Silencing of FGF6 hampers aerobic glycolysis and angiogenesis in bladder cancer by regulating PI3K/Akt and MAPK signaling pathways.

Metabolic abnormalities and uncontrolled angiogenesis are two vital features of malignant tumors. Although fibroblast growth factor 6 (FGF6) is known to promote the proliferation and migration of bladder cancer (BC) cells, its influences on aerobic glycolysis and angiogenesis in BC remain unclear. Gene expression at messenger RNA and protein levels were examined by reverse transcription-quantitative polymerase chain reaction and Western blot analyses, respectively. Lactate production and glucose uptake in BC cells were evaluated by performing aerobic glycolysis assays. A vasculogenic mimicry assay was executed for assessing the angiogenesis of BC cells. The viability, migration, and angiogenesis of human umbilical vein endothelial cells (HUVECs) cocultured with supernatants of BC cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, wound healing assay, and tube formation assay. It was found that FGF6 displayed a high level in BC cell lines. Silencing of FGF6 reduced the levels of lactate production, glucose uptake, and the expression of angiogenic factors and glycolytic enzymes in BC cells, which also inhibited the viability and migration of HUVECs. In addition, FGF6 depletion or aerobic glycolysis inhibitor 2-deoxy-d-glucose treatment decreased the total branching length and intersection number of both BC cells and HUVECs. Moreover, glucose or lactate treatment reversed FGF6-induced suppression of cell viability, migration, tube formation, and vasculogenic mimicry. The activation of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) signaling pathways was blocked by silenced FGF6. Furthermore, PI3K/Akt inhibitor (LY2940002) and p38-MAPK inhibitor (SB203580) inhibited the levels of aerobic glycolysis-related proteins. In conclusion, FGF6 knockdown suppressed aerobic glycolysis, thereby inhibiting angiogenesis in BC via regulation of the PI3K/Akt and MAPK signaling pathways.

Highly selective and sensitive benzopyran-based fluorescent probes for imaging exogenous and endogenous peroxynitrite.

Peroxynitrite is widely present in organisms and closely related to many pathophysiological functions. Therefore, it is of great physiological significance to develop capable probes for detecting ONOO-. In this work, a novel fluorescent probe B-Ch was designed based on the intramolecular charge transfer (ICT) effect. By means of molecular engineering, the replacement from diethylamine group to hydroxyl group has improved the detection sensitivity of the probe. After the addition of ONOO-, the solution color and fluorescence showed noticeable changes, which were visible to the naked eye. The probe showed excellent advantages: visualization, good selectivity, low sensitivity (22.4 nM), good stability and biocompatibility, exogenous and endogenous imaging of ONOO- in HeLa cells.

A coumarin-based fluorescent probe: single-wavelength excitation, discrimination of Cys/Hcy and GSH by naked eyes.

Biothiols mainly include cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), which play an important role in life activities and abnormal changes in their concentrations are closely related to certain diseases. Therefore, the quantitative tracking and analysis of biothiols in living organisms has become a hot research topic in recent years. In this work, a coumarin-based fluorescent probe COUN was designed and synthesized for the comparable color recognition of Cys/Hcy and GSH by introducing the phenylethynyl group as the recognition site of biothiols, which showed significant fluorescence enhancement and green fluorescence under the UV light at 365 nm. The probe specifically recognized Hcy, showing 40-fold fluorescence enhancement and strong green fluorescence at 492 nm. Moreover, there was a good linear relationship between the fluorescence intensity of the probe and certain concentrations of Cys/Hcy and GSH, with detection limits of 36.6 nM, 86.4 nM, and 174 nM, respectively. The recognition mechanism of COUN to distinguish Cys/Hcy and GSH was studied by TDDFT calculations. More importantly, COUN was successfully used for imaging biothiols in living cells. The results showed that this probe could provide an effective contribution to the understanding of the role of biothiols, especially Hcy.

Signature Based on Six Autophagy-related Genes to Predict Prognosis of Head and Neck Squamous Cell Carcinoma.

