Demonstration of Two-Atom Entanglement with Ultrafast Optical Pulses

We demonstrate quantum entanglement of two trapped atomic ion qubits using a sequence of ultrafast laser pulses. Unlike previous demonstrations of entanglement mediated by the Coulomb interaction, this scheme does not require confinement to the Lamb-Dicke regime and can be less sensitive to ambient noise due to its speed. To elucidate the physics of an ultrafast phase gate, we generate a high entanglement rate using just ten pulses, each of ∼20  ps duration, and demonstrate an entangled Bell state with (76±1)% fidelity. These results pave the way for entanglement operations within a large collection of qubits by exciting only local modes of motion.

Suppressing the loss of ultracold molecules via the continuous quantum Zeno effect

We investigate theoretically the suppression of two-body losses when the on-site loss rate is larger than all other energy scales in a lattice. This work quantitatively explains the recently observed suppression of chemical reactions between two rotational states of fermionic KRb molecules confined in one-dimensional tubes with a weak lattice along the tubes [Yan et al., Nature (London) 501, 521 (2013)]. New loss rate measurements performed for different lattice parameters but under controlled initial conditions allow us to show that the loss suppression is a consequence of the combined effects of lattice confinement and the continuous quantum Zeno effect. A key finding, relevant for generic strongly reactive systems, is that while a single-band theory can qualitatively describe the data, a quantitative analysis must include multiband effects. Accounting for these effects reduces the inferred molecule filling fraction by a factor of 5. A rate equation can describe much of the data, but to properly reproduce the loss dynamics with a fixed fillingfraction for all lattice parameters we develop a mean-field model and benchmark it with numerically exacttime-dependent density matrix renormalization group calculations.

Abstract 5563: Targeting the PH domain of TIAM1 to inhibit prostate cancer metastasis

TIAM1 (T-lymphoma invasion and metastasis-inducing protein-1) is a highly conserved guanine nucleotide exchange factor and contains an Dbl Homology (DH)/C-terminal Pleckstrin Homology (PH) domain. The crystal structure of DH-PH of TIAM1 in complex with Rac-1 has been reported. TIAM1 has been found to be over-expressed cancers such as breast, colon and prostate cancers. An increase in TIAM1 expression has been shown to be associated with increased metastatic potential of breast cancer cell lines and is also correlated with poor prognosis of patients with prostate cancer. TIAM1 is thus a novel PH domain-containing drug target directly related to cancer progression, metastasis and patient survival. We have identified and characterized novel small molecule inhibitors targeting the phosphoinositide lipid binding PH domain of TIAM1 in order to selectively inhibit cell migration, invasion and survival. An In Silico screen of our internal and Maybridge library using the crystal structure of TIAM1 has identified 11 compounds that bind to the PH domain. In vitro assays revealed that compounds TPH-3 and TPH-15 significantly reduced the amount of active Rac1 in PC-3 prostate cancer cells (EC50 of 2.73±0.13 and 2.38±0.98 μM) by binding to PH-TIAM1 with high affinity (KD in the micromolar range) using surface plasmon resonance (SPR) spectrometry. Both compounds displaced PtdIns-3,4,5-P3 in a SPR competitive binding assay. TPH-3 and TPH-15 inhibited cell proliferation with EC50 of 19.8±3.2 and 28.7±1.7 μM in prostate cancer cells LnCaP and EC50 of 18.6±1.8 and 33.3±6.7 μM in PC-3. Wound healing assays and lamellipodia formation were both inhibited by the compounds. TPH-15 inhibited ≈70% of PC-3 invasion using a matrigel invasion assay. Finally, TPH-15 exhibits anti-tumor properties in a PC-3 mouse xenograft study (%T/C≈38.8) with good pharmacokinetic properties (T1/2≈5 hours). Cardio-injection of prostate PC-3 cells in SCID mice was used to test the effects of TPH-15 in the prevention of bone metastasis. Mice were treated with 50mg/kg ip of TPH-15 once a day for 5 days. TPH-15-treated mice developed significantly less pelvic bone lesions than the untreated group and TPH-15 treated mice lived longer, on average, than the untreated group. Overall, we have identified novel compounds which exhibit the ability to reduce prostate cancer bone metastasis by binding to the PH domain of TIAM1, an important GEF in the process of metastasis.

