scholarly journals Global Approaches to the Role of miRNAs in Drug-Induced Changes in Gene Expression

2012 ◽  
Vol 3 ◽  
Author(s):  
Jodi E. Eipper-Mains ◽  
Betty A. Eipper ◽  
Richard E. Mains
Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3623-3623 ◽  
Author(s):  
Neha S Bhise ◽  
Vishal Lamba ◽  
Jatinder Lamba

Abstract Abstract: Acute myeloid leukemia (AML) is a heterogeneous disorder, which is characterized by chromosomal abnormalities and genetic alterations. Cytarabine (Ara-C) is the most commonly used nucleoside analog for treatment of AML. However, the use of Ara-C is associated with two important clinical complications namely, inter-patient variability in response and development of intrinsic resistance. The inter-patient variability in response can be partly associated with polymorphisms in proteins that are required for intracellular uptake and activation of Ara-C to its phosphorylated form. Apart from genetic polymorphisms, expression of proteins involved in the uptake, activation, and inactivation of Ara-C have been shown to correlate with the overall patient survival. Over the past decade, various studies have identified microRNAs as important post-transcriptional regulators of gene expression. However, there are no studies till date that have identified key miRNAs involved in regulation of Ara-C pathway genes. Identification of these miRNAs will help in targeting these miRNAs to further understand inter-patient differences in gene expression. Additionally, drugs can also influence gene expression. However, there is critical gap in literature regarding role of Ara-C in inducing changes in gene expression. Understanding the dynamics of gene expression due to miRNAs and drug-induced changes would help open new opportunities for development of improved treatment strategies. Thus, the objective of this study is to understand the role of microRNAs in altering cytarabine cytotoxicity by influencing expression of pharmacokinetics (PK) and pharmacodynamics (PD) genes (n=18) in AML cell lines representing different risk groups. We evaluated genome-wide miRNA expression in 7 AML cell lines from different risk groups (favorable risk group: Kasumi-1, ME-1; intermediate risk group: AML-193, KG-1; adverse risk group: HL-60, MV-4-11, MOLM-16). We also evaluated the impact of cytarabine-induced gene expression changes in these AML cell lines. The gene expression changes were correlated with the in vitro chemosensitivity. Our preliminary results indicate that there was a significant correlation between the baseline miRNA expression for 16 miRNAs and Ara-C IC50 values (selected shown in Figure 1). We also observed that 57 microRNAs were associated with gene expression levels of the selected 18 Ara-C pharmacogenes (selected shown in Figure 1). Four miRNAs (miR-425-5p, miR-517a-3p, miR-519b-5p+hsa-miR-519c-5p, miR-522-3p) were found to be significantly associated with both gene expression and Ara-C IC50 values. We found that there were significant changes in gene expression of Ara-C pathway genes following treatment with 1uM or 10uM Ara-C. Briefly, there were significant changes in DCK, SLC29A1, CTPS1, CMPK1, NME1 and XRCC1 expression when treated with 10uM Ara-C and RRM2, NME1 and XRCC1 expression when treated with 1uM Ara-C. In conclusion, drug-induced changes in gene expression and miRNAs expression were found to correlate with chemosensitivity of AML cell lines. The preliminary results from our study help provide an insight into potential/additional molecular mechanisms associated with resistance observed in AML patients. Such knowledge is clinically significant, as identification of factors that contribute to the variable drug response would help in understanding and thus improving the variability in efficacy associated with cytarabine therapy. Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Author(s):  
Alexander C. West ◽  
Yasutaka Mizoro ◽  
Shona H. Wood ◽  
Louise M. Ince ◽  
Marianne Iversen ◽  
...  

AbstractAnadromous salmonids begin life adapted to the freshwater environments of their natal streams before a developmental transition, known as smoltification, transforms them into marine-adapted fish. In the wild, the extending photoperiods of spring stimulates smoltification, typified by radical reprogramming of the gill from an ion-absorbing organ to ion-excreting organ. Prior work has highlighted the role of specialized “mitochondrion-rich” cells in delivering this phenotype. However, transcriptomic studies identify thousands of smoltification-driven differentially regulated genes, indicating that smoltification causes a multifaceted, multicellular change; but direct evidence of this is lacking.Here, we use single-nuclei RNAseq to characterize the Atlantic salmon gill during smoltification and seawater transfer. We identify 20 distinct clusters of nuclei, including known, but also novel gill cell types. These data allow us to isolate cluster-specific, smoltification-induced changes in gene expression. We also show how cellular make-up of the gill changes through smoltification. As expected, we noted an increase in the proportion of seawater mitochondrion-rich cells, however, we also identify a reduction of several immune-related cells. Overall, our results provide unrivaled detail of the cellular complexity in the gill and suggest that smoltification triggers unexpected immune reprogramming directly preceding seawater entry.


