The Impact of MMP-2 and Its Specific Inhibitor TIMP-2 Expression on the WHO Grade and Prognosis of Gliomas in Chinese Population: a Meta-Analysis

The Role of microRNAs in Multidrug Resistance of Glioblastoma

Simple Summary

Glioblastoma (GBM) is one of the most malignant types of central nervous system tumor which accounts for more than 60% of all brain tumors in adults. Owing to poor prognosis and drug resistance of most GBM, it is urged to further develop the diagnosis and treatment strategies. The aim of this article is to highlight the roles of some functional microRNAs in the diagnosis and treatment of drug-resistant GBM. Besides, we suggest effective treatment strategies based on the expression profiles of these effective miRNAs to provide an alternative solution to deal with this cancer.

Abstract

Glioblastoma (GBM) is an aggressive brain tumor that develops from neuroglial stem cells and represents a highly heterogeneous group of neoplasms. These tumors are predominantly correlated with a dismal prognosis and poor quality of life. In spite of major advances in developing novel and effective therapeutic strategies for patients with glioblastoma, multidrug resistance (MDR) is considered to be the major reason for treatment failure. Several mechanisms contribute to MDR in GBM, including upregulation of MDR transporters, alterations in the metabolism of drugs, dysregulation of apoptosis, defects in DNA repair, cancer stem cells, and epithelial–mesenchymal transition. MicroRNAs (miRNAs) are a large class of endogenous RNAs that participate in various cell events, including the mechanisms causing MDR in glioblastoma. In this review, we discuss the role of miRNAs in the regulation of the underlying mechanisms in MDR glioblastoma which will open up new avenues of inquiry for the treatment of glioblastoma.

LINC01433 targets miR-506-3p to promote the biological progress of nasopharyngeal carcinoma cells

PURPOSE

The current study aimed to investigate the role of long intergenic noncoding 01433 (LINC01433) in the proliferation, migration and invasion of nasopharyngeal carcinoma (NPC).

METHODS

Real-time quantitative PCR (RT-qPCR) was performed to determine the expressions of LINC01433 and miR-506-3p in NPC samples and cell lines. The effects of LINC01433 on cell proliferation, migration and invasion were measured by CCK-8, wound healing assay and Transwell, respectively. In addition, Pearson correlation analysis, starBase, RNA immunoprecipitation, luciferase assay, Western blot and functional experiments were conducted to detect and confirm the relationship between LINC01433 and miR-506-3p.

RESULTS

LINC01433 level was noticeably elevated in NPC tissues and cell lines. As the expression of LINC01433 in 5-8F cells was the highest in NPC cell lines and the expression of LINC01433 in SUNE1 cells was the lowest, 5-8F and SUNE1 cells were therefore selected as the target cells for following experiments. Furthermore, miR-506-3p was predicted as the target of LINC01433, and the two were negatively correlated with each other. Interestingly, overexpression of LINC01433 promoted proliferation, migration and invasion of NPC cells, while miR-506-3p reversed such effects of LINC01433. Moreover, LINC01433 silencing had the opposite effects to LINC01433 overexpression. Furthermore, miR-506-3p overexpression inhibited the expressions of MMP2, N-cadherin, p-PI3K and p-Akt, and promoted the expressions of E-cadherin and TIMP-2, and partially reversed the role of LINC01433 in promoting cancer development.

CONCLUSION

The current findings reveal that LINC01433 regulates NPC cell biological progress through miR-506-3p.

Pharmacological Inhibition of CA-IX Impairs Tumor Cell Proliferation, Migration and Invasiveness

Carbonic anhydrase IX (CA-IX) plays a pivotal role in regulation of pH in tumor milieu catalyzing carbonic acid formation by hydrating CO₂. An acidification of tumor microenvironment contributes to tumor progression via multiple processes, including reduced cell-cell adhesion, increased migration and matrix invasion. We aimed to assess whether the pharmacological inhibition of CA-IX could impair tumor cell proliferation and invasion. Tumor epithelial cells from breast (MDA-MB-231) and lung (A549) cancer were used to evaluate the cytotoxic effect of sulfonamide CA-IX inhibitors. Two CA-IX enzyme blockers were tested, SLC-0111 (at present in phase Ib clinical trial) and AA-06-05. In these cells, the drugs inhibited cell proliferation, migration and invasion through shifting of the mesenchymal phenotype toward an epithelial one and by impairing matrix metalloprotease-2 (MMP-2) activity. The antitumor activity was elicited via apoptosis pathway activation. An upregulation of p53 was observed, which in turn regulated the activation of caspase-3. Inhibition of proteolytic activity was accompanied by upregulation of the endogenous tissue inhibitor TIMP-2. Collectively, these data confirm the potential use of CA-IX inhibitors, and in particular SLC-0111 and AA-06-05, as agents to be further developed, alone or in combination with other conventional anticancer drugs.

