Non-Coding RNAs in Glioma.

Glioma is the most aggressive brain tumor of the central nervous system. The ability of glioma cells to migrate, rapidly diffuse and invade normal adjacent tissue, their sustained proliferation, and heterogeneity contribute to an overall survival of approximately 15 months for most patients with high grade glioma. Numerous studies indicate that non-coding RNA species have critical functions across biological processes that regulate glioma initiation and progression. Recently, new data emerged, which shows that the cross-regulation between long non-coding RNAs and small non-coding RNAs contribute to phenotypic diversity of glioblastoma subclasses. In this paper, we review data of long non-coding RNA expression, which was evaluated in human glioma tissue samples during a five-year period. Thus, this review summarizes the following: (I) the role of non-coding RNAs in glioblastoma pathogenesis, (II) the potential application of non-coding RNA species in glioma-grading, (III) crosstalk between lncRNAs and miRNAs (IV) future perspectives of non-coding RNAs as biomarkers for glioma.

Microenvironment and Dose-Delivery-Dependent Response after Exposure to Ionizing Radiation in Human Colorectal Cancer Cell Lines.

A significant body of knowledge about radiobiology is based on studies of single dose cellular irradiation, despite the fact that conventional clinical applications using dose fractionation. In addition, cellular radiation response strongly depends on cell-cell and cell-extracellular matrix (ECM) interactions, which are poorly established in cancer cells grown under standard 2D cell culture conditions. In this study, we investigated the response of human colorectal carcinoma (CRC) DLD1 and HT29 cell lines, bearing distinct p53 mutations, to a single 2 or 10 Gy dose or fractionated 5 × 2 Gy doses of radiation using global transcriptomics analysis. To examine cellular response to radiation in a cell-ECM-interaction-dependent manner, CRC cells were grown under laminin-rich ECM 3D cell culture conditions. Microarray data analysis revealed that, overall, a total of 1,573 and 935 genes were differentially expressed (fold change >1.5; P < 0.05) in DLD1 and HT29 cells, respectively, at 4 h postirradiation. However, compared to a single dose of radiation, fractionated doses resulted in significantly different transcriptomic response in both CRC cell lines. Furthermore, pathway enrichment analysis indicated that p53 pathway and cell cycle/DNA damage repair or immune response functional categories were most significantly altered in DLD1 or HT29 cells, respectively, after fractionated irradiations. Novel observations of radiation-response-mediated activation of pro-survival pathways in CRC cells grown under lr-ECM 3D cell culture conditions using fractionated doses provide new directions for the development of more efficient radiotherapy strategies. Our results also indicated that cell line specific radiation response with or without activation of the conventional p53 pathway is ECM dependent, suggesting that the ECM is a key component in cellular radiation response.

Optimal differentiation of high- and low-grade glioma and metastasis: a meta-analysis of perfusion, diffusion, and spectroscopy metrics.

INTRODUCTION: To perform a meta-analysis of advanced magnetic resonance imaging (MRI) metrics, including relative cerebral blood volume (rCBV), normalized apparent diffusion coefficient (nADC), and spectroscopy ratios choline/creatine (Cho/Cr) and choline/N-acetyl aspartate (Cho/NAA), for the differentiation of high- and low-grade gliomas (HGG, LGG) and metastases (MTS). METHODS: For systematic review, 83 articles (dated 2000-2013) were selected from the NCBI database. Twenty-four, twenty-two, and eight articles were included respectively for spectroscopy, rCBV, and nADC meta-analysis. In the meta-analysis, we calculated overall means for rCBV, nADC, Cho/Cr (short TE-from 20 to 35 ms, medium-from 135 to 144 ms), and Cho/NAA for the HGG, LGG, and MTS groups. We used random effects model to obtain weighted averages and select thresholds. RESULTS: Overall means (with 95% CI) for rCBV, nADC, Cho/Cr (short and medium echo time, TE), and Cho/NAA were: for HGG 5.47 (4.78-6.15), 1.38 (1.16-1.60), 2.40 (1.67-3.13), 3.27 (2.78-3.77), and 4.71 (3.24-6.19); for LGG 2.00 (1.71-2.28), 1.61 (1.36-1.87), 1.46 (1.20-1.72), 1.71 (1.49-1.93), and 2.36 (1.50-3.23); for MTS 5.06 (3.85-6.27), 1.35 (1.06-1.64), 1.89 (1.72-2.06), 3.14 (1.57-4.72), (Cho/NAA was not available). LGG had significantly lower rCBV, Cho/Cr, and Cho/NAA values than HGG or MTS. No significant differences were found for nADC. CONCLUSIONS: Best differentiation between HGG and LGG is obtained from rCBV, Cho/Cr, and Cho/NAA metrics. MTS could not be reliably distinguished from HGG by the methods investigated.