Promoter hypomethylation of the LINE-1 retrotransposable elements activates sense/antisense transcription and marks the progression of chronic myeloid leukemia

Aberrant genome-wide hypomethylation is thought to be related to tumorigenesis by promoting genomic instability. Since DNA methylation is considered an important mechanism for the silencing of retroelements, hypomethylation in human tumors may lead to their reactivation. However, the role of DNA hypomethylation in chronic myeloid leukemia (CML) remains to be elucidated. In this study, the methylation status of the LINE-1 (L1) retrotransposon promoter was analysed in CML samples from the chronic-phase (CP, n=140) and the blast crisis (BC, n=47). L1 hypomethylation was significantly more frequent in BC (74.5%) than in CP (38%) (P<0.0001). Furthermore, L1 hypomethylation led to activation of both ORF1 sense transcription (P<0.0001) and c-MET gene antisense transcription (P<0.0001), and was significantly associated with high levels of BCR-ABL (P=0.02) and DNMT3b4 (P=0.001) transcripts. Interestingly, in CP-CML, extensive L1 hypomethylation was associated with poorer prognosis in terms of cytogenetic response to interferon (P=0.004) or imatinib (P=0.034) and progression-free survival (P=0.005). The above results strongly suggest that activation of both sense and antisense transcriptions by aberrant promoter hypomethylation of the L1 elements plays a role in the progression and clinical behavior of the CML.

Reliable quantification of hematopoietic chimerism after allogeneic transplantation for acute leukemia using amplification by real-time PCR of null alleles and insertion/deletion polymorphisms

Increasing mixed chimerism (MC) after allogeneic stem cell transplantation (SCT) has been associated with a high risk of relapse in acute leukemia. We evaluated a new method for chimerism detection, based on the quantitative real-time PCR (qrt-PCR) amplification of null alleles or insertion/deletion polymorphisms (indels). All qrt-PCR assays with null alleles and indels attained a sensitivity of at least 10(-4), as well as good intra- and interassay concordance, and a high accuracy in experiments with cell mixtures. Informativeness was found in 80.3% of the 61 donor/recipient pairs tested. Nonrelapsed patients showed a progressive decrease in peripheral blood chimerism to values below 0.01% (complete chimerism (CC)). Bone marrow chimerism failed to reach CC more than 4 years after SCT. Increasing MC was observed prior to relapse in 88.2% of patients. Compared with conventional PCR amplification of variable number of tandem repeats, qrt-PCR predicted a significantly higher number of relapses (88.2 vs 44.4%) with a median anticipation period of 58 days. In conclusion, chimerism determination by qrt-PCR amplification of null alleles and indels constitutes a useful tool for the follow-up of patients with acute leukemia after SCT, showing better results than those obtained with conventional PCR.

Promoter hypermethylation of cancer-related genes: a strong independent prognostic factor in acute lymphoblastic leukemia

Promoter hypermethylation plays an important role in the inactivation of cancer-related genes. This abnormality occurs early in leukemogenesis and seems to be associated with poor prognosis in acute lymphoblastic leukemia (ALL). To determine the extent of hypermethylation in ALL, we analyzed the methylation status of the CDH1, p73, p16, p15, p57, NES-1, DKK-3, CDH13, p14, TMS-1, APAF-1, DAPK, PARKIN, LATS-1, and PTEN genes in 251 consecutive ALL patients. A total of 77.3% of samples had at least 1 gene methylated, whereas 35.9% of cases had 4 or more genes methylated. Clinical features and complete remission rate did not differ among patients without methylated genes, patients with 1 to 3 methylated genes (methylated group A), or patients with more than 3 methylated genes (methylated group B). Estimated disease-free survival (DFS) and overall survival (OS) at 11 years were 75.5% and 66.1%, respectively, for the nonmethylated group; 37.2% and 45.5% for methylated group A; and 9.4% and 7.8% for methylated group B (P &lt; .0001 and P = .0004, respectively). Multivariate analysis demonstrated that the methylation profile was an independent prognostic factor in predicting DFS (P &lt; .0001) and OS (P = .003). Our results suggest that the methylation profile may be a potential new biomarker of risk prediction in ALL.

