Review Article

The Role of Methylation in Chronic Lymphocytic Leukemia and Its Prognostic and Therapeutic Impacts in the Disease: A Systematic Review

Table 6

TGF-β pathway.

Gene nameRelated pathwayFindings in CLLRef.

DCLK2 and TNFRSF1BTGF-β pathway, TNF superfamily-associated functionsLocus-specific hypomethylation of retrotransposons proximal to DCLK2 and TNFRSF1B was detected and higher levels of DCLK2 and TNFRSF1B expression were associated with inferior survival[88]
BCL2MIF-mediated glucocorticoid regulation, TGF-β pathwayMethylated BCL2 gene body has been reported in IGVH-mutated patients[26, 89]
IL17RCNF-kB MAPK pathwayUnmethylated gene body status was identified in IGVH-unmutated patients[26, 90]
WT1Transcription suppressor of multiple proteins including M-CSF, TGF-β, and RAR-aWT1 expression was absent suggesting that WT1 expression was lacking in more mature cell lines; other studies revealed that WT1 promoter was methylated to a large extent of CLL patients; gene promoter regions in normal B cells were completely unmethylated[51, 91, 92]
FMODKeratan sulfate biosynthesis, TGF-β pathway, hematopoietic stem cells and lineage-specific markers, TCR signalingFMOD was highly expressed whereas both hypomethylated gene promoter and gene body were identified[37, 93, 94]

CLL: chronic lymphocytic leukemia, Ref.: reference, TGF-β: transforming growth factor-β, DCLK2: doublecortin-like kinase 2, TNFRSF1B: tumor necrosis factor receptor superfamily member 1B, BCL2: B cell lymphoma 2, IL17RC: interleukin 17 receptor C, WT1: Wilms tumor 1 protein, FMOD: fibromodulin, TNF: tumor necrosis factor, MIF: macrophage migration inhibitory factor, NF-kB: nuclear factor kappa-beta, MAPK: mitogen-activated protein kinase, M-CSF: macrophage colony-stimulating factor, RAR-a: retinoic acid receptor alpha, TCR: T-cell receptor, IGVH: immunoglobulin variable heavy chain gene.