Biomedical subjects

R Iuliano

Publications and source records attributed to R Iuliano.

At least 19 recordsLinked to original sources

PubMed2001

Rat protein tyrosine phosphatase eta physically interacts with the PDZ domains of syntenin.

The tyrosine phosphatase r-PTPeta is able to suppress the malignant phenotype of rat thyroid tumorigenic cell lines. To identify r-PTPeta interacting proteins, a yeast two-hybrid screening was performed and an insert corresponding to the full-length syntenin cDNA was isolated. It encodes a protein containing two PDZ domains that mediates the binding of syntenin to proteins such as syndecan, proTGF-alpha, beta-ephrins and neurofascin. We show that r-PTPeta is able to interact with syntenin also in mammalian cells, and although syntenin is a tyrosine-phosphorylated protein it is not a substrate of r-PTPeta. The integrity of both PDZ domains of syntenin and the carboxy-terminal region of r-PTPeta are required for the interaction between syntenin and r-PTPeta.

Carrier Proteins↗

PubMed2001

RNF4 is a growth inhibitor expressed in germ cells but not in human testicular tumors.

The RING-finger protein RNF4 modulates both steroid-receptor-dependent and basal transcription and interacts with a variety of nuclear proteins involved in cell growth control. RNF4 is expressed at very high levels in testis and at much lower levels in several other tissues. We show that in germ cells RNF4 expression is strongly modulated during progression of spermatogonia to spermatids, with a peak in spermatocytes. Analysis of human testicular germ cell tumors shows that RNF4 is not expressed in all tumors analyzed including seminomas, the highly malignant embryonal carcinomas, yolk sac, and mixed germ cell tumors. We also show that the ectopically expressed RNF4 gene inhibits cell proliferation of both somatic and germ cell tumor-derived cells. Mutation of critical cysteine residues in the RING finger domain abolished the RNF4 growth inhibition activity. Our results suggest that the lack of RNF4 expression may play a role in the progression of testicular tumors.

Animals↗

PubMed2001

The activation of the phosphotyrosine phosphatase eta (r-PTP eta) is responsible for the somatostatin inhibition of PC Cl3 thyroid cell proliferation.

The aim of this study was the characterization of the intracellular effectors of the antiproliferative activity of somatostatin in PC Cl3 thyroid cells. Somatostatin inhibited PC Cl3 cell proliferation through the activation of a membrane phosphotyrosine phosphatase. Conversely, PC Cl3 cells stably expressing the v-mos oncogene (PC mos) were completely insensitive to the somatostatin antiproliferative effects since somatostatin was unable to stimulate a phosphotyrosine phosphatase activity. In PC mos cells basal phosphotyrosine phosphatase activity was also reduced, suggesting that the expression of a specific phosphotyrosine phosphatase was impaired in these transformed cells. We suggested that this phosphotyrosine phosphatase could be r-PTP eta whose expression was abolished in the PC mos cells. To directly prove the involvement of r-PTP eta in somatostatin's effect, we stably transfected this phosphatase in PC mos cells. This new cell line (PC mos/PTP eta) recovered somatostatin's ability to inhibit cell proliferation, showing dose-dependence and time course similar to those observed in PC Cl3 cells. Conversely, the transfection of a catalytically inactive mutant of r-PTP eta did not restore the antiproliferative effects of somatostatin. PC mos/PTP eta cells showed a high basal phosphotyrosine phosphatase activity which, similarly to PC Cl3 cells, was further increased after somatostatin treatment. The specificity of the role of r-PTP eta in somatostatin receptor signal transduction was demonstrated by measuring its specific activity after somatostatin treatment in an immunocomplex assay. Somatostatin highly increased r-PTP eta activity in PCCl3 and PC mos/PTP eta (+300%, P < 0.01) but not in PCmos cells. Conversely, no differences in somatostatin-stimulated SHP-2 activity, (approximately +50%, P < 0.05), were observed among all the cell lines. The activation of r-PTP eta by somatostatin caused, acting downstream of MAPK kinase, an inhibition of insulin-induced ERK1/2 activation with the subsequent blockade of the phosphorylation, ubiquitination, and proteasome degradation of the cyclin-dependent kinase inhibitor p27(kip1). Ultimately, high levels of p27(kip1) lead to cell proliferation arrest. In conclusion, somatostatin inhibition of PC Cl3 cell proliferation requires the activation of r-PTP eta which, through the inhibition of MAPK activity, causes the stabilization of the cell cycle inhibitor p27(kip1).

