Microbial community structure and activity linked to contrasting biogeochemical gradients in bog and fen environments of the Glacial Lake Agassiz Peatland

The abundances, compositions, and activities of microbial communities were investigated at bog and fen sites in the Glacial Lake Agassiz Peatland of northwestern Minnesota. These sites contrast in the reactivity of dissolved organic matter (DOM) and the presence or absence of groundwater inputs. Microbial community composition was characterized using pyrosequencing and clone library construction of phylogenetic marker genes. Microbial distribution patterns were linked to pH, concentrations of dissolved organic carbon and nitrogen, C/N ratios, optical properties of DOM, and activities of laccase and peroxidase enzymes. Both bacterial and archaeal richness and rRNA gene abundance were >2 times higher on average in the fen than in the bog, in agreement with a higher pH, labile DOM content, and enhanced enzyme activities in the fen. Fungi were equivalent to an average of 1.4% of total prokaryotes in gene abundance assayed by quantitative PCR. Results revealed statistically distinct spatial patterns between bacterial and fungal communities. Fungal distribution did not covary with pH and DOM optical properties and was vertically stratified, with a prevalence of Ascomycota and Basidiomycota near the surface and much higher representation of Zygomycota in the subsurface. In contrast, bacterial community composition largely varied between environments, with the bog dominated by Acidobacteria (61% of total sequences), while the Firmicutes (52%) dominated in the fen. Acetoclastic Methanosarcinales showed a much higher relative abundance in the bog, in contrast to the dominance of diverse hydrogenotrophic methanogens in the fen. This is the first quantitative and compositional analysis of three microbial domains in peatlands and demonstrates that the microbial abundance, diversity, and activity parallel with the pronounced differences in environmental variables between bog and fen sites.

Perifosine downregulates MDR1 gene expression and reverses multidrug-resistant phenotype by inhibiting PI3K/Akt/NF-κB signaling pathway in a human breast cancer cell line

P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) is the major clinical impediment to chemotherapy of breast cancers. Down-regulation of PI3K/Akt pathway has been described as related to reversal of MDR in cancer cells. Here, we investigated the reversal effect on MDR phenotype of perifosine, a new Akt inhibitor, in breast cancer cell lines. In this study, MCF-7/ADM cells and MCF-7 cells were treated with different concentrations of perifosine. Our results suggested that perifosine reversed MDR partially by downregulation of P-gp expression and inhibition of PI3K/Akt/NF-κB pathway in the MCF-7/ADM cell line. The novel Akt inhibitor perifosine may be a promising new drug due to its ability to reverse MDR in human breast cancer cells.

Solid pseudopapillary tumour of the pancreas in children: clinical and computed tomography manifestation

PURPOSE

The purpose of our study was to retrospectively assess imaging features of computed tomography (CT) and clinical characteristics of children with solid pseudopapillary tumours (SPTs) of the pancreas in comparison with those of SPTs in adults.

MATERIALS AND METHODS

CT images and clinical data of 86 patients with histopathologically proven SPTs were reviewed. Eighteen patients were classified as children (≤18 years old), and 68 were classified as adults (>18 years old) according to age at diagnosis. Statistical analysis was performed using the χ (2) test and the Student's t test.

RESULTS

Eighteen patients (15 girls and three boys) were children, with an average age of 15.1 years at operation. Abdominal pain or discomfort was the most common manifestation in children (66.7%). Mean tumour size in children was significantly larger than in adults (9.1 vs. 5.7 cm; p=0.001). Except for tumour size, no significant statistical difference was observed in clinical factors or imaging features between SPTs in children and adults.

CONCLUSIONS

Ours is the largest single-centre study to demonstrate the features of pancreatic SPT in children. SPT diagnosis should always be considered when a large pancreatic mass with typical imaging is found in a child, especially in adolescent girls.

