miRNA-mediated TUSC3 deficiency enhances UPR and ERAD to promote metastatic potential of NSCLC

Molecular and therapeutic insight into ER stress signalling in NSCLC

Endoplasmic Reticulum (ER) stress is intricately involved in cancer development, progression and response to chemotherapy. ER stress related genes might play an important role in predicting the prognosis in lung adenocarcinoma patients and may be manipulated to improve the treatment outcome and overall survival rate. In this review, we analysed the contribution of the three major ER stress pathways-IRE1, ATF6, and PERK-in lung cancer pathogenesis via modulation of tumour microenvironment (TME) and processes as metastasis, angiogenesis, apoptosis and N-glycosylation. Furthermore, we discuss the regulatory role of microRNAs in fine-tuning ER stress pathways in Non-Small Cell Lung Cancer (NSCLC). Our review also highlights various promising strategies to overcome chemoresistance by targeting ER stress pathways, offering new therapeutic opportunities.

Identification of Endoplasmic Reticulum Stress-related Genes for Predicting Prognosis, Immunotherapy Response, and Drug Sensitivity in Thyroid Cancer

ER stress has emerged as a promising target for cancer therapy. RNA sequencing data of patients with THCA were obtained from the TCGA database to identify differentially expressed genes associated with ER stress. Signature genes were selected through univariate Cox regression, LASSO, and multivariate Cox regression analyses. The predictive performance of the model was assessed using Kaplan-Meier survival analysis and ROC curves. GSEA was conducted to explore pathway enrichment between high-risk and low-risk groups. The immune landscape of risk groups was characterized using ssGSEA, ESTIMATE and CIBERSORT algorithms. Quantitative real-time PCR was employed to investigate the mRNA expression of the signature genes. Finally, immunotherapy response and potential drug sensitivity were evaluated. The prognostic model based on the signature genes ANK2, APOE, ERP27, FPR2, and NOS1, demonstrated robust predictive performance. GSEA results revealed distinct pathway enrichment patterns in the high-risk and low-risk groups. Furthermore, ssGSEA revealed that low-risk patients exhibited enhanced immune-related functions and increased immune cell infiltration. The RT-qPCR results revealed that in thyroid cancer cells, APOE and ERP27 expression levels were elevated, and ANK1, NOS1, and FPR2 expression levels were decreased. Immunotherapy, as well as Palbociclib and Perifosine, were predicted to be more effective for low-risk patients. Conversely, high-risk patients were more likely to benefit from Axitinib, Imatinib, Nilotinib, and Temsirolimus. This study identified 5 signature genes as potential biomarkers and therapeutic targets for THCA. These findings provide novel insights into the prognosis and targeted therapy of THCA, offering a foundation for furture clinical applications.

DOGpred: A Novel Deep Learning Framework for Accurate Identification of Human O-linked Threonine Glycosylation Sites

O-linked glycosylation is a crucial post-translational modification that regulates protein function and biological processes. Dysregulation of this process is associated with various diseases, underscoring the need to accurately identify O-linked glycosylation sites on proteins. Current experimental methods for identifying O-linked threonine glycosylation (OTG) sites are often complex and costly. Consequently, developing computational tools that predict these sites based on protein features is crucial. Such tools can complement experimental approaches, enhancing our understanding of the role of OTG dysregulation in diseases and uncovering potential therapeutic targets. In this study, we developed DOGpred, a deep learning-based predictor for precisely identifying human OTGs using high-latent feature representations. Initially, we extracted nine different conventional feature descriptors (CFDs) and nine pre-trained protein language model (PLM)-based embeddings. Notably, each feature was encoded as a 2D tensor, capturing both the sequential and inherent feature characteristics. Subsequently, we designed a stacked convolutional neural network (CNN) module to learn spatial feature representations from CFDs and a stacked recurrent neural network (RNN) module to learn temporal feature representations from PLM-based embeddings. These features were integrated using attention-based fusion mechanisms to generate high-level feature representations for final classification. Ablation analysis and independent tests demonstrated that the optimal model (DOGpred), employing a stacked 1D CNN and a stacked attention-based RNN modules with cross-attention feature fusion, achieved the best performance on the training dataset and significantly outperformed machine learning-based single-feature models and state-of-the-art methods on independent datasets. Furthermore, DOGpred is publicly available at https://github.com/JeonRPM/DOGpred/ for free access and usage.

Chemical Glycoproteomic Profiling in Rice Seedlings Reveals N-glycosylation in the ERAD-L Machinery

As a ubiquitous and essential posttranslational modification occurring in both plants and animals, protein N-linked glycosylation regulates various important biological processes. Unlike the well-studied animal N-glycoproteomes, the landscape of rice N-glycoproteome remains largely unexplored. Here, by developing a chemical glycoproteomic strategy based on metabolic glycan labeling, we report a comprehensive profiling of the N-glycoproteome in rice seedlings. The rice seedlings are incubated with N-azidoacetylgalactosamine-a monosaccharide analog containing a bioorthogonal functional group-to metabolically label N-glycans, followed by conjugation with an affinity probe via click chemistry for the enrichment of the N-glycoproteins. Subsequent mass spectrometry analyses identify a total of 403 N-glycosylation sites and 673 N-glycosylated proteins, which are involved in various important biological processes. In particular, the core components of the endoplasmic reticulum-associated protein degradation machinery are N-glycosylated, and the N-glycosylation is important for the endoplasmic reticulum-associated protein degradation-L function. This work not only provides an invaluable resource for studying rice N-glycosylation but also demonstrates the applicability of metabolic glycan labeling in glycoproteomic profiling for crop species.

Astragaloside IV Overcomes Anlotinib Resistance in Non-small Cell Lung Cancer through miR-181a-3p/UPR-ERAD Axis

BACKGROUND

Astragaloside IV (AS-IV) has been shown to have a curative effect on non-small cell lung cancer (NSCLC). This study aimed to elucidate the role of AS-IV in NSCLC cell anlotinib resistance (AR).

METHODS

The NSCLC/AR cells, resistant to anlotinib, have been produced. The role of AS-IV in the AR of NSCLC cells about the miR-181a-3p/unfolded protein response (UPR)- endoplasmic reticulum associated degradation (ERAD) pathway was then discussed by treating the cells with anlotinib or AS-IV, or by manipulating them with inhibitors or mimics of miR- 181a-3p, HRD1 or Derlin-1 overexpression plasmids.

RESULTS

We found that AS-IV could suppress the AR of NSCLC cells. In addition, miR-181a- 3p was elevated in NSCLC/AR cells. Functionally, AS-IV limited the AR of NSCLC cells by reducing miR-181a-3p. Further, activation of the UPR-ERAD pathway was correlated with AR in NSCLC cells. Increased sensitivity of NSCLC cells to anlotinib caused by miR-181a-3p inhibitor could be reversed by overexpression of HRD1 or Derlin-1.

CONCLUSION

This research revealed a promising NSCLC/AR treatment approach by showing that AS-IV exposed NSCLC cells to anlotinib by inhibiting the miR-181a-3p/UPR-ERAD axis.

