Biomedical subjects

A Guarini

Publications and source records attributed to A Guarini.

At least 19 recordsLinked to original sources

PubMed2006

Occurrence of thrombotic events in acute promyelocytic leukemia correlates with consistent immunophenotypic and molecular features.

Although the occurrence of thrombosis in acute promyelocytic leukemia (APL) has been reported during retinoic acid treatment, no studies carried out in large clinical cohorts have specifically addressed this issue. We analyzed 124 APL patients treated with the all-trans retinoic acid and idarubicin protocol and compared clinico-biologic characteristics of 11 patients who developed thrombosis with those of 113 patients who had no thrombosis. In seven patients, the events were recorded during induction, whereas in four patients deep vein thrombosis occurred in the post-induction phase. Comparison of clinico-biological characteristics of patients with and without thrombosis revealed in the former group higher median white blood cell (WBC) count (17 x 10(9)/l, range 1.2-56, P=0.002), prevalence of the bcr3 transcript type (72 vs 48%, P=0.01), of FLT3-ITD (64 vs 28%, P=0.02), CD2 (P=0.0001) and CD15 (P=0.01) expression. No correlation was found with sex, age, French-American-British subtype, all-trans-retinoic acid syndrome or with thrombophilic state that was investigated in 5/11 patients. Our findings suggest that, in APL patients consistent biologic features of leukemia cells may predict increased risk of developing thrombosis.

Adult↗

PubMed2006

Poor mobilization is an independent prognostic factor in patients with malignant lymphomas treated by peripheral blood stem cell transplantation.

Haemopoietic stem cell therapy is an increasingly adopted procedure in the treatment of patients with malignant lymphoma. In this retrospective analysis, we evaluated 262 patients, 57 (22%) with Hodgkin's and 205 (78%) with non-Hodgkin's lymphomas (NHL), and 665 harvesting procedures in order to assess the impact of poor mobilization on survival and to determine the factors that may be predictive of CD34(+) poor mobilization. The mobilization chemotherapy regimens consisted of high-dose cyclophosphamide in 92 patients (35.1%) and a high-dose cytarabine-containing regimen (DHAP in 87 patients -(33.2%), MAD in 83 (31.7%)). The incidence of poor mobilizers (<2 x 10(6) CD34(+) cells/kg) was 17.9% overall, with a 10% of very poor mobilizers (< or = 1 x 10(6)/kg). Refractory disease status and chemotherapeutic load (>3 regimens) before mobilization played a negative role and were associated with poor mobilization. Survival analysis of all harvested patients showed an overall survival at 3 years of 71% in good mobilizers vs 33% in poor mobilizers (P=0.002). The event-free survival at 3 years was 23% in poor mobilizers and 58% in good mobilizers (P=0.04). We conclude that in NHL patients, poor mobilization status is predictive of survival.

Adult↗

PubMed2004

Evidence of biased immunoglobulin variable gene usage in highly stable B-cell chronic lymphocytic leukemia.

Recognition of biased immunoglobulin variable (IgV) gene usage in B-cell chronic lymphocytic leukemia (B-CLL) may yield insight into leukemogenesis and may help to refine prognostic categories. We explored Ig variable heavy (VH) and light (VL) chain gene usage in highly stable and indolent B-CLL (n=25) who never required treatment over 10 or more years. We observed an unexpectedly high usage of mutated VH3-72 (6/25; 24.0%), a gene that was otherwise rare in B-CLL (7/805; 0.87%; P<0.01), including mutated cases (6/432; 1.39%; P<0.01) and was exceptional among indolent (1/230, 0.435%; P<0.01), and aggressive B-cell lymphomas (0/105; P<0.01). Three of six VH3-72 B-CLL cases utilized the same VL Vkappa4-1 gene. Two V(H)3-72 B-CLL cases had highly homologous VH complementarity determining regions 3 (CDR3s), encoding Cys-XXXX-Cys domains, and utilized Vkappa4-1 genes with homologous IgVL CDR3s. An identical threonine to isoleucine change at codon 84 of V(H)3-72 framework region 3 (FR3) recurred in four cases of highly stable VH3-72 B-CLL. This mutation is expected to cause a conformational change of FR3 proximal to CDR3 that might critically affect high-affinity antigen binding. B-cell receptors encoded by VH3-72 may identify a specific B-CLL group and be implicated in leukemogenesis through an antigen-driven expansion of B cells.

