Sociodemographic profile, health-related behaviours and experiences of healthcare access in Italian transgender and gender diverse adult population.

PURPOSE: Information on the general health of transgender and gender diverse (TGD) individuals continues to be lacking. To bridge this gap, the National Institute of Health in Italy together with the National Office against Racial Discriminations, clinical centres, and TGD organizations carried out a cross-sectional study to define the sociodemographic profile, health-related behaviours, and experiences of healthcare access in Italian TGD adult population. METHODS: A national survey was conducted by Computer-Assisted Web Interviewing (CAWI) technique. Collected data were compared within the TGD subgroups and between TGD people and the Italian general population (IGP). RESULTS: TGD respondents were 959: 65% assigned female at birth (AFAB) and 35% assigned male at birth (AMAB). 91.8% and 8.2% were binary and non-binary TGD respondents, respectively. More than 20% of the TGD population reported to be unemployed with the highest rate detectable in AMAB and non-binary people. Cigarette smoking and binge drinking were higher in the TGD population compared with IGP (p < 0.05), affecting TGD subgroups differently. A significant lower percentage of AFAB TGD people reported having had screening for cervical and breast cancer in comparison with AFAB IGP (p < 0.0001, in both cases). Over 40% was the percentage of AFAB and non-binary TGD people accessing healthcare who felt discriminated against because of their gender identity. CONCLUSIONS: Our results are a first step towards a better understanding of the health needs of TGD people in Italy in order to plan the best policy choices for a more inclusive public health.

Mass screening for hepatitis B and C viruses in a population of persons with disabilities with and without HIV status in Cameroon.

Hepatitis viral infections are one of major threat to public health worldwide. The vast majority of people infected with viral hepatitis are found in resources limited countries of Africa and Asia. There is a lack of accurate data to better determine the burden of this disease in Cameroon, moreover among vulnerable people. The aim of this study was to estimate the seroprevalence of HBV and HCV viruses among persons with disabilities (PwD) with or without HIV status.

Effects of whole body vibration plus diet on insulin-resistance in middle-aged obese subjects.

We investigated the early effects of whole body vibration (WBV) added to hypocaloric diet on insulin-resistance and other parameters associated with glucose regulation in sedentary obese individuals. We randomly assigned 34 patients to WBV plus hypocaloric diet (WBV group) or diet alone (CON group) for 8 weeks. Fasting and post-load glucose, insulin, lipids, C-reactive protein, tumor necrosis factor-α, leptin, adiponectin were assessed. Insulin sensitivity index (ISI) was derived from oral-glucose-tolerance test. Body composition was evaluated with dual-energy X-ray absorptiometry. Both groups lost approximately 5% of weight, with greater reduction of body fat in WBV than in CON (-7.1±1.2 Kg vs. -5.3±1.0 Kg, p=0.003). Percent variation of ISI was more pronounced in WBV than in CON group (+35±4% vs. + 22±5%, p=0.002), accompanied by slight improvement in post-load glucose (-1.07±0.02 vs. - 0.12±0.01 mmol/l, p=0.031) but without changes in fasting levels. Adiponectin significantly increased in WBV group compared with CON (p=0.021 for comparison) whereas no differences in leptin and inflammatory markers were observed. In middle-aged sedentary obese subjects, WBV added to hypocaloric diet for 8 weeks improved body composition, insulin-resistance, glucose regulation and adiponectin levels to a greater extent compared with diet alone. Efficacy and feasibility of this approach in the long term need to be ascertained.

Muscle-specific microRNAs as biomarkers of Duchenne Muscular Dystrophy progression and response to therapies.

