Arousal-related reticular neurons during reduced oxygen tension: resilience and recovery of electrical activity

Whole-cell patch clamp recordings of the electrical activity of large medullary reticular formation neurons, in nucleus gigantocellularis, were performed under control conditions and under conditions of hypoxia or anoxia. Neurons were discovered whose activity was remarkably resilient during and after the reduction or loss of oxygen. Such cells may relate to the ability of the newborn brain to survive hypoxia/anoxia, and also may demonstrate the preservation of neurons involved in generalized CNS arousal, as would be appropriate for activating behavioral responses to the reduction or loss of oxygen.

Measurement of annexin V uptake and lactadherin labeling for the quantification of apoptosis in adherent Tca8113 and ACC-2 cells

Phosphatidylserine (PS) exposure occurs during the cell death program and fluorescein-labeled lactadherin permits the detection of PS exposure earlier than annexin V in suspended cell lines. Adherent cell lines were studied for this apoptosis-associated phenomenon to determine if PS probing methods are reliable because specific membrane damage may occur during harvesting. Apoptosis was induced in the human tongue squamous carcinoma cell line (Tca8113) and the adenoid cystic carcinoma cell line (ACC-2) by arsenic trioxide. Cells were harvested with a modified procedure and labeled with lactadherin and/or annexin V. PS exposure was localized by confocal microscopy and apoptosis was quantified by flow cytometry. The detachment procedure without trypsinization did not induce cell damage. In competition binding experiments, phospholipid vesicles competed for more than 95 and 90% of lactadherin but only about 75 and 70% of annexin V binding to Tca8113 and ACC-2 cells. These data indicate that PS exposure occurs in three stages during the cell death program and that fluorescein-labeled lactadherin permitted the detection of early PS exposure. A similar pattern of PS exposure has been observed in two malignant cell lines with different adherence, suggesting that this pattern of PS exposure is common in adherent cells. Both lactadherin and annexin V could be used in adherent Tca8113 and ACC-2 cell lines when an appropriate harvesting procedure was used. Lactadherin is more sensitive than annexin V for the detection of PS exposure as the physical structure of PS in these blebs and condensed apoptotic cell surface may be more conducive to binding lactadherin than annexin V.

High expression levels of putative hepatic stem/progenitor cells biomarkers related to tumor angiogenesis and poor prognosis of hepatocellular carcinoma

e22121

Background: To investigate the prognostic values of putative hepatic stem/progenitor cells (HSCs/HPCs) biomarkers in hepatocellular carcinoma (HCC) patients. Methods: Fourteen biomarkers related with HSCs/HPCs or tumor angiogenesis were assessed by qRT-PCR and then validated by tissue microarrays (TMAs) in three independent cohorts of HCC patients underwent curative resection (n=67, 314 and 73). Results: Most of the biomarkers were found over-expressed in recurrent HCC patients by qRT-PCR. HSCs/HPCs biomarkers cytokeratin 19, ABCG2, CD133, Nestin, CD44 and angiogenesis agents CD34, VEGF and PD-ECGF, were confirmed as significant predictors for overall survival (OS) and/or relapse-free survival (RFS) in TMAs analysis. Compared with the low HSCs/HPCs profile group, patients with high HSCs/HPCs profile had significantly lower OS and RFS (p<0.0001), expressed higher VEGF levels (p = 0.012) and microvessel density (MVD, determined by CD34 immunostaining, p = 0.030). Based on Cox regression, a simplified model including CD133, CD44, Nestin, and MVD was constructed and confirmed as an independent predictor for OS (p<0.0001) and RFS (p<0.0001), regardless of alpha-fetoprotein level, tumor stage and recurrence time (p<0.0001 for all). Conclusions: High expression levels of HSCs/HPCs biomarkers are related to tumor angiogenesis and poor prognosis of HCC. The simplified model based on HSCs/HPCs and tumor angiogenesis profile can be used to classify HCC patients with high risk of tumor recurrence after operation.

No significant financial relationships to disclose.