Amino Acid Sequence↗

PubMed2002

Mobilization of peripheral blood stem cells with high-dose cyclophosphamide or the DHAP regimen plus G-CSF in non-Hodgkin's lymphoma.

Our study analyzes the mobilization of hematopoietic stem cells after two chemotherapeutic regimens in non-Hodgkin's lymphoma (NHL) patients. The study included 72 patients with NHL (42 follicular and 30 large cells). The mean age was 37 years (range 17-60). Sixty-four patients (88.9%) had stage III-IV disease. Forty-eight patients (66.7%) had bone marrow involvement. Systemic B symptoms were present in 42 patients (58.3%). Mobilization chemotherapy regimens were randomly assigned as DHAP in 38 patients (52.7%) or cyclophosphamide (CPM) (5 g/m(2)) in 34 (47.2%) and the results of 132 procedures were analyzed. At the time of PBSC mobilization, 46 patients (63.9%) were considered to be responsive (complete remission, partial remission or sensitive relapse) and 26 (36.1%) not responsive (refractory relapse or refractory to therapy). Pre-apheresis CD34+ blood cell count and number of previous chemotherapy treatments were used to predict the total number of CD34+ cells in the apheresis product. The mobilizing regimens (CPM or DHAP) were similar in achieving the threshold CD34+ cell yield, for optimal engraftment. Since DHAP was very effective as salvage treatment, we suggest using DHAP as a mobilizing regimen in patients with active residual lymphoma at the time of stem cell collection.

Adolescent↗

PubMed2001

Phenotypic and functional characterization of the host immune compartment of chronic myeloid leukaemia patients in complete haematological remission.

The role of the host immune compartment in the control of chronic myeloid leukaemia (CML) has been suggested by numerous biological and clinical evidence. In the present study, the phenotypic and functional machinery of both T and cytotoxic lymphocytes was evaluated in a series of CML patients in complete haematological, and frequently also in cytogenetic, remission after treatment with interferon (IFN) alpha or hydroxyurea, and compared with the profile observed in patients at diagnosis and in normal controls. In particular, the lymphocyte subset distribution, the cytotoxic activity and the intracellular production of tumour necrosis factor (TNF)alpha and IFN gamma by CD4(+), CD8(+) and CD56(+) cells were investigated. CML patients in complete haematological remission showed a normalized CD4/CD8 T-cell subset distribution, as well as a restored spontaneous and interleukin 2 (IL-2) induced cytotoxic function compared with the pattern observed at diagnosis. This was associated with a significantly increased proportion of activated CD4(+) lymphocytes (CD25(+)). TNF alpha and IFN gamma production by CD4(+), CD8(+) and CD56(+) lymphocytes was significantly enhanced compared with that of patients at diagnosis. However, the values were lower than those of normal controls. These results indicate that, in contrast to the observations at presentation, CML patients, at the time of the best possible response to treatment, show a normalized T-cell subset distribution associated with an activated CD4 T-cell compartment and a restored cytotoxic activity. In addition, they also show a markedly increased intracellular cytokine production by the lymphoid populations that play an important role in the process of specific tumour recognition. The design of therapeutic strategies aimed at stimulating the host immune compartment finds a further rationale for CML patients responsive to treatment with both IFN alpha and hydroxyurea.

Adult↗

PubMed2001

Developmental approaches in immunological control of acute myelogenous leukaemia.

After many years of hope and disillusionment, the possibility of utilizing immune-mediated approaches to control neoplastic clones has become a reality in various haematological malignancies. This is largely a consequence of the continuous advances in knowledge and the progressive development of more refined technologies that have led to a better understanding of the biology of the malignant cells and of the host immune system, to a more precise definition of disease entities and to the design of innovative therapeutic programmes. In this chapter, we will review different immunological strategies that have reached clinical practice in patients with acute myelogenous leukaemia (AML), the focus of this volume, and discuss pre-clinical developments that may in the near future translate into the design of new immunotherapeutic protocols for the management of AML. Treatment of AML with antibody directed therapy will also be discussed.

