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Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and its dismal prognosis indicates the urgent need to elucidate the potential oncogenic mechanisms. SIRT7 is a classic NAD+-dependent deacetylase that stabilizes the transformed state of cancer cells. However, its functional roles in PDAC are still unclear. Here, we found that SIRT7 expression is upregulated and predicts poor prognosis in PDAC. Then we screened the new interacting proteins of SIRT7 by mass spectrometry and the results showed that SIRT7 can interact with O-GlcNAc transferase (OGT). O-GlcNAcylation stabilizes the SIRT7 protein by inhibiting its interaction with REGγ to prevent degradation, and hyper-O-GlcNAcylation in pancreatic cancer cells leads to hypoacetylation of H3K18 via SIRT7, which promotes transcriptional repression of several tumour suppressor genes. In addition, SIRT7 O-GlcNAcylation at the serine 136 residue (S136) is required to maintain its protein stability and deacetylation ability. In vivo and in vitro experiments showed that blocking SIRT7 O-GlcNAcylation at S136 attenuates tumour progression. Collectively, we demonstrate that O-GlcNAcylation is an important post-translational modification of SIRT7 in pancreatic cancer cells, and elucidating this mechanism of SIRT7 is expected to pave the way for the development of novel therapeutic methods in the future.

Multidrug resistance (MDR) restricts chemotherapy efficacy due to P-glycoprotein (P-gp) mediated drug efflux, whereas current approaches to suppressing P-gp expression suffer from intrinsic challenges, such as low transfection, high toxicity and poor specificity. Here, hollow ferric-tannic acid complex nanocapsules (HFe-TA), which can be effectively degraded by the reaction with adenosine triphosphate (ATP), are synthesized for the delivery of glucose oxidase (GOx) and doxorubicin (DOX) for tumor treatment. The findings indicate that the intracellular ATP is significantly decreased due to the combined effect of HFe-TA degradation and GOx-mediated glucose consumption. Along with this ATP down-regulation, P-gp expression of tumor cells is suppressed remarkably, which in turn promotes the intracellular accumulation and anticancer efficacy of DOX. In addition, the production of •OH by Fe ions released from HFe-TA is promoted by the by-products of the oxidation of glucose process by GOx. In consequence, HFe-TA nanocapsules loaded with DOX and GOx enable significant inhibition effect to tumors both in vitro and in vivo due to the synergistic effect of cascade reactions. This study has therefore provided an alternative therapeutic platform for effective tumor inhibition with the potential in overcoming intrinsic MDR.

The prognosis for patients with liver metastases from gastric cancer is very poor. Nevertheless, standard therapeutic strategies have not been established yet. The impact of hepatic surgical treatment on survival of patients with metachronous liver metastases from gastric cancer still remains controversial. We conducted a retrospective analysis on records of 436 patients who received radical gastrectomy (with D2 lymphadenectomy, regardless of hepatic surgical treatment) for gastric cancer with metachronous (≥ 3 months after gastrectomy) liver metastases in our center between 2001 and 2016. All patients were followed until 2017/10/31 or withdrawn from the follow-up because of death. The median interval for non-hepatic metastases of the 436 patients who underwent radical gastrectomy is 14 months. T (P = 0.041), N (P = 0.023) and lymphovascular invasion (P

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”.

Aberrant expression of DJ-1 has been proven to be associated with tumorigenesis in many carcinomas. However, its role in pancreatic cancer is unknown. The aims of this study were to investigate whether the serum DJ-1 might be a potential biomarker for pancreatic cancer and to determine the biologic function of DJ-1 expression in gemcitabine-induced chemoresistance of pancreatic cancer. The serum level of DJ-1 was higher in 128 pancreatic cancer patients compared with 62 healthy controls by ELISA. To determine the effect of DJ-1 on pancreatic tumor chemoresistance, a siRNA-targeting DJ-1 was synthesized and a stably transfected cell line with DJ-1 over-expression was constructed. The mechanism of tumor chemoresistance was assessed by multiple methods, such as MTT assay, real-time PCR, Western blot and flow cytometry. The serum level of DJ-1 was higher in pancreatic cancer patients than healthy controls, and it has the relationship with tumor differentiation in pancreatic cancer. Down-regulation of DJ-1 enhanced gemcitabine-induced apoptosis in three pancreatic cancer cell lines. On the contrary, over-expression of DJ-1 desensitized the MIA PaCa-2 to the induction of apoptosis by gemcitabine. Our results suggest that the serum level of DJ-1 may be a potential biomarker for pancreatic cancer, and that DJ-1 plays critical roles in the pancreatic tumor chemoresistance, supporting the development of chemotherapeutic approaches targeting this oncogene.

