Knockdown of lncRNA HULC inhibits proliferation, migration, invasion, and promotes apoptosis by sponging miR-122 in osteosarcoma

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 epigenetics orchestra of Notch signaling: a symphony for cancer therapy

The aberrant regulation of the Notch signaling pathway, which is a fundamental developmental pathway, has been implicated in a wide range of human cancers. The Notch pathway can be activated by both canonical and noncanonical Notch ligands, and its role can switch between acting as an oncogene or a tumor suppressor depending on the context. Epigenetic modifications have the potential to modulate Notch and its ligands, thereby influencing Notch signal transduction. Consequently, the utilization of epigenetic regulatory mechanisms may present novel therapeutic opportunities for both single and combined therapeutics targeted at the Notch signaling pathway. This review offers insights into the mechanisms governing the regulation of Notch signaling and explores their therapeutic potential.

Connection of Cancer Exosomal LncRNAs, Sponging miRNAs, and Exosomal Processing and Their Potential Modulation by Natural Products

Cancerous exosomes contain diverse biomolecules that regulate cancer progression. Modulating exosome biogenesis with clinical drugs has become an effective strategy for cancer therapy. Suppressing exosomal processing (assembly and secretion) may block exosomal function to reduce the proliferation of cancer cells. However, the information on natural products that modulate cancer exosomes lacks systemic organization, particularly for exosomal long noncoding RNAs (lncRNAs). There is a gap in the connection between exosomal lncRNAs and exosomal processing. This review introduces the database (LncTarD) to explore the potential of exosomal lncRNAs and their sponging miRNAs. The names of sponging miRNAs were transferred to the database (miRDB) for the target prediction of exosomal processing genes. Moreover, the impacts of lncRNAs, sponging miRNAs, and exosomal processing on the tumor microenvironment (TME) and natural-product-modulating anticancer effects were then retrieved and organized. This review sheds light on the functions of exosomal lncRNAs, sponging miRNAs, and exosomal processing in anticancer processes. It also provides future directions for the application of natural products when regulating cancerous exosomal lncRNAs.

Long Noncoding RNAs and Circular RNAs Regulate AKT and Its Effectors to Control Cell Functions of Cancer Cells

AKT serine-threonine kinase (AKT) and its effectors are essential for maintaining cell proliferation, apoptosis, autophagy, endoplasmic reticulum (ER) stress, mitochondrial morphogenesis (fission/fusion), ferroptosis, necroptosis, DNA damage response (damage and repair), senescence, and migration of cancer cells. Several lncRNAs and circRNAs also regulate the expression of these functions by numerous pathways. However, the impact on cell functions by lncRNAs and circRNAs regulating AKT and its effectors is poorly understood. This review provides comprehensive information about the relationship of lncRNAs and circRNAs with AKT on the cell functions of cancer cells. the roles of several lncRNAs and circRNAs acting on AKT effectors, such as FOXO, mTORC1/2, S6K1/2, 4EBP1, SREBP, and HIF are explored. To further validate the relationship between AKT, AKT effectors, lncRNAs, and circRNAs, more predicted AKT- and AKT effector-targeting lncRNAs and circRNAs were retrieved from the LncTarD and circBase databases. Consistently, using an in-depth literature survey, these AKT- and AKT effector-targeting database lncRNAs and circRNAs were related to cell functions. Therefore, some lncRNAs and circRNAs can regulate several cell functions through modulating AKT and AKT effectors. This review provides insights into a comprehensive network of AKT and AKT effectors connecting to lncRNAs and circRNAs in the regulation of cancer cell functions.

HULC targets the IGF1R-PI3K-AKT axis in trans to promote breast cancer metastasis and cisplatin resistance

Insulin-like growth factor I receptor (IGF1R) is frequently upregulated in breast cancer. Due to its intrinsic tyrosine kinase activity, aberrant activation of the IGF1R signaling axis may enhance tumor cell proliferation and cancer stemness, causing tumor relapse, metastasis and resistance to chemotherapy. We utilized a chromatin RNA in situ reverse transcription (CRIST) approach to characterize molecular factors that regulate the IGF1R network. We identified lncRNA HULC (Highly Upregulated in Liver Cancer) as a key trans-regulator of IGF1R in breast cancer cells. Loss of HULC suppressed the expression of IGF1R and the activation of its downstream PI3K/AKT pathway, while HULC overexpression activated the axis in breast cancer cells. Using a transcription-associated trap (RAT) assay, we demonstrated that HULC functioned as a nuclear lncRNA and epigenetically activated IGF1R by directly binding to the intragenic regulatory elements of the gene, orchestrating intrachromosomal interactions, and promoting histone H3K9 acetylation. The activated HULC-IGF1R/PI3K/AKT pathway mediated tumor resistance to cisplatin through the increased expression of cancer stemness markers, including NANOG, SOX2, OCT4, CD44 and ALDH1A1. In immunodeficient mice, stimulation of the HULC-IGF1R pathway promoted tumor metastasis. These data suggest that HULC may be a new epigenetic target for IGF1R axis-targeted therapeutic intervention.

Crosstalk between lncRNAs in the apoptotic pathway and therapeutic targets in cancer

The assertion that a significant portion of the mammalian genome has not been translated and that non-coding RNA accounts for over half of polyadenylate RNA have received much attention. In recent years, increasing evidence proposes non-coding RNAs (ncRNAs) as new regulators of various cellular processes, including cancer progression and nerve damage. Apoptosis is a type of programmed cell death critical for homeostasis and tissue development. Cancer cells often have inhibited apoptotic pathways. It has recently been demonstrated that up/down-regulation of various lncRNAs in certain types of tumors shapes cancer cells' response to apoptotic stimuli. This review discusses the most recent studies on lncRNAs and apoptosis in healthy and cancer cells. In addition, the role of lncRNAs as novel targets for cancer therapy is reviewed here. Finally, since it has been shown that lncRNA expression is associated with specific types of cancer, the potential for using lncRNAs as biomarkers is also discussed.

MicroRNA-766-3p-mediated downregulation of HNF4G inhibits proliferation in colorectal cancer cells through the PI3K/AKT pathway

Nuclear receptors (NRs) are a class of transcription factors that play a pivotal role in carcinogenesis, but their function in colorectal cancer (CRC) remains unclear. Here, we investigate the role NRs play in CRC pathogenesis. We found that hepatocyte nuclear factor 4 gamma (HNF4G; NR2A2), hepatocyte nuclear factor 4α (HNF4A; NR2A1), and retinoid-related orphan receptor γ (RORC; NR1F3) were significantly upregulated in CRC tissues analyzed by GEPIA bioinformatics tool. The expression of HNF4G was examined in CRC samples and cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. Increased expression of HNF4G was strongly associated with high tumor-node-metastasis stage and poor prognosis. Moreover, overexpression of HNF4G significantly promoted the proliferation of CRC cells in vitro. Next, we found that HNF4G promoted CRC proliferation via the PI3K/AKT pathway through targeting of GNG12 and PTK2. In addition, HNF4G was verified as a direct target of microRNA-766-3p (miR-766-3p). miR-766-3p inhibited the proliferation of CRC cells by targeting HNF4G in vitro and in vivo. Collectively, our study indicates that miR-766-3p reduces the proliferation of CRC cells by targeting HNF4G expression and thus inhibits the PI3K/AKT pathway. Therefore, development of therapies which target the miR-766-3p/HNF4G axis may aid in the treatment of CRC.