Elevated serum IL-16 and RANTES levels in patients with autoimmune thyroid diseases and modulation by methimazole therapy

Interleukine-16 (IL-16) and RANTES (regulated upon activation, normal T cell expressed and secreted) are 2 cytokines with the function of T helper cell recruitment, which might play a key role in pathogenesis of autoimmune thyroid diseases (AITD). This study was aimed to evaluate the IL-16 and RANTES in patients with AITD. Serum IL-16 and RANTES levels were measured in patients with Graves' disease (GD; n=45), Hashimoto's thyroiditis (HT; n=68), nontoxic multinodular goiter (NTMNG; n=20), and healthy individuals (n=61). The results showed that serum IL-16 and RANTES levels were elevated both in HT and higher in untreated GD patients when compared to NTMNG patients and the healthy individuals, which were decreased after MMI therapy in untreated GD patients. However, in HT patients, serum IL-16 and RANTES levels were comparable among the conditions of hyperthyroid and euthyroid received by l-thyroxine therapy and untreated hypothyroid. Furthermore, serum IL-16 levels were correlated with FT3, FT4, TRAb in GD, but not in HT patients. The data did not show any correlation between RANTES levels and clinical factors. In conclusion, IL-16 and RANTES might be involved in the pathogenesis of GD and HT, and serum IL-16 levels in GD maybe a potential marker of disease activity and severity.

A phase I study of sunitinib combined with modified FOLFOX6 in patients with advanced solid tumors

PURPOSE

This phase I study assessed the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, and preliminary antitumor effects of sunitinib combined with modified FOLFOX6 (mFOLFOX6).

METHODS

Patients with advanced solid malignancies received mFOLFOX6 in 2-week cycles with escalating sunitinib doses (25, 37.5, and 50 mg/day) on three schedules: 2 weeks on, 2 weeks off (2/2); 4 weeks on, 2 weeks off (4/2); or continuous daily dosing (CDD). Patients received up to 8 treatment cycles (Schedule 2/2 and CDD schedule) or 6 cycles (Schedule 4/2). An expansion cohort enrolled patients with metastatic colorectal cancer at the Schedule 2/2 MTD.

RESULTS

Overall, 53 patients were enrolled, with 43 evaluable for dose-limiting toxicity (DLT). On Schedule 2/2 (n = 18), DLTs occurred in three patients at 50 mg/day (grade 4 neutropenia [n = 1]; grades 3 and 4 thrombocytopenia [n = 2]) and two patients achieved partial responses (PRs). On Schedule 4/2 (n = 13), 37.5 mg/day exceeded the MTD with two DLTs (febrile neutropenia and grade 4 hypokalemia, respectively). On the CDD schedule (n = 12), the MTD was 25 mg/day; one DLT (grade 3 stomatitis) was reported and two patients achieved PRs. The most common adverse events were neutropenia, fatigue, and thrombocytopenia. No clinically significant drug-drug interactions were apparent between sunitinib, its metabolite SU12662, and mFOLFOX6.

CONCLUSIONS

Sunitinib combined with mFOLFOX6 had acceptable tolerability. The MTDs were sunitinib 50 mg/day on Schedule 2/2 and 25 mg/day on the CDD schedule. A MTD for Schedule 4/2 was not established.

Basic anatomy and tumor biology of the RPS6KA6 gene that encodes the p90 ribosomal S6 kinase-4

The RPS6KA6 gene encodes the p90 ribosomal S6 kinase-4 (RSK4) that is still largely uncharacterized. In this study we identified a new RSK4 transcription initiation site and several alternative splice sites with a 5’RACE approach. The resulting mRNA variants encompass four possible first start codons. The first 15 nucleotides (nt) of exon 22 in mouse and the penultimate exon in both human (exon 21) and mouse (exon 24) RSK4 underwent alternative splicing, although the penultimate exon deleted variant appeared mainly in cell clines, but not in most normal tissues. Demethylation agent 5-azacytidine inhibited the deletion of the penultimate exon whereas two indolocarbazole-derived inhibitors of cyclin dependent kinase 4 or 6 induced deletion of the first 39 nt from exon 21 of human RSK4. In all human cancer cell lines studied, the 90-kD wild type RSK4 was sparse but, surprisingly, several isoforms at or smaller than 72-kD were expressed as detected by seven different antibodies. On immunoblots, each of these smaller isoforms often appeared as a duplet or triplet and the levels of these isoforms varied greatly among different cell lines and culture conditions. Cyclin D1 inhibited RSK4 expression and serum starvation enhanced the inhibition, whereas c-Myc and RSK4 inhibited cyclin D1. The effects of RSK4 on cell growth, cell death and chemoresponse depended on the mRNA variant or the protein isoform expressed, on the specificity of the cell lines, as well as on the anchorage-dependent or -independent growth conditions and the in vivo situation. Moreover, we also observed that even a given cDNA might be expressed to multiple proteins; therefore, when using a cDNA, one needs to exclude this possibility before attribution of the biological results from the cDNA to the anticipated protein. Collectively, our results suggest that whether RSK4 is oncogenic or tumor suppressive depends on many factors.

