## Replication Study: Melanoma exosomes educate bone marrow progenitor cells toward a pro-metastatic phenotype through MET
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**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.
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### 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")
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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.
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- [Generation and characterization of shMet B16-F10 cells and exosome][9]
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-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]
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-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].
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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