19 research outputs found
Caratterizzazione fenotipica di mutanti di Trametes trogii a ridotta attività endoglucanasica
No full textIdentification of an optimal concentration of platelet gel for promoting angiogenesis in human endothelial cells
No full textNumerous studies have supported the use of topical blood components to improve wound healing and tissue regeneration. Platelet gel (PG), a hemocomponent obtained from mix of activated platelets (PLTs) and cryoprecipitate, is currently being used clinically in an attempt to improve tissue healing. The present study sought to define the most effective PG concentration to promote angiogenesis in vitro. The effects of PG-released supernatant at different concentrations on human endothelial cells were studied using different in vitro assays (proliferation, migration, invasion, cord formation, and wound healing). The concentration of PG-released supernatant had a significant influence on the angiogenic potential of endothelial cells. The optimal concentration for the stimulation of angiogenesis was 1.5 x 10(6) PLTs per mu L in most of the in vitro experiments used in this study. Lower or higher concentrations of PG displayed a lower angiogenic potential. An optimal concentration of PG to promote angiogenesis in human endothelial cells was identified. Excessively high PG concentrations may inhibit the angiogenic process, thereby being counterproductive for wound healing in a clinical setting
Chronic azacitidine treatment results in differentiating effects, sensitizes against bicalutamide in androgen-independent prostate cancer cells
No full textBACKGROUND: About 20-30% of hormone-independent PCa are characterized by the extensive loss of AR expression that appears to occur at the transcriptional level. Treatment of AR-negative PCa cells with demethylating agents (Aza-CR) leads to expression of AR mRNA and protein. Here, we investigate the effect of Aza-CR administered both acutely and chronically on AR expression, PSA expression, cell survival, and proliferation in androgen-independent/AR-negative PCa cells. We also studied whether epigenetically reactivated AR is a target for bicalutamide therapy. METHODS: The in vitro effect of Aza-CR as single agent and its ability to induce AR expression and to augment the efficacy to bicalutamide were assessed using two androgen-independent and AR-negative cell lines (PC3 and DU145). RESULTS: Our results show that acute treatment (4 days) with Aza-CR results in a relatively low decrease in cell proliferation with G2 cell cycle arrest and no significant evidence of apoptosis or AR expression. Interestingly, when Aza-CR was chronically administered (20 days), this treatment resulted in marked decrease in tumor cell proliferation with significant increase in AR and PSA protein levels. Furthermore, following Aza-CR chronic treatment the formerly androgen-independent PC3 and DU145 cells increase their susceptibility to the apoptotic effects of bicalutamide. CONCLUSIONS: Aza-CR acute treatment has modest effects on androgen-independent and AR-negative PCa cell survival and proliferation, but chronic administration results in profound decrease in proliferation and in sensitization to antiandrogen agents. All these effects seem, in some measure, dependent on a partial restoration of androgen regulation
Bicalutamide demonstrates biologic effectiveness in prostate cancer cell lines and tumor primary cultures irrespective of Her2/neu expression levels.