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Radioresistance is one of the key obstacles that may lead to the failure of cancer treatment. The underlying mechanisms of radioresistance remain largely unknown; however, increasing evidence has shown that long noncoding RNAs (lncRNAs) are involved in radiotherapy resistance of several cancers. In the present study, we demonstrated that radiation-elevated transcript (RET), a newly identified lnRNA, was highly expressed in cancer cells. Knockdown of RET significantly inhibited the proliferation and colony formation of cancer cells and markedly inhibited apoptosis. Furthermore, downregulation of RET in cancer cells significantly inhibited cell growth, decreased colony survival fractions, and promoted apoptosis in response to radiation treatment, indicating a role in radiation resistance. Moreover, RET knockdown significantly increased the expression of γ-H2AX, an indicator of DNA double strand damage, and reversed radiation-induced EMT, both of which contributed to its radiation resistance. In addition, a negative correlation was found between the expression of RET and PTEN. Rescue assays confirmed RET knockdown enhanced radiosensitivity of cancer cells by upregulating the expression of PTEN. Mechanistically, RET positively regulated Slug, a repressor of PTEN transcription, by acting as a molecular sponge of miR-3179. Our present study showed that RET conferred radioresistance by regulating miR-3179/Slug/PTEN axis, indicating that RET may be a potential target for the clinical application in cancer patients with radioresistance.

Hepatocyte nuclear factor 4 gamma (HNF4G) is correlated with poor prognosis and promotes tumor cell growth by inhibiting caspase-dependent intrinsic apoptosis in colorectal cancer

The hepatocyte nuclear factor 4 gamma (HNF4G), a member of orphan nuclear receptors, is up-regulated and functions as an oncoprotein in a variety of tumors. Recent advances in understanding the biologic function and action mechanism of HNF4G in colorectal cancer (CRC) have not been fully elucidated. In the present study, we observed that HNF4G expression levels were significantly increased in CRC tissues compared with adjacent normal tissues, and HNF4G overexpression correlated with worse prognosis in colorectal cancer. Transfection with a small interference RNA (siRNA) targeting HNF4G in HCT116 and SW480 CRC cell lines significantly inhibited cell proliferation and promoted apoptosis in vitro. In contrast, overexpression of HNF4G increased cell proliferation and decreased the percentage of apoptotic cells. Moreover, we discovered that HNF4G was involved in CRC cell apoptosis via the caspase-dependent intrinsic pathway. Finally, knockdown of HNF4G expression led to attenuated colorectal cancer growth and promoted apoptosis in a xenograft mouse model. Collectively, these results indicate that HNF4G exerts as an oncogenic role in colorectal cancer and provides a potential therapeutic target.

Pseudogene RPL32P3 regulates the blood-tumor barrier permeability via the YBX2/HNF4G axis

The existence of the blood–tumor barrier (BTB) severely hinders the transport of anti-tumor drugs to brain tumor tissues. Selectively opening BTB is of great significance to improve the chemotherapy effect of glioma. Pseudogenes have been recognized as important regulators in various biologic processes. In this study, we identified that ribosomal protein L32 pseudogene 3 (RPL32P3) was highly expressed in glioma-exposed endothelial cells (GECs). Knockdown of RPL32P3 decreased the expression of tight junction-related proteins (TJPs) and increased BTB permeability. Subsequent analysis of the underlying mechanism indicated that RPL32P3 recruited lysine methyltransferase 2 A (KMT2A) to the Y-box binding protein 2 (YBX2) promoter region and mediated H3K4me3 to promote YBX2 transcription. Highly expressed YBX2 bound and stabilized hepatocyte nuclear factor 4 gamma (HNF4G) mRNA. Highly expressed HNF4G directly bound to the promoters of TJPs ZO-1, occludin and claudin-5 to promote their transcriptional activities and regulated BTB permeability. The simultaneous knockdown of RPL32P3, YBX2, and HNF4G combined with doxorubicin (DOX) increased the apoptosis of glioma cells. In conclusion, the current study indicated that RPL32P3 knockdown increased BTB permeability through the YBX2/HNF4G pathway. These findings may provide new targets for the comprehensive treatment of glioma.

Emerging role of long non-coding RNAs in endothelial dysfunction and their molecular mechanisms

Long non-coding RNAs (lncRNAs) are the novel class of transcripts involved in transcriptional, post-transcriptional, translational, and post-translational regulation of physiology and the pathology of diseases. Studies have evidenced that the impairment of endothelium is a critical event in the pathogenesis of atherosclerosis and its complications. Endothelial dysfunction is characterized by an imbalance in vasodilation and vasoconstriction, oxidative stress, proinflammatory factors, and nitric oxide bioavailability. Disruption of the endothelial barrier permeability, the first step in developing atherosclerotic lesions is a consequence of endothelial dysfunction. Though several factors interfere with the normal functioning of the endothelium, intrinsic epigenetic mechanisms governing endothelial function are regulated by lncRNAs and perturbations contribute to the pathogenesis of the disease. This review comprehensively addresses the biogenesis of lncRNA and molecular mechanisms underlying and regulation in endothelial function. An insight correlating lncRNAs and endothelial dysfunction-associated diseases can positively impact the development of novel biomarkers and therapeutic targets in endothelial dysfunction-associated diseases and treatment strategies.

LncRNA UCC promotes epithelial-mesenchymal transition via the miR-143-3p/SOX5 axis in non-small-cell lung cancer

Long non-coding RNAs (lncRNAs) have been found to play regulatory roles in cancers; for example, UCC was reported to promote colorectal cancer progression. However, the function of UCC in non-small-cell lung cancer (NSCLC) remains unclear. Therefore, mRNA and protein levels were assessed using qPCR and western blots. Cell viability was assessed by colony-formation assays. The interaction between lncRNAs and miRNAs was detected by dual-luciferase reporter and RIP assays. The tumorigenesis of NSCLC cells in vivo was determined by xenograft assays. LncRNA UCC was highly expressed in both NSCLC tissues and cells. Knockdown of UCC expression suppressed the proliferation of NSCLC cells. In addition, a dual-luciferase reporter system and RIP assays showed that UCC specifically bound to miR-143-3p and acted as a sponge of miR-143-3p in NSCLC cells. The miR-143-3p inhibitor rescued the inhibitory effect of sh-UCC on the proliferation of NSCLC cells. Moreover, miR-143-3p and UCC showed opposite effects on the expression of SOX5, which promoted EMT in NSCLC cells. In addition, in a mouse model, knockdown of UCC expression alleviated EMT and NSCLC progression in vivo, which was consistent with the in vitro results. In the current study, we found that UCC induced the proliferation and migration of NSCLC cells both in vitro and in vivo by inducing the expression of SOX5 via miR-143-3p and subsequently promoted EMT in NSCLC.

