Efficiencies and mechanisms of nuclear reprogramming

The differentiated state of somatic cells is highly stable, but it can be experimentally reversed. The resulting cells can then be redirected into many different pathways. Nuclear reprogramming has been achieved by nuclear transfer to eggs, cell fusion, and overexpression of transcription factors. The mechanisms of nuclear reprogramming are not understood, but some insight into them is provided by comparing the efficiencies of different reprogramming strategies. Here, we compare these efficiencies by describing the frequency and rapidity with which reprogramming is induced and by the proportion of cells and level of expression in which reprogramming is achieved. We comment on the mechanisms that lead to successful somatic-cell reprogramming and on those that resist in helping to maintain the differentiated state of somatic cells.

Experimental realization of a three-dimensional topological insulator phase in ternary chalcogenide TlBiSe₂

We report the first observation of a topological surface state on the (111) surface of the ternary chalcogenide TlBiSe₂ by angle-resolved photoemission spectroscopy. By tuning the synchrotron radiation energy we reveal that it features an almost ideal Dirac cone with the Dirac point well isolated from bulk continuum states. This suggests that TlBiSe₂ is a promising material for realizing quantum topological transport.

Hexagonally deformed Fermi surface of the 3D topological insulator Bi2Se3

A hexagonal deformation of the Fermi surface of Bi2Se3 has been for the first time observed by angle-resolved photoemission spectroscopy. This is in contrast to the general belief that Bi2Se3 possesses an ideal Dirac cone. The hexagonal shape is found to disappear near the Dirac node, which would protect the surface state electrons from backscattering. It is also demonstrated that the Fermi energy of naturally electron-doped Bi2Se3 can be tuned by 1% Mg doping in order to realize the quantum topological transport.

Strong rashba-type spin polarization of the photocurrent from bulk continuum States: experiment and theory for Bi(111)

Strong spin polarization of the photocurrent from bulk continuum states of Bi(111) is experimentally observed. On the basis of ab initio one-step photoemission theory the effect is shown to originate from the strong polarization of the initial states at the surface and to be the result of the surface sensitivity of photoemission. Final state effects cause deviations of the k{∥} dependence of polarization from strictly antisymmetric relative to Γ.

No difference in adherence to paroxetine between depressed patients with early remission and those with late remission based on monitoring of plasma paroxetine concentrations

Selective serotonin reuptake inhibitors (SSRIs) are widely used to treat both anxiety disorders and depressive disorders. However, nonadherence to SSRIs is a major issue in recurrence. In the present study, we investigated paroxetine adherence in depressed patients by monitoring the plasma paroxetine concentrations between patients with rapid and those with a late response to paroxetine treatment. Twenty inpatients in our university hospital, who met the DSM-IV-TR diagnosis of major depressive disorder in a single episode, were enrolled in the study. Twelve patients (M/F: 7/13, age: 37.4 +/- 10.4 years) were treated with paroxetine (40 mg/day), and all achieved remission (HAMD < or = 7) within at least 12 weeks. We divided the patients into two groups, an early-remission group (HAMD < or = 7 within 4 weeks) and a late-remission group (HAMD < or = 7 within 8-12 weeks). Their dosages of paroxetine were constant because of no emerging adverse effects. Blood samples were obtained on the day the subjects were discharged (B) and 12 weeks after discharge. The paroxetine concentrations in the early-remission group were significantly decreased 12 weeks after discharge, and no difference was found between the early- and late-remission groups. These results suggest that adherence to paroxetine was independent of the duration of the depressive state suffered by the patients. Clinicians always take their cautions for the adherence to paroxetine regardless of the clinical time courses the patients recovering from their depressive symptoms.

