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Simona Sica

Publications and source records attributed to Simona Sica.

At least 19 recordsLinked to original sources
PubMed2006

ZAP-70 enhances B-cell-receptor signaling despite absent or inefficient tyrosine kinase activation in chronic lymphocytic leukemia and lymphoma B cells.

Expression of ZAP-70 is an important negative prognostic factor in chronic lymphocytic leukemia (CLL). This protein tyrosine kinase is a key mediator of T-cell receptor (TCR) signaling and is structurally homologous to Syk, which plays an analogous role in B-cell receptor (BCR) signaling. Recent studies indicate that ZAP-70 may participate in BCR signaling as well, but the mechanism of action is not completely understood. We have now compared antigen receptor-induced activation of ZAP-70 in B cells and T cells by analyzing phosphorylation of critical regulatory tyrosine residues. We show that BCR-mediated activation of ZAP-70 is very inefficient in CLL and lymphoma B cells and is negligible when compared to activation of Syk. Despite the inefficient catalytic activation, the ability of ZAP-70 to recruit downstream signaling molecules in response to antigen receptor stimulation appeared relatively preserved. Moreover, ectopic expression of ZAP-70 enhanced and prolonged activation of several key mediators of BCR signaling, such as the Syk, ERK, and Akt kinases, and decreased the rate of ligand-mediated BCR internalization. We conclude that the role of ZAP-70 in BCR signaling is quite distinct from its role in TCR signaling and is likely mediated by inhibition of events that terminate the signaling response.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Low-dose thalidomide in combination with oral fludarabine and cyclophosphamide is ineffective in heavily pre-treated patients with chronic lymphocytic leukemia.

Elevated levels of TNF-alpha have been associated with progressive disease in patients with chronic lymphocytic leukemia (CLL). Thalidomide has been shown to inhibit production of TNF-alpha. We investigated the effects of thalidomide on clinical outcome and TNF-alpha serum levels in five pre-treated CLL patients. The schedule consisted on daily thalidomide (Thal), oral fludarabine (Flu) and oral cyclophosphamide (CTX). Median duration of treatment was 60 days; four patients stopped treatment for disease progression and one patient for neurological toxicity. Serum TNF-alpha levels did not show any decrease during treatment. Low-dose thalidomide is not effective in CLL patients with refractory disease.

Administration, Oral↗
PubMed2006

Analysis of MTHFR polymorphisms and P16 methylation and their correlation with clinical-biological features of multiple myeloma.

BACKGROUND: Low folate intake and changes in folate metabolism due to polymorphisms in the methylentetrahydrofolate reductase (MTHFR) gene have been associated with myelomagenesis. However, controversial data have been published regarding a protective role of variant alleles of MTHFR on MM. PATIENTS AND METHODS: To investigate the influence of two common polymorphisms of MTHFR C677T and A1298C on the risk of multiple myeloma (MM), we performed a matched case-control study. The methylation status pattern of p16 was also addressed. RESULTS: The frequency each of 677 CC, 677CT, and 677TT was 31, 44, and 25%, respectively, whereas, the frequency each of 1298 AA, AC, CC was 48, 44, and 8% in MM patients. In the control group, the frequency each of 677CC, 677CT, and 677TT was 36, 45, and 19%, respectively, while the frequency each of 1298 AA, AC, CC was 37, 50, and 13%, respectively. No significant association between susceptibility to MM, 677, and 1298 MTHFR variants was detected. As regards p16 methylation, we confirmed a high prevalence of p16 methylation (40%) in patients affected by MM and demonstrated that MTHFR 677CC is associated with a higher prevalence of p16 hypermethylation. CONCLUSIONS: Our data demonstrated that variant alleles did not play a key role neither in protection nor in increased risk for MM, suggesting that the effect of MTHFR on folate metabolism might be modified by diet intake. Moreover, our findings demonstrated that p16 hypermethylation might be a frequent genetic aberration in MM and may contribute with other molecular aberrations in the pathogenesis of this malignant disorder.

