analysis revealed the efficacy of bevacizumab in patients with colorectal cancer in terms of OS(HR = 0.848, 95%CI:0.747-0.963), progressionfree survival(HR = 0.617, 95%CI:0.530-0.719), and overall response rate(OR = 1.627, 95%CI:1.199-2.207).Regarding safety, higher rates of grade ≥ 3 hypertension, proteinuria, bleeding, thrombosis, and gastrointestinal perforation were observed in the bevacizumab treatment group(P < 0.05); however, the incidence of serious toxicity was very low.There was no publication bias in the 10 reports included in this meta-analysis.CONCLUSION:The clinical application of bevacizumab in colorectal cancer is effective with good safety.

Antifibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline on bile duct ligation induced liver fibrosis in rats

AIM:To investigate the preventive effect of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) on bile duct ligation (BDL)induced liver fibrosis in rats. METHODS:Liver fibrosis in rats was induced by BDL and AcSDKP was infused subcutaneously for 2 wkvia a osmotic minipump (Alzet 2ML4) immediately after BDL operation. After scarifying, serum and liver specimens were collected. Hematoxylin and eosin staining, Sirius red staining, enzyme linked immunosorbent assay, Western blot or real-time polymerase chain reaction were used to determinate liver functions, histological alterations, collagen deposition, mRNA expression of markers for fibroblasts, transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein-7 (BMP-7). RESULTS:When compared to model rats, chronic exogenous AcSDKP infusion suppressed profibrogenicTGF-β1 signaling, α-smooth muscle actin positivity (α-SMA), fibroblast specific protein-1 (FSP-1) staining and collagen gene expression. Col Ⅰ, Col Ⅲ, matrix metalloproteinase-2, tissue inhibitors of metallopro-teinase-1 and tissue inhibitors of metalloproteinase-2 mRNA expressions were all significantly downregulated by AcSDKP infusion (2.02 ± 1.10vs 14.16 ± 6.50, 2.02 ± 0.45vs 10.00 ± 3.35, 2.91 ± 0.30vs 7.83 ± 1.10, 4.64 ± 1.25 vs 18.52 ± 7.61, 0.46 ± 0.16 vs 0.34 ± 0.12, respectively, P < 0.05). Chronic exogenous AcSDKP infusion attenuated BDL-induced liver injury, inflammation and fibrosis. BDL caused a remarkable increase in alanine transaminase, aspartate transaminase, total bilirubin, and prothrombin time, all of which were reduced by AcSDKP infusion. Mast cells, collagen accumulation, α-SMA, TGF-β1, FSP-1 and BMP-7 increased. The histological appearance of liver specimens was also improved. CONCLUSION:Infusion of exogenous AcSDKP attenu-ated BDL-induced fibrosis in the rat liver. Preservation of AcSDKP may be a useful therapeutic approach in the management of liver fibrosis.

Comparison between air and carbon dioxide insufflation in the endoscopic submucosal excavation of gastrointestinal stromal tumors

AIM:To evaluate the safety and efficacy of CO2 insufflation compared with air insufflation in the endoscopic submucosal excavation(ESE) of gastrointestinal stromal tumors.METHODS:Sixty patients were randomized to undergo endoscopic submucosal excavation,with the CO2 group(n = 30) and the air group(n = 30) undergoingCO2 insufflation and air insufflation in the ESE,respectively.The end-tidal CO2 level(pETCO2) was observed at 4 time points:at the beginning of ESE,at total removal of the tumors,at completed wound management,and 10 min after ESE.Additionally,the patients' experience of pain at 1,3,6 and 24 h after the examination was registered using a visual analog scale(VAS).RESULTS:Both the CO2 group and air group were similar in mean age,sex,body mass index(all P > 0.05).There were no significant differences in PetCO2 values before and after the procedure(P > 0.05).However,the pain scores after the ESE at different time points in the CO2 group decreased significantly compared with the air group(1 h:21.2 ± 3.4 vs 61.5 ± 1.7;3 h:8.5 ± 0.7 vs 42.9 ± 1.3;6 h:4.4 ± 1.6 vs 27.6 ± 1.2;24 h:2.3 ± 0.4 vs 21.4 ± 0.7,P < 0.05).Meanwhile,the percentage of VAS scores of 0 in the CO2 group after 1,3,6 and 24 h was significantly higher than that in the air group(60.7 ± 1.4 vs 18.9 ± 1.5,81.5 ± 2.3 vs 20.6 ± 1.2,89.2 ± 0.7 vs 36.8 ± 0.9,91.3 ± 0.8 vs 63.8 ± 1.3,respectively,P < 0.05).Moreover,the condition of the CO2 group was better than that of the air group with respect to anal exsufflation.CONCLUSION:Insufflation of CO2 in the ESE of gastrointestinal stromal tumors will not cause CO2 retention and it may significantly reduce the level of pain,thus it is safe and effective.

