Single-Cell Profiling of Tumor Immune Microenvironment Reveals Immune Irresponsiveness in Gastric Signet-Ring Cell Carcinoma.

BACKGROUND & AIMS: Gastric cancer (GC) is a major cancer type characterized by high heterogeneity in both tumor cells and the tumor immune microenvironment (TIME). One intractable GC subtype is gastric signet-ring cell carcinoma (GSRCC), which is associated with poor prognosis. However, it remains unclear what the GSRCC TIME characteristics are and how these characteristics may contribute to clinical outcomes. METHODS: We enrolled 32 patients with advanced GC of diverse subtypes and profiled their TIME using an immune-targeted single-cell profiling strategy, including (1) immune-targeted single-cell RNA sequencing (n = 20 patients) and (2) protein expression profiling by a targeted antibody panel for mass cytometry (n = 12 patients). We also generated matched V(D)J (variable, diversity, and joining gene segments) sequencing of T and B cells along CD45+ immunocytes. RESULTS: We found that compared to non-GSRCC, the GSRCC TIME appears to be quiescent, where both CD4+ and CD8+ T cells are difficult to be mobilized, which further impairs the proper functions of B cells. CXCL13, mainly produced by follicular helper T cells, T helper type 17, and exhausted CD8+ T cells, is a central coordinator of this transformation. We show that CXCL13 expression can predict the response to immune checkpoint blockade in GC patients, which may be related to its effects on tertiary lymphoid structures. CONCLUSIONS: Our study provides a comprehensive molecular portrait of immune cell compositions and cell states in advanced GC patients, highlighting adaptive immune irresponsiveness in GSRCC and a mediator role of CXCL13 in TIME. Our targeted single-cell transcriptomic and proteomic profiling represents a powerful approach for TIME-oriented translational research.

A novel immune-related lncRNA pair signature for prognostic prediction and immune response evaluation in gastric cancer: a bioinformatics and biological validation study.

BACKGROUND: Gastric cancer (GC), the most commonly diagnosed cancer worldwide with poor 5-year survival rate in advanced stages. Although immune-related and survival-related biomarkers, which typically comprise aberrantly expressed long non-coding RNAs (lncRNAs) and genes, have been identified, there are no reports of immune-related lncRNA pair (IRLP) signatures for GC. METHODS: In this study, we acquired lncRNA expression profiles from The Cancer Genome Atlas (TCGA) and used the least absolute shrinkage and selection operator (LASSO) Cox proportional hazards model (iteration = 1000) to develop a IRLP prognostic signature. The area under curve (AUC) was used to assess the prognosis predictive power. The multivariate Cox regression analysis was performed to identify whether this signature was an independent prognostic factor. The immune cell infiltration analysis was performed between the two risk groups. Last, molecular experiments were performed to explore LINC01082 is involved in the development of GC. RESULTS: We acquired lncRNA expression profiles and used the LASSO Cox model to develop an 18-IRLP signature with a strong prognostic predictive power. The 5-year AUC values of the training, validation, and overall TCGA datasets were 0.77, 0.86, and 0.80, respectively. The different prognostic outcomes between the high- and low-risk groups were determined using our 18-IRLP signature. Moreover, our 18-IRLP signature was an independent prognostic factor as per the multivariate Cox regression analysis, and showed better prognostic evaluation than the traditional TNM staging system as well as other clinical features. We also found differences in cancer-associated fibroblast and macrophage M2 infiltration and the expression of PD-L1, CTLA4, LAG3, and HLA were also observed between the two risk groups (P < 0.05). Analysis of biological functions revealed that target genes of the lncRNAs in the IRLP signature were enriched in focal adhesion and regulation of actin cytoskeleton. Finally, as one of significant candidates of IRLP signature, overexpression of LINC01082 suppressed the invasion ability of GC cells as well as PD-L1 expression profiles. CONCLUSIONS: Our novel 18-IRLP signature provides new insights regarding immunological biomarkers, imparts a better understanding of the tumor immune microenvironment, and can be used for predicting prognosis and evaluating immune response in GC.

