<h2>Replication Study: Melanoma exosomes educate bone marrow progenitor cells toward a pro-metastatic phenotype through MET</h2> <p><br> <strong>Abstract:</strong></p> <p>In 2016, as part of the <a href="https://osf.io/e81xl/wiki/home/" rel="nofollow">Reproducibility Project: Cancer Biology</a>, we published a Registered Report (<a href="https://elifesciences.org/articles/07383" rel="nofollow">Lesnik et al., 2016</a>), that described how we intended to replicate selected experiments from the paper "Melanoma exosomes educate bone marrow progenitor cells toward a pro-metastatic phenotype through MET" (<a href="http://www.nature.com/articles/nm.2753" rel="nofollow">Peinado et al., 2012</a>). Here we report the results. We regenerated tumor cells stably expressing a short hairpin to reduce Met expression (shMet) using the same highly metastatic mouse melanoma cell line (B16-F10) as the original study (Supplementary Figure 5A; <a href="http://www.nature.com/articles/nm.2753" rel="nofollow">Peinado et al., 2012</a>). Exosomes from control cells expressed Met and phosphorylated Met, which were reduced in exosomes from shMet cells. We then tested the effect of exosome-dependent Met signaling on primary tumor growth and metastasis. We did not find a statistically significant change in primary tumor growth; a result similar to what was reported in the original study. Measuring lung and femur metastases we found a small increase in metastatic burden with exosomes from control cells that was diminished when Met expression was reduced; however, while the effects were in the same direction as the original study (Figure 4E; <a href="http://www.nature.com/articles/nm.2753" rel="nofollow">Peinado et al., 2012</a>), they were not statistically significant. Finally, we report meta-analyses for each result.</p> <hr> <h3>Contents</h3> <p><strong>Reports:</strong> Read the <a href="https://elifesciences.org/articles/39944" rel="nofollow">Replication Study</a> or view the <a href="https://osf.io/pc5an/" rel="nofollow">preprint versions</a>.</p> <p><strong>Note</strong>: In order to successfully run and knit the Replication Study Manuscript R Markdown file, you must install a series of necessary R packages. You can review the necessary packages included in the checkpoint manifest in the markdown file <a href="https://osf.io/hz3k7/" rel="nofollow">here</a> or run and knit the following r markdown file and they will be downloaded automatically.</p> <p>To reproduce the Replication Study manuscript text run this in <a href="https://www.rstudio.com" rel="nofollow">R Studio</a> (note: downloads <a href="https://osf.io/hz3k7/" rel="nofollow">R markdown file</a> directly from <a href="http://osf.io" rel="nofollow">osf.io</a>:</p> <pre class="highlight"><code>library(httr) library(rmarkdown) GET(&quot;<a href="https://osf.io/hz3k7/?action=download" rel="nofollow">https://osf.io/hz3k7/?action=download</a>&quot;,write_disk(&quot;Replication_Study_42.Rmd&quot;, overwrite = T)) render(&quot;Replication_Study_42.Rmd&quot;, output_format = &quot;word_document&quot;)</code></pre> <p><br> Also, explore the Registered Report and materials related to the Registered Report <a href="https://osf.io/nyb8d/wiki/home/" rel="nofollow">here</a>.</p> <p><strong>Data and Material Availability:</strong> All associated data, protocols, analysis scripts, and other digital materials are available within this OSF project.</p> <p><strong>Experiments replicated</strong>: Reproduce and explore the figures, analyses, data, and methods generated in this replication attempt. <br> - <a href="https://osf.io/aqm2m/wiki/home/?edit&view&menu" rel="nofollow">Generation and characterization of shMet B16-F10 cells and exosome</a> <br> -Replication of Figures Figures S5A and S1C (right panel) of Peinado et al., 2012</p> <ul> <li><a href="https://osf.io/mzywk/wiki/home/?edit&view&menu" rel="nofollow">Exosome-dependent MET signaling on primary tumor growth and metastasis</a> <br> -Replication of Figure 4E of Peinado et al., 2012</li> </ul> <p><strong>Meta-analysis</strong>: As a measure of evaluating reproducibility a meta-analysis of each effect was performed. The forest plots, analyses, and data are available <a href="https://osf.io/c69jx/wiki/home/?edit&view&menu" rel="nofollow">here</a>. <br></p> <p>Questions about the project can be directed to <a href="mailto:contact+rpcb@cos.io">contact+rpcb@cos.io.</a></p>