LncRNA Expression Discriminates Karyotype and Predicts Survival in B-lymphoblastic Leukemia (Affymetrix)
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ABSTRACT: Long non-coding RNAs (lncRNAs) have been found to play a role in gene regulation with dysregulated expression in various cancers. The precise role that lncRNA expression plays in the pathogenesis of B-acute lymphoblastic leukemia (B-ALL) is unknown. Therefore, unbiased microarray profiling was performed on human B-ALL specimens and it was determined that lncRNA expression correlates with cytogenetic abnormalities, which was confirmed by RT-qPCR in a large set of B-ALL cases. Importantly, high expression of BALR-2 correlated with poor overall survival and diminished response to prednisone treatment. In line with a function for this lncRNA in regulating cell survival, BALR-2 knockdown led to reduced proliferation, increased apoptosis, and increased sensitivity to prednisolone treatment. Conversely, overexpression of BALR-2 led to increased cell growth and resistance to prednisone treatment. Interestingly, BALR-2 expression was repressed by prednisolone treatment and its knockdown led to upregulation of the glucocorticoid response pathway in both human and mouse B-cells. Together, these findings indicate that BALR-2 plays a functional role in the pathogenesis and/or clinical responsiveness of B-ALL and that altering the levels of particular lncRNAs may provide a future direction for therapeutic development. To define gene expression changes attributable to expression of lncRNAs, we transduced RS4;11 cells with a siRNA against BALR-2 or control vector. These cells were left untreated or treated with prednisolone.
Project description:Long non-coding RNAs (lncRNAs) have been found to play a role in gene regulation with dysregulated expression in various cancers. The precise role that lncRNA expression plays in the pathogenesis of B-acute lymphoblastic leukemia (B-ALL) is unknown. Therefore, unbiased microarray profiling was performed on human B-ALL specimens and it was determined that lncRNA expression correlates with cytogenetic abnormalities, which was confirmed by RT-qPCR in a large set of B-ALL cases. Importantly, high expression of BALR-2 correlated with poor overall survival and diminished response to prednisone treatment. In line with a function for this lncRNA in regulating cell survival, BALR-2 knockdown led to reduced proliferation, increased apoptosis, and increased sensitivity to prednisolone treatment. Conversely, overexpression of BALR-2 led to increased cell growth and resistance to prednisone treatment. Interestingly, BALR-2 expression was repressed by prednisolone treatment and its knockdown led to upregulation of the glucocorticoid response pathway in both human and mouse B-cells. Together, these findings indicate that BALR-2 plays a functional role in the pathogenesis and/or clinical responsiveness of B-ALL and that altering the levels of particular lncRNAs may provide a future direction for therapeutic development.
Project description:Long non-coding RNAs (lncRNAs) have been found to play a role in gene regulation with dysregulated expression in various cancers. The precise role that lncRNA expression plays in the pathogenesis of B-acute lymphoblastic leukemia (B-ALL) is unknown. Therefore, unbiased microarray profiling was performed on human B-ALL specimens and it was determined that lncRNA expression correlates with cytogenetic abnormalities, which was confirmed by RT-qPCR in a large set of B-ALL cases. Importantly, high expression of BALR-2 correlated with poor overall survival and diminished response to prednisone treatment. In line with a function for this lncRNA in regulating cell survival, BALR-2 knockdown led to reduced proliferation, increased apoptosis, and increased sensitivity to prednisolone treatment. Conversely, overexpression of BALR-2 led to increased cell growth and resistance to prednisone treatment. Interestingly, BALR-2 expression was repressed by prednisolone treatment and its knockdown led to upregulation of the glucocorticoid response pathway in both human and mouse B-cells. Together, these findings indicate that BALR-2 plays a functional role in the pathogenesis and/or clinical responsiveness of B-ALL and that altering the levels of particular lncRNAs may provide a future direction for therapeutic development.
