Long Intergenic Non-Protein Coding RNA 519 Promotes the Biological Activities of Tongue Squamous Cell Carcinoma by Sponging microRNA-876-3p and Consequently Upregulating MACC1

Construction of a Novel Disulfidptosis-Related lncRNA Prognostic Signature in Pancreatic Cancer

Pancreatic cancer is a lethal, extremely aggressive gastrointestinal tumor with a poor prognosis and limited treatment alternatives. Disulfidptosis is a newly defined type of cell death with potential influence on cancer. Research on the association between disulfidptosis and pancreatic cancer is scarce. The expression data of disulfidptosis-related genes were downloaded from The Cancer Genome Atlas-Pancreatic Adenocarcinoma (TCGA). Disulfidptosis-related lncRNA signature (DRLS) was developed through the Cox and the least absolute shrinkage and selection operator (LASSO) analysis. Differences in enrichment functions, mutational landscape, immune microenvironment, and predicted therapeutic efficacy between high- and low-risk groups were assessed. Consensus clustering analysis was applied to identify the DRLS-related subtypes. Among 98 disulfidptosis-related lncRNAs, 5 lncRNAs were screened thus constructing a prognostic DRLS. DRLS showed high predictive accuracy and was an independent prognostic factor for pancreatic cancer. According to the risk scores calculated from the signature, samples were categorized into high- and low- risk groups. Overall, low-risk patients had a better prognosis, lower mutational occurrences, higher immune cell infiltration and more sensitivity to anti-tumor agents. The DRLS performed well in predicting prognosis and revealed intimate correlation with biological function, mutation status and immune infiltration landscape of pancreatic cancer, providing some insights for future research on the relationship between disulfidptosis and pancreatic cancer.

Downregulation of hsa_circTLK1 represses non-small cell lung cancer progression by regulating miR-876-3p/SRSF7 axis

Background

This study clarified the expression of cicrTLK1 in non-small cell lung cancer (NSCLC) and explored its role in cancer growth, metastasis and immune escape, providing a potential molecular target and theoretical basis for NSCLC treatment.

Methods

The expression levels of circTLK1, miR-876-3p and SRSF7 were determined by RT-qPCR assay. The localization of circTLK1 in NSCLC cells was determined by FISH assay. EdU and cell plate clone formation assay were applied to explore cell proliferation. Wound healing test and Transwell assay were applied to measure the migration and invasion ability. Cell apoptosis rate was detected by FCM assay. Western blotting assay was adopted to measure the protein expression of SRSF7. Dual-luciferase reporter gene assay was applied to assess the interaction between miR-876-3p and circTLK1, and between miR-876-3p and SRSF7. The ability of cirTLK1 to regulate tumor formation in vivo was examined by tumor transplantation experiments in nude mice.

Results

The relative expression of circTLK1 was increased in NSCLC cell lines. Knockdown of circTLK1 prohibited the proliferation, migration, and invasion, and promoted apoptosis rate, but miR-876-3p inhibitor reversed the effects of circTLK1 knockdown. In addition, silencing of circTLK1 overtly restrained the growth of transplanted tumors in vivo, and inhibited immune escape. In addition, circTLK1 interacted with miR-876-3p, and SRSF7 was concluded to be the target gene of miR-876-3p.

Conclusion

In this study, we researched the inhibitory effect of circTLK1knockdown on NSCLC progression and immune escape, and further elucidated the potential regulatory mechanism of circTLK1/miR876-3p/SRSF7 axis.

Identification and validation of a novel anoikis-related long non-coding RNA signature for pancreatic adenocarcinoma to predict the prognosis and immune response

OBJECTIVE

To provide more precise treatment options for pancreatic adenocarcinoma (PAAD) patients and improve their prognosis,we established a novel anoikis-related long non-coding RNA signature (ARLSig) to predict the prognosis and immune response for PAAD patients.

