Photodynamic activities of sulfonamide derivatives of porphycene on nasopharyngeal carcinoma cells

Two sulfonamide derivatives of porphycene, namely PS6 and PS6A, were synthesized, and their photodynamic efficacies on the nasopharyngeal carcinoma (NPC) cell line NPC/CNE-2 were evaluated. By comparing the 50% lethal concentrations (LC(50)) of these photosensitizers, we found that PS6A with a cationic ammonium group on the side chain exhibited potent photocytotoxicity on the NPC cell line. At a light dose of 1 J/cm(2), the LC(50) values of PS6 and PS6A for NPC cells were 11.6 and 1.92 microM, respectively. CNE-2 was found to rapidly take up PS6A in the first hour of incubation, and the uptake kinetics steadily increased to a plateau level after 18 h of incubation. The uptake of PS6A was temperature dependent. Over 99% of CNE-2 cells were sensitized by PS6A 24 h after drug treatment. Collapse of the mitochondrial membrane potential was also observed in PS6A photodynamic therapy (PDT)-treated CNE-2 cells 1.5 h after PDT. Confocal microscopy revealed that PS6A was predominantly localized in the mitochondria, lysosomes and Golgi bodies of NPC cells. Significant genotoxicity was not observed in CNE-2 cells. In functional studies, the in vitro formation of a capillary-like network of human umbilical vein endothelial cells in Matrigel was greatly inhibited by PS6A PDT in a dose-dependent manner. In conclusion, PS6A mediates both in vitro antitumor and antiangiogenic activities. PS6A might be a candidate for photodynamic treatment of NPCs.     

Measurement of nicotine, cotinine and trans-3'-hydroxycotinine in meconium by liquid chromatography-tandem mass spectrometry

Nicotine (NIC), cotinine (COT) and trans-3'-hydroxycotinine (OHCOT) are the most prevalent and abundant tobacco biomarkers in meconium. We have developed and validated an accurate and precise method for the measurement of these analytes in meconium in which potassium hydroxide is used to digest the meconium sample, followed by solid phase extraction from the liquified sample. The precision of OHCOT, COT and NIC measurements (intra-day and inter-day) were 4.8-10.6%, 3.4-11.6% and 9.3-15.8%, respectively. Evaluation of accuracy indicated bias of -4.0, 2.0 and 0.8% for OHCOT at concentrations of 0.5, 2.5 and 7.5 ng/g. The accuracy estimates for COT at concentrations of 0.5, 2.5 and 7.5 ng/g are 4.0, 4.0 and 5.7%, respectively. For NIC at 2, 10 and 30 ng/g the accuracy was calculated to be 3.0, 5.0 and 5.1%, respectively. The linear range of standard solutions was 0.125-37.5 ng/mL for OHCOT and COT, and 0.75-150 ng/mL for NIC. This method was applied to the analysis of 374 meconium samples from infants of both smoking and nonsmoking mothers. Positive correlations with r(2)≥0.63 were observed between NIC and COT, COT and OHCOT, NIC and OHCOT, and NIC and (OHCOT+COT) in these samples.     

Specific β-containing integrins exert differential control on proliferation and two-dimensional collective cell migration in mammary epithelial cells

Understanding how cell cycle is regulated in normal mammary epithelia is essential for deciphering defects of breast cancer and therefore for developing new therapies. Signals provided by both the extracellular matrix and growth factors are essential for epithelial cell proliferation. However, the mechanisms by which adhesion controls cell cycle in normal epithelia are poorly established. In this study, we describe the consequences of removing the β1-integrin gene from primary cultures of mammary epithelial cells in situ, using CreER. Upon β1-integrin gene deletion, the cells were unable to progress efficiently through S-phase, but were still able to undergo collective two-dimensional migration. These responses are explained by the presence of β3-integrin in β1-integrin-null cells, indicating that integrins containing different β-subunits exert differential control on mammary epithelial proliferation and migration. β1-Integrin deletion did not inhibit growth factor signaling to Erk or prevent the recruitment of core adhesome components to focal adhesions. Instead the S-phase arrest resulted from defective Rac activation and Erk translocation to the nucleus. Rac inhibition prevented Erk translocation and blocked proliferation. Activated Rac1 rescued the proliferation defect in β1-integrin-depleted cells, indicating that this GTPase is essential in propagating proliferative β1-integrin signals. These results show that β1-integrins promote cell cycle in mammary epithelial cells, whereas β3-integrins are involved in migration.     

