Systematic name M3021
Brief description Genes up-regulated in MM-LH cells (malignant melanoma) after treatment with the HDAC inhibitor romidepsin (FK228) [PubChem=5352062].
Full description or abstract Histone deacetylase (HDAC) inhibitors are expected to be effective for refractory cancer because their mechanism of action differs from that of conventional antineoplastic agents. In this study, we examined the effect of the HDAC inhibitor FK228 on malignant melanoma, as well as its molecular mechanisms. FK228 was highly effective against melanoma compared with other commonly used drugs. By comparing the gene expression profiles of melanoma cells and normal melanocytes, we defined a subset of genes specifically upregulated in melanoma cells by FK228, which included Rap1, a small GTP-binding protein of the Ras family. The expression of Rap1 mRNA and protein increased in FK228-treated melanoma cells in both a dose- and a time-dependent manner. A decrease in the phosphorylation of c-Raf, MEK1/2, and ERK1/2 was accompanied by an increase in Rap1 expression in both FK228-treated and Rap1-overexpressing cells. Inhibition of Rap1 upregulation by small interfering RNA (siRNA) abrogated the induction of apoptosis and suppression of ERK1/2 phosphorylation in FK228-treated melanoma cells. These results indicate that the cytotoxic effects of FK228 are mediated via the upregulation of Rap1. Furthermore, we found that Rap1 was overexpressed and formed a complex with B-Raf in melanoma cell lines with a V599E mutation of B-Raf. The siRNA-mediated abrogation of Rap1 overexpression increased the viability of these cells, suggesting that Rap1 is also an endogenous regulator of Ras-MAP kinase signaling in melanomas.
Collection C2: Curated
      CGP: Chemical and Genetic Perturbations
Source publication Pubmed 16186804   Authors: Kobayashi Y,Ohtsuki M,Murakami T,Kobayashi T,Sutheesophon K,Kitayama H,Kano Y,Kusano E,Nakagawa H,Furukawa Y
Exact source Table 1
Related gene sets (show 8 gene sets from the same authors)
External links
Filtered by similarity ?
Source species Homo sapiens
Contributed by Arthur Liberzon (MSigDB Team)
Source platform or
identifier namespace
Dataset references  
Download gene set format: grp | gmt | xml | json | TSV metadata
Compute overlaps ? (show collections to investigate for overlap with this gene set)
Compendia expression profiles ? NG-CHM interactive heatmaps
(Please note that clustering takes a few seconds)
GTEx compendium
Human tissue compendium (Novartis)
Global Cancer Map (Broad Institute)
NCI-60 cell lines (National Cancer Institute)

Legacy heatmaps (PNG)
GTEx compendium
Human tissue compendium (Novartis)
Global Cancer Map (Broad Institute)
NCI-60 cell lines (National Cancer Institute)
Advanced query Further investigate these 19 genes
Gene families ? Categorize these 19 genes by gene family
Show members (show 19 source identifiers mapped to 19 genes)
Version history 3.0: First introduced

See MSigDB license terms here. Please note that certain gene sets have special access terms.