Second messenger 2'3'-cyclic GMP-AMP (2'3'-cGAMP): the cell autonomous and non-autonomous roles in cancer progression.

Cytosolic double-stranded DNA (dsDNA) is frequently accumulated in cancer cells due to chromosomal instability or exogenous stimulation. Cyclic GMP-AMP synthase (cGAS) acts as a cytosolic DNA sensor, which is activated upon binding to dsDNA to synthesize the crucial second messenger 2'3'-cyclic GMP-AMP (2'3'-cGAMP) that in turn triggers stimulator of interferon genes (STING) signaling. The canonical role of cGAS-cGAMP-STING pathway is essential for innate immunity and viral defense. Recent emerging evidence indicates that 2'3'-cGAMP plays an important role in cancer progression via cell autonomous and non-autonomous mechanisms. Beyond its role as an intracellular messenger to activate STING signaling in tumor cells, 2'3'-cGAMP also serves as an immunotransmitter produced by cancer cells to modulate the functions of non-tumor cells especially immune cells in the tumor microenvironment by activating STING signaling. In this review, we summarize the synthesis, transmission, and degradation of 2'3'-cGAMP as well as the dual functions of 2'3'-cGAMP in a STING-dependent manner. Additionally, we discuss the potential therapeutic strategies that harness the cGAMP-mediated antitumor response for cancer therapy.

Xanthine dehydrogenase rewires metabolism and the survival of nutrient deprived lung adenocarcinoma cells by facilitating UPR and autophagic degradation.

Xanthine dehydrogenase (XDH) is the rate-limiting enzyme in purine catabolism by converting hypoxanthine to xanthine and xanthine to uric acid. The altered expression and activity of XDH are associated with the development and prognosis of multiple types of cancer, while its role in lung adenocarcinoma (LUAD) remains unknown. Herein, we demonstrated that XDH was highly expressed in LUAD and was significantly correlated with poor prognosis. Though inhibition of XDH displayed moderate effect on the viability of LUAD cells cultured in the complete medium, it significantly attenuated the survival of starved cells. Similar results were obtained in XDH-knockout cells. Nucleosides supplementation rescued the survival of starved LUAD cells upon XDH inhibition, while inhibition of purine nucleoside phosphorylase abrogated the process, indicating that nucleoside degradation is required for the XDH-mediated survival of LUAD cells. Accordingly, metabolic flux revealed that ribose derived from nucleoside fueled key carbon metabolic pathways to sustain the survival of starved LUAD cells. Mechanistically, down-regulation of XDH suppressed unfolded protein response (UPR) and autophagic flux in starved LUAD cells. Inhibition of XDH decreased the level of amino acids produced by autophagic degradation, which was accompanied with down-regulation of mTORC1 signaling. Supplementation of amino acids including glutamine or glutamate rescued the survival of starved LUAD cells upon knockout or inhibition of XDH. Finally, XDH inhibitors potentiated the anti-cancer activity of 2-deoxy-D-glucose that induced UPR and/or autophagy in vitro and in vivo. In summary, XDH plays a crucial role in the survival of starved LUAD cells and targeting XDH may improve the efficacy of drugs that induce UPR and autophagy in the therapy of LUAD.

The double faced role of xanthine oxidoreductase in cancer.

Xanthine oxidoreductase (XOR) is a critical, rate-limiting enzyme that controls the last two steps of purine catabolism by converting hypoxanthine to xanthine and xanthine to uric acid. It also produces reactive oxygen species (ROS) during the catalytic process. The enzyme is generally recognized as a drug target for the therapy of gout and hyperuricemia. The catalytic products uric acid and ROS act as antioxidants or oxidants, respectively, and are involved in pro/anti-inflammatory actions, which are associated with various disease manifestations, including metabolic syndrome, ischemia reperfusion injury, cardiovascular disorders, and cancer. Recently, extensive efforts have been devoted to understanding the paradoxical roles of XOR in tumor promotion. Here, we summarize the expression of XOR in different types of cancer and decipher the dual roles of XOR in cancer by its enzymatic or nonenzymatic activity to provide an updated understanding of the mechanistic function of XOR in cancer. We also discuss the potential to modulate XOR in cancer therapy.

