LINC00470 promotes tumour proliferation and invasion, and attenuates chemosensitivity through the LINC00470/miR-134/Myc/ABCC1 axis in glioma

MiRNAs: main players of cancer drug resistance target ABC transporters

Chemotherapy remains the cornerstone of cancer treatment; however, its efficacy is frequently compromised by the development of chemoresistance. Multidrug resistance (MDR), characterized by the refractoriness of cancer cells to a wide array of chemotherapeutic agents, presents a significant barrier to achieving successful and sustained cancer remission. One critical factor contributing to this chemoresistance is the overexpression of ATP-binding cassette (ABC) transporters. Furthermore, additional mechanisms, such as the malfunctioning of apoptosis, alterations in DNA repair systems, and resistance mechanisms inherent to cancer stem cells, exacerbate the issue. Intriguingly, microRNAs (miRNAs) have demonstrated potential in modulating chemoresistance by specifically targeting ABC transporters, thereby offering promising new avenues for overcoming drug resistance. This narrative review aims to elucidate the molecular underpinnings of drug resistance, with a particular focus on the roles of ABC transporters and the regulatory influence of miRNAs on these transporters.

Macrophage-derived lncRNAs in cancer: regulators of tumor progression and therapeutic targets

Macrophages are key tumor microenvironment (TME) regulators, exhibiting remarkable plasticity that enables them to either suppress or promote cancer progression. Emerging evidence highlights the critical role of macrophage-derived long non-coding RNAs (lncRNAs) in shaping tumor immunity, influencing macrophage polarization, immune evasion, angiogenesis, metastasis, and therapy resistance. This review comprehensively elucidates the functional roles of M1- and M2-associated lncRNAs, detailing their molecular mechanisms and impact on cancer pathogenesis. In summary, elucidating the roles of lncRNAs derived from macrophages in cancer progression offers new avenues for therapeutic strategies, significantly improving patient outcomes in the fight against the disease. Further research into the functional significance of these lncRNAs and the development of targeted therapies is essential to harness their potential fully in clinical applications. We further explore their potential as biomarkers for cancer prognosis and therapeutic targets for modulating macrophage activity to enhance anti-cancer immunity. Targeting macrophage-derived lncRNAs represents a promising avenue for precision oncology, offering novel strategies to reshape the TME and improve cancer treatment outcomes.

Role of Non-coding RNAs in the Response of Glioblastoma to Temozolomide

Chemotherapy and radiotherapy are widely used in clinical practice across the globe as cancer treatments. Intrinsic or acquired chemoresistance poses a significant problem for medical practitioners and researchers, causing tumor recurrence and metastasis. The most dangerous kind of malignant brain tumor is called glioblastoma multiforme (GBM) that often recurs following surgery. The most often used medication for treating GBM is temozolomide chemotherapy; however, most patients eventually become resistant. Researchers are studying preclinical models that accurately reflect human disease and can be used to speed up drug development to overcome chemoresistance in GBM. Non-coding RNAs (ncRNAs) have been shown to be substantial in regulating tumor development and facilitating treatment resistance in several cancers, such as GBM. In this work, we mentioned the mechanisms of how different ncRNAs (microRNAs, long non-coding RNAs, circular RNAs) can regulate temozolomide chemosensitivity in GBM. We also address the role of these ncRNAs encapsulated inside secreted exosomes.

Adaptive Significance of Non-coding RNAs: Insights from Cancer Biology

The molecular basis of adaptive evolution and cancer progression are both complex processes that share many striking similarities. The potential adaptive significance of environmentally-induced epigenetic changes is currently an area of great interest in both evolutionary and cancer biology. In the field of cancer biology intense effort has been focused on the contribution of stress-induced non-coding RNAs (ncRNAs) in the activation of epigenetic changes associated with elevated mutation rates and the acquisition of environmentally adaptive traits. Examples of this process are presented and combined with more recent findings demonstrating that stress-induced ncRNAs are transferable from somatic to germline cells leading to cross-generational inheritance of acquired adaptive traits. The fact that ncRNAs have been implicated in the transient adaptive response of various plants and animals to environmental stress is consistent with findings in cancer biology. Based on these collective observations, a general model as well as specific and testable hypotheses are proposed on how transient ncRNA-mediated adaptive responses may facilitate the transition to long-term biological adaptation in both cancer and evolution.

LINC00470 promotes malignant progression of testicular germ cell tumors

BACKGROUND

Testicular germ cell tumor (TGCT) is a common malignant tumor in adolescents. Now, many long non-coding RNAs (LncRNAs) have been found to have an important function in TGCT. LINC00470 is specifically and highly expressed in TGCT, however, there is still no definite information concerning its role and underlying mechanism in TGCT. The purpose of this research was to look into the involvement of LINC00470 in TGCT and its intrinsic mechanism.