A novel risk score system for prognostic evaluation in adenocarcinoma of the oesophagogastric junction: a large population study from the SEER database and our center.

BACKGROUND: The incidence rate of adenocarcinoma of the oesophagogastric junction (AEG) has significantly increased over the past decades, with a steady increase in morbidity. The aim of this study was to explore a variety of clinical factors to judge the survival outcomes of AEG patients. METHODS: We first obtained the clinical data of AEG patients from the Surveillance, Epidemiology, and End Results Program (SEER) database. Univariate and least absolute shrinkage and selection operator (LASSO) regression models were used to build a risk score system. Patient survival was analysed using the Kaplan-Meier method and the log-rank test. The specificity and sensitivity of the risk score were determined by receiver operating characteristic (ROC) curves. Finally, the internal validation set from the SEER database and external validation sets from our center were used to validate the prognostic power of this model. RESULTS: We identified a risk score system consisting of six clinical features that can be a good predictor of AEG patient survival. Patients with high risk scores had a significantly worse prognosis than those with low risk scores (log-rank test, P-value < 0.0001). Furthermore, the areas under ROC for 3-year and 5-year survival were 0.74 and 0.75, respectively. We also found that the benefits of chemotherapy and radiotherapy were limited to stage III/IV AEG patients in the high-risk group. Using the validation sets, our novel risk score system was proven to have strong prognostic value for AEG patients. CONCLUSIONS: Our results may provide new insights into the prognostic evaluation of AEG.

Relationship Between Postoperative Complications and the Prognosis of Gastric Carcinoma Patients Who Underwent Surgical Resection: A Systematic Review and Meta-Analysis.

BACKGROUND: Whether the presence of postoperative complications was associated with poor prognosis of gastric carcinoma (GC) patients remain controversial. This meta-analysis was designed and reported to compare the survival difference between patients with complications and non-complications. METHODS: Cochrane Library, PubMed and Embase databases were comprehensively searched for published literatures to review current evidence on this topic. The survival data were extracted, and a random-effect or fixed-effect model was used to analyze the correlation between postoperative complications and oncologic outcome of GC patients. RESULTS: Of all studies identified, 32 were eligible for this pooled analysis, with a total of 32,067 GC patients. The incidence of postoperative complications was approximately 12.5% to 51.0%. Among them, infectious complications varied from 3.0% to 28.6%, anastomotic leakage varied from 1.1% to 8.7% and postoperative pneumonia varied from 1.6% to 12.8%. The presence of postoperative complications resulted in a significant poorer overall survival (OS) of gastric carcinoma patients (hazard ratio [HR]:1.49, 95% confidence interval [CI]: 1.33-1.67, P < 0.001). Additionally, the pooled results showed a significant correlation between infectious complications and decreased OS (HR: 1.61, 95%CI: 1.38-1.88, P < 0.001). Concerning specific postoperative complications, we found that both anastomotic leakage (HR: 2.36, 95%CI: 1.62-3.42, P < 0.001) and postoperative pneumonia (HR: 1.74, 95%CI: 1.22-2.49, P = 0.002) impaired the OS of gastric carcinoma patients. CONCLUSION: Postoperative complications were significantly correlated to recurrence and poor survival in gastric carcinoma patients. To gain a better surgical outcome and long-term oncological outcome, postoperative complications should be minimized as much as possible.

A novel prognostic signature of immune-related genes for patients with colorectal cancer.