Low Expression of SCN4B Predicts Poor Prognosis in Non-small Cell Lung Cancer

BACKGROUND

Sodium voltage-gated channel beta subunit 4 (SCN4B) plays a suppressive role in various tumors. However, the role of SCN4B in non-small cell lung cancer (NSCLC) is not yet clear. This study aims to investigate the expression of SCN4B in NSCLC patients and its correlation with prognosis.

METHODS

Firstly, the expression of SCN4B in non-small cell lung cancer (NSCLC) was analyzed using The Cancer Genome Atlas (TCGA) database. Then, differential expression genes (DEGs) were identified using R software. Next, DEG enrichment pathways were analyzed using the R package clusterProfiler. Protein-protein interaction networks were revealed through STRING analysis. A heatmap showed significant differential expression of SCN4B. Further analysis included examining SCN4B expression in a pan-cancer context and its correlation with 24 types of immune cells in NSCLC. Subsequently, quantitative real-time polymerase chain reaction (qRT-PCR), Western Blot, immunohistochemistry, and clinical data were used to validate SCN4B expression and prognostic value in NSCLC patients.

RESULTS

SCN4B mRNA expression in non-small cell lung cancer tissues was significantly lower than in adjacent normal tissues (p < 0.001). Clinical correlation analysis confirmed its association with clinical pathology. Gene set enrichment analysis (GSEA) and tumor immune-related analyses indicated that SCN4B is involved in NSCLC-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and participates in immune infiltration. qRT-PCR, Western Blot, and immunohistochemistry also confirmed that SCN4B is downregulated in NSCLC patients and is associated with poor prognosis.

CONCLUSION

SCN4B is downregulated in tumor tissues of NSCLC patients and is associated with a poor prognosis.

XBP1s activates METTL3/METTL14 for ER-phagy and paclitaxel sensitivity regulation in breast cancer

Cancer cells employ the unfolded protein response (UPR) or induce autophagy, especially selective removal of certain ER domains via reticulophagy (termed ER-phagy), to mitigate endoplasmic reticulum (ER) stress for ER homeostasis when encountering microenvironmental stress. N6-methyladenosine (m6A) is one of the most abundant epitranscriptional modifications and plays important roles in various biological processes. However, the molecular mechanism of m6A modification in the ER stress response is poorly understood. In this study, we first found that ER stress could dramatically elevate m6A methylation levels through XBP1s-dependent transcriptional upregulation of METTL3/METTL14 in breast cancer (BC) cells. Further MeRIP sequencing and relevant validation results confirmed that ER stress caused m6A methylation enrichment on target genes for ER-phagy. Mechanistically, METTL3/METTL14 increased ER-phagy machinery formation by promoting m6A modification of the ER-phagy regulators CALCOCO1 and p62, thus enhancing their mRNA stability. Of note, we further confirmed that the chemotherapeutic drug paclitaxel (PTX) could induce ER stress and increase m6A methylation for ER-phagy. Furthermore, the combination of METTL3/METTL14 inhibitors with PTX demonstrated a significant synergistic therapeutic effect in both BC cells and xenograft mice. Thus, our data built a novel bridge on the crosstalk between ER stress, m6A methylation and ER-phagy. Most importantly, our work provides novel evidence of METTL3 and METTL14 as potential therapeutic targets for PTX sensitization in breast cancer.

Emerging mechanisms of the unfolded protein response in therapeutic resistance: from chemotherapy to Immunotherapy

The accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and activates the unfolded protein response (UPR). As an adaptive cellular response to hostile microenvironments, such as hypoxia, nutrient deprivation, oxidative stress, and chemotherapeutic drugs, the UPR is activated in diverse cancer types and functions as a dynamic tumour promoter in cancer development; this role of the UPR indicates that regulation of the UPR can be utilized as a target for tumour treatment. T-cell exhaustion mainly refers to effector T cells losing their effector functions and expressing inhibitory receptors, leading to tumour immune evasion and the loss of tumour control. Emerging evidence suggests that the UPR plays a crucial role in T-cell exhaustion, immune evasion, and resistance to immunotherapy. In this review, we summarize the molecular basis of UPR activation, the effect of the UPR on immune evasion, the emerging mechanisms of the UPR in chemotherapy and immunotherapy resistance, and agents that target the UPR for tumour therapeutics. An understanding of the role of the UPR in immune evasion and therapeutic resistance will be helpful to identify new therapeutic modalities for cancer treatment. Video Abstract.

MiR-196b-5p activates NF-κB signaling in non-small cell lung cancer by directly targeting NFKBIA

BACKGROUND

Our recent study found that QKI-5 regulated miRNA, miR-196b-5p, promotes non-small cell lung cancer (NSCLC) progression by directly targeting GATA6, TSPAN12 and FAS. However, the biological functions of miR-196b-5p in NSCLC progression and metastasis still remain elusive.

METHODS

Cell proliferation, migration, colony formation, cell cycle assays were used to investigate cellular phenotypic changes. Quantitative real-time PCR (qRT-PCR) and western blot analyses were used to measure expressions of relative gene and protein. Interaction between QKI-5 and miR-196b-5p was determined by RNA immunoprecipitation (RIP) assay. Luciferase reporter assay was used to determine direct binding between miR-196b-5p and NFKBIA 3'-UTR. ELISA assay was used to measure secreted IL6 proteins. Mice xenograft model was used to assess the functions of NFKBIA on in vivo tumor growth.

RESULTS

We demonstrated that the miR-196b-5p facilitates lung cancer cell proliferation, migration, colony formation, and cell cycle by directly targeting NFKBIA, a negative regulator of NFκB signaling. Knocking down NFKBIA increases IL6 mediated phosphorylation of signal transducer and activator of transcription 3 (STAT3) to promote lung cancer cell growth by activating NFκB signaling. The expression of NFKBIA was significantly downregulated in NSCLC tissue samples, and was negatively correlated with the expression miR-196b-5p. In addition, we found that downregulated QKI-5 expression was associated with the elevated miR-224 expression in NSCLC.

CONCLUSIONS

Our findings indicated that the miR-224/QKI-5/miR-196b-5p/NFKBIA signaling pathway might play important functions in the progression of NSCLC, and suggested that targeting this pathway might be an effective therapeutic strategy in treating NSCLC.

SYVN1-mediated ubiquitylation directs localization of MCT4 in the plasma membrane to promote the progression of lung adenocarcinoma

Tumour cells mainly generate energy from glycolysis, which is commonly coupled with lactate production even under normoxic conditions. As a critical lactate transporter, monocarboxylate transporter 4 (MCT4) is highly expressed in glycolytic tissues, such as muscles and tumours. Overexpression of MCT4 is associated with poor prognosis for patients with various tumours. However, how MCT4 function is post-translationally regulated remains largely unknown. Taking advantage of human lung adenocarcinoma (LUAD) cells, this study revealed that MCT4 can be polyubiquitylated in a nonproteolytic manner by SYVN1 E3 ubiquitin ligase. The polyubiquitylation facilitates the localization of MCT4 into the plasma membrane, which improves lactate export by MCT4; in accordance, metabolism characterized by reduced glycolysis and lactate production is effectively reprogrammed by SYVN1 knockdown, which can be reversed by MCT4 overexpression. Biologically, SYVN1 knockdown successfully compromises cell proliferation and tumour xenograft growth in mouse models that can be partially rescued by overexpression of MCT4. Clinicopathologically, overexpression of SYVN1 is associated with poor prognosis in patients with LUAD, highlighting the importance of the SYVN1-MCT4 axis, which performs metabolic reprogramming during the progression of LUAD.

