Efficient apoptosis and necrosis induction by proteasome inhibitor: bortezomib in the DLD-1 human colon cancer cell line

The inhibition of the 26S proteasome evokes endoplasmic reticulum stress, which has been shown to be implicated in the antitumoral effects of proteasome inhibitors. The cellular and molecular effects of the proteasome inhibitor—bortezomib—on human colon cancer cells are as yet poorly characterized. Bortezomib selectively induces apoptosis in some cancer cells. However, the nature of its selectivity remains unknown. Previously, we demonstrated that, in contrast to normal fibroblasts, bortezomib treatment evoked strong effect on apoptosis of breast cancer cells incubated in hypoxic and normoxic conditions. The study presented here provides novel information on the cellular effects of bortezomib in DLD-1 colon cancer cells line. We observe twofold higher percentage of apoptotic cells incubated for 48 h with 25 and 50 nmol/l of bortezomib in hypoxic conditions and four-, fivefold increase in normoxic conditions in comparison to control cells, incubated without bortezomib. It is of interest that bortezomib evokes strong effect on necrosis of DLD-1 colon cancer cell line. We observe the sixfold increase in necrosis of DLD-1 cells incubated with 25 or 50 nmol/l of bortezomib for 48 h in hypoxia and fourfold increase in normoxic conditions in comparison to adequate controls. We suggest that bortezomib may be candidates for further evaluation as chemotherapeutic agents for human colon cancer.     

Chlorobium limicola forma thiosulfatophilum: Biocatalyst in the Production of Sulfur and Organic Carbon from a Gas Stream Containing H2S and CO2

Chlorobium limicola forma thiosulfatophilum (ATCC 17092) was grown in a 1-liter continuously stirred tank reactor (800-ml liquid volume) at pH 6.8, 30°C, saturated light intensity, and a gas flow rate of 23.6 ml/min from a gas cylinder blend consisting of 3.9 mol% H₂S, 9.2 mol% CO₂, 86.4 mol% N₂, and 0.5 mol% H₂. This is the first demonstration of photoautotrophic growth of a Chlorobium sp. on a continuous inorganic gas feed. A significant potential exists for applying this photoautotrophic process to desulfurization and CO₂ fixation of gases containing acidic components (H₂S and CO₂).     

Interference by Trypsin in the Interaction of Staphylococcal Enterotoxin B and Cell Cultures of Human Embryonic Intestine

The inhibitory effect of trypsin on the cytotoxicity of staphylococcal enterotoxin B acting with human embryonic intestine cell cultures was examined. Trypsin treatment of the cells rendered them resistant to enterotoxin for a period of 48 hr. The resistance increased proportionally with increased time of exposure of the cells to trypsin. Neither ethylenediaminetetraacetic acid nor scraping, which were used as alternate means of cell suspension, caused any resistance to the toxin. The effect is enzymatic and appears to be similar to the inhibitory action of trypsin and chymotrypsin on the attachment of polioviruses and coxsackieviruses to HeLa cells.     

Lead as an inductor of some morphological and functional changes in synaptosomes from rat brain

Summary 1. The effect of lead (in vivo) on the uptake of GABA, dopamine, and histidine as a precursor of histamine in synaptosomes obtained from chronically lead-treated rats was studied.2. Lead decreased the uptake of GABA, increased the uptake of dopamine, and did not change the uptake of histidine. These effects were independent of calcium concentration.3. Lead administration to the rat changed the morphology of the synaptosomes, as manifested in the decreased number of synaptic vesicles and disturbed mitochondrial structure.4. The results suggest the existence of several mechanisms of lead toxicity on uptake, related to individual neurotransmitters, which are not necessarily connected with a Pb²⁺/Ca²⁺ interaction.     

The SF36 health survey questionnaire: an outcome measure suitable for routine use within the NHS?

OBJECTIVE--To assess the validity, reliability, and acceptability of the short form 36 (SF 36) health survey questionnaire (a shortened version of a battery of 149 health status questions) as a measure of patient outcome in a broad sample of patients suffering from four common clinical conditions. DESIGN--Postal questionnaire, followed up by two reminders at two week intervals. SETTING--Clinics and four training practices in north east Scotland. SUBJECTS--Over 1700 patients aged 16-86 with one of four conditions--low back pain, menorrhagia, suspected peptic ulcer, or varicose veins--and a comparison sample of 900 members of the general population. MAIN OUTCOME MEASURES--The eight scales within the SF36 health profile. RESULTS--The response rate exceeded 75% in the patient population (1310 respondents). The SF36 satisfied rigorous psychometric criteria for validity and internal consistency. Clinical validity was shown by the distinctive profiles generated for each condition, each of which differed from that in the general population in a predictable manner. Furthermore, SF36 scores were lower in referred patients than in patients not referred and were closely related to general practitioners'' perceptions of severity. CONCLUSIONS--These results provide support for the SF36 as a potential measure of patient outcome within the NHS. The SF36 seems acceptable to patients, internally consistent, and a valid measure of the health status of a wide range of patients. Before it can be used in the new health service, however, its sensitivity to changes in health status over time must also be tested.     