Adult↗
PubMed2006

Mitoxantrone, carboplatin, cytosine arabinoside, and methylprednisolone followed by autologous peripheral blood stem cell transplantation: a salvage regimen for patients with refractory or recurrent non-Hodgkin lymphoma.

BACKGROUND: The objective of the current study was to evaluate a salvage chemotherapy regimen consisting of mitoxantrone, carboplatin, cytosine arabinoside, and methylprednisolone (MiCMA) for the treatment of patients with primary refractory or recurrent non-Hodgkin lymphoma (NHL). METHODS: From September 1991 to August 2002, 94 consecutive patients ages 16-60 years who had either recurrent or refractory NHL (mainly diffuse large-cell lymphomas) were treated on the MiCMA protocol. Patients had peripheral blood stem cells collected successfully for autologous stem cell transplantation after two or three cycles of MiCMA. RESULTS: Sixty-four of 85 evaluable patients achieved a response to the MiCMA regimen: 24 patients (26%) achieved a complete response and 40 patients (44%) achieved a partial response, for a total response rate of 70%. Sixty-two patients underwent autologous stem cell transplantation. After a median follow-up of 58 months, 47 patients (55%) remained alive; among these patients, 32 were free of disease (37%). No toxic deaths related to MiCMA were observed. Three patients died of infectious complications after transplantation. CONCLUSIONS: The current results suggested that MiCMA chemotherapy is an effective therapeutic alternative salvage regimen for patients with primary refractory or recurrent NHL. Response rates, overall survival, and freedom from disease progression were found to be associated significantly with response to MiCMA. Peripheral blood stem cell transplantation was feasible in virtually all patients, and its outcome was influenced strongly by chemosensitivity.

Adolescent↗
PubMed2006

Treatment of acute graft-versus-host disease with prednisolone: significant survival advantage for day +5 responders and no advantage for nonresponders receiving anti-thymocyte globulin.

Newly diagnosed patients with acute graft-versus-host disease (GvHD, grades I-IV; n = 211) were given 6-methylprednisolone (6MPred) 2 mg/kg per day for 5 consecutive days; 150 patients (71%) tapered 6MPred on day +5 and were considered responders; 61 patients (29%) could not taper their steroid dose and were considered nonresponders. The cumulative incidence of transplant-related mortality (TRM) for responders and nonresponders is, respectively, 27% and 49% (P = .009), and the 5-year survival is 53% and 35% (P = .007). Nonresponders on day +5 (n = 61) were randomized to receive 6MPred 5 mg/kg per day for 10 days alone (n = 34) or in combination with rabbit anti-thymocyte globulin (ATG, 6.25 mg/kg in 10 days; n = 27). The 2 groups were balanced for clinical and GvHD characteristics. One month after randomization, 26% had a complete response; 23%, a partial response; 33%, stable GvHD; 10%, worsened; and 8%, died. There was no significant difference in response, TRM, and survival between the non-ATG and ATG group. In conclusion, 5 days of prednisolone as first-line therapy of acute GvHD identifies patients with different risk of TRM, and second-line therapy with a combination of 6MPred + ATG does not improve patient outcome, compared with 6MPred alone.

Adolescent↗
PubMed2005

Sustained signaling through the B-cell receptor induces Mcl-1 and promotes survival of chronic lymphocytic leukemia B cells.

