Chromosome 20 deletions in myelodysplastic syndromes and Philadelphia-chromosome-negative myeloproliferative disorders: characterization by molecular cytogenetics of commonly deleted and retained regions

Deletion of the long arm of chromosome 20 is a recurrent abnormality observed in myelodysplastic syndromes (MDS) and in Philadelphia-chromosome-negative myeloproliferative disorders (MPD). Our objective was to characterize the deletion size among 38 MDS and MPD patients using fluorescence in situ hybridization (FISH) with bacterial artificial chromosome (BAC) probes and to define commonly deleted and retained regions on chromosome 20. Patients were distributed in three groups according to the World Health Organization classification: MDS (22 patients), MPD (12 patients) and myelodysplastic/myeloproliferative diseases (four patients). FISH with centromeric, subtelomeric, and unique sequence probes was performed to characterize the deletion whereas its size was delineated using BAC clones. All 38 deletions were found to be interstitial. A commonly deleted region was identified for each of the three groups; it varied from 6.62 to 10.4 Mb and showed considerable overlapping. Two commonly retained regions (CRR), also showing overlapping, were identified in all three groups, one in the centromeric region, the other in the telomeric region. The deletion size is highly variable, with no apparent recurrent breakpoint. The deletion may result in the loss of one or several tumor suppressor genes but the target genes remain unknown. Loss of genes plays an important part in the myeloid leukemic process associated with del(20q). However, genes located in the retained chromosomal regions may also play a role in the oncogenetic mechanisms. Nathalie Douet-Guilbert and Audrey Basinko contributed equally to the study.     

Severe acute pancreatitis: advances and insights in assessment of severity and management

The patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Often, there is no correlation between the degree of structural damage to pancreas and clinical manifestation of the disease. The effectiveness of any treatment is related to the ability to predict severity accurately, but there is no ideal predictive system or biochemical marker. Severity assessment is indispensable to the selection of proper initial treatment in the management of acute pancreatitis. The use of multiparametric criteria and the evaluation of severity index permit us to select high-risk patients. Furthermore, contrast-enhanced computed tomographic scanning and contrast-enhanced MRI play an important role in severity assessment. The adoption of multiparametric criteria proposed together with morphological evaluation consents the formulation of a discreetly reliable prognosis on the evolution of the disease a few days from onset.     

Distinguishing visceral leishmaniasis from intolerance to pegylated interferon-alpha in a thalassemic splenectomized patient treated for chronic hepatitis C

A 37-year-old splenectomized man affected by beta-thalassemia and chronic hepatitis, recently treated with pegylated interferon-alpha (Peg-IFN), was admitted because of elevated fever lasting 3 months and unresponsiveness to broad-spectrum antibiotics. Laboratory studies showed white blood cell and platelet counts within the normal range but lower than observed before Peg-IFN treatment and an elevated erythrocyte sedimentation rate. The blood transfusion rate was reported to be increased compared with the period preceding Peg-IFN treatment. A diagnosis of visceral leishmaniasis (VL) was made after Leishmania amastigotes were identified from Giemsa-stained smears of bone marrow aspirates. Cure occurred after liposomal amphotericin B was administered. Symptoms of VL may be difficult to distinguish from the manifestations of Peg-IFN intolerance. We suggest that VL must be suspected in any immunodepressed patient with an unexplained fever and a history of exposure in an endemic area.     

Prognostic significance of peak oxygen consumption ≤ 10 ml/kg/min in heart failure: Context vs. criteria

Background

Both heart failure (HF) treatment and management may distort or enhance the predictive accuracy of low peak oxygen consumption (pVO₂ ≤ 10 ml/kg/min), blurring the identification of specific patients in whom heart transplantation (HT) could make a clinical difference. The aim of this study was to re-evaluate the prognostic significance of pVO₂ ≤ 10 ml/kg/min in systolic HF in light of changes in medical treatment and management.

Methods

Two-year outcomes were compared across the “millennium dawn” (MD) between two HF cohorts with pVO₂ ≤ 10 ml/kg/min and gas exchange ratio > 1.10: 116 patients were recorded between 1994 and 1999 (pre-MD: mean pVO₂ 8.6 ± 1.1 ml/kg/min) and 90 between 2001 and 2008 (post-MD: mean pVO₂ 8.8 ± 1.0 ml/kg/min). Cardiac-related death was considered an event and event censoring was interrupted at 24 months for surviving patients.

