Distribution of HLA-G 14-bp insertion/deletion polymorphism in six Chinese ethnic groups

Recently, a 14-bp insertion/deletion polymorphism (+14 bp/-14 bp) in exon 8 of the Human leucocyte antigen-G (HLA-G) gene has been studied extensively because this polymorphism has been associated with HLA-G mRNA stability and could influence HLA-G mRNA expression. We investigated the distribution of the 14-bp insertion/deletion polymorphism in six different Chinese ethnic groups (Bulang, Wa, Hani, Jinuo, Maonan and Zhuang), which originated from three major ancient tribes (Di-Qiang, Baipu and Baiyue) in China. Comparison of the 14-bp insertion frequency in the six groups with other Chinese groups showed marked variation among the three ancient tribes, Di-Qing (0.490-0.534), Baipu (0.470-0.609) and Baiyue (0.280-0.344). Furthermore, the frequencies of the 14-bp insertion were similar in groups that came from the same ancient tribe, which indicated that the individuals who share the 14-bp insertion have the most probably inherited the 14-bp element from a common ancestor. In addition, an intra-tribal comparison of the 14-bp insertion/deletion frequencies between the descendants of the ancient ancestral tribes suggests that population histories or some environmental effects, such as founder effect or isolation, might also influence the distribution.

Novel hydrophilic docetaxel (CQMU-0519) analogue inhibits proliferation and induces apoptosis in human A549 lung, SKVO3 ovarian and MCF7 breast carcinoma cell lines

OBJECTIVE

Objectives of this investigation were not merely to perform a comparative study with original docetaxel, but to define anti-proliferative and apoptotic effects of novel hydrophilic docetaxel (CQMU-0519) analogue on A549 lung, SKVO3 ovary and MCF7 breast carcinoma cell lines.

MATERIALS AND METHODS

The materials for the study consist of a completely new docetaxel analogue (CQMU-0519), synthesized by the Department of Pharmacology, Chongqing Medical University, China, which is completely soluble in water. 50 nm of drug concentration was utilized on all three cell lines where cell population growth was assessed using cell culture kit-8 and flow cytometry analysis, whereas apoptotic pathways were unveiled by use of annexin-V FITC, apoptosis DNA ladder, caspases-3, 6, 8 and 9; in the meanwhile, regulation of Bcl-2 family members was analysed by western blotting.

RESULT

The novel docetaxel analogue (CQMU-0519) suppressed cell proliferation in all three cell lines, inhibition of cell proliferation and cell cycle arrest being more evident in G(2) /M phase. Also, in both lung and ovarian cell lines, apoptotic levels were higher as measured by the various tests performed, and downregulation of Bcl-2 and Bcl-xL with increased expressions of Bad and Bax indicated the intrinsic pathway for apoptosis. Nevertheless, it was found that MCF7 cells, although also manifesting high levels of apoptosis, used the extrinsic pathway instead. Hence, it was shown that novel docetaxel analogue (CQMU-0519) may have some prospective use in future clinical trials.

CONCLUSIONS

Novel hydrophilic docetaxel analogue (CQMU-0519) inhibited cell proliferation and enhanced the intrinsic apoptotic pathway in lung and ovarian carcinoma cells, whereas it used the extrinsic one in breast adenocarcinoma cells.

SU-E-J-139: Feasibility of Using EPID for Real-Time Target Localization during Treatment

PURPOSE

This study aims to investigate the feasibility of using the images of the treatment fields acquired by an electronic portal imaging device (EPID) for real-time target localization.

METHODS

Forty one patients treated with IMRT and RapidArc were recruited in this study including 37 prostate patients and 4 lung patients. These patients were grouped as: prostate IMRT with lymph node (n=14), prostate IMRT without lymph node (n=17), prostate RapidArc (n=6), and lung IMRT (n=4). For each patient, two to four fiducial markers were implanted inside the tumor. The DRR, which projects the patient anatomy and the fiducial marker at the EPID location, was reconstructed for each field. The MLC aperture of each control point was overlay on its corresponding DRR to evaluate the fractional time when the fiducial marker was seen on the EPID image. The probability of seeing at least one, two, three, and four fiducial markers during the treatment was recorded.

