Genistein enhances the effect of trichostatin A on inhibition of A549 cell growth by increasing expression of TNF receptor-1

Our previous study has shown that genistein enhances apoptosis in A549 lung cancer cells induced by trichostatin A (TSA). The precise molecular mechanism underlying the effect of genistein, however, remains unclear. In the present study, we investigated whether genistein enhances the anti-cancer effect of TSA through up-regulation of TNF receptor-1 (TNFR-1) death receptor signaling. We incubated A549 cells with TSA (50 ng/mL) alone or in combination with genistein and then determined the mRNA and protein expression of TNFR-1 as well as the activation of downstream caspases. Genistein at 5 and 10 μM significantly enhanced the TSA-induced decrease in cell number and apoptosis in a dose-dependent manner. The combined treatment significantly increased mRNA and protein expression of TNFR-1 at 6 and 12 h, respectively, compared with that of the control group; while TSA alone had no effect. TSA in combination with 10 μM of genistein increased TNFR-1 mRNA and protein expression by about 70% and 40%, respectively. The underlying mechanism for this effect of genistein may be partly associated with the estrogen receptor pathway. The combined treatment also increased the activation of caspase-3 and ‐10 as well as p53 protein expression in A549 cells. The enhancing effects of genistein on the TSA-induced decrease in cell number and on the expression of caspase-3 in A549 cells were suppressed by silencing TNFR-1 expression. These data demonstrated that the upregulation of TNFR-1 death receptor signaling plays an important role, at least in part, in the enhancing effect of genistein on TSA-induced apoptosis in A549 cells.     

5-Aza-dC和TSA对胰腺癌Panc-1细胞TFPI-2基因甲基化水平及表达的影响

目的探讨甲基化酶抑制剂5-氮杂-2′-脱氧胞苷(5-Aza-dC)及组蛋白去乙酰化酶抑制剂曲古菌素A(TSA)对胰腺癌Panc-1细胞系中TFPI-2基因甲基化水平及基因表达的影响。方法 Panc-1细胞经5-Aza-dC和TSA单独或联合处理后,应用甲基化特异性聚合酶链反应(MSP),逆转录聚合酶链反应(RT-PCR),蛋白印迹法(Western Blot)检测细胞TFPI-2基因启动子区甲基化状态和mRNA及蛋白表达情况。结果 Panc-1细胞经5-Aza-dC单独处理或与TSA联合处理后,TFPI-2基因启动子区高甲基化状态产生逆转,表现为非甲基化,原本不表达TFPI-2 mRNA及蛋白的Panc-1细胞重新表达,TFPI-2mRNA相对表达量为0.821±0.050和0.887±0.042,蛋白表达量为0.613±0.092和0.712±0.059,两者作用效果相似。经TSA单独处理的Panc-1细胞TFPI-2基因启动子区仍为异常高甲基化状态,原本不表达的TFPI-2基因未见重新表达。结论 Panc-1细胞中TFPI-2基因启动子区高甲基化可能是导致该基因失活的主要原因;5-Aza-dC单独作用或与...     

Effect of Trichostatin A on miRNA expression in cultures of primary rat hepatocytes

In the present study, the effect of Trichostatin A (TSA), a histone deacetylase inhibitor, was investigated on the microRNA (miR, miRNA) expression profile in cultured primary rat hepatocytes by means of microarray analysis. Simultaneously, albumin secretory capacity and morphological features of the hepatocytes were evaluated throughout the culture time. In total, 25 out of 348 miRNAs were found to be differentially expressed between freshly isolated hepatocytes and 7-day cultured cells. Nineteen of these miRNAs were connected with ‘general metabolism’. miR-21 and miR-126 were shown to be the most up and down regulated miRs upon cultivation and could be linked to the proliferative response triggered in the hepatocytes upon their isolation from the liver. miR-379 and miR-143, on the other hand, were found to be the most up and down regulated miRs upon TSA treatment. Together with the higher expression of miR-122 observed in TSA-treated versus non-treated cultures, we hypothesize that the changes observed for miR-122, miR-143 and miR-379 could be related to the inhibitory effects of TSA on hepatocellular proliferation.     

