Disruption of the ETV6 gene as a consequence of a rare translocation (12;12)(p13;q13) in treatment-induced acute myeloid leukemia after breast cancer

Acute myeloid leukemia carrying ETV6 mutations: biologic and clinical features

OBJECTIVES

E26 transformation-specific variant 6 gene (ETV6) is one of the most consistently rearranged genes in acute leukaemia. It encodes a principal hematopoietic transcription factor.

METHODS

We performed a systematic review focusing on the mechanisms responsible for etv6 acquisition, and its effect on the development of AML. We also review the Characteristics of ETV6 mutations and its fusion genes. Finally, for using ETV6 as a molecular target, we discuss future therapeutic approaches available to mitigate the associated disease.

RESULTS

ETV6 rearrangements often accompany other molecular mutations. Thirty-three distinct partner bands of ETV6 that contain various fusion genes were detected which plays a vital role in obtaining information about leukaemia genesis. RXDX-101 and PKC412 were reported to be inhibitors of ETV6-NTRK3.

DISCUSSION

Future researches are needed to explain how ETV6 mutations act within the microenvironment of leukemic cells and how it affects the progression of leukaemia.

S-1 induced secondary acute erythroid leukemia with a chromosome inv(12)(p13;q13)

Adjuvant chemotherapy by S-1 following gastrectomy is considered standard treatment in Japan. Analysis of follow-up data have proved the efficacy of S-1 administration, and that hematological adverse events were relatively rare. Pyrimidine anti-metabolites, including S-1, have shown relatively lower risks for secondary hematological malignancies in comparison to alkylating agents and topoisomerase-II inhibitors. We here report a case of therapy-related leukemia after S-1 administration. A patient who had received S-1as the sole adjuvant chemotherapy was diagnosed with acute erythroid leukemia. To the best of our knowledge, our patient represents the first report of S-1 induced acute leukemia.

Characterization of a newly identified ETV6-NTRK3 fusion transcript in acute myeloid leukemia

Background

Characterization of novel fusion genes in acute leukemia is important for gaining information about leukemia genesis. We describe the characterization of a new ETV6 fusion gene in acute myeloid leukemia (AML) FAB M0 as a result of an uncommon translocation involving chromosomes 12 and 15.

Methods

The ETV6 locus at 12p13 was shown to be translocated and to constitute the 5' end of the fusion product by ETV6 break apart fluorescence in situ hybridisation (FISH). To identify a fusion partner 3' rapid amplification of cDNA-ends with polymerase chain reaction (RACE PCR) was performed followed by cloning and sequencing.

Results

The NTRK3 gene on chromosome 15 was found to constitute the 3' end of the fusion gene and the underlying ETV6-NTRK3 rearrangement was verified by reverse transcriptase PCR. No RNA of the reciprocal NTRK3-ETV6 fusion gene could be detected.

Conclusion

We have characterized a novel ETV6-NTRK3 fusion transcript which has not been previously described in AML FAB M0 by FISH and RACE PCR. ETV6-NTRK3 rearrangements have been described in secretory breast carcinoma and congenital fibrosarcoma.