Long non-coding RNAs regulating multiple proliferative pathways in cancer cell

Long non-coding RNAs (lncRNAs) belong to an extremely heterogeneous class of non-coding RNAs with a length ranging from 200 to 100,000 bp. They modulate a series of cellular pathways in both physiological and pathological context. It is no coincidence that they are expressed in an aberrant way in pathologies such as cancer, so as to deserve to be subclassified as oncogenes or tumor suppressors. These molecules are also involved in the regulation of cancer cell proliferation. Several lncRNAs are able to modulate cell growth both positively and negatively, and in this review we have focused on a small group of them, characterized by the simultaneous action on different pathways regulating cell proliferation. They have been considered in the light of their behavior in three different subtypes of proliferative pathways that we can define as (I) tumor suppressor, (II) oncogenic and (III) transcriptionally-driven. More specifically, we have characterized some lncRNAs considered oncogenes (such as H19, linc-ROR, MALAT1, HULC, HOTAIR and ANRIL), tumor suppressors (such as MEG3 and lincRNA-p21), and both oncogenes/tumor suppressors (UCA1 and TUG1) in a little more detail. As can be understood from the review, the interactions between lncRNAs and their molecular targets, only in the context of controlling cell proliferation, give rise to an intricate molecular network, the understanding of which, in the future, will certainly be of help for the treatment of molecular diseases such as cancer.

microRNA-320b suppresses HNF4G and IGF2BP2 expression to inhibit angiogenesis and tumor growth of lung cancer

We examined the effect of microRNA-320b (miR-320b) on tumor growth and angiogenesis in lung cancer and also determined its downstream molecular mechanisms. Lung cancer tissues and adjacent non-cancerous tissues were collected from 66 patients with lung cancer. miR-320b expression was experimentally determined to be expressed at low level in cancer tissues. The results of gain-of-function experiments suggested that miR-320b overexpression suppressed cancer cell invasion, tube formation, tumor volume and angiogenesis in xenografted nude mice. Hepatocyte nuclear factor 4 gamma (HNF4G) was identified as a target of miR-320b based on in silico analysis. Dual-luciferase reporter gene assays further identified the binding relationship between HNF4G and miR-320b. Lung cancer tissues exhibited increased expression of HNF4G and insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2). Meanwhile, HNF4G knockdown suppressed IGF2BP2 expression, thereby repressing cancer cell invasion and tube formation. Furthermore, IGF2BP2 modified m6A to increase the expression of thymidine kinase 1 (TK1), thus promoting angiogenesis. In nude mice, restoration of TK1 reversed the suppressive effect of miR-320b overexpression on tumor growth rate and CD31 expression. In conclusion, miR-320b suppresses lung cancer growth and angiogenesis by inhibiting HNF4G, IGF2BP2 and TK1.

lncRNA‑CASC15 promotes osteosarcoma proliferation and metastasis by regulating epithelial‑mesenchymal transition via the Wnt/β‑catenin signaling pathway

Osteosarcoma (OS) is a rare type of tumor and mostly occurs in children and adolescents. Approximately 10–25% of patients with OS have lung metastases, and lung damage caused by lung metastasis is the main cause of mortality. Therefore, studying the growth and metastasis of OS is key in reducing OS mortality and improving prognosis. The expression of long non-coding RNA (lncRNA) cancer susceptibility 15 (CASC15) in OS patients or OS cell lines were quantified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression of vimentin, E-cadherin, N-cadherin, and cyclin D were detected by RT-qPCR and western blotting. Mice were injected with OS cell lines via the tail vein to observe tumor formation in the lung. CCK-8 and EdU assays were utilized to evaluate cell proliferation. Both Ttranswell assay and cell scratch test detected cell migration. The results revealed that lncRNA-CASC15 was highly expressed in clinical samples and OS cells. In vitro verification experiments revealed that CASC15 promoted the growth of OS cells. Rescue experiments demonstrated that CASC15 affected the cell cycle by activating the Wnt/β-catenin pathway, thereby promoting cell proliferation. Furthermore, the transfection dose test indicated that lentiviruses expressing various doses of CASC15-overexpression (oe-CASC15) altered the proliferation and migration status of OS cells. CASC15 promoted OS cell metastasis both in vivo and in vitro. The overexpression of CASC15 revealed that the occurrence of metastasis was also related to the Wnt/β-catenin pathway. The western blotting results revealed that CASC15 could lead to β-catenin entering the nucleus via the Wnt pathway to promote the epithelial-mesenchymal transition (EMT) of OS cells. To sum up, CASC15 promoted the proliferation of OS cells in vitro and the growth of OS xenograft tumors in vivo. Moreover, CASC15 promoted the entry of β-catenin into the nucleus, thus activating the Wnt pathway and subsequently promoting the EMT of OS cells.

DNA damage response and repair in osteosarcoma: Defects, regulation and therapeutic implications

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents which has the survival rate of 20% in its advanced stages. Osteosarcomas are mostly resistance to our common treatments. DNA damage response (DDR) is a specialized multistep process containing abundant proteins which are necessary for the survival of any cell and organism. DDR machinery detects a diversity of DNA lesions and inhibits the cell cycle progression if these lesions are not repairable. DDR is involved in aging, age-related diseases, and cancer. In recent years, DDR inhibitors have gained the attention of researches due to their potentials in offering novel therapeutic targets and improving the response of many cancers to either chemo- or radio-therapy. In this regard, we tried to gather a great body of evidence about the role of DDR ingredients in osteosarcoma's initiation/progression, prognosis, and treatment.

β-Elemene suppresses tumor growth of diffuse large B-cell lymphoma through regulating lncRNA HULC-mediated apoptotic pathway

Background: Diffuse large B-cell lymphoma (DLBCL) is considered the most common aggressive subtype of lymphoma. A number of DLBCL patients fail to achieve a response to currently available therapies or develop resistance. β-Elemene is derived from herb Curcuma wenyujin, and exhibits anti-tumor activity in both solid and non-solid tumors through modulating several molecular signaling pathways. We aimed to explore the role of β-elemene in DLBCL treatment and elucidate the involved mechanism.

Materials and methods: Cell viability, apoptosis and expressions of related proteins were assessed and in vivo study were performed to determine the tumor suppressive effect of β-elemene and explore the molecular mechanisms.

Results: β-Elemene significantly suppressed the viability of DLBCL cells, and β-elemene down-regulated the lncRNA HULC expression and regulated key pro-apoptotic and anti-apoptotic proteins to induce significant apoptosis of DLBCL cells. HULC overexpression could decrease the β-elemene induced apoptosis, while HULC knockdown increased the apoptosis in DLBCL cells. In vivo study further confirmed that β-elemene could suppress the growth of DLBCL xenograft and regulate the HULC expression and the critical proteins of the apoptotic pathway.

Conclusion: β-Elemene performs as a tumor suppressor and modulator of HULC-mediated apoptotic pathway in DLBCL and will be an alternative candidate for clinical application.

