SNHG16 is regulated by the Wnt pathway in colorectal cancer and affects genes involved in lipid metabolism

Deciphering ETS2: An indispensable conduit to cancer

E26 Transformation-Specific homolog 2 (ETS2) is a founding member of the ETS family of transcription factors and has been implicated in several developmental and survival functions. The predominant route of its action is by directly binding and regulating the promoters of its target genes, although it can function through other regulatory mechanisms as well. In this review, a comprehensive understanding of the contribution of ETS2 in health and disease is described with specific focus on cancer. ETS2 demonstrates extreme complexity as it can act as a double-edged sword in cancer with tumour suppressive or oncogenic functions in a context specific manner. Here, we delineate the different signalling pathways, post-translational modifications, miRNA regulations and protein-protein interactions that illustrate the role of ETS2 as an emerging biomarker with special emphasis on its contribution to 'hallmarks of cancer'. Given the evidently opposing effects of ETS2 in different cancers, elucidating the critical mechanisms in its development and progression can validate ETS2's potential as a novel therapeutic target. Finally, we provide insights into frontier areas of research focus that implicate ETS2 and can translate into clinical outcomes.

Intestinal IncRNAs and circRNAs Regulated by Dietary-Lipid Stimuli

A diet rich in lipids can lead to many deleterious conditions, which involve many regulatory molecules, such as non-coding (nc)RNAs. We aimed to analyze the effects of high dietary lipid exposure on the expression of intestinal ncRNAs (long non-coding [lncRNAs] and circular [circRNAs]). lncRNAs and circRNAs were screened, both in vivo (mice) and in vitro (human intestinal organoids). In vivo, 15 lncRNAs (9 up- and 6 downregulated) and 41 circRNAs (13 up- and 28 downregulated) were modulated 3 h after a lipid challenge, while the expression of 11 lncRNAs (4 up- and 7 downregulated) was altered after 4 days of daily high-fat diet intake. In vitro, 251 up- and 387 downregulated lncRNAs, along with 19 up- and 16 downregulated circRNAs, were found 3 h after the exposure to a dietary-lipid stimulus, whereas 111 up- and 86 downregulated lncRNAs were found 24 h after exposure. Concord between the differently expressed ncRNAs found in both studies was scarce. Numerous differentially expressed lncRNAs and circRNAs have been found in response to dietary lipids both in mice and humans organoids. A potential association between many of these ncRNAs and lipid metabolism is suggested, but ncRNAs found differ greatly between humans and mice.

MYOSLID: A Critical Modulator of Cancer Hallmarks

Despite being the leading cause of death worldwide, cancer still lacks precise biomarkers for effective targeting, limiting efforts to reduce mortality rates. This review explores the role and clinical significance of a newly identified long non-coding RNA, MYOSLID, in cancer progression. MYOSLID has emerged as a critical modulator in cancer progression by influencing key hallmarks such as proliferation, immune evasion, metastasis, and metabolic reprogramming. It promotes tumor cell growth by stabilizing hypoxia-inducible factor 1 and acting as a competing endogenous RNA (ceRNA) to sequester tumor-suppressive microRNAs like miR-29c-3p, thereby enhancing oncogene expression. It facilitates immune evasion by upregulating PD-L1, suppressing T cell activation, and modulating necroptosis pathways involving RIPK1 and RIPK3. Additionally, MYOSLID drives metastasis by regulating epithelial-mesenchymal transition markers such as LAMB3 and Slug while promoting RAB13-mediated cytoskeletal remodeling and enhancing cancer cell invasion. We have obtained the expression of MYOSLID from TCGA and the ENCORI database. The expression of colorectal adenocarcinoma (COAD) and head and neck squamous cell carcinoma (HNSCC) is associated with poor prognosis and lower survival rate. Given its significant potential as a diagnostic biomarker and therapeutic target, further research is required to elucidate its precise molecular mechanisms and therapeutic applications in cancer treatment.

LncRNA SNHG16 Drives PD-L1-Mediated Immune Escape in Colorectal Cancer through Regulating miR-324-3p/ELK4 Signaling

Colorectal cancer (CRC) is a common malignancy that claims the life of many patients. Nucleolar RNA host gene 16 (SNHG16) has been identified as an oncogene in CRC development. However, the role and mechanism of SNHG16 in CRC remain unclear. A total of 27 cases of CRC tumor tissues and adjacent tissues were collected to investigate the expression and correlation among SNHG16, miR-324-3p, ELK4 and PD-L1 using qRT-PCR, western blot and Pearson analysis. Cell proliferation, migration and invasion abilities were determined using CCK-8 and transwell assays. The cytotoxicity of CD8 + T cells and the apoptosis of CD8+ T cells was evaluated by LDH assay and flow cytometry, respectively. Dual luciferase assay, RIP and ChIP methods were performed to verify molecular interactions. Our results showed that SNHG16, ELK4 and PD-L1 expression were abnormally elevated and miR-324-3p expression was decreased in tumor tissues from CRC patients and CRC cells. SNHG16 silencing resulted in suppression of cell growth, metastasis, and immune escape of CRC cells, which was reversed by miR-324-3p inhibitor and ELK4 overexpression. Mechanistically, SNHG16 acted as a competitive endogenous RNA to enhance ELK4 expression by sponging miR-324-3p, thereby provoking the transcription of PD-L1. Our results demonstrated that SNHG16 silencing led to the suppression of cell growth, metastasis, and immune escape of CRC cells through mediating miR-324-3p/ELK4/PD-L1 axis, offering promising targets for CRC treatment.

Construction of a cell cycle-specific lncRNA-miRNA-mRNA network reveals novel key lncRNAs in colorectal cancer

OBJECTIVE

The current study aimed to determine the roles of pivotal and novel lncRNAs associated with the cell cycle in the occurrence and development of Colorectal cancer (CRC).

METHODS

The TCGA-COAD project related to CRC was downloaded, and differential expression analysis was performed to identify differentially expressed lncRNAs, miRNAs, and mRNAs. A cell cycle-associated lncRNA-miRNA-mRNA regulatory network was constructed, and two novel lncRNAs were selected. Two subnetworks were constructed for selected lncRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were illustrated for the genes in each sub-network. qPCR analysis was used to validate the expression levels of the selected lncRNAs in CRC tissues compared to those adjacent normal tissues.

RESULTS

The differential expression analysis identified 416 lncRNAs, 317 miRNAs, and 117 mRNAs. The ceRNA subnetwork genes were associated with different pathways, including cellular senescence, DNA replication, human T-cell leukemia virus 1 infection, and oocyte meiosis. The bioinformatic results based on the TCGA project indicated the dysregulation of two novel lncRNAs, MIR29B2CHG and HELLPAR, in CRC tissues compared to adjacent normal tissues. Moreover, qPCR confirmed the dysregulation of lncRNAs in the CRC tissues. ROC curves revealed that both selected lncRNAs had acceptable specificity and sensitivity as biomarkers.

CONCLUSION

In conclusion, novel cell cycle-associated lncRNAs have the potential to be understood as the underlying molecular mechanisms that influence CRC. Therefore, these lncRNAs can be considered as promising biomarkers for the diagnosis and treatment of CRC.

