STAT1-induced regulation of lncRNA ZFPM2-AS1 predicts poor prognosis and contributes to hepatocellular carcinoma progression via the miR-653/GOLM1 axis

Interplay between JAK/STAT pathway and non-coding RNAs in different cancers

Progress in the identification of core multi-protein modules within JAK/STAT pathway has enabled researchers to develop a better understanding of the linchpin role of deregulated signaling cascade in carcinogenesis and metastasis. More excitingly, complex interplay between JAK/STAT pathway and non-coding RNAs has been shown to reprogramme the outcome of signaling cascade and modulate immunological responses within tumor microenvironment. Wealth of information has comprehensively illustrated that most of this complexity regulates the re-shaping of the immunological responses. Increasingly sophisticated mechanistic insights have illuminated fundamental role of STAT-signaling in polarization of macrophages to M2 phenotype that promotes disease aggressiveness. Overall, JAK/STAT signaling drives different stages of cancer ranging from cancer metastasis to the reshaping of the tumor microenvironment. JAK/STAT signaling has also been found to play role in the regulation of infiltration and activity of natural killer cells and CD4/CD8 cells by PD-L1/PD-1 signaling. In this review, we have attempted to set spotlight on regulation of JAK/STAT pathway by microRNAs, long non-coding RNAs and circular RNAs in primary tumors and metastasizing tumors. Therefore, existing knowledge gaps need to be addressed to propel this fledgling field of research to the forefront and bring lncRNAs and circRNAs to the frontline of clinical practice. Leveraging the growing momentum will enable interdisciplinary researchers to gain transition from segmented view to a fairly detailed conceptual continuum.

Identification and validation of a five-necroptosis-related lncRNAs signature for prognostic prediction in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is among the most prevalent digestive system malignancies and is associated with a poor prognosis. Necroptosis, a form of regulated death mediated by death receptors, exhibits characteristics of both necrosis and apoptosis. Long non-coding RNAs (lncRNAs) have been identified as crucial regulators in tumor necroptosis. This study aims to identify the necroptosis-related lncRNAs (np-lncRNA) in HCC and investigate their relationships with prognosis.

Method

The RNA-sequencing data, along with clinicopathological and survival information of HCC patients were sourced from The Cancer Genome Atlas (TCGA) database. The np-lncRNAs were analyzed to assess their potential in predicting HCC prognosis. Prognostic signatures related to necroptosis were constructed using stepwise multivariate Cox regression analysis. The prognosis of patients was compared using Kaplan-Meier (KM) analysis. The accuracy of the prognostic signature was evaluated using Receiver operating characteristic (ROC) analysis and decision curve analysis (DCA). Quantitative real-time polymerase chain reaction(qPCR) was employed to validate the lncRNAs expression levels of lncRNAs among samples from an independent cohort.

Results

The np-lncRNAs ZFPM2-AS1, AC099850.3, BACE1-AS, KDM4A-AS1 and MKLN1-AS were identified as potential prognostic biomarkers. The prognostic signature constructed from these np-lncRNAs achieved an Area Under the Curve (AUC) of 0.773. Based on the risk score derived from the signature, patients were divided into two groups, with the high-risk group exhibiting poorer overall survival. Gene Set Enrichment Analysis (GSEA) revealed significantly different between the low risk and high risk groups in tumor-related pathways (such as mTOR, MAPK and p53 signaling pathways) and immune-related functions (like T cell receptor signaling pathway and natural killer cell mediated cytotoxicity). The increased expression of np-lncRNAs was confirmed in another independent HCC cohort.

Conclusions

This signature offers a dependable method for forecasting the prognosis of HCC patients. Our findings indicate a subset of np-lncRNA biomarkers that could be utilized for prognosis prediction and personalized treatment strategies of HCC patients.

LOXL4 Shuttled by Tumor Cells-derived Extracellular Vesicles Promotes Immune Escape in Hepatocellular Carcinoma by Activating the STAT1/PD-L1 Axis

Emerging evidence has validated that extracellular vesicles (EVs) regulate hepatocellular carcinoma (HCC) progression, while its role in HCC immune escape remains to be elucidated. This study investigates the role of EVs-encapsulated lysyl oxidase like-4 (LOXL4) derived from tumor cells in HCC immune escape. HCC-related microarray data sets GSE36376 and GSE87630 were obtained for differential analysis, followed by identifying the essential genes related to the prognosis of HCC patients. Bone marrow-derived macrophages were treated with EVs derived from mouse Hepa 1-6 cells and cocultured with CD8 + T cells to observe the CD8 + T-cell activity. At last, a mouse HCC orthotopic xenograft model was constructed to verify the effects of HCC cell-derived EVs on the immune escape of HCC cells and tumorigenicity in vivo by delivering LOXL4. It was found that ACAT1, C4BPA, EHHADH, and LOXL4 may be the essential genes related to the prognosis of HCC patients. On the basis of the TIMER database, there was a close correlation between LOXL4 and macrophage infiltration in HCC. Besides, STAT1 was closely related to LOXL4. In vitro experiments demonstrated that LOXL4 could induce programmed death-ligand 1 expression in macrophages and immunosuppression by activating STAT1. In vivo experiments also verified that HCC cell-derived EVs promoted the immune escape of HCC cells and tumorigenicity by delivering LOXL4. LOXL4 was delivered into macrophages via EVs to induce programmed death-ligand 1 by activating STAT1 and inhibiting the killing ability of CD8 + T cells to HCC cells, thus promoting immune escape in HCC.

