Following the discovery of its anti-angiogenic properties and despite its tragic history, thalidomide has re-surfaced in the field of oncology. Concurrent with its evaluation in various clinical ...trials for cancer, thalidomide's mechanism of action is sought and new analogues with improved efficacy and pharmacological profile are emerging. This review is a critical evaluation of thalidomide metabolism, molecular targets, anti-angiogenic activity and clinical efficacy with an emphasis on metastatic prostate cancer.
Plasmacytoid dendritic cells (pDCs) recognize pathogen-associated molecules, particularly viral, and represent an important mechanism in innate defense. They may however, also have roles in ...steady-state tolerogenic responses at mucosal sites. pDCs can be isolated from blood, mucosa, and lymph nodes (LNs). Although pDCs can express peripherally derived Ags in LNs and at mucosal sites, it is not clear whether pDCs actually migrate from the periphery in lymph or whether LN pDCs acquire Ags by other mechanisms. To determine whether pDCs migrate in lymph, intestine or liver-draining LNs were removed and thoracic duct leukocytes (TDLs) were collected. TDLs expressing MHC-II and CD45R, but not TCRalphabeta or CD45RA, were then analyzed. These enriched TDLs neither transcribe type I IFNs nor secrete inflammatory cytokines in response to viral stimuli in vitro or after a TLR7/8 stimulus in vivo. In addition, these TDLs do not express CD5, CD90, CD200, or Siglec-H, but do express Ig, and therefore represent B cells, despite their lack of CD45RA expression. Intestinal and hepatic lymph are hence devoid of bona fide pDCs under both steady-state conditions and after TLR7/8 stimulation. This shows that any role for pDCs in Ag-specific T cell activation or tolerance must differ from the roles of classical dendritic cells, because it cannot result from peripheral Ag capture, followed by migration of pDCs via lymph to the LN.
The metastasis of prostate cancer cells to the bone marrow constitutes the major source of morbidity and mortality in prostate cancer. Studying this process has been hampered by the lack of ...preclinical models to evaluate novel therapeutics and to study the biology of the disease. One proposed model utilizes human fetal bone implants to serve as the target for prostate cancer cells injected via the tail vein. We employed this model to test the ability of zoledronic acid to prophylax and to treat bone metastases. To improve the rate of bone metastasis, we used two bone implants instead of one to evaluate the cell lines PC3 and PC3M, a more metastatic subline. For this purpose we generated the novel cell line PC3EGFPLuc, which can be used for luminescence and/or fluorescence imaging in vivo. We did not observe bone implant metastases in 52 mice, with 90 bone implants following tail vein injection of 1x10(6) PC3 or PC3M cells. Soft tissue lesions in the buttocks and hind limbs as well as cellular growth in the hindlimbs were observed via bioluminescence imaging. This evidence together with literature findings suggests that this model produces artifactual 'bone metastasis' lesions.
Breast cancer exhibits familial aggregation, consistent with variation in genetic susceptibility to the disease. Known susceptibility genes account for less than 25% of the familial risk of breast ...cancer, and the residual genetic variance is likely to be due to variants conferring more moderate risks. To identify further susceptibility alleles, we conducted a two-stage genome-wide association study in 4,398 breast cancer cases and 4,316 controls, followed by a third stage in which 30 single nucleotide polymorphisms (SNPs) were tested for confirmation in 21,860 cases and 22,578 controls from 22 studies. We used 227,876 SNPs that were estimated to correlate with 77% of known common SNPs in Europeans at r2 > 0.5. SNPs in five novel independent loci exhibited strong and consistent evidence of association with breast cancer (P < 10(-7)). Four of these contain plausible causative genes (FGFR2, TNRC9, MAP3K1 and LSP1). At the second stage, 1,792 SNPs were significant at the P < 0.05 level compared with an estimated 1,343 that would be expected by chance, indicating that many additional common susceptibility alleles may be identifiable by this approach.
Summary
CD38 is a cell surface molecule with ADP‐ribosyl cyclase activity, which is predominantly expressed on lymphoid and myeloid cells. CD38 has a significant role in B‐cell function as some ...anti‐CD38 antibodies can deliver potent growth and differentiation signals, but the ligand that delivers this signal in mice is unknown. We used a chimeric protein of mouse CD38 and human immunogobulin G (IgG) (CD38‐Ig) to identify a novel ligand for murine CD38 (CD38L) on networks of follicular dendritic cells (FDCs) as well as dendritic cells (DCs) in the spleen. Flow‐cytometry found that all DC subsets expressed cytoplasmic CD38L but only fresh ex vivo CD11c+ CD11b– DCs had cell surface CD38L. Anti‐CD38 antibody blocked the binding of CD38‐Ig to CD38L, confirming the specificity of detection. CD38‐Ig immuno‐precipitated ligands of 66 and 130 kDa. Functional studies found that CD38‐Ig along with anti‐CD40 and anti‐major histocompatibility complex (MHC) class II antibody provided maturation signals to DCs in vitro. When CD38‐Ig was administered in vivo with antigen, IgG2a responses were significantly reduced, suggesting that B and T cells expressing CD38 may modulate the isotype of antibodies produced through interaction with CD38L on DCs. CD38‐Ig also expanded FDC networks when administered in vivo. In conclusion, this study has identified a novel ligand for CD38 which has a role in functional interactions between lymphocytes and DCs or FDCs.
