Prognostic microRNAs in high-grade glioma reveal a link to oligodendrocyte precursor differentiation

Novel biomarkers for the diagnosis and prognosis of gallbladder cancer

Gallbladder cancer (GBC) is the most common form of biliary tract malignancy with a dismal prognosis. A poor outcome in patients with GBC is related to the aggressive nature of the tumor, delayed diagnosis, and a lack of reliable biomarkers and effective treatment. Therefore, early diagnosis and accurate disease assessment are crucial to prolonging the patient survival. Identification of novel prognostic and diagnostic biomarkers may help improve the early diagnostic rate and develop specific targeted treatments for patients with GBC. We herein review the novel biomarkers that may be associated with the diagnosis and prognosis in GBC and their potential clinical significance in the management of GBC.

P68 RNA helicase promotes invasion of glioma cells through negatively regulating DUSP5

Gliomas are the most common central nervous system tumors. They show malignant characteristics indicating rapid proliferation and a high invasive capacity and are associated with a poor prognosis. In our previous study, p68 was overexpressed in glioma cells and correlated with both the degree of glioma differentiation and poor overall survival. Downregulating p68 significantly suppressed proliferation in glioma cells. Moreover, we found that the p68 gene promoted glioma cell growth by activating the nuclear factor-κB signaling pathway by a downstream molecular mechanism that remains incompletely understood. In this study, we found that dual specificity phosphatase 5 (DUSP5) is a downstream target of p68, using microarray analysis, and that p68 negatively regulates DUSP5. Upregulating DUSP5 in stably expressing cell lines (U87 and LN-229) suppressed proliferation, invasion, and migration in glioma cells in vitro, consistent with the downregulation of p68. Furthermore, upregulating DUSP5 inhibited ERK phosphorylation, whereas downregulating DUSP5 rescued the level of ERK phosphorylation, indicating that DUSP5 might negatively regulate ERK signaling. Additionally, we show that DUSP5 levels were lower in high-grade glioma than in low-grade glioma. These results suggest that the p68-induced negative regulation of DUSP5 promoted invasion by glioma cells and mediated the activation of the ERK signaling pathway.

Fragile X mental retardation protein promotes astrocytoma proliferation via the MEK/ERK signaling pathway

Objective

To examine the association between fragile X mental retardation protein (FMRP) expression and astrocytoma characteristics.

Methods

Pathologic grade and expressions of glial fibrillary acidic protein (GFAP), Ki67 (proliferation marker), and FMRP were determined in astrocytoma specimens from 74 patients. Kaplan-Meier survival analysis was undertaken. Pathologic grade and protein levels of FMRP were determined in 24 additional patients with astrocytoma and 6 controls (cerebral trauma). In cultured U251 and U87 cell lines, the effects of FMRP knock-down on cell proliferation, AKT/mTOR/GSK-3β and MEK/ERK signaling were studied. The effects of FMRP knock-down on the volumes and weights of U251 cell-derived orthotopic tumors in mice were investigated.

Results

In patients, FMRP expression was increased in grade IV (5.1-fold, P<0.01) and grade III (3.2-fold, P<0.05) astrocytoma, compared with controls. FMRP and Ki67 expressions were positively correlated (R²=0.877, P<0.001). Up-regulation of FMRP was associated with poorer survival among patients with FMRP integrated optical density >30 (P<0.01). In astrocytoma cell lines, FMRP knock-down slowed proliferation (P<0.05), inhibited total MEK levels P<0.05, and reduced phosphorylation of MEK (Ser217/221) and ERK (Thr202/Tyr204) (P<0.05). In mice with orthotopic tumors, FMRP knock-down decreased FMRP and Ki67 expressions, and reduced tumor volume and weight (36.3% or 61.5% on day 15, both P<0.01). Also, phosphorylation of MEK (Ser217/221) and ERK (Thr202/Tyr204), and total MEK in xenografts were decreased in sh-FMRP xenografts compared with non-transfected ones (all P<0.05).

Conclusion

Enhanced FMRP expression in astrocytoma may promote proliferation through activation of MEK/ERK signaling.