Transcriptional silencing of the Dickkopfs-3 (Dkk-3) gene by CpG hypermethylation in acute lymphoblastic leukaemia

Dkk-3 is a newly characterised mortalisation-related gene and an antagonist of the Wnt oncogenic signalling pathway whose expression is decreased in a variety of cancer cell lines, suggesting that the Dkk-3 gene, located at chromosome 11p15.1, functions as a tumour suppressor gene. Although 11p15 is a ‘hot spot’ for methylation in acute lymphoblastic leukaemia (ALL), the role of Dkk-3 abnormalities has never been evaluated in this disease. We analysed CpG island methylation of the Dkk-3 promoter in six ALL cell lines and 183 ALL patients. We observed Dkk-3 hypermethylation in all cell lines and in cells from 33% (60/183) of ALL patients. Moreover, Dkk-3 methylation was associated with decreased Dkk-3 mRNA expression and this expression was restored after exposure to the demethylating agent 5-AzaC. Clinical features did not differ between hypermethylated and unmethylated patients. Estimated disease-free survival (DFS) and overall survival at 10 and 11 years, respectively, were 49.8 and 45.6% for normal patients and 10.5 and 15.1% for hypermethylated patients (P=0.001 and 0.09). Multivariate analysis demonstrated that Dkk-3 methylation was an independent prognostic factor predicting DFS (P=0.0009). Our data suggest that Dkk-3 methylation occurs at an early stage in ALL pathogenesis and probably influences the clinical behaviour of the disease.

The suppressor of cytokine signaling-1 is constitutively expressed in chronic myeloid leukemia and correlates with poor cytogenetic response to interferon-alpha

BACKGROUND AND OBJECTIVES

Interferon-alpha (IFN-alpha) has proven useful for treating chronic myeloid leukemia (CML). However, only 7% of patients achieve a complete cytogenetic response. Although efforts to understand the molecular basis of this resistance to IFN-alpha have been made, the mechanism is still unknown. Because suppressor of cytokine signaling (SOCS) proteins are negative regulators of cytokine-induced signaling, it has been hypothesized that aberrant SOCS expression could confer resistance against cytokine therapy.

DESIGN AND METHODS

In order to analyze the role of SOCS-1 in the acquisition of IFN-alpha resistance in this setting, we examined SOCS-1 mRNA expression using reverse transcription polymerase chain reaction (RT-PCR) in 75 newly diagnosed chronic phase-CML patients who received IFN-alpha therapy.

RESULTS

SOCS-1 was constitutively expressed in 49 (65%) of 75 CML patients at diagnosis. Constitutive SOCS-1 expression was more frequently observed among Hasford high-risk patients (p = 0.05) and was also independently associated with a shorter median progression-free survival time (p = 0.001) and poor cytogenetic response to IFN-alpha treatment (p 0.0001).

INTERPRETATION AND CONCLUSIONS

Our data indicate that constitutive expression of SOCS-1 occurs at an early stage in CML pathogenesis and probably influences the clinical behavior of the disease.

Chimerism status is a useful predictor of relapse after allogeneic stem cell transplantation for acute leukemia

BACKGROUND AND OBJECTIVES

The role of hematopoietic chimerism after allogeneic stem cell transplantation (SCT) for acute leukemia remains controversial. We studied the relationship between hematopoietic chimerism and several prognostic variables on the outcome of SCT in patients with acute leukemia.

DESIGN AND METHODS

Chimerism was determined by a semiquantitative method, based on polymerase chain reaction (PCR) amplification of variable number tandem repeat (VNTR) minisatellites, in 133 consecutive patients who underwent allogeneic SCT for acute leukemia (68 myeloid, 58 lymphoid and 7 biphenotypic), all receiving a myeloablative conditioning regimen.

