Significance and implications of FHIT gene expression and promoter hypermethylation in acute lymphoblastic leukemia (ALL).

BACKGROUND: Fragile histidine triad (FHIT) has been documented to play a vital role in various cancers including acute lymphoblastic leukemia (ALL). Keeping in view the plausible role of FHIT gene, we aimed to examine DNA promoter hypermethylation and mRNA expression in ALL cases in Kashmir (North India).

METHODS: A total of 66 cases of ALL were analyzed for FHIT mRNA expression and promoter methylation by qRT-PCR and Methylation Specific-PCR (MS-PCR) respectively.

RESULTS: FHIT mRNA expression showed significantly decreased expression in ALL cases with mean fold change of 9.24 ± 5.44 as compared to healthy controls (p = 0.01). The pattern of FHIT deregulation in ALL cases differed significantly between decreased and increased expression (p < 0.0001). A threefold decreased expression was observed in 75% of ALL cases than healthy controls (- 3.58 ± 2.32). ALL patients with FHIT gene promoter hypermethylation presented significantly higher in 80% (53/66) of cases (p = 0.0005). The association of FHIT gene hypermethylation and its subsequent expression showed FHIT mRNA expression as significantly lower in ALL cases with hypermethylation (p = 0.0008). B-ALL cases exhibited a highly significant association between the methylation pattern and its mRNA expression (p = 0.000). In low range WBC group, a significant association was found between increased expression (26%) of the cases and methylated (4%)/unmethylated group 86% (p = 0.0006).

CONCLUSION: The present study conclude that FHIT gene hypermethylation and its altered expression may be linked in the pathogenesis of ALL and provide an evidence for the role of FHIT in the development of ALL.