METHODS AND RESULTS

UCSC and GEPIA2 databases were used to analyze the expression of LINC00470, and the BEST website was used to perform GSEA enrichment analysis, immune infiltration analysis, and drug susceptibility analysis. SiRNA transfection was used to silence LINC00470 in TCAM-2 and NCCIT cells. Clone formation and Transwell assays were performed in TGCT cells to confirm the effects of LINC00470 on clone formation, migration, and invasion. Western Blot was performed to determine the expression of proteins related to the EMT and AKT signaling pathways. LINC00470 was specifically highly expressed in TGCT, and played a role in promoting tumor cell clone formation and cell metastasis by affecting the TGF-β and PI3K-AKT-mTOR signaling pathways to regulate the epithelial-mesenchymal transition (EMT) process; LINC00470 may also play a pro-tumor role by negatively regulating immune infiltration; in addition, the expression of LINC00470 was negatively correlated with the chemosensitivity of cisplatin in TGCT patients.

CONCLUSIONS

LINC00470 may play a significant role in the etiology and metastasis of TGCT through EMT and AKT-mediated signaling pathways.

Principles in the Management of Glioblastoma

Glioblastoma, the most aggressive and common malignant primary brain tumour, is characterized by infiltrative growth, abundant vascularization, and aggressive clinical evolution. Patients with glioblastoma often face poor prognoses, with a median survival of approximately 15 months. Technological progress and the subsequent improvement in understanding the pathophysiology of these tumours have not translated into significant achievements in therapies or survival outcomes for patients. Progress in molecular profiling has yielded new omics data for a more refined classification of glioblastoma. Several typical genetic and epigenetic alterations in glioblastoma include mutations in genes regulating receptor tyrosine kinase (RTK)/rat sarcoma (RAS)/phosphoinositide 3-kinase (PI3K), p53, and retinoblastoma protein (RB) signalling, as well as mutation of isocitrate dehydrogenase (IDH), methylation of O6-methylguanine-DNA methyltransferase (MGMT), amplification of epidermal growth factor receptor vIII, and codeletion of 1p/19q. Certain microRNAs, such as miR-10b and miR-21, have also been identified as prognostic biomarkers. Effective treatment options for glioblastoma are limited. Surgery, radiotherapy, and alkylating agent chemotherapy remain the primary pillars of treatment. Only promoter methylation of the gene MGMT predicts the benefit from alkylating chemotherapy with temozolomide and it guides the choice of first-line treatment in elderly patients. Several targeted strategies based on tumour-intrinsic dominant signalling pathways and antigenic tumour profiles are under investigation in clinical trials. This review explores the potential genetic and epigenetic biomarkers that could be deployed as analytical tools in the diagnosis and prognostication of glioblastoma. Recent clinical advancements in treating glioblastoma are also discussed, along with the potential of liquid biopsies to advance personalized medicine in the field of glioblastoma, highlighting the challenges and promises for the future.

Pan-cancer analysis of ABCC1 as a potential prognostic and immunological biomarker

ABCC1 belongs to the ATP-binding cassette (ABC) superfamily, which encompasses a total of 48 constituent members. ABCC1 has been shown to be associated with the growth, progression, and drug resistance of various types of cancer. However, the impact of ABCC1 on cancer immune infiltration and pan-cancer prognosis has been rarely studied. Our comprehensive pan-cancer analysis unveiled elevated ABCC1 expression across various cancers. ABCC1 overexpression consistently predicted unfavorable outcomes based on TCGA data. Moreover, ABCC1 expression exhibited intricate associations with diverse immune-related genes and demonstrated a close correlation with immune scores across multiple tumor types. Analysis of scRNA-seq data from the GEO database revealed that the expression of ABCC1 in hepatocellular carcinoma (HCC) cells is significant positively correlated with macrophage infiltration. Furthermore, various in vitro and in vivo experiments substantiated the role of ABCC1 in promoting the progression of HCC, along with increased macrophage recruitment. Based on the results, we propose ABCC1 as a potentially valuable prognostic indicator and a prospective target for immune-based cancer therapies.

Utilizing non-coding RNA-mediated regulation of ATP binding cassette (ABC) transporters to overcome multidrug resistance to cancer chemotherapy

Multidrug resistance (MDR) is one of the primary factors that produces treatment failure in patients receiving cancer chemotherapy. MDR is a complex multifactorial phenomenon, characterized by a decrease or abrogation of the efficacy of a wide spectrum of anticancer drugs that are structurally and mechanistically distinct. The overexpression of the ATP-binding cassette (ABC) transporters, notably ABCG2 and ABCB1, are one of the primary mediators of MDR in cancer cells, which promotes the efflux of certain chemotherapeutic drugs from cancer cells, thereby decreasing or abolishing their therapeutic efficacy. A number of studies have suggested that non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), play a pivotal role in mediating the upregulation of ABC transporters in certain MDR cancer cells. This review will provide updated information about the induction of ABC transporters due to the aberrant regulation of ncRNAs in cancer cells. We will also discuss the measurement and biological profile of circulating ncRNAs in various body fluids as potential biomarkers for predicting the response of cancer patients to chemotherapy. Sequence variations, such as alternative polyadenylation of mRNA and single nucleotide polymorphism (SNPs) at miRNA target sites, which may indicate the interaction of miRNA-mediated gene regulation with genetic variations to modulate the MDR phenotype, will be reviewed. Finally, we will highlight novel strategies that could be used to modulate ncRNAs and circumvent ABC transporter-mediated MDR.