Improved Visualization of Cell Nuclei in Unstained Cultured Cells

Nuclear morphology is useful in tissue culture studies in determining the presence and grade of transformed cells as well as in determining the heterogeneity of the cell population (Grogan el al. 1981, Hustin 1976, Siracky et al. 1978, Siracky 1979). The ratio of long and short nuclear axes provides a useful numerical expression of nuclear shape (Hustin 1976). Clear visualization of nuclei is critical for making the necessary measurements.     

Targeting histone acetylation dynamics and oncogenic transcription by catalytic P300/CBP inhibition

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Life Cycle Assessment Software: Selection Can Impact Results

When software is used to facilitate life cycle assessments (LCAs), the implicit assumption is that the results obtained are not a function of the choice of software used. LCAs were done in both SimaPro and GaBi for simplified systems of creation and disposal of 1 kilogram each of four basic materials (aluminum, corrugated board, glass, and polyethylene terephthalate) to determine whether there were significant differences in the results. Data files and impact assessment methodologies (Impact 2002, ReCiPe, and TRACI 2) were ostensibly identical (although there were minor variations in the available ReCiPe version between the programs that were investigated). Differences in reported impacts of greater than 20% for at least one of the four materials were found for 9 of the 15 categories in Impact 2002+, 7 of the 18 categories in ReCiPe, and four of the nine categories in TRACI. In some cases, these differences resulted in changes in the relative rankings of the four materials. The causes of the differences for 14 combinations of materials and impact categories were examined by tracing the results back to the life cycle inventory data and the characterization factors in the life cycle impact assessment (LCIA) methods. In all cases examined, a difference in the characterization factors used by the two programs was the cause of the differing results. As a result, when these software programs are used to inform choices, the result can be different conclusions about relative environmental preference that are functions purely of the software implementation of LCIA methods, rather than of the underlying data.     

Role of DDC-4/sFRP-4, a secreted frizzled-related protein,at the onset of apoptosis in mammary involution

Using differential display, we isolated DDC-4, a secreted frizzled-related protein (sFRP), which is induced in the physiological apoptosis of hormonally regulated, reproductive tissues such as mammary gland, prostate, corpus luteum and uterus. The role of this gene in apoptosis was studied in animals overexpressing ectopic DDC-4/sFRP-4. Transgenic mice bearing the DDC-4/sFRP-4 cDNA under the control of the MMTV-LTR promoter showed lactational insufficiency and many apoptotic cells in the alveoli between day 19 of pregnancy and day 4 of lactation as demonstrated by TUNEL reaction and the presence of activated caspase-3. We performed a PKB/Akt kinase assay and studied several of its substrates using phosphorylation-specific antibodies to show reduced phosphorylation in PKB/Akt itself, as well as in glycogen synthetase kinase-3beta (GSK-3beta), BAD, and Forkhead. Taken together, our results show a role for DDC-4/sFRP-4 in abrogating an epithelial cell survival pathway at the onset of mammary gland involution.     

A polyomic approach to elucidate the fluoranthene-degradative pathway in Mycobacterium vanbaalenii PYR-1

Mycobacterium vanbaalenii PYR-1 is capable of degrading a wide range of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs), including fluoranthene. We used a combination of metabolomic, genomic, and proteomic technologies to investigate fluoranthene degradation in this strain. Thirty-seven fluoranthene metabolites including potential isomers were isolated from the culture medium and analyzed by high-performance liquid chromatography, gas chromatography-mass spectrometry, and UV-visible absorption. Total proteins were separated by one-dimensional gel and analyzed by liquid chromatography-tandem mass spectrometry in conjunction with the M. vanbaalenii PYR-1 genome sequence (http://jgi.doe.gov), which resulted in the identification of 1,122 proteins. Among them, 53 enzymes were determined to be likely involved in fluoranthene degradation. We integrated the metabolic information with the genomic and proteomic results and proposed pathways for the degradation of fluoranthene. According to our hypothesis, the oxidation of fluoranthene is initiated by dioxygenation at the C-1,2, C-2,3, and C-7,8 positions. The C-1,2 and C-2,3 dioxygenation routes degrade fluoranthene via fluorene-type metabolites, whereas the C-7,8 routes oxidize fluoranthene via acenaphthylene-type metabolites. The major site of dioxygenation is the C-2,3 dioxygenation route, which consists of 18 enzymatic steps via 9-fluorenone-1-carboxylic acid and phthalate with the initial ring-hydroxylating oxygenase, NidA3B3, oxidizing fluoranthene to fluoranthene cis-2,3-dihydrodiol. Nonspecific monooxygenation of fluoranthene with subsequent O methylation of dihydroxyfluoranthene also occurs as a detoxification reaction.