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers with an estimated 1.8 million new cases worldwide and associated with high mortality rates of 881 000 CRC-related deaths in 2018. Screening programs and new therapies have only marginally improved the survival of CRC patients. Immune-related genes (IRGs) have attracted attention in recent years as therapeutic targets. The aim of this study was to identify an immune-related prognostic signature for CRC. To this end, we combined gene expression and clinical data from the CRC data sets of The Cancer Genome Atlas (TCGA) into an integrated immune landscape profile. We identified a total of 476 IRGs that were differentially expressed in CRC vs normal tissues, of which 18 were survival related according to univariate Cox analysis. Stepwise multivariate Cox proportional hazards analysis established an immune-related prognostic signature consisting of SLC10A2, FGF2, CCL28, NDRG1, ESM1, UCN, UTS2 and TRDC. The predictive ability of this signature for 3- and 5-year overall survival was determined using receiver operating characteristics (ROC), and the respective areas under the curve (AUC) were 79.2% and 76.6%. The signature showed moderate predictive accuracy in the validation and GSE38832 data sets as well. Furthermore, the 8-IRG signature correlated significantly with tumour stage, invasion, lymph node metastasis and distant metastasis by univariate Cox analysis, and was established an independent prognostic factor by multivariate Cox regression analysis for CRC. Gene set enrichment analysis (GSEA) revealed a relationship between the IRG prognostic signature and various biological pathways. Focal adhesions and ECM-receptor interactions were positively correlated with the risk scores, while cytosolic DNA sensing and metabolism-related pathways were negatively correlated. Finally, the bioinformatics results were validated by real-time RT-qPCR. In conclusion, we identified and validated a novel, immune-related prognostic signature for patients with CRC, and this signature reflects the dysregulated tumour immune microenvironment and has a potential for better CRC patient management.

Metformin-Induced Stromal Depletion to Enhance the Penetration of Gemcitabine-Loaded Magnetic Nanoparticles for Pancreatic Cancer Targeted Therapy.

Pancreatic ductal adenocarcinoma, as one of the most aggressive cancers, is characterized by rich desmoplastic stroma that forms a physical barrier for anticancer drugs. To address this issue, we herein report a two-step sequential delivery strategy for targeted therapy of pancreatic cancer with gemcitabine (GEM). In this sequential strategy, metformin (MET) was first administrated to disrupt the dense stroma, based on the fact that MET downregulated the expression of fibrogenic cytokine TGF-ß to suppress the activity of pancreatic stellate cells (PSCs), through the 5'-adenosine monophosphate-activated protein kinase pathway of PANC-1 pancreatic cancer cells. In consequence, the PSC-mediated desmoplastic reactions generating α-smooth muscle actin and collagen were inhibited, which promoted the delivery of GEM and pH (low) insertion peptide (pHLIP) comodified magnetic nanoparticles (denoted as GEM-MNP-pHLIP). In addition, pHLIP largely increased the binding affinity of the nanodrug to PANC-1 cells. The targeted delivery and effective accumulation of MET/GEM-MNP-pHLIP in vivo were confirmed by magnetic resonance imaging enhanced by the underlying magnetic nanoparticles. The tumor growth inhibition of the sequential MET and GEM-MNP-pHLIP treatment were investigated on both subcutaneous and orthotopic tumor mice models. A remarkably improved therapeutic efficacy, for example, up to 91.2% growth inhibition ratio over 30 d of treatment, well-exemplified the novel cascade treatment for pancreatic cancer and the innovative use of MET.

VNN1 overexpression in pancreatic cancer cells inhibits paraneoplastic islet function by increasing oxidative stress and inducing ß­cell dedifferentiation.

Vanin­1 (VNN1) may be a potential biomarker for the early screening of pancreatic cancer (PC)­associated diabetes (PCAD). A previous study by the authors reported that cysteamine secreted by VNN1­overexpressing PC cells induced the dysfunction of paraneoplastic insulinoma cell lines by increasing oxidative stress. In the present study, it was observed that both cysteamine and exosomes (Exos) secreted by VNN1­overexpressing PC cells aggravated the dysfunction of mouse primary islets. PC­derived VNN1 could be transported into islets through PC cell­derived Exos (PC­Exos). However, ß­cell dedifferentiation, and not cysteamine­mediated oxidative stress, was responsible for the islet dysfunction induced by VNN1­containing Exos. VNN1 inhibited the phosphorylation of AMPK and GAPDH, and prevented Sirt1 activation and FoxO1 deacetylation in islets, which may be responsible for the induction of ß­cell dedifferentiation induced by VNN1­overexpressing PC­Exos. Furthermore, it was demonstrated that VNN1­overexpressing PC cells further impaired the functions of paraneoplastic islets in vivo using diabetic mice with islets transplanted under the kidney capsule. On the whole, the present study demonstrates that PC cells overexpressing VNN1 exacerbate the dysfunction of paraneoplastic islets by inducing oxidative stress and ß­cell dedifferentiation.

