LncRNA TTN-AS1 regulates osteosarcoma cell apoptosis and drug resistance via the miR-134-5p/MBTD1 axis

A prediction of the CRNDE role by modulating NF-κB pathway in inflammatory bowel disease (IBD)

Long non-coding RNAs (lncRNAs) regulate multiple pathways and cellular mechanisms. Recent research has emphasized their involvement in the pathogenesis of complex diseases, such as Inflammatory Bowel Disease (IBD) which is characterized by chronic inflammation of the intestines. The two most common types of IBD are ulcerative colitis and Crohn's disease. CRNDE lncRNA was initially detected in colorectal cancer (CRC) and found to be involved in the tumorigenesis pathways. Further studies revealed the role of CRNDE in activating inflammation and promoting the release of inflammatory cytokines. This study utilizes the RNA-seq data analysis and bioinformatics tools to clarify the role of CRNDE in the IBD pathogenesis and confirms its expression in inflamed HT-29 and Caco-2 cell lines and also colonic and blood samples of UC patients and controls ex vivo. Based on our results, CRNDE was significantly upregulated in IBD samples compared to controls in RNA-seq data analysis and Real-time PCR of inflamed HT-29 cell line and colonic biopsies from UC patients. Additionally, predicted that its expression is positively correlated with the pro-inflammatory cytokines production. CRNDE interactions was investigated with several inflammation-related miRNAs and regulatory proteins computationally. Thus, CRNDE upregulation in the colon of IBD patients could be involved in IBD pathogenesis by promoting inflammatory pathways and targeting anti-inflammatory miRNAs.

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

Deciphering chemoresistance in osteosarcoma: Unveiling regulatory mechanisms and function through the lens of noncoding RNA

Osteosarcoma (OS) is a primary malignant bone tumor and is prevalent in children, adolescents, and elderly individuals. It has the characteristics of high invasion and metastasis. Neoadjuvant chemotherapy combined with surgical resection is the most commonly used treatment for OS. However, the efficacy of OS is considerably diminished by chemotherapy resistance. In recent years, noncoding RNAs (ncRNAs), including microRNAs, long noncoding RNAs, and circular RNAs, are hot topics in the field of chemotherapy resistance research. Several studies have demonstrated that ncRNAs are substantially associated with chemoresistance in OS. Thus, the present study overviews the abnormally expressed ncRNAs in OS and the molecular mechanisms involved in chemoresistance, with an emphasis on their function in promoting or inhibiting chemoresistance. ncRNAs are expected to become potential therapeutic targets for overcoming drug resistance and predictive biomarkers in OS, which are of great significance for enhancing the therapeutic effect and improving the prognosis.

Decreased expression of H19/miR-675 ameliorates hypoxia-induced oxaliplatin resistance in colorectal cancer

Hypoxic microenvironment, a hallmark of solid tumors, contributes to chemoresistance, and long noncoding (lnc) RNAs are involved in hypoxia-induced drug resistance. However, the role of lncRNAs in hypoxic tumor chemotherapy resistance remains unclear. Here, we aimed to elucidate the effects of lncRNAs in hypoxia-mediated resistance in colorectal cancer (CRC), as well as the underlying mechanisms. The results indicated that the expression of lncRNA H19 was enhanced in hypoxia- or oxaliplatin-treated CRC cells; moreover, H19 contributed to drug resistance in CRC cells both in vitro and in vivo. Mechanistically, H19 was noted to act as a competitive endogenous RNA of miR-675-3p to regulate epithelial-mesenchymal transition (EMT). Notably, an miR-675-3p mimic could attenuate the effects of H19 deficiency in CRC cells with hypoxia-induced chemoresistance. In conclusion, H19 downregulation may counteract hypoxia-induced chemoresistance by sponging miR-675-3p to regulate EMT; as such, the H19/miR-675-3p axis might be a promising therapeutic target for drug resistance in CRC.

Emerging roles of long non-coding RNAs in osteosarcoma

Osteosarcoma (OS) is a highly aggressive and lethal malignant bone tumor that primarily afflicts children, adolescents, and young adults. However, the molecular mechanisms underlying OS pathogenesis remain obscure. Mounting evidence implicates dysregulated long non-coding RNAs (lncRNAs) in tumorigenesis and progression. These lncRNAs play a pivotal role in modulating gene expression at diverse epigenetic, transcriptional, and post-transcriptional levels. Uncovering the roles of aberrant lncRNAs would provide new insights into OS pathogenesis and novel tools for its early diagnosis and treatment. In this review, we summarize the significance of lncRNAs in controlling signaling pathways implicated in OS development, including the Wnt/β-catenin, PI3K/AKT/mTOR, NF-κB, Notch, Hippo, and HIF-1α. Moreover, we discuss the multifaceted contributions of lncRNAs to drug resistance in OS, as well as their potential to serve as biomarkers and therapeutic targets. This review aims to encourage further research into lncRNA field and the development of more effective therapeutic strategies for patients with OS.

The knockdown of lncRNA DLGAP1-AS2 suppresses osteosarcoma progression by inhibiting aerobic glycolysis via the miR-451a/HK2 axis

Osteosarcoma (OS) is one of the most aggressive bone tumors worldwide. Emerging documents have shown that long noncoding RNAs (lncRNAs) elicit crucial regulatory functions in the process of tumorigenesis. LncRNA DLGAP1-AS2 is recognized as a regulator in several types of cancers, but its biological functions and molecular mechanisms in OS remain to be elucidated. RT-qPCR and In situ hybridization (ISH) were used to evaluate DLGAP1-AS2 expression in OS samples. Western blotting was used for the measurement of the protein levels of hexokinase 2 (HK2) and epithelial-mesenchymal transition (EMT)-related markers. The proliferation of OS cells was determined using a CCK-8 assay and EdU assay. TUNEL assay and flow cytometry were performed to assess OS cell apoptosis. Glucose metabolism in vitro assays were used. The binding relations among miR-451a, HK2, and DLGAP1-AS2 were validated by luciferase reporter assay. The cellular distribution of DLGAP1-AS2 in OS cells was determined by FISH and subcellular fractionation assays. Mouse xenograft models were established to perform the experiments in vivo. We found that DLGAP1-AS2 expression was upregulated in OS tissues and cells. Downregulation of DLGAP1-AS2 expression suppressed the malignancy of OS cells by restraining cell proliferation, the EMT process, invasiveness, migration, and aerobic glycolysis and accelerating apoptotic behaviors. Of note, silenced DLGAP1-AS2 restrained tumor growth and metastasis in vivo. However, DLGAP1-AS2 overexpression accelerated the progression of OS. We further found that DLGAP1-AS2 upregulation was induced by hypoxia and low glucose. Additionally, DLGAP1-AS2 bound to miR-451a to upregulate HK2 expression. Rescue assays revealed that the DLGAP1-AS2/miR-451a/HK2 axis contributed to OS cell malignancy by promoting aerobic glucose metabolism. Overall, these findings revealed a new regulatory pathway where DLGAP1-AS2 upregulated HK2 expression by sponging miR-451a to accelerate OS development.

LncRNA EBLN3P Facilitates Osteosarcoma Metastasis by Enhancing Annexin A3 mRNA Stability and Recruiting HuR

BACKGROUND

Osteosarcoma (OS) represents a common type of bone cancer. Long non-coding RNAs (LncRNAs) have shown their potential in therapeutic modalities for OS. This study's purpose was to reveal the action of lncRNA EBLN3P on OS growth and metastasis and its mechanism.

METHODS

Expressions of EBLN3P/Hu antigen R (HuR)/Annexin A3 (ANXA3) were determined by RT-qPCR/Western blot. Proliferation/migration/invasion of OS cells were assessed via CCK-8/Transwell assays after interfering EBLN3P/ANXA3/HuR. The co-localization of EBLN3P/ANXA3/HuR cells was observed by FISH/immunofluorescence assays. Interplays among EBLN3P/ANXA3/HuR and the half-life period of ANXA3 were assessed by RNA immunoprecipitation/RNA pull-down/RNA stability experiment. The nude mouse xenograft model was established, followed by EBLN3P treatment to assess the function of EBLN3P on OS.

RESULTS

EBLN3P/ANXA3 was highly expressed in OS cells. Silencing EBLN3P or ANXA3 limited the proliferation/migration/invasion of OS cells. Mechanically, EBLN3P/ANXA3 can bind to HuR, and EBLN3P enhanced ANXA3 mRNA stability by recruiting HuR, thus facilitating OS cell growth. Upregulated HuR or ANXA3 counteracted the suppressive action of silencing EBLN3P on OS cells. In vivo experiments revealed facilitated tumor growth and metastasis in vivo fomented by EBLN3P through manipulation of HuR/ANXA3.

CONCLUSIONS

EBLN3P enhanced proliferative/migrative/invasive potentials of OS cells via increasing ANXA3 mRNA stability and protein level by recruiting HuR, which provided new potential therapeutic targets for OS clinical treatment. EBLN3P and ANXA3 might have potential roles in OS diagnosis, treatment, and prognosis. This study provided a theoretical reference for further clinical research in tumor surgery.

