Osteosarcoma Proliferation Research Articles

MiRNA-23b-5p affects the proliferation, migration and invasion of osteosarcoma by targeting TMEM127

BackgroundOsteosarcoma (OS) has become one of the highest mortality cancers in the world due to its late diagnosis, rapid metastasis and rapid recurrence. MicroRNAs can regulate a variety of signaling pathwas involved in cancer development, such as cell proliferation, apoptosis and migration.ObjectiveIn this study, we studied the biological effects and molecular regulation of mir-23b-5p on human osteosarcoma cells.MethodsThe proliferation of mir-23b-5p in osteosarcoma was measured by CCK8 method and EDU method. In addition, the target population was screened through the database, and the luciferase reporter gene was used to determine the association between miRNA and target gene TMEM127. We verified this result by Western blot.ResultsWe found that mir-23b-5p promotes the progression of osteosarcoma by regulating TMEM127.ConclusionsThe results of this study show that mir-23b-5p affects the proliferation, metastasis and invasion of OS by targeting TMEM127.

Chondroitin Polymerizing Factor (CHPF) promotes cell proliferation and tumor growth in human osteosarcoma by inhibiting SKP2's ubiquitination while activating the AKT pathway

Osteosarcoma is a common malignant tumor occurring in children and young adults. Chondroitin sulfate (CS) participates in cell adhesion, cell division, and the formation of neural networks in the body, the biosynthesis of which requires the participation of glycosyltransferases. CHPF, a glycosyltransferase, plays a role in the extension of CS. Recently, CHPF's biological roles and functional importance in human diseases including malignant tumors have been widely discussed. However, whether CHPF is involved in osteosarcoma development and growth has not been revealed. The present work aimed to investigate the expression levels, functional significance and molecular mechanism of CHPF in osteosarcoma progression. Our results revealed that CHPF is strongly expressed in osteosarcoma tissues and cells. Furthermore, CHPF serves as a tumor promoter in the development and progression of osteosarcoma through enhancing cell proliferation and migration while suppressing apoptosis. Exploration of the mechanism by which CHPF promotes osteosarcoma indicated that CHPF promotes osteosarcoma through counteracting SKP2's ubiquitination and activating the Akt signaling pathway. For the first time, we clarified the roles of CHPF in osteosarcoma, and our results suggested that CHPF might be a novel therapeutic target in the treatment strategies for osteosarcoma.

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

BackgroundThe long-noncoding RNA colorectal neoplasia differentially expressed (CRNDE) gene has been found to be upregulated in several solid tumors. Whether CRNDE affects osteosarcoma (OS) and its underling mechanism remains unknown.MethodsTumor tissues and corresponding normal tissues were collected from 45 patients with OS. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was applied to determine lncRNA CRNDE level in the tissues. Participants were divided into a high CRNDE group and a low CRNDE group according to the median value of lncRNA CRNDE expression detected by in situ hybridization (ISH). The differences between high and low expression of lncRNA CRNDE in patients were compared clinically by chi-square test. Kaplan-Meier survival analysis was applied to analyze the relationship between lncRNA CRNDE expression and patient survival. Subsequently, silencing or overexpression of lncRNA CRNDE were performed in MG63 and 143B cell lines, qRT-PCR was applied to verify the expression of lncRNA CRNDE, miR-136-5p, and MRP9; dual-luciferase reporter assay was used to evaluate the targeting relationship between miR-136-5p, lncRNA CRNDE, and Cell Counting Kit-8 (CCK8), wound-healing, and Transwell assays were used to analyze for cell proliferation, migration, and invasion, respectively, and western blot was used to detect expression in cells.ResultsThe expression of CRNDE in OS tissues was higher than that in normal tissues. High lncRNA CRNDE expression was significantly associated with clinical stage, lung metastasis, and poor prognosis in OS patients. Additionally, overexpression of lncRNA CRNDE promoted proliferation and migration of OS cells. Bioinformatics analysis showed that lncRNA CRNDE competitively inhibited miR-136-5p through acting as a competitive endogenous RNA (ceRNA). It was also revealed that miR-136-5p is a binding target gene of lncRNA CRNDE and that MRP9 is involved in this process as a downstream target gene of miR-136-5p.ConclusionsThe lncRNA CRNDE promotes the proliferation and migration of OS cells by regulating the miR-136-5p/MRP9 pathway, and lncRNA CRNDE can be a significant marker of OS prognosis.