Effects of integrin-targeted photodynamic therapy on pancreatic carcinoma cell

AIM:To investigate the effects of photodynamic therapy with quantum dots-arginine-glycine-aspartic acid(RGD)probe as photosensitizer on the proliferation and apoptosis of pancreatic carcinoma cells.METHODS:Construction of quantum dots-RGD probe as photosensitizer for integrin-targeted photodynamic therapy was accomplished.After cells were treated with photodynamic therapy(PDT),the proliferation of SW1990 cells were measured by methyl thiazolyl tetrazolium assay.Morphologic changes,cell cycle retardance and apoptosis were observed under fluoroscope and flow cytometry.The expression of myeloid cell leukemia-1(Mcl-1),protein kinase B(Akt)and tumor necrosis factor-related apoptosis-inducing ligand(TRAIL)mRNA were detected by reverse transcriptionpolymerase chain reaction.The amount of reactive oxygen species were also evaluated by fluorescence probe.RESULTS:The photodynamic therapy with quantum dots-RGD probe as photosensitizer significantly inhibited cell proliferation(P<0.01).Apoptotic cells and morphologic changes could be found under optical microscope.The FCM revealed PDT group had more significant cell apoptosis rate compared to control cells(F=130.617,P<0.01)and cell cycle G0/G1and S retardance(P<0.05)compared to control cells.The expression of Mcl-1 and Akt mRNA were down-regulated,while expression of TRAIL mRNA was up-regulated after cells treated with PDT.PDT group had more significant number of cells producing reactive oxygen species compared to control cells(F=3262.559,P<0.01).CONCLUSION:The photodynamic therapy with quantum dots-RGD probe as photosensitizer significantly inhibits cell proliferation and increases apoptosis in SW1990 cells.

Application of single balloon enteroscopy-assisted therapeutic endoscopic retrograde cholangiopancreatography in patients after bilioenteric Roux-en-Y anastomosis: Experience of multi-disciplinary collaboration

BACKGROUND Bilioenteric Roux-en-Y anastomosis is one of the most complicated approaches for reconstructing the gastrointestinal tract, and endoscopic retrograde cholangiopancreatography (ERCP) is technically challenging in patients after bilioenteric Roux-en-Y anastomosis. The optimal endoscopic strategies for such cases remain unknown. AIM To explore the feasibility and effectiveness of single balloon enteroscopy-assisted (SBE-assisted) therapeutic ERCP in patients after bilioenteric Roux-en-Y anastomosis based on multi-disciplinary collaboration between endoscopists and surgeons as well as report the experience from China. METHODS This is a single center retrospective study. All of the SBE-assisted therapeutic ERCP procedures were performed by the collaboration between endoscopists and surgeons. The operation time, success rate, and complication rate were calculated. RESULTS Forty-six patients received a total of 64 SBE-assisted therapeutic ERCP procedures, with successful scope intubation in 60 (93.8%) cases and successful diagnosis in 59 (92.2%). All successfully diagnosed cases received successful therapy. None of the cases had perforation or bleeding during or after operation, and no post-ERCP pancreatitis occurred. CONCLUSION Based on multi-disciplinary collaboration, SBE-assisted therapeutic ERCP in patients after bilioenteric Roux-en-Y anastomosis is relatively safe and effective and has a high success rate.