Analysis of signal pathway activation in hepatocellular carcinoma: Association with clinical outcomes to sorafenib in Chinese patients

e15529

Background: The pathogenesis of hepatocellular carcinoma invovles multi-stage development of molecular aberrations affecting signaling pathways that regulate cancer growth and progression. Treatment strategies have focused on inhibition of the Ras effector pathway with inhibitors of Raf, such as sorafenib in HCC. Greater understanding of the cellular response to sorafenib is needed to tailor targeted therapy for individual patients and identify those more likely to benefit. Methods: We performed immunohistochemistry on a tissue microarray of tumor and adjacent liver tissue from 40 HBV-infected HCC patients who were treated with sorafenib, and 20 normal liver. We compared the levels of 8 signaling proteins including growth factor receptors (PDGFRa, VEGFR1, VEGFR2, VEGFR3, c-kit, c-met, IGF-R, EGFR), tumor suppressors (PTEN) and their downstream phosphorylated (p-) signal transducers (p-RAF, p-MEK1/2, p-ERK1/2; PI3K, p-AKT, NFkB, axin, β-catenin,p-GSK3β, p-mTOR, p-S6, p-70S6K, p-JNK, p-SRC, p-STAT3, c-fos, c-jun) in cancer cells and endothelial cells of HCC to those in non-neoplastic liver. Results: The overall profiles of signalling protein expression levels, activation states and subcellular distribution in HCC cells and endothelial cells were distinguishable from non-neoplastic hepatocytes. The ERK pathway activation was correlated with low level of nuclear β-cat and high level of p-mTOR (p<0.05). Long survival (>6m) patients were characterized by high level of nuclear pERK and low level of p-AKT, p-GSK3β (p<0.05) in tumor cells. The high microvessel density and the presence of micrometastases correlated with high level of VEGFR, p-ERK and p-SRC in endothelial cells. Conclusions: Sorafenib may affect signalling through the Ras/Raf/MAPK/ERK pathway. HBV-related HCC patients with. overactivation of signal transduction cascade MAPK/ERK and PI3K/AKT pathways in tumor cells and/or endothelial cells may benefit from the targeted treatment.

No significant financial relationships to disclose.

Antitumor activity of patient-derived renal cell carcinoma cells fused with allogeneic dendritic cells: In vitro results and clinical responses

3056

Background: Renal cell carcinoma (RCC) has been shown to be highly susceptible to immune-based treatment strategies. Methods: In the present study, patient-derived tumor cells were fused with allogeneic dendritic cells (DC) to elicit antitumor activity against RCC. DC from HLA-A2+ healthy donors were fused with primary RCC cells from 10 patients. Phenotype of fusion cells was characterized by flow cytometer and confocal microscopy. In vitro, T-cell proliferation, IFN-γ secretion, and cytotocic T lymphocytes (CTL) activity elicited by allogeneic DC/RCC fusion cells were assessed. Clinically, 10 patients were vaccinated with allogeneic DC/RCC fusion vaccine. The adverse effects and toxicity were observed. The clinical response was evaluated by CT scans. Results: After fusion, the created hybrids expressed both tumor-associated antigen and DC-derived molecules and could stimulate the proliferation and IFN-γ secretion of T-cells as well as elicit strong CTL activity against RCC cells in vitro. In vivo, neither serious adverse effects nor signs of autoimmune disease were observed after vaccination therapy. Percentage of T lymphocyte subsets in peripheral blood of patients was increased significantly. One of 10 patients exhibited a partial response with regression of lung metastases. Six patients showed stable disease with stabilization of previously progressive disease (follow-up 1.5 year). Conclusions: The data suggest that allogeneic DC/RCC fusion vaccine is safe and can elicit immunological responses in patients with RCC.

No significant financial relationships to disclose.