Antibodies, Monoclonal↗

PubMed2000

Interleukin-2 gene-transduced human leukemic cells induce major histocompatibility complex-restricted and -unrestricted anti-leukemic effectors in mixed lymphocyte-tumor cultures.

To explore the feasibility of designing vaccination protocols in acute leukemia patients with cytokine gene-transduced leukemic cells, we studied in vitro the growth potential of human leukemic cells transduced with the interleukin-2 (IL-2), IL-7, or IL-7 plus IL-2 genes, as well as the capacity of generating both autologous and allogeneic cytotoxic lymphocytes directed against the parental cells. A lymphoblastic T-cell line, ST4, obtained from a patient in long-lasting complete remission, was retrovirally engineered with the IL-2, IL-7, and IL-7 plus IL-2 genes; in addition, clones releasing different amounts of the cytokines were obtained by limiting dilution. Mixed lymphocyte-tumor cultures (MLTCs) were set up with parental or transduced leukemic cells as stimulators and with autologous or allogeneic lymphocytes as responders. When nonirradiated ST4 parental cells or clones producing <50 international units (IU)/mL/10(6) cells/72 hours of IL-2 were used as stimulators, leukemic overgrowth was observed in MLTCs within 16 days of culture. When clones producing >80 IU/mL/10(6) cells/72 hours of IL-2 were used as stimulators, the proliferation of leukemic cells was blocked and the transduced leukemic cells were completely cleared from the cultures by day 16; repeated restimulations with IL-2-producing leukemic cells were required to sustain long-term lymphocyte survival. On the contrary, when IL-7- or IL-7-IL-2-producing cells were used as stimulators, only a delay in leukemic cell overgrowth was observed, and lymphocytes were completely cleared from the cultures after day 60. IL-7 production by the different clones ranged between 11 and 36 ng/mL/10(6) cells/72 hours, whereas the highest IL-2-producing IL-7-IL-2 clone released 50 IU/mL/10(6) cells/72 hours of IL-2. When the stimulator efficacy of the highest IL-2-producing clone (ST4/IL-2#A7) was compared with that of exogenous IL-2 plus parental cells, a 7-fold higher amount of exogenous IL-2 was required to achieve the same results obtained with IL-2-producing leukemic cells. Autologous and allogeneic long-term MLTCs (up to 35 days) with ST4/IL-2#A7 as the stimulator were capable of generating cytotoxic effectors equally endowed with both major histocompatibility complex (MHC) class I-unrestricted and -restricted activity against parental ST4 cells. By day 18 of both autologous and allogeneic cultures, a substantial proportion of CD56+ cells was consistently recorded; this was coupled to a predominantly MHC-unrestricted cytotoxic activity directed against parental ST4 cells. CD56+ cells decreased considerably at the end of the different MLTCs, together with the unrestricted cytotoxic activity. At this time, >50% of the cells were CD8+, and 55% of the activity could be blocked by an anti-MHC class I monoclonal antibody. The results of this study demonstrate that IL-2 gene-transduced human acute leukemia cells cocultured with both autologous and allogeneic lymphocytes are capable of inducing a strong MHC-unrestricted anti-leukemic activity and subsequently "educating" MHC class I-restricted anti-leukemic effectors. The evidence that the immunogenic potential of human leukemic blasts can be boosted after transfer of the IL-2 gene suggests that the possibility of using leukemic cells engineered to release IL-2 as a therapeutic vaccine needs to be explored further.

Cancer Vaccines↗

PubMed2000

Chronic myeloid leukemia cells resistant to interferon-alpha lack STAT1 expression.