Association of genetic variation in FTO with risk of obesity and type 2 diabetes with data from 96,551 East and South Asians

AIMS/HYPOTHESIS

FTO harbours the strongest known obesity-susceptibility locus in Europeans. While there is growing evidence for a role for FTO in obesity risk in Asians, its association with type 2 diabetes, independently of BMI, remains inconsistent. To test whether there is an association of the FTO locus with obesity and type 2 diabetes, we conducted a meta-analysis of 32 populations including 96,551 East and South Asians.

METHODS

All studies published on the association between FTO-rs9939609 (or proxy [r (2) > 0.98]) and BMI, obesity or type 2 diabetes in East or South Asians were invited. Each study group analysed their data according to a standardised analysis plan. Association with type 2 diabetes was also adjusted for BMI. Random-effects meta-analyses were performed to pool all effect sizes.

RESULTS

The FTO-rs9939609 minor allele increased risk of obesity by 1.25-fold/allele (p = 9.0 × 10(-19)), overweight by 1.13-fold/allele (p = 1.0 × 10(-11)) and type 2 diabetes by 1.15-fold/allele (p = 5.5 × 10(-8)). The association with type 2 diabetes was attenuated after adjustment for BMI (OR 1.10-fold/allele, p = 6.6 × 10(-5)). The FTO-rs9939609 minor allele increased BMI by 0.26 kg/m(2) per allele (p = 2.8 × 10(-17)), WHR by 0.003/allele (p = 1.2 × 10(-6)), and body fat percentage by 0.31%/allele (p = 0.0005). Associations were similar using dominant models. While the minor allele is less common in East Asians (12-20%) than South Asians (30-33%), the effect of FTO variation on obesity-related traits and type 2 diabetes was similar in the two populations.

CONCLUSIONS/INTERPRETATION

FTO is associated with increased risk of obesity and type 2 diabetes, with effect sizes similar in East and South Asians and similar to those observed in Europeans. Furthermore, FTO is also associated with type 2 diabetes independently of BMI.

FOXC1 regulates the functions of human basal-like breast cancer cells by activating NF-κB signaling

Human basal-like breast cancer (BLBC) is an enigmatic and aggressive malignancy with a poor prognosis. There is an urgent need to identify therapeutic targets for BLBC, because current treatment modalities are limited and not effective. The forkhead box transcription factor FOXC1 has recently been identified as a critical functional biomarker for BLBC. However, how it orchestrates BLBC cells was not clear. Here we show that FOXC1 activates the transcription factor nuclear factor-κB (NF-κB) in BLBC cells by increasing p65/RelA protein stability. High NF-κB activity has been associated with estrogen receptor-negative breast cancer, particularly BLBC. The effect of FOXC1 on p65/RelA protein stability is mediated by increased expression of Pin1, a peptidyl-prolyl isomerase. FOXC1 requires NF-κB for its regulation of cell proliferation, migration and invasion. Notably, FOXC1 overexpression renders breast cancer cells more susceptible to pharmacological inhibition of NF-κB. These results suggest that BLBC cells may rely on FOXC1-driven NF-κB signaling. Interventions of this pathway may provide modalities for the treatment of BLBC.

Assessing immunologic function through CD4 T-lymphocyte ahenosine triphosphate levels by ImmuKnow assay in Chinese patients following renal transplantation

OBJECTIVE

Balancing immunosuppression to prevent rejection while minimizing infection/drug toxicity risk is a challenge in organ transplantation. Drug monitoring alone or with functional monitoring is inadequate to measure the immune response after transplantation. The Food and Drug Administration (FDA)-approved immune monitoring assay, ImmuKnow, offers an noninvasive method to assess the immune status of transplanted patients by measuring adenosine triphosphate (ATP) released from CD4 T cells. Herein, we have evaluated ATP levels reflecting the immune responses of Chinese kidney transplant recipients as a monitoring parameter to guide treatment after transplantation.

METHODS

From October 2008 to March 2010, we recruited 259 kidney transplant patients who were divided into four groups: stable (n = 174), postoperative infection (n = 32), postoperative rejection (n = 16), and high-dose corticosteroid treatment (n = 33). The ImmuKnow assay was performed to measure CD4 T-cell ATP levels. No prisoners or organs from prisoners were used in the study.