Recent studies have revealed the contribution of fibro-adipogenic progenitors (FAPs) to the pathogenesis and progression of Duchenne Muscular Dystrophy (DMD). While FAPs direct compensatory regeneration at early stages of disease, as the disease progresses they contribute to the progressive replacement of contractile myofibers with fibrotic scars and fatty infiltration. Using the mouse model of DMD - the mdx mice - we have recently reported that FAPs mediate the ability of HDAC inhibitors (HDACi) to promote muscle regeneration and prevent fibro-adipogenic degeneration at early stages of disease. This effect is mediated by the induction of myomiRs that, in turn, target the SWI/SNF components BAF60A and B, thereby favoring the formation of BAF60C-based SWI/SNF complex, which directs the switch from the fibro-adipogenic to the myogenic lineage. Here we show direct evidence of induction of miR-206 and BAF60C, and reduction of BAF60A, in FAPs isolated from mdx muscles exposed to the HDACi Trichostatin A (TSA). We also discuss how increased expression of myomiRs in dystrophic muscles can be integrated with circulating myomiRs to provide accurate biomarkers of disease progression and response to treatment.

Increased frequency of immunoglobulin (Ig)A-secreting cells following Toll-like receptor (TLR)-9 engagement in patients with Kawasaki disease.

Kawasaki disease (KD) is an acute vasculitis affecting mainly infants and children. Human B cells express Toll-like receptor (TLR)-9, whose natural ligands are unmethylated cytosine-guanine dinucleotide (CpG) motifs characteristic of bacterial DNA. The aim of this study was to clarify the pathogenesis of KD analysing the activation status of peripheral blood mononuclear cells (PBMC), focusing on B lymphocyte activation and functions. Ten patients and 10 age-matched healthy donors were recruited from the Bambino Gesù Hospital of Rome, Italy and enrolled into this study. We determined phenotype profile and immunoglobulin (Ig) production of PBMC from KD patients and age-matched controls. We found that the frequency of CD19(+) B lymphocytes and CD19(+) /CD86(+) activated B lymphocytes from KD patients during the acute phase before therapy was increased significantly. Moreover, B lymphocytes of acute-phase KD patients were more prone to CpG oligodeoxynucleotide (ODN) activation compared with the age-matched controls, as assessed by a significant increase of the number of IgA-secreting cells (SC). In the same patients we found a marked increase of IgM, IgG, interleukin (IL)-6 and tumour necrosis factor (TNF)-α production compared with the control group. In addition, in two convalescent KD patients, conventional treatment with intravenous immunoglobulin (IVIG) restored the normal frequency of CD19(+) B cells, the number of IgA-, IgM- and IgG-SC and the production of IL-6 and TNF-α. Our findings indicate that the percentages of peripheral B lymphocytes of acute-phase KD patients are increased and are prone to bacterial activation in terms of increased numbers of IgA-SC and increased production of IL-6 and TNF-α inflammatory cytokines. Thus, our data support the hypothesis of an infectious triggering in KD.

17beta-Hydroxysteroid dehydrogenase-3 deficiency: from pregnancy to adolescence.

OBJECTIVE: Aim of this study is to report on basal clinical phenotype and follow up after diagnosis, of patients with 17beta-hydroxysteroid-dehydrogenase type 3 (17beta-HSD3) deficiency in Italy. SETTING: Pediatric Endocrine Departments, University Hospitals. PATIENTS: The cases of 5 Italian subjects affected by 17beta-HSD3 deficiency are presented in this study. INTERVENTIONS: Laboratory and genetic assessment. Gonadectomy and female sex assignment (4 patients) or GnRH analog therapy to regress puberty and gender identity disorder (1 patient). RESULTS: Presentation lasted from pregnancy (pre-natal diagnosis of a 46,XY fetus with female external genitalia) to infancy (inguinal hernia containing testes/clitoromegaly) and adolescence (virilisation). All subjects but one (subject 1, Central-Northern Italy) were from small areas of Southern Italy. Endocrine data (baseline and/or stimulated testosterone/ Delta4-androstenedione ratio) were informative. Two girls were homozygous for 17beta-HSD3 gene mutations (G289S/G289S; R80W/R80W), while the others were compound heterozygous (IVS325+4 A>T/A203V; L212Q/M235V; R80W/A235E). Four patients were confirmed as females and were well-adjusted with assigned sex; gender identity disorder improved during treatment with GnRH analog in the last subject. CONCLUSIONS: 17betaHSD3 deficiency may present from pregnancy to puberty for different clinical issues. Albeit testosterone/Delta4-androstenedione ratio represents the most accurate endocrine marker to diagnose the disorder, hCGstimulation is mandatory in pre-puberty. Molecular analysis of 17beta-HSD3 gene should be performed to confirm the diagnosis. Temporary GnRH analog treatment may regress gender identity disorder and provide time to confirm or change the birth sex assignment. Female individuals seems to be compliant with their sex, providing that virilisation does not occur. In Italy, the disorder seems to be more prevalent in the Southern regions and shows genetic heterogeneity.