Nucleus-localized circSLC39A5 suppresses hepatocellular carcinoma development by binding to STAT1 to regulate TDG transcription

Accumulating evidence indicates that circular RNAs (circRNAs) are inextricably linked to cancer development. However, the function and mechanism of nucleus-localized circRNAs in hepatocellular carcinoma (HCC) still require investigation. Here, qRT-PCR and receiver-operating characteristic curve were used to detect the expression and diagnostic potential of circSLC39A5 for HCC. The biological function of circSLC39A5 in HCC was investigated in vitro and in vivo. Nucleoplasmic separation assay, fluorescence in situ hybridization, RNA pulldown, RNA immunoprecipitation, the HDOCK Server, the NucleicNet Webserver, crosslinking-immunoprecipitation, MG132 treatment, and chromatin immunoprecipitation were utilized to explore the potential molecular mechanism of circSLC39A5 in HCC. The results showed that circSLC39A5 was downregulated in both HCC tissues and plasma and was associated with satellite nodules and lymph node metastasis/vascular invasion. CircSLC39A5 was stably expressed in plasma samples under different storage conditions, showing good diagnostic potential for HCC (AUC = 0.915). CircSLC39A5 inhibited proliferation, migration, and invasion, facilitated the apoptosis of HCC cells, and was associated with low expression of Ki67 and CD34. Remarkably, circSLC39A5 is mainly localized in the nucleus and binds to the transcription factor signal transducer and activator of transcription 1 (STAT1), affecting its stabilization and expression. STAT1 binds to the promoter of thymine DNA glycosylase (TDG). Overexpression of circSLC39A5 elevates TDG expression and reverses the increase of proliferating cell nuclear antigen (PCNA) expression and the overactive cell proliferation caused by TDG silencing. Our findings uncovered a novel plasma circRNA, circSLC39A5, which may be a potential circulating diagnostic marker for HCC, and the mechanism by which nucleus-localized circSLC39A5 exerts a transcriptional regulatory role in HCC by affecting STAT1/TDG/PCNA provides new insights into the mechanism of circRNAs.

Cuproptosis-related miRNAs signature and immune infiltration characteristics in colorectal cancer

BACKGROUND

A novel form of cell death termed cuproptosis was proposed recently. miRNAs play important roles in colorectal cancer (CRC). However, their relationships have not been reported.

METHODS

miRNAs that negatively regulate 16 cuproptosis regulators were predicted using Targetscan database. The univariate Cox, LASSO, and multivariate Cox regression analyses were performed to select cuproptosis-related miRNAs. GSEA and ssGSEA analysis was carried out for functional enrichment analysis. The immune cell proportion score (IPS) and the efficiencies of multiple chemotherapy drugs were compared between different risk groups. The CCK8, cell colony, edu, and flow cytometry assays were performed to validate the roles of miRNA. Luciferase reporter assay confirmed the regulatory mechanism of miRNA on cuproptosis.

RESULTS

Six cuproptosis-related miRNAs (hsa-miR-653, hsa-miR-216a, hsa-miR-3684, hsa-miR-4437, hsa-miR-641, and hsa-miR-552) were screened out for model construction. The risk score could act as an independent prognostic indicator in CRC (p < 0.001, 95% HR = 1.243 (1.129-1.369)). The nomogram could efficiently predict the overall survival rate (AUC = 0.836). Then, the level of immunosuppressive pathways, immunosuppressive cells, stromal-activated genes, and stromal score was higher in the high-risk group. The IPS analysis showed a better response to immunotherapy in the low-risk group. Also, the risk score was closely correlated with efficiencies of multiple chemotherapy drugs. Furthermore, miR-653 was highly expressed in CRC tissues (p < 0.001), closely correlated with T stage (p < 0.001), metastasis (p < 0.001), and tumor stage (p < 0.001). High expression of miR-653 predicted a shorter overall survival (p = 0.0282) and disease-free survival (p = 0.0056). In addition, miR-653 promoted cell proliferation, inhibited apoptosis, and negatively regulated the expression of DLD through directly binding to the 3'-UTR of DLD mRNA.

CONCLUSION

We constructed a cuproptosis-related miRNA signature for the prediction of CRC patient survival and immunotherapy sensitivity. miR-653 was highly expressed in CRC tissues, promoted cell proliferation, and inhibited apoptosis by negatively regulating the expression of DLD.

Making Sense of Antisense lncRNAs in Hepatocellular Carcinoma

Transcriptome complexity is emerging as an unprecedented and fascinating domain, especially by high-throughput sequencing technologies that have unveiled a plethora of new non-coding RNA biotypes. This review covers antisense long non-coding RNAs, i.e., lncRNAs transcribed from the opposite strand of other known genes, and their role in hepatocellular carcinoma (HCC). Several sense-antisense transcript pairs have been recently annotated, especially from mammalian genomes, and an understanding of their evolutionary sense and functional role for human health and diseases is only beginning. Antisense lncRNAs dysregulation is significantly involved in hepatocarcinogenesis, where they can act as oncogenes or oncosuppressors, thus playing a key role in tumor onset, progression, and chemoradiotherapy response, as deduced from many studies discussed here. Mechanistically, antisense lncRNAs regulate gene expression by exploiting various molecular mechanisms shared with other ncRNA molecules, and exploit special mechanisms on their corresponding sense gene due to sequence complementarity, thus exerting epigenetic, transcriptional, post-transcriptional, and translational controls. The next challenges will be piecing together the complex RNA regulatory networks driven by antisense lncRNAs and, ultimately, assigning them a function in physiological and pathological contexts, in addition to defining prospective novel therapeutic targets and innovative diagnostic tools.

The members of the miR-148/152 family inhibit cancer stem cell-like properties in gastric cancer via negative regulation of ITGA5

BACKGROUND

The role of microRNA (miRNA) in modulating the function of cancer stem cells through diverse signaling pathway has been evidenced. We here identified a role of microRNA (miRNA) family, specifically miR-148/152, in gastric cancer and delineated its functional effects on gastric cancer stem cells.

METHODS

Bioinformatics analysis was conducted to analyze expression of integrin α5 (ITGA5) which was verified through expression determination in clinical tissue samples. Next, the upstream regulatory factors of ITGA5 were determined. CD44⁺EpCAM (high) cells sorted from AGS cells subjected to gain-of-function experiments, followed by evaluation of their capacity of colony formation, generation of tumorosphere, cell migration and viability in vitro and xenograft tumor formation in vivo.

RESULTS

ITGA5 was elevated in gastric cancer tissues and confirmed as a target gene of the miR-148/152 family members. The miR-148/152 family members were downregulated in gastric cancer tissues and cells. Decreased expression of miR-148/152 family members was also detected in gastric cancer stem cells. However, the raised expression led to reduced colony formation, tumorosphere, cell migration, cell viability, and drug resistance of CD44+EpCAM (high) AGS cells in vitro, and tumorigenesis in vitro. ITGA5 overexpression reversed the effect of the miR-148/152 family members.

CONCLUSIONS

This study demonstrates that the miR-148/152 family members may prevent gastric cancer stem cell-like properties by targeting ITGA5, which can serve as an appealing target for gastric cancer treatment.