OBJECTIVE: The present study aimed to develop an autophagy-related gene prognostic prediction model to provide survival risk prediction for head and neck squamous cell carcinoma (HNSCC) patients. METHODS: The K-mean cluster analysis was performed on HNSCC samples based on the expression values of 210 autophagy-related genes for candidate signature gene selection. LASSO Cox regression analysis was generated using the potential genes and the risk score was calculated from the prognosis model. The risk score was processed as an independent prognostic indicator to construct the nomogram model. The immune status including immune cell infiltration ratio and checkpoints of patients with HNSCC in high- and low-risk groups was also explored. RESULTS: LASSO Cox regression analysis was performed on the selected autophagy-related genes. According to the lambda value corresponding to the number of different genes in the LASSO Cox analysis, six genes (GABARAPL2, SAR1A, ST13, GAPDH, FADD and LAMP1) were finally chosen. The risk score based on the genes was generated, which was an independent prognostic marker for HNSCC. The prognostic prediction model (nomogram) was further optimized by the independent prognostic factors (risk score), which can better predict the prognosis and survival of patients. With the risk score and prognosis model, eight types of immune cells and six key immune checkpoints (CTLA4, PD1, IDO1, TDO2, LAG3, TIGIT) displayed expression specificity. CONCLUSION: This study identified several potential prognostic biomarkers and established an autophagy-related prognostic prediction model for HNSCC, which provides a valuable reference for future clinical research.

Comprehensive Analysis of the Potential Immune-Related Biomarker ATG101 that Regulates Apoptosis of Cholangiocarcinoma Cells After Photodynamic Therapy.

Autophagy related gene 101 (ATG101) plays a significant role in the occurrence and development of tumours by responding to stress. Our research aims to illustrate the correlation between the expression of ATG101 and tumor prognosis and its potential role and mechanism in tumor immunity and photodynamic therapy (PDT). First, integrated analysis of The Cancer Genome Atlas and Genotype-Tissue Expression portals were used to analyse the expression of ATG101. Then, Kaplan-Meier curves was applied in cholangiocarcinoma (CHOL) and liver hepatocellular carcinoma (LIHC) datasets for survival analysis. Next, the relationship between ATG101 expression and six immune cells, the immune microenvironment and immune checkpoints was analysed. Besides, the relationship between the expression of ATG101 and methyltransferase. GSEA was used to study the function and the related transcript factors of ATG101 in CHOL and LIHC. The effect of PDT on ATG101 was verified by microarray, qPCR and western blot. Then the effect of ATG101 and its regulatory factors on apoptosis were verified by siRNA, lentivirus transfection and Chip-qPCR. Comprehensive analysis showed that ATG101 was overexpressed in different tumours. Kaplan-Meier curves found that ATG101 was associated with poor prognosis in tumours (including CHOL and LIHC). We found that ATG101 can be used as a target and prognostic marker of tumour immunotherapy for different tumours. We also found that ATG101 regulates DNA methylation. GSEA analysis showed that ATG101 may play a critical role in CHOL and LIHC. Subsequent validation tests confirmed that the up-regulated ATG101 after PDT treatment is not conducive to the occurrence of apoptosis of cholangiocarcinoma cells. The high expression of ATG101 may be induced by the early stress gene EGR2. Our study highlights the significance of ATG101 in the study of tumour immunity and photodynamic therapy from a pan-cancer perspective.

Minimally invasive treatment of hepatic hemangioma by transcatheter arterial embolization combined with microwave ablation: A case report.

BACKGROUND: Hepatic hemangioma is the most common benign tumor of the liver. However, patients with large hemangiomas that cause compression symptoms or that are at risk of rupture may need further intervention. It is necessary to explore additional minimally invasive and personalized treatment options for hemangiomas. CASE SUMMARY: A 47-year-old woman was diagnosed with a right hepatic hemangioma for more than 10 years. Abdominal contrast-enhanced computed tomography (CT) and contrast-enhanced ultrasound revealed that there was a large hemangioma in the right liver, with a size of approximately 95 mm × 97 mm × 117 mm. Due to the patient's refusal of surgical treatment, hepatic artery embolization was performed in the first stage. After 25 d of liver protection treatment, the liver function indexes decreased to normal levels. Then, ultrasound-guided microwave ablation of the giant hepatic hemangioma was performed. Ten days after the treatment, hepatobiliary ultrasonography showed that the hemangioma of the right liver was smaller than the previous size (the volume was reduced by approximately 30%). Then the patient was discharged from the hospital. One year after discharge, CT showed that the hepatic hemangioma had shrunk by about 80. CONCLUSION: Transcatheter arterial embolization combined with microwave ablation is a safe and effective minimally invasive treatment for hepatic hemangioma.