METHODS

We downloaded information on PAAD from The Cancer Genome Atlas (TCGA) database, and screened long non-coding RNA (lncRNA) linked with anoikis, and prognostic signatures with these lncRNAs. After that, ARLSig was verified using receiver operating characteristic (ROC) and C-index curves. To further investigate the role of ARLSig, we also performed enrichment analyses using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO). Additionally, using immunological correlation analysis and single-sample genetic enrichment analysis, we investigated the effectiveness of PAAD immunotherapy.

RESULTS

We screened 7 lncRNAs to construct a novel ARLSig and utilized it to predict the efficacy of immunotherapy and the prognosis of PAAD patients.

CONCLUSION

ARLSig can identify patients who will benefit from immunotherapy and improve the prediction of PAAD patient prognosis.

Hsa_circ_0043949 reinforces temozolomide resistance via upregulating oncogene ITGA1 axis in glioblastoma

Temozolomide (TMZ) resistance limits its use in glioblastoma (GBM). Exosomes can carry circular RNAs (circRNAs) to regulate chemoresistance. To date, the role of exosomal hsa_circ_0043949 (circ_0043949) in GBM resistance to TMZ is unclear. Relative expression of circ_0043949 in clinical samples, GBM cell lines, and exosomes was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The half-maximal inhibitory concentration (IC₅₀) of TMZ, cell proliferation, apoptosis, invasion, and migration were analyzed via MTT, EdU, flow cytometry, transwell, and wound-healing assays. Relative protein levels were evaluated by western blotting. Target relationship was predicted by bioinformatics analysis and validated by dual-luciferase reporter and RNA pull-down assays. Exosomes were isolated by ultracentrifugation and verified by transmission electron microscopy, nanoparticle tracking analysis (NTA), and western blotting. The effect of exosomal circ_0043949 on TMZ resistance was validated by xenograft assay. Higher expression of circ_0043949 was gained in TMZ-resistant GBM samples and cells. Inhibition of circ_0043949 reduced TMZ resistance via decreasing IC₅₀ of TMZ, repressing proliferation, invasion, migration, and inducing apoptosis in TMZ-resistant GBM cells. Circ_0043949 mediated integrinalpha1 (ITGA1) expression via function as a miR-876-3p sponge. Circ_0043949 was also upregulated in TMZ-resistant GBM cells-derived exosomes, and exosomal circ_0043949 increased the resistance of TMZ-resistant GBM cells to TMZ in xenograft models. TMZ-resistant GBM cells-derived exosomal circ_0043949 promoted TMZ resistance via upregulating ITGA1 expression via sequestering miR-876-3p, offering a potential target for the treatment of TMZ resistance in GBM.

A Comprehensive Analysis of Pyroptosis-Related lncRNAs Signature Associated With Prognosis and Tumor Immune Microenvironment of Pancreatic Adenocarcinoma

Background: Globally, pancreatic adenocarcinoma (PAAD) is a common and highly devastating gastrointestinal malignancy that seriously threatens human health. Pyroptosis refers to an emerging form of programmed cell death that has been discovered in recent years, and studies have demonstrated that long non-coding RNA (lncRNA) may act as a moderator in the pyroptosis process of cancer cells. However, relevant explorations about lncRNAs and pyroptosis are still insufficient in PAAD. Therefore, our research is designed to make a comprehensive analysis of the potential values of pyroptosis-related lncRNAs in PAAD.

Methods: By integrating the RNA-sequencing, somatic mutation, and copy number variation (CNV) datasets, as well as the clinicopathological features, we established and validated a risk signature based on pyroptosis-related lncRNAs, and comprehensively analyzed its clinical significance and the potential connection with the tumor immune microenvironment (TIME).

Consequences: The genetic variation landscape displayed that the somatic mutations were rare while CNV changes were general and mainly concentrated on copy number amplification of these 52 pyroptosis-related genes. Subsequently, a risk signature consisting of 10 lncRNAs (TRAF3IP2-AS1, LINC00519, LINC01133, LINC02251, AC005332.6, AL590787.1, AC090114.2, TRPC7-AS1, MIR223HG, and MIR3142HG) was constructed and patients were divided into different subgroups according to the median risk score; patients with high-risk scores presented worse outcomes compared to those with low-risk scores in the training, testing, and entire cohorts. Furthermore, patients at low-risk scores possessed a higher infiltration abundance of immune cells compared with high-risk patients, which was consistent with the expression levels of lncRNAs between the high/low-risk groups. Drug sensitivity analysis showed that low-risk scores were related to anti-cancer agents like AICAR and Axitinib, whereas high-risk scores were connected with certain drugs such as AUY922. These results demonstrated that our risk signature could be used for prognosis prediction; additionally, it was also related to the TIME that might act as a potential indicator to instruct immunotherapeutic strategies.