Distinct molecular phenotype and the potential prognostic value of immune prognostic index and tumor infiltrating lymphocytes in hepatoid adenocarcinoma of stomach.

Hepatoid adenocarcinoma of the stomach (HAS) is a particular subtype of Gastric cancer (GC) with distinct pathological characteristics and genetic profile, but most HAS patients were received identical regimens as common GC. To date, only a few studies has been conducted to investigate the molecular characteristics of HAS, which may prevent the rational application of new anticancer strategies. To further obtain the genetic features and potential predictive and prognostic biomarkers of HAS, our current study evaluated the clinical implications of spectrum molecular markers in 36 surgical resection specimens. None Epstein-Barr virus (EBV) positive and/or micro-satellite instable high (MSI-h) tumors occurred in our study implies that the molecular classification of HAS should be mainly categorized into genomic stable (GS) and chromosomal instability (CIN) phenotypes, and wild type P53 status predicts better prognosis. More importantly, although the prognosis and clinical characteristics were independent of programmed cell death-ligand 1 (PD-L1), the presence of tumor infiltrating lymphocytes (TILs) still suggested that a portion of the enrolled HAS patients are potentially appropriate candidates for immune checkpoint blockade therapy. Additionally, the immune prognostic index (IPI) and derived neutrophil to lymphocyte ratio (dNLR) demonstrated their potential as reliable and economic indicators for predicting prognosis of HAS. We hope this first systematic evaluation will help in deciphering the molecular characterization and potential individualized regimens for this particular subtype of GC.

Successful outcome of neoadjuvant PD-1 blockade, VEGFR-2 inhibitor plus chemotherapy for potentially unresectable esophagogastric junctional squamous cell carcinoma: a case report.

Background: Esophagogastric junctional squamous cell carcinoma (EJSCC) is quite rare among all gastric carcinoma, its potential resectable rate is low due to the late diagnosis. Recently, programmed death-1 (PD-1) blockade combined with anti-angiogenesis have gained accumulated clinical experiences in treating solid tumors. This is the first reported case with EJSCC who achieved a partial remission (PR) after neoadjuvant PD-1 blockade, vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitor plus chemotherapy. Case Description: We present an EJSCC case treated with novel neoadjuvant treatment. A 64-year-old Chinese male had the symptom of chocking for 3 months. An enhanced abdominal computed tomography (CT) scan found a locally advanced, potentially unresectable esophagogastric junctional (EGJ) mass, and the preoperative immunohistochemistry result exhibited a highly positive programmed death-ligand 1 (PD-L1) expression, so the patient received three courses of neoadjuvant camrelizumab (200 mg/day), apatinib (750 mg/day), albumin paclitaxel (200 mg/day) and nedaplatin (70 mg/day), he was well tolerant without any adverse event, and he underwent radical surgery after a significant tumor shrinkage. The patient recovered well after surgery, and he has received four cycles of camrelizumab and apatinib as maintenance treatment. There is no recurrence 7 months after surgery. Conclusions: PD-1 blockade, VEGFR-2 inhibitor plus chemotherapy is effective and safe for the patient with EJSCC.

Efficacy and safety of long-term transcutaneous electroacupuncture versus sham transcutaneous electroacupuncture for delayed gastric emptying after distal gastrectomy: study protocol for a randomized, patient-assessor blinded, controlled trial.