Emerging roles of ncRNAs regulating ABCC1 on chemotherapy resistance of cancer - a review

In the process of chemotherapy, drug resistance of cancer cells is a common and difficult problem of chemotherapy failure, and it is also the main cause of cancer recurrence and metastasis. Non-coding RNAs (ncRNAs) refer to the RNA that does not encode proteins, including microRNA (miRNA), long non-coding RNA (lncRNA) and circularRNA (circRNA), etc. NcRNAs are involved in a series of important life processes and further regulate the expression of ABCC1 by directly or indirectly up-regulating or down-regulating the expression of targeted mRNAs, making cancer cells more susceptible to drug resistance. A growing number of studies have shown that ncRNAs have effects on cancer cell proliferation, invasion, metastasis, and drug sensitivity, by regulating the expression of ABCC1. In this review, we will discuss the emerging roles of ncRNAs regulating ABCC1 in chemotherapy resistance and mechanisms to reverse drug resistance as well as provide potential targets for future cancer treatment.

Exploring the relationship between metabolism and immune microenvironment in osteosarcoma based on metabolic pathways

BACKGROUND

Metabolic remodeling and changes in tumor immune microenvironment (TIME) in osteosarcoma are important factors affecting prognosis and treatment. However, the relationship between metabolism and TIME needs to be further explored.

METHODS

RNA-Seq data and clinical information of 84 patients with osteosarcoma from the TARGET database and an independent cohort from the GEO database were included in this study. The activity of seven metabolic super-pathways and immune infiltration levels were inferred in osteosarcoma patients. Metabolism-related genes (MRGs) were identified and different metabolic clusters and MRG-related gene clusters were identified using unsupervised clustering. Then the TIME differences between the different clusters were compared. In addition, an MRGs-based risk model was constructed and the role of a key risk gene, ST3GAL4, in osteosarcoma cells was explored using molecular biological experiments.

RESULTS

This study revealed four key metabolic pathways in osteosarcoma, with vitamin and cofactor metabolism being the most relevant to prognosis and to TIME. Two metabolic pathway-related clusters (C1 and C2) were identified, with some differences in immune activating cell infiltration between the two clusters, and C2 was more likely to respond to two chemotherapeutic agents than C1. Three MRG-related gene clusters (GC1-3) were also identified, with significant differences in prognosis among the three clusters. GC2 and GC3 had higher immune cell infiltration than GC1. GC3 is most likely to respond to immune checkpoint blockade and to three commonly used clinical drugs. A metabolism-related risk model was developed and validated. The risk model has strong prognostic predictive power and the low-risk group has a higher level of immune infiltration than the high-risk group. Knockdown of ST3GAL4 significantly inhibited proliferation, migration, invasion and glycolysis of osteosarcoma cells and inhibited the M2 polarization of macrophages.

CONCLUSION

The metabolism of vitamins and cofactors is an important prognostic regulator of TIME in osteosarcoma, MRG-related gene clusters can well reflect changes in osteosarcoma TIME and predict chemotherapy and immunotherapy response. The metabolism-related risk model may serve as a useful prognostic predictor. ST3GAL4 plays a critical role in the progression, glycolysis, and TIME of osteosarcoma cells.

Aberrantly Expressed lncRNA LINC00847 May Serve as a Promising Prognostic Factor for Thyroid Cancer

Thyroid cancer is a tumor that occurs in the head and neck, which originates from the thyroid follicular epithelial cells. The current research is discussed and elaborated from the perspective of molecular prognostic biomarkers to gain a deeper understanding of the molecular mechanism of thyroid cancer and to provide more effective treatment and prognostic methods for patients. Thyroid cancer patients were explored from histological, cellular and clinical levels. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of LINC00847 and miR-146b-5p in the tissues and cells of the subjects. Cell growth and thyroid cancer progression were determined by the cell counting kit-8 (CCK-8) and transwell assays. The LINC00847 sponge miR-146b-5p was assessed by bioinformatics tools and luciferase reporter assay, and the Kaplan-Meier method and multivariate Cox regression analysis suggested the prognostic value of high expression of LINC00847. In thyroid cancer tissues and cells, the expression of LINC00847 was decreased. Overexpression of LINC00847 remarkably inhibited the proliferation level, migration ability and invasion ability of thyroid cancer cells. Besides, miR-146b-5p was upregulated in thyroid cancer tissues and cells. It was confirmed that LINC00847 targeting miR-146b-5p had a regulatory effect on the progression of thyroid cancer, and LINC00847 was negatively correlated with miR-146b-5p. LINC00847 may be considered a meaningful prognostic marker to influence tumor growth through sponge miR-146b-5p, which provides a new basis for the prognosis and treatment of thyroid cancer.