Adult duodenal intussusception with horizontal adenoma: A rare case report.

BACKGROUND: Adult duodenal intussusception rarely occurs, and the majority of duodenal adenomas are located in the descending part of the duodenum. Therefore, adenomas in the horizontal part of the duodenum presenting as duodenal intussusception in adults are extremely rare. CASE SUMMARY: A 36-year-old man complained of abdominal pain for 13 d. Blood analysis showed anemia. Magnetic resonance cholangiopancreatography and computed tomography revealed a tumor in the horizontal part of the duodenum as the main finding, leading to duodeno-duodenal intussusception. No obvious abnormalities were found on endoscopy or upper gastrointestinal radiography. He was diagnosed with duodenal intussusception secondary to duodenal adenoma. Laparotomy showed duodeno-duodenal intussusception and a tumor in the horizontal part of the duodenum near the ascending part. Postoperative pathology revealed tubular-villous adenoma with low-grade glandular intraepithelial neoplasia (local high-grade intraepithelial neoplasia). He was discharged without complications. CONCLUSION: This case highlights that rational use of computed tomography, magnetic resonance cholangiopancreatography, endoscopy and upper gastrointestinal radiography for preoperative diagnosis and timely surgery is an effective strategy for the treatment of adult duodenal intussusception with duodenal masses.

Photodynamic therapy regulates fate of cancer stem cells through reactive oxygen species.

Photodynamic therapy (PDT) is an effective and promising cancer treatment. PDT directly generates reactive oxygen species (ROS) through photochemical reactions. This oxygen-dependent exogenous ROS has anti-cancer stem cell (CSC) effect. In addition, PDT may also increase ROS production by altering metabolism, endoplasmic reticulum stress, or potential of mitochondrial membrane. It is known that the half-life of ROS in PDT is short, with high reactivity and limited diffusion distance. Therefore, the main targeting position of PDT is often the subcellular localization of photosensitizers, which is helpful for us to explain how PDT affects CSC characteristics, including differentiation, self-renewal, apoptosis, autophagy, and immunogenicity. Broadly speaking, excess ROS will damage the redox system and cause oxidative damage to molecules such as DNA, change mitochondrial permeability, activate unfolded protein response, autophagy, and CSC resting state. Therefore, understanding the molecular mechanism by which ROS affect CSCs is beneficial to improve the efficiency of PDT and prevent tumor recurrence and metastasis. In this article, we review the effects of two types of photochemical reactions on PDT, the metabolic processes, and the biological effects of ROS in different subcellular locations on CSCs.

Rare recurrent gallstone ileus: A case report.

BACKGROUND: The management of recurrent gallstone ileus (GSI) is unsatisfactory, and there is no consensus on how to reduce the incidence of recurrent GSI. CASE SUMMARY: A 79-year-old man presented to the Emergency Department of our hospital complaining of abdominal pain. An abdominal computed tomography (CT) scan revealed cholecystolithiasis, intrahepatic bile duct dilatation, gas accumulation, small intestinal obstruction, and circular high-density shadow in the intestinal cavity. Emergency surgery revealed that the small intestine had extensive adhesions, unclear gallbladder exposure, obvious adhesions, and difficult separation. The obstruction was located 70 cm between the ileum and the ileocecum, which was incarcerated by gallstones, and a simple enterolithotomy was carried out. On the third day after the operation, he had passed gas and defecated and had begun a liquid diet. On the fifth day after the operation, he suddenly experienced abdominal distension and discomfort. Emergency CT examination revealed recurrent GSI, and the diameter of the stone was approximately 2.0 cm (consistent with the shape of cholecystolithiasis on the abdominal CT scan before the first operation). The patient's symptoms were not significantly relieved after conservative treatment. On the ninth day after the operation, emergency enterolithotomy was performed again along the original surgical incision. On the twentieth day after the second operation, the patient fully recovered and was discharged from the hospital. CONCLUSION: We believe that a thorough examination of the bowel and gallbladder for gallstones based on preoperative imaging during surgery and removal of them as far as possible on the premise of ensuring the safety of patients are an effective strategy to reduce the recurrence of GSI.

Adult pancreatic hemangioma: a rare case report and literature review.

