Tiam1 regulates proliferation, invasion, and differentiation in neuroblastoma through the Tiam1/Rac1 signaling pathway.

Neuroblastoma is the most common extracranial solid tumor in children. The purpose of the present study is to detect the prognostic role and potential therapeutic efficacy of the T lymphoma invasion and metastasis 1 (Tiam1) in neuroblastoma. The overexpression of Tiam1 protein is frequently observed in neuroblastoma. Tiam1 expression is closely associated with adverse prognosis of neuroblastoma and risk group classification. Knockdown of TIAM1 by lentivirus expressing short hairpin RNA against TIAM1 (sh-TIAM1) inhibited the proliferation, invasion and cell-cycle progression, and promoted apoptosis of the neuroblastoma cell lines SH-SY5Y and SK-N-AS. Additionally, downregulation of the differentiation-related protein expression and decreased Rac1 expression was observed in the sh-TIAM1-transfected SH-SY5Y cells. In vivo, nude mice bearing TIAM1 knockdown SH-SY5Y cells showed improved overall survival and tumor growth suppression. The results demonstrate that inhibition of Tiam1 expression is a potential strategy for targeted therapy in neuroblastoma.

Prolonged thrombocytopenia in a neonate with Noonan syndrome: a case report.

We report a case of a Chinese neonate who was diagnosed with Noonan syndrome and had persistent, self-limited thrombocytopenia. The neonate was admitted to the Neonatology Department 20 minutes after birth because of respiratory distress. From birth until 2 months of age, platelet values fluctuated between approximately 6 and 30 × 109/L. There was no intracranial hemorrhage. However, the child had a transient hypocalcemic seizure and fever. We excluded thrombocytopenia caused by perinatal asphyxia, immune thrombocytopenia, fetomaternal alloimmune thrombocytopenia, juvenile myelomonocytic leukemia, and chromosome 13, 18, and 21 trisomy syndromes. Despite treatment with anti-infective agents and transfusion of platelets and immunoglobulin, the platelet count did not return to the normal range. Genetic testing confirmed a PTPN11 gene mutation, which led to the diagnosis of Noonan syndrome. At 3 months of age, the platelet count gradually increased without intervention and returned to the normal range by 6 months. We speculate that the thrombocytopenia in this case was closely related to Noonan syndrome.

Wnt/ß­catenin inhibition reverses multidrug resistance in pediatric acute lymphoblastic leukemia.

Although ~80% of newly diagnosed pediatric patients with acute lymphoblastic leukemia (ALL) become disease­free following appropriate treatment, relapses frequently occur, with dismal prognosis. Therefore, it is urgent to develop novel therapeutic modalities. Resistance to chemotherapy is a major obstacle for the treatment of relapsed ALL. It has been indicated that Wnt pathway is potentially associated with leukemia recurrence. In the current study, a vincristine (VCR)­resistant variant of the human ALL cell line BALL­1 (BALL­1/VCR) that also had relatively specific resistance to both doxorubicin and etoposide was generated. Over­activation of the Wnt/ß­catenin signaling pathway was observed in BALL­1/VCR cells, whereas Dickkopf­related protein 1 selectively suppressed the Wnt signaling pathway and sensitized the response of BALL­1/VCR to anticancer agents. In addition, prednisolone exposure in combination with Wnt inhibition restored chemo­sensitivity in relapsed ALL blasts. Since the resistance of BALL­1/VCR cells is potentially attributed to the overexpression of MDR­associated protein 1 (MRP1), the development of drug resistance in relapsed ALL may associated with the overexpression of MRP1 and P­glycoprotein. The results of this study demonstrated that, as a potential candidate to mimic relapsed ALL, BALL­1/VCR could be used in further research, while Wnt­inhibition may become a promising therapeutic approach for treating ALL.

Retrospective analysis of rhabdomyosarcoma (RMS) in children in a single center.

BACKGROUND: This study was conducted to explore the influence of clinical features of rhabdomyosarcoma (RMS) and a refined therapeutic protocol on the therapeutic efficacy and prognosis in children in the past five years. METHODS: Forty children diagnosed with RMS were retrospectively studied, using a version of the therapeutic protocol refined by Shanghai Children's Medical Center (version 2009.9.1). The patients' demographic characteristics, clinical manifestations, pathological features, therapeutic efficacy, and prognosis were analyzed. RESULTS: Of the 40 children, 17 abandoned treatment. Of the remaining 23 cases, two children were rated as low risk, 12 as medium risk, and nine as high risk, and all received treatment. Patients in the low and medium-risk groups had better prognosis than those in the high-risk group, and treated patients had higher survival rates and longer survival than untreated patients. CONCLUSION: Children with RMS should be treated positively. Combined treatment shows better therapeutic efficacy and prognosis. The refined therapeutic protocol seems more effective than the standard treatment, with a significant impact on long-term RMS prognosis.