Exosomal non-coding RNAs in glioma progression: insights into tumor microenvironment dynamics and therapeutic implications

Gliomas are the most common and deadly types of brain tumors, known for their extensive genetic and epigenetic variability, which poses considerable challenges for pharmacological treatment. Glioma heterogeneity is also related to their intricate and dynamic tumor microenvironment (TME), which comprises a diverse array of cell types, including immune cells, vascular cells, glial cells, and neural precursors, collectively influencing tumor behavior and progression. A pivotal aspect of this intercellular communication relies on the exchange of extracellular vesicles (EVs), which contain and transfer complex molecular cargoes typical of their cells of origin, such as proteins, lipids, carbohydrates, metabolites, and non-coding RNAs (ncRNAs), that encompass microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Glioma cells actively release EVs loaded with specific ncRNAs that can target genes and other ncRNAs in recipient cells residing within the TME. Among these recipient cells, prominent players include tumor-associated macrophages and microglia (TAMs), non-neoplastic astrocytes and endothelial cells. The intricate interplay between EVs derived from glioma cells and these recipient cells significantly contributes to the establishment of a tumor-permissive microenvironment, promoting tumor cell proliferation, migration, angiogenesis, and invasion, by targeting various downstream pathways. This review critically examines the current understanding of the intricate interplay between glioma, exosomal ncRNAs, and various components of the glioma TME. By shedding light on the roles of ncRNAs in mediating intercellular communication, this review underscores their significance in orchestrating TME transformation and highlights their potential as novel therapeutic targets for effectively tackling glioma progression.

Epigenetic regulation of temozolomide resistance in human cancers with an emphasis on brain tumors: Function of non-coding RNAs

Brain tumors, which are highly malignant, pose a significant threat to health and often result in substantial rates of mortality and morbidity worldwide. The brain cancer therapy has been challenging due to obstacles such as the BBB, which hinders effective delivery of therapeutic agents. Additionally, the emergence of drug resistance further complicates the management of brain tumors. TMZ is utilized in brain cancer removal, but resistance is a drawback. ncRNAs are implicated in various diseases, and their involvement in the cancer is particularly noteworthy. The focus of the current manuscript is to explore the involvement of ncRNAs in controlling drug resistance, specifically in the context of resistance to the chemotherapy drug TMZ. The review emphasizes the function of ncRNAs, particularly miRNAs, in modulating the growth and invasion of brain tumors, which significantly influences their response to TMZ treatment. Through their interactions with various molecular pathways, miRNAs are modulators of TMZ response. Similarly, lncRNAs also associate with molecular pathways and miRNAs, affecting the efficacy of TMZ chemotherapy. Given their functional properties, lncRNAs can either induce or suppress TMZ resistance in brain tumors. Furthermore, circRNAs, which are cancer controllers, regulate miRNAs by acting as sponges, thereby impacting the response to TMZ chemotherapy. The review explores the correlation between ncRNAs and TMZ chemotherapy, shedding light on the underlying molecular pathways involved in this process.

Temozolomide protects against the progression of glioblastoma via SOX4 downregulation by inhibiting the LINC00470-mediated transcription factor EGR2

OBJECTIVE

Temozolomide is extensively applied in chemotherapy for glioblastoma with unclear exact action mechanisms. This article seeks to address the potential molecular mechanisms in temozolomide therapy for glioblastoma involving LINC00470.

METHODS

Bioinformatics analysis was conducted to predict the potential mechanism of LINC00470 in glioblastoma, which was validated by dual-luciferase reporter, RIP, ChIP, and RNA pull-down assays. LINC00470 expression and the predicted downstream transcription factor early growth response 2 (EGR2) were detected in the collected brain tissues from glioblastoma patients. Following temozolomide treatment and/or gain- and loss-of-function approaches in glioblastoma cells, cell viability, invasion, migration, cycle distribution, angiogenesis, autophagy, and apoptosis were measured. In addition, the expression of mesenchymal surface marker proteins was assessed by western blot. Tumor xenograft in nude mice was conducted for in vivo validation.

RESULTS

Mechanistic analysis and bioinformatics analysis revealed that LINC00470 transcriptionally activated SRY-related high-mobility-group box 4 (SOX4) through the transcription factor EGR2. LINC00470 and EGR2 were highly expressed in brain tissues of glioblastoma patients. LINC00470 and EGR2 mRNA expression gradually decreased with increasing concentrations of temozolomide in glioblastoma cells, and SOX4 expression was reduced in cells by temozolomide and LINC00470 knockdown. Temozolomide treatment induced cell cycle arrest, diminished cell viability, migration, invasion, and angiogenesis, and increased apoptosis and autophagy in glioblastoma, which was counteracted by overexpressing LINC00470 or SOX4 but was further promoted by LINC00470 knockdown. Temozolomide restrained glioblastoma growth and angiogenesis in vivo, while LINC00470 or SOX4 overexpression nullified but LINC00470 knockdown further facilitated these trends.

