Hepatitis B virus protein preS2 potentially promotes HCC development via its transcriptional activation of hTERT

BACKGROUNDS AND AIMS

Telomerase is significantly reactivated in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). Our previous studies showed that the transactivation unit of HBV surface (S) gene, preS2, could upregulate human telomerase reverse transcriptase (hTERT) expression and telomerase activity of HepG2 cells. Here, we aim to explore the functions, and the underlying mechanisms, of this preS2-mediated hTERT upregulation during HCC development.

METHODS

An antisense blocking assay was performed on HBV-integrated HepG2.2.15 cells. The expression of hTERT was examined in clinical samples to test the role of the preS2-mediated hTERT upregulation in HCC development in vivo. In order to explore the mechanisms of preS2-mediated hTERT upregulation, co-transfection, reporter assays and electrophoretic mobility shift assays (EMSA) were performed.

RESULTS

Blocking preS2 expression reduced hTERT expression, telomerase activity, cell proliferation and tumorigenicity of HepG2.2.15. A region located between -349 and -329 bp upstream of the transcription initiation site of hTERT was identified as responsible for the preS2-mediated effect. preS2 interacted with the preS2-responsible region (PRR) and activated the hTERT promoter. Importantly, hTERT was also highly expressed in preS2-positive human HCC samples. All these findings strongly suggest that preS2 may promote HCC development via hTERT activation.

CONCLUSIONS

HBV protein preS2 upregulates hTERT via the PRR element in promoting HCC development.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

K/pi Fluctuations at relativistic energies

We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.

Effects of carotenoids from Deinococcus radiodurans on protein oxidation

AIMS

To evaluate the antioxidant effect of carotenoids from Deinococcus radiodurans on protein.

METHODS AND RESULTS

Deinococcus radiodurans strain R1 (ATCC 13939) and its mutant strain R1DeltacrtB were used for this study. The total carotenoids (R1ex) from D. radiodurans were obtained by extraction with acetone/methanol (7 : 2, by vol), and their antioxidant activity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl) system. The protein oxidation level, in vitro and in the cell, was measured using the DNPH (2,4-dinitrophenyl hydrazine) method. The carotenoid extract R1ex scavenged 40.2% DPPH radicals compared to beta-carotene (31.7%) at a concentration of 0.5 mg ml(-1). The intracellular level of protein oxidation in mutant R1DeltacrtB, which does not contain carotenoid, was 0.0212 mmol mg(-1) protein which is significantly greater than that in the wild type (0.0169 mmol mg(-1) protein) following the treatment with H(2)O(2). The purified major carotenoid product (deinoxanthin) from the wild type showed a greater inhibition of oxidative damage in bovine serum albumin than lycopene or lutein.

CONCLUSIONS

Carotenoids prevent protein oxidation and contribute to the resistance to cell damage in D. radiodurans.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results provide the evidence that carotenoids can protect proteins in D. radiodurans against oxidative stress.

Bone fractures among postmenopausal patients with endocrine-responsive early breast cancer treated with 5 years of letrozole or tamoxifen in the BIG 1-98 trial

BACKGROUND

To compare the incidence and timing of bone fractures in postmenopausal women treated with 5 years of adjuvant tamoxifen or letrozole for endocrine-responsive early breast cancer in the Breast International Group (BIG) 1-98 trial.

METHODS

We evaluated 4895 patients allocated to 5 years of letrozole or tamoxifen in the BIG 1-98 trial who received at least some study medication (median follow-up 60.3 months). Bone fracture information (grade, cause, site) was collected every 6 months during trial treatment.

RESULTS

The incidence of bone fractures was higher among patients treated with letrozole [228 of 2448 women (9.3%)] versus tamoxifen [160 of 2447 women (6.5%)]. The wrist was the most common site of fracture in both treatment groups. Statistically significant risk factors for bone fractures during treatment included age, smoking history, osteoporosis at baseline, previous bone fracture, and previous hormone replacement therapy.

