Molecular cloning and characterization of a novel Dehydrogenase/reductase (SDR family) member 1 genea from human fetal brain

Initial characterization of human DHRS1 (SDR19C1), a member of the short-chain dehydrogenase/reductase superfamily

Many enzymes from the short-chain dehydrogenase/reductase superfamily (SDR) have already been well characterized, particularly those that participate in crucial biochemical reactions in the human body (e.g. 11β-hydroxysteroid dehydrogenase 1, 17β-hydroxysteroid dehydrogenase 1 or carbonyl reductase 1). Several other SDR enzymes are completely or almost completely uncharacterized, such as DHRS1 (also known as SDR19C1). Based on our in silico and experimental approaches, DHRS1 is described as a likely monotopic protein that interacts with the membrane of the endoplasmic reticulum. The highest expression level of DHRS1 protein was observed in human liver and adrenals. The recombinant form of DHRS1 was purified using the detergent n-dodecyl-β-D-maltoside, and DHRS1 was proven to be an NADPH-dependent reductase that is able to catalyse the in vitro reductive conversion of some steroids (estrone, androstene-3,17-dione and cortisone), as well as other endogenous substances and xenobiotics. The expression pattern and enzyme activities fit to a role in steroid and/or xenobiotic metabolism; however, more research is needed to fully clarify the exact biological function of DHRS1.

Sequence analysis of a human RhoGAP domain-containing gene and characterization of its expression in human multiple tissues

Rho GTPase activating proteins (GAPs) stimulate the intrinsic GTP hydrolysis activity of Rho family proteins. Here we isolated a rhoGAP domain-containing protein gene with the same reading frame with ARHGAP19 gene, which has an ORF of 1485 bp encoding a putative protein of 494 amino acid residues with a predicted molecular mass of 55.806 kDa. Protein pattern analysis shows that it contains a bipartite nuclear localization signal (NLS) besides the rhoGAP domain, and it is consistent with the result of sub-cellular localization. ARHGAP19 is located in chromosome 10q24.1 and consists of 12 exons according to the Blastn result. Weak expression was detected in adult pancreas, spleen, thymus and ovary of the 16 adult tissues examined, while it had a more abundant expression pattern in eight important human fetal tissues. The expression pattern of ARHGAP19 shows it may have functions related to fetus development and gives us some clues on its probable functions in adult tissues.

Anticancer drug clustering in lung cancer based on gene expression profiles and sensitivity database

background

The effect of current therapies in improving the survival of lung cancer patients remains far from satisfactory. It is consequently desirable to find more appropriate therapeutic opportunities based on informed insights. A molecular pharmacological analysis was undertaken to design an improved chemotherapeutic strategy for advanced lung cancer.

Methods

We related the cytotoxic activity of each of commonly used anti-cancer agents (docetaxel, paclitaxel, gemcitabine, vinorelbine, 5-FU, SN38, cisplatin (CDDP), and carboplatin (CBDCA)) to corresponding expression pattern in each of the cell lines using a modified NCI program.

Results

We performed gene expression analysis in lung cancer cell lines using cDNA filter and high-density oligonucleotide arrays. We also examined the sensitivity of these cell lines to these drugs via MTT assay. To obtain our reproducible gene-drug sensitivity correlation data, we separately analyzed two sets of lung cancer cell lines, namely 10 and 19. In our gene-drug correlation analyses, gemcitabine consistently belonged to an isolated cluster in a reproducible fashion. On the other hand, docetaxel, paclitaxel, 5-FU, SN-38, CBDCA and CDDP were gathered together into one large cluster.

Conclusion

These results suggest that chemotherapy regimens including gemcitabine should be evaluated in second-line chemotherapy in cases where the first-line chemotherapy did not include this drug. Gene expression-drug sensitivity correlations, as provided by the NCI program, may yield improved therapeutic options for treatment of specific tumor types.