1989 ◽  
Vol 109 (6) ◽  
pp. 3053-3062 ◽  
Author(s):  
D K Vaughan ◽  
S K Fisher ◽  
S A Bernstein ◽  
I L Hale ◽  
K A Linberg ◽  
...  

The organization of the rod photoreceptor cytoskeleton suggests that microtubules (MTs) and F actin are important in outer segment (OS) membrane renewal. We studied the role of the cytoskeleton in this process by first quantifying OS membrane assembly in rods from explanted Xenopus eyecups with a video assay for disc morphogenesis and then determining if the rate of assembly was reduced after drug disassembly of either MTs or F actin. Membrane assembly was quantified by continuously labeling newly forming rod OS membranes with Lucifer Yellow VS (LY) and following the tagged membranes' distal displacement along the OS. LY band displacement displayed a linear increase over 16 h in culture. These cells possessed a longitudinally oriented network of ellipsoid MTs between the sites of OS protein synthesis and OS membrane assembly. Incubation of eyecups in nocodazole, colchicine, vinblastine, or podophyllotoxin disassembled the ellipsoid MTs. Despite their absence, photoreceptors maintained a normal rate of OS assembly. In contrast, photoreceptors displayed a reduced distal displacement of LY-labeled membranes in eyecups treated with cytochalasin D, showing that our technique can detect drug-induced changes in basal rod outer segment assembly. The reduction noted in the cytochalasin-treated cells was due to the abnormal lateral displacement of newly added OS disc membranes that occurs with this drug (Williams, D. S., K. A. Linberg, D. K. Vaughan, R. N. Fariss, and S. K. Fisher. 1988. J. Comp. Neurol. 272:161-176). Together, our results indicate that the vectorial transport of OS membrane constituents through the ellipsoid and their assembly into OS disc membranes are not dependent on elliposid MT integrity.


1996 ◽  
Vol 27 (6) ◽  
pp. 1534-1542 ◽  
Author(s):  
Michael R. Ujhelyi ◽  
Michael Schur ◽  
Thomas Frede ◽  
Michael B. Bottorff ◽  
Marjorie Gabel ◽  
...  

1989 ◽  
Vol 9 (3) ◽  
pp. 323-328 ◽  
Author(s):  
Thomas D. Hansen ◽  
David S. Warner ◽  
Michael M. Todd ◽  
Laverle J. Vust

The effects of equipotent doses of halothane (1.05%) versus isoflurane (1.38%) anesthesia on CMRglc were determined autoradiographically using the 2-[14C]deoxyglucose technique in the rat. Eight anatomically standardized coronal sections were selected and digitized from the autoradiographs. Mean CMRglc was determined for hemispheric, neocortical, and subcortical regions at each anatomic level, and a neocortical/subcortical CMRglc ratio was calculated. In addition, the current CMRglc autoradiographs, as well as previous CBF autoradiographs obtained under identical experimental conditions were examined to characterize and compare flow/metabolism relationships for the two anesthetics. For this analysis, CBF was determined in 80 selected anatomic areas, and the values from each area were plotted against CMRglc values obtained from identical areas. In all major regions, mean CMRglc was greater with halothane than with isoflurane. The neocortical/subcortical ratio, reflecting the pattern of CMRglc distribution, was also greater during halothane anesthesia. This suggests that isoflurane has a disproportionate effect on neocortical metabolism resembling patterns previously seen for CBF. Analysis of CBF versus CMRglc plots for each anesthetic group showed two parallel lines with nearly identical slopes, but different Y intercepts. We conclude that the distribution of CMRglc observed during 1 MAC (minimum alveolar concentration) halothane and isoflurane anesthesia parallels the distribution of CBF. This finding supports the conclusion that flow-metabolism coupling is intact during halothane and isoflurane anesthesia, and that drug induced changes in cerebral metabolism may play an important role in determining the CBF response to that drug. Furthermore, there is evidence that, at a given level of CMRglc, isoflurane may have greater vasodilating capabilities than halothane.


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