CONCLUSIONS

Consistent with other trials comparing aromatase inhibitors to tamoxifen, letrozole was associated with an increase in bone fractures. Benefits of superior disease control associated with letrozole and lower incidence of fracture with tamoxifen should be considered with the risk profile for individual patients.

The effect of endocrine responsiveness on high-risk breast cancer treated with dose-intensive chemotherapy: results of International Breast Cancer Study Group Trial 15-95 after prolonged follow-up

BACKGROUND

The role of adjuvant dose-intensive chemotherapy and its efficacy according to baseline features has not yet been established.

PATIENTS AND METHODS

Three hundred and forty-four patients were randomized to receive seven courses of standard-dose chemotherapy (SD-CT) or three cycles of dose-intensive epirubicin and cyclophosphamide (epirubicin 200 mg/m(2) plus cyclophosphamide 4 mg/m(2) with filgrastim and progenitor cell support). All patients were assigned tamoxifen at the completion of chemotherapy. The primary end point was disease-free survival (DFS). This paper updates the results and explores patterns of recurrence according to predicting baseline features.

RESULTS

At 8.3-years median follow-up, patients assigned DI-EC had a significantly better DFS compared with those assigned SD-CT [8-year DFS percent 47% and 37%, respectively, hazard ratio (HR) 0.76; 95% confidence interval 0.58-1.00; P = 0.05]. Only patients with estrogen receptor (ER)-positive disease benefited from the DI-EC (HR 0.61; 95% confidence interval 0.39, 0.95; P = 0.03).

CONCLUSIONS

After prolonged follow-up, DI-EC significantly improved DFS, but the effect was observed only in patients with ER-positive disease, leading to the hypothesis that efficacy of DI-EC may relate to its endocrine effects. Further studies designed to confirm the importance of endocrine responsiveness in patients treated with dose-intensive chemotherapy are encouraged.

A randomized trial of anthracycline dose intensification during induction of younger patients with acute myeloid leukemia: Results of Eastern Cooperative Oncology Group study E1900

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Background: In younger adults with newly diagnosed acute myeloid leukemia (AML), anthracycline dose intensification during induction may improve complete remission (CR) rates; however, an improvement in overall survival (OS) in a randomized trial has not been demonstrated. This unresolved issue led the ECOG to compare standard dose (SDD) to high-dose daunorubicin (HDD) in induction. Methods: Adult patients with previously untreated AML were randomized to receive either SDD (45 mg/m2/d) or HDD (90 mg/m2/d) each for 3days combined with standard-dose cytarabine (100 mg/m2/d) for 7 days by continuous intravenous infusion. Those achieving a CR were allocated to allogeneic hematopoietic stem cell transplantation (HSCT) or high-dose cytarabine (with or without a single dose of gemtuzumab ozogamicin) prior to autologous HSCT. Intravenous busulfan and cyclophosphamide was the preparative regimen for both allogeneic and autologous HSCT. The primary end point of this study was OS from the time of induction randomization. Results: 633 patients, age 18 to 60 (median 48) years, were entered in this study. There were no differences in patient demographics or disease characteristics between the two groups at presentation. In an intention-to-treat analysis, HDD resulted in a significantly higher CR rate (63.3% vs. 47.7%, p = 0.0003) than SDD. Induction deaths were similar between the two groups (5.4 vs. 5.0%, p = ns). 334 (52.8%) patients entered the consolidation phase. 57.4% of HDD and 48.1% of the SDD patients, received consolidation therapy on study, and 28.7% and 23.1% proceeded to HSCT respectively. Median OS was superior for the HDD (23.7 months) over the SDD (15.1 months) group (p = 0.005). In subgroup analysis, patients with favorable or intermediate-risk cytogenetics or age <55 years benefited from the HDD. Conclusions: We demonstrate for the first time in a prospective randomized trial that intensifying induction therapy through a higher daily anthracycline dose, in the setting of identical intensive consolidation therapy, results in a higher CR rate as well as prolonged OS. In younger AML patients a higher dose of anthracycline in induction should be considered the new standard of care.

No significant financial relationships to disclose.