The clinical course of chronic lymphocytic leukemia (CLL) differs significantly between patients with mutated (M-CLL) and unmutated (U-CLL) immunoglobulin (Ig) variable heavy-chain (V(H)) genes, implying a role for B-cell receptor (BCR) signaling in the pathogenesis of this disease. We have now investigated activation of downstream BCR signaling pathways in U-CLL and M-CLL B cells using soluble anti-IgM (sol-IgM) and immobilized anti-IgM (imm-IgM) antibodies as models for antigenic stimulation. Ligation of the BCR with sol-IgM induced incomplete responses in both CLL subsets, resembling the pattern described for tolerant B cells. This response was characterized by transient phosphorylation of extracellular signal-related kinase (ERK) and Akt (protein kinase B [PKB]), lack of activation of c-JUN NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), and variable activation of phospholipase Cgamma2 (PLCgamma2) and nuclear factor-kappaB (NF-kappaB). Stimulation with imm-IgM elicited a more complete BCR signal and significantly prolonged phosphorylation of ERK and Akt, indicating persistent or repetitive BCR signaling. Moreover, this type of stimulation increased the levels of the antiapoptotic protein myeloid cell leukemia-1 (Mcl-1) and protected from chemotherapy-induced apoptosis, whereas induction of apoptosis and down-regulation of Mcl-1 was observed following stimulation with sol-IgM. These data demonstrate that only sustained BCR signaling can promote survival of CLL B cells and indicate that the main difference between CLL with mutated and unmutated V(H) genes may reside in the availability of such stimulation.

Apoptosis↗
PubMed2005

Repeated sequences in CASPASE-5 and FANCD2 but not NF1 are targets for mutation in microsatellite-unstable acute leukemia/myelodysplastic syndrome.

Microsatellite instability (MSI) in tumors is diagnostic for inactive DNA mismatch repair. It is widespread among some tumor types, such as colorectal or endometrial carcinoma, but is rarely found in leukemia. Therapy-related acute myeloid leukemia/myelodysplastic syndrome (tAML/MDS) is an exception, and MSI is frequent in tAML/MDS following cancer chemotherapy or organ transplantation. The development of MSI+ tumors is associated with an accumulation of insertion/deletion mutations in repetitive sequences. These events can cause inactivating frameshifts or loss of expression of key growth control proteins. We examined established MSI+ cell lines and tAML/MDS cases for frameshift-like mutations of repetitive sequences in several genes that have known, or suspected, relevance to leukemia. CASPASE-5, an acknowledged frameshift target in MSI+ gastrointestinal tract tumors, was frequently mutated in MSI+ cell lines (67%) and in tAML/MDS (29%). Frameshift-like mutations were also observed in the NF1 and FANCD2 genes that are associated with genetic conditions conferring a predisposition to leukemia. Both genes were frequent targets for mutation in MSI+ cell lines and colorectal carcinomas. FANCD2 mutations were also common in MSI+ tAML/MDS, although NF1 mutations were not observed. A novel FANCD2 polymorphism was also identified.

Alleles↗
PubMed2005

Low-dose intravenous alemtuzumab therapy in pretreated patients affected by chronic lymphocytic leukemia. A single center experience.

We report the efficacy and safety of intravenous low-dose alemtuzumab (10 mg three times weekly for 10 weeks) in 12 patients with relapsed or refractory chronic lymphocytic leukemia. Low-dose alemtuzumab induced significant responses in these patients (16% complete remission, 25% partial remission), with mild hematologic and extrahematologic side effects and a low rate of infections, even in the presence of long-lasting severe immunosuppression.

Aged↗
PubMed2005

Comparison of ZAP-70/Syk mRNA levels with immunoglobulin heavy-chain gene mutation status and disease progression in chronic lymphocytic leukemia.

