170 research outputs found

    Cyclin E correlates with manganese superoxide dismutase expression and predicts survival in early breast cancer patients receiving adjuvant epirubicin-based chemotherapy.

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    Anthracycline-based chemotherapy represents a milestone in the treatment of breast cancer. We previously demonstrated in an in vitro model that cyclin E overexpression is associated with increased expression of manganese superoxide dismutase (MnSOD) and resistance to doxorubicin. In the present study, immunohistochemical expression of cyclin E and MnSOD was evaluated in 134 early breast cancer patients receiving adjuvant epirubicin-based chemotherapy regimens containing epirubicin. Both parameters were correlated with the available clinicopathological parameters and with the outcome of patients. Overexpression of cyclin E and MnSOD was detected in 46 (34.3%) and 56 (41.8%) patients, respectively, and expression levels of the two proteins were related. Disease-free and alive patients displayed a lower mean percentage of cyclin E-expressing cells than relapsed and dead patients, respectively. Kaplan-Meier survival analysis demonstrated a significant separation between high versus low cyclin E-expressing tumors in terms of overall survival (P = 0.038 by log-rank). Similar results were obtained considering the subset of node-negative patients separately. No significant relationship with patient outcome was observed for MnSOD expression levels. At multivariate analysis cyclin E failed to demonstrate an independent prognostic value. In conclusion, the results of the present study support previous evidence that increased cyclin E expression is associated with higher MnSOD expression levels and poorer outcome, at least as evaluated in terms of overall survival. Further studies are warranted to evaluate the usefulness of cyclin E as a prognostic marker to identify breast cancer patients at higher risk of death from the disease when treated with adjuvant anthracycline-based therapy

    Primary chemotherapy with gemcitabine, epirubicin and taxol (GET) in operable breast cancer: a phase II study

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    This trial was conducted to assess the activity and tolerability of the gemcitabine, epirubicin, taxol triplet combination in patients with operable breast cancer. After core biopsy, 43 women with stage II–IIIA breast cancer were treated with gemcitabine 1000 mg m−2 over 30 min on days 1 and 4, epirubicin 90 mg m−2 as an intravenous bolus on day 1, and taxol 175 mg m−2 as a 3-h infusion on day 1, every 21 days for four cycles. The primary end point was the percentage of pathological complete responses (pCR) in the breast; secondary end points were tolerability, clinical response rates, overall and progression-free survival, tumour biomarkers before and after primary chemotherapy (PCT). All patients were included in safety and survival analyses; 41 eligible patients were evaluated for response. The overall clinical response rate was 87.8% (95% CI 77.8–97.8), with 26.8% complete responses (95% CI 13.3–40.3). A pCR in the breast was observed in six patients (14.6%; 95% CI 3.8–25.4); 15 patients (36.6%; 95% CI 21.9–51.3) had negative axillary lymph nodes. Grade 4 neutropenia was observed in 67.4% of the patients; febrile neutropenia occurred in 1.9% of cycles (granulocyte colony-stimulating factor was used in 3.2% of the cycles to shorten the duration of neutropenia). A statistically significant difference between Mib-1 at baseline (⩾20% in 71.4% of the patients) and at definitive surgery (28.6%, P<0.05) was observed. The gemcitabine, epirubicin, taxol regimen is active and well tolerated as PCT for operable breast cancer. This combination allows the administration of full doses of active agents with a low incidence of febrile neutropenia

    Targeting cyclin B1 inhibits proliferation and sensitizes breast cancer cells to taxol