BACKGROUND: Delayed gastric emptying (DGE) after distal gastrectomy impacts patients' nutritional status and quality of life. The current treatments of DGE seem unsatisfactory or need invasive interventions. It is unknown whether transcutaneous electroacupuncture (TEA) is effective in treating DGE. METHODS: A total of 90 eligible participants who underwent distal gastrectomy will be randomly allocated to either the TEA group (n = 60) or the sham transcutaneous electroacupuncture (sham-TEA) group (n = 30). Each participant will receive TEA on the bilateral acupoints of Zusanli (ST36) and Neiguan (PC6) for 4 weeks. The primary outcomes will be the residual rates of radioactivity in the stomach by gastric scintigraphy and total response rates. The secondary outcomes will be endoscopic features, autonomic function, nutritional and psychological status, serum examination, and quality of life (QoL). The adverse events will also be reported. The patients will be followed up 1 year after the treatment. DISCUSSION: The findings of this randomized trial will provide high-quality evidence regarding the efficacy and safety of long-term TEA for treating DGE after distal gastrectomy. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000033965. Registered on 20 June 2020.

MiR-877 suppresses gastric cancer progression by downregulating AQP3.

OBJECTIVES: Gastric cancer (GC) is the leading cause of cancer-related deaths worldwide; however, the underlying molecular mechanisms of GC remain unclear. This study investigated the role of the miR-877-AQP3 axis in GC tumorigenesis. METHODS: The levels of miR-877 expression were measured in GC tissues and cell lines by qRT-PCR. Functional assays were performed to elucidate the role of miR-877 in GC development. RESULTS: Our results showed that miR-877 levels were lower in GC tissues and cell lines compared with the corresponding controls. Additionally, reduced miR-877 levels were associated with unfavorable prognoses. Increased miR-877 expression suppressed proliferation, invasion, and epithelial-mesenchymal transition, while promoting apoptosis in GC cells. Luciferase reporter assays showed that aquaporin 3 (AQP3) was a direct downstream target of miR-877. Overexpression of AQP3 partially rescued the tumor suppressive effects of miR-877 in GC cells. Moreover, miR-877 was negatively correlated with AQP3 mRNA expression in GC tissues. CONCLUSIONS: This study demonstrated that miR-877 plays a suppressive role in GC tumorigenesis by regulating AQP3.

Labeling transplanted mice islet with polyvinylpyrrolidone coated superparamagnetic iron oxide nanoparticles for in vivo detection by magnetic resonance imaging.

Superparamagnetic iron oxide nanoparticles (SPIO) are emerging as a novel probe for noninvasive cell tracking with magnetic resonance imaging (MRI) and have potential wide usage in medical research. In this study, we have developed a method using high-temperature hydrolysis of chelate metal alkoxide complexes to synthesize polyvinylpyrrolidone coated iron oxide nanoparticles (PVP-SPIO), as a biocompatible magnetic agent that can efficiently label mice islet beta-cells. The size, crystal structure and magnetic properties of the as-synthesized nanoparticles have been characterized. The newly synthesized PVP-SPIO with high stability, crystallinity and saturation magnetization can be efficiently internalized into beta-cells, without affecting viability and function. The imaging of 100 PVP-SPIO-labeled mice islets in the syngeneic renal subcapsular model of transplantation under a clinical 3.0 T MR imager showed high spatial resolution in vivo. These results indicated the great potential application of the PVP-SPIO as an MRI contrast agent for monitoring transplanted islet grafts in the clinical management of diabetes in the near future.

Pancreatic cancer-derived exosomes promoted pancreatic stellate cells recruitment by pancreatic cancer.