Self-assembled miR-134-5p inhibitor nanoparticles ameliorate experimental bronchopulmonary dysplasia (BPD) via suppressing ferroptosis

Bronchopulmonary dysplasia (BPD) is a chronic lung disease in premature infants with increased levels of reactive oxygen species (ROS) and ferroptosis. Herein, we designed a peptide-based nanoparticle to deliver therapeutic molecules to pulmonary, thereby ameliorating BPD. The BPD-induced damages of lung tissues were detected by H&E and immunohistochemistry staining. Inflammatory cytokines, Fe2+, and ROS levels were quantified by the indicated kits, respectively. The targeting relationship was verified by luciferase reporter assay and pull-down assay. Subsequently, self-assembled miR-134-5p inhibitor nanoparticles with pulmonary epithelial cell-targeting were synthesized. The characteristics were detected by transmission electron microscopy, luminescence imaging, and dynamic light scattering. A significant ferroptosis was observed in the BPD mice. The protein level of GPX4 was decreased significantly compared to the control group. Constantly, miR-134-5p showed positive regulation on ferroptosis by targeting GPX4. The designed nanoparticles were mainly accumulated in the lung region. Besides, it ameliorated experimental bronchopulmonary dysplasia via suppressing ferroptosis, in vivo and in vitro. Our findings provided a miR-134-5p/GPX4 axis in regulating ferroptosis of BPD and prompted the potential of applying the peptide-based nanoparticle to BPD treatment.

Long noncoding RNA XLOC_006786 inhibits the proliferation, invasion and metastasis of osteosarcoma cells through NOTCH3 signaling pathway by targeting miR-491-5p

Recent research has indicated that Long noncoding RNAs (LncRNAs) are crucial in many disorders, especially tumors. However, the exact role of LncRNA XLOC_006786 (LncRNA-SPIDR-2:1) in malignancies, especially in human osteosarcoma, is unclear. The results of RT‒qPCR, western blotting, CCK-8 assays, and Transwell assays showed that LncRNA XLOC_006786 inhibited osteosarcoma cell proliferation, invasion, and migration, indicating that it may be a tumor suppressor gene in osteosarcoma. We found that LncRNA XLOC_006786 negatively regulated NOTCH3, which is an oncogenic gene in osteosarcoma, as we previously reported. Bioinformatics analysis showed that miR-491-5p may be a direct target of LncRNA XLOC_006786, while NOTCH3 is a key target of miR-491-5p. Then, we verified that LncRNA XLOC_006786 could prevent lung metastatic osteosarcoma in vivo. Taken together, our research showed that LncRNA XLOC_006786 suppresses osteosarcoma proliferation, invasion, and metastasis through the NOTCH3 signaling pathway by targeting miR-491-5p.

Competitive endogenous network of circRNA, lncRNA, and miRNA in osteosarcoma chemoresistance

Osteosarcoma is the most prevalent and fatal type of bone tumor. Despite advancements in the treatment of other cancers, overall survival rates for patients with osteosarcoma have stagnated over the past four decades Multiple-drug resistance-the capacity of cancer cells to become simultaneously resistant to multiple drugs-remains a significant obstacle to effective chemotherapy. The recent studies have shown that noncoding RNAs can regulate the expression of target genes. It has been proposed that "competing endogenous RNA" activity forms a large-scale regulatory network across the transcriptome, playing important roles in pathological conditions such as cancer. Numerous studies have highlighted that circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) can bind to microRNA (miRNA) sites as competitive endogenous RNAs, thereby affecting and regulating the expression of mRNAs and target genes. These circRNA/lncRNA-associated competitive endogenous RNAs are hypothesized to play significant roles in cancer initiation and progression. Noncoding RNAs (ncRNAs) play an important role in tumor resistance to chemotherapy. However, the molecular mechanisms of the lncRNA/circRNA-miRNA-mRNA competitive endogenous RNA network in drug resistance of osteosarcoma remain unclear. An in-depth study of the molecular mechanisms of drug resistance in osteosarcoma and the elucidation of effective intervention targets are of great significance for improving the overall recovery of patients with osteosarcoma. This review focuses on the molecular mechanisms underlying chemotherapy resistance in osteosarcoma in circRNA-, lncRNA-, and miRNA-mediated competitive endogenous networks.

FTO-mediated epigenetic upregulation of LINC01559 confers cell resistance to docetaxel in breast carcinoma by suppressing miR-1343-3p

This study was to explore the regulatory effect of long non-coding RNA LINC01559 on Docetaxel resistance in breast carcinoma (BCa) and its underlying mechanism. In the present study, we found that LINC01559 expression was elevated and LINC01559 overexpression facilitated docetaxel resistance in BCa cells. Moreover, it was revealed that the upregulation of LINC01559 in BCa cells was induced by FTO-mediated demethylation in an m6A-YTHDF2-dependent manner. Additionally, Dual-luciferase reporter assay confirmed the binding ability between LINC01559 and miR-1343-3p, and Pearson correlation analysis showed a negative correlation between them. Particularly, miR-1343-3p inhibition partly abolished the suppression on docetaxel resistance in BCa cells caused by LINC01559 knockdown. To sum up, FTO-mediated epigenetic upregulation of LINC01559 promoted cell resistance to Docetaxel in BCa by negatively regulating miR-1343-3p.

Construction of an efferocytosis-related long non-coding ribonucleic acid scoring system to predict clinical outcome and immunotherapy response in pancreatic adenocarcinoma

Background

Efferocytosis suppresses antitumour immune responses by inducing the release and secretion of cytokines. Long non-coding ribonucleic acids (lncRNAs) have various functions in different forms of programmed cell death and in immune regulation. This study aims to explore the potential role of efferocytosis-related lncRNAs as biomarkers in pancreatic adenocarcinoma (PAAD).

Methods

Transcriptome profiles, simple nucleotide variations and clinical data of patients with PAAD were extracted from The Cancer Genome Atlas (TCGA) database. Co-expression algorithms identified efferocytosis-related lncRNAs. The efferocytosis-related lncRNA scoring system (ERLncSys) was established using Cox regression and the Least Absolute Shrinkage and Selection Operator algorithm. Additionally, Kaplan-Meier (K-M) curves, Cox regression, receiver operating characteristic (ROC) curves and clinical parameter stratification analyses were used to evaluate ERlncSys. Moreover, ERlncSys was explored through Gene Set Variation Analysis, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Furthermore, the TIMER platform, ESTIMATE algorithm, single sample Gene Set Enrichment Analysis and immune checkpoint analysis were utilised to explore the predictive power of ERlncSys for the tumour immune microenvironment (TIME). Finally, a consensus clustering algorithm identified distinct molecular profiles among patients with PAAD, aiding in the identification of potential beneficiaries for immunotherapy.

Results

K-M, Cox regression and ROC analyses confirmed the robust prognostic efficacy of ERlncSys. Clinical stratification analysis indicated the broad applicability of ERlncSys in PAAD. Additionally, mmunological analyses indicated that ERlncSys can determine immune cell infiltration status in the TIME. Furthermore, consensus clustering analysis based on ERlncSys divided the TCGA-PAAD cohort into two clusters. Cluster 1 exhibited characteristics consistent with an immune 'hot tumour' compared to cluster 2, suggesting cluster 1 is a more suitable population for immune checkpoint inhibitor therapy.

Conclusion

The established ErlncSys aids in predicting the prognosis and understanding the TIME landscape of patients with PAAD. In turn, it facilitates the identification of optimal candidates for immunotherapy. This study introduces novel insights into the potential value of efferocytosis-related lncRNAs as biomarkers in PAAD.

CircZNF236 facilitates malignant progression in oral squamous cell carcinoma by sequestering miR-145-5p

BACKGROUND

A number of non-coding circular RNAs (circRNAs) have recently been implicated in the modulation of gene expression in cancer models. We therefore sought to explore if circZNF236 has a role in oral squamous cell carcinoma (OSCC).

METHODS

We first examined circZNF236 expression in 32 pairs of OSCC and noncancerous tissues. We then investigated a functional role for circZNF236 using knockdown and overexpression approaches in OSCC cancer cell lines. Cell counting kit-8, wound healing, Transwell, and flow cytometry were employed to assess circZNF236 function in vitro. The association between circZNF236 and miR-145-5p, or that between miR-145-5p and malignant brain tumor domain containing 1 (MBTD1) was predicted by bioinformatics and demonstrated by dual-luciferase reporter assays, RNA pull-down assays as well as RNA immunoprecipitation (RIP) assays. A mouse OSCC xenograft model was employed to demonstrate the impacts of circZNF236 inhibition on tumor development in vivo.

RESULTS

OSCC tissues and cells had higher levels of circZNF236 expression compared with normal controls. Furthermore, high circZNF236 levels in patients with OSCC correlated with a poor prognosis. CircZNF236 silencing decreased the malignant properties of OSCC cells and suppressed OSCC tumor formation in the mouse model. We then noticed that miR-145-5p can be regulated by circZNF236, and that circZNF2361 promoted OSCC development by absorbing miR-145-5p and consequently upregulating MBTD1 expression.

CONCLUSION

CircZNF236 modulates OSCC via the miR-145-5p/MBTD1 axis. These results support the potential of circZNF236 as a treatment target for OSCC.

LncRNA STK4 antisense RNA 1 (STK4-AS1) promoted osteosarcoma by inhibiting p53 expression

BACKGROUND

LncRNA STK4 antisense RNA 1 (STK4-AS1) has been identified as a potential biomarker associated with multiple cancers. We proposed that STK4-AS1 plays a role in the proliferation of osteosarcoma by regulating the cell cycle.