Project description:Long non-coding RNAs (lncRNAs) have been found to play a role in gene regulation with dysregulated expression in various cancers. The precise role that lncRNA expression plays in the pathogenesis of B-acute lymphoblastic leukemia (B-ALL) is unknown. Therefore, unbiased microarray profiling was performed on human B-ALL specimens and it was determined that lncRNA expression correlates with cytogenetic abnormalities, which was confirmed by RT-qPCR in a large set of B-ALL cases. Importantly, high expression of BALR-2 correlated with poor overall survival and diminished response to prednisone treatment. In line with a function for this lncRNA in regulating cell survival, BALR-2 knockdown led to reduced proliferation, increased apoptosis, and increased sensitivity to prednisolone treatment. Conversely, overexpression of BALR-2 led to increased cell growth and resistance to prednisone treatment. Interestingly, BALR-2 expression was repressed by prednisolone treatment and its knockdown led to upregulation of the glucocorticoid response pathway in both human and mouse B-cells. Together, these findings indicate that BALR-2 plays a functional role in the pathogenesis and/or clinical responsiveness of B-ALL and that altering the levels of particular lncRNAs may provide a future direction for therapeutic development. B-lymphoblastic leukemia is characterized by several translocations. In this study, we hybridized patient bone marrow samples from a total of 44 patients including 14 patients with B-ALL carrying a TEL-AML1 translocation, 15 patients with E2A-PBX1 translocation, and 15 patients carrying MLL translocations. The hybridizations were carried out in two sets, a discovery set and a validation set. In addition, we utilized samples from a human cell line (NALM6) and control CD10+CD19+ cells from human bone marrow.
Project description:Functional studies of long noncoding RNAs (lncRNAs) have long been hindered by a lack of methods to assess their evolution. Here, we present lncHOME (lncRNA Homology Explorer), a computational pipeline that identifies a unique coPARSE-lncRNA class with conserved genomic locations and patterns of RNA binding protein (RBP) binding sites. Remarkably, several hundred human coPARSE-lncRNAs can be evolutionarily traced to zebrafish. Using CRISPR-Cas12a knockout and rescue assays, we found that knocking out many human coPARSE-lncRNAs led to cell proliferation defects that were rescued by predicted zebrafish homologs. Knocking down the coPARSE-lncRNAs in zebrafish embryos caused severe developmental delays that were rescued by human homologs. Moreover, we verified that human, mouse, and zebrafish coPARSE-lncRNA homologs tend to bind similar RBPs with their conserved fuctions relying on specific RBP binding sites. Overall, our study demonstrates a comprehensive approach for studying functional conservation of lncRNAs and implicates numerous lncRNAs in regulating cellular physiology.
Project description:Long noncoding RNAs (lncRNAs) are important regulators of cell fate, and their mis-expression has been implicated in many diseases. While distinct polymerases generate messenger vs. noncoding ribosomal or tRNAs3, little is known about distinct mechanisms controlling lncRNA expression. Here we show that transcription of lncRNAs is quantitatively different from that of messenger RNAs (mRNAs)--as revealed by deficiency of Dicer (Dcr), a key ribonuclease that generates microRNAs (miRNAs). Loss of Dcr in mouse embryonic stem cells (mESCs) led surprisingly to decreased level of the majority of lncRNAs. The canonical Dgcr8-Dcr-miRNA pathway is required for robust lncRNA expression, at the level of transcriptional initiation and elongation of lncRNA genes rather than at the level of their stability. cMyc, an oncogenic transcription factor, whose expression is indirectly regulated by Dcr-miRNA in mESCs, is partly responsible for lncRNA transcription. Loss of cMyc led to a more dramatic decrease of lncRNAs than mRNAs, and cMyc overexpression rescues lncRNA expression in Dcr KO cells. A quantitative metric of “mRNA-lncRNA decoupling” revealed that Dcr and cMyc differentially regulate lncRNAs vs. mRNAs in diverse cell types and in vivo, as evidenced by hundreds of microarray experiments. Thus, Dcr and cMyc may allow numerous lncRNAs to be activated or deactivated as a class, implicating lncRNAs to potential regulatory roles in development and disease states where Dcr and cMyc have been associated with. RNA was sequenced from WT and Dcr KO mESCs and the expression of lncRNAs and mRNAs are compared between WT and Dcr KO mESCs.
