LINC00665 Promotes the Progression of Multiple Myeloma by Adsorbing miR-214-3p and Positively Regulating the Expression of PSMD10 and ASF1B

A Feedback Loop of LINC00665 and the Wnt Signaling Pathway Expedites Osteosarcoma Cell Proliferation, Invasion, and Epithelial-Mesenchymal Transition

OBJECTIVES

Osteosarcoma (OS) is a malignant tumor with frequent occurrence among teenagers. Long non-coding RNAs (lncRNAs) play pro-cancer roles in many tumors. The purpose of this study was to figure out the functional role of a novel lncRNA long intergenic non-protein coding RNA 665 (LINC00665) in OS by observing the OS cell behaviors.

METHODS

Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to analyze LINC00665 expression in OS cells. Cell function assays assessed the impacts of LINC00665 on OS cell phenotype. Immunofluorescence and western blot analyzed the function of LINC00665 on epithelial-mesenchymal transition (EMT) in OS. Moreover, mechanistic assays analyzed the downstream mechanism of LINC00665 in OS cells.

RESULTS

LINC00665 was significantly up-regulated in OS cells. LINC00665 silence facilitated OS cell proliferation, migration, invasion, and EMT while inhibiting cell apoptosis. Mechanically, LINC00665 acted as a competing endogenous RNA (ceRNA) to sponge miR-1249-5p and thereby modulated Wnt family member 2B (WNT2B) to activate Wnt pathway. Wnt pathway activated LINC00665 expression transcriptionally.

CONCLUSIONS

Our study uncovered the cancer-promoting role of LINC00665 in OS, and the feedback loop of LINC00665/miR-1249-5p/WNT2B/Wnt might be a potential target for OS treatment.

Silencing LINC00665 inhibits cutaneous melanoma in vitro progression and induces apoptosis via the miR-339-3p/TUBB

Background

LncRNAs are closely related to cutaneous melanoma (CM) tumorigenesis and metastasis, and it can affect the progression of CM by regulating cell proliferation, migration, invasion, apoptosis, and other cellular mechanisms. This study investigated the role of LINC00665 in CM.

Methods

Expressions of LINC00665, miR‐339‐3p, and tubulin beta chain (TUBB) in CM cells were analyzed by qRT‐PCR and/or Western blot. The LINC00665/miR‐339‐3p/TUBB targeting network was predicted by bioinformatics tools, screened out by Venn diagrams and analyzed by Pearson's correlation coefficients, followed by validation via dual‐luciferase reporter assay and/or pull‐down assay. Transfection of siLINC00665 or miR‐339‐3p inhibitor/mimic was conducted with CM cells whose viability, proliferation, migration, invasion, cell cycle progression, and apoptosis were measured by CCK‐8 assay, colony formation assay, wound healing assay, Transwell assay, and flow cytometry. The associations of TUBB with tumor biological characteristics and other proteins were analyzed by CanserSEA and String, respectively.

Results

High‐expressed LINC00665 was detected in CM cells. Silencing LINC00665 decreased CM cell viability; inhibited colony formation, cell cycle progression, migration and invasion; enhanced apoptosis; and upregulated miR‐339‐3p. LINC00665 targeted miR‐339‐3p which targeted TUBB. MiR‐339‐3p upregulation induced effects similar to the LINC00665‐silencing‐induced effects and could downregulate TUBB, which was associated with malignant behaviors and related to other five proteins. MiR‐339‐3p downregulation induced the opposite effects of what miR‐339‐3p upregulation induced, and the miR‐339‐3p downregulation‐induced effects could be reversed by LINC00665 silencing.

Conclusion

Silencing LINC00665 inhibits in vitro CM progression and induces apoptosis via the miR‐339‐3p/TUBB axis.

