Spectral karyotyping and fluorescence in situ hybridization analyses identified a novel three-way translocation involving inversion 16 in therapy-related acute myeloid leukemia M4eo

Fluorescent in situ hybridization of DNA probes in the interphase and metaphase stages of the cell cycle

In the past decade, fluorescent in situ hybridization (FISH) has been used routinely in detecting molecular abnormalities in the interphase and metaphase stages of the cell cycle. Many of the molecular anomalies which are detected in this manner are diagnostic of a prenatal, postnatal, or neoplastic genetic disorder. With the continuous isolation of commercially available DNA probes specific to a particular chromosome region, FISH analysis has become standardized in its ability to detect characteristic chromosomal anomalies in association with genetic and neoplastic diseases. In recent years, FISH has also become automated to accommodate the increased volume of slide preparations necessary for the number of DNA probes needed to detect characteristic molecular anomalies in cancer tissues and bone marrow samples. FISH technology provides essential information to the physician regarding the diagnosis, response to treatment, and ultimately the prognosis of their patients' disorder. It has become an important source of information routinely used in conjunction with chromosome analyses, and presently to confirm molecular alterations detected by array comparative genomic hybridization (aCGH) analyses. In this chapter we describe the methods for performing FISH analyses in order to determine the presence or the absence of genetic abnormalities which define whether the patient has either a genetic syndrome or malignant disease.

Advances in molecular genetics and treatment of core-binding factor acute myeloid leukemia

PURPOSE OF REVIEW

Core-binding factor (CBF) acute myeloid leukemia (AML) is among the most common cytogenetic subtypes of AML, being detected in approximately 13% of adults with primary disease. Although CBF-AML is associated with a relatively favorable prognosis, only one-half of the patients are cured. Herein we review recent discoveries of genetic and epigenetic alterations in CBF-AML that may represent novel prognostic markers and therapeutic targets and lead to improvement of the still disappointing clinical outcome of these patients.

RECENT FINDINGS

Several acquired gene mutations and gene-expression and microRNA-expression changes that occur in addition to t(8;21)(q22;q22) and inv(16)(p13q22)/t(16;16)(p13;q22), the cytogenetic hallmarks of CBF-AML, have been recently reported. Alterations that may represent cooperative events in CBF-AML leukemogenesis include mutations in the KIT, FLT3, JAK2 and RAS genes, haploinsufficiency of the putative tumor suppressor genes TLE1 and TLE4 in t(8;21)-positive patients with del(9q), MN1 overexpression in inv(16) patients, and epigenetic and posttranscriptional silencing of CEBPA. Genome-wide gene-expression and microRNA-expression profiling identifying subgroups of CBF-AML patients with distinct molecular signatures, different clinical outcomes, or both, have also been reported.

SUMMARY

Progress has been made in delineating the genetic basis of CBF-AML that will likely result in improved prognostication and development of novel, risk-adapted therapeutic approaches.