ALTERATION IN CHROMATIN CONFORMATION OF PROLIFERATING AND DIFFERENTIATING ENZYME GENES IN NORMAL MOUSE LIVER AND ASCITES HEPATOMA CELLS AND ITS RELATION TO THE GENE EXPRESSION OF ENZYMES

Nuclei from the normal mouse liver were partially digested with micrococcal nuclease, followed by DNA extraction, agarose gel clectrophoresis and dot blot hybridization with ~(32)P-labeled cDNA probes of CPS_1 and ACT complex, It was clearly shown that the CPS_1 genes were distributed on the monomer, dimer. and trimer of nucleosomes, while the genes coding for ACT complex were distributed on the condensed oligonucleosomes. An opposite manner of distribution of CPS_1 and ACT complex genes was, however, noted in the case of ascites hepatoma cells, in which the specific activity of ACT was 13 times higher than that in the normal liver, while that of CPS_1 was remarkably reduced. Similar patterns of change in mRNA level of CPS_1 and ACT complex were observed in the normal mouse liver and ascites hepatoma cells, indicating a close relationship between chromatin structure and gene expression of these enzymes.     

稀土元素对人肝癌细胞SMMC-7721增殖的影响

用MTT法研究了14种稀土元素(La，Ce，Pr，Nd，Sm，Eu，Gd，Tb，Dy，Ho，Er，Tm，Yb和Lu)对人肝癌细胞SMMC-7721增殖的影响。他们对肝癌细胞的生长作用可分为3类。其中La^3 、Ce^3 和Eu^3 对肝癌细胞的增殖有剂量依赖性正效应，能够在一定浓度范围内刺激细胞生长；Sm^3 ，Gd^3 ，Ho^3 ，Er^3 ，Yb^3 对肝癌细胞生长的刺激作用没有剂量依赖性特征；而Pr^3 ，Nd^3 ，Tb^3 ，Dy^3 ，Tm^3 和Lu^3 则表现出对肝癌细胞的增殖具有不用程度的抑制。推测14种稀土元素作用方式的不同与他们的原子结构有一定的关系，它们对肝癌细胞的相对增殖率随着原子序数的增加呈现出一定的规律性。     

Facile Synthesis and in Vitro Cytotoxic Evaluation of Novel Thiadiazole,Pyrazole, and Dithiole-Androstane Derivatives

In the aim of identifying new steroidal cytotoxic agents with potential antiproliferative activity against hepatoma cell lines (Hep-G₂), we synthesized modified steroids containing the thiadiazole, pyrazole, or dithiole moiety. Epiandrosterone 1 reacted with carbon disulfide and sodium hydride to furnish α-oxoketene dithio-disodium salt 2. Treatment of 2 with the hydrazonoyl halides 5a–d produced the thiadiazole anellated androstanone 7a–d, respectively. The reaction of 1 with hydrazine hydrate produced the hydrazide adduct 8, which cyclized upon reflux in acetic acid to form the condensed pyrazoloandrostanone derivative 9. Interaction of 8 with carbon disulfide and sodium hydride formed the disodium salt 10, which reacted with ethylchloroacetate to furnish the final adduct, dithioloandrostane derivative, 13. Compounds 7a, 7d, 9, and 13 were examined for their cytotoxicity against a panel of hepatoma cell lines (Hep-G₂) using MTT assay. The results provide that, at incubation time 72 h, in DMSO, compound 7d (50 μ mol/mL) showed the most significant cytotoxic effect at P < 0.05. The higher dose (100 μ mol/mL) of compound 7d, at 48 h incubation, reversed the effect causing resistance and the growth rate return to the control level.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Polarity guided extraction,HPLC based phytochemical quantification,and multimode biological evaluation of Otostegia limbata (Benth.) Boiss