Nitrogen fixation by thermophilic blue-green algae (cyanobacteria): temperature characteristics and potential use in biophotolysis

Thermophilic, nitrogen-fixing, blue-green algae (cyanobacteria) were investigated for use in biophotolysis. Three strains of Mastigocladus laminosus were tested and were found to be equally effective in biophotolysis as judged by nitrogenase activity. The alga, M. laminosus NZ-86-m, which was chosen for further study, grew well in the temperature range from 35 to 50 degrees C, with optimum growth at 45 degrees C, at which temperature acetylene reduction activity was also greatest. The maximum tolerable temperature was 55 degrees C. Acetylene reduction activity was saturated at a light intensity of 1 x 10 ergs cm s. Atmospheric oxygen tension was found to be slightly inhibitory to acetylene reduction of both slowly growing and exponentially growing cultures. Nonsterile continuous cultures, which were conducted to test problems of culture maintenance, could be operated for 2 months without any significant decrease in nitrogenase activity or contamination by other algae. Nitrogen-starved cultures of M. laminosus NZ-86-m produced hydrogen at comparable rates to Anabaena cylindrica. The conversion efficiency of light to hydrogen energy at maximum rates of hydrogen production was 2.7%.

Organic-solvent-tolerant bacterium which secretes organic-solvent-stable lipolytic enzyme

A bacterial strain which could be grown in a medium containing organic solvents and which could secrete lipolytic enzyme was isolated. The stability of the lipolytic activity of the supernatant of the culture increased significantly in the presence of organic solvents such as toluene, cyclohexane, ethanol, and acetone.

Mammalian nuclear transplantation to Germinal Vesicle stage Xenopus oocytes - a method for quantitative transcriptional reprogramming

Full-grown Xenopus oocytes in first meiotic prophase contain an immensely enlarged nucleus, the Germinal Vesicle (GV), that can be injected with several hundred somatic cell nuclei. When the nuclei of mammalian somatic cells or cultured cell lines are injected into a GV, a wide range of genes that are not transcribed in the donor cells, including pluripotency genes, start to be transcriptionally activated, and synthesize primary transcripts continuously for several days. Because of the large size and abundance of Xenopus laevis oocytes, this experimental system offers an opportunity to understand the mechanisms by which somatic cell nuclei can be reprogrammed to transcribe genes characteristic of oocytes and early embryos. The use of mammalian nuclei ensures that there is no background of endogenous maternal transcripts of the kind that are induced. The induced gene transcription takes place in the absence of cell division or DNA synthesis and does not require protein synthesis. Here we summarize new as well as established results that characterize this experimental system. In particular, we describe optimal conditions for transplanting somatic nuclei to oocytes and for the efficient activation of transcription by transplanted nuclei. We make a quantitative determination of transcript numbers for pluripotency and housekeeping genes, comparing cultured somatic cell nuclei with those of embryonic stem cells. Surprisingly we find that the transcriptional activation of somatic nuclei differs substantially from one donor cell-type to another and in respect of different pluripotency genes. We also determine the efficiency of an injected mRNA translation into protein.

Aberration of a negative ion beam caused by space charge effect

Aberrations are inevitable when the charged particle beams are extracted, accelerated, transmitted, and focused with electrostatic and magnetic fields. In this study, we investigate the aberration of a negative ion accelerator for a neutral beam injector theoretically, especially the spherical aberration caused by the negative ion beam expansion due to the space charge effect. The negative ion current density profiles with the spherical aberration are compared with those without the spherical aberration. It is found that the negative ion current density profiles in a log scale are tailed due to the spherical aberration.

Spontaneous acute subdural haematoma and intracerebral haemorrhage in patient with HELLP syndrome: case report

HELLP (haemolysis, elevated liver enzymes, and low platelet count) syndrome can result in a fatal intracranial haemorrhage during the perinatal period. We report treatment of a 32-year-old primigravida who fell into a deep coma during labour with fetal distress, complicated by a spontaneous acute subdural haematoma and intracerebral haemorrhage. Simultaneous emergency operations, evacuation of the acute subdural haematoma and a caesarean section, were performed, during which a diagnosis of HELLP syndrome with disseminated intravascular coagulation was made. Both mother and infant recovered, though hemiparesis persisted in the mother. Patients with HELLP syndrome should be managed as high-risk, which requires an excellent working relationship of the physicians involved. Prompt recognition of intracranial haemorrhagic complications and neurosurgical intervention are particularly important.