INTRODUCTION: Interferon-alpha (IFN) plays a role in the management of different neoplasias, particularly those of hematological origin. The mechanisms of action of IFN are still poorly understood and the individual response is unpredictable. In the present study, the pattern of intracellular gene expression following in vitro and in vivo exposure of chronic myeloid leukemia (CML) cells to IFN was evaluated and correlated with the response to in vivo treatment with IFN. MATERIALS AND METHODS: CML patients in different phases of the disease were studied. The pattern of expression of two IFN-inducible proteins involved in IFN-mediated biological activities, the p91 and p84 proteins (STAT1alpha and STAT1beta), components of the IFN-stimulated gene factor 3 (ISGF3) complex and the enzyme 2'-5' oligoadenylate synthetase (2'-5' OASE) were investigated by Western blot in peripheral blood mononuclear cells stimulated or not in vitro by IFN. RESULTS AND CONCLUSIONS: In 6/9 patients evaluated before starting treatment, STAT1 was expressed either constitutively or after in vitro stimulation by IFN. In three cases, STAT1 remained negative even after in vitro activation. The pattern of protein expression correlated with the subsequent hematological response to prolonged in vivo IFN administration: the presence of STAT1 being associated with the clinical response to IFN and the absence and non-inducibility of STAT1 with resistance to IFN. This was further substantiated by studies carried out in ten patients analyzed at the time of a documented clinico-hematological response or resistance to the in vivo administration of IFN. Finally, in order to establish whether the pattern of response to IFN treatment could be predicted at diagnosis, cells cyropreserved at diagnosis from patients with a documented complete response, confirmed also by cytogenetic negativity, or resistance, were studied. While complete responders proved STAT1 positive, none of the four resistant cases ever expressed STAT1. The expression of 2'-5' OASE did not correlate with the clinical response to IFN. This study documents the pivotal role of STAT1 in the in vitro and in vivo responses of CML cells to IFN. The constitutive or induced presence or absence of STAT1 shows a predictive correlation with the response or resistance to treatment with IFN and could be utilized to identify, at diagnosis, resistant patients who may be spared an expensive and unnecessary prolonged IFN administration.

Adult↗

PubMed2000

Accessory cells, cytokine loops and cell-to-cell interactions in chronic lymphocytic leukemia.

In addition to the extensive work that has been conducted in order to understand better the biological features of the leukemic population in B-cell chronic lymphocytic leukemia (CLL), over the years considerable interest has been directed towards other related studies that may have important implications for the accumulation of the leukemic clone and for the immunoparesis typical of this disease. In the present review article, we discuss some of these areas of investigation and, in particular, we focus on: (1) the multiple abnormalities recorded within the T and cytotoxic compartment of patients with CLL; (2) cytokine loops occurring in this disease, with particular emphasis on the cytokines that appear to play a more critical role; and (3) the cell-to-cell cross talk that may be actively operational in CLL. These findings will be discussed in relation with the possible implications that each of them have in the expansion and clinical behavior of a disease that is increasingly proving its heterogeneity.

Antigen-Presenting Cells↗

PubMed1999

Interleukin-2 gene transfer into human transitional cell carcinoma of the urinary bladder.

Transitional cell carcinoma of the bladder is one of the human cancers most responsive to immunotherapy, and local interleukin-2 (IL-2) production appears to be an important requirement for immunotherapy to be effective. In this study, we engineered two human bladder cancer cell lines (RT112 and EJ) to constitutively release human IL-2 by retroviral vector-mediated gene transfer. Following infection and selection, stable and consistent production of biologically active IL-2 was demonstrated at both the mRNA and the protein level. Morphology, in vitro growth rate and proliferation, as well as other cytokine gene mRNA or membrane adhesion receptor expression, were not altered in IL-2 transduced cells as compared to their parental or control vector-infected counterparts. Moreover, IL-2 engineered cells lost their tumorigenicity into nu/nu mice and the mechanism of rejection appeared to involve multiple host effector cell populations, among which a prominent role was played by neutrophils and radiosensitive cells. These findings may offer support to the development of an IL-2-based gene therapy approach to human bladder cancer.

Animals↗

PubMed1999

IL4 production and increased CD30 expression by a unique CD8+ T-cell subset in B-cell chronic lymphocytic leukaemia.

Phenotypic and functional abnormalities within the residual non-B-cell compartment of B-cell chronic lymphocytic leukaemia (CLL) suggest an interaction between tumour cells and host immune effectors. To explore the possibility of a polarized Th1/Th2 response we have studied CD30 antigen expression and the pattern of cytokine production by purified CLL T cells. Activated T cells from CLL patients showed a significant increase in the expression of CD30 compared to normal controls. Accordingly, high levels of soluble CD30 were detected in supernatants from activated T-cell cultures, as well as in CLL serum samples. Messenger RNA for IL4 was found in both resting and, to a greater extent, in activated CLL T lymphocytes. The latter cells were also capable of releasing IL4. Three-colour immunofluorescence analyses revealed a strong CD30 expression in the CD3+/CD8+/CD28- large granular lymphocyte subset, which is considerably expanded in CLL. Production of IL4, as well as expression and release of CD30 by these T cells, was conclusively demonstrated at the clonal level. These findings document an expansion of a peculiar subset of 'Th2-like' cells in CLL, with an increased IL4 production and CD30 expression and release, that are likely to contribute to both the B-cell accumulation and immune-defects characteristic of this disease.

