Oncogenic LncRNA CASC9 in Cancer Progression

Long non-coding RNAs in cancer: multifaceted roles and potential targets for immunotherapy

Cancer remains a major global health concern with high mortality rates mainly due to late diagnosis and poor prognosis. Long non-coding RNAs (lncRNAs) are emerging as key regulators of gene expression in human cancer, functioning through various mechanisms including as competing endogenous RNAs (ceRNAs) and indirectly regulating miRNA expression. LncRNAs have been found to have both oncogenic and tumor-suppressive roles in cancer, with the former promoting cancer cell proliferation, migration, invasion, and poor prognosis. Recent research has shown that lncRNAs are expressed in various immune cells and are involved in cancer cell immune escape and the modulation of the tumor microenvironment, thus highlighting their potential as targets for cancer immunotherapy. Targeting lncRNAs in cancer or immune cells could enhance the anti-tumor immune response and improve cancer immunotherapy outcomes. However, further research is required to fully understand the functional roles of lncRNAs in cancer and the immune system and their potential as targets for cancer immunotherapy. This review offers a comprehensive examination of the multifaceted roles of lncRNAs in human cancers, with a focus on their potential as targets for cancer immunotherapy. By exploring the intricate mechanisms underlying lncRNA-mediated regulation of cancer cell proliferation, invasion, and immune evasion, we provide insights into the diverse therapeutic applications of these molecules.

ARAP1-AS1: a novel long non-coding RNA with a vital regulatory role in human cancer development

Long non-coding RNAs (lncRNAs) have garnered significant attention in biomedical research due to their pivotal roles in gene expression regulation and their association with various human diseases. Among these lncRNAs, ArfGAP With RhoGAP Domain, Ankyrin Repeat, And PH Domain 1 - Antisense RNA 1 (ARAP1-AS1) has recently emerged as an novel oncogenic player. ARAP1-AS1 is prominently overexpressed in numerous solid tumors and wields influence by modulating gene expression and signaling pathways. This regulatory impact is realized through dual mechanisms, involving both competitive interactions with microRNAs and direct protein binding. ARAP1-AS1 assumes an important role in driving tumorigenesis and malignant tumor progression, affecting biological characteristics such as tumor expansion and metastasis. This paper provides a concise review of the regulatory role of ARAP1-AS1 in malignant tumors and discuss its potential clinical applications as a biomarker and therapeutic target. We also address existing knowledge gaps and suggest avenues for future research. ARAP1-AS1 serves as a prototypical example within the burgeoning field of lncRNA studies, offering insights into the broader landscape of non-coding RNA molecules. This investigation enhances our comprehension of the complex mechanisms that govern the progression of cancer.

LncRNA PITPNA-AS1 mediates the diagnostic potential of miR-129-5p in prostate cancer

BACKGROUND

LncRNA has an effective value in many diseases, which has long been applied in the diagnosis, treatment and prognosis of prostate cancer. This study focused on lncRNA PITPNA-AS1, and its diagnostic potential in prostate cancer has been explored.

METHODS

The expression of PITPNA-AS1 and miR-129-5p in prostate cancer serum and sample cells was determined by real-time quantitative polymerase chain reaction (RT-qPCR). The relationship between the expression of PITPNA-AS1 and clinicopathological parameters was considered. ROC curve prompted the diagnostic value of PITPNA-AS1. The effect of PITPNA-AS1 on prostate cancer cells was verified using vitro cells assay. Luciferase activity assay and RIP assay demonstrated the sponge relationship of PITPNA-AS1 to miR-129-5p.

RESULTS

PITPNA-AS1 level was increased, while miR-129-5p was obviously decreased in prostate cancer. PITPNA-AS1 expression was associated with Gleason grade, lymph node metastasis and TNM stage in patients. The area under the curve (AUC) was 0.910, with high sensitivity and specificity. PITPNA-AS1 was elucidated to directly target miR-129-5p, whereas silencing PITPNA-AS1 negatively affected prostate cancer cell proliferation, migration and invasion. Intervention of miR-129-5p inhibitor reversed the effect of silencing PITPNA-AS1 on cells.

