Processing and cellular localization of exogenous <i>BIC</i> transcripts.

<p>Levels of total <i>BIC</i> (A) and miR-155 (B) determined upon overexpression of the three constructs and empty vector (EV) in ST486, Ramos and U-HO1 cells. For the three <i>BIC</i> overexpression constructs, the increase in total <i>BIC</i> was variable and the highest levels were observed for the short <i>BIC</i> transcript containing the exon 2-derived 5’ pre-miR-155 flanking sequence (s-ex<i>BIC</i>). However, miR-155 induction was similar for all <i>BIC</i> overexpression constructs. (C) The levels of spliced and unspliced <i>BIC</i> transcripts in nuclear and cytoplasmic fractions of Ramos EV and Ramos full-length spliced <i>BIC</i> (fl-ex<i>BIC</i>). For both Ramos EV and fl-ex<i>BIC</i>, unspliced <i>BIC</i> showed significantly higher (p<0.001) levels in the nucleus than in the cytoplasm. Spliced <i>BIC</i> was not detectable (ND) in Ramos EV. Upon overexpression of the fl-ex<i>BIC</i> construct, spliced <i>BIC</i> transcripts showed similar levels in the cytoplasm and in the nucleus. Transcript levels in the cytoplasm and the nucleus were calculated relative to the total fraction and corrected for the amount of RNA per cell. Average of three independent experiments was presented. P values were determined by 2-way ANOVA and Bonferroni posttest (** p<0.01, ns - not significant). Relative amounts of unspliced (D) and spliced (E) <i>BIC</i> transcripts in DGCR8-IP compared to IgG-IP in Jiyoye, Ramos fl-ex<i>BIC</i> and U-HO1 fl-ex<i>BIC</i> cells. Endogenous unspliced, endogenous spliced and exogenous spliced <i>BIC</i> transcripts were significantly enriched in DGCR8-IP compared to IgG-IP. (F) No enrichment of <i>HPRT</i> transcript was observed in DGCR8-IP. Amounts were calculated relative to tRNA-Lys levels. P values were determined by Student’s <i>t</i>-test (** p<0.01, *** p<0.001, **** p<0.0001, ns - not significant).