The NSD3L histone methyltransferase regulates cell cycle and cell invasion in breast cancer cells

► Identifies target genes regulated by the NSD3L histone methyltransferase. ► Identifies a regulatory function of NSD3L in cell cycle. ► Identifies a regulatory function of NSD3L in cell invasion. NSD3/WHSC1L1 histone methyltransferase gene aberrations are observed in leukemia and in breast and lung carcinomas, suggesting that NSD3 is implicated in carcinogenesis. In this study we examined in human breast cancer cells the NSD3L isoform which contains the catalytic histone methyltransferase SET-domain. siRNA directed depletion of NSD3L followed by genome-wide microarray analysis identified NSD3L regulated genes which could be functionally linked to cellular signaling pathways such as cell growth, cell cycle, cell motility, transcription, and apoptosis. Notably up-regulated genes are the cell cycle regulators E2F2 and Arl2. In accordance with a function of NSD3L in cell cycle regulation NSD3L depletion resulted in an increase in the number of cells in the S and G2/M cell cycle phases. Moreover, NSD3L depletion increased the invasiveness of MDA-MB-231 breast cancer cells indicating that NSD3L normally restrain cellular metastatic potential. Together the presented data indicates that NSD3L is a candidate tumor suppressor.