Citation Format: Emmanuelle J. Meuillet, Sylvestor A. Moses, Jana Jandova, Eugene A. Mash, Shuxing Zhang. Targeting the PH domain of TIAM1 to inhibit prostate cancer metastasis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5563. doi:10.1158/1538-7445.AM2013-5563

Anisotropic polarizability of ultracold polar 40K87Rb molecules

We report the measurement of the anisotropic ac polarizability of ultracold polar (40)K(87)Rb molecules in the ground and first rotationally excited states. Theoretical analysis of the polarizability agrees well with experimental findings. Although the polarizability can vary by more than 30%, a "magic" angle between the laser polarization and the quantization axis is found where the polarizability of the |N=0,m(N)=0> and the |N=1,m(N)=0> states match. At this angle, rotational decoherence due to the mismatch in trapping potentials is eliminated, and we observe a sharp increase in the coherence time. This paves the way for precise spectroscopic measurements and coherent manipulations of rotational states as a tool in the creation and probing of novel quantum many-body states of polar molecules.

Abstract 2835: Discovery of novel inhibitors for ECT2 as a novel therapeutic strategy for lung cancer

The Epithelial Cell Transforming sequence 2 (ECT2) proto-oncogene is a Guanine Exchange Factor (GEF) for RhoA, Rac1 and Cdc42 and is essential to the regulation of cytokinesis. ECT2 contains the Dbl homology and pleckstrin homology (PH) domains, which are the hallmarks of GEFs. ECT2 is over-expressed in primary non-small cell lung cancer (NSCLC) tumors, and injection of ECT2 transfectants into nude mice efficiently induces tumor formation. High level of ECT2 expression is associated with poor prognosis for patients with NSCLC. Knock down of ECT2 expression by small interfering RNAs effectively suppresses lung cancer cell growth, suggesting a specific role of ECT2 in lung cancer development. Taken together, ECT2 may represent an attractive molecular target for inhibiting lung tumor growth. Our studies are based on the hypothesis that ECT2 plays an important role in lung cancer progression and is a novel target for the development of drugs to treat lung cancer. We have built a model for ECT2 PH domain using protein homology modeling. Docking of new compounds selected from commercial drug-like libraries has led to the identification of novel inhibitors of ECT2 PH domain. We have identified several compounds that bind ECT2 PH domain in the low micromolar range (KD<1μM) as measured using surface plasmon resonance spectroscopy and that inhibit the proliferation of a panel of 23 lung cancer cell lines (EC50<50μM). Importantly, inhibition occurred only in mutant-KRAS cells. Two compounds were shown to inhibit actin polymerization using a phalloidin-rhodamine stain as well as in vitro tumor formation using a colony forming assay and migration using a wound healing assay. These two compounds are being evaluated for their anti-tumor activity against several human lung cancer xenografts in SCID mice. The objectives of our studies are 1) to conduct molecular mechanistic studies of the precise role of ECT2 in the development of lung cancer in vivo animal model of lung cancer; 2) to test the most active compounds in cells in culture to provide a mechanistic rationale for their biological activity and 3) to test the anti-tumor properties of the lead compounds in a in vivo model of lung cancer. The overall goals of our work are to validate ECT2 as a therapeutic target for lung cancer and to develop a novel therapeutic strategy and agents for the improved treatment and the eventual cure of lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2835. doi:1538-7445.AM2012-2835

Abstract 3752: Nanoparticles delivery of a novel AKT/PDK1 inhibitor inhibits pancreatic cancer tumor growth

