LncRNA AFAP1-AS1 promotes tumorigenesis and epithelial-mesenchymal transition of osteosarcoma through RhoC/ROCK1/p38MAPK/Twist1 signaling pathway

Lnc-CLSTN2-1:1 Promotes Osteosarcoma Progression by Disrupting Redox Balance through PI3K/AKT Signaling Pathway

Objective: Most patients with osteosarcoma (OS) have an extremely poor prognosis. The primary purpose of this investigation was to explore the biological effect of Lnc-CLSTN2-1:1 on OS and the potential processes involved. Materials and procedures: We selected differentially overexpressed Lnc-CLSTN2-1:1 from our laboratory's existing RNA sequence analysis data (fibroblast osteoblast (hFOB 1.19) and three osteosarcoma cell lines (HOS, MG63, and U2OS) as the research object. Next, we detected Lnc-CLSTN2-1:1 in the osteosarcoma HOS cell line and fibroblast cells using qRT-PCR. We evaluated cell proliferation ability using EdU incorporation test, CCK-8 test, and cell clone formation; cell invasion and migration were assessed using the Transwell test, while flow cytometry examined cell cycle, apoptosis, and reactive oxygen species (ROS); Subsequently, the activity changes of selenase (GPx) glutathione peroxidase and (TrxR) thioredoxin reductase were detected. In addition, changes in related proteins were analyzed through Western blotting. Results: The expression of Lnc-CLSTN2-1:1 in osteosarcoma cells was significantly increased. The proliferation, invasion, and migration of osteosarcoma cells were significantly inhibited by knockdown of the expression of Lnc-CLSTN2-1:1, and the cell cycle-related signaling pathway PI3K/AKT/GSK-3β/cycinD1 was also inhibited. However, insulin-like growth factor-1 (igf-1) could reverse this process. In addition, we examined the activity of two selenophenases (TrxR and GPx) and the changes of ROS before and after Lnc-CLSTN2-1:1 knockdown. The results showed that both TrxR and GPx activities were reduced after Lnc-CLSTN2-1:1 knockdown, resulting in the inhibition of antioxidant stress levels, while intracellular ROS levels were high, which eventually caused killing effects on tumor cells due to the imbalance between oxidative stress and antioxidant stress. Conclusion: Our results showed that Lnc-CLSTN2-1:1 enhanced anti-oxidative stress TrxR and GPx selenoprotein activities through the PI3K/AKT signaling pathway while counteracting the loss of reactive oxygen species ROS produced by mitochondria to osteosarcoma cells, which protected osteosarcoma cells and thus promoted the proliferation and metastatic ability of OS.

LINC01060 knockdown inhibits osteosarcoma cell malignant behaviors in vitro and tumor growth and metastasis in vivo through the PI3K/Akt signaling

Despite its low frequency, osteosarcoma is one of the deadliest malignancies in children and adolescents. The phosphatidylinositol 3-kinase (PI3K)/Akt signaling activation and epithelial-to-mesenchymal transition (EMT) are critical issues during osteosarcoma development. This study found long intergenic non-protein coding RNA 1060 (LINC01060) to be an EMT-related long non-coding RNA (lncRNA) up-regulated in osteosarcoma; higher LINC01060 expression was linked to a worse prognosis in osteosarcoma patients. In vitro, knocking down LINC01060 significantly inhibits osteosarcoma cell malignant behaviors, including hyperproliferation, invasion, migration, and EMT. In vivo, LINC01060 knockdown inhibited tumor growth and metastasis, and suppressed PI3K and Akt phosphorylation. In osteosarcoma cells, Akt agonist SC79 exerted opposite effects to those of LINC01060 knockdown through the promotion of cell viability, cell migration, and cell invasion. Moreover, the Akt agonist SC79 partially eliminated LINC01060 knockdown effects on osteosarcoma cells, suggesting that LINC01060 exerts its effects through the PI3K/Akt signaling. Therefore, it is deduced that LINC01060 is overexpressed in osteosarcoma. In vitro, LINC01060 knockdown inhibits cancer cell malignant behaviors; in vivo, LINC01060 knockdown inhibits tumor development and metastasis. The PI3K/Akt signaling is involved in LINC01060 functions in osteosarcoma.

Advancements in Understanding the Role of Circular RNA in Osteosarcoma

Osteosarcoma, the most prevalent primary malignant bone tumor and the third most frequent cancer in children and adolescents worldwide, still poses a significant therapeutic challenge. Even though combined chemotherapy and surgical resection have improved survival rates up to 60%, the prognosis for most patients with metastatic osteosarcoma continues to be dismal. The specific pathogenesis and key regulators of tumor invasion and metastasis remain largely elusive. Circular RNAs (circRNAs), novel endogenous non-coding RNA molecules that form covalently closed continuous loops through splicing, play a crucial role in the development, progression, clinical diagnosis, and treatment of various diseases. Recently, an escalating number of circular structures have been identified in osteosarcoma. Understanding their role in osteosarcoma is advantageous for early detection, diagnosis, and treatment of this disease. The primary function of circRNA involves its unique ability to bind specifically to miRNA, although their biological functions also extend to interacting with proteins, regulating gene transcription, and serving as translation templates. In this review, we explore the mechanisms and clinical applications of circRNAs in the pathogenesis and progression of osteosarcoma, with a particular emphasis on the regulatory mechanisms and functions of circRNAs as miRNA sponges in osteosarcoma development.

LncRNA-HOTAIRM1 promotes aerobic glycolysis and proliferation in osteosarcoma via the miR-664b-3p/Rheb/mTOR pathway

Osteosarcoma (OS), which is a common and aggressive primary bone malignancy, occurs mainly in children and adolescent. Long noncoding RNAs (lncRNAs) are reported to play a pivotal role in various cancers. Here, we found that the lncRNA HOTAIRM1 is upregulated in OS cells and tissues. A set of functional experiments suggested that HOTAIRM1 knockdown attenuated the proliferation and stimulated the apoptosis of OS cells. A subsequent mechanistic study revealed that HOTAIRM1 functions as a competing endogenous RNA to elevate ras homologue enriched in brain (Rheb) expression by sponging miR-664b-3p. Immediately afterward, upregulated Rheb facilitates proliferation and suppresses apoptosis by promoting the mTOR pathway-mediated Warburg effect in OS. In summary, our findings demonstrated that HOTAIRM1 promotes the proliferation and suppresses the apoptosis of OS cells by enhancing the Warburg effect via the miR-664b-3p/Rheb/mTOR axis. Understanding the underlying mechanisms and targeting the HOTAIRM1/miR-664b-3p/Rheb/mTOR axis are essential for OS clinical treatment.

SP1-Induced Upregulation of LncRNA AFAP1-AS1 Promotes Tumor Progression in Triple-Negative Breast Cancer by Regulating mTOR Pathway

The long non-coding RNA (lncRNA) actin fiber-associated protein-1 antisense RNA 1 (AFAP1-AS1) exerted oncogenic activity in triple-negative breast cancer (TNBC). We designed this study and conducted it to investigate the upstream regulation mechanism of AFAP1-AS1 in TNBC tumorigenesis. In this work, we proved the localization of AFAP1-AS1 in the cytoplasm. We elucidated the mechanism by which the transcription factor specificity protein 1 (SP1) modulated AFAP1-AS1 in TNBC progression, which has yet to be thoroughly studied. Dual luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay revealed a strong affinity of SP1 toward the promoter regions P3 of AFAP1-AS1, proving the gene expression regulation of AFAP1-AS1 via SP1 in TNBC. Additionally, SP1 could facilitate the tumorigenesis of TNBC cells in vitro and in vivo by regulating the AFAP1-AS1 expression. Furthermore, silenced AFAP1-AS1 suppressed the expression of genes in the mTOR pathway, such as eukaryotic translation initiation factor 4B (EIF4B), mitogen-activated protein kinase-associated protein 1 (MAPKAP1), SEH1-like nucleoporin (SEH1L), serum/glucocorticoid regulated kinase 1 (SGK1), and its target NEDD4-like E3 ubiquitin protein ligase (NEDD4L), and promoted the gene expression of s-phase kinase-associated protein 2 (SKP2). Overall, this study emphasized the oncogenic role of SP1 and AFAP1-AS1 in TNBC and illustrated the AFAP1-AS1 upstream interaction with SP1 and the downstream modulatory of mTOR signaling, thus offering insights into the tumorigenesis mechanism in TNBC.

