Differential WNT Gene Expression in Various Subtypes of Acute Lymphoblastic Leukemia

Background: Dysregulation of WNT signaling has been reported in many malignancies. Objective: This study was conducted to investigate the expression pattern of 14 members of the WNT gene family in different immunophenotypic subtypes of ALL. Methods: Semi-quantitative RT-PCR was performed on samples from 71 ALL patients and 36 age-matched healthy individuals. The ALL patients were categorized into BALL (76%), T-ALL (22.6%) and mixed lineage (1.4%) and the B-ALL cases were further classified into pro-B, pre-BI, pre-BII and immature/mature-B based on immunophenotypic results. Results: Among the WNT genes, WNT-7B (p=0.026), WNT-9A (p=0.020) and WNT-16B (p=0.023) were significantly over-expressed, whereas WNT- 2B (p=0.033), WNT-5A (p=0.016), WNT-7A (p<0.0001) and WNT-10A (p<0.0001) were down-regulated in B-ALL. Among the T-ALL subtype, however, significant down-regulation of WNT-2B, WNT-5B, WNT-7A, WNT-10A and WNT-11 was evident. Comparison between B-ALL subtypes showed significant over-expression of WNT-7B, WNT-9A and WNT-5B in certain subtypes. Conclusion: Our results suggest contribution of the WNT genes in leukemogenesis of ALL.