IFN-alpha amplifies human naive B cell TLR-9-mediated activation and Ig production.

TLRs are a family of molecules that function as sensors for the detection of pathogens. TLR-9, expressed on B cells and pDCs, recognizes CpG motifs of unmethylated bacterial DNA and plays a role in the development of autoimmunity. The present study was designed to investigate the effects of IFN-alpha in combination with CpG ODN on the activation of CD27(-) naïve B cells and on Ig production. We provide evidence that CpG ODN not only induces a total and T-dependent, specific IgM response by naïve B cells but also their phenotypic differentiation in plasma cells, as demonstrated by the up-regulation of CD38 expression. We found that TLR-9 stimulation with CpG ODN induces IL-1beta, TNF-alpha, IL-10, and IL-6 production. Interestingly, we also found that CpG ODN induces naïve B cell maturation into memory cells, as demonstrated by the induction of CD27, AID mRNA expression, and IgG production. More importantly, our results demonstrate that IFN-alpha amplifies the inductive effect of CpG ODN on naïve B activation and on Ig production through a mechanism involving TLR-9/MyD88-dependent signaling. Moreover, we found that IFN-alpha enhances the frequency of CpG ODN-induced memory B cells. Our results may contribute to clarify the events promoting IFN-alpha-induced amplification of naïve B cell activation via TLR-9 for a better understanding of the pathogenesis of autoimmune disorders and may guide treatments targeting this pathway within B cells.

Clinical, endocrine, and molecular findings in 17beta-hydroxysteroid dehydrogenase type 3 deficiency.

The 17beta-hydroxysteroid dehydrogenases (17betaHSD) gene family comprises different enzymes involved in the biosynthesis of active steroid hormones. The 17betaHSD type 3 (17betaHSD3) isoenzyme catalyzes the reductive conversion of the inactive C19-steroid, Delta4-androstenedione (Delta4- A), into the biologically active androgen, testosterone (T), in the Leydig cells of the testis. It is encoded by the 17beta-hydroxysteroid dehydrogenase type 3 (HSD17B3) gene, which maps to chromosome 9q22. Mutations in the HSD17B3 gene are associated with a rare form of 46,XY disorder of sex development referred to as 17betaHSD3 deficiency (or as 17-ketosteroid reductase deficiency), due to impaired testicular conversion of Delta4-A into T. 46,XY patients with 17betaHSD3 deficiency are usually classified as female at birth, raised as such, but develop secondary male features at puberty. Diagnosis, and consequently early treatment, is difficult because clinical signs from birth until puberty may be mild or absent. Biochemical diagnosis of 17betaHSD3 deficiency requires measurement of serum T/Delta4-A ratio after hCG stimulation test in pre-pubertal subjects, while baseline values seem to be informative in early infancy and adolescence. However, low basal T/Delta4-A ratio is not specific for 17betaHSD3 deficiency, being sometimes also found in patients with other defects in T synthesis or with Leydig cells hypoplasia. Mutational analysis of the 17HSDB3 gene is useful in confirming the clinical diagnosis of 17betaHSD3 deficiency. This review describes clinical findings, diagnosis, and molecular basis of this rare disease.

