Tactile exploration of virtual objects for blind and sighted people: the role of beta 1 EEG band in sensory substitution and supramodal mental mapping.

The neural correlates of exploration and cognitive mapping in blindness remain elusive. The role of visuo-spatial pathways in blind vs. sighted subjects is still under debate. In this preliminary study, we investigate, as a possible estimation of the activity in the visuo-spatial pathways, the EEG patterns of blind and blindfolded-sighted subjects during the active tactile construction of cognitive maps from virtual objects compared with rest and passive tactile stimulation. Ten blind and ten matched, blindfolded-sighted subjects participated in the study. Events were defined as moments when the finger was only stimulated (passive stimulation) or the contour of a virtual object was touched (during active exploration). Event-related spectral power and coherence perturbations were evaluated within the beta 1 band (14-18 Hz). They were then related to a subjective cognitive-load estimation required by the explorations [namely, perceived levels of difficulty (PLD)]. We found complementary cues for sensory substitution and spatial processing in both groups: both blind and sighted subjects showed, while exploring, late power decreases and early power increases, potentially associated with motor programming and touch, respectively. The latter involved occipital areas only for blind subjects (long-term plasticity) and only during active exploration, thus supporting tactile-to-visual sensory substitution. In both groups, coherences emerged among the fronto-central, centro-parietal, and occipito-temporal derivations associated with visuo-spatial processing. This seems in accordance with mental map construction involving spatial processing, sensory-motor processing, and working memory. The observed involvement of the occipital regions suggests that a substitution process also occurs in sighted subjects. Only during explorations did coherence correlate positively with PLD for both groups and in derivations, which can be related to visuo-spatial processing, supporting the existence of supramodal spatial processing independently of vision capabilities.

Role of alpha7-nicotinic acetylcholine receptor in human non-small cell lung cancer proliferation.

OBJECTIVES: Lung cancer is the most common cause of cancer death in the world. Cigarette smoking represents the major risk factor. Nicotine, an active component of cigarettes, can induce cell proliferation, angiogenesis and apoptosis resistance. All these events are mediated through the nicotinic acetylcholine receptor (nAChR) expressed on lung cancer cells. We speculate that new insights into the pathophysiological roles of nAChR may lead to new therapeutic avenues to reduce non-small cell lung cancer (NSCLC) tumour growth. MATERIALS AND METHODS: Human samples of NSCLC, cell lines and mouse models were utilized in Western blotting, reverse transcriptase polymerase chain reaction and apoptosis studies. RESULTS: Human NSCLC tissues expressed alpha7-nAChR. This expression was higher in smoking patients with squamous carcinomas than those with adenocarcinomas and in male smoking patients than in females. All the data support the hypothesis that major expression of alpha7-nAChR is related to major activation of the Rb-Raf-1/phospho-ERK/phospho-p90RSK pathway. alpha7-nAChR antagonists, via mitochondria associated apoptosis, inhibited proliferation of human NSCLC primary and established cells. Nicotine stimulates tumour growth in a murine model, A549 cells orthotopically grafted. The effects of nicotine were associated with increases in phospho-ERK in tumours. Proliferation effects of nicotine could be blocked by inhibition of alpha7-nAChR by the high affinity ligand alpha-cobratoxin. CONCLUSION: These results showed that alpha7-nAChR plays an important role in NSCLC cell growth and tumour progression as well as in cell death.

Characterization of apoptosis induced by marine natural products in non small cell lung cancer A549 cells.

The effects of different marine derived agents were studied in A549 cell growth. These drugs induced cell cycle arrest at the G2-M phase associated with the up-regulation of GADD45alpha-gamma and down-regulation of c-Myc. In treated cells, GADD45alpha-gamma and c-Myc were up- and down-regulated, respectively. A cascade of events leading to apoptotic mitochondrial 'intrinsic' pathway was observed in treated cells: (1) dephosphorylation of BAD serine136; (2) BAD dissociation from 14-3-3 followed by its association with BCL-XL; (3) cytochrome c release; (4) caspase-3 activation, and (5) cleavage of vimentin. Caspase(s) inhibitor prevented the formation of cleavage products and, in turn, apoptosis was inhibited through a p53-independent mechanism. Moreover, these compounds did not activate NF-kappaB. Our findings may offer new insights into the mechanisms of action of these agents in A549 cells. The better understanding of their effects might be important to fully exploit the potential of these new drugs.