Laboratory Research and Evaluation on Design and Application Performance of High-Performance Cold-Mix Resin.

To improve the safety of orthotropic steel bridge decks and the construction efficiency of bridge deck pavement by enhancing the performance of pavement materials, a new-generation, high-performance cold-mix resin was prepared by carrying out the combination of micro-characteristic analysis and performance test. Meanwhile, the pavement performance and fatigue performance of high-performance cold-mix resin mixtures and hot-mix epoxy saphalt mixtures as a control group were studied experimentally. The results show that different kinds of epoxy resins show bisphenol structure in essence. The curing exothermic peak temperature of the cold-mix resin increases with the heating rate. Both the specific heat capacity (△CP) of cold-mix resin and cold-mix resin asphalts exhibit a sudden change between -20 °C and 40 °C. In resin asphalt mixtures, cold-mix resin forms the network structure skeleton whereas the asphalt distributed in the form of tiny particles. The dosage of respective component has a significant effect on the tensile strength and elongation at break of cold-mix resin. Compared with hot-mix epoxy asphalt mixtures, cold-mix resin mixtures exhibit comparable water stability and high and low-temperature performance, as well as greater fatigue life.

AZn4Ga5Se12 (A = K, Rb, or Cs): Infrared Nonlinear Optical Materials with Simultaneous Large Second Harmonic Generation Responses and High Laser-Induced Damage Thresholds.

Despite the fact that nonlinear optical (NLO) crystals such as AgGaS2 and AgGaSe2 have been widely used in the infrared (IR) range due to their large second harmonic generation (SHG) coefficients and wide range of IR transparency windows, the small laser-induced damage threshold (LIDT) remains a great issue hindering their high-power applications. Herein, three noncentrosymmetric (NCS) chalcogenides AZn4Ga5Se12 (A = K, Rb, or Cs) are successfully obtained through an appropriate flux method after the extensive design and synthesis of the A/Zn/Ga/Q system. Single-crystal X-ray diffraction data demonstrate that they adopt trigonal space group R3 (No. 146) with three-dimensional diamond-like frameworks composed of [M9Se24] layers (M = Zn or Ga) stacking in the same direction and filled by charge-balancing A+ cations. Noticeably, they all exhibit strong powder SHG responses (2.8-3.7 × AgGaS2) and amazing LIDTs (19.2-23.4 × AgGaS2). In addition, theoretical calculations are performed to further determine the relationship between NCS structures and NLO properties. This work provides effective solutions for overcoming the trade-off between strong SHG and high LIDT in IR-NLO materials.

Expression of ghrelin or growth hormone secretagogue receptor in the brain of postpartum stress mice.

Postpartum depression is one of the most common mental diseases that occur in women after childbirth; this disorder is extremely painful for women and represents a major burden on the society. Therefore, we designed this study to explore the possible material basis of the disease, and provide potential novel antidepressants therapy using a mouse model. We established a postpartum immobilization stress model. Maternal body weight changes and food intake were recorded for half a month after delivery, and levels of ghrelin and its receptor, growth hormone secretagogue receptor (GHSR) were measured. The mice in the immobilization stress group showed stress activity as well as low body weight and low feeding status. Ghrelin expression was elevated in blood whereas ghrelin or GHSR expression decreased in the hippocampus and prefrontal cortex of the immobilization stress mice, and the number of ghrelin-active and GHSR cells reduced.

919 syrup inhibits ROS-mediated leptin-induced anorexia by activating PPARγ and improves gut flora abnormalities.

