Selective targeting of death receptor 5 circumvents resistance of MG-63 osteosarcoma cells to TRAIL-induced apoptosis

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a tumor necrosis factor superfamily member, targets death receptors and selectively kills malignant cells while leaving normal cells unaffected. However, unlike most cancers, many osteosarcomas are resistant to TRAIL. To investigate this resistance, we characterized the response of MG-63 osteosarcoma cells and hPOB-tert osteoblast-like cells to TRAIL and agonist antibodies to death receptor 4 (DR4) and death receptor 5 (DR5). We found that MG-63 osteosarcoma cells and hPOB-tert osteoblast-like cells show no or very little response to TRAIL or a DR4 agonist, but MG-63 cells undergo apoptosis in response to a DR5 agonist. Analysis of TRAIL receptor expression showed that normal osteoblastic and osteosarcoma cells express a variety of TRAIL receptors but this does not correlate to TRAIL responsiveness. Production of the soluble decoy receptor osteoprotegerin also could not explain TRAIL resistance. We show that TRAIL activates the canonical caspase-dependent pathway, whereas treatment with cycloheximide increases the sensitivity of MG-63 cells to TRAIL and anti-DR5 and can also sensitize hPOB-tert cells to both agents. Proapoptotic and antiapoptotic protein expression does not significantly differ between MG-63 and hPOB-tert cells or change following treatment with TRAIL or anti-DR5. However, sequencing the death domain of DR4 in several osteoblast-like cells showed that MG-63 osteosarcoma cells are heterozygous for a dominant-negative mutation, which can confer TRAIL resistance. These results suggest that although the dominant-negative form of the receptor may block TRAIL-induced death, an agonist antibody to the active death receptor can override cellular defenses and thus provide a tailored approach to treat resistant osteosarcomas.

Addition of allochthonous fungi to a historically contaminated soil affects both remediation efficiency and bacterial diversity

Botryosphaeria rhodina DABAC P82 and Pleurotus pulmonarius CBS 664.97 were tested for their ability to grow and to degrade aromatic hydrocarbons in an aged contaminated soil. To evaluate the impact of indigenous microflora on the overall process, incubations were performed on both fumigated and nonfumigated soils. Fungal colonization by B. rhodina was unexpectedly lower in the fumigated than in the nonfumigated soil while the growth of P. pulmonarius showed an opposite response. Degradation performances and detoxification by both fungi in the nonfumigated soil were markedly higher than those observed in the fumigated one. Heterotrophic bacterial counts in nonfumigated soil augmented with either B. rhodina or P. pulmonarius were significantly higher than those of the corresponding incubation control (6.7 +/- 0.3 x 10(8) and 8.35 +/- 0.6 x 10(8), respectively, vs 9.2 +/- 0.3 x 10(7)). Bacterial communities of both incubation controls and fungal-augmented soil were compared by numerical analysis of denaturing gradient gel electrophoresis profiles of polymerase chain reaction (PCR)-amplified 16S ribosomal RNA (rRNA) genes and cloning and sequencing of PCR-amplified 16S rRNA genes. Besides increasing overall diversity, fungal augmentation led to considerable qualitative differences with respect to the pristine soil.

Leaching and microbial treatment of a soil contaminated by sulphide ore ashes and aromatic hydrocarbons

Contaminated soil from a historical industrial site and containing sulfide ore ashes and aromatic hydrocarbons underwent sequential leaching by 0.5 M citrate and microbial treatments. Heavy metals leaching was with the following efficiency scale: Cu (58.7%) > Pb (55.1%) > Zn (44.5%) > Cd (42.9%) > Cr (26.4%) > Ni (17.7%) > Co (14.0%) > As (12.4%) > Fe (5.3%) > Hg (1.1%) and was accompanied by concomitant removal of organic contaminants (about 13%). Leached metals were concentrated into an iron gel, produced during ferric citrate fermentation by the metal-resistant strain BAS-10 of Klebsiella oxytoca. Concomitantly, the acidic leached soil was bioaugmented with Allescheriella sp. DABAC 1, Stachybotrys sp. DABAC 3, Phlebia sp. DABAC 9, Pleurotus pulmonarius CBS 664.97, and Botryosphaeria rhodina DABAC P82. B. rhodina was most effective, leading to a significant depletion of the most abundant contaminants, including 7-H-benz[DE]anthracene-7-one, 9,10-anthracene dione and dichloroaniline isomers, and to a marked detoxification as assessed by the mortality test with the Collembola Folsomia candida Willem. The overall degradation activities of B. rhodina and P. pulmonarius appeared to be significantly enhanced by the preliminary metal removal.