Antiproliferative activity and interactions with cell-cycle related proteins of the organotin compound triethyltin(IV)lupinylsulfide hydrochloride.

Organotin compounds, particularly tri-organotin, have demonstrated cytotoxic properties against a number of tumor cell lines. On this basis, triethyltin(IV)lupinylsulfide hydrochloride (IST-FS 29), a quinolizidine derivative, was synthesized and developed as a potential antitumor agent. This tin-derived compound exhibited potent antiproliferative effects on three different human cancer cell lines: teratocarcinoma of the ovary (PA-1), colon carcinoma (HCT-8) and glioblastoma (A-172). Cytotoxic activity was assessed by MTT and cell count assays during time course experiments with cell recovery after compound withdrawal. Significant cell growth inhibition (up to 95% in HCT-8 after 72 h of exposure), which also persisted after drug-free medium change, was reported in all the cell lines by both assays. In addition, the cytocidal effects exerted by IST-FS 29 appeared more consistent with necrosis or delayed cell death, rather than apoptosis, as shown by morphologic observations under light microscope, DNA fragmentation analysis and flow cytometry. In the attempt to elucidate whether this compound might affect genes playing a role in G1/S phase transition, the expressions of p53, p21(WAF1), cyclin D1 and Rb, mainly involved in response to DNA-damaging stress, were analyzed by Western blot. Heterogeneous patterns of expression during exposure to IST-FS 29 were evidenced in the different cell lines suggesting that these cell-cycle-related genes are not likely the primary targets of this compound. Thus, the present data seem more indicative of a direct effect of IST-FS-29 on macromolecular synthesis and cellular homeostasis, as previously hypothesized for other organotin complexes.

Unsymmetrical methylene derivatives of indoles as antiproliferative agents.

Indole-3-carbinol is a natural product which has been shown to reduce the incidence of spontaneous and carcinogen-induced mammary tumours in animals. Eighteen unsymmetrical methylene derivatives of indoles were prepared by reaction of Mannich bases of 7-hydroxycoumarins with substituted indoles in acetic or propionic anhydride. The synthesised molecules were tested in vitro against the MCF7 and MDA-MB-231 breast cancer cell lines by MTT and cell count assays. Results from 16 tested compounds showed that 60% of them exerted some effects against the MDA-MB-231 compared to about 30% towards the MCF7. Among all, the 3-(7'-acetoxy-4-methylcoumarin-8'-yl)methyl-2-methylindole resulted the most effective in both cell lines, compared to indole-3-carbinol. In conclusion, these preliminary results report that some of these compounds might be promising potential antiproliferative agents.

Cytotoxicity in vitro and preliminary antitumor activity in vivo of a novel organotin compound.

The cytotoxic effect and antitumor activity induced by the novel organotin compound triethyltin(IV)lupinyisulfide hydrochloride, have been investigated. Different patterns of antiproliferative effects have been observed in a panel of human tumor cell lines in vitro. Toxicity studies in mice reported acute toxicity at the doses of 21 and 17.5 mg/kg which progressively disappeared at lower concentrations. On this basis, the doses of 3.5, 7 and 14 mg/kg were selected to assess the antitumor activity in vivo against the P388 leukemic cells xenografted in mice. This compound was able to induce a dose-dependent significant reduction of tumor volume, up to 46%, at the highest concentration (p = 0.0062) without important toxicity, as also confirmed by histological analysis of the main organ tissues. This preliminary study seems to hold interest for further investigations in different tumor models as well as for the evaluation of optimal drug route and schedule.

Increased cyclin D1 expression is associated with features of malignancy and disease recurrence in ovarian tumors.

Alterations in the expression of cyclin D1 have been reported frequently in several human cancers, but their significance in the multistep model of carcinogenesis has been scantly described. To define the pattern of cyclin D1 expression in the development of ovarian cancer and clinical outcome, 55 cases of benign ovarian tumors, 12 borderline cases, and 37 ovarian carcinomas (32 primary and 5 recurrent carcinomas) were studied. Analyses were carried out on fresh tumor specimens by Western blotting and reverse transcription-PCR and provided significant superimposable results (P = 0.00001). Cyclin D1 abundance was classed according to the densitometric values as undetectable, detectable, well detectable, and highly detectable. A significant increase (P < 0.000001) in median cyclin D1 values was observed from benign (0.038; range, 0.001-0.705) to borderline (0.226; range, 0.001-0.623) to malignant (0.347; range, 0.027-2.330) to recurrent (0.887; range, 0.309-2.2260) tumors. In addition, higher median cyclin D1 values were reported in serous carcinomas (P = 0.058) and advanced-stage diseases (P = 0.003). Survival analyses carried out in the 32 primary carcinomas showed no significant difference in overall survival between detectable versus well/highly detectable cyclin D1 neoplasms. Conversely, a significant relationship between cyclin D1 expression and progression-free survival was found (P = 0.031). These results may elucidate the function of altered cyclin D1 expression in ovarian tumorigenesis and provide a basis for additional studies on its prognostic role.

