Somatic copy number profiling from hepatocellular carcinoma circulating tumor cells.

Somatic copy number alterations (SCNAs) are important genetic drivers of many cancers. We investigated the feasibility of obtaining SCNA profiles from circulating tumor cells (CTCs) as a molecular liquid biopsy for hepatocellular carcinoma (HCC). CTCs from ten HCC patients underwent SCNA profiling. The Cancer Genome Atlas (TCGA) SCNA data were used to develop a cancer origin classification model, which was then evaluated for classifying 44 CTCs from multiple cancer types. Sequencing of 18 CTC samples (median: 4 CTCs/sample) from 10 HCC patients using a low-resolution whole-genome sequencing strategy (median: 0.88 million reads/sample) revealed frequent SCNAs in previously reported HCC regions such as 8q amplifications and 17p deletions. SCNA profiling revealed that CTCs share a median of 80% concordance with the primary tumor. CTCs had SCNAs not seen in the primary tumor, some with prognostic implications. Using a SCNA profiling model, the tissue of origin was correctly identified for 32/44 (73%) CTCs from 12/16 (75%) patients with different cancer types.

Study on Antioxidant Activity of Amino Acids at Frying Temperatures and Their Interaction with Rosemary Extract, Green Tea Extract, and Ascorbic Acid.

Some amino acids have strong antioxidant activity in frying oil. This study aimed to obtain further information including antioxidant activity at different concentrations and interactions with rosemary extract, green tea extract, and ascorbic acid. Antioxidant activity of arginine, cysteine, lysine, methionine, and tryptophan was examined by increasing the concentration in soybean oil (SBO) at 180 °C within the concentration range of 0 to 15 mM. These amino acids showed increased activity with increasing concentration without showing prooxidant activity at the given concentration range. Addition of 15 mM methionine did not inhibit the prooxidant activity of α-tocopherol at high concentrations in SBO while it significantly increased the activity at each concentration of α-tocopherol. Methionine showed an additive effect with a commercial rosemary extract while lysine had an antagonistic interaction in SBO at the total concentration of 5.5 mM. Mixtures of green tea extract and methionine did not show better activity than methionine alone in SBO and stripped SBO. (-)-Epigallocatechin gallate, the major active component in green tea, showed a synergistic effect with methionine in stripped SBO but there was no significant interaction effect in SBO. Although ascorbic acid had a synergistic effect with methionine in stripped SBO, it showed a significant antagonistic effect in SBO. Methionine had strong antioxidant activity in six other vegetable oils showing a moderate correlation (R2 = 0.45 to 0.52) with the ratio of unsaturated fatty acids to saturated fatty acids indicating the effectiveness may be related to the fatty acid composition of oil. PRACTICAL APPLICATION: Some amino acid such as methionine and lysine showed stronger antioxidant activity than the leading commercial natural antioxidant, rosemary extract. These amino acids showed great potential as a natural antioxidant in frying. The price of food-grade L-methionine is generally lower than rosemary extract and green tea extract. This paper provides information on the concentration effect and interactions with currently used antioxidants such as tocopherols, rosemary extract, green tea extract, and ascorbic acid.

Enhancing antioxidant activity of sesamol at frying temperature by addition of additives through reducing volatility.

Additives were evaluated to investigate their effects on volatility of sesamol at frying temperature with the hypothesis that the interaction between an additive and sesamol would reduce sesamol volatility. Twenty-two additive : sesamol combinations were examined by thermogravimetric analysis (TGA) under nitrogen in neat form and in soybean oil. The results indicate that these additives could bind to or interact with sesamol and consequently reduced its volatility. (1) H NMR study provided evidence for hydrogen bonding between sesamol and a hydroxyl group, an amino group, and ether groups. Subsequent heating tests were conducted to investigate the effect of the reduced volatility of sesamol on antioxidant activity in soybean oil at 180 °C. Oxidation of soybean oil was monitored with gel permeation chromatography for formation of polymerized triacylglycerols and with (1) H NMR for loss of olefinic and bisallylic protons. Sesamol retained in soybean oil during the heating process was determined by high-performance liquid chromatography. A strong correlation between the retained sesamol and the antioxidant activity was observed. The mixture of 830 ppm sesamol and mono-/diglycerides, polysorbate 20 or l-carnosine showed much improved antioxidant activity compared to sesamol itself and slightly better antioxidant activity than 200 ppm tert-butylhydroquinone. It is believed that this method can also be used for many other antioxidants for which volatility is a problem.