Cytotoxic activity of the casein kinase 2 inhibitor CX-4945 against T-cell acute lymphoblastic leukemia: targeting the unfolded protein response signaling.

Constitutively active casein kinase 2 (CK2) signaling is a common feature of T-cell acute lymphoblastic leukemia (T-ALL). CK2 phosphorylates PTEN (phosphatase and tensin homolog) tumor suppressor, resulting in PTEN stabilization and functional inactivation. Downregulation of PTEN activity has an impact on PI3K/Akt/mTOR signaling, which is of fundamental importance for T-ALL cell survival. These observations lend compelling weight to the application of CK2 inhibitors in the therapy of T-ALL. Here, we have analyzed the therapeutic potential of CX-4945-a novel, highly specific, orally available, ATP-competitive inhibitor of CK2α. We show that CX-4945 treatment induced apoptosis in T-ALL cell lines and patient T lymphoblasts. CX-4945 downregulated PI3K/Akt/mTOR signaling in leukemic cells. Notably, CX-4945 affected the unfolded protein response (UPR), as demonstrated by a significant decrease in the levels of the main UPR regulator GRP78/BIP, and led to apoptosis via upregulation of the ER stress/UPR cell death mediators IRE1α and CHOP. In vivo administration of CX-4945 to a subcutaneous xenotransplant model of human T-ALL significantly delayed tumor growth. Our findings indicate that modulation of the ER stress/UPR signaling through CK2 inhibition could be exploited for inducing apoptosis in T-ALL cells and that CX-4945 may be an efficient treatment for those T-ALLs displaying upregulation of CK2α/PI3K/Akt/mTOR signaling.

Activity of the pan-class I phosphoinositide 3-kinase inhibitor NVP-BKM120 in T-cell acute lymphoblastic leukemia.

Constitutively active phosphoinositide 3-kinase (PI3K) signaling is a common feature of T-cell acute lymphoblastic leukemia (T-ALL), where it upregulates cell proliferation, survival and drug resistance. These observations lend compelling weight to the application of PI3K inhibitors in the therapy of T-ALL. Here, we have analyzed the therapeutic potential of the pan-PI3K inhibitor NVP-BKM120 (BKM120), an orally bioavailable 2,6-dimorpholino pyrimidine derivative, which has entered clinical trials for solid tumors, on both T-ALL cell lines and patient samples. BKM120 treatment resulted in G2/M phase cell cycle arrest and apoptosis, being cytotoxic to a panel of T-ALL cell lines and patient T lymphoblasts, and promoting a dose- and time-dependent dephosphorylation of Akt and S6RP. BKM120 maintained its pro-apoptotic activity against Jurkat cells even when cocultured with MS-5 stromal cells, which mimic the bone marrow microenvironment. Remarkably, BKM120 synergized with chemotherapeutic agents currently used for treating T-ALL patients. Moreover, in vivo administration of BKM120 to a subcutaneous xenotransplant model of human T-ALL significantly delayed tumor growth, thus prolonging survival time. Taken together, our findings indicate that BKM120, either alone or in combination with chemotherapeutic drugs, may be an efficient treatment for T-ALLs that have aberrant upregulation of the PI3K signaling pathway.

Ongoing outbreak of visceral leishmaniasis in Bologna Province, Italy, November 2012 to May 2013.

An increased number of autochthonous visceral leishmaniasis (VL) cases has recently been reported in Bologna Province in northern Italy. Over six months from November 2012 to May 2013, 14 cases occurred, whereas the average number of cases per year was 2.6 (range: 0-8) in 2008 to 2012. VL was diagnosed in a median of 40 days (range: 15-120) from disease onset. This delay in diagnosis shows the need for heightened awareness of clinicians for autochthonous VL in Europe.

Metachronous bilateral ovarian teratoma: a germ-line familial disorder and review of surgical management options.

BACKGROUND: Germ cell tumors in females are uncommon, and bilateral metachronous ovarian teratoma is even exceptional, with sporadic cases described in the literature. CASE: We report on a girl in whom a metachronous ovarian teratoma occurred 6 years after the first. The simultaneous onset of germ-line anomalies in other members of the family supports the existence of genetic or environmental factors conferring susceptibility to germ cell lesions. SUMMARY AND CONCLUSION: The case here illustrated reminds the issue of the appropriate follow-up of these patients and of their families.