Aged↗

PubMed1999

Primary non Hodgkin's lymphoma of the vagina.

The genital tract as a primary site of malignant lymphoma in women is extremely rare. This report concerns a 64 year old patient with a primary vaginal non-Hodgkin lymphoma (large cell B lineage according to the REAL classification--centroblastic type according to the Kiel classification--"G" according Working Formulation) with an unusual clinical presentation--pelvic discomfort accompanied by frequent ureteral-like colic. Due to gynecological onset symptoms and the rarity of this extranodal primary site misinterpretation of a primary vaginal lymphoma as a benign inflammatory disease or endometriosis may occur. We emphasize the importance of their recognition and also the differential diagnosis of cervical lymphoma from other neoplastic and non-neoplastic lesions.

Abdominal Pain↗

PubMed1999

Evaluation of trisomy 12 by fluorescence in situ hybridization in peripheral blood, bone marrow and lymph nodes of patients with B-cell chronic lymphocytic leukemia.

BACKGROUND AND OBJECTIVE: Trisomy 12 is the most common numerical chromosomal aberration in patients with B-cell chronic lymphocytic leukemia (B-CLL). Fluorescence in situ hybridization (FISH) has improved the detection of this cytogenetic abnormality and has made detection possible in all phases of the cell cycle. The presence of the trisomy 12 positive (+12) cell population has generally been investigated in leukemic cells obtained from the peripheral blood of CLL patients. To ascertain whether trisomy 12 is expressed homogeneously in cells of different hemopoietic tissues, we applied FISH to lymph node, peripheral blood and bone marrow samples obtained simultaneously from 23 untreated B-CLL patients. DESIGN AND METHODS: Twenty-three newly diagnosed patients with B-CLL, 15 in stage B and 8 in stage C, were included in the present study. Peripheral blood smears, bone marrow aspirate smears and lymph node touch imprints were collected from each patient at diagnosis. Cytologic preparations were examined by light microscopy in order to assess the lymphocyte morphology. Immunophenotyping was performed by cytofluorimetric analysis of the peripheral blood, bone marrow and lymph node mononuclear cell suspensions. The diagnosis was supported in all cases by histologic findings in bone marrow biopsy and lymph node biopsy specimens. Fluorescence in situ hybridization was performed on smears of blood and aspirated bone-marrow and lymph node touch imprints obtained by fresh tissue apposition. RESULTS: In 6 of the 23 cases (26%) trisomy 12 was clearly present in all tissues examined. A comparative analysis of the three different hemopoietic tissues was performed. A higher percentage of leukemic CD5+CD23+ cells was detected in lymph nodes than in peripheral blood and bone marrow. A significantly higher proportion of trisomic cells was observed in lymph nodes samples than in peripheral blood or bone marrow smears of trisomy 12 positive CLL patients. INTERPRETATION AND CONCLUSIONS: Several previous reports show that only a proportion of malignant B-CLL cells carry trisomy 12 when analyzed by interphase FISH. The higher proportion of +12 cells in lymph nodes than in peripheral blood or bone marrow of CLL patients with trisomy 12 could reflect different cell distributions in different tissues, or lymph node specific tropism, or proliferative advantage in selected tissue. At present, the role of trisomy 12 in the pathogenesis of lymphoproliferative disorders is unclear.

Aged↗

PubMed1998

Platelet-activating factor synthesized by IL-12-stimulated polymorphonuclear neutrophils and NK cells mediates chemotaxis.

