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Korkola JE, Houldsworth J, Chadalavada RS, Olshen AB, Dobrzynski D, Reuter VE et al.. Down-regulation of stem cell genes, including those in a 200-kb gene cluster at 12p13.31, is associated with in vivo differentiation of human male germ cell tumors. Cancer Res 66: 820-827

Cell Biology Program and Departments of Medicine, Epidemiology and Biostatistics, and Pathology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
Cancer Research (Impact Factor: 9.28). 02/2006; 66(2):820-7. DOI: 10.1158/0008-5472.CAN-05-2445
Source: PubMed

ABSTRACT Adult male germ cell tumors (GCTs) comprise distinct groups: seminomas and nonseminomas, which include pluripotent embryonal carcinomas as well as other histologic subtypes exhibiting various stages of differentiation. Almost all GCTs show 12p gain, but the target genes have not been clearly defined. To identify 12p target genes, we examined Affymetrix (Santa Clara, CA) U133A+B microarray ( approximately 83% coverage of 12p genes) expression profiles of 17 seminomas, 84 nonseminoma GCTs, and 5 normal testis samples. Seventy-three genes on 12p were significantly overexpressed, including GLUT3 and REA (overexpressed in all GCTs) and CCND2 and FLJ22028 (overexpressed in all GCTs, except choriocarcinomas). We characterized a 200-kb gene cluster at 12p13.31 that exhibited coordinated overexpression in embryonal carcinomas and seminomas, which included the known stem cell genes NANOG, STELLA, and GDF3 and two previously uncharacterized genes. A search for other coordinately regulated genomic clusters of stem cell genes did not reveal any genomic regions similar to that at 12p13.31. Comparison of embryonal carcinoma with seminomas revealed relative overexpression of several stem cell-associated genes in embryonal carcinoma, including several core "stemness" genes (EBAF, TDGF1, and SOX2) and several downstream targets of WNT, NODAL, and FGF signaling (FGF4, NODAL, and ZFP42). Our results indicate that 12p gain is a functionally relevant change leading to activation of proliferation and reestablishment/maintenance of stem cell function through activation of key stem cell genes. Furthermore, the differential expression of core stem cell genes may explain the differences in pluripotency between embryonal carcinomas and seminomas.

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    • "A gene centric analysis with graphical representation of the microarray data was exported from Oncomine TM (Compendia Bioscience, Ann Arbor, MI, USA). The following datasets were used: Korkola Seminoma (Korkola et al., 2006), Hendrix Ovarian (Hendrix et al., 2006), Bittner Ovarian (GSE2109) and Giordano adrenal (Giordano et al., 2003). "
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    • "Within individual histological subtypes, however, tumours shared similar protein-coding transcriptomes, regardless of whether they were gonadal or extragonadal in origin (Palmer et al., 2008). As seen for adult seminomas (Korkola et al., 2006), paediatric seminomas were enriched for genes associated with pluripotency and the undifferentiated state [e.g. NANOG, POU5F1 (OCT3/4), TFAP2C and UTF] and paediatric YSTs were associated with genes such as AFP, those involved in differentiation (KRT8, KRT19), lipid metabolism (APOA1, APOA2) and proliferation pathways (Palmer et al., 2008). "
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