title: Replication Study: Melanoma genome sequencing reveals frequentPREX2mutations.
abstract: In 2015, as part of the Reproducibility Project: Cancer Biology, we published a Registered Report (Chroscinski et al., 2014) that described how we intended to replicate selected experiments from the paper "Melanoma genome sequencing reveals frequentPREX2mutations" (Berger et al., 2012). Here we report the results of those experiments. We regenerated cells stably expressing ectopic wild-type and mutant phosphatidylinositol-3,4,5-trisphosphate-dependent Rac exchange factor 2 (PREX2) using the same immortalized human NRASG12Dmelanocytes as the original study. Evaluation of PREX2 expression in these newly generated stable cells revealed varying levels of expression among the PREX2 isoforms, which was also observed in the stable cells made in the original study (Figure S6A; Berger et al., 2012). Additionally, ectopically expressed PREX2 was found to be at least 5 times above endogenous PREX2 expression. The monitoring of tumor formation of these stable cellsin vivoresulted in no statistically significant difference in tumor-free survival driven byPREX2variants, whereas the original study reported that thesePREX2mutations increased the rate of tumor incidence compared to controls (Figure 3B and S6B; Berger et al., 2012). Surprisingly, the median tumor-free survival was 1 week in this replication attempt, while 70% of the control mice were reported to be tumor-free after 9 weeks in the original study. The rapid tumor onset observed in this replication attempt, compared to the original study, makes the detection of accelerated tumor growth inPREX2expressing NRASG12Dmelanocytes extremely difficult. Finally, we report meta-analyses for each result.
authors.affiliation: Noble Life Sciences, Sykesville, United States.
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Horrigan
authors.affiliation: BioFactura, Rockville, United States.
authors.forename: Pascal
authors.initials: P
authors.lastname: Courville
authors.affiliation: BioFactura, Rockville, United States.
authors.forename: Darryl
authors.initials: D
authors.lastname: Sampey
authors.affiliation: TACGen, Richmond, United States.
authors.forename: Faren
authors.initials: F
authors.lastname: Zhou
authors.affiliation: TACGen, Richmond, United States.
authors.forename: Steve
authors.initials: S
authors.lastname: Cai
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics*; D020558:GTP Phosphohydrolases / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D015894:Genome, Human; D020662:Guanine Nucleotide Exchange Factors / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D008545:Melanoma / Q000235:genetics* / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D009154:Mutation; D015203:Reproducibility of Results; D023041:Xenograft Model Antitumor Assays
chemical_list: D020662:Guanine Nucleotide Exchange Factors; D008565:Membrane Proteins; C490712:PREX2 protein, human; D020558:GTP Phosphohydrolases; C579846:NRAS protein, human
keywords: Reproducibility Project: Cancer Biology; cancer biology; driver mutation; melanoma; metascience; mouse; replication; reproducibility