title: Melanoma-Derived BRAF(V600E) Mutation in Peritumoral Stromal Cells: Implications for in Vivo Cell Fusion.
abstract: Melanoma often recurs in patients after the removal of the primary tumor, suggesting the presence of recurrent tumor-initiating cells that are undetectable using standard diagnostic methods. As cell fusion has been implicated to facilitate the alteration of a cell's phenotype, we hypothesized that cells in the peritumoral stroma having a stromal phenotype that initiate recurrent tumors might originate from the fusion of tumor and stromal cells. Here, we show that in patients with BRAF(V600E) melanoma, melanoma antigen recognized by T-cells (MART1)-negative peritumoral stromal cells express BRAF(V600E) protein. To confirm the presence of the oncogene at the genetic level, peritumoral stromal cells were microdissected and screened for the presence of BRAF(V600E) with a mutation-specific polymerase chain reaction. Interestingly, cells carrying the BRAF(V600E) mutation were not only found among cells surrounding the primary tumor but were also present in the stroma of melanoma metastases as well as in a histologically tumor-free re-excision sample from a patient who subsequently developed a local recurrence. We did not detect any BRAF(V600E) mutation or protein in the peritumoral stroma of BRAF(WT) melanoma. Therefore, our results suggest that peritumoral stromal cells contain melanoma-derived oncogenic information, potentially as a result of cell fusion. These hybrid cells display the phenotype of stromal cells and are therefore undetectable using routine histological assessments. Our results highlight the importance of genetic analyses and the application of mutation-specific antibodies in the identification of potentially recurrent-tumor-initiating cells, which may help better predict patient survival and disease outcome.
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Szeged 6720, Hungary. kurgyis.zsuzsanna@med.u-szeged.hu.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kurgyis
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Szeged 6720, Hungary. kemeny.lajos@gmail.com.
authors.forename: Lajos V
authors.initials: LV
authors.lastname: Kemény
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Szeged 6720, Hungary. buknicz.tunde@med.u-szeged.hu.
authors.forename: Tünde
authors.initials: T
authors.lastname: Buknicz
authors.affiliation: MTA-SZTE Dermatological Research Group, Szeged 6720, Hungary. groma.gergo@gmail.com.
authors.forename: Gergely
authors.initials: G
authors.lastname: Groma
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Szeged 6720, Hungary. lazarne.olah.judit@med.u-szeged.hu.
authors.forename: Judit
authors.initials: J
authors.lastname: Oláh
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Szeged 6720, Hungary. yakoo@freemail.hu.
authors.forename: Ádám
authors.initials: Á
authors.lastname: Jakab
authors.affiliation: MTA-SZTE Dermatological Research Group, Szeged 6720, Hungary. hilda@mail.derma.szote.u-szeged.hu.
authors.forename: Hilda
authors.initials: H
authors.lastname: Polyánka
authors.affiliation: Institute of Immunology &amp; Experimental Oncology, Witten/Herdecke University, Witten 58453, Germany. kurt.zaenker@uni-wh.de.
authors.forename: Kurt
authors.initials: K
authors.lastname: Zänker
authors.affiliation: Institute of Immunology &amp; Experimental Oncology, Witten/Herdecke University, Witten 58453, Germany. thomas.dittmar@uni-wh.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dittmar
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Szeged 6720, Hungary. kemeny.lajos@med.u-szeged.hu.|MTA-SZTE Dermatological Research Group, Szeged 6720, Hungary. kemeny.lajos@med.u-szeged.hu.
authors.forename: Lajos
authors.initials: L
authors.lastname: Kemény
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Szeged 6720, Hungary. nemeth.istvan.balazs@med.u-szeged.hu.
authors.forename: István B
authors.initials: IB
authors.lastname: Németh
mesh_terms: D002459:Cell Fusion; D006801:Humans; D008545:Melanoma / Q000235:genetics* / Q000473:pathology; D020125:Mutation, Missense; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D017154:Stromal Cells / Q000378:metabolism* / Q000473:pathology
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: BRAFV600E; cell fusion; fibroblast; macrophage; melanoma; mutation detection