Results

Patients across the MD had the same age, NYHA class, left ventricular ejection fraction and pVO₂ (pre-MD: mean pVO₂ 8.6 ± 1.1; post-MD: mean pVO₂ 8.8 ± 1.0 ml/kg/min: NS). Seventy-one patients (34%) died: 51 (44%) in the pre-MD and 20 (22%) in the post-MD group (p < 0.01). The post-MD group showed a better mean 1-year (83% vs. 68%; χ² = 5.17, p = 0.0229) and 2-year survival (77% vs. 56%; χ² = 8.87, p = 0.0029) compared to pre-MD patients.

Conclusions

Two-year outcome of HF patients with pVO₂ ≤ 10 ml/kg/min has significantly improved in the post-MD era, suggesting the HT indication should not rely on a single CPET parameter, rather on a multifactorial clinical approach.     

Mechanism of human Hb switching: a possible role of the kit receptor/miR 221-222 complex

Background

The human hemoglobin switch (HbF→HbA) takes place in the peri/post-natal period. In adult life, however, the residual HbF (<1%) may be partially reactivated by chemical inducers and/or cytokines such as the kit ligand (KL). MicroRNAs (miRs) play a pivotal role in normal hematopoiesis: downmodulation of miR-221/222 stimulates human erythropoietic proliferation through upmodulation of the kit receptor.

Design and Methods

We have explored the possible role of kit/KL in perinatal Hb switching by evaluating: i) the expression levels of both kit and kit ligand on CD34⁺ cells and in plasma isolated from pre-, mid- and full-term cord blood samples; ii) the reactivation of HbF synthesis in KL-treated unilineage erythroid cell cultures; iii) the functional role of miR-221/222 in HbF production.

Results

In perinatal life, kit expression showed a gradual decline directly correlated to the decrease of HbF (from 80–90% to <30%). Moreover, in full-term cord blood erythroid cultures, kit ligand induced a marked increase of HbF (up to 80%) specifically abrogated by addition of the kit inhibitor imatinib, thus reversing the Hb switch. MiR-221/222 expression exhibited rising levels during peri/post-natal development. In functional studies, overexpression of these miRs in cord blood progenitors caused a remarkable decrease in kit expression, erythroblast proliferation and HbF content, whereas their suppression induced opposite effects.

Conclusions

Our studies indicate that human perinatal Hb switching is under control of the kit receptor/miR 221–222 complex. We do not exclude, however, that other mechanisms (i.e. glucocorticoids and the HbF inhibitor BCL11A) may also contribute to the peri/post-natal Hb switch.     

Cystic echinococcosis of the liver and lung treated by radiofrequency thermal ablation： An ex-vivo pilot experimental study in animal models

AIM： To evaluate radiofrequency thermal ablation （RTA） for treatment of cystic echinococcosis in animal models （explanted organs）.
METHODS： Infected livers and lungs from slaughtered animals, 10 bovine and two ovine, were collected. Cysts were photographed, and their volume, cyst content, germinal layer adhesion status, wall calcification and presence of daughter or adjacent cysts were evaluated by ultrasound. Some cysts were treated with RTA at 150 W, 80℃, 7 min. Temperature was monitored inside and outside the cyst. A second needle was placed inside the cyst for pressure stabilization. After treatment, all cysts were sectioned and examined by histology. Cysts were defined as alive if a preserved germinal layer at histology was evident, and as successfully treated if the germinal layer was necrotic.
RESULTS： The subjects of the study were 17 cysts （nine hepatic and eight pulmonary）, who were treated with RTA. Pathology showed 100% success rate in both hepatic （919） and lung cysts （8/8）; immediate volume reduction of at least 65%; layer of host tissue necrosis outside the cyst, with average extension of 0.64 cm for liver and 1.57 cm for lung; and endocyst attached to the pericystium both in hepatic and lung cysts with small and focal de novo endocyst detachment in just 3/9 hepatic cysts.
CONCLUSION： RTA appears to be very effective in killing hydatid cysts of explanted liver and lung. Bile duct and bronchial wall necrosis, persistence of endocyst attached to pericystium, should help avoid or greatly decrease in v/vo post-treatment fistula occurrence and consequent overlapping complications that are common after surgery or percutaneous aspiration, injection and reaspiration. In vivo studies are required to confirm and validate this new therapeutic approach.     