Purpose of studyOtostegia limbata (Benth.) Boiss. (Family: Lamiacae) is an important underexplored ethnomedicinal plant that has been used as antinflammatory, anticancer and antibacterial herbal remedy previously. The present work was aimed to evaluate the antioxidant, antimicrobial, antileishmanial, and anticancer prospective of O. limbata stem and leaf extracts.ResultsThe highest amount of phenolic and flavonoid content was obtained in the methanol-acetone and methanol stem extracts i.e., 53.29 ± 1.33 and 28.64 ± 1.16, respectively with highest DPPH scavenging in MeH stem extract (IC₅₀ = 34.5 ± 1.34 μg/ml). Significant amount of catechin, gallic acid, apigenin and rutin was quantified. A moderate antibacterial and substantial antifungal activity was observed. Cytotoxicity against brine shrimps categorized 21% of stem (3 out of 14 extracts) and 57% (8 out of 14 extracts) of leaf extracts as potent. Substantial cytotoxicity against THP-1 cell line (IC₅₀ = 3.46 ± 0.25 μg/ml) and Leishmania (IC₅₀ = 1.50 ± 0.23 μg/ml) was exhibited by methanol-distilled water leaf extract while noteworthy antiproliferative activity against Hep-G2 (IC₅₀ = 0.44 ± 0.45 μg/ml) was manifested by n-hexane stem extract. Absence of hemolysis in normal RBCs signified plant’s selective cytotoxicity. Methanol-distilled water and chloroform stem extracts displayed prominent protein kinase inhibition and antidiabetic potential of plant.ConclusionThe results of present study recommend O. limbata as a potential source of antifungal, antileishmanial, anticancer, and α-amylase inhibitory agents.     

Paradoxical high signal intensity of hepatocellular carcinoma in the hepatobiliary phase of Gd-EOB-DTPA enhanced MRI: initial experience

Purpose

To describe the paradoxical high signal intensity of hepatocellular carcinoma (HCC) in the hepatobiliary phase on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI).

Materials and Methods

A database search was performed to identify cases of HCC that showed unusual prolonged enhancement in the hepatobiliary phase of Gd-EOB-DTPA MRI. All patients received 3.0-T liver MRI including precontrast T1-weighted images, T2-weighted images and a post Gd-EOB-DTPA-enhanced dynamic study. The signal intensity of HCC was measured at pre-enhanced, arterial, portal, delayed and hepatobiliary phase using regions of interest. Radiologic and pathologic correlation was performed for the paradoxically prolonged enhancing portion of HCC in the hepatobiliary phase.

Results

Four patients (all male, age range 44-70; mean 57.5 years) were included in this study. All patients showed HCC lesions that were low signal intensity (SI) on T1-WI, high SI on T2-WI, enhanced in arterial phase, and washed-out in delayed phase. All cases showed paradoxically high SI in hepatobiliary phase, which was unusual for HCC. Pathologically, they were all diagnosed as well-differentiated HCC with prominent cytoplasm and a bile secreting appearance.

Conclusion

HCC may demonstrate the prolonged high signal intensity at the hepatobiliary phase on Gd-EOB-DTPA enhanced MRI. These HCCs tended to be highly differentiated and to have prominent bile secretion.     

Ellagic Acid Suppresses ApoB Secretion and Enhances ApoA-1 Secretion from Human Hepatoma Cells,HepG2

The effect of ellagic acid (EA), a naturally occurring polyphenolic compound, on the secretion of apolipoproteins from human hepatocytes, HepG2, was investigated. The levels of apoB and apoA-1 secreted in the cell culture medium were determined by sandwich ELISA. EA did not affect cell viability at the tested concentrations (up to 50 µM). EA suppressed the secretion of apoB and enhanced that of apoA-1 from HepG2 cells. However, cellular apoB levels were increased, suggesting that EA inhibited the trafficking of apoB during the process of secretion. In contrast, the increase in the cellular levels of apoA-1 was consistent with its secreted levels. These results indicate that EA inhibits the secretion of apoB from hepatocytes and increases the secretion of apoA-1. Both of these effects are beneficial for lipoprotein metabolism in the prevention of lifestyle-related diseases. The detailed mechanism underlying these effects of EA on lipoprotein metabolism should be elucidated in the future, but this naturally occurring polyphenolic compound might be antihyperlipidemic. Based on these results, EA is suggested as a candidate food-derived compound for the prevention of hyperlipidemia.     