Cancer-associated fibroblasts (CAFs), which are an important component of the tumor microenvironment, have been identified in the blood circulation of patients with cancer metastasis, and metastatic cancer cells can recruit circulating CAFs. However, primary carcinoma sites usually regulate the behavior of metastatic cancer cells through exosomes. Here, we hypothesized that cancer-derived exosomes could enhance CAF recruitment. Exosomes secreted by pancreatic cancer cells (PANC-1 and MIA PaCa-2) were isolated and characterized. The ability of pancreatic cancer to recruit pancreatic stellate cells (PSCs) was assessed with Transwell assays in vitro and bioluminescent imaging in a mouse model in vivo, and the underlying molecular mechanism was also investigated. The results showed that pancreatic cancer cell-derived exosomes (Exo-Pan and Exo-Mia) promoted the pancreatic cancer recruitment of PSCs. This effect was mediated partially by the transfer of the exosomal protein Lin28B to the recipient cells to activate the Lin28B/let-7/HMGA2/PDGFB signaling pathway. These results suggested that exosomes derived from local cancer could promote the formation of distant metastases through transferring the exosomal protein Lin28B to the metastatic cancer cells.

Resection of GIST in the duodenum and proximal jejunum: A retrospective analysis of outcomes.

INTRODUCTION: Gastrointestinal stromal tumors (GISTs), with a primary occurrence in the duodenum and proximal jejunum, are rare and treatment is poorly understood. This study aimed to evaluate the main factors influencing the prognosis of GIST resection in this complex anatomical structure. MATERIALS AND METHODS: This retrospective study included 47 patients who underwent surgery for primary GIST of the duodenum (20) and proximal jejunum (27) between 2012 and 2017. Perioperative clinical data as well as relapse and survival information were collected. RESULTS: All patients underwent negative margin resection (R0) of duodenal and proximal jejunum GISTs. Complications occurred more frequently in treatment of duodenal GISTs than proximal jejunum GISTs (p = 0.003). GISTs in D3 (the 3rd portion of duodenum) were related to larger tumor size (p = 0.001), higher probability of severe complication rate (p = 0.042), longer hospital stays (p = 0.023) and fasting time (p = 0.020). More complications were found for patients with digestive reconstruction than limited resection (p = 0.010). Additionally, patients with a tumor mass larger than 5 cm or a mitotic index greater than 5 mitoses/50 HPFs showed poorer therapeutic outcomes. The 1- and 3-year overall survival was 97.9% and 86.1%, respectively and were not influenced by operation type (p = 0.061) or GIST position (p = 0.447). CONCLUSION: With negative operational margins, limited resection is a safe and feasible procedure for duodenal and proximal jejunum GIST patients and unnecessary digestive reconstruction should be avoided. Considering the severe complication rate, resection for GISTs in D3 should be performed with care.

Concurrent Treatment with Anti-DLL4 Enhances Antitumor and Proapoptotic Efficacy of a γ-Secretase Inhibitor in Gastric Cancer.

The Notch signaling pathway has been identified as a therapeutic target for cancers. γ-Secretase inhibitors (GSIs) have been progressively recognized as potential anticancer drugs. The present study aimed to investigate the effects of anti-delta like legend 4 (anti-DLL4) treatment on the anticancer efficacy of GSIs in gastric cancer. SGC-7901-GFP human gastric cancer cells were tested for DLL4 expression by rosette formation test and immunofluorescence, and then were treated with anti-DLL4 antibody N-[N-(3,5-difluorophenacetyl)-L-ananyl]-S-phenylglycine t-butyl ester (DAPT, a type of GSI), or a combination of anti-DLL4 antibody and DAPT. The effects of in vitro treatments on cell apoptosis, cell cycle, and cell invasion were analyzed. For in vivo study, an orthotopic mouse model of gastric cancer was established with green fluorescence expressing SGC-7901. Ultrasound targeted microbubble destruction was used to treat tumor-bearing mice with anti-DLL4 antibody conjugated microbubbles, DAPT, and a combination of the two. Real-time fluorescence imaging was performed to assess tumor cell inhibition in each group. Following in vivo treatments, apoptosis of tumor cells and the expression of apoptosis-related genes BAX, Bcl-2, and P53 were detected by TUNEL and immunohistochemical staining. In vivo combined treatment of anti-DLL4 and DAPT led to a higher rate of cell apoptosis and greater inhibition of cell invasion than that observed with DAPT treatment alone. DAPT and anti-DLL4 combination therapy resulted in decreased cell distribution at G1 phase and increased cell distribution at S phase, compared to the untreated control group (P < .01). In vivo combined therapy with anti-DLL4 and DAPT significantly increased tumor growth inhibition and tumor cell apoptosis when compared to DAPT therapy alone (P < .05). In addition, combined treatment significantly increased expression of BAX and P53 and reduced Bcl-2 expression (P < .05). Conversely, treatment with DAPT alone only increased expression of BAX and P53 (P < .05), suggesting that the reduction of Bcl-2 expression may play an important role in the synergetic antitumor and proapoptosis effects of the combined treatment. Concurrent treatment with anti-DLL4 enhances the antitumor and proapoptotic efficacy of the γ-secretase inhibitor in gastric cancer both in vitro and in vivo.