LncRNA highly upregulated in liver cancer regulates imatinib resistance in chronic myeloid leukemia via the miR-150-5p/MCL1 axis

Chronic myeloid leukemia (CML) is a type of myeloproliferative neoplasm. Aberrant expression of long noncoding RNA highly upregulated in liver cancer (HULC) has been implicated in tumor progression, including CML. This study aimed to investigate the role of HULC in CML. The levels of HULC, miR-150-5p and myeloid cell leukemia 1 (MCL1) were examined by quantitative real-time PCR or western blot assay. Cell counting kit-8 assay was used to detect cell viability and half inhibition concentration. Cell apoptosis was monitored by flow cytometry and western blot. The interaction among HULC, miR-150-5p and MCL1 was validated by dual-luciferase reporter assay. The expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and phosphorylation-AKT was evaluated using western blot assay. HULC and MCL1 were upregulated, whereas miR-150-5p was downregulated in bone marrow mononuclear cells of CML patients and CML cells. HULC overexpression increased imatinib resistance in K562 cells, and HULC depletion enhanced imatinib sensitivity in imatinib-resistant cells (K562-R). Mechanically, HULC was a sponge of miR-150-5p. HULC contributed to imatinib resistance through regulation of miR-150-5p. MCL1 bound to miR-150-5p and reversed the effect of HULC on imatinib resistance. HULC regulated the PI3K/AKT pathway via the miR-150-5p/MCL1 axis. These findings indicated that HULC enhanced imatinib resistance in CML by modulating the miR-150-5p/MCL1 axis, providing a promising biomarker for CML.

LncRNA PTCSC3 and lncRNA HULC Negatively Affect Each Other to Regulate Cancer Cell Invasion and Migration in Gastric Cancer

Background

LncRNA PTCSC3 (PTCSC3) inhibits thyroid cancer cervical carcinoma and glioma, while its roles in gastric cancer are unknown. Studies have reported that HULC could serve as a potential biomarker for the diagnosis and prognosis of gastric cancer (GC). Our study aimed to investigate the potential interaction between PTCSC3 and HULC in gastric cancer.

Methods

This study enrolled 77 gastric cancer patients at the First Affiliated Hospital of Anhui Medical University from January 2016 to January 2018. RT-qPCR was performed to analyze gene expression levels. Cell transfections were carried out to evaluate gene interactions. Transwell assays and wound healing assays were used to analyze the effects of transfection on cell invasion and migration. Western blotting was also used to illustrate the possibility that lncRNA PTCSC3 and lncRNA HULC negatively affected each other through WNT signal path.

Results

We showed that PTCSC3 was downregulated in tumor tissues of gastric cancer patients in comparison to that in adjacent healthy tissues, and an inverse correlation between the expression levels of PTCSC3 and AJCC stage was observed. LncRNA HULC (HULC) was upregulated in tumor and inversely correlated with PTCSC3 in tumor tissues. Overexpression of PTCSC3 mediated the inhibition of HULC, while overexpression of HULC also mediated the inhibition of PTCSC3. PTCSC3 inhibited, while HULC promoted invasion and migration of gastric cancer cells. In addition, overexpression of HULC attenuated the effects of overexpression of PTCSC3. However, overexpression of PTCSC3 showed no significant effects on cell proliferation. We also found that PTCSC3/HULC affected each other to regulate cell invasion and migration through the Wnt/β-catenin signaling.

Conclusion

Therefore, overexpression of PTCSC3 inhibited the invasion and migration of gastric cancer cells, and the function of PTCSC3 is associated with HULC.

LINC00662 Long Non-Coding RNA Knockdown Attenuates the Proliferation, Migration, and Invasion of Osteosarcoma Cells by Regulating the microRNA-15a-5p/Notch2 Axis

Purpose

Osteosarcoma (OS) is a frequently occurring malignancy in children and adolescents. In this study, we aimed to investigate the effects of the long non-coding RNA (lncRNA) LINC00662 (LINC00662) in OS and the underlying molecular mechanism.

Methods

The expression of LINC00662, microRNA-15a-5p (miR-15a-5p), and Notch2 in OS was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration, and invasion of OS cells were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound-healing, and transwell assay. The interactions among LINC00662, miR-15a-5p, and Notch2 were determined by dual-luciferase reporter assays. A tumor xenograft model was established in mice for evaluating tumor growth in vivo.

Results

The expression of LINC00662 and Notch2 was found to be upregulated in OS, but the expression of miR-15a-5p was downregulated. The results demonstrated that LINC00662 knockdown attenuated the proliferation, migration, and invasion of OS cells and suppressed tumor growth in mice. The study further demonstrated that LINC00662 directly interacted with miR-15a-5p, and that Notch2 was a target of miR-15a-5p. The inhibition of miR-15a-5p or Notch2 overexpression markedly reversed the suppressive effect of sh-LINC00662 on the proliferation, migration, and invasion of OS cells.

Conclusion

The study demonstrated that LINC00662 could be a potential biomarker for OS therapy, and LINC00662 knockdown suppressed the proliferation, migration, and invasion of OS cells by regulating the miR-15a-5p/Notch2 axis.

Knockdown of m6A methyltransferase METTL3 in gastric cancer cells results in suppression of cell proliferation

N6-methyladenosine (m6A) RNA modification regulates multiple biological functions. Methyltransferase like 3 (METTL3), one of the major N6-methyltransferases, is highly expressed in gastric cancer, but its potential role in disease is unclear. The current study knocked out METTL3 (METTL3-KO) in human gastric cancer AGS cells using CRISPR/Cas9. METTL3-KO AGS cells exhibited decreased m6A methylation levels. A significant inhibition of cell proliferation was observed in METTL3-KO AGS cells. Silencing METTL3 in AGS cells altered the expression profile of many effector molecules that were previously demonstrated to serve key roles in AGS cell proliferation, including the suppressor of cytokine signaling (SOCS) family of proteins. The results further demonstrated that SOCS2 upregulation in METTL3-KO AGS cells was associated with a decreased RNA decay rate. Furthermore, SOCS2 KO or SOCS2 overexpression caused a significant increase and decrease in AGS cell proliferation, respectively. The current data suggested that METTL3-KO in gastric cancer cells resulted in the suppression of cell proliferation by inducing SOCS2, suggesting a potential role of elevated METTL3 expression in gastric cancer progression.

Quantitative Proteomics Analysis Indicates That Upregulation of lncRNA HULC Promotes Pathogenesis of Glioblastoma Cells

Purpose

Glioblastoma (GBM) is an aggressive central nervous system (CNS) cancer and a serious threat to human health. The long noncoding RNA (lncRNA) HULC has been implicated in GBM, but the molecular mechanism is uncertain. This study used quantitative proteomic analysis for global identification of HULC-regulated proteins in glioblastoma cells and identification of potential biomarkers.

Materials and Methods

qRT-PCR was used to determine the expression of HULC in U87 cells stably transfected with HULC or an empty vector (control). The CCK-8 assay, transwell assay, and wound-scratch assay were used to measure cell proliferation, invasion, and migration. Quantitative proteomics using Tandem Mass Tag (TMT) labeling, high-performance liquid chromatography (HPLC) fractionation, and liquid chromatography–mass spectrometry (LC-MS/MS) analysis were used to identify differentially expressed proteins (DEPs). Screened proteins were validated by parallel reaction monitoring (PRM) and Western blotting.