METHODS

We compared the expression of STK4-AS1, p53, and p21 in osteosarcoma vs normal samples in clinical tissues and cell lines. We determined the effect of overexpression and knockdown of STK4-AS1 in p53 expressing osteosarcoma cells U2OS, p53 muted osteosarcoma cells MG63, and osteoblast cells hFOB on p53 and p21 expression and the cell viability. For U2OS and MG63, the cell cycle was analyzed and the expression of cyclin proteins was determined. We overexpressed p53 or p21 in STK4-AS1 overexpressed cells to explore the association of STK4-AS1 and p53 in U2OS.

RESULTS

The STK4-AS1 expression was higher and p53 and p21 expression were lower in osteosarcoma tissue and cells than in their non-cancer counterparts. The expression of STK4-AS1 was negatively correlated with the expression of p53 or p21. Knockdown of STK4-AS1 in U2OS decreased the cell viability, increased cells in the G0/G1 phase, decreased cells in the S and G2/M phase, decreased expression of cyclin A and B, increased p53 and p21, and had no effect on cyclin D and cyclin E, while overexpression of STK4-AS1 did the opposes. Overexpression of p53 or p21 recovered some changes caused by STK4-AS1 overexpression in U2OS. MG63 expressed no p53 and the expression of p21, cyclin A, and cyclin B, cell viability, and cell cycle were not affected by altered STK4-AS1 levels. In hFOB cells, the expression of p53 and p21 was decreased and the cell viability was increased when STK4-AS1 was overexpressed, but they were not affected when STK4-AS1 was knocked down.

CONCLUSION

LncRNA STK4-AS1 promoted the cell cycle of osteosarcoma cells by inhibiting p53 expression.

LncSNHG14 promotes nutlin3a resistance by inhibiting ferroptosis via the miR-206 /SLC7A11 axis in osteosarcoma cells

The most prevalent form of primary osseous malignant tumor in adolescents and children is osteosarcoma (OS). A combination of surgery and neoadjuvant/post-surgery chemotherapy is currently the standard therapy. While the chemoresistance associated with OS generally leads to poor efficacy of therapeutic agents, the relevant molecular interaction is still elusive. Here, the lncRNA (long non-coding RNA) SNHG14 was found to be significantly upregulated in the nutlin3a-resistant OS cell line NR-SJSA1 and contributes to treatment resistance by suppressing ferroptosis. In NR-SJSA1 cells, knockdown of LncRNA SNHG14 resulted in a reversal of drug resistance and activation of ferroptosis, which disappeared when ferrostatin-1, a ferroptosis inhibitor, was added. Mechanistically, lncRNA SNHG14 targeted and down-regulated the expression of miR-206, further affecting the common ferroptosis inhibitor SLC7A11, and preventing NR-SJSA1 cells from undergoing ferroptosis. In conclusion, our findings highlight the involvement of lncRNA SNHG14 in ferroptosis and chemotherapy resistance of nutlin3a-resistant NR-SJSA1 cells, thus shedding new insight on how to overcome drug resistance in osteosarcoma cells and improve treatment efficacy.

A novel cuproptosis-related lncRNA signature predicts prognosis and therapeutic response in bladder cancer

Bladder cancer (BC) ranks the tenth in the incidence of global tumor epidemiology. LncRNAs and cuproptosis were discovered to regulate the cell death. Herein, we downloaded transcriptome profiling, mutational data, and clinical data on patients from The Cancer Genome Atlas (TCGA). High- and low-risk BC patients were categorized. Three CRLs (AL590428.1, AL138756.1 and GUSBP11) were taken into prognostic signature through least absolute shrinkage and selection operator (LASSO) Cox regression. Worse OS and PFS were shown in high-risk group (p < 0.05). ROC, independent prognostic analyses, nomogram and C-index were predicted via CRLs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated IncRNAs play a biological role in BC progression. Immune-related functions showed the high-risk group received more benefit from immunotherapy and had stronger immune responses, and the overall survival was better (p < 0.05). Finally, a more effective outcome (p < 0.05) was found from clinical immunotherapy via the TIDE algorithm and many potential anti-tumor drugs were identified. In our study, the cuproptosis-related signature provided a novel tool to predict the prognosis in BC patients accurately and provided a novel strategy for clinical immunotherapy and clinical applications.

Long non-coding RNA ZMIZ1-AS1 promotes osteosarcoma progression by stabilization of ZMIZ1

BACKGROUND

Osteosarcomas (OS) are frequent primary sarcomas of the bone in children and adolescents. The long non-coding RNAs (lncRNAs) can affect the progression of many cancers by their sense transcripts. The present study was designed to probe the role of ZMIZ1-AS1 and the downstream pathway in OS progression.

METHODS

Cell proliferation, invasion, and migration were detected by colony formation, transwell, and wound healing assays. The binding of SOX2 or MYC protein with ZMIZ1-AS1 promoter was explored by ChIP assay and dual-luciferase reporter assay. Interaction between PTBP1 protein and ZMIZ1-AS1 (or ZMIZ1 mRNA) was detected by RIP assay.

RESULTS

SOX2 and MYC are the downstream effectors of the Hippo pathway and transcriptionally activated ZMIZ1-AS1. Compared to the controls, OS tissues and cells contained higher ZMIZ1-AS1 expression. Silencing of ZMIZ1-AS1 repressed OS cell viability, proliferation, migration, and invasion. Our findings further showed that ZMIZ1-AS1 recruits RNA-binding protein PTBP1 to stabilize ZMIZ1 mRNA. PTBP1 or ZMIZ1 overexpression rescues the suppressive effects of silenced ZMIZ1-AS1 on OS cellular processes. Importantly, ZMIZ1-AS1 promotes OS growth in vivo by stabilization of ZMIZ1.

CONCLUSIONS

Long non-coding RNA ZMIZ1-AS1 promotes OS progression by stabilization of ZMIZ1. The Hippo pathway is inactivated in osteosarcoma. Transcriptional factors SOX2 and MYC downstream the Hippo pathway induce the upregulation of ZMIZ1-AS1 in osteosarcoma. ZMIZ1-AS1 recruits RNA binding protein PTBP1 that stabilizes ZMIZ1, the sense transcript of ZMIZ1-AS1. ZMIZ1-AS1 promotes osteosarcoma cell viability, proliferation, migration, and invasion by ZMIZ1 in a PTBP1 dependent manner.

Modulation of immunosuppressive cells and noncoding RNAs as immunotherapy in osteosarcoma

The most common bone cancer is osteosarcoma (OS), which mostly affects children and teenagers. Early surgical resection combined with chemotherapy significantly improves the prognosis of patients with OS. Existing chemotherapies have poor efficacy in individuals with distant metastases or inoperable resection, and these patients may respond better to novel immunotherapies. Immune escape, which is mediated by immunosuppressive cells in the tumour microenvironment (TME), is a major cause of poor OS prognosis and a primary target of immunotherapy. Myeloid-derived suppressor cells, regulatory T cells, and tumour-associated macrophages are the main immunosuppressor cells, which can regulate tumorigenesis and growth on a variety of levels through the interaction in the TME. The proliferation, migration, invasion, and epithelial-mesenchymal transition of OS cells can all be impacted by the expression of non-coding RNAs (ncRNAs), which can also influence how immunosuppressive cells work and support immune suppression in TME. Interferon, checkpoint inhibitors, cancer vaccines, and engineered chimeric antigen receptor (CAR-T) T cells for OS have all been developed using information from studies on the metabolic properties of immunosuppressive cells in TME and ncRNAs in OS cells. This review summarizes the regulatory effect of ncRNAs on OS cells as well as the metabolic heterogeneity of immunosuppressive cells in the context of OS immunotherapies.

Non-coding RNAs as potential biomarkers in osteosarcoma

Osteosarcoma (OS) is a primary solid malignant tumor that occurs most frequently in the metaphysis of long bones. More likely to happen to children and adolescents. OS has high mortality and disability rate. However, the etiology and pathogenesis of OS have not been fully understood till now. Due to the lack of effective biomarkers, OS cannot be precisely detected in the early stage. With the application of next-generation and high-throughput sequencing, more and more abnormally expressed non-coding RNAs(ncRNAs) have been identified in OS. Growing evidences have suggested the ncRNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), have played an important role in the tumorigenesis and progression of OS. Thus, they can be served as novel biomarkers for diagnosis, treatment and prognosis. This review summarized the application of ncRNA as biomarkers in OS in detail, and discussed the limitation and future improvement of the potential biomarkers.

Silencing of lncRNA KLF3-AS1 represses cell growth in osteosarcoma via miR-338-3p/MEF2C axis

BACKGROUND

Osteosarcoma (OS) is a highly recurrent malignancy occurring among adolescents. The goal of this research was to scrutinize the role and action mechanism of KLF3-AS1 in OS.

METHODS

Western blotting and quantitative reverse transcription real-time PCR were conducted to ascertain the mRNA expressions of miR-338-3p, KLF3-AS1, and MEF2C in OS cell lines and tissue samples. Colony formation and CCK-8 experiments were done to evaluate the proliferative capacity of the cells. Western blotting was also executed to measure the relative expressions of the proteins Bcl-2 and Bax. RNA immunoprecipitation and dual luciferase reporter experiments were carried out to validate the target relationships among MEF2C, KLF3-AS1, and miR-338-3p. Mouse xenograft models were created to assess the influences of KLF3-AS1 on the growth of tumors in vivo.