Indirubin Increases CD4+CD25+Foxp3+ Regulatory T Cells to Prevent Immune Thrombocytopenia in Mice.

Indirubin, a traditional Chinese medicine, is used to treat autoimmune diseases in clinics. However, the effects of indirubin on the immunosuppressive CD4+CD25+Foxp3+ regulatory T cells (Treg) have not been addressed. Thus, we aimed to investigate the effects of indirubin on CD4+CD25+Treg cells in immune thrombocytopenia (ITP) CBA mice, which were established by immunization with Wistar rat platelets. 50 mg/kg indirubin treatment daily for 4 weeks significantly decreased anti-platelet antibody production and prevented the decrease of platelets caused by immunization in ITP mice. Consistently, indirubin significantly enhanced the percentage and cell number of CD4+CD25+Foxp3+Treg cells in the peripheral blood, spleen and lymph nodes. We also observed a significant increase of the frequency and cell number of CD4+CD25+Foxp3+Treg cells in the thymus upon indirubin treatment. Furthermore, CD4+CD25+Treg cells from indirubin-treated mice showed similar immunosuppression on T effector cells as compared to those from control mice. Altogether, indirubin ameliorates ITP by enhancing CD4+CD25+Foxp3+Treg cell level with preserving immunosuppressive function.

Upregulation of AIOLOS induces apoptosis and enhances etoposide chemosensitivity in Jurkat leukemia cells.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder of immature hematopoietic precursors committed to T-cell lineage. T-ALL accounts for ~15% of pediatric ALL cases and is prone to early relapse. With new and improved treatment protocols, the prognosis of T-ALL has improved particularly in children; however, the outcome of relapsed T-ALL cases remains poor. The AIOLOS gene is necessary to control lymphocyte differentiation and may be a potential target of T-ALL therapy. In the present study, Jurkat cells were divided into three groups: untransfected (UT) control, lentiviral vector control (Lenti-Mock) and AIOLOS-overexpressing (Lenti-AIOLOS) groups. Lenti-AIOLOS Jurkat cells were constructed by lentiviral transduction; cell cycle analysis, apoptosis and cytotoxicity assays were then performed to evaluate the effects of AIOLOS on cell cycle distribution, apoptosis and cell chemosensitivity to etoposide of Jurkat cells in vitro. Moreover, the expression levels of genes associated with apoptosis and cell cycle were investigated by quantitative reverse transcription-polymerase chain reaction. Results showed that the percentage of Jurkat cells in the G0/G1 phase increased from 71.5 (UT) to 85.4% (Lenti-AIOLOS; P<0.05), yet the percentage of cells in the S-phase decreased from 15.1 (UT) to 11.6% (Lenti­AIOLOS; P<0.05). The percentage of total apoptotic cells was significantly increased in the AIOLOS-transfected Jurkat cells (21.93%) compared with this percentage in the Lenti-Mock (13.35%) or the UT group (13.30%; P<0.05). Consistent with these results, AIOLOS overexpression induced P21 and P27 upregulation and CCND3 and SKP2 downregulation. Furthermore, AIOLOS overexpression synergistically increased the cytotoxic effects of etoposide and downregulated NF-κB expression. Our findings revealed that lentivirus-mediated AIOLOS overexpression in Jurkat cells induced cell apoptosis, arrested the cell cycle at the G0/G1 phase, and synergistically increased the sensitivity of Jurkat cells to etoposide by inhibiting NF-κB activity.

Two pairs of monozygotic twins with concordant acute lymphoblastic leukemia (ALL): case report.

The occurrence of leukemia in twins is rare but has a crucial implication in the genetic research of leukemia. This report presents 2 pairs of monozygotic twins with precursor B-cell acute lymphoblastic leukemia. Mixed lineage leukemia (MLL)-AF4 fusion genes were found in the twin sisters. This study is the first to report on infant ALL harboring the 46,XY, -4, +10, -13, del(14)(q24), -15, +2mar[4 cells] complex chromosome abnormality. Our report showed that the unified cytogenetic features in monozygotic twins and MLL-AF4 fusion gene may be necessary but insufficient for the clinical development and prognosis of identical twins with leukemia.

Tolerogenic dendritic cells generated with IL-10/TGFß1 relieve immune thrombocytopenia in mice.