Results

Overexpression of HULC led to increased cell proliferation, invasion, and migration. HULC overexpression also led to significant upregulation of 37 proteins and downregulation of 78 proteins. Bioinformatics analysis indicated these proteins had roles in cellular component, biological process, and molecular function. PRM results of 8 of these proteins (PTK2, TNC, ITGAV, LASP1, MAPK14, ITGA1, GNA13, RRAS) were consistent with the LC-MS/MS and Western blotting results.

Conclusion

The results of present study suggest that lncRNA HULC promotes GBM cell proliferation, invasion, and migration by regulating RRAS expression, suggesting that RRAS may be a potential biomarker or therapeutic target for this cancer.

YY1-induced lncRNA DSCR8 promotes the progression of ovarian cancer via miR-3192-5p/YY1 axis

Ovarian cancer endangers the life of women worldwide. Plenty of lncRNAs have been found modulating the progression of ovarian cancer. Meanwhile, lncRNA DSCR8 (Down syndrome critical region 8) has been reported as an oncogene in hepatocellular carcinoma. In this study, we aimed to search the function of DSCR8 in ovarian cancer. qRT-PCR analysis assessed the expression of DSCR8 in ovarian cancer cells. EdU assay and colony formation assay was used to test cell proliferation. Flow cytometry analysis and TUNEL assay were conducted to investigate cell apoptosis. Wound healing assay and transwell invasion assay assessed cell migration and invasion. DSCR8 was significantly up-regulated in ovarian cancer cells. Inhibited DSCR8 could suppress the progression of ovarian cancer. Also, YY1 could activate the expression of DSCR8 in ovarian cancer cells. Meanwhile, DSCR8/miR-3192-5p/YY1 axis was identified in ovarian cancer cells. MiR-3192-5p could function as tumor suppresser in ovarian cancer cells. Furthermore, DSCR8 and YY1 (Yin Yang 1) transcription factor could play the regulatory network in ovarian cancer cells. In a word, YY1-induced lncRNA DSCR8 promotes the progression of ovarian cancer via miR-3192-5p/YY1 axis.

LncRNA SNHG4 promotes osteosarcoma proliferation and migration by sponging miR-377-3p

Background

Long non‐coding RNAs (lncRNAs) have been identified as crucial regulatory factors in the occurrence and progression of osteosarcoma.

Methods

Quantitative real‐time polymerase chain reaction was used for detecting small nucleolar RNA host gene 4 (SNHG4) and miR‐377‐3p in osteosarcoma cells and tissues. Kaplan–Meier method was applied for evaluating the association between SNHG4 expression and the overall survival of osteosarcoma patients. CCK8, EdU, flow cytometry, and transwell assay were performed to examine the cell proliferation, apoptosis, cycle, and migration of osteosarcoma cells.

Results

In our study, we found that lncRNA SNHG4 was highly expressed in osteosarcoma tissues and cell lines. Additionally, the SNHG4 expression was related to distant metastasis, TNM stage, and survival of osteosarcoma patients. Through SNHG4 knockdown, the proliferation of osteosarcoma cells was considerably restrained and the cell apoptosis was induced in vivo and in vitro. Moreover, downregulated SNHG4 inhibited the cell migration and epithelial‐mesenchymal transition in HOS and MG63 cells. In mechanism, we found that SNHG4 acts as a competing endogenous RNA to sponge miR‐377‐3p, which is downregulated in osteosarcoma. Our results showed that there is a negative correlation between SNHG4 and miR‐377‐3p expression in osteosarcoma patients.

Conclusion

Taken together, SNHG4 promotes cell proliferation and migration by sponging miR‐377‐3p in osteosarcoma.

The Emerging Roles of Long Noncoding RNAs in Bone Homeostasis and Their Potential Application in Bone-Related Diseases

Increasing evidence has announced the emerging roles of long noncoding RNAs (lncRNAs) in modulating bone homeostasis due to their potential regulating effects on bone-related cells' proliferation, migration, differentiation and apoptosis. Thus, lncRNAs have been considered as a promising gene tool to facilitate the bone regeneration process and then to predict and cure bone-related diseases such as osteosarcoma, osteoporosis, and osteoarthritis. In this review, we first enumerated several kinds of dysregulated lncRNAs and concisely summarized their regulating role in bone formation as well as resorption process. The related mechanisms were also discussed, respectively. Then, the positive or negative behavior of these lncRNAs in bone-related diseases was elucidated. This review provides an in-depth sight about the lncRNA's clinical values and limitations, which is conducive to explore new gene targets and further establish new therapeutic strategies for bone-related disease.

The multiple function of long noncoding RNAs in osteosarcoma progression, drug resistance and prognosis

Osteosarcoma is a bone tumor prevalent in children and young adults. LncRNAs are a family of non-protein-coding transcripts longer than 200 nucleotides. The tumor-related pathological functions of lncRNAs include proliferation, migration, and chemotherapy resistance, all of which have been widely acknowledged in research on osteosarcoma. In addition, compelling evidence suggests that lncRNAs could serve as diagnostic indicators, prognostic biomarkers, and targets for disease treatment. In this review, we systematically summarize how lncRNAs regulate tumorigenesis, invasion and therapeutic resistance. By deepening our knowledge of the relationship between lncRNAs and osteosarcoma, we hope to translate research findings into clinical applications as soon as possible.

Long noncoding RNA HIF1A-AS2 facilitates cell survival and migration by sponging miR-33b-5p to modulate SIRT6 expression in osteosarcoma

Long noncoding RNAs (lncRNAs) are emerging as vital regulators in various physiological and pathological processes. It was recently found that lncRNA HIF1A-AS2 could play oncogenic roles in several cancers. However, the function and regulatory mechanism of lncRNA HIF1A-AS2 in osteosarcoma (OS) remain largely unclear. In this study, we demonstrated that HIF1A-AS2 was overexpressed in OS tissues and cells. Downregulation of HIF1A-AS2 significantly affects multiple biological functions in OS cells, including cell proliferation, cell cycle progression, cell apoptosis, cell migration, and cell invasiveness. Mechanistic investigations demonstrated that HIF1A-AS2 can interact with miR-33b-5p and negatively regulate its expression, thereby upregulating the protein expression of miR-33b-5p’s target SIRT6. Additionally, in vivo experiments using a xenograft tumor mouse model revealed that downregulation of HIF1A-AS2 suppresses tumor growth in OS. Taken together, a newly identified regulatory mechanism for the lncRNA HIF1A-AS2–miR-33b-5p–SIRT6 axis was systematically studied in OS, which could be a promising target for the treatment of OS.