MicroRNA-409-5p Inhibits GIST Tumorigenesis and Improves Imatinib Resistance by Targeting KDM4D Expression

OBJECTIVE

Gastrointestinal stromal tumors (GISTs) can rapidly proliferate through angiogenesis. Previous studies indicated the potential influence of microRNA on the progression of tumor immature angiogenesis. This study aimed to explore the specific mechanism by which microRNA-409-5p (miR-409-5p) contributes to GIST.

METHODS

To identify genes potentially involved in the development and progression of GIST, the differences of miR-409-5p between tumors and adjacent tissues were first analyzed. Following this analysis, target genes were predicted. To further investigate the function of miRNA in GIST cells, two GIST cell lines (GIST-T1 and GIST882) were transfected with lentiviruses that stably expressed miR-409-5p and scrambled miRNA (negative control). Later, the cells were subjected to Western blotting and ELSA to determine any differences in angiogenesis-related genes.

RESULTS

In GISTs, there was a decrease in the expression levels of miR-409-5p compared to the adjacent tissues. It was observed that the upregulation of miR-409-5p in GIST cell lines effectively inhibited the proteins hypoxia-inducible transcription factor 1β (HIF1β) and vascular endothelial growth factor A (VEGF-A). Further investigations revealed that miR-409-5p acted as an inhibitor of angiogenesis by binding to the 3'-UTR of Lysine-specific demethylase 4D (KDM4D) mRNA. Moreover, the combination of miR-409-5p with imatinib enhanced its inhibitory effect on angiogenesis.

CONCLUSION

This study demonstrated that the miRNA-409-5p/KDM4D/HIF1β/VEGF-A signaling pathway could serve as a novel target for the development of therapeutic strategies for the treatment of imatinib-resistance in GIST patients.

MIR503HG: A potential diagnostic and therapeutic target in human diseases

LncRNAs are involved in many physiological and pathological processes, including chromatin remodeling, transcription, posttranscriptional gene expression, mRNA stability, translation, and posttranslational modification, and their functions depend on subcellular localization. MIR503HG is a lncRNA as well as a host gene for the miRNAs miR-503 and miR-424. MIR503HG functions independently or synergistically with miR-503. MIR503HG affects cell proliferation, invasion, metastasis, apoptosis, angiogenesis, and other biological behaviors. The mechanism of MIR503HG in disease includes interaction with protein, sponging miRNA to regulate downstream target gene, and participation in NF-κB, TGF-β, ERK/MAPK, and PI3K/AKT signaling pathways. In this review, we summarize the molecular mechanisms of MIR503HG in disease and its potential applications in diagnosis, prognosis, and treatment. We also raise some unanswered questions in this area, providing insights for future research.

Identification of WD-Repeat Protein 72 as a Novel Prognostic Biomarker in Non-Small-Cell Lung Cancer

WD-repeat protein 72(WDR72; OMIM^∗613214), a scaffolding protein lacking intrinsic enzymatic activity, produces numerous β-propeller blade formations, serves as a binding platform to assemble protein complexes and is critical for cell growth, differentiation, adhesion, and migration. Despite evidence supporting a basic role of WDR72 in the tumorigenesis of particular cancers, the value of WDR72 in non-small-cell lung cancer (NSCLC), the tumor with the highest mortality rate globally, is undocumented. We investigated the prognostic value of WDR72 in NSCLC and studied its potential immune function and its correlation with ferroptosis. According to The Cancer Genome Atlas, Cancer Cell Line Encyclopedia, Genotype-Tissue Expression, and Gene Set Cancer Analysis, we used multiple bioinformatic strategies to investigate the possible oncogenic role of WDR72, analyze WDR72 and prognosis, and immune cell infiltration in different tumors correlation. WDR72 exhibited a high expression in NSCLC and a positive association with prognosis. WDR72 expression was related to immune cell infiltration and tumor immune microenvironment in NSCLC. Finally, we validated WDR72 in human NSCLC; it has a predictive value in NSCLC related to its function in tumor progression and immunity. The significance of our study is that WDR72 can be used as a potential indicator of lung cancer prognosis. Helping physicians more accurately predict patient survival and risk of disease progression.

MiR-1286 inhibits lung cancer growth through aerobic glycolysis by targeting PKM2

INTRODUCTION

This study aims to explore the effects of microRNA-1286 (miR-1286) on the development of non-small cell lung cancer (NSCLC) via the aerobic glycolysis pathway by targeting pyruvate kinase muscle isozyme M2 (PKM2).

MATERIAL AND METHODS

The mRNA levels of miR-1286 in NSCLC tissues and mouse tumor tissues were detected by q-PCR. MiR-1286 was knocked down and overexpressed separately in A549 cells. The effect of miR-1286 on cell proliferation was determined by CCK8 assay. Western blotting was used to measure the expression of PKM2 protein. Lactate production assay was used to detect the aerobic glycolysis in A549 cells. The effect of miR-1286 in vivo was determined by xenograft assay.

RESULTS

The mRNA level of miR-1286 decreased in NSCLC tissues compared with paired, tumor adjacent normal tissues. In addition, miR-1286 inhibited A549 cell proliferation in vitro. Moreover, knockdown of miR-1286 increased PKM2 expression and lactate production. Thus, miR-1286 expression negatively correlated with PKM2 in A549 cells. At the same time, in vivo experiments also showed that miR-1286 suppressed the growth of A549 cells and PKM2 was the target gene of miR-1286.

CONCLUSIONS

These data show that miR-1286 inhibits lung cancer proliferation via aerobic glycolysis by targeting PKM2, which suggests that the functions of miR-1286 in NSCLC may play a key role in tumor progression and that miR-1286 can be a promising predictive biomarker and potential therapeutic target for NSCLC.

Inflammatory Cytokines Rewire the Proinsulin Interaction Network in Human Islets

CONTEXT

Aberrant biosynthesis and secretion of the insulin precursor proinsulin occurs in both type I and type II diabetes. Inflammatory cytokines are implicated in pancreatic islet stress and dysfunction in both forms of diabetes, but the mechanisms remain unclear.

OBJECTIVE

We sought to determine the effect of the diabetes-associated cytokines on proinsulin folding, trafficking, secretion, and β-cell function.

METHODS

Human islets were treated with interleukin-1β and interferon-γ for 48 hours, followed by analysis of interleukin-6, nitrite, proinsulin and insulin release, RNA sequencing, and unbiased profiling of the proinsulin interactome by affinity purification-mass spectrometry.

RESULTS

Cytokine treatment induced secretion of interleukin-6, nitrites, and insulin, as well as aberrant release of proinsulin. RNA sequencing showed that cytokines upregulated genes involved in endoplasmic reticulum stress, and, consistent with this, affinity purification-mass spectrometry revealed cytokine induced proinsulin binding to multiple endoplasmic reticulum chaperones and oxidoreductases. Moreover, increased binding to the chaperone immunoglobulin binding protein was required to maintain proper proinsulin folding in the inflammatory environment. Cytokines also regulated novel interactions between proinsulin and type 1 and type 2 diabetes genome-wide association studies candidate proteins not previously known to interact with proinsulin (eg, Ataxin-2). Finally, cytokines induced proinsulin interactions with a cluster of microtubule motor proteins and chemical destabilization of microtubules with Nocodazole exacerbated cytokine induced proinsulin secretion.

