Outcomes Following Ischemic Myelopathies and Traumatic Spinal Injury.

Background: As the general population ages, the rising prevalence of vascular lesions of the spinal cord will become significant. Purpose: The aim of this study was to compare the neurological and functional outcomes of patients with ischemic spinal cord injury (ISCI) and traumatic spinal cord injury (TSCI). Methods: We conducted a retrospective study in a spinal cord unit of 2 rehabilitation hospitals. We studied 168 patients with a TSCI and 72 with an ISCI. At admission and discharge, patients were evaluated by American Spinal Injury Association Impairment Scale (AIS) standards and Spinal Cord Independence Measure (SCIM). Length of stay, occurrence of complications, and discharge dispositions were also recorded. Linear and logistic regression models were used to analyze the effects of the etiology of the lesion, AIS level at admission, and level of the lesion. Results: Patients with an ISCI were older and experienced fewer cervical lesions and fewer complete lesions than patients with TSCI. By linear and logistic regression, etiology was a predictor (together with lesion features) of functional (SCIM improvement and SCIM at discharge) outcome, with traumatic patients having better outcome than ischemic ones. Age, AIS level, and lesion level were the chief predictors of length of stay, occurrence of complications, and discharge dispositions. Conclusions: A diagnosis of ischemia and trauma could be a determinant of functional recovery in SCI patients.

Coordinated sumoylation and ubiquitination modulate EGF induced EGR1 expression and stability.

BACKGROUND: Human early growth response-1 (EGR1) is a member of the zing-finger family of transcription factors induced by a range of molecular and environmental stimuli including epidermal growth factor (EGF). In a recently published paper we demonstrated that integrin/EGFR cross-talk was required for Egr1 expression through activation of the Erk1/2 and PI3K/Akt/Forkhead pathways. EGR1 activity and stability can be influenced by many different post-translational modifications such as acetylation, phosphorylation, ubiquitination and the recently discovered sumoylation. The aim of this work was to assess the influence of sumoylation on EGF induced Egr1 expression and/or stability. METHODS: We modulated the expression of proteins involved in the sumoylation process in ECV304 cells by transient transfection and evaluated Egr1 expression in response to EGF treatment at mRNA and protein levels. RESULTS: We demonstrated that in ECV304 cells Egr1 was transiently induced upon EGF treatment and a fraction of the endogenous protein was sumoylated. Moreover, SUMO-1/Ubc9 over-expression stabilized EGF induced ERK1/2 phosphorylation and increased Egr1 gene transcription. Conversely, in SUMO-1/Ubc9 transfected cells, EGR1 protein levels were strongly reduced. Data obtained from protein expression and ubiquitination analysis, in the presence of the proteasome inhibitor MG132, suggested that upon EGF stimuli EGR1 sumoylation enhanced its turnover, increasing ubiquitination and proteasome mediated degradation. CONCLUSIONS: Here we demonstrate that SUMO-1 modification improving EGR1 ubiquitination is involved in the modulation of its stability upon EGF mediated induction.

Estrogen receptor-beta affects the prognosis of human malignant mesothelioma.

Malignant pleural mesothelioma is an asbestos-related neoplasm with poor prognosis, refractory to current therapies, the incidence of which is expected to increase in the next decades. Female gender was identified as a positive prognostic factor among other clinical and biological prognostic markers for malignant mesothelioma, yet a role of estrogen receptors (ERs) has not been studied. Our goal was to investigate ERs expression in malignant mesothelioma and to assess whether their expression correlates with prognosis. Immunohistochemical analysis revealed intense nuclear ERbeta staining in normal pleura that was reduced in tumor tissues. Conversely, neither tumors nor normal pleura stained positive for ERalpha. Multivariate analysis of 78 malignant mesothelioma patients with pathologic stage, histologic type, therapy, sex, and age at diagnosis indicated that ERbeta expression is an independent prognostic factor of better survival. Moreover, studies in vitro confirmed that treatment with 17beta-estradiol led to an ERbeta-mediated inhibition of malignant mesothelioma cell proliferation as well as p21(CIP1) and p27(KIP1) up-regulation. Consistently cell growth was suppressed by ERbeta overexpression, causing a G(2)-M-phase cell cycle arrest, paralleled by cyclin B1 and survivin down-regulation. Our data support the notion that ERbeta acting as a tumor suppressor is of high potential relevance to prediction of disease progression and to therapeutic response of malignant mesothelioma patients.

Flavonoid-induced autophagy in hormone sensitive breast cancer cells.