PSKH1 affects proliferation and invasion of osteosarcoma cells via the p38/MAPK signaling pathway

Malignant osteosarcoma (OS) is a tumor of bone and soft tissue that metastasizes early and has a high mortality rate. Protein serine kinase H1 (PSKH1), an autophosphorylating human protein serine kinase, controls the trafficking of serine/arginine-rich domain, with downstream effects on mRNA processing. It is also associated with tumor progression. However, how this protein contributes to OS progression and metastasis is unknown. The present study evaluated the potential effect of PSKH1 on proliferation of human OS cells. OS cell lines were used in Cell Counting Kit-8, colony formation, wound-healing and Transwell assays, to investigate cellular processes such as proliferation, migration and invasion and underlying molecular mechanisms. Expression of PSKH1 in OS tissue was significantly greater than in adjacent non-malignant tissue. PSKH1 knockdown inhibited the proliferation, migration and invasion of OS cells. Conversely, PSKH1 overexpression promoted proliferation of OS cells. PSKH1 upregulated phosphorylated-p38 in OS cells. Moreover, the p38 MAPK inhibitor SB203580 effectively blocked the tumor-promoting action of PSKH1. Furthermore, PSKH1 knockdown inhibited tumor growth and metastasis in vivo. In conclusion, these findings suggested that PSKH1 promoted OS proliferation, migration and invasion. Thus, PSKH1 may serve an oncogenic role in the development of human OS.

Regulation of the Epithelial to Mesenchymal Transition in Osteosarcoma

The epithelial to mesenchymal transition (EMT) is a cellular process that has been linked to the promotion of aggressive cellular features in many cancer types. It is characterized by the loss of the epithelial cell phenotype and a shift to a more mesenchymal phenotype and is accompanied by an associated change in cell markers. EMT is highly complex and regulated via multiple signaling pathways. While the importance of EMT is classically described for carcinomas-cancers of epithelial origin-it has also been clearly demonstrated in non-epithelial cancers, including osteosarcoma (OS), a primary bone cancer predominantly affecting children and young adults. Recent studies examining EMT in OS have highlighted regulatory roles for multiple proteins, non-coding nucleic acids, and components of the tumor micro-environment. This review serves to summarize these experimental findings, identify key families of regulatory molecules, and identify potential therapeutic targets specific to the EMT process in OS.

Dasabuvir suppresses esophageal squamous cell carcinoma growth in vitro and in vivo through targeting ROCK1

Esophageal squamous cell carcinoma (ESCC) is an upper gastrointestinal cancer with high morbidity and mortality. New strategies are urgently needed to prolong patients' survival. Through screening FDA-approved drugs, we found dasabuvir, a drug approved for hepatitis C virus (HCV) treatment, suppressed ESCC proliferation. Dasabuvir could inhibit the growth of ESCC cells in a time and dose-dependent manner and arrested cell cycle at the G0/G1 phase. The antitumor activity was further validated in vivo using patient-derived xenograft tumor models. In terms of mechanism, we unveil that dasabuvir is a Rho-associated protein kinase 1 (ROCK1) inhibitor. Dasabuvir can bind to ROCK1 and suppress its kinase activity, thus downregulating the phosphorylation of ERK1/2 by ROCK1 and the expression of cyclin-dependent kinase 4 (CDK4) and cyclin D1. These results provide evidence that dasabuvir suppresses ESCC growth in vivo and in vitro through blocking ROCK1/ERK signaling pathway.

Rho A/ROCK1 signaling-mediated metabolic reprogramming of valvular interstitial cells toward Warburg effect accelerates aortic valve calcification via AMPK/RUNX2 axis

The aberrant differentiation of valvular interstitial cells (VICs) to osteogenic lineages promotes calcified aortic valves disease (CAVD), partly activated by potentially destructive hemodynamic forces. These involve Rho A/ROCK1 signaling, a mechano-sensing pathway. However, how Rho A/ROCK1 signaling transduces mechanical signals into cellular responses and disrupts normal VIC homeostasis remain unclear. We examined Rho A/ROCK1 signaling in human aortic valves, and further detected how Rho A/ROCK1 signaling regulates mineralization in human VICs. Aortic valves (CAVD n = 22, normal control (NC) n = 12) from patients undergoing valve replacement were investigated. Immunostaining and western blotting analysis indicated that Rho A/ROCK1 signaling, as well as key transporters and enzymes involved in the Warburg effect, were markedly upregulated in human calcified aortic valves compared with those in the controls. In vitro, Rho A/ROCK1-induced calcification was confirmed as AMPK-dependent, via a mechanism involving metabolic reprogramming of human VICs to Warburg effect. Y-27632, a selective ROCK1 inhibitor, suppressed the Warburg effect, rescued AMPK activity and subsequently increased RUNX2 ubiquitin-proteasome degradation, leading to decreased RUNX2 protein accumulation in human VICs under pathological osteogenic stimulus. Rho A/ROCK1 signaling, which is elevated in human calcified aortic valves, plays a positive role in valvular calcification, partially through its ability to drive metabolic switching of VICs to the Warburg effect, leading to altered AMPK activity and RUNX2 protein accumulation. Thus, Rho A/ROCK1 signaling could be an important and unrecognized hub of destructive hemodynamics and cellular aerobic glycolysis that is essential to promote the CAVD process.

Neferine, a novel ROCK1-targeting inhibitor, blocks EMT process and induces apoptosis in non-small cell lung cancer

The compounds derived from Traditional Chinese Medicines have shown various pharmacological activities with unique advantages, especially in the aspect of antitumor. Neferine (Nef), a natural compound, extracted from green seed embryos of Lotus (Nelumbo nucifera Gaertn.) also exerts antitumor effects on cancers. In this study, the effects and mechanisms of Nef on epithelial-to-mesenchymal transition (EMT) process in non-small cell lung cancer (NSCLC) were evaluated. The results showed that Nef had the antitumor effects in vivo and in vitro. Nef significantly suppressed cell viability and induced apoptosis in NSCLC cells, with elevated reactive oxygen species and reduced BCL2/BAX ratio. Nef was also demonstrated to inhibit the invasion, metastasis and EMT process of NSCLC cells, and attenuate EMT-related changes of E-cadherin, N-cadherin and Vimentin at both transcriptional and translational levels. Moreover, we concluded that the inhibitory effects of Nef on EMT was achieved by targeting Rho-associated protein kinase 1, a protein mediating the process of EMT in various cancers. These results showed that Nef had a significant antitumor effect on NSCLC cells by inducing apoptosis and blocking EMT, providing the therapeutical prospect on NSCLC treatment.

