BCL11B suppression does not influence CD34(+) cell differentiation and proliferation

B-cell lymphoma/leukaemia 11B (BCL11B) expression status helps distinguish early T-cell precursor acute lymphoblastic leukaemia/lymphoma (ETP-ALL/LBL) from other subtypes of T-cell ALL/LBL

B-cell lymphoma/leukaemia 11B (BCL11B) is an essential transcription factor for T-cell lineage commitment and maturation. We investigated BCL11B expression by immunohistochemistry in T-lymphoblastic leukaemia/lymphoma (T-ALL/LBL) (n = 115). The majority (83%) of early T-cell precursor T-ALL/LBL (ETP-ALL) cases showed negative BCL11B expression, while most (84%) of non-ETP-ALL/LBL were positive for BCL11B. A simplified three-marker [BCL11B, cluster of differentiation 5 (CD5), CD13] immunophenotypic score discriminated reliably between ETP-ALL and non-ETP-ALL/LBL. In ETP-ALL, patients with positive BCL11B expression had a better overall survival than those with negative BCL11B (P = 0·009). In summary, BCL11B is a valuable marker for T-ALL/LBL subtyping and serves as a potential prognostic marker in patients with ETP-ALL.

Analysis of the expression of PHTF1 and related genes in acute lymphoblastic leukemia

Background

Previous study showed that downregulated BCL11B expression in T cell acute lymphoblastic leukemia (T-ALL) cell line Molt-4 inhibited cell proliferation and induce apoptosis, which may be related to PHTF1 gene overexpression. The objective of this study was to investigate the expression of PHTF1 and related genes in ALL and further explore its function in T-ALL cell lines.

Methods

Real-time PCR was used to determine the gene expression level of PHTF1 in hematologic malignancies. The PHTF1, BCL11B, FEM1B and Apaf-1 gene expression levels and correlations were analyzed in patients with primary ALL (including T-ALL and B-ALL) and healthy individuals (HIs). Inhibition and overexpression of PHTF1 by lentiviral transduction were performed using the Molt-4 and Jurkat cell lines. Cell growth and apoptosis were measured by the Cell Counting Kit-8 assay and flow cytometry, respectively. Upon PHTF1 overexpression, the BCL11B, FEM1B and Apaf-1 gene expression levels were determined by real-time PCR.

Results

PHTF1 overexpression was found in both T-ALL (p = 0.004) and B-ALL (p < 0.001) groups compared with HIs group. A trend toward a negative correlation between the PHTF1 and BCL11B genes was detected for the T-ALL group, while positively correlated expression was found for the PHTF1 and BCL11B genes in HIs (P = 0.001). FEM1b and Apaf-1 overexpression was found in recently diagnosed ALL patients compared with HIs (p < 0.05). Positively correlated expression was found for the PHTF1, FEM1b and Apaf-1 genes in patients with ALL (p < 0.05) and HIs (p < 0.05). Direct up-regulation of PHTF1 expression inhibited the proliferation of Jurkat and Molt-4 cells and effectively induced apoptosis in Molt-4 cells. Direct inhibition of PHTF1 expression had no significant effect on the proliferation or apoptosis of Jurkat and Molt-4 cells. FEM1b and Apaf-1 overexpression, which did not obviously alter the BCL11B expression level, was detected in PHTF1-transduced T-ALL cell lines.

Conclusions

PHTF1 overexpression is responsible for regulating cell proliferation and apoptosis in T-ALL cell lines. PHTF1 may be a tumor-suppressor like gene and a therapeutic target for triggering the PHTF1-FEM1b-Apaf-1 apoptosis pathway.

The role of BCL11B in hematological malignancy

The B-cell leukemia/lymphoma 11B (BCL11B) gene is a member of the BCL family which plays a crucial role in the development, proliferation, differentiation and subsequent survival of T cells. BCL11B gene alterations are related to malignant T cell transformation that occurs in hematological malignancies. Remarkably, the BCL11B gene is responsible for the regulation of the apoptotic process and cell proliferation. This review summarizes current data and knowledge concerning the alteration of BCL11B in hematological malignancies and its role as a potential target for therapies directed against T cell malignancies.