BACKGROUND: Adult pancreatic hemangioma is an extremely rare type of benign vascular tumor. To date, about 20 cases have been reported in the English literature. Adult patients with pancreatic hemangiomas usually have no specific symptoms, particularly in early stages. Therefore, it is difficult to detect and diagnose these lesions, which usually are identified during cross sectional imaging for an apparently unrelated causes or when biliary obstruction occurs because of compression by a tumor. CASE PRESENTATION: This study presents the case of a 52-year-old female with a chief complaint of epigastric pain. Contrast-enhanced computed tomography revealed a well-defined mass with mildly inhomogeneous enhancement in the body of the pancreas. Endoscopic ultrasonography showed calcifications in the lesion, and a few small vessels were detected by Doppler imaging. The patient received a central pancreatectomy, and pathological examination confirmed the diagnosis of pancreatic hemangioma. CONCLUSION: In this report, we reviewed the clinical manifestations, radiologic features, preoperative diagnosis, pathologic characteristics, and surgical treatment of adult pancreatic hemangioma.

A diazabenzoperylene derivative as ratiometric fluorescent probe for cysteine with super large Stokes shift.

Biothiols, including cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), play key roles in biological processes, and detecting such thiols selectively is critical for understanding functions of biothiols. In this work, a pyridazine annelated perylene-based fluorescent probe PAPC is synthesized for highly selective detection of Cys. PAPC exhibits strong blue emission in PBS, while the red emission at 605 nm can be observed in the presence of Cys. The probe PAPC shows ratiometric fluorescence (I605/I460) detection of Cys with wide linear range of 1-120 µM and low detection limit of 0.19 µM. Super large Stokes shift (170 nm) and ratiometric fluorescence endow the probe low background signal. The discrimination of Cys over Hcy and GSH can be achieved through the difference of the ratiometric fluorescence. In addition, the probe has been proven to track Cys in real samples such as urine and HeLa cells. Therefore, PAPC probe is a promising candidate for detecting Cys in practical application. Graphical abstract.

Tetrahydro[5]helicene fused nitrobenzoxadiazole as a fluorescence probe for hydrogen sulfide, cysteine/homocysteine and glutathione.

Biological thiols including homocysteine (Hcy), cysteine (Cys), hydrogen sulfide (H2S) and glutathione (GSH) play crucial roles in various pathological and physiological processes. The development of optical probes for biothiols has been an active research area in recent years. Herein, a new turn-on fluorescence probe (HD-NBD) was designed and synthesized by fusing tetrahydro[5]helicene and 7-nitro-2,1,3-benzoxadiazole (NBD) for simultaneous discrimination of Hcy/Cys, H2S and GSH in aqueous solution. This probe is able to show unique absorbance enhancement at 548 nm for H2S and additional fluorescence enhancement at 536 nm only for Cys/Hcy, which can be used to discriminate H2S, Cys/Hcy and GSH simultaneously. In addition, HD-NBD also shows low background without any self-fluorescence, as well as high selectivity toward common biothiols. The low detection limits of this probe are about 0.15 µM for Hcy with a wide linear range (1-80 µM), 0.36 µM for Cys (linear range: 1-45 µM), 0.79 µM for H2S (linear range: 1-80 µM) and 4.44 µM for GSH (linear range: 1-60 µM). Moreover, HD-NBD can identify Hcy/Cys, H2S from GSH and other amino acids with high sensitivity and selectivity, therefore it could be used for detecting endogenous and exogenous Hcy/Cys under biological condition.

Application of the Ethyl Acetate Extract of Cichorium as a Potential Photosensitizer in Photodynamic Therapy Induces Apoptosis and Autophagy in Colorectal Cancer Cell Lines via the Protein Kinase R-Like Endoplasmic Reticulum Kinase Pathway.

