Isolation and Characterization of Genes Responsible for Naphthalene Degradation from Thermophilic Naphthalene Degrader, Geobacillus sp. JF8

Geobacillus sp. JF8 is a thermophilic biphenyl and naphthalene degrader. To identify the naphthalene degradation genes, cis-naphthalene dihydrodiol dehydrogenase was purified from naphthalene-grown cells, and its N-terminal amino acid sequence was determined. Using a DNA probe encoding the N-terminal region of the dehydrogenase, a 10-kb DNA fragment was isolated. Upstream of nahB, a gene for dehydrogenase, there were two open reading frames which were designated as nahAc and nahAd, respectively. The products of nahAc and nahAd were predicted to be alpha and beta subunit of ring-hydroxylating dioxygenases, respectively. Phylogenetic analysis of amino acid sequences of NahB indicated that it did not belong to the cis-dihydrodiol dehydrogenase group that includes those of classical naphthalene degradation pathways. Downstream of nahB, four open reading frames were found, and their products were predicted as meta-cleavage product hydrolase, monooxygenase, dehydrogenase, and gentisate 1,2-dioxygenase, respectively. A reverse transcriptase-PCR analysis showed that transcription of nahAcAd was induced by naphthalene. These findings indicate that we successfully identified genes involved in the upper pathway of naphthalene degradation from a thermophilic bacterium.

Diagnostic value of serum dihydrodiol dehydrogenase 2 levels in patients with non-small-cell lung cancer

Objectives: Dihydrodiol dehydrogenase 2 (DDH2) plays an important role in pathogenesis of non-small-cell lung cancer (NSCLC). This study aimed to evaluate the value of serum DDH2 levels in NSCLC patients. Methods: Serum samples were obtained from 863 NSCLC patients and 439 healthy controls. The samples were randomly divided into a training set and a test set. Serum DDH2 levels were assayed by enzyme-linked immunosorbent assay (ELISA). Results: The levels of DDH2 in NSCLC patients were significantly higher than those in healthy controls ( P < 0.001). The diagnostic use of DDH2 in lung adenocarcinoma was significantly greater than that of carcinoembryonic antigen, cytokeratin 19 fragment (CYFRA21-1), and carbohydrate antigen 125 ( P < 0.001). Combining DDH2 with carcinoembryonic antigen, CYFRA21-1, and carbohydrate antigen 125 was more effective for lung adenocarcinoma diagnosis than DDH2 alone. In addition, the levels of DDH2 could contribute to the diagnosis of lung squamous cell carcinoma. Conclusions: The measurement of serum DDH2 is a valuable diagnostic marker for NSCLC patients.

Common variants of the ALDH2 and DHDH genes and the risk of Dupuytren’s disease

The object of this study was the investigation of four common variants of single nucleotide polymorphisms of the aldehyde dehydrogenase H2 gene and dihydrodiol dehydrogenase gene and their association with the occurrence of Dupuytren’s disease. DNA samples were obtained from the peripheral blood of 300 consecutive patients. The control group comprised 300 healthy adults who were age matched with the Dupuytren’s patients. All four common variants were analysed using TaqMan® genotyping assays and sequencing. The differences in the frequencies of variants of single nucleotide polymorphisms in patients and the control group were statistically tested. No significant differences were found in the frequencies of the variants of the aldehyde dehydrogenase H2 and dihydrodiol dehydrogenase genes between the groups. Likewise, no significant differences were found in the frequencies of the variants of the genes between men and women. We noted a statistically significantly higher prevalence of the variants of the dihydrodiol dehydrogenase gene ( rs2270941 and rs11666105) in the group with a positive familial history of Dupuytren’s disease, in comparison with the group with a negative familial history.