BACKGROUND AND OBJECTIVES: The protein tyrosine kinase ZAP-70 has recently emerged as a major prognostic indicator in chronic lymphocytic leukemia (CLL). ZAP-70 is structurally and functionally homologous to Syk, a key mediator of B-cell receptor signaling. We therefore evaluated ZAP-70 expression in CLL B cells using Syk as an intracellular standard. DESIGN AND METHODS: The relative amounts of ZAP-70 and Syk were determined in purified B cells from 92 CLL patients using a novel reverse transcriptase/polymerase chain reaction (RT-PCR) procedure that co-amplifies both transcripts with equal efficiency. The ZAP-70/Syk mRNA ratio was correlated with VH gene mutation status, median treatment-free survival and FACS analysis of ZAP-70 expression. RESULTS: ZAP-70 was expressed in the majority of cases with unmutated VH genes (88%), but also at lower levels in a substantial fraction of cases with mutated VH genes (44%). High levels of ZAP-70, defined as ZAP-70/Syk mRNA ratios above 0.25, were observed mainly in cases with unmutated VH genes and correlated with short treatment-free survival. In contrast, no difference was observed in the median treatment-free survival between patients with low ZAP-70/Syk ratios (0.05-0.25) and patients with no or negligible ZAP-70 expression (ZAP-70/Syk<0.05). In 73 cases ZAP-70 expression was investigated by RT/PCR and FACS analysis; concordance with VH gene mutation status was 86% and 71%, respectively. INTERPRETATION AND CONCLUSIONS: ZAP-70 is frequently expressed in CLL B cells, but only high levels correlate with unmutated VH gene status and progressive disease. Expression of ZAP-70 can be accurately assessed by analysis of the ZAP-70/Syk mRNA ratio, thus providing an alternative to FACS analysis.

Adult↗
PubMed2004

Hormonal replacement therapy after stem cell transplantation.

OBJECTIVE: To evaluate HRT compliance and efficacy in the treatment of symptomatic ovarian failure in pre-menopausal women after stem cell transplantation (SCT) for malignancies. METHODS: Thirty-one females were selected and prospectively followed in a university bone marrow transplantation unit and gynecologic outpatient clinic in a university teaching hospital. The patients received regular gynecological examinations, hormonal assessment every 6 months including plasma levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), 17-beta estradiol (E2), and transvaginal pelvic ultrasonography, mammography, and computerized bone mineralometry every 12 months. Self-assessment form of menopausal symptoms perception was filled in by all patients before HRT and during the observation period. RESULTS: All patients developed gonadal failure after SCT. The menopausal symptoms more frequently reported were: vasomotor (90%), muscleskeletal symptoms (61%), vulvo-vaginal atrophy (54%), and mood changes (54%). Fifteen premenopausal women out of 31 (51.6%) received systemic HRT on the basis of age (<45 years), absence of medical contraindication or subjective refusal, and complete remission of underlying malignancies post-SCT. The remaining patients (48.4%) did not receive HRT mainly for patient's refusal (29%), relapse of malignancy (13%) or liver toxicity (9.6%). HRT was effective in HRT treated patients promptly relieving unpleasant symptoms of gonadal failure. HRT was tolerated without minimal complications or serious side effects. CONCLUSIONS: Dramatic improvement in menopausal symptoms was observed in women on HRT although treatment was feasible only in nearly half of the patients. HRT alleviates unnecessary discomfort and improves the well-being of female patients post-transplant also by preventing menopause related complications. Feasibility and patients' compliance of HRT should be carefully evaluated in long-term survivors after stem cell transplantation.

Adult↗
PubMed2004

Immune recovery of lymphocyte subsets 6 years after autologous peripheral blood stem cell transplantation (PBSCT) for lymphoproliferative diseases. A comparison between NHL, HD and MM in group of 149 patients.