Autophagy-mediated chemosensitizing effect of the plant alkaloid voacamine on multidrug resistant cells

In our previous studies, voacamine, a bisindolic alkaloid extracted from Peschiera fuchsiaefolia, was examined for its possible capability of enhancing the cytotoxic effect of doxorubicin (DOX) on multidrug resistant (MDR) human osteosarcoma cells (U-2 OS-R). Voacamine induced in resistant cells a significant increase of drug retention and intranuclear location which became comparable to those observed in the parental sensitive counterparts (U-2 OS-WT). In the present study, the cell survival analysis and the electron microscopic observations confirmed the evident cytotoxicity of DOX on MDR cells after pre-treatment with the plant extract. Moreover, an increase of the reactivity of P-glycoprotein (P-gp) with the monoclonal antibody UIC2, which recognizes an epitope of the drug transporter in its functional conformation, was revealed, demonstrating that voacamine is a substrate of P-gp, thus acting as a competitive antagonist of the cytotoxic agent. Moreover, to investigate if the enhancement of the cytotoxic effect induced by voacamine could be due to an apoptotic process, we carried out the analysis of cell morphology after Hoechst staining and the quantification of apoptosis by Annexin V-FITC assay. These evaluations showed a very low rate of apoptosis in U-2 OS-R cells treated with voacamine and DOX given in association. In addition, the combined treatment induced ultrastructural modifications suggestive of autophagic cell death. In particular, transmission electron microscopy observations revealed the presence of numerous lysosomes and the formation of a large number of autophagosomes containing residual digested material. In conclusion, these findings seem to indicate that voacamine is capable of enhancing the cytotoxic effect of DOX on MDR cells by favouring a lethal autophagic process.

Voacamine, an alkaloid extracted from Peschiera fuchsiaefolia, inhibits P-glycoprotein action in multidrug-resistant tumor cells

Multidrug resistance (MDR) in tumor cells is generally associated with increased efflux of the cytotoxic compounds, due to the activation of mechanisms of intracellular transport and to the overexpression of surface proteins, such as P-glycoprotein (Pgp), which act as ATP-dependent molecular pumps. In a previous study, voacamine, a bisindolic alkaloid from Peschiera fuchsiaefolia, was examined for its possible capability of enhancing the cytotoxic effect of doxorubicin (DOX) on resistant human osteosarcoma cells. The effects of voacamine on the cell survival and on accumulation of DOX were investigated on both the parental cell line, U-2 OS-WT, and its resistant counterpart, U-2 OS-R. A differential effect between sensitive and resistant cells on the intracellular DOX concentration and distribution was revealed. In particular, voacamine induced a significant increase of drug retention and intranuclear location in resistant cells. Moreover, the cell survival analysis and the electron microscopic observations revealed an enhancement of the cytotoxic effect of DOX induced by the plant extract. In the present study, a panel of monoclonal antibodies (MAbs), recognizing different and specific structural and functional state of Pgp, was used. By flow cytometry and immunofluorescence confocal microscopy, a dose-dependent increase of the reactivity of Pgp with MAb UIC2, which specifically recognizes an epitope of the drug transporter in its functional conformation, was detected in voacamine-treated U-2 OS-R cells. Conversely, the expression of the epitope recognized by MAb MC57 was downregulated while MAb MM4.17 did not change its binding level to treated and untreated MDR cells. These data suggest that the plant extract reacts with Pgp producing conformational changes with consequent epitope modulation. Taken together, our observations seem to demonstrate that voacamine is a substrate for Pgp and, therefore, interferes with the Pgp-mediated drug export, acting as a competitive antagonist of cytotoxic agents.