Machine learning-based construction of a ferroptosis and necroptosis associated lncRNA signature for predicting prognosis and immunotherapy response in hepatocellular cancer

Introduction

Liver hepatocellular carcinoma (LIHC), one of the most common malignancies worldwide, occurs with high incidence and mortality. Ferroptosis and necroptosis are critically associated with LIHC prognosis. Some long non-coding RNAs (lncRNAs) have been found to induce ferroptosis and necroptosis in hepatocellular carcinoma cells.

Methods

Cox regression analysis was used to construct a risk model for LIHC based on differentially expressed ferroptosis and necroptosis related lncRNAs (F-NLRs), and their expression in SMMC7721, HepG2 and WRL68 cells was detected by qPCR.

Results

Five F-NLRs were associated with LIHC prognosis, including KDM4A-AS1, ZFPM2-AS1, AC099850.3, MKLN1-AS, and BACE1-AS. Kaplan-Meier survival analysis indicated that patients with LIHC in the high-risk group were associated with poor prognosis. The combined F-NLR signature model demonstrated a prognostic AUC value of 0.789 and was more accurate than standard clinical variables for predicting LIHC prognosis. T cell functions and immunotherapy responses differed significantly between patients in the low- and high-risk groups. Additionally, immune checkpoints and m6A-related genes were differentially expressed between patients in the two risk groups. Furthermore, proteins encoded by the five F-NLRs were overexpressed in four liver cancer cell lines compared to that in human liver cell line WRL68. Pan-cancer examination revealed that expression levels of the five F-NLRs differed between most common tumor types and normal tissues.

Conclusion

F-NLRs identified in this study provide a predictive signature representing ferroptosis and necroptosis in LIHC, which correlated well with patient prognosis, clinicopathological characteristics, and immunotherapy responses. The study findings help to elucidate the mechanisms of F-NLRs in LIHC and provide further guidance for the selection and development of immunotherapeutic agents for LIHC.

The crucial role of LncRNA MIR210HG involved in the regulation of human cancer and other disease

Long noncoding RNAs (lncRNAs) have evoked considerable interest in recent years due to their critical functions in the regulation of disease processes. Abnormal expression of lncRNAs is found in multiple diseases, and lncRNAs have been exploited for diverse medical applications. The lncRNA MIR210HG is a recently discovered lncRNA that is widely dysregulated in human disease. MIR210HG was described to have biological functions with potential roles in disease development, including cell proliferation, invasion, migration, and energy metabolism. And MIR210HG dysregulation was confirmed to have promising clinical values in disease diagnosis, treatment, and prognosis. In this review, we systematically summarize the expression profiles, roles, underlying mechanisms, and clinical applications of MIR210HG in human disease.

Circ_0091579 exerts an oncogenic role in hepatocellular carcinoma via mediating miR-136-5p/TRIM27

BACKGROUND

Circular RNAs (circRNAs) act as crucial regulators in tumorigenesis. In this study, the working mechanism of circ_0091579 in hepatocellular carcinoma (HCC) progression was investigated.

METHODS

The expression of RNA and protein was measured via RT-qPCR and Western blot assay. Cell proliferation ability was analyzed via CCK8, EdU and colony formation assays. Cell migration and invasion abilities were detected via transwell assays. Flow cytometry was applied to assess cell cycle and apoptosis. The target relation between miR-136-5p and circ_0091579 or tripartite motif containing 27 (TRIM27) was certified using dual-luciferase reporter assay. Xenograft tumor model was utilized to assess the role of circ_0091579 in tumor growth in vivo. The protein level of Ki67 in tumor tissues was analyzed by immunohistochemistry (IHC) assay.

RESULTS

Circ_0091579 expression was elevated in HCC tissues and cell lines. HCC patients with high circ_0091579 expression displayed low survival rate. Circ_0091579 knockdown suppressed the proliferation, migration, invasion, cell cycle progression and epithelial-mesenchymal transition (EMT) and induced apoptosis of HCC cells. Circ_0091579 acted as a molecular sponge for miR-136-5p, and circ_0091579 silencing-mediated effects were largely overturned by the knockdown of miR-136-5p in HCC cells. MiR-136-5p interacted with the 3' untranslated region (3'UTR) of TRIM27, and TRIM27 overexpression largely counteracted miR-136-5p overexpression-induced influences in HCC cells. Circ_0091579 sponged miR-136-5p to up-regulate TRIM27 expression in HCC cells. Circ_0091579 silencing suppressed xenograft tumor growth in vivo.

CONCLUSION

Circ_0091579 exhibited an oncogenic role to enhance the malignant potential of HCC cells through mediating miR-136-5p/TRIM27 axis in vitro and in vivo.

Tumour-derived exosomal lncRNA SNHG16 induces telocytes to promote metastasis of hepatocellular carcinoma via the miR-942-3p/MMP9 axis

BACKGROUND

Hepatocellular carcinoma (HCC) cell-derived exosomal LncRNA SNHG16 is highly expressed and associated with poor overall survival of patients. Telocytes (TCs), as novel interstitial cells, have been reported to promote HCC metastasis. Therefore, in our study, we investigated whether a molecular interaction occurred between exosomal LncSNHG16 and TCs in the tumor microenvironment.

METHODS

LncSNHG16 expression in HCC tissues and cell lines was measured, and bioinformatics analysis was performed. Exosomes were isolated and purified from HCC cells with LncSNHG16 overexpression/knockdown vectors and cocultured with TCs. Then, markers of the LncSNHG16/miR-942-3p/MMP9 axis were tested in TCs. Transwell assays and cell wound healing assays were designed to examine the invasion and migration of HCC cells after coincubation with TCs. RNA immunoprecipitation (RIP) assays and dual-luciferase gene reporter assays were performed to verify the binding effect of LncSNHG16, miR-942-3p, and MMP9 mRNA. In vivo, experimental animal models were established to confirm the effect of exosomal LncSNHG16-induced MMP9 expression on HCC metastasis.

RESULTS

Exosomal LncSNHG16 was phagocytized by TCs and downregulated miR-942-3p, which induced targeted MMP9 upregulation, and it had specific binding sites with miR-942-3p in TCs to facilitate the migration of HCC cells in vitro and in vivo. Exosomal LncSNHG16 was found to act as a competing endogenous RNA of the miR-942-3p/MMP9 axis in TCs.

