Inhibition of Phosphoinositide 3-Kinase/Protein Kinase B Signaling Hampers the Vasopressin-dependent Stimulation of Myogenic Differentiation

Arginine-vasopressin (AVP) promotes muscle differentiation, hypertrophy, and regeneration through the combined activation of the calcineurin and Calcium/Calmodulin-dependent Protein Kinase (CaMK) pathways. The AVP system is impaired in several neuromuscular diseases, suggesting that AVP may act as a physiological factor in skeletal muscle. Since the Phosphoinositide 3-kinases/Protein Kinase B/mammalian Target Of Rapamycin (PI3K/Akt/mTOR) signaling plays a significant role in regulating muscle mass, we evaluated its role in the AVP myogenic effect. In L6 cells AKT1 expression was knocked down, and the AVP-dependent expression of mTOR and Forkhead box O3 (FoxO) was analyzed by Western blotting. The effect of the PI3K inhibitor LY294002 was evaluated by cellular and molecular techniques. Akt knockdown hampered the AVP-dependent mTOR expression while increased the levels of FoxO transcription factor. LY294002 treatment inhibited the AVP-dependent expression of Myocyte Enhancer Factor-2 (MEF2) and myogenin and prevented the nuclear translocation of MEF2. LY294002 also repressed the AVP-dependent nuclear export of histone deacetylase 4 (HDAC4) interfering with the formation of multifactorial complexes on the myogenin promoter. We demonstrate that the PI3K/Akt pathway is essential for the full myogenic effect of AVP and that, by targeting this pathway, one may highlight novel strategies to counteract muscle wasting in aging or neuromuscular disorders.

Levetiracetam enhances the temozolomide effect on glioblastoma stem cell proliferation and apoptosis

Background

Glioblastoma multiforme (GBM) is a highly aggressive brain tumor in which cancer cells with stem cell-like features, called cancer stem cells (CSCs), were identified. Two CSC populations have been previously identified in GBM, one derived from the GBM area called enhanced lesion (GCSCs) and the other one from the brain area adjacent to the tumor margin (PCSCs) that greatly differ in their growth properties and tumor-initiating ability. To date the most effective chemotherapy to treat GBM is represented by alkylating agents such as temozolomide (TMZ), whose activity can be regulated by histone deacetylases (HDACs) inhibitors through the modulation of O6-methylguanine-DNA methyltransferase (MGMT) expression. Levetiracetam (LEV), a relatively new antiepileptic drug, modulates HDAC levels ultimately silencing MGMT, thus increasing TMZ effectiveness. However, an improvement in the therapeutic efficacy of TMZ is needed.

Methods

Cell proliferation was investigated by BrdU cell proliferation assay and by Western Blot analysis of PCNA expression. Apoptosis was evaluated by Western Blot and Immunofluorescence analysis of the cleaved Caspase-3 expression. MGMT and HDAC4 expression was analyzed by Western Blotting and Immunofluorescence. Statistical analysis was performed using the Student's t test and Mann-Whitney test.

Results

Here we evaluated the effect of TMZ on the proliferation rate of the IDH-wildtype GCSCs and PCSCs derived from six patients, in comparison with the effects of other drugs such as etoposide, irinotecan and carboplatin. Our results demonstrated that TMZ was less effective compared to the other agents; hence, we verified the possibility to increase the effect of TMZ by combining it with LEV. Here we show that LEV enhances the effect of TMZ on GCSCs proliferation (being less effective on PCSCs) by decreasing MGMT expression, promoting HDAC4 nuclear translocation and activating apoptotic pathway.

Conclusions

Although further studies are needed to determine the exact mechanism by which LEV makes GBM stem cells more  sensitive to TMZ, these results suggest that the clinical therapeutic efficacy of TMZ in GBM might be enhanced by the combined treatment with LEV.