CONCLUSIONS

PITPNA-AS1 was relatively highly expressed in prostate cancer and mediated the pathophysiological process of patients, which may serve as a diagnostic indicator. Silencing of the PITPNA-AS1 sponge miR-129-5p inhibited the biological function of the cells, indicating that PITPNA-AS1 may represent a novel therapeutic target for prostate cancer.

Abnormal activation of genomic LINE1 elements caused by DNA demethylation contributes to lncRNA CASC9 overexpression in esophageal squamous cell carcinoma

Long noncoding RNA (lncRNA) cancer susceptibility 9 (CASC9) has been found to be overexpressed and functions as an oncogene in many cancer types. We investigated the molecular mechanism underlying CASC9 overexpression in esophageal squamous cell carcinoma (ESCC). Transcripts containing exons 2 and 6 and exons 4 and 6 showed the highest CASC9 expression levels in ESCC, no transcripts were detected in the normal esophageal epithelial Het1A cell line. The Long Interspersed Nuclear Element-1 (LINE1 or L1) element in the genome was found to participate in the evolution of lncRNA CASC9, the antisense promoter (ASP) of L1 provides the cis-regulatory elements necessary for CASC9 activation, and the antisense chain of L1 participates in the formation of exons of CASC9. The activation of the antisense promoter was due to the aberrant hypomethylation of L1 elements. An active enhancer element was identified in the downstream region of CASC9 gene by ChIP-seq and ChIP-qPCR. The interaction between ASP and the enhancer elements was confirmed by chromosome conformation capture (3C). Thus, our results suggest that the L1 ASP activation due to aberrant hypomethylation and downstream enhancer interaction plays a key role in the overexpression of lncRNA CASC9 in ESCC.

Single Nucleotide Polymorphisms (SNPs) in the Shadows: Uncovering their Function in Non-Coding Region of Esophageal Cancer

Esophageal cancer is a complex disease influenced by genetic and environmental factors. Single nucleotide polymorphisms (SNPs) in non-coding regions of the genome have emerged as crucial contributors to esophageal cancer susceptibility. This review provides a comprehensive overview of the role of SNPs in non-coding regions and their association with esophageal cancer. The accumulation of SNPs in the genome has been implicated in esophageal cancer risk. Various studies have identified specific locations in the genome where SNPs are more likely to occur, suggesting a location-specific response. Chromatin conformational studies have shed light on the localization of SNPs and their impact on gene transcription, posttranscriptional modifications, gene expression regulation, and histone modification. Furthermore, miRNA-related SNPs have been found to play a significant role in esophageal squamous cell carcinoma (ESCC). These SNPs can affect miRNA binding sites, thereby altering target gene regulation and contributing to ESCC development. Additionally, the risk of ESCC has been linked to base excision repair, suggesting that SNPs in this pathway may influence disease susceptibility. Somatic DNA segment alterations and modified expression quantitative trait loci (eQTL) have also been associated with ESCC. These alterations can lead to disrupted gene expression and cellular processes, ultimately contributing to cancer development and progression. Moreover, SNPs have been found to be associated with the long non-coding RNA HOTAIR, which plays a crucial role in ESCC pathogenesis. This review concludes with a discussion of the current and future perspectives in the field of SNPs in non-coding regions and their relevance to esophageal cancer. Understanding the functional implications of these SNPs may lead to the identification of novel therapeutic targets and the development of personalized approaches for esophageal cancer prevention and treatment.

