Comparing the effects of MITF on transcriptional regulation to the TEN1-ICD

We identified histidine triad nucleotide binding protein 1 (HINT1) as a human teneurin-1 ICD interaction partner in a yeast-2 hybrid screen. This interaction was confirmed in human cells, where HINT1 is known to inhibit the transcription of target genes by directly binding to transcription factors at the promoter. In a whole transcriptome analysis of BS149 glioblastoma cells overexpressing the teneurin-1 ICD, several microphthalmia-associated transcription factor (MITF) target genes were found to be up-regulated. Interestingly, MITF is one of the transcription factors inhibited by HINT1. Thus, we directly compare the transcriptomes of MITF versus TEN1-ICD overexpressing BS149 cells in this study, in order to reveal any co-regulated genes. For the whole transcriptome analysis of MITF, cells were transiently transfected in triplicates with either, pcDNA3.1-RFP-HA (negative control) or pcDNA3.1-MITF-RFP-HA. The overexpressing cells were then FACS-sorted directly into RLT lysis buffer (Qiagen) at a 3:1 volume ratio of lysis buffer to cells in PBS, 24 h post-transfection.