N-acetylcysteine inhibits the induction of an antigen-specific antibody response down-regulating CD40 and CD27 co-stimulatory molecules.

We investigated the effect of N-acetylcysteine (NAC) on normal human B cell functions. We found that NAC significantly inhibited both the induction of the specific antibody response to the T-dependent antigen Candida albicans and T-dependent pokeweed mitogen (PWM)-induced polyclonal Ig production. NAC did not induce either cell death due to a non-specific toxicity or apoptosis. The NAC-induced inhibitory effect might be a functional consequence of: (i) a down-regulation of the expression on the B cell surface of CD40 and CD27 co-stimulatory molecules and (ii) a down-regulation of interleukin (IL-4) production. In contrast, NAC up-regulated interferon-gamma (IFN-gamma) production. NAC did not induce any effect on the T cell-independent B cell polyclonal activation system. These results indicate that NAC down-regulates T dependent B cell activation and leads to T helper cell type 1 (Th1) polarization.

HIV-1 Nef protein inhibits the in vitro induction of a specific antibody response to Candida albicans by an early up-regulation of IL-15 production.

We have previously demonstrated that exogenous Nef protein induced activation of normal human T cells up-regulating IL-15 production by monocytes. Since HIV-1 infection results in the early impairment of immune functions we decided to evaluate if Nef is able to modulate the induction of a specific antibody response. Human peripheral blood mononuclear cells from healthy donors were induced in vitro to mount a specific antibody response to the Candida albicans antigen. We show that Nef inhibited, in a dose-dependent manner, the induction of the anti-C. albicans antibody response. The ability of an anti-Nef antibody to prevent such inhibition indicates that the effect was indeed Nef-specific. In the Nef-treated cultures an early increase of IL-15 production was observed and the addition of anti-IL-15 antibody abrogated the Nef-induced inhibitory effect. Moreover the addition of IL-15 to the cultures inhibited, as well as Nef, the induction of the specific antibody response. Thus, our results suggest that Nef may inhibit the induction of a specific antibody response by an early up-regulation of IL-15 production. A better comprehension of this phenomenon may be important for unravelling some aspects of the B cell defects in HIV infection.

Reduced expression of transforming growth factor-beta receptor type III in high stage neuroblastomas.

Transforming growth factor beta (TGF-beta) is a powerful inhibitor of cell proliferation and a potent inducer of differentiation. Resistance to TGF-beta action is a characteristic of many malignancies and has been attributed to alterations of TGF-beta receptors as well as disturbance of downstream transduction pathways. To analyse the TGF-beta response in neuroblastoma, the expression of TGF-beta1 and TGF-beta type I, II and III receptor genes was investigated in 61 cancer samples by means of reverse transcription polymerase chain reaction. The specimens analysed belong to different stages, namely nine samples of stage 1, ten of stage 2, nine of stage 3 and 28 of stage 4. Moreover, five samples were of stage 4S, which represents a tumour form undergoing spontaneous regression. The results obtained show that TGF-beta1 and TGF-beta type I and II receptor genes appear to be almost equally expressed in neuroblastomas of all stages. Conversely, TGF-beta type III receptor gene expression, which is required for an efficacious TGF-beta binding and function, is strongly reduced exclusively in neuroblastomas of stages 3 and 4. These findings were directly confirmed by immunohistochemical analyses of ten neuroblastoma specimens. Our results suggest the occurrence of an altered TGF-beta response in advanced neuroblastomas which might be an important mechanism for escaping growth control and for developing invasiveness. Moreover, our findings allow the proposal of a novel mechanism, namely down-regulation of TGF-beta type III receptor gene expression, to avoid TGF-beta inhibitory activity.

Possible role of the plasminogen receptor as a site of interaction of the human immunodeficiency virus p24 immunosuppressive heptapeptide Ch7 with the host immune system.

Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7: RGSDIAG), corresponding to a conserved sequence of human immunodeficiency virus (HIV) core protein p24 (amino acids 232- 238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood mononuclear cells (PBMC), probably acting at the level of monocytes. The Ch7 peptide displays sequence homology to human plasminogen. In the present report we show that a compound (6-aminoexanoic acid), known to prevent plasminogen binding to monocyte-like cells, greatly reduced the immunosuppressive capacity of Ch7. We suggest that the plasminogen receptor may represent a target structure on human monocytes for the immunosuppressive p24 sequence.

Bilirubin levels in the acute hemolytic crisis of G6PD deficiency are related to Gilbert's syndrome.

In this study we analyzed the effect of the (TA)7 polymorphism of the UGT1A gene associated with Gilbert's syndrome in G6PD-deficient subjects during an acute hemolytic crisis (fabic crisis). DNA from 44 subjects originating from the same geographic area in Sardinia was analyzed for the UGT1A promoter polymorphism. The increase of unconjugated bilirubin level during fabic crisis and its relationship with UGT1A polymorphism was evaluated. The UGT1A (TA)7 TATA box variant was found in 9/44 (21%) of the G6PD deficient subjects examined. The median value for unit of increase of bilirubin (mg/dl)/unit of decrease of hemoglobin (g/dl) was higher in variant homozygous than in heterozygous and normal subjects. These findings imply a contribution of the UGT1A polymorphism associated to Gilbert's syndrome to development of the hyperbilirubinemia in G6PD deficient subjects during acute hemolytic anemia.

Neuroblastoma in two siblings supports the role of 1p36 deletion in tumor development.

Familial neuroblastoma occurs rarely. We studied a family with three children; one of them has a disseminated (stage 4) and another has a localized (stage 2) neuroblastoma. We observed subtelomeric locus D1Z2 (1p36) deletion in both tumors by using double-color fluorescence in situ hybridization. The MYNC gene was found in single copy in both tumors. Loss of heterozygosity (LOH) and restriction fragment length polymorphism analyses were performed by using DNA from frozen tumor cells and from microdissected tumor areas excised from paraffin-embedded sections. We detected somatic LOH at locus D1S468 (1p36) in a tumor-cell population with a trisomy 1 of the stage-2 patient. Neuroblastoma cells of the stage-4 patient were diploid and showed allelic loss at the following loci: D1S172, D1S80, D1S94, D1S243, D1S468, D1S214, D1S241, and D1S164. Haplotype study showed that the siblings inherited the same paternal 1p36-->pter chromosome region by homologous recombination and that, in the two tumors, arm 1p of different chromosomes of maternal origin was damaged. Our results suggest that the siblings inherited the predisposition to neuroblastoma associated with paternal 1p36 region and that tumors developed as a consequence of somatic loss of the maternal 1p36 allele.

Expression of cell cycle regulatory genes in chronic myelogenous leukemia.

BACKGROUND AND OBJECTIVE: Cell cycle regulatory genes are frequently altered in a variety of malignancies. The structure and pattern of expression of eight genes involved in cell division cycle control were studied in leukemic cell samples prepared from bone marrow of patients affected by chronic myelogenous leukemia. DESIGN AND METHODS: Ten cell preparations were obtained from patients in the chronic phase, five from those in myeloid blast crisis and five from those in the lymphoid acute phase. Moreover, bone marrow CD34+ cells, purified from healthy subjects and patients with chronic myelogenous leukemia (both during chronic and acute phases), were analyzed. The investigated genes were RB1, p53 and six cyclin-dependent kinase inhibitor genes (p15INK4B, p16INK4A, p18INK4C, p21WAF1/CIP1, p27Kip1, p57Kip2). RESULTS: We found that none of these genes is structurally altered in either the chronic or acute phases, with the single exception of the p16INK4A gene, which was homozygously deleted in 1 case of lymphoid evolution. p57Kip2 expression is down-regulated during the evolution towards the blast crisis both in malignant and CD34+ cells. In addition, a significant up-regulation of p15INK4B gene expression is observable during the development of the acute phase of malignancy. INTERPRETATIONS AND CONCLUSIONS: The transcriptional modulation of some cyclin-dependent kinase inhibitors might contribute to the fatal blast crisis of chronic myelogenous leukemia.