Project description:Although the prognosis for childhood Acute Lymphoblastic Leukemia (ALL) in general has improved tremendously over the last decades, the survival chances for infants (<1 year of age) with ALL remains poor. A major obstacle hampering successful treatment results in infant ALL is cellular resistance to several drugs currently used in the treatment of ALL, especially to prednisolone (or prednisone). Therefore we set out to search for genes differentially expressed between from infant (children <1 year of age) and non-infant (children >1 year of age) ALL samples either resistant or sensitive to prednisolone.
Project description:Although the prognosis for childhood Acute Lymphoblastic Leukemia (ALL) in general has improved tremendously over the last decades, the survival chances for infants (<1 year of age) with ALL remains poor. A major obstacle hampering successful treatment results in infant ALL is cellular resistance to several drugs currently used in the treatment of ALL, especially to prednisolone (or prednisone). Therefore we set out to search for genes differentially expressed between from infant (children <1 year of age) and non-infant (children >1 year of age) ALL samples either resistant or sensitive to prednisolone. The in vitro prednisolone response in primary infant and non-infant ALL samples was determined by 4-day cytotoxicity (MTT) assays. Patient samples were characterized as either sensitive or resistant based on the LC50 value (i.e. the concentration of prednisolone lethal to 50% of the leukemic cells). Prednisolone sensitivity was defined by LC50 values <0.1 ug/mL prednisolone, and prednisolone resistance by LC50 values >150 ug/mL. Samples showing intermediate in vitro prednisolone responses were excluded. In total 25 infant (<1 year of age) and 27 non-infant (>1 year of age) ALL samples were selected for RNA extraction and hybridization on Affymetrix HU133A microarrays. The obtained gene expression signatures were used to identify gene differentially expressed between prednisolone resistant and sensitive patients, in order to gain insights into the mechanism(s) underlying prednisolone resistance in infant and non-infant ALL.
Project description:Small, compact genomes confer a selective advantage to viruses, yet human cytomegalovirus (HCMV) expresses the long non-coding RNAs (lncRNAs) RNA1.2, RNA2.7, RNA4.9, and RNA5.0. These lncRNAs account for majority of the viral transcriptome, but their functions remain largely unknown. Here, we showed that HCMV lncRNAs, except for RNA5.0, are required throughout the entire viral life cycle. Deletion of each lncRNA resulted in a decrease in viral progeny during lytic replication and failing to efficiently establish latent reservoirs and reactivate. Nanopore direct RNA sequencing of native lncRNA molecules revealed that each lncRNA exhibited a dynamic modification landscape, depending on the state of infection. Global analysis of the lncRNA interactome identified 32, 11, and 89 host factors that specifically bind to RNA1.2, RNA2.7, and RNA4.9, respectively. Moreover, 52 proteins commonly bound to the three lncRNAs were identified, including 11 antiviral immunity-related proteins. Our molecular analyses found that three lncRNAs are modified with N⁶-methyladenosine (m6A) and interact with m6A readers in all infection states. In-depth functional analysis revealed that m6A–mediated lncRNA stabilization as the key mechanism by which lncRNAs are maintained at high levels. Our study lays the groundwork for understanding viral lncRNA–mediated regulation of host-virus interaction throughout the HCMV life cycle.
Project description:Long non-coding RNAs (lncRNAs) regulate diverse processes, yet a potential role for lncRNAs in maintaining the undifferentiated state in somatic tissue progenitor cells remains uncharacterized. We used transcriptome sequencing and tiling arrays to compare lncRNA expression in epidermal progenitor populations versus differentiating cells. We identified ANCR (anti differentiation ncRNA) as an 855 bp lncRNA down-regulated during differentiation. Depleting ANCR in progenitor-containing populations, without any other stimuli, led to rapid differentiation gene induction. In epidermis, ANCR loss abolished the normal exclusion of differentiation from the progenitor-containing compartment. The ANCR lncRNA is thus required to enforce the undifferentiated cell state within epidermis. Custom tiling arrays designed to assay the intergenic space corresponding to regions of H3K4me3-H3K36me3 domains (Khalil et al., 2009) were used to assay changes in RNA expression of putative lncRNAs. RNA from progenitor populations and terminally differentiated populations of human keratinocytes, adipocytes, and osteoblasts were hybridized to these arrays and differential expression was assessed.