RESULTS

For the prostate IMRT patients without lymph nodes included in the target volume, the average probability of seeing at least one, two, three, and four fiducial markers during the treatment was 50% (35%-59%), 39% (23%-51%), 24% (7%-38%), and 12% (4%-29%), respectively. For the prostate IMRT patients with lymph nodes, the probability was 41% (24%-51%), 29% (12%-42%), 15% (3%-24%), and 7% (4%-15%), respectively. For prostate RapidArc treatments using two arcs, the average probability of seeing at least one fiducial marker was 81% (58%-90%) for the full arc and 74% (53%-94%) for the partial arc. For the lung IMRT treatment, the average probability of seeing at least one fiducial marker was 34% (20%-52%).

CONCLUSIONS

The continuous image acquisition from the EPID during the treatment provides sufficient target movement information for real-time target localization and intrafractional target motion correction for advanced radiotherapy treatments.

Right lobe living-donor liver transplantation with or without middle hepatic vein: a meta-analysis

OBJECTIVE

The purpose of this meta-analysis was to compare outcomes after right-lobe living-donor liver transplantation (LDLT) with or without the middle hepatic vein (MHV).

METHODS

Studies were identified through a computerized search of Pubmed, Embase, Ovid, the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials, the Cochrane Library database, and the Web of Science. Two reviewers independently assessed the quality of each study and abstracted outcome data. We extracted data for liver functional recovery in donors, donor hospital stay, donor complications and liver functional recovery in recipients. We synthesized published data using random-effects and fixed-effect models, expressing results as weighted mean differences (WMD) or relative risk (RR).

RESULTS

The 11 included eligible studies came from medical centers worldwide. Significant differences between "with MHV" versus "without MHV" groups were not observed for liver functional recovery (P=.08; WMD=-2.88), donor hospital stay (P=.00; WMD=0.00), or donor complications (P=.90; RR=1.02). However, our meta-analysis showed a significant benefit for recipients liver functional recovery favoring the MHV group (P=.02; WMD=-33.06).

CONCLUSIONS

Our meta-analysis discovered that right lobes with MHV not only experienced better liver functional recovery in recipients, but also caused no greater harm or risk to donors.

UVB-induced COX-2 expression requires histone H3 phosphorylation at Ser10 and Ser28

Cyclooxygenase-2 (COX-2) is an inducible enzyme that contributes to the generation of chronic inflammation in response to chemical carcinogens and environmental stresses, including ultraviolet B (UVB) irradiation. Although post-translational histone modifications are believed to play an important role in modulating transcriptional regulation of UVB-induced COX-2, the underlying biochemical mechanisms are completely unknown. Here, we show that UVB activates the p38 MAPK/MSK1 kinase cascade to phosphorylate histone H3 at Ser10 and Ser28, contributing to UVB-induced COX-2 expression. UVB has no effect on the global trimethylation level of histone H3 (H3K4me3, H3K9me3, and H3K27me3). We observed that selected mammalian 14-3-3 proteins bind to UVB-induced phosphorylated histone H3 (Ser10 and Ser28). In particular, 14-3-3ε is critical for recruiting MSK1 and Cdk9 to the chromatin and subsequently phosphorylating the C-terminal domain (CTD) of RNA polymerase II in the cox-2 promoter. We propose that histone H3 phosphorylation at Ser10 and Ser28 serve as critical switches to promote cox-2 gene expression by facilitating the recruitment of MSK1 and Cdk9 to the cox-2 promoter, thereby promoting RNA polymerase II phosphorylation.

Synthesis of Fe-group metal oxide nanostructures by thermal oxidation and their magnetic properties

In this paper, we review the preparation of Fe-group metal oxide nanostructures by the thermal oxidation method developed in our lab. By this method, we have prepared several kinds of nanostructures, including nanowires and nanoleaves. The magnetic properties of these nanostructures have also been studied. By carefully controlling the reacting time, temperature, and humidity, we have prepared alpha-Fe2O3, gamma-Fe2O3, Fe3O4, and Co3O4 nanowires and alpha-Fe2O3 nanoleaves by heating the substrates in proper atmosphere. The alpha-Fe2O3 and Co3O4 nanowires are produced by directly oxygenating pure metal at 550 to approximately 650 degrees C and 480-520 degrees C, separately. The gamma-Fe2O3 and Fe3O4 nanowires are produced by reducing as-prepared alpha-Fe2O3 nanowires in a mixture of N2 and H2. The nanowires are about 10-20 microm, with diameter of about 20 to approximately 100 nm. Most of the nanowire arrays are grown vertically from the surface of the substrate at a high surface density (10(8)-10(9) cm(-2)). Compared with the nanowires prepared by hydrothermal process and template method, Most of our nanowires are structurally uniform and single crystallites. The magnetic properties of these nanostructures are also studied, and demonstrate some novel properties.