TYMSOS-miR-101-3p-NETO2 axis promotes osteosarcoma progression

BACKGROUND

Osteosarcoma (OS) is a type of bone cancer most often affects pre-teens and teens, but it is still a rare disorder. Neuropilin and tolloid-like 2 (NETO2) has been reported to promote OS progression, but its upstream mechanism in OS cells remains obscure.

METHODS

Quantitative real-time PCR (RT-qPCR) and Western blot were conducted to examine RNA and protein levels, separately. Functional assays were performed to assess the impact of NETO2 on OS cell malignancy. Moreover, bioinformatics analyses and mechanism experiments were performed to identify the upstream mechanism of NETO2 in OS cells.

RESULTS

Functionally, NETO2 depletion repressed cell proliferation, migration and invasion as well as epithelial-mesenchymal transition (EMT) but triggered the apoptosis of OS cells. NETO2 is directly targeted and negatively regulated by microRNA-101-3p (miR-101-3p). Mechanically, miR-101-3p could combine with long noncoding RNA (lncRNA) TYMS opposite strand RNA (TYMSOS) in OS cells. In addition, our study proved that TYMSOS promotes the malignancy of OS via elevating NETO2 expression as miR-101-3p sponge.

CONCLUSION

TYMSOS-miR-101-3p-NETO2 axis promotes the malignant behaviors of OS cells, which might offer a novel sight for OS treatment.

LncRNAs could play a vital role in osteosarcoma treatment: Inhibiting osteosarcoma progression and improving chemotherapy resistance

Osteosarcoma (OS) is one of the most common primary solid malignant tumors in orthopedics, and its main clinical treatments are surgery and chemotherapy. However, a wide surgical resection range, functional reconstruction of postoperative limbs, and chemotherapy resistance remain as challenges for patients and orthopedists. To address these problems, the discovery of new effective conservative treatments is important. Long non-coding RNAs (lncRNAs) are RNAs longer than 200 nucleotides in length that do not encode proteins. Researchers have recently found that long non-coding RNAs are closely associated with the development of OS, indicating their potentially vital role in new treatment methods for OS. This review presents new findings regarding the association of lncRNAs with OS and summarizes potential clinical applications of OS with lncRNAs, including the downregulation of oncogenic lncRNAs, upregulation of tumor suppressive lncRNAs, and lncRNAs-based treatment to improve chemotherapy resistance. We hope these potential methods will be translated into clinical applications and greatly reduce patient suffering.

LncRNA ZFAS1 contributes to osteosarcoma progression via miR-520b and miR-520e-mediated inhibition of RHOC signaling

OBJECTIVES

We examined the expression of Lnc-ZFAS1 in osteosarcoma and comprehensively evaluated its effects on osteosarcoma in vitro and vivo. Moreover, we revealed the regulatory mechanism between Lnc-ZFAS1 and miR-520b/miR-520e-mediated RHOC and provided a novel clue for ameliorating osteosarcoma.

METHOD

The expression of Long non-coding RNA Zinc Finger Antisense 1 (LncRNA ZFAS1) osteosarcoma tissues and normal tissues in the TCGA database was analyzed. Then, LncRNA ZFAS1 expression was further verified in clinical samples and osteosarcoma cell lines (U2OS and KHOS), as well as the human osteoblast cell line hFOB1.19 by qRT-PCR. Thereafter, LncRNA ZFAS1 was overexpressed or silenced to explore its effects on cell proliferation, apoptosis, migration, invasion, and Epithelial-Mesenchymal Transition (EMT). The fundamental mechanism through which Lnc-ZFAS1 affects osteosarcoma progression was further investigated and verified.

RESULTS

We found that LncRNA ZFAS1 was upregulated in osteosarcoma, and Lnc-ZFAS1 overexpression facilitated osteosarcoma cells proliferation, migration, invasion and EMT, while Lnc-ZFAS1 silence exerted reverse influence. Mechanistically, Lnc-ZFAS1 functionally acted as a sponger of microRNA-520b (miR-520b) and microRNA-520e (miR-520e) to up-regulate Ras Homologue C (RHOC). In addition, depleted Lnc-ZFAS1 restrained osteosarcoma cells proliferation, migration, and invasion, which could be rescued by RHOC overexpression. Lnc-ZFAS1 was upregulated in osteosarcoma and Lnc-ZFAS1 could exert promoted impact upon osteosarcoma cells proliferation, migration, invasion, and EMT in vitro.

CONCLUSIONS

Lnc-ZFAS1 acted sponger of miR-520b and miR-520e to promote RHOC, indicating that Lnc-ZFAS1/miR-520b/RHOC and Lnc-ZFAS1/miR-520e/RHOC axes might serve as potential therapeutic strategies against osteosarcoma.

Cellular functions and molecular mechanisms of ubiquitination in osteosarcoma

Although some advances have been made in the treatment of osteosarcoma in recent years, surgical resection remains the mainstream treatment. Initial and early diagnosis of osteosarcoma could be very difficult to achieve due to the insufficient sensitivity for the means of examination. The distal metastasis of osteosarcoma also predicts the poor prognosis of osteosarcoma. In order to solve this series of problems, people begin to discover a new method of diagnosing and treating osteosarcoma. Ubiquitination, as an emerging posttranslational modification, has been shown to be closely related to osteosarcoma in studies over the past decades. In general, this review describes the cellular functions and molecular mechanisms of ubiquitination during the development of osteosarcoma.

LACTB suppresses migration and invasion of glioblastoma via downregulating RHOC/Cofilin signaling pathway

Glioblastoma (GBM) is the most malignant tumor in human brain. High invasiveness of this tumor is the main reason causing treatment failure and recurrence. Previous study has found that LACTB is a novel tumor suppressor in breast cancer. Moreover, the function of LACTB in other tumors and mechanisms involving LACTB were also reported. However, the role and relevant mechanisms of LACTB in GBM invasion remains to be revealed. Our aim is to investigate the role LACTB in GBM migration and invasion. We found that LACTB was downregulated in gliomas compared to normal brain tissues. Overexpression of LACTB suppressed migration and invasion of LN229 and U87 cell lines. Mechanistically, LACTB overexpression downregulated the mesenchymal markers. Moreover, LACTB overexpression downregulated the expression of RHOC and inhibited RHOC/Cofilin signaling pathway. The study suggests that LACTB suppresses migration and invasion of GBM cell lines via downregulating RHOC/Cofilin signaling pathway. These findings suggest that LACTB may be a potential treatment target of GBM.

Long non-coding RNA NR2F2-AS1 regulates human osteosarcoma growth and metastasis through miR-425-5p-mediated HMGB2

BACKGROUND

Multiple studies have revealed that long non-coding RNA (lncRNA) NR2F2-AS1 plays a role in affecting cancer cell proliferation and metastasis. Here, both in vitro and in vivo experiments were performed for investigating the function and mechanism of NR2F2-AS1 in human osteosarcoma (OS).

METHODS

The NR2F2-AS1 level in human OS tissues and adjacent non-tumor tissues was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The NR2F2-AS1 overexpression model was constructed in OS cells, then cell proliferation, invasion, and apoptosis were monitored. The OS xenograft model was established in nude mice using NR2F2-AS1-overexpressed OS cells. The downstream target genes of NR2F2-AS1 were predicted. qRT-PCR and Western blot were implemented to validate the profiles of miR-425-5p and HMGB2. The targeting link between NR2F2-AS1 and miR-425-5p, miR-425-5p and HMGB2 was further probed by dual-luciferase reporter experiment.