CONCLUSION

Together, the data shed new light on mechanisms by which diabetes-associated cytokines dysregulate β-cell function. For the first time, we show that even short-term exposure to an inflammatory environment reshapes proinsulin interactions with critical chaperones and regulators of the secretory pathway.

Lucidumol A, Purified Directly from Ganoderma lucidum, Exhibits Anticancer Effect and Cellular Inflammatory Response in Colorectal Cancer

Colorectal cancer (CRC) is a deadly disease regardless of sex, and a few therapeutic approaches have been fully developed at advanced stages, even if some strategies have durable clinical benefits, such as immunotherapy and chemotherapy. Ganoderma lucidum has been recognized as an organism that suppresses tumors and inflammation; however, the molecular mechanisms induced by a triterpenoid in Ganoderma lucidum, Lucidumol A, have not yet been fully explored in CRC and inflammatory responses. To this end, we extracted Lucidumol A from Ganoderma lucidum and analyzed its anticancer effect and anti-inflammatory potential in CRC cell lines and RAW264.7 macrophage-derived cell lines, respectively. A series of in vitro experiments including cell survival, wound healing, and migration assays were performed to determine the role of Lucidumol A in the CRC cell line. We also analyzed inflammatory responses using qRT-PCR, Western Blot, and ELISA in RAW 264.7 macrophaged-derived cell lines exposed to various concentrations of Lucidumol A. Lucidumol A efficiently suppressed the metastatic potential of CRC at very low concentrations. Furthermore, significant anti-inflammatory activities were observed in Lucidumol A-treated RAW264.7 cells through modulation of inflammation-associated marker genes and cytokines. In conclusion, Lucidumol A plays an important role in Ganoderma lucidum-dependent tumor suppression and anti-inflammation, suggesting different strategies to treat CRC patients, and other diseases evoked by proinflammatory cytokines, despite the need to explore further its mechanism of action.

Exosomal miR-181a-3p Regulates the Anlotinib Resistance of Lung Cancer Cells

This study investigates the mechanism of Anlotinib in the treatment of lung cancer drug resistance. A total of 30 lung cancer tissue specimens were retrospectively analyzed and 30 normal lung tissues were included as a control. Real-time PCR detected miR-181a-3p expression along with analysis of cell viability by MTT assay, cell invasion by transwell, and the exosomal miR-181a-3p/UPR/ERAD signaling pathway. The expression of miR-181a-3p in peripheral blood of lung cancer was increased and the overall survival rate of patients with high miR-181a-3p in exosomes was shorter than patients with low expression. In A549 and H292 cell lines, anlotinib is added to overexpress exosomal miR-181a-3p, cell viability and invasion were significantly increased. After knocking down exosomal miR-181a-3p, cell viability and invasion were significantly reduced. The expression of miR-181a-3p is directly regulated by exosomes UPR/ERAD. After overexpression of exosomes miR-181a-3p, the protein levels of UPR and ERAD were significantly reduced and increased after knockdown of exosomes miR-181a-3p. In conclusion, the secretory miR-181a-3p/UPR/ERAD pathway promotes the proliferation of A549 and H292 cells, regulates the resistance of Anlotinib, and can increase the resistance of lung cancer to Anlotinib by promoting the proliferation signaling pathway, and promote the growth of tumor cells.

The role of endoplasmic reticulum stress in the regulation of long noncoding RNAs in cancer

Cancer cells must overcome a variety of external and internal stresses to survive and proliferate. These unfavorable conditions include the accumulation of mutations, nutrient deficiency, oxidative stress, and hypoxia. These stresses can cause aggregation of misfolded proteins inside the endoplasmic reticulum. Under these conditions, the cell undergoes endoplasmic reticulum stress (ER-stress), and consequently initiates the unfolded protein response (UPR). Activation of the UPR triggers transcription factors and regulatory factors, including long noncoding RNAs (lncRNAs), which control the gene expression profile to maintain cellular stability and hemostasis. Recent investigations have shown that cancer cells can ensure their survival under adverse conditions by the UPR affecting the expression of lncRNAs. Therefore, understanding the relationship between lncRNA expression and ER stress could open new avenues, and suggest potential therapies to treat various types of cancer.

N6-methyladenosine-mediated CELF2 regulates CD44 alternative splicing affecting tumorigenesis via ERAD pathway in pancreatic cancer

Background

Alternative splicing (AS) of genes has been found to affect gene stability, and its abnormal regulation can lead to tumorigenesis. CELF2 is a vital splicing factor to participate in mRNA alternative splicing. Its downregulation has been confirmed to promote the occurrence and development of pancreatic cancer (PC). However, the regulatory role and mechanisms in PC has not been elucidated.

Results

CELF2 was downregulated in PC tissues, which affected tumor TNM stage and tumor size, and low expression of CELF2 indicated a poor prognosis of PC. In vivo and in vitro experiments showed that abnormal expression of CELF2 affected the stemness, apoptosis, and proliferation of PC cells. Furthmore, we also found that CELF2 was targeted by ALKBH5 for m6A modification, leading to CELF2 degradation by YTHDF2. Bioinformatic analysis of AS model based on the TCGA database indicated that CELF2 could target CD44 to form different spliceosomes, thereby affecting the biological behavior of PC cells. The conversion of CD44s to CD44V is the key to tumorigenesis. Transcriptomic analysis was conducted to reveal the mechanism of CELF2-mediated CD44 AS in PC. We found that CELF2-mediated splicing of CD44 led to changes in the level of endoplasmic reticulum stress, further regulating the endoplasmic reticulum-associated degradation (ERAD) signaling pathway, thereby affecting apoptosis and cell stemness. In addition, ERAD signaling pathway inhibitor, EerI, could effectively reverse the effect of CD44 on tumors.

Conclusions

This study indicates that N6-methyladenosine-mediated CELF2 promotes AS of CD44, affecting the ERAD pathway and regulating the biological behavior of PC cells. CELF2 is expected to be a new target for targeted-drug development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00844-0.

Ascendancy of unfolded protein response over glioblastoma: estimating progression, prognosis and survival

Glioblastoma (GBM) is presented with a poor prognosis. The endoplasmic reticulum stress (ERS) has been implicated as a major contributor to disease progression and chemoresistance in GBM. Triggering ERS by chemical agents or genetic modulations is identified as some of the reasons for regulating gene expression and the pathogenesis of GBM. ERS initiates unfolded protein response (UPR), an integrated system useful in restoring homeostasis or inducing apoptosis. Modulation of UPR might have positive outcomes in GBM treatment as UPR inducers have been shown to alter cell survival and migration. In the current review, we have utilized GSE7806, a publicly available dataset from Gene Expression Omnibus (GEO), to evaluate the genes expressed during 6.5 hr and 18 hr, which can be comparable to the early and late-onset of the disease. Subsequently, we have elucidated the prognosis and survival information whilst the expression of these genes in the GBM was noted in previous studies. This is the first of its kind review summarizing the most recent gene information correlating UPR and GBM.

