Survivin knockdown by short hairpin RNA abrogates the growth of human hepatocellular carcinoma xenografts in nude mice

Abnormal high activation of survivin is involved in carcinogenesis of various types of cancer. Survivin has been shown to promote cell proliferation in human hepatocellular carcinoma (HCC). Survivin-targeting approaches have become a promising strategy for treating HCC. Here, we used a reporter system to screen effective survivin siRNA sequences. The effect of vector-based survivin short hairpin RNA (shRNA) on the malignant phenotype of HCC cells in vitro and in vivo was determined, and an adenovirus-mediated shRNA expression vector was developed to decrease survivin expression of the established HCC tumor in nude mice. In vitro study showed that stable survivin knockdown inhibited cancer cell proliferation, enhanced apoptotic susceptibility, arrested cell cycle in the G1 phase and resulted in apparent mitotic catastrophe. Moreover, cells stably expressing survivin shRNA showed decreased tumorigenicity in nude mice. An additional in vivo study showed that intratumoral injection of adenovirus-delivered survivin shRNA suppressed tumor growth by spontaneous apoptosis of cancer cells and significantly prolonged animal survival. In conclusion, we proved the therapeutic potential of survivin shRNA for the treatment of HCC. And our results indicated that adenovirus-delivered shRNA may serve as a novel therapeutic for HCC.

Studies on the pharmacokinetics and metabolism of a gamma-secretase inhibitor BMS-299897, and exploratory investigation of CYP enzyme induction

BMS-299897 is a gamma-secretase inhibitor that was effective in reducing amyloid beta-peptide (A beta) in transgenic mice and guinea pigs. Therefore, pharmacokinetic and drug metabolism studies were conducted in animals to support its clinical development. The compound appeared to have low to intermediate total body clearance and was orally bioavailable (24-100%). The oral absorption of BMS-299897 from solid dosage forms appeared to be dissolution rate-limited. BMS-299897 was distributed into extravascular space (V(ss) >or= 1.3 l kg(-1)), including brain (brain-to-plasma ratio = 0.13-0.50). BMS-299897 appeared to be a P-glycoprotein (P-gp) substrate as the brain-to-plasma ratio was two-fold higher in the mdr1a knockout mouse as compared with the wild-type. Apparent autoinduction by BMS-299897 was observed in murine and rat efficacy and toxicity studies. In vitro, BMS-299897 was a weaker inducer of cytochrome P450 3A4 (CYP3A4) and a weaker transactivator of human pregnane X receptor (hPXR) as compared with rifampicin. Induction of human UGT1A and UGT2B was evaluated in primary human hepatocytes, but the results were inconclusive. A low potential for autoinduction in humans was predicted at a clinical dose of 250 mg and the prediction was consistent with the findings from a clinical multiple-dose study with BMS-299897 in probable Alzheimer's patients.

Expression and localization of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 in human epidermal appendages: a comparison study by immunofluorescence

BACKGROUND

Vascular endothelial growth factor (VEGF) promotes angiogenesis and plays important roles in neovascularization and development of tissues. VEGF receptors (VEGFRs) are high-affinity receptors for VEGF and are originally considered specific to endothelial cells. We have previously shown that keratinocytes from human normal skin express VEGFRs. This poses the question of whether these receptors are also expressed by epidermal appendages, as epidermal appendages are lined with epithelial cells.

OBJECTIVE

To investigate the expression of VEGFR-2 compare with VEGF in epidermal appendages, including hair follicles, eccrine sweat glands and sebaceous glands.

METHODS

Monoclonal antibodies to VEGF and VEGFR-2 were used for immunohistochemical examination of cryostat-cut sections of normal human skin specimens from 11 donors undergoing cosmetic surgery.

RESULTS

Immunoreactivities for VEGF and VEGFR-2 principally showed parallel intense expression in anagen hair follicle (including outer root sheat, inner root sheath, dermal papillae epidermal matrix), sebaceous glands (ductal and secretory portions) and eccrine sweat glands (ductal and secretory portions), respectively. In particular, abundant expression of VEGF was found in the follicular basement membrane zone surrounding the bulb matrix and in the ductal and secretory portions of eccrine sweat glands.

