Dataset: Increased expression of Bcl11b in human transformed T cell lines leads to chemoresistance accompanied by G1 accumulation.

ABSTRACT Background: The expression of BCL11B has been reported in normal and transformed cells derived from T-lymphocytes, neurons, keratinocytes and recently in a subset of squamous cell carcinomas. Despite the rapidly accumulating knowledge concerning Bcl11b biology, the contribution of this protein to normal or transformed cell homeostasis remains open. Methodology/Principal Findings: Here, by employing an overexpression strategy and cells endogenously expressing BCL11B we revealed formerly unidentified features of Bcl11b which shed some light on the potential involvement of the protein in tumor maintenance. Two different T cell lines were forced to overexpress BCL11B which resulted in markedly increased resistance to radiomimetic drugs while no influence on death-receptor apoptotic pathway was observed. Apoptosis resistance triggered by BCL11B overexpression was accompanied by a cell cycle delay caused by accumulation of cells at G1. This cell cycle restriction was associated with upregulation of CDKN1C (p57) and CDKN2C (p18) cyclin dependent kinase inhibitors. Moreover, p27 and p130 proteins accumulated and the SKP2 gene encoding a protein of the ubiquitin-binding complex responsible for their degradation was repressed. Furthermore, the expression of the MYCN oncogene was silenced which resulted in significant depletion of the protein in cells expressing high BCL11B levels. Both cell cycle restriction and resistance to DNA-damage-induced apoptosis coincided and required the histone deacetylase binding N-terminal domain of Bcl11b. The sensitivity to genotoxic stress could be restored by the histone deacetylase inhibitor trichostatine A. Conclusions: The data presented here suggest a potential role of BCL11B in tumor survival and encourage developing Bcl11b-inhibitory approaches as a potential tool to specifically target chemoresistant tumor cells. Using a retroviral-vector-based system in Jurkat cells BCL11B overexpression was compared to controls transfected with the empty vector. Of each group one biological replicate was analyzed on one array.

Species:

human

Samples:

2

Source:

E-GEOD-21382

Updated:

Dec.12, 2014

Registered:

Sep.15, 2014