Epigenetic silencing of UBXN8 contributes to leukemogenesis in t(8;21) acute myeloid leukemia

The formation of the RUNX1-RUNX1T1 fusion protein, resulting from the t(8;21) translocation, is considered to be one of the initiating events of t(8;21) acute myeloid leukemia (AML). However, the mechanisms of the oncogenic mechanism of RUNX1-RUNX1T1 remain unclear. In this study, we found that RUNX1-RUNX1T1 triggers the heterochromatic silencing of UBXN8 by recognizing the RUNX1-binding sites and recruiting chromatin-remodeling enzymes to the UBXN8 promoter region. Decitabine, a specific inhibitor of DNA methylation, upregulated the expression of UBXN8 in RUNX1-RUNX1T1⁺ AML cell lines. Overexpression of UBXN8 inhibited the proliferation and colony-forming ability of and promoted cell cycle arrest in t(8;21) AML cell lines. Enhancing UBXN8 levels can significantly inhibit tumor proliferation and promote the differentiation of RUNX1-RUNX1T1⁺ cells in vivo. In conclusion, our results indicated that epigenetic silencing of UBXN8 via methylation of its promoter region mediated by the RUNX1-RUNX1T1 fusion protein contributes to the leukemogenesis of t(8;21) AML and that UBXN8 targeting may be a potential therapeutic strategy for t(8;21) AML.

The protein byproduct of a common chromosomal rearrangement in acute myeloid leukemia (AML) promotes cancerous growth by inhibiting a tumor suppressor protein. AML cells that exhibit an abnormal coupling of segments from chromosomes 8 and 21 produce a fusion protein known as RUNX1-RUNX1T1. Erna Yang of Shenzhen University General Hospital, China, and colleagues have identified a mechanism by which this protein promotes AML progression. Experiments with AML cell lines showed that RUNX1-RUNX1T1 recruits DNA-binding proteins that introduce numerous chemical modifications to the UBXN8 gene, which inhibit production of the tumor suppressor protein it codes for. Drugs that block these modifications and stimulate UBXN8 activity also arrest tumor cell division. Experiments in mice confirmed that enhanced UBXN8 expression offers a defense against AML progression, suggesting a promising therapeutic approach.

Predictive and Prognostic Biomarkers for Lung Cancer Bone Metastasis and Their Therapeutic Value

Lung cancer is the leading cause of cancer-related death worldwide. Bone metastasis, which usually accompanies severe skeletal-related events, is the most common site for tumor distant dissemination and detected in more than one-third of patients with advanced lung cancer. Biopsy and imaging play critical roles in the diagnosis of bone metastasis; however, these approaches are characterized by evident limitations. Recently, studies regarding potential biomarkers in the serum, urine, and tumor tissue, were performed to predict the bone metastases and prognosis in patients with lung cancer. In this review, we summarize the findings of recent clinical research studies on biomarkers detected in samples obtained from patients with lung cancer bone metastasis. These markers include the following: (1) bone resorption-associated markers, such as N-terminal telopeptide (NTx)/C-terminal telopeptide (CTx), C-terminal telopeptide of type I collagen (CTx-I), tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), pyridinoline (PYD), and parathyroid hormone related peptide (PTHrP); (2) bone formation-associated markers, including total serum alkaline phosphatase (ALP)/bone specific alkaline phosphatase(BAP), osteopontin (OP), osteocalcin (OS), amino-terminal extension propeptide of type I procollagen/carboxy-terminal extension propeptide of type I procollagen (PICP/PINP); (3) signaling markers, including epidermal growth factor receptor/Kirsten rat sarcoma/anaplastic lymphoma kinase (EGFR/KRAS/ALK), receptor activator of nuclear factor κB ligand/receptor activator of nuclear factor κB/osteoprotegerin (RANKL/RANK/OPG), C-X-C motif chemokine ligand 12/C-X-C motif chemokine receptor 4 (CXCL12/CXCR4), complement component 5a receptor (C5AR); and (4) other potential markers, such as calcium sensing receptor (CASR), bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2), cytokeratin 19 fragment/carcinoembryonic antigen (CYFRA/CEA), tissue factor, cell-free DNA, long non-coding RNA, and microRNA. The prognostic value of these markers is also investigated. Furthermore, we listed some clinical trials targeting hotspot biomarkers in advanced lung cancer referring for their therapeutic effects.

Knockdown of PPARδ Induces VEGFA-Mediated Angiogenesis via Interaction With ERO1A in Human Colorectal Cancer

Angiogenesis is an important mechanism underlying the development and metastasis of colorectal cancer (CRC) and has emerged as a therapeutic target for metastatic CRC (mCRC). Our recent studies found that Peroxisome proliferator-activated receptor β/δ/D (PPARδ) regulates vascular endothelial growth factor A(VEGFA) secretion and the sensitivity to bevacizumab in CRC. However, its exact effect and underlying mechanisms remain unidentified. In this study, we showed that PPARδ expression was inversely associated with the microvascular density in human CRC tissues. Knockdown of PPARδ enhanced VEGFA expression in HCT116 cells and HUVEC angiogenesis in vitro; these phenomena were replicated in the experimental in vivo studies. By tandem mass tag (TMT)-labeling proteomics and chromatin immunoprecipitation sequencing (ChIP-seq) analyses, endoplasmic reticulum oxidoreductase 1 alpha (ERO1A) was screened and predicted as a target gene of PPARδ. This was verified by exploring the effect of coregulation of PPARδ and ERO1A on the VEGFA expression in HCT116 cells. The results revealed that PPARδ induced VEGFA by interacting with ERO1A. In conclusion, our results suggest that knockdown of PPARδ can promote CRC angiogenesis by upregulating VEGFA through ERO1A. This pathway may be a potential target for mCRC treatment.

MicroRNA and ER stress in cancer

The development of biological technologies in genomics, proteomics, and bioinformatics has led to the identification and characterization of the complete set of coding genes and their roles in various cellular pathways in cancer. Nevertheless, the cellular pathways have not been fully figured out like a jigsaw puzzle with missing pieces. The discovery of noncoding RNAs including microRNAs (miRNAs) has provided the missing pieces of the cellular pathways. Likewise, miRNAs have settled many questions of inexplicable patches in the endoplasmic reticulum (ER) stress pathways. The ER stress-caused pathways typified by the unfolded protein response (UPR) are pivotal processes for cellular homeostasis and survival, rectifying uncontrolled proteostasis and determining the cell fate. Although various factors and pathways have been studied and characterized, the understanding of the ER stress requires more wedges to fill the cracks of knowledge about the ER stress pathways. Moreover, the roles of the ER stress and UPR are still controversial in cancer despite their strong potential to promote cancer. The noncoding RNAs, in particular, miRNAs aid in a better understanding of the ER stress and its role in cancer. In this review, miRNAs that are the more-investigated subtype of noncoding RNAs are focused on the interpretation of the ER stress in cancer, following the introduction of miRNA and ER stress.