Downregulation of ASF1B inhibits tumor progression and enhances efficacy of cisplatin in pancreatic cancer

Pancreatic cancer is an aggressive and lethal cancer with the highest mortality rate. Hence, the development of new targeting and innovative treatment strategies is needed. Recent studies reported that the histone chaperone anti-silencing function 1B (ASF1B) can be used as a diagnosis and prognosis cancer biomarker. However, functional studies of ASF1B in pancreatic cancer have not been performed. This study compared expression levels of ASF1B in pancreatic cancer specimens with those of normal tissues using publicly available online databases. We found that ASF1B was commonly overexpressed in pancreatic cancer specimens, which is associated with poor prognosis. ASF1B downregulation in pancreatic cancer cells reduced their colony formation, proliferation, migration, and invasion abilities, and inhibited MMP9 activity. Furthermore, ASF1B expression downregulation increased cell cycle S-phase arrest and DNA damage though activation of the checkpoint kinases Chk1 and Chk2 pathways. Additionally, increased caspase (caspases-3 and -9) activation and PARP cleavage led to enhanced caspase-dependent apoptosis and improved cisplatin sensitivity. Collectively, our results indicate that ASF1B may serve as a potential biomarker of pancreatic cancer and a novel therapeutic target.

LINC00665: An Emerging Biomarker for Cancer Diagnostics and Therapeutics

Long intergenic noncoding RNA 00665 (LINC00665) is located on human chromosome 19q13.12. LINC00665 was upregulated in eighteen cancers and downregulated in two cancers. LINC00665 not only inhibits 25 miRNAs but also directly affects the stability of ten protein-coding genes. Notably, LINC00665 also encodes a micro-peptide CIP2A-BP that promotes triple-negative breast cancer progression. LINC00665 can participate in five signaling pathways to regulate cancer progression, including the Wnt/β-catenin signaling pathway, TGF-β signaling pathway, NF-κB signaling pathway, PI3K/AKT signaling pathway, and MAPK signaling pathway. Aberrant expression of LINC00665 in breast cancer, gastric cancer, and hepatocellular carcinoma can be used for disease diagnosis. In addition, aberrant expression of LINC00665 is closely associated with clinicopathological features and poor prognosis of various cancers. LINC00665 is closely associated with the effects of anticancer drugs, including gefitinib and cisplatin in non-small cell lung cancer, gemcitabine in cholangiocarcinoma, and cisplatin-paclitaxel in breast cancer. This work systematically summarizes the diagnostic and prognostic values of LINC00665 in various tumors, and comprehensively analyzes the molecular regulatory mechanism related to LINC00665, which is expected to provide clear guidance for future research.

Comprehensive Analysis Identified ASF1B as an Independent Prognostic Factor for HBV-Infected Hepatocellular Carcinoma

Purpose

Hepatitis B (HBV)-infected hepatocellular carcinoma is one of the most common cancers, and it has high incidence and mortality rates worldwide. The incidence of hepatocellular carcinoma has been increasing in recent years, and existing treatment modalities do not significantly improve prognosis. Therefore, it is important to find a biomarker that can accurately predict prognosis.

Methods

This study was analyzed using the The Cancer Genome Atlas (TCGA) database and validated by the International Cancer Genome Consortium (ICGC) database. The STRING database was used to construct a gene co-expression network and visualize its functional clustering using Cytoscape. A prognostic signature model was constructed to observe high and low risk with prognosis, and independent prognostic factors for HBV-infected hepatocellular carcinoma were identified by Cox regression analysis. The independent prognostic factors were then analyzed for expression and survival, and their pathway enrichment was analyzed using gene set enrichment analysis (GSEA).

Results

805 differentially expressed genes (DEGs) were obtained by differential analysis. Protein–protein interaction (PPI) showed that DEGs were mostly clustered in functional modules, such as cellular matrix response, cell differentiation, and tissue development. Prognostic characterization models showed that the high-risk group was associated with poor prognosis, while Cox regression analysis identified ASF1B as the only independent prognostic factor. As verified by expression and prognosis, ASF1B was highly expressed in HBV-infected hepatocellular carcinoma and led to a poor prognosis. GSEA showed that high ASF1B expression was involved in cell cycle-related signaling pathways.

Conclusion

Bioinformatic analysis identified ASF1B as an independent prognostic factor in HBV-infected hepatocellular carcinoma, and its high expression led to a poor prognosis. Furthermore, it may promote hepatocellular carcinoma progression by affecting cell cycle-related signaling pathways.