Increased PGE2 production mediates the in vitro inhibitory effect of the human immunodeficiency virus P24 immunosuppressive heptapeptide Ch7.

Previous work from our laboratory demonstrated that a synthetic heptapeptide (Ch7), corresponding to a conserved sequence of human immunodeficiency virus (HIV) core protein p24 (amino acids 232-238), was able to specifically abrogate antigen-induced responses in cultures of normal human peripheral blood lymphocytes (PBL). Addition of recombinant human interferon-gamma (IFN-gamma) to Ch7-suppressed cultures restored the capacity to mount an antigen-specific antibody response, suggesting that a cytokine imbalance may be at the basis of the Ch7 immunosuppressive activity. In the present paper we show that the Ch7-dependent in vitro immunosuppression was accompanied by a significant up-regulation of prostaglandin E2 (PGE2) production and induction of interleukin-10 (IL-10)-secreting cells. In the presence of the PGE2 inhibitor indomethacin, IL-10 up-regulation was prevented and the induction of a specific antibody response was partially restored. PGE2 is indeed an important regulator of immune responses with the ability to differentially affect cytokine production. Thus, our results demonstrate that the Ch7 immunosuppressive epitope may primarily act by up-regulating PGE2 production and, through this mediator, by causing a cytokine dysregulation, finally responsible for immune response suppression.

Interstitial and large chromosome 1p deletion occurs in localized and disseminated neuroblastomas and predicts an unfavourable outcome.

We studied chromosome 1p loss of heterozygosity (1p-LOH) in 53 neuroblastomas (NBs) using 15 (CA)n repeat loci, which covered a region of 90 cM. We also assessed chromosome 1p36 deletion by fluorescence in situ hybridization (FISH) on interphase nuclei. 1p-LOH was found in 19 (36%, 95% confidence interval (CI) 23-50%) NBs. We detected interstitial and large deletion in both localized and disseminated tumours and in one tumour of a patient at stage 4S. Allelic loss was frequently observed in 1p36 and 1p32 regions. In patients older than 1 year of age (53 versus 13%, P < 0.002) we detected significant chromosome 1p deletion and it was associated with MYCN amplification (P = 0.001). Overall survival (OS) analysis showed that 1p-LOH is predictive of a poor outcome (odds ratio 16.5, 95% CI 5.4-50.9%); therefore, 1p-LOH should be regarded as an additional tumour progression marker in neuroblastoma.

Analysis of CDKN2A, CDKN2B, CDKN2C, and cyclin Ds gene status in hepatoblastoma.