The present study aims to evaluate the effect of the ethyl acetate extract of Cichorium (EAEC) as a novel photosensitizer in photodynamic therapy (PDT) of colorectal carcinoma (CRC) HCT116 and SW620 cells. The absorption and fluorescence spectra of EAEC were measured using a UV-vis spectrophotometer and fluorescence spectrophotometer, respectively. EAEC-induced reactive oxygen species (ROS) production in HCT116 and SW620 cells was detected using 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and glutathione/glutathione disulfide (GSH/GSSG). The photo- and dark toxicities of EAEC were estimated using the Cell Counting Kit-8 (CCK-8) assay. Cellular uptake and localization of EAEC were detected by confocal laser fluorescence microscopy. Annexin V-FITC/PI staining, Western blotting and immunofluorescence staining were used to assess apoptosis and autophagy. The antitumor activity of EAEC was confirmed in a xenograft model. Finally, effects on the PERK pathway were verified using qRT-PCR and Western blotting. EAEC displayed absorption and fluorescence emission peaks at 660 nm and 678 nm, respectively. EAEC induced ROS production in CRC cells. Assessment of dark toxicity showed that treatment with EAEC alone induced little cytotoxicity in CRC or normal cells but that EAEC-PDT induced significant photocytotoxicity in CRC cells in a time- and dose-dependent manner. After cellular uptake, EAEC was located in the mitochondria. Treatment with EAEC-PDT reduced xenograft tumor size. Further evaluation suggested that activation of the PERK pathway mediates these effects, as the apoptotic rate and autophagy flux increased markedly after EAEC-PDT. EAEC, a natural photosensitizer extracted from Cichorium, displays potential utility in PDT of CRC by targeting the PERK pathway.

circZFR promotes cell proliferation and migration by regulating miR-511/AKT1 axis in hepatocellular carcinoma.

BACKGROUND: Emerging data suggest the crucial regulatory roles of circular RNAs (circRNAs) in hepatocellular carcinoma (HCC). However, the pathophysiology role of circZFR in HCC remains largely unknown. AIMS: This study aims to disclose the functions of circZFR in HCC progression and its potential molecular mechanism. METHODS: circZFR and miR-511 were identified by qRT-PCR. Colony formation assay, wound-healing assay, transwell assay, and flow cytometry assay were performed to determine the cell proliferation, migration, invasion and apoptosis. Western blotting and immunohistochemistry (IHC) were utilized to evaluate the expression level of AKT1, GSK3ß, ß-catenin and cascades of proliferation-related proteins both in vitro and in vivo. Dual luciferase reporter assay was conducted to evaluate the interactions among circZFR, miR-511 and AKT1. RESULTS: The expression of circZFR was enhanced and the expression of miR-511 was down-regulated in HCC tissues and cells. Functionally, circZFR silencing or miR-511 overexpression suppressed cell proliferation, migration and invasion, and induced apoptosis of HCC cells. Mechanistically, circZFR acted as a miR-511 sponge to up-regulate its target gene AKT1, which activated cascades of proliferation-related proteins (c-Myc, cyclin D1, Survivin and Bcl-2). Furthermore, depletion of circZFR inhibited tumorigenesis and decreased the expression level of AKT1 in xenograft models. CONCLUSION: circZFR promotes HCC progression by directly down-regulating miR-511 to activate AKT1 signaling, suggesting that circZFR is a potential target in HCC treatment. Targeting circZFR may provide therapeutic benefits for HCC.

A fluorescent probe based on tetrahydro[5]helicene derivative with large Stokes shift for rapid and highly selective recognition of hydrogen sulfide.

In this work, we have designed and synthesized a dinitrobenzene-sulfonate tetrahydro[5]helicene (H-DNP) as an effective fluorescent probe for detection of hydrogen sulfide (H2S). Upon the addition of H2S, a significant fluorescence enhancement (75-fold) at 495 nm can be observed with a distinct color change from colorless to yellow. Additionally, H-DNP shows low background spectroscopic signal, large Stokes Shift up to ~140 nm, good sensitivity, rapid response time less than 2 min, low detection limit (48 nM) and high selectivity toward common bio-thiols (Cysteine, Homocysteine and Glutathione). Compared with the previous dinitrophenoxy tetrahydro[5]helicene, this probe has shorter response time and lower detection limit. Most importantly, this probe H-DNP has low toxicity to cells and excellent cell permeability, which can be applied to visualize H2S in living cells.

A coumarin-based dual optical probe for homocysteine with rapid response time, high sensitivity and selectivity.

In this study, a new coumarin-based fluorescent and chromogenic dual channel probe (DC) was used for the selective detection of homocysteine (Hcy) over other amino acids, especially for cysteine (Cys) and glutathione (GSH). When Hcy is present in the solution, the remarkable fluorescence enhancement and obvious blue shift in UV-vis spectra can be observed. In addition, the color change from purple to yellow can be observed clearly by unaided eyes. This probe DC has fast response time, excellent sensitivity and selectivity to Hcy. A linear relationship exists between the ratio of emissions at 486 and 625 nm, and Hcy can be detected in a wide concentration range (0-200 µM). The signal-to-background ratio of fluorescence at 486 nm can reach 8.4, and the detection limit is calculated to be 3.5 µM. The response mechanism is proved to be the Michael addition reaction by Hcy. Preliminary results on cell imaging enable the practical application of Hcy tracing in living cells.