Blotting, Northern↗

PubMed2001

[Ovarian cysts in adolescence: epidemiologic, clinical and management assessment].

BACKGROUND: To evaluate the frequency of ovarian cyst formation in the adolescents and to report on the clinical implications of these cysts. METHODS: A prospective analysis of data on 94 girls (aged 10-19) with diagnosed ovarian cysts was performed at the Gynecology Department of Aversa and Naples hospitals between 1995-2000. Operations were performed because of pains or ultrasound suspected features. The patients who were not operated on were kept under observation and had ultrasound tests monthly, receiving gestogen to facilitate resolution of the cyst and as treatment of menstrual disorders. The site, number, size and type of the cysts were examined. RESULTS: The ovarian cysts were unilateral, unilocular, and simple, with the size varying between 3 cm and 5 cm in 83 cases, more than 5 cm in 8 cases and less than 3 cm in 3 cases. Among 94 patients 6 (6.4%) were initially qualified for the operation because of the strong pains or ultrasound equivocal aspect. Hormonal treatment was given in 74 cases, whereas in 14 cases only follow up sonography was performed. Cysts resolved spontaneously in 2 months on average, or in 1 month after hormonal treatment. No malignant tumors were found in the observed group. CONCLUSIONS: Clinical observation periodically repeated ultrasound tests seems to be the most appropriate procedure employed at adolescent girls with asymptomatic ovarian cysts. Hormonal treatment shortened the duration of the cysts somewhat, even if in a not significant manner, and thus was useful mainly in the treatment of concomitant menstrual disorders.

Adolescent↗

PubMed2001

[Borderline ovarian tumors. Retrospective analysis of 20 cases].

BACKGROUND: To evaluate the clinical features, the surgical management and outcome of 20 patients with stage-I borderline ovarian tumors. METHODS: Twenty cases of FIGO stage-I ovarian tumors, aged from 31 to 58 years (mean 37 years) have been reviewed. All informations of clinical stage, surgical intervention and prognosis were achieved by reviewing hospital records. Minimal requirements for conservative management were adequate staging and complete information about the therapeutic options. Factors important in the choice of the treatment were, age, wish to preserve fertility, histologic type and grade, and the stage of the tumour. RESULTS: Eleven of the 20 patients (55%) were at stage IA, 6 cases (30%) were at stage IB, 3 cases (15%) were at stage IC. Thirteen (65%) were with mucinous cystadenoma of borderline malignancy, 7 cases (35%) were of serous type. Thirteen patients underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH and BSO). Seven patients were treated with unilateral oophorectomy or unilateral salpingo-oophorectomy (USO). One patient underwent enucleation of ovarian tumor and biopsy of contralateral ovary. Any patient were treated with chemotherapy after operation. With a median follow up of two years, we observed no recurrence of carcinoma in women treated conservatively or in those treated more radically. CONCLUSIONS: Conservative surgery remains a therapeutic option in selected patients with borderline ovarian tumors. Prolonged intensive follow-up is required for women treated conservatively for borderline malignant ovarian tumours.

Adult↗

PubMed2001

[The activation of the phosphotyrosine phosphatase eta is responsible for the somatostatin inhibition of PCCl3 thyroid cell proliferation].