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    Background Cyclin B1, the regulatory subunit of cyclin-dependent kinase 1 (Cdk1), is essential for the transition from G2 phase to mitosis. Cyclin B1 is very often found to be overexpressed in primary breast and cervical cancer cells as well as in cancer cell lines. Its expression is correlated with the malignancy of gynecological cancers. Methods In order to explore cyclin B1 as a potential target for gynecological cancer therapy, we studied the effect of small interfering RNA (siRNA) on different gynecological cancer cell lines by monitoring their proliferation rate, cell cycle profile, protein expression and activity, apoptosis induction and colony formation. Tumor formation in vivo was examined using mouse xenograft models. Results Downregulation of cyclin B1 inhibited proliferation of several breast and cervical cancer cell lines including MCF-7, BT-474, SK-BR-3, MDA-MB-231 and HeLa. After combining cyclin B1 siRNA with taxol, we observed an increased apoptotic rate accompanied by an enhanced antiproliferative effect in breast cancer cells. Furthermore, control HeLa cells were progressively growing, whereas the tumor growth of HeLa cells pre-treated with cyclin B1 siRNA was strongly inhibited in nude mice, indicating that cyclin B1 is indispensable for tumor growth in vivo. Conclusion Our data support the notion of cyclin B1 being essential for survival and proliferation of gynecological cancer cells. Concordantly, knockdown of cyclin B1 inhibits proliferation in vitro as well as in vivo. Moreover, targeting cyclin B1 sensitizes breast cancer cells to taxol, suggesting that specific cyclin B1 targeting is an attractive strategy for the combination with conventionally used agents in gynecological cancer therapy

    Breast cancer response to neoadjuvant chemotherapy: predictive markers and relation with outcome

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    The aim of this study was to provide a better insight into breast cancer response to chemotherapy. Chemotherapy improves outcome in breast cancer patients. The effect of cytotoxic treatment cannot be predicted for individual patients. Therefore, the identification of tumour characteristics associated with tumour response and outcome is of great clinical interest. We studied 97 patients, who received anthracycline-based neoadjuvant chemotherapy. Tumour samples were taken prior to and after chemotherapy. We quantified the response to chemotherapy clinically and pathologically and determined histological and molecular tumour characteristics. We assessed changes in the expression of Bcl-2, ER, P53 HER2 and Ki-67. Association with response and outcome was tested for all parameters. The experimental results showed 15 clinical (17%) and three (3%) pathological complete remissions. There were 18 (20%) clinical vs 29 (33%) pathological nonresponders. The expression of most markers was similar before and after chemotherapy. Only Ki-67 was significantly decreased after chemotherapy. Factors correlated with response were: large tumour size, ER negativity, high Ki-67 count and positive P53 status. Tumour response and marker expression did not predict disease-free or overall survival. In conclusion, clinical and pathological response assessments are poorly associated. Proliferation decreases significantly after chemotherapy. ER negativity and a high proliferation index are associated with better response. HER2 status does not predict response, and outcome is not related to tumour response

    Evaluation of ER, PgR, HER-2 and Ki-67 as predictors of response to neoadjuvant anthracycline chemotherapy for operable breast cancer

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    Primary systemic therapy (PST) for operable breast cancer enables the identification of in vivo biological markers that predict response to treatment. A total of 118 patients with T2–4 N0–1 M0 primary breast cancer received six cycles of anthracycline-based PST. Clinical and radiological response was assessed before and after treatment using UICC criteria. A grading system to score pathological response was devised. Diagnostic biopsies and postchemotherapy surgical specimens were stained for oestrogen (ER) and progesterone (PgR) receptor, HER-2 and cell proliferation (Ki-67). Clinical, radiological and pathological response rates were 78, 72 and 38%, respectively. There was a strong correlation between ER and PgR staining (P<0.0001). Higher Ki-67 proliferation indices were associated with PgR− tumours (median 28.3%, PgR+ 22.9%; P=0.042). There was no relationship between HER-2 and other biological markers. No single pretreatment or postchemotherapy biological parameter predicted response by any modality of assessment. In all, 10 tumours changed hormone receptor classification after chemotherapy (three ER, seven PgR); HER-2 staining changed in nine cases. Median Ki-67 index was 24.9% before and 18.1% after treatment (P=0.02); the median reduction in Ki-67 index after treatment was 21.2%. Tumours displaying >75% reduction in Ki-67 after chemotherapy were more likely to achieve a pathological response (77.8 vs 26.7%, P=0.004)

    Fluvastatin synergistically enhances the antiproliferative effect of gemcitabine in human pancreatic cancer MIAPaCa-2 cells

