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OBJECTIVES:The prognosis of pancreatic cancer is still very poor, and the ability to detect pancreatic cancer in high-risk groups at an early stage is therefore essential for improving its long-term survival. The purpose of this study was to explore specific biomarkers that can differentiate pancreatic cancer–associated diabetes from type 2 diabetes, for the early detection of pancreatic cancer.METHODS:From January 2006 to July 2008, 102 peripheral blood samples were collected from 25 patients diagnosed with pancreatic cancer and diabetes, 27 patients with pancreatic cancer without diabetes, 25 patients with diabetes mellitus >5 years, and 25 healthy controls. Thirty-two samples were used in microarray experiments to find differentially expressed genes specific for pancreatic cancer–associated diabetes. The results were further validated by quantitative real-time PCR for 101 blood samples. Protein expression of selected genes in serum and tissues was also detected.RESULTS:Using microarray analysis, we found 58 genes to be unique in patients with pancreatic cancer–associated diabetes, including 23 upregulated genes and 35 downregulated genes. Eleven upregulated genes were further validated by RT-PCR, and two of these genes—vanin-1 (VNN1) and matrix metalloproteinase 9 (MMP9)—were selected for logistic regression analysis. The combination of VNN1 and MMP9 showed the best discrimination of pancreatic cancer–associated diabetes from type 2 diabetes. The protein expression of MMP9 and VNN1 was in accordance with the gene expression.CONCLUSIONS:Our results indicate that the combination of VNN1 and MMP9 may be used as a novel blood biomarker panel for the discrimination of pancreatic cancer–associated diabetes from type 2 diabetes. [ABSTRACT FROM AUTHOR]

The gene cluster involved in the choline-glycine betaine conversion pathway was cloned from chromosomal DNA of the Gram-positive moderate halophile Halobacillus dabanensis D-8T. Nucleotide sequence analysis revealed four genes, designated gbsT, gbsI, gbsA, and gbsB, which are clustered in a 5.1-kb fragment. After heterologous expression of gbsAB in the Escherichia coli mutant strain PD141, the transformed cells were able to grow in a selective M63 medium containing 0.7 M NaCl and 1 mM choline, in contrast to the mutant strain. Glycine betaine biosynthesis was restored and its accumulation was confirmed by using 13C nuclear magnetic resonance spectroscopy. [ABSTRACT FROM AUTHOR]

A mercaptoacetic acid (MAA)-modified cadmium sulfide (CdS) nanoparticle was synthesized in aqueous solution and used as an oligonucleotide label for the electrochemical detection of nopaline synthase (NOS) terminator gene sequence. The carboxyl groups on the surface of the CdS nanoparticle can be easily covalently linked with NH2-modified NOS oligonucleotide probe sequences. The target ssDNA sequence was fixed onto the electrode surface by covalently linking to a mercaptoethanol self-assembled gold electrode, and the DNA hybridization of target ssDNA with probe ssDNA was accomplished on the electrode surface. The CdS nanoparticles anchored on the hybrids were dissolved in the solution by the oxidation with HNO3 and further detected by a sensitive differential pulse anodic stripping voltammetric method. The detection results can be used for monitoring the hybridization, and the NOS target sequence was satisfactorily detected in the approximate range from 8.0 × 10−12 to 4.0 × 10−9 mol L−1 with a detection limit of 2.75 × 10−12 mol L−1 (3 σ). The established method extended the nanoparticle-labeled electrochemical DNA analysis to genetically modified organisms (GMOs) specific sequence samples with higher sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

By using Southern blot hybridization and inverse polymerase chain reaction, a 5.5-kb DNA fragment was obtained from the genomic DNA of Halobacillus trueperi DSM10404T. Sequence analysis revealed that it contained a potential operon with high levels of sequence similarity to the opuA operon encoding glycine betaine transporter from Bacillus subtilis, which is a member of the ATP-binding cassette (ABC) substrate binding the protein-dependent transporter superfamily. The potential operon, designated as qatA (quaternary amine transporter), consists of three structural genes, which are predicted to encode an ATP-binding protein (QatAA), a membrane-associated protein (QatAB), and an extracellular substrate-binding protein (QatAC). Moreover, the putative promoter region of the operon was found with close homology to the σA-dependent promoter of B. subtilis. Reverse transcription (RT)–PCR analysis revealed that qatAA, qatAB, and qatAC genes were transcribed in cells of H. trueperi. Cells of Escherichia coli mutant MKH13 harboring qatA on pAY41 were able to grow on selective M9 salt medium containing glycine betaine and accumulated glycine betaine in the cytoplasm, showing that qatAA, qatAB, and qatAC genes together encode a functional glycine betaine transporter. [ABSTRACT FROM AUTHOR]

By using Southern blot hybridization and inverse polymerase chain reaction, a 5.5-kb DNA fragment was obtained from the genomic DNA of Halobacillus trueperi DSM10404T. Sequence analysis revealed that it contained a potential operon with high levels of sequence similarity to the opuA operon encoding glycine betaine transporter from Bacillus subtilis, which is a member of the ATP-binding cassette (ABC) substrate binding the protein-dependent transporter superfamily. The potential operon, designated as qatA (quaternary amine transporter), consists of three structural genes, which are predicted to encode an ATP-binding protein (QatAA), a membrane-associated protein (QatAB), and an extracellular substrate-binding protein (QatAC). Moreover, the putative promoter region of the operon was found with close homology to the σA-dependent promoter of B. subtilis. Reverse transcription (RT)–PCR analysis revealed that qatAA, qatAB, and qatAC genes were transcribed in cells of H. trueperi. Cells of Escherichia coli mutant MKH13 harboring qatA on pAY41 were able to grow on selective M9 salt medium containing glycine betaine and accumulated glycine betaine in the cytoplasm, showing that qatAA, qatAB, and qatAC genes together encode a functional glycine betaine transporter. [ABSTRACT FROM AUTHOR]

The gene cluster involved in the choline-glycine betaine conversion pathway was cloned from chromosomal DNA of the Gram-positive moderate halophile Halobacillus dabanensis D-8T. Nucleotide sequence analysis revealed four genes, designated gbsT, gbsI, gbsA, and gbsB, which are clustered in a 5.1-kb fragment. After heterologous expression of gbsAB in the Escherichia coli mutant strain PD141, the transformed cells were able to grow in a selective M63 medium containing 0.7 M NaCl and 1 mM choline, in contrast to the mutant strain. Glycine betaine biosynthesis was restored and its accumulation was confirmed by using 13C nuclear magnetic resonance spectroscopy. [ABSTRACT FROM AUTHOR]