To evaluate the normalization of lymphocyte subsets several years after autologous peripheral blood stem cell transplantation (aPBSCT) and to detect any differences based on the underlying lymphoproliferative diseases, we analyzed the immunological recovery of 149 patients with Non Hodgkin's Lymphoma (NHL), Hodgkin's Disease (HD), Multiple Myeloma (MM). Lymphocyte recovery was assessed before the transplant, on days 15, 30, 60, 90, 120 and on years 1, 2, 4, 6. Analysis of a total of 709 lymphocytes, including total lymphocyte count, CD3 +, CD4 +, CD8 +, CD4 +/CD8 + ratio, CD19 +, CD3 + HLA-DR +, CD16 + 56 +, was performed. The normalization of total lymphocyte counts was achieved between days 14 to 22 following PBSCT. CD3 + cells count showed a normalization after 2 years in the HD and NHL groups and after 4 years in MM group. CD4 + subset achieved normalization during the sixth year in the 3 groups. The CD8 + and CD19 + lymphocytes subsets achieved normal values in the 3 groups at day 60 and at day 120 respectively. CD16 + 56 + and CD3 +/HLA-DR + lymphocytes showed median values above the normal range starting from day 30. Immunological recovery was similar in all 3 groups. Moreover, the recovery of all subsets evaluated was similarly demonstrated within 6 years after aPBSCT.

Adolescent↗
PubMed2004

Methylenetetrahydrofolate reductase genotypes do not play a role in acute lymphoblastic leukemia pathogenesis in the Italian population.

BACKGROUND AND OBJECTIVES: Methylenetetrahydrofolate reductase (MTHFR) is one of the enzymes involved in folate metabolism and DNA methylation and synthesis. Some genotypes of this highly polymorphic enzyme are associated with decreased activity. Previous studies have suggested that individuals with the MTHFR 677TT, 1298AC and 1298CC have a lower risk of adult acute lymphoblastic leukemia (ALL). DESIGN AND METHODS: In order to test this association we studied the presence of the C677T and A1298C mutant alleles in 174 patients with acute lymphoblastic leukemia and in 110 controls from central Italy. RESULTS: We did not find any association between the different polymorphisms and susceptibility to ALL. In multivariate analysis different genotypes did not show any correlation with the risk of ALL. The adjusted odds ratios and 95% confidence intervals for MTHFR C677T were 0.69 (0.4-1.19) for 677CT versus 677CC wild type, and 0.99 (0.50-1.97) for 677TT versus 677CC. The corresponding values for MTHFR A1298C were 0.93 (0.56-1.53) for 1298AC versus 1298AA wild type and 1.14 (0.36-3.61) for 1298CC versus 1298AA. INTERPRETATION AND CONCLUSIONS: These results do not support the suggestion that populations carrying different genotypes of the two MTHFR polymorphisms, C677T and A1298C, have a different susceptibility to ALL, at least in the Mediterranean area.

Alleles↗
PubMed2004

Polymorphisms of CYP1A1 and glutathione S-transferase and susceptibility to adult acute myeloid leukemia.

BACKGROUND AND OBJECTIVES: The origin of acute myeloid leukemia (AML) may be explained by a combination of genetic susceptibility factors and environmental exposure. We studied the polymorphisms of cytochrome P450 CYP1A1 and glutathione S-transferase (GST), enzymes involved in the metabolism of carcinogens and anti-cancer drugs, as risk factors for adult AML. DESIGN AND METHODS: The prevalence of CYP1A1*2A, *2B and *4 alleles and of GSTM1 and GSTT1 homozygous deletions was examined in 193 patients with AML and 273 normal individuals using polymerase chain reaction (PCR)-based methods. RESULTS: A higher prevalence of the CYP1A1*4 allele was found in AML patients than in controls (19.1% vs 9.9%, OR =2.2, 95% C.I. 1.3-3.7, p=0.006). GSTT1 homozygous deletions were also more frequent in AML patients (29% vs 19%, OR = 1.7, 95% CI 1.1-2.7, p=0.02). The combination of GSTT1 null genotype and CYP1A1 *2B and *4 alleles further increased the risk of AML (OR =10.2, 95% CI 1.2-83.9, p=0.01, and OR =7.0, 95% CI 2.0-24.8, p=0.001, respectively). INTERPRETATION AND CONCLUSIONS: Polymorphic variants in xenobiotic-metabolism genes, including CYP1A1 and GSTT1, may increase the risk of adult AML, particularly when present together.

Acute Disease↗