Portal hypertension predicts short-term and long-term outcomes after hepatectomy in hepatocellular carcinoma patients.

BACKGROUND AND AIMS: The impact of portal hypertension (PH) on postoperative short-term outcomes and long-term survival in hepatocellular carcinoma (HCC) patients has lately been discussed controversially. This study aimed to explore the influence of PH on postoperative outcomes in HCC patients undergoing surgical resection. METHODS: Patients undergoing hepatectomy for HCC from 2010 to 2014 were enrolled. The impact of PH on postoperative complications, posthepatectomy liver failure (PHLF) and overall survival (OS) was evaluated. RESULTS: A total of 355 HCC patients were enrolled; 129 (36.3%) experienced postoperative complications and 21 (5.9%) developed PHLF. PH was identified as an independent predictor of PHLF. Patients with PH experienced a higher incidence of complications and PHLF than patients without PH. On the Cox proportional hazards regression model, PH was verified as a risk factor of OS for BCLC stage 0/A and B patients. Patients without PH had significantly better long-term survival compared to patients with PH both in the total cohort and in cirrhosis subgroup. CONCLUSION: Liver resection in HCC patients with PH showed a significantly increased postoperative complications and PHLF, and revealed a decreasing long-term survival than non-PH patients. Besides, tumor burden also played an important role in determining the OS. However, due to the improvement in surgical technique and perioperative management, surgery was feasible in carefully selected HCC patients with PH.

A fluorescent probe based on tetrahydro[5]helicene for highly selective recognition of hydrogen sulfide.

Endogenous hydrogen sulfide plays an important role in various physiological and pathological processes and the convenient and selective recognition of hydrogen sulfide has become a research hotspot. We designed and synthesized a tetrahydro[5]helicene and 2,4-dinitrobenzene conjugate (HD-DNP) as an effective fluorescent probe for selective detection of H2S. The selective deprotection of 2,4-dinitrophenyl ether group of HD-DNP by H2S led to a dramatic fluorescent enhancement (101-fold) at 500 nm and colorimetric change in DMSO-PBS solution. HD-DNP displays many advantages including low background without any self-fluorescence, as well as high selectivity towards common bio-thiols such as Cysteine, Homocysteine and Glutathione. The detection limit of this probe for H2S was found to be about 2.4 µM with a wide linear range (10-70 µM). The response mechanism of the probe with HS- is confirmed to be thiolysis of the dinitrophenyl ether induced by HS- through 1H NMR comparison investigations.

Morphine protects SH-SY5Y human neuroblastoma cells against Dickkopf1-induced apoptosis.

Morphine is used to relieve pain in patients with cancer in terminal phases. Dickkopf­1 (DKK1), a secreted protein, is a negative regulator of the Wnt/ß­catenin signaling pathway. Morphine and DKK1 are associated with tumorigenesis. However, to the best of our knowledge, there is no study evaluating the effects of these two factors simultaneously. In the present study, the effects of morphine and DKK1 on neuroblastoma cells in vivo and in vitro were evaluated. To establish the in vitro effects of DKK1 and morphine, human neuroblastoma SH­SY5Y cells were transfected with a DKK1­expressing plasmid and cell migration, apoptosis, migration and invasion were evaluated prior to and following morphine treatment. The results indicated that DKK1 induced apoptosis and inhibited the mobility of neuroblastoma cells and that morphine attenuated these DKK1­induced effects. To evaluate the effects of DKK1 and morphine in vivo, a mouse model of neuroblastoma was established, where mice bearing tumors of native SH-SY5Y cells were injected with DKK1. Tumor size, spatial memory and survival rate were investigated in untreated, DKK1­treated and DKK1+morphine­treated mice. Water maze and T­maze tests were performed, which revealed that DKK1­treated mice exhibited a better memory than DKK1 + morphine­treated mice. The expression of DKK1 in established xenografted tumors was associated with decreased tumor size and an increased survival rate, whereas morphine reversed these effects. Furthermore, it was confirmed that morphine and DKK1 take effect, at least in part, via the Wnt/ß­catenin signaling pathway. The results of the present study indicate that morphine may protect neuroblastoma cells and thus, it may be used in neuroblastoma patients.