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Lab-on-Chip are miniaturized systems able to perform biomolecular analysis in shorter time and with lower reagent consumption than a standard laboratory. Their miniaturization interferes with the multiple functions that the biochemical procedures require. In order to address this issue, our paper presents, for the first time, the integration on a single glass substrate of different thin film technologies in order to develop a multifunctional platform suitable for on-chip thermal treatments and on-chip detection of biomolecules. The proposed System on-Glass hosts thin metal films acting as heating sources; hydrogenated amorphous silicon diodes acting both as temperature sensors to monitor the temperature distribution and photosensors for the on-chip detection and a ground plane ensuring that the heater operation does not affect the photodiode currents. The sequence of the technological steps, the deposition temperatures of the thin films and the parameters of the photolithographic processes have been optimized in order to overcome all the issues of the technological integration. The device has been designed, fabricated and tested for the implementation of DNA amplification through the Polymerase Chain Reaction (PCR) with thermal cycling among three different temperatures on a single site. The glass has been connected to an electronic system that drives the heaters and controls the temperature and light sensors. It has been optically and thermally coupled with another glass hosting a microfluidic network made in polydimethylsiloxane that includes thermally actuated microvalves and a PCR process chamber. The successful DNA amplification has been verified off-chip by using a standard fluorometer. [ABSTRACT FROM AUTHOR]

Epstein–Barr virus (EBV) encoded latent membrane protein 1 (LMP1) is noted for its transforming potential. Yet, it also acts as a cytostatic and growth-relenting factor in Burkitt's lymphoma (BL) cells. The underlying molecular mechanisms of the growth inhibitory property of LMP1 have remained largely unknown. In this study, we show that LMP1 negatively regulates a major oncogene, TCL1, in diffuse large B-cell lymphoma (DLBCL) and BL cells. MicroRNA (miR) profiling of LMP1 transfectants showed that among others, miR-29b, is upregulated. LMP1 diminished TCL1 by inducing miR-29b through C-terminus activation region 1 (CTAR1) and CTAR2. miR-29b locked nucleic acid (LNA) antisense oligonucleotide transfection into LMP1-expressing cells reduced miR-29b expression and consequently reconstituted TCL1, suggesting that LMP1 negatively regulates TCL1 through miR-29b upregulation. The miR-29b increase by LMP1 was due to an increase in the cluster pri-miR-29b1-a transcription, derived from human chromosome 7. Using pharmacological inhibitors, we found that p38 mitogen-activated protein kinase-activating function of LMP1 is important for this effect. The ability of LMP1 to negatively regulate TCL1 through miR-29b might underlie its B-cell lymphoma growth antagonistic property. As LMP1 is also important for B-cell transformation, we suggest that the functional dichotomy of this viral protein may depend on a combination of levels of its expression, lineage and differentiation of the target cells and regulation of miRs, which then directs the outcome of the cellular response. [ABSTRACT FROM AUTHOR]

In the acute promyelocytic leukemia (APL) bearing the t(15;17), all-trans-retinoic acid (ATRA) treatment induces granulocytic maturation and complete remission of leukemia. We identified miR-342 as one of the microRNAs (miRNAs) upregulated by ATRA during APL differentiation. This miRNA emerged as a direct transcriptional target of the critical hematopoietic transcription factors PU.1 and interferon regulatory factor (IRF)-1 and IRF-9. IRF-1 maintains miR-342 at low levels, whereas the binding of PU.1 and IRF-9 in the promoter region following retinoic ATRA-mediated differentiation, upregulates miR-342 expression. Moreover, we showed that enforced expression of miR-342 in APL cells stimulated ATRA-induced differentiation. These data identified miR-342 as a new player in the granulocytic differentiation program activated by ATRA in APL.Leukemia (2009) 23, 856–862; doi:10.1038/leu.2008.372; published online 8 January 2009 [ABSTRACT FROM AUTHOR]

We describe a pathway by which the master transcription factor PU.1 regulates human monocyte/macrophage differentiation. This includes miR-424 and the transcriptional factor NFl-A. We show that PU.1 and these two components are interlinked in a finely tuned temporal and regulatory circuitry: PU.1 activates the transcription of miR-424, and this up-regulation is involved in stimulating monocyte differentiation through miR-424-dependent translational repression of NFl-A. In turn, the decrease in NFl-A levels is important for the activation of differentiation-specific genes such as M-CSFr. In line with these data, both RNAi against NFl-A and ectopic expression of miR-424 in precursor cells enhance monocytic differentiation, whereas the ectopic expression of NFl-A has an opposite effect. The interplay among these three components was demonstrated in myeloid cell lines as well as in human CD34+ differentiation. These data point to the important role of miR-424 and NFl-A in controlling the monocyte/macrophage differentiation program. [ABSTRACT FROM AUTHOR]

The article presents the results of a study on the interrelationship of microribonucleic acids (miRNAs) and hematopoietic differentiation. miRNA expression was found to be higher in normal tissue than in tumors which imply the differentiation state of the cell. The transcription factors GATA1, C/EBPα protein and PU.1 affect the miRNA expression in hematopoieses. The repression of NFI-A, a family of nuclear factor 1 proteins, is made through activation of specific classes of miRNAs.