AKT (protein kinase B), a pleckstrin homology (PH) lipid binding domain and a serine/threonine kinase containing protein is a key component of the phophatidylinositol-3-kinase (PtdIns3-K) cell survival signaling pathway which is activated in pancreatic cancers. In this study, we describe the effects of a novel inhibitor of AKT/PDK1 (PH-427) that binds to the PH domain of AKT (Ki = 2.67 ± 0.37 μM) and PDK1 (Ki = 5.20 ± 0.45 μM) [1] thus preventing its binding to PtIns-(3,4,5)P3 at the plasma membrane and subsequent activation of both kinases. PH-427 inhibits AKT/PDK1 activities at low micromolar concentrations in BxPC-3 (wt-KRAS) and not in MiaPaCa2 (mt-KRAS) human pancreatic cancer cell lines. Accordingly, we have shown that in vivo, PH-427 is poorly efficient in MiaPaCa2 xenografts as compared to BxPC-3 xenografts. In order to increase the potency and delivery of PH-427 to the tumor, we have encapsulated the compound (>10% of the compound) into (poly-d, l-lactide-co-glycolide) (PLGA) nanoparticles (PNP). We demonstrate that PH-427 incorporates well in the nanoparticles (PH-427-PNP) (<200 nm in size) and is slowly released from the polymer with a 90% released over a period of 30 days. We show that PH-427-PNP were very efficient in reducing MiaPaCa-2-Luc orthotopic pancreatic tumor growth as evaluated by luminescence using an AMI-1000 scanner. MiaPaCa2-Luc pancreas tumor volume was significantly reduced in animals treated with PH-427-PNP as compared to animal treated with PH-427 alone or the PNP alone (41.4±29.9 versus 2051±387 and 631±45 mm3). In conclusion, PH-427 alone did not alter tumor growth in MiaPaCa-2-Luc but was able to reduce tumor growth significantly when encapsulated in PNP. Finally and interestingly, metastasis to the liver and other organs was also significantly inhibited by PH-427-PNP as compared to PNP or PH-427 alone. [1]. Meuillet EJ, Ihle N, Lemos R, Moses SA, Song Z, Zhang S, Mash EA, Powis G (2010). Mol Cancer Ther 9(3):706-717.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3752. doi:1538-7445.AM2012-3752

Development of sulfonamide AKT PH domain inhibitors

Disruption of the phosphatidylinositol 3-kinase/AKT signaling pathway can lead to apoptosis in cancer cells. Previously we identified a lead sulfonamide that selectively bound to the pleckstrin homology (PH) domain of AKT and induced apoptosis when present at low micromolar concentrations. To examine the effects of structural modification, a set of sulfonamides related to the lead compound was designed, synthesized, and tested for binding to the expressed PH domain of AKT using a surface plasmon resonance-based competitive binding assay. Cellular activity was determined by means of an assay for pAKT production and a cell killing assay using BxPC-3 cells. The most active compounds in the set are lipophilic and possess an aliphatic chain of the proper length. Results were interpreted with the aid of computational modeling. This paper represents the first structure-activity relationship (SAR) study of a large family of AKT PH domain inhibitors. Information obtained will be used in the design of the next generation of inhibitors of AKT PH domain function.

Abstract 1559: Targeting the PH domain of Tiam-1 to inhibit breast cancer metastasis

TIAM-1 (T-lymphoma invasion and metastasis-inducing protein-1) is a highly conserved guanine nucleotide exchange factor and contains an N-terminal pleckstrin homology domain (PHn) and a Dbl homology (DH)/C-terminal PH domain (PHc). While no crystal structure exists for the PHn of TIAM-1, the crystal structure of DH-PHc of TIAM-1 in complex with Rac-1 has been reported. TIAM-1 has been found to be over-expressed in breast, colon and prostate cancers. An increase in TIAM-1 expression has been shown to be associated with increased metastatic potential of breast cancer cell lines. TIAM-1 is thus an ideal PH domain drug target directly related to cancer progression, metastasis and patient survival. In this study, we have identified novel small molecule inhibitors targeting the phosphoinositide (PtdIns) lipid binding PHc domain of TIAM-1 in order to selectively inhibit cell migration and survival. Utilizing an In Silico screen of our internal and Maybridge library and the crystal structure of TIAM-1, we have found 29 compounds that bind to PHc TIAM-1. In vitro assays have revealed that compound PH-210 and #10 significantly reduced the amount of active Rac1 and binds to PHc-TIAM-1 with high affinity (KD in the micromolar range) using surface plasmon resonance (SPR) spectrometry. Both compounds displace PtdIns-3,4,5-P3 in a SPR competitive binding assay. Ongoing in vivo studies using MDA-231 breast cancer cell lines will determine the anti-tumor activity of these compounds. Overall, these novel compounds could exhibit the ability to significantly reduce breast cancer metastasis by binding to PHc-TIAM-1 and could have the potential to be used with other chemotherapeutic compounds as part of an effective breast cancer treatment regimen.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1559.

