Classical epidemiology is poorly equipped to determine multifactorial causality for common commensal tumor viruses, such as EBV.

<p>Multifactorial causal reasoning is shown for a simple electrical circuit (inset) with two switches, Switch 1 and Switch 2, either of which can “cause” the light bulb to turn on. An analogous pathway is shown for the genesis of Burkitt lymphoma, in which EBV is responsible for a portion of tumors, but also only in the biological context of other factors, such as cMYC translocations. Since EBV is nearly ubiquitous, teasing out its contribution to a rare cancer like Burkitt lymphoma is supremely difficult using standard epidemiologic methods, but is readily evident using molecular biologic information that has been available for decades. EBV is clonal in these tumors based on terminal repeat copies and Epstein–Barr encoding region (EBER) in situ hybridization typically reveals the presence of EBV genome in all tumor cells but not surrounding nontumor cells. These facts are biologically implausible for a non-causal passenger infection [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006078#ppat.1006078.ref006" target="_blank">6</a>].</p

A General Approach for Generating Fluorescent Probes to Visualize Piconewton Forces at the Cell Surface

Mechanical forces between cells and their extracellular matrix (ECM) are mediated by dozens of different receptors. These biophysical interactions play fundamental roles in processes ranging from cellular development to tumor progression. However, mapping the spatial and temporal dynamics of tension among various receptor–ligand pairs remains a significant challenge. To address this issue, we have developed a synthetic strategy to generate modular tension probes combining the native chemical ligation (NCL) reaction with solid phase peptide synthesis (SPPS). In principle, this approach accommodates virtually any peptide or expressed protein amenable to NCL. We generated a small library of tension probes displaying different ligands, flexible linkers, and fluorescent reporters, enabling the mapping of integrin and cadherin tension, and demonstrating the first example of long-term (∼3 days) molecular tension imaging. This approach provides a toolset to better understand mechanotransduction events fundamental to cell biology

A General Approach for Generating Fluorescent Probes to Visualize Piconewton Forces at the Cell Surface

Mechanical forces between cells and their extracellular matrix (ECM) are mediated by dozens of different receptors. These biophysical interactions play fundamental roles in processes ranging from cellular development to tumor progression. However, mapping the spatial and temporal dynamics of tension among various receptor–ligand pairs remains a significant challenge. To address this issue, we have developed a synthetic strategy to generate modular tension probes combining the native chemical ligation (NCL) reaction with solid phase peptide synthesis (SPPS). In principle, this approach accommodates virtually any peptide or expressed protein amenable to NCL. We generated a small library of tension probes displaying different ligands, flexible linkers, and fluorescent reporters, enabling the mapping of integrin and cadherin tension, and demonstrating the first example of long-term (∼3 days) molecular tension imaging. This approach provides a toolset to better understand mechanotransduction events fundamental to cell biology

Various chemotherapeutics combined with YM155 induce MCC cell death in an additive manner, <i>in</i><i>vitro</i>.

<p>CellTiter-GLO assays were performed using multiple MCC cell lines as well as the control primary human fibroblast, BJ. Corresponding dose-response curves are shown for the following chemotherapeutic agents and drug combinations: <b>A</b>) YM155; <b>B</b>) Bortezomib; <b>C</b>) Bortezomib + 3nM YM155; <b>D</b>) Docetaxel; <b>E</b>) Docetaxel + 3nM YM155; <b>F</b>) Etoposide; <b>G</b>) Etoposide + 3nM YM155 <b>H</b>) Topotecan; and <b>I</b>) Topotecan + 3nM YM155. </p

Kaplan-Meier curves of multiple MCC mouse xenograft models on different treatments.