RESULTS

Elevated levels of KLF3-AS1 and MEF2C and reduced amounts of miR-338-3p were identified in OS. KLF3-AS1 targeted miR-338-3p, and miR-338-3p further targeted MEF2C. Silencing KLF3-AS1 induced apoptosis and attenuated proliferation in vitro and repressed the tumor growth in vivo. Inhibiting miR-338-3p inverted the cancer-suppressing effects of KLF3-AS1 silencing. Meanwhile, loss of MEF2C partially eliminated the effects brought about by miR-338-3p downregulation, namely the stimulation of cell growth and suppression of apoptosis.

CONCLUSIONS

Silencing of KLF3-AS1 could repress the growth of cells and induce apoptosis by regulating miR-338-3p/MEF2C in OS. This suggests that the regulatory axis KLF3-AS1/miR-338-3p/MEF2C is a prospective target for OS treatment.

Bone Marrow Mesenchymal Stem Cells (BMSC)-Derived miR-134 Inhibits Cervical Cancer Metastasis

The miRNA had been brand-new hot spot for study on pathogenesis of malignant tumor and seeking prevention strategy. The occurrence and development of tumor could be regulated by Gli1/Snail signaling pathway through Hedgehog channel. Our study intends to discuss the role of miRNA derived from BMSC in HPV. The miR-134 derived from BMSC was analyzed through nano-particles and observed under fluorescence microscope along with analysis of miR-134 expression by RTPCR. The HPV rat model was established to analyze miR-134’s role in HPV metastasis in vivo. The level of miR-134 in the staging of N2–N3 was lower than that in N0–N1 staging and lower in patients with metastatic cervical cancer tissue than patients without distant metastasis. Gli1 level could be targeted by miR-134. miR-134 inhibits HPV proliferation and migration by regulating the Gli1/Snail channel through Hedgehog pathway. The inhibitory effect of miR-134 on HH signal pathway could be reversed by Gli1 overexpression. The rats’ EMT and HPV growth was significantly restrained by miR-134 through silencing of Gli1. In conclusion, the growth of HPV is restrained by miR-134 derived from BMSC by regulating Gli1/Snail pathway through Hedgehog channel.

Cuproptosis-related lncRNA predict prognosis and immune response of lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) accounts for 50% of lung cancers, with high mortality and poor prognosis. Long non-coding RNA (lncRNA) plays a vital role in the progression of tumors. Cuproptosis is a newly discovered form of cell death that is highly investigated. Therefore, in the present study, we aimed to investigate the role of cuproptosis-related lncRNA signature in clinical prognosis prediction and immunotherapy and the relationship with drug sensitivity.

MATERIAL AND METHODS

Genomic and clinical data were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and cuproptosis-related genes were obtained from cuproptosis-related studies. The prognostic signature was constructed by co-expression analysis and Cox regression analysis. Patients were divided into high and low risk groups, and then, a further series of model validations were carried out to assess the prognostic value of the signature. Subsequently, lncRNAs were analyzed for gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes Enrichment (KEGG), immune-related functions, and tumor mutation burden (TMB). Finally, we used tumor immune dysfunction and exclusion (TIDE) algorithms on immune escape and immunotherapy of cuproptosis-related lncRNAs, thereby identifying its sensitivity toward potential drugs for LUAD.

RESULTS

A total of 16 cuproptosis-related lncRNAs were obtained, and a prognostic signature was developed. We found that high-risk patients had worse overall survival (OS) and progression-free survival (PFS) and higher mortality. Independent prognostic analyses, ROC, C-index, and nomogram showed that the cuproptosis-related lncRNAs can accurately predict the prognosis of patients. The nomogram and heatmap showed a distinct distribution of the high- and low-risk cuproptosis-related lncRNAs. Enrichment analysis showed that the biological functions of lncRNAs are associated with tumor development. We also found that immune-related functions, such as antiviral activity, were suppressed in high-risk patients who had mutations in oncogenes. OS was poorer in patients with high TMB. TIDE algorithms showed that high-risk patients have a greater potential for immune escape and less effective immunotherapy.

CONCLUSION

To conclude, the 16 cuproptosis-related lncRNAs can accurately predict the prognosis of patients with LUAD and may provide new insights into clinical applications and immunotherapy.

The long non-coding RNA CRNDE promotes osteosarcoma proliferation and migration by sponging miR-136-5p/MRP9 axis

Background

The long-noncoding RNA colorectal neoplasia differentially expressed (CRNDE) gene has been found to be upregulated in several solid tumors. Whether CRNDE affects osteosarcoma (OS) and its underling mechanism remains unknown.

Methods

Tumor tissues and corresponding normal tissues were collected from 45 patients with OS. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was applied to determine lncRNA CRNDE level in the tissues. Participants were divided into a high CRNDE group and a low CRNDE group according to the median value of lncRNA CRNDE expression detected by in situ hybridization (ISH). The differences between high and low expression of lncRNA CRNDE in patients were compared clinically by chi-square test. Kaplan-Meier survival analysis was applied to analyze the relationship between lncRNA CRNDE expression and patient survival. Subsequently, silencing or overexpression of lncRNA CRNDE were performed in MG63 and 143B cell lines, qRT-PCR was applied to verify the expression of lncRNA CRNDE, miR-136-5p, and MRP9; dual-luciferase reporter assay was used to evaluate the targeting relationship between miR-136-5p, lncRNA CRNDE, and Cell Counting Kit-8 (CCK8), wound-healing, and Transwell assays were used to analyze for cell proliferation, migration, and invasion, respectively, and western blot was used to detect expression in cells.

Results

The expression of CRNDE in OS tissues was higher than that in normal tissues. High lncRNA CRNDE expression was significantly associated with clinical stage, lung metastasis, and poor prognosis in OS patients. Additionally, overexpression of lncRNA CRNDE promoted proliferation and migration of OS cells. Bioinformatics analysis showed that lncRNA CRNDE competitively inhibited miR-136-5p through acting as a competitive endogenous RNA (ceRNA). It was also revealed that miR-136-5p is a binding target gene of lncRNA CRNDE and that MRP9 is involved in this process as a downstream target gene of miR-136-5p.

Conclusions

The lncRNA CRNDE promotes the proliferation and migration of OS cells by regulating the miR-136-5p/MRP9 pathway, and lncRNA CRNDE can be a significant marker of OS prognosis.

The functions of long noncoding RNAs on regulation of F-box proteins in tumorigenesis and progression

Accumulated evidence has revealed that F-box protein, a subunit of SCF E3 ubiquitin ligase complexes, participates in carcinogenesis and tumor progression via targeting its substrates for ubiquitination and degradation. F-box proteins could be regulated by cellular signaling pathways and noncoding RNAs in tumorigenesis. Long noncoding RNA (lncRNA), one type of noncoding RNAs, has been identified to modulate the expression of F-box proteins and contribute to oncogenesis. In this review, we summarize the role and mechanisms of multiple lncRNAs in regulating F-box proteins in tumorigenesis, including lncRNAs SLC7A11-AS1, MT1JP, TUG1, FER1L4, TTN-AS1, CASC2, MALAT1, TINCR, PCGEM1, linc01436, linc00494, GATA6-AS1, and ODIR1. Moreover, we discuss that targeting these lncRNAs could be helpful for treating cancer via modulating F-box protein expression. We hope our review can stimulate the research on exploration of molecular insight into how F-box proteins are governed in carcinogenesis. Therefore, modulation of lncRNAs is a potential therapeutic strategy for cancer therapy via regulation of F-box proteins.

Mechanisms of cancer cell death induction by paclitaxel: an updated review

Chemoresistance of cancer cells is a major problem in treating cancer. Knowledge of how cancer cells may die or resist cancer drugs is critical to providing certain strategies to overcome tumour resistance to treatment. Paclitaxel is known as a chemotherapy drug that can suppress the proliferation of cancer cells by inducing cell cycle arrest and induction of mitotic catastrophe. However, today, it is well known that paclitaxel can induce multiple kinds of cell death in cancers. Besides the induction of mitotic catastrophe that occurs during mitosis, paclitaxel has been shown to induce the expression of several pro-apoptosis mediators. It also can modulate the activity of anti-apoptosis mediators. However, certain cell-killing mechanisms such as senescence and autophagy can increase resistance to paclitaxel. This review focuses on the mechanisms of cell death, including apoptosis, mitotic catastrophe, senescence, autophagic cell death, pyroptosis, etc., following paclitaxel treatment. In addition, mechanisms of resistance to cell death due to exposure to paclitaxel and the use of combinations to overcome drug resistance will be discussed.

Anesthetic propofol enhances cisplatin-sensitivity of non-small cell lung cancer cells through N6-methyladenosine-dependently regulating the miR-486-5p/RAP1-NF-κB axis

BACKGROUND

Drug resistance is a considerable challenge for chemotherapy in non-small cell lung cancer (NSCLC). Propofol, a commonly used intravenous anesthetics, has been reported to suppress the malignancy of various cancers. However, the effects of propofol on cisplatin (DDP) sensitivity in NSCLC and its molecular mechanisms have not been clearly clarified yet, and the present study aimed to resolve this problem.