Identification of antibacterial constituents from the indigenous Australian medicinal plant Eremophila duttonii F. Muell. (Myoporaceae)

This paper reports on the isolation and identification of antibacterial constituents from the indigenous Australian medicinal plant Eremophila duttonii F. Muell. (Myoporaceae). Preparations derived from this plant are used by indigenous populations in the topical treatment of minor wounds, otitis and ocular complaints, and as a gargle for sore throat. Several authors have reported extracts of this plant to effect rapid bacteriolysis and inhibit growth of a wide range of Gram-positive micro-organisms. In other studies involving screening of native medicinal plants for antibacterial activity, extracts of Eremophila duttonii have been reported to consistently exhibit the highest potency amongst all species included. From a hexane extract, we identified two diterpenes of the serrulatane class, the principal constituents responsible for antibacterial activity and present as major constituents of the resinous leaf cuticle: serrulat-14-en-7,8,20-triol (1) and serrulat-14-en-3,7,8,20-tetraol (2). In addition, a hydroxylated furanosesquiterpene with mild antibacterial activity which appeared to be a novel compound was isolated from the extract and tentatively identified as 4-hydroxy-4-methyl-1-(2,3,4,5-tetrahydro-5-methyl[2,3'-bifuran]-5-yl) pentan-2-one. Minimum inhibitory concentrations for each of the compounds against three Gram-positive bacteria: Staphylococcus aureus (ATCC 29213), Staphylococcus epidermidis (ATCC 12228) and Streptococcus pneumoniae (ARL 10582), were determined using a micro-titre plate broth dilution assay.     

High prevalence of sessile serrated adenomas with BRAF mutations: a prospective study of patients undergoing colonoscopy

BACKGROUND & AIMS: Sporadic colorectal cancers with a high degree of microsatellite instability are a clinically distinct subgroup with a high incidence of BRAF mutation and are widely considered to develop from serrated polyps. Previous studies of serrated polyps have been highly selected and largely retrospective. This prospective study examined the prevalence of sessile serrated adenomas and determined the incidence of BRAF and K-ras mutations in different types of polyps. METHODS: An unselected consecutive series of 190 patients underwent magnifying chromoendoscopy. Polyp location, size, and histologic classification were recorded. All polyps were screened for BRAF V600E and K-ras codon 12 and 13 mutations. RESULTS: Polyps were detected in 72% of patients. Most (60%) were adenomas (tubular adenomas, tubulovillous adenomas), followed by hyperplastic polyps (29%), sessile serrated adenomas (SSAs; 9%), traditional serrated adenomas (0.7%), and mixed polyps (1.7%). Adenomas were more prevalent in the proximal colon (73%), as were SSAs (75%), which tended to be large (64% >5 mm). The presence of at least one SSA was associated with increased polyp burden (5.0 vs 2.5; P < .0001) and female sex (P < .05). BRAF mutation was rare in adenomas (1/248 [0.4%]) but common in SSAs (78%), traditional serrated adenomas (66%), mixed polyps (57%), and microvesicular hyperplastic polyps (70%). K-ras mutations were significantly associated with goblet cell hyperplastic polyps and tubulovillous adenomas (P < .001). CONCLUSIONS: The prevalence of SSAs is approximately 9% in patients undergoing colonoscopy. They are associated with BRAF mutation, proximal location, female sex, and presence of multiple polyps. These findings emphasize the importance of identifying and removing these lesions for endoscopic prevention of colorectal cancer.     

白花丹参总酚酸提取物对大鼠血栓闭塞性脉管炎的影响

目的 探讨白花丹参总酚酸提取物对血栓闭塞性脉管炎模型大鼠的影响,为其临床用于治疗血栓闭塞性脉管炎提供科学依据.方法 采用LC-UV-MS法对白花丹参总酚酸提取物中的主要成分进行定性分析.Wistar大鼠随机分为假手术组,模型组,白花丹参总酚酸提取物高、中、低剂量( 5.63、2.82、1.41 g/kg)组,通塞脉片(0.66 g/kg)阳性对照组.大鼠股动脉注射月桂酸溶液制备血栓闭塞性脉管炎模型后第2天ig给药,每天给药1次,连续给药1周,观察用药前后大鼠的体征、血管平滑肌和纤维组织等病理变化,以及血清中血栓素B2 (TXB2)、6-酮前列腺素1α (6-k-PGF1a)、内皮素(ET)水平.结果 白花丹参总酚酸提取物明显减轻血栓闭塞性脉管炎大鼠患肢病变程度和范围,减轻炎症反应,减少血管内血栓形成,降低血清中TXB2、ET水平,升高6-k-PGF1α水平.结论 白花丹参总酚酸提取物对血栓闭塞性脉管炎大鼠具有较好的治疗作用,其作用机制与其抗氧化、减轻血管壁炎症反应有关.