Cognitive function in postmenopausal women receiving adjuvant letrozole or tamoxifen in the Breast International Group (BIG) 1–98 trial

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Background: Hormonal therapy for breast cancer (BC) may affect cognition. Methods: Post-menopausal women with hormone receptor positive, early-stage BC were randomized to receive either: A) tamoxifen for 5 years; B) letrozole for 5 years; C) tamoxifen for 2 years followed by letrozole for 3 years; or D) letrozole for 2 years followed by tamoxifen for 3 years, as adjuvant endocrine treatment. During the fifth year of trial treatment, objective cognitive function (speed of psychomotor function, visual attention, working and verbal memory, learning) was evaluated by computerized tests. The difference in the composite score for patients taking letrozole (B+C; N= 65) versus tamoxifen (A+D; N = 55) at the time of testing was the primary comparison. Scores for each domain were standardized according to age-specific norms. Two-way ANOVA controlling for language was used to test the effect of treatment on cognitive function. Self-reported subjective cognitive function, psychological distress, fatigue and quality of life were also assessed. Results: Patient characteristics were balanced between groups. Both groups performed below age norms on most domains. The group taking letrozole had better overall cognitive function than the tamoxifen group (difference in mean composite scores = 0.278, p = 0.038, 95% CI: 0.015–0.540) and outperformed patients on tamoxifen for all domains (n.s.). Comparison of monotherapy arms A versus B supported better cognitive function among letrozole patients. Subjective cognitive function, psychological distress, fatigue, and quality of life did not differ between groups. Conclusions: Although letrozole results in lower circulating estrogen levels than tamoxifen, in this study BC patients taking adjuvant letrozole during the fifth year of treatment had better cognitive functioning than those taking tamoxifen.

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Advanced Glycation End-products Enhance Calcification in Vascular Smooth Muscle Cells

Advanced glycation end-products (AGEs), senescent macroprotein derivatives formed at an accelerated rate in diabetes, are closely associated with vascular calcification in humans. In this study, the hypothesis that AGEs enhance calcification in cultured vascular smooth muscle cells (VSMCs) was tested. Using real-time polymerase chain reaction (PCR) and specific protein assays, it was demonstrated that rat aortic VSMCs incubated with AGEs exhibited an increased expression of the AGE receptor (RAGE) and typical bone proteins, such as osteopontin and alkaline phosphatase. Incubation with AGEs also enhanced calcium accumulation in VSMCs in time-and dose-dependent manners. These AGEs-mediated changes in VSMCs were partially attenuated by a neutralizing antibody to RAGE. The results suggest that AGEs that accumulate in diabetes could elicit the osteoblastic differentiation of VSMCs, thereby contributing to vascular calcification via the RAGE pathway. Interruption of the AGE-RAGE interaction might be a promising target for therapeutic intervention to prevent diabetic vascular calcification.

MicroRNA-101 regulates expression of the v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) oncogene in human hepatocellular carcinoma

MicroRNAs (miRNAs) have recently been proposed as a versatile class of molecules involved in regulation of various biological processes. Although there is emerging evidence that some microRNAs can function as oncogenes or tumor suppressors, the specific role of miRNA in human hepatocellular carcinoma (HCC) is unclear at this point. In this study, we examined the microRNA expression profiles in a set of 20 human HCC specimens by miRNA microarray and quantitative real-time polymerase chain reaction. The results showed that among the 20 HCC samples analyzed, microRNA-101 was significantly down-regulated twofold or more (twofold to 20-fold) in 16 samples compared with the matching nontumoral liver tissues. Using both a luciferase reporter assay and Western blot analysis, we showed that microRNA-101 repressed the expression of v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) oncogene, a key component of the activator protein-1 (AP-1) transcription factor. Moreover, using a luciferase expression vector (pAP-1-Luc) driven by seven copies of an AP-1 cis-element, we observed that microRNA-101 expression inhibited phorbol 12-myristate 13-acetate (PMA)-induced AP-1 activity. In in vitro Matrigel invasion and Transwell migration assays, enhanced microRNA-101 expression inhibited the invasion and migration of cultured HCC cells, respectively. These findings suggest that microRNA-101 may play an important role in HCC.