Evaluation of rat C6 malignant glioma using spectral computed tomography

To investigate the use of multi-parameter spectral computed tomography (CT) for the evaluation of rat C6 glioma, 15 male Wistar rats were seeded with C6 glioma cells into the right basal ganglia and scanned 12 days later using spectral CT. Brain sections corresponding to scanned regions were immunostained for proliferation marker protein Ki67 (Ki67). Pearson's correlation coefficients between spectral CT parameters and Ki67 expression were determined. Thirteen rats survived 12 days and developed tumors. Optimal contrast-to-noise ratio achieved was 65 keV. Brain regions containing liquefactive necrosis, solid tumor, peripheral tumor and normal tissue differed significantly with regard to the spectral curve slope (0.24±0.46, 1.81±1.09, 0.8±0.43 and 0.11±0.27, respectively; P<0.01), CT value (27.2±4.51, 103.18±35.48, 65.19±13.72 and 38.07±7.36, respectively; P<0.01) and iodine concentration (2.41±3.86, 16.05±9.75, 6.76±3.66 and 1.06±2.35, respectively; P<0.0001). The percentage of Ki67-positive cells correlated with the CT value (r=0.903; P<0.001), spectral curve slope (r=0.821; P<0.001) and iodine concentration (r=0.813; P<0.001). Spectral CT can detect microstructural changes within malignant gliomas and potentially provide important information regarding tumor proliferation and the extent of the invasion.

The role of Alix in the proliferation of human glioma cells

Apoptosis-linked-gene-2-interacting protein 1 (Alix) is involved in the endosome-lysosome system in the cytoplasm. The normal function of Alix may be altered by ALG-2 toward a destructive role during active cell death. Alix also may play a role in regulation of cell proliferation. However, the role of Alix in human glioma has not been elucidated yet. This study intended to clarify the relationship between Alix and glioma pathologic grades and its role in the proliferation of glioma cells. Our findings showed that Alix protein concentrations were significantly elevated in high-grade glioma tissue compared with low-grade glioma (P < .0001). Immunohistochemical study revealed that Alix was overexpressed in 75 resected glioma tissues and may forecast poor survival. Alix expression was increased in resting serum-stimulated glioma cells. Additionally, we reduced Alix expression in U251MG cells and then found that cell viability was decreased significantly when p21 expression increased. Colony formation assay and flow cytometry analysis demonstrated that reduced Alix expression may lead to growth inhibition and cell cycle arrest. In summary, our findings suggest that Alix plays an important role in the proliferation of glioma cells and may be a novel therapeutic target.

The role of microRNAs expression in laryngeal cancer

MicroRNAs (miRs, miRs) is a class of small non-coding RNAs, which posttranscriptionally regulate gene expression. Deregulated miRs are frequently obseved in patients with laryngeal cancer. In addition, numerous studies have showed miRs play significant roles in the pathogenesis of laryngeal cancer through regulating tumor cell proliferation, metastasis, invasion and apoptosis. miR can play either an oncogenic or tumor suppressive role in laryngeal cancer. In our review, we summarize the recent researches on laryngeal cancer-associated miRs, focusing on their role in the pathogenesis of laryngeal cancer. As changes in the levels of specific miRs in tissues or serum associate with diagnosis and prognosis of patients, we will also discuss the potential use of miRs in laryngeal cancer diagnosis and prognosis. Furthermore, supplementation of oncomiRs or inhibition of tumor suppressive miRs in vivo may be future therapeutic strategy for laryngeal cancer.

Inhibitory effect of miR-184 on the potential of proliferation and invasion in human glioma and breast cancer cells in vitro

MiR-184 was an important suppressor to tumor cells proliferation and invasion and some studies show that it was down-regulated in aggressive human tumor cells and a potential tumor therapy target through expression of miR-184 results in reduced tumor cell aggressiveness. In this study, miR-184 showed an inhibitive activity of glioma U87MG cell line and breast cancer MCF-7 cell line in proliferation and invasion by MTS and transwell assay. We found that the miR-184 also could arrest cell cycle and adhesion by up-regulating the expression of p53 and p21 and activity of caspase-3/8, suppressing the expression of SND1, MMP-2/9, CD44 and activity of AKT/NF-κB pathway. The results showed that miR-184 could be a potential target for glioma and breast cancer treatment.

MicroRNA expression and its implications for diagnosis and therapy of gallbladder cancer

Gallbladder cancer is the most common biliary tract malignancy with poor prognosis. MicroRNAs (miRNAs) are a class of small, endogenous, non-coding RNAs of 19-23 nucleotides in length, which regulate gene expression at post-transcriptional and translational levels. Several studies have demonstrated aberrant expression of miRNAs in gallbladder cancer tissues. Recent evidences also demonstrated that specific miRNAs are functionally involved in gallbladder cancer development through modulating cell proliferation, apoptosis, migration, invasion and metastasis. In this review, we explore the possibilities of using miRNAs as prognostic, diagnostic markers and therapeutic targets in gallbladder cancer.