Knockdown of TBRG4 suppresses proliferation, invasion and promotes apoptosis of osteosarcoma cells by downregulating TGF-β1 expression and PI3K/AKT signaling pathway

Transforming growth factor beta regulator 4 (TBRG4) is a novel regulator in tumorigenic progression of several tumors. However, so far, the expression and functions of TBRG4 in osteosarcoma are unknown. The aim of this study was to investigate the potential biological functions of TBRG4 in osteosarcoma. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of TBRG4 in osteosarcoma tissues and cell lines. The levels of TBRG4 protein in osteosarcoma tissues were assessed by immunohistochemistry. Lentivirus-mediated short hairpin (sh) RNA was employed to knock down TBRG4 in osteosarcoma cells, and the expressions of TBRG4 mRNA and protein were determined by qRT-PCR and Western blot assay, respectively. Subsequently, the proliferation, clonogenic ability, apoptosis and invasion of osteosarcoma cells were measured using high content screening analysis and CCK8 assay, tumor sphere formation assay, flow cytometry and Transwell invasion assays, respectively. Furthermore, the osteosarcoma cells growth and metastasis in vivo were detected, and the effect of TBRG4 on the transforming growth factor β1 (TGF-β1) and PI3K/AKT signaling pathway was explored by qRT-PCR and Western blot assay, respectively. The results showed the levels of TBRG4 were overexpressed in osteosarcoma tissues and cell lines, confirming that the high TBRG4 expression was related to advanced tumor stages, large tumor size, and lymph node metastasis. Functional assays showed knockdown of TBRG4 could inhibit proliferation, invasion and induce apoptosis of osteosarcoma cells in vitro, and could also suppress osteosarcoma growth and metastasis in vivo. By examining the expression levels of TGF-β1, p-PI3K, PI3K, p-AKT and AKT, it showed that the suppression of TBRG4 would reduce TGF-β1 expression and inactivate the PI3K/AKT signaling pathway. These results showed for the first time that TBRG4 knockdown could suppress osteosarcoma progression, suggesting TBRG4 might be a promising therapeutic target for osteosarcoma treatment.

LncRNA HULC induces the progression of osteosarcoma by regulating the miR-372-3p/HMGB1 signalling axis

Background

Osteosarcoma is a malignancy that normally affects children, adolescents, and young adults. Although accumulating evidence has demonstrated the importance of HULC in osteosarcoma, little is reported about its functional roles and molecular mechanisms.

Methods

The expression of HULC and miR-372-3p in osteosarcoma tissues was quantified by qRT-PCR. The regulatory roles of HULC and miR-372-3p on cell proliferation, apoptosis, migration and invasion were determined by CCK-8, colony formation, flow cytometry, wound healing, and transwell assays, respectively. The bioinformatics prediction software RAID v2.0 was used to predict the putative binding sites. The interactions among HULC, miR-372-3p and HMGB1 were explored by luciferase assay and western blot assay.

Results

Our results revealed elevated HULC and decreased miR-372-3p expression in both osteosarcoma tissues and cell lines. Overexpression of HULC or knockdown of miR-372-3p promoted osteosarcoma cell proliferation, migration and invasion and induced cell apoptosis. Bioinformatics and luciferase assays verified that HULC directly interacted with miR-372-3p to attenuate miR-372-3p binding to the HMGB1 3′-UTR. Furthermore, mechanistic investigations confirmed that activation of the miR-372-3p/HMGB1 regulatory loop by knockdown of miR-372-3p or overexpression of HMGB1 reversed the in vitro roles of HULC in promoting osteosarcoma cell proliferation, migration and invasion.

Conclusion

Our study is the first to demonstrate that HULC may act as a ceRNA to modulate HMGB1 expression by competitively sponging miR-372-3p, leading to the regulation of osteosarcoma progression, which provides new insight into osteosarcoma diagnosis and treatment.

Long noncoding RNA HULC accelerates the growth of human liver cancer stem cells by upregulating CyclinD1 through miR675-PKM2 pathway via autophagy

BACKGROUND

The functions of HULC have been demonstrated in several cancers. However, its mechanism has not been elucidated in human liver cancer stem cells.

METHODS

Liver cancer stem cells were isolated from Huh7 cells; gene infection and tumorigenesis test in vitro and in vivo were performed.

RESULTS

We demonstrate that HULC promotes growth of liver cancer stem cells in vitro and in vivo. Mechanistically, HULC enhances the expression of Sirt1 dependent on miR675 and then induces the cellular autophagy through Sirt1. HULC enhances CyclinD1 and thereby increases pRB and inhibited P21 WAF1/CIP 1 via autophagy-miR675-PKM2 pathway in human liver cancer stem cells. Ultimately, our results demonstrate that CyclinD1 is required for the oncogenic functions of HULC in liver cancer stem cells.

CONCLUSIONS

It reveals the key molecular signaling pathways for HULC and provides important basic information for finding effective tumor therapeutic targets based on HULC.

LncRNA RP11-361F15.2 promotes osteosarcoma tumorigenesis by inhibiting M2-Like polarization of tumor-associated macrophages of CPEB4

Long non-coding RNAs (lncRNAs) regulates the initiation and progression of osteosarcoma (OS), specifically lncRNA RP11-361F15.2 has been shown to play prominent roles in tumorigenesis. Previously, M2-Like polarization of tumor-associated macrophages (TAMs) has been identified to play a key role in cancer migration/invasion. Hence, it is essential to understand the role of RP11-361F15.2 in tumorigenesis and its association with M2-Like polarization of TAMs. The results indicate that RP11-361F15.2 is significantly increased in OS tissues, and its expression is positively correlated with cytoplasmic polyadenylation element binding protein 4 (CPEB4) expression and negatively associated with miR-30c-5p expression. Further, overexpression of RP11-361F15.2 increased OS cell migration/invasion and M2-Like polarization of TAMs in vitro, as well as promoted xenograft tumor growth in vivo. Mechanistically, luciferase reporter assays indicated that RP11-361F15.2 upregulated CPEB4 expression by competitively binding to miR-30c-5p. Further, we have identified that RP11-361F15.2 promotes CPEB4-mediated tumorigenesis and M2-Like polarization of TAMs through miR-30c-5p in OS. We also identified that RP11-361F15.2 acts as competitive endogenous RNA (ceRNA) against miR-30c-5p thereby binding and activating CPEB4. This RP11-361F15.2/miR-30c-5p/CPEB4 loop could be used as a potential therapeutic strategy for the treatment of OS.

Long Noncoding RNA HULC Promoter Polymorphism rs1041279 Is Associated with an Increased Risk of Cervical Squamous Cell Carcinoma

Hepatocellular carcinoma upregulated long noncoding RNA (HULC), identified as an oncogene in cervical cancer, is involved in not only the clinical stage, lymph node metastasis, and depth of cervical invasion but also outcome. In this study, we aimed to investigate the association between 3 polymorphisms (i.e., rs1041279, rs3005167, and rs7770772) in the promoter of HULC and the risk of cervical squamous cell carcinoma (CSCC). The polymorphisms were genotyped using the multiplex ligase detection reaction assay. The promoter activity was measured using the dual-luciferase reporter assay kit. The rs1041279 GG genotype and G allele revealed a significantly higher risk of CSCC compared with the rs1041279 CC genotype and C allele (GG vs. CC, adjusted OR = 1.79, 95% CI, 1.17-2.73, P = 0.007; G vs. C, adjusted OR = 1.36, 95% CI, 1.09-1.69, P = 0.006). Haplotype analysis revealed that the rs3005167C-rs7770772G-rs1041279C or rs3005167C-rs7770772G-rs1041279G haplotype had a significantly higher risk of CSCC compared to the rs3005167G-rs7770772G-rs1041279C haplotype (CGC vs. GGC, OR = 2.38, 95% CI, 1.53-3.75, P < 0.001; CGG vs. GGC, OR = 3.76, 95% CI, 2.12-6.68, P < 0.001). Dual-luciferase reporter assay showed that the rs1041279 G promoter resulted in higher transcriptional activity compared with the rs1041279 C (P < 0.01). Additionally, the rs1041279 GG genotype carriers had an increased level of HULC expression (P = 0.03). These findings suggest that the HULC rs1041279 may be a useful marker for the etiology of CSCC.