CONCLUSION

MicroRNA-101, which is aberrantly expressed in HCC, could repress the expression of the FOS oncogene.

Transcription and splicing regulation in human umbilical vein endothelial cells under hypoxic stress conditions by exon array

Background

The balance between endothelial cell survival and apoptosis during stress is an important cellular process for vessel integrity and vascular homeostasis, and it is also pivotal in angiogenesis during the development of many vascular diseases. However, the underlying molecular mechanisms remain largely unknown. Although both transcription and alternative splicing are important in regulating gene expression in endothelial cells under stress, the regulatory mechanisms underlying this state and their interactions have not yet been studied on a genome-wide basis.

Results

Human umbilical vein endothelial cells (HUVECs) were treated with cobalt chloride (CoCl₂) both to mimic hypoxia and to induce cell apoptosis and alternative splicing responses. Cell apoptosis rate analysis indicated that HUVECs exposed to 300 μM CoCl₂ for 24 hrs were initially counterbalancing apoptosis with cell survival. We therefore used the Affymetrix exon array system to determine genome-wide transcript- and exon-level differential expression. Other than 1583 differentially expressed transcripts, 342 alternatively spliced exons were detected and classified by different splicing types. Sixteen alternatively spliced exons were validated by RT-PCR. Furthermore, direct evidence for the ongoing balance between HUVEC survival and apoptosis was provided by Gene Ontology (GO) and protein function, as well as protein domain and pathway enrichment analyses of the differentially expressed transcripts. Importantly, a novel molecular module, in which the heat shock protein (HSP) families play a significant role, was found to be activated under mimicked hypoxia conditions. In addition, 46% of the transcripts containing stress-modulated exons were differentially expressed, indicating the possibility of combinatorial regulation of transcription and splicing.

Conclusion

The exon array system effectively profiles gene expression and splicing on the genome-wide scale. Based on this approach, our data suggest that transcription and splicing not only regulate gene expression, but also carry out combinational regulation of the balance between survival and apoptosis of HUVECs under mimicked hypoxia conditions. Since cell survival following the apoptotic challenge is pivotal in angiogenesis during the development of many vascular diseases, our results may advance the knowledge of multilevel gene regulation in endothelial cells under physiological and pathological conditions.

Juvenile hormone regulation of male accessory gland activity in the red flour beetle, Tribolium castaneum

Male accessory gland proteins (Acps) act as key modulators of reproductive success in insects by influencing the female reproductive physiology and behavior. We used custom microarrays and identified 112 genes that were highly expressed in male accessory glands (MAG) in the red flour beetle, Tribolium castaneum. Out of these 112 identified genes, 59 of them contained sequences coding for signal peptide and cleavage site and the remaining 53 contained transmembrane domains. The expression of 14 of these genes in the MAG but not in other tissues of male or female was confirmed by quantitative real-time PCR. In virgin males, juvenile hormone (JH) levels increased from second day post adult emergence (PAE), remained high on third day PAE and declined on fourth day PAE. The ecdysteroid titers were high soon after adult emergence but declined to minimal levels from 1 to 5 days PAE. Feeding of juvenile hormone analog, hydroprene, but not the ecdysteroid analog, RH-2485, showed an increase in size of MAGs, as well as an increase in total RNA and protein content of MAG. Hydroprene treatment also increased the expression of Acp genes in the MAG. RNAi-mediated knock-down in the expression of JHAMT gene decreased the size of MAGs and expression of Acps. JH deficiency influenced male reproductive fitness as evidenced by a less vigor in mating behavior, poor sperm transfer, low egg and the progeny production by females mated with the JH deficient males. These data suggest a critical role for JH in the regulation of male reproduction especially through MAG secretions.

