Role of Long Intergenic Noncoding RNAs in Cancers with an Overview of MicroRNA Binding

A 5-lncRNA signature predicts clinical prognosis and demonstrates a different mRNA expression in adult soft tissue sarcoma

Background

Adult soft tissue sarcoma (SARC) is a highly aggressive malignancy. A growing number of long non-coding RNAs (lncRNAs) have been linked to malignancies, and many researchers consider lncRNAs potential biomarkers for prognosis. However, there is limited evidence available to determine the role of lncRNAs in the prognosis of SARC. In this study, we collected The Cancer Genome Atlas (TCGA) data to identify prognosis-related lncRNAs for SARC and explore the relationship between lncRNAs and gene expression.

Methods

TCGA datasets, which included 259 samples, served as data sources in this study. Univariable Cox regression analysis, robust analysis, and multivariable Cox regression analysis were used to construct a 5-lncRNA signature Cox regression model. Then, based on the median risk score, high- and low-risk groups were identified. The Kaplan-Meier method was applied to survival analysis in the training set, testing set, complete set, and different pathological type sets. To explore the relationship between lncRNAs and messenger RNAs (mRNAs), differentially expressed mRNAs (DEmRNAs) between the high- and low-risk groups were identified. The function of DEmRNAs was predicted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The relationships between the 5 lncRNAs and DEmRNAs were calculated using the Spearman correlation coefficient. A total of 18 DEmRNAs that showed a strong correlation with risk score (|Spearman's r|>0.6) in leiomyosarcoma (LMS) samples were identified, and a protein-protein interaction (PPI) network was built using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database.

Results

A Cox regression model was built in this study with the risk score= (-0.5698*AC018645.2) + 0.1732*LINC02454 + 0.387*ERICD + 0.6262*DSCR9 + 0.9781*AL031770.1. The study found that this 5-lncRNA signature could predict prognosis well, especially in LMS, a subtype of SARC, with P value =1.19e-06 [hazard ratio (HR) 6.134, 95% confidence interval (CI): 2.951-12.752]. Additionally, 44 DEmRNAs were observed between the high- and low-risk groups, and the expression levels of DEmRNAs in LMS samples differed from other pathology types. The PPI network analysis revealed that MYH11, MYLK, and CNN1 were the most important hub genes among the 18 DEmRNAs, all of which are essential for muscle function.

Conclusions

In this study, a predictive clinical model for SARC was successfully established, showing better prediction accuracy in patients with LMS. Importantly, we identified MYH11, MYLK, and CNN1 as potential therapeutic targets for SARC.

microRNA-875-5p-conjugated gold nanoparticles suppress breast cancer progression through the MTDH/PTEN/AKT signaling pathway

OBJECTIVE

A lack of effective delivery methods has hampered the study of therapeutics targeting miR-875-5p for breast cancer (BC).

METHODS

The miR-875-5p mimic was conjugated to AuNPs to produce AuNP-miR-875-5p. Then, the effect of AuNP-miR-875-5p on the proliferative, migratory, invasive activities, and apoptosis of BC cells was detected, as well as on tumor growth in animals. The involvement of the MTDH/PTEN/AKT pathway in miR-875-5p-mediated BC progression was identified.

RESULTS

AuNP-miR-875-5p was delivered to BC cells and hampered cell malignancy. MTDH was targeted by miR-875-5p. MTDH expression was negatively correlated with miR-875-5p expression in BC tissues. The anti-tumor effect of AuNP-miR-875-5p in BC cells was counteracted by MTDH overexpression. AuNP-miR-875-5p enhanced PTEN protein expression, thereby inhibiting AKT activation by targeting MTDH. AuNP-miR-875-5p blocked MCF-7 tumor growth in vivo.

CONCLUSION

AuNPs can deliver miR-875-5p to BC cells, and AuNP-miR-875-5p has clinical potential for treating unresectable BC.

Novel function of U7 snRNA in the repression of HERV1/LTR12s and lincRNAs in human cells

U7 snRNA is part of the U7 snRNP complex, required for the 3' end processing of replication-dependent histone pre-mRNAs in S phase of the cell cycle. Here, we show that U7 snRNA plays another function in inhibiting the expression of a subset of long terminal repeats of human endogenous retroviruses (HERV1/LTR12s) and LTR12-containing long intergenic noncoding RNAs (lincRNAs), both bearing sequence motifs that perfectly match the 5' end of U7 snRNA. We demonstrate that U7 snRNA inhibits LTR12 and lincRNA transcription and propose a mechanism in which U7 snRNA hampers the binding/activity of the NF-Y transcription factor to CCAAT motifs within LTR12 elements. Thereby, U7 snRNA plays a protective role in maintaining the silencing of deleterious genetic elements in selected types of cells.