Molecular pharmacology and antitumor activity of PHT-427, a novel Akt/phosphatidylinositide-dependent protein kinase 1 pleckstrin homology domain inhibitor

Phosphatidylinositol 3-kinase/phosphatidylinositide-dependent protein kinase 1 (PDPK1)/Akt signaling plays a critical role in activating proliferation and survival pathways within cancer cells. We report the molecular pharmacology and antitumor activity of PHT-427, a compound designed to bind to the pleckstrin homology (PH) binding domain of signaling molecules important in cancer. Although originally designed to bind the PH domain of Akt, we now report that PHT-427 also binds to the PH domain of PDPK1. A series of PHT-427 analogues with variable C-4 to C-16 alkyl chain length were synthesized and tested. PHT-427 itself (C-12 chain) bound with the highest affinity to the PH domains of both PDPK1 and Akt. PHT-427 inhibited Akt and PDPK1 signaling and their downstream targets in sensitive but not resistant cells and tumor xenografts. When given orally, PHT-427 inhibited the growth of human tumor xenografts in immunodeficient mice, with up to 80% inhibition in the most sensitive tumors, and showed greater activity than analogues with C4, C6, or C8 alkyl chains. Inhibition of PDPK1 was more closely correlated to antitumor activity than Akt inhibition. Tumors with PIK3CA mutation were the most sensitive, and K-Ras mutant tumors were the least sensitive. Combination studies showed that PHT-427 has greater than additive antitumor activity with paclitaxel in breast cancer and with erlotinib in non-small cell lung cancer. When given >5 days, PHT-427 caused no weight loss or change in blood chemistry. Thus, we report a novel PH domain binding inhibitor of PDPK1/Akt signaling with significant in vivo antitumor activity and minimal toxicity.

Abstract B139: Molecular pharmacology and antitumor activity of PHT-427 a novel AKT/PDPK1 pleckstrin homology domain inhibitor

The pleckstrin homology (PH) domain is a highly conserved three dimensional superfold found in many high valued pharmaceutical target proteins. While for the majority of PH domain proteins PtdIns binding is weak and non-specific, a subclass of approximately 40 PH domain containing proteins show high affinity for phosphatidylinositol-3-phosphates (PtdIns-3-P) causing their translocation to the plasma membrane and/or activation. Akt and PDKP1 are two such PH domain containing serine threonine kinase members of the PtdIns-3-kinase signaling pathway that plays a critical role in activating survival and anti-apoptotic signaling in cancer cells. This pathway is constitutively activated through mutation, overexpression and loss of the tumor suppressor PTEN in many different cancer types. There is emerging evidence that Akt and PDKP1 play complimentary yet independent roles in signaling by the pathway. Attempts to develop ATP catalytic site inhibitors of Akt and PDKP1 have generally resulted in toxic agents because of inhibition of off-target kinase family members. Through a process of reiterative molecular docking and structure refinement using a proprietary computational platform, and measurement of binding affinities by surface plasmon resonance (SPR) spectroscopy, we have developed inhibitors of these proteins that bind to the PH domain. We report here the development of PHT-427 a compound that binds to the PH domain of AKT and PDKP1. To develop PHT-427 an initial pharmacophore that bound to the PH domain PtdIns binding pocket was first identified. During the docking/modeling we identified a channel whithin the PH domains of both AKT and PDPK1 that could accommodate the binding of an alkyl chain. A series of analogs with C-4 to C-16 alkyl chain length were therefore synthesized and PHT-427 (C-12 chain) was found to bind with the highest affinity to the PH domains of both PDPK1 and AKT. PHT-427 gives a transient inhibition of AKT signaling in cells and tumor xenografts and a longer lasting inhibition of PDPK1 signaling. This inhibition correlated with decreased activation of downstream signaling targets for both proteins. PHT-427 given ias an oral formulation on a twice daily schedule inhibited the growth rate of human tumor xenografts in immunodeficient mice with up to an 80% inhibition in the most sensitive tumors and showed greater activity than analogs with C4, C6 or C8 alkyl chains. Tumors with a K-Ras mutation were less sensitive to PHT-427 as it has been seen for other inhibitors of the PtdIns-3-K signaling pathway. Combination antitumor studies showed that PHT-427 has greater than additive activity with paclitaxel in breast cancer and with erlotinib in non small cell lung cancer. There was minimal toxicity of PH-427 at doses that gave antitumor activity. PHT-427 given twice daily for 5 days caused no weight loss or change in blood chemistry. In summary we have identified a novel PH domain binding inhibitor of PDPK1/AKT signaling that has minimal toxicity and antitumor activity against human tumor xenografts..