Effect of fluoride on the morphology of calcium phosphate crystals grown on acid-etched human enamel

The aim of this study was to examine the effect of fluoride ion concentration on the morphology of calcium phosphate crystals grown on acid-etched enamel as a model for tooth enamel erosion. Samples were immersed in calcification solution for 16 h and changes in crystal morphology were monitored by field emission scanning electron microscopy. Without fluoride, plate-like octacalcium phosphate crystals (20 nm thick, 2-10 microm wide) were formed. With 1-10 mg/l fluoride, arrays of denser needle-like nanocrystals (20-30 nm wide, >500 nm in length) were formed. We conclude that there is a minimal fluoride concentration (1 mg/l) that dramatically affects the morphology of calcium phosphate crystals grown on etched enamel in vitro.

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.

Clinicopathological Variables Associated with Lymph Node Metastasis and Prognostic Factors in pT2 Gastric Cancer

This retrospective study investigated the clinicopathological variables associated with lymph node metastasis and prognosis in 325 patients with pT2 gastric cancer in order to set out a foundation for the surgical management of this condition. Univariate and multivariate analyses identified factors that were predictive of lymph node metastasis. Cox regression analysis evaluated the effect of prognostic factors on survival. Tumour location, maximum tumour diameter, lymphatic invasion and total retrieved lymph nodes (tLN) were revealed as independent factors for lymph node metastasis in pT2a gastric cancer, whereas histological type, lymphatic invasion and tLN were associated with lymph node metastasis in patients with pT2b gastric cancer. Maximum tumour diameter, lymphatic invasion and metastatic lymph node (mLN) ratio, but not tLN, were independent prognostic factors in pT2a cancer. Maximum tumour diameter and mLN ratio, but not tLN, were independent prognostic factors in pT2b cancer. Overall, it is concluded that maximum tumour diameter and mLN ratio are important prognostic factors in pT2 gastric cancer.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

The impact of N-ratio in minimizing stage migration phenomenon in gastric cancer patients with insufficient number or level of lymph node retrieved: results from a Chinese mono-institutional study in 2159 patients

BACKGROUND

Previous studies indicate that N-ratio has significant superiority in minimizing 'stage migration' for patients with >15 lymph nodes retrieved. Whether the result is applicable to patients with < or =15 lymph nodes retrieved is still in question.

PATIENTS AND METHODS

Overall survival rates of 2159 gastric cancer patients who underwent radical resection were compared between patients with different number and level of lymph nodes retrieved according to pN [International Union Against Cancer (Union Internationale Contre le Cancer)/AJCC N stage], n (JGCA N stage) and rN (N-ratio) staging system.

RESULTS

Patient number was significantly different between insufficient and sufficient number or level retrieved group in pN and n system, respectively, but not in rN system, while overall survival rates were not significantly different between those groups. The 5-year survival rates of patients with insufficient nodes retrieved were significantly lower than those with sufficient nodes retrieved in pN and n system, but not in rN system. The hazard risk for patients with insufficient nodes retrieved was significantly higher than that for patients with sufficient nodes retrieved in pN and n system, but not in rN system.

CONCLUSION

The rN stage has more potential advantages in minimizing stage migration phenomenon for patients with insufficient number or level of lymph nodes retrieved.

Enamel proteases reduce amelogenin-apatite binding

Organic matrix degradation and crystal maturation are extracellular events that occur simultaneously during enamel biomineralization. We hypothesized that enamel proteases control amelogenin-mineral interaction, which, in turn can affect crystal nucleation, organization, and growth. We used a recombinant amelogenin (rP172), a homolog of its major cleavage product (rP148), and a native amelogenin lacking both N- and C-termini (13k). We compared apatite binding affinity between amelogenins and their digest products during proteolysis. We further compared binding affinity among the 3 amelogenins using a Langmuir model for protein adsorption. Amelogenin-apatite binding affinity was progressively reduced with the proteolysis at the C- and N- termini by recombinant pig MMP-20 (rpMMP20) and recombinant human kallikrein-4 (rhKLK4), respectively. The binding affinity of amelogenin to apatite was found to be in the descending order of rP172, rP148, and 13k. Analysis of our data suggests that, before its complete degradation during enamel maturation, stepwise processing of amelogenin by MMP-20 and then KLK4 reduces amelogenin-apatite interaction.