RESULTS

The median follow-up for the surviving patients was 44.8 months (range: 12.0-129.0). Recipient hematopoiesis (mixed chimerism, MC) was detected in 40 cases (30.1%). Two types of patients could be distinguished in this MC group: 29 with increasing MC and 9 with decreasing MC. The remaining 93 cases maintained complete donor chimerism (CC) over the whole follow-up period. Patients with increasing MC showed a significantly higher (p<0.001) rate of relapse (93.1%) and death (89.7%) in comparison to both those with CC (26.9% relapse, 44.1% dead) or decreasing MC (11.1% relapse, 44.4% dead). The detection of increasing MC preceded relapse by a median of 74 days (range: 5-434) and was significantly related with the absence of chronic graft-versus-host disease. Univariate and multivariate analysis confirmed that chimerism was the most significant variable involved in relapse, leukemia-free survival and overall survival after SCT.

INTERPRETATION AND CONCLUSIONS

These results demonstrate that sequential determination of chimerism allows the prediction of relapse and death after SCT for acute leukemia. The interval between detection of increasing MC and relapse may permit timely implementation of therapeutic measures.

Febrile pancytopenia and psychosis revealing pernicious anemia

The rare case of a 42-year-old woman of African origin presenting with persecution mania leading to admission to a psychiatric hospital is reported. The outcome was rapidly marked by febrile pancytopenia and ataxia leading to the diagnosis of pernicious anemia. Although the hematologic abnormalities and mania were corrected within 2 weeks under vitamin therapy, neural improvement was slower as observed classically. The literature regarding pancytopenia and psychiatric presentations is briefly reviewed, suggesting that vitamin B(12) deficiency may induce paranoid delusion.

5' CpG island hypermethylation is associated with transcriptional silencing of the p21(CIP1/WAF1/SDI1) gene and confers poor prognosis in acute lymphoblastic leukemia

The p21 is a downstream effector of p53/p73 and belongs to the CIP/KIP family of cyclin-dependent kinase inhibitors (CDKIs). It is, therefore, a potential tumor suppressor gene and probably plays an important role in tumor development. Moreover, reduced expression of p21 has been reported to have prognostic value in several human malignancies. In contrast with other CDKIs, mutational inactivation of p21 is infrequent, but gene inactivation by an alternative mechanism seems to be the general pathway. In this study, we analyzed the methylation status of the p21 promoter region using semiquantitative polymerase chain reaction in 124 patients with acute lymphoblastic leukemia (ALL). We observed p21 hypermethylation in bone marrow cells from 41% (51 of 124) of ALL patients. Hypermethylation within promoter strongly correlated with decreased p21 messenger RNA expression in tumoral cells. Clinical, molecular, and laboratory features and complete remission rate did not differ significantly between hypermethylated and normally methylated patients. Estimated disease-free survival (DFS) and overall survival at 7 and 9 years, respectively, were 59% and 65% for healthy patients and 6% and 8% for hypermethylated patients (P =.00001 and P =.006). Multivariate analysis of potential prognostic factors demonstrated that p21 methylation status was an independent prognostic factor in predicting DFS (P =.0001). Our results indicate that the p21 gene is subject to methylation regulation at the transcription level in ALL and seems to be an important factor in predicting the clinical outcome of these patients.

[Relation of the cerebellum with cognitive function: neuroanatomical, clinical and neuroimaging evidence]

INTRODUCTION

Published studies in the last decades, employing a variety of methodologies, suggest that the cerebellum function is not only limited to motor control but also has an important role in cognition and emotion.