Predicting lncRNA-disease associations based on heterogeneous graph convolutional generative adversarial network

There is a growing body of evidence indicating the crucial roles that long non-coding RNAs (lncRNAs) play in the development and progression of various diseases, including cancers, cardiovascular diseases, and neurological disorders. However, accurately predicting potential lncRNA-disease associations remains a challenge, as existing methods have limitations in extracting heterogeneous association information and handling sparse and unbalanced data. To address these issues, we propose a novel computational method, called HGC-GAN, which combines heterogeneous graph convolutional neural networks (GCN) and generative adversarial networks (GAN) to predict potential lncRNA-disease associations. Specifically, we construct a lncRNA-miRNA-disease heterogeneous network by integrating multiple association data and sequence information. The GCN-based generator is then employed to aggregate neighbor information of nodes and obtain node embeddings, which are used to predict lncRNA-disease associations. Meanwhile, the GAN-based discriminator is trained to distinguish between real and fake lncRNA-disease associations generated by the generator, enabling the generator to improve its ability to generate accurate lncRNA-disease associations gradually. Our experimental results demonstrate that HGC-GAN performs better in predicting potential lncRNA-disease associations, with AUC and AUPR values of 0.9591 and 0.9606, respectively, under 10-fold cross-validation. Moreover, our case study further confirms the effectiveness of HGC-GAN in predicting potential lncRNA-disease associations, even for novel lncRNAs without any known lncRNA-disease associations. Overall, our proposed method HGC-GAN provides a promising approach to predict potential lncRNA-disease associations and may have important implications for disease diagnosis, treatment, and drug development.

PI3K/Akt signalling pathway-associated long noncoding RNA signature predicts the prognosis of laryngeal cancer patients

The PI3K/Akt signalling pathway is associated with the occurrence and development of tumours and significantly affects the prognosis of patients. We established a predictive signature based on the PI3K/Akt pathway to predict the prognosis of patients. The RNA-seq and clinical data of laryngeal cancer patients were downloaded from The Cancer Genome Atlas (TCGA) database. Three lncRNAs (MNX1-AS1, LINC00330, LSAMP-AS1) were selected through univariate, multivariate Cox and log-rank test analysis to establish a prognostic signature. The patients were then divided into high-risk and low-risk groups based on their risk score. In the TCGA training set, the survival time of the high-risk group was shorter than that of the low-risk group (P < 0.01). Follicular helper T cells were lower in the high-risk group (P = 0.022), and CCR, inflammation promotion, parainflammation, and type I IFN immune function were suppressed. The results of the drug sensitivity analysis suggest that the high-risk group is sensitive to AKT inhibitors. The establishment of the signature was also verified based on the clinical data. Three lncRNAs can facilitate the migration, invasion, and vitality of cancer cells in vitro, and vice versa. Moreover, p-AKT (Ser473) and p-PI3K were highly activated in the cells overexpressing the abovementioned three lncRNAs. The PI3K/Akt signalling pathway-associated prognosis signature has a good predictive effect.

Identification and analysis of key hypoxia- and immune-related genes in hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM), an autosomal dominant genetic disease, is the main cause of sudden death in adolescents and athletes globally. Hypoxia and immune factors have been revealed to be related to the pathology of HCM. There is growing evidence of a role for hypoxia and inflammation as triggers and enhancers in the pathology in HCM. However, the role of hypoxia- and immune-related genes in HCM have not been reported.

METHODS

Firstly, we obtained four HCM-related datasets from the Gene Expression Omnibus (GEO) database for differential expression analysis. Immune cells significantly expressed in normal samples and HCM were then screened by a microenvironmental cell population counter (MCP-counter) algorithm. Next, hypoxia- and immune-related genes were screened by the LASSO + support vector machine recursive feature elimination (SVM-RFE) and weighted gene co-expression network analysis (WGCNA). Single-gene enrichment analysis and expression validation of key genes were then performed. Finally, we constructed a competing endogenous RNA (ceRNA) network of key genes.

RESULTS

In this study, 35 differentially expressed hypoxia genes were found. By using LASSO + SVM-RFE analysis, 10 more targets with differentially expressed hypoxia genes were identified. The MCP-count algorithm yielded five differentially expressed immune cells, and after assessing them for WGCNA characteristics, 612 immune genes were discovered. When hypoxia and immune genes were combined for cross-tabulation analysis, three hypoxia- and immune-related genes (ATP2A2, DDAH1, and OMA1) were identified.

