title: Gene expression differences predict treatment outcome of merkel cell carcinoma patients.
abstract: Due to the rarity of Merkel cell carcinoma (MCC), prospective clinical trials have not been practical. This study aimed to identify biomarkers with prognostic significance. While sixty-two patients were identified who were treated for MCC at our institution, only seventeen patients had adequate formalin-fixed paraffin-embedded archival tissue and followup to be included in the study. Patients were stratified into good, moderate, or poor prognosis. Laser capture microdissection was used to isolate tumor cells for subsequent RNA isolation and gene expression analysis with Affymetrix GeneChip Human Exon 1.0 ST arrays. Among the 191 genes demonstrating significant differential expression between prognostic groups, keratin 20 and neurofilament protein have previously been identified in studies of MCC and were significantly upregulated in tumors from patients with a poor prognosis. Immunohistochemistry further established that keratin 20 was overexpressed in the poor prognosis tumors. In addition, novel genes of interest such as phospholipase A2 group X, kinesin family member 3A, tumor protein D52, mucin 1, and KIT were upregulated in specimens from patients with poor prognosis. Our pilot study identified several gene expression differences which could be used in the future as prognostic biomarkers in MCC patients.
authors.affiliation: Department of General Surgery, Beaumont Health System, Royal Oak, MI 48073, USA.
authors.forename: Loren
authors.initials: L
authors.lastname: Masterson
authors.affiliation: Department of Beaumont BioBank, Beaumont Health System, 3811 West 13 Mile Road 105-RI, Royal Oak, MI 48073, USA.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Thibodeau
authors.affiliation: Department of Beaumont BioBank, Beaumont Health System, 3811 West 13 Mile Road 105-RI, Royal Oak, MI 48073, USA.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Fortier
authors.affiliation: Department of Beaumont BioBank, Beaumont Health System, 3811 West 13 Mile Road 105-RI, Royal Oak, MI 48073, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Geddes
authors.affiliation: Department of Beaumont BioBank, Beaumont Health System, 3811 West 13 Mile Road 105-RI, Royal Oak, MI 48073, USA.
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Pruetz
authors.affiliation: Department of Anatomic Pathology, Beaumont Health System, Royal Oak, MI 48073, USA.
authors.forename: Rajwant
authors.initials: R
authors.lastname: Malhotra
authors.affiliation: Department of General Surgery, Beaumont Health System, Royal Oak, MI 48073, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Keidan
authors.affiliation: Department of Beaumont BioBank, Beaumont Health System, 3811 West 13 Mile Road 105-RI, Royal Oak, MI 48073, USA.
authors.forename: George D
authors.initials: GD
authors.lastname: Wilson