Sub-100 W picosecond output from a phase-conjugate Nd:YVO4 bounce amplifier

We demonstrated >80 W picosecond output at a pulse repetition frequency of 100 MHz from a dual Nd:YVO(4) amplifier laser system consisting of a phase-conjugate Nd:YVO(4) bounce amplifier combined with a second diode-side-pumped Nd:YVO(4) bounce amplifier. The output exhibited high quality spatial form with M(2) < 1.8 and a pulse duration (FWHM) of 9.2 ps. A peak power of >7.4 MW with an average power of 78.5 W was also achieved at a pulse repetition frequency of 1.0 MHz.

SHARP-2 gene silencing by lentiviral-based short hairpin RNA interference prolonged rat kidney transplant recipients' survival time

Split- and hairy-related protein-2 (SHARP-2) controls the expression of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), which both play a key role in transplant rejection. This study was designed to investigate whether SHARP-2 short hairpin RNA interference (shRNAi) could prolong the survival of rat kidney transplant recipients. A lentiviral-based shRNAi construct, LV-SHARP-2iC, showed a SHARP-2 gene silencing efficiency of 84% in normal rat kidney cells. In activated T-cells, SHARP-2 gene silencing with the LV-SHARP-2iC construct resulted in 61% and 69% down-regulation of IL-2 and IFN-gamma, respectively, compared with a scramble control construct. When donor kidney was perfused with 5 x 10(7) transforming units of the LV-SHARP-2iC construct, the median survival time of the transplant recipients was prolonged by 4 - 5 days compared with control groups. In conclusion, recombinant lentiviral LV-SHARP-2iC construct effectively silenced SHARP-2 gene expression, which reduced IL-2 and IFN-gamma mRNA expression and prolonged rat kidney transplant recipients' survival.

Reduction in the appearance of facial hyperpigmentation after use of moisturizers with a combination of topical niacinamide and N-acetyl glucosamine: results of a randomized, double-blind, vehicle-controlled trial

BACKGROUND

Topical niacinamide and N-acetyl glucosamine (NAG) each individually inhibit epidermal pigmentation in cell culture. In small clinical studies, niacinamide-containing and NAG-containing formulations reduced the appearance of hyperpigmentation.

OBJECTIVES

To assess the effect of a combination of niacinamide and NAG in a topical moisturizing formulation on irregular facial pigmentation, including specific detection of changes in colour features associated with melanin.

METHODS

This was a 10-week, double-blind, vehicle-controlled, full-face, parallel-group clinical study conducted in women aged 40-60 years. After a 2-week washout period, subjects used a daily regimen of either a morning sun protection factor (SPF) 15 sunscreen moisturizing lotion and evening moisturizing cream each containing 4% niacinamide + 2% NAG (test formulation; n = 101) or the SPF 15 lotion and cream vehicles (vehicle control; n = 101). Product-induced changes in apparent pigmentation were assessed by capturing digital photographic images of the women after 0, 4, 6 and 8 weeks of product use and evaluating the images by algorithm-based computer image analysis for coloured spot area fraction, by expert visual grading, and by chromophore-specific image analysis based on noncontact SIAscopy for melanin spot area fraction and melanin chromophore evenness.

RESULTS

By all four measures, the niacinamide + NAG formulation regimen was significantly (P < 0.05) more effective than the vehicle control formulation regimen in reducing the detectable area of facial spots and the appearance of pigmentation.

CONCLUSIONS

A formulation containing the combination of niacinamide + NAG reduced the appearance of irregular pigmentation including hypermelaninization, providing an effect beyond that achieved with SPF 15 sunscreen.