CONCLUSION

Based on hypoxia characteristic genes, three key genes were identified. These were also significantly related to immune activation, which proves a theoretical basis and reference value for studying the relationship between HCM and hypoxia and immunity.

Identification of a novel lncRNA prognostic signature and analysis of functional lncRNA AC115619.1 in hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) is the deadliest malignancy. Long non-coding RNAs (lncRNAs) are involved in the development of multiple human malignancies. This study aimed to establish a reliable signature and identify novel biomarkers for HCC patients. Methods: Differentially expressed lncRNAs (DElncRNAs) were identified from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Univariate, LASSO, and multivariate Cox regression analyses were applied to screen the prognostic lncRNAs and establish a prognostic model. Receiver operating characteristic (ROC) curves and Kaplan-Meier analyses were conducted to validate the prognostic value of this model. The association between lncRNAs and differential m6A genes was analyzed by Spearman's analysis. A series of bioinformatic and in vitro experiments were applied to explore the function of hub lncRNA. Results: A total of 32 DElncRNAs were identified, and 12 DElncRNAs were associated with the prognosis of HCC patients. A prognostic signature comprising six prognostic lncRNAs (LINC02428, LINC02163, AC008549.1, AC115619.1, CASC9, and LINC02362) was constructed, and the model exhibited an excellent capacity for prognosis prediction. Furthermore, 12 differential m6A regulators were identified, and RBMX was found to be correlated negatively with the hub lncRNA AC115619.1. The expression level of AC115619.1 was lower in HCC tissues than that in normal tissues and was significantly related to clinicopathologic features, survival rate, and drug sensitivity. Overexpression of AC115619.1 notably inhibited the proliferation, migration, and invasion of HCC cells. Conclusion: This study provided a promising prognostic signature for HCC patients and identified AC115619.1 as a novel biomarker, which plays an essential role in regulating the progression of HCC.

Long noncoding RNA CASC9 promotes pancreatic cancer progression by acting as a ceRNA of miR-497-5p to upregulate expression of CCND1

BACKGROUND

Pancreatic cancer (PC) is an aggressive malignancy with poor prognosis. Accumulating studies have showed that long non-coding RNA (lncRNA) is a crucial regulator in various tumorigenesis and progression including PC. This research aims to explore the roles and molecular mechanism of lncRNA cancer susceptibility candidate 9 (CASC9) in PC.

METHODS

The expression levels of lncRNA CASC9 and miR-497-5p were evaluated in PC tissues and paired adjacent healthy tissues by quantitative real-time PCR. PC cell lines were transfected with lentivirus targeting lncRNA CASC9, and cells proliferation, migration and invasion tests were conducted. Dual luciferase reporter assays were also carried out to explore the relationship between lncRNA CASC9, miR-497-5p and Cyclin D1 (CCND1).

RESULTS

LncRNA CASC9 was significantly up-regulated in PC tissues, while miR-497-5p expression was down-regulated. Down-regulation of lncRNA CASC9 in PC cells can significantly suppress the cell aggressiveness both in vitro and in vivo; moreover, knock-down of miR-497-5p could neutralize this impact. Additionally, the luciferase activity assay has assured that CCND1 was a downstream target of miR-497-5p.

CONCLUSION

LncRNA CASC9 can promote the PC progression by modulating miR-497-5p/CCND1 axis, which is potential target for PC treatment.

Comprehensive Analysis of Quantitative Proteomics With DIA Mass Spectrometry and ceRNA Network in Intrahepatic Cholestasis of Pregnancy

Background: Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific complication characterized by pruritus without skin damage and jaundice. The poor perinatal outcomes include fetal distress, preterm birth, and unexpected intrauterine death. However, the mechanism of ICP leading to poor prognosis is still unclear.

Methods: We analyzed 10 ICP and 10 normal placental specimens through quantitative proteomics of data-independent acquisition (DIA) to screen and identify differentially expressed proteins. GO, KEGG, COG/KOG, StringDB, InterProScan, Metascape, BioGPS, and NetworkAnalyst databases were used in this study. PITA, miRanda, TargetScan, starBase, and LncBase Predicted v.2 were used for constructing a competing endogenous RNA (ceRNA) network. Cytoscape was used for drawing regulatory networks, and cytoHubba was used for screening core nodes. The ICP rat models were used to validate the pathological mechanism.