METHODS

NSCLC cells were co-treated with propofol and DDP, Cell Counting kit-8 assay, colony formation assay and flow cytometry were conducted to test the role of propofol in regulating DDP-resistance in NSCLC. Next, through conducting quantitative real-time polymerase chain reaction, dual-luciferase gene reporter system and western blot, the responsible molecular axis in propofol regulating the DDP sensitivity in NSCLC was uncovered, and the function verification experiments were performed by transfection with the inhibitors or small interfering RNAs of those molecules.

RESULTS

Propofol suppressed cell viability, colony formation ability, tumorigenesis, and promoted cell apoptosis to enhance DDP-sensitivity in NSCLC in vitro and in vivo. Propofol increased miR-486-5p level in NSCLC cells and xenograft tumors tissues in a N6-methyladenosine (m6A)-dependent manner, thus inactivating the Ras-associated protein1 (RAP1)-NF-kappaB (NF-κB) axis. Propofol regulated the miR-486-5p/RAP1-NF-κB axis to improve DDP-sensitivity in NSCLC.

CONCLUSIONS

Taken together, this study firstly investigates the detailed molecular mechanisms by which propofol enhanced DDP-sensitivity in NSCLC cells, and a novel m6A-dependent miR-486-5p/RAP1-NF-κB axis is identified to be closely associated with the process.

Deciphering Prognostic Value of TTN and Its Correlation With Immune Infiltration in Lung Adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is the most common type of lung cancer, accounting for around 40%. Despite achievements in the treatment approach, the prognosis is still dismal, with overall survival of fewer than five years. Thus, novel prognostic biomarkers are needed to predict the clinical outcomes of individual patients better. TTN has a high mutation rate in the LUAD, which encodes a large abundant protein of striated muscle. However, the value of TTN in prognosis and the immune environment are poorly understood.

Methods

We investigated the clinicopathological characteristics, transcriptional and protein level, prognostic value, biological function, and its relationship with immune infiltration of TTN gene in LUAD patients through bioinformatics analysis.

Results

TTN expression was significantly lower in LUAD than that in normal lung tissue. Lower TTN expression was associated with worse survival. Besides, TTN is highly expressed in alveolar type 2 cells which were surmised as the origin of LUAD.

Conclusion

Our findings indicated the potential prognostic value of TTN and its role as a biomarker for determining the immune infiltration levels in patients with LUAD.

LncRNA NDRG1 aggravates osteosarcoma progression and regulates the PI3K/AKT pathway by sponging miR-96-5p

BACKGROUND

Osteosarcoma (OS) is the most common primary malignant bone tumors in children and adolescents. Large numbers of studies have focused on the long non-coding RNA (lncRNA) that plays essential roles in the progression of osteosarcoma. Nevertheless, the functions and underlying mechanisms of LncRNA NDRG1 in osteosarcoma remain unknown.

METHODS

Differentially expressed lncRNAs between osteosarcoma and adjacent normal tissues were identified through RNA sequencing. The role of LncRNA NDRG1 in osteosarcoma proliferation and metastasis were investigated through in vitro and in vivo functional experiments. The interaction between LncRNA NDRG1 and miR-96-5p was verified through bioinformatic analysis and luciferase reporter assay. Regulation relationship between LncRNA NDRG1 and miR-96-5p was further evaluated by the rescue experiments. Additionally, the changes in the expression of epithelial-mesenchymal transition (EMT) and the PI3K/AKT pathway were verified by Western blot.

RESULTS

LncRNA NDRG1 was up-regulated in osteosarcoma cell lines and tissues and the expression of LncRNA NDRG1 was correlated with the overall survival of osteosarcoma patients. Functional experiments exhibited that LncRNA NDRG1 aggravated osteosarcoma proliferation and migration in vitro; meanwhile, animals experiments showed that LncRNA NDRG1 promoted osteosarcoma growth and metastasis in vivo. Mechanistically, LncRNA NDRG1 was found to aggravate osteosarcoma progression and regulate the PI3K/AKT pathway by sponging miR-96-5p.

CONCLUSIONS

LncRNA NDRG1 aggravates osteosarcoma progression and regulates the PI3K/AKT pathway by sponging miR-96-5p. Therefore, LncRNA NDRG1 could act as a prognostic marker and a therapeutic target for osteosarcoma in the future.

Bioinformatics analysis of lncRNAs in the occurrence and development of osteosarcoma

BACKGROUND

Osteosarcoma (OS) is a disease with high mortality in children and adolescents, and metastasis is one of its important clinical features. However, the molecular mechanism of OS occurrence is not completely clear. Thus, we screened potential biomarkers of OS and analyze their prognostic value.

METHODS

The Cancer Genome Atlas (TCGA) datasets were used to analyze the differential lncRNAs in patients with OS of different immune score and the lncRNAs expressed by immune cells. Cox regression was used to develop the prognosis prediction model and specify the prognosis outcomes. Risk-proportional regression model was constructed, and the samples were divided into high and low groups based on the risk scores for the survival analysis. The areas under the receiver operating characteristic (ROC) curve were calculated and the risk-score model was verified. Finally, using 4 gene sets (comprising chemokines, immune checkpoint blockades, immune activity-related genes, and immune cells), and 4 analysis tools (CIBERSORT, TIMER, XCELL and MCP) to evaluated tumor immune infiltration.

RESULTS

Twenty-nine long non-coding ribonucleic acids (lncRNAs) were obtained from the intersection of the screened lncRNAs. Caspase recruitment domain-containing protein 8-antisense RNA 1 (CARD8-AS1), lncRNA five prime to Xist (FTX), KAT8 regulatory NSL complex unit 1-antisense RNA 1 (KANSL1-AS1), Neuroplastin Intronic Transcript 1 (NPTN-IT1), oligodendrocyte maturation-associated long intervening non-coding RNA (OLMALINC) and RPARP Antisense RNA 1 (RPARP-AS1) were found to be correlated with survival. Univariate and multivariate regression analysis showed risk score [HR (hazard ratio) 3.5, P value 0.0043; HR 3.7, P value 0.0033] and metastasis (HR 4.7, P value 6.60E-05; HR 4.8, P value 8.36E-05) were the key factors of patients with OS. The areas under curves (AUCs) of the 1-, 3-, and 5-year ROC curves of the prognostic model were 0.715, 0.729, and 0.771. The low-risk patients tended to have a high abundance of immune cells.

CONCLUSIONS

This study showed that a risk score based on 6 lncRNAs has potential value in the prognosis of OS, and patients with low-risk scores have high immune cell infiltration and good prognosis. This study may enrich understandings of underlying mechanisms related to the occurrence and development of OS.

EBF1-mediated up-regulation of lncRNA FGD5-AS1 facilitates osteosarcoma progression by regulating miR-124-3p/G3BP2 axis as a ceRNA

Background

As a skeletal malignancy, osteosarcoma has high incidence among primary malignant bone tumors. With increasing researches on molecules which mediate cancer progression, molecular mechanism has gradually become the pivot of osteosarcoma research and treatment.

Aim

Our study aimed at investigating the function of G3BP stress granule assembly factor 2 (G3BP2), which is an oncogene for breast cancer (BC) and prostate cancer but remains unknown in osteosarcoma cells.

Methods

Related gene expression was confirmed by RT-qPCR. Functional assays including immunofluorescence (IF), colony formation, transferase-mediated dUTP nick-end labeling (TUNEL) as well as transwell assays were utilized to test the cell biological process caused by the genes. Meanwhile, RNA pull-down assay, along with luciferase reporter and RNA immunoprecipitation (RIP) assays, was utilized to detect the interaction G3BP2, miR-124-3p and FGD5 antisense RNA 1 (FGD5-AS1) may exert on the regulation of osteosarcoma cells.

Results

G3BP2 was with high expression in osteosarcoma cells, and it aggravated the malignant cell behaviors in osteosarcoma. Additionally, miR-124-3p was verified to negatively regulate G3BP2 expression in osteosarcoma cells. Moreover, lncRNA FGD5-AS1 was predicted and testified to be the sponge of miR-124-3p and modulated G3BP2 expression positively. Subsequently, FGA5-AS1 accelerated osteosarcoma cell proliferation through up-regulating G3BP2. Furthermore, we identified EBF transcription factor 1 (EBF1) as the transcription factor for FGA5-AS1, and EBF1 served as a tumor facilitator in osteosarcoma cells.

Conclusion

EBF1 induced-FGA5-AS1 aggravated osteosarcoma cell malignancy by targeting miR-124-3p and G3BP2.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03181-7.

Novel insights into the interaction between N6-methyladenosine methylation and noncoding RNAs in musculoskeletal disorders

BACKGROUND

Musculoskeletal disorder (MSD) are a class of inflammatory and degener-ative diseases, but the precise molecular mechanisms are still poorly understood. Noncoding RNA (ncRNA) N6-methyladenosine (m6A) modification plays an essential role in the pathophysiological process of MSD. This review summarized the interaction be-tween m6A RNA methylation and ncRNAs in the molecular regulatory mechanism of MSD. It provides a new perspective for the pathophysiological mechanism and ncRNA m6A targeted therapy of MSD.

