Gene expression changes in HEI-193 (NF2-deficient Schwannoma) cells by Nf18001 or TEW7197 treatment.

Loss of NF2 (merlin) has been suggested as a genetic cause of neurofibromatosis type 2 and malignant peripheral nerve sheath tumor (MPNST). Previously, we demonstrated that NF2 sustained TGF- receptor 2 (TR2) expression and reduction or loss of NF2 activated non-canonical TGF- signaling, which reduced RKIP expression via TR1 kinase activity. Here, we show that a selective RKIP inducer (novel chemical, Nf18001) inhibits tumor growth and promotes schwannoma cell differentiation into mature Schwann cells under NF2-deficient conditions. In addition, Nf18001 is not cytotoxic to cells expressing NF2 and is not disturb canonical TGF- signaling. Moreover, the novel chemical induces expression of SOX10, a marker of differentiated Schwann cells, and promotes nuclear export and degradation of SOX2, a stem cell factor. Treatment with Nf18001 inhibited tumor growth in an allograft model with mouse schwannoma cells. These results strongly suggest that selective RKIP inducers could be useful for the treatment of neurofibromatosis type 2 as well as NF2-deficient MPNST. To know the global effect of Nf18001, we performed the microarray with HEI-193. For differential gene expression analysis by Nf18001 and TEW7197 treatment, microarray was performed using the Affymetrix GeneChip (Human Gene 2.0 ST Array X 6; DNA Link, Inc, Korea). Total RNA obtained from HEI-193 treated with Nf18001 (1μM for 2, 4, 6 day or 2μM for 6 day) or TEW7197 10μM for 6 day) was quantified and used for analysis. For differentially expressed gene (DEG) analysis, probes were selected if the difference in expressions were 2 fold compared to the HEI-193 control, and were statistically filtered by t-test (p<0.05). For the functional analysis, only DEG probes were used. Web tool DAVID (david.abcc.ncifcrf.gov/home.jsp), data base of which are Gene Ontology, KEGG, BIOCARTA was used for functional grouping of probes. All statistical and functional analysis were performed by DNA Link, Inc.