Tooth slice/scaffold model of dental pulp tissue engineering

Multipotency is a defining characteristic of post-natal stem cells. The human dental pulp contains a small subpopulation of stem cells that exhibit multipotency, as demonstrated by their ability to differentiate into odontoblasts, neural cells, and vascular endothelial cells. These discoveries highlight the fundamental role of stem cells in the biology of the dental pulp and suggest that these cells are uniquely suited for dental pulp tissue-engineering purposes. The availability of experimental approaches specifically designed for studies of the differentiation potential of dental pulp stem cells has played an important role in these discoveries. The objective of this review is to describe the development and characterization of the Tooth Slice/Scaffold Model of Dental Pulp Tissue Engineering. In addition, we discuss the multipotency of dental pulp stem cells, focusing on the differentiation of these cells into functional odontoblasts and into vascular endothelial cells.

Effects of poly(lactic-co-glycolic acid) on preparation and characteristics of plasmid DNA-loaded solid lipid nanoparticles

Poly(lactic-co-glycolic acid) (PLGA) was used as a polymeric emulsifier to encapsulate plasmid DNA into hydrogenated castor oil (HCO)-solid lipid nanoparticles (SLN) by w/o/w double emulsion and solvent evaporation techniques. The effects of PLGA on the preparation, characteristics and transfection efficiency of DNA-loaded SLN were studied. The results showed that PLGA was essential to form the primary w/o emulsion and the stability of the emulsion was enhanced with the increase of PLGA content. DNA-loaded SLN were spherical with smooth surfaces. The SLN had a negative charge in weak acid and alkaline environment but acquired a positive charge in acidic pH and the cationisation capacity of the SLN increased with the increase of PLGA/HCO ratio. Agarose gel electrophoresis demonstrated that the majority of the DNA maintained its structural integrity after preparation and being extracted or released from DNA-loaded SLN. When PLGA/HCO ratio increased from 5 to 15%, the encapsulation efficiency, loading capacity and transfection efficiency of the nanoparticles increased significantly, whereas the changes of particle size and polydispersity index were insignificant. Cytotoxicity study in cell culture demonstrated that the SLN was not toxic.

Enhancement of antibacterial activity of tilmicosin against Staphylococcus aureus by solid lipid nanoparticles in vitro and in vivo

This study aimed to enhance the antibacterial activity of tilmicosin by solid lipid nanoparticles (SLN). Tilmicosin-loaded hydrogenated castor oil (HCO)-SLN was prepared using a hot homogenisation and ultrasonication method. The physicochemical characteristics of SLN were investigated by scanning electron microscopy (SEM) and photon correlation spectroscopy (PCS). The antibacterial activity of tilmicosin-SLN against Staphylococcus aureus was evaluated by growth inhibition and colony-counting method. A therapeutic study of tilmicosin-SLN was conducted by subcutaneous injection in a mouse mastitis model infected with S. aureus by teat canal infusion. Therapeutic efficacy was assessed by physical appearance of the mammary gland and measurement of colony-forming units (CFU) per gland. The results showed that the diameter, polydispersivity index, zeta potential, encapsulation efficiency and loading capacity of the nanoparticles were 343±26 nm, 0.33±0.08, -7.9±0.4 mV, 60.4±3.3% and 11.2±0.47%, respectively. Tilmicosin-SLN showed a sustained-release effect and sustained and enhanced antibacterial activity in vitro. SLN significantly enhanced the therapeutic efficacy of tilmicosin determined by lower CFU counts and a decreased degree of inflammation. These results demonstrated that the HCO-SLN is an effective carrier to enhance the antibacterial activity of tilmicosin.