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B139.

In vitro and in vivo activity of novel small-molecule inhibitors targeting the pleckstrin homology domain of protein kinase B/AKT

The phosphatidylinositol 3-kinase/AKT signaling pathway plays a critical role in activating survival and antiapoptotic pathways within cancer cells. Several studies have shown that this pathway is constitutively activated in many different cancer types. The goal of this study was to discover novel compounds that bind to the pleckstrin homology (PH) domain of AKT, thereby inhibiting AKT activation. Using proprietary docking software, 22 potential PH domain inhibitors were identified. Surface plasmon resonance spectroscopy was used to measure the binding of the compounds to the expressed PH domain of AKT followed by an in vitro activity screen in Panc-1 and MiaPaCa-2 pancreatic cancer cell lines. We identified a novel chemical scaffold in several of the compounds that binds selectively to the PH domain of AKT, inducing a decrease in AKT activation and causing apoptosis at low micromolar concentrations. Structural modifications of the scaffold led to compounds with enhanced inhibitory activity in cells. One compound, 4-dodecyl-N-(1,3,4-thiadiazol-2-yl)benzenesulfonamide, inhibited AKT and its downstream targets in cells as well as in pancreatic cancer cell xenografts in immunocompromised mice; it also exhibited good antitumor activity. In summary, a pharmacophore for PH domain inhibitors targeting AKT function was developed. Computer-aided modeling, synthesis, and testing produced novel AKT PH domain inhibitors that exhibit promising preclinical properties.

Clastogenicity of PvuII and EcoRI in electroporated CHO cells assayed by metaphase chromosomal aberrations and by micronuclei using the cytokinesis-block technique

The clastogenicity of two restriction endonucleases with almost equal cutting frequencies: PvuII, generating blunt-ended DNA double-strand breaks (dsb) and EcoRI, generating cohesive-ended dsb, has been measured after treatment of electroporated CHO cells with these enzymes. Chromosome damage was assessed by the micronucleus cytokinesis-block technique, and for certain electroporation voltages by analysis of metaphase preparations. As has been found in previous studies, PvuII was found to be more effective in causing chromosomal damage than EcoRI, indicating the greater importance of blunt-ended dsb in chromosome aberration induction. These findings also validate the use of the micronucleus cytokinesis-block technique for evaluating chromosomal damage from restriction endonucleases. The results show a biphasic induction of micronuclei in binucleate cells as a function of time after treatment. This pattern is interpreted as indicating variable sensitivity of cells to restriction endonucleases at different stages of the cell cycle. The micronucleus data show that late collection times (40-48 h after treatment) give higher frequencies than short times. Both micronucleus and metaphase aberration data indicate that voltages in excess of 260 V are more efficient in porating cells than lower voltages and, as a result, lower restriction endonuclease concentrations could be used.

The fallacy of impoverishment

Several recent studies have challenged the assumption that Medicaid requires impoverishment. Although two-thirds of the elderly poor are not covered by Medicaid, many nursing home Medicaid recipients retain sizeable assets, which pass to their heirs without repayment of public costs. The magnitude of asset spenddown is much smaller than previously believed. This article discusses these findings and explores their significance to the long-term care financing crisis.