CONCLUSION

Tumour-derived exosomal LncSNHG16 modulates MMP9 via competitively binding to miR-942-3p in TCs, thus promoting the metastasis of HCC.

Cytosolic TGM2 promotes malignant progression in gastric cancer by suppressing the TRIM21-mediated ubiquitination/degradation of STAT1 in a GTP binding-dependent modality

BACKGROUND

Previous studies have revealed the critical role of transglutaminase 2 (TGM2) as a potential therapeutic target in cancers, but the oncogenic roles and underlying mechanisms of TGM2 in gastric cancer (GC) are not fully understood. In this study, we examined the role and potential mechanism of TGM2 in GC.

METHODS

Western blotting, immunohistochemistry, CCK8, colony formation and transwell assays were used to measure TGM2 expression in the GC cells and tissues and to examine the in vitro role of TGM2 in GC. Xenograft and in vivo metastasis experiments were performed to examine the in vivo role of TGM2 in GC. Gene set enrichment analysis, quantitative PCR and western blotting were conducted to screen for potential TGM2 targets involved in GC. Gain/loss-of-function and rescue experiments were conducted to detect the biological roles of STAT1 in GC cells in the context of TGM2. Co-immunoprecipitation, mass spectrometry, quantitative PCR and western blotting were conducted to identify STAT1-interacting proteins and elucidate their regulatory mechanisms. Mutations in TGM2 and two molecules (ZM39923 and A23187) were used to identify the enzymatic activity of TGM2 involved in the malignant progression of GC and elucidate the underlying mechanism.

RESULTS

In this study, we demonstrated elevated TGM2 expression in the GC tissues, which closely related to pathological grade, and predicted poor survival in patients with GC. TGM2 overexpression or knockdown promoted (and inhibited) cell proliferation, migration, and invasion, which were reversed by STAT1 knockdown or overexpression. Further studies showed that TGM2 promoted GC progression by inhibiting STAT1 ubiquitination/degradation. Then, tripartite motif-containing protein 21 (TRIM21) was identified as a ubiquitin E3 ligase of STAT1 in GC. TGM2 maintained STAT1 stability by facilitating the dissociation of TRIM21 and STAT1 with GTP-binding enzymatic activity. A23187 abolished the role of TGM2 in STAT1 and reversed the pro-tumor role of TGM2 in vitro and in vivo.

CONCLUSIONS

This study revealed a critical role and regulatory mechanism of TGM2 on STAT1 in GC and highlighted the potential of TGM2 as a therapeutic target, which elucidates the development of medicine or strategies by regulating the GTP-binding activity of TGM2 in GC.

Development of a novel immune-related lncRNA prognostic signature for patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common neoplasm and the major cause of cancer-associated death worldwide. The high mortality rate of HCC is mainly attributed to its widespread prevalence and the lack of effective treatment. Immunotherapy as a promising, innovative approach has revolutionised the treatment of solid tumours. However, owing to the heterogeneity and complex tumour microenvironment of HCC, an efficient biomarker for immunotherapy has yet to be identified. We investigated the role of immune-related long non-coding RNAs (lncRNAs) as prognostic biomarkers in patients with HCC from The Cancer Genome Atlas (TCGA) database. Spearman correlation, univariate and multivariate Cox, and lasso regression analyses were utilised to screen lncRNAs associated with prognosis. Four lncRNAs were filtered out to develop an immune-associated lncRNA prognostic signature in TCGA training as well as validation cohorts. Patients with HCC were then categorised into low- and high-risk groups according to the median value of the risk scores to evaluate the ability of the prognostic model between training and validation cohorts. A nomogram (based on risk score and stage) was constructed to appraise the general overall survival (OS) of patients with HCC. Differences in immune cell infiltration, immune checkpoint inhibitor (ICI) treatment response, gene mutation, and drug sensitivity were observed between the two groups. Thus, the lncRNA prognostic signature can serve as a sensitive prognostic biomarker with potential in individualised immunotherapy for HCC patients.

Histone deacetylase 2 regulates STAT1-dependent upregulation of atypical chemokine receptor 3 to induce M2 macrophage migration and immune escape in hepatocellular carcinoma

Atypical chemokine receptor 3 (ACKR3) has been linked to the tumor microenvironment. This work investigates the effects of ACKR3 and its regulatory molecules on the chemotactic migration of tumor-associated macrophages (TAMs) in hepatocellular carcinoma (HCC). RT-qPCR and western blot assays identified elevated ACKR3 and HDAC2 levels in HCC tissues and cells. Knockdown or overexpression of ACKR3 was induced in HCC cells through vectors of lentivirus plasmids, and then the conditioned medium of the HCC cells was collected to stimulate TAMs. The stimulated TAMs were co-cultured with CD3⁺ T cells. ACKR3 knockdown in HCC cells inhibited migration of TAMs and promoted M1 polarization, which restored the activity of T cells. Histone deacetylase 2 (HDAC2) recruited signal transducer and activator of transcription 1 (STAT1) to the ACKR3 promoter to activate ACKR3 transcription. HDAC2 silencing suppressed nuclear translocation of STAT1 and decreased ACKR3 expression. HDAC2 knockdown in HCC cells similarly suppressed TAM migration, promoted M1 polarization, and restored T cell function, but these changes were inversed by ACKR3 upregulation. HDAC2 or ACKR3 silencing weakened tumor growth and immune escape in mice. In conclusion, this study demonstrates that HDAC2 upregulates ACKR3 via STAT1 to induce migration of M2 macrophages and immune escape in HCC.

The integrated comprehension of lncRNA HOXA-AS3 implication on human diseases

Long non-coding RNA (lncRNA) is a non-protein-coding RNA with a length of more than 200 nucleotides. Studies have shown that lncRNAs have vital impacts on various pathological processes and participate in the development of human diseases, usually through acting as competing endogenous RNAs to modulate miRNA expression and biological functions. lncRNA HOXA Cluster Antisense RNA 3 (HOXA-AS3) was a newly discovered lncRNA and has been demonstrated to be abnormally expressed in many diseases. Moreover, HOXA-AS3 expression was closely correlated with the clinicopathologic characteristics in cancer patients. In addition, HOXA-AS3 exhibited significant properties in regulating several biological processes, including cell proliferation, invasion, and migration. Furthermore, HOXA-AS3 has provided promising values in the diagnosis, prognosis, and therapeutic strategies of several diseases such as liver cancer, glioma, lung cancer, oral cancer, gastric cancer, and even atherosclerosis. In this review, we discuss the abnormal expression of HOXA-AS3 in several human disorders and some pathobiological processes and its clinical characteristics, followed by a summary of HOXA-AS3 functions, regulatory mechanisms, and clinical application potential.