Conclusion: This work explored the significance of the risk model constructed by pyroptosis-related lncRNAs in prognosis prediction and its internal link with the immune microenvironment of PAAD. The results are expected to assist in the diagnosis, prognostic assessment, and management of patients with PAAD.

Circ_0062558 promotes growth, migration, and glutamine metabolism in triple-negative breast cancer by targeting the miR-876-3p/SLC1A5 axis

BACKGROUND

Circular RNAs (circRNAs) have been reported to function as vital regulators in cancers, including triple-negative breast cancer (TNBC). This study aimed to explore the role of circ_0062558 in TNBC.

METHODS

The real-time quantitative polymerase chain reaction (RT-qPCR) was conducted to quantify the expressions of circ_0062558, microRNA-876-3p (miR-876-3p), and solute carrier family 1 (neutral amino acid transporter), member 5 (SLC1A5) in TNBC tissues and cells. 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT), thymidine analog 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, wound healing, and Transwell assays were employed for cell phenotype analyses. Protein expression was tested by western blot analysis. Dual-luciferase reporter was used to confirm the association among circ_0062558, miR-876-3p, and SLC1A5 in TNBC. Xenograft experiments were performed to elucidate the function of circ_0062558 in vivo.

RESULTS

TNBC tissues and cells showed the higher level of circ_0062558 when compared with control samples. Downregulation of circ_0062558 inhibited proliferation, migration, invasion, and glutamine metabolism, while enhanced apoptosis of TNBC cells, and silencing of circ_0062558 also inhibited the growth of tumor in vivo. MiR-876-3p was confirmed as a target of circ_0062558, and circ_0062558 knockdown repressed TNBC cell malignant behaviors by increasing miR-876-3p. Furthermore, miR-876-3p inhibited malignant behaviors of TNBC cells by down-regulating SLC1A5, a newly identified target of miR-876-3p.

CONCLUSION

Circ_0062558 promoted TNBC progression by enhancing proliferation, survival, migration, invasion, and glutamine metabolism via miR-876-3p/SLC1A5 axis, which was helpful for understanding the carcinogenic roles of circ_0062558.

Long Intergenic Non-Coding RNAs in HNSCC: From "Junk DNA" to Important Prognostic Factor

Head and neck squamous cell carcinoma is one of the most common and fatal cancers worldwide. Even a multimodal approach consisting of standard chemo- and radiotherapy along with surgical resection is only effective in approximately 50% of the cases. The rest of the patients develop a relapse of the disease and acquire resistance to treatment. Especially this group of individuals needs novel, personalized, targeted therapy. The first step to discovering such solutions is to investigate the tumor microenvironment, thus understanding the role and mechanism of the function of coding and non-coding sequences of the human genome. In recent years, RNA molecules gained great interest when the complex character of their impact on our biology allowed them to come out of the shadows of the "junk DNA" label. Furthermore, long non-coding RNAs (lncRNA), specifically the intergenic subgroup (lincRNA), are one of the most aberrantly expressed in several malignancies, which makes them particularly promising future diagnostic biomarkers and therapeutic targets. This review contains characteristics of known and validated lincRNAs in HNSCC, such as XIST, MALAT, HOTAIR, HOTTIP, lincRNA-p21, LINC02487, LINC02195, LINC00668, LINC00519, LINC00511, LINC00460, LINC00312, and LINC00052, with a description of their prognostic abilities. Even though much work remains to be done, lincRNAs are important factors in cancer biology that will become valuable biomarkers of tumor stage, outcome prognosis, and contribution to personalized medicine.