Cancer stem cells from peritumoral tissue of glioblastoma multiforme: the possible missing link between tumor development and progression

In glioblastoma multiforme (GBM), cancer stem cells (CSCs) are thought to be responsible for gliomagenesis, resistance to treatment and recurrence. Unfortunately, the prognosis for GBM remains poor and recurrence frequently occurs in the peritumoral tissue within 2 cm from the tumor edge. In this area, a population of CSCs has been demonstrated which may recapitulate the tumor after surgical resection. In the present study, we aimed to characterize CSCs derived from both peritumoral tissue (PCSCs) and GBM (GCSCs) in order to deepen their significance in GBM development and progression. The stemness of PCSC/GCSC pairs obtained from four human GBM surgical specimens was investigated by comparing the expression of specific stem cell markers such as Nestin, Musashi-1 and SOX2. In addition, the growth rate, the ultrastructural features and the expression of other molecules such as c-Met, pMet and MAP kinases, involved in cell migration/invasion, maintenance of tumor stemness and/or resistance to treatments were evaluated. Since it has been recently demonstrated the involvement of the long non-coding RNAs (lncRNAs) in the progression of gliomas, the expression of H19 lncRNA, as well as of one of its two mature products miR-675-5p was evaluated in neurospheres. Our results show significant differences between GCSCs and PCSCs in terms of proliferation, ultrastructural peculiarities and, at a lower extent, stemness profile. These differences might be important in view of their potential role as a therapeutic target.

Pivotal role of human stearoyl-CoA desaturases (SCD1 and 5) in breast cancer progression: oleic acid-based effect of SCD1 on cell migration and a novel pro-cell survival role for SCD5

The influence of cell membrane fluidity on cancer progression has been established in different solid tumors. We previously reported that “cancer-associated fibroblasts” (CAFs) induced epithelial-mesenchymal transition and increased cell membrane fluidity and migration in poorly (MCF-7) and highly invasive (MDA-MB-231) breast cancer cells. We also found that the membrane fluidity regulating enzyme stearoyl-CoA desaturase 1 (SCD1) was upregulated in tumor cells co-cultured with CAFs and established its essential role for both intrinsic and CAF-driven tumor cell motility. Here, we further explored the mechanisms involved in the SCD1-based modulation of breast cancer cell migration and investigated the role of the other human SCD isoform, SCD5. We showed that the addition of oleic acid, the main SCD1 product, nullified the inhibitory effects produced on MCF-7 and MDA-MB-231 cell migration by SCD1 depletion (pharmacological or siRNA-based). Conversely, SCD5 seemed not involved in the regulation of cancer cell motility. Interestingly, a clear induction of necrosis was observed as a result of the depletion of SCD5 in MCF-7 cells, where the expression of SCD5 was found to be upregulated by CAFs. The necrotic effect was rescued by a 48-h treatment of cells with oleic acid. These results provide further insights in understanding the role of SCD1 in both intrinsic and CAF-stimulated mammary tumor cell migration, unveiling the metabolic basis of this desaturase-triggered effect. Moreover, our data suggest the ability of CAFs to promote the maintenance of tumor cell survival by the induction of SCD5 levels.

Characterization of inflammatory cell infiltrate of scleroderma skin: B cells and skin score progression

BACKGROUND

The purpose of this study was to investigate the frequency and the distribution of inflammatory cell infiltrate in two sets of cutaneous biopsies derived from clinically affected and unaffected skin in patients with systemic sclerosis (SSc) and to test correlation between the cell infiltrate and the progression of skin involvement.

METHODS

Skin was immunohistochemically assessed to identify CD68, CD3, CD20 and CD138-positive (+) cells in clinically affected and unaffected skin in 28 patients with SSc. Patients were followed for 6 months and the characteristics of the infiltrate were analyzed according to disease duration, clinical features and skin involvement progression.