Background TGFβ-induced (TGFBI/βig-H3) is a protein inducible by TGFβ1 and secreted by many types of cells. It binds to collagen, forms part of the extracellular matrix (ECM), and interacts with integrins on cell surfaces. In this study, we investigated the role of TGFBI in tumorigenesis and the underlying mechanisms. Methods Patient serum TGFBI levels were determined by ELISA. TGFBI transgenic and gene knockout mice and TGFBI-overexpressing liver cells were used for mechanistic studies. Results We demonstrated that patients with cholangiocarcinomas, hepatic carcinomas or gastric carcinomas presented significantly elevated serum TGFBI levels, and the excess TGFBI was derived from the tumor masses. TGFBI overexpression in mice resulted in increased incidence of spontaneous tumors and N,N-diethylnitrosamine (DEN)-induced liver tumor nodules, compared to that in wild type (WT) mice, while TGFBI knockout mice were comparable to WT controls in these 2 aspects. TGFBI promoted the survival of Aml-12 liver cells with DNA damage after irradiation, and augmented their post-irradiation proliferation. It activated the FAK/AKT/AKT1S1/PRS6/EIF4EBP pathway, which is known to modulate cell survival and proliferation. Conclusions Our data suggest that TGFBI functions as a promoter of certain gastrointestinal tract cancers. It provides a survival advantage to cells with DNA damage. Over a long time span, this advantage could translate into increased tumor risks.

To evaluate the safety and feasibility of a new operative procedure called binding pancreaticojejunostomy (BPJ) for the prevention of pancreatic leakage after pancreatoduodenectomy (PD). Binding pancreaticojejunostomy was performed in 100 patients from 1996 to 2000. During the operation, the cut end of the jejunum (3 cm) was everted, the everted mucosa of the jejunum was destroyed with carbolic acid. Meanwhile 3 cm long remnant of pancreas was isolated and sutured to 3 cm away form the jejunum cut end, care being taken not to penetrate the sero—muscular layer. Then, the everted jejunum was restituted to its normal position and the remnant of the pancreas was naturally pushed into the jejunal lumen for 3 cm. Finally, the surface of pancreatic remnant was closely in contact with destroyed jejunal mucosa surface, and a piece of absorbable thread was used to bind circumferentially this jejunum and the pancreatic remnant together, so no gap existed between the jejunal mucosa and pancreatic remnant. No pancreatic leakage occurred in the 100 patients with BPJ. Binding pancreaticojejunostomy procedure can effectively prevent the occurrance of anastomatic leakage and can be applied broadly.

We developed a novel one-pot polyol approach for the synthesis of biocompatible CdSe quantum dots (QDs) using poly(acrylic acid) (PAA) as a capping ligand at 240°C. The morphological and structural characterization confirmed the formation of biocompatible and monodisperse CdSe QDs with several nanometers in size. The encapsulation of CdS thin layers on the surface of CdSe QDs (CdSe/CdS core–shell QDs) was used for passivating the defect emission (650 nm) and enhancing the fluorescent quantum yields up to 30% of band-to-band emission (530–600 nm). Moreover, the PL emission peak of CdSe/CdS core–shell QDs could be tuned from 530 to 600 nm by the size of CdSe core. The as-prepared CdSe/CdS core–shell QDs with small size, well water solubility, good monodispersity, and bright PL emission showed high performance as fluorescent cell labels in vitro. The viability of QDs-labeled 293T cells was evaluated using a 3-(4,5-dimethylthiazol)-2-diphenyltertrazolium bromide (MTT) assay. The results showed the satisfactory (>80%) biocompatibility of as-synthesized PAA-capped QDs at the Cd concentration of 15 μg/ml.