RESULTS

Receiver operating characteristics measurements indicated an ATP predictive range of 238 to 497 ng/mL to monitor immune responses after transplantation and immunosuppressive therapy. To identify patients with infection, we used a cutoff ATP value of 238 ng/mL with 100% specificity and positive predictive value and 92.9% sensitivity. To identify patients with rejection, we used a value of 497 ng/mL with 91.5% sensitivity. Compared with the 225 to 525 ng/mL ATP levels recommended by the FDA, our target values showed similar or better diagnostic accuracy.

CONCLUSION

We provide additional data to monitor immunosupressant treatment of Chinese kidney transplant patients.

Aggressive angiomyxoma of the vulva: intra-operative pathological diagnosis is useful in deciding the scope of surgery and reducing recurrence

Aggressive angiomyxoma (AA) is a rare, slow-growing myxoid neoplasm of the pelvi-perineum. Because of its rarity, it is often initially misdiagnosed, frequently as a gynaecological malignancy. Surgical resection is the main treatment modality of AA, but, local recurrence rates are high. In order to reduce recurrence, the scope of surgical resection should be as broad as possible. Intra-operative pathological diagnosis is useful in deciding the scope of surgery, and wide excision may reduce recurrence.

P4-01-17: TIMP-1 Over-Expression Confers Resistance of MCF-7 Breast Cancer Cells to Fulvestrant

Background

Endocrine resistance represents a major challenge in the management of estrogen receptor (ER) positive breast cancer. Currently no predictive biomarkers for endocrine resistance in ERpositive breast cancer patients are in clinical use.

In a clinical study, patients with metastatic breast cancer and high levels of serum Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) had less benefit from endocrine therapy than patients with a lower level of serum TIMP-1 [1].

Therefore, we evaluated the association between TIMP-1 and response to endocrine therapy using an in vitro approach.

We have previously presented initial results on TIMP-1 and response to endocrine therapy [2].

Materials and Methods: MCF-7 cells were stably transfected with pcDNA3.1(Hyg)-TIMP-1 plasmid, and a panel of 11 subclones with different expression levels of TIMP-1 was generated. TIMP-1 expression levels were confirmed using enzyme-linked immunosorbent assay (ELISA).

Four subclones with high or low TIMP-1 expression were analyzed for the growth response to estrogen, 4-hydroxytamoxifen and fulvestrant. These four subclones were analyzed for protein expression by western blotting. All subclones were analyzed by whole human genome oligo microarrays 4×44K for determination of gene expression levels. Data were analyzed using the limma R/Bioconductor package. Paired-end Solexa sequencing was applied to selected subclones with high and low TIMP-1 levels to identify transcriptomic changes.

Results: High expression of TIMP-1 was associated with resistance to fulvestrant, whereas growth response to either estrogen or 4-hydroxytamoxifen was independent of TIMP-1 expression levels. High expression of TIMP-1 protein and mRNA was associated with undetectable levels of progesterone receptor (PgR) protein and mRNA whereas ER protein and mRNA levels were unaffected by TIMP-1. To characterize the potential role of TIMP-1 in estrogen signaling we analyzed the expression of reported estrogen-responsive genes and no general change was observed. We identified genes that correlated positively or negatively to TIMP-1 expression. Among the identified genes was PgR, which is a direct target for ER.

Conclusion: Our data suggest that a high expression of TIMP-1 in vitro is associated with resistance to fulvestrant but not to 4-hydroxytamoxifen. Estrogen-regulated genes are not generally affected by changes in TIMP-1 expression levels and therefore TIMP-1 appears to affect endocrine resistance through other mechanisms than globally regulating ER signaling. However, high expression of TIMP-1 is associated with loss of PgR and this may be related to the resistance towards fulvestrant.

References:

[1] Lipton, A et al: Serum TIMP-1 and Response to the Aromatase Inhibitor Letrozole Versus Tamoxifen in Metastatic Breast Cancer. J Clin Oncol; 2008; 26;(16); 2653–8

[2] Effect of TIMP-1 Overexpression on Endocrine Sensitivity of MCF-7 ER-positive Human Breast Cancer Cells In Vitro. Cancer Res; 2009; 69(24 suppl); abstract nr 2029

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-01-17.