RESULTS

In all SSc cutaneous specimens, cellular infiltrates were found in a perivascular location predominantly in the mid and deeper portions of the dermis. All the analyzed biopsies showed a CD3⁺ and CD68⁺ cell infiltrate and the mean number of CD3⁺ and of CD68⁺ cells was higher in clinically involved skin (CD3⁺, 71.7 ± 34.6 and CD68⁺, 26.3 ± 8.4, respectively) than in clinically uninvolved skin (CD3⁺, 45.7 ± 36.0 and CD68⁺, 13.6 ± 6.1, respectively) (p < 0.001 for both comparisons). CD20⁺ cells were found in 17 (60.7%) patients and in these patients the mean number of CD20⁺ cells was higher in clinically involved (4.7 ± 5.9) than in uninvolved skin (1.9 ± 2.9), (p = 0.04). There was a greater number of CD20⁺ cells in patients with early SSc compared with patients with long-standing disease. CD138⁺ cells were found in 100% of biopsies of clinically involved skin and in 89.3% of biopsies of uninvolved skin. The mean number of CD138⁺ cells was higher in clinically involved skin (3.6 ± 2.3) than in clinically uninvolved skin (1.9 ± 1.7), (p < 0.001). Seven patients experienced more than 20% worsening in the skin score after 6 months of follow up; all of them had a CD20⁺ skin infiltrate on biopsy of clinically involved skin.

CONCLUSIONS

Our results confirm that mononuclear cells are present in the skin of all patients with SSc, underlining the role of inflammatory cell infiltrates in skin involvement in SSc. B cells in the skin seem to characterize patients with early diffuse skin disease and to correlate with skin progression.

Analysis of angiogenesis related factors in glioblastoma, peritumoral tissue and their derived cancer stem cells

The formation of new blood vessels represents a crucial event under both physiological and pathological circumstances. In this study, we evaluated by immunohistochemistry, and/or Western blotting and/or quantitative real time-PCR the expression of HIF1α, HIF2α, VEGF, VEGFR1 and VEGFR2 in surgical glioblastoma multiforme (GBM) and peritumoral tissue samples obtained from 50 patients as well as in cancer stem cells (CSCs) isolated from GBM (GCSCs) and peritumoral tissue (PCSCs) of 5 patients. We also investigated the contribution of both GCSCs and PCSCs on the behavior of endothelial cells (ECs) in vitro. Immunohistochemistry demonstrated the expression of angiogenesis markers in both GBM and peritumoral tissue. In addition, in vitro tube formation assay indicated that both GCSCs and PCSCs stimulate EC proliferation as well as tube-like vessel formation. An increased migration aptitude was mainly observed when ECs were cultured in the presence of GCSCs rather than in the presence of PCSCs. These findings suggest that relevant neoangiogenetic events may occur in GBM. In particular, VEGF/VEGFR co-expression in PCSCs leads to hypothesize the involvement of an autocrine signaling. Moreover, our results suggest that both GCSCs and PCSCs own the skill of activating the "angiogenic switch" and the capability of modulating EC behavior, indicating that both cell types are either responsive to angiogenic stimuli or able to trigger angiogenic response. Together with our previous findings, this study adds a further piece to the challenging puzzle of the characterization of peritumoral tissue and of the definition of its real role in GBM pathophysiology.

Progenitor/Stem Cell Markers in Brain Adjacent to Glioblastoma: GD3 Ganglioside and NG2 Proteoglycan Expression

Characterization of tissue surrounding glioblastoma (GBM) is a focus for translational research because tumor recurrence invariably occurs in this area. We investigated the expression of the progenitor/stem cell markers GD3 ganglioside and NG2 proteoglycan in GBM, peritumor tissue (brain adjacent to tumor, BAT) and cancer stem-like cells (CSCs) isolated from GBM (GCSCs) and BAT (PCSCs). GD3 and NG2 immunohistochemistry was performed in paired GBM and BAT specimens from 40 patients. Double-immunofluorescence was carried out to characterize NG2-positive cells of vessel walls. GD3 and NG2 expression was investigated in GCSCs and PCSCs whose tumorigenicity was also evaluated in Scid/bg mice. GD3 and NG2 expression was higher in tumor tissue than in BAT. NG2 decreased as the distance from tumor margin increased, regardless of the tumor cell presence, whereas GD3 correlated with neoplastic infiltration. In BAT, NG2 was coexpressed with a-smooth muscle actin (a-SMA) in pericytes and with nestin in the endothelium. Higher levels of NG2 mRNA and protein were found in GCSCs while GD3 synthase was expressed at similar levels in the 2 CSC populations. PCSCs had lower tumorigenicity than GCSCs. These data suggest the possible involvement of GD3 and NG2 in pre/pro-tumorigenic events occurring in the complex microenvironment of the tissue surrounding GBM.