Construction of a ceRNA network in hepatocellular carcinoma and comprehensive analysis of immune infiltration patterns

BACKGROUND

Hepatocellular carcinoma (HCC) is a type of refractory malignant tumor with high fatality rate. Currently, immunotherapy and competitive endogenous RNA (ceRNA) are research hotspots in HCC, but the relationship between ceRNA and the immune microenvironment in HCC is unclear.

METHODS

Firstly, a differentially expressed circRNA-miRNA-mRNA network was constructed from the GEO database, and functional enrichment analysis was performed. Next, combine the TCGA database to construct a ceRNA prognosis-related subnetwork. Establish a risk prediction model based on the mRNA in the sub-network, and evaluate the impact of the model on the prognosis. Use clinical samples to verify the expression of genes in the model. Finally, we analyzed the distribution of tumor infiltrating immune cells (TIC) in HCC, and explored the correlation between mRNAs in the ceRNA sub-network and immune infiltration.

RESULTS

We used the HCC ceRNA network (including 12 circRNA, 5 miRNA, and 8 mRNA) as a starting point for the identification of target genes (PSMD10, ESR1 and PPARGC1A) in the ceRNA prognosis-related subnetwork to establish a risk prediction model and elucidated its important role in predicting the poor prognosis of HCC. The differences in mRNA expression verified by clinical samples are consistent with the database. In addition, we found that the mRNAs in the ceRNA prognosis subnetwork are closely related to different types of TICs and immune checkpoints.

CONCLUSIONS

This study is expected to serve as a reference for the study of mechanisms underlying liver cancer, the screening of prognostic markers and the evaluation of the immune response.

Comprehensive analysis of pan-cancer reveals potential of ASF1B as a prognostic and immunological biomarker

Background

Anti‐silencing function 1 (ASF1) is a conserved histone H3–H4 chaperone protein. ASF1B, a paralog of ASF1, acts by promoting cell proliferation and influencing cell cycle progression. Although there is some evidence demonstrating that ASF1B plays a key role in the development, progression, and prognosis of certain cancers, there are no pan‐cancer analyses of ASF1B.

Methods

We used a range of bioinformatics approaches to investigate the predictive role of ASF1B, including its correlation with prognosis, tumor mutational burden (TMB), microsatellite instability (MSI), tumor microenvironment (TME), and immune cell infiltration, in diverse cancer types.

Results

We found that ASF1B was highly expressed in 22 cancers and was negatively correlated with the prognosis of multiple major cancer types. Furthermore, ASF1B expression was correlated with TMB in 21 cancers and with MSI in 7 cancers. We found that ASF1B was coexpressed with genes encoding immune activators, immune suppressors, major histocompatibility complexes, chemokines, and chemokine receptors. We further found that the role of ASF1B in the infiltration of different types of immune cells varied across tumor types. ASF1B may potentially affect several key immune‐related pathways, such as those involved in antigen processing and presentation, natural killer cell‐mediated cytotoxicity, and autoimmune thyroid disease.

Conclusions

Our findings show that ASF1B may serve as a prognostic marker and potential immunotherapeutic target for several malignancies due to its role in tumorigenesis and immune infiltration.