CONCLUSION

A potential VEGF/VEGFR-2 autocrine pathway may be defined by the coexpression of VEGF and VEGFR-2 in human skin epidermal appendages.

Measurement of semivolatile carbonaceous aerosols and its implications: a review

Measurement of carbonaceous aerosols is complicated by positive and negative artifacts. An organic denuder with high efficiency for removing gaseous organics is an effective approach to eliminate the positive artifact, and it is a precondition for the accurate determination of SVOC by an adsorbent backup filter. Evaluations of different configurations of the organic denuder, and SVOC determined by different denuder-based samplers, both integrated and semi-continuous, are reviewed. A new equation for determination of the denuder efficiency is estimated, considering the efficiency of removing both the gaseous organics that could be adsorbed by the quartz and the gaseous passing through the quartz that could be subsequently adsorbed by the backup adsorbent filter. The origin of OC on the backup quartz filter, behind either quartz or Teflon filter, is quantitatively evaluated by the denuder-based method based on the data published. The backup-OC is shown to be dominated by either gaseous organics passing through the front filter or the evaporated particulate organic carbon depending on the sampling environment.

Aortic and mitral valve endocarditis caused by Gemella morbillorum in a haemodialysis patient

Gemella morbillorum is part of the commensal flora of the upper respiratory tract, intestinal tract and genitourinary tract. On rare occasions, it causes endocarditis. We report a 67-year-old Chinese man with end-stage renal disease on maintenance intermittent haemodialysis, who developed Gemella morbillorum endocarditis complicated by severe aortic and mitral regurgitation. Most cases of Gemella morbillorum endocarditis have satisfactory outcomes with antibiotics or surgical treatment.

Energy of K-momentum dark excitons in carbon nanotubes by optical spectroscopy

Phonon sideband optical spectroscopy determines the energy of the dark K-momentum exciton for (6,5) carbon nanotubes. One-phonon sidebands appear in absorption and emission, split by two zone-boundary (K-point) phonons. Their average energy locates the E11 K-momentum exciton 36 meV above the E11 bright level, higher than available theoretical estimates. A model for exciton-phonon coupling shows the absorbance sideband depends sensitively on the K-momentum exciton effective mass and has minimal contributions from zone-center phonons, which dominate the Raman spectra of carbon nanotubes.

Effects of cilostazol on thrombospondin-1 (TSP-1) expression changes in the myocardium of diabetic rats

Myocardial protective effects of the phosphodiesterase 3 inhibitor, cilostazol, in streptozotocin-induced diabetic rats were investigated. Four weeks after induction of diabetes, we measured thrombospondin-1 (TSP-1) expression in the left ventricular myocardium. Microstructural and ultrastructural changes were also analysed. Four weeks after the induction of diabetes there were significant differences in body weight and blood glucose between the control, diabetic and cilostazol-treated diabetic animals. TSP-1 expression was significantly increased in the myocardium of diabetic rats compared with the control group. Although significantly higher than the control group, TSP-1 expression was significantly lower in the cilostazol group compared with the diabetes group. There were obvious ultrastructural changes in the myocardium of diabetic rats, which were rarely seen in cilostazol-treated diabetic rats. In conclusion, this study provides experimental evidence that cilostazol treatment of diabetic rats effectively prevents pathological myocardial alterations, possibly via the down-regulation of TSP-1 expression.

Direct measurement of the lifetime of optical phonons in single-walled carbon nanotubes

Time-resolved anti-Stokes Raman spectroscopy has been applied to probe the dynamics of optical phonons created in single-walled carbon nanotubes by femtosecond laser excitation. From measurement of the decay of the anti-Stokes Raman signal in semiconducting nanotubes of (6,5) chiral index, a room-temperature lifetime for G-mode phonons of 1.1+/-0.2 ps has been determined. This lifetime, which reflects the anharmonic coupling of the G-mode phonons to lower-frequency phonons, is important in assessing the role of nonequilibrium phonon populations in high-field transport phenomena.

