Abstract 4243: Regulation of H3K9 methylation by the demethyltransferase gene JMJD1C in multiple myeloma

• Published in: Cancer research (Chicago, Ill.) Ill.), 2013-04, Vol.73 (8_Supplement), p.4243-4243
• Main Authors: LoBello, Janine, DiPerna, Danielle, Gale, Moly, Watanabe, Aprill, Hostetter, Galen, Fonseca, Rafael, Salhia, Bodour
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2013-4243

Increasing evidence points towards the importance of epigenetic changes in the pathogenesis of multiple myeloma (MM). The biochemical modifications that govern epigenetics are DNA methylation, and post-translational modifications of histone proteins. Histone methylation is catalyzed by histone methyltransferases (HMT) and histone demethylases (HDMT). The purpose of our study was to interrogate genomics data to identify HMT or HDMT genes that are altered in MM. We mined copy number, gene expression and whole genome sequencing data generated as part of the Multiple Myeloma Research Consortium Genomics Initiative. Collectively, the datasets converged on numerous alterations involving histone methylation of lysine 9 (H3K9). One of these genes, the HDMT JMJD1C, was over-expressed in approximately 15% of MM samples examined. We validated over-expression of JMJD1C expression by RT-PCR in over 50 clinical MM samples and 10 human myeloma cell lines (HMCLs). We also confirmed over-expression of JMJD1C by immunohistochemistry (IHC) in a tissue microarray (TMA) consisting of over 60 MM samples. Next we demonstrated a negative correlation between JMJD1C expression and H3K9 methylation by IHC and western blot in 6/10 HMCL and in over 60% of clinical samples examined on the TMA. This validates the H3K9 demethylase activity of JMJD1C. Furthermore, we demonstrated that, in general, H3K9 methylation, a repressive mark associated with heterochromatin, is low in a large percentage of samples. To study the functional significance, we generated a double knockout isogenic cell line pair in U266 cells using zinc finger nuclease technology. We performed ChIP-seq and RNA-seq analyses to identify genes affected by JMJD1C binding to H3K9. Our data indicate that loss of JMJD1C expression alleviates the repression conferred by H3K9 methylation in MM. Studies are ongoing to realize JMJD1C as a potential and novel therapeutic target in MM. Citation Format: Janine LoBello, Danielle DiPerna, Moly Gale, Aprill Watanabe, Galen Hostetter, Rafael Fonseca, Bodour Salhia. Regulation of H3K9 methylation by the demethyltransferase gene JMJD1C in multiple myeloma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4243. doi:10.1158/1538-7445.AM2013-4243