The status and the expression of cyclin-dependent kinase inhibitor A (CDKN2A) family genes, named CDKN2A, CDKN2B, and CDKN2C and of cyclin Ds (D1, D2, and D3) genes were investigated in 14 cases of human hepatoblastomas. These genes were selected because: 1) CDKN2A and CDKN2B are very frequently inactivated in human cancers; 2) cyclin Ds are overexpressed in several tumors and 3) CDKN2A is posttranscriptionally silenced in hepatocellular carcinomas. Structural analysis of the CDKN2A, CDKN2B, and CDKN2C genes in hepatoblastoma cases showed the absence of deletions and/or point mutations. Moreover, a detailed investigation of loss of heterozygosity at 9p21 and 1p32 (the chromosomal regions where CDKN2A genes are located) rules out the possible loss of one allele. Messenger RNA (mRNA) analysis showed that CDKN2C is expressed in all hepatoblastoma samples studied, while both CDKN2A and CDKN2B genes are not transcribed in the cancer specimens as well as in the matched normal liver tissues. Interestingly, an alternative mRNA expressed by the CDKN2A gene (beta-transcript) is detectable in 100% of the samples investigated. The analysis of cyclin D genes expression revealed that cyclin D1 is highly transcribed in normal hepatic tissue while cyclin D2 or D3 genes were extensively expressed in the matched transformed samples. Investigation at protein level confirmed the data obtained on RNA analysis. Indeed, p16INK4A and p15INK4B (products of expression of CDKN2A and CDKN2B respectively) were not observable while pl8INK4C (which is codified by CDKN2C) was clearly detectable in the samples analyzed. Moreover, a noticeable decrease of cyclin D1 content and increase of cyclin D3 level were observable in tumor tissues versus normal counterparts. Our findings demonstrated the following: 1) CDKN2A, CDKN2B, and CDKN2C genes are structurally unmodified in human hepatoblastoma, and 2) CDKN2A (alpha-transcript) and CDKN2B are transcriptionally silenced in normal liver whereas CDKN2A (beta-transcript) and CDKN2C were clearly expressed. Finally, a clear shift in cyclin D type expression was observable during malignant transformation. These results show that CDKN2A gene family alterations are not involved in hepatoblastoma development, whereas changes in cyclin D types might play a role in this type of tumor. Furthermore, a highly regulated expression of CDKN2A seems to occur in normal hepatic tissue.

HIV-1 gp120 accelerates Fas-mediated activation-induced human lamina propria T cell apoptosis.

Intestinal mucosa represents an important portal of entry of HIV and a site of virus reservoir and active replication. Recently, in HIV patients, an early depletion of intestinal lamina propria T lymphocytes (LPT) has been described. HIV-1 gp120 has been demonstrated to promote apoptosis in noninfected isolated peripheral blood T cells, therefore we investigated whether gpl20 modulates apoptosis of normal human intestinal lamina propria T cells. Purified T cells were obtained by immunomagnetic negative selection from human lamina propria mononuclear cells isolated from surgical specimens by enzymatic procedure. Cells were incubated with or without recombinant gpl20 (10 microg/ml) and cultured either in the absence of any stimulus or in the presence of plate-bound anti-CD3 Ab (OKT3) or soluble anti-CD2 Ab (T11(2) + T11[3]). Apoptosis was assessed by flow cytometric analysis after propidium iodide staining. We demonstrated that preincubation of normal LPT cells with HIV-1 gpl20 accelerates the apoptosis observed during CD2-pathway stimulation of LPT cells. This process is mediated by Fas/Fas ligand interaction and related to an increased induction of Fas ligand mRNA by gpl20. Therefore HIV-1 gp120 could contribute to the depletion of noninfected LPT cells inducing a premature cell death.

Structural and functional analysis of cyclin-dependent kinase inhibitor genes (CDKN2A, CDKN2B, and CDKN2C) in neuroblastoma.

The status of the CDKN2A gene family, including CDKN2A, CDKN2B, and CDKN2C, was investigated in 24 cases of neuroblastoma. These genes were selected on the basis of 1) high incidence of their inactivation in several human cancers and 2) their localization on chromosomal regions (9p and 1p) frequently rearranged in neuroblastomas. Detailed molecular analyses indicated the absence of homozygous deletions and point mutations involving these genes in all investigated tumor samples. However, when loss of heterozygostity for chromosome 9p21 (the region where CDKN2A and CDKN2B are localized) was investigated, 16% of cases showed abnormalities in an area telomeric to the CDKN2A locus. To study transcriptional silencing of the CDKN2A gene, the methylation status of exon 1 was examined. In about 35% of cases, a partial methylation was evidenced. Analysis of the CDKN2A mRNA expression, however, did not show any relationship between methylation status and gene transcription. Finally, expression of the CDKN2B gene was demonstrated in all stage IV neuroblastomas, whereas none of stage I tumors expressed this gene. This finding suggests the occurrence of a correlation between CDKN2B transcription and tumor phenotype.