Down regulation of BCL11B expression inhibits proliferation and induces apoptosis in malignant T cells by BCL11B-935-siRNA

Abstract

To screen the highly efficient and specific B-cell chronic lymphocytic leukemia/lymphoma 11B (BCL11B) small interfering RNA (siRNA) which are able to downregulate the BCL11B gene expression in human T-cell acute lymphoblastic leukemia, thereby inhibiting the leukemic T-cell proliferation and inducing apoptosis, four BCL11B-siRNAs and the scrambled non-silencing siRNA control (sc) were designed and obtained by chemosynthesis. After nucleofection, BCL11B expression in the mRNA and the protein levels were measured by qRT-PCR and immunoblotting, respectively. The biological consequences based on the highly efficient and specific BCL11B-siRNA were demonstrated by CCK-8 kit, morphological changes (Hoechst 33258 staining), high-resolution imaging, and flow cytometry. Reduction in the BCL11B mRNA level was observed at 24 or 48 hours in molt-4 T cells with BCL11B-935-siRNA, BCL11B-434-siRNA, or BCL11B-748-siRNA, respectively. BCL11B protein expression levels were reduced by 34·77% and 41·73% in the BCL11B-935-siRNA- and BCL11B-434-siRNA-treated cells, compared with the control level at 72 hours. In comparison with BCL11B-434-siRNA treatment group, the Molt-4 cells transfected with the BCL11B-935-siRNA showed significantly inhibited proliferation and effectively induced apoptosis (P<0·05). When highly efficient and specific BCL11B-935-siRNA was used to analyze the inhibition of BCL11B mRNA level in primary T-cell acute lymphoblastic leukemia (T-ALL) cells, similar result was obtained. In conclusion, siRNAs targeting the different exon domains resulted in different silencing effects and biological consequences. Suppression of BCL11B by RNA interference could inhibit the proliferation and induce the apoptosis effectively in leukemic T cells, which might be considered as a new target therapeutic strategy in T-cell malignancies.

Downregulation of BCL11A by siRNA induces apoptosis in B lymphoma cell lines

“…Our findings are in accordance with the known antiapoptotic role of BCL11B in T-cell malignancies (18)(19)(20). Recently, it has been shown that BCL11B is one of the necessary genes for T-cell differentiation and is associated with T-cell malignancies (21)(22)(23).…”

Protein Kinase C-Mediated Phosphorylation of BCL11B at Serine 2 Negatively Regulates Its Interaction with NuRD Complexes during CD4+ T-Cell Activation

“…Indeed, the prior inactivation of the highly expressed endogenous BCL11B proteins will rapidly inhibit the proliferation of Jurkat cells and induce apoptosis (51,64). To obtain further evidence of the specific involvement of PKC in regulating BCL11B interactions with MTA1 and P300, Jurkat cells were activated in the presence of a pan-PKC inhibitor, Gö6983.…”

The role of BCL11B in regulating the proliferation of human naive T cells

“…However, our study did not specifically examine the Th1 and Th2 subsets, and more experiments are needed to verify whether BCL11B can regulate Th1 differentiation in human naive T cells. We and others have reported that BCL11B loss may induce apoptosis in malignant T cells such as Jurkat, huT78, and Molt-4; however, the detailed cell death mechanisms are not fully understood [16,18]. The mitochondrial apoptotic pathway [32], BCL-2 family genes [17,33], the TNF-related apoptosis inducing ligand pathway [17,34], and the transforming growth factor-␤ signaling pathway may be involved.…”

“…BCL11B overexpression was confirmed by comparing the pBCL11B and pI2 groups, and BCL11B knockdown was determined by comparing the si-935 and SC groups. MOCK nucleofected without plasmids and siRNA and NC served as controls [18].…”