IL-12 is chemotactic for NK cells and polymorphonuclear neutrophils (PMN), but not for monocytes. In the present study, we evaluated whether the chemotactic effect of IL-12 is a direct phenomenon or is dependent on the generation of secondary mediators. The results obtained indicate that IL-12 induces a dose- and time-dependent synthesis of platelet-activating factor (PAF) from PMN and NK cells and of reactive oxygen radicals (ROS) from PMN. Monocytes and CD56-negative PBMC cells did not synthesize PAF or ROS after challenge with IL-12. The production of ROS by PMN was significantly inhibited by two chemically different PAF receptor antagonists (WEB 2170 and CV 3988), suggesting an autocrine stimulation of PMN by PAF newly synthesized after the challenge with IL-12. Moreover, the IL-12-induced chemotaxis of PMN and NK cells was significantly reduced by both WEB 2170 and CV 3988, suggesting that synthesized PAF mediates the chemotactic effect of IL-12. Preincubation with superoxide dismutase, which blocks the formation of superoxide anions, also reduced the chemotactic effect of IL-12 on PMN, but not on NK cells, suggesting that superoxide anion generation is relevant only for the IL-12-induced chemotaxis of PMN. In conclusion, the results of the present study indicate that IL-12-induced PAF synthesis plays a critical role in triggering the events involved in the motogenic response of PMN and NK to IL-12.

Chemotaxis, Leukocyte↗

PubMed1998

Cytotoxic effectors activated by low-dose IL-2 plus IL-12 lyse IL-2-resistant autologous acute myeloid leukaemia blasts.

We have investigated the susceptibility of primary acute myeloid leukaemia (AML) samples to the lytic action of normal peripheral blood mononuclear cells (PBMC), as well as of the patients' autologous and allogeneic PBMC collected at the time of remission following stimulation with different concentrations of interleukin (IL)-2 and IL-12, both alone and in variable combinations. Primary AML blasts were resistant to IL-2-activated PBMC effectors generated from normal individuals, allogeneic and autologous patients in five, six and eight of the 10 AML samples tested, respectively, IL-12 alone proved ineffective in generating anti-leukaemic activity, whereas, in combination, the two cytokines induced anti-leukaemic killing in all five cases resistant to normal PBMC, in 4/6 samples resistant to allogeneic AML effectors and in 5/8 cases resistant to autologous effectors. In each case the lytic effect was maintained at the lowest cytokine combination (10 + 10 IU/ml) utilized. The suggestion of a synergistic effect was further strengthened by the evidence that at the lowest doses of IL-2 and IL-12 the degree of killing was greater than that promoted by each cytokine independently. The results of this study suggest that two major limitations associated with the administration of IL-2 to AML patients, the resistance of the blasts to IL-2-generated killing and the toxicity associated with high-dose IL-2, may be overcome by the combined use of very low doses of IL-2 and IL-12. As IL-2-resistant blasts may be lysed by a low-dose combination of IL-2/IL-12, feasibility studies with this cytokine combination are worthy of exploration in vivo.

Adult↗

PubMed1998

[High prevalence of hepatitis C virus infection in patients with non-Hodgkin's lymphoma at the onset. Preliminary results of an Italian multicenter study].

143 patients with non-Hodgkin lymphoma (NHL) at the onset entered this perspective study on NHL-associated risk factors. They were 87 males and 56 females with a mean age of 52.3 years (range 14.6-82.3). An associated hepatitis C virus (HCV) infection was found in 16 of the 143 NHL cases (11.2%; 95% CI 6.5-17.5). They were 11 males and 5 females [mean age 59.9] year with disseminated (13/16) or localized NHL disease (3/16)]. The NHL histological subgroup was low grade (6/16), intermediate grade (2/16) or high grade (8/16). The cell origin was B in 15/16 cases and B cell-T cell rich in 1/16. The discovery of HCV infection was contemporary to lymphoma diagnosis in 6/16 cases but preceded the NHL onset in the other 10 patients. In these 10 patients the median time between HCV infection diagnosis and NHL onset was 3.6 years (range 1-14.5). These data confirm that in Italy the prevalence of HCV infection in patients with NHL (11.2%) is significantly higher than expected in the general population (1.3-3.2%). The finding that, in most cases, HCV infection was definitely antecedent to NHL onset, usually by years, adds evidence to the possible causative role of the HCV in lymphomagenesis.

Adolescent↗

PubMed1998

Microsatellite analysis in childhood acute lymphoblastic leukemia.