Regulation of transferrin receptor 2 in human cancer cell lines

In a recent study we have explored TfR2 expression in a panel of cancer cell lines and we observed that about 40% of these cell lines clearly express TfR2. Taking advantage of this observation and considering the frequent overexpression of c-Myc in cancer cells we have explored the existence of a possible relationship between c-Myc and TfR2 in these cell lines. Our results provided evidence that TfR2⁺ cell lines express low c-Myc levels and low TfR1 levels, while TfR2^? cell lines express high c-Myc and TfR1 levels. Using the erythroleukemic K562 TfR2⁺ cells as a model, we observed that agents that enhance c-Myc expression, such as iron, determine a decrease of TfR2 expression, while molecules that induce a decreased c-Myc expression, such as the iron chelator desferoxamine or the kinase inhibitor ST 1571, induce an enhanced TfR2 expression. On the other hand, we have evaluated a possible effect of hypoxia and nitric oxide on TfR2 expression in erythroleukemia K526 and hepatoma HepG2 cells, providing evidence that: (i) agents inducing cellular hypoxia, such as CoCl₂, elicited a marked upmodulation of TfR1, but a downmodulation of TfR2 expression; (ii) NO⁺ donors, such as sodium nitroprusside (SNP), induced a moderate decrease of TfR1, associated with a marked decline of TfR2 expression; (iii) NO donors, such as S-Nitroso-N-Acetylpenicillamine (SNAP), induced a clear increase of TfR1, associated with a moderate upmodulation of TfR2 expression. The ensemble of these observations suggests that in cancer cell lines TfR2 expression can be modulated through stimuli similar to those known to act on TfR1 and these findings may have important implications for our understanding of the role of TfR2 in the regulation of iron homeostasis.     

Highly tumorigenic lung cancer CD133+ cells display stem-like features and are spared by cisplatin treatment

The identification of lung tumor-initiating cells and associated markers may be useful for optimization of therapeutic approaches and for predictive and prognostic information in lung cancer patients. CD133, a surface glycoprotein linked to organ-specific stem cells, was described as a marker of cancer-initiating cells in different tumor types. Here, we report that a CD133⁺, epithelial-specific antigen-positive (CD133⁺ESA⁺) population is increased in primary nonsmall cell lung cancer (NSCLC) compared with normal lung tissue and has higher tumorigenic potential in SCID mice and expression of genes involved in stemness, adhesion, motility, and drug efflux than the CD133⁻ counterpart. Cisplatin treatment of lung cancer cells in vitro resulted in enrichment of CD133⁺ fraction both after acute cytotoxic exposure and in cells with stable cisplatin-resistant phenotype. Subpopulations of CD133⁺ABCG2⁺ and CD133⁺CXCR4⁺ cells were spared by in vivo cisplatin treatment of lung tumor xenografts established from primary tumors. A tendency toward shorter progression-free survival was observed in CD133⁺ NSCLC patients treated with platinum-containing regimens. Our results indicate that chemoresistant populations with highly tumorigenic and stem-like features are present in lung tumors. The molecular features of these cells may provide the rationale for more specific therapeutic targeting and the definition of predictive factors in clinical management of this lethal disease.     

The direct effects of tacrolimus and cyclosporin A on isolated human islets: A functional, survival and gene expression study

The use of immunosuppressive drugs in transplanted patients is associated with the development of diabetes, possibly due to β-cell toxicity. To better understand the mechanisms leading to post-transplant diabetes, we investigated the actions of prolonged exposure of isolated human islets to therapeutical levels of tacrolimus (Tac) or cyclosporin A (CsA). Islets were isolated from the pancreas of multiorgan donors by enzymatic digestion and density gradient centrifugation. Functional, survival and molecular studies were then performed after 4 days of incubation with therapeutical concentrations of Tac or CsA. Glucose-induced insulin secretion was significantly decreased in Tac, but not in CsA exposed islets, which was associated with a reduction of the amount of insulin granules as shown by electron microscopy. The percentage of apoptotic β-cells was higher in Tac than CsA exposed islets. Microarray experiments followed by Gene Set Enrichment Analysis revealed that gene expression was more markedly affected upon Tac treatment. In conclusion, Tac and CsA affect features of beta-cell differently, with several changes occurring at the molecular level.