Fetal bone cells for tissue engineering

We envision the use of human fetal bone cells for engineered regeneration of adult skeletal tissue. A description of their cellular function is then necessary. To our knowledge, there is no description of human primary fetal bone cells treated with differentiation factors. The characterization of fetal bone cells is particularly important as the pattern of secreted proteins from osteoblasts has been shown to change during aging. In the first part of this work, human primary fetal bone cells were compared to adult bone cells and mesenchymal stem cells for their ability to proliferate and to differentiate into osteoblasts in vitro. Cell proliferation, gene expression of bone markers, alkaline phosphatase (ALP) activity, and mineralization were analyzed during a time-course study. In the second part of this paper, bone fetal cells behavior exposed to osteogenic factors is further detailed. The doubling time of fetal bone cells was comparable to mesenchymal stem cells but significantly shorter than for adult bone cells. Gene expression of cbfa-1, ALP, alpha1 chain of type I collagen, and osteocalcin were upregulated in fetal bone cells after 12 days of treatment, with higher inductions than for adult and mesenchymal stem cells. The increase of ALP enzymatic activity was stronger for fetal than for adult bone cells reaching a maximum at day 10, but lower than for mesenchymal stem cells. Importantly, the mineralization process of bone fetal cells started earlier than adult bone and mesenchymal stem cells. Proliferation of fetal and adult bone cells was increased by dexamethasone, whereas 1alpha,25-dihydroxyvitamin D3 did not show any proliferative effect. Mineralization studies clearly demonstrated the presence of calcium deposits in the extracellular matrix of fetal bone cells. Nodule formation and calcification were strongly increased by the differentiation treatment, especially by dexamethasone. This study shows for the first time that human primary fetal bone cells could be of great interest for bone research, due to their fast growth rate and their ability to differentiate into mature osteoblasts. They represent an interesting and promising potential for therapeutic use in bone tissue engineering.

Voacamine, a bisindolic alkaloid from Peschiera fuchsiaefolia, enhances the cytotoxic effect of doxorubicin on multidrug-resistant tumor cells

Multidrug-resistance (MDR) is largely caused by the efflux of therapeutics from the tumor cell by means of P-glycoprotein (P-gp), resulting in reduced efficacy of the chemotherapy. In order to overcome MDR, substances, such as verapamil and cyclosporin A (CsA), were employed. As these P-gp modulating agents did not seem promising in clinical practice, new compounds with a low degree of undesirable side effects, were introduced. In this study, bisindolic alkaloid voacamine was examined for its possible capability of enhancing the cytotoxic effect of doxorubicin (DOX) on drug resistant cells. Two different pairs of tumor cell lines were analyzed: the parental lymphoblastoid cell line CEM-WT and its MDR derivative CEM-R, the parental osteosarcoma cell line U-2 OS-WT and its resistant counterpart U-2 OS-R. These cell lines were characterized for their morphological features by scanning electron microscopy (SEM) and for the expression of the main drug transporters by flow cytometric analysis. The effects of voacamine on the cell survival and on both accumulation and efflux of DOX were then investigated. The intracellular distribution of DOX, given alone or in association with CsA or voacamine, was observed by laser scanning confocal microscopy. A differential effect of voacamine between sensitive and resistant cells on the intracellular DOX concentration and distribution was shown. In particular, voacamine induced a significant increase of drug retention and intranuclear location in resistant cells. The results of cell survival experiments revealed an enhancement of the cytotoxic effect of DOX induced by voacamine, confirmed by evident morphological changes observed by SEM. These findings suggest promising applications of this natural substance against MDR tumors.

High isoflavone content and estrogenic activity of 25 year-old Glycine max tissue cultures

Soy isoflavones are phytoestrogens which have been associated with several health benefits. In the present study, we report the production of isoflavones in a collection of 40 strains of soya cell cultures established in 1975. A large variability in the isoflavone composition was observed and high-producing strains, with an isoflavone content of up to 46.3 mg g(-1) dry wt., were found. In comparison with soybeans, many callus strains had a higher isoflavone concentration (10-40 times) and a different ratio of genistin to daidzin forms. The highest producing strain was transferred to liquid medium in an Erlenmeyer flask and in a 10 l stirred-tank bioreactor where high isoflavone content (7% dry wt.), concentration (880 mg l(-1)) and a maximum productivity estimated to 60 mg l(-1) d(-1) were obtained. We further studied the estrogenic activity of pure compounds compared to plant cell culture extracts in the estrogen-responsive human endometrial Ishikawa cell line. Estrogen was confirmed to be 1000-10,000 times more active than isoflavones. The estrogenic activity of the extracts correlated to their isoflavone content. The activity of the malonyl isoflavones, assessed here for the first time, was lower than the aglycones. Taken together, these results suggest that soya cell cultures can be used as an alternative source to soybeans to provide high concentrations of bioactive isoflavones.

7-Epimer oxindole alkaloids of Cabucala cryptophlebia: their (13)C-NMR and CD data

The isolation, (13)C-NMR and CD data of two 7-epimer oxindole alkaloids, 10,11-dimethoxyisomitraphylline (1) and 10,11-dimethoxymitraphylline (2) from Cabucala cryptophlebia are reported.