CONCLUSION

Conclusively, temozolomide repressed glioblastoma progression by repressing the LINC00470/EGR2/SOX4 axis.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

Pan-cancer analyses reveal molecular and clinical characteristics of cuproptosis regulators

Imbalance in copper homeostasis can be lethal. A recent study found that excess copper induces cell death in a way that has never been characterized before, which is dependent on mitochondrial stress and is referred to as "cuproptosis." The role of cuproptosis in tumors has not yet been elucidated. In this study, we revealed the complex and important roles of cuproptosis regulators and cuproptosis activity in tumors via a comprehensive analysis of multiomics data from more than 10,000 samples of 33 tumor types. We found that the cyclin-dependent kinase inhibitor 2A is the most frequently altered cuproptosis regulator, and the cuproptosis regulator expression is dysregulated in various tumors. Additionally, we developed a cuproptosis activity score to reflect the overall cuproptosis level. On the basis of the expression levels of cuproptosis regulators, tumors can be divided into two clusters with different cuproptosis activities and survival outcomes. Importantly, cuproptosis activity was found to be associated with the prognosis of multiple tumors and multiple tumor-related pathways, including fatty acid metabolism and remodeling of the tumor microenvironment. Furthermore, cuproptosis increased the sensitivity to multiple drugs and exhibited potential to predict the outcome of immunotherapy. We also comprehensively identified cuproptosis-related microRNAs, long noncoding RNAs, and transcription factors. We provided the code corresponding to the results of this study in GitHub (https://github.com/Changwuuu/Cuproptosis-pancancer.git) for reference. In summary, this study reveals important molecular and clinical characteristics of cuproptosis regulators and cuproptosis activity in tumors, and suggests the use of cuproptosis as a promising tumor therapeutic approach. This study provides an important reference point for future cuproptosis-related research.

Preliminary Study of Genome-Wide Association Identified Novel Susceptibility Genes for Hemorheological Indexes in a Chinese Population

Background

Genome-wide association studies for various hemorheological characteristics have not been reported. We aimed to identify genetic loci associated with hemorheological indexes in a cohort of healthy Chinese Han individuals.

Methods

Genotyping was performed using Applied Biosystems Axiom™ Precision Medicine Diversity Array in 838 individuals, and 6,423,076 single nucleotide polymorphisms were available for genotyping. The relations were examined in an additive genetic model using mixed linear regression and combined with identical by descent matrix.

Results

We identified 38 genetic loci (p < 5 × 10^-6) related to hemorheological traits. In which, LOC102724502-OLIG2 rs28371438 was related to the levels of nd30 (p = 8.58 × 10^-07), nd300 (p = 1.89 × 10^-06), erythrocyte rigidity (p = 1.29 × 10^-06), assigned viscosity (p = 6.20 × 10^-08) and whole blood high cut relative (p = 7.30 × 10^-08). The association of STK32B rs4689231 for nd30 (p = 3.85 × 10^-06) and nd300 (p = 2.94 × 10^-06) and GTSCR1-LINC01541 rs11661911 for erythrocyte rigidity (p = 9.93 × 10^-09) and whole blood high cut relative (p = 2.09 × 10^-07) was found. USP25-MIR99AHG rs1297329 was associated with erythrocyte rigidity (p = 1.81 × 10^-06) and erythrocyte deformation (p = 1.14 × 10^-06). Moreover, the association of TMEM232-SLC25A46 rs3985087 and LINC00470-METTL4 rs9966987 for fibrinogen (p = 1.31 × 10^-06 and p = 4.29 × 10^-07) and plasma viscosity (p = 1.01 × 10^-06 and p = 4.59 × 10^-07) was found.

Conclusion

These findings may represent biological candidates for hemorheological indexes and contribute to hemorheological study.