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    The new combination between the nucleoside analogue gemcitabine and the cholesterol-lowering drug fluvastatin was investigated in vitro and in vivo on the human pancreatic tumour cell line MIAPaCa-2. The present study demonstrates that fluvastatin inhibits proliferation, induces apoptosis in pancreatic cancer cells harbouring a p21ras mutation at codon 12 and synergistically potentiates the cytotoxic effect of gemcitabine. The pharmacologic activities of fluvastatin are prevented by administration of mevalonic acid, suggesting that the shown inhibition of geranyl-geranylation and farnesylation of cellular proteins, including p21rhoA and p21ras, plays a major role in its anticancer effect. Fluvastatin treatment also indirectly inhibits the phosphorylation of p42ERK2/mitogen-activated protein kinase, the cellular effector of ras and other signal transduction peptides. Moreover, fluvastatin administration significantly increases the expression of the deoxycytidine kinase, the enzyme required for the activation of gemcitabine, and simultaneously reduces the 5′-nucleotidase, responsible for deactivation of gemcitabine, suggesting a possible additional role of these enzymes in the enhanced cytotoxic activity of gemcitabine. Finally, a significant in vivo antitumour effect on MIAPaCa-2 xenografts was observed with the simultaneous combination of fluvastatin and gemcitabine, resulting in an almost complete suppression and a marked delay in relapse of tumour growth. In conclusion, the combination of fluvastatin and gemcitabine is an effective cytotoxic, proapoptotic treatment in vitro and in vivo against MIAPaCa-2 cells by a mechanism of action mediated, at least in part, by the inhibition of p21ras and rhoA prenylation. The obtained experimental findings might constitute the basis for a novel translational research in humans

    Large needle aspiration biopsy and galectin-3 determination in selected thyroid nodules with indeterminate FNA-cytology

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    Thyroid fine-needle aspiration biopsy (FNA)-cytology is widely used for the preoperative characterisation of thyroid nodules but this task is difficult for follicular lesions, which often remain undefined. We propose a strategy for improving the preoperative characterisation of selected follicular thyroid proliferations, which is based on large needle aspiration biopsy (LNAB) and galectin-3 expression analysis. Eighty-five thyroid specimens were obtained by LNAB (20-gauge needles) from thyroid nodules with indeterminate follicular FNA-cytology. Aspirated material was processed as a tissue microbiopsy to obtain cell blocks for both cyto/histo-morphological evaluation and galectin-3 expression analysis, by using a purified monoclonal antibody to galectin-3 and a biotin-free immunoperoxidase staining method. Preoperative diagnosis was compared to the final histology. LNAB and cell-block technique allow a preliminary distinction between nodules with a homogeneous microfollicular/trabecular structure, as frequently observed in tumours, and lesions with mixed normo–micro–macrofollicular architecture, as observed in goitre. Furthermore, LNAB provides optimal substrates for galectin-3 expression analysis. Among 85 cases tested, 14 galectin-3-positive cases were discovered preoperatively (11 thyroid cancers and three adenomas confirmed at the final histology), whereas galectin-3-negative cases were 71 (one carcinoma and 70 benign proliferations at the final histology). Sensitivity, specificity and diagnostic accuracy of this integrated morphologic and phenotypic diagnostic approach were 91.6, 97.2 and 95.3%, respectively. In conclusion, LNAB plus galectin-3 expression analysis when applied preoperatively to selected thyroid nodules candidate to surgery can potentially reduce unnecessary thyroid resections

    Dynamic Models of the Flight Control Actuation System for an All-Electric Regional Transport Aircraft

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    In the modern technological frame, in order to reduce costs and to obtain advantages in terms of eco-compatibility, a new concept of aircraft is developing: the All-Electric Aircraft, in which all on-board systems are electrically-powered. In the first phases of the aeronautical design, the virtual iron bird is the most modern instrument used for the analysis and the test of new systems and components. In this context, the aim of this thesis is to develop a simulation model of a Flight Control Actuation System, to be used within an overall aircraft systems simulation model designed for the monitoring and the optimization of the power absorption, thermal flows and performance parameters of all the aircraft’s onboard systems. The developed model includes the simulation of the dynamic behaviour of the Electro Mechanical Actuators which move the control surfaces, on which gravity, inertial and aerodynamic loads act. The modelling of the aerodynamic loads is based on the estimation of the aerodynamic hinge moments acting on the control surfaces and on the analysis of the aircraft local airflow-field due to the aerodynamic interference (down-wash, side-wash, engine thrust) and to the A/C manoeuvres. The physical-mathematical model is implemented in the Matlab/Simulink software and some test campaigns have been developed to ensure the validity of the model
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