Cytotoxic activity of the novel Akt inhibitor, MK-2206, in T-cell acute lymphoblastic leukemia.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder arising from T-cell progenitors. T-ALL accounts for 15% of newly diagnosed ALL cases in children and 25% in adults. Although the prognosis of T-ALL has improved, due to the use of polychemotherapy schemes, the outcome of relapsed/chemoresistant T-ALL cases is still poor. A signaling pathway that is frequently upregulated in T-ALL, is the phosphatidylinositol 3-kinase/Akt/mTOR network. To explore whether Akt could represent a target for therapeutic intervention in T-ALL, we evaluated the effects of the novel allosteric Akt inhibitor, MK-2206, on a panel of human T-ALL cell lines and primary cells from T-ALL patients. MK-2206 decreased T-ALL cell line viability by blocking leukemic cells in the G(0)/G(1) phase of the cell cycle and inducing apoptosis. MK-2206 also induced autophagy, as demonstrated by an increase in the 14-kDa form of LC3A/B. Western blotting analysis documented a concentration-dependent dephosphorylation of Akt and its downstream targets, GSK-3α/ß and FOXO3A, in response to MK-2206. MK-2206 was cytotoxic to primary T-ALL cells and induced apoptosis in a T-ALL patient cell subset (CD34(+)/CD4(-)/CD7(-)), which is enriched in leukemia-initiating cells. Taken together, our findings indicate that Akt inhibition may represent a potential therapeutic strategy in T-ALL.

Idiopathic pulmonary haemosiderosis in a child with Down's syndrome: case report and review of the literature.

We report the case of a female child with Down's syndrome affected by idiopathic pulmonary haemosiderosis (IPH), who was successfully treated with hydroxychloroquine. First-line conventional treatment of IPH is traditionally based on systemic corticosteroids; however, many steroid-sparing agents are being increasingly used as adjuncts to corticosteroids in children with recurrent or refractory bleeding. The use of these drugs is particularly promising for maintenance treatment, because it tends to avoid the adverse effects of long-term corticosteroids.

AMP-dependent kinase/mammalian target of rapamycin complex 1 signaling in T-cell acute lymphoblastic leukemia: therapeutic implications.

The mammalian target of rapamycin (mTOR) serine/threonine kinase is the catalytic subunit of two multi-protein complexes, referred to as mTORC1 and mTORC2. Signaling downstream of mTORC1 has a critical role in leukemic cell biology by controlling mRNA translation of genes involved in both cell survival and proliferation. mTORC1 activity can be downmodulated by upregulating the liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) pathway. Here, we have explored the therapeutic potential of the anti-diabetic drug, metformin (an LKB1/AMPK activator), against both T-cell acute lymphoblastic leukemia (T-ALL) cell lines and primary samples from T-ALL patients displaying mTORC1 activation. Metformin affected T-ALL cell viability by inducing autophagy and apoptosis. However, it was much less toxic against proliferating CD4(+) T-lymphocytes from healthy donors. Western blot analysis demonstrated dephosphorylation of mTORC1 downstream targets. Unlike rapamycin, we found a marked inhibition of mRNA translation in T-ALL cells treated with metformin. Remarkably, metformin targeted the side population of T-ALL cell lines as well as a putative leukemia-initiating cell subpopulation (CD34(+)/CD7(-)/CD4(-)) in patient samples. In conclusion, metformin displayed a remarkable anti-leukemic activity, which emphasizes future development of LKB1/AMPK activators as clinical candidates for therapy in T-ALL.

Targeted inhibition of mTORC1 and mTORC2 by active-site mTOR inhibitors has cytotoxic effects in T-cell acute lymphoblastic leukemia.