Long noncoding RNA CERS6-AS1 modulates glucose metabolism and tumor progression in hepatocellular carcinoma by promoting the MDM2/p53 signaling pathway

Hepatocellular carcinoma (HCC) is one of the most serious malignant cancers and has a high fatality rate. However, clinical strategies for the effective treatment of HCC remain lacking. Long non-coding RNAs (lncRNAs) with aberrant expression have been closely correlated with the occurrence and development of HCC. Here we investigated the underlying mechanism of the lncRNA CERS6-AS1 in HCC progression. The expression and prognosis of CERS6-AS1 in HCC patients was explored using The Cancer Genome Atlas. PCR analysis was utilized to measure the expression of CERS6-AS1 in tissues and cell lines. Transwell, wound healing, proliferation and glycolysis assays were conducted to evaluate the function of CERS6-AS1 on HCC cell functions. Bioinformation methods and luciferase assays were used to screen and verify potential target miRNAs and genes. A subcutaneous tumorigenesis model was constructed in nude mice to assess the effect of CERS6-AS1 on tumorigenesis in vivo. CERS6-AS1 was highly expressed in HCC tissues and cell lines. Upregulated CERS6-AS1 expression was remarkably correlated with poor prognosis of HCC patients. High CERS6-AS1 expression facilitated cell growth, invasion and glycolysis of HCC cells. Bioinformatics analyses combining with PCR analysis identified miR-30b-3p as the potential target of CERS6-AS1, and MDM2 mRNA was verified as the target of miR-30b-3p. The expression of miR-30b-3p was negatively correlated with CERS6-AS1, whereas MDM2 was positively associated with CERS6-AS1. Mechanistic studies showed that CERS6-AS1 may sponge miR-30b-3p to elevate MDM2, thus promoting the MDM2-mediated ubiquitin-dependent degradation of the p53 tumor suppressor. MDM2 overexpression or miR-30b-3p inhibitors blocked the inhibitory effect of CERS6-AS1 knockdown on proliferation, migration and glycolysis. CERS6-AS1 depletion reduced tumor formation in the in vivo mouse model. The CERS6-AS1/miR-30b-3p/MDM2/p53 signaling axis may play key roles in regulating HCC progression. CERS6-AS1 may exert as a novel biomarker or therapeutic target for HCC.

LncRNA PCGEM1 promotes colorectal cancer cell proliferation and migration in positive feedback loop through PCGEM1/miR-433-3p/CTCF axis

BACKGROUND AND OBJECTIVES

Prostate cancer gene expression marker 1 (PCGEM1) has been identified as an oncogenic long non-coding RNA (lncRNA) in diverse cancers, but it has never been linked with colorectal cancer (CRC). Former studies have shown the mutual regulation between lncRNAs and transcription factors (TFs) in cancer. CCCTC binding factor (CTCF) has been reported to transcriptionally activate lncRNAs in cancers. We predicted the binding of CTCF on PCGEM1 promoter through UCSC (https://genome.ucsc.edu/), but their relation has not been studied. We aimed to investigate whether and how PCGEM1 functioned in CRC cells and the interaction between PCGEM1 and CTCF.

METHODS AND RESULTS

The impacts of PCGEM1 and CTCF inhibition on CRC cells were verified through loss-of-function experiments. Mechanism experiments were used to prove the binding between CTCF and PCGEM1 in CRC progression. PCGEM1 possessed a high expression level in CRC cells as well as tumors. CTCF transcriptionally activated PCGEM1 expression. Knockdown of PCGEM1 or CTCF impeded proliferation and migration and drove apoptosis of CRC cells. Moreover, PCGEM1 bound miR-433-3p to prevent miR-433-3p from targeting CTCF.

CONCLUSION

We first revealed PCGEM1/miR-433-3p/CTCF positive feedback loop as an oncogenic axis in CRC cells, which potentially provides new clues for the advancement of CRC treatment.

The emerging role of miR-653 in human cancer

MicroRNAs (miRNAs) refer to a family of non-coding RNA with ~22 nucleotides in length. A high number of studies show evidence that deregulation in miRNAs expression could be implicated in the processes of many pathologies such as cancer, hypoxia, and stroke. Herein, we aimed to summarize the miR-653 expression level and molecular mechanisms through which it functions in human cancer. It was found that variations in miR-653 expression are linked to tumor aggressiveness and unfavorable prognosis in human cancer, and it plays an inhibitory effect in some types of cancer, such as breast, cervical, liver, renal, and lung cancers. In contrast, it plays an acceleratory impact in some other cancers, such as bladder and prostate cancers. In gastric cancer, the role played by miR-653 is still controversial and will need to be elucidated in future studies. Future studies could definitely establish targeting miR-653 as a novel strategy in human cancer, from diagnosis to effective treatment.

Title: Multi-Omics and Immune Landscape of Proliferative LncRNA Signatures: Implications for Risk Stratification and Immunotherapy in Hepatocellular Carcinoma

Background: Long noncoding RNAs (lncRNAs) are significantly implicated in tumor proliferation. Nevertheless, proliferation-derived lncRNAs and their latent clinical significance remain largely unrevealed in hepatocellular carcinoma (HCC).

Methods: This research enrolled 658 HCC patients from five independent cohorts. We retrieved 50 Hallmark gene sets from the MSigDB portal. Consensus clustering was applied to identify heterogeneous proliferative subtypes, and the nearest template prediction (NTP) was utilized to validate the subtypes. We introduced an integrative framework (termed “ProLnc”) to identify proliferation-derived lncRNAs. Moreover, a proliferation-related signature was developed and verified in four independent cohorts.