Molecular mechanisms underlying roles of long non-coding RNA small nucleolar RNA host gene 16 in digestive system cancers

This editorial reviews the molecular mechanisms underlying the roles of the long non-coding RNA (lncRNA) small nucleolar RNA host gene 16 (SNHG16) in digestive system cancers based on two recent studies on lncRNAs in digestive system tumors. The first study, by Zhao et al, explored how hBD-1 affects colon cancer, via the lncRNA TCONS_00014506, by inhibiting mTOR and promoting autophagy. The second one, by Li et al, identified the lncRNA prion protein testis specific (PRNT) as a factor in oxaliplatin resistance by sponging ZNF184 to regulate HIPK2 and influence colorectal cancer progression and chemoresistance, suggesting PRNT as a potential therapeutic target for colorectal cancer. Both of these two articles discuss the mechanisms by which lncRNAs contribute to the development and progression of digestive system cancers. As a recent research hotspot, SNHG16 is a typical lncRNA that has been extensively studied for its association with digestive system cancers. The prevailing hypothesis is that SNHG16 participates in the development and progression of digestive system tumors by acting as a competing endogenous RNA, interacting with other proteins, regulating various genes, and affecting downstream target molecules. This review systematically examines the recently reported biological functions, related molecular mechanisms, and potential clinical significance of SNHG16 in various digestive system cancers, and explores the relationship between SNHG16 and digestive system cancers. The findings suggest that SNHG16 may serve as a potential biomarker and therapeutic target for human digestive system cancers.

siRNA-based strategies to combat drug resistance in gastric cancer

Chemotherapy is a key treatment option for gastric cancer, but over 50% of patients develop either inherent or acquired resistance to these drugs, resulting in a 5-year survival rate of only about 20%. The primary treatment for advanced gastric cancer typically involves chemotherapy based on platinum or fluorouracil. Several factors can contribute to platinum resistance, including decreased drug uptake, increased drug efflux or metabolism, enhanced DNA repair, activation of pro-survival pathways, and inhibition of pro-apoptotic pathways. In recent years, there has been significant progress in biology aimed at finding innovative and more effective methods to overcome chemotherapy resistance. Small interfering RNAs (siRNAs) have emerged as a significant advancement in gene expression regulation, showing promise in enhancing the sensitivity of gastric cancer cells to chemotherapy drugs. However, siRNA therapies still face major challenges, particularly in terms of stability and efficient delivery in vivo. This article discusses the advances in siRNA therapy and its potential role in overcoming resistance to chemotherapeutic drugs such as cisplatin, 5-FU, doxorubicin, and paclitaxel in the treatment of gastric cancer.

LncRNAs are involved in regulating ageing and age-related disease through the adenosine monophosphate-activated protein kinase signalling pathway

A long noncoding RNA (lncRNA) is longer than 200 bp. It regulates various biological processes mainly by interacting with DNA, RNA, or protein in multiple kinds of biological processes. Adenosine monophosphate-activated protein kinase (AMPK) is activated during nutrient starvation, especially glucose starvation and oxygen deficiency (hypoxia), and exposure to toxins that inhibit mitochondrial respiratory chain complex function. AMPK is an energy switch in organisms that controls cell growth and multiple cellular processes, including lipid and glucose metabolism, thereby maintaining intracellular energy homeostasis by activating catabolism and inhibiting anabolism. The AMPK signalling pathway consists of AMPK and its upstream and downstream targets. AMPK upstream targets include proteins such as the transforming growth factor β-activated kinase 1 (TAK1), liver kinase B1 (LKB1), and calcium/calmodulin-dependent protein kinase β (CaMKKβ), and its downstream targets include proteins such as the mechanistic/mammalian target of rapamycin (mTOR) complex 1 (mTORC1), hepatocyte nuclear factor 4α (HNF4α), and silencing information regulatory 1 (SIRT1). In general, proteins function relatively independently and cooperate. In this article, a review of the currently known lncRNAs involved in the AMPK signalling pathway is presented and insights into the regulatory mechanisms involved in human ageing and age-related diseases are provided.

Tumor Lipid Signatures Are Descriptive of Acquisition of Therapy Resistance in an Endocrine-Related Breast Cancer Mouse Model

The lipid metabolism adaptations of estrogen and progesterone receptor-positive breast cancer tumors from a mouse syngeneic model are investigated in relation to differences across the transition from hormone-dependent (HD) to hormone-independent (HI) tumor growth and the acquisition of endocrine therapy (ET) resistance (HIR tumors). Results are articulated with reported polar metabolome results to complete a metabolic picture of the above transitions and suggest markers of tumor progression and aggressiveness. Untargeted nuclear magnetic resonance metabolomics was used to analyze tumor and mammary tissue lipid extracts. Tumor progression (HD-HI-HIR) was accompanied by increased nonesterified cholesterol forms and phospholipids (phosphatidylcholine, phosphatidylethanolamine, sphingomyelins, and plasmalogens) and decreased relative contents of triglycerides and fatty acids. Predominating fatty acids became shorter and more saturated on average. These results were consistent with gradually more activated cholesterol synthesis, β-oxidation, and phospholipid biosynthesis to sustain tumor growth, as well as an increase in cholesterol (possibly oxysterol) forms. Particular compound levels and ratios were identified as potential endocrine tumor HD-HI-HIR progression markers, supporting new hypotheses to explain acquired ET resistance.

Roles of long non‑coding RNA SNHG16 in human digestive system cancer (Review)

The incidence of tumors in the human digestive system is relatively high, including esophageal cancer, liver cancer, pancreatic cancer, gastric cancer and colorectal cancer. These malignancies arise from a complex interplay of environmental and genetic factors. Among them, long non‑coding RNAs (lncRNAs), which cannot be translated into proteins, serve an important role in the development, progression, migration and prognosis of tumors. Small nucleolar RNA host gene 16 (SNHG16) is a typical lncRNA, and its relationship with digestive system tumors has been widely explored. The prevailing hypothesis suggests that the principal molecular mechanism of SNHG16 in digestive system tumors involves it functioning as a competitive endogenous RNA that interacts with other proteins, regulates various genes and influences a downstream target molecule. The present review summarizes recent research on the relationship between SNHG16 and numerous types of digestive system cancer, encompassing its biological functions, underlying mechanisms and potential clinical implications. Furthermore, it outlines the association between SNHG16 expression and pertinent risk factors, such as smoking, infection and diet. The present review indicated the promise of SNHG16 as a potential biomarker and therapeutic target in human digestive system cancer.

Functional role of lncRNAs in gastrointestinal malignancies: the peculiar case of small nucleolar RNA host gene family

Long noncoding RNAs (lncRNAs) play crucial roles in normal physiology and are often de-regulated in disease states such as cancer. Recently, a class of lncRNAs referred to as the small nucleolar RNA host gene (SNHG) family have emerged as important players in tumourigenesis. Here, we discuss new findings describing the role of SNHGs in gastrointestinal tumours and summarize the three main functions by which these lncRNAs promote carcinogenesis, namely: competing with endogenous RNAs, modulating protein function, and regulating epigenetic marking. Furthermore, we discuss how SNHGs participate in different hallmarks of cancer, and how this class of lncRNAs may serve as potential biomarkers in cancer diagnosis and therapy.

The m6A modification mediated-lncRNA POU6F2-AS1 reprograms fatty acid metabolism and facilitates the growth of colorectal cancer via upregulation of FASN

BACKGROUND

Long noncoding RNAs (lncRNAs) have emerged as key players in tumorigenesis and tumour progression. However, the biological functions and potential mechanisms of lncRNAs in colorectal cancer (CRC) are unclear.

METHODS

The novel lncRNA POU6F2-AS1 was identified through bioinformatics analysis, and its expression in CRC patients was verified via qRT-PCR and FISH. In vitro and in vivo experiments, such as BODIPY staining, Oil Red O staining, triglyceride (TAG) assays, and liquid chromatography mass spectrometry (LC-MS) were subsequently performed with CRC specimens and cells to determine the clinical significance, and functional roles of POU6F2-AS1. Biotinylated RNA pull-down, RIP, Me-RIP, ChIP, and patient-derived organoid (PDO) culture assays were performed to confirm the underlying mechanism of POU6F2-AS1.

RESULTS

The lncRNA POU6F2-AS1 is markedly upregulated in CRC and associated with adverse clinicopathological features and poor overall survival in CRC patients. Functionally, POU6F2-AS1 promotes the growth and lipogenesis of CRC cells both in vitro and in vivo. Mechanistically, METTL3-induced m6A modification is involved in the upregulation of POU6F2-AS1. Furthermore, upregulated POU6F2-AS1 could tether YBX1 to the FASN promoter to induce transcriptional activation, thus facilitating the growth and lipogenesis of CRC cells.

CONCLUSIONS

Our data revealed that the upregulation of POU6F2-AS1 plays a critical role in CRC fatty acid metabolism and might provide a novel promising biomarker and therapeutic target for CRC.