The LncRNA MIR503HG/miR-224-5p/TUSC3 Signaling Cascade Suppresses Gastric Cancer Development via Modulating ATF6 Branch of Unfolded Protein Response

Background

Unfolded protein response (UPR)-mediated tumor-promoting functions have been identified in multiple cancers, and this study focused on investigating the role and molecular mechanisms of UPR in modulating gastric cancer (GC) pathogenesis.

Methods

The bioinformatics analysis was performed to examine the expression status of cancer associated genes in patients with stomach adenocarcinoma (STAD) and predict the targeting sites of miR-224-5p with LncRNA MIR503HG and TUSC3. Genes expressions were quantified by Real-Time qPCR, Western Blot and immunohistochemistry (IHC). Cell proliferation, viability, apoptosis and mobility were evaluated by MTT assay, trypan blue staining assay, flow cytometer and transwell assay, respectively. The binding sites were validated by dual-luciferase reporter gene system assay.

Results

LncRNA MIR503HG and TUSC3 were downregulated, but miR-224-5p was upregulated in GC tissues and cells, in contrast with their normal counterparts. Further gain- and loss-of-function experiments validated that the malignant phenotypes in GC cells, including cell proliferation, invasion, epithelial-mesenchymal transition (EMT) and tumorigenesis, were negatively regulated by LncRNA MIR503HG. Mechanistically, LncRNA MIR503HG upregulated TUSC3 in GC cells through sponging miR-224-5p, resulting in the repression of GC progression. Finally, we validated that knock-down of ATF6, but not other two branches of UPR (PERK1 and IRE1), partially rescued cell proliferation and EMT in the GC cells with LncRNA MIR503HG overexpression.

Conclusions

Targeting the LncRNA MIR503HG/miR-224-5p/TUSC3 signaling cascade suppressed ATF6-mediated UPR, resulting in the blockage of GC development.

Subcellular Localization of miRNAs and Implications in Cellular Homeostasis

MicroRNAs (miRNAs) are thought to act as post-transcriptional regulators in the cytoplasm by either dampening translation or stimulating degradation of target mRNAs. With the increasing resolution and scope of RNA mapping, recent studies have revealed novel insights into the subcellular localization of miRNAs. Based on miRNA subcellular localization, unconventional functions and mechanisms at the transcriptional and post-transcriptional levels have been identified. This minireview provides an overview of the subcellular localization of miRNAs and the mechanisms by which they regulate transcription and cellular homeostasis in mammals, with a particular focus on the roles of phase-separated biomolecular condensates.

A minor review of microRNA-338 exploring the insights of its function in tumorigenesis

MicroRNAs(miRNAs) are small non-coding RNAs which have a critical role in various biological processes via direct binding and post-transcriptionally regulating targeted genes expression. More than one-half of human genes were regulated by miRNAs and their aberrant expression was detected in various human diseases, including cancers. miRNA-338 is a new identified miRNA and increasing evidence show that miRNA-338 participates in the progression of lots of cancers, such as lung cancer, hepatocellular cancer, breast cancer, glioma, and so on. Although a range of targets and signaling pathways such as MACC1 and Wnt/β-catenin signaling pathway were illustrated to be regulated by miRNA-338, which functions in tumor progression are still ambiguous and the underlying molecular mechanisms are also unclear. Herein, we reviewed the latest studies in miRNA-338 and summarized its roles in different type of human tumors, which might provide us new idea for further investigations and potential targeted therapy.

Frontiers of MicroRNA Signature in Non-small Cell Lung Cancer

Lung cancer is the leading cause of cancer-related deaths worldwide and non-small cell lung cancer (NSCLC) accounts for more than 80% of all lung cancer cases. Recent advancements in diagnostic tools, surgical treatments, chemotherapies, and molecular targeted therapies that improved the therapeutic efficacy in NSCLC. However, the 5-years relative survival rate of NSCLC is only about 20% due to the inadequate screening methods and late onset of clinical symptoms. Dysregulation of microRNAs (miRNAs) was frequently observed in NSCLC and closely associated with NSCLC development, progression, and metastasis through regulating their target genes. In this review, we provide an updated overview of aberrant miRNA signature in NSCLC, and discuss the possibility of miRNAs becoming a diagnostic and therapeutic tool. We also discuss the possible causes of dysregulated miRNAs in NSCLC.

The Common miRNAs between Tuberculosis and Non-Small Cell Lung Cancer: A Critical Review

Tuberculosis (TB) and non-small cell lung cancer (NSCLC) are two major contributors to mortality and morbidity worldwide. In this regard, TB and NSCLC have similar symptoms, and TB has symptoms that are identical to malignancy; therefore, sometimes it is mistakenly diagnosed as lung cancer. Moreover, patients with active pulmonary TB are at a higher risk of dying due to lung cancer. In addition, several signaling pathways involved in TB and NSCLC have been identified. Also, the miRNAs are biological molecules shown to play essential roles in the above-mentioned diseases through targeting the signaling pathways' genes. Most of the pathways affected by miRNAs are immune responses such as autophagy and apoptosis in TB and NSCLC, respectively. Several studies have separately investigated the expression of miRNAs profile in patients with NSCLC and infectious TB. In this critical review, we attempted to gather common miRNAs between TB and NSCLC and to explain the involved-pathways, which are affected by miRNAs in both TB and NSCLC. Results of this critical review show that the expressions of miR-155, miR-146a, miR-125b, miR-30a, miR-29a, and miR-Let7 have significantly changed in TB and NSCLC. The data suggest that miRNAs expression may provide a new method for screening or differential diagnosis of NSCLC and TB.

Interplay between endoplasmic reticulum stress and non-coding RNAs in cancer

To survive, cancer cells are subjected to various internal and external adverse factors, including genetic mutations, hypoxia, nutritional deficiencies, and drug toxicity. All of these factors result in the accumulation of unfolded proteins in the endoplasmic reticulum, which leads to a condition termed endoplasmic reticulum stress (ER stress) and triggers the unfolded protein response (UPR). UPR downstream components strictly control transcription and translation reprogramming to ensure selective gene expression, including that of non-coding RNA (ncRNAs), to adapt to adverse environments. NcRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), play important roles in regulating target gene expression and protein translation, and their aberrant expression is related to tumor development. Dysregulation of ncRNAs is involved in the regulation of various cellular characteristics of cancer cells, including growth, apoptosis, metastasis, angiogenesis, drug sensitivity, and tumor stem cell properties. Notably, ncRNAs and ER stress can regulate each other and collaborate to determine the fate of tumor cells. Therefore, investigating the interaction between ER stress and ncRNAs is crucial for developing effective cancer treatment and prevention strategies. In this review, we summarize the ER stress-triggered UPR signaling pathways involved in carcinogenesis followed by the mutual regulation of ER stress and ncRNAs in cancer, which provide further insights into the understanding of tumorigenesis and therapeutic strategies.

Endoplasmic reticulum stress induces growth retardation by inhibiting growth hormone IGF-I axis

OBJECTIVE

Insulin-like growth factor 1 (IGFI) is one of several growth factors which is induced by growth hormone (GH), which activates the Janus kinase 2 (JAK2)-signal transducer and activator of transcription 5 (STAT5) pathway, and plays crucial roles in normal human growth, metabolism, and systemic energy homeostasis. However, little is known about the negative regulation of IGF-I production under different physiological or pathological conditions. Herein, we explore whether activation of endoplasmic reticulum (ER) stress regulates IGF-I production and normal body growth.

