Astrocyte elevated gene-1 is a proliferation promoter in breast cancer via suppressing transcriptional factor FOXO1

We have previously reported that astrocyte elevated gene-1 (AEG-1) was upregulated in human breast cancer. However, the biological function of AEG-1 in the development and progression of breast cancer remains to be clarified. In this study, we examined the effect of AEG-1 on cell proliferation and found that AEG-1 upregulation was significantly linked to increased Ki67 (P<0.001). Ectopic expression of AEG-1 in MCF-7 and MDA-MB-435 breast cancer cells dramatically enhanced cell proliferation and their ability of anchorage-independent growth, whereas silencing endogenous AEG-1 with shRNAs inhibited cell proliferation and colony-forming ability of the cells on soft agar. Furthermore, these proliferative effects were significantly associated with decreases of p27Kip1 and p21Cip1 two key cell-cycle inhibitors. Moreover, we further demonstrated that AEG-1 could downregulate the transcriptional activity of FOXO1 by inducing its phosphorylation through the PI3K/Akt signaling pathway. These observations were further confirmed in clinical human primary breast cancer specimens, in which high-level expression of AEG-1 was inversely correlated with the expression of FOXO1. Taken together, our results provide the first demonstration of a novel mechanism by which AEG-1 induces proliferation of breast cancer cell, and our findings suggest that AEG-1 might play an important role in tumorigenesis of breast cancer.

Upregulation of survivin during immortalization of nontransformed human fibroblasts transduced with telomerase reverse transcriptase

These investigations demonstrate that expression of the inhibitor of apoptosis family member, survivin, is dramatically increased during immortalization of nontransformed human fibroblasts that were transduced with telomerase reverse transcriptase (hTERT). Expression of survivin in immortalized fibroblasts peaked during G(2)/M phase of the cell cycle. However, the upregulation of survivin was dissociated from the rate of proliferation and proportion of G(2)/M cells. Depletion of survivin from immortal fibroblasts increased sensitivity to stress-induced apoptosis and resulted in an accumulation of cells with 4N DNA content. Conversely, overexpression of survivin in mortal fibroblasts conferred resistance to apoptosis. In contrast, very low levels of survivin in proliferating parental fibroblasts had no bearing on sensitivity to apoptosis. The upregulation of survivin did not appear to be a direct consequence of hTERT transduction. However, repression of hTERT resulted in the rapid downregulation of survivin in telomerase-immortalized fibroblasts and tumor cell lines, but not in cells immortalized via an Alternative Lengthening of Telomeres mechanism. These results have important therapeutic implications, as telomerase and survivin are both broadly expressed in human cancers. Selection during the immortalization process for cells expressing high levels of survivin may account for the abundance of survivin in diverse tumor types.

Dose-dense (DD) cyclophosphamide, methotrexate, and fluorouracil (CMF) at 14-day intervals: A pilot study of every 14- and 10–11-day dosing intervals for women with early-stage breast cancer

590

Background: CMF (C 600 mg/m2, M 40 mg/m2, F 600 mg/m2) is an option for adjuvant therapy for patients with low risk early stage breast cancer. DD regimens as predicted by mathematical models of cancer growth and treatment response are superior. We previously demonstrated the safety of DD EC (epirubicin/cyclophosphamide) followed by paclitaxel at 10–11 day (d) intervals. We investigated the feasibility of administering DD adjuvant CMF every 14 d and then every 10–11 d in a 2-stage phase II trial. Methods: An initial cohort (A) was treated q 14 d with PEG-filgrastim (Neulasta) support. A second cohort (B) was treated every 10–11 d with filgrastim/Neupogen x 5 d and then, based on feasibility, modified (cohort C) to use 7 d filgrastim. The primary end point was feasibility defined as having ANC > 1.5 x 103/uL on day 1 of planned treatment for all 8 cycles with no grade 3 or higher non-hematologic toxicity. All three cohorts were tested using a Simon's two-stage optimal design with type I and type II errors set at 10%. This design would effectively discriminate between true tolerability (as protocol-defined) rates of< 60% and> 80%. Cohort A: 38 pts with early stage breast cancer were accrued from 3/2008 though 6/2008. Cohort B: 7 pts were accrued from June 2008 through August 2008. Cohort C: Is still open with 16 pts accrued from August 2008 through December 5, 2008. Results: Median age 51: range 38 to 78. Cohort A: 29/38 pts completed 8 cycles of CMF. The regimen was considered feasible. 2 other pts completed 7 cycles and were withdrawn for depression and grade 2 transaminitis. The 7 other pts completed between 1 and 6 cycles of CMF were withdrawn as follows: 3 personal, 1 (grade 3) bone pain, 2 allergy unrelated to CMF, and 1 seizure. Cohort B: 7 pts were accrued. 6 out of 7 pts could not complete 8 cycles of chemotherapy secondary to neutropenia and 1 secondary to grade 3 ALT elevation. Cohort C: Accrual has not been completed. 16 pts are currently enrolled. Conclusions: Dose dense adjuvant CMF is feasible at 14 d intervals with PEG-filgrastim support. Adjuvant CMF every 10–11 days with filgrastim given for 5 days beginning day 2 is not feasible. Accrual is ongoing for CMF at 10–11 days with filgrastim x 7 days. Updated results will be available for Cohort C.