Hypermethylation and aberrant expression of Wnt-antagonist family genes in gastric cardia adenocarcinoma

The canonical Wnt signalling pathway plays a key role during embryogenesis and pathogenesis of various types of tumors. Recently, several studies have shown that the promoter hypermethylation of Wnt-antagonist genes, including sFRP-1, sFRP-2, sFRP-4, sFRP-5, Wif-1 and Dkk-3, have been certified to contribute to the tumorigenesis of several cancers. The aim of this study was to investigate the promoter methylation of Wnt-antagonist genes in gastric cardia adenocarcinoma (GCA) and corresponding adjacent non-cancerous tissues, and to establish the possible relationship between DNA methylation status and the pathogenesis of GCA. MSP, RT-PCR methods were applied respectively to examine the CpG methylation of the Wnt-antagonist genes and its mRNA expression in tumors and corresponding non-cancerous tissues, and immunohistochemistry method was used to determine protein expression of β-catenin(the key factor of the Wnt signalling pathway) and cyclin D1(the target gene of this pathway). The frequency of promoter methylation of sFRP-1, sFRP-2, sFRP-4, sFRP-5, Wif-1 and Dkk-3 genes in GCA tumor tissues were 78.7%(74/94), 76.6%(72/94), 70.2%(66/94), 77.1%(73/94), 61.7%(58/94) and 21.3%(20/94), respectively, which were significantly higher than those in adjacent non-cancerous tissues. Furthermore, the frequencies of silenced mRNA expression of these six genes in GCA tumor tissues were significantly higher than those in adjacent non-cancerous tissues. Methylation levels of these six genes were all correlated with loss of mRNA expression. The ectopic expression of β-catenin and cyclin D1 was significantly more frequent in GCA tumor tissues than that in adjacent non-cancerous tissues and correlated with each Wnt-antagonist genes hypermethylation status. Epigenetic silencing of Wnt-antagonist genes expression by promoter hypermethylation may play an important role in gastric cardia adenocarcinoma.

Abstract P1-02-02: Processing of GPNMB by ADAM-10 in Breast Tumors Releases an Extracellular Domain with Angiogenic Properties

Background: Glycoprotein non-metastatic B (GPNMB), also known as Osteoactivin, is a cell surface bound, transmembrane protein that is expressed in 41-74% of breast cancers. We have shown that it promotes migration, invasion and metastasis of breast cancer cells, that it is associated with shorter recurrence-free and overall survival times, and that it is most commonly expressed among breast tumors of the basal/triple-negative subtypes. Patients with basal/triple-negative breast cancer have aggressive disease and are not amenable to currently available targeted therapies. For these reasons GPNMB is an attractive target for therapeutic intervention in breast cancer; indeed, a GPNMB-targeted antibody-drug conjugate (CDX-011) has shown impressive clinical response among patients with GPNMB-positive breast cancer and is being investigated in Phase IIb clinical trials. Despite its promise as a therapeutic target in breast cancer, little is known about the functional role of GPNMB the primary tumor microenvironment.

Materials and Methods: We have employed 66cl4 murine mammary carcinoma cells and human BT549 breast cancer cells to investigate the effects of GPNMB on tumor growth and angiogenesis, respectively in vivo. Control and GPNMB-expressing tumors were analyzed using immunohistochemistry for degree of proliferation apoptosis and angiogenesis. To better characterize functionally important domains of GPNMB we employed immunoblot and ELISA analyses to assess levels of full length, intact GPNMB and shed GPNMB ectodomain in breast cancer cells. Transient siRNA-mediated knockdown studies were used to identify sheddases responsible for GPNMB shedding. Finally, we employed in vitro migration assays to assess function of the shed extracellular domain (ECD) of GPNMB.

Results: In this study we show that GPNMB promotes the outgrowth of mammary tumors in vivo and enhances their microvascular density. In an effort to investigate the functional domains of GPNMB that are responsible for this pro-angiogenic effect, we found that that the extracellular domain (ECD) of GPNMB is constitutively shed in breast cancer cells and show that this ECD is capable of inducing endothelial migration. Finally, we have implicated a disintegrin and metalloprotease-10 (ADAM10) as a novel sheddase responsible for liberation GPNMB ectodomain.

