Experimental study of single-pin puncture asymmetrical hydroablation using a conformational radiofrequency ablation electrode in ex vivo ox liver

OBJECTIVE

The aim of this study was to evaluate the feasibility of single-pin puncture asymmetrical hydroablation in liver using the multipole cluster conformable radiofrequency ablation electrode.

METHODS

The conformable electrode used in this study consists of both a main electrode in a central cannula and a circle of subelectrodes comprising two groups of six subelectrodes located on opposite sides (A and B) of the circle. The two subelectrode groups can be extended to different lengths independently of one another, resulting in asymmetrical shapes. Ablation experiments were performed using ex vivo ox liver. The experiments included six groups based on six potential electrode deployments in which the subelectrodes on sides A and B were fully extended, half extended or fully retracted. After ablation, the transverse diameters of the resulting necrotic tissue from sides A and B were measured. The experiment was conducted in 12 separate sites for each group.

RESULTS

When the subelectrodes were arranged symmetrically (either fully extended or half extended on both sides), the mean transverse diameter of necrotic tissue was similar for both sides A and B. When the subelectrodes were arranged asymmetrically, the fully extended side showed a significantly greater mean transverse diameter of necrotic tissue than the half extended or fully retracted side.

CONCLUSION

In this study, the WHK 3-8-4 multipole cluster conformable radiofrequency ablation electrode was able to produce both symmetrical and asymmetrical necrotic tissue patterns in the liver.

ADVANCES IN KNOWLEDGE

The size and shape of the ablation can be altered by both withdrawing and extending the subelectrodes to different lengths.

CYP2C9*3(1075A>C), MDR1 G2677T/A and MDR1 C3435T are determinants of inter-subject variability in fluvastatin pharmacokinetics in healthy Chinese volunteers

To evaluate the impact of single-nucleotide polymorphisms (SNPs) in CYP2C9, MDR1, SLCO1B1 and ABCG2 on the pharmacokinetics of fluvastatin in Chinese participants.A pharmacokinetic study of fluvastatin (single dose 40 mg) was conducted in 12 healthy Chinese volunteers. Plasma concentrations of fluvastatin were determined by a high-performance liquid chromatography with fluorescence detection. Pharmacokinetic parameters were calculated by non-compartmental method. The SNPs were determined by TaqMan®(MGB) genotyping assay.Effect of CYP2C9*3 (c.1075A>C) on area under the plasma concentration-time curve (AUC) of fluvastatin was statistically significant. Heterozygous variant (C/A) carriers had higher AUC values compared to homozygous wild type (A/A) carriers (922.03±148.17 µg · h · L - 1 vs. 496.00±168.93 µg · h · L - 1, P=0.003092). The elimination half-life (T 1/2) values of fluvastatin were longer in MDR1 2677non-G carriers than in MDR1 2677G carriers (2.21±0.47 h vs. 1.25±0.62 h, P=0.02319), and also they were longer in MDR1 1236T-2677non-G-3435T carriers than in MDR1 1236C-2677G-3435C carriers (2.31±0.51 h vs. 1.32±0.62 h, P=0.03320). MDR1 C3435T polymorphism had a significant effect on maximal plasma concentrations (C max) of fluvastatin. Mutation gene T (TT+CT) carriers had higher C max values compared to homozygous wild type (C/C) carriers (688.54±142.67 µg · L - 1 vs. . 413.78±177.83 µg · L - 1, P=0.01448). Some SNPs such as MDR1 C1236T, ABCG2 c.34G>A, ABCG2 c.421C>A, SLCO1B1 c.388 A>G, SLCO1B1 c.521 T>C, SLCO1B1 c.571 T>C and SLCO1B1 c.597 C>T have no significant effects on fluvastatin pharmacokinetics.CYP2C9*3(1075A>C), MDR1 C3435T and MDR1 G2677T/A were determinants of inter-subject variability in fluvastatin pharmacokinetics in healthy Chinese volunteers.