BACKGROUND AND OBJECTIVE: Genetic alterations, including genomic instability, represent possible steps towards a malignant transformation. One approach to delineate replication errors in cancer cells is to determine alterations of microsatellites that are short tandem repeat sequences dispersed throughout the human genome. We have investigated whether genomic instability may be a possible event in the leukemogenic process by evaluating the pattern of instability in 41 cases of childhood acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: Eighty-two samples of genomic DNA (41 at diagnosis and 41 at remission) were analyzed by PCR with microsatellite markers chosen on five different chromosomes (2, 10, 11, 13, 18) known to be frequently involved in tumors of various origins. Since deletions of the short arm of chromosome 12 are relatively common in children with ALL, we also analyzed one region flanked by the microsatellite marker D12S308 on 12p. This area encompasses a genetic locus which contains the putative suppressor gene KIP1. RESULTS: A pattern of MI at one or two loci on different chromosomes could be documented in 4 of the 41 cases analyzed (9.7%). Three were common ALL and 1 was a T-ALL. One case showed two concomitant sites of instability, while 1 revealed two additional bands by using simultaneously microsatellite markers D2S123 and D18S58. INTERPRETATION AND CONCLUSIONS: These results indicate that genetic instability of microsatellite repeat sequences occurs in a proportion of childhood ALL. Mismatched repair errors documented in hereditary and sporadic solid tumors may thus be involved in hematological malignancies. While in such cases the pattern of genomic instability appears indicative of a mutator phenotype and of a potential predisposition towards a leukemic transformation, other genomic loci close to cytogenetic and molecular alterations known to occur in ALL need to be investigated in depth in cases with an apparently non mutated phenotype.

Child↗

PubMed1997

Transfer of the interleukin-2 gene into human cancer cells induces specific antitumor recognition and restores the expression of CD3/T-cell receptor associated signal transduction molecules.

Normal peripheral blood mononuclear cells (PBMC) were co-cultured with a human lung cancer cell line (LC89) transduced with the interleukin-2 (IL-2), IL-7, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha) genes to evaluate the capacity of the engineered cells to: allow survival of CD3+ and CD56+ cells, generate cytotoxic effectors with HLA class I restricted and unrestricted antitumor activity, and interfere in the molecular organization of the CD3/T-cell receptor associated signal transduction machinery. When PBMC were cultured up to 3 weeks with IL-2 releasing LC89 cells (LC89/IL-2), the number of viable CD3+ and CD56+ lymphocytes was much greater than in cultures with parental cells or with LC89 cells transduced with the other cytokine genes. After 1 week of coculture, a variable degree of restricted and unrestricted killing directed against different targets was observed. When the cultures were prolonged up to 3 weeks, LC89/IL-2 cells induced a marked increase in specific cytotoxic activity, which was coupled to a further enhancement of unrestricted lytic function. In the presence of LC89/IL-7 cells the degree of specific lysis remained unchanged, whereas unrestricted effectors were markedly decreased. No cytotoxic activity could be induced by LC89/GM-CSF and LC89/TNF-alpha cells in the few lymphocytes surviving after 3 weeks of culture. Coculture of parental LC89 cells with PBMC was consistently associated with a downmodulation in the expression of the CD3 zeta chain, as well as of the tyrosine kinases p56ick and ZAP-70. On the contrary, LC89/IL-2 cells, and not LC89 cells transduced with the IL-7, GM-CSF, or TNF-alpha gene, were capable of reverting the immunosuppressive effect exerted by the tumor cells. This protective effect could be maintained in cultures prolonged up to 4 weeks. When the same cultures were set up in Transwell, ie, with a membrane separation between cancer cells and PBMC, the expression of the CD3 zeta chain and of the p56ick and ZAP-70 tyrosine kinases remained unchanged under all culture conditions, indicating that the downmodulation of T-cell signal transduction molecules requires a direct cell to cell contact. These results show that transfer of the IL-2 gene into the DNA of human cancer cells promotes both restricted and unrestricted antitumor activity, and is capable of restoring and maintaining the expression of molecules involved in the process of T-cell mediated tumor cell recognition, thus underlining the potential role of the IL-2 gene in the design of vaccination protocols with cytokine gene transduced cancer cells.

Adenocarcinoma↗