Expression of CD24 as a predictor of prognosis of hepatocellular carcinoma after operation

e22043

Background: CD24 expression has previously been reported in hepatocellular carcinoma (HCC), although little is known about its prognostic significance. The aim of this study is to evaluate the relation of CD24 expression and its prognostic significance in HCC. Methods: CD24 expression in stepwise metastatic HCC cell lines and tumor tissues from 50 HCC patients was investigated by quantitative real-time reverse transcription-PCR and Western blot analyses. The role of CD24 was investigated by depletion CD24 expression in HCC cells through small-interfering RNA. Tumor tissue microarrays of 314 HCC patients who underwent resection between 1997 and 2000 were used to detect the expressions of CD24, β-catenin and PCNA expression. The prognostic significance was assessed using Kaplan-Meier survival estimates and log-rank tests. Results: CD24 was overexpressed in the high metastatic HCC cell line and in tumor tissues of recurrent patients. Depletion of CD24 caused a notable decrease in cell proliferation, migration and invasiveness in vitro. CD24 was confirmed as an independent predictor for overall survival (p<0.001) and relapse-free survival (p<0.001), regardless of recurrence time, AFP level, TNM stage and Edmondson stage. High expression of CD24 in HCC tissues was significantly associated cytoplasmic/nuclear accumulation of β-catenin (p=0.023), high tumor proliferate status (p=0.018) and diffused intrahepatic recurrence and distance metastasis (p=0.026). Adjuvant TACE after operation reduced the early recurrence (≤1 year) in CD24+ HCC patients (p=0.024), while there had no significant changes in CD24- patients (p=0.284). Conclusions: High expression levels of CD24 were related with high invasive and metastatic potential, high tumor proliferation status and activation of Wnt/β-catenin pathway. The expression of CD24 provides new prognostic information about HCC prognosis and targeted therapy to CD24+fraction in HCC may comprise a promising anti-recurrence strategy for HCC patients after surgery.

No significant financial relationships to disclose.

Beneficial effects of danshensu, an active component of Salvia miltiorrhiza, on homocysteine metabolism via the trans-sulphuration pathway in rats

BACKGROUND AND PURPOSE

Elevated plasma total homocysteine (tHcy) level has been established as an independent risk factor for cardiovascular diseases. Danshensu, an active ingredient of Salvia miltiorrhiza, shows wide cardiovascular benefit. However, in terms of its own methylation, danshensu could elevate tHcy level, which would act against its cardiovascular benefit, thus posing a 'therapeutic paradox'. As this paradox has not been fully assessed, we have evaluated the effects of danshensu on tHcy levels to uncover the underlying mechanisms. EXPERIMENT APPROACH: We evaluated the influence of danshensu on homocysteine (Hcy) metabolism in rats with normal tHcy levels and in rat models of elevated tHcy (single intravenous methionine loading model and a hyperhomocysteinemic model after 3 weeks methionine dosing, with and without 3 weeks of danshensu treatment). We also quantified some metabolic intermediates (S-adenosyl methionine, S-adenosyl-l-homocysteine, cysteine and glutathione) relevant to Hcy metabolism in rat liver and kidney.

KEY RESULTS

Acute treatment with a single dose of danshensu in rats with normal tHcy did not change plasma tHcy. In contrast, danshensu significantly lowered tHcy in rats with elevated tHcy. The relatively higher cysteine and glutathione levels after treatment with danshensu indicated that its tHcy-lowering effect was via increased activity of the trans-sulphuration pathway.

CONCLUSIONS AND IMPLICATIONS

Our results suggested that danshensu may act both acutely to increase trans-sulphuration and after chronic exposure to up-regulate the activity of the trans-sulphuration enzymes. The tHcy-lowering effect of danshensu is another cardiovascular benefit provided by S. miltiorrhiza and suggests a potential tHcy-lowering therapy.

Increased expression of integrin alpha2 and abnormal response to TGF-beta1 in hereditary gingival fibromatosis

OBJECTIVE

To investigate the possible correlation between integrin alpha1, alpha2, and beta1 expression and excessive collagen synthesis in fibroblasts from 3 unrelated Chinese families with hereditary gingival fibromatosis (HGF).

DESIGN

Gingival fibroblasts from three Chinese HGF patients and three healthy subjects were included. The expression of alpha1, alpha2, and beta1 integrin subunits was examined by immunohistochemistry, quantitative PCR, and flow cytometry. We also investigated the effects of transforming growth factor-beta1 (TGF-beta1) on the expression of these integrin subunits.