Gene expression profile of glioblastoma peritumoral tissue: an ex vivo study

The gene expression pattern of glioblastoma (GBM) is well documented but the expression profile of brain adjacent to tumor is not yet analysed. This may help to understand the oncogenic pathway of GBM development. We have established the genome-wide expression profiles of samples isolated from GBM tumor mass, white matter adjacent to tumor (apparently free of tumor cells), and white matter controls by using the Affymetrix HG-U133 arrays. Array-CGH (aCGH) was also performed to detect genomic alterations. Among genes dysregulated in peritumoral white matter, 15 were over-expressed, while 42 were down-regulated when compared to white matter controls. A similar expression profile was detected in GBM cells. Growth, proliferation and cell motility/adhesion-associated genes were up-regulated while genes involved in neurogenesis were down-regulated. Furthermore, several tumor suppressor genes along with the KLRC1 (a member of natural killer receptor) were also down-regulated in the peritumoral brain tissue. Several mosaic genomic lesions were detected by aCGH, mostly in tumor samples and several GBM-associated mosaic genomic lesions were also present in the peritumoral brain tissue, with a similar mosaicism pattern. Our data could be explained by a dilution of genes expressed from tumor cells infiltrating the peritumour tissue. Alternatively, these findings could be substained by a relevant amount of “apparently normal” cells presenting a gene profile compatible with a precancerous state or even “quiescent” cancer cells. Otherwise, the recurrent tumor may arise from both infiltrating tumor cells and from an interaction and recruitment of apparently normal cells in the peritumor tissue by infiltrating tumor cells.

Epithelial-stromal interactions in human breast cancer: effects on adhesion, plasma membrane fluidity and migration speed and directness

Interactions occurring between malignant cells and the stromal microenvironment heavily influence tumor progression. We investigated whether this cross-talk affects some molecular and functional aspects specifically correlated with the invasive phenotype of breast tumor cells (i.e. adhesion molecule expression, membrane fluidity, migration) by co-culturing mammary cancer cells exhibiting different degrees of metastatic potential (MDA-MB-231>MCF-7) with fibroblasts isolated from breast healthy skin (normal fibroblasts, NFs) or from breast tumor stroma (cancer-associated fibroblasts, CAFs) in 2D or 3D (nodules) cultures. Confocal immunofluorescence analysis of the epithelial adhesion molecule E-cadherin on frozen nodule sections demonstrated that NFs and CAFs, respectively, induced or inhibited its expression in MCF-7 cells. An increase in the mesenchymal adhesion protein N-cadherin was observed in CAFs, but not in NFs, as a result of the interaction with both kinds of cancer cells. CAFs, in turn, promoted N-cadherin up-regulation in MDA-MB-231 cells and its de novo expression in MCF-7 cells. Beyond promotion of “cadherin switching”, another sign of the CAF-triggered epithelial-mesenchymal transition (EMT) was the induction of vimentin expression in MCF-7 cells. Plasma membrane labeling of monolayer cultures with the fluorescent probe Laurdan showed an enhancement of the membrane fluidity in cancer cells co-cultured with NFs or CAFs. An increase in lipid packing density of fibroblast membranes was promoted by MCF-7 cells. Time-lapsed cell tracking analysis of mammary cancer cells co-cultured with NFs or CAFs revealed an enhancement of tumor cell migration velocity, even with a marked increase in the directness induced by CAFs.

Our results demonstrate a reciprocal influence of mammary cancer and fibroblasts on various adhesiveness/invasiveness features. Notably, CAFs' ability to promote EMT, reduction of cell adhesion, increase in membrane fluidity, and migration velocity and directness in mammary cancer cells can be viewed as an overall progression- and invasion-promoting effect.

