Integrating machine learning and bioinformatics analysis to m6A regulator-mediated methylation modification models for predicting glioblastoma patients' prognosis and immunotherapy response.

BACKGROUND: Epigenetic regulations of immune responses are essential for cancer development and growth. As a critical step, comprehensive and rigorous explorations of m6A methylation are important to determine its prognostic significance, tumor microenvironment (TME) infiltration characteristics and underlying relationship with glioblastoma (GBM). METHODS: To evaluate m6A modification patterns in GBM, we conducted unsupervised clustering to determine the expression levels of GBM-related m6A regulatory factors and performed differential analysis to obtain m6A-related genes. Consistent clustering was used to generate m6A regulators cluster A and B. Machine learning algorithms were implemented for identifying TME features and predicting the response of GBM patients receiving immunotherapy. RESULTS: It is found that the m6A regulatory factor significantly regulates the mutation of GBM and TME. Based on Europe, America, and China data, we established m6Ascore through the m6A model. The model accurately predicted the results of 1206 GBM patients from the discovery cohort. Additionally, a high m6A score was associated with poor prognoses. Significant TME features were found among the different m6A score groups, which demonstrated positive correlations with biological functions (i.e., EMT2) and immune checkpoints. CONCLUSIONS: m6A modification was important to characterize the tumorigenesis and TME infiltration in GBM. The m6Ascore provided GBM patients with valuable and accurate prognosis and prediction of clinical response to various treatment modalities, which could be useful to guide patient treatments.

LncRNA SNHG14 is beneficial to oxygen glucose deprivation/reoxygenation-induced neuro-2a cell injury via mir-98-5p sequestration-caused BCL2L13 upregulation.

BACKGROUND: The deregulation of long non-coding RNA (lncRNA) is associated with diverse human disorders, including cerebral ischemia/reperfusion injury (CI/RI). LncRNA SNHG14 was reported to function in CI/RI. Whereas, molecular mechanisms regulated by SNHG14 are not fully unveiled. METHODS: Mice subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) were used as CI/RI animal models. Neuro-2a (N2A) cells subjected to oxygen glucose deprivation/reoxygenation (OGD/R) were used as CI/RI cell models. The expression of SNHG14, miR-98-5p and BCL2 like 13 (BCL2L13) was examined using quantitative real-time PCR (qPCR) or western blot. Apoptosis was monitored by flow cytometry assay. Apoptosis-related markers and endoplasmic reticulum (ER) stress-related markers were quantified by western blot. Inflammatory factors and oxidative stress were detected using matched commercial kits. The predicted relationship between miR-98-5p and SNHG14 or BCL2L13 was validated by dual-luciferase reporter assay, RIP assay and pull-down assay. RESULTS: The high expression of SNHG14 was monitored in MCAO/R-treated mice and OGD/R-treated N2A cells. OGD/R-induced N2A cell apoptosis, ER stress, inflammation and oxidative stress were attenuated by SNHG14 knockdown. SNHG14 targeted miR-98-5p to positively regulate BCL2L13 expression. Inhibition of miR-98-5p recovered cell apoptosis, ER stress, inflammation and oxidative stress that were repressed by SNHG14 knockdown. Overexpression of BCL2L13 enhanced cell apoptosis, ER stress, inflammation and oxidative stress that were repressed by miR-98-5p enrichment. CONCLUSIONS: SNHG14 knockdown alleviated OGD/induced N2A cell apoptosis, ER stress, inflammation and oxidative stress by depleting BCL2L13 via increasing miR-98-5p.

microRNA-1296 Inhibits Glioma Cell Growth by Targeting ABL2.

Aberrant expression of microRNAs (miRNAs) has been reported to play a role in tumorigenesis. Dysfunction of miR-1296 was found in a variety of cancers, however, the function of miR-1296 in the progression of glioma remains largely understood. Here, our results showed that miR-1296 was significantly down-regulated in glioma tissues and cell lines. Decreased expression of miR-1296 was associated with the tumor size, WHO grade and karnofsky performance scale (KPS) of glioma patients. Low expression of miR-1296 was significantly correlated with the shorter 5-year overall survival of glioma patients. Overexpression of miR-1296 inhibited the proliferation, colony formation, migration and induced apoptosis of glioma cells. MiR-1296 was found to bind the 3'-untranslated region (UTR) of ABL proto-oncogene 2 (ABL2) and subsequently repressed both the mRNA and protein expression of ABL2. ABL2 was overexpressed in glioma tissues and inversely correlated with that of miR-1296. Ectopic expressed ABL2 could reverse the inhibitory effects of miR-1296 on glioma cell proliferation. Our results illustrated the novel tumor-suppressive function of miR-1296 in glioma via repressing ABL2, suggesting a potential application of miR-1296 in the treatment of glioma.