The activity of 8-prenylapigenin (8-PA) and its 3'-methoxylated analogue isocannflavin B (IsoB) was investigated in estrogen-dependent T47-D and estrogen-independent MDA-MB-231 human breast cancer cell lines. 8-PA showed a biphasic effect on T47-D cell proliferation, while no significant effect was observed on MDA-MB-231 cells. Conversely, IsoB exhibited only an inhibitory effect on T47-D cell proliferation, accompanied by the appearance of an intense intracytoplasmic vacuolization of autophagic origin. Moreover, biochemical analysis showed that IsoB reduced Akt phosphorylation and p21(Cip1) expression in T47-D cells. These data show that the prenylflavone moiety is a versatile platform for the induction and modulation of bioactivity.

8-Prenylnaringenin inhibits epidermal growth factor-induced MCF-7 breast cancer cell proliferation by targeting phosphatidylinositol-3-OH kinase activity.

8-Prenylnaringenin (8PN), one of the strongest plant-derived oestrogen receptors (ERs) ligand, has been suggested to have potential cancer chemo-preventive activities and anti-angiogenic properties. Because published data suggest that ERs serve as nodal point that allows interactions between hormones and growth factors mediated pathways, we decided to investigate the effects exerted by 8PN on Epidermal growth factor (EGF)-elicited pathways in breast cancer cells. Here we show that in ER positive MCF-7 cells, 8PN interferes with EGF induced cell proliferation by strongly inhibiting activation of PI(3)K/Akt pathway, without affecting EGFR expression or tyrosine phosphorylation, and exerting a synergistic activation of Erk1/2 phosphorylation. Moreover, we demonstrate that 8PN is a direct inhibitor of PI(3)K activity as it is shown by in vitro experiments with the purified enzyme and by its inability to impair serine phosphorylation of a constitutive active form of Akt. These findings suggest that inhibition of PI(3)K is a novel mechanism which contributes to 8PN activity to inhibit cancer cell survival and EGF induced proliferation.

Convergence of integrins and EGF receptor signaling via PI3K/Akt/FoxO pathway in early gene Egr-1 expression.

The early gene early growth response (Egr-1), a broadly expressed member of the zing-finger family of transcription factors, is induced in many cell types by a variety of growth and differentiation stimuli, including epidermal growth factor (EGF). Here we demonstrate that Egr-1 expression is mainly regulated by integrin-mediated adhesion. Integrin-dependent adhesion plays a dual role in Egr-1 regulation, either being sufficient "per se" to induce Egr-1, or required for EGF-dependent expression of Egr-1, which occurs only in adherent cells and not in cells in suspension. To dissect the molecular basis of integrin-dependent Egr-1 regulation, we show by FLIM-based FRET that in living cells beta1-integrin associates with the EGF receptor (EGFR) and that EGF further increases the extent complex formation. Interestingly, Egr-1 induction depends on integrin-dependent PI3K/Akt activation, as indicated by the decrease in Egr-1 levels in presence of the pharmacological inhibitor LY294002, the kinase-defective Akt mutant and Akt1/2 shRNAs. Indeed, upon adhesion activated Akt translocates into the nucleus and phosphorylates FoxO1, a Forkhead transcription factors. Consistently, FoxO1silencing results in Egr-1-increased levels, indicating that FoxO1 behaves as a negative regulator of Egr-1 expression. These data demonstrate that integrin/EGFR cross-talk is required for expression of Egr-1 through a novel regulatory cascade involving the activation of the PI3K/Akt/Forkhead pathway.

8-Prenylnaringenin, inhibits estrogen receptor-alpha mediated cell growth and induces apoptosis in MCF-7 breast cancer cells.

The discovery that the hop constituent 8-prenylnaringenin (8PN) shows potent estrogenic activity, higher than that of the known phytoestrogens coumestrol, genistein and daidzein, has spurred an intense activity aimed at elucidating its biological profile and its dietary relevance connected with the consumption of beer. We have investigated if 8PN can induce signal transduction pathways via rapid estrogen receptor (ER) activation. Under conditions of estrogen-dependent growth, treatment of MCF-7 human breast cancer cells with 8PN induced a rapid and transient activation of the MAP kinase Erk-1 and Erk-2, with kinetics similar to those induced by 17beta-estradiol (E2). 8PN could trigger the MAP kinase pathway via dual c-Src kinase activation and association with ERalpha. Co-treatment with the ER antagonist ICI 182,780 blocked each step of this transduction pathway, confirming its ER dependence. However, and in striking contrast with E2, 8PN could not induce the PI3K/Akt pathway, resulting in altered kinetics and levels of cyclin D1 expression. In accordance with these observations, flow cytometric and biochemical analysis showed that 8PN inhibited cell cycle progression and induced apoptosis in MCF-7 cells. Interference with an ER associated PI3K pathway is proposed as a possible mechanism underlying the inhibition of survival and proliferation of estrogen responsive cells by 8PN. Taken together, our finding show that 8PN is an interesting new chemotype to explore the biology of ERs.