Combining protein arginine methyltransferase inhibitor and antiprogrammed death-ligand-1 inhibits pancreatic cancer progression

BACKGROUND Immunotherapy targeting programmed death-1(PD-1)or programmed deathligand-1(PD-L1)has been shown to be effective in a variety of malignancies but has poor efficacy in pancreatic ductal adenocarcinoma(PDAC).Studies have shown that PD-L1 expression in tumors is an important indicator of the efficacy of immunotherapy.Tumor cells usually evade chemotherapy and host immune surveillance by epigenetic changes.Protein arginine methylation is a common posttranslational modification.Protein arginine methyltransferase(PRMT)1 is deregulated in a wide variety of cancer types,whose biological role in tumor immunity is undefined.AIM To investigate the combined effects and underlying mechanisms of anti-PD-L1 and type I PRMT inhibitor in pancreatic cancer in vivo.METHODS PT1001B is a novel type I PRMT inhibitor with strong activity and good selectivity.A mouse model of subcutaneous Panc02-derived tumors was used to evaluate drug efficacy,toxic and side effects,and tumor growth in vivo.By flow cytometry,we determined the expression of key immune checkpoint proteins,detected the apoptosis in tumor tissues,and analyzed the immune cells.Immunohistochemistry staining for cellular proliferation-associated nuclear protein Ki67,TUNEL assay,and PRMT1/PD-L1 immunofluorescence were used to elucidate the underlying molecular mechanism of the antitumor effect.RESULTS Cultured Panc02 cells did not express PD-L1 in vitro,but tumor cells derived from Panc02 transplanted tumors expressed PD-L1.The therapeutic efficacy of anti-PD-L1 mAb was significantly enhanced by the addition of PT1001B as measured by tumor volume(1054.00±61.37 mm3 vs 555.80±74.42 mm3,P<0.01)and tumor weight(0.83±0.06 g vs 0.38±0.02 g,P<0.05).PT1001B improved antitumor immunity by inhibiting PD-L1 expression on tumor cells(32.74%±5.89%vs 17.95%±1.92%,P<0.05).The combination therapy upregulated tumorinfiltrating CD8+T lymphocytes(23.75%±3.20%vs 73.34%±4.35%,P<0.01)and decreased PD-1+leukocytes(35.77%±3.30%vs 6.48%±1.08%,P<0.001)in tumor tissue compared to the control.In addition,PT1001B amplified the inhibitory effect of anti-PD-L1 on tumor cell proliferation and enhanced the induction of tumor cell apoptosis.PRMT1 downregulation was correlated with PD-L1 downregulation.CONCLUSION PT1001B enhances antitumor immunity and combining it with anti-PD-L1 checkpoint inhibitors provides a potential strategy to overcome anti-PD-L1 resistance in PDAC.

Effect of photodynamic therapy with(17R,18R)-2-(1-hexyloxyethyl)-2-devinyl chlorine E6 trisodium salt on pancreatic cancer cells in vitro and in vivo

AIM To investigate the antitumor effects and underlying mechanisms of(17 R,18 R)-2-(1-hexyloxyethyl)-2-devinyl chlorine E6 trisodium salt(YLG-1)-induced photodynamic therapy(PDT) on pancreatic cancer in vitro and in vivo.METHODS YLG-1 is a novel photosensitizer extracted from spirulina. Its phototoxicity, cellular uptake and localization, as well as its effect on reactive oxygen species(ROS) production, apoptosis, and expression of apoptosis-associated proteins were detected in vitro. An in vivo imaging system(IVIS), the Lumina K imaging system, and mouse models of subcutaneous Panc-1-bearing tumors were exploited to evaluate the drug delivery pathway and pancreatic cancer growth in vivo.RESULTS YLG-1 was localized to the mitochondria, and the appropriate incubation time was 6 h. Under 650 nm light irradiation, YLG-1-PDT exerted a potent cytotoxic effect on pancreatic cancer cells in vitro, which could be abolished by the ROS scavenger N-acetyl-L-cysteine(NAC). The death mode caused by YLG-1-PDT was apoptosis, accompanied by upregulated Bax and cleaved Caspase-3 and decreased Bcl-2 expression. The results from the IVIS images suggested that the optimal administration route was intratumoral(IT) injection and that the best time to conduct YLG-1-PDT was 2 h post-IT injection. Consistent with the results in vitro, YLG-1-PDT showed great growth inhibition effects on pancreatic cancer cells in a mouse model.CONCLUSION YLG-1 is a potential photosensitizer for pancreatic cancer PDT via IT injection, the mechanisms of which are associated with inducing ROS and promoting apoptosis.