Rapid response to paroxetine is associated with plasma paroxetine levels at 4 but not 8 weeks of treatment, and is independent of serotonin transporter promoter polymorphism in Japanese depressed patients

In the present study, we investigated the relationship between the serotonin transporter gene linked polymorphic regions (5-HTTLPR) or plasma paroxetine levels and clinical response to paroxetine in depressed patients. Sixty patients who met the DSM-IV criteria for major depressive disorder were enrolled in the study. Twenty-two were male and 38 were female, with ages ranging from 25 to 71 (mean +/- SD = 42 +/- 16) years. The clinical improvement of patients was assessed using the Hamilton rating scale for depression (Ham-D) before and every week after paroxetine administration. According to the data reported previously, patients with an at least 50% decrease in their Ham-D score were classified as responders. The results showed that the plasma paroxetine levels at 4 weeks were significantly higher in responders (rapid responders) than in nonresponders. On the other hand, no significant associations were found between the L genotype (L/L, L/S) or S genotype (S/S) and the response rates either at 4 weeks or 8 weeks. These results suggest that patients with higher plasma levels at 4 weeks might respond rapidly to paroxetine treatment, but the final response rate at 8 weeks will be independent of the plasma paroxetine levels and the 5-HTTLPR L/S genotype.

Down-regulation of MDR1 by epigenetic alteration in human epithelial ovarian cancer cells

e16556

Background: Ovarian cancer is one of the most lethal malignancies in women. Despite recent studies of many oncogenes and tumor-suppressor genes concerning about its progression, the details of ovarian cancer biology still remains to be unclear. P-glycoprotein (P-gp) encoded by the MDR1 gene is a membrane protein that can export many kinds of antineoplastic agents from cells, and overexpression of P-gp has been reported to be implicated in treatment failure in cancer. DNA methylation, a major epigenetic process, can affect every step in carcinogenesis as well as genetic alterations. The contribution of such epigenetic alteration to the expression of MDR1 remains largely unexplored in human ovarian cancer. Methods: In this study, we evaluated the DNA methylation status of the MDR1 gene by methylation-specific PCR. Then, the expression of MDR-1 mRNA and protein in primary epithelial ovarian cancer specimens were evaluated by real-time RT-PCR and immunohistochemistry using anti-mouse P-gp F4 monoclonal antibody, respectively. The correlation between these results and clinicopathological features was examined. Results: MDR1 was hypermethylated in 12 of 12 (100%) ovarian cancer cell lines, and 5 of 13 (38%) primary ovarian cancers by methylation-specific PCR analysis. MDR1 mRNA expression was subsequently found to be lost in ovarian cancer cell lines with methylation by both real-time RT-PCR and immunohistochemistry. Thus, MDR1expression was associated with the DNA methylation status of the MDR1 gene. Conclusions: In conclusion, MDR1 was frequently hypermethylated in human ovarian cancers. Our results suggest that epigenetic regulation might play a role in the expression of MDR1 and clinical treatment outcomes in human ovarian cancer.

No significant financial relationships to disclose.

Clinicopathologic and prognostic features of triple-negative breast cancer analyzed in registration data of the Japanese Breast Cancer Society, 11705 cases

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Background: Triple-negative (TN) breast cancers which are negative for ER, PgR, and HER2 by immunohistochemistry are associated with a poor prognosis. To clarify the characteristics of TN tumors, the data of the registration committee of the Japanese Breast Cancer Society were analyzed with respect to clinicopathologic factors, response to neoadjuvant chemotherapy (NAC) and prognosis. Methods: Of 14,748 cases that were registered in 2004, 11,705 cases (79.4%) were examined for ER, PgR, and HER2 status, which was based on local institute. In the 2,331 cases of all registered cases, the prognosis and details of the treatment were analyzed with 47.8 months as median follow-up period. In 184 cases (7.9%), NAC was mainly performed using anthracycline and taxane based chemotherapy. Results: Luminal A type with positive for ER and/or PgR and negative for HER2 was most prevalent (53.8%), followed by TN type (15.5%). TN cancers were diagnosed at a slightly advanced stage and more of the cases had lymph node metastases compared to other types. Mucinous or tubular carcinoma was frequently seen in the Luminal A type. Squamous cell, spindle cell carcinoma, or metaplastic carcinoma with bone/cartilage metaplasia was found in only TN type. The HER2 type and TN type had statistically worse outcome compared to Luminal type in DFS and OS (P<.0001 and P<.0001, respectively). Pathological response rate of NAC, including grade 2 and 3, was higher in TN tumor as 51.5 % (22/53) than in Luminal A tumor as 16.7% (12/72). Responders in TN tumors have a better prognosis than non-responder (P=.0016), but this tendency was not recognized in non-TN tumors (P=.15). Conclusions: The ratio of the TN tumors in Japan was 15–6%. Central reviews of immunohistochemistry, such as ER, PgR, HER2, CK5/6, EGFR etc, will be confirmed in this cohort, for TN tumors are similar to basal-like tumors discriminated by gene- profiling.