Long noncoding RNA HCP5 promotes osteosarcoma cell proliferation, invasion, and migration via the miR-29b-3p-LOXL2 axis.

Osteosarcoma (OS) is the second most common primary malignant bone tumors in adolescents that causes cancer-related deaths. Previous studies have confirmed the promoting role of lncRNA HCP5 in the development of OS, but the specific mechanism is still not well understood. MiRNA levels were measured via RT-qPCR and protein expression was detected via western blotting. Cell proliferation was analyzed by CCK-8 assays and colony formations assay were conducted to measure colony formation ability. Dual-luciferase reporter assay was performed to detect the targeting relationship between HCP5 and miR-29b-3p, and between miR-29b-3p and LOXL2. Wound healing assays and Transwell assays were conducted to verify the migration and invasion abilities of OS cells. Correlations between the levels of HCP5 and miR-29b-3p, and between miR-29b-3p and LOXL2 were determined by Pearson correlation coefficient analysis. MiR-29b-3p expression was decreased and HCP5 and LOXL2 levels were increased in OS tissues and cell lines. MiR-29b-3p could directly act on LOXL2 and knockdown of LOXL2 restrained the proliferation, migration, and invasion of OS cells. Moreover, transfection with sh-HCP5-1 and sh-HCP5-2 suppressed the malignant biological behavior of OS cells. HCP5 directly targeted miR-29b-3p, and promoted OS proliferation, migration, and invasion via the miR-29b-3p/LOXL2 axis. The lncRNA HCP5 may upregulate LOXL2 expression by targeting miR-29b-3p, thereby promoting OS proliferation, migration, and invasion.

PDCD10 promotes proliferation, migration, and invasion of osteosarcoma by inhibiting apoptosis and activating EMT pathway.

Osteosarcoma, a common primary malignant tumor, occurs in children and adolescents with a poor prognosis. The current treatment methods are various, while the five-year survival rate of patients has not been significantly improved. As a member of the programmed death factor (PDCD) family, programmed death factor 10 (PDCD10) plays a role in regulating cell apoptosis. Several studies of PDCD10 in CCM and cancers have been reported before. However, there are no relevant research reports on the effects of PDCD10 on osteosarcoma. We used bioinformatics analysis, IHC, and clinical data to confirm the expression of PDCD10 and its correlation with prognosis in osteosarcoma. Then, we used shRNAs and cDNA to knock down or overexpress PDCD10 in U2OS and MG63 cell lines. A series of function assays such as CCK8, Wound healing test, Plate cloning formation assay, and Transwell were done to confirm how PDCD10 affects osteosarcoma. Animal assays were done to confirm the conclusions in cell lines. At last, WB was used to measure the protein expression levels of apoptosis and the EMT pathway. PDCD10 was highly expressed in patients with osteosarcoma and correlated with prognosis; PDCD10 knockdown inhibited osteosarcoma growth, proliferation, migration, and invasion; PDCD10 overexpression promoted osteosarcoma growth, proliferation, migration, and invasion. In vivo experiments confirmed the conclusions in cell lines; PDCD10 inhibited apoptosis and activated the EMT pathway. In this study, it was found that PDCD10 was highly expressed in patients with osteosarcoma, and it was closely related to patient prognosis. PDCD10 inhibited tumor cell apoptosis and promoted tumor progression by activating the EMT pathway. These findings may provide a potential target for gene therapy of osteosarcoma.

LncRNA MALAT1-related signaling pathways in osteosarcoma.

