miR-124-3p Regulates FGF2-EGFR Pathway to Overcome Pemetrexed Resistance in Lung Adenocarcinoma Cells by Targeting MGAT5

Lentinan mitigates pemetrexed chemoresistance by the PI3K/Akt pathway in non-small cell lung cancer

Pemetrexed is a folate analog metabolic inhibitor that is given for therapy of non-small cell lung cancer (NSCLC). Drug resistance affects the efficacy of pemetrexed in NSCLC. Lentinan is a polysaccharide extracted from Shiitake mushrooms which has antitumor roles in multiple cancers, including lung cancer. However, the effects of lentinan on pemetrexed resistance in NSCLC remain unclear. In present study, The pemetrexed-resistant NSCLC cells were established and exposed to pemetrexed and lentinan. Oxidative stress was investigated via mitochondrial membrane potential (JC-1 staining), levels of MDA and SOD.The phosphorylation and total of PI3K and Akt levels were actuated using specific activator 740Y-P and measured through western blot. We observed that Lentinan decreased IC50 of pemetrexed in resistant NSCLC cells. Lentinan aggravated pemetrexed-induced proliferation inhibition of resistant NSCLC cells via reducing PCNA levels. Lentinan exacerbated pemetrexed-triggered oxidative stress through increasing ROS and MDA levels, and reducing mitochondrial membrane potential and SOD levels. Lentinan inhibited PI3K/Akt signaling activation in pemetrexed-treated cells. Activated PI3K/Akt pathway using activator 740Y-P reversed the effects of lentinan on pemetrexed-mediated proliferation inhibition and oxidative stress. Our findings uncover that Lentinan mitigates pemetrexed resistance in NSCLC through inhibiting cell proliferation and inducing oxidative stress by suppressing PI3K/Akt signaling.

Communication between the stem cell niche and an adjacent differentiation niche through miRNA and EGFR signaling orchestrates exit from the stem cell state in the Drosophila ovary

The signaling environment, or niche, often governs the initial difference in behavior of an adult stem cell and a derivative that initiates a path towards differentiation. The transition between an instructive stem cell niche and differentiation niche must generally have single-cell resolution, suggesting that multiple mechanisms might be necessary to sharpen the transition. Here, we examined the Drosophila ovary and found that Cap cells, which are key constituents of the germline stem cell (GSC) niche, express a conserved microRNA (miR-124). Surprisingly, loss of miR-124 activity in Cap cells leads to a defect in differentiation of GSC derivatives. We present evidence that the direct functional target of miR-124 in Cap cells is the epidermal growth factor receptor (EGFR) and that failure to limit EGFR expression leads to the ectopic expression of a key anti-differentiation BMP signal in neighboring somatic escort cells (ECs), which constitute a differentiation niche. We further found that Notch signaling connects EFGR activity in Cap cells to BMP expression in ECs. We deduce that the stem cell niche communicates with the differentiation niche through a mechanism that begins with the selective expression of a specific microRNA and culminates in the suppression of the major anti-differentiation signal in neighboring cells, with the functionally important overall role of sharpening the spatial distinction between self-renewal and differentiation environments.

Aberrant N-glycosylation in cancer: MGAT5 and β1,6-GlcNAc branched N-glycans as critical regulators of tumor development and progression

BACKGROUND

Changes in protein glycosylation are widely observed in tumor cells. N-glycan branching through adding β1,6-linked N-acetylglucosamine (β1,6-GlcNAc) to an α1,6-linked mannose, which is catalyzed by the N-acetylglucosaminyltransferase V (MGAT5 or GnT-V), is one of the most frequently observed tumor-associated glycan structure formed. Increased levels of this branching structure play a pro-tumoral role in various ways, for example, through the stabilization of growth factor receptors, the destabilization of intercellular adhesion, or the acquisition of a migratory phenotype.

CONCLUSION

In this review, we provide an updated and comprehensive summary of the physiological and pathophysiological roles of MGAT5 and β1,6-GlcNAc branched N-glycans, including their regulatory mechanisms. Specific emphasis is given to the role of MGAT5 and β1,6-GlcNAc branched N-glycans in cellular mechanisms that contribute to the development and progression of solid tumors. We also provide insight into possible future clinical implications, such as the use of MGAT5 as a prognostic biomarker.

Matched Analyses of Brain Metastases versus Primary Non-Small Cell Lung Cancer Reveal a Unique microRNA Signature

Distant spreading of tumor cells to the central nervous system in non-small cell lung cancer (NSCLC) occurs frequently and poses major clinical issues due to limited treatment options. RNAs displaying differential expression in brain metastasis versus primary NSCLC may explain distant tumor growth and may potentially be used as therapeutic targets. In this study, we conducted systematic microRNA expression profiling from tissue biopsies of primary NSCLC and brain metastases from 25 patients. RNA analysis was performed using the nCounter Human v3 miRNA Expression Assay, NanoString technologies, followed by differential expression analysis and in silico target gene pathway analysis. We uncovered a panel of 11 microRNAs with differential expression and excellent diagnostic performance in brain metastasis versus primary NSCLC. Five microRNAs were upregulated in brain metastasis (miR-129-2-3p, miR-124-3p, miR-219a-2-3p, miR-219a-5p, and miR-9-5p) and six microRNAs were downregulated in brain metastasis (miR-142-3p, miR-150-5p, miR-199b-5p, miR-199a-3p, miR-199b-5p, and miR-199a-5p). The differentially expressed microRNAs were predicted to converge on distinct target gene networks originating from five to twelve core target genes. In conclusion, we uncovered a unique microRNA profile linked to two target gene networks. Our results highlight the potential of specific microRNAs as biomarkers for brain metastasis in NSCLC and indicate plausible mechanistic connections.