MRCP and 3D LAVA imaging of extrahepatic cholangiocarcinoma at 3 T MRI

Extrahepatic cholangiocarcinoma (CCA) is a primary bile duct malignant tumour with poor prognosis. Familiarity with their varied imaging characteristics can be helpful in developing a correct diagnosis and in optimal treatment planning, and thus contribute to a better prognosis. The purpose of this article is to illustrate the typical appearances of extrahepatic CCA on magnetic resonance cholangiopancreatography (MRCP) and three-dimensional (3D) LAVA (liver acquisition with volume acceleration) sequences at 3 T magnetic resonance imaging (MRI), and to discuss the superiority of the two techniques in the diagnosis of CCA.

Tumor vasculature is a key determinant for the efficiency of nanoparticle-mediated siRNA delivery

Delivering small interfering RNA (siRNA) to tumors using clinically viable formulations remains the primary technical hurdle that prevents the development of siRNA therapy for cancer treatment. Over the past several years, significant effort has been devoted to explore novel delivery strategies, whereas relatively little attention has been paid to understand the impact of physiological constrains such as tumor vasculature on the efficiency of siRNA delivery. Using the previously described positive-readout tumor models where successful siRNA delivery leads to an upregulation of β-galactosidase within tumor sections, we analyzed the spatial distribution of localized target knockdown within tumor sections relative to tumor hypoxia and found that stable nucleic acid lipid particle (SNALP), a lipid nanoparticle-based delivery system, predominantly delivers siRNA to areas adjacent to functional tumor blood vessels. Increasing tumor vascularity by ectopic expression of VEGF resulted in more efficient siRNA delivery to tumors using SNALP. SNALP-mediated delivery of a siRNA-targeting Ran GTPase led to target knockdown and significant antitumor efficacy in the highly vascularized HepG2-derived liver tumors, but not in the poorly vascularized HCT-116-derived liver tumors. These results highlight the significant impact of tumor vasculature on siRNA delivery and call for a more focused effort on addressing tumor penetration after extravasation, an area of only limited attention currently.

Visualization and simulated surgery of the left ventricle in the virtual pathological heart of the Virtual Physiological Human

Ischaemic heart failure remains a significant health and economic problem worldwide. This paper presents a user-friendly software system that will form a part of the virtual pathological heart of the Virtual Physiological Human (VPH2) project, currently being developed under the European Commission Virtual Physiological Human (VPH) programme. VPH2 is an integrated medicine project, which will create a suite of modelling, simulation and visualization tools for patient-specific prediction and planning in cases of post-ischaemic left ventricular dysfunction. The work presented here describes a three-dimensional interactive visualization for simulating left ventricle restoration surgery, comprising the operations of cutting, stitching and patching, and for simulating the elastic deformation of the ventricle to its post-operative shape. This will supply the quantitative measurements required for the post-operative prediction tools being developed in parallel in the same project.

Proinflammatory protein CARD9 is essential for infiltration of monocytic fibroblast precursors and cardiac fibrosis caused by Angiotensin II infusion

Background

Angiotensin II (Ang II)–induced cardiac remodeling with the underlying mechanisms involving inflammation and fibrosis has been well documented. Cytosolic adaptor caspase recruitment domain 9 (CARD9) has been implicated in the innate immune response. We aimed to examine the role of CARD9 in inflammation and cardiac fibrosis induced by Ang II.

Methods

Two-month-old CARD9-deficient (CARD9^−/−) and wild-type (WT) male mice were infused with Ang II (1,500 ng/kg/min) or saline for 7 days. Heart sections were stained with hematoxylin and eosin and Masson trichrome and examined by immunohistochemistry; and activity and protein levels were measured in macrophages obtained from mice.

Results

WT mice with Ang II infusion showed a marked increase in CARD9⁺ macrophages in the heart, but CARD9^−/− mice showed significantly suppressed macrophage infiltration and expression of proinflammatory cytokines, including interleukin-1β (IL-1β) and connective tissue growth factor (CTGF). Importantly, Ang II–induced cardiac fibrosis (extracellular matrix and collagen I deposition) was diminished in CARD9^−/− hearts, as was the expression of transforming growth factor-β (TGF-β) and level of myofibroblasts positive for α-smooth muscle actin (α-SMA). Furthermore, Ang II activation of nuclear factor-κB (NF-κB), JNK and p38 mitogen-activated protein kinases (MAPKs) in WT macrophages was reduced in CARD9^−/− macrophages.

Conclusion

CARD9 plays an important role in regulating cardiac inflammation and fibrosis in response to elevated Ang II.