ADAMTS9 is a functional tumor suppressor through inhibiting AKT/mTOR pathway and associated with poor survival in gastric cancer

Using genome-wide promoter methylation analysis, we identified a disintegrin-like and metalloprotease with thrombospondin type 1 motif 9 (ADAMTS9) is methylated in cancer. We aim to clarify its epigenetic inactivation, biological function and clinical implication in gastric cancer. ADAMTS9 was silenced in 6 out of 8 gastric cancer cell lines. The loss of ADAMTS9 expression was regulated by promoter hypermethylation and could be restored by demethylation agent. Ectopic expression of ADAMTS9 in gastric cancer cell lines (AGS, BGC823) inhibited cell growth curve in both the cell lines (P<0.0001), suppressed colony formation (P<0.01) and induced apoptosis (P<0.001 in AGS, P<0.01 in BGC823). Moreover, conditioned culture medium from ADAMTS9-transfected cell lines significantly disrupted the human umbilical vein endothelial cell tube formation capacity on Matrigel (P<0.01 in AGS, P<0.001 in BGC823). The in vivo growth of ADAMTS9 cells in nude mice was also markedly diminished after stable expression of ADAMTS9 (P<0.001). On the other hand, ADAMTS9 knockdown promoted cell proliferation (P<0.001). We further revealed that ADAMTS9 inhibited tumor growth by blocking activation of Akt and its downstream target the mammalian target of rapamycin (mTOR). ADAMTS9 also reduced phosphorylation of mTOR downstream targets p70 ribosomal S6 kinase, eIF4E-binding protein and downregulated hypoxia-inducible factor-1α. Therefore, this is the first demonstration that ADAMTS9 is a critical tumor suppressor of gastric cancer progression at least in part through suppression of oncogenic AKT/mTOR signaling. Moreover, promoter methylation of ADAMTS9 was detected in 29.2% (21/72) of primary gastric tumors. Multivariate analysis showed that patients with ADAMTS9 methylation had a poorer overall survival (relative risk (RR)=2.788; 95% confidence interval, 1.474-5.274; P=0.002). Kaplan-Meier survival curves showed that ADAMTS9 methylation was significantly associated with shortened survival in gastric cancer patients (P=0.001, log-rank test). In conclusion, ADAMTS9 acts as a functional tumor suppressor in gastric cancer through inhibiting oncogenic AKT/mTOR signaling pathway. Methylation of ADAMTS9 is an independent prognostic factor of gastric cancer.

Identification of Wnt pathway, uPA, PAI-1, MT1-MMP, S100A4 and CXCR4 associated with enhanced metastasis of human large cell lung cancer by DNA microarray

AIM

The aim of this paper was to investigate the differentially expressed genes in large cell lung cancer cell lines with different metastatic potential, and to screen out new candidate genes related to metastasis of lung cancer.

METHODS

The total RNAs of low and high metastatic large cell lung cancer cell lines (NL9980 and L9981) were extracted and processed, then hybridized to Affymetrix HG U133 Plus 2.0 array. The hybridization signals were scanned and compared to find out the differentially expressed genes. Chosen genes were verified by Western Blot. Bioinformatics were used to analyze the functions and related pathways of the genes.

RESULTS

There were 933 differentially expressed genes between NL9980 and L9981 cell lines. In the high metastatic cell line L9981, 672 genes were up-regulated and 260 genes were down-regulated compared with the low metastatic cell line NL9980. The differentially expressed genes were mainly associated with binding, catalytic activity, signal transducer activity and transporter activity, and mainly involved in pathways including, pathways in cancer, focal adhesion, regulation of actin cytoskeleton, ECM-receptor interaction.

CONCLUSION

Differentially expressed genes with the functions including binding, catalytic activity, signal transducer activity and transporter activity may promote metastasis of lung cancer cells through complicated networks including Wnt pathway and metastasis-related genes such as uPA, PAI-1, MT1-MMP, S100A4 and CXCR4.

