Background and ObjectivesWith the increasing survival of preterm infants, pulmonary hypertension (PH) related to bronchopulmonary dysplasia (BPD) has become an important complication. The aim of this study was to investigate the characteristics and outcome of PH in preterm infants with BPD and to identify the risk factors for PH.Subjects and MethodsWe reviewed the records of 116 preterm infants with BPD cared for at a single tertiary center between 2004 and 2008.ResultsTwenty-nine (25%) infants had PH >2 months after birth. PH occurred initially at a median age of 65 days (range, 7-232 days). Severe BPD, a birth weight <800 g, long-term ventilator care and oxygen supplementation, a high ventilator setting, infection, and a patent ductus arteriosus (PDA) were related to PH based on univariate analysis (p<0.05). The infants who had longer oxygen supplementation were significantly more likely to have PH (odds ratio, 18.5; 95% confidence interval, 4.1-84.6; p<0.001). PH was improved in 76% of infants after a median of 85 days (range, 20-765 days). Four infants (14%) died. The death of 3 infants was attributed to PH.ConclusionBPD was frequently complicated by PH. Although PH resolved in the majority of infants, PH in preterm infants with BPD can be fatal. Regular screening for PH and adequate management are required.

Major vault protein (MVP), the main component of vault complex, is overexpressed in many multidrug-resistant cancer cell lines, suggesting a possible role for MVP in cell signaling and survival. In this study, we have found that MVP is markedly increased in senescent human diploid fibroblasts (HDFs) as well as in aged organs. We examined whether MVP expression might be affected by apoptotic stress in an aging-dependent manner. We treated young and senescent HDFs with apoptosis-inducing agents such as H 2 O 2 , staurosporine and thapsigargin, and monitored MVP expression. We found that MVP expression is markedly reduced in young HDFs but not in senescent HDFs, in response to apoptotic stresses. Downregulation of MVP increased the sensitivity of senescent HDFs to apoptosis. Also, the level of antiapoptotic B-cell lymphoma protein-2 (Bcl-2) was significantly reduced and the accumulation of c-Jun increased in MVP knocked-down senescent HDFs. Moreover, treatment of MVP knocked-down senescent HDFs with SP600125, a specific c-Jun NH (2) Vaults are large ribonucleoprotein particles found in a great portion of eukaryotic cells. The vault particle is a multimeric structure composed of three proteins -the major vault protein (MVP), two minor vault proteins, vault poly (ADP-ribose) polymerase (VPARP) and telomerase-associated protein-1 (TP-1), and four small untranslated vault RNAs (vRNAs). 1 MVP is the main component of the vault complex accounting for 75% of the total particle mass. 2 The vault particle has been so named because it has a barrel-shaped structure, reminiscent of the vaulted ceilings in cathedrals. 3 The interaction of MVP by its coiled coil domain is involved in the formation of the basic vault complex. 4 MVP expression is upregulated in cancers such as melanoma, 5 colon cancer 6 and gliomas 7 during acquisition of multidrug resistance 8,9 and during differentiation of dendritic cells. 10 MVP expression has also been shown to be induced by histone deacetylase inhibitors such as sodium butyrate, 11 phorbol 12-myristate 13-acetate (PMA) and cytarabine 12 as well as by cytotoxic drugs. 12-14 MVP/vaults have been proposed to be important in intracellular transport, 15-17 innate immunity 18 and virus infection. 19 Several studies demonstrated that MVP is important in cell signaling [20][21][22] and in cell survival. 10,20,23 For example, serumdeprived MVP-deficient mouse embryonic fibroblasts (MEFs) exhibit significantly increased cell death when compared with wild-type MEFs. 20 Therefore, the role of MVP as a scaffolding protein for signaling proteins, especially for cell survival, has received more attention than as a transport vehicle. However, the exact role of MVP in cell survival is not well understood. In this study, we found that apoptotic resistance of senescent human diploid fibroblasts (HDFs) correlates with the increased content of MVP in the senescent cells. This is the first report implicating MVP in apoptosis resistance of senescent HDFs. ResultsIncreased expression of MVP in aged cells and organs...

Although tetraarsenic hexoxide is known to exert an anti-tumor effect by inducing apoptosis in various cancer cells, its effect on other forms of regulated cell death remains unclear. Here, we show that tetraarsenic hexoxide induces the pyroptotic cell death through activation of mitochondrial reactive oxygen species (ROS)-mediated caspase-3/gasdermin E (GSDME) pathway, thereby suppressing tumor growth and metastasis of triple-negative breast cancer (TNBC) cells. Interestingly, tetraarsenic hexoxide-treated TNBC cells exhibited specific pyroptotic characteristics, including cell swelling, balloon-like bubbling, and LDH releases through pore formation in the plasma membrane, eventually suppressing tumor formation and lung metastasis of TNBC cells. Mechanistically, tetraarsenic hexoxide markedly enhanced the production of mitochondrial ROS by inhibiting phosphorylation of mitochondrial STAT3, subsequently inducing caspase-3-dependent cleavage of GSDME, which consequently promoted pyroptotic cell death in TNBC cells. Collectively, our findings highlight tetraarsenic hexoxide-induced pyroptosis as a new therapeutic strategy that may inhibit cancer progression of TNBC cells.

Metformin, which is widely used as an anti-diabetic drug, reduces cancer related morbidity and mortality. However, the role of metformin in cancer is not fully understood. Here, we first describe that the anti-cancer effect of metformin is mediated by cyclin D1 deregulation via AMPK/GSK3β axis in ovarian cancer cells. Metformin promoted cytotoxic effects only in the cancer cells irrespective of the p53 status and not in the normal primary-cultured cells. Metformin induced the G1 cell cycle arrest, in parallel with a decrease in the protein expressions of cyclin D1 without affecting its transcriptional levels. Using a proteasomal inhibitor, we could address that metformin-induced decrease in cyclin D1 through the ubiquitin/proteasome process. Cyclin D1 degradation by metformin requires the activation of GSK3β, as determined based on the treatment with GSK3β inhibitors. The activation of GSK3β correlated with the inhibitory phosphorylation by Akt as well as p70S6K through AMPK activation in response to metformin. These findings suggested that the anticancer effects of metformin was induced due to cyclin D1 degradation via AMPK/GSK3β signaling axis that involved the ubiquitin/proteasome pathway specifically in ovarian cancer cells. © 2016 Wiley Periodicals, Inc.