Pancreatic cancer-derived exosomes suppress the production of GIP and GLP-1 from STC-1 cells in vitro by down-regulating the PCSK1/3.

One hallmark of pancreatic cancer (PC) is the high prevalence of pancreatic cancer-associated diabetes mellitus (PC-DM), but the mechanisms remain to be elucidated. Patients with PC who are diagnosed with new-onset diabetes/prediabetes have recently been shown to display significantly lower levels of glucose-dependent insulinotropic peptide (GIP) secreted mainly by enteroendocrine cells. We hypothesized that PC-derived exosomes are responsible for the decreased levels of incretins in patients with PC-DM. In this study, exosomes were successfully isolated from PANC-1, MIA PaCa-2 and SW620 cells and characterized. Only the exosomes from MIA PaCa-2 cells (Exo-Mia) reduce the production of GIP and glucagon-like peptide-1 (GLP-1) from STC-1 cells in vitro in a concentration- and time-dependent manner. Moreover, Exo-Mia increased the levels of the Gip and proglucagon mRNAs and decreased the expression of proprotein convertase subtilisin/kexin type 1/3 (PCSK1/3), which is responsible for the post-translational processing of Gip and proglucagon. Furthermore, differentially expressed exosomal miRNAs (miR-6796-3p, miR-6763-5p, miR-4750-3p and miR-197-3p) were identified and considered to be responsible for the inhibitory effects on GIP and GLP-1 production. To further determine the approach of cancer-derived exosomes reaching enteroendocrine cells, we analyzed the uptake and distribution of exosomes in animal model. It was observed that exosomes infused into the intestinal cavity were more easily internalized by the intestinal epithelium than exosomes injected into blood. In conclusion, pancreatic cancer-derived exosomes (Exo-Mia) suppress the synthesis of GIP and GLP-1 from STC-1 cells in vitro by down-regulating the PCSK1/3. Moreover, it may be the pancreatic juice that transport cancer-derived exosomes to target cells (K and L cells) in the gut.

Thymidylate synthase prompts metastatic progression through the dTMP associated EMT process in pancreatic ductal adenocarcinoma.

As a fundamental metabolic enzyme, anti-Thymidylate synthase (TS) strategy has been shown to be an effective therapy for human cancers. However, the genuine effects of TS in pancreatic ductal adenocarcinoma (PDA) are still conflicting. We systemically assessed the prognostic value and whether TS associated with malignant progression in PDA. Protein and mRNA expression level of TS were evaluated in en bloc PDA samples, the prognostic effect of TS expressed in cytoplasm or cytonuclear was determined separately in the first time. The impact of TS on tumor cell behaviors was assessed in in vitro assays, and the TS associated metastatic potential was further determined in two different PDA metastatic models. The retrospective clinical analysis firstly demonstrated that tumor cytonuclear TS expression was positively correlated with lymphatic metastasis and negatively correlated with the overall survival (OS) in PDA patients. The subsequent experiments further confirmed that TS depletion can effectively abate EMT (epithelial to mesenchymal) process in in vitro and decline most of the metastatic lesions in two different PDA mice models, and the deoxythymidine monophosphate (dTMP) biosynthesis malfunction resulted imbalanced dNTP pools may be the fundamental causation. Collectively, the present study suggested the prospective strategy of combined anti-TS scheme for metastatic PDA, and we strongly suggest further clinical standardization research with a large cohort to verify the prognostic value and the therapeutic potential of TS in PDA.