Soluble E-cadherin and IL-6 serum levels in patients affected by prostate cancer before and after prostatectomy

Prostate specific antigen (PSA) is still the best available tumour marker in prostate cancer (PCa), but presents some limits. Therefore, there is a need for novel markers in the detection and management of PCa. The 80-kDa soluble form of E-cadherin (sE-cad) and the cytokine IL-6 are being discussed as supplemental serum markers for PCa. In this study, sE-cad and IL-6 serum levels were determined in patients with pathological localized or locally advanced PCa without any previous treatment. These patients underwent radical retropubic prostatectomy (RRP) in accordance with the EAU Guidelines on Prostate Cancer. The molecules were determined via immunoenzymatic assays in samples collected before and after surgery. Statistical analysis was performed by Student's t-test and Pearson's correlation test. sE-cad levels were 6.0 ± 2.7 and 4.6 ± 2.3 µg/ml, before and after RRP, respectively. A highly statistically significant decrease in sE-cad concentrations after RRP was observed (p<0.0001), in 50/61 patients (82%). sE-cad levels before and after surgery were correlated (Pearson's correlation coefficient, r=0.6993, p<0.0001). sE-cad values detected after surgery were higher in patients with PSA levels >10 ng/ml (p<0.05). sE-cad levels before RRP were significantly higher in patients with G3 tumours compared to those with G2 tumours (p<0.02). Finally, sE-cad concentrations both before and after surgery were higher in tumours with Gleason score =7 compared to those with Gleason score <7 (p<0.002 and p<0.05, respectively). Preliminary data from 20 patients indicated a statistically significant increase in IL-6 levels after RRP (11.2 vs. 7.2 pg/ml, p<0.001). This is the first study on the reduction in sE-cad levels after RRP in PCa patients. Moreover, it shows that preoperative sE-cad concentrations are higher in patients with less differentiated PCa. Promising findings of this pilot study may lead to investigation of sE-cad in a larger study with follow-up.

Abstract 4676: Understanding progenitor cells in the peritumor region of glioblastoma: GD3 ganglioside and NG2 proteoglycan expression

Invasion is a defining hallmark of glioblastoma (GBM) and its infiltrative capacity is supported by the presence of tumor cells at a distance greater than 4 cm from the tumor margin. Several studies have suggested that the space demanding growth, the production of soluble factors and the peculiar vasculature of GBM induce changes in surroundings. We previously reported that the presence of activated MAP kinases and stem cell marker nestin in peritumor tissue of GBM, even in the absence of tumor cells, carries a prognostic significance, and that neoangiogenesis occurs in peritumor areas. GD3 ganglioside is linked with malignant transformation that promotes migration, invasion and neoangiogenesis. Neuro-glial proteoglycan 2 (NG2) is also involved in invasion and angiogenesis; it is expressed by pericytes that have multipotent stem cell properties. Both markers are present in several precursor cells. To gain a deeper insight into the characteristics of GBM peritumor tissue, we investigated GD3 and NG2 expression in peritumor areas compared to the enhanced lesion. Patients (n=40) recruited in this study had a supratentorial GBM and underwent “en bloc” surgery. Tissue samples from the enhanced lesion (1st area), white matter at a distance &lt;1 cm (2nd area) and between 1 and 3.5 cm from the tumor margin (3rd area) were obtained using adopted surgical technique. Immunohistochemical analysis using anti-GD3 (n=40) monoclonal and anti-NG2 (n=15) polyclonal antibody was performed in paraffin-embedded sections and frozen sections, respectively. Results showed cell membrane and cytoplasmic GD3 and NG2 expression in both GBM and peritumor tissue. Specifically, GD3 was expressed in tumor and endothelial cells; it was present in reactive astrocytes and in apparently normal cells in peritumor areas. Percentage of GD3 positive cells was higher in GBM than in 2nd and 3rd areas (P&lt; 0.001); GD3 was higher in peritumor areas when tumor cells were present (P&lt; 0.005). NG2 was expressed in GBM and in cells of various morphology in peritumor tissue. Double labelled confocal microscopy analysis showed that NG2 was co-expressed with alpha-smooth muscle actin in pericytes while CD105 was present in endothelium of the vessel walls in tumor and peritumor tissue. Percentage of NG2 positive cells was higher in GBM than in peritumor areas (P&lt; 0.001), and was lower in the 3rd compared to the 2nd area (P&lt; 0.05). Our findings confirm that peritumor tissue undergoes a significant transformation. Apparently normal glial cells expressing GD3 and NG2 might represent precursor cells in peritumor tissue. Marker expression in both these cells and pericytes may indicate the acquisition of properties linked to proliferation, motility and neovascularization contributing to tumor progression. Importantly, our results provide a useful tool to develop informed and unified approaches to diagnosis and therapy of GBM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4676.

