CRISPR/Cas9 Technique for Temperature, Drought, and Salinity Stress Responses.

Global warming and climate change have severely affected plant growth and food production. Therefore, minimizing these effects is required for sustainable crop yields. Understanding the molecular mechanisms in response to abiotic stresses and improving agricultural traits to make crops tolerant to abiotic stresses have been going on unceasingly. To generate desirable varieties of crops, traditional and molecular breeding techniques have been tried, but both approaches are time-consuming. Clustered regularly interspaced short palindromic repeat/Cas9 (CRISPR/Cas9) and transcription activator-like effector nucleases (TALENs) are genome-editing technologies that have recently attracted the attention of plant breeders for genetic modification. These technologies are powerful tools in the basic and applied sciences for understanding gene function, as well as in the field of crop breeding. In this review, we focus on the application of genome-editing systems in plants to understand gene function in response to abiotic stresses and to improve tolerance to abiotic stresses, such as temperature, drought, and salinity stresses.

3-Nitro-2-pyridinesulfenates as Efficient Solution- and Solid-Phase Disulfide Bond Forming Agents.

In this paper, a new disulfide-forming agent based on the finding that alkoxy 3-nitro-2-pyridinesulfenates (Npys-OR) can oxidize thiol groups is reported. Methyl 3-nitro-2-pyridinesulfenate (Npys-OMe), which is easily prepared from 3-nitro-2-pyridinesulfenyl chloride in a one-step reaction and has a reduction peak potential (Epc ) of -0.541 V versus Ag/AgCl, produces the cyclic nonapeptide oxytocin from its linear form in good yield (92 %) with minimal oligomer formation. Npys-OMe in the solid phase also demonstrated excellent results in oxytocin synthesis. Other disulfide-containing peptides, such as α-human atrial natriuretic peptide and α-conotoxin ImI, were also successfully synthesized. During these syntheses, no side reactions of methionine (Met) and tryptophan (Trp) residues or the S-acetamidomethyl (Acm) protecting group were detected. These results suggested that Npys-OMe or its solid-phase analog provides a new strategy for regioselective disulfide bond formation to assist the synthesis of complex disulfide-rich peptides.

[A three-week regimen of S-1 monotherapy reduced gastrointestinal toxicity and maintained efficacy in patients with gemcitabine-refractory advanced pancreatic cancer].

S-1 administration for 28 consecutive days followed by 14 days of rest (6-week cycle) is often chosen as second-line chemotherapy for advanced pancreatic cancer (PC), but it causes gastrointestinal toxicity. In comparison, in gastric cancer or head and neck cancer, S-1 administration for 14 consecutive days followed by a 7-day rest period (3-week cycle) reduced gastrointestinal toxicity. This study retrospectively evaluated the efficacy and safety of a 3-week S-1 schedule compared to a 6-week schedule in patients with gemcitabine (GEM)-refractory advanced PC. Fifty-seven patients were treated with the 6- week S-1 schedule and 68 patients were treated with the 3-week S-1 schedule. There were no statistical differences in overall survival (p=0.13) and progression-free survival (p=0.190). With regard to adverse events, the rates of nausea (p<0.01) and vomiting (p=0.04) were lower with the 3-week schedule than with the 6-week schedule. Thus, S-1 therapy with a 3- week schedule as second-line chemotherapy in patients with GEM-refractory advanced PC was associated with reduced gastrointestinal toxicity and similar efficacy, when compared to a 6-week schedule.

Evocalcet prevents ectopic calcification and parathyroid hyperplasia in rats with secondary hyperparathyroidism.

BACKGROUND: Elevated parathyroid hormone (PTH) levels in secondary hyperparathyroidism (SHPT) lead to vascular calcification, which is associated with cardiovascular events and mortality. Increased PTH production is caused by the excessive proliferation of parathyroid gland cells, which is accelerated by abnormal mineral homeostasis. Evocalcet, an oral calcimimetic agent, inhibits the secretion of PTH from parathyroid gland cells and has been used for the management of SHPT in dialysis patients. We observed the effects of evocalcet on ectopic calcification and parathyroid hyperplasia using chronic kidney disease (CKD) rats with SHPT. METHODS: CKD rats with SHPT induced by adenine received evocalcet orally for 5 weeks. The calcium and inorganic phosphorus content in the aorta, heart and kidney was measured. Ectopic calcified tissues were also assessed histologically. To observe the effects on the proliferation of parathyroid gland cells, parathyroid glands were histologically assessed in CKD rats with SHPT induced by 5/6 nephrectomy (Nx) after receiving evocalcet orally for 4 weeks. RESULTS: Evocalcet prevented the increase in calcium and inorganic phosphorus content in the ectopic tissues and suppressed calcification of the aorta, heart and kidney in CKD rats with SHPT by reducing the serum PTH and calcium levels. Evocalcet suppressed the parathyroid gland cell proliferation and reduced the sizes of parathyroid cells in CKD rats with SHPT. CONCLUSIONS: These findings suggest that evocalcet would prevent ectopic calcification and suppress parathyroid hyperplasia in patients with SHPT.