Subverting the Canon: Novel Cancer-Promoting Functions and Mechanisms for snoRNAs

Small nucleolar RNAs (snoRNAs) constitute a class of intron-derived non-coding RNAs ranging from 60 to 300 nucleotides. Canonically localized in the nucleolus, snoRNAs play a pivotal role in RNA modifications and pre-ribosomal RNA processing. Based on the types of modifications they involve, such as methylation and pseudouridylation, they are classified into two main families-box C/D and H/ACA snoRNAs. Recent investigations have revealed the unconventional synthesis and biogenesis strategies of snoRNAs, indicating their more profound roles in pathogenesis than previously envisioned. This review consolidates recent discoveries surrounding snoRNAs and provides insights into their mechanistic roles in cancer. It explores the intricate interactions of snoRNAs within signaling pathways and speculates on potential therapeutic solutions emerging from snoRNA research. In addition, it presents recent findings on the long non-coding small nucleolar RNA host gene (lncSNHG), a subset of long non-coding RNAs (lncRNAs), which are the transcripts of parental SNHGs that generate snoRNA. The nucleolus, the functional epicenter of snoRNAs, is also discussed. Through a deconstruction of the pathways driving snoRNA-induced oncogenesis, this review aims to serve as a roadmap to guide future research in the nuanced field of snoRNA-cancer interactions and inspire potential snoRNA-related cancer therapies.

Fatty acid metabolism-related lncRNAs are potential biomarkers for survival prediction in clear cell renal cell carcinoma

Metabolic reprogramming of energy is a newly recognized characteristic of cancer. In our current investigation, we examined the possible predictive importance of long noncoding RNAs (lncRNAs) associated to fatty acid metabolism in clear cell renal cell carcinoma (ccRCC). We conducted an analysis of the gene expression data obtained from patients diagnosed with ccRCC using the Cancer Genome Atlas (TCGA) database and the ArrayExpress database. We performed a screening to identify lncRNAs that are differentially expressed in fatty acid metabolism. Based on these findings, we developed a prognostic risk score model using these fatty acid metabolism-related lncRNAs. We then validated this model using Cox regression analysis, Kaplan-Meier survival analysis, and principal-component analysis (PCA). Furthermore, the prognostic risk score model was successfully validated using both the TCGA cohort and the E-MTAB-1980 cohort. We utilized gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) to determine the correlation between fatty acid metabolism and the PPAR signaling pathway in patients with ccRCC at various clinical stages and prognoses. We have discovered compelling evidence of the interaction between immune cells in the tumor microenvironment and tumor cells, which leads to immune evasion and resistance to drugs. This was achieved by the utilization of advanced techniques such as the CIBERSORT method, ESTIMATE R package, ssGSEA algorithm, and TIMER database exploration. Ultimately, we have established a network of competing endogenous RNA (ceRNA) that is related to fatty acid metabolism. The findings of our study suggest that medicines focused on fatty acid metabolism could be clinically significant for individuals with ccRCC. The utilization of this risk model, which is centered around the lncRNAs associated with fatty acid metabolism, could potentially provide valuable prognostic information and hold immunotherapeutic implications for patients with ccRCC.

LncRNA RPARP-AS1 promotes the progression of osteosarcoma cells through regulating lipid metabolism

Osteosarcoma (OS) is a highly malignant tumor, and its dysregulated lipid metabolism is associated with tumorigenesis and unfavorable prognosis. Interestingly, long noncoding RNAs (lncRNAs) have emerged as pivotal regulators of lipid metabolism, exerting notable impacts on tumor proliferation. Nevertheless, the involvement of RPARP-AS1, a novel lipid metabolism-associated lncRNA, remains unexplored in the context of OS. This study aims to identify functionally relevant lncRNAs impacting OS proliferation and lipid metabolism and seeks to shed light on the upstream regulatory mechanisms governing lipogenic enzyme activity. Based on comprehensive bioinformatic analysis and the establishment of a risk model, we identified seven lncRNAs significantly associated with clinical characteristics and lipid metabolism-related genes in patients with OS. Among these, RPARP-AS1 was selected for in-depth investigation regarding its roles in OS proliferation and lipid metabolism. Experimental techniques including RT-qPCR, Western blot, cell viability assay, assessment, and quantification of free fatty acids (FFAs) and triglycerides (TGs) were utilized to elucidate the functional significance of RPARP-AS1 in OS cells and validate its effects on lipid metabolism. Manipulation of RPARP-AS1 expression via ectopic expression or siRNA-mediated knockdown led to alterations in epithelial-mesenchymal transition (EMT) and expression of apoptosis-associated proteins, thereby influencing OS cell proliferation and apoptosis. Mechanistically, RPARP-AS1 was found to augment the expression of key lipogenic enzymes (FABP4, MAGL, and SCD1) and potentially modulate the Akt/mTOR pathway, thereby contributing to lipid metabolism (involving alterations in FFA and TG levels) in OS cells. Collectively, our findings establish RPARP-AS1 as a novel oncogene in OS cells and suggest its role in fostering tumor growth through the enhancement of lipid metabolism.

The roles and molecular mechanisms of non-coding RNA in cancer metabolic reprogramming

One of the key features of cancer is energy metabolic reprogramming which is tightly related to cancer proliferation, invasion, metastasis, and chemotherapy resistance. NcRNAs are a class of RNAs having no protein-coding potential and mainly include microRNAs, lncRNAs and circRNAs. Accumulated evidence has suggested that ncRNAs play an essential role in regulating cancer metabolic reprogramming, and the altered metabolic networks mediated by ncRNAs primarily drive carcinogenesis by regulating the expression of metabolic enzymes and transporter proteins. Importantly, accumulated research has revealed that dysregulated ncRNAs mediate metabolic reprogramming contributing to the generation of therapeutic tolerance. Elucidating the molecular mechanism of ncRNAs in cancer metabolic reprogramming can provide promising metabolism-related therapeutic targets for treatment as well as overcome therapeutic tolerance. In conclusion, this review updates the latest molecular mechanisms of ncRNAs related to cancer metabolic reprogramming.

Role of long non-coding RNAs in metabolic reprogramming of gastrointestinal cancer cells

Metabolic reprogramming, which is recognized as a hallmark of cancer, refers to the phenomenon by which cancer cells change their metabolism to support their increased biosynthetic demands. Tumor cells undergo substantial alterations in metabolic pathways, such as glycolysis, oxidative phosphorylation, pentose phosphate pathway, tricarboxylic acid cycle, fatty acid metabolism, and amino acid metabolism. Latest studies have revealed that long non-coding RNAs (lncRNAs), a group of non-coding RNAs over 200 nucleotides long, mediate metabolic reprogramming in tumor cells by regulating the transcription, translation and post-translational modification of metabolic-related signaling pathways and metabolism-related enzymes through transcriptional, translational, and post-translational modifications of genes. In addition, lncRNAs are closely related to the tumor microenvironment, and they directly or indirectly affect the proliferation and migration of tumor cells, drug resistance and other processes. Here, we review the mechanisms of lncRNA-mediated regulation of glucose, lipid, amino acid metabolism and tumor immunity in gastrointestinal tumors, aiming to provide more information on effective therapeutic targets and drug molecules for gastrointestinal tumors.

LncRNAs-circRNAs as Rising Epigenetic Binary Superstars in Regulating Lipid Metabolic Reprogramming of Cancers

As one of novel hallmarks of cancer, lipid metabolic reprogramming has recently been becoming fascinating and widely studied. Lipid metabolic reprogramming in cancer is shown to support carcinogenesis, progression, distal metastasis, and chemotherapy resistance by generating ATP, biosynthesizing macromolecules, and maintaining appropriate redox status. Notably, increasing evidence confirms that lipid metabolic reprogramming is under the control of dysregulated non-coding RNAs in cancer, especially lncRNAs and circRNAs. This review highlights the present research findings on the aberrantly expressed lncRNAs and circRNAs involved in the lipid metabolic reprogramming of cancer. Emphasis is placed on their regulatory targets in lipid metabolic reprogramming and associated mechanisms, including the clinical relevance in cancer through lipid metabolism modulation. Such insights will be pivotal in identifying new theranostic targets and treatment strategies for cancer patients afflicted with lipid metabolic reprogramming.

Long non‑coding RNAs, lipid metabolism and cancer (Review)

Cancer has emerged as the most common cause of death in China. The change in lipid metabolism has been confirmed to have a role in several tumor types, such as esophageal, gastric, colorectal and liver cancer. Cancer cells use lipid metabolism for energy and then rapidly proliferate, invade and migrate. The main pathway by which cancer cell lipid metabolism influences cancer progression is increased fatty acid synthesis. Long non-coding (lnc)RNAs are important ncRNAs that were indicated to have significant roles in the development of human tumors. They are considered potential tumor biomarkers. Increased lipid synthesis or uptake due to deregulation of lncRNAs contributes to rapid tumor growth. In the present review, current studies on the relationship between lncRNAs, lipid metabolism and the occurrence and development of tumors were collated and summarized, and their mechanism of action was discussed. The review is expected to provide a theoretical basis for tumor treatment and prognosis evaluation based on the effective regulation of lncRNAs and lipid metabolism.

