Changes in IDH2, TET2 and KDM2B Gene Expression After Treatment With Classic Chemotherapeutic Agents and Decitabine in Myelogenous Leukemia Cell Lines.

BACKGROUND: Hematological malignancies are a heterogeneous group of tumors with increased proliferative and auto-replicative capacity. Despite treatment advances, post-treatment quality of life remains highly affected. Studies addressing the molecular mechanisms of these diseases are critical for the development of effective, rapid and selective therapies, since few therapeutic strategies succeed in being effective without triggering high-grade toxicities or debilitating late effects. Our aim of this study was to verify changes in the expression of genes involved in the malignant phenotype of hematological malignancies, by treating human cell lines in vitro with classic chemotherapeutic agents and the demethylating agent, decitabine. METHODS: KASUMI-1 and K-562 human myeloid leukemia cell lines were plated at a density of 3 × 104 cells/well and treated with increasing concentrations of different chemotherapeutic agents commonly used in the clinical setting. After 24 and 48 h of treatment, cell viability was tested, and RNA was extracted. Complementary DNA (cDNA) was synthesized and quantitative real-time polymerase chain reaction (qPCR) was performed to evaluate the gene expression of IDH2, TET2 and KDM2B. RESULTS: A modulation in gene expression was observed before and after treatment with classic chemotherapeutic agents. It was possible to demonstrate a difference in gene expression when cells were treated with chemotherapeutic agents or decitabine alone when compared to chemotherapeutic agents in association with decitabine. CONCLUSIONS: The genes tested, and the modulation of their expression during in vitro treatments suggest that IDH2, TET2, and KDM2B should be further investigated as potential biomarkers for ongoing treatment response and follow-up for patients diagnosed with hematological malignancies of the myeloid lineage.

Structural modeling and mRNA expression of epididymal ß-defensins in GnRH immunized boars: A model for secondary hypogonadism in man.

Human secondary hypogonadism is associated with impaired testicular function, however, little is known about its impact on sperm epididymal maturation. Endocrine disruption in the epididymis could impair the secretion of key proteins, such as ß-defensins, responsible for spermatozoa maturation during epididymal transit. This study evaluated the sequence and structural similarities between porcine epididymal ß-defensins porcine ß-defensins (pBD3), pBD4, pBD125, and pEP2C and their human homologs using bioinformatics integrated with information derived from protein databanks. We then verified whether the expression of pBD3, pBD4, pBD125, and pEP2C genes in the testis and epididymis are influenced by disruption of the hypothalamic-pituitary-testicular (HPT) axis in a pig model for male human secondary hypogonadism. Upon modeling porcine ß-defensins, structural and functional analysis confirmed the presence of motifs associated with ß-defensin function, validating the models generated in silico. pBD3 and pBD4 showed acceptable structural alignments with human ß-defensins BDEF103 and BDEF110, respectively. In addition, evaluation of hormonal regulation of ß-defensins was assessed by analyzing the expression of these four ß-defensins in adult boars immunized against gonadotropin-releasing hormone (GnRH). Our results indicate that HPT axis disruption modifies the expression of pBD3, pBD4, pBD125, and pEP2C in boar testis and epididymis, suggesting an endocrine-dependent regulation of ß-defensins in swine epididymis. In conclusion, sequence and structural homology between pBD3 and pBD4 and their human homologs provide a basis for using the pig as a model for the study of human secondary hypogonadism. Further investigation of the human homologs in hypogonadal men could elucidate the connections between fertility and epididymal expression of ß-defensins.

DNA Methylation Events as Markers for Diagnosis and Management of Acute Myeloid Leukemia and Myelodysplastic Syndrome.

During the onset and progression of hematological malignancies, many changes occur in cellular epigenome, such as hypo- or hypermethylation of CpG islands in promoter regions. DNA methylation is an epigenetic modification that regulates gene expression and is a key event for tumorigenesis. The continuous search for biomarkers that signal early disease, indicate prognosis, and act as therapeutic targets has led to studies investigating the role of DNA in cancer onset and progression. This review focuses on DNA methylation changes as potential biomarkers for diagnosis, prognosis, response to treatment, and early toxicity in acute myeloid leukemia and myelodysplastic syndrome. Here, we report that distinct changes in DNA methylation may alter gene function and drive malignant cellular transformation during several stages of leukemogenesis. Most of these modifications occur at an early stage of disease and may predict myeloid/lymphoid transformation or response to therapy, which justifies its use as a biomarker for disease onset and progression. Methylation patterns, or its dynamic change during treatment, may also be used as markers for patient stratification, disease prognosis, and response to treatment. Further investigations of methylation modifications as therapeutic biomarkers, which may correlate with therapeutic response and/or predict treatment toxicity, are still warranted.