Conclusion: In this study we have described ADAM10-mediated shedding of GPNMB ECD - a protein fragment that induces endothelial cell migration - as a novel mechanism by which GPNMB can promote angiogenesis in breast cancer. Further efforts to characterize the effect of GPNMB on endothelial cell function will be discussed.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-02-02.

SHED differentiate into functional odontoblasts and endothelium

Studies on mechanisms underlying the differentiation of dental pulp stem cells are critical for the understanding of the biology of odontogenesis and for dental tissue engineering. Here, we tested the hypothesis that stem cells from exfoliated deciduous teeth (SHED) differentiate into functional odontoblasts and endothelial cells. SHED were seeded in tooth slice/scaffolds and implanted subcutaneously into immunodeficient mice. SHED differentiated into functional odontoblasts that generated tubular dentin, as determined by tetracycline staining and confocal microscopy. These cells also differentiated into vascular endothelial cells, as determined by beta-galactosidase staining of LacZ-tagged SHED. In vitro, vascular endothelial growth factor (VEGF) induced SHED to express VEGFR2, CD31, and VE-Cadherin (markers of endothelium) and to organize into capillary-like sprouts. VEGF induced ERK and AKT phosphorylation (indicative of differentiation), while inhibiting phosphorylation of STAT3 (indicative of 'stemness'). Collectively, this work demonstrates that SHED can differentiate into angiogenic endothelial cells and odontoblasts capable of generating tubular dentin.

Role of Aggregatibacter actinomycetemcomitans in glutathione catabolism

INTRODUCTION

Our previous studies demonstrated that three enzymes, gamma-glutamyltransferase (GGT), cysteinylglycinase (CGase) and cystalysin, are required for the catabolism of glutathione to produce hydrogen sulfide (H(2)S) in Treponema denticola. In this study, we examined glutathione catabolism in Aggregatibacter actinomycetemcomitans.

METHODS

The GGT and CGase of A. actinomycetemcomitans were determined by biological methods and GGT was characterized using a molecular biological approach.

RESULTS

A. actinomycetemcomitans showed GGT and CGase activity, but could not produce H(2)S from glutathione. The addition of recombinant T. denticola cystalysin, an l-cysteine desulfhydrase, to whole cells of A. actinomycetemcomitans resulted in the production of H(2)S from glutathione. Subsequently, we cloned A. actinomycetemcomitans GGT gene (ggt) and overexpressed the 63 kDa GGT protein. The recombinant A. actinomycetemcomitans GGT was purified and identified. The K(cat)/K(m) of the recombinant GGT from N-gamma-l-glutamyl-4-nitroaniline as substrate was 31/microm/min. The activity of GGT was optimum at pH 6.9-7.1 and enhanced by thiol-containing compounds.

CONCLUSION

The results demonstrated that A. actinomycetemcomitans had GGT and CGase activities and that the GGT was characterized. The possible role of A. actinomycetemcomitans in glutathione metabolism and H(2)S production from oral bacteria was discussed.

A phase I/II study of CR011-vcMMAE, an antibody-drug conjugate, in patients (pts) with locally advanced or metastatic breast cancer (MBC)

1067

Background: Glycoprotein NMB (GPNMB), also known as osteoactivin, has been shown to regulate metastasis of breast cancer in vivo. CR011-vcMMAE, a fully-human monoclonal anti-GPNMB antibody conjugated to the tubulin inhibitor monomethylauristatin E, is safe and active in pts with advanced melanoma. This is the first study of CR011-vcMMAE in breast cancer. Methods: Eligible pts with MBC had ≥ 2 prior chemotherapy regimens, including a taxane, an anthracycline, and capecitabine; and ECOG PS ≤ 2. Doses were escalated to 1.88 mg/kg IV q3w (the maximum tolerated dose [MTD] in melanoma) using a standard 3+3 design. Immunohistochemistry (IHC) with goat polyclonal antibody to GPNMB was performed on pt biopsy specimens and on tissue microarrays containing normal breast, DCIS, breast tumor and lymph node metastases. Results: 10 pts with MBC (median age 57, range 36 - 69) had a median of 7 prior regimens and were treated with CR011-vcMMAE for a median of 2 cycles (range 1–4). In the first 2 pts at 1.34 mg/kg, dose limiting toxicity of worsening peripheral sensory neuropathy was observed. Pts with baseline neuropathy worse than grade 1 were subsequently excluded. Pts were treated at 1.0 mg/kg (n = 3), 1.34 mg/kg (n = 5), and 1.88 mg/kg (n = 2); enrollment at 1.88 mg/kg is continuing. Other adverse events (AEs) were grade 1/2 anorexia and pain in 4 pts; diarrhea, rash, fatigue, and neuropathy in 3 pts; and grade 3 rash in 1 pt. Evidence of antitumor activity has been observed. A response of 37% tumor shrinkage was seen in a pt after only 2 cycles and is ongoing. A second pt had a 51% reduction after 2 cycles, but had PD after 12 weeks. Breast tumor samples were more likely to stain positive for GPNMB than normal breast tissues. Conclusions: CR011-vcMMAE 1.34 mg/kg IV q3w is well-tolerated in heavily pretreated pts with MBC. The 1.88 mg/kg q3w dose is being assessed and phase II expansion is planned at the MTD. IHC of pt tumor specimens is being evaluated.