<p><b>A</b>) Estimated survival means and 95% confidence intervals are reported along compressed survival summaries per cell line and treatment arm, where open circles correspond survival of individual mice. <b>B</b>) Mice with MKL-1 xenografts exhibit significantly prolonged survival (****P < 0.0001) on any of the three YM155 treatment groups (3-weeks at 2mg/kg = red; continuous treatment at 2mg/kg = purple; continuous treatment at 4mg/kg = orange) relative to saline treatment (green). Increasing the duration of YM155 treatment from 3-weeks to continuous treatment at the 2mg/kg dose significantly prolongs survival (****P < 0.0001). Increasing the dose of YM155 from 2mg/kg to 4mg/kg on continuous treatment significantly prolongs survival (****P < 0.0001). <b>C</b>) Mice with MS-1 xenografts do not exhibit prolonged survival with YM155 continuous treatment (either at 2mg/kg or 4mg/kg) relative to saline treatment (NS = not significant). One mouse on saline treatment spontaneously regressed for over 5-weeks and was euthanized early (as indicated by <b>x</b>). <b>D</b>) Mice with WaGa xenografts exhibit significantly prolonged survival (**P = 0.0034) with continuous YM155 treatment at 4mg/kg relative to saline treatment. <b>E</b>) Mice with MKL-2 xenografts exhibit significantly prolonged survival (****P < 0.0001) with continuous YM155 treatment at 4mg/kg relative to saline treatment. Two mice did not reach the final 20mm tumor dimension by day 105 and were euthanized early (as indicated by <b>##</b>). </p

Mouse weights by treatment regimen.

<p>Average mouse weights with standard deviations are reported according to treatment regimen, where weights were normalized to day zero of treatment (100%): <b>A</b>) mouse weights on saline, continuous-treatment (green line); <b>B</b>) mouse weights on 2mg/kg YM155, continuous-treatment (purple line); and <b>C</b>) mouse weights on 4mg/kg YM155, continuous-treatment (orange line). Mouse weights were adjusted to remove the weight of tumors prior to normalization. Weights from mice with significant liver metastases were not included as metastatic-tumor weights could not be determined during the course of treatment. </p

Effect of MAPK-specific inhibitors on expression of fibronectin and collagen I induced by TGF

<p>-β1 <b>in THSF cells.</b> THSF cells were pretreated with ERK inhibitor (PD98059, 30 µM), p38MAPK inhibitor (SB203580, 10 µM) or JNK inhibitor (SP600125, 30 µM) for 1 hour, respectively. Subsequently they were treated with TGF-β1 (3 ng/ml) for 24 hour. Expression of fibronectin and collagen I protein was determined by Western blot analysis. (A) SB203580 or SP600125 significant inhibited TGF-β1 induced fibronectin expression. (B) SP600125 significant suppressed TGF-β1 induced collagen I expression. Data are representative of three independent experiments. *, P<0.05 vs. control; <b>#</b>, P<0.05 vs. TGF-β1 group.</p

SP600125 inhibited TGF-β1 induced CTGF expression and secretion in THSF cells.

<p>THSF cells were pretreated with ERK inhibitor (PD98059, 30 µM), p38MAPK inhibitor (SB203580, 10 µM) or JNK inhibitor (SP600125, 30 µM) for 1 hour, respectively. Subsequently they were treated with TGF-β1 (3 ng/ml) for 24 hour. (A) CTGF mRNA expression levels were detected by real time PCR. (B) CTGF protein was measured in conditioned medium samples using ELISA and results were normalized for total protein concentration. Data are representative of tree independent experiments. *, P<0.05 vs. control; #, P<0.05 vs. TGF-β1 group.</p

Immunohistochemistry of MCV-LT in a MKL-1 xenograft primary tumor and a liver metastasis.

<p>Shown are paired hemotoxylin & eosin (H&E) stained slides and adjacent sections stained with CM2B4, the MCV-LT antibody (LT-IHC), in mice with MKL-1 xenografts: <b>A</b>) MKL-1 xenograft primary tumor, H&E; <b>B</b>) MKL-1 xenograft primary tumor, LT-IHC; <b>C</b>) MKL-1 xenograft liver metastasis, H&E; and <b>D</b>) MKL-1 xenograft liver metastasis, LT-IHC. MKL-1 cells contains nuclear staining of LT, consistent with an intact nuclear localization signal (NLS). Original magnification = 200X; insets = 600X. </p

TGF-β1 induced MAPK pathways phosphorylation in THSF cells.

<p>THSF cells were incubated with TGF-β1 (3 ng/ml) for the times indicated. The total and phosphorylation of ERK (A), p38 (B) and JNK (C) MAPK were determined by using Western blot analysis. Data are representative of three independent experiments. *, P<0.05 vs. control cells without TGF-β1 stimulation.</p