Downregulation of microRNA-126 in endothelial progenitor cells from diabetes patients, impairs their functional properties, via target gene Spred-1

Diabetes mellitus (DM) adversely affects the number and function of circulating endothelial progenitor cells (EPCs). Consequently, there is also a reduction in the repair mechanism of these cells, which is a critical and initiating factor in the development of diabetic vascular disease. The aim of the present study was to analyze miR expression profiles in EPCs from patients with DM and choose the most significantly regulated miR to study its possible role on EPC dysfunction and elucidate its mechanism of action. EPCs were collected from subjects with Type II DM and non-diabetic control subjects. Total RNA was harvested from EPCs, and a total of 5 candidate miRNAs were identified by microarray screening and were quantified by TaqMan real-time PCR. Lentiviral vectors expressing miR-126 and miR-126 inhibitor (anti-miR-126) were transfected into EPCs, and the EPC colony-forming capacity, proliferation activity, migratory activity, differentiation capacity, and apoptotic susceptibility were determined and Western Blotting and mRNA real-time PCR analyses were performed. To study the mechanisms, lentiviral vectors expressing Spred-1 and a short interfering RNA (siRNA) targeting Spred-1 were prepared. Five miRs were aberrantly downregulated in EPCs from DM patients. These miRs included miR-126, miR-21, miR-27a, miR-27b and miR-130a. Anti-miR-126 inhibited EPC proliferation, migration, and enhanced apoptosis. Restored miR-126 expression in EPCs from DM promoted EPC proliferation, migration, and inhibited EPC apoptosis ability. Despite this, miR-126 had no effect on EPC differentiation. miR-126 overexpression significantly downregulated Spred-1 in EPCs. The knockdown of Spred-1 expression in EPCs from DM promoted proliferation, migration, and inhibited apoptosis of the cells. The signal pathway of miR-126 effecting on EPCs is partially mediated through Ras/ERK/VEGF and PI3K/Akt/eNOS regulation. This study provides the first evidence that miR-126 is downregulated in EPCs from diabetic patients, and impairs EPCs-mediated function via its target, Spred-1, and through Ras/ERK/VEGF and PI3K/Akt/eNOS signal pathway.

Relationship between Serum Aminotransferase Levels and Metabolic Disorders in Northern China

BACKGROUND

Increasing evidence suggests an association between elevated serum aminotransferase levels and metabolic disorders (metabolic syndrome, hyperlipemia and diabetes mellitus). However, the significance of relatively low levels of aminotransferases in relation to metabolic disorders has not been fully investigated in the general population. We investigated the association between serum amiontransferase levels and metabolic disorders using data from a survey in Jilin province, China.

METHODS

In 2007, a survey was conducted throughout Jilin, China, covering both urban and rural areas. A total of 3835 people, 18 to 79 years old including 1761 men and 2074 women, underwent real-time ultrasonography, blood tests including aspartate aminotransferase and alanine aminotransferase, and had interviews with a structured questionnaire.

RESULTS

Serum aminotransferase levels within the normal range were associated with metabolic syndrome independent of age, occupation, cultural and educational level, income, body mass index, waist circumference, smoking, and alcohol intake. Compared with the lowest level (<20 IU/L), the adjusted odds ratios for ALT levels of 20-29, 30-39, 40-49 and >50 IU/L were 1.92, 2.50, 2.97, and 3.52 in men, and 1.38, 1.54, 3.06, and 2.62 in women, respectively. Near-normal serum aminotransferase levels associated with hyperlipemia, NAFLD, DM were also found in the study.

CONCLUSIONS

Normal to near-normal serum aminotransferase levels are associated with metabolic disorders. Serum ALT levels of 21-25 IU/L for men, and 17-22 IU/L for women are suggested as cutoff levels that detect metabolic disorders affecting the liver.

Noninvasive Evaluation of Cerebral Glioma Grade by Using Diffusion-Weighted Imaging-Guided Single-Voxel Proton Magnetic Resonance Spectroscopy