Osteosarcoma (OS) is a common and malignant form of bone cancer, which affects children and young adults. OS is identified by osteogenic differentiation and metastasis. However, the exact molecular mechanism of OS development and progression is still unclear. Recently, long non-coding RNAs (lncRNA) have been proven to regulate OS proliferation and drug resistance. LncRNAs are longer than 200 nucleotides that represent the extensive applications in the processing of pre-mRNA and the pathogenesis of human diseases. Metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) is a well-known lncRNA known as a transcriptional and translational regulator. The aberrant expression of MALAT1 has been shown in several human cancers. The high level of MALAT1 is involved in OS cell growth and tumorigenicity by targeting several signaling pathways and miRNAs. Hence, MALAT1 might be a suitable approach for OS diagnosis and treatment. In this review, we will summarize the role of lncRNA MALAT1 in the pathophysiology of OS.

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

BackgroundOsteosarcoma (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.MethodsDifferentially 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.ResultsLncRNA 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.ConclusionsLncRNA 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.

Circular RNA ROCK1, a novel circRNA, suppresses osteosarcoma proliferation and migration via altering the miR-532-5p/PTEN axis

As the most prevalent bone tumor in children and adolescents, the pathogenesis and metastasis of osteosarcoma (OS) remain largely unclear. Here, we investigated the expression and function of a novel circular RNA (circRNA), circROCK1-E3/E4, which is back-spliced from exons 3 and 4 of Rho-associated coiled-coil containing protein kinase 1 (ROCK1) in OS. We found that circROCK1-E3/E4, regulated by the well-known RNA-binding protein quaking (QKI), was downregulated in OS and correlated with unfavorable clinical features of patients with OS. Functional proliferation and cell motility assays indicated that circROCK1-E3/E4 serves as a tumor suppressor in OS cells. Mechanistically, circROCK1-E3/E4 suppressed proliferation and migration by upregulating phosphatase and tensin homolog (PTEN) through microRNA-532-5p (miR-532-5p) sponging. In the constructed nude mouse model, circROCK1-E3/E4 inhibited tumor growth and lung metastasis in vivo. This study demonstrates the functions and molecular mechanisms of circROCK1-E3/E4 in the progression of OS. These findings may identify novel targets for the molecular therapy of OS.

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.

Retraction: Exosomes function as nanoparticles to transfer miR-199a-3p to reverse chemoresistance to cisplatin in hepatocellular carcinoma.

This Retraction follows an Expression of Concern relating to this article previously published by Portland Press.This article is being retracted from Bioscience Reports at the request of the authors following receipt of a notification from a reader, alerting the Editorial Office to potential issues surrounding the scientific validity of this paper, including identical image panels that appear across multiple publications. Figure panels 3C and 3D contains identical images with the following papers: ‘The Long Non-coding RNA LINC01705 Regulates the Development of Breast Cancer by Sponging miR-186-5p to Mediate TPR Expression as a Competitive Endogenous RNA’ (Figure 7C and 7D respectively; https://doi.org/10.3389/fgene.2020.00779), ‘Circular RNA circ-0016068 Promotes the Growth, Migration, and Invasion of Prostate Cancer Cells by Regulating the miR-330-3p/BMI-1 Axis as a Competing Endogenous RNA’ (Figure 2C and 2D respectively; https://doi.org/10.3389/fcell.2020.00827), and ‘LncRNA SNHG4 promotes osteosarcoma proliferation and migration by sponging miR‐377‐3p’ (Figure 2D; https://doi.org/10.1002%2Fmgg3.1349). Figure panels 3E and 3F share identical images with those of article ‘Long Non-Coding RNA ELFN1-AS1 Promoted Colon Cancer Cell Growth and Migration via the miR-191-5p/Special AT-Rich Sequence-Binding Protein 1 Axis’ (Figure 3C; (https://doi.org/10.3389%2Ffonc.2020.588360). The authors wish to retract the article. The Editor-in-Chief and Editorial Board agree with the retraction.