Results: GO, KEGG, and COG/KOG functional enrichment analysis results showed the differentially expressed proteins participated in autophagy, autophagosome formation, cofactor binding, JAK-STAT signaling pathway, and coenzyme transport and metabolism. DisGeNET analysis showed that these differentially expressed proteins were associated with red blood cell disorder and slow progression. We further analyzed first 12 proteins in the upregulated and downregulated differentially expressed proteins and incorporated clinicopathologic parameters. Our results showed HBG1, SPI1, HBG2, HBE1, FOXK1, KRT72, SLC13A3, MBD2, SP9, GPLD1, MYH7, and BLOC1S1 were associated with ICP development. ceRNA network analysis showed that MBD2, SPI1, FOXK1, and SLC13A3 were regulated by multiple miRNAs and lncRNAs.

Conclusion: ICP was associated with autophagy. The ceRNA network of MBD2, SPI1, FOXK1, and SLC13A3 was involved in ICP progression, and these core proteins might be potential target.

LncRNA GATA2-AS1 suppresses esophageal squamous cell carcinoma progression via the mir-940/PTPN12 axis

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor worldwide. Long noncoding RNAs (lncRNAs) exhibit a regulatory role in the progression of ESCC. Our research was performed to investigate the potential molecular mechanism of lncRNA GATA2-AS1 in ESCC.

METHODS

The expression of GATA2-AS1 was identified by qRT-PCR. Cell function assays explored the potential effect of GATA2-AS1 on ESCC progression. The subcellular hierarchical localization method was executed to identify the subcellular localization of GATA2-AS1 in ESCC cells. A prediction website was utilized to discover the relationships among GATA2-AS1, miR-940 and PTPN12. Dual luciferase reporter gene, pull-down assays and RIP assays were executed to verify the binding activity among GATA2-AS1, miR-940 and PTPN12. Xenograft tumor experiments were performed to evaluate ESCC cell growth in vivo.

RESULTS

The expression of GATA2-AS1 and PTPN12 was reduced, while miR-940 expression was enhanced in ESCC tissues and cell lines. In vivo experiments showed that GATA2-AS1 inhibited the progression of ESCC cells toward malignancy. Bioinformatics analysis, dual luciferase and RIP assays revealed that GATA2-AS1 upregulated PTPN12 expression by competitively targeting miR-940. miR-940 reversed the inhibitory effect of GATA2-AS1 on the biological behavior of ESCC cells.

CONCLUSION

Our findings suggested that GATA2-AS1, expressed at low levels in ESCC, plays a crucial role in the progression of ESCC by targeting the miR-940/PTPN12 axis and could be a potential drug target to treat ESCC patients.

Long Non-Coding RNA in Esophageal Cancer: A Review of Research Progress

In recent years, there has been significant progress in the diagnosis and treatment of esophageal cancer. However, owing to the lack of early diagnosis strategies and treatment targets, the prognosis of patients with esophageal cancer remains unsatisfactory. There is an urgent need to identify novel biomarkers and treatment targets for esophageal cancer. With the development of genomics, long-chain non-coding RNAs (LncRNAs), which were once considered transcriptional “noise,” are being identified and characterized rapidly in large numbers. Recent research shows that LncRNAs are closely related to a series of steps in tumor development and play an important regulatory role in DNA replication, transcription, and post-transcriptional regulation. The abnormal expression of LncRNAs leads to tumor cell proliferation, migration, invasion, and treatment resistance. This review focuses on the latest progress in research on the abnormal expression and functional mechanisms of LncRNAs in esophageal cancer. Further, it discusses the potential applications of these findings towards achieving an early diagnosis, improving treatment efficacy, and evaluating the prognosis of esophageal cancer.