BACKGROUND: This study was aimed to identify possible intracellular effectors of the somatostatin (SST) antiproliferative activity, in PCCl3 thyroid cells. METHODS: To prove the involvement of r-PTPeta in SST's effect, we studied th proliferative activity of subclones of PCCl3 cells that do or do not express this PTP. RESULTS: SST inhibited PCCl3 TSH+insulin-dependent cell proliferation through the induction of a phosphotyrosine phosphatase (PTP) activity, detected using the synthetic substrate pNPP (+150%, p<0.01). Conversely, PCCl3 cells stably expressing the v-mos oncogene (PCmos) were completely insensitive to SST antiproliferative effects due to the incapability of SST to increase PTP activity, that correlated with the abolishment of the expression of the receptor-like PTP, r-PTPeta. In the cells in which r-PTPeta was transfected (PCmos/ PTPeta) SST inhibited cell proliferation showing a dose-dependence similar to that observed in PCCl3 cells. Conversely, the transfection of a catalytically inactive mutant of r-PTPeta did not restore the responsivity to SST. Also in PCmos/PTPeta cells SST, treatment increased membrane PTP activity. CONCLUSIONS: SST inhibition of PCC13 cell proliferation requires the activation of r-PTPeta.

Animals↗

PubMed2000

Pivotal role of the RB family proteins in in vitro thyroid cell transformation.

Rat thyroid differentiated cells (PC Cl 3) are an excellent model system with which to study the interaction between differentiation and cell transformation. We previously demonstrated that PC Cl 3 cells expressing the adenovirus E1A gene no longer depend on thyrotropin for growth and do not express thyroid differentiation markers. Here we show that an E1A mutant unable to bind the RB protein failed to transform the PC Cl 3 cells. Conversely, mutations in the E1A p300 interacting region did not affect its transforming ability. The pivotal role of RB family proteins in the thyroid cell transformation is supported by the thyrotropin independence induced by the E7 gene of human papilloma virus type 16, but not by a mutated form in the RB-binding region.

Adenovirus E1A Proteins↗

PubMed2000

Rat protein tyrosine phosphatase eta suppresses the neoplastic phenotype of retrovirally transformed thyroid cells through the stabilization of p27(Kip1).

The r-PTPeta gene encodes a rat receptor-type protein tyrosine phosphatase whose expression is negatively regulated by neoplastic cell transformation. Here we first demonstrate a dramatic reduction in DEP-1/HPTPeta (the human homolog of r-PTPeta) expression in a panel of human thyroid carcinomas. Subsequently, we show that the reexpression of the r-PTPeta gene in highly malignant rat thyroid cells transformed by retroviruses carrying the v-mos and v-ras-Ki oncogenes suppresses their malignant phenotype. Cell cycle analysis demonstrated that r-PTPeta caused G(1) growth arrest and increased the cyclin-dependent kinase inhibitor p27(Kip1) protein level by reducing the proteasome-dependent degradation rate. We propose that the r-PTPeta tumor suppressor activity is mediated by p27(Kip1) protein stabilization, because suppression of p27(Kip1) protein synthesis using p27-specific antisense oligonucleotides blocked the growth-inhibitory effect induced by r-PTPeta. Furthermore, we provide evidence that in v-mos- or v-ras-Ki-transformed thyroid cells, the p27(Kip1) protein level was regulated by the mitogen-activated protein (MAP) kinase pathway and that r-PTPeta regulated p27(Kip1) stability by preventing v-mos- or v-ras-Ki-induced MAP kinase activation.

Animals↗

PubMed2000

The highly malignant phenotype of anaplastic thyroid carcinoma cell lines is recessive.