Biological activities of the plant-derived bisindole voacamine with reference to malaria

The in vivo antiplasmodial activity of voacamine was assessed in a 4-day test. It was shown to exhibit in vivo activity with 25.4% and 43.4% inhibition of parasitaemia with 2.5 and 10 mg/kg, respectively. In synchronized cultures, it was found to act on trophozoite and schizont stages of Plasmodium falciparum. Using the FMC29 strain of Plasmodium falciparum as parasite and the isobologram curve as a method to assess interaction in drug combination, it was shown to lack any chloroquine-enhancing activity and its in vitro antiplasmodial effect was not potentiated by the chemosensitizer malagashanine.

Benzylbenzoate and norlignan glucosides from Curculigo pilosa: structural analysis and in vitro vascular activity

From the rhizomes of Curculigo pilosa, two benzylbenzoate diglucosides, piloside A and piloside B, and a glucosyl-fused norlignan, pilosidine, previously obtained only as the tetra-O-methyl derivative, were isolated. Pilosidine showed facilitating effect on adrenaline evoked contractions in rabbit aorta isolated preparations.

Antiplasmodial activity of the alkaloids of Peschiera fuchsiaefolia

The tertiary and quaternary alkaloids isolated from the stem bark, root bark and seeds of Peschiera fuchsiaefolia are reported. The tertiary alkaloid crude extract from the stem bark was tested in vitro against Plasmodium falciparum on the basis of the antimalarial use of the plant. It showed good activity against both the D6 strain (IC50 = 495 ng/ml) and chloroquine-resistant W2 strain (IC50 = 817 ng/ml) and voacamine was the most active of the tested alkaloids (IC50 = 238 ng/ml for D6 and 290 ng/ml for W2). The tertiary alkaloid crude extract from the root bark of the same plant is more active than voacamine (IC50 = 179 ng/ml for D6 and 282 ng/ml for W2 strain), and is particularly rich in dimeric alkaloids (0.22% of the vegetable material).

Expansile subchondral degenerative bone cyst secondary to osteoarthritis

A 53-year-old man known to have osteoarthritis of the left knee was examined because of a soft-tissue swelling overlying the pes anserinus tendon. Plain radiography and computed tomography revealed an expansile subchondral cyst of the proximal tibia. The cyst was multiloculated, had a sclerotic margin and an extraosseous soft-tissue component, and interrupted the cortex. Proof of a degenerative cyst was obtained by open biopsy. Such presentation in the knee is rare. Awareness of the possible aggressive behaviour of such degenerative cysts should help avoid confusion with neoplasm.

[Blood levels of cortisol and prolactin. Are they indices of the degree of protection against surgical stress?]

The paper evaluates the level of analgesic protection by assaying cortisol and prolactin levels in two groups of 20 patients each undergoing general anesthesia using two different techniques: TIVA with propofol and fentanyl, and BPN-nitrous oxide. The results showed that TIVA caused a very slight increase in residue cortisol which was, however, within normal limits. With BPN-nitrous oxide anesthesia there was a greater increase in cortisol, reaching a statistically significant level in blood collected one hour after the end of surgery. With regard to prolactin, there was a marked increase in this hormone using both techniques although in percentage terms this increase was lower in TIVA. These results show that plasma prolactin is a more sensitive test than cortisol assay in evaluating antalgic protection and that, of the two anesthetic techniques used, the most protective appears to be TIVA with propofol and fentanyl.

[The heterotopic autograft of spleen fragments following splenectomy for trauma in the healthy subject]

Authors report their experience on self-grafting of the spleen on 3 patients, among which a 9-year-old child. The surgical method is easy and quick and in their opinion it has given satisfactory results. In fact, basing themselves on the computation of the platelets values close to normality have been observed.

[Methylprednisolone sodium succinate in the profile of respiratory complications after thoracic surgical intervention]

Methylprednisolone sodium succinate (MPSS) was compared in a randomized double blind study to placebo in the prevention of respiratory complications in 40 patients submitted to thoracic surgery. The results indicate that the patients who received MPSS showed a lower incidence of respiratory complications, adverse reactions, chest pain and metabolic acidosis.

[Mandibular dysfunction syndrome: relation to orthodontics]

The authors, on the basis of a neuro-muscular and occlusal examination of the mandibular dysfunctional syndrome, take in account the malocclusions which may favour the uprisal of such a syndrome. The authors then describe their own therapeutic approach through the use of an occlusal splint which takes advantage of the periodontium started inhibitory reflexes.