Contact informationPlease contact Ioannis Panagopoulos for more information
Identifying Novel Fusion Genes
Identification of novel fusion genes in hematologic malignancies and solid tumors
A fusion gene is a hybrid gene which is created through melting together parts of two previously separate genes at transcript or genomic level. Acquired fusion genes in somatic cells may disturb proliferation regulation so as to unleash cancer. They are caused by chromosomal rearrangements in the cells of the neoplastic parenchyma such as translocations, inversions, deletions or insertions. A characteristic example in sarcomas is the EWSR1-FLI1 fusion gene which is the result of the chromosomal translocation t(11;22)(q23;q12). It codes for an abnormal transcription factor which plays a critical role in the development of Ewing sarcoma. Cancer specific fusion genes can be the targets of molecular therapy, play a key role for the accurate pathogenetic diagnosis and classification of neoplasms, and have prognostic impact. The identification of novel fusion genes in various neoplasms therefore not only has obvious research importance, but also potentially major clinical significance.
Continuing the same methodology
The “traditional” methodology to detect fusion genes in tumors has begun with cytogenetic analysis to find the chromosomal rearrangement, followed by utilization of fluorescence in situ hybridization techniques to find the probe which spans the chromosomal breakpoint. Eventually, molecular cloning is performed to localize the breakpoint more precisely and identify the genes fused by the chromosomal rearrangement. Although laborious, the above-mentioned sequential approach is quite robust and reliable and we have cloned a number of fusion genes by such means.
The introduction of next generation sequencing has opened up new possibilities to detect fusion genes in cancer. We are using a combination of banding cytogenetics and next generation RNA sequencing to identify novel fusion genes in solid tumors and hematologic malignancies. Among them the IRF2BP2-CDX1 in mesenchymal chondrosarcoma with t(1;5)(q42;q32), the recurrent ZC3H7B-BCOR fusion gene in endometrial stromal sarcomas with the t(X;22)(p11;q13) chromosomal aberration, the KAT6B-KANSL1 fusion gene in retroperitoneal leiomyoma with a t(10;17)(q22;q21), ZMYND8-RELA in acute erythroid leukemia with t(11;20)(p11;q11), ZEB2-BCL11B in acute myeloid leukemia with t(2;14)(q22;q32) etc.