OBJECTIVE: The aim of our studies was to determine whether the phenotype of the anaplastic thyroid carcinomas is dominant or recessive. In fact, it is hypothesized, on the basis of epidemiological and pathological data, that undifferentiated thyroid carcinomas are derived from differentiated tumours through a mechanism of tumour progression. DESIGN: Cell hybrids have been generated by cell fusion of anaplastic thyroid carcinoma cell lines, which show a highly malignant phenotype, to cell lines deriving from differentiated thyroid carcinoma, which show a non-tumorigenic or a poorly tumorigenic phenotype. All of the parental cell lines showed impaired p53 gene function. RESULTS: The cell hybrids contained alleles from the parental cell lines. All of the cell hybrids showed a lower growth rate compared with the parental undifferentiated carcinoma cell lines and were unable to grow in soft agar and to induce tumours after injection into athymic mice. CONCLUSION: Taken together, these findings suggest that the highly malignant phenotype of the anaplastic thyroid carcinoma is achieved by the impairment of gene functions that negatively regulate cell growth, rather than by the activation of dominant oncogenes.

Animals↗

PubMed1999

Bioactive IL-18 expression is up-regulated in Crohn's disease.

An imbalance of immunoregulatory factors is believed to contribute to uncontrolled mucosal Th1 cell activation in Crohn's disease (CD). IL-18, a macrophage-like cell-derived cytokine, is involved in Th1 clone development, and IFN-gamma production. Therefore, IL-18 expression was investigated in CD. Whole mucosal intestinal tissue and lamina propria mononuclear cells (LPMC) of 12 CD and 9 ulcerative colitis (UC) patients and 15 non-inflammatory bowel disease (IBD) controls were tested for IL-18 by semiquantitative RT-PCR and Western blot analysis. Transcripts for IL-18 were found in all samples tested. However, increased IL-18 mRNA accumulation was detected in both mucosal and LPMC samples from CD in comparison to UC and controls. In CD, transcripts for IL-18 were more abundant in the mucosal samples taken from involved areas. An 18-kDa band consistent with mature IL-18 was predominantly found in CD mucosal samples. In mucosal samples from non-IBD controls, IL-18 was present as a 24-kDa polypeptide. Consistently, active IL-1beta-converting enzyme (ICE) subunit (p20) was expressed in samples from either CD or UC, whereas, in colonic mucosa from non-IBD controls, ICE was synthesized as precursor (p45) only. To confirm that IL-18 produced in CD tissue was functionally active, CD LPMC were treated with a specific IL-18 antisense oligonucleotide. In these cultures, IL-18 down-regulation was accompanied by a decrease in IFN-gamma expression. In aggregate, our data indicate that IL-18 up-regulation is a feature of CD and suggest that IL-18 may contribute to the local immunoinflammatory response in CD.

Caspase 1↗

PubMed1999

Iodide symporter gene expression in normal and transformed rat thyroid cells.

OBJECTIVE: Decrease or loss of the Na+/I- symporter (NIS) activity profoundly affects the suitability of the use of radioiodine to detect or treat metastatic thyroid tissues. The aim of our study was to verify whether specific oncogene abnormalities were responsible for the alteration in NIS activity in thyroid cells. DESIGN AND METHODS: Expression of the NIS gene was investigated by Northern blot analysis in normal and in some oncogene-transformed cell lines with different degrees of malignancy which had lost the iodide uptake ability. RESULTS: NIS gene expression was up-regulated by TSH in a dose-dependent and time-dependent way in normal PC Cl 3 cells. The same effect was observed by activating the cAMP-dependent pathway by forskolin. Conversely, insulin and 12-O-tetradecanoylphorbol-13-acetate (TPA) showed a partial inhibitory effect on NIS gene expression. The oncogene-transformed cell lines PC v-erbA, PC HaMSV, PC v-raf, and PC E1A cells showed reduced NIS mRNA levels compared with the normal PC Cl 3 cells. Conversely, an almost complete absence of NIS gene expression was found in PC RET/PTC, PC KiMSV, PC p53(143ala), and PC PyMLV cell lines. CONCLUSIONS: Our data show that oncogene activation could play a role in affecting the iodide uptake ability in thyroid tumoral cells; different mechanisms are involved in the oncogene-dependent loss of NIS activity in transformed thyroid cells.