RESULTS

In comparison to adjacent non-tumor tissues, OS tissues showed upregulated NR2F2-AS1 expression. Higher NR2F2-AS1 level was predominantly correlated with worse clinical stages. In vivo and in vitro tests corroborated that NR2F2-AS1 overexpression spurred OS cell proliferation, growth, invasion, and choked apoptosis. Mechanistically, NR2F2-AS1 hampered miR-425-5p expression as its competitive endogenous RNA (ceRNA). Thus, NR2F2-AS1 facilitated the HMGB2 expression. However, miR-425-5p inhibited HMGB2 expression by targeting the latter.

CONCLUSION

NR2F2-AS1 expedited the evolution of OS by elevating HMGB2 levels through sponging miR-425-5p. The NR2F2-AS1/miR-425-5p/HMGB2 regulatory axis is a promising target in treating human OS.

Non-coding RNAs and epithelial mesenchymal transition in cancer: molecular mechanisms and clinical implications

Epithelial-mesenchymal transition (EMT) is a fundamental process for embryonic development during which epithelial cells acquire mesenchymal characteristics, and the underlying mechanisms confer malignant features to carcinoma cells such as dissemination throughout the organism and resistance to anticancer treatments. During the past decades, an entire class of molecules, called non-coding RNA (ncRNA), has been characterized as a key regulator of almost every cellular process, including EMT. Like protein-coding genes, ncRNAs can be deregulated in cancer, acting as oncogenes or tumor suppressors. The various forms of ncRNAs, including microRNAs, PIWI-interacting RNAs, small nucleolar RNAs, transfer RNA-derived RNA fragments, long non-coding RNAs, and circular RNAs can orchestrate the complex regulatory networks of EMT at multiple levels. Understanding the molecular mechanism underlying ncRNAs in EMT can provide fundamental insights into cancer metastasis and may lead to novel therapeutic approaches. In this review, we describe recent advances in the understanding of ncRNAs in EMT and provide an overview of recent ncRNA applications in the clinic.

LINC01140 regulates osteosarcoma proliferation and invasion by targeting the miR-139-5p/HOXA9 axis

Osteosarcoma is one of the commonest metastatic tumor in children and teenagers, and has a hopeless, prognosis. Long non-coding RNA (lncRNA) acts momentous roles as a regulator on the proliferation and migration of cancer. Here, we performed GEO database analysis and qPCR to identify differentially expressed lncRNAs in osteosarcoma cells. Knockdown of lncRNA LINC01140 was used to detect the effect of LINC01140 on the proliferation, invasion, and epithelial-mesenchymal transition (EMT) of osteosarcoma cells. Bioinformatics analysis and qPCR identified the LINC01140/miR-139-5p/Homeobox A9 (HOXA9) regulatory axis. RNA immunoprecipitation assay, Dual-luciferase assay, and rescue experiments confirmed the interaction of LINC01140/miR-139-5p/HOXA9 in osteosarcoma. LINC01140 was overexpressed in osteosarcoma and knocking down LINC01140 restrained the proliferation and invasion of osteosarcoma cells and EMT. In Saos2 and MG63 cells, LINC01140 sponged miR-139-5p, and a miR-139-5p inhibitor overturned the suppression of LINC01140 knockdown on the proliferation and migration of osteosarcoma cells. Moreover, miR-139-5p depressed the invasion, proliferation, and EMT of osteosarcoma cells via targeting HOXA9. Our results indicate that LINC01140 downregulation inhibits the invasion, proliferation, and EMT in osteosarcoma cells through targeting the miR-139-5p/HOXA9 axis. Therefore, LINC01140 is a potential therapeutic target for osteosarcoma.

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LINC01140 is a newly discovered lncRNA associated with osteosarcoma growth and metastasis in this study.

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GEO and dbDEMC databases were used to analyze LINC01140 as a ceRNA to regulate the growth and metastasis of osteosarcoma.

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LINC01140/miR-139-5p/HOXA9 axis was confirmed to be related to the proliferation, migration and invasion of osteosarcoma.

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.

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.

Navigating the genomic instability mine field of osteosarcoma to better understand implications of non-coding RNAs

Osteosarcoma is one of the most genomically complex cancers and as result, it has been difficult to assign genomic aberrations that contribute to disease progression and patient outcome consistently across samples. One potential source for correlating osteosarcoma and genomic biomarkers is within the non-coding regions of RNA that are differentially expressed. However, it is unsurprising that a cancer classification that is fraught with genomic instability is likely to have numerous studies correlating non-coding RNA expression and function have been published on the subject. This review undertakes the formidable task of evaluating the published literature of noncoding RNAs in osteosarcoma. This is not the first review on this topic and will certainly not be the last. The review is organized with an introduction into osteosarcoma and the epigenetic control of gene expression before reviewing the molecular function and expression of long non-coding RNAs, circular RNAs, and short non-coding RNAs such as microRNAs, piwi RNAs, and short-interfering RNAs. The review concludes with a review of the literature and how the biology of non-coding RNAs can be used therapeutically to treat cancers, especially osteosarcoma. We conclude that non-coding RNA expression and function in osteosarcoma is equally complex to understanding the expression differences and function of coding RNA and proteins; however, with the added lens of both coding and non-coding genomic sequence, researchers can begin to identify the patterns that consistently associate with aggressive osteosarcoma.

MicroRNA-744-5p suppresses tumorigenesis and metastasis of osteosarcoma through the p38 mitogen-activated protein kinases pathway by targeting transforming growth factor-beta 1

Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents. Accumulating evidence has revealed that microRNAs (miRNAs) play a crucial role in the progression of OS. In this study, we found that miR-744-5p was the least expressed miRNA in patients with OS by analyzing GSE65071 from the GENE EXPRESSION OMNIBUS (GEO) database. Through real-time quantitative PCR (qRT-PCR), western blotting, colony formation assay, 5-Ethynyl-2-Deoxyuridine (EdU) incorporation assay, transwell migration, and invasion assays, we demonstrated its ability to inhibit the proliferation, migration, and invasion of OS cells in vitro. According to the luciferase reporter assay, transforming growth factor-β1 (TGFB1) was negatively regulated by miR-744-5p and reversed the effects of miR-744-5p on OS. Subcutaneous tumor-forming animal models and tail vein injection lung metastatic models were used in animal experiments, and it was found that miR-744-5p negatively regulated tumor growth and metastasis in vivo. Furthermore, rescue assays verified that miR-744-5p regulates TGFB1 expression in OS. Further experiments revealed that the p38 MAPK signaling pathway is involved in the miR-744-5p/TGFB1 axis. Generally, this study suggests that miR-744-5p is a negative regulator of TGFB1 and suppresses OS progression and metastasis via the p38 MAPK signaling pathway.

Up-regulation of LINC00665 contributes to the progression of glioma and correlates with its MRI characteristics

BACKGROUND

LncRNA LINC00665 partakes in controlling the malignant phenotype of cancer cells, but its role in glioma and the related regulatory mechanism remain uncertain.

METHODS

RT-PCR was exploited to examine LINC00665 expression. The relationships among the LINC00665 expression, the clinicopathologic values and magnetic resonance imaging (MRI) characteristics of glioma were analyzed. The multiplication, movement, and aggressiveness of glioma cell lines were evaluated by CCK-8, EdU, and Transwell experiments after constructing LINC00665 overexpression and LINC00665 knockdown cell models. A dual-luciferase reporter gene experiment and RIP experiment were executed to validate the interactions between LINC00665 and miR-129-5p, and between miR-129-5p and HMGB1. Western blot and RT-PCR were conducted to find the impact of LINC00665 and miR-129-5p on HMGB1 expression. Nude mouse model was also constructed to examine the impact of LINC00665 on multiplication and aggressiveness of glioma cells in vivo.

