Project description:Glioblastoma multiforme (GBM) is the most common and lethal malignant primary brain tumor. Temozolomide (TMZ) is a promising chemo-therapeutic agent to treat GBM. However, resistance to TMZ develops quickly with a high frequency. The mechanisms underlying GBM cells’ resistance to TMZ are not fully understood. Long non-coding RNAs (lncRNAs) are aberrantly expressed in many cancers and are highly involved in their pathogenesis including drug-resistence. In order to systematically study the role of lncRNAs in GBM cells' resistence to TMZ , we built gene expression profiles of TMZ-resistant cell line and TMZ-sensitive cell line using lncRNA and mRNA gene expression microarrays.

2020-07-03 | GSE100736 | GEO

Transcriptome (RNA-Seq) of the stable overexpression of lncRNA XLOC013218 U251 cells

Project description:We present RNA-Seq data obtained from U251 control cells and U251 cells with stable overexpression of lncRNA XLOC13218 to identify differentially expressed genes. The discovery of long non-coding RNAs (lncRNAs) has improved the understanding of development and progression in various cancer sub-types. However, the role of lncRNAs in temozolomide (TMZ) resistance in glioblastoma (GBM) remains largely undefined. In this present study, the differential expression of lncRNAs were identified between U87 and U87TR (TMZ-resistant) cells. LncRNA XLOC013218 (XLOC) was drastically upregulated in TMZ-resistant cells and was associated with poor prognosis in glioma. Overexpression of XLOC markedly increased TMZ resistance, promoted proliferation, and inhibited apoptosis in vitro and in vivo. In addition, RNA-seq analysis and gain-of-function or loss-of-function studies revealed that PIK3R2 was the potential target of XLOC. Mechanistically, XLOC recruited Specificity Protein 1 (Sp1) transcription factor and promoted the binding of Sp1 to the promoters of PIK3R2, which elevated the expression of PIK3R2 in both mRNA and protein levels. Finally, PIK3R2-mediated activation of the PI3K/AKT signaling pathway promoted TMZ resistance and cell proliferation, but inhibited cell apoptosis. In conclusion, these data highlight the vital role of XLOC/Sp1/PIK3R2/PI3K/AKT axis in GBM TMZ resistance.

2022-04-05 | GSE200031 | GEO

Microarray profiling analysis of lncRNAs expression in glioma cells

Project description:Tremendous studies have found that the abnormality of long noncoding RNA (lncRNA) contributed to cancer initiation, progression, and recurrence via multiple signaling cascades. Nevertheless, the possible underlying mechanisms of lncRNA in temozolomide (TMZ)-resistant glioma were not well understood, hindering the improvement of TMZ-based therapies against glioma. The present study illustrated that the lncRNA KCNQ1OT1 increased in TMZ-resistant gliomas cells compared to the parental cells. Introduction of KCNQ1OT1 boosted glioma cell viability, clonogenicity and rhodamine 123 efflux while hampered apoptosis post-exposure to TMZ. Consistent with bioinformatic prediction, KCNQ1OT1 directly sponged miR-761, which was downregulated in TMZ-resistant glioma cell lines. Overexpression of miR-761 attenuated glioma cell viability and clonogenicity while triggered apoptosis and rhodamine 123 cellular accumulation post-exposure to TMZ, leading to rehabilitated glioma TMZ-sensitivity, which was against the function of KCNQ1OT1. miR-761 bound to 3’-untranslated region of PIM1, a proto-oncogene with constitutive serine/threonine kinase activity, attenuated PIM1-mediated signaling cascades. Furthermore, stable knockdown of KCNQ1OT1 by small hairpin RNA amplified the TMZ-induced tumor regression in TMZ-resistant U251 mouse models. Briefly, the present study evaluated KCNQ1OT1 conferred TMZ resistance by sponging miR-761 and releasing PIM1 expression, resulting in activation of PIM-mediated MDR1/c-Myc/Survivin signaling pathways. The findings mentioned above extended the knowledge of lnRNA KCNQ1OT1 in the regulation of chemoresistance in glioma and provided a promising therapeutic target for TMZ-resistant glioma patients. Long noncoding RNA profiling by array

2020-10-13 | GSE144784 | GEO

Homo sapiens

Project description:Noncoding RNA expression profiling of cisplatin-resistant cells derived from the A549 lung cell line (lncRNA and mRNA)

| PRJNA186568 | ENA

MiRNA expression data from TMZ-resistant GBM cell line

Project description:Glioblastoma multiforme(GBM) is the most common and lethal malignant primary brain tumor. Temozolomide (TMZ) is a promising chemo-therapeutic agent to treat GBM. However, resistance to TMZ develops quickly with a high frequency. The mechanisms underlying GBM cells’ resistance to TMZ are not fully understood. Non-coding RNAs are aberrantly expressed in many cancers and are highly involved in their pathogenesis including drug-resistence. In order to systematically study the role of miRNAs in GBM cells' resistence to TMZ , we built gene expression profiles of TMZ-resistant cell line and TMZ-sensitive cell line using miRNA gene expression microarrays.

2020-07-04 | GSE100775 | GEO

Gene expression profile of wildtype glioblastoma cell lines and their resistant subclones

Project description:In order to identify factors involved in TMZ-resistance, we engineered different TMZ-resistant glioblastoma cell lines. Wildtype cells were treated twice a week in duplicate with a clinically relevant concentration of TMZ (33 ÂµM) for multiple weeks, until two individual resistant subclones were generated. Gene expression profiling was performed to identify differentially expressed genes in the resistant cells compared to their wildtype cells. three wildtype glioblastoma cell lines (U87, LNZ308, Hs683) and their resistant subclones, two of each wildtype, were analyzed The experiments were performed technically as dual channel but processed/normalized as single channel (i.e. two sample records per one raw data file). The raw data file for each sample is indicated in the sample description field but linked as Series supplementary file.

2014-01-01 | E-GEOD-53014 | biostudies-arrayexpress

Homo sapiens whole blood.

Project description:RNA extracted at 240min. Samples are rRNA depleted. Expression measurement of Homo sapiens genes.

2019-07-31 | GSE114179 | GEO