Results: In 50 Hallmarks, seven proliferation pathways were significantly upregulated and correlated with a worse prognosis. Subsequently, we deciphered two heterogeneous proliferative subtypes in TCGA-LIHC. Subtype 2 displayed enhanced proliferative activities and a worse prognosis, whereas subtype 1 was associated with hyperproliferative HCC and a favorable prognosis. The NTP further verified the robustness and reproducibility of two subtypes in four cohorts derived from different platforms. Combining the differentially expressed lncRNAs from two subtypes with proliferative lncRNA modulators from our ProLnc pipeline, we determined 230 proliferation-associated lncRNAs. Based on the bootstrapping channel and the verification of multiple cohorts, we further identified ten lncRNAs that stably correlated with prognosis. Subsequently, we developed and validated a proliferative lncRNA signature (ProLncS) that could independently and accurately assess the overall survival (OS) and relapse-free survival (RFS) of HCC patients in the four cohorts. Patients with high ProLncS score displayed significantly genomic alterations (e.g., TP53 mutation, 8p23-8p24 copy number variation) and higher abundances of immune cells and immune checkpoint molecules, which suggested immunotherapy was more suitable for patients with high ProLncS score.

Conclusion: Our work provided new insights into the heterogeneity of tumor proliferation, and ProLncS could be a prospective tool for tailoring the clinical decision and management of HCC.

Comprehensive analysis of ZFPM2-AS1 prognostic value, immune microenvironment, drug sensitivity, and co-expression network: from gastric adenocarcinoma to pan-cancers

BACKGROUND

ZFPM2-AS1, as an oncogenic lncRNA, plays an essential role in the progression of several tumors. However, the prognostic significance, biological function, and molecular mechanism of ZFPM2-AS1 in most tumors have not been fully elucidated.

METHODS

We analyzed differentially expressed immune-related lncRNAs (IRlncRNAs) and clustered gastric adenocarcinoma (GAC) samples based on these lncRNAs expression. Then, WGCNA and survival analysis were performed to determine key IRlncRNA (ZFPM2-AS1) in GAC. The comprehensive analysis was performed to evaluate the association between ZFPM2-AS1 expression and survival, tumor microenvironment (TME), immune-related factors, and related signal pathways in pan-cancers. Furthermore, we constructed a co-expression network of ZFPM2-AS1, and NUP107 and C8orf76 were identified as target mRNAs. We further evaluated the role of NUP107 and C8orf76 in the GAC microenvironment. More importantly, real-time polymerase chain reaction (qRT-PCR) was employed to validate ZFPM2-AS1, NUP107 and C8orf76 expression.

RESULTS

ZFPM2-AS1 was remarkably overexpressed and correlated with poor overall survival in most tumors. Further analysis showed that ZFPM2-AS1 was related to various immune cells infiltrated in the microenvironment of most tumors. GSEA revealed that ZFPM2-AS1 in GAC was primarily involved in immune-related pathways. Furthermore, NUP107 and C8orf76 were identified as potential target mRNAs of ZFPM2-AS1, which was related to infiltrating immune cells in the GAC microenvironment. qRT-PCR verified that ZFPM2-AS, NUP107 and C8orf76 were highly expressed in gastric cancer cells.

CONCLUSION

ZFPM2-AS1 could be a potential biomarker for cancer prognosis, and a promising immune target for cancer therapy. Furthermore, ZFPM2-AS1 might play an immunosuppressive role in the GAC microenvironment.

Emerging Roles and Mechanisms of lncRNA FOXD3-AS1 in Human Diseases

Numerous long noncoding RNAs (lncRNAs) have been identified as powerful regulators of human diseases. The lncRNA FOXD3-AS1 is a novel lncRNA that was recently shown to exert imperative roles in the initialization and progression of several diseases. Emerging studies have shown aberrant expression of FOXD3-AS1 and close correlation with pathophysiological traits of numerous diseases, particularly cancers. More importantly, FOXD3-AS1 was also found to ubiquitously impact a range of biological functions. This study aims to summarize the expression, associated clinicopathological features, major functions and molecular mechanisms of FOXD3-AS1 in human diseases and to explore its possible clinical applications.

Immune-Related lncRNA Pairs Clinical Prognosis Model Construction for Hepatocellular Carcinoma

Background

Long non-coding RNA (lncRNA) plays an essential regulatory role in the occurrence and development of hepatocellular carcinoma (HCC). This paper aims to establish an immune-related lncRNA (irlncRNA) pairs model independent of expression level for risk assessment and prognosis prediction of HCC.

Methods

Transcriptome data and corresponding clinical data were downloaded from TCGA. HCC patients were randomly divided into training group and test group. Univariate Cox regression analysis, LASSO regression analysis, and stepwise multiple Cox regression analysis were used to establish a prognostic model. The prediction ability of the model was verified by ROC curves. Next, the patients were divided into low-risk and high-risk groups. We compared the differences between the two groups in survival rate, clinicopathological characteristics, tumor immune cell infiltration status, chemotherapeutic drug sensitivity and immunosuppressive molecules.

Results

A prognosis prediction model was established based on 7 irlncRNA pairs, namely irlncRNA pairs (IRLP). ROC curves of the training group and test group showed that the IRLP model had high sensitivity and specificity for survival prediction. Kaplan–Meier analysis showed that the survival rate of the high-risk group was significantly lower than that of the low-risk group. Immune cell infiltration analysis showed that the high-risk group was significantly correlated with various immune cell infiltration. Finally, there were statistically significant differences in chemosensitivity and molecular marker expression between the two groups.

Conclusion

The prognosis prediction model established by irlncRNA pairs has a certain guiding significance for the prognosis prediction of HCC. It may provide valuable clinical applications in antitumor immunotherapy.

