Prediction of the prognosis of advanced hepatocellular carcinoma by TERT promoter mutations in circulating tumor DNA

Background and Aim Human telomerase reverse transcriptase (TERT) promoter mutations were the most prevalent mutations in patients with hepatocellular carcinoma (HCC). We tried to detect the mutations with plasma circulating tumor DNA (ctDNA) in patients with advanced HCC and elucidated their clinical utility. Methods Circulating tumor DNA in plasma was extracted from 130 patients with advanced HCC who were treated with systemic chemotherapy (n = 86) or transcatheter arterial chemoembolization (n = 44), and TERT promoter mutations were examined with digital droplet polymerase chain reaction. The correlations between these mutations and the clinical outcome of patients were analyzed. Results Of the 130 patients examined, 71 patients (54.6%) were positive for TERT promoter mutations in ctDNA, of which 64 patients were −124bp G > A and 10 were −146bp G > A. The presence of TERT promoter mutations was correlated with large intrahepatic tumor size (P = 0.05) and high des‐gamma carboxyprothrombin (P = 0.005). Overall survival of the patients with the mutations was significantly shorter than those without them (P Conclusions TERT promoter mutations in ctDNA were associated with short survival and could be a valuable biomarker for predicting the prognosis of patients with advanced HCC

Development of mutant microalgae that accumulate lipids under nitrate-replete conditions

Microalgal biofuels have attracted global attention as an alternative energy source to fossil fuels. Microalgae generally accumulate triacylglycerols (lipids) under nitrogen-deficient conditions; however, cell growth is highly suppressed under these conditions, subsequently reducing lipid productivity. Therefore, microalgae that can accumulate lipids even under nitrogen-replete conditions are needed to realize the one-step nutrient-replete cultivation with improved lipid productivity. Thus, the aim of this study was to develop a method for screening mutant microalgae showing high lipid accumulation in the presence of a nitrogen source. Mutant cells were generated by irradiating the oleaginous green microalga Chlamydomonas sp. KOR1 with carbon-ion beams, followed by cultivation under nitrate-replete conditions, and then subjected to fluorescence-activated cell sorting-based screening for detecting lipid-rich cells. By repeatedly performing the sequential procedures of cultivation and selection, the strains KAC1710 and KAC1801, which showed high lipid accumulation under nitrate-replete conditions, were obtained. In the presence of abundant nitrate, these mutants formed a large number of lipid droplets in the cells, and achieved 1.5-fold (KAC1710) and 2.1-fold (KAC1801) higher lipid content than KOR1. Metabolome analysis revealed that the pool size of pyruvate was significantly increased in KAC1710 and KAC1801, consistent with the activation of lipid synthesis under nitrate-replete conditions. In conclusion, this study reports the use of a novel nitrogen-based screening method for developing mutant microalgae that accumulate lipids in the presence of a nitrogen source, and found that an increase in pyruvate pool size is an important metabolic phenomenon associated with lipid production

Evaluation of <i>Brachypodium distachyon</i> L-Tyrosine Decarboxylase Using L-Tyrosine Over-Producing <i>Saccharomyces cerevisiae</i>

<div><p>To demonstrate that herbaceous biomass is a versatile gene resource, we focused on the model plant <i>Brachypodium distachyon</i>, and screened the <i>B</i>. <i>distachyon</i> for homologs of tyrosine decarboxylase (TDC), which is involved in the modification of aromatic compounds. A total of 5 candidate genes were identified in cDNA libraries of <i>B</i>. <i>distachyon</i> and were introduced into <i>Saccharomyces cerevisiae</i> to evaluate TDC expression and tyramine production. It is suggested that two TDCs encoded in the transcripts Bradi2g51120.1 and Bradi2g51170.1 have L-tyrosine decarboxylation activity. Bradi2g51170.1 was introduced into the L-tyrosine over-producing strain of <i>S</i>. <i>cerevisiae</i> that was constructed by the introduction of mutant genes that promote deregulated feedback inhibition. The amount of tyramine produced by the resulting transformant was 6.6-fold higher (approximately 200 mg/L) than the control strain, indicating that <i>B</i>. <i>distachyon</i> TDC effectively converts L-tyrosine to tyramine. Our results suggest that <i>B</i>. <i>distachyon</i> possesses enzymes that are capable of modifying aromatic residues, and that <i>S</i>. <i>cerevisiae</i> is a suitable host for the production of L-tyrosine derivatives.</p></div

Strains, plasmids, transformants, and oligonucleotide primers used in this study.

<p>Strains, plasmids, transformants, and oligonucleotide primers used in this study.</p

Proposed biosynthesis pathway for tyramine (ARO3, ARO4; 3-deoxy-D-heptulosonate-7-phosphate synthase: ARO7; chorismate mutase: TDC; L-tyrosine decarboxylase).

<p>ARO3, ARO4 and ARO7 are derived from <i>S</i>. <i>cerevisiae</i>, whereas TDC is originated from <i>B</i>. <i>distachyon</i>.</p

Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma : A Case Report

We present a rare case of a 26-year old woman with diffuse sclerosing variant of papillary thyroid carcinoma. The patient was referred to our hospital with diffuse enlargement of the thyroid accompanied with palpable bilateral cervical lymph nodes. Ultrasonography showed a heterogeneous pattern with ill-defined hypoechoic areas in both thyroid lobes. There were multiple small punctate echogenic foci. Fine-needle aspiration cytology revealed typical signs of papillary carcinoma. The patient underwent a total thyroidectomy using a bilateral modified neck dissection. Pathological findings demonstrated diffuse involvement and continuous infiltration of the tumors to both thyroid lobes, lymph nodes and cervical soft tissue. Postoperatively, 100 mCi of 131I was administrated to the small amount of residual thyroid tissue. The patient is free from recurrence one year after the operation

Enhancing carbohydrate repartitioning into lipid and carotenoid by disruption of microalgae starch debranching enzyme

Light/dark cycling is an inherent condition of outdoor microalgae cultivation, but is often unfavorable for lipid accumulation. This study aims to identify promising targets for metabolic engineering of improved lipid accumulation under outdoor conditions. Consequently, the lipid-rich mutant Chlamydomonas sp. KOR1 was developed through light/dark-conditioned screening. During dark periods with depressed CO2 fixation, KOR1 shows rapid carbohydrate degradation together with increased lipid and carotenoid contents. KOR1 was subsequently characterized with extensive mutation of the ISA1 gene encoding a starch debranching enzyme (DBE). Dynamic time-course profiling and metabolomics reveal dramatic changes in KOR1 metabolism throughout light/dark cycles. During light periods, increased flux from CO2 through glycolytic intermediates is directly observed to accompany enhanced formation of small starch-like particles, which are then efficiently repartitioned in the next dark cycle. This study demonstrates that disruption of DBE can improve biofuel production under light/dark conditions, through accelerated carbohydrate repartitioning into lipid and carotenoid