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| Status |
Public on Jul 01, 2008 |
| Title |
Genotypic and gene expression studies in Congenital Melanocytic Nevi: insight into initial step of tumoral melanogenesis |
| Organism |
Homo sapiens |
| Experiment type |
Expression profiling by array
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| Summary |
Large Congenital Melanocytic Naevi have a higher propensity to malignant transformation compared to acquired naevi. They thus represent a good model for studying initial steps of melanocarcinogenesis. We have performed genotypic (karyotype, FISH and mutational analyses) and differential expression studies on a large cohort of medium (n=3) and large (n=24) congenital melanocytic naevi. Unlike malignant melanoma, chromosomal abnormalities were rare and single, a feature probably reflecting the benignity of these lesions. Mutational screening showed a high frequency of NRAS mutations in our series, while BRAF mutations were less common. Differential expression study between tumoral and normal melanocytes did not show significant alterations of cellular processes such as cell proliferation, cell migration/invasion, angiogenesis, apoptosis, and immune/inflammatory responses. However, significant down-regulation of genes involved in pigmentation and up-regulation of genes playing a role in DNA protection were observed. Lastly, our micro-arrays displayed up-regulation of genes mediating chemoresistance in cancer. As alteration of pigmentation mechanisms can trigger oxidative damage, increased expression of genes involved in maintenance of DNA integrity might reflect the ability of naevocytic cells to self protection against cellular stress. Furthermore, the observed alterations linked to chemoresistance might partially account for the well known inefficacy of chemotherapy in malignant melanoma.
Keywords: cell type comparison
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| Overall design |
6 Large Congenital Melanocytic Naevi (CMN), (4 BRAFV600E mutated samples and 2 cases with chromosomal translocations involving BRAF) were co-hybridized with normal control (pool of 13 foreskins) on Human Exonic Evidence Based Oligonucleotide (HEEBO) arrays (Stanford Functional Genomics Facility, California, USA) containing 44544 70mer probes. Hybridizations were replicated with dye swap.
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| Contributor(s) |
Dessars B, De Raeve L, El Housni H, Lefort A, Morandini R, Ghanem G, Van den Eynde B, Ma W, Roseeuw D, Vassart G, Libert F, Heimann P |
| Citation(s) |
18633438 |
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| Submission date |
Jul 19, 2007 |
| Last update date |
Mar 17, 2012 |
| Contact name |
Frederick Libert |
| E-mail(s) |
flibert@ulb.ac.be
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| Organization name |
ULB
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| Department |
IRIBHM
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| Lab |
C2-140
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| Street address |
808 route de Lennik
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| City |
Brussels |
| ZIP/Postal code |
B-1070 |
| Country |
Belgium |
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| Platforms (1) |
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| Samples (12)
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| GSM211573 |
Large Congenital Melanocytic Naevi (CMN) : NCG21_1 |
| GSM211574 |
Large Congenital Melanocytic Naevi (CMN) : NCG21_2 |
| GSM211577 |
Large Congenital Melanocytic Naevi (CMN) : NCG22_1 |
| GSM211620 |
Large Congenital Melanocytic Naevi (CMN) : NCG22_2 |
| GSM211634 |
Large Congenital Melanocytic Naevi (CMN) : NCG23_1 |
| GSM211658 |
Large Congenital Melanocytic Naevi (CMN) : NCG23_2 |
| GSM211659 |
Large Congenital Melanocytic Naevi (CMN) : NCG24_1 |
| GSM211660 |
Large Congenital Melanocytic Naevi (CMN) : NCG24_2 |
| GSM211661 |
Large Congenital Melanocytic Naevi (CMN) : NCG26_1 |
| GSM211662 |
Large Congenital Melanocytic Naevi (CMN) : NCG26_2 |
| GSM211663 |
Large Congenital Melanocytic Naevi (CMN) : NCG27_1 |
| GSM211664 |
Large Congenital Melanocytic Naevi (CMN) : NCG27_2 |
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| Relations |
| BioProject |
PRJNA101651 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE8525_RAW.tar |
49.2 Mb |
(http)(custom) |
TAR (of GPR) |
| Processed data included within Sample table |
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