RESULTS

Our results demonstrate that the expression of alpha2 was significantly higher in HGF fibroblasts compared with control fibroblasts (P < 0.01). No significant differences in the expression of alpha1 and beta1 were detected. Furthermore, TGF-beta1 promoted the expression of alpha1 and alpha2 in fibroblasts from both HGF patients and controls. However, it had a larger effect on the expression of alpha2 in HGF fibroblasts than in control cells. In contrast, alpha1 expression was stimulated more in control fibroblasts.

CONCLUSION

The increased expression of integrin alpha2 and the increased response to TGF-beta1 of HGF fibroblasts may be related to the excessive collagen deposition in HGF patients.

Possible involvement of brain tumour stem cells in the emergence of a fast-growing malignant meningioma after surgical resection and radiotherapy of high-grade astrocytoma: case report and preliminary laboratory investigation

The case of a 62-year old man diagnosed with radiation-induced meningioma (RIM) after treatment for astrocytoma with an unusually short latency period of 7 months is reported. The patient first presented with a 2-month history of memory decline. Magnetic resonance imaging (MRI) showed a tumour in the left parieto-temporal lobe. Gross total resection was performed and the tumour was confirmed to be an astrocytoma. The patient received cranial radiotherapy 2 weeks later, however 7 months after radiation treatment the patient presented with headache and vomiting. MRI showed massive meningeal enhancement in the left frontal lobe, which progressively enlarged. The patient's clinical condition deteriorated and a second craniotomy was performed with complete removal of the secondary tumour, which was shown to be a malignant meningioma. Immunohistochemical staining identified CD133-positive cells in both tumours. A rare fraction of brain tumour stem cells (BTSC) was isolated from the primary astrocytoma using a serum-free culture system, suggesting that BTSC may have been involved in the rapid emergence of RIM after resection and radiation of the primary astrocytoma.

Inactivation of AMPK alters gene expression and promotes growth of prostate cancer cells

AMP-activated protein kinase (AMPK) serves as a fuel-sensing enzyme that is activated by binding of AMP and subsequent phophorylation by upstream kinases such as the tumor suppressor LKB1, when cells sense an increase in the ratio of AMP to ATP. Acute activation of AMPK stimulates fatty acid oxidation to generate more ATP and simultaneously inhibits ATP-consuming processes including fatty acid and protein syntheses, thereby preserving energy for acute cell surviving program, while the chronic activation leads to inhibition of cell growth. The goal of the present study is to explore the mechanisms by which AMPK regulates cell growth. Toward this end, we established stable cell lines by introducing a dominant negative mutant of AMPK α1 subunit or its shRNA into the prostate cancer C4-2 cells and other cells, or wild type LKB1 into the lung adenocarcinoma A549 and breast MB-MDA-231 cancer cells, both of which lack functional LKB1. Our results showed that the inhibition of AMPK accelerated cell proliferation and promoted malignant behavior such as increased cell migration and anchorage-independent growth. This was associated with decreased G1 population, downregulation of p53 and p21, and upregulation of S6K, IGF-1 and IGF1R. Conversely, treatment of the C4-2 cells with 5-aminoimidazole-4-carboxamide 1-Dribonucleoside (AICAR), a prototypical AMPK activator, caused opposite changes. In addition, our study using microarray and RT-PCR revealed that AMPK regulated gene expression involved in tumor cell growth and survival. Thus, our study provides novel insights into the mechanisms of AMPK action in cancer cells and presents AMPK as an ideal drug target for cancer therapy.

Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

A comparative study on urinary purine derivative excretion of yak (Bos grunniens), cattle (Bos taurus), and crossbred (Bos taurus x Bos grunniens) in the Qinghai-Tibetan plateau, China