Long Non-Coding RNA HULC Promotes the Development of Breast Cancer Through Regulating LYPD1 Expression by Sponging miR-6754-5p

Introduction

Long non-coding RNAs (lncRNAs) were found to regulate many biological processes including cancer development, immunology and other diseases. LncRNA HULC was found to be oncogenes in many cancer progression. However, the role of HULC in the regulation of breast cancer remains unclear.

Methods

The expression of HULC and miR-6754-5p was examined by RT-PCR. Through knockdown of HULC, we found that the proliferation abilities coupled with migration and invasion abilities were significantly decreased. And also, we verified that overexpression of miR-6754-5p significantly decreased the proliferation ability of breast cancer cells.

Results

In this study, we found that lncRNA HULC was overexpressed in breast cancer tissues and cell lines compared to normal healthy breast tissues and normal breast cell line. Moreover, the high expression of HULC was associated with metastasis and malignancy of breast cancers. Mechanically, we found that HULC can bind to miR-6754-5p directly through complementary base pairing. Furthermore, we found that HULC regulates the expression of LYPD1 through sponging miR-6754-5p. Moreover, overexpression of LYPD1 can rescue the migration and invasion abilities of breast cancer cells decreased by knockdown of HULC or overexpression of miR-6754-5p.

Conclusion

Our study showed the role of HULC in promoting breast cancer development and explained the detailed molecular mechanisms.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

LncRNA HULC promotes the progression of gastric cancer by regulating miR-9-5p/MYH9 axis

Long non-coding RNAs (lncRNAs) highly upregulated in liver cancer (HULC) has been identified as an oncogene involved in many human cancers. Herein, we aimed to further explore the role and molecular mechanism of HULC in gastric cancer (GC) progression. The levels of HULC, miR-9-5p and myosin heavy chain 9 (MYH9) mRNA were detected by qRT-PCR. The targeted interaction between HULC and miR-9-5p was verified by dual-luciferase reporter and RNA pull-down assays. Cell proliferation assay, cell colony formation, flow cytometry and transwell assay were used to determine cell proliferation, colony formation, apoptosis and migration and invasion, respectively. Xenograft assay was used to observe the effect of HULC on GC growth in vivo. Our results revealed that HULC was upregulated and miR-9-5p was downregulated in GC, and both were associated with clinicopathologic features of GC patients. A positive correlation was found between HULC expression and epithelial-to-mesenchymal transition (EMT) of GC tissues. Moreover, HULC repressed miR-9-5p expression by binding to miR-9-5p. The regulatory effects of HULC knockdown on GC cell proliferation, migration, invasion, EMT and apoptosis were reversed by introduction of anti-miR-9-5p. HULC regulated MYH9 expression by acting as a molecular sponge of miR-9-5p in GC cells. HULC knockdown inhibited tumor growth in vivo. In conclusion, our data demonstrated that HULC knockdown repressed GC progression at least partly by regulating miR-9-5p/MYH9 axis.

LncRNA HULC Polymorphism Is Associated With Recurrent Spontaneous Abortion Susceptibility in the Southern Chinese Population

Previous studies have revealed that genetic variation in genes that regulate cell migration might be associated with susceptibility to recurrent spontaneous abortion. HULC regulates the migration of a variety of cells, and genetic polymorphisms of HULC are associated with susceptibility to a variety of diseases, but their association with susceptibility to recurrent spontaneous abortion has not been reported. This study included 610 cases of recurrent spontaneous abortion and 817 normal controls, and the polymorphisms of the four SNPs were genotyped using the TaqMan method. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the associations between selected SNPs and susceptibility to recurrent spontaneous abortion. Our results showed that three SNPs were significantly associated with a reduced risk of recurrent spontaneous abortion: rs1041279 (GG vs. GC/CC: adjusted OR = 0.745, 95% CI = 0.559–0.993, P = 0.0445), rs7770772 (GC/CC vs. GG: adjusted OR = 0.757, 95% CI = 0.606–0.946, P = 0.0143), and rs17144343 (AA/GA vs GG adjusted OR = 0.526, 95% CI = 0.366–0.755, P = 0.0005). Individuals with one to four genotypes showed a reduced risk of recurrent spontaneous abortion (adjusted OR = 0.749, 95% CI = 0.598–0.939, P = 0.0123). This cumulative effect on protection increased with increases in the observed number of genotypes (adjusted OR = 0.727, 95% CI = 0.625–0.846, ptrend < 0.0001). Our study suggests that HULC might be a biomarker for risk for recurrent spontaneous abortion, but larger sample studies are needed to verify this result.

BMSC-derived exosomes carrying microRNA-122-5p promote proliferation of osteoblasts in osteonecrosis of the femoral head

Mesenchymal stem cells (MSCs) with multipotential differentiation capacity can differentiate into bone cells under specific conditions and can be used to treat osteonecrosis (ON) of the femoral head (ONFH) through cell transplantation. The current study aims to explore the role of bone marrow (BM) MSCs (BMSCs)-derived exosomes carrying microRNA-122-5p (miR-122-5p) in ONFH rabbit models.First, rabbit models with ONFH were established. ONFH-related miRNAs were screened using the Gene Expression Omnibus (GEO) database. A gain-of-function study was performed to investigate the effect of miR-122-5p on osteoblasts and BMSCs and effects of exosomes carrying miR-122-5p on ONFH. Co-culture experiments for osteoblasts and BMSCs were performed to examine the role of exosomal miR-122-5p in osteoblast proliferation and osteogenesis. The target relationship between miR-122-5p and Sprouty2 (SPRY2) was tested.MiR-122, significantly decreased in ONFH in the GSE89587 expression profile, was screened. MiR-122-5p negatively regulated SPRY2 and elevated the activity of receptor tyrosine kinase (RTK), thereby promoting the proliferation and differentiation of osteoblasts. In vivo experiments indicated that bone mineral density (BMD), trabecular bone volume (TBV), and mean trabecular plate thickness (MTPT) of femoral head were increased after over-expressing miR-122-5p in exosomes. Significant healing of necrotic femoral head was also observed.Exosomes carrying over-expressed miR-122-5p attenuated ONFH development by down-regulating SPRY2 via the RTK/Ras/mitogen-activated protein kinase (MAPK) signaling pathway. Findings in the present study may provide miR-122-5p as a novel biomarker for ONFH treatment.

NOTCH signaling pathway and non-coding RNAs in cancer

Malignant tumors, known as cancer, seriously threaten human life and health. Cancer has the characteristics of abnormal cell differentiation, proliferation, invasion and metastasis. As a result, cancer often accompanied by poor prognosis and a lower survival rate. Notch signaling pathway is a highly conserved system in many multicellular organisms, and which has been proved to play a biological role in many cancers. In recent years, increasing evidence has shown that non-coding RNA can not only activate or inhibit NOTCH pathway, but also regulate the occurrence and development of cancer through NOTCH pathway. Therefore, we focus on the cancer-NOTCH-non-coding RNA axis in this review, and provide new ideas for cancer therapy.

