Human Natural Killer-1 Sulfotransferase (HNK-1ST)-induced Sulfate Transfer Regulates Laminin-binding Glycans on α-Dystroglycan

Retinoic acid (RA) is a well established anti-tumor agent inducing differentiation in various cancer cells. Recently, a robust up-regulation of human natural killer-1 sulfotransferase (HNK-1ST) was found in several subsets of melanoma cells during RA-mediated differentiation. However, the molecular mechanism underlying the tumor suppression mediated by HNK-1ST remains unclear. Here, we show that HNK-1ST changed the glycosylation state and reduced the ligand binding activity of α-dystroglycan (α-DG) in RA-treated S91 melanoma cells, which contributed to an attenuation of cell migration. Knockdown of HNK-1ST restored the glycosylation of α-DG and the migration of RA-treated S91 cells, indicating that HNK-1ST functions through glycans on α-DG. Using CHO-K1 cells, we provide direct evidence that HNK-1ST but not other homologous sulfotransferases (C4ST1 and GalNAc4ST1) suppresses the glycosylation of α-DG. The activity-abolished mutant of HNK-1ST did not show the α-DG-modulating function, indicating that the sulfotransferase activity of HNK-1ST is essential. Finally, the HNK-1ST-dependent incorporation of [(35)S]sulfate groups was detected on α-DG. These findings suggest a novel role for HNK-1ST as a tumor suppressor controlling the functional glycans on α-DG and the importance of sulfate transfer in the glycosylation of α-DG.     

Decreased Susceptibility to Nitroimidazoles Among Bacteroides Species in Brazil

In this study, 197 strains of Bacteroides genus from different species and origins were evaluated with regard to their susceptibility to 5-nitroimidazoles (5-Ni)—such as tinidazole, ornidazole, and metronidazole—using the agar dilution method. The presence of nim genes was also investigated by polymerase chain reaction. It was found that 5.6% of Bacteroides strains among all origins showed decreased susceptibility (minimum inhibitory concentrations varying from 4 to 16 μg/ml) to at least one of the imidazoles studied without any known nim gene associate. Also, we detected one strain isolated from a polluted aquatic environment in which one nim gene was found and characterized as nim B using restriction fragment length polymorphism and sequencing. Hence, resistance to 5-Ni should be monitored closely because they constitute, among few drugs, the ones quite effective in treating Bacteroides infections.     

Fragile lives with fragile rights: Justice for babies born at the limit of viability

There is an inconsistency in the ways that doctors make clinical decisions regarding the treatment of babies born extremely prematurely. Many experts now recommend that clinical decisions about the treatment of such babies be individualized and consider many different factors. Nevertheless, many policies and practices throughout Europe and North America still appear to base decisions on gestational age alone or on gestational age as the primary factor that determines whether doctors recommend or even offer life‐sustaining neonatal intensive care treatment. These policies are well intentioned. They aim to guide doctors and parents to make decisions that are best for the baby. That is an ethically appropriate goal. But in relying so heavily on gestational age, such policies may actually do the babies a disservice by denying some babies treatment that might be beneficial and lead to intact survival. In this paper, we argue that such policies are unjust to premature babies and ought to be abolished. In their place, we propose individualized treatment decisions for premature babies. This would treat premature babies as we treat all other patients, with clinical decisions based on an individualized estimation of likelihood that treatment would be beneficial.