Long non-coding RNA SNHG1/microRNA-195-5p/Yes-associated protein axis affects the proliferation and metastasis of gastric cancer via the Hippo signaling pathway

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) has been found to be highly expressed in gastric cancer (GC). However, the study for exploring the effects of SNHG1 and microRNA (miR)-195-5p on GC is limited. This research commits to unravel the regulatory effects of SNHG1, miRNA-195-5p, and Yes-associated protein 1 (YAP1) on GC. SNHG1, miR-195-5p and YAP1 levels in GC tissues and GC cells were detected. The GC cells were treated with various constructs altering SNHG1 or miR-195-5p expression to determine the biological activities of GC cell in vitro. The effect of SNHG1 inhibition on subcutaneous tumorigenesis of GC cells in a nude mouse model in vivo was detected. The binding relation among SNHG1, miR-195-5p, and YAP1 was validated. SNHG1 and YAP1 levels were elevated and miR-195-5p level was reduced in GC. Reduction of SNHG1 or elevation of miR-195-5p retarded GC cell biological activity in vitro. Downregulated SNHG1 suppressed tumor growth in vivo. SNHG1 bound to miR-195-5p, and miR-195-5p directly targeted YAP1. The downregulated SNHG1 hinders the biological behaviors of GC cells via the modulation of the miR-195-5p/YAP1 axis.

The polymorphisms of FGFR2 and MGAT5 affect the susceptibility to COPD in the Chinese people

Background

Chronic obstructive pulmonary disease (COPD) is characterized by incomplete reversible airflow limitation and chronic inflammatory response lesions. This study mainly explored whether FGFR2 and MGAT5 polymorphisms affected the risk of COPD in the Chinese people.

Methods

Five variants in FGFR2 and MGAT5 were chosen and genotyped using Agena MassARRAY platform from 315 COPD patients and 314 healthy controls. The correlation of FGFR2 and MGAT5 with COPD susceptibility was evaluated with odds ratio (OR) and 95% confidence interval (CI) via logistic regression.

Results

We found rs2420915 enhanced the risk of COPD, while rs6430491, rs2593704 reduced the susceptibility of COPD (p < 0.05). Rs2420915 could promote the incidence of COPD in the elderly and nonsmokers. Rs1907240 and rs2257129 also increased the susceptibility to COPD in nonsmokers (p < 0.05). MGAT5-rs2593704 played a protective role in COPD development in different subgroups (age ≤ 70, male, smokers, and individuals with BMI ≤ 24 kg/m²). Meanwhile, rs6430491 was linked with a lower risk of COPD in nonsmoking and BMI ≤ 24 kg/m² subgroups.

Conclusions

We concluded that FGFR2 and MGAT5 genetic polymorphisms are correlated with the risk of COPD in the Chinese people. These data underscored the important role of FGFR2 and MGAT5 gene in the occurrence of COPD and provided new biomarkers for COPD treatment.

Trial registration: NA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01498-3.

The miR-124-3p/Neuropilin-1 Axis Contributes to the Proliferation and Metastasis of Triple-Negative Breast Cancer Cells and Co-Activates the TGF-β Pathway

Triple-negative breast cancer (TNBC) accounts for 90% of breast cancer-associated mortality. Neuropilin-1 (NRP-1) acts as a non-tyrosine kinase receptor for several cellular signaling pathways involved in the proliferation and metastasis of cancer cells. However, the miRNAs that regulate NRP-1 expression and the underlying mechanisms in TNBC cells remain unclear. In the present study, we found that TNBC cells expressed higher levels of NRP-1 than non-TNBC cells. Stable transfectants depleted of NRP-1 were generated from two TNBC cell lines, human MDA-MB-231 and mouse 4T1 cells. NRP-1 depletion significantly suppressed the proliferation of TNBC cells by arresting the cell cycle at phase G0/G1 by upregulating p27 and downregulating cyclin E and cyclin-dependent kinase 2. NRP-1 depletion also repressed cell migration and epithelial-mesenchymal transition (EMT) by inducing the upregulation of E-cadherin and the downregulation of N-cadherin, matrix metalloproteinase (MMP)-2 and MMP-9, and reducing MMP-2 and MMP-9 activities as detected by gelatin zymography assay. By applying multiple miRNA-target prediction tools, we screened potential miRNAs with binding sites with the 3’-untranslated region of the NRP-1 gene and selected 12 miRNA candidates, among which miR-124-3p displayed the most vigorous activity to downregulate NRP-1 as validated by luciferase assay and miRNA transfection assay. By downregulating NRP-1, miR-124-3p mimics inhibited the proliferation, migration, and invasion of TNBC cells, and antagomiR-124-3p could partially abolish the effects of NRP-1 depletion. In the animal experiments, NRP-1 depletion inhibited tumorigenesis and liver metastasis of TNBC cells, while miR-124-3p mimics inhibited the growth of established TNBC tumors. In the mechanistic exploration, we revealed that NRP-1 co-interacted with transforming growth factor (TGF)-β to activate the TGF-β pathway, which regulates EMT-related molecules. In summary, the present results indicate that the miR-124-3p/NRP-1 axis contributes to the proliferation and metastasis of TNBC cells and co-activates the TGF-β pathway, suggesting that these molecules may present as potential therapeutic targets and valuable biomarkers for TNBC.