RESULTS

LINC00665 expression was markedly increased in glioma. High LINC00665 expression in glioma was closely linked to larger tumor diameter, higher pathologic grade, heterogeneous MRI signal of the tumor, increased peritumoral edema, and stronger MRI enhancement characteristics. LINC00665 overexpression facilitated the malignant behavior of glioma cells, while LINC00665 knockdown played the reverse role. Mechanistically, LINC00665 could decoy miR-129-5p, and indirectly increased HMGB1 expression.

CONCLUSION

LINC00665 functions as an oncogenic lncRNA in glioma, to accelerate glioma progression by modulating miR-129-5p and increasing HMGB1 expression.

LncCCAT1 interaction protein PKM2 upregulates SREBP2 phosphorylation to promote osteosarcoma tumorigenesis by enhancing the Warburg effect and lipogenesis

Pyruvate kinase M2 (PKM2) plays an important role in the consumption of glucose and the production of lactic acid, the striking feature of cancer metabolism. The association of PKM2 with osteosarcoma (OS) has been reported but its role in OS has yet to be elucidated. To study this, PKM2‑bound RNAs in HeLa cells, a type of cancer cells widely used in the study of molecular function and mechanism, were obtained. Peak calling analysis revealed that PKM2 binds to long noncoding RNAs (lncRNAs), which are associated with cancer pathogenesis and development. Validation of the PKM2‑lncRNA interaction in the human OS cell line revealed that lncRNA colon cancer associated transcript‑1 (lncCCAT1) interacted with PKM2, which upregulated the phosphorylation of sterol regulatory element‑binding protein 2 (SREBP2). These factors promoted the Warburg effect, lipogenesis, and OS cell growth. PKM2 appears to be a key regulator in OS by binding to lncCCAT1. This further extends the biological functions of PKM2 in tumorigenesis and makes it a novel potential therapeutic for OS.

Long non-coding RNA CATIP antisense RNA 1 (lncRNA CATIP-AS1) downregulation contributes to the progression and metastasis of thyroid cancer via epithelial-mesenchymal transition (EMT) pathway

Thyroid cancer (THCA) is the most common cancer of the endocrine system across the globe. To date, the mechanism of development of THCA remains scarcely known. In this study, we aim to elucidate the long non-coding RNA CATIP antisense RNA 1 (lncRNA CATIP-AS1/CATIP-AS1) role in the pathogenesis of THCA and its regulatory mechanism. The result shows that the CATIP-AS1 was significantly downregulated in THCA tissues and cells and was associated with a poor prognosis of patients diagnosed with THCA. The overexpression of CATIP-AS1 significantly inhibited THCA cell proliferation, migration, and epithelial–mesenchymal transition (EMT) but increased the THCA cell apoptosis. We found that CATIP-AS1 endogenously sponges miR-515-5p and its overexpression could inhibit miR-515-5p regulatory effect. Moreover, the overexpression of miR-515-5p repressed the Smad4 expression level, consequently reversed the inhibiting effect of overexpressed CATIP-AS1 on the proliferation, and migration of THCA cell. It also reversed the increased THCA cell apoptosis and the downregulated-CATIP-AS1-induced cell EMT inhibition. Summarily, we demonstrated that the CATIP-AS1 promotes the progression and metastasis of THCA via EMT pathway partly through regulating the miR-515-5p and Smad4 expression in THCA cell. The CATIP-AS1 could be a promising biomarker for early THCA detection and prognosis and a possible therapeutic target for its treatment.

Recent Advances in Nanoplatforms for the Treatment of Osteosarcoma

Osteosarcoma (OS) is the most common primary bone tumor in children and young people. Traditional surgical excision combined with chemotherapy presents many limitations, such as resistance and systemic side effects of chemotherapy drugs, postoperative recurrence, and bone defects. Given these limitations, novel therapeutic modalities for OS treatment using nanometer-sized platform-based chemotherapeutic delivery have emerged as a promising alternative therapy. This form of therapy offers multiple advantages, such as accurate delivery of the drug to the tumor site and repair of limited bone defects after tumor resection. In this review, we briefly summarize nanoplatforms, including liposomes, polymeric nanoparticles, inorganic nanoparticles, nanomicelles, dendrimers, nanocapsules, and exosomes. The essential shortcomings involved in these nanoplatforms, such as poor stability, immunogenicity, insufficient circulation, and drug leakage are also discussed, and related solutions are briefly proposed. Finally, the application prospects of nanoplatforms in the treatment of OS are discussed.

Long non-coding RNA Linc00205 promotes hepatoblastoma progression through regulating microRNA-154-3p/Rho-associated coiled-coil Kinase 1 axis via mitogen-activated protein kinase signaling

Hepatoblastoma (HB) is the most common pediatric liver tumor. The significant tumor heterogeneity of HB leads to varied prognoses among children with the disease. Recent studies have suggested that long non-coding RNAs (lncRNAs) can serve as novel therapies for HB treatment. Thus, in this study, we aimed to reveal the function and mechanism of the lncRNA Linc00205 in HB. Our results exhibited that, in both HB tissues and cell lines, levels of Linc00205 were significantly increased. In addition, knockdown of Linc00205 led to suppression of HB development. Moreover, we identified that Linc00205 was able to directly bind to miR-154-3p, thus isolating miR-154-3p from its target Rho-associated coiled-coil Kinase 1 (ROCK1). Further cellular behavioral experiments elucidated that the miR-154-3p inhibitor and ROCK1 overexpression were able to reverse the effect of downregulated Linc00205 on proliferation, migration, invasion, and apoptosis of HB cells by rescue assays via mitogen-activated protein kinase (MAPK) signaling. Our results demonstrated that Linc00205 enhanced HB progression by regulating ROCK1 expression via sponging miR-154-3p through MAPK signaling, which suggests a novel potential therapeutic target for HB.

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.

The bioinformatic approach identifies PARM1 as a new potential prognostic factor in osteosarcoma

Objective

To explore the key factors affecting the prognosis of osteosarcoma patients.

Methods

Based on the GEO dataset and differential expression analysis of normal and osteosarcoma tissues, the gene modules related to the prognosis of osteosarcoma patients were screened by WGCNA, and intersecting genes were taken with differential genes, and the risk prognosis model of osteosarcoma patients was constructed by LASSO regression analysis of intersecting genes, and the prognosis-related factors of osteosarcoma patients were obtained by survival analysis, followed by target for validation, and finally, the expression of prognostic factors and their effects on osteosarcoma cell migration were verified by cellular assays and lentiviral transfection experiments.

Results

The prognosis-related gene module of osteosarcoma patients were intersected with differential genes to obtain a total of 9 common genes. PARM1 was found to be a prognostic factor in osteosarcoma patients by LASSO regression analysis, followed by cellular assays to verify that PARM1 was lowly expressed in osteosarcoma cells and that overexpression of PARM1 in osteosarcoma cells inhibited cell migration. Pan-cancer analysis showed that PARM1 was lowly expressed in most cancers and that low expression of PARM1 predicted poor prognosis for patients.

Conclusion

The data from this study suggest that PARM1 is closely associated with the prognosis of osteosarcoma patients, and PARM1 may serve as a novel potential prognostic target for osteosarcoma, providing a heartfelt direction for the prevention and treatment of osteosarcoma.