METHODS

A comprehensive search of databases was conducted with musculoskeletal disorders, noncoding RNA, N6-methyladenosine, intervertebral disc degeneration, oste-oporosis, osteosarcoma, osteoarthritis, skeletal muscle, bone, and cartilage as the key-words. Then, summarized all the relevant articles.

RESULTS

Intervertebral disc degeneration (IDD), osteoporosis (OP), osteosarcoma (OS), and osteoarthritis (OA) are common MSDs that affect muscle, bone, cartilage, and joint, leading to limited movement, pain, and disability. However, the precise pathogenesis remains unclear, and no effective treatment and drug is available at present. Numerous studies confirmed that the mutual regulation between m6A and ncRNAs (i.e., microRNAs, long ncRNAs, and circular RNAs) was found in MSD, m6A modification can regulate ncRNAs, and ncRNAs can also target m6A regulators. ncRNA m6A modification plays an essential role in the pathophysiological process of MSDs by regulating the homeostasis of skeletal muscle, bone, and cartilage.

CONCLUSION

m6A interacts with ncRNAs to regulate multiple biological processes and plays important roles in IDD, OP, OS, and OA. These studies provide new insights into the pathophysiological mechanism of MSD and targeting m6A-modified ncRNAs may be a promising therapy approach.

Osteosarcoma Cell-Derived Exosomal ELFN1-AS1 Mediates Macrophage M2 Polarization via Sponging miR-138-5p and miR-1291 to Promote the Tumorgenesis of Osteosarcoma

Background

Exosomes play an important role in cell-cell communication by transferring genetic materials such as long non-coding RNAs (lncRNAs) between cancer cells and tumor-associated macrophages (TAMs) in the tumor microenvironment (TME). Recent studies revealed that lncRNA ELFN1-AS1 could function as an oncogene in many human cancers. However, the role of extracellular lncRNA ELFN1-AS1 in cell-to-cell communication of osteosarcoma (OS) has not been fully investigated.

Methods

Functional studies, including CCK-8, EdU staining and transwell assay were performed to investigate the role of ELFN1-AS1 in the progression of OS. 143B via xenograft mouse model was established to assess the role of ELFN1-AS1 in vivo. In addition, transmission electron microscopy (TEM) and real-time quantitative PCR (RT-qPCR) assay were used to verify the existence of exosomal ELFN1-AS1.

Results

The level of ELFN1-AS1 was markedly upregulated in patients with advanced OS and in OS cells. In addition, overexpression of ELFN1-AS1 significantly promoted the proliferation, migration and invasion of OS cells, while knockdown of ELFN1-AS1 exhibited the opposite effects. Meanwhile, ELFN1-AS1 could be transferred from OS cells to macrophages via exosomes. Exosomal ELFN1-AS1 from 143B cells was able to promote macrophage M2 polarization, and M2 macrophage in return facilitated OS progression. Mechanistically, overexpression of ELFN1-AS1 upregulated CREB1 level via sponging miR-138-5p and miR-1291 in macrophage via.

Conclusion

OS cell-derived exosomal ELFN1-AS1 was able to induce macrophage M2 polarization via sponging miR-138-5p and miR-1291, and M2 macrophage notably facilitated the progression of OS. These data suggested that ELFN1-AS1 might serve as a potential therapeutic target for osteosarcoma.

LncRNA CBR3-AS1 promotes osteosarcoma progression through the network of miR-140-5p/DDX54-NUCKS1-mTOR signaling pathway

Long noncoding RNA (lncRNA) CBR3-AS1 (termed as CBR3-AS1) has been reported to be upregulated in several cancers including osteosarcoma. Its positive impact on the proliferation, migration, and invasion of osteosarcoma cells has been unveiled; nevertheless, whether it also affects the stemness and epithelial-mesenchymal transition (EMT) of osteosarcoma cells is unclear. The purpose for this study was to explore the effects of CBR3-AS1 on the stemness and EMT of osteosarcoma cells as well as its underlying mechanism. qRT-PCR and western blot were applied to detect target gene expression. Function assays were conducted to evaluate the effect of genes on the stemness and EMT of osteosarcoma cells. Mechanism assays were done to verify the association among different genes. In vivo assays were also performed. The obtained data showed that CBR3-AS1 demonstrated a high expression in osteosarcoma cells. CBR3-AS1 could promote stemness and EMT of osteosarcoma cells as well as osteosarcoma tumor growth. Mechanically, CBR3-AS1 sponged miR-140-5p and recruited DDX54 to upregulate NUCKS1, thus activating the mTOR signaling pathway. Furthermore, NUCKS1 could facilitate stemness and EMT of osteosarcoma cells. In summary, this study reveals that CBR3-AS1 exerts an oncogenic role in osteosarcoma through modulating the network of the miR-140-5p/DDX54-NUCKS1-mTOR signaling pathway.

Protective Role of lncRNA TTN-AS1 in Sepsis-Induced Myocardial Injury Via miR-29a/E2F2 Axis

OBJECTIVE

Approximately 50% of patients with sepsis encounter myocardial injury. The mortality of septic patients with cardiac dysfunction (approx. 70%) is much higher than that of patients with sepsis only (20%). A large number of studies have suggested that lncRNA TTN-AS1 promotes cell proliferation in a variety of diseases. This study delves into the function and mechanism of TTN-AS1 in sepsis-induced myocardial injury in vitro and in vivo.

METHODS

LPS was used to induce sepsis in rats and H9c2 cells. Cardiac function of rats was assessed by an ultrasound system. Myocardial injury was revealed by hematoxylin-eosin (H&E) staining. Gain and loss of function of TTN-AS1, miR-29a, and E2F2 was achieved in H9c2 cells before LPS treatment. The expression levels of inflammatory cytokines and cTnT were monitored by ELISA. The expression levels of cardiac enzymes as well as reactive oxygen species (ROS) activity and mitochondrial membrane potential (MMP) were measured using the colorimetric method. The expression levels of TTN-AS1, miR-29a, E2F2, and apoptosis-related proteins were measured by RT-qPCR and/or western blotting. The proliferation and apoptosis of H9c2 cells were separately detected by CCK-8 and flow cytometry. Luciferase reporter assay was used to verify the targeting relationships among TTN-AS1, miR-29a and E2F2, and RIP assay was further used to confirm the binding between miR-29a and E2F2.

RESULTS

TTN-AS1 was lowly expressed, while miR-29a was overexpressed in the cell and animal models of sepsis. Overexpression of TTN-AS1 or silencing of miR-29a reduced the expression levels of CK, CK-MB, LDH, TNF-B, IL-1B, and IL-6 in the supernatant of LPS-induced H9c2 cells, attenuated mitochondrial ROS activity, and enhanced MMP. Consistent results were observed in septic rats injected with OE-TTN-AS1. Knockdown of TTN-AS1 or overexpression of miR-29a increased LPS-induced inflammation and injury in H9c2 cells. TTN-AS1 regulated the expression of E2F2 by targeting miR-29a. Overexpression of miR-29a or inhibition of E2F2 abrogated the suppressive effect of TTN-AS1 overexpression on myocardial injury.

CONCLUSION

This study indicates TTN-AS1 attenuates sepsis-induced myocardial injury by regulating the miR-29a/E2F2 axis and sheds light on lncRNA-based treatment of sepsis-induced cardiomyopathy.

PITPNA-AS1/miR-98-5p to Mediate the Cisplatin Resistance of Gastric Cancer

Gastric cancer (GC) is the most deadly gastrointestinal malignancy with high incidence and mortality. Although, molecular mechanisms which drive gastric cancer progression are extensively investigated, the roles of long noncoding RNA (lncRNA) in gastric cancer growth and drug sensitivity remain unclear. Platinum is a mainstay to treat gastric cancer, and platinum resistance always leads to the local recurrence of gastric cancer. Therefore, it is important to identify biomarkers or therapeutic targets to sensitize gastric cancer to platinum. In this study, we employ noncoding RNA sequencing and found that lncRNA PITPNA-AS1 is overexpressed in gastric cancer tissues and associated with poor survival of gastric cancer patients. Kockdown of PITPNA-AS1 in gastric cancer cells significantly inhibited cell growth and triggered apoptotic cell death in gastric cancer cells. Also, cisplatin treatment could decrease PITPNA-AS1 levels in gastric cancer cells through inhibiting H3K27ac. Besides, PITPNA-AS1 is elevated in cisplatin-resistant gastric cancer cells and tissues, PITPNA-AS1 knockdown could sensitize gastric cancer cells to cisplatin treatment. Furthermore, we identified that PITPNA-AS1 directly interacts and inhibits miR-98-5p. Therefore, PITPNA-AS1 could be served as a potential biomarkers and curative therapeutic targets for gastric cancer progression.

