## Replication Study: Melanoma exosomes educate bone marrow progenitor cells toward a pro-metastatic phenotype through MET <br> **Abstract:** In 2016, as part of the [Reproducibility Project: Cancer Biology][1], we published a Registered Report ([Lesnik et al., 2016][2]), 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" ([Peinado et al., 2012][3]). 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; [Peinado et al., 2012][3]). 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; [Peinado et al., 2012][3]), they were not statistically significant. Finally, we report meta-analyses for each result. ---------- ### Contents **Reports:** Read the [Replication Study][4] or view the [preprint versions][5]. **Note**: 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 [here][6] or run and knit the following r markdown file and they will be downloaded automatically. To reproduce the Replication Study manuscript text run this in [R Studio][7] (note: downloads [R markdown file][6] directly from osf.io: library(httr) library(rmarkdown) GET("https://osf.io/hz3k7/?action=download",write_disk("Replication_Study_42.Rmd", overwrite = T)) render("Replication_Study_42.Rmd", output_format = "word_document") <br> Also, explore the Registered Report and materials related to the Registered Report [here][8]. **Data and Material Availability:** All associated data, protocols, analysis scripts, and other digital materials are available within this OSF project. **Experiments replicated**: Reproduce and explore the figures, analyses, data, and methods generated in this replication attempt. <br> - [Generation and characterization of shMet B16-F10 cells and exosome][9] <br> -Replication of Figures Figures S5A and S1C (right panel) of Peinado et al., 2012 - [Exosome-dependent MET signaling on primary tumor growth and metastasis][10] <br> -Replication of Figure 4E of Peinado et al., 2012 **Meta-analysis**: As a measure of evaluating reproducibility a meta-analysis of each effect was performed. The forest plots, analyses, and data are available [here][11]. <br> Questions about the project can be directed to [contact+rpcb@cos.io.][12] [1]: https://osf.io/e81xl/wiki/home/ [2]: https://elifesciences.org/articles/07383 [3]: http://www.nature.com/articles/nm.2753 [4]: https://elifesciences.org/articles/39944 [5]: https://osf.io/zh4j9/ [6]: https://osf.io/hz3k7/ [7]: https://www.rstudio.com [8]: https://osf.io/nyb8d/wiki/home/ [9]: https://osf.io/aqm2m/wiki/home/ [10]:https://osf.io/mzywk/wiki/home/ [11]:https://osf.io/c69jx/wiki/home/ [12]:mailto:contact+rpcb@cos.io