Cytotoxic phenazine and antiallergic phenoxazine alkaloids from an arctic Nocardiopsis dassonvillei SCSIO 502F.

Microbes well-adapted to the Arctic Ocean are promising for producing novel compounds, due to their fancy strategies for adaptation and being under-investigated. Two new phenazine alkaloids (1 and 2) and one new phenoxazine (3) were isolated from Nocardiopsis dassonvillei 502F, a strain originally isolated from Arctic deep-sea sediments. AntiSMASH analysis of the genome of Nocardiopsis dassonvillei 502F revealed the presence of 16 putative biosynthetic gene clusters (BGCs), including a phenazine BGC. Most of the isolated compounds were evaluated for their antibacterial, antiallergic, and cytotoxic activities. Among them, compounds 4 and 5 exhibited potent in vitro cytotoxic activities against osteosarcoma cell line 143B with IC50 values 0.16 and 20.0 µM, respectively. Besides, the results of antiallergic activities of compounds 6-8 exhibited inhibitory activities with IC50 values of 10.88 ± 3.05, 38.88 ± 3.29, and 2.44 ± 0.17 µg/mL, respectively (IC50 91.6 µM for the positive control loratadine).

Precatalyst-Enabled Selectivity: Enantioselective NiH-Catalyzed anti-Hydrometalative Cyclization of Alkynones to Endo- and Heterocyclic Allylic Alcohols.

A highly enantioselective NiH-catalyzed hydrocyclization of alkynones with unparalleled anti- and endocyclic selectivities is described. The choice of the precatalysts has significant influence in tuning the regio- and enantioselectivity. Using Ni(OTs)2 /Phox as a precatalyst and (EtO)2 MeSiH as a hydride source, an array of enantioenriched O-, N-, and S-containing heterocyclic tertiary allylic alcohols are obtained in 24-81 % yields with 80:20-99:1 er. Mechanistic investigations and synthetic application are also carried out. This study represents an efficient access to a set of allylic alcohols that are unable to access by the state-of-the-art coupling reactions.

Restenosis after recanalization for Budd-Chiari syndrome: Management and long-term results of 60 patients.

BACKGROUND: Budd-Chiari syndrome is defined as hepatic venous outflow tract obstruction. For Asian Budd-Chiari syndrome patients, the major treatment modality is recanalization (percutaneous transluminal angioplasty with or without stent implantation). The cumulative 1-, 5-, and 10-year primary patency rates and survival rates are reported to be excellent or satisfactory, but the long-term outcome of patients with restenosis (the most common complication after recanalization) is unknown. AIM: To explore the treatment strategy for restenosis in patients with Budd-Chiari syndrome after interventional therapy and to evaluate the long-term follow-up results. METHODS: The clinical data and follow-up results of 60 patients with restenosis after interventional therapy from November 1983 to December 2013 were retrospectively analyzed. RESULTS: Sixty patients with restenosis were retrospectively divided into a percutaneous transluminal angioplasty (PTA) group (40 patients) and a PTA + stent group (20 patients) according to the primary recanalization method. For the patients with restenosis in the PTA group, 13 refused treatment, and 27 received further treatment; among these patients, five had a second restenosis, two had a third restenosis, and one had a fourth restenosis. For the patients with restenosis in the PTA + stent group, nine refused treatment, ten received PTA alone, and the other received PTA + stent implantation. Among the patients who received further treatment, five had a second restenosis, three had a third restenosis, and one had a fourth restenosis. The 1-, 5-, 10-, 20-, and 25-year cumulative survival rates of the 38 patients who received further treatment after restenosis were 100%, 78.3%, 78.3%, 70.5%, and 70.5%, respectively; however, for the 22 patients who refused treatment, the survival rates were 72.7%, 45.9%, 30.6%, 10.2%, and unavailable, respectively (P < 0.001). CONCLUSION: Long-term follow-up after interventional therapy is very important. Active treatment for patients with restenosis can improve prognosis, and minimally invasive treatment strategies for restenosis allows to obtain satisfactory results.

Effects of MCRS1 on proliferation, migration, invasion, and epithelial mesenchymal transition of gastric cancer cells by interacting with Pkmyt1 protein kinase.

Microspherule protein 1(MCRS1) is known to be an oncogene in several tumors. However, recent studies have shown that MCRS1 inhibits lymphatic metastasis in gastric cancer (GC) patients by inhibiting telomerase activity. Protein kinase, membrane associated tyrosine/threonine 1(Pkmyt1), a member of the WEE1 family, has been found to interact with MCRS1 by yeast two-hybrid assay; however, how these two proteins interact in GC is still unclear. Hence, this study aimed to investigate the effect of MCRS1 interaction with Pkmyt1 on GC cell proliferation, migration, and invasion. Initially, we observed increased expression of MCRS1 in GC SGC-7901 cells and decreased expression in GC BGC-823 cells. Hence, we down-regulated MCRS1 expression in SGC-7901 cells and up-regulated it in BGC-823 cells. Our results showed that overexpression of MCRS1 inhibits the growth, invasion and migration of GC cells, while downregulation of MCRS1 promotes the growth, invasion and migration of GC cells. When MK1775, an inhibitor of WEE1 kinase, was added after downregulation of MCRS1, phenotypic recovery effects were observed. Overexpression of MCRS1 also inhibited the expression of Pkmyt1 and vice versa. This indicated that there might be a possible interaction between MCRS1 and Pkmyt1. Furthermore, immunoprecipitation assay revealed the interaction between MCRS1 and Pkmyt1 in virto, and immunofluorescence experiments showed that the two proteins were co-localized in the cytoplasm. In conclusion, our study confirmed the specific tumor suppressive activity of MCRS1 in GC proliferation, invasion and migration and suggested that it might inhibit the progression of GC through its interaction with Pkmyt1.