MATERIALS AND METHODS

C57BL/6 J mice were challenged with tunicamycin (Tm) to induce ER stress activation. 24 h after stimulation, hepatic mRNA expression was analyzed by RNA-Seq and validated by qPCR. Enzyme-linked immunosorbent assay (ELISA) was performed 24 h after Tm stimulation. Body growth was determined 16 days after Tm stimulation. Animals were then sacrificed and liver tissues were collected for further analysis.

RESULTS

Mice challenged with Tm displayed a retardation of growth. Molecularly, we found that ER stress inhibited phosphorylation of STAT5. IGF-I transcription and circulating IGF-I were also dramatically decreased under ER stress activation. Moreover, our results demonstrate that IGF-I administration ameliorates Tm-induced growth retardation.

CONCLUSIONS

ER stress induces growth retardation. ER stress inhibits hepatic GH-JAK2 signaling activation and its downstream target gene expression. These results warrant further research to explore the crosstalk between ER stress and growth hormone signaling in improving body growth.

Regenerating Urethral Striated Muscle by CRISPRi/dCas9-KRAB-Mediated Myostatin Silencing for Obesity-Associated Stress Urinary Incontinence

Overweight females are prone to obesity-associated stress urinary incontinence (OA-SUI), and there are no definitive medical therapies for this common urologic condition. This study was designed to test the hypothesis that regenerative therapy to restore urethral striated muscle (stM) and pelvic floor muscles might represent a valuable therapeutic approach. For the in vitro experiment, single-guide RNAs targeting myostatin (MSTN) were used for CRISPRi/dCas9-Kruppel associated box (KRAB)-mediated gene silencing. For the in vivo experiment, a total of 14 female lean ZUC-Leprfa 186 and 14 fatty ZUC-Leprfa 185 rats were used as control and CRISPRi-MSTN treated groups, respectively. The results indicated that lentivirus-mediated expression of MSTN CRISPRi/dCas9-KRAB caused sustained downregulation of MSTN in rat L6 myoblast cells and significantly enhanced myogenesis in vitro. In vivo, the urethral sphincter injection of lentiviral-MSTN sgRNA and lentiviral-dCas9-KRAB significantly increased the leak point pressure, the thickness of the stM layer, the ratio of stM to smooth muscle, and the number of neuromuscular junctions. Downregulation of MSTN with CRISPRi/dCas9-KRAB-mediated gene silencing significantly enhanced myogenesis in vitro and in vivo. It also improved urethral continence in the OA-SUI rat model.

circDCUN1D4 suppresses tumor metastasis and glycolysis in lung adenocarcinoma by stabilizing TXNIP expression

Aberrant expression of circular RNAs (circRNAs) is involved in cancer progression through interaction with RNA-binding proteins (RBPs). Herein, we screened circRNA expression of A549 cells in circBase and the crosslinking immunoprecipitation (CLIP) data of human antigen R (HuR), an extensively studied RBP, and identified a circRNA, circ-defective in cullin neddylation 1 domain containing 4 (circDCUN1D4), originating from the DCUN1D4 gene transcript. circDCUN1D4 is downregulated in tumor samples under the mediation of DExH-box helicase 9 (DHX9), which inhibits the formation of circRNA by binding inverted repeat Alus (IRAlus) in flanking sequences. circDCUN1D4 depletion promoted invasion in vitro and metastasis in vivo. Importantly, the interaction between circDCUN1D4 and HuR increased the transportation of HuR to the cytoplasm. circDCUN1D4 acts as a scaffold to facilitate the interaction between the HuR protein and thioredoxin-interacting protein (TXNIP) mRNA, which enhances the stability of the TXNIP mRNA. Additionally, circDCUN1D4 directly interacts with TXNIP mRNA through base complementation, indicating the formation of the circDCUN1D4/HuR/TXNIP RNA-protein ternary complex. Furthermore, circDCUN1D4 suppressed metastasis and glycolysis of lung cancer cells in a TXNIP-dependent manner. Clinically, the downregulated expression of circDCUN1D4 was more prevalent in lymph node metastatic tissues and served as an independent risk factor for the overall survival of lung adenocarcinoma (LUAD) patients. These findings demonstrated that a novel circRNA, circDCUN1D4, is involved in the metastasis and glycolysis of LUAD.

Recruitment of miR-8080 by luteolin inhibits androgen receptor splice variant 7 expression in castration-resistant prostate cancer

A need exists for seeking effective treatments for castration-resistant prostate cancer (CRPC) in response to its emergence following androgen deprivation therapy as a major clinical problem. In the present study, we investigated the chemopreventive and chemotherapeutic potential of luteolin, a flavonoid with antioxidative properties, on prostate cancer, including CRPC. Luteolin inhibited the progression of rat prostate carcinogenesis by induction of apoptosis in a transgenic rat for adenocarcinoma of prostate (TRAP) model. Luteolin decreased cell proliferation in a dose-dependent manner and induced apoptosis with the activation of caspases 3 and 7 in both rat (PCai1, established from a TRAP prostate tumor) and human (22Rv1) CRPC cells. Dietary luteolin also suppressed tumor growth via an increase in apoptosis and inhibition of angiogenesis in PCai1 and 22Rv1 xenografts implanted in castrated nude mice. We also focused on androgen receptor splice variant 7 (AR-V7), which contributes to cell proliferation and therapeutic resistance in CRPC. Luteolin dramatically suppressed AR-V7 protein expression in 22Rv1 cells in vitro and ex vivo. Microarray analysis identified MiR-8080, which contains a possible target sequence for AR-V7 3'-UTR, as a gene upregulated by luteolin. MiR-8080 transfection decreased the AR-V7 expression level and the induction of apoptosis in 22Rv1 cells. Furthermore, miR-8080 knockdown canceled luteolin decreasing AR-V7 and the cell growth of 22Rv1. MiR-8080 induced by luteolin intake enhanced the therapeutic effect of enzalutamide on 22Rv1 xenografts under castration conditions. These results indicate luteolin inhibits CRPC by AR-V7 suppression through miR-8080, highlighting luteolin and miR-8080 as promising therapeutic agents for this disease.