[Table: see text]

Epigenetic alteration of BRCA1 in human ovarian tumors

e16532

Background: The breast cancer susceptibility gene 1 (BRCA1) is mutated in half of hereditary breast cancers, and in about 80% of hereditary breast and ovarian cancers. Also, BRCA1 expression is decreased in sporadic breast cancers by other mechanisms, such as epigenetic alteration, suggesting its important role in sporadic breast cancers. The epigenetic alteration of BRCA1 and its contribution in sporadic ovarian tumors are not fully understood. Methods: We evaluated the DNA methylation status of the BRCA1 5’ CpG island by methylation-specific PCR in 12 human ovarian cancer cell lines and 39 primary epithelial ovarian tumor specimens. Cases included the following: malignant (n = 16), borderline (n = 8), and benign (n = 16) tumors. The correlation between these results and clinicopathological features was examined. Results: BRCA1 was hypermethylated in one of 12 (8%) ovarian cancer cell lines and 15 of 39 (38%) primary ovarian tumors. Relative to clinicopathological features, BRCA1 methylation was detected in 39% of malignant and borderline tumors and in 38% of benign tumors, suggesting the importance of BRCA1 pathway in both types of tumors. Some adjacent nontumorous tissues also showed aberrant methylation. Conclusions: BRCA1 was found to be frequently hypermethylated both in benign and malignant ovarian tumors. Our results suggest that epigenetic alteration of BRCA1 might play a role in the development of benign and malignant sporadic ovarian tumors.

No significant financial relationships to disclose.

MicroRNAs and epigenetics in human breast cancer

Abstract #4051

MicroRNAs (miRNAs), which regulate gene expression at the post-transcriptional level, are suggested to play important roles in carcinogenesis. To clarify the miRNAs dysregulation and the relation to epigenetic mechanisms in human breast cancer, we analyzed a breast cancer cell line, MDA-MB-468 that has previously been used for the genome-wide epigenetic analysis: methylation-sensitive-representational difference analysis (MS-RDA). Normal human mammary epithelial cells (HMEC) were compared with MDA-MB-468. The global expression profile (471 miRNAs) of these samples was examined using 3D-Gene Human miRNA oligo chip (Toray, Tokyo, Japan). We identified 4 miRNAs (0.8%), hsa-miR-200a, hsa-miR-429, hsa-miR-652 and hsa-miR-200b, which were expressed at ten-times higher levels in cancer cells and, conversely, 12 miRNAs (2.5%), hsa-miR-137, hsa-miR-138, hsa-miR-34b, hsa-miR-34c, hsa-miR-374, hsa-miR-376a, hsa-miR-422b, hsa-miR-452, hsa-miR-520e, hsa-miR-455, hsa-miR-554 and hsa-miR-574 that were silenced in the cancer cells. Expression analyses using other breast cancer cells (MCF-7, YMB-1-E, T-47D, MDA-MB-231) revealed a significant overexpression of 4 miRNAs, hsa-miR-200a, hsa-miR-429, hsa-miR-652 and hsa-miR-200b and frequent silencing of 5 miRNAs, hsa-miR-138, hsa-miR-34c, hsa-miR-376a, hsa-miR-452, and hsa-miR-455 in breast cancer cells. As for epigenetic mechanisms, overexpressed miRNAs were found to target silenced genes in the MDA-MB-468 cell line, and treatment of MDA-MB-468 with a demethylating agent, 5-aza-2'-deoxycytidine, restored the expression of 5 miRNAs, hsa-miR-137, hsa-miR-374, hsa-miR-520e, hsa-miR-554 and hsa-miR-574. Our results show the existence of a novel miRNA signature in breast cancer, suggesting that epigenetic mechanisms may be involved in the regulation of miRNA expression.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4051.