SOX7 expression correlates with better prognosis in pancreatic cancer patients and is negatively related to pancreatic cancer associated diabetes.

Pancreatic cancer carries a dismal prognosis with a 5-year survival rate of about 5%, and researches have shown that the malignant level and tumor associated glucose metabolism abnormality may both influence the pancreatic cancer progression and prognosis. Recently, growing evidence suggest an association of SOX7 with tumor development. However, there are no studies focusing on the prognostic effect of SOX7 in pancreatic cancer, or its relationship with pancreatic cancer associated diabetes. To investigate the association of SOX7 and prognosis in pancreatic cancer, and further to verify whether SOX7 involves in the regulation of pancreatic cancer associated diabetes. 100 pancreatic cancer-related cases with follow-up information were made into tissue microarrays. Subsequently, the relationship between SOX7 and clinicopathological characteristics was analyzed. SOX7 expression level has a positive correlation with the prognosis of pancreatic cancer patients, especially in the subgroup of tumor size < 5 cm with pathological grades I-II (P=0.014). Moreover, the results showed that SOX7 is significantly negative with diabetes history in the same subgroup (r2=-0.405, P=0.014). SOX7 may exert a tumor suppressor effect in pancreatic cancer, and this effect may correlate with the pathogenesis of paraneoplastic islet injury.

Advantage of sorafenib combined with radiofrequency ablation for treatment of hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a leading cause of death worldwide. Among the surgical and nonsurgical treatments available, radiofrequency ablation (RFA) and sorafenib have been shown to have efficacy. There is little evidence whether combination of these therapies would have additional benefits. METHODS: In a mouse model of HCC, effects of sorafenib were determined by tumor size, RFA-induced necrosis area (triphenyltetrazolium chloride staining), microvascular density (MVD; 4',6-diamidino-2-phenylindole and anti-CD31 antibody staining), and tumor perfusion (magnetic resonance imaging). RESULTS: The RFA-induced necrosis area was 80.98 ± 9.14 and 69.49 ± 7.46 mm2 in mice administered 80 and 40 mg/kg sorafenib, respectively, but only 57.29 ± 3.39 mm2 in controls. Sorafenib also reduced tumor volume and enhanced RFA-induced tumor destruction in a dose-dependent manner, and reduced both MVD and tumor perfusion. CONCLUSIONS: The results of our study suggest a potential role for combining RFA with sorafenib for treatment of HCC. Sorafenib could enhance RFA efficiency, possibly through its angiogenesis suppressive effects.

Exosomes derived from pancreatic cancer cells induce insulin resistance in C2C12 myotube cells through the PI3K/Akt/FoxO1 pathway.

Prospective epidemiological studies have consistently suggested that pancreatic cancer-associated new-onset diabetes mellitus (PC-DM) represents a potential platform for early diagnose of pancreatic cancer (PC). Despite the studies performed, the mechanism behind this phenomenon remains ambiguous. In this study, we explored the effects of two types of exosomes released by murine pancreatic cancer and ductal epithelial cells on murine skeletal muscle cells. The results show that PC-derived exosomes can readily enter C2C12 myotubes, triggering lipidosis and glucose intake inhibition. We also demonstrate that PC-derived exosomes can inhibit insulin and PI3K/Akt signalling, in which insulin-induced FoxO1 nuclear exclusion is preserved and Glut4 trafficking is impaired. Microarray and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses show that exosomal microRNAs (miRNAs) probably play key roles in this process, an assumption that is corroborated by in vitro studies. These results confirm that the insulin resistance (IR) of skeletal muscle cells is governed by PC-derived exosomes through the insulin and PI3K/Akt/FoxO1 signalling pathways, where exosomal miRNAs potentially contribute to this phenomenon. These novel findings pave the way towards a comprehensive understanding of the cancer theories: "metabolic reprogramming" and "metabolic crosstalk".