MicroRNA-140-5p suppresses invasion and proliferation of glioma cells by targeting glutamate-ammonia ligase (GLUL)

The clinical prognostic significance of miR-140-5p expression in patients with cancer: A Meta and Bioinformatic analysis

The prognostic value of microRNA-140-5p (miR-140-5p) expression in cancer patients has been investigated, but with inconsistent results. This meta-analysis aims to determine the prognostic significance of miR-140-5p expression in patients with various malignancies. A comprehensive literature search was conducted using PubMed, Web of Science, ProQuest, Cochrane, and Google Scholar to identify relevant studies published before June 2023. Pooled hazard ratios (HR) and odds ratios (OR) with 95 % confidence intervals (CI) were calculated to assess the prognostic importance and clinicopathological features of miR-140-5p in overall survival (OS) and disease-free survival (DFS) of cancer patients, respectively. The CancerMIRNome database and other OS analysis webservers were utilized to explore the prognostic value and expression profile of miR-140-5p. A total of 17 studies were included in the final analysis. The results demonstrated that decreased miR-140-5p expression was significantly associated with inferior OS (pooled HR 0.63; 95 % CI, 0.51-0.79; p < 0.001) and DFS (pooled HR 0.40; 95 % CI, 0.25-0.64; p < 0.001). Pooled ORs indicated a significant correlation between reduced miR-140-5p expression and positive lymph node metastasis (LNM; OR = 3.42; 95 % CI, 2.36-4.94; p < 0.001), advanced tumor stage (OR = 2.80; 95 % CI, 2.07-3.78; p < 0.001), and positive distant metastasis (DM; OR = 10.81; 95 % CI, 3.31-35.30; p < 0.001). No significant associations were observed between miR-140-5p expression and gender (OR = 0.94; 95 % CI, 0.70-1.28; p = 0.70), age (OR = 1.31; 95 % CI, 0.99-1.74; p = 0.06), tumor size (OR = 1.55; 95 % CI, 0.77-3.10; p = 0.22), and histological grade (OR = 1.20; 95 % CI, 0.46-3.10; p = 0.71). Subgroup analyses revealed that decreased miR-140-5p expression was associated with shorter OS in subgroups based on sample size (<100 or >100), tumor origin (GI or non-GI), and cancer type (GC/CRC). Bioinformatic analysis supported the finding that miR-140-5p was downregulated in most tumor tissues, and its reduced expression was linked to poor prognosis in patients with multiple malignancies. The prognostic significance of miR-140-5p in predicting reduced OS and DFS suggests that measuring miR-140-5p expression levels before treatment could serve as a valuable biomarker for identifying cancer patients with an unfavorable prognosis and improving clinical management.

Phosphomimetic Dicer S1016E triggers a switch to glutamine metabolism in gemcitabine-resistant pancreatic cancer

Objective

Dicer is an enzyme that processes microRNAs (miRNAs) precursors into mature miRNAs, which have been implicated in various aspects of cancer progressions, such as clinical aggressiveness, prognosis, and survival outcomes. We previously showed that high expression of Dicer is associated with gemcitabine (GEM) resistance in pancreatic ductal adenocarcinoma (PDAC); thus, in this study, we aimed to focus on how Dicer is involved in GEM resistance in PDAC, including cancer prognosis, cell proliferation, and metabolic regulation.

Methods

We generated stable shRNA knockdown of Dicer in GEM-resistant PANC-1 (PANC-1 GR) cells and explored cell viability by MTT and clonogenicity assays. Metabolomic profiling was employed to investigate metabolic changes between parental cells, PANC-1, and PANC-1 GR cells, and further implied to compare their sensitivity to the glutaminase inhibitor, CB839, and GEM treatments. To identify putative phosphorylation site involves with Dicer and its effects on GEM resistance in PDAC cells, we further generated phosphomimetic or phosphomutant Dicer at S1016 site and examined the changes in drug sensitivity, metabolic alteration, and miRNA regulation.

Results

We observed that high Dicer levels in pancreatic ductal adenocarcinoma cells were positively correlated with advanced pancreatic cancer and acquired resistance to GEM. Metabolomic analysis indicated that PANC-1 GR cells rapidly utilised glutamine as their major fuel and increased levels of glutaminase (GLS): glutamine synthetase (GLUL) ratio which is related to high Dicer expression. In addition, we found that phosphomimetic Dicer S1016E but not phosphomutant Dicer S1016A facilitated miRNA maturation, causing an imbalance in GLS and GLUL and resulting in an increased response to GLS inhibitors.

Conclusion

Our results suggest that phosphorylation of Dicer on site S1016 affects miRNA biogenesis and glutamine metabolism in GEM-resistant pancreatic cancer.

•

Dicer expression is positively correlated with advanced pancreatic cancer.

•

Dicer expression is significantly correlated with high level of GLS and GLS/GLUL ratio.

•

Phosphomimetic Dicer S1016E enhances glutamine consumption and GLS inhibitor sensitivity.

•

Phosphomimetic Dicer S1016E facilitates miRNAs maturation to increase GLS/GLUL ratio.