Two experiments were conducted to determine the urinary purine derivative (PD) excretion rates and to analyze potential variations in PD excretions between yak, Tibetan indigenous cattle, and their crossbreds under similar ecological environment, and to develop prediction equations based on PD excretion for estimating rumen microbial protein supply. Three Tibetan castrated male yaks, and similar numbers of indigenous cattle and their crossbreds, were used in a fasting trial followed by a feeding trial, using three 3 x 3 Latin squares (1 for each breedtype), to measure responses of PD excretion to different feeding levels. The results showed that i) daily endogenous PD excretion for yak, indigenous cattle, and their crossbreds was 134, 163, and 138 micromol/kg of BW(0.75) (P = 0.38), respectively; and ii) crossbreds have greater PD excretion rate per unit digestible OM intake than indigenous cattle (P = 0.03). However, there were no significant differences between yaks and the crossbreds (P = 0.24) or between yaks and the indigenous cattle (P = 0.25). The proportion of allantoin to total PD in urine ranged from 0.83 to 0.88, with the crossbreds having greater values compared with the 2 parents (P = 0.03). Daily glomerular filtration rate, calculated using endogenous creatinine as an internal marker, for the above animals was 3.85, 4.23, and 3.61 L/kg of BW(0.75), respectively, in fasting trial (P = 0.59). The alpine animals may develop special regulating mechanisms in the kidney in terms of glomerular filtration rate and PD excretion, which would help the animals in adapting to the harsh environment of the Qinghai-Tibetan plateau.

Protective effect of ginsenoside against acute renal failure and expression of tyrosine hydroxylase in the locus coeruleus

Acute renal failure (ARF) is mainly characterized by acute tubular necrosis. No significant change was found for mortality rates over the past few decades despite significant advances in supportive care. In recent years, great effort has been focused on traditional and herbal medicine, which is much less toxic than those agents conventionally used and which is nowadays considered as a novel therapeutic agent for ARF. However, the effect of ginsenosides (GS) administered orally on ARF has not been reported yet and little is known about its cellular and molecular mechanism. The purpose of the study is to investigate the protective effect of ginsenoside in rats with ARF on the changes of tyrosine hydroxylase immunoreactivity (TH-IR) as well as on the involvement of mitogen-activated protein kinases (MAPK) in the locus coeruleus. In our assay, glycerol-induced acute renal failure in rats was employed to study the protective effects of ginsenoside. Our results indicated that the treatment of ARF rats with ginsenosides for 48 h significantly reduced the serum blood urea nitrogen, creatinine level, and lipid peroxidation, restored the GSH level and the normal renal morphology. Immunohistochemistry showed that an obvious increase of TH-IR was further enhanced in ARF+GS group. The same effect was also observed in the changes of p-ERK1/2-IR in the locus coeruleus. Our results suggest that ginsenoside administered orally may have a strong renal protective effect against glycerol-induced ARF, and ginsenoside can also activate the brain catecholaminergic neurons in the locus coeruleus. Our future attention will be focused to the question whether there is a correlation between the renal protective effect of ginsenosides against acute renal failure and the activation of tyrosine hydroxylase in the locus coeruleus.

Sirolimus-based immunosuppression therapy in liver transplantation for patients with hepatocellular carcinoma exceeding the Milan criteria

AIM

Sirolimus (SRL) acts as a primary immunosuppressant or antitumor agent. The aim of the present study was to evaluate the influence of SRL on the recurrence rate and survival of patients after orthotopic liver transplantation (OLT) for hepatocellular carcinoma (HCC) exceeding the Milan criteria.

MATERIALS AND METHODS

We retrospectively examined 73 consecutive patients who underwent OLT for HCC exceeding the Milan criteria from March 2004 through December 2005. Among them, 27 patients were treated with SRL-based immunosuppressive protocols after OLT, and 46 patients by an FK506-based protocol. Statistical analysis was based on the intent-to-treat method.

RESULTS

The 2 groups were comparable in all clinicopathologic parameters. The mean overall survival was 594 +/- 35 days in the SRL group and 480 +/- 42 days in the FK506 group (P = .011); the mean disease-free survival period was 519 +/- 43 days in the SRL group and 477 +/- 48 days in the FK506 group (P = .234). Multivariate analysis revealed Child's status (P = .004) and immunosuppressive protocol (P = .015) were the significant factors affecting overall survival. Only microvascular invasion (P = .004) was significantly associated with disease-free survival. Among 24 surviving patient in the SRL group, 2 patients had SRL discontinued for toxicity; 10 had SRL monotherapy immunosuppression.

CONCLUSION

The SRL-based immunosuppressive protocol improved the overall survival of patients after OLT for HCC exceeding the Milan criteria, probably by postponing recurrence and with better tolerability.