No full textOBJECTIVES: To evaluate the role of Her2/neu as a molecular marker predictive of the treatment response to bicalutamide in prostate cancer (PCa). METHODS: Four PCa cell lines with graded Her2/neu expression levels and 63 primary tumor cultures derived from men with PCa and selected according to Her2/neu tumor levels were used. Primary tumor cultures and PCa cell lines were treated with bicalutamide (0.1-10 microM) in the presence of dehydrotestosterone (10(-12) M) for 4 days. The presence of a significant correlation between Her2/nue expression and drug efficacy was used to define the role of Her2/neu as molecular predictor of bicalutamide effectiveness. As an indicator of drug effectiveness we used the concentration that inhibits 50% values determined after bicalutamide treatment. RESULTS: After bicalutamide treatment, no significant differences in the concentration that inhibits 50% were found among the different tumor cell lines (P = .081). In this experimental model, the correlation analysis suggested that the effectiveness of this drug was not influenced by Her2/neu levels (r = 0.053, P = .823). In primary cultures with high Her2/neu levels (43 tumor cultures), the mean value of the concentration that inhibits 50% for bicalutamide was 0.43 +/- 0.13 microM, and in cultures with low Her2/neu levels (20 tumor cultures), the same parameter was 0.5 +/- 0.16 microM (P = .14). The correlation analysis suggested that the effectiveness of this drug was not influenced by Her2/neu levels (r = 0.33, P = .101). CONCLUSIONS: Our biologic data seem to indicate that the antitumor effect of bicalutamide is independent of Her2/neu levels in preclinical models of PCa. Bicalutamide could be configured as a pharmacologic option to treat patients with high or low levels of Her2/neu
Lack of ceramide generation and altered sphingolipid composition are associated with drug resistance in human ovarian carcinoma cells
No full textPTX (Paclitaxel (R)) is an antimitotic agent used in the treatment of a number of major solid tumours, particularly in breast and ovarian cancer. This study was undertaken to gain insight into the molecular alterations producing PTX resistance in ovarian cancer. PTX treatment is able to induce apoptosis in the human ovarian carcinoma cell line, CABA I. PTX-induced apoptosis in CABA I cells was accompanied by an increase in the cellular Cer (ceramide) levels and a decrease in the sphingomyelin levels, due to the activation of sphingomyelinases. The inhibition of acid sphingomyelinase decreased PTX-induced apoptosis. Under the same experimental conditions, PTX had no effect on Cer and sphingonlyelin levels in the stable PTX-resistant ovarian carcinoma cell line, CABA-PTX. The acquisition of the PTX-resistant phenotype is accompanied by unique alterations in the complex sphingolipid pattern found on lipid extraction. In the drug-resistant cell line, the levels of sphingomyelin and neutral glycosphingolipids were unchanged compared with the drug-sensitive cell line. The ganglioside pattern in CABA I cells is more complex compared with that of CABA-PTX cells. Specifically, we found that the total ganglioside content in CABA-PTX cells was approximately half of that in CABA I cells, and GM3 ganglioside content was remarkably higher in the drug-resistant cell line. Taken together our findings indicate that: i) Cer generated by acid sphingomyelinase is involved in PTX-induced apoptosis in ovarian carcinoma cells, and PTX-resistant cells are characterized by their lack of increased Cer upon drug treatment, ii) PTX resistance might be correlated with an alteration in metabolic Cer patterns specifically affecting cellular ganglioside composition
Suberoylanilide hydroxamic acid partly reverses resistance to paclitaxel in human ovarian cancer cell lines
No full textOBJECTIVES: The purpose of this study was to determine whether the addition of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) to paclitaxel (PTX) can sensitize PTX-resistant human ovarian cancer cell lines (CABA-PTX and IGROV-PTX) in vitro. METHODS: SAHA was studied in combination with paclitaxel in PTX-sensitive and PTX-resistant human ovarian cancer cell lines. Using cell proliferation analysis, immunofluorescence, and flow cytometric assays, we can determine whether the resistance was partly removed when the cells were treated with a combination of SAHA and PTX. Cells were also assayed for cytochrome c release. The levels of acetylated tubulin, beta-tubulin, and HDAC6 were quantified by Western blots. RESULTS: SAHA in combination with PTX led to a more pronounced inhibition of cell growth compared with PTX alone. In addition, the combined exposure to PTX and SAHA resulted in a marked arrest in the G2/M phase of the cell cycle and in a significant increase in the percentage of apoptotic cells. The expression of acetylated tubulin was dramatically increased by exposure to the combination of PTX and SAHA. These data paralleled the findings of an increased expression of HDAC6 in the presence of PTX in PTX-resistant cell lines. CONCLUSIONS: The results of this study suggest the existence of a novel resistance mechanism based upon the upregulation of HDAC6 and that the histone deacetylase inhibitor SAHA holds promise to overcome PTX resistance in ovarian cancer cell lines