The Role of N-myc Downstream-Regulated Gene Family in Glioma Based on Bioinformatics Analysis

Glioma is the most common type of primary tumor in the central nervous system, and the molecular mechanisms remain elusive. N-myc downstream-regulated gene (NDRG) family is reported to take part in the pathogenesis of various diseases, including some preliminary exploration in glioma. However, there has been no bioinformatics analysis of NDRG family in glioma yet. Herein, we focused on the expression changes of NDRGs with their value in predicting patients' prognoses, upstream regulatory mechanisms (DNA mutation, DNA methylation, transcription factors, and microRNA regulation) and gene enrichment analysis based on co-expressed genes with data from public databases. Furthermore, the expression pattern of NDRGs was verified by the paired glioma and peritumoral samples in our institute. It was suggested that NDRGs were differentially expressed genes in glioma. In particular, the lower expression of NDRG2 or NDRG4 could serve as a predictor of higher grade tumor and poorer prognosis. Also, NDRGs might play a crucial role in signal transduction, energy metabolism, and cross-talk among cells in glioma, under the control of a complex regulatory network. This study enables us to better understand the role of NDRGs in glioma and with further research, it may contribute to the development of glioma treatment.

miR-140 inhibits osteosarcoma progression by impairing USP22-mediated LSD1 stabilization and promoting p21 expression

Osteosarcoma is a bone tumor frequently diagnosed in children and young adults. Despite advances in chemotherapy and surgical resection, tumors metastasize in 30% of osteosarcoma patients. In addition, side effects caused by chemotherapeutic drugs, as well as the development of chemoresistance, highlight the need to identify the molecular mechanisms involved in the pathogenesis of osteosarcoma. We compared 65 osteosarcoma samples to their adjacent normal tissues, as well as commercially obtained osteosarcoma cell lines with normal osteoblast cell lines, and identified a role for the microRNA (miR)-140/ubiquitin-specific protease 22 (USP22)/lysine-specific demethylase 1 (LSD1)/p21 axis in the development of osteosarcoma. Osteosarcoma tissues and cells exhibited poor miR-140 and p21 expression, whereas the expression of USP22 and LSD1 was increased. Overexpression of miR-140 inhibited cell proliferation, migration, and invasion and promoted cell apoptosis by directly targeting USP22, resulting in its decreased expression. Overexpression of USP22 reversed the effects of miR-140 overexpression in osteosarcoma cells. Overexpression of miR-140 or USP22 knockdown led to the ubiquitination and degradation of LSD1. miR-140 overexpression also suppressed tumorigenesis in vivo. This study revealed a role for miR-140 in the restriction of osteosarcoma development and identified miR-140 as a potential target for therapeutic intervention.

MiR-140 Resensitizes Cisplatin-Resistant NSCLC Cells to Cisplatin Treatment Through the SIRT1/ROS/JNK Pathway

Background

Although cisplatin is an effective chemotherapeutic drug that is commonly used for non-small-cell lung cancer (NSCLC) treatment, the drug resistance usually occurs during the long-term use of it. It is urgent to develop strategies to reduce the resistance of NSCLC cells to cisplatin.

Methods

Cisplatin-resistant NSCLC cell lines (PC9/R and A549/R) were acquired through long-term exposure of PC9 and A549 cells to cisplatin. QRT-PCR analysis was performed to compare the expression of miR-140 between routine NSCLC cells and cisplatin-resistant NSCLC cells. CCK-8 assay was used to evaluate the effect of miR-140 on the sensitivity of PC9/R and A549/R to cisplatin. Western blot assay and luciferase reporter assay were used to confirm the regulation of miR-140 on SIRT1. Western blot and flow cytometry analysis were performed to evaluate the effect of miR-140 on the apoptosis pathway induced by cisplatin.

Results

PC9/R and A549/R exhibited obviously lower sensitivity compared to their parental PC9 and A549 cells, respectively. Furthermore, PC9/R and A549/R cells expressed significantly lower levels of miR-140 compared to their parental PC9 and A549 cells, respectively. However, transfection with miR-140 mimics significantly resensitized the PC9/R and A549/R to cisplatin-induced cytotoxicity. In the mechanism research, we confirmed that SIRT1 was overexpressed and was targeted by miR-140 in PC9/R and A549/R. Furthermore, overexpression of SIRT1 was responsible for the resistance to cisplatin in PC9/R and A549/R cells. Transfection with miR-140 was able to inhibit the expression of SIRT1 and thus inhibited the SIRT1/ROS/JNK pathway. As a result, the PC9/R and A549/R cells restored the sensitivity to cisplatin-induced apoptosis.

Conclusion

MiR-140 resensitizes cisplatin-resistant NSCLC cells to cisplatin treatment through the SIRT1/ROS/JNK pathway.

Non-Coding RNAs as Key Regulators of Glutaminolysis in Cancer

Cancer cells exhibit exacerbated metabolic activity to maintain their accelerated proliferation and microenvironmental adaptation in order to survive under nutrient-deficient conditions. Tumors display an increase in glycolysis, glutaminolysis and fatty acid biosynthesis, which provide their energy source. Glutamine is critical for fundamental cellular processes, where intermediate metabolites produced through glutaminolysis are necessary for the maintenance of mitochondrial metabolism. These include antioxidants to remove reactive oxygen species, and the generation of the nonessential amino acids, purines, pyrimidines and fatty acids required for cellular replication and the activation of cell signaling. Some cancer cells are highly dependent on glutamine consumption since its catabolism provides an anaplerotic pathway to feed the Krebs cycle. Intermediate members of the glutaminolysis pathway have been found to be deregulated in several types of cancers and have been proposed as therapeutic targets and prognostic biomarkers. This review summarizes the main players in the glutaminolysis pathway, how they have been found to be deregulated in cancer and their implications for cancer maintenance. Furthermore, non-coding RNAs are now recognized as new participants in the regulation of glutaminolysis; therefore, their involvement in glutamine metabolism in cancer is discussed in detail.