OBJECTIVE: To investigate the usefulness of diffusion-weighted imaging (DWI)-guided, single-voxel proton magnetic resonance spectroscopy (SVS) for preoperative evaluation of cerebral glioma grade. METHODS: For SVS, placement of volume-of-interest was guided by the minimal apparent diffusion coefficient value obtained from DWI. Spectral data for N-acetylaspartate (NAA), choline (Cho), and phosphocreatine (Cr) were analysed in 33 patients with primary gliomas. RESULTS: Cho/Cr and Cho/NAA ratios were significantly higher in high-grade than in low-grade gliomas; NAA/Cr ratios were significantly lower in high-grade than in low-grade gliomas. Receiver operating characteristic curve analysis demonstrated a threshold value of 2.01 for Cho/Cr for sensitivity, specificity, positive predictive and negative predictive values of 86.36%, 90.00%, 95.00% and 75.00%, respectively. Threshold values of 2.49 and 0.97 were obtained for Cho/NAA and NAA/Cr, respectively. Despite no significant difference in diagnostic accuracy between the metabolite ratios, diagnostic accuracy using the Cho/Cr ratio was slightly better than that of Cho/NAA or NAA/Cr. CONCLUSION: DWI-guided SVS has potential value for the preoperative prediction of glioma grade.

35 DYNAMICS OF PERICENTRIC REPETITIVE SEQUENCES IN PREIMPLANTATION RABBIT EMBRYOS UNDERLINES INADEQUATE SPATIO-TEMPORAL REORGANIZATION AFTER NUCLEAR TRANSFER

Nowadays, a critical question in the epigenetic field is how chromatin is organised within the cell nucleus and how it affects gene expression. In this study we hypothesise that nuclear structure could be involved in the control of gene expression during early rabbit embryonic development. We focused on pericentric/centric heterochromatin, a peculiar region within nuclei known to form higher-order chromatin structures. We therefore performed immunostaining of associated proteins (HP1 and CENP) as well as FISH (fluorescent in situ hybridization) with probes corresponding to these genomic regions. Fertilized embryos were collected from New Zealand white rabbit female, cultured in vitro and fixed at different developmental stages up to 16-cell. Nuclear transfer of rabbit fetal skin fibroblasts was performed by electrofusion and electroactivation (Chesne et al., 2002). Immunostaining experiments were performed as previously described (Martin et al., 2006) and FISH experiments were performed using DNA probes specific to Rsat I and Rsat II sequences (Ekes et al., 2004) according to our published protocol (Maalouf et al., 2010). Three-dimensional images were acquired by confocal laser microscopy (each group included 20 to 40 embryos) and then analysed through automated 3D image processes (according to Ballester et al., 2008; Pichugin et al., 2010). Briefly, after segmentation of the nuclei, immunostaining signals were analysed using an automatic threshold segmentation procedure and FISH spots distributions were analysed with the eroded volume fraction (EVF) method. In in vivo fertilized rabbit embryos, we observed that during the 1- and 2-cell cycles pericentric heterochromatin was dispersed throughout the embryonic nuclei. Large foci of pericentric heterochromatin then progressively appeared at the 4-cell stage and increased in frequency and size by the 8/16-cell stage [∼75% of the embryos, n = 40; i.e. the stage of major transcriptional activation also called MET (maternal to embryonic-transition)]. This suggested that dramatic aggregation of pericentric heterochromatin is associated to the onset of transcription. Interestingly, after nuclear transfer, the donor nuclear organisation was quickly reverted into an early embryonic dispersed form in most 1-cell embryos (80%, n = 35). Subsequently, a somatic-like nuclear reorganization with large heterochromatin foci was re-established in 86% of the 4-cell stage cloned embryos (n = 35). This pattern was similar to the one observed in fertilized embryos at MET; it also appeared one stage earlier (4-cell vs 8-cell). Coincidently, most cloned embryos stopped developing at that stage (85% of cleavage until the 4-cell but only 38% at morula, n = 173). Together, the results suggested that inadequate spatio-temporal reorganization of the donor nucleus could be deleterious during early development in rabbit clones. The present work was supported by INRA « Jeune Equipe » funding, the European CLONET (MRTN-CT-2006-035468) grant and the Ambassade de France en Chine.

