Physician preferences for bone metastasis drug therapy in Canada

BACKGROUND

Currently in Canada, several bone-targeted agents (btas) with varying characteristics are available for the prevention of skeletal-related events (sres) in patients with bone metastasis secondary to solid tumours. In the present study, we evaluated the preferences of physicians in Canada for the various attributes of the available btas.

METHODS

Physicians treating patients with bone metastasis from solid tumours were invited to complete an online discrete-choice experiment. Respondents were asked to choose between pairs of hypothetical medications for virtual patients. Each hypothetical medication was described based on predefined key attributes: time until first sre, time until worsening of pain, medication-related annual risk of osteonecrosis of the jaw (onj), medication-related annual risk of renal impairment, and mode of administration. A random-parameters logit model was used to analyze the choices between hypothetical medications and thus infer physician preferences for medication attributes.

RESULTS

Responses from the 200 physicians who completed the discrete-choice experiment suggested that months until first sre, risk of renal impairment, and months until worsening of pain were considered the most important attributes affecting choice of bta. The annual risk of onj was considered the least important attribute.

CONCLUSIONS

When making treatment decisions about the choice of bta for patients with bone metastasis from solid tumours, delaying sres and worsening of pain, and reducing the risk of renal impairment are primary considerations for physicians in Canada.

Infusion of dendritic cells carrying donor lymphocytes treated with 8-methoxypsoralen and ultraviolet A light induces CD19+ IL-10+ regulatory B cells and promotes skin allograft survival

PUVA-SP DCs are immature dendritic cells (imDCs) that have taken up donor splenic lymphocytes treated with 8-methoxypsoralen and ultraviolet A light (PUVA-SPs). Phagocytosis of donor PUVA-SPs does not stimulate phenotype maturation of recipient imDCs, and infusion of PUVA-SP DCs can induce CD4(+)CD25(high)Foxp3(+) regulatory T cells (Treg). However, the regulatory effect of PUVA-SP DCs on B cells is poorly understood. In this study, we compared PUVA-SP DCs with imDCs in terms of lipopolysaccharide (LPS) responsiveness and flow cytometric analysis of interleukin (IL) 10 expression in splenic CD19(+)B cells. Our results demonstrate that PUVA-SP DCs can suppress subsequent LPS-induced DC maturation and that infusion of PUVA-SP DCs, in the absence of an immunosuppressant, significantly promotes skin allograft survival. This effect was associated with up-regulation of circulating regulatory B cells exhibiting preferential IL-10 secretion. Our results suggest that effective treatments involving infusion of PUVA-SP DCs is likely related to the modulation not only of T-cell and Treg functions but also of B-cell and regulatory B-cell (Breg) functions.

Glucose- and Triglyceride-lowering Dietary Penta-O-galloyl-α-D-Glucose Reduces Expression of PPARγ and C/EBPα, Induces p21-Mediated G1 Phase Cell Cycle Arrest, and Inhibits Adipogenesis in 3T3-L1 Preadipocytes

Plant polyphenols, such as hydrolysable tannins, are present in the human diet and known to exhibit anti-diabetic and anti-obesity activity. We previously reported that the representative hydrolysable tannin compound α-penta-galloyl-glucose (α-PGG) is a small molecule insulin mimetic that, like insulin, binds to insulin receptor (IR) and activates the IR-Akt-GLUT4 signaling pathway to trigger glucose transport and reduce blood glucose levels in db/db and ob/ob diabetic mice. However, its effects on adipogenesis and lipid metabolism were not known. In this study, high fat diet (HFD)-induced diabetic and obese mice were treated with α-PGG to determine its effects on blood glucose and triglycerides. 3T3-L1 preadipocytes were used as a cell model for identifying the anti-adipogenic activity of α-PGG at molecular and cellular levels as a first step in elucidating the mechanism of action of the compound. In vivo, oral administration of α-PGG significantly reduced levels of blood glucose, triglyceride, and insulin in HFD-induced diabetic/obese mice (P<0.05). In vitro, α-PGG inhibited the differentiation of 3T3-L1 preadipocytes into mature adipocytes. α-PGG suppressed the expression of positive adipogenic factors PPARγ C/EBPα and mTOR and augmented the negative adipogenic factor Pref-1. Furthermore, α-PGG induced upregulation of p21 and G1 phase cell cycle arrest. In contrast, adipogenic signaling pathways mediated by insulin, the cAMP response element binding protein (CREB) and glucocorticoid receptor (GR), were not inhibited. RNAi knockdown of p21 led to a 4-fold increase in triglyceride level in 3T3-L1 preadipocytes treated with MDI and α-PGG compared to regular preadipocytes. These results indicate, for the first time, that α-PGG is blood triglyceride- and glucose-lowering in HFD-induced obese and diabetic mice. It selectively inhibited some but not all major adipogenic pathways as well as the mTOR-p21-mediated cell cycle regulatory pathway. It is very likely that these apparently diverse but coordinated activities together inhibited adipogenesis. These results expand our knowledge on how PGG works in adipocytes and further confirm that α-PGG functions as an orally-deliverable natural insulin mimetic with adipogenetic modulatory functions.