MMP-2 expression and correlation with pathology and MRI of glioma

The expression of matrix metalloproteinase-2 (MMP-2) in brain glioma and its correlation with patients' clinicopathological characteristics and magnetic resonance imaging (MRI) features were investigated. A total of 104 patients with brain glioma admitted and treated in the First Affiliated Hospital of Anhui Medical University from June 2010 to September 2014 were randomly enrolled. MRI examination was performed before operation. Immunohistochemistry (IHC) was used to detect the expression levels of MMP-2 in brain glioma tissues and paired normal brain tissues after operation and to analyze the associations of MMP-2 expression with the clinicopathological characteristics of brain glioma and survival time of patients. The relationship between MMP-2 expression and preoperative MRI features of glioma was analyzed. The positive rate of MMP-2 expression in brain glioma was 73.08% (76/104), while that in paired normal brain tissues was only 12.5% (13/104), obviously lower than that in brain glioma tissues (P<0.05). The MMP-2 expression in the body of glioma was not related to the patients' sex, age, tumor location and pathological type (P>0.05), but there was a significant correlation with the tumor diameter and pathological grade of the patients (P<0.05). Analysis by Cox model suggested that tumor diameter, pathological grade and MMP-2 were independent prognostic factors for glioma (P<0.05). The overall survival (OS) of patients in the positive MMP-2 expression group was 16.4 months, while the OS in the negative MMP-2 expression group was 20.16 months, and the difference between the two groups was statistically significant (P<0.05). The positive expression of MMP-2 in glioma was closely related to the uniformity of MRI signal for tumor, tumor diameter, severity of peritumoral edema, degree of enhancement and pathological grade of tumor (P<0.05). MMP-2 is highly expressed in brain glioma, and it is a negative factor for prognosis. Therefore, the MRI manifestations of glioma can reflect to some extent the intensity of MMP-2 expression.

C6 glioma-derived microvesicles stimulate the proliferative and metastatic gene expression of normal astrocytes

The interaction between glioma cells and the surrounding microenvironment plays a key role in tumor invasion and infiltration ability. Recent studies reported the importance of glioma-derived microvesicles in the interaction of the tumor and the surrounding environment. The purpose of this study was to scrutinize the role of glioma-derived microvesicles in the interaction between tumor and normal astrocytes, which are the most abundant non-neoplastic cells in the tumor microenvironment (TME). To this end, we examined the effect of C6 tumor cell-derived microvesicles in the activation of normal rat astrocytes. The results showed that exposing normal astrocytes to C6MVs increase the expression of the glial fibrillary acidic protein (GFAP), and activate normal astrocytes. In addition, incubation of normal astrocytes with C6MVs affects the expression of genes involved in tumor invasion and growth in these cells. Our findings suggest that C6 tumor cells through the secretion of microvesicles (MVs) can alter the phenotype of surrounding astrocytes as well as through the changes in the expression of the genes involved in extracellular matrix remodeling can predispose their invasion and growth.

CD147 and glioma: a meta-analysis

Gliomas are the most common primary brain tumors. This meta-analysis aimed to systematically evaluate the relationship between CD147 expression in tissues and the clinicopathological features of patients with glioma. We searched PubMed (1966-2016), EMBASE (1980-2016), Cochrane Library (1996-2016), Web of Science (1945-2016), China National Knowledge Infrastructure (1982-2016), and Wan Fang databases (1988-2016). Quality assessment of the literature was performed using the Newcastle-Ottawa Scale, with Revman 5.3 and Stata 14.0 for analysis. In total, 1806 glioma patients from 19 studies were included, and patients with CD147 overexpression had poorer overall survival [hazard ratio (HR) = 2.211, P < 0.0001], a higher risk of recurrence (HR = 2.20, P = 0.0025), and a lower 5-year survival rate [odds ratio (OR) 0.12; 95% CI 0.08-0.19; P < 0.00001]. We observed significant differences in CD147 expression when comparing glioma tissues versus non-cancerous brain tissues (OR 20.42; 95% CI 13.94-29.91; P < 0.00001), tumor grades III-IV versus grades I-II (OR 5.88, 95% CI 4.15-8.34; P < 0.00001), and large versus small tumors (OR 1.58, 95% CI 1.04-2.40; P = 0.03). We also observed a significant correlation with matrix metalloproteinase (MMP) 2 (OR 39.11, 95% CI 11.47-133.34; P < 0.00001) and MMP9 (OR 13.35, 95% CI 4.67-38.18; P < 0.00001). CD147 expression did not differ based on patient's age (young vs. old, P = 0.89) or gender (female vs. male, P = 0.57). CD147 expression may be a potential prognostic biomarker for poorer overall and relapse-free survival, and may affect the 5-year survival rate in glioma patients. CD147 expression is also closely correlated with poor clinical characteristics in glioma patients.