A phase II study of nilotinib administered to patients with imatinib resistant or intolerant chronic myelogenous leukemia (CML) in chronic phase (CP), accelerated phase (AP) or blast crisis (BC) who also failed dasatinib

7038

Background: Nilotinib and dasatinib are two new second generation tyrosine kinase inhibitors used in the treatment of imatinib-resistant/intolerant CML. There is limited data regarding the efficacy and safety of these therapies when given sequentially. Methods: This phase II open-label study was designed to evaluate the safety and efficacy of nilotinib at a dose of 400mg BID in CML-CP, -AP, and -BC pts who previously received and either failed or were intolerant to imatinib and dasatinib. Results: A total of 42 pts are reported - CP (16), AP (9), and BC (17 total; 13 myeloid, 4 lymphoid). Overall 10 (24%) pts had extramedullary disease at baseline. For all pts, median time from first diagnosis was 16.8 (0.6–265) months. The median duration of nilotinib exposure was 81 days with median dose intensity of 800mg/day. A total of 13 (31%) pts with dasatinib failure remain on treatment, 29 (69%) discontinued (6 for AEs, 16 for disease progression). CP: Of the 16 pts, 5 (31%) had a MCyR (3 complete, 2 partial). Complete hematologic response (CHR) was reported in 5/13 (39%) pts without CHR at baseline. Disease progression only occurred in 2 pts. AP: 2/9 (22%) pts had a return to chronic phase (RTC), 6 pts were not evaluable and there was 1 death. Disease progression occurred in 5 pts. BC: 3/17 (18%) achieved CHR, 1 (6%) had RTC, and 4 (24%) pts had disease progression. For all pts, the most common Grade 3/4 AEs reported were thrombocytopenia (26%), neutropenia (24%), and anemia (7%) pts. Conclusions: Nilotinib has significant clinical activity in CML-CP, AP, and BC patients who have failed imatinib and dasatinib. Nilotinib is safe and well tolerated, consistent with its kinase selectivity profile.

No significant financial relationships to disclose.

Systems approach to modeling the neuronal CPG for leech swimming

This paper proposes a mathematical model of the neuronal central pattern generator (CPG) for leech swimming. The model is developed through the "systems approach" where dynamical components and their connections are first identified through input/output data from physiological experiments and then integrated into a chain of nonlinear oscillators. Our approach leads to a model of moderate complexity when compared with existing models developed through biophysical principles. We show through numerical simulations that our model can successfully reproduce the phase coordination observed in the isolated nerve cord of the leech CPG. As a byproduct, a prediction is obtained for the intrinsic period gradient along the nerve cord.

Modulation of the oxidative stress and nuclear factor kappaB activation by theaflavin 3,3'-gallate in the rats exposed to cerebral ischemia-reperfusion

The major pathobiological mechanisms of IR injury include excitotoxicity, oxidative stress, and inflammation. TF3, a major constituent of black tea, possesses biological functions such as anti-oxidative and anti-inflammatory activities. The purpose of this study was to verify the neuronal protective potential of TF3 and its mechanisms against cerebral IR injury in rats. TF3 administration (10 and 20 mg.kg-1) ameliorated the infarct volume. TF3 also decreased the content of MDA and NO. TF3 significantly increased the activity of SOD and GSH-Px, which were reduced by IR injury. Administration of TF3 decreased mRNA and protein expression of COX-2 and iNOS. DNA binding and Western blotting revealed an increase in NF-kappaB activation and IkappaB depletion in IR brain tissue. Pretreatment with TF3 markedly inhibited IRinduced increase in nuclear localization of NF-kappaB, and preserved IkappaB in the cytoplasm. The results show that TF3 exerts protective effects against cerebral IR injury by reducing oxidative stress and modulating the NF-kappaB activation.

Photoluminescence from intertube carrier migration in single-walled carbon nanotube bundles

Photoluminescence (PL) identifies spectroscopic signatures of intertube transfer of optically pumped carriers in single-walled carbon nanotube (SWNT) ensembles. Resonant photoexcitation of large band gap SWNTs produces strong PL from smaller band gap SWNTs. Magnetic alignment measurements associate the energy-transfer PL peaks with the formation of SWNT bundles, suggesting that efficient coupling results from physical contact.

