RNA-sequencing of acute promyelocytic leukemia primary blasts reveals novel molecular biomarkers of early death events
LEUKEMIA & LYMPHOMA
Authors: Jann, Johann-Christoph; Streuer, Alexander; Hecht, Anna; Nolte, Florian; Nowak, Verena; Danner, Justine; Oblaender, Julia; Palme, Iris; Lengfelder, Eva; Platzbecker, Uwe; Hofmann, Wolf-Karsten; Flach, Johanna; Nowak, Daniel
Abstract
Although acute promyelocytic leukemia (APL) has evolved to the AML entity with the best prognosis, typical 'early death' (ED) events still account for mortality rates of similar to 20% in population-based studies. To investigate this poorly understood issue we performed whole transcriptome analysis ofn = 7 APL ED cases compared ton = 7 APL cases with long term remission. We discovered the proteins S100A8/S100A9 and EFEMP1 as the most differentially expressed factors. In an independent cohort ofn = 58 APL patients EFEMP1 over-expression was associated with a worse overall survival. Furthermore, a subgroup analysis of ED caused by hemorrhagic complications revealed an association of metallothioneins (MT1G/MT1E) with higher bleeding rates, ED events and negative prognostic effects on overall survival. Finally, we identified a novel TPM4-KLF2 fusion transcripts in 44/64 APL samples. In summary, we report a comprehensive transcriptomic analysis and novel potential biomarkers of ED biology, which highlight novel pathways in ED events in APL.
Epigenetic regulation of EFEMP1 in prostate cancer: biological relevance and clinical potential
JOURNAL OF CELLULAR AND MOLECULAR MEDICINE
Authors: Almeida, Mafalda; Costa, Vera L.; Costa, Natalia R.; Ramalho-Carvalho, Joao; Baptista, Tiago; Ribeiro, Franclim R.; Paulo, Paula; Teixeira, Manuel R.; Oliveira, Jorge; Lothe, Ragnhild A.; Lind, Guro E.; Henrique, Rui; Jeronimo, Carmen
Abstract
Epigenetic alterations are common in prostate cancer (PCa) and seem to contribute decisively to its initiation and progression. Moreover, aberrant promoter methylation is a promising biomarker for non-invasive screening. Herein, we sought to characterize EFEMP1 as biomarker for PCa, unveiling its biological relevance in prostate carcinogenesis. Microarray analyses of treated PCa cell lines and primary tissues enabled the selection of differentially methylated genes, among which EFEMP1 was further validated by MSP and bisulfite sequencing. Assessment of biomarker performance was accomplished by qMSP. Expression analysis of EFEMP1 and characterization of histone marks were performed in tissue samples and cancer cell lines to determine the impact of epigenetic mechanisms on EFEMP1 transcriptional regulation. Phenotypic assays, using transfected cell lines, permitted the evaluation of EFEMP1's role in PCa development. EFEMP1 methylation assay discriminated PCa from normal prostate tissue (NPT; P<0.001, Kruskall-Wallis test) and renal and bladder cancers (96% sensitivity and 98% specificity). EFEMP1 transcription levels inversely correlated with promoter methylation and histone deacetylation, suggesting that both epigenetic mechanisms are involved in gene regulation. Phenotypic assays showed that EFEMP1 de novo expression reduces malignant phenotype of PCa cells. EFEMP1 promoter methylation is prevalent in PCa and accurately discriminates PCa from non-cancerous prostate tissues and other urological neoplasms. This epigenetic alteration occurs early in prostate carcinogenesis and, in association with histone deacetylation, progressively leads to gene down-regulation, fostering cell proliferation, invasion and evasion of apoptosis.