Development and Validation of Genome Instability-Associated lncRNAs to Predict Prognosis and Immunotherapy of Patients With Hepatocellular Carcinoma

The pathophysiology of hepatocellular carcinoma (HCC) is prevalently related to genomic instability. However, research on the association of extensive genome instability lncRNA (GILnc) with the prognosis and immunotherapy of HCC remains scarce. We placed the top 25% of somatic mutations into the genetically unstable group and placed the bottom 25% of somatic mutations into the genetically stable group, and then to identify different expression of GILnc between the two groups. Then, LASSO was used to identify the most powerful prognostic GILnc, and a risk score for each patient was calculated according to the formula. Based on a computational frame, 245 different GILncs in HCC were identified. An eight GILnc model was successfully established to predict overall survival in HCC patients based on LASSO, then we divided HCC patients into high-risk and low-risk groups, and a significantly shorter overall survival in the high-risk group was observed compared to those in the low-risk group, and this was validated in GSE76427 and Tongji cohorts. GSEA revealed that the high-risk group was more likely to be enriched in cancer-specific pathways. Besides, the GILnc signature has greater prognostic significance than TP53 mutation status alone, and it is capable of identifying intermediate subtype groups existing with partial TP53 functionality in TP53 wild-type patients. Importantly, the high-risk group was associated with the therapeutic efficacy of PD-L1 blockade, suggesting that the development of potential drugs targeting these GILnc could aid the clinical benefits of immunotherapy. Finally, the GILnc signature model is better than the prediction performance of two recently published lncRNA signatures. In summary, we applied bioinformatics approaches to suggest that an eight GILnc model could serve as prognostic biomarkers to provide a novel direction to explore the pathogenesis of HCC.

Golgi Phosphoprotein 73: The Driver of Epithelial-Mesenchymal Transition in Cancer

Golgi phosphoprotein 73 (GP73, also termed as GOLM1 or GOLPH2) is a glycosylated protein residing on cis-Golgi cisternae and highly expressed in various types of cancer tissues. Since GP73 is a secretory protein and detectable in serum derived from cancer patients, it has been regarded as a novel serum biomarker for the diagnosis of different cancers, especially hepatocellular carcinoma (HCC). However, the functional roles of GP73 in cancer development are still poorly understood. In recent years, it has been discovered that GP73 acts as a multifunctional protein-facilitating cancer progression, and strikingly, it has been identified as a leading factor promoting epithelial-mesenchymal transition (EMT) of cancer cells and causing cancer metastasis. In this review, we have overviewed the latest findings of the functional roles of GP73 in elevating cancer progression, especially in facilitating EMT and cancer metastasis through modulating expression, transactivation, and trafficking of EMT-related proteins. In addition, unsolved research fields of GP73 have been lightened, which might be helpful to elucidate the regulatory mechanisms of GP73 on EMT and provide potential approaches in therapeutics against cancer metastasis.

A Mutation-Related Long Noncoding RNA Signature of Genome Instability Predicts Immune Infiltration and Hepatocellular Carcinoma Prognosis

Background: Long noncoding RNAs (lncRNAs) have been discovered to play a regulatory role in genomic instability (GI), which participates in the carcinogenesis of various cancers, including hepatocellular carcinoma (HCC). We endeavored to establish a GI-derived lncRNA signature (GILncSig) as a potential biomarker and explore its impact on immune infiltration and prognostic significance. Methods: Combining expression and somatic mutation profiles from The Cancer Genome Atlas database, we identified GI-related lncRNAs and conducted functional analyses on co-expressed genes. Based on Cox regression analysis, a GILncSig was established in the training cohort (n = 187), and an independent testing patient cohort (n = 183) was used to validate its predictive ability. Kaplan-Meier method and receiver operating characteristic curves were adopted to evaluate the performance. The correlation between GI and immune infiltration status was investigated based on the CIBERSORT algorithm and single sample gene set enrichment analysis. In addition, a comprehensive nomogram integrating the GILncSig and clinicopathological variables was constructed to efficiently assess HCC patient prognosis in clinical applications. Results: A total of 88 GI-related lncRNAs were screened out and the functional analyses indicated diversified effects on HCC progression. The GILncSig was established using four independent lncRNAs (AC116351.1, ZFPM2-AS1, AC145343.1, and MIR210HG) with significant prognostic value (p < 0.05). Following evaluation with the GILncSig, low-risk patients had significantly better clinical outcomes than high-risk patients in the training cohort (p < 0.001), which was subsequently validated in the independent testing cohort. High-risk group exhibited more immunocyte infiltration including B cells memory, macrophages M0 and neutrophils and higher expression of HLA gene set and immune checkpoint genes. Compared to existing HCC signatures, the GILncSig showed better prognosis predictive performance [area under the curve (AUC) = 0.709]. Furthermore, an integrated nomogram was constructed and validated to efficiently and reliably evaluate HCC patient prognosis (3-years survival AUC = 0.710 and 5-years survival AUC = 0.707). Conclusion: The GILncSig measuring GI and impacting immune infiltration serves as a potential biomarker and independent predictor of HCC patient prognosis. Our results highlight further investigation of GI and HCC molecular mechanisms.

SP1-induced lncRNA ZFPM2 antisense RNA 1 (ZFPM2-AS1) aggravates glioma progression via the miR-515-5p/Superoxide dismutase 2 (SOD2) axis

Glioma is a common life-threatening tumor with high malignancy and high invasiveness. LncRNA ZFPM2 antisense RNA 1 (ZFPM2-AS1) was confirmed to be implicated in numerous tumors, while its biological function and mechanism have not been thoroughly understood in glioma. The gene expression was measured by RT-qPCR. Cell proliferation, cell cycle, and cell apoptosis of glioma cells were validated by CCK-8, colony formation, flow cytometry and TUNEL assays. The effect of ZFPM2-AS1 on tumor growth was verified by in vivo assay. The exploration on ZFPM2-AS1-mediated mechanism was carried out via ChIP, luciferase reporter, and RIP assays. In the present study, ZFPM2-AS1 was demonstrated as a highly-expressed lncRNA in glioma tissues and cells. ZFPM2-AS1 silencing suppressed cell proliferation and cell cycle, but facilitated cell apoptosis. In addition, the inhibitive effect of silenced ZFPM2-AS1 was also observed in tumor growth. Furthermore, we found that SP1 interacted with ZFPM2-AS1 promoter to transcriptionally activate ZFPM2-AS1 expression. Moreover, ZFPM2-AS1 was identified as a competing endogenous RNA (ceRNA) for miR-515-5p to target SOD2. Rescue assays verified that SOD2 overexpression partially abolished the suppressive impact of ZFPM2-AS1 silencing on glioma cell growth. In conclusion, this study corroborated the regulatory mechanism of SP1/ZFPM2-AS1/miR-515-5p/SOD2 axis in glioma, indicating that targeting ZFPM2-AS1 might be an effective way to treat glioma.