[Table: see text]

Challenges of using MR spectroscopy to detect neural progenitor cells in vivo

A recent report of detection of neural progenitor cells (NPCs) in living human brain by using in vivo proton MR spectroscopy ((1)H-MR spectroscopy) has sparked great excitement in the field of biomedicine because of its potential influence and utility in clinical neuroscience research. On the other hand, the method used and the findings described in the report also caused heated debate and controversy. In this article, we will briefly detail the reasons for the debate and controversy from the point of view of the in vivo (1)H-MR spectroscopy methodology and will propose some technical strategies in both data acquisition and data processing to improve the feasibility of detecting NPCs in future studies by using in vivo (1)H-MR spectroscopy.

Effects of VEGF and FGF2 on the revascularization of severed human dental pulps

The long-term outcome of replanted avulsed permanent teeth is frequently compromised by lack of revascularization, resulting in pulp necrosis. The purpose of this study was to evaluate the effects of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF-2) on the revascularization of severed human dental pulps. Tooth slices were prepared from non-carious human molars and treated with 0-50 ng/mL rhVEGF(165) or rhFGF-2 for 7 days in vitro. Both angiogenic factors enhanced pulp microvessel density compared with untreated controls (p < 0.05). Tooth slices were also treated with 0 or 50 ng/mL rhVEGF(165) for one hour prior to implantation into the subcutaneous space of immunodeficient mice. Treatment with rhVEGF(165) increased pulp microvessel density in vivo (p < 0.05). These results demonstrate that rhVEGF(165) enhanced neovascularization of severed human dental pulps and suggest that topical application of an angiogenic factor prior to replantation might be beneficial for the treatment of avulsed teeth.

Effect of PTK/ZK on the angiogenic switch in head and neck tumors

Transformation of small avascular masses of tumor cells into rapidly progressive cancers is triggered by the angiogenic switch, a process that involves vascular endothelial growth factor (VEGF) signaling. We have shown that VEGF enhances the survival and angiogenic potential of endothelial cells by activating the Bcl-2-CXCL8 signaling axis. The purpose of this study was to evaluate the effect of a small-molecule inhibitor of VEGF receptors (PTK/ZK) on the initial stages of head and neck tumor angiogenesis. In vitro, PTK/ZK blocked head and neck tumor cell (OSCC3 or UM-SCC-17B)-induced Bcl-2 and CXCL8 expression in endothelial cells. Oral administration of PTK/ZK decreased xenograft head and neck tumor microvessel density, and inhibited Bcl-2 and CXCL8 expression in tumor-associated endothelial cells. Analysis of these data demonstrates that PTK/ZK blocks downstream targets of VEGF signaling in endothelial cells, and suggests that PTK/ZK may inhibit the angiogenic switch in head and neck tumors.

