ACOT12-Dependent Alteration of Acetyl-CoA Drives Hepatocellular Carcinoma Metastasis by Epigenetic Induction of Epithelial-Mesenchymal Transition.

Metabolic reprogramming plays an important role in supporting tumor growth. However, little is known about the metabolic alterations that promote cancer metastasis. In this study, we identify acyl-CoA thioesterase 12 (ACOT12) as a key player in hepatocellular carcinoma (HCC) metastasis. The expression of ACOT12 is significantly down-regulated in HCC tissues and is closely associated with HCC metastasis and poor survival of HCC patients. Gain- and loss-of-function studies demonstrate that ACOT12 suppresses HCC metastasis both in vitro and in vivo. Further mechanistic studies reveal that ACOT12 regulates the cellular acetyl-CoA levels and histone acetylation in HCC cells and that down-regulation of ACOT12 promotes HCC metastasis by epigenetically inducing TWIST2 expression and the promotion of epithelial-mesenchymal transition. Taken together, our findings link the alteration of acetyl-CoA with HCC metastasis and imply that ACOT12 could be a prognostic marker and a potential therapeutic target for combating HCC metastasis.

Multi-spectroscopic study on interaction of bovine serum albumin with lomefloxacin-copper(II) complex.

The binding reactions of lomefloxacin-copper(II) complex (LMF-Cu) or LMF to bovine serum albumin (BSA) in physiological solution were investigated by multi-spectroscopy. The binding constant, the number of binding sites and the binding distance between LMF-Cu or LMF and BSA were obtained by a fluorescence quenching method and according to the mechanism of Forster-type dipole-dipole non-radioactive energy-transfer, respectively. Enthalpy and entropy changes for two systems were calculated to be -7.970 kJ mol(-1) and 47.438 J mol(-1)K(-1) for LMF-BSA, -12.469 kJ mol(-1) and 33.542 J mol(-1)K(-1) for LMF-Cu-BSA, respectively. The highly positive values observed for the entropy give evidence for a strong interaction. The values of DeltaH and DeltaS in two systems are similar, indicating that electrostatic interactions in two systems play major role. The effect of LMF-Cu or LMF on the conformation of BSA was also analyzed by synchronous fluorescence, three-dimensional fluorescence and circular dichroism spectra. The results showed that the presence of Cu ion in LMF-Cu can affect the conformation of BSA to some degree. All the results revealed that the addition of copper ion promotes the interaction of lomefloxacin with bovine serum albumin.

[Fluorescence and visible spectroscopic studies on interaction of beta-cyclodextrin-thionine inclusion complex with DNA].

The inclusion of beta-cyclodextrin (CD) for thionine (TH) and the interaction of DNA with CD-TH inclusion complex were investigated by fluorescence and visible absorption spectrometry. TH with beta-CD formed a 1 : 1 inclusion complex with the stability constant of 527 L x mol(-1) (visible spectrometry)/444 L x mol(-1) (fluorescence) in the pH 7.2 PBS buffer solutions. The addition of DNA makes the absorbance of the inclusion complex decrease and the absorption spectrum shift toward long wavelengths. The fluorescence experiments indicated that the presence of DNA makes the emission peak of CD-TH shift toward short wavelengths and the fluorescence of inclusion complex quench, and the quenching constant was calculated to be 6.12 x 10(4) L x mol(-1) by Stern-Volmer method. All the data confirmed that CD-TH reacted with DNA in intercalative mode, and the binding numbers and the binding constant were estimated to be 1 and 3.47 X 10(4) L x mol(-1) by spectrophotometry.

Simultaneous determination of benserazide and levodopa by capillary electrophoresis-chemiluminescence using an improved interface.

A capillary electrophoresis coupling with indirect chemiluminescence detection method for the simultaneous determination of benserazide and levodopa has been developed. The detection interface was improved to simplify the capillary electrophoresis-chemiluminescence (CE-CL) system and the features of this improved interface were illustrated in this paper. The CE-CL conditions for the simultaneous determination of benserazide and levodopa were optimized. Under the optimal conditions, the CL intensity was linear with concentrations of levodopa in the range of 1.0 to 100.0 microg ml(-1), and benserazide in the range of 10.0 to 1,000 microg ml(-1), respectively. The detection limits (S/N=3) in turn were 1.85 microg ml(-1) for BS and 0.12 microg ml(-1) for L-dopa with relative standard deviations of less than 3%. The proposed method has been successfully applied to the determination of benserazide and levodopa in medopar tablets and spiked urine samples, demonstrating the feasibility and reliability of the proposed method.

Binding of anti-inflammatory drug cromolyn sodium to bovine serum albumin.

Fluorescence spectroscopy in combination with circular dichroism (CD) and UV-vis absorption spectroscopy were employed to investigate the binding of anti-inflammatory drug cromolyn sodium (Intal) to bovine serum albumin (BSA) under the physiological conditions with Intal concentrations of 0-6.4 x 10(-5)mol L(-1). In the mechanism discussion, it was proved that the fluorescence quenching of BSA by Intal is a result of the formation of Intal-BSA complex. Quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between Intal and BSA. The thermodynamic parameters Delta G, Delta H, Delta S at different temperatures (298, 304, and 310 K) were calculated and the results indicate the electrostatic interactions play a major role in Intal-BSA association. Binding studies concerning the number of binding sites (n=1) and apparent binding constant K(b) were performed by fluorescence quenching method. Utilizing fluorescence resonant energy transfer (FRET) the distance R between the donor (BSA) and acceptor (Intal) has been obtained. Furthermore, CD and synchronous fluorescence spectrum were used to investigate the structural change of BSA molecules with addition of Intal, the results indicate that the secondary structure of BSA molecules was changed in the presence of Intal.