UHPLC-MS/MS-based central carbon metabolism unveils the biomarkers related to colon cancer.

Even though colon cancer ranks among the leading causes of cancer mortality, early detection dramatically increases survival rates. Many studies have been conducted to determine whether altered metabolite levels may serve as a potential biomarker of cancer that affects key metabolic pathways. The goal of the study was to detect metabolic biomarkers in patients with colon cancer using liquid chromatography-mass spectrometry (LC-MS). This study consisted of 30 patients with colon cancer. An analysis of the metabolomes of cancer samples and para-carcinoma tissues was conducted. We identified a series of important metabolic changes in colon cancer by analyzing metabolites in cancerous tissues compared to their normal counterparts. They are mainly involved in the pentose phosphate pathway, the TCA cycle, glycolysis, galactose metabolism, and butanoate metabolism. As well, we observed dysregulation of AMP, dTMP, fructose, and D-glucose in colon cancer. Additionally, the AUCs for AMP, dTMP, fructose, and D-glucose were greater than 0.7 for the diagnosis of colon cancer. In conclusion, AMP, dTMP, fructose, and D-glucose showed excellent diagnostic performance and could serve as novel disease biomarkers for colon cancer diagnosis.

Diurnal Variations in High Time-Resolved Molecular Distributions and Formation Mechanisms of Biogenic Secondary Organic Aerosols at Mt. Huang, East China.

The molecular characteristics and formation mechanism of biogenic secondary organic aerosols (BSOAs) in the forested atmosphere are poorly known. Here, we report the temporal variations in and formation processes of BSOA tracers derived from isoprene, monoterpenes, and ß caryophyllene in PM2.5 samples collected at the foot of Mt. Huang (483 m a. s. l) in East China during the summer of 2019 with a 3 h time resolution. The concentrations of nearly all of the detected species, including organic carbon (OC), elemental carbon (EC), levoglucosan, and SIA (sum of SO42-, NO3-, and NH4+), were higher at night (19:00-7:00 of the next day) than in the daytime (7:00-19:00). In addition, air pollutants that accumulated by the dynamic transport of the mountain breeze at night were also a crucial reason for the higher BSOA tracers. Most of the BSOA tracers exhibited higher concentrations at night than in the daytime and peaked at 1:00 to 4:00 or 4:00 to 7:00. Those BSOA tracers presented strong correlations with O3 in the daytime rather than at night, indicating that BSOAs in the daytime were primarily derived from the photo-oxidation of BVOCs with O3. The close correlations of BSOA tracers with SO42- and particle acidity (pHis) suggest that BSOAs were primarily derived from the acid-catalyzed aqueous-phase oxidation. Considering the higher relative humidity and LWC concentration at night, the promoted aqueous oxidation was the essential reason for the higher concentrations of BSOA tracers at night. Moreover, levoglucosan exhibited a robust correlation with BSOA tracers, especially ß-caryophyllinic acid, suggesting that biomass burning from long-distance transport exerted a significant impact on BSOA formation. Based on a tracer-based method, the estimated concentrations of secondary organic carbon (SOC) derived from isoprene, monoterpenes, and ß caryophyllene at night (0.90 ± 0.57 µgC m-3) were higher than those (0.53 ± 0.34 µgC m-3) in the daytime, accounting for 14.5 ± 8.5% and 12.2 ± 5.0% of OC, respectively. Our results reveal that the BSOA formation at the foot of Mt. Huang was promoted by the mountain-valley breezes and anthropogenic pollutants from long-range transport.

[Effects of selenium on benzo[a] pyrene-induce DNA damage in mouse lung cells].

OBJECTIVE: To explore the effects of selenium on DNA damage induced by benzo[a] pyrene (BaP) in mouse lung cells. METHODS: Sodium selenite was given to Kunming male mice by i.p. and BaP was given by oral gavage. The control group was given solvent only with the same method. DNA damage was detected by single cell gel electrophoresis (or comet assay). RESULTS: The damage degrees in mice treated with 125, 250 and 500 mg/kg of BaP were more severe than that of control (P < 0.01). The rates of comet cells in the BaP-treated groups (43.50%, 84.00%, 95.63%) were significantly higher than that of control (9.75%, P < 0.01), and there was obvious dose-response relationship. 0.75, 1.50 and 3.00 mg/kg of sodium selenite presented antagonistic effects against DNA damage induced by 250 mg/kg of BaP in mouse's lung cells. The antagonistic effect of sodium selenite at the dose of 1.50 mg/kg was better than those of sodium selenite at the doses of 0.75, 3.00 mg/kg. CONCLUSION: BaP at the doses of 125 approximately 500 mg/kg could significantly induce DNA damage of lung cells in mice. 0.75 approximately 3.00 mg/kg of sodium selenite could inhibit DNA damage of lung cells in mice induced by 250 mg/kg of BaP.