Disulfidptosis-associated long non-coding RNA signature predicts the prognosis, tumor microenvironment, and immunotherapy and chemotherapy options in colon adenocarcinoma

BACKGROUND

Disulfidptosis is independent of apoptosis, ferroptosis, and cuproptosis and is associated with cancer progression, treatment response, and prognosis. However, the predictive potential of disulfidptosis-associated lncRNAs in colon adenocarcinoma (COAD) and their features in the tumor immune microenvironment (TIME) require further elucidation.

METHODS

RNA transcriptome, clinical information, and mutation data of COAD samples were obtained from the TCGA database. The risk model was first constructed by co-expression analysis of disulfidptosis genes and lncRNAs, and prognostic lncRNAs were screened using Cox regression, followed by least absolute shrinkage and selection operator analysis. Enrichment analyses were performed to explore the underlying biological functions and signaling of model-associated differentially expressed genes (MADEGs). Moreover, TIME of MADEGs was analyzed to assess the immunotherapy. Finally, the expression levels of the lncRNAs were verified by taking specimens of patients with COAD from the Affiliated Hospital of Qingdao University.

RESULTS

We constructed a prognosis-related risk model based on four disulfidptosis-associated lncRNAs (ZEB1-AS1, SNHG16, SATB2-AS1, and ALMS1-IT1). By analyzing the survival of patients in the whole, training, and test groups, we found that patients with COAD in the low-risk group had better overall survival than those in the high-risk group. Validation of the model via Cox analysis and clinical indicators demonstrated that the model had a decent potential for predicting the prognosis of patients with COAD. Enrichment analyses revealed that the MADEGs were related to disulfidptosis-associated biological functions and cancer pathways. Furthermore, patients with COAD in the high-risk group had more positive responses to immune checkpoint inhibitors (ICIs) than those in the low-risk group, as confirmed by TIME analysis. ZEB1-AS1, SNHG16, and ALMS1-IT1 were expressed at higher levels in tumor samples than those in the corresponding paracancerous samples (p < 0.05), whereas SATB2-AS1 was upregulated in the paracancerous samples (p < 0.05).

CONCLUSIONS

This signature may guide prognosis, molecular mechanisms, and treatment strategies, including ICIs and chemotherapy, in patients with COAD.

Roles of long non-coding RNAs in digestive tract cancer and their clinical application

Long non-coding RNAs (lncRNAs) are strongly related to the occurrence and development of digestive tract cancer in human. Firstly, lncRNAs target and regulate the expression of downstream cancer genes to affect the growth, metastasis, apoptosis, metabolism and immune escape of cancer cells. Secondly, lncRNAs are considered to be important regulating factors for lipid metabolism in cancer, which is related to signaling pathways of adipogenesis and involved in the occurrence and development of digestive tract cancer. Finally, lncRNAs have application value in the diagnosis and treatment of digestive tract cancer. For example, lncRNAMALAT1 has been reported as a target for diagnosis and treatment of hepatocellular carcinoma. This article reviews current progress on the regulatory role of lncRNAs in digestive tract cancer, to provide references for the research and clinical application in the prevention and treatment of digestive tract cancer.

The implication of necroptosis-related lncRNAs in orchestrating immune infiltration and predicting therapeutic efficacy in colon adenocarcinoma: an integrated bioinformatic analysis with preliminarily experimental validation

Background: Necroptosis contributes significantly to colon adenocarcinoma (COAD). We aim to assess the relationship between immunoinfiltration and stemness in COAD patients through the development of a risk score profile using necroptosis-related long noncoding RNAs (NRLs). Methods: Our study was based on gene expression data and relevant clinical information from The Cancer Genome Atlas (TCGA). Necroptosis-related genes (NRGs) were obtained from the Kyoto Encyclopedia of Genes and Genome (KEGG) database. Pearson correlation analysis, Cox regression, and least absolute shrinkage and selection operator (LASSO) regression were used to determine the NRL prognositic signature (NRLPS). NRLs expression was examined using qRT-PCR method. Several algorithms were used to identify relationships between immune cell infiltration and NRLPS risk scores. Further analysis of somatic mutations, tumor stemness index (TSI), and drug sensitivity were also explored. Results: To construct NRLPS, 15 lncRNAs were investigated. Furthermore, NRLPS patients with high-risk subgroups had lower survival rates than that of patients with low-risk subgroups. Using GSEA analysis, NRL was found to be enriched in Notch, Hedgehog and Smoothened pathways. Immune infiltration analysis showed significant differences in CD8+ T cells, dendritic cell DCs, and CD4+ T cells between the two risk groups. In addition, our NRLPS showed a relevance with the regulation of tumor microenvironment, tumor mutation burden (TMB) and stemness. Finally, NRLPS demonstrated potential applications in predicting the efficacy of immunotherapy and chemotherapy in patients with COAD. Conclusion: Based on NRLs, a prognostic model was developed for COAD patients that allows a personalized tailoring immunotherapy and chemotherapy to be tailored.

snoRNAs in hematopoiesis and blood malignancies: A comprehensive review

Small nucleolar RNAs (snoRNAs) are noncoding RNA molecules of highly variable size, usually ranging from 60 to 150 nucleotides. They are classified into H/ACA box snoRNAs, C/D box snoRNAs, and scaRNAs. Their functional profile includes biogenesis of ribosomes, processing of rRNAs, 2'-O-methylation and pseudouridylation of RNAs, alternative splicing and processing of mRNAs and the generation of small RNA molecules like miRNA. The snoRNAs have been observed to have an important role in hematopoiesis and malignant hematopoietic conditions including leukemia, lymphoma, and multiple myeloma. Blood malignancies arise in immune system cells or the bone marrow due to chromosome abnormalities. It has been estimated that annually over 1.25 million cases of blood cancer occur worldwide. The snoRNAs often show a differential expression profile in blood malignancies. Recent reports associate the abnormal expression of snoRNAs with the inhibition of apoptosis, uncontrolled cell proliferation, angiogenesis, and metastasis. This implies that targeting snoRNAs could be a potential way to treat hematologic malignancies. In this review, we describe the various functions of snoRNAs, their role in hematopoiesis, and the consequences of their dysregulation in blood malignancies. We also evaluate the potential of the dysregulated snoRNAs as biomarkers and therapeutic targets for blood malignancies.

The Ratio of Monocyte to Apolipoprotein A1 is an Independent Predictor of Breast Cancer: A Retrospective Study

Objective

To explore the predictive value of the ratio of monocyte to apolipoprotein A1 (MAR) (a new index related to inflammation and lipid in breast cancer (BC)) and its relationship with clinicopathological staging.

Methods

The hematological test results of 394 patients with breast diseases, including 276 cases of BC, 118 cases of benign breast disease (BBD), and 219 healthy volunteers (HV), were retrospectively collected. The clinical value of MAR was analyzed with binary logistic regression.

Results

Using statistical software analysis, the results showed that MAR level (P<0.001) was the largest in the BC group, followed by BBD, and the lowest in the HV group, and it was found to be an indicator to distinguish BC from BBD, also an independent risk factor for BC. The increase in MAR level showed that the risk of BC was 3.733 times higher than that of HV (P<0.001). In addition, there was a notable difference in MAR between early, middle and late stages of BC patients (P=0.047), with the highest MAR level in late stage (0.510±0.078) and the lowest MAR level in early stage (0.392±0.011); the MAR level of those with tumor invasion depth of Phase 4 was the highest (0.484±0.072), and that of Phase 1/2 was the lowest (0.379±0.010), with a statistically significant difference (P<0.001). MAR was positively correlated with tumor invasion depth (P<0.001, r=0.210), that's, the size of MAR increased when there was more deeper tumor invasion.

Conclusion

MAR is a new indicator for the auxiliary differential diagnosis of benign and malignant breast diseases, and is also an independent risk factor for BC. High-level MAR is closely related to late staging and tumor invasion depth of BC. It can be seen that MAR is a potentially valuable predictor of BC, and this is the first study to explore the clinical value of MAR in BC.

