The ETV6 gene, located on 12p13.2, is involved in numerous translocations found in myeloid and lymphoid malignancies. Two mechanisms are common: fusion to a tyrosine kinase resulting in a constitutively active tyrosine kinase and fusions to transcription factors driving aberrant expression of target genes. The frequent translocation t(12;21)(p13;q22) results in the formation of the chimeric transcription factor ETV6-RUNX1 which can be identified in about 25% of childhood B-cell acute lymphoblastic leukemia (B-ALL) cases. ETV6-RUNX1 causes expansion of B-cell precursors with impaired ability of differentiation to mature B-cells. Another important aberration is t(5;12)(q33;p13), found in chronic myelomonocytic leukemia (CML) and myeloproliferative diseases, resulting in the fusion of ETV6 with the receptor tyrosine kinase PDGFRB. The resulting oncogene is sensitive to the kinase inhibitor imatinib. t(7;12)(q36;p13) can be identified in pediatric acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) and is resulting in the fusion gene MNX1-ETV6.
Besides hematological malignancies, ETV6 is also involved in the development of the pediatric congenital mesoblastic nephroma and fibrosarcoma. t(12;15)(p13;q25) fuses ETV6 to the tyrosin receptor kinase NTRK3 resulting in the ETV6-NTRK3 fusion gene, a constitutively active tyrosine kinase.
Clinical Applications
- Acute Lymphoblastic Leukemia (ALL)
- Acute Myelogenous Leukemia (AML)
- Chronic Myelogenous Leukemia and Myeloproliferative Neoplasms (CML/MPN)