Economic assessment of climate adaptation options for urban drainage design in Odense, Denmark

Climate change is likely to influence the water cycle by changing the precipitation patterns, in some cases leading to increased occurrences of precipitation extremes. Urban landscapes are vulnerable to such changes due to the concentrated population and socio-economic values in cities. Feasible adaptation requires better flood risk quantification and assessment of appropriate adaptation actions in term of costs and benefits. This paper presents an economic assessment of three prevailing climate adaptation options for urban drainage design in a Danish case study, Odense. A risk-based evaluation framework is used to give detailed insights of the physical and economic feasibilities of each option. Estimation of marginal benefits of adaptation options are carried out through a step-by-step cost-benefit analysis. The results are aimed at providing important information for decision making on how best to adapt to urban pluvial flooding due to climate impacts in cities.

P5-13-13: The Role of Topoisomerase IIa in Predicting Sensitivity to Anthracyclines in Breast Cancer Patients: A Meta-Analysis of Published Literatures

Topoisomerase IIα is not only a proliferation marker of tumor cells but also a target for anthracycline-based chemotherapy. Both in vitro and in vivo studies have shown that there was a relationship between topo IIα and chemosensitivity to anthracyclines, but the predictive role of topo IIα is still controversial in breast cancer patients. A meta-analysis based on published studies was performed with the aim of obtaining an accurate evaluation of the association between topo IIα and sensitivity to anthracycline-based chemotherapy. A total of 13 eligible studies including 2,633 cases and 2,118 controls were identified. Topo IIα was associated with sensitivity to anthracyclines in locally advanced breast cancer patients who received neoadjuvant chemotherapy (RR = 1.93, 95%CI: 1.27−2.94, P=0.002; RR =1.98, 95%CI: 1.37−2.86, P&lt;0.001). In early breast cancer patients who received anthracycline-based adjuvant chemotherapy compared with non-taxane-based polychemotherapy, amplification(HR = 0.64, 95%CI: 0.49−0.83, P=0.001; HR = 0.59, 95% CI: 0.35−1.01, P=0.056) or deletion (HR = 0.82, 95%CI: 0.67−1.00, P=0.051; HR =0.58, 95%CI: 0.35−0.97, P=0.036) of topo IIα was significantly associated with better RFS and OS. The subgroup analysis in the early breast cancer patients indicated that taxane could be an interference for evaluation of the predictive role of topo IIα. In summary, the present meta-analysis suggests that topo IIα is a predictive factor for breast cancer patients who received anthracycline-based chemotherapy. Larger and well-designed prospective studies are required to further evaluate the predictive role of topo IIα in clinical practice.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-13.

P3-16-10: The Efficacy of Zoledronic Acid in Breast Cancer Adjuvant Therapy: A Meta-Analysis of Randomized Controlled Trials

Background: The effect of zoledronic acid in breast cancer adjuvant therapy concerning improvement of patient survival has yet to be confirmed. We performed a meta-analysis of published and unpublished randomized controlled trials with the aim of accurate evaluation between clinical outcome and the association of the addition of zoledronic acid to adjuvant therapy.

Methods: We searched Pubmed (from 1966 to present) and online abstracts from the proceeding Annual Meetings of the American Society of Clinical Oncology (ASCO) (years 1992–2010) and online abstracts from San Antonio Breast Cancer Symposium (years 2004–2010). A total of five eligible studies including 3676 subjects and 3678 controls met our search criteria and were evaluated. Random and fixed-effects meta-analytical models were used where indicated, and between-study heterogeneity was assessed. The primary study endpoints were the DFS. Secondary endpoints were OS, distant or loco-regional recurrence free survival and bone metastasis free survival.

Results: Compared with the control arm, adjuvant breast cancer treatment with zoledronic acid did not significantly improve overall survival (OS), disease free survival (DFS), bone metastasis free survival, distant and locoregional recurrence free survival. However, in the postmenopausal subgroup, the addition of zoledronic acid to standard therapy could significantly improve DFS (RR=0.763, 95%CI 0.658−0.884, p&lt;0.001) and reduce the risk of distant (RR=0.744, 95% CI 0.611−0.906, p=0.003) and locoregional recurrence (RR=0.508, 95% CI 0.340−0.760, p=0.001).

Discussion: Adjuvant zoledronic acid may potentially improve the prognosis of postmenopausal patients. Additional studies are needed to evaluate the value of adjuvant treatment of zoledronic acid in premenopausal couterparts, differing disease stages, and various pathological types of breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-16-10.