DEVELOPMENT

In the present paper we review the main neuroanatomical and functional neuroimaging studies supporting the idea that the cerebellum has a role in non motor behavior. On the other hand, we expound the results of the neuropsychological studies of patients with cerebellar lesions. The deficits showed after cerebellar lesions include disturbances in executive functions, learning, memory, attention, visuo-spatial functions, language and personality change. Some studies propose that the cerebellum, through its afferent and efferent circuits with the cerebrum, perform a global function capable to influencing motor behavior, in cognitive functions and in emotion. A fault in this function would cause the behavioral deficits shown in patients with cerebellar lesions.

CONCLUSION

The evidence available in the anatomical, functional and clinical studies support the conclusion that the cerebellum participates not only in motor functions, but also in cognitive functions and in emotion.

E1A3 as a unique, naturally occurring BCR-ABL transcript in an indolent case of chronic myeloid leukaemia

A woman with Ph-positive chronic myeloid leukaemia (CML) with an atypical e1a3 BCR-ABL hybrid gene is described. To our knowledge, this is the first report of this transcript type as a unique naturally occurring BCR-ABL fusion in a CML patient. This case was characterized by a low leucocyte count and a very indolent course without treatment. Because the deletion of ABL exon 2 sequences results in deletion of an essential part of the ABL SH3 domain, our case suggests that this ABL SH3 domain is not absolutely necessary for efficient induction of a myeloproliferative disease in the context of BCR-ABL/p190.

Multisystem sarcoidosis and carcinoma of the uterine cervix: an unusual association

Sarcoidosis malignancy syndrome is a rare phenomenon which remains controversial. We report here the case of a 46-year-old woman presenting with multisystem sarcoidosis 12 months after the completion of combined treatment for stage III squamous cell carcinoma of the uterine cervix; at the time she was still in complete remission of the tumor. The outcome was rapidly favorable under oral corticosteroid therapy. The time interval between the two illnesses as well as patient's age strongly suggest a relationship. Possible pathophysiologic mechanisms and the literature regarding uterine tumors are briefly reviewed.

Angiosarcoma variant of Kasabach-Merritt syndrome

Kasabach-Merritt syndrome is characterized by the occurrence of disseminated intravascular coagulation (DIC) usually caused by benign angiomatous tumours. Here we report the case of a 70-year-old man in whom DIC revealed a locally advanced hepatic tumour. Although DIC resolved with heparin, antithrombin III, fresh frozen plasma and corticosteroids, the patient died from haemoperitoneum following a fall, 3 months after the initial observation. Histopathological examination by autopsy allowed the diagnosis of hepatic angiosarcoma. The physiopathogenic mechanisms and treatment options are discussed.

Hypermethylation of the calcitonin gene in acute lymphoblastic leukaemia is associated with unfavourable clinical outcome

We analysed calcitonin (CALC1) gene hypermethylation using semiquantitative differential polymerase chain reaction in 105 patients with adult (n = 49) and childhood (n = 56) acute lymphoblastic leukaemia (ALL), and studied the association of CALC1 hypermethylation with clinical presentation features and disease outcome. We also investigated the possible relationship between CALC1 methylation status and expression of the cell cycle inhibitor gene p57KIP2. We observed CALC1 hypermethylation in bone marrow cells from 43% (45 out of 105) of ALL patients. Clinical, molecular and laboratory features did not differ significantly between hypermethylated and hypomethylated patients, only T-cell lineage was associated with hypermethylation (14% vs. 47%, P = 0025). Complete remission rate was similar in both groups although hypermethylated patients had a higher relapse rate (68% vs. 19%, P < 0.00001) and mortality rate (55% vs. 36%, P = 0.06) than hypomethylated patients. Estimated disease-free survival (DFS) at 6 years was 66.1% for hypomethylated patients and 5.3% for hypermethylated patients (P < 0,00001). Multivariate analysis from potential prognostic factors demonstrated that CALC1 methylation status was an independent prognostic factor in predicting DFS (P = 0.0001). Separate analysis of adult and childhood ALL patients showed similar results to the whole series. In addition, hypermethylated patients showed downregulation of p57KIP2 expression. Our results suggest that CALC1 gene hypermethylation is associated with an enhanced risk of relapse independently of known poor-prognostic factors and we describe, for the first time, a possible implication of the p57KIP2 gene in the genesis and prognosis of ALL.