NcRNAs: Multi‑angle participation in the regulation of glioma chemotherapy resistance (Review)

As the most common primary tumour of the central nervous system, gliomas have a high recurrence rate after surgical resection and are resistant to chemotherapy, particularly high‑grade gliomas dominated by glioblastoma multiforme (GBM). The prognosis of GBM remains poor despite improvements in treatment modalities, posing a serious threat to human health. At present, although drugs such as temozolomide, cisplatin and bevacizumab, are effective in improving the overall survival of patients with GBM, most patients eventually develop drug resistance, leading to poor clinical prognosis. The development of multidrug resistance has therefore become a major obstacle to improving the effectiveness of chemotherapy for GBM. The ability to fully understand the underlying mechanisms of chemotherapy resistance and to develop novel therapeutic targets to overcome resistance is critical to improving the prognosis of patients with GBM. Of note, growing evidence indicates that a large number of abnormally expressed noncoding RNAs (ncRNAs) have a central role in glioma chemoresistance and may target various mechanisms to modulate chemosensitivity. In the present review, the roles and molecular mechanisms of ncRNAs in glioma drug resistance were systematically summarized, the potential of ncRNAs as drug resistance markers and novel therapeutic targets of glioma were discussed and prospects for glioma treatment were outlined. ncRNAs are a research direction for tumor drug resistance mechanisms and targeted therapies, which not only provides novel perspectives for reversing glioma drug resistance but may also promote the development of precision medicine for clinical diagnosis and treatment.

Identification and validation of an eight-lncRNA signature that predicts prognosis in patients with esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is correlated with worse clinical prognosis and lacks available targeted therapy. Thus, identification of reliable biomarkers is required for the diagnosis and treatment of ESCC.

Methods

We downloaded the GSE53625 dataset as a training dataset to screen differentially expressed RNAs (DERs) with the criterion of false discovery rate (FDR) < 0.05 and |log₂fold change (FC)| > 1. A support vector machine classifier was used to find the optimal feature gene set that could conclusively distinguish different samples. An eight-lncRNA signature was identified by random survival forest algorithm and multivariate Cox regression analysis. The RNA sequencing data from The Cancer Genome Atlas (TCGA) database were used for external validation. The predictive value of the signature was assessed using Kaplan–Meier test, time-dependent receiver operating characteristic (ROC) curves, and dynamic area under the curve (AUC). Furthermore, a nomogram to predict patients’ 3-year and 5-year prognosis was constructed. CCK-8 assay, flow cytometry, and transwell assay were conducted in ESCC cells.

Results

A total of 1136 DERs, including 689 downregulated mRNAs, 318 upregulated mRNAs, 74 downregulated lncRNAs and 55 upregulated lncRNAs, were obtained in the GES53625 dataset. From the training dataset, we identified an eight-lncRNA signature, (ADAMTS9-AS1, DLX6-AS1, LINC00470, LINC00520, LINC01497, LINC01749, MAMDC2-AS1, and SSTR5-AS1). A nomogram based on the eight-lncRNA signature, age, and pathologic stage was developed and showed good accuracy for predicting 3-year and 5-year survival probability of patients with ESCC. Functionally, knockdown of LINC00470 significantly suppressed cell proliferation, G1/S transition, and migration in two ESCC cell lines (EC9706 and TE-9). Moreover, knockdown of LINC00470 downregulated the protein levels of PCNA, CDK4, and N-cadherin, while upregulating E-cadherin protein level in EC9706 and TE-9 cells.

Conclusion

Our eight-lncRNA signature and nomogram can provide theoretical guidance for further research on the molecular mechanism of ESCC and the screening of molecular markers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-022-00331-x.

Targeting multidrug resistance-associated protein 1 (MRP1)-expressing cancers: Beyond pharmacological inhibition

Resistance to chemotherapy remains one of the most significant obstacles to successful cancer treatment. While inhibiting drug efflux mediated by ATP-binding cassette (ABC) transporters is a seemingly attractive and logical approach to combat multidrug resistance (MDR), small molecule inhibition of ABC transporters has so far failed to confer clinical benefit, despite considerable efforts by medicinal chemists, biologists, and clinicians. The long-sought treatment to eradicate cancers displaying ABC transporter overexpression may therefore lie within alternative targeting strategies. When aberrantly expressed, the ABC transporter multidrug resistance-associated protein 1 (MRP1, ABCC1) confers MDR, but can also shift cellular redox balance, leaving the cell vulnerable to select agents. Here, we explore the physiological roles of MRP1, the rational for targeting this transporter in cancer, the development of small molecule MRP1 inhibitors, and the most recent developments in alternative therapeutic approaches for targeting cancers with MRP1 overexpression. We discuss approaches that extend beyond simple MRP1 inhibition by exploiting the collateral sensitivity to glutathione depletion and ferroptosis, the rationale for targeting the shared transcriptional regulators of both MRP1 and glutathione biosynthesis, advances in gene silencing, and new molecules that modulate transporter activity to the detriment of the cancer cell. These strategies illustrate promising new approaches to address multidrug resistant disease that extend beyond the simple reversal of MDR and offer exciting routes for further research.