Long Noncoding RNA 00472: A Novel Biomarker in Human Diseases

Long non-coding RNAs (lncRNAs) play important roles in human diseases. They control gene expression levels and influence various biological processes through multiple mechanisms. Functional abnormalities in lncRNAs are strongly associated with occurrence and development of various diseases. LINC00472, which is located on chromosome 6q13, is involved in several human diseases, particularly cancers of the breast, lung, liver, osteosarcoma, bladder, colorectal, ovarian, pancreatic and stomach. Importantly, LINC00472 can be used as a biomarker for breast cancer cell sensitivity to chemotherapeutic regimens, including doxorubicin. LINC00472 is regulated by microRNAs and several signaling pathways. However, the significance of LINC00472 in human diseases has not been clearly established. In this review, we elucidate on the significance of LINC00472 in various human diseases, indicating that LINC00472 may be a diagnostic, prognostic as well as therapeutic target for these diseases.

Changes and Prognostic Value of lncRNA CASC9 in Patients with Advanced Colon Cancer after Chemotherapy

OBJECTIVE

Colon cancer (CC) shows a gradual increasing incidence in recent years, and chemotherapy is a frequently adopted treatment for patients with middle or advanced colon cancer (ACC), but it lacks prognostic markers after CC.

METHODS

The changes of lncRNA CASC9 in 58 patients with CC were determined using a real-time quantitative PCR (qRT-PCR) assay before and after chemotherapy, and the correlation of serum lncRNA CASC9 with efficacy of FOLFOX4 regimen (oxaliplatin + calcium folinate + fluorouracil) was analyzed. The patients were followed up to understand the association of lncRNA CASC9 with overall survival (OS) and progression-free survival (PFS).

RESULTS

Patients with CC showed notably higher lncRNA CASC9 expression than controls, and lncRNA CASC9 presented an association with the clinical stage of the patients. In addition, lncRNA CASC9 demonstrated a clinical value in predicting efficacy on patients and acted as one independent prognostic factor for PFS in patients with ACC.

CONCLUSIONS

With increased expression of serum lncRNA CASC9, patients with ACC suffered an unfavorable chemotherapy effect. In addition, serum lncRNA CASC9 is a promising sensitive indicator for prediction of ACC and is related to the clinical efficacy and prognosis of patients.

LncRNAs as Architects in Cancer Biomarkers with Interface of Epitranscriptomics- Incipient Targets in Cancer Therapy

Long non-coding RNAs (LncRNAs) epitomize a class of non-coding regulatory RNAs with more than 200 nucleotides, which are long and situated in the nucleus or cytoplasm and rarely encode proteins. Accruing evidence signposts that lncRNAs act as molecular switches in different cellular activities like differentiation, apoptosis, as well as reprogramming of cellular states by modifying gene expression patterns. The revelation of immense numbers of lncRNA with their wide variety of expression patterns in different kinds of malignancy, tumor explicitness, and their steadiness in circulating body fluids deliver an innovative groundwork for emerging diagnosis and treatments for cancer. Mechanisms associating lncRNAs in carcinogenesis are conquered by deregulation of cellular signaling pathways and altered epitranscriptome along with their expression. Specified these attributes, it becomes clear that the improvement of new tools to identify lncRNAs with higher affectability will be fundamental to allow the identification of the expression pattern of lncRNAs in various kinds of malignant growth and may likewise be utilized to envisage cancer prognosis in addition to the patients' outcome. Improvement of RNA targeting-based therapeutics is delivering incredible prospects to modulate lncRNAs for anti-cancer initiatives. Henceforth, lncRNAs can be used exclusively as possible cancer biomarkers for early diagnosis and anticipation of malignancy, as well as metastasis. In addition to the basic curative targets and along these, lncRNAs hold resilient assurance towards the revelation of innovative diagnostics and therapeutics for malignant growth with the interface of epitranscriptomics information. This review aims to briefly discuss the latest findings regarding the roles and mechanisms of some important lncRNAs in the pathogenesis, regulation, and lncRNA-associated epigenetics of cancer along with targeting lncRNAs with potential approaches for impending diagnosis and therapeutic intervention in malignancies.