Fig 1: ZBTB28 and BCL6 inhibit and depend on each other. (A) ZBTB28 and BCL6 expression in multiple carcinoma cells. (B) Inverse association of ZBTB28 and BCL6 expression in lung cancer and ESCC, obtained from TCGA cancer dataset, accessed through cBioPortal (www.cbioportal.org). (C) Co-localization of BCL6 and ZBTB28 as determined using confocal microscopy. (D) Co-IP outcome revealing the binding between BCL6 and ZBTB28. Anti-HA (#ab1424, Abcam), BCL6 (sc-7388; Santa Cruz, Germany) or IgG (#2729, Cell Signaling Technology) antibodies were used. (E) ZBTB28 inhibits BCL6 promoter activities, as detected by dual luciferase reporter system. (F) qRT-PCR results of BCL6 mRNA expression in HONE1, KYSE150, and A549 cells. Cells were transfected with vector and ZBTB28 with or without BCL6. (G) qRT-PCR of BCL6 mRNA in A549 underwent with vector, BCL6 siRNA, and ZBTB28 with or without BCL6 siRNA. (H) Knock-down BCL6 by siRNA increased ZBTB28 mRNA expression levels. (I) Structure of wild type and mutant ZBTB28 reporter plasmid. (J) Promoter luciferase activity of wild-type and mutant ZBTB28 in HONE1 cells. Cells were transfected with BCL6, or ZBTB28 or both plasmids. (K) BCL6 inhibits ZBTB28 reporter activity in BCL6-null K562 cells. (L) The interdependent role of ZBTB28 and BCL6 was detected using MTS assay in a tumor cell line which lack of ZBTB28 expression.