Systems-level modeling of neuronal circuits for leech swimming

This paper describes a mathematical model of the neuronal central pattern generator (CPG) that controls the rhythmic body motion of the swimming leech. The systems approach is employed to capture the neuronal dynamics essential for generating coordinated oscillations of cell membrane potentials by a simple CPG architecture with a minimal number of parameters. Based on input/output data from physiological experiments, dynamical components (neurons and synaptic interactions) are first modeled individually and then integrated into a chain of nonlinear oscillators to form a CPG. We show through numerical simulations that the values of a few parameters can be estimated within physiologically reasonable ranges to achieve good fit of the data with respect to the phase, amplitude, and period. This parameter estimation leads to predictions regarding the synaptic coupling strength and intrinsic period gradient along the nerve cord, the latter of which agrees qualitatively with experimental observations.

mda-7 gene transfer sensitizes breast carcinoma cells to chemotherapy, biologic therapies and radiotherapy: correlation with expression of bcl-2 family members

Current therapies used in the treatment of breast cancer are limited by systemic toxicity, rapid drug metabolism and intrinsic and acquired drug resistance. We have previously shown that adenoviral-mediated transfer of the melanoma differentiation-associated gene-7 (mda-7) elicits growth inhibition and apoptosis in various tumor types. Here, we evaluate the effects of Ad-mda7, alone and in combination with other therapies, against a panel of nine breast tumor cell lines and their normal counterparts; we report selective Ad-mda7-mediated p53-independent growth inhibition, G2/M cell cycle arrest, and apoptosis. In vivo, Ad-mda7 induced p53-independent tumor growth inhibition (P<0.004) in multiple xenograft models. We then evaluated the combination of Ad-mda7 with agents commonly used to treat breast cancer: radiotherapy (XRT), Tamoxifen, Taxotere, Adriamycin, and Herceptin. These agents exhibit diverse modes of action, including formation of bulky adducts, inhibition of DNA replication (Adriamycin, XRT), damage to microtubules (Taxotere), nonsteroidal estrogen antagonists (Tamoxifen), or Her2/neu receptor blockade (Herceptin). Treated with conventional anticancer drugs or radiation, MDA-7-expressing cells display additive or synergistic cytotoxicity and apoptosis that correlates with decreased BCL-2 expression and BAX upregulation. In vivo, animals that received Ad-mda7 and XRT underwent significant reduction of tumor growth (P<0.002). This is the first report of the synergistic effects of Ad-mda7 combined with chemotherapy or radiotherapy on human breast carcinoma cells.

Combinatorial synergy induced by adenoviral-mediated mda-7 and Herceptin in Her-2+ breast cancer cells

The melanoma differentiation-associated gene-7 (mda-7) is a member of the interleukin-10 cytokine family and a novel tumor suppressor gene. Adenoviral-mediated mda-7 (Ad-mda7) gene transfer has tumor-specific growth inhibitory and proapoptotic effects in a broad spectrum of cancer cells. In breast cancer cells, adenoviral-induced mda-7 expression triggers antiproliferative effects by downregulation of survival signals, such as Bcl-2 and Akt. The anti-human epidermal growth factor receptor-2 (Her-2) monoclonal antibody, Trastuzumab (Herceptin), increases the sensitivity of Her-2/neu-overexpressing breast cancer cells to chemotherapeutic agents and radiotherapy. In this study, we evaluate the effects of treatment with Ad-mda7 and Herceptin combination therapy in a panel of Her-2/neu-overexpressing cell lines, and in established tumors in nude mice. Compared to individual treatments, the combination of Ad-mda7 and Herceptin elicits supra-additive antitumor activity in Her-2/neu-overexpressing tumor cell lines: increased cell death, cell cycle block and apoptosis. The Ad-mda7 and Herceptin interaction was shown to be synergistic by isobologram analysis. Ad-mda7 does not alter cell surface Her-2/neu levels, but the combination of Ad-mda7+Herceptin results in increased expression of cell surface E-cadherin with concomitant translocation of beta-catenin from the nucleus to the cell membrane. In vivo, the combination of Ad-mda7 and Herceptin showed significantly increased antitumor activity (P<0.003) against Her-2/neu-overexpressing tumors. These data suggest that the combination of Ad-mda7 with Herceptin may be a novel therapy for breast cancer patients whose tumors overexpress Her-2/neu. The observed synergistic effect may improve treatment options for otherwise poorly responsive, Her-2-positive, breast cancer patients.