High circ-SEC31A expression predicts unfavorable prognoses in non-small cell lung cancer by regulating the miR-520a-5p/GOT-2 axis

Dysregulation of circular RNAs (circRNAs) has recently been shown to play important regulatory roles in cancer development and progression, including non-small cell lung cancer (NSCLC). However, the roles of most circRNAs in NSCLC are still unknown. In this study, we found that hsa_circ_0001421 (circ-SEC31A) was upregulated in NSCLC tissues and cell lines. Increased circ-SEC31A expression in NSCLC was significantly correlated with malignant characteristics and served as an independent risk factor for the post-surgical overall survival of NSCLC patients. Reduced circ-SEC31A expression in NSCLC decreased tumor cell proliferation, migration, invasion, and malate-aspartate metabolism. Mechanistically, we demonstrated that silencing circ-SEC31A downregulated GOT-2 expression by relieving the sponging effect of miR-520a-5p, which resulted in significantly reduced malate-aspartate metabolism in NSCLC cells. Taken together, these results revealed the important role of circ-SEC31A in the proliferation, migration, invasion, and metabolic regulation of NSCLC cells, providing a new perspective on circRNAs in NSCLC progression.

miR-25 promotes invasion of human non-small cell lung cancer via CDH1

MicroRNA-25 (miR-25) has been reported to be overexpressed in numerous human tumors and plays a key role in tumor promotor. However, there are few reports about miR-25 expression and function in non-small cell lung cancer (NSCLC). In this study, we investigated the biological role of miR-25 in NSCLC and its underlying molecular mechanisms. We found that the upregulation of miR-25 was correlated with lymph node metastasis and TNM stage in 113 NSCLC patients. Moreover, the up-regulation of miR-25 was associated with poor survival of NSCLC patients and might be used as an independent prognostic factor. Moreover, forced expression of miR-25 enhanced H358 and Calu-1 cell migration and invasion, but not apoptosis and proliferation in vitro. Elevation of invasion and metastasis by miR-25 directly and significantly correlated with inactivation of CDH1 expression. Therefore, patients with up-regulated miR-25 are prone to lymph node metastasis and thus have a poor prognosis.

N6-methyladenosine induced miR-143-3p promotes the brain metastasis of lung cancer via regulation of VASH1

BACKGROUND

Brain metastasis (BM) is one of the principal causes of mortality for lung cancer patients. While the molecular events that govern BM of lung cancer remain frustrating cloudy.

METHODS

The miRNA expression profiles are checked in the paired human BM and primary lung cancer tissues. The effect of miR-143-3p on BM of lung cancer cells and its related mechanisms are investigated.

RESULTS

miR-143-3p is upregulated in the paired BM tissues as compared with that in primary cancer tissues. It can increase the invasion capability of in vitro blood brain barrier (BBB) model and angiogenesis of lung cancer by targeting the three binding sites of 3'UTR of vasohibin-1 (VASH1) to inhibit its expression. Mechanistically, VASH1 can increase the ubiquitylation of VEGFA to trigger the proteasome mediated degradation, further, it can endow the tubulin depolymerization through detyrosination to increase the cell motility. m6A methyltransferase Mettl3 can increase the splicing of precursor miR-143-3p to facilitate its biogenesis. Moreover, miR-143-3p/VASH1 axis acts as adverse prognosis factors for in vivo progression and overall survival (OS) rate of lung cancer.

CONCLUSIONS

Our work implicates a causal role of the miR-143-3p/VASH1 axis in BM of lung cancers and suggests their critical roles in lung cancer pathogenesis.

Oligosaccharyltransferase: A Gatekeeper of Health and Tumor Progression

Oligosaccharyltransferase (OST) is a multi-span membrane protein complex that catalyzes the addition of glycans to selected Asn residues within nascent polypeptides in the lumen of the endoplasmic reticulum. This process, termed N-glycosylation, is a fundamental post-translational protein modification that is involved in the quality control, trafficking of proteins, signal transduction, and cell-to-cell communication. Given these crucial roles, N-glycosylation is essential for homeostasis at the systemic and cellular levels, and a deficiency in genes that encode for OST subunits often results in the development of complex genetic disorders. A growing body of evidence has also demonstrated that the expression of OST subunits is cell context-dependent and is frequently altered in malignant cells, thus contributing to tumor cell survival and proliferation. Importantly, a recently developed inhibitor of OST has revealed this enzyme as a potential target for the treatment of incurable drug-resistant tumors. This review summarizes our current knowledge regarding the functions of OST in the light of health and tumor progression, and discusses perspectives on the clinical relevance of inhibiting OST as a tumor treatment.

miR-873-5p inhibits the progression of colon cancer via repression of tumor suppressor candidate 3/AKT signaling

BACKGROUND AND AIM

We previously discovered that tumor suppressor candidate 3 (TUSC3) was overexpressed and predicted worse prognosis in colon cancer patients. However, the mechanisms of upregulation of TUSC3 in colon cancer remained unclear.

METHODS

MiR-873-5p was predicted and identified as the regulator of TUSC3 via online programs and luciferase reporter assays. The roles of miR-873-5p in regulating colon cancer cell proliferation, colony formation, and invasion were evaluated in vitro. Animal studies were performed to investigate the effects of miR-873-5p on proliferation and lung metastasis. Moreover, the miR-873-5p/TUSC3 related signaling pathway and the prognostic value of combining miR-873-5p and TUSC3 for colon cancer patients were also explored.

RESULTS

Here, we identified miR-873-5p as a novel regulator of TUSC3 in colon cancer. Functionally, ectopic expression or silencing of miR-873-5p, respectively, inhibited or promoted colon cancer cells proliferation, colony formation, and invasion, as well as prevented or enhanced the metastasis of colon cancer cells in vitro and in vivo. Molecularly, miR-873-5p functioned as a tumor suppressor by inhibiting the TUSC3/AKT pathway. Overexpression or silencing of TUSC3 could partially reverse the effects of the overexpression or repression of miR-873-5p on colon cancer progression caused by activation of the AKT pathway. Clinically, low miR-873-5p expression predicted poor survival in colon cancer patients, especially combined with high TUSC3 expression.

CONCLUSIONS

We identified miR-873-5p as a tumor suppressor, which acts by directly repressing TUSC3 in colon cancer.

Recent advances in signal integration mechanisms in the unfolded protein response

Since its discovery more than 25 years ago, great progress has been made in our understanding of the unfolded protein response (UPR), a homeostatic mechanism that adjusts endoplasmic reticulum (ER) function to satisfy the physiological demands of the cell. However, if ER homeostasis is unattainable, the UPR switches to drive cell death to remove defective cells in an effort to protect the health of the organism. This functional dichotomy places the UPR at the crossroads of the adaptation versus apoptosis decision. Here, we focus on new developments in UPR signaling mechanisms, in the interconnectivity among the signaling pathways that make up the UPR in higher eukaryotes, and in the coordination between the UPR and other fundamental cellular processes.

The Comprehensive Roles of ATRANORIN, A Secondary Metabolite from the Antarctic Lichen Stereocaulon caespitosum, in HCC Tumorigenesis

Hepatocellular carcinoma (HCC) is one of the most deadly genetic diseases, but surprisingly chemotherapeutic approaches against HCC are only limited to a few targets. In particular, considering the difficulty of a chemotherapeutic drug development in terms of cost and time enforces searching for surrogates to minimize effort and maximize efficiency in anti-cancer therapy. In spite of the report that approximately one thousand lichen-derived metabolites have been isolated, the knowledge about their functions and consequences in cancer development is relatively limited. Moreover, one of the major second metabolites from lichens, Atranorin has never been studied in HCC. Regarding this, we comprehensively analyze the effect of Atranorin by employing representative HCC cell lines and experimental approaches. Cell proliferation and cell cycle analysis using the compound consistently show the inhibitory effects of Atranorin. Moreover, cell death determination using Annexin-V and (Propidium Iodide) PI staining suggests that it induces cell death through necrosis. Lastly, the metastatic potential of HCC cell lines is significantly inhibited by the drug. Taken these together, we claim a novel functional finding that Atranorin comprehensively suppresses HCC tumorigenesis and metastatic potential, which could provide an important basis for anti-cancer therapeutics.