Autophagy1 is a complex of adaptive cellular response that enhances cancer cell survival in the face of cellular stresses such as chemothery. Here we show that in human gallbladder carcinoma (GBC) cells lines, SGC-996 and GBC-SD, autophagy is induced by the DNA damaging agent 5-fluorouracil (5-FU). While in combination with the pre-treatment of chloroquine (CQ), a inhibitor of autophagy, the inhibition of 5-FU to the proliferation and viability of GBC cells was potentiated. Furthermore, 5-FU treatment resulted in a general increase of the apoptotic rate and G0/G1 arrest of GBC cells, and the effect was potentiated by CQ pre-treatment. Since 5-FU induced autophagy in GBC cells, and CQ inhibited autophagy, our findings suggest a possible mechanism that CQ inhibited 5-FU-induced autophagy, which modified the cytotoxicity of 5-FU. The combination therapy of CQ and 5-FU should be considered as an effective strategy for the treatment of gallbladder carcinoma.

Objective:5-Fluorouracil (5-FU)-based combination therapies are standard treatments for gastrointestinal cancer, where the modulation of autophagy is becoming increasingly important in offering effective treatment for patients in clinical practice. This review focuses on the role of autophagy in 5-FU-induced tumor suppression and cancer therapy in the digestive system.Data Sources:All articles published in English from 1996 to date those assess the synergistic effect of autophagy and 5-FU in gastrointestinal cancer therapy were identified through a systematic online search by use of PubMed. The search terms were “autophagy” and “5-FU” and (“colorectal cancer” or “hepatocellular carcinoma” or “pancreatic adenocarcinoma” or “esophageal cancer” or “gallbladder carcinoma” or “gastric cancer”).Study Selection:Critical reviews on relevant aspects and original articles reporting in vitro and/or in vivo results regarding the efficiency of autophagy and 5-FU in gastrointestinal cancer therapy were reviewed, analyzed, and summarized. The exclusion criteria for the articles were as follows: (1) new materials (e.g., nanomaterial)-induced autophagy; (2) clinical and experimental studies on diagnostic and/or prognostic biomarkers in digestive system cancers; and (3) immunogenic cell death for anticancer chemotherapy.Results:Most cell and animal experiments showed inhibition of autophagy by either pharmacological approaches or via genetic silencing of autophagy regulatory gene, resulting in a promotion of 5-FU-induced cancer cells death. Meanwhile, autophagy also plays a pro-death role and may mediate cell death in certain cancer cells where apoptosis is defective or difficult to induce. The dual role of autophagy complicates the use of autophagy inhibitor or inducer in cancer chemotherapy and generates inconsistency to an extent in clinic trials.Conclusion:Autophagy might be a therapeutic target that sensitizes the 5-FU treatment in gastrointestinal cancer.

Molecular characterization of individual patients’ tumor cells is becoming increasingly important in offering effective treatment for patients in clinical practice. Recent advances in the field have indicated that circulating tumor DNA (ctDNA) has huge potential to serve as a biomarker for early detection and precision treatment as well as prognosis of hepatocellular carcinoma (HCC). As ctDNA in HCC patients harbors the molecular characteristics of HCC tumor cells, ctDNA analysis in the blood may be sufficient for convenient, non-invasive and accurate detection, providing information for HCC diagnosis, treatment and prognosis. In this review, we will summarize and discuss current trends and challenges of ctDNA application in HCC.

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Traditional electromagnetic interference (EMI) shielding films generally have constant shielding efficiencies that cannot respond to the real-time changing shielding requirements of smart wearable electronics. Here, we report a stress-gated EMI shielding fabric with a high elastic strain of 470% that exhibits variable shielding performance by stretching the fabric to different deformations. The fabric is fabricated through electroless plating Cu nanoparticles on the electrospun polyurethane nanofiber films, which can change from conducting to insulating when the stretch deformation reaches 50% and then back to conducting as the stress is released. The deformation causes repeated separation and contact of Cu nanoparticles on the surfaces of polyurethane nanofibers, resulting in a reversible transition between conducting and insulating. The fabric with tensile stress-gated conductivity can capture and weaken electromagnetic waves through absorption, reflection, and scattering, which shows real-time changing EMI shielding efficiencies from 0 to 52.31 dB. More importantly, the developed method of electroless plating for the deposition of continuous metal nanoparticles on elastic polyurethane nanofibers is new and scalable, which shows broad application prospects in smart EMI shielding fields.

DUSP1/MKP1 is a dual-specific phosphatase that regulates MAPK activity and is known to play a key role in tumor biology. Its function in gallbladder cancer (GBC) remains largely unknown, however. By exploring its activities in two GBC cell lines (SGC996 and GBC-SD), DUSP1 was found to inhibit GBC cell proliferation, migration and invasion. Moreover, DUSP1 inhibited GBC growth and metastasis in nude mice subcutaneously xenografted with SGC996 cells. The tumor suppression appeared to be mediated via the DUSP1-pERK/MAPK-MMP2 signal pathway. Angiogenesis was associated with the tumor metastasis in the mouse model and was impaired by DUSP1, which suppressed VEGF expression. These results suggest that DUSP1 suppresses GBC growth and metastasis by targeting the DUSP1-pERK-MMP2/VEGF axis. Identification of the DUSP1-pERK-MMP2/VEGF signals may provide new biomarkers and/or therapeutic targets to better suppress GBC metastasis in the future.

High-purity titanium aluminum carbide (Ti 3 AlC 2 ) powders were synthesized by a microwave sintering method using different titanium sources as raw materials. The prepared products were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated that the synthesized Ti 3 AlC 2 powders have high purity (97.5%) and even distribution of the grain size when using a 3TiH 2 /1.2Al/2C mixture as raw materials when the microwave sintering temperature and time were 1300°C and 30 minutes, respectively. The formation mechanism of the Ti 3 AlC 2 is described as proceeding via four stages. The solid-phase reaction between titanium and aluminum occurs below the melting point of aluminum and the main product is a Ti 3 Al phase, which is an observed intermediate compound for the formation of Ti 2 AlC and Ti 3 AlC 2 . Thus, this study provides a beneficial approach to low-temperature synthesis of high-purity Ti 3 AlC 2 materials. K E Y W O R D Shigh purity, MAX phases, microwave, powders, synthesis How to cite this article: Chen W, Tang J, Shi X, Ye N, Yue Z, Lin X. Synthesis and formation mechanism of high-purity Ti 3 AlC 2 powders by microwave sintering. Int J Appl Ceram Technol. 2020;17:778-789. https ://doi.

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