Glycoprotein encoded by the Friend spleen focus-forming virus.

The Friend spleen focus-forming virus (F-SFFV) released from cultured erythroleukemia cells (cell line F4-6/K) was cloned free of its helper lymphatic leukemia virus (F-MuLV). After allowing adsorption to Sc-1 fibroblasts at a low multiplicity of infection, the cells were seeded individually into wells of a microtitier test plate and the resulting colonies were grown into large cultures. Among 14 of these cell cultures that have been analyzed thoroughly, 6 contained F-SFFV alone, 1 contained F-MuLV plus F-SFFV, and 7 were uninfected. Each of the Sc-1 cell lines which had been infected with cloned F-SFFV contained a glycoprotein with an apparent molecular weight of 55,000 (gp55) that was absent from the cell lines that lacked F-SFFV. gp55 was also present in Friend erythroleukemia cells and in fibroblasts infected with an F-SFFV that had been doubly cloned in another laboratory. These results indicate that gp55 is encoded by the F-SFFV genome. gp55 has the following additional properties. It can be immunoprecipitated with antiserum made to the F-MuLV virion envelope glycoprotein (gp75). Its unglycosylated polypeptide, formed in cells treated with 2-deoxy-D-glucose, has a molecular weight of approximately 45,000. Its tryptic peptide map contains peptides in common with F-MuLV gp75 but it also contains unique peptides. It appears to be absent or present in only low concentrations in erythroleukemia cell plasma membranes as determined by lactoperoxidase-catalyzed iodination, and it accumulates intracellularly in large amounts. In addition, it is absent from released virions. The majority of the cellular gp55 has an isoelectric point of 8.5 to 9.0. These results are consistent with the idea that an env gene recombination event was involved in the origin of F-SFFV.     

A murine leukemia virus mutant with a temperature-sensitive defect in membrane glycoprotein synthesis.

Cells infected with a temperature-sensitive mutant (ts-26) of Rauscher murine leukemia virus (R-MuLV) or with wild-type virus were labeled with 35S-methionine, and cell extracts were examined for radioactive polypeptides which could be precipitated by monospecific antisera to viral proteins. When shifted from permissive (31 degrees C) to nonpermissive (39 degrees C) temperature, cells infected with ts-26 rapidly begin to accumulate gPr90enr, the glycoprotein precursor to the membrane envelope glycoprotein gp70 and to the membrane-associated protein p15E. Simultaneously, formation of these mature virion proteins ceases. In addition, lactoperoxidase-catalyzed surface labeling with 125I--iodine indicates that the plasma membrane of cells infected with ts-26 becomes depleted of gp70 antigens at 39 degrees C. Nevertheless, at 39 degrees C these cells release defective MuLVs which lack gp70 and p15E but contain an outer membrane. The released particles also contain an aberrantly processed form of the major virion core protein p30, and many of these virion cores have an unusual immature crescent shape. It has previously been reported that cells infected with the ts-26 mutant of R-MuLV process a 65,000 dalton precursor (Pr65gag) of the virion core proteins more slowly at 39 degrees C than do cells infected with wild-type virus (Stephenson, Tronick and Aaronson, 1975). Although we have confirmed these results, this effect is relatively small and it is known that various alterations of MuLV assembly can lead secondarily to inhibited processing of Pr65gag. We propose that the ts-26 mutant has a primary temperature-sensitive defect in membrane glycoprotein synthesis and that this change causes pleiotropic effects on core morphogenesis.     

Interactions of vasopressin and oxytocin receptors with vasopressin analogues substituted in position 2 with 3,3′‐diphenylalanine – a molecular docking study

Vasopressin and oxytocin receptors belong to the superfamily of G protein‐coupled receptors and play an important role in many physiological functions. They are also involved in a number of pathological conditions being important drug targets. In this work, four vasopressin analogues substituted at position 2 with 3,3′‐diphenylalanine have been docked into partially flexible vasopressin and oxytocin receptors. The bulky residue at position 2 acts as a structural restraint much stronger in the oxytocin receptor (OTR) than in the vasopressin V2 receptor (V2R), resulting in a different location of the analogues in these receptors. This explains the different, either agonistic or antagonistic, activities of the analogues in V2R and OTR, respectively. In all complexes, the conserved polar residues serve as anchor points for the ligand both in OTR and V2R. Strong interactions of the C‐terminus of analogue II ([Mpa¹,d ‐Dpa²,Val⁴,d ‐Arg⁸]VP) with extracellular loop 3 may be responsible for its highest activity at V2R. It also appears that V2R adapts more readily to the docking analogues by conformational changes in the aromatic side chains triggering receptor activation. A weak activity at V1a vasopressin receptor appears to be caused by weak receptor–ligand interactions. Results of this study may facilitate a rational design of new analogues with the highest activity/selectivity at vasopressin and OTRs. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.