Using an approach based on polymerase chain reaction (PCR), we examined the diversity of polyketide synthase (PKS) genes present in 160 marine fungal isolates, representing 142 species. We obtained ...ketosynthase (KS) domain PCR products from 99 fungal isolates, representing Dothideomycetes, Sordariomycetes, Eurotiomycetes, and incertae sedis. Sequence similarity searches and phylogenetic analysis of 29 marine partial-KS-encoding sequences revealed domains predicted to encode reducing, nonreducing, and 6-methylsalicylic acid PKSs. Bioinformatic analysis of an alignment of the KS sequences from marine-derived fungi revealed no unique motifs in this region. However, several specificity-determining positions were apparent between fungal 6-methylsalicylic acid PKSs as compared with either reducing or nonreducing PKSs. Evaluation of these positions in the context of a modelled three-dimensional protein structure highlighted their potential use as PKS classification markers. Evaluating primer-binding sites was necessary to obtain KS domain fragments from putative PKSs while maintaining a level of sequence information adequate to properly classify and characterize them.
Recent evidence demonstrates that dendritic cells (DCs) can insert dendrites between the epithelial cells that form the barrier protecting the body from the gut contents. Although first observed ...almost a decade ago, this is a controversial area of DC biology and the physiological importance of this phenomenon is only now being clarified. A recent study by Niess and colleagues shows that this behaviour enables efficient sampling of both invasive and non-invasive bacteria and might enhance the ability of an organism to resist infections by a pathogenic strain of
Salmonella.
Steady state migrating rat lymph dendritic cells (LDC) are semimature, expressing high levels of surface MHC class II, but low levels of surface costimulatory molecules. In this study, we show that ...surface CD40 is not detectable, but LDC contain intracellular CD40. Multiple isoforms of CD40 were detected, including the type 1 isoform required for signal transduction. Culture of LDC with syngeneic T cells does not induce redistribution of cytoplasmic CD40. When LDC were cultured with naive allogeneic CD4(+) T lymphocytes, polarization of CD40 to the immune synapse occurred between 3 and 6 h postculture. By 24 h, although large numbers of T cells were engaged with LDC, CD40 could not be detected in LDC or at the synapses. We conclude that migrating LDC contain stores of CD40 that can be mobilized rapidly to the sites of interaction with Ag-specific T cells. The disappearance of CD40 by 24 h may help in the regulation of T cell activation.
Abstract Indigenous entrepreneurial ecosystem development is not addressed in research. We define and characterise Indigenous entrepreneurial ecosystems and their evolution based on a qualitative ...study comparing Indigenous entrepreneurship in Chile and in Aotearoa New Zealand. We draw on interviews with 10 Mapuche entrepreneurs in Araucanía and 10 Māori entrepreneurs in the Bay of Plenty, observation, and a literature review to address the question – how does an Indigenous entrepreneurial ecosystem develop along with the social, economic, and political development of mainstream society? We find that Indigenous entrepreneurial ecosystems evolve with the economic and social environments of their countries because of an internal imperative towards cultural continuity and the resilience of culture to change. We find that mature Indigenous entrepreneurial ecosystems are associated with higher states of development and support a broader range of business models. Implications for policy, practice, and research are discussed.
Endostatin is an endogenous inhibitor of angiogenesis derived from the extracellular matrix protein collagen XVIII. It has been reported that a variation at the 104 position (D104N) of human ...endostatin is associated with an increased risk of prostate cancer, potentially indicating that this protein variant is less active as an anti-angiogenic agent. Herein we reported the results of genotyping 389 patients with androgen independent prostate cancer (AIPC) and 352 normal control individuals for D104N endostatin. There was no significant association between the frequency of 104N endostatin and the incidence of AIPC in either Caucasian or African American patients compared to controls (15% Caucasian AIPC versus 13.7% in Caucasian controls, p=0.79; 7.4% African American AIPC versus 5.6% in African American controls, p=0.64). Actuarial analysis revealed no statistically significant association between incidence of the DN heterozygous genotype and survival (p=0.62 by logrank test). To study the functional significance of the D104N conversion, we have expressed and purified insoluble recombinant human 104D and 104N endostatin and compared their respective activities in human umbilical vein endothelial cell (HUVEC) tube formation assays. The 104N variant of human endostatin inhibited HUVEC tube formation at least as well as the wild-type form. We concluded that the D104N variation in human endostatin is neither clinically relevant nor suitable as a pharmacogenomic endpoint to assess the risk for developing AIPC.
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