Dural repair using autologous fat: Our experience and review of the literature
No full textVarious materials have been proposed to obliterate dead spaces and to reconstruct dural defects during a neurosurgical approach. This study describes our technique of using the abdominal autologous fat graft and evaluates the complications and characteristics related to the use of this tissue during cranial procedures
Detrimental effects of anabolic steroids on human endothelial cells
No full textThe aim of this study is to investigate the effects in vitro induced by androgenic anabolic steroids (AAS) (testosterone, nandrolone, androstenedione, norandrostenedione, and norandrostenediol) used illicitly in sport competitions, on the proliferation ability, apoptosis and the intracellular calcium concentration ([Ca2+](i)) in human umbilical vein endothelial cells (HUVECs), selected as a prototype of a biological target system whose structure and function can be affected by steroids. For this purpose, we evaluated the proliferation inhibition by cytotoxic assay expressed as the concentration of drug inducing a 50% decrease in growth (IC50). The IC50 was reached for testosterone at 100 mu M, androstenedione at 375 mu M, nandrolone at 9 mu M, norandrostenedione at 500 mu M. The IC50 value for norandrostenediol was not reached until a concentration of 6000 mu M. The apoptotic effect was evaluated by flow cytometry at IC50 for each drug. We observed that testosterone induced 31% of apoptotic cells, norandrostenedione 25%, androstenedione 15% and nandrolone 18%. We have analyzed the effects of these drugs on [Ca2+], both in the immediate and long-term continuous presence of each compound. Our data show a statistically significant increase of [Ca2+](i) in the acute condition and in long-term treated cultures, suggesting that androgen steroids modulate intracellular levels of calcium independent of incubation time or compound identity. As a whole, this study demonstrates that AAS might alter endothelial homeostasis, predisposing to the early endothelial cell activation that is responsible for vascular complications observed frequently in AAS users. (c) 2007 Elsevier Ireland Ltd. All rights reserved
Endoscope-assisted microneurosurgery for neurovascular compression syndromes: Basic principles, methodology, and technical notes
No full textBackground: Microscopic microvascular decompression (MVD) has a low but not negligible failure
rate due to some missed conflicts, especially in case of multiple offending vessels. The reported
study is aimed to assess the principles, methodology, technical notes, and effectiveness of the
endoscope‐assisted (EA) MVD for neurovascular compression syndromes (NVCS) in the posterior
fossa. Materials and Methods: A series of 43 patients suffering from an NVCS and undergone
to an EA MVD were retrospectively reviewed. Syndromes were trigeminal neuralgia in 25 cases,
hemifacial spasm in nine cases, positional vertigo in six cases, glossopharyngeal neuralgia in two
cases, and spasmodic torticollis in one case. In all cases, a 0°–30° specially designed endoscope
was inserted into the surgical field to find/treat those conflicts missed by the microscopic
exploration. Each procedure was judged in terms of the effectiveness of the adjunct of the endoscope
according to a three types classification system: Type I – improvement in the visualization of the
nerve’s root entry/exit zone; Type II – endoscopic detection of one or more conflicts involving
the ventral aspects of the nerve and missed by the microscope; Type III – endoscope‐controlled
release of the neurovascular conflict otherwise difficult to treat under the only microscopic view.
Results: A total of 55 conflicts were found and treated. Twenty‐eight procedures were classified as
Type I, nine as Type II, and six as Type III. All the patients had a full recovery from their symptoms.
Conclusions: In selected cases, EA MVD offers some advantages in the detection and treatment of
neurovascular conflicts in the posterior fossa
Dural repair using autologous fat: Our experience and review of the literature
No full textVarious materials have been proposed to obliterate dead spaces and to reconstruct dural defects during a neurosurgical approach. This study describes our technique of using the abdominal autologous fat graft and evaluates the complications and characteristics related to the use of this tissue during cranial procedures