[Table: see text]

Cytokine changes in castrate metastatic prostate cancer (CPMC) patients (pts) treated with ipilimumab (Ipi)

e16149

Background: Ipilimumab (Ipi) is a human IgG1 monoclonal antibody that blocks the inhibitory action of the checkpoint molecule CTLA-4. Recent data [Proc Amer Soc Clin Onc, Abstr#5004, 2008] from castrate metastatic PC pts suggested that Ipi was active but was associated with grade 3 autoimmune adverse events (AEs), such as colitis, hepatitis, hypophysitis or rash, which required high dose steroids. We studied pts who were treated on a clinical trial with Ipi 10 mg/kg alone or with radiation to a single site in bone to determine whether there was any correlation between serum cytokine levels and autoimmune AEs. Methods: Thirteen pts were treated, of whom 10 had sufficient specimens for analysis. Of the 10 pts, 8 had ≥1 AE during treatment. Pts were stratified by ascertainment of clinical benefit (CB) vs. no clinical benefit (NCB) based on time-to-PSA-baseline relapse (TTBR) and also by toxicity (tox) using standard NCI tox criteria. TTBR was defined as time from study entry until the time when a PSA measurement reached or exceeded the baseline value. Pts with a TTBR greater than the median value were judged to have CB; those with a TTBR less than the median value had NCB. Pts with grade (gd) 0/1/2 tox were termed “low tox” while those with gd 3/4 tox were “high tox”. Sera at serial time points were analyzed for interferon-gamma (IFN-γ), tumor necrosis factor α and interleukins (IL)-1b, 2, 4, 8, 10, 12, 13 with the Meso Scale Discovery Multiplex Assay (MSD, Gaithersburg, MD). Results: IFN-γ was the predominant cytokine produced in 4 of 5 pts with CB and AEs; it increased at week 4 or 7 after two doses of Ipi, then declined. Four of 5 pts with NCB had minimal IFN-γ production. There was no difference in IL-10 production between those with CB vs. NCB or high vs. low tox. However, there was a suggestion that the IFN-γ /IL-10 ratio may be increased in pts who had high tox and/or CB vs. pts with low tox and NCB. This awaits confirmation. Conclusions: While this experience with Ipi in PC is small, there may be differences between pts with CB vs. NCB and pts with low vs. high tox. Investigation of the immunophenotype of pts who remain in follow- up and continue to be enrolled is ongoing as well as the impact of prior chemotherapy on development of toxicities.

[Table: see text]

Response of blood vessels in vitro to hyperbaric oxygen (HBO): modulation of VEGF and NO(x) release by external lactate or arginine

Hyperbaric oxygen therapy (HBO) is suggested to promote angiogenesis during wound healing, but the mechanisms involved are not understood. This study used a novel isolated blood vessel preparation to explore the effects of air, normobaric oxygen or hyperbaric oxygen (2.2 ATA for 90 min) on the angiogenesis factor, vascular endothelial growth factor (VEGF), nitrite and nitrate (NO(x)), lactate dehydrogenase (LDH) and lactate release from the tissue in normal Krebs Ringer, and the Ringer supplemented with either l-arginine, or 15 mM lactate to mimic a wound environment, or both (l-arginine+lactate). The in vitro blood vessel preparation remained viable during all experiments. There were no effects of HBO treatment on any of the parameters measured in normal Krebs Ringer, but some treatment-dependent effects were observed in supplemented Krebs Ringer. In the lactate supplemented Krebs Ringer, medium LDH levels increased in response to either normobaric oxygen (NBO) or HBO, compared to air alone. There were also small, but statistically significant increases in total glutathione due to HBO treatment, compared to NBO or air in the lactate supplemented medium, and in the combined supplement. There were no effects of HBO on NO(x), changes in external medium lactate levels, or tissue VEGF in any of the Krebs Ringers tested. However, post treatment increases in VEGF were observed in the lactate supplemented medium, and for lactate release into the medium for the combined supplement. We conclude that HBO does not cause NO or VEGF production from the blood vessel in normal Krebs Ringer, but the data from supplemented medium show that the response of the tissue is subtly affected by the chemical environment around the blood vessel, and the tissue is more responsive to HBO when wound conditions are mimicked.