Animals↗

PubMed1998

Protein tyrosine phosphatase-eta expression is upregulated by the PKA-dependent and is downregulated by the PKC-dependent pathways in thyroid cells.

We have recently reported the isolation of a rat cDNA encoding a receptor-type tyrosine phosphatase, which appears to be a marker of thyroid differentiation. To elucidate the molecular mechanisms underlying r-PTPeta expression in normal thyroid cells both in vitro and in vivo, we investigated the regulation of r-PTPeta expression in cultured thyrocytes (the rat cell line PC Cl 3) and in an animal model of TSH-dependent thyroid goitrogenesis. In vitro studies showed that mRNA expression of r-PTPeta in thyroid cells is induced in a time- and dose-dependent manner by the activation of growth- and differentiation-linked PKA pathways (TSH and forskolin), whereas it is down-regulated by the activation of the proliferative dedifferentiating PKC-dependent transduction pathway (TPA). However, the regulation of r-PTPeta expression by TSH and TPA, respectively, is observed only in normal thyroid cells, but is lost in transformed thyroid cells. In vivo studies with thiouracil-fed rats demonstrated that increased serum levels of TSH up-regulated r-PTPeta mRNA expression in parallel with the stimulation of thyroid growth and function. The reduction of blood TSH levels due to iodide refeeding to goitrous rats determined a marked down-regulation of r-PTPeta expression, in parallel with involution of thyroid hyperplasia. Taken together these results demonstrate that the phosphatase r-PTPeta is regulated by the two main thyroid regulatory pathways and suggest that it may play an important role in the growth and differentiation of thyroid cells.

Animals↗

PubMed1997

Correlation between plasma HIV-1 RNA levels and the rate of immunologic decline.

To determine the influence of HIV-1 replication on immunologic decline and clinical outcome, we quantified the HIV-1 plasma viral load in 20 patients at different times over a mean period of 10.8 months. Quantitation was performed by branched DNA signal amplification (bDNA) and p24 antigenemia. Immunologic status was assessed through beta 2-microglobulin and CD4+ cell count determinations. CD4+ cell decline was expressed as a slope of the regression line constructed by the logarithms of CD4+ cell count observations. Mean values of plasma viral load were correlated with CD4+ cell decline and mean beta 2-microglobulin levels. Significant correlation was observed between plasma viral load quantified by the bDNA technique and CD4+ cell decline. No significant correlation was observed between plasma viral load quantified by p24 antigenemia and CD4+ cell decline. A significant correlation was observed between plasma viral load and beta 2-microglobulin levels. Immunologic decline was better predicted from HIV-1 RNA levels than from the CD4+ cell count. Significantly higher plasma viral load was observed in patients who had clinical progression of HIV-1 infection. Thus, HIV-1 plasma viral load quantified by a highly reliable technique such as bDNA showed that the immunologic decline is closely related to HIV-1 RNA replication.

Anti-HIV Agents↗

PubMed1997

Human herpesvirus-6 reactivation in a longitudinal study of two HIV-1 infected patients.

After primary infection, human herpesvirus-6 (HHV-6) persists in latent form and can be reactivated in immunocompromised subjects. A longitudinal study of HHV-6 infection was carried out in two HIV-1 seropositive patients to provide in vivo evidence of HHV-6 reactivation. Concomitant with a significant rise of anti-HHV-6 IgG detected by IFA, a transient increase of HHV-6 viral load was shown in PBLs by PCR. During HHV-6 reactivation it was also identified either cell-free HHV-6 by PCR in plasma or IgM antibody titers. HHV-6 reactivation was followed by a temporary decrease in CD4+ count and by a progressive dramatic loss of CD4+ during the following 18 months. HHV-6 strain characterization by PCR demonstrated that first patient (MM) initially showed the B variant, followed by reactivation and persistence of the A variant, while in the second (SG) only the A variant was detected. The evidence of HHV-6 reactivation suggests its involvement in immunologic damage underlying the disease.