LncRNA HULC promotes lung squamous cell carcinoma by regulating PTPRO via NF-κB

Accumulating studies have implicated that long noncoding RNA (lncRNA) plays a vital role in lung cancer. However, little is known of the role of lncRNA highly upregulated in liver cancer (HULC) in the pathogenesis of lung squamous cell carcinoma (LSCC). In this study, we investigated the modifying effects and underlying mechanisms of lncRNA HULC in LSCC. Significantly decreased level of lncRNA HULC was observed in LSCC samples compared with adjacent tissues. Besides, the expression of lncRNA HULC was negatively associated with protein tyrosine phosphatase receptor type O (PTPRO) in LSCC. Moreover, lncRNA HULC could promote the proliferation of LSCC cells by downregulating the expression PTPRO dependent on the phosphorylation and activation of nuclear factor-κB (NF-κB). The present study firstly shows strong evidence supporting a critical role of lncRNA HULC in promoting LSCC by regulating PTPRO/NF-κB signaling pathway, which provides new promising biomarkers for LSCC.

Contextual Regulation of Skeletal Physiology by Notch Signaling

PURPOSE OF REVIEW

This article reviews the past 2 years of research on Notch signaling as it relates to bone physiology, with the goal of reconciling seemingly discrepant findings and identifying fruitful areas of potential future research.

RECENT FINDINGS

Conditional animal models and high-throughput omics have contributed to a greater understanding of the context-dependent role of Notch signaling in bone. However, significant gaps remain in our understanding of how spatiotemporal context and epigenetic state dictate downstream Notch phenotypes. Biphasic activation of Notch signaling orchestrates progression of mesenchymal progenitor cells through the osteoblast lineage, but there is a limited understanding of ligand- and receptor-specific functions. Paracrine Notch signaling through non-osteoblastic cell types contributes additional layers of complexity, and we anticipate impactful future work related to the integration of these cell types and signaling mechanisms.

Hepatocellular carcinoma up-regulated long non-coding RNA: a putative marker in multiple sclerosis

Highly up-regulated in liver cancer (HULC) is a cancer-associated long non-coding RNA (lncRNA) which may regulate expression of other genes by working as a competing RNA for microRNAs. In the current study, we assessed transcript levels of this lncRNA in peripheral blood of multiple sclerosis (MS) patients and healthy persons to evaluate its possible role in the pathogenesis of this inflammatory disease and its diagnostic power. The results of Multilevel Bayesian showed no significant difference between cases and controls (P = 0.002, 95% confidence interval (CI) = [3.08, 13.3]). However, based on the results of Quantile regression, there was a significant difference in HULC expression between cases and controls after controlling the effects of sex and age (P = 0.002, 95% CI = [3.08, 13.3]) which shows different trends in males and females. HULC expression was inversely correlated with age of male subjects but not female subjects. HULC transcript levels had 91.1% accuracy in diagnosis of MS disease (Specificity: 80%, Sensitivity: 86.6%). The diagnostic power of HULC was higher in male subjects aged less than 50 years (AUC = 0.923, Specificity: 80%, Sensitivity: 100%). The present study shows the possibility of application of transcript levels of HULC as diagnostic marker in MS disease. However, future studies with larger sample sizes are necessary to validate our results.

Long non-coding RNA HAND2-AS1 targets glucose metabolism and inhibits cancer cell proliferation in osteosarcoma

Long non-coding RNA heart and neural crest derivatives expressed 2-antisense RNA 1 (lncRNA HAND2-AS1) is a known tumor suppressor gene in endometrioid endometrial carcinoma; however, its function in osteosarcoma is currently unknown. In the present study, HAND2-AS1 expression in the tumor tissues and adjacent healthy tissues of patients with osteosarcoma, and in the serum of patients and heathy controls was detected by reverse transcription-quantitative polymerase chain reaction. lncRNA HAND2-AS1 small interfering RNA was transfected into osteosarcoma cells, and cell proliferation, glucose transporter 1 (GLUT1) expression and glucose uptake were detected using the Cell Counting Kit-8, western blotting and glucose uptake assays, respectively. The results revealed that the expression levels of HAND2-AS1 were reduced in cancer tissues compared with those in healthy tissues. Levels of HAND2-AS1 were also reduced in the serum of patients with osteosarcoma compared with those of the control subjects. A significant association was observed between serum levels of HAND2-AS1 and tumor size, but not tumor metastasis. HAND2-AS1-knockdown promoted osteosarcoma cell proliferation, increased glucose uptake and upregulated GLUT1 expression. It was therefore concluded that lncRNA HAND2-AS1 may inhibit the proliferation of osteosarcoma cells by targeting glucose metabolism.

HULC functions as an oncogene in ovarian carcinoma cells by negatively modulating miR-125a-3p

The aberrant expression of highly upregulated in liver cancer (HULC) has been reported to participate in ovarian cancer development. A recent research has revealed that HULC-modulated microRNAs (miRNAs) in tumorigenesis. To confirm the functions of HULC on tumorigenesis of ovarian, we explored the effects of HULC expression on ovarian cancer cell development, as well as the underlying mechanism. We transfected SKOV3 cells with pEX-HULC, sh-HULC, and miR-125a-3p mimic as well as their corresponding negative controls (pEX-3, sh-NC, and NC) to alter the expression of HULC and miR-125a-3p, which were analyzed by quantitative reverse transcription PCR (qRT-PCR). Expression of proteins associated with cell cycle, apoptosis, and signaling pathways was determined by Western blot assay. The proliferation, apoptosis, migration, and invasion were explored by bromodeoxyuridine (BrdU) incorporation assay, Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) method, and transwell migration and invasion assays, respectively. HULC overexpression promoted proliferation, migration, and invasion, while inhibited apoptosis of SKOV3 cells. In addition, HULC negatively regulated the expression of miR-125a-3p. Besides, miR-125a-3p mimic reversed the effects of HULC on proliferation, migration, and invasion as well as apoptosis of SKOV3 cells. Moreover, we found that HULC enhanced phosphorylated expression of regulatory factors in phosphatidylinositol 3 kinase/protein kinase B/mammalian targets of rapamycin (PI3K/AKT/mTOR) signaling pathway by downregulating expression of miR-125a-3p. Overexpression of HULC promoted ovarian carcinoma development by activating PI3K/AKT/mTOR signaling pathway via downregulating miR-125a-3p.

Targeting PI3K in cancer: mechanisms and advances in clinical trials

Phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling is one of the most important intracellular pathways, which can be considered as a master regulator for cancer. Enormous efforts have been dedicated to the development of drugs targeting PI3K signaling, many of which are currently employed in clinical trials evaluation, and it is becoming increasingly clear that PI3K inhibitors are effective in inhibiting tumor progression. PI3K inhibitors are subdivided into dual PI3K/mTOR inhibitors, pan-PI3K inhibitors and isoform-specific inhibitors. In this review, we performed a critical review to summarize the role of the PI3K pathway in tumor development, recent PI3K inhibitors development based on clinical trials, and the mechanisms of resistance to PI3K inhibition.