Construction of Novel lncRNA-miRNA-mRNA Network Associated With Recurrence and Identification of Immune-Related Potential Regulatory Axis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant diseases globally. Despite continuous improvement of treatment methods, high postoperative recurrence rate remains an urgent problem. In order to determine the mechanism underlying recurrence of liver cancer and identify prognostic genes, data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were integrated and analyzed. Differentially expressed genes (DEGs) between HCC tissue and normal liver tissue were identified, and a protein–protein interaction network was constructed to find hub genes. Clinical correlation analysis and disease-free survival (DFS) analysis were performed using the R language and GEPIA to identify relapse-related genes. Correlation analysis was used to identify a potential regulatory axis. Dual-luciferase reporter gene assay was used to confirm the reliability of the long non-coding RNA (lncRNA)–microRNA (miRNA)–mRNA regulatory axis. Immune infiltration analysis was performed using the TIMER database. Correlations between immune gene markers and ASF1B were verified using quantitative real-time polymerase chain reaction (RT-qPCR). In this work, we found that nine lncRNAs and five mRNAs were significantly overexpressed in HCC tissues from patients with recurrence. SNHG3, LINC00205, ASF1B, AURKB, CCNB1, CDKN3, and DTL were also closely related to HCC grade and stage. Survival analysis showed that these seven DEGs were significantly correlated with poor DFS. Correlation analysis identified SNHG3–miR-214-3p–ASF1B as a potential regulatory axis. Dual-luciferase reporter gene assay showed that SNHG3 and ASF1B directly bound to miR-214-3p. ASF1B was negatively regulated by miRNA-214-3p, and overexpression of SNHG3 could inhibit the expression of miRNA-214-3p. In addition, ASF1B was positively correlated with immune infiltration. A reduction in ASF1B could markedly inhibit the expression of CD86, CD8, STAT1, STAT4, CD68, and PD1 in HCC cells. Flow cytometry showed that SNHG3 promoted the PD-1 expression by regulating ASF1B. Meanwhile, elevated ASF1B predicted poor prognosis of HCC patients in subgroups with decreased B cells, CD8+ T cells, or neutrophils, and those with enriched CD4+ T cells. In conclusion, we found that a novel lncRNA SNHG3/miR-214-3p/ASF1B axis could promote the recurrence of HCC by regulating immune infiltration.

The Long Noncoding RNA LINC00665 Facilitates c-Myc Transcriptional Activity via the miR-195-5p MYCBP Axis to Promote Progression of Lung Adenocarcinoma

Long noncoding RNAs (lncRNAs) have recently received growing substantial attention in cancer research due to their important roles in various cancer types. However, the underlying mechanisms and functions of lncRNAs, especially in lung adenocarcinoma (LUAD), remain elusive. Based on pan-cancer screening analyses, we identified that the noncoding RNA LINC00665 was up-regulated in lung adenocarcinoma, which was subsequently confirmed in clinical samples and cell lines. Higher expression of LINC00665 was positively associated with poor prognosis and advanced T stage. Next, using gain- and loss- of function approaches, we revealed that LINC00665 promotes cell proliferation, cell migration, invasion, and suppresses cell apoptosis in LUAD through in vitro and in vivo experiments. Additionally, our findings showed that LINC00665 was predominately localized in the cytoplasm so as to interact with Ago2 protein, which could function as miRNA sponges. The results of bioinformatics prediction and RNA pull-down assay indicated that LINC00665 directly interacted with miR-195-5p. This was also confirmed by fluorescence colocalization. Furthermore, luciferase reporter assay demonstrated that Myc binding protein (MYCBP, also called AMY-1), which enhanced c-Myc transcriptional activity, was the target gene of LINC00665 dependent on miR-195-5p. Finally, rescue functional assay results uncovered that the oncogenic capability of LINC00665 was dependent on miR-195-5p and c-Myc transcriptional activity. In summary, this work elucidates that LINC00665 accelerates LUAD progression via the miR-195-5p/MYCBP axis by acting as a competing endogenous RNA (ceRNA), suggesting that LINC00665 may represent a potential therapeutic target for clinical intervention of LUAD.

The Role of lncRNAs in the Pathobiology and Clinical Behavior of Multiple Myeloma

Simple Summary

Multiple myeloma (MM), the second most common hematological neoplasm, is still considered an incurable disease. Long non-coding RNAs (lncRNAs), genes that do not encode proteins, participate in numerous biological processes, but their deregulation, like that of coding genes, can contribute to carcinogenesis. Increasing evidence points to the relevant role of lncRNAs in the development of human tumors, such that they emerge as attractive biomarkers and therapeutic targets for cancer treatment, including MM. Here we review the oncogenic or tumor-suppressor functions of lncRNAs in MM and provide an overview of novel therapeutic approaches based on lncRNAs that will help to improve the management of these patients.