Prognostic and Predictive Biomarkers in Gliomas

Gliomas are the most common central nervous system tumors. New technologies, including genetic research and advanced statistical methods, revolutionize the therapeutic approach to the patient and reveal new points of treatment options. Moreover, the 2021 World Health Organization Classification of Tumors of the Central Nervous System has fundamentally changed the classification of gliomas and incorporated many molecular biomarkers. Given the rapid progress in neuro-oncology, here we compile the latest research on prognostic and predictive biomarkers in gliomas. In adult patients, IDH mutations are positive prognostic markers and have the greatest prognostic significance. However, CDKN2A deletion, in IDH-mutant astrocytomas, is a marker of the highest malignancy grade. Moreover, the presence of TERT promoter mutations, EGFR alterations, or a combination of chromosome 7 gain and 10 loss upgrade IDH-wildtype astrocytoma to glioblastoma. In pediatric patients, H3F3A alterations are the most important markers which predict the worse outcome. MGMT promoter methylation has the greatest clinical significance in predicting responses to temozolomide (TMZ). Conversely, mismatch repair defects cause hypermutation phenotype predicting poor response to TMZ. Finally, we discussed liquid biopsies, which are promising diagnostic, prognostic, and predictive techniques, but further work is needed to implement these novel technologies in clinical practice.

MicroRNA-361-5p slows down gliomas development through regulating UBR5 to elevate ATMIN protein expression

MicroRNA (miR)-361-5p has been studied to suppress gliomas development. Based on that, an insight into the regulatory mechanism of miR-361-5p in gliomas was supplemented from ubiquitin protein ligase E3 component N-recognin 5 (UBR5)-mediated ubiquitination of ataxia-telangiectasia mutated interactor (ATMIN). miR-361-5p, ATMIN, and UBR5 levels were clinically analyzed in gliomas tissues, which were further validated in gliomas cell lines. Loss/gain-of-function method was applied to determine the roles of miR-361-5p and UBR5 in gliomas, as to cell viability, migration, invasion, colony formation ability, and apoptosis in vitro and tumorigenesis in vivo. The relationship between miR-361-5p and UBR5 was verified and the interaction between UBR5 and ATMIN was explored. It was detected that reduced miR-361-5p and ATMIN and enhanced UBR5 levels showed in gliomas. Elevating miR-361-5p was repressive in gliomas progression. UBR5 was directly targeted by miR-361-5p. UBR5 can ubiquitinate ATMIN. miR-361-5p suppressed gliomas by regulating UBR5-mediated ubiquitination of ATMIN. Downregulating UBR5 impeded gliomas tumor growth in vivo. Upregulating miR-361-5p targets UBR5 to promote ATMIN protein expression, thus to recline the malignant phenotype of gliomas cells.

The Roles Played by Long Non-Coding RNAs in Glioma Resistance

Glioma originates in the central nervous system and is classified based on both histological features and molecular genetic characteristics. Long non-coding RNAs (lncRNAs) are longer than 200 nucleotides and are known to regulate tumorigenesis and tumor progression, and even confer therapeutic resistance to glioma cells. Since oncogenic lncRNAs have been frequently upregulated to promote cell proliferation, migration, and invasion in glioma cells, while tumor-suppressive lncRNAs responsible for the inhibition of apoptosis and decrease in therapeutic sensitivity in glioma cells have been generally downregulated, the dysregulation of lncRNAs affects many features of glioma patients, and the expression profiles associated with these lncRNAs are needed to diagnose the disease stage and to determine suitable therapeutic strategies. Accumulating studies show that the orchestrations of oncogenic lncRNAs and tumor-suppressive lncRNAs in glioma cells result in signaling pathways that influence the pathogenesis and progression of glioma. Furthermore, several lncRNAs are related to the regulation of therapeutic sensitivity in existing anticancer therapies, including radiotherapy, chemotherapy and immunotherapy. Consequently, we undertook this review to improve the understanding of signaling pathways influenced by lncRNAs in glioma and how lncRNAs affect therapeutic resistance.

Expression profile of serum-related exosomal miRNAs from parathyroid tumor

OBJECTIVE

The expression pattern of exosomal miRNAs derived from parathyroid tumor is still unknown. In the present work, we aimed to examine the differences on microRNA (miRNA) expression, present in serum exosomes, by comparing parathyroid carcinoma (PC) and parathyroid adenoma (PA).

METHODS

MiRNA expression profile of serum exosomes, derived from 4 PC patients and 4 PA patients, were analyzed by next-generation sequencing technology. The differential expressions of target miRNAs were further verified in both serum exosomes and tissues of PC/PA patients by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Lastly, receiver operating characteristic (ROC) curves were plotted to investigate the efficiency of target exosomal miRNAs in distinguishing PC patients from PA controls.

RESULTS

Multiple differentially expressed miRNAs of serum exosomes were screened out by sequencing. Based on this screening, hsa-miR-146b-5p (p = 0.0846), hsa-miR-27a-5p (p = 0.0412), hsa-miR-93-5p (p = 0.73), hsa-miR-381-3p (p = 0.1239) and hsa-miR-134-5p (p = 0.0694) were upregulated in the serum exosomes of PC patients. These results were validated by qPCR, where the trend on differential miRNA expression was consistent with the sequencing results. Specifically, the expression of exosomal hsa-miR-27a-5p was able to clearly distinguish PC patients from PA controls, and related analysis indicated that the area under the ROC curve was 0.8594 (p = 0.0157).