GABPB1-AS1 Promotes the Development of Osteosarcoma by Targeting SP1 and Activating the Wnt/β-Catenin Pathway

In this study, the role of GABPB1-AS1 in osteosarcoma (OS) was analyzed. The expression of GABPB1-AS1 in different OS cell lines U2OS, HOS, MG63, and hFOB1.19 was detected. SiRNA GABPB1-AS1 was transfected with U2OS and HOS cell lines. The effects of GABPB1-AS1 silencing on proliferation, clonal formation, and migration of U2OS and HOS were detected by CCK-8 method, plate cloning method, and Transwell chamber. Western blot analysis was used to detect the protein levels of SP1, Wnt, β-catenin, c-Myc, and SOX2 in osteosarcoma cells. The binding relationship between GABPB1-AS1 and miR-199a-3p in OS cells was detected by a dual-luciferase reporter gene assay. Results showed that GABPB1-AS1 was higher in OS cells than that in hFOB1.19. Silencing GABPB1-AS1 inhibited the proliferation, clonal formation, migration, and epithelial-mesenchymal transformation of U2OS and HOS. There was a binding relationship between GABPB1-AS1 and miR-199a-3p in OS cells. GABPB1-AS1 mediated osteosarcoma cells via the SP1/Wnt/β-catenin signaling pathway. This study suggested that GABPB1-AS1 plays a carcinogenic role in OS through the SP1/Wnt/β-catenin signaling pathway through competitive binding and inhibition of miR-199a-3p.

Selection of lncRNAs That Influence the Prognosis of Osteosarcoma Based on Copy Number Variation Data

Osteosarcoma is the most common primary malignancy in the musculoskeletal system. It is reported that copy number variation- (CNV-) derived lncRNAs contribute to the progression of osteosarcoma. However, whether CNV-derived lncRNAs affect the prognosis of osteosarcoma remains unclear. Here, we obtained osteosarcoma-related CNV data and gene expression profiles from The Cancer Genome Atlas (TCGA) database. CNV landscape analysis indicated that copy number amplification of lncRNAs was more frequent than deletion in osteosarcoma samples. Thirty-four CNV-lncRNAs with DNA-CNV frequencies greater than 30% and their corresponding 294 mRNAs were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway enrichment analyses revealed that these mRNAs were mainly enriched in olfaction, olfactory receptor activity, and olfactory transduction processes. Furthermore, we predicted that a total of 23 genes were cis-regulated by 16 CNV-lncRNAs, while 30 transcription factors (TFs) were trans-regulated by 5 CNV-lncRNAs. Through $t$ -tests, univariate Cox regression analysis, and the least absolute shrinkage and selection operator (LASSO), we constructed a CNV-related risk model including 3 lncRNAs (AC129492.1, PSMB1, and AC037459.4). The Kaplan-Meier (K-M) curves indicated that patients with high-risk scores showed poor prognoses. The areas under the receiver operating characteristic (ROC) curves (AUC) for predicting 3-, 5-, and 7-year overall survival (OS) were greater than 0.7, showing a satisfactory predictive efficiency. Gene set enrichment analysis (GSEA) revealed that the prognostic signature was intimately linked to skeletal system development, immune regulation, and inflammatory response. Collectively, our study developed a novel 3-CNV-lncRNA prognostic signature that would provide theoretical guidance for the clinical prognostic management of osteosarcoma.

Necdin, one of the important pathway proteins in the regulation of osteosarcoma progression by microRNA-200c

MicroRNA-200c (miR-200c) generally acts as a tumor suppressor in multiple cancer types and a promising therapeutic target in tumorigenesis. However, only a few studies have explained the role of miR-200c in the development of osteosarcoma (OS). In this study, we investigated the role of miR-200c in OS progression and identified the regulatory pathway protein NDN involved in inhibiting the occurrence and development of OS. Firstly, we found that miR-200c is downregulated in OS cells and tissues. As well, in vitro and in vivo experiments showed that upregulating miR-200c inhibits the proliferation, invasion, metastasis of Saos-2 cells, promotes the apoptosis of Saos-2 cells and suppresses tumor growth in mice, indicating miR-200c plays a major role in regulating the OS progression. Furthermore, bioinformatics analysis showed that an anti-tumor protein, necdin (NDN), might be a potential target by miR-200c. To verify this hypothesis, we measured the expression level of NDN in OS cells and tissues and found NDN is downregulated, suggesting NDN is functional in OS progression. Moreover, we found that the expression levels of NDN and miR-200c in in vivo and in vitro experiments were positively correlated. However, the results of dual-luciferase reporter gene experiment showed miR-200c does not directly act on the 3ʹ untranslated region (UTR) of NDN gene, indicating that NDN might be an important pathway protein which regulates OS progression in the presence of miR-200c. Therefore, miR-200c/NDN could be potential targets for developing effective treatment against OS.

Identification of Ferroptosis-Related Genes as Biomarkers for Sarcoma

Sarcomas are seen as mixed-up nature with genetic and transcriptional heterogeneity and poor prognosis. Although the genes involved in ferroptosis are still unclear, iron loss is considered to be the core of glioblastoma, tumor progression, and tumor microenvironment. Here, we developed and tested the prognosis of SARC, which is a genetic marker associated with iron residues. The ferroptosis-related gene expression, one-way Cox analysis, and least-selection absolute regression algorithm (LASSO) are used to track prognostic-related genes and create risk assessment models. Finally, immune system infiltration and immune control point analysis are used to study the characteristics of the tumor microenvironment related to risk assessment. Moreover, LncRNA–miRNA–mRNA network was contributed in our studies. We determined the biomarker characteristics associated with iron degradation in gene 32 and developed a risk assessment model. ROC analysis showed that its model was accurately predicted, with 1, 2, 3, 4, and 5 years of overall survival in TCGA cohort of SARC patients. A comparative analysis of settings found that overall survival (OS) was lower in the high-risk than that in the low-risk group. The nomogram survival prediction model also helped to predict the OS of SARC patients. The nomogram survival prediction model has strong predictive power for the overall survival of SARC patients in TCGA dataset. GSEA analysis shows that high-risk groups are rich in inflammation, cancer-related symptoms, and pathological processes. High risk is related to immune cell infiltration and immune checkpoint. Our prediction model is based on SARC ferritin-related genes, which may support SARC prediction and provide potential attack points.

LncRNA-miRNA-mRNA regulatory axes in endometrial cancer: a comprehensive overview

INTRODUCTION

Recent research on tumorigenesis and progression has opened up an array of novel molecular mechanisms in the form of interactions between cellular non-coding RNAs (long non-coding RNA[lncRNA]/microRNA [miRNA]) and coding transcripts that regulate health and disease. Endometrial cancer (EC) is a prominent gynecological malignancy with a high incidence rate and poorly known etiology and prognostic factors that hinder the success of disease management. The emerging role of lncRNA-miRNA-mRNA interactions and their dysregulation in the pathophysiology of EC has been elucidated in many recent studies.

METHODS

A thorough literature review was conducted to explore information about lncRNA-miRNA-mRNA axes in EC.

RESULTS

Several lncRNAs act as molecular sponges that sequester various tumor suppressor miRNAs to inhibit their function, leading to the dysregulation of their target mRNA transcripts that contribute to the EC regulation.

CONCLUSIONS

This review summarizes these networks of molecular mechanisms and their contribution to different aspects of endometrial carcinogenesis, leading to a better conceptualization of the molecular pathways that underlie the disease and helping establish novel diagnostic biomarkers and therapeutic intervention points to aid the curative intent of EC.

SNHG15, a p53-regulated lncRNA, suppresses cisplatin-induced apoptosis and ROS accumulation through the miR-335-3p/ZNF32 axis

Small nucleolar RNA host gene 15 (SNHG15) is upregulated in many malignancies and mediates the development of multiple cancers, including osteosarcoma (OS). However, data on the regulatory mechanisms and role of SNHG15 in the chemoresistance of OS remain scarce. Here, we show that p53 binds to the SNHG15 promoter, leading to decreased SNHG15 expression. Decreased SNHG15 expression promotes cisplatin-induced apoptosis and reactive oxygen species (ROS) accumulation in OS cells. Furthermore, SNHG15 sponges and inhibits the activity of endogenous miR-335-3p, leading to the upregulation of zinc finger protein 32 (ZNF32). Taken together, these findings reveal that p53 downregulates SNHG15 expression in OS. In addition, SNHG15 suppresses cisplatin-induced apoptosis and ROS accumulation through the miR-335-3p/ZNF32 pathway.

Long non-coding RNA ACTA2-AS1 inhibits the cisplatin resistance of non-small cell lung cancer cells through inhibiting autophagy by suppressing TSC2

Long non-coding RNA (lncRNA) ACTA2-AS1 has been reported to play an important role in the progression of multiple human malignancies. The article aims to explore the role of ACTA2-AS1 on the cisplatin resistance of non-small cell lung cancer (NSCLC). RT-qPCR was performed to investigate the expression of ACTA2-AS1 in cisplatin-resistant NSCLC cell lines. Western blot was used to investigate the effects of ACTA2-AS1 on autophagy-related protein expression. RIP assay and RNA pull down were used to analyze the combination of ACTA2-AS1 and enhancer of zeste homolog 2 (EZH2), and CHIP was used to analyze the combination of tuberous sclerosis complex-2 (TSC2) gene promoter and Lys-27 of histone H3 (H3K27me3). In this study, ACTA2-AS1 was downregulated in cisplatin-resistant NSCLC cell lines. ACTA2-AS1 negatively regulated the cell viability and positively regulated the cell apoptosis of cisplatin-resistant NSCLC cell lines. Furthermore, our results demonstrated that ACTA2-AS1 promoted cisplatin-resistant NSCLC cells apoptosis through inhibiting autophagy. The regulation of ACTA2-AS1 to the cisplatin-resistant NSCLC cell autophagy was reversed by TSC2 increasing. Importantly, our results displayed that ACTA2-AS1 bound with EZH2, and TSC2 gene promoter combined with H3k27me3. The inhibition of ACTA2-AS1 to TSC2 expression was recused by EZH2 silencing. In conclusion, ACTA2-AS1 inhibited the cisplatin resistances of NSCLC cell lines through suppressing TSC2 expressing by recruiting EZH2 to TSC2 gene promoter.