In vitro Anti-malignant Property of PCMT1 Silencing and Identification of the SNHG16/miR-195/PCMT1 Regulatory Axis in Breast Cancer Cells

BACKGROUND

Protein L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) is a highly conserved protein repair enzyme that participates in regulating the progression of human cancers. We therefore studied the function and the related mechanisms of PCMT1 in breast cancer cells.

METHODS

Expression profile and prognostic analysis of PCMT1 in breast cancer patients were analyzed using online databases. PCMT1 expression in breast cancer cells was detected by western blot analysis. Cell proliferation was determined by CCK-8 and colony formation assays. Apoptosis was evaluated using flow cytometry analysis and caspase-3/7 activity assay. Cell invasion was assessed by Transwell invasion assay. The small nucleolar RNA host gene 16 (SNHG16)/miR-195/PCMT1 regulatory axis was identified using bioinformatics analysis.

RESULTS

PCMT1 expression was increased in breast cancer tissues and cells. High PCMT1 expression was correlated with poor prognosis in breast cancer patients. PCMT1 knockdown suppressed cell proliferation and colony formation ability in breast cancer cells. Moreover, PCMT1 knockdown induced apoptosis and restrained the invasive ability in breast cancer cells. PCMT1 overexpression increased the proliferative and invasive abilities of breast cancer cells. miR-195 was identified as the unique upstream miRNA of PCMT1. SNHG16 was identified as the unique upstream lncRNA of miR-195. SNHG16 knockdown downregulated PCMT1 by increasing miR-195 expression. Breast cancer cell proliferation was regulated by the SNHG16/miR-195/PCMT1 axis.

CONCLUSION

PCMT1 silencing inhibited cell proliferation and invasion and induced apoptosis in breast cancer cells and the SNHG16/miR-195/PCMT1 regulatory axis might serve as a potential therapeutic target for breast cancer.

Development and validation of cuproptosis-related lncRNA signatures for prognosis prediction in colorectal cancer

BACKGROUND

Cuproptosis, a novel form of programmed cell death, plays an essential role in various cancers. However, studies of the function of cuproptosis lncRNAs (CRLs) in colorectal cancer (CRC) remain limited. Thus, this study aims to identify the cuprotosis-related lncRNAs (CRLs) in CRC and to construct the potential prognostic CRLs signature model in CRC.

METHODS

First, we downloaded RNA-Seq data and clinical information of CRC patients from TCGA database and obtained the prognostic CRLs based on typical expression analysis of cuproptosis-related genes (CRGs) and univariate Cox regression. Then, we constructed a prognostic model using the Least Absolute Shrinkage and Selection Operator algorithm combined with multiple Cox regression methods (Lasso-Cox). Next, we generated Kaplan-Meier survival and receiver operating characteristic curves to estimate the performance of the prognostic model. In addition, we also analysed the relationships between risk signatures and immune infiltration, mutation, and drug sensitivity. Finally, we performed quantitative reverse transcription polymerase chain reaction (qRT -PCR) to verify the prognostic model.

RESULT

Lasso-Cox analysis revealed that four CRLs, SNHG16, LENG8-AS1, LINC0225, and RPARP-AS1, were related to CRC prognosis. Receiver operating characteristic (ROC) and Kaplan-Meier analysis curves indicated that this model performs well in prognostic predictions of CRC patients. The DCA results also showed that the model included four gene signatures was better than the traditional model. In addition, GO and KEGG analyses revealed that DE-CRLs are enriched in critical signalling pathway, such as chemical carcinogenesis-DNA adducts and basal cell carcinoma. Immune infiltration analysis revealed significant differences in immune infiltration cells between the high-risk and low-risk groups. Furthermore, significant differences in somatic mutations were noted between the high-risk and low-risk groups. Finally, we also validated the expression of four CRLs in FHCs cell lines and CRC cell lines using qRT-PCR.

CONCLUSION

The signature composed of SNHG16, LENG8-AS1, LINC0225, and RPARP-AS1, which has better performance in predicting colorectal cancer prognosis and are promising biomarkers for prognosis prediction of CRC.

SnoRNA and lncSNHG: Advances of nucleolar small RNA host gene transcripts in anti-tumor immunity

The small nucleolar RNA host genes (SNHGs) are a group of genes that can be transcript into long non-coding RNA SNHG (lncSNHG) and further processed into small nucleolar RNAs (snoRNAs). Although lncSNHGs and snoRNAs are well established to play pivotal roles in tumorigenesis, how lncSNHGs and snoRNAs regulate the immune cell behavior and function to mediate anti-tumor immunity remains further illustrated. Certain immune cell types carry out distinct roles to participate in each step of tumorigenesis. It is particularly important to understand how lncSNHGs and snoRNAs regulate the immune cell function to manipulate anti-tumor immunity. Here, we discuss the expression, mechanism of action, and potential clinical relevance of lncSNHGs and snoRNAs in regulating different types of immune cells that are closely related to anti-tumor immunity. By uncovering the changes and roles of lncSNHGs and snoRNAs in different immune cells, we aim to provide a better understanding of how the transcripts of SNHGs participate in tumorigenesis from an immune perspective.

Identifying Oxidized Lipid Metabolism-Related LncRNAs as Prognostic Biomarkers of Head and Neck Squamous Cell Carcinoma

The relationship between oxidized lipid metabolism and the immunological function of cancer is well known. However, the functions and regulatory mechanisms of lncRNAs associated with oxidized lipid metabolism in head and neck squamous cell carcinoma (HNSCC) remain to be fully elucidated. In this study, we established an oxidized lipid metabolism-related lncRNA prognostic signature to assess the prognosis and immune infiltration of HNSCC patients. The HNSCC transcriptome was obtained from The Cancer Genome Atlas. The choice of the target genes with a relevance score greater than 10 was performed via a correlation analysis by GeneCards. Patients were categorized by risk score and generated with multivariate Cox regression, which was then validated and evaluated using the Kaplan–Meier analysis and time-dependent receiver operating characteristics (ROC). A nomogram was constructed by combining the risk score with the clinical data. We constructed a risk score with 24 oxidized lipid metabolism-related lncRNAs. The areas’ 1-, 2-, and 3-year OS under the ROC curve (AUC) were 0.765, 0.724, and 0.724, respectively. Furthermore, the nomogram clearly distinguished the survival probabilities of patients in high- and low-risk groups, between which substantial variations were revealed by immune infiltration analysis. The results supported the fact that oxidized lipid metabolism-related lncRNAs might predict prognoses and assist with differentiating amid differences in immune infiltration in HNSCC.

Metabolic reprogramming in colorectal cancer: regulatory networks and therapy

With high prevalence and mortality, together with metabolic reprogramming, colorectal cancer is a leading cause of cancer-related death. Metabolic reprogramming gives tumors the capacity for long-term cell proliferation, making it a distinguishing feature of cancer. Energy and intermediate metabolites produced by metabolic reprogramming fuel the rapid growth of cancer cells. Aberrant metabolic enzyme-mediated tumor metabolism is regulated at multiple levels. Notably, tumor metabolism is affected by nutrient levels, cell interactions, and transcriptional and posttranscriptional regulation. Understanding the crosstalk between metabolic enzymes and colorectal carcinogenesis factors is particularly important to advance research for targeted cancer therapy strategies via the investigation into the aberrant regulation of metabolic pathways. Hence, the abnormal roles and regulation of metabolic enzymes in recent years are reviewed in this paper, which provides an overview of targeted inhibitors for targeting metabolic enzymes in colorectal cancer that have been identified through tumor research or clinical trials.

Lipid metabolism reprogramming in colorectal cancer

The hallmark feature of metabolic reprogramming is now considered to be widespread in many malignancies, including colorectal cancer (CRC). Of the gastrointestinal tumors, CRC is one of the most common with a high metastasis rate and long insidious period. The incidence and mortality of CRC has increased in recent years. Metabolic reprogramming also has a significant role in the development and progression of CRC, especially lipid metabolic reprogramming. Many studies have reported that lipid metabolism reprogramming is similar to the Warburg effect with typical features affecting tumor biology including proliferation, migration, local invasion, apoptosis, and other biological behaviors of cancer cells. Therefore, studying the role of lipid metabolism in the occurrence and development of CRC will increase our understanding of its pathogenesis, invasion, metastasis, and other processes and provide new directions for the treatment of CRC. In this paper, we mainly describe the molecular mechanism of lipid metabolism reprogramming and its important role in the occurrence and development of CRC. In addition, to provide reference for subsequent research and clinical diagnosis and treatment we also review the treatments of CRC that target lipid metabolism.