Abstract

MM is a hematological neoplasm that is still considered an incurable disease. Besides established genetic alterations, recent studies have shown that MM pathogenesis is also characterized by epigenetic aberrations, such as the gain of de novo active chromatin marks in promoter and enhancer regions and extensive DNA hypomethylation of intergenic regions, highlighting the relevance of these non-coding genomic regions. A recent study described how long non-coding RNAs (lncRNAs) correspond to 82% of the MM transcriptome and an increasing number of studies have demonstrated the importance of deregulation of lncRNAs in MM. In this review we focus on the deregulated lncRNAs in MM, including their biological or functional mechanisms, their role as biomarkers to improve the prognosis and monitoring of MM patients, and their participation in drug resistance. Furthermore, we also discuss the evidence supporting the role of lncRNAs as therapeutic targets through different novel RNA-based strategies.

NF-κB 1-induced LINC00665 regulates inflammation and apoptosis of neurons caused by spinal cord injury by targeting miR-34a-5p

Background: Spinal cord injury (SCI) has high disability rate and low cure rate, which frustrates the patients and brings a heavy burden to their families. This study aimed to explore whether NF-κB1 could induce the expression of LINC00665 and form a feedback loop with miR-34a-5p to regulate inflammation and apoptosis of neurons. Results: Basso, Beattie, and Bresnahan (BBB) scoring was decreased, damage for spinal cord tissue was aggravated and neuron number was decreased in SCI rats. The levels of TNF-α, IL-1β and IL-6 in serum and the expression of LINC00665 and NF-κB1 in spinal cord tissues were all increased in SCI rats. After LPS induction, PC12 cell viability was decreased. The expression of LINC00665 and NF-κB1 in LPS-induced PC12 cells was increased, which was partially reversed by BAY11-7082 (NF-κB inhibitor). Inhibition of LINC00665 improved cell viability, suppressed apoptosis and inflammation and down-regulated the NF-κB1 expression in LPS-induced PC12 cells. Furthermore, miR-34a-5p expression was decreased in LPS-induced PC12 cells, which could be promoted by inhibition of LINC00665. miR-34a-5p inhibitor restrained the effect of inhibition of LINC00665 on NF-κB1 expression in LPS-induced PC12 cells. Conclusion: inhibition of LINC00665 improved cell viability, suppressed apoptosis and inflammation in LPS-induced PC12 cells, and the NF-κB1/LINC00665/miR-34a-5ploop might be a useful therapeutic target in SCI treatment.

LINC00665 enhances tumorigenicity of endometrial carcinoma by interacting with high mobility group AT-hook 1

Background

Endometrial carcinoma is a frequently diagnosed cancer among females. LncRNAs are reported to be associated with various cancers. Their biological roles in endometrial carcinoma progression is an emerging scientific area. LINC00665 can exert a significant role in many cancers. However, its potential function in endometrial carcinoma is still poorly known.

Method

qRT-PCR was carried out to test expression of LINC00665 and HMGA1. Western blot analysis was carried out to detect protein expression of HMGA1. Cell proliferation was evaluated using Cell Counting Kit-8 (CCK-8) and EdU assay. Flow cytometry assay was used to determine cell apoptosis and cell cycle. Wound healing and transwell invasion assay was carried out to test cell migration and invasion. Immunohistochemical staining and HE staining were conducted to assess Ki-67 and tumor growth respectively.

Results

Expression of LINC00665 in clinical endometrial carcinoma tissues and cells was obviously up-regulated. Loss of LINC00665 could repress endometrial carcinoma cell viability, induce cell apoptosis and block cell cycle in G1 phase. KLE and HHUA cell migration and invasion ability were depressed by LINC00665 shRNA. Decrease of LINC00665 suppressed endometrial carcinoma tumorigenicity in vivo. RIP assay proved that LINC00665 directly bound with HMGA1 protein. shRNA of HMGA1 obviously restrained endometrial carcinoma cell growth and cell invasion.

Conclusions

LINC00665 might promote endometrial carcinoma progression by positively modulating HMGA1.