Direct synthesis of aryl-annulated [c]carbazoles by gold(i)-catalysed cascade reaction of azide-diynes and arenes.

The gold-catalysed annulation of conjugated alkynes bearing an azido group with arenes gave annulated [c]carbazoles. Using benzene, pyrrole, and indole derivatives as the nucleophiles, benzo[c]-, pyrrolo[2,3-c]-, and indolo[2,3-c]carbazoles were produced, respectively. The reaction proceeded through pyrrole and benzene ring construction accompanied by the formation of two carbon-carbon and one carbon-nitrogen bond and the cleavage of two aromatic C-H bonds. The mechanism of the reaction with pyrrole was investigated by density functional theory calculations. N,N'-dimethylated indolo[2,3-c]carbazole showed dual ultraviolet-visible-near-infrared and fluorescence spectral changes upon electrolysis.

Structure-Activity Relationship Study of Leucyl-3-epi-deoxynegamycin for Potent Premature Termination Codon Readthrough.

(+)-Negamycin, isolated from Streptomyces purpeofuscus, shows antimicrobial activity against Gram-negative bacteria and readthrough activity against nonsense mutations. Previously, we reported that two natural negamycin analogues, 5-deoxy-3-epi-negamycin and its leucine adduct, have more potent readthrough activity in eukaryocytes (COS-7 cells) than negamycin but possess no antimicrobial activity and no in vitro readthrough activity in prokaryotic systems. In the present study, on leucyl-3-epi-deoxynegamycin, a structure-activity relationship study was performed to develop more potent readthrough agents. In a cell-based readthrough assay, the derivative 13b with an o-bromobenzyl ester functions as a prodrug and exhibits a higher readthrough activity against TGA-type PTC than the aminoglycoside G418. This ester (13b) shows an in vivo readthrough activity with low toxicity, suggesting that it has the potential for treatment of hereditary diseases caused by nonsense mutations.

Efficacy of prophylactic minocycline treatment for skin toxicities induced by erlotinib plus gemcitabine in patients with advanced pancreatic cancer: a retrospective study.

BACKGROUND: Erlotinib has been reported as being associated with a high incidence of skin toxicities such as acneiform rash, paronychia, and xerosis. OBJECTIVE: The aim of this study was to evaluate the efficacy of prophylactic minocycline treatment for the skin toxicities induced by erlotinib as compared with deferred minocycline treatment in patients with pancreatic cancer treated with erlotinib plus gemcitabine. METHODS: A total of 96 patients were studied retrospectively, of whom 44 received prophylactic minocycline between August 2012 and June 2013 and 52 received deferred minocycline treatment between August 2011 and July 2012 at the National Cancer Center Hospital East, Kashiwa, Japan. In the prophylactic minocycline group, 200 mg/day oral minocycline was prophylactically administered during the treatment period. RESULTS: The incidence rate of acneiform rash and xerosis of any grade during the first 6 weeks of treatment was significantly reduced in the prophylactic minocycline group compared with the deferred minocycline treatment group (47.7 vs. 80.8%, p<0.001; 2.3 vs. 19.2%, p=0.01). Multivariate analysis identified prophylactic minocycline as a significant independent factor associated with the incidence of acneiform rash and xerosis of any severity (odds ratio [OR] 0.16, 95% confidence interval [CI] 0.06-0.46, p<0.001; OR 0.11, 95% CI 0.01-0.90, p=0.04). CONCLUSION: Prophylactic minocycline appears to be useful for the management of erlotinib-related acneiform rash and xerosis during chemotherapy in patients with advanced pancreatic cancer.