Tuning Glutamine Binding Modes in Gd‐DOTA‐Based Probes for an Improved MRI Visualization of Tumor Cells

Three new magnetic resonance imaging probes that target glutamine transporters have been synthesized. They consist of a Gd‐DOTA‐monoamide moiety (DOTA=1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid) linked through a six carbon atom chain to a vector represented by a glutamine residue bound through α‐carboxylic, γ‐carboxamidic, or α‐amino functionalities. Their uptake by HTC (rat hepatocarcinoma) and healthy rat hepatocytes has shown that the system containing the glutamine vector bound through the α‐carboxylic group displays a markedly higher affinity for tumor cells. The observed behavior is rationalized in terms of the exploitation of an additional glutamine transporter active in hepatic tumor cells.     

Gas challenge-blood oxygen level-dependent (GC-BOLD) MRI in the rat Novikoff hepatoma model

Purpose

The purpose of the study was to investigate the relationship between gas challenge-blood oxygen level-dependent (GC-BOLD) response angiogenesis and tumor size in rat Novikoff hepatoma model.

Materials and Methods

Twenty adult male Sprague-Dawley rats (weighting 301-325 g) were used for our Animal Care and Use Committee-approved experiments. N1-S1 Novikoff hepatomas were grown in 14 rats with sizes ranging from 0.42 to 2.81 cm. All experiments were performed at 3.0 T using a custom-built rodent receiver coil. A multiple gradient-echo sequence was used for R2^? measurements, first during room air (78% N₂/20% O₂) breathing and then after 10 min of carbogen (95% O₂/5% CO₂) breathing. After image acquisition, rats were euthanized, and the tumors were harvested for histological evaluation.

Results

The R2^? change between air and carbogen breathing for small hepatomas was positive; R2^? changes changed to negative values for larger hepatomas. We found a significant positive correlation between tumor R2^? change and tumor microvessel density (MVD) (r=0.798, P=.001) and a significant inverse correlation between tumor R2^? change and tumor size (r=−0.840, P<.0001).

Conclusions

GC-BOLD magnetic resonance imaging measurements are well correlated to MVD levels and tumor size in the N1-S1 Novikoff hepatoma model; GC-BOLD measurements may serve as noninvasive biomarkers for evaluating angiogenesis and disease progression and/or therapy response.     

微流控细胞芯片LED诱导荧光检测微系统

基于微流控细胞芯片分析技术和微机电系统(MEMS)加工技术, 设计制作了阵列式微流控细胞检测芯片, 采用自组装的顶窗型光电倍增管(PMT)和信号采集电路采集芯片微管道内流动细胞的荧光信号, 构建了一种针对低浓度细胞悬浮液的微流控细胞芯片发光二极管(LED)诱导荧光的快速检测微系统, 实现了对低浓度(≤40 Cell/mL)荧光标记的HepG2肝癌细胞悬浮液样本的定量计数和测试, 而且在血液细胞共存的条件下, 仍可以有效地对血液中少量HepG2肝癌细胞进行荧光计数和测试. 整个系统结构简单, 操作方便且检测灵敏度较高.     

Cu(II)、Ni(II)配合物的合成、抗肿瘤作用及其对细胞周期分布的影响

以2-氨基-5-氯苯酚和2-喹啉甲醛合成的席夫碱作为配体,分别与氯化镍、氯化铜反应合成了2个金属配合物C1和C2,其结构通过单晶X-射线衍射进行了解析。采用MTT法测试了配合物C1和C2对不同人肝癌细胞系和正常肝细胞系HL-7702增殖抑制活性,结果表明C1、C2对人肝癌细胞系的抑制活性均优于顺铂,且对正常肝细胞系HL-7702的毒性要弱于顺铂。通过活性氧实验、细胞周期等实验,可以推断出配合物C1、C2抗肿瘤机制是通过产生活性氧造成肿瘤细胞的氧化损伤,以及使细胞周期停滞在G0/G1期阻滞细胞复制。