AIDS-Related Opportunistic Infections↗

PubMed1995

Minute and small early gastric cancers in a Western population: a clinicopathologic study.

Early endoscopic diagnosis improves the prognosis of patients with gastric cancer, as shown by the finding that 5-year survival rates exceeding 90% are observed in Japanese patients with early gastric cancer. It has been hypothesized that tumor size may have prognostic significance; therefore, a distinction between minute, small, and large early gastric cancers has been proposed. The aim of this study was to determine the prevalence of minute and small early gastric cancers in Western countries and to compare their clinicopathologic features with those of large early gastric cancers. Of 465 Italian patients with gastric cancer who were studied, 20.5% had an early gastric cancer, and 34.7% of these were minute or small. Tumor size is correlated with intramural spreading and metastasis to perigastric lymph nodes. Nodal involvement occurs more frequently in the diffuse than in the intestinal type of early gastric cancer. Long-term survival rate is not correlated with tumor size, intramural spreading, or nodal metastasis. The minute and small early gastric cancers of Italian patients are indistinguishable from those occurring in Japanese patients. These lesions are more common than previously thought and should be carefully searched for by endoscopists. The correlation of tumor size with intramural invasion and perigastric lymph node metastasis suggests that minute and small early gastric cancers are precursors of large early gastric cancers. Although the distinction between minute, small, and large early gastric cancers is of low prognostic value, the distinction might be useful for selecting different therapeutic approaches.

Female↗

PubMed1995

HIV-plasma viral load detection by branched DNA signal amplification.

To detect HIV-1 plasma viral load in seropositive patients, we applied a new molecular quantitation technique: branched DNA signal amplification (bDNA). We performed bDNA with 99 sera from HIV-1 seropositive patients undergoing antiretroviral therapy. We compared the results obtained with p24 antigenemia and CD4+ cell count. The bDNA proved quite sensitive and available for routine use in laboratories.

Antibodies, Monoclonal↗

PubMed1991

[Lactoferrin].

Lactoferrin is a protein present in many fluids of the human organism and in the secondary granules of polymorphonuclear cells (PMN). In the blood stream lactoferrin favours the segregation of PMN by mediating and amplifying the immune response, and realizes a negative feedback control on the Colony Forming Unit Granulocyte/Macrophage (CFU-GM) proliferation. At intestinal level it promotes iron absorption and prevents bacterial overgrowth. The antibacterial effect of lactoferrin is used clinically to prevent bacterial infections in neutropenic patients submitted to chemotherapy for leukemic diseases type M1, M2, M4 and M5, according to FAB criteria. In patients affected by chronic pancreatitis the lactoferrin concentration, in duodenal juice, is found to be significantly higher than in normal subjects. This finding suggests a pathogenetic role of the protein in chronic pancreatitis.

Bacteria↗

PubMed1989

Antitissue antibodies in chronic pancreatitis.

Organ- and nonorgan-specific autoantibodies (AA) have been investigated in 49 patients affected by alcoholic or idiopathic chronic pancreatitis (CP) to evaluate their prevalence and correlation with the clinical features of the disease. AA have been found in about 50% of CP and their recurrence rate was similar to that of alcoholic or cryptogenic liver cirrhosis (LC); age- and sex-matched healthy subjects (C) showed only about 8% positive sera (C vs. CP, p less than 0.001). Quite different IFL patterns between CP and LC have been detected. Antibrush border, antireticulin and antigastric parietal cell antibodies alone or combined prevailed in CP, while antinuclear and antismooth muscle AA prevailed in LC. No correlation with sex, age, etiology, presence of pancreatic stones, diabetes, symptoms and years of CP was found for one or more AA. In conclusion, the detection of AA in CP is a quite common finding of still unclear clinical significance.

Alcoholism↗