Activated platelet-specific autoreactive T cells play a key role in the pathophysiology of immune thrombocytopenia (ITP). Tolerogenic dendritic cells (tDCs) that induce T cells tolerance to platelet autoantigens are a promising strategy for specific cellular therapy in autoimmunity. In this study, we generated three kinds of GPIIb-specific tDCs stimulated by IL-10 (10-DCs), TGFß1 (T-DCs), or a combination of IL-10 and TGFß1 (10T-DCs), respectively, and compared their phenotypes and biological function. Our data demonstrate that GPIIb-specific 10T-DCs induced the weakest memory lymphocytes responses and exhibited stronger tolerogenic potential than others, making them suitable for tolerance inducing therapies. Furthermore, in ITP mice model we found that 10T-DCs abrogated the decrease in platelet counts and the increase in serum IFN-γ level, confirming the in vivo tolerogenic potential of 10T-DCs. Our study provides a promising strategy for ITP intervention in the clinic by the induction of platelet-specific immune tolerance.

Differential microRNA expression in childhood B-cell precursor acute lymphoblastic leukemia.

MiRNAs play important roles in the development of both hematopoiesis and leukemogenesis. The analysis of differential microRNA expression profiles may be a powerful tool to allow us insight on the mechanisms of childhood B-cell precursor acute lymphoblastic leukemia (pre-B-ALL). The present study provides an informative profile of the expression of miRNAs in pre-B-ALL using two independent and quantitative methods: miRNA chip and qRT-PCR of mature miRNA from 40 newly diagnosed pre-B-ALL children. Additionally, putative hematopoiesis-specific target genes were analyzed with informatics technique. Both approaches showed that miR-222, miR-339, and miR-142-3p were dramatically overexpressed in pre-B-ALL patients, and downregulation of hsa-miR-451 and hsa-miR-373* was confirmed. The results of this study offer a comprehensive and quantitative profile of miRNA expression in pre-B-ALL and their healthy counterpart, suggesting that miRNAs could play a primary role in the disease itself.

[In vitro expansion and function of cord blood megakaryocyte].

OBJECTIVE: Cord blood (CB) provides a rich source of stem cells for transplantation. CB transplantation has been used widely after myeloablative therapy. One major disadvantage of CB transplantation is delayed platelet engraftment. The aim of this study was to hasten platelet engraftment by investigating the ability of different hematopoietic growth factor combinations to generate large numbers of megakaryocyte (Mk) from CB and by evaluating the biologic characteristics and function of the expanded Mk. METHODS: CB samples were obtained at the end of normal full-term deliveries with informed consent. Mononuclear cells (MNCs) were isolated from CB using Ficoll density centrifugation. MNC population was positively selected for CD(34) expression by magnetic cell sorting (MACS). CD(34)(+) cells were cultured in serum-free and stroma-free medium containing the following two different cytokine combinations: thrombopoietin (TPO) + stem cell factor (SCF) + interleukin (IL) -3 + IL-6 and TPO + SCF. Cultures were characterized after 3, 7, 10 and 14 days by flow cytometry, colony forming unit-megakaryocyte (CFU-Mk) and maturation evaluation (Mk ploidy). The expanded Mk function was examined by the platelet activation in vitro and severe combined immunodiffiency (SCID) mice transplantation in vivo. RESULTS: Different results were observed with different culture conditions. With the first cytokine combination optimal expansion of CD(41)(+) cells was observed on day 10, but the optimal expansion of Mk progenitors (CD(34)(+)CD(41)(+)) was observed on day 7, with a median 121 and 44-fold increase at the starting cell dose. This result was also proven by CFU-Mk. The largest numbers of CFU-Mk were also observed on day 7. The degree of maturation of Mk cells also increased as suggested by DNA content of CD(41)(+) cells, which means that CD(34)(+) cells cultured for 3 - 7 days were richer in primitive Mks, while those cultured for 10 - 14 days had greater numbers of more differentiated Mks. For the second cytokine combination, CD(41)(+) and CD(34)(+)CD(41)(+) cells were fewer than the first one, but it produced 36 and 85-fold CD(34)(+)CD(41)(+) and CD(41)(+) respectively on day 7. Platelet activation test confirmed that the expanded Mks had normal function. Therefore, the expanded Mks could be transplanted into the SCID mice bone marrow and produce human platelet in the peripheral blood of the mice. CONCLUSION: Ex vivo expanded Mk might facilitate CB transplantation and help shorten the period of post-transplant thrombocytopenia.