Role of a lipid metabolism-related lncRNA signature in risk stratification and immune microenvironment for colon cancer

Background

Energy metabolism disorder, especially lipid metabolism disorder, is an important biological characteristic of colon cancer. This research sought to examine the association between lipid metabolism-related long non-coding RNAs (lncRNAs) and prognoses among colon cancer patients.

Methods

The transcriptome profile and clinical data of patients with colon cancer were retrieved from The Cancer Genome Atlas database. Using consensus clustering, cases were divided into two clusters and Kaplan–Meier analysis was executed to analyze differences in their prognoses. The gene set enrichment analysis (GSEA) was used to discover biological processes and signaling pathways. A lipid metabolism-related lncRNA prognostic model (lipid metabolism-LncRM) was created utilizing the least absolute shrinkage and selection operator (LASSO) regression. The tumor microenvironment was evaluated on the basis of the composition of immune and stromal cells.

Results

The patients in Cluster 2 were found to have a better prognosis and higher expression of programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) relative to Cluster 1. The results of GSEA showed the enrichment of energy metabolism pathways in Cluster 2. LASSO regression was used to identify the five LncRNAs that were shown to be most substantially linked to patient prognosis. These were NSMCE1-DT, LINC02084, MYOSLID, LINC02428, and MRPS9-AS1. Receiver operating characteristic (ROC) curves and survival analysis illustrated that the lipid metabolism-LncRM had a significant prognostic value. Further analysis showed that high- and low-risk groups were significantly different in terms of clinical characteristics and immune cells infiltration.

Conclusions

Lipid metabolism-related lncRNAs could predict the prognoses and tumor microenvironment of colon cancer and might be important biomarkers relevant to immunotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01369-8.

LncRNA SNHG16 promotes development of oesophageal squamous cell carcinoma by interacting with EIF4A3 and modulating RhoU mRNA stability

BACKGROUND

Numerous studies have revealed that long noncoding RNAs (lncRNAs) are closely related to the development of many diseases and carcinogenesis. However, their specific biological function and molecular mechanism in oesophageal squamous cell carcinoma (ESCC) remains unclear.

METHODS

RNA-Seq was performed to determine the differential expressions of lncRNAs in ESCC, and the level of SNHG16 expression was detected in ESCC and intraepithelial neoplasia (IEN) samples. In vitro and in vivo experiments were performed to explore the role of SNHG16 and the interaction of EIF4A3 and Ras homologue family member U (RhoU) signalling.

RESULTS

One hundred and seventy-five upregulated and 134 downregulated lncRNAs were identified by RNA-Seq. SNHG16 was highly expressed in ESCC and intraepithelial neoplasia (IEN) samples, and its expression level was correlated with tumour differentiation and T stage. Overexpression of SNHG16 can facilitate ESCC cell proliferation and metastasis. Mechanistically, we noticed that SNHG16 could bind RNA binding protein (RBP)-eukaryotic translation initiation factor (EIF4A3) and interact with it to form a complex. Importantly, the coalition of SNHG16 and EIF4A3 ultimately regulated Ras homologue family member U (RhoU). SNHG16 modulated RhoU expression by recruiting EIF4A3 to regulate the stability of RhoU mRNA. Knockdown of RhoU further alleviated the effect of the SNHG16 oncogene in ESCC cells.

CONCLUSIONS

The newly identified SNHG16-EIF4A3-RhoU signalling pathway directly coordinates the response in ESCC pathogenesis and suggests that SNHG16 is a promising target for potential ESCC treatment.

Novel lncRNA SNHG16 Promotes the Growth and Metastasis of Malignant Melanoma by Regulating miR-205-5p/PAK2 Axis

Background

Long non-coding RNAs (lncRNAs) play an key role in the biological processes of various malignant tumors. SNHG16 has been confirmed to be associated with the progression of various cancers. However, function and molecular mechanism of SNHG16 in melanoma have not been studied by scholars.

Methods

The expression of SNHG16 in melanoma tissues were detected by using qRT-PCR. Melanoma cases from The Cancer Genome Atlas (TCGA) and GEO#GSE15605 were included in this study. CCK-8 assay, EdU assay, transwell and scratch wound assay were used to explore the role of SNHG16 in melanoma cells. Luciferase reporter assays and RNA pull-down assay were used to explore the molecular mechanism of SNHG16 in melanoma.

Results

Here, we found that SNHG16 was up-regulated in melanoma. SNHG16 enhances the growth and metastasis of melanoma. SNHG16 can promote the expression of P21-activated kinases 2 (PAK2) by sponging miR-205-5p. PAK2 is the target gene of miR-205-5p. We demonstrated that SNHG16 promotes the metastasis and growth of melanoma through miR-205-5p/PAK2 axis.

Conclusion

This study firstly confirmed the role and mechanism of SNHG16 in the occurrence and development of melanoma. Therefore, SNHG16 may become a key point in the diagnosis, prognosis and treatment of melanoma patients in the future.

Cuproptosis-Related lncRNAs are Biomarkers of Prognosis and Immune Microenvironment in Head and Neck Squamous Cell Carcinoma

Background: Cuproptosis is a new type of cell death that induces protein toxic stress and eventually leads to cell death. Hence, regulating cuproptosis in tumor cells is a new therapeutic approach. However, studies on cuproptosis-related long noncoding RNA (lncRNA) in head and neck squamous cell carcinoma (HNSC) have not been found. This study aimed to explore the cuproptosis-related lncRNAs prognostic marker and their relationship to immune microenvironment in HNSC by using bioinformatics methods.

Methods: RNA sequencing, genomic mutations, and clinical data of TCGA_HNSC were downloaded from The Cancer Genome Atlas. HNSC patients were randomly assigned to either a training group or a validation cohort. The least absolute shrinkage and selection operator Cox regression and multivariate Cox regression models were used to determine the prognostic model in the training cohort, and its independent prognostic effect was further confirmed in the validation and entire cohorts.

Results: Based on previous literature, we collected 19 genes associated with cuproptosis. Afterward, 783 cuproptosis-related lncRNAs were obtained through coexpression. Cox model revealed and constructed eight cuproptosis-related lncRNAs prognostic marker (AL132800.1, AC090587.1, AC079160.1, AC011462.4, AL157888.1, GRHL3-AS1, SNHG16, and AC021148.2). Patients were divided into high- and low-risk groups based on the median risk score. The Kaplan–Meier survival curve revealed that the overall survival between the high- and low-risk groups was statistically significant. The receiver operating characteristic curve and principal component analysis demonstrated the accurate prognostic ability of the model. Univariate and multivariate Cox regression analysis showed that risk score was an independent prognostic factor. In addition, we used multivariate Cox regression to establish a nomogram of the predictive power of prognostic markers. The tumor mutation burden showed significant differences between the high- and low-risk groups. HNSC patients in the high-risk group responded better to immunotherapy than those in the low-risk group. We also found that risk scores were significantly associated with drug sensitivity in HNSC.

Conclusion: In summary, our study identified eight cuprotosis-related lncRNAs signature of HNSC as the prognostic predictor, which may be promising biomarkers for predicting the benefit of HNSC immunotherapy as well as drug sensitivity.

Competing Endogenous RNAs (ceRNAs) in Colorectal Cancer: A Review

Colorectal cancer (CRC) is a common type of cancer and the second leading cause of cancer-related deaths worldwide. Competing endogenous RNAs (ceRNAs) that contain microRNA response elements (MREs) are involved in CRC progression. They can compete with microRNAs (miRNAs) via their MREs, which can combine non-coding and coding RNAs via complex ceRNA networks. This molecular interaction has the potential to affect a wide variety of biological processes, and many cancers can occur as a result of an imbalanced ceRNA network. Recent research indicates that numerous dysregulated RNAs in CRC may function as ceRNAs, regulating multiple biological functions of the tumour, including proliferation, apoptosis, metastasis, invasion and migration. In this review, we discuss the role of protein-coding and non-coding RNAs, such as long non-coding RNAs, circular RNAs and pseudogenes, in the occurrence of ceRNA networks in CRC, and their function in cancer-related pathways, such as Wnt/β-catenin, mitogen-activated protein kinase and transforming growth factor-β signalling pathways. Additionally, we discuss validated ceRNAs associated with CRC biological functions and their potential role as novel prognostic and diagnostic biomarkers. Examining the role of ceRNAs in CRC sheds new light on cancer treatment and pathogenesis.