Hot spots and waves in Bi2Sr2CaCu2O8 intrinsic Josephson junction stacks: a study by low temperature scanning laser microscopy

Recently, it has been shown that large stacks of intrinsic Josephson junctions in Bi2Sr2CaCu2O8 emit synchronous THz radiation, the synchronization presumably triggered by a cavity resonance. To investigate this effect we use low temperature scanning laser microscopy to image electric field distributions. We verify the appearance of cavity modes at low bias and in the high input-power regime we find that standing-wave patterns are created through interactions with a hot spot, possibly pointing to a new mode of generating synchronized radiation in intrinsic Josephson junction stacks.

First measurement of the neutron beta asymmetry with ultracold neutrons

We report the first measurement of an angular correlation parameter in neutron beta decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for approximately 30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in a 2x2pi solenoidal spectrometer. We determine a value for the beta-asymmetry parameter A_{0}=-0.1138+/-0.0046+/-0.0021.

Genetically confirmed patients with merosin-deficient congenital muscular dystrophy in China

We report a family and a single patient in China involved with merosin-deficient congenital muscular dystrophy (MDC1A) with typical clinical symptoms. Pathological analysis of biopsied skeletal muscle showed dystrophic changes with proliferated fibrotic tissue elements as the predominant finding. Immunohistochemical analysis demonstrated the complete absence of the laminin alpha2 chain (merosin) around muscle fibers. In patient 1, a double mutation, c.[9101_9104dupAACA:3412G>A] p.[H3035QfsX4:V1138M] was detected, whereas her parents and another sibling were heterozygous carriers. Patient 2 had a novel homozygous nonsense mutation, c.2907C>A (p.Cys969X), in exon 21. The genotype-phenotype correlation of Chinese children with novel merosin-deficient congenital muscular dystrophy is reported.

Self-learning active noise control

An important step for active noise control (ANC) systems to be practical is to develop model independent ANC (MIANC) systems that tolerate parameter variations in sound fields. Reliabilities and stabilities of many MIANC systems depend on results of online system identifications. Parameter errors due to system identifications may threaten closed-loop stabilities of MIANC systems. A self-learning active noise control (SLANC) system is proposed in this study to stabilize and optimize an ANC system in case identified parameters are unreliable. The proposed system uses an objective function to check closed-loop stability. If partial or full value of the objective function exceeds a conservatively preset threshold, a stability threat is detected and the SLANC system will stabilize and optimize the controller without using parameters of sound fields. If the reference signal is available, the SLANC system can be combined with a feedforward controller to generate both destructive interference and active damping in sound fields. The self-learning method is simple and stable for many feedback ANC systems to deal with a worst case discussed in this study.

Role of retinoids in differentiation and growth of embryonal carcinoma cells

To study how retinoids promote differentiation and inhibit proliferation of embryonal carcinoma (EC) cells, we have followed their intracellular fate. Retinoic acid (RA) is effectively metabolized to more polar compounds by many EC lines. Unlike RA, retinol is slowly metabolized. Our inability to detect conversion of retinol to RA might indicate that the two retinoids elicit their effects on EC cells in different ways. Retinol added to cultures quickly appears in the nuclear fraction; the proportion associated with nuclei after detergent extraction is initially very low but increases with time. Retinol and RA might be translocated to nuclei by their respective binding proteins [cellular retinol-binding protein (CRBP) and cellular retinoic acid-binding protein (CRABP)]: isolated EC nuclei have specific, independent binding sites for both holoproteins but not their ligands. CRABP cannot be detected in the nucleoplasm of untreated EC cells, but activity is measurable after cells are exposed to RA. Interestingly, incubation with retinol promotes movement of both CRBP and CRABP into the nucleoplasmic fraction. Finally, we have demonstrated that brief exposure to RA dramatically reduces the cloning efficiency of EC cells. Since some cells are unaffected even by lengthy exposures to RA whereas the growth of their progeny is inhibited, we suggest that EC cells can become epigenetically refractory to RA.

Accessibility of a critical prion protein region involved in strain recognition and its implications for the early detection of prions

Human prion diseases are characterized by the accumulation in the brain of proteinase K (PK)-resistant prion protein designated PrP27-30 detectable by the 3F4 antibody against human PrP109-112. We recently identified a new PK-resistant PrP species, designated PrP^*20, in uninfected human and animal brains. It was preferentially detected with the 1E4 antibody against human PrP 97-108 but not with the anti-PrP 3F4 antibody, although the 3F4 epitope is adjacent to the 1E4 epitope in the PrP^*20 molecule. The present study reveals that removal of the N-terminal amino acids up to residue 91 significantly increases accessibility of the 1E4 antibody to PrP of brains and cultured cells. In contrast to cells expressing wild-type PrP, cells expressing pathogenic mutant PrP accumulate not only PrP^*20 but also a small amount of 3F4-detected PK-resistant PrP27-30. Remarkably, during the course of human prion disease, a transition from an increase in 1E4-detected PrP^*20 to the occurrence of the 3F4-detected PrP27-30 was observed. Our study suggests that an increase in the level of PrP^*20 characterizes the early stages of prion diseases.