Synthesis and biological activity of gold and tin compounds in ovarian cancer cells.

We have investigated the patterns of in vitro cytotoxicity, induced by six newly synthesized gold and tin compounds, in three human ovarian cancer cell lines (SW 626, IGROV 1 and OVCAR-3). Four gold compounds, i.e. gold(I)lupinylsulfide hydrochloride [1] (containing a naked gold atom), triethylphosphinogold(I)lupinylsulfide hydrochloride [2], triphenyl-phosphinogold(I)lupinylsulfide hydrochloride [3] and 1 ,2-bis(diphenylphosphino)ethane bis[gold(I)lupinylsulfide] dihydrochloride [4] (all containing a gold atom coordinated with different phosphines), were prepared. Moreover, the triethylphosphinogold(I)(2-diethylamino)ethylsulfide hydrochloride [5] in which the simple diethylaminoethylthiol replaced the bulky lupinylthiol was synthesized. The tin compound, triethyltin(IV)lupinylsulfide hydrochlorlde [6], was also studied. Comparative tests with cisplatin, the most widely used antitumor agent in ovarian cancer, were carried out in biological Investigations. In vitro cytotoxicity, by MTT assay, showed that compound [4] and compound [6] exhibited interesting antiproliferative activity in all the three cell lines (mean IC50=1.3 and 0.7 microM, respectively) compared to cisplatin (mean IC50=4.8 microM). In addition, the PA-1 cell line, more sensitive to cisplatin (IC50=0.6 microM), was included as a comparison in the study. Cell count assays confirmed the cytotoxic properties of compounds [4] and [6] against the four cell lines, reporting higher growth Inhibition potency than cisplatin, with IC50 values in the sub-micromolar range.

Control of cyclin D1 expression by antisense oligonucleotides in three ovarian cancer cell lines.

Cyclin D1 is a critical gene controlling the G1 phase progression through the cell cycle. Alterations of cyclin D1 have been demonstrated in a variety of cancer types. We recently reported that increased cyclin D1 expression is associated with malignancy also in ovarian tumors. Three human ovarian cancer cell lines (SW626, OVCAR-3, IGROV1), expressing high levels of this gene, were used to investigate the effects induced by antisense oligonucleotides to cyclin D1 as antiproliferative compounds. Unmodified 18 mer oligomers, targeted to the translation start site of the cyclin D1 cDNA, were able to inhibit the growth of the three cell lines after a single administration of 40 microM. The pattern of cell number reduction ranged between 30 and 55% after 48 h of treatment. Moreover, by RT-PCR and Western blotting, a marked decrease of the cyclin D1 transcript and protein (up to 77% in the SW626) was detected after 24 and 48 h, respectively, from antisense exposure. Conversely, no relevant inhibition was reported in the sense-treated cells. The present data confirm the role of cyclin D1 expression in the proliferative behavior of ovarian cancer and provide additional information that might be helpful in the search for new therapeutic strategies of this disease.

HPLC determination of azidothymidine (AZT) and its metabolite in human plasma.

In order to evaluate the amount of Azidothymidine (AZT) and its metabolite (GAZT) in human plasma, the HPLC retention times of both compounds on a C18 column as well as on an anionic column by using, as eluent, the same mobile phase have been studied. The two chromatographic systems did not allow, separately, a simultaneous determination of AZT and GAZT. In fact AZT is easily revealed by a C18 column whereas the GAZT elution results too fast and the peak falls into plasmatic matrix. The opposite situation, namely the fastest AZT elution, has been observed by using the anionic column. In contrast by using the two columns linked together (max. back-pressure 21-22 MPa) both peaks were delayed conveniently and did not overlap with the plasmatic matrix. The total analysis time was about 11 min. long. The methodology reported here was further proved rapid and reliable as assessed by preliminary assays in plasma of an AZT treated patient.