Osteosarcoma and Metastasis

Osteosarcoma is the most common primary bone malignancy in adolescents. Its high propensity to metastasize is the leading cause for treatment failure and poor prognosis. Although the research of osteosarcoma has greatly expanded in the past decades, the knowledge and new therapy strategies targeting metastatic progression remain sparse. The prognosis of patients with metastasis is still unsatisfactory. There is resonating urgency for a thorough and deeper understanding of molecular mechanisms underlying osteosarcoma to develop innovative therapies targeting metastasis. Toward the goal of elaborating the characteristics and biological behavior of metastatic osteosarcoma, it is essential to combine the diverse investigations that are performed at molecular, cellular, and animal levels from basic research to clinical translation spanning chemical, physical sciences, and biology. This review focuses on the metastatic process, regulatory networks involving key molecules and signaling pathways, the role of microenvironment, osteoclast, angiogenesis, metabolism, immunity, and noncoding RNAs in osteosarcoma metastasis. The aim of this review is to provide an overview of current research advances, with the hope to discovery druggable targets and promising therapy strategies for osteosarcoma metastasis and thus to overcome this clinical impasse.

A Review on the Role of AFAP1-AS1 in the Pathoetiology of Cancer

AFAP1-AS1 is a long non-coding RNA which partakes in the pathoetiology of several cancers. The sense protein coding gene from this locus partakes in the regulation of cytophagy, cell motility, invasive characteristics of cells and metastatic ability. In addition to acting in concert with AFAP1, AFAP1-AS1 can sequester a number of cancer-related miRNAs, thus affecting activity of signaling pathways involved in cancer progression. Most of animal studies have confirmed that AFAP1-AS1 silencing can reduce tumor volume and invasive behavior of tumor cells in the xenograft models. Moreover, statistical analyses in the human subjects have shown strong correlation between expression levels of this lncRNA and clinical outcomes. In the present work, we review the impact of AFAP1-AS1 in the carcinogenesis.

Rho-GEF Trio regulates osteosarcoma progression and osteogenic differentiation through Rac1 and RhoA

Osteosarcoma (OS) is the most common primary bone tumor. Its high mortality rate and metastasis rate seriously threaten human health. Currently, the treatment has reached a plateau, hence we urgently need to explore new therapeutic directions. In this paper, we found that Trio was highly expressed in osteosarcoma than normal tissues and promoted the proliferation, migration, and invasion of osteosarcoma cells. Furthermore, Trio inhibited osteosarcoma cells' osteogenic differentiation in vitro and accelerated the growth of osteosarcoma in vivo. Given Trio contains two GEF domains, which have been reported as the regulators of RhoGTPases, we further discovered that Trio could regulate osteosarcoma progression and osteogenic differentiation through activating RhoGTPases. In summary, all our preliminary results showed that Trio could be a potential target and prognostic marker of osteosarcoma.

LncRNA NONHSAT009968 inhibits the osteogenic differentiation of hBMMSCs in SA-induced inflammation via Wnt3a

Osteomyelitis is one of the most challenging diseases in the field of orthopedics for its complex pathogenesis and unsatisfactory treatment. The mechanism underlying its occurrence and development is still unclear. In our previous study, we found that long non-coding RNA (lncRNA) NONHSAT009968 inhibited the ability of osteogenic differentiation in staphylococcal protein A (SPA)-treated human bone marrow mesenchymal stem cells (hBMMSCs), but the underlying mechanism remains unclear. The current study was aimed at elucidating the possible mechanism of NONHSAT009968 in regulating osteogenic differentiation and bone defect repairability of hBMMSCs under infection. It was revealed that Wnt3a played a key role in promoting osteogenic differentiation of hBMMSCs treated with SPA in vitro. In addition, NONHSAT009968 inhibited osteogenic differentiation of hBMMSCs treated with SPA via Wnt3a, both in vivo and in vitro. In sum, the results suggested that lncNONHSAT009968 inhibited osteogenic differentiation of hBMMSCs in SA-induced inflammation through Wnt3a, which may have affected the occurrence and development of osteomyelitis. This study might provide novel insights regarding osteomyelitis and infectious bone defects.

An Update on Molecular Pathways Regulating Vasculogenic Mimicry in Human Osteosarcoma and Their Role in Canine Oncology

Canine tumors are valuable comparative models for human counterparts, especially to explore novel biomarkers and to understand pathways and processes involved in metastasis. Vasculogenic mimicry (VM) is a unique property of malignant cancer cells which promote metastasis. Thus, it represents an opportunity to investigate both the molecular mechanisms and the therapeutic targets of a crucial phenotypic malignant switch. Although this biological process has been largely investigated in different human cancer types, including osteosarcoma, it is still largely unknown in veterinary pathology, where it has been mainly explored in canine mammary tumors. The presence of VM in human osteosarcoma is associated with poor clinical outcome, reduced patient survival, and increased risk of metastasis and it shares the main pathways involved in other type of human tumors. This review illustrates the main findings concerning the VM process in human osteosarcoma, search for the related current knowledge in canine pathology and oncology, and potential involvement of multiple pathways in VM formation, in order to provide a basis for future investigations on VM in canine tumors.

Role of RhoC in cancer cell migration

Migration is one of the five major behaviors of cells. Although RhoC—a classic member of the Rho gene family—was first identified in 1985, functional RhoC data have only been widely reported in recent years. Cell migration involves highly complex signaling mechanisms, in which RhoC plays an essential role. Cell migration regulated by RhoC—of which the most well-known function is its role in cancer metastasis—has been widely reported in breast, gastric, colon, bladder, prostate, lung, pancreatic, liver, and other cancers. Our review describes the role of RhoC in various types of cell migration. The classic two-dimensional cell migration cycle constitutes cell polarization, adhesion regulation, cell contraction and tail retraction, most of which are modulated by RhoC. In the three-dimensional cell migration model, amoeboid migration is the most classic and well-studied model. Here, RhoC modulates the formation of membrane vesicles by regulating myosin II, thereby affecting the rate and persistence of amoeba-like migration. To the best of our knowledge, this review is the first to describe the role of RhoC in all cell migration processes. We believe that understanding the detail of RhoC-regulated migration processes will help us better comprehend the mechanism of cancer metastasis. This will contribute to the study of anti-metastatic treatment approaches, aiding in the identification of new intervention targets for therapeutic or genetic transformational purposes.

Overexpression of lncRNA AFAP1-AS1 as a diagnostic biomarker in non-small cell lung cancer

Background

Long non-coding RNAs (lncRNAs) play important roles in lung tumorigenesis. Among different lncRNAs, overexpression of the lncRNA actin filament‐associated protein 1‐antisense RNA 1 (AFAP1-AS1) in lung tumors has been reported in different studies. In the current study, we aimed to investigate the potential value of lncRNA AFAP1-AS1 as a diagnostic biomarker in lung cancer. Ninety samples from patients with lung cancer were collected from Noor-E-Nejat hospital, Tabriz, Iran. The expression of AFAP1-AS1 was assessed using quantitative reverse transcriptase-PCR (qRT-PCR), followed by the ROC curve analysis to investigate the biomarker potency of AFAP1-AS1.

Results

Our results revealed an upregulation of AFAP1-AS1 in tumor samples as compared to the adjacent non-tumor tissues. We found a significant positive association between AFAP1-AS1 expression and tumor size, as well as tumor stage.

Conclusions

Our results showed overexpression of AFAP1-AS1 and its capacity as a diagnostic biomarker in lung cancer.