CRNDE silencing promotes apoptosis and enhances cisplatin sensitivity of colorectal carcinoma cells by inhibiting the Akt/mTORC1-mediated Warburg effect

Colorectal cancer (CRC) is one of the most prevalent gastrointestinal tumors worldwide, with a high mortality rate. The lncRNA colorectal neoplasia differentially expressed (CRNDE) is upregulated in CRC and is involved in regulating the apoptosis, proliferation, and drug sensitivity of CRC cells. However, the specific underlying mechanisms remain to be elucidated. The aim of the present study was to investigate the effects of CRNDE on the Warburg effect in CRC cells, as well as the associated mechanisms. The expression of CRNDE in HCT-116 cells was overexpressed or silenced by transfection. Apoptosis, cisplatin sensitivity, the Warburg effect, and Akt/mTOR activation were evaluated. The results demonstrated that CRNDE inhibition decreased the proliferation and increased the apoptosis and cisplatin sensitivity of HCT-116 cells. In addition, CRNDE inhibition attenuated the Warburg effect in HCT-116 cells, as verified by a decrease in ATP production, lactic acid levels, glucose uptake, and the expression of Warburg effect-related enzymes (GLUT1, LDHA, HK2, and PKM2). CRNDE inhibition also suppressed the activity of the Akt/mTORC1 pathway, as demonstrated by the decreased phosphorylation of Akt, S6K, S6, and mTOR and the increased phosphorylation of 4EBP-1 and EIF-4E. The CRNDE overexpression-induced increase in ATP and lactic acid levels and glucose uptake in HCT-116 cells was reversed by Akt and mTOR inhibitors. These findings indicate that CRNDE silencing promotes apoptosis and enhances cisplatin sensitivity in colorectal carcinoma cells, which may be mediated by the regulation of the Warburg effect via the Akt/mTORC1 pathway. The present study thus provides a potential strategy for the treatment of CRC.

Long Noncoding RNA GAS5: A New Factor Involved in Bone Diseases

Long noncoding RNAs (lncRNAs), as an important type of RNA encoded in the human transcriptome, have shown to regulate different genomic processes in human cells, altering cell type and function. These factors are associated with carcinogenesis, cancer metastasis, bone diseases, and immune system diseases, among other pathologies. Although many lncRNAs are involved in various diseases, the molecular mechanisms through which lncRNAs contribute to regulation of disease are still unclear. The lncRNA growth arrest-specific 5 (GAS5) is a key player that we initially found to be associated with regulating cell growth, differentiation, and development. Further work has shown that GAS5 is involved in the occurrence and prognosis of bone diseases, such as osteoporosis, osteosarcoma, and postosteoporotic fracture. In this review, we discuss recent progress on the roles of GAS5 in bone diseases to establish novel targets for the treatment of bone diseases.

miR-134-5p promotes inflammation and apoptosis of trophoblast cells via regulating FOXP2 transcription in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a prevalent and risky pregnant complication which warrants targeted therapy for restriction the inflammation and apoptosis of trophoblast cells. This study sought to analyze the aberrant expression and regulatory mechanism of microRNA (miR)-134-5p in GDM. The miR-134-5p expression in the serum of GDM patients and normal participants was detected via qRT-PCR, followed by receiver operating characteristic (ROC) curve analysis. In vitro GDM cell model was established in the HTR-8/SVneo cells using 25 mmol/L glucose, followed by transfection with miR-134-5p inhibitor and si-Forkhead box p2(FOXP2). The miR-134-5p and FOXP2 expressions, TNF-α, IL-1β, and IL-10 levels, cell proliferation, migration, and apoptosis were determined by a combination of qRT-PCR, western blot, ELISA, and cell counting Kit-8, Transwell assay, and flow cytometry. The binding relationship between miR-134-5p and FOXP2 was predicted and verified. Our results revealed that miR-134-5p was increased in the serum of GDM patients and could serve as a critical diagnostic marker for GDM. Moreover, miR-134-5p was upregulated in the high glucose (HG)-induced HTR-8/SVneo cells. The miR-134-5p inhibition suppressed the inflammation and apoptosis of HG-induced HTR-8/SVneo cells. miR-134-5p inhibited FOXP2 expression. FOXP2 expression was decreased in GDM. FOXP2 inhibition attenuated the function of miR-134-5p in HG-induced HTR-8/SVneo cells. Overall, miR-134-5p inhibited the FOXP2 expression to facilitate the inflammation and apoptosis of trophoblast cells, thereby exacerbating GDM.

Long non-coding RNA titin-antisense RNA1 contributes to growth and metastasis of cholangiocarcinoma by suppressing microRNA-513a-5p to upregulate stratifin

Cholangiocarcinoma (CCA) is one of the most common histological types of primary hepatic malignancy and is associated with poor overall prognosis, causing a ponderous burden on human life. Hence, it is necessary to elucidate the pathogenesis of CCA. The objective of our research was to shed light on the mechanism through which long non-coding RNA titin-antisense RNA1 (lncRNA TTN-AS1) is involved in the development of CCA. Reverse transcription quantitative polymerase chain reaction was used to detect TTN-AS1 expression in CCA samples and cells. Functional experiments were performed using the Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, transwell, and in vivo tumor growth assays. The relationship between TTN-AS1, miR-513a-5p, and stratifin (SFN) was explored using a dual luciferase reporter assay, RNA immunoprecipitation (RIP) experiment, and Pearson correlation analysis. The result showed that TTN-AS1 and SFN are highly expressed in CCA tissues. Bioinformatics analysis, luciferase reporter and RIP experiments revealed the correlation between TTN-AS1, miR-513a-5p, and SFN. In addition, silencing TTN-AS1 mitigated CCA cell proliferation and migration. Mechanistically, miR-513a-5p is sponged by TTN-AS1. The miR-513a-5p inhibitor abolished the effect of TTN-AS1 silencing on the aggressive behaviors of CCA cells. Furthermore, we showed that miR-513a-5p is a regulator of CCA by targeting SFN. TTN-AS1 induced CCA cell growth and metastasis via the miR-513a-5p/SFN pathway, which offers a new strategy for therapeutic interventions for CCA.

Involvement of Non-Coding RNAs in Chemo- and Radioresistance of Nasopharyngeal Carcinoma

The crucial treatment for nasopharyngeal carcinoma (NPC) is radiation therapy supplemented by chemotherapy. However, long-term radiation therapy can cause some genetic and proteomic changes to produce radiation resistance, leading to tumour recurrence and poor prognosis. Therefore, the search for new markers that can overcome the resistance of tumor cells to drugs and radiotherapy and improve the sensitivity of tumor cells to drugs and radiotherapy is one of the most important goals of pharmacogenomics and cancer research, which is important for predicting treatment response and prognosis. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), may play important roles in regulating chemo- and radiation resistance in nasopharyngeal carcinoma by controlling the cell cycle, proliferation, apoptosis, and DNA damage repair, as well as other signalling pathways. Recent research has suggested that selective modulation of ncRNA activity can improve the response to chemotherapy and radiotherapy, providing an innovative antitumour approach based on ncRNA-related gene therapy. Therefore, ncRNAs can serve as biomarkers for tumour prediction and prognosis, play a role in overcoming drug resistance and radiation resistance in NPC, and can also serve as targets for developing new therapeutic strategies. In this review, we discuss the involvement of ncRNAs in chemotherapy and radiation resistance in NPC. The effects of these molecules on predicting therapeutic cancer are highlighted.

Long noncoding RNA KCNQ1 opposite strand/antisense transcript 1 promotes osteosarcoma progression through miR-154-3p/KLF12

OBJECTIVE

Osteosarcoma (OS) is a common bone cancer that usually influences children. Metastasis and recurrence are the main reasons for the poor prognosis. In this study, we investigated the functions and mechanisms of KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in OS.

METHODS

Cell viability and proliferation were detected using the CCK-8 assay and the 5-Ethynyl-2'-deoxyuridine (EdU) assay. Wound-healing assays, transwell assay and flow cytometry were used to identify cell migration, invasion, and apoptosis, respectively. The relationship among KCNQ1OT1, miR-154-3p, and KLF12 was verified by luciferase reporter assay and restricting protein immunoprecipitation (RIP) assay. Xenograft models were established to confirm the function of KCNQ1OT1 in vivo.

RESULTS

The expression of KCNQ1OT1 was higher in OS than in non-tumor tissues and cells. Knockdown of KCNQ1OT1 could reduce OS cell proliferation, migration, and invasion and promoted cell death. Mechanistically, KCNQ1OT1 contributed to OS formation by acting as a competitive endogenous RNA (ceRNA) and influencing miR-154-3p expression. Furthermore, we confirmed that miR-154-3p affected KLF12 expression through binding the 3'UTR region. Finally, rescue experiments determined that KCNQ1OT1 exerted major roles in OS through the miR-154-3p/KLF12 axis.

CONCLUSION

In conclusion, our research explains the mechanism of KCNQ1OT1 in OS progression, which could serve as a new therapeutic target.