Dietary folate drives methionine metabolism to promote cancer development by stabilizing MAT IIA.

Folic acid, served as dietary supplement, is closely linked to one-carbon metabolism and methionine metabolism. Previous clinical evidence indicated that folic acid supplementation displays dual effect on cancer development, promoting or suppressing tumor formation and progression. However, the underlying mechanism remains to be uncovered. Here, we report that high-folate diet significantly promotes cancer development in mice with hepatocellular carcinoma (HCC) induced by DEN/high-fat diet (HFD), simultaneously with increased expression of methionine adenosyltransferase 2A (gene name, MAT2A; protein name, MATIIα), the key enzyme in methionine metabolism, and acceleration of methionine cycle in cancer tissues. In contrast, folate-free diet reduces MATIIα expression and impedes HFD-induced HCC development. Notably, methionine metabolism is dynamically reprogrammed with valosin-containing protein p97/p47 complex-interacting protein (VCIP135) which functions as a deubiquitylating enzyme to bind and stabilize MATIIα in response to folic acid signal. Consistently, upregulation of MATIIα expression is positively correlated with increased VCIP135 protein level in human HCC tissues compared to adjacent tissues. Furthermore, liver-specific knockout of Mat2a remarkably abolishes the advocating effect of folic acid on HFD-induced HCC, demonstrating that the effect of high or free folate-diet on HFD-induced HCC relies on Mat2a. Moreover, folate and multiple intermediate metabolites in one-carbon metabolism are significantly decreased in vivo and in vitro upon Mat2a deletion. Together, folate promotes the integration of methionine and one-carbon metabolism, contributing to HCC development via hijacking MATIIα metabolic pathway. This study provides insight into folate-promoted cancer development, strongly recommending the tailor-made folate supplement guideline for both sub-healthy populations and patients with cancer expressing high level of MATIIα expression.

[The effects of joint administration of 6% hydroxyethyl starch 130/0.4 and high-volume hemofiltration on patients with acute lung injury and acute kidney injury].

OBJECTIVE: To evaluate the effects of administration of 6% hydroxyethyl starch (6% HES 130/0.4, voluven) in combination with high volume hemofiltration (HVHF) in patients with ALI and AKI. METHODS: One hundred and eight patients with acute lung injury (ALI) and acute kidney injury (AKI) were enrolled from Department of Intensive Care Unit (ICU) of the provincial Hospital Affiliated to Shandong University between August 2006 and May 2011. The patients were randomly divided into two groups A (n = 68) and B (n = 40) to receive voluven (i.v., for volume resuscitation) and voluven+HVHF for 72 hours. The arterial blood lactate concentration (Lac), high sensitivity C-reactive protein (hs-CRP) serum concentration, pulmonary function index alveolar-arterial oxygen pressure difference [P(A-a)DO2] and oxygenation index (OI), as well as kidney function index serum cystatin C (Cyst C) and serum creatinine clearance rate (CCr) were measured at the time of admission and 72 hours after the treatment for statistical analysis. RESULTS: In comparison with group A, group B had significantly (all P < 0.01) lower mean value in the level of arterial Lac (mmol/L: 1.7 ± 0.7 vs. 2.7 ± 1.5), serum hs-CRP (mg/L: 35.8 ± 18.8 vs. 99.5 ± 20.4), P(A-a)DO2 (mm Hg, 1 mm Hg=0.133 kPa: 115.5 ± 23.1 vs. 155.4 ± 27.4), Cyst C (mg/L: 2.06 ± 1.12 vs. 3.95 ± 2.06) and significantly higher (both P < 0.01) mean value of OI (mm Hg: 295.2 ± 38.8 vs. 239.5 ± 32.7) and CCr (ml/min: 108.71 ± 31.33 vs. 90.21 ± 30.35) 72 hours after treatment. The mortality rate of group B was significantly lower than group A [10.00%(4/40) vs. 29.41%(20/68), P < 0.05] 7 days after the admission. CONCLUSION: 6% HES 130/0.4 in combination with HVHF could improve the lung and kidney function of the patients with ALI and AKI, prevent the development of multiple organ dysfunction syndrome (MODS), therefore improve the survival rate of these patients.

[Determination of trace lead and iron in nickel chloride and manganese sulfate by flame atomic absorption spectrometry after coprecipitation with yttrium phosphate].

Using yttrium phosphate as the coprecipitation collector for the separation and preconcentration of trace lead and iron in nickel chloride and manganese sulfate, flame atomic absorption spectrometric (FAAS) determination was described in the present paper. Coprecipitation parameters including the pH of the solution, and the amounts of YCl3 and H3 PO4 were discussed. It was found that lead and iron in nickel chloride could be coprecipitated quantitatively in the range of pH 3.0-4.0, and so could be lead in manganese sulfate. The detection limits (3sigma) of lead and iron in 20 mL solution were 1.63 x 10(-2) mg x L(-1) and 4.58 x 10(-2) mg x L(-1) respectively. In NiCl2 solution the standard addition recoveries for lead and iron were 100.91% and 99.73% respectively, and in MnSO4 solution the standard addition recoveries were 99.45% and 98.98% respectively. The method has eliminated the interference of matrix, and the result is satisfied.

[Determination of trace copper and cadmium in water by flame atomic absorption spectrometry coupled with flow injection on-line preconcentration using air segmentation].

The flow injection on-line preconcentration with a knotted reactor (KR) system for the determination of copper and cadmium in water by flame atomic absorption spectrometry (FAAS) was described in the present paper. The precipitation preconcentration of trace copper and cadmium was achieved by on-line merging of the sample and ammonia solutions. The resultant precipitates were on-line collected by a knotted reactor (KR) without filtration, and then the authors used a process of air segmentation. A solution of 1 mol x L(-1) HNO3 was employed to dissolve the collected precipitates and to deliver the analyte into the FAAS system for on-line detection. With a sample loading flow rate of 4.4 mL x min(-1) and a preconcentration time of 90 s, the enhancement factor was 34 (for Cu) and 36 (for Cd) as compared with the conventional FAAS method. The detection limits (3sigma) are found to be 1.9 and 0.3 microg x L(-1) for copper and cadmium respectively. The precision (RSD, n = 11) was found to be 2.3% at the level of 30.0 microg x L(-1) of Cu (II), and 2.6% at the level of 20.0 microg x L(-1) of Cd (II). The proposed method has been successfully applied to the determination of Cu (II) and Cd (II) in water samples.