LncRNACASC9 promotes proliferation, metastasis, and cell cycle inovarian carcinoma cells through cyclinG1/TP53/MMP7 signaling

Ovarian cancer (OC) brings about serious physical and psychological burden for female patients. LncRNA CASC9 has been reported to be intimately linked with the occurrence and development of several tumors. However, the biological role of lncRNA CASC9 in OC still lacks sufficient evidence. The expressions of CASC9 and miR-488-3p in OC cell lines and xenograft mice were detected by qRT-PCR assay. Cell Counting Kit-8 (CCK-8) assay was used to assess cell inhibition rate and cell proliferation in OVCAR-3 and OVCAR-3/DDP cells. Wound healing assay and transwell assay were performed to evaluate the capacity of migration and invasion, respectively. In addition, cell apoptosis was measured by TUNEL assay and cell cycle was assessed by flow cytometric analysis. Moreover, western blotting was carried out to detect the cyclinG1 (CCNG1)/TP53/MMP7 signaling and apoptosis-related proteins. Furthermore, luciferase reporter assay was performed to verify the combination of CASC9 with CCNG1 and miR-488-3p. The results of our study revealed that CASC9 expression was upregulated while miR-488-3p and CCNG1 expression was downregulated in OC cells with significant higher TP53 and MMP7 protein levels compared with normal ovarian surface epithelial cells. Additionally, luciferase reporter assay confirmed CASC9 bond to miR-488-3p/CCNG1. CASC9 silencing inhibited cell proliferation, migration, and invasion whereas promoted cell inhibition rate and apoptosis in vitro and in vivo. However, CASC9 overexpression showed the opposite effects. In summary, LncRNA CASC9 played a regulative role in ovarian carcinoma by cyclinG1/TP53/MMP7 signaling via binding to miR-488-3p in vivo and in vitro.

LncRNA MATN1-AS1 for Prediction of Prognosis in Osteosarcoma Patients and Its Cellular Function

Long non-coding RNAs show essential roles in various cancer processes. This study aimed at the expression features, prognosis significance, and biological effect of lnc MATN1-AS1 in osteosarcoma (OS). Five kinds of cell lines and 117 pairs of tissues were analyzed by qRT-PCR for quantification of lnc MATN1-AS1 and miR-1299 level. Clinical data were analyzed using Chi-Square Tests to show the association with lnc MATN1-AS1 level. Kaplan-Meier analysis and Cox regression were used to judge the prognostic value. Cell counting kit-8 and Transwell assay were conducted, respectively, to analyze the effect of lnc MATN1-AS1 on cell proliferation and metastasis. The target miRNA was predicted. lnc MATN1-AS1 level was significantly elevated in OS cells and tissues and related to Enneking staging, lung metastasis, and histologic type. Patients with high lnc MATN1-AS1 level showed a shorter overall survival and recurrence-free survival. Lnc MATN1-AS1 knockdown inhibited OS cell proliferation, migration, and invasion by sponging miR-1299. Lnc MATN1-AS1 has oncogenic features and prognostic significance in OS and is a novel therapeutic strategy for OS.

A Novel Six Metastasis-Related Prognostic Gene Signature for Patients With Osteosarcoma

Osteosarcoma is the most common malignant bone tumor, and although there has been significant progress in its management, metastases often herald incurable disease. Here we defined genes differentially expressed between primary and metastatic osteosarcoma as metastasis-related genes (MRGs) and used them to construct a novel six-MRG prognostic signature for overall survival of patients with osteosarcoma. Validation in internal and external datasets confirmed satisfactory accuracy and generalizability of the prognostic model, and a nomogram based on the signature and clinical variables was constructed to aid clinical decision-making. Of the six MRGs, FHIT is a well-documented tumor suppressor gene that is poorly defined in osteosarcoma. Consistent with tumor suppressor function, FHIT was downregulated in osteosarcoma cells and human osteosarcoma samples. FHIT overexpression inhibited osteosarcoma proliferation, migration, and invasion both in vitro and in vivo. Mechanistically, FHIT overexpression upregulate the epithelial marker E-cadherin while repressing the mesenchymal markers N-cadherin and vimentin. Our six-MRG signature represents a novel and clinically useful prognostic biomarker for patients with osteosarcoma, and FHIT might represent a therapeutic target by reversing epithelial to mesenchymal transition.

The Role of lncRNA PCAT6 in Cancers

Long non-coding RNA (lncRNA) PCAT6 is a member of the Prostate Cancer Associated Transcripts family of molecules. In this review, we focus on the latest studies involving PCAT6 in the diagnosis, treatment, and prognosis of malignant tumors of the digestive, respiratory, urinary, reproductive, motion, and nervous systems. PCAT6 was found to be highly expressed in gastric cancer, colon cancer, hepatocellular carcinoma, lung cancer, bladder cancer, ovarian cancer, breast cancer, cervical cancer, osteosarcoma, glioblastoma, and other tumors. PCAT6 can promote the development and progression of different types of malignant tumors through various mechanisms. Overall, these findings suggest that PCAT6 may play an increasingly vital role in the clinical assessment of these malignant tumors. It can function as an oncogene and may be used as a potential new prognostic biomarker of these tumors.

CircRAB3IP upregulates twist family BHLH transcription factor (TWIST1) to promote osteosarcoma progression by sponging miR-580-3p

Circular RNAs (circ RNAs) have been found to play an important role in cancer development. However, the role of circRAB3IP in osteosarcoma (OS) is unclear.

In the present study, We found that circRAB3IP was highly expressed in OS tissues and OS cells. High levels of circRAB3IP was correlated with advanced TNM stage, distant metastasis. CircRAB3IP knockdown inhibited cell proliferation, migration, and invasion. Moreover, circRAB3IP directly binds to miR-580-3p. TWIST1 is directly targeted by miR-580-3p. We also demonstrated that circRAB3IP act as the sponge of miR-580-3p to promote TWIST1 expression. CircRAB3IP promotes OS cells proliferation, migration, and invasion through modulating miR-580-3p/TWIST1 axis. Moreover, circRAB3IP facilitated tumor formation in vivo. Our findings suggested that circRAB3IP acts as an oncogene in OS by regulating miR-580-3p/TWIST1 axis.

Silencing of AFAP1-AS1 lncRNA impairs cell proliferation and migration by epigenetically promoting DUSP5 expression in pre-eclampsia

As a unique and common obstetric complication of pregnant women, pre-eclampsia (PE) has been the first leading cause of maternal and perinatal morbidity and mortality in the world. Mounting studies have demonstrated that an abnormality of long noncoding RNA (lncRNA) expression was related to the pathological process of PE. Here, we showed that lncRNA AFAP1-AS1 was markedly downregulated in pre-eclamptic placentas. We further investigated the mechanism underlying the regulatory role of AFAP1-AS1 in PE using human trophoblast cells. In vitro functional assays revealed that AFAP1-AS1 knockdown inhibited trophoblast proliferation, migration, and invasion. Moreover, AFAP1-AS1 interacts with EZH2 and inhibits DUSP5 expression through modulating H3K27m3 in the DUSP5 promoter of trophoblast cells, thus being involved in PE pathogenesis. Overall, these findings suggest that AFAP1-AS1 could potentially become a prognostic biomarker as well as a new therapeutic target for PE.