New Findings on Anaplasmosis Caused by Infection withAnaplasma phagocytophilum

Ixodes ricinus (I. ricinus) is one of the vectors of Anaplasma phagocytophilum (A. phagocytophilum) in Europe, in which rates of infection range from 1.9% to 34%. In 1998, human granulocytic ehrlichiosis-like (HGE-like) Ehrlichia DNA was detected in Italy, by PCR technique in one I. ricinus nymph out of 55 ticks that were examined. In 1996, 6.3% of 310 human sera in high-risk subjects from Italy were found positive for antibodies to Ehrlichia phagocytophila (E. phagocytophila). In the same year, the authors reported the first case of equine granulocytic ehrlichiosis. In 1997, only 2 out of 563 equine blood samples examined were found positive for antibodies to E. phagocytophila in the Latium region. In 1998, serological positivity was not observed in 14 symptomatic race horses. In 2002, a symptomatic horse living in Rome was found positive for Ehrlichia equi (E. equi) antibodies, as confirmed by PCR. E. equi was also demonstrated in horses by detection of specific antibodies from two asymptomatic ponies. We tested 128 sera from sheep in different flocks, and antibodies to E. phagocytophila were detected in 17 sera (13.3%) of these sheep. From 2000 to 2004, 147 dog sera were tested for antibodies against A. phagocytophilum, and 7 of these sera were positive (4.8%). These data confirm the presence of the infection in human, domestic animals, and pets in Italy. Studies are under way to correlate the distributions of the disease and tick vector, I. ricinus.

Increased accuracy of biopsy Gleason score obtained by extended needle biopsy

PURPOSE

Accurate tumor grading is critical for adequate prostate cancer treatment. Nonetheless, the Gleason score of standard sextant biopsy correctly predicts the Gleason score of the radical prostatectomy specimen in about 50% of cases. We investigated if extended needle biopsy could improve biopsy Gleason score accuracy.

MATERIALS AND METHODS

Laparoscopic transperitoneal radical prostatectomy was performed in 135 patients. Prostate cancer was diagnosed in 89 cases by standard sextant transrectal (6 to 8 cores) biopsy and in 46 by extended needle (12 core transperineal under transrectal guidance) biopsy. Preoperative evaluation included digital rectal examination, prostatic specific antigen measurement, transrectal ultrasonography and endorectal coil magnetic resonance imaging in all patients. All biopsy and prostatectomy specimens were reviewed by a single pathologist.

RESULTS

Clinical characteristics were similar in the 2 groups. The concordance between prostate biopsy and radical prostatectomy Gleason score was 32 of 46 cases (70%) and 44 of 89 (49%) for 12 core and standard transrectal biopsy, respectively (z test p = 0.0127). Biopsy under grading was found in 11 of 46 cases (24%) and 35 of 89 (39%) (z test p = 0.0366), and biopsy over grading was found in 3 of 46 (6%) and 10 of 89 (11%) (z test p = 0.1894) with 12 core and standard transrectal biopsy, respectively. Primary Gleason pattern was predicted exactly by biopsy in 40 of 46 cases (87%) and 56 of 89 (63%) with 12 core and standard sextant biopsy, respectively (z test p = 0.0018).