The mammalian Target Of Rapamycin (mTOR) serine/threonine kinase belongs to two multi-protein complexes, referred to as mTORC1 and mTORC2. mTOR-generated signals have critical roles in leukemic cell biology by controlling mRNA translation of genes that promote proliferation and survival. However, allosteric inhibition of mTORC1 by rapamycin has only modest effects in T-cell acute lymphoblastic leukemia (T-ALL). Recently, ATP-competitive inhibitors specific for the mTOR kinase active site have been developed. In this study, we have explored the therapeutic potential of active-site mTOR inhibitors against both T-ALL cell lines and primary samples from T-ALL patients displaying activation of mTORC1 and mTORC2. The inhibitors affected T-ALL cell viability by inducing cell-cycle arrest in G(0)/G(1) phase, apoptosis and autophagy. Western blot analysis demonstrated a Ser 473 Akt dephosphorylation (indicative of mTORC2 inhibition) and a dephosphorylation of mTORC1 downstream targets. Unlike rapamycin, we found a marked inhibition of mRNA translation in T-ALL cell lines treated with active-site mTOR inhibitors. The inhibitors strongly synergized with both vincristine and the Bcl-2 inhibitor, ABT-263. Remarkably, the drugs targeted a putative leukemia-initiating cell sub-population (CD34(+)/CD7(-)/CD4(-)) in patient samples. In conclusion, the inhibitors displayed remarkable anti-leukemic activity, which emphasizes their future development as clinical candidates for therapy in T-ALL.

Acute liver failure associated with a prolonged course of acetaminophen at recommended dosages in paediatric age.

Acetaminophen is considered as a safe analgesic and antipyretic drug in paediatric age. The main problem in the use of acetaminophen is acute liver failure after an overdose or an acute intoxication. We report a case of fulminant liver failure and spontaneous recovery in a patient treated with a prolonged course of acetaminophen at recommended dosages.

Phase I study of high-dose thiotepa with busulfan, etoposide, and autologous stem cell support in children with disseminated solid tumors.

BACKGROUND: The aim of this phase I study was to define the maximum tolerated dose (MTD) of thiotepa (TT), administered with busulfan (BU) 480 mg/m(2) and etoposide 2,400 mg/m(2), followed by autologous bone marrow transplantation (ABMT) or peripheral blood stem cell transplantation (APBSCT) support in children with solid tumors either disseminated at diagnosis or after relapse. PROCEDURE: Nineteen patients, between 2 and 16 years of age, received a high-dose chemotherapy regimen including escalating doses of TT starting from 150 mg/m(2). Subsequent dose escalation was determined by a modified Fibonacci scheme. Whenever one patient at one dosage level showed a grade III or grade IV reversible toxicity, additional patients were admitted (one by one) up to a maximum number of 6. Upon observing grade III or IV reversible toxicity in two or more systems, in 3 of the 6 patients, no further escalation was performed, and the corresponding dosage was taken as the MTD. WHO criteria were adopted to assess grade of toxicity. RESULTS: All patients had hematological recovery; and neutrophils and platelet engraftment were observed after median times of 12 and 29 days from stem cell infusion, respectively. The MTD of TT was determined to be 750 mg/ m(2). At this level, 3 of 6 patients experienced grade III mucositis and/or grade III gastrointestinal toxicity. No patient died of treatment-related toxicity. CONCLUSIONS: A dose of 750 mg/m(2) TT is the MTD when it is associated with BU 480 mg/m(2) and etoposide 2, 400 mg/m(2). This ablative regimen represents a feasible and tolerable combination for high-dose chemotherapy followed by hematopoietic stem cell rescue (HSCR). Phase II studies in children with poor-prognosis solid tumors are required to evaluate the effectiveness of this treatment.

G-CSF-primed peripheral blood progenitor cells (PBPC) support in high-risk Ewing sarcoma of childhood.

Since 1993 pediatric patients affected by high-risk Ewing sarcoma for the presence at onset of a large pelvic mass and/or metastatic disease, were enrolled in a national pilot study comprehensive, finally, of a high-dose chemotherapy (HDCT) procedure with hemopoietic stem cell support. The HDCT procedure considered as consolidation of the disease status obtained after the first-line therapy was followed by the reinfusion of granulokine colony-stimulating factor-primed (G-CSF) peripheral blood progenitor cell (PBPCT). Here we present the results in terms of treatment-related toxicity, hospitalization and rescue of the bone marrow function, in 17 pediatric patients enrolled in such a pilot protocol and submitted to HDCT and PBPCT at the end of first-line therapy.