The Role of Copper Suppression as an Antiangiogenic Strategy in Head and Neck Squamous Cell Carcinoma

OBJECTIVE

To determine whether tetrathiomolybdate (TM), a powerful chelator of copper, is capable of lowering the body stores of copper and suppressing the growth of head and neck squamous cell carcinoma in an orthotopic murine model.

STUDY DESIGN

In vivo, murine model.

METHODS

Twelve 8-week-old male C3H/HeJ mice were assigned to either a TM treatment group (n = 7) or a control group (n = 5). Serum samples were obtained from a single mouse in each group to measure the level of ceruloplasmin as a surrogate marker of total body copper on days 0, 4, and 7. Mice in both groups received a floor-of-mouth injection of 1.5 x 105 SCC VII/SF cells. After 7 to 10 days of tumor growth the treatment group received fresh water daily, to which TM was added to achieve an oral intake of 50 mg per mouse. The control group received only fresh drinking water daily. Tumor volume measurements were obtained every other day. Microvessel density counts were assessed in the tumors by Factor VIII analysis.

RESULTS

Measurable tumor growth was achieved in 100% of the mice by the tenth day. Total body copper was reduced by 28% from baseline levels in mice in the treatment group. The difference in mean tumor volume in the control group was 4.7 times greater than the TM-treated group at the completion of treatment (3004 mm3 and 633mm3, respectively). This accounted for an overall suppression rate of 79% (P =.008; two-tailed Student t test). In addition, microvessel density was reduced by 50% in the TM-treated group.

CONCLUSION

In this initial study, the first of its kind in head and neck squamous cell carcinoma, we have demonstrated the ability of TM to significantly suppress both the growth of squamous cell carcinoma and tumor vascularity in this orthotopic murine model, suggesting its potential for efficacy in the treatment of this disease in humans.

Detection of genetic diversity among bovine immunodeficiency virus population by single-strand conformation polymorphism analysis

Serial virus specimens rescued from rabbits, experimentally infected with bovine immunodeficiency (BIV) strain R29, were monitored for changes in quasispecies population, using the single-strand conformation polymorphism (SSCP) analysis. The generation of characteristic SSCP patterns enables the rapid differentiation of BIV variants derived from the conserved part on the env region of the BIV genome, reducing the need for expensive and time-consuming direct sequencing analyses. Our results showed genetic polymorphism among a number of sampled BIV population in experimentally infected rabbits. At least three SSCP patterns (BIV quasispecies) were detected. The SSCP analysis allows for an easy, sensitive, and rapid screening of genetic variants of the virus and the assessment of variation at a number of tissue target sites. These variations may relate to cell-type targets and/or disease progression, and could be significant to our understanding of lentiviral pathogenesis.

Correlation of atrophy measures on MRI with neuropsychological sequelae in children and adolescents with traumatic brain injury

To examine the relationship between neuropsychological sequelae and atrophy parameters from magnetic resonance imaging (MRI) following paediatric moderate-to-severe traumatic brain injury (TBI), 19 head injured children and adolescents were studied at least 6 years after injury. Three-dimensional MRI scans were obtained. A semi-automatic computerized method was used to estimate ventricular volumes and the corpus callosum area. Tests of intellectual, memory, visuospatial, frontal lobe, and motor speed functioning were administered to all patients and to 19 matched normal control subjects. Patients' performance significantly differed from controls in general intellectual function, visual memory, visuospatial and frontal lobe tests. The corpus callosum area correlated strongly with several measures involving processing speed and visuospatial function. Ventricular enlargement was less related to neuropsychological outcome. In conclusion, quantitative measurement of the corpus callosum on MRI reflects neuropsychological outcome better than ventricular dilation in paediatric patients.