Transforming growth factor-beta1 is the predominant isoform required for breast cancer cell outgrowth in bone

Transforming growth factor (TGF)-beta signaling is a potent modulator of the invasive and metastatic behavior of breast cancer cells. Indeed, breast tumor responsiveness to TGF-beta is important for the development of osteolytic bone metastases. However, the specific TGF-beta isoforms that promote breast cancer outgrowth in bone is unknown. We demonstrate that expression of a TGF-beta ligand trap, which neutralizes TGF-beta1 and TGF-beta3, in MDA-MB-231 breast cancer cells diminished their outgrowth in bone and reduced the severity of osteolytic lesion formation when compared with controls. We further show that a reduction or loss of TGF-beta1 expression within the bone microenvironment of TGF-beta1+/- and TGF-beta1-/- mice significantly reduced the incidence of breast tumor outgrowth compared with wild-type animals. Interestingly, those tumors capable of growing within the tibiae of TGF-beta1-deficient mice had upregulated expression of all three TGF-beta isoforms. Finally, breast cancer cells expressing the TGF-beta ligand trap showed a pronounced reduction in their ability to form osteolytic lesions when injected into the tibiae of TGF-beta1+/- mice. Thus, our studies show that both host- and tumor-derived TGF-beta expression plays a critical role during the establishment and outgrowth of breast cancer cells in bone.

Sequence-based typing reveals the novel HLA-DRB1*1467 allele in a Chinese individual

We report here a novel DRB1*1467 allele identified by sequence-based typing in a Chinese individual. The novel DRB1*1467 is identical to DRB1*140301 with an exception of one base substitution at position 186 (C>A) of exon 2 resulting in codon 67 changed from CTC (Leu) to ATC (Ile).

Cancer gene therapy with iCaspase-9 transcriptionally targeted to tumor endothelial cells

Antiangiogenic therapies have shown varying results partly because each tumor type secretes a distinct panel of angiogenic factors to sustain its own microvascular network. In addition, recent evidence demonstrated that tumors develop resistance to antiangiogenic therapy by turning on alternate angiogenic pathways when one pathway is therapeutically inhibited. Here, we test the hypothesis that expression of a caspase-based artificial death switch in tumor-associated endothelial cells will disrupt tumor blood vessels and slow down tumor progression irrespective of tumor type. Adenoviral vectors expressing inducible Caspase-9 (iCaspase-9) under transcriptional regulation with the endothelial cell-specific vascular endothelial growth factor receptor-2 (VEGFR2) promoter (Ad-hVEGFR2-iCaspase-9) induced apoptosis of proliferating human dermal microvascular endothelial cells (HDMECs), but not human tumor cells (UM-SCC-17B, head and neck squamous cell carcinoma; HepG2, hepatocellular carcinoma; PC-3, prostate adenocarcinoma; SLK, Kaposi's sarcoma; MCF-7, breast adenocarcinoma). Notably, apoptosis was dependent upon activation of iCaspase-9 with the dimerizer drug AP20187. Local delivery of Ad-hVEGFR2-iCaspase-9 followed by intraperitoneal injection of AP20187 ablated tumor microvessels and inhibited xenografted tumor growth in all tumor models evaluated here. We conclude that a cancer gene therapy strategy based on a transcriptionally targeted viral vector expressing an inducible caspase allows for selective and controlled ablation of microvessels of histopathologically diverse tumor types.

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.

Identification of a novel HLA-B*54 allele, B*5411, by sequence-based typing in a Chinese individual

We report here a novel human leukocyte antigen (HLA)-B*5411 allele identified by sequence-based typing in a Chinese individual. The novel B*5411 is identical to B*5404, with the exception of four base substitutions at position 120 (A>C), 134 (G>C), 143 (C>G), and 156 (A>T) of exon 3 resulting in codon no. 131, changed from AGC (Ser) to CGC (Arg), and codon no. 143, changed from ACC (Thr) to TCC (Ser).

Cisplatin nephrotoxicity: mechanisms and renoprotective strategies

Cisplatin is one of the most widely used and most potent chemotherapy drugs. However, side effects in normal tissues and organs, notably nephrotoxicity in the kidneys, limit the use of cisplatin and related platinum-based therapeutics. Recent research has shed significant new lights on the mechanism of cisplatin nephrotoxicity, especially on the signaling pathways leading to tubular cell death and inflammation. Renoprotective approaches are being discovered, but the protective effects are mostly partial, suggesting the need for combinatorial strategies. Importantly, it is unclear whether these approaches would limit the anticancer effects of cisplatin in tumors. Examination of tumor-bearing animals and identification of novel renoprotective strategies that do not diminish the anticancer efficacy of cisplatin are essential to the development of clinically applicable interventions.