BACKGROUND: Women with postpartum psychiatric disorders are prone to severe anorexia. Clinical studies have revealed the efficacy of 919 syrup, a traditional Chinese medicine mixture against postpartum illnesses, such as in regulating maternal mood and improving postpartum anorexia. AIM: This study investigated the mechanisms through which 919 syrup improved anorexia induced by postpartum stress, focussing on the combined peroxisome proliferator-activated receptor gamma (PPARγ) and leptin signalling pathway, and its effects on the structure of the gut flora. METHODS: Mice were randomly divided into five groups-control group, immobilisation stressed (IS) group (normal saline), pioglitazone (Piog; western medicine control) group, 919 syrup low-dose (TJD; 13.5 g/kg) group, and 919 syrup high-dose (TJG; 27.0 g/kg) group. The control group was housed normally. The other groups received IS for 3 h daily for 21 days. The treatments were initiated following the first postnatal day and were administered by gastric gavage. All mice were sacrificed under anaesthesia on postnatal day 22. Blood, hypothalamus, stomach, and faecal specimens were collected. Gene and protein expression levels of components of the PPARγ-leptin signalling pathway in the serum, hypothalamus, and stomach were determined. Immunofluorescence staining for proopiomelanocortin (POMC), phosphorylated signal transducer and activator of transcription 3 (pSTAT3), and leptin was performed to observe their spatial distributions in the hypothalamus and stomach. 16s rRNA gene sequencing and bioinformatics analysis of fecal specimens were performed. RESULTS: After IS, postpartum mice showed significantly reduced appetite and body weight, accompanied by abnormalities in the structure of the gut flora. Treatment with 919 syrup (27.0 g/kg) downregulated malondialdehyde and upregulated catalase, glutathione peroxidase, and superoxide dismutase by activating PPARγ, thereby affecting the expression of leptin signalling pathway components (leptin, leptin receptor, pSTAT3, POMC, and cocaine and amphetamine-related transcript and neuropeptide Y), and modulated the gut flora in stressed mice. CONCLUSION: 919 syrup improved appetite in mice with postnatal stress by activating PPARγ to induce crosstalk with the leptin signalling pathway, this mechanism was similar to that of PPARγ agonists. 919 syrup also improved gut flora structure, and the changes in the relative abundances of the gut flora strongly correlated with the expression levels of PPARγ and leptin pathway components.

Lymph node mapping with carbon nanoparticles and the risk factors of lymph node metastasis in gastric cancer.

The study aimed to examine the applicability of carbon nanoparticles as a tracer for lymph node mapping and the related factors of lymph node and No.8p subgroup metastasis in patients with gastric cancer. Clinical data of 50 patients with gastric cancer, who had not received treatment preoperatively and underwent gastrectomy in Department of Gastrointestinal Surgery, Wuhan Union Hospital, between October 2014 and August 2015, were retrospectively analyzed. These patients were found to have no distant metastasis preoperatively. Thirty-five out of 50 patients were subjected to lymphatic mapping technique using carbon nanoparticles as the tracer, and the rest 15 cases did not experience the lymphatic mapping and served as controls. The sensitivity, specificity, false positive rate and false negative rate were calculated according to the number of lymph nodes, and the staining and metastasis condition of lymph nodes. The diagnostic value of carbon nanoparticles on metastatic lymph nodes was evaluated. The relationship between the metastasis of lymph nodes or subgroup No.8p lymph nodes and clinicopathologic features was analyzed by χ2-test or Fisher's exact test. All patients underwent D2 surgery (lymph node dissection including all the group 1 and group 2 nodes) plus the dissection of the subgroup No.8p lymph nodes. It was found that the average number of harvested lymph nodes in lymphatic mapping technique group (45.7±14.5) was greater than that in control group (39.2±11.7), but the difference was not significantly different (P=0.138>0.05). The success rate, the accuracy, sensitivity, specificity and false negative rate was 97%, 57%, 28%, 62% and 72% respectively. The metastasis of lymph nodes was correlated to the depth of cancer invasion (T stage) (P=0.004<0.05), and the metastasis of No.8p lymph nodes was correlated to the extent of lymph node involvement (N stage) (P=0.007<0.05). Six cases had lymph node metastasis in subgroup No.8p, and their TNM stages and clinical stages were as follows: T1N2M0 IIA, T3N3M0 IIIB, T4aN3M0 IIIC, T4aN3M0 IIIC, T4aN3M0 IIIC, and T4bN3M0 IIIC. In conclusion, our study indicated that carbon nanoparticles failed to show good selectivity for metastatic lymph nodes; the result of lymphatic mapping does not achieve a satisfactory performance; the incidence of lymph node metastasis may increase, accompanying with the increase of the depth of cancer invasion; No.8p lymph node metastasis tends to occur for gastric carcinoma patients with the extent of lymph node metastasis over N2 stage.