Small nucleolar RNAs and SNHGs in the intestinal mucosal barrier: Emerging insights and current roles

BACKGROUND

Previous studies have focused on the involvement of small nucleolar RNAs (snoRNAs) and SNHGs in tumor cell proliferation, apoptosis, invasion, and metastasis via multiple pathways, including phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT), Wnt/β catenin, and mitogen-activated protein kinase (MAPK). These molecular mechanisms affect the integrity of the intestinal mucosal barrier.

AIM OF REVIEW

Current evidence regarding snoRNAs and SNHGs in the context of the mucosal barrier and modulation of homeostasis is fragmented. In this review, we collate the established information on snoRNAs and SNHGs as well as discuss the major pathways affecting the mucosal barrier.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Intestinal mucosal immunity, microflora, and the physical barrier are altered in non-neoplastic diseases such as inflammatory bowel diseases. Dysregulated snoRNAs and SNHGs may impact the intestinal mucosal barrier to promote the pathogenesis and progression of multiple diseases. SnoRNAs or SNHGs has been shown to be associated with poor disease behaviors, indicating that they may be exploited as prognostic biomarkers. Additionally, clarifying the complicated interactions between snoRNAs or SNHGs and the mucosal barrier may provide novel insights for the therapeutic treatment targeting strengthen the intestinal mucosal barrier.

Circ_0006174 promotes the malignancy of colorectal cancer cell via the miR‑1205/CCBE1/Wnt pathway

Circular RNAs (circRNAs) are novel RNA transcripts that participate in cancer development. Nonetheless, in colorectal cancer (CRC), the information ~circRNA expression and function is largely unknown. The present study aimed to investigate the expression, function and underlying mechanism of circ_0006174 in CRC. Reverse transcription-quantitative PCR analysis was performed to detect circ_0006174, miR-1205 and calcium-binding epidermal growth factor domain-containing protein 1 (CCBE1) expression levels in CRC tissues and cell lines. Circ_0006174 knockdown CRC cell models were established. CCK-8, TUNEL and Transwell methods were utilized to explore the function of circ_0006174 on the malignant phenotype of CRC cells. Moreover, a xenograft nude mouse model was constructed to verify the effects of circ_0006174 on lung metastasis in vivo. Dual-luciferase reporter gene assay was adopted to prove the association between circ_0006174 and miR-1205, miR-1205 and CCBE1. Gene set enrichment analysis was performed using the LinkedOmics database. Western blotting was performed to evaluate the expression of CCBE1, Ki67 and Wnt pathway-related proteins (c-Myc and cyclin D1) in CRC cell lines. Circ_0006174 showed a notable upregulation in CRC tissues and cell lines and its overexpression was linked to larger tumor diameter and advanced T stage of CRC patients. Circ_0006174 knockdown significantly suppressed cell growth and metastatic potential and promoted cell apoptosis in vitro. Circ_0006174 knockdown accelerated the lung metastasis in vivo. Mechanistically, circ_0006174 could decoy miR-1205 to up-modulate CCBE1 expression and Wnt pathway-related proteins (c-Myc and cyclin D1). Circ_0006174 is an oncogenic circRNA, which participates in the promotion of CRC progression by regulating the miR-1205/CCBE1/Wnt pathway.

Circulating lncRNA- and miRNA-Associated ceRNA Network as a Potential Prognostic Biomarker for Non-Hodgkin Lymphoma: A Bioinformatics Analysis and a Pilot Study

Non-Hodgkin lymphoma (NHL) is characterized by a great variability in patient outcomes, resulting in the critical need for identifying new molecular prognostic biomarkers. This study aimed to identify novel circulating prognostic biomarkers based on an miRNA/lncRNA-associated ceRNA network for NHL. Using bioinformatic analysis, we identified the miRNA-lncRNA pairs, and using RT-qPCR, we analyzed their plasma levels in a cohort of 113 NHL patients to assess their prognostic value. Bioinformatic analysis identified SNHG16 and SNHG6 as hsa-miR-20a-5p and hsa-miR-181a-5p sponges, respectively. Plasma levels of hsa-miR-20a-5p/SNHG16 and hsa-miR-181a-5p/SNG6 were significantly associated with more aggressive disease and IPI/FLIPI scores. Moreover, we found that patients with risk expression profiles of hsa-miR-20a-5p/SNHG16 and hsa-miR-181a-5p/SNHG6 presented a higher risk of positive bone marrow involvement. Moreover, hsa-miR-20a-5p/SNHG16 and hsa-miR-181a-5p/SNHG6 pairs’ plasma levels were associated with overall survival and progression-free survival of NHL patients, being independent prognostic factors in a multivariate Cox analysis. The prediction models incorporating the ceRNA network expression analysis improved the predictive capacity compared to the model, which only considered the clinicopathological variables. There are still few studies on using the ceRNA network as a potential prognostic biomarker, particularly in NHL, which may permit the implementation of a more personalized management of these patients.

Long Noncoding RNA SNHG16 Regulates the Growth of Human Lung Cancer Cells by Modulating the Expression of Aldehyde Dehydrogenase 2 (ALDH2)

The involvement of long noncoding RNA (lncRNA) SNHG16 has been reported in several human cancers. Notwithstanding, the role of lncRNA SNHG16 is yet largely unknown in human lung cancer. Consequently, this study was undertaken to investigate the role and therapeutic potential of SNHG16 in human lung cancer. The results showed a significant (P < 0.05) transcriptional upregulation of SNHG16 in lung cancer tissues and cell lines. However, downregulation of SNHG16 resulted in significant (P < 0.05) inhibition of lung cancer A549 and SK-LU-1 cell proliferation. DAPI and annexin V/PI assays revealed apoptosis to be responsible for inhibition of cell proliferation and colony formation observed upon SNHG16 knockdown. This was accompanied by enhancement of Bax and suppression of Bcl-2 expression in A549 and SK-LU-1 cells. Transwell assays revealed that silencing of SNHG16 also significantly (P < 0.05) inhibited migration and invasion of A549 and SK-LU-1 cells. Bioinformatic analysis revealed that SNHG16 interacted with ALDH2 to exert its effects in human lung cancer cells. The expression of ALDH2 was found to be significantly (P < 0.05) suppressed in human lung cancer tissues and cell lines. Overexpression of ALDH2 inhibited the proliferation and colony formation of the A549 and SK-LU-1 cells. However, silencing of ALDH2 could avoid the tumor-suppressive effects of SNHG16 knockdown. Finally, SNHG16 silencing was also found to inhibit in vivo tumor growth. Collectively, the study unveils the molecular role of SNHG16 in regulating the development of lung cancer by interacting with ALDH2.

Potentials of long non-coding RNAs as biomarkers of colorectal cancer

Colorectal cancer (CRC) is the third most common malignant tumor worldwide and the fourth major cause of cancer-related death, with high morbidity and increased mortality year by year. Although significant progress has been made in the therapy strategies for CRC, the great difficulty in early diagnosis, feeble susceptibility to radiotherapy and chemotherapy, and high recurrence rates have reduced therapeutic efficacy resulting in poor prognosis. Therefore, it is urgent to understand the pathogenesis of CRC and unravel novel biomarkers to improve the early diagnosis, treatment and prediction of CRC recurrence. Long non-coding RNAs (lncRNAs) are non-coding RNAs with a length of more than 200 nucleotides, which are abnormally expressed in tumor tissues and cell lines, activating or inhibiting specific genes through multiple mechanisms including transcription and translation. A growing number of studies have shown that lncRNAs are important regulators of microRNAs (miRNAs, miRs) expression in CRC and may be promising biomarkers and potential therapeutic targets in the research field of CRC. This review mainly summarizes the potential application value of lncRNAs as novel biomarkers in CRC diagnosis, radiotherapy, chemotherapy and prognosis. Additionally, the significance of lncRNA SNHGs family and lncRNA-miRNA networks in regulating the occurrence and development of CRC is mentioned, aiming to provide some insights for understanding the pathogenesis of CRC and developing new diagnostic and therapeutic strategies.