DNA methylation profiles in placenta and its association with gestational diabetes mellitus

Emerging evidences indicate that placenta plays a critical role in gestational diabetes mellitus (GDM). DNA methylation could be associated with altered placental development and functions. This study is to uncover the genome-wide DNA methylation patterns in this disorder. DNA methylation was measured at >385,000 CpG sites using methylated DNA immunoprecipitation (MeDIP) and a huamn CpG island plus promoter microarray. We totally identified 6,641 differentially methylated regions (DMRs) targeting 3,320 genes, of which 2,729 DMRs targeting 1,399 genes, showed significant hypermethylation in GDM relative to the controls, whereas 3,912 DMRs targeting 1,970 genes showed significant hypomethylation. Functional analysis divided these genes into different functional networks, which mainly involved in the pathways of cell growth and death regulation, immune and inflammatory response and nervous system development. In addition, the methylation profiles and expressions of 4 loci (RBP4, GLUT3, Resistin and PPARα) were validated by BSP for their higher log2 ratio and potential functions with energy metabolism. This study demonstrates aberrant patterns of DNA methylation in GDM which may be involved in the pathophysiology of GDM and reflect the fetal development. Future work will assess the potential prognostic and therapeutic value for these findings in GDM.

MLK3 promotes melanoma proliferation and invasion and is a target of microRNA-125b

BACKGROUND

Metastatic melanoma is a disease with high mortality and limited therapeutic options. MicroRNAs (miRNAs) can be used to classify melanoma stage.

METHODS

Expression of the miRNA miR-125b and serine/threonine kinase mixed lineage kinase (MLK)3 was assessed in primary malignant melanoma tissues and several melanoma cell lines by quantitative reverse transcription PCR. The effect of MLK3 and miR-125b on cell proliferation was evaluated by MTS assay, and cell invasion was evaluated by Transwell invasion assays. Targeting of MLK3 by miR-125b was evaluated using luciferase reporter assay and western blotting.

RESULTS

We found significantly increased levels of MLK3 in metastatic primary malignant melanomas and melanoma cell lines, with levels being especially high in metastatic lines. To investigate the functional significance of MLK3, we used knockdown MLK3, which was found to suppress cell growth and invasion. Using bioinformatics, we identified MLK3 as one potential target of miR-125b. miRNA transfection and luciferase assay confirmed that MLK3 was regulated by miR-125b at both the transcriptional and translational levels. Cell proliferation and cell invasion was inhibited by overexpression of miR-125b.

CONCLUSIONS

MLK3 is upregulated in metastatic melanoma, and regulates cell proliferation and invasion in melanoma cells. MLK3 is a direct target of miR-125b.

Long Noncoding RNA: its partners and their roles in cancer

RNA transcripts, which do not encode proteins, have received considerable attention in recent years. These non-coding RNAs are classified into two groups: small non-coding RNAs and long non-coding RNAs (lncRNAs). Increasing evidence suggests that lncRNAs are emerging as key regulators in many biological processes. However, knowledge of the underlying mechanisms whereby they act is still limited. Here, we try to elucidate the way that lncRNAs function in the context of DNA, RNA and protein interaction networks. It is noteworthy that lncRNA and another type of non-coding RNA microRNA (miRNA) may 'talk' to each other more frequently than ever expected. Additionally, lncRNAs display aberrant expression profiles in different kinds of cancers, with their potential roles in carcinogenesis and cancer metastasis. We summarize the effect of some cancer related lncRNAs upon tumor biological events, including cell proliferation, apoptosis, invasion and metastasis. Finally, we focus on the clinical value of lncRNAs, considering their potential application in cancer diagnosis, prognosis and therapeutic intervention.