Construction of a genome instability-derived lncRNA-based risk scoring system for the prognosis of hepatocellular carcinoma

Emerging evidence revealed the critical roles of long non-coding RNAs (lncRNAs) in maintaining genomic instability. However, genome instability-associated lncRNAs (GILncRNAs) and their performance in clinical prognostic significance in hepatocellular carcinoma (HCC) are rarely reported. Our study constructed a computational framework integrating somatic mutation information and lncRNA expression profiles of HCC genome and we identified 88 GILncRNAs of HCC. Function enrichment analysis revealed that GILncRNAs were involved in various metabolism processes and genome instability of cancer. A genome instability-derived lncRNA-based gene signature (GILncSig) was constructed using training set data. The performance of GILncSig for outcome prediction was validated in testing set and The Cancer Genome Atlas (TCGA) set. The multivariate cox regression analysis and stratification analysis demonstrated GILncSig could serve as an independent prognostic factor for the overall survival of HCC patients. The time-dependent Receiver Operating Characteristic (ROC) curve illustrated GILncSig outperformed two recently published lncRNA signatures for overall survival prediction. The combination of GILncSig and tumor protein p53 (TP53) mutation status exhibited better prognostic performance in survival evaluation compared to TP53 mutation status alone. AC145343.1 was further validated to be a risk factor for HCC in vitro among GILncSig. Overall, our study provided a novel approach for identification of genome instability-associated lncRNAs and established an independent risk score system for outcome prediction of HCC patients, which provided a new insight for exploring in-depth mechanism and potential therapy strategy.

Construction of a genome instability-derived lncRNA-based risk scoring system for the prognosis of hepatocellular carcinoma

Emerging evidence revealed the critical roles of long non-coding RNAs (lncRNAs) in maintaining genomic instability. However, genome instability-associated lncRNAs (GILncRNAs) and their performance in clinical prognostic significance in hepatocellular carcinoma (HCC) are rarely reported. Our study constructed a computational framework integrating somatic mutation information and lncRNA expression profiles of HCC genome and we identified 88 GILncRNAs of HCC. Function enrichment analysis revealed that GILncRNAs were involved in various metabolism processes and genome instability of cancer. A genome instability-derived lncRNA-based gene signature (GILncSig) was constructed using training set data. The performance of GILncSig for outcome prediction was validated in testing set and The Cancer Genome Atlas (TCGA) set. The multivariate cox regression analysis and stratification analysis demonstrated GILncSig could serve as an independent prognostic factor for the overall survival of HCC patients. The time-dependent Receiver Operating Characteristic (ROC) curve illustrated GILncSig outperformed two recently published lncRNA signatures for overall survival prediction. The combination of GILncSig and tumor protein p53 (TP53) mutation status exhibited better prognostic performance in survival evaluation compared to TP53 mutation status alone. AC145343.1 was further validated to be a risk factor for HCC in vitro among GILncSig. Overall, our study provided a novel approach for identification of genome instability-associated lncRNAs and established an independent risk score system for outcome prediction of HCC patients, which provided a new insight for exploring in-depth mechanism and potential therapy strategy.

Identification of Mutator-Derived lncRNA Signatures of Genomic Instability for Promoting the Clinical Outcome in Hepatocellular Carcinoma

BACKGROUND

Accumulating evidence proves that long noncoding RNA (lncRNA) plays a crucial role in maintaining genomic instability. However, it is significantly absent from exploring genomic instability-associated lncRNAs and discovering their clinical significance.

OBJECTIVE

To identify crucial mutator-derived lncRNAs and construct a predictive model for prognosis and genomic instability in hepatocellular carcinoma.

METHODS

First, we constructed a mutator hypothesis-derived calculative framework through uniting the lncRNA expression level and somatic mutation number to screen for genomic instability-associated lncRNA in hepatocellular carcinoma. We then selected mutator-derived lncRNA from the genome instability-associated lncRNA by univariate Cox analysis and Lasso regression analysis. Next, we created a prognosis model with the mutator-derived lncRNA signature. Furthermore, we verified the vital role of the model in the prognosis and genomic instability of hepatocellular carcinoma patients. Finally, we examined the potential relationship between the model and the mutation status of TP53.

RESULTS

In this study, we screened 88 genome instability-associated lncRNAs and built a prognosis model with four mutator-derived lncRNAs. Moreover, the model was an independent predictor of prognosis and an accurate indicator of genomic instability in hepatocellular carcinoma. Finally, the model could catch the TP53 mutation status, and the model was a more effective indicator than the mutation status of TP53 for hepatocellular carcinoma patients.

CONCLUSION

This research adopted a reliable method to analyze the role of lncRNA in genomic instability. Besides, the prognostic model with four mutator-derived lncRNAs is an excellent new indicator of prognosis and genomic instability in hepatocellular carcinoma. In addition, this finding may help clinicians develop therapeutic systems.

ATF2-Induced Overexpression of lncRNA LINC00882, as a Novel Therapeutic Target, Accelerates Hepatocellular Carcinoma Progression via Sponging miR-214-3p to Upregulate CENPM

Background

Long intergenic non-protein coding RNA 882 (LINC00882) are abnormally expressed in several tumors. Our research aimed to uncover the functions and the potential mechanisms of LINC00882 in hepatocellular carcinoma (HCC) progression.

Methods

RT-qPCR was applied to identify LINC00882 and miR-214-3p levels in HCC specimens and cells. Luciferase reporter was applied for the exploration of whether activating transcription factor 2 (ATF2) could bind to the promoter region of LINC00882. Cell proliferation, invasion, and migration were evaluated. In vivo tumor xenograft models were constructed to assess tumorigenicity. RT-PCR, Western blot and Luciferase reporter assays were conducted to examine the regulatory relationships among LINC00882, miR-214-3p and ATF2.

Results

LINC00882 was markedly upregulated in HCC cells and clinical specimens. Additionally, ATF2 could bind directly to the LINC00882 promoter region and activate its transcription. Loss-of-function studies further demonstrated that LINC00882 knockdown inhibited proliferation, invasion, and migration of HCC cells. Mechanistically, LINC00882 adsorbed miR-214-3p, thus promoting the expressions of CENPM. Rescue assays demonstrated that functions of LINC00882 deficiency in HCC cells were reversed through suppressing miR-214-3p.

Conclusion

Our group identified a novel regulatory axis of ATF2/LINC00882/miR-214-3p/CENPM, which may provide potential therapeutic targets for HCC.