CONCLUSIONS

Extended needle biopsy significantly increases the accuracy of biopsy Gleason score for assessing final prostate cancer grade.

Analysis of dystroglycan regulation and functions in mouse mammary epithelial cells and implications for mammary tumorigenesis

Abnormalities in the interactions of cells with the extracellular matrix (ECM) play an important role in the development and progression of many types of cancer and are a hallmark of malignant transformation. The dystroglycan (DG) complex is a transmembrane glycoprotein that forms a continuous link from the ECM to the actin cytoskeleton, providing structural integrity and perhaps transducing signal, in a manner similar to integrins. Deregulated expression of DG has been reported in a variety of human malignancies and related to tumor differentiation and aggressiveness. In breast cancer, reduced DG expression has been associated with patient survival and with loss of differentiation of tumor cells. Limited data are available on DG physiology in epithelial cells. In this study, we used the HC11 spontaneously immortalized murine mammary epithelial cells to study DG function(s) and regulation in normal cells. We found that expression of DG protein and mRNA is cell-cycle and cell-density regulated in these cells. Moreover, expression of both DG subunits increased upon lactogenic differentiation of the HC11 cells. The turnover of cell-surface-expressed DG was evaluated in the same cells and half-life of DG subunits was evaluated to be about 12 h. DG-specific small inhibitory RNAs were used to analyze the effects of a reduced expression of DG in these cells. Cells in which DG expression was suppressed were growth inhibited, accumulated in the S-phase of the cell cycle, failed to undergo lactogenic differentiation, and displayed an increase in the percentage of apoptotic cells. Moreover, changes were observed in the expression and/or activity of several molecules involved in cell growth control. These results demonstrate that DG expression is tightly regulated in normal mammary epithelial cells and support the hypothesis that DG is involved in several functions other than structural integrity in these cells. This finding provides new insight into the roles played by DG in epithelial cell physiology and will contribute to our understanding of its involvement in the process of epithelial cell transformation.

A man with worsening weakness

The contemporary presence of organomegaly, skin manifestations, polyneuropathy, endocrinopathy and monoclonal component characterises the POEMS syndrome, often associated with osteosclerotic myeloma and Castelman's disease and more frequent in the Japanese. Clinical manifestations seem to be related to the production of many interleukins, mainly IL-1, IL-6 and TNF. Several endocrinopathies have been described, the most frequent being diabetes. Only one previous case of hypoparathyroidism associated with the syndrome has been described in medical reviews. Polyneuropathy is often sensitivo-motory and skin disease accounts for Raynaud phenomenon, skin pigmentation, hypertricosis and others. We describe the case of a 74-year-old man who underwent clinical examination for weakness mainly in the legs. Clinical and instrumental data showed rhabdomyolysis due to hypoparathyroidism. The contemporary presence of a monoclonal band of light chains on proteic electrophoresis, organomegaly and distal leg neuropathy allowed us to make a diagnosis of POEMS syndrome.

Constituents of essential oil of Commiphora guidotti

From the essential oil of Commiphora guidotti seven sesquiterpene hydrocarbons and a furanosesquiterpenoid, furanodiene, were isolated.

The effect of some flavolignans on lipid synthesis in ethanol-intoxicated hepatocytes in primary culture

Rat liver cells in primary culture have been used to investigate the effect of ethanol and of two flavolignans 3,7-dihydroxy-2-(1,4-benzodioxan-6-yl)chroman-4-one (I) and 3,7-dihydroxy-2-[(2,3-diphenyl)-1,4-benzodioxan-6-yl]chroman-4-one (II) on the incorporation of [2-3H]-glycerol into lipids. Ethanol produces a decrease of the incorporation of labelled glycerol into lipids, whereas at the longest times of incubation flavolignans have an opposite effect. Neutral lipid/phospholipid labelling ratio is modified by ethanol in favour of neutral lipids. This action is counteracted by both flavolignans, which are therefore able to hinder, at least partially, the actions of ethyl alcohol on liver lipid metabolism.