Ferroptosis-Related Long Noncoding RNAs as Prognostic Marker for Colon Adenocarcinoma

Background

The incidence of colon adenocarcinoma (COAD) has been increasing over time. Although ferroptosis and long noncoding RNAs (lncRNAs) have been extensively reported to participate in the tumorigenesis and development of COAD, few studies have investigated the role of ferroptosis-related lncRNAs in the prognosis of COAD.

Methods

Gene-sequencing and clinical data for COAD were obtained from The Cancer Genome Atlas database. The coexpression network was constructed using known ferroptosis-related genes. Cox and least absolute shrinkage and selection operator regression were used to screen ferroptosis-related lncRNAs with prognostic value and to identify a predictive model of COAD. Patients with COAD were divided into low- and high-risk groups according to their risk score. Cases of COAD in the International Cancer Genome Consortium database were included as the testing cohort.

Results

In total, nine lncRNAs (LINC02381, AC105219.1, AC009283.1, LINC01011, ELFN1-AS1, EIF3J-DT, NKILA, LINC01063, and SNHG16) were considered prognostic factors for COAD. Then, a risk score model was established. The overall survival rate of COAD patients was negatively associated with the risk score. Kaplan-Meier analyses in the original and testing cohorts showed similar results. The expression of the lncRNAs in tissue was consistent with the risk score, and the relationship with tumor mutation burden, immunity, and drug sensitivity presented a marked link between the signature and COAD. A nomogram was established for clinical applications.

Conclusions

Nine ferroptosis-related lncRNAs and the established signature have a certain predictive value for prognosis of COAD patients and can be used as potential research targets for exploring treatment of COAD.

A Quartet Network Analysis Identifying Mechanically Responsive Long Noncoding RNAs in Bone Remodeling

Mechanical force, being so ubiquitous that it is often taken for granted and overlooked, is now gaining the spotlight for reams of evidence corroborating their crucial roles in the living body. The bone, particularly, experiences manifold extraneous force like strain and compression, as well as intrinsic cues like fluid shear stress and physical properties of the microenvironment. Though sparkled in diversified background, long noncoding RNAs (lncRNAs) concerning the mechanotransduction process that bone undergoes are not yet detailed in a systematic way. Our principal goal in this research is to highlight the potential lncRNA-focused mechanical signaling systems which may be adapted by bone-related cells for biophysical environment response. Based on credible lists of force-sensitive mRNAs and miRNAs, we constructed a force-responsive competing endogenous RNA network for lncRNA identification. To elucidate the underlying mechanism, we then illustrated the possible crosstalk between lncRNAs and mRNAs as well as transcriptional factors and mapped lncRNAs to known signaling pathways involved in bone remodeling and mechanotransduction. Last, we developed combinative analysis between predicted and established lncRNAs, constructing a pathway–lncRNA network which suggests interactive relationships and new roles of known factors such as H19. In conclusion, our work provided a systematic quartet network analysis, uncovered candidate force-related lncRNAs, and highlighted both the upstream and downstream processes that are possibly involved. A new mode of bioinformatic analysis integrating sequencing data, literature retrieval, and computational algorithm was also introduced. Hopefully, our work would provide a moment of clarity against the multiplicity and complexity of the lncRNA world confronting mechanical input.

Long noncoding RNA polymorphisms and colorectal cancer risk: Progression and future perspectives

Colorectal cancer (CRC) is one of the most common cancers causing death worldwide. Many long noncoding RNAs (lncRNAs) have possible carcinogenic or tumor suppressor functions. Some lncRNA polymorphisms are useful for predicting cancer risk, and may help advance personalized therapy management. While the use of lncRNAs as biomarkers is promising, there are still drawbacks, and further studies are needed to verify the consistency of current outcomes in large-scale populations and different ethnicities. Single nucleotide polymorphisms (SNPs) can disrupt a lncRNAs' function, thus enhancing or hindering disease occurrence. SNPs can directly influence the lncRNA expression by interfering with transcription factor binding or affecting indirectly a regulatory factors' expression. Moreover, the association between lncRNAs and other RNAs or proteins may be disrupted by SNPs. This research sought to assess the association between lncRNA polymorphisms and CRC risk, as well as clinical and therapeutic consequences in certain cases.

New Insights into the Importance of Long Non-Coding RNAs in Lung Cancer: Future Clinical Approaches

In mammals, a large part of the gene expression products come from the non-coding ribonucleotide sequences of the protein. These short and long sequences are within the range of tens to hundreds of nucleotides, encompassing more than 200 RNA molecules, and their function is known as the molecular structure of long non-coding RNA (lncRNA). LncRNA molecules are unique nucleotides that have a substantial role in epigenetic regulation, transcription, and post-transcriptional modifications in different ways. According to the results of recent studies, lncRNAs have been shown to assume various roles, including tumor suppression or oncogenic functions in common types of cancer such as lung and breast cancer. These non-coding RNAs (ncRNAs) play a pivotal role in activating transcription factors, managing the ribonucleoproteins, the framework for collecting co-proteins, intermittent processing regulations, chromatin status alterations, and maintaining the control within the cell. Cutting-edge technologies have been introduced to disclose several types of lncRNAs within the nucleus and the cytoplasm, which have accomplished important achievements that are applicable in medicine. Due to these efforts, various data centers have been created to facilitate and modify scientific information related to these molecules, including detection, classification, biological evolution, gene status, spatial structure, status, and location of these small molecules. In the present study, we attempt to present the impacts of these ncRNAs on lung cancer with an emphasis on their mechanisms and functions.

Close interactions between lncRNAs, lipid metabolism and ferroptosis in cancer

Abnormal lipid metabolism including synthesis, uptake, modification, degradation and transport has been considered a hallmark of malignant tumors and contributes to the supply of substances and energy for rapid cell growth. Meanwhile, abnormal lipid metabolism is also associated with lipid peroxidation, which plays an important role in a newly discovered type of regulated cell death termed ferroptosis. Long noncoding RNAs (lncRNAs) have been proven to be associated with the occurrence and progression of cancer. Growing evidence indicates that lncRNAs are key regulators of abnormal lipid metabolism and ferroptosis in cancer. In this review, we mainly summarized the mechanism by which lncRNAs regulate aberrant lipid metabolism in cancer, illustrated that lipid metabolism can also influence the expression of lncRNAs, and discussed the mechanism by which lncRNAs affect ferroptosis. A comprehensive understanding of the interactions between lncRNAs, lipid metabolism and ferroptosis could help us to develop novel strategies for precise cancer treatment in the future.

Steroid receptor RNA activator gene footprint in the progression and drug resistance of colorectal cancer through oxidative phosphorylation pathway

BACKGROUND

The steroid receptor RNA activator 1 (SRA1) gene is involved in the progression of various cancers via different molecular mechanisms mediated by long non-coding RNA SRA (lncRNA SRA). This study aimed to evaluate the lncRNA SRA effect on the tumor progression of colorectal cancer (CRC).

METHODS

SRA1 expression was assessed in the cancer genome atlas datasets, CRC cell lines, and tumor specimens. Meta-analysis and gene co-expression network analysis were performed to identify pathways related to SRA1. RNA interference and cell treatment were utilized to examine the role of SRA1 expression in HT-29 and Caco-2 cell lines. Also, the effect of SRA1 expression was investigated on drug resistance, clinical parameters, and mutations in CRC samples.

RESULTS

The SRA1 transcripts, especially lncRNA SRA, were dysregulated in CRC tissue samples compared with normal tissue samples. Furthermore, SRA1 depletion decreased colony formation and proliferation while induced apoptosis in HT-29 and Caco-2 cells. In silico analyses indicated that SRA1 level was correlated with expression levels of oxidative phosphorylation (OXPHOS) genes. LncRNA SRA expression increased in response to the increased oxidative capacity, and when lncRNA SRA was knocked down, the expression level of OXPHOS pathway genes, including NDUFB5 and ATP5F1B, was changed. Also, KRAS-mutant samples had the highest SRA1 expression level.

CONCLUSIONS

LncRNA SRA could function as an oncogene through the OXPHOS pathway in CRC, and serve as a potential biomarker for identifying CRC subtype with KRAS mutations. The findings suggest that lncRNA SRA might be a therapeutic target to inhibit cell proliferation in CRC.