Updated review on analysis of long non-coding RNAs as emerging diagnostic and therapeutic targets in prostate cancers

Despite advancements, prostate cancers (PCa) pose a significant global health challenge due to delayed diagnosis and therapeutic resistance. This review delves into the complex landscape of prostate cancer, with a focus on long-noncoding RNAs (lncRNAs). Also explores the influence of aberrant lncRNAs expression in progressive PCa stages, impacting traits like proliferation, invasion, metastasis and therapeutic resistance. The study elucidates how lncRNAs modulate crucial molecular effectors, including transcription factors and microRNAs, affecting signaling pathways such as androgen receptor signaling. Besides, this manuscript sheds light on novel concepts and mechanisms driving PCa progression through lncRNAs, providing a critical analysis of their impact on the disease's diverse characteristics. Besides, it discusses the potential of lncRNAs as diagnostics and therapeutic targets in PCa. Collectively, this work highlights state of art mechanistic comprehension and rigorous scientific approaches to advance our understanding of PCa and depict innovations in this evolving field of research.

MicroRNA-21's role in PTEN suppression and PI3K/AKT activation: Implications for cancer biology

MicroRNA-21 (miR-21) was recognized as a key figure in the intricate web of tumor biology, with a prominent role in regulating the PTEN tumor suppressor gene and the PI3K/AKT cascade. This review elucidates the multifaceted interactions between miR-21, PTEN, and the PI3K/AKT signaling, shedding light on their profound implications in cancer initiation, progression, and therapeutic strategies. The core of this review delves into the mechanical intricacies of miR-21-mediated PTEN suppression and its consequent impact on PI3K/AKT pathway activation. It explores how miR-21, as an oncogenic miRNA, targets PTEN directly or indirectly, resulting in uncontrolled activation of PI3K/AKT, fostering cancerous cell survival, proliferation, and evasion of apoptosis. Furthermore, the abstract emphasizes the clinical relevance of these molecular interactions, discussing their implications in various cancer types, prognostic significance, and potential as therapeutic targets. The review provides insights into ongoing research efforts to develop miR-21 inhibitors and strategies to restore PTEN function, offering new avenues for cancer treatment. This article illuminates the critical function of miR-21 in PTEN suppression and PI3K/AKT activation, offering profound insights into its implications for cancer biology and the potential for targeted interventions.

The Diagnostic and Therapeutic Role of snoRNA and lincRNA in Bladder Cancer

Bladder cancer is one of the most common malignancies of the urinary tract and can be divided into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Although the means of diagnosis and treatment have continually improved in recent years, the recurrence rate of bladder cancer remains high, and patients with MIBC typically have an unfavourable prognosis and a low quality of life. Emerging evidence demonstrates that long noncoding RNAs play a crucial role in the carcinogenesis and progression of bladder cancer. Long intergenic noncoding RNAs (lincRNAs) are a subgroup of long noncoding RNAs (lncRNAs) that do not overlap protein-coding genes. The potential role of lincRNAs in the regulation of gene expression has been explored in depth in recent years. Small nucleolar RNAs (snoRNAs) are a class of noncoding RNAs (ncRNAs) that mainly exist in the nucleolus, are approximately 60-300 nucleotides in length, and are hosted inside the introns of genes. Small nucleolar RNA host genes (SNHGs) have been associated with the origin and development of bladder cancer. In this review, we aim to comprehensively summarize the biological functions of these molecules in bladder cancer.

Long Noncoding RNAs and Cancer Stem Cells: Dangerous Liaisons Managing Cancer

Decades of research have investigated the mechanisms that lead to the origin of cancer, striving to identify tumor-initiating cells. These cells, also known as cancer stem cells, are characterized by the ability to self-renew, to give rise to differentiated tumor populations, and on a larger scale, are deemed responsible not only for tumor initiation but also for recurrent tumors, often resistant to chemotherapy and radiotherapy. Long noncoding RNAs are RNA molecules longer than 200 nt, lacking the ability to code for proteins, with recognized roles as fine regulators of gene expression. They can exert these functions through a variety of mechanisms, acting at almost all steps of gene expression, from modulation of the epigenetic state of chromatin to modulation of protein stability. In all cases, lncRNAs do not work alone, but they always interact with other RNA molecules, either coding or non-coding, or with protein factors. In this review, we summarize the latest results obtained about the involvement of lncRNAs in the initiating cells of several types of tumors, and highlight the different mechanisms through which they work, while discussing how the modulation of a lncRNA can affect several aspects of tumor onset and progression.

Long Noncoding RNAs in the Pathogenesis of Insulin Resistance

Insulin resistance (IR), designated as the blunted response of insulin target tissues to physiological level of insulin, plays crucial roles in the development and progression of diabetes, nonalcoholic fatty liver disease (NAFLD) and other diseases. So far, the distinct mechanism(s) of IR still needs further exploration. Long non-coding RNA (lncRNA) is a class of non-protein coding RNA molecules with a length greater than 200 nucleotides. LncRNAs are widely involved in many biological processes including cell differentiation, proliferation, apoptosis and metabolism. More recently, there has been increasing evidence that lncRNAs participated in the pathogenesis of IR, and the dysregulated lncRNA profile played important roles in the pathogenesis of metabolic diseases including obesity, diabetes and NAFLD. For example, the lncRNAs MEG3, H19, MALAT1, GAS5, lncSHGL and several other lncRNAs have been shown to regulate insulin signaling and glucose/lipid metabolism in various tissues. In this review, we briefly introduced the general features of lncRNA and the methods for lncRNA research, and then summarized and discussed the recent advances on the roles and mechanisms of lncRNAs in IR, particularly focused on liver, skeletal muscle and adipose tissues.