CONCLUSIONS

Here we present, for the first time, the miRNA expression profile of serum exosomes derived from PC patients. Based on this result, we presently suggest that the exosomal hsa-miR-27a-5p may serve as a putative tumor marker for preoperative identification of PC and PA subjects.

The role of non-coding RNAs in ABC transporters regulation and their clinical implications of multidrug resistance in cancer

INTRODUCTION

Multi-drug resistance (MDR) is a hindrance toward the successful treatment of cancers. The primary mechanism that gives rise to acquired chemoresistance is the overexpression of adenosine triphosphate-binding cassette (ABC) transporters. The dysregulation of non-coding RNAs (ncRNAs) is a widely concerned reason contributing to this phenotype.

AREAS COVERED

In this review, we describe the role of intracellular and exosomal ncRNAs including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) in ABC transporters-induced tumor MDR. Meanwhile, we will introduce the potential therapeutic strategies which reverse MDR in terms of reducing the expression of ABC transporters via targeting ncRNAs, like nucleic acid delivery with nanoparticles as well as miRNAs-targeted small molecular compounds.

EXPERT OPINION

The dysregulated ncRNAs-mediated overexpression of ABC transporters in chemo-resistant cancer is not negligible. Finding out the underlying mechanism may provide a theoretical basis for clinical therapy of cancer MDR, and the emergence of new approaches for gene therapy targeting ncRNAs to suppress ABC transporters makes reversing cancer MDR possible despite its clinical application requires further investigations. Also, the discovered ncRNAs regulating ABC transporters in chemo-resistant cancers are just a tip of the iceberg of the genetic transcripts, especially for circRNAs, which justify more concern.Abbreviations: MDR, multi-drug resistance; ABC, adenosine triphosphate-binding cassette; NcRNAs, non-coding RNAs; MiRNAs, microRNAs; LncRNAs, long non-coding RNAs; CircRNAs, circular RNAs; CeRNAs, competing endogenous RNAs; 3'UTR, 3'-untranslated regions; SLC, solute carrier; ABCB1/MDR1, ABC subfamily B member 1; ABCG2/BCRP, ABC subfamily G member 2; ABCCs/MRPs, ABC subfamily C 1 to 12; DLL1: Delta-like protein 1; DTX, docetaxel; DOX/ADM/ADR, doxorubicin/adriamycin; PTX, paclitaxel; VBL, vinblastine; VCR, vincristine; MTX, methotrexate; CDDP/DDP, cisplatin/cis-diaminedichloroplatinum; OXA/L-OHP, oxaliplatin; TMZ, temozolomide; 5-FU, 5-fluorouracil; MTA, pemetrexed; NSCLC, non-small cell lung carcinoma; HCC, hepatocellular carcinoma; CRC, colorectal carcinoma; RB, retinoblastoma; RCC, renal cell carcinoma; OS, osteosarcoma; PDAC, pancreatic ductal adenocarcinoma; TNBC, triple-negative breast cancer.

LINC00470 promotes tumour proliferation and invasion, and attenuates chemosensitivity through the LINC00470/miR-134/Myc/ABCC1 axis in glioma

Glioma is the most common primary malignant tumour in the brain; temozolomide (TMZ) is the most prevalent chemotherapeutic drug currently used to combat this cancer. We reported previously that the long intergenic non‐protein coding RNA 470 (LINC00470) is a novel prognostic biomarker for glioma and promotes the tumour growth in an intracranial transplantation mouse model. However, the effects of LINC00470 on glioma cell proliferation, invasion and TMZ chemosensitivity, as well as its molecular mechanism, remain unclear. In this study, we found elevated expression levels of LINC00470 and MYC in glioma tissues and cells and decreased expression of microRNA‐134 (miR‐134). Functional studies have shown that LINC00470 promotes proliferation and invasion, and attenuates chemosensitivity of glioma cells, while miR‐134 exerts the opposite effect. In the rescue experiments, the tumorigenic effect of LINC00470 was offset by miR‐134. In the mechanism study, we found that LINC00470 was a competitive endogenous RNA (ceRNA) of miR‐134 and that miR‐134 can directly target MYC and negatively regulate its expression. Furthermore, MYC was positively correlated with ATP‐binding cassette subfamily C member 1 (ABCC1) expression in glioma cells and MYC up‐regulated ABCC1 expression. Further studies found that LINC00470 regulated MYC by sponging miR‐134 to regulate the expression of ABCC1. We concluded that LINC00470 promoted the expression of MYC and ABCC1 by suppressing miR‐134, thus promoting glioma cell proliferation and invasion, and attenuating TMZ chemosensitivity. Moreover, the LINC00470/miR‐134/MYC/ABCC1 axis constitutes a potential therapeutic target.