Functional interplay between long non-coding RNAs and the Wnt signaling cascade in osteosarcoma

Osteosarcoma is a common and highly malignant bone tumor among children, adolescents and young adults. However, the underlying molecular mechanisms remain largely unexplored. LncRNAs are transcripts with no or limited protein-coding capacity in human genomes, and have been demonstrated to play crucial functions in initiation, progression, therapeutic resistance, recurrence and metastasis of tumor. Considerable studies revealed a dysregulated lncRNA expression pattern in osteosarcoma, which may act as oncogenes or suppressors to regulate osteosarcoma progression. Wnt signaling pathway is an important cascade in tumorigenesis by modulation of pleiotropic biological functions including cell proliferation, apoptosis, differentiation, stemness, genetic stability and chemoresistance. Hyperactivation or deficiency of key effectors in Wnt cascade is a common event in many osteosarcoma patients. Recently, increasing evidences have suggested that lncRNAs could interplay with component of Wnt pathway, and thereby contribute to osteosarcoma onset, progression and dissemination. In this review, we briefly summarize Wnt signaling-related lncRNAs in osteosarcoma progression, aiming to gain insights into their underlying crosstalk as well as clinical application in osteosarcoma therapeutic modalities.

Cooperative participation of epigenomic and genomic alterations in the clinicopathological diversity of gastric adenocarcinomas: significance of cell adhesion and epithelial-mesenchymal transition-related signaling pathways

The present study was conducted to clarify the cooperative significance of epigenomic and genomic abnormalities during gastric carcinogenesis. Using 21 samples of normal control gastric mucosa (C), 109 samples of non-cancerous gastric mucosa (N) and 105 samples of cancerous tissue (T) from 109 patients with primary gastric adenocarcinomas, genome-wide DNA methylation analysis was performed using Infinium assay. Among these samples, 66 paired N and corresponding T samples were subjected to whole-exome and single nucleotide polymorphism array analyses. As had been shown in our previous study, 109 patients were clustered clinicopathologically into least aggressive Cluster A (n = 20), most aggressive Cluster B1 (n = 20) and Cluster B2 (n = 69). Most DNA methylation alterations in each cluster had already occurred even in N samples compared with C samples, and DNA methylation alterations at the precancerous N stage were inherited by the established cancers themselves. Recurrent single nucleotide variants and insertions/deletions resulting in functional disruption of the proteins encoded by the ABCA10, BNC2, CDH1, CTNNB1, SMAD4 and VAV2 genes were specific to Cluster B1, whereas those of the APC, EGFR, ERBB2, ERBB3, MLH1 and MUC6 genes were specific to Cluster A. MetaCore pathway analysis revealed that the epigenomically affected TWIST1 gene and genomically affected CDH1, CTNNB1, MMP9, TLN2, ROCK1 and SMAD4 genes were accumulated in signaling pathways related to cell adhesion, cytoskeleton remodeling and epithelial–mesenchymal transition in Cluster B1. These data indicate that epigenomic alterations at the precancerous stage are important in gastric carcinogenesis and that epigenomic and genomic alterations cooperatively underlie the aggressiveness of gastric adenocarcinomas.

Emerging role of lncRNAs in the regulation of Rho GTPase pathway

The Ras homolog (Rho) family of small GTPases comprise several proteins with prominent roles in regulation of cell cycle transition, cell migration, and remodeling of actin cytoskeleton. Expression of these proteins is regulated by several factors among them are long non-coding RNAs (lncRNAs). The impact of lncRNAs on Rho GTPases signaling can be exerted through direct modulation of expression of these proteins or influencing expression of miRNAs that negatively regulate Rho GTPases. LINC00974/miR-122/RhoA, MALAT1/miR-429/RhoA, ZFAS1/miR-3924/RhoA/ROCK2, PCAT6/miR-326/RhoA/ROCK, SMILR/miR-141/RhoA/ROCK, DAPK1/miR-182/RhoA, GAS5/miR663a/RhoB, H19/miR-15b/CDC42/PAK1, TDRG1/miR-93/RhoC, TUG1/miR-498/CDC42, UCA1/miR-18a/Cdc42 and UCA1/miR-182/Cdc42 are examples of lncRNAs/miRNAs axes that regulate Rho GTPases. In the present manuscript, we describe the role of lncRNAs on Rho GTPases.

AFAP1-AS1: a rising star among oncogenic long non-coding RNAs

Long non-coding RNAs (lncRNAs) have become a hotspot in biomedical research. This interest reflects their extensive involvement in the regulation of the expression of other genes, and their influence on the occurrence and development of a variety of human diseases. Actin filament associated protein 1-Antisense RNA 1(AFAP1-AS1) is a recently discovered oncogenic lncRNA. It is highly expressed in a variety of solid tumors, and regulates the expression of downstream genes and signaling pathways through adsorption and competing microRNAs, or by the direct binding to other proteins. Ultimately, AFAP1-AS1 promotes proliferation, chemotherapy resistance, and resistance to apoptosis, maintains stemness, and enhances invasion and migration of tumor cells. This paper summarizes the research concerning AFAP1-AS1 in malignant tumors, including the clinical application prospects of AFAP1-AS1 as a potential molecular marker and therapeutic target of malignant tumors. We also discuss the limitations in the knowledge of AFAP1-AS1 and directions of further research. AFAP1-AS1 is expected to provide an example for studies of other lncRNA molecules.

The interplay between non-coding RNAs and Twist1 signaling contribute to human disorders

Twist-related protein 1 (Twist1) is a basic helix-loop-helix (bHLH) transcription factor (TF) being coded by the TWIST1 gene. This TF has a fundamental effect on the normal development and in the pathogenesis of various diseases especially cancer. Twist1 has interactions with some long non-coding RNAs and miRNAs. The interactions between this TF and various miRNAs such as miR-16, miR-26b-5p, miR-1271, miR-539, miR-214, miR-200b/c, miR-335, miR-10b, and miR-381 are implicated in the carcinogenic processes. TP73-AS1, LINC01638, ATB, NONHSAT101069, CASC15, H19, PVT1, LINC00339, LINC01385, TANAR, SNHG5, DANCR, CHRF, and TUG1 are among long non-coding RNAs which interact with Twist1 and participate in the carcinogenesis. This review aims at depicting the interaction between these non-coding transcripts and Twist1 and the consequence of these interactions in human neoplasms.

LncRNA UCA1 attenuated the killing effect of cytotoxic CD8 + T cells on anaplastic thyroid carcinoma via miR-148a/PD-L1 pathway

BACKGROUND

LncRNAs play an important role in the regulation of the killing effect of cytotoxic CD8 + T cells in various cancers. However, the role and underlying mechanisms of UCA1 in the killing effect of cytotoxic CD8 + T cells in anaplastic thyroid carcinoma (ATC) are not clear.

METHODS

UCA1, miR-148a, and PD-L1 expression were detected by quantitative real-time PCR and/or Western blot. The ratio of PD-L1⁺ATC cells/ATC cells was determined using flow cytometry. The ability of CD8 + T cells to kill target ATC cells was detected by Chromium-51 (⁵¹Cr) release assay. The targeted relationship between UCA1 and miR-148a was confirmed by dual-luciferase reporter gene assay.

RESULTS

UCA1 and PD-L1 expression levels were elevated in ATC tissues and cells. Silencing UCA1 and PD-L1 enhanced the killing effect of cytotoxic CD8 + T cells on ATC cells. UCA1 negatively regulated the expression of miR-148a, and miR-148a targeted PD-L1 to down-regulate its expression. Besides, we found that UCA1 attenuated the killing effect of cytotoxic CD8 + T cells and reduced cytokine secretion through PD-L1 and miR-148a. Finally, silencing UCA1 or PD-L1 in ATC cells restored the suppression of the killing effect of CD8 + T cells in vivo.

CONCLUSION

UCA1 attenuated the killing effect of cytotoxic CD8 + T cells on ATC cells through the miR-148a/PD-L1 pathway.