Mitochondria-Targeting Polymer Micelle of Dichloroacetate Induced Pyroptosis to Enhance Osteosarcoma Immunotherapy.

Pyroptosis has been reported to improve the immunosuppressive tumor microenvironment and may be a strategy to enhance osteosarcoma treatment. The extent to which modulation of mitochondria could induce tumor pyroptosis to enhance immunotherapy has not been characterized. We synthesized a mitochondria-targeting polymer micelle (OPDEA-PDCA), in which poly[2-(N-oxide-N,N-diethylamino)ethyl methacrylate] (OPDEA) was used to target mitochondria and the conjugated dichloroacetate (DCA) was used to inhibit pyruvate dehydrogenase kinase 1 (PDHK1). This conjugate induced pyroptosis through initiation of mitochondrial oxidative stress. We found that OPDEA-PDCA targeted mitochondria and induced mitochondrial oxidative stress through the inhibition of PDHK1, resulting in immunogenic pyroptosis in osteosarcoma cell lines. Moreover, we showed that OPDEA-PDCA could induce secretion of soluble programmed cell death-ligand 1 (PD-L1) molecule. Therefore, combined therapy with OPDEA-PDCA and an anti-PD-L1 monoclonal antibody significantly suppressed proliferation of osteosarcoma with prolonged T cell activation. This study provided a strategy to initiate pyroptosis through targeted modulation of mitochondria, which may promote enhanced antitumor efficacy in combination with immunotherapy.

HIF-1α-mediated augmentation of miRNA-18b-5p facilitates proliferation and metastasis in osteosarcoma through attenuation PHF2

Extensive evidence has explored the involvement of microRNAs (miRNAs) in osteosarcoma (OS). Limitedly, the concrete function of microRNA-18b-5p (miR-18b-5p) in OS remains unexplored and largely elusive. Here, we validated that miR-18b-5p significantly elevated in OS via analyzing the data from GEO database. The results showed that miR-18b-5p was overexpressed in human OS tissues and cell lines. The clinical evidence suggested that high level of miR-18b-5p was negatively correlated with the poor prognosis of OS. Meanwhile, miR-18b-5p upregulation facilitated the proliferation and metastasis of OS cells in vitro and in vivo. The mechanism exploration demonstrated that miR-18b-5p acted as a potential inhibitor of PHF2, a tumor suppressor gene, at post-transcriptional level. Moreover, hypoxia induced gene expression of miR-18b-5p was clarified to be transcriptionally mediated by HIF-1α. The clinicopathological analysis in samples of OS patients further supported that miR-18b-5p had a positive correlation with HIF-1α expression, and negative correlation with PHF2. Collectively, the present study uncovered a new molecular mechanism of OS tumorigenesis and development and miR-18b-5p might be a prognostic biomarker and potential therapeutic target for OS treatment.

Abstract 988: Epigenetic upregulation of neuropilin-1 promotes osteosarcoma progression and metastasis

Abstract Background: Osteosarcoma (OS) frequently metastasizes to lung and the prognosis for these patients is grim with 5-year overall survival rates as low as 30%. There has been little change in the treatment paradigm for this disease and new targeted therapies are an urgent and unmet clinical need. Previously, we showed that the epigenetic regulators, histone deacetylase 1 and 2 (HDAC1 and 2) are key mediators of OS progression and lung metastasis and that the HDAC1/2 selective inhibitor (romidepsin) significantly prevented OS lung metastasis in vivo. Yet, inhibition of HDACs by romidepsin has noted toxicities in humans and here we define the potential mechanisms through which HDAC1/2 mediate their effects in a bid to identify additional therapeutic targets. Methods: Human OS cell lines were treated with vehicle or romidepsin for 24h before undergoing RNA/protein isolation for microarray/proteomics to identify differentially regulated genes. Standard siRNA, proliferation, migration and molecular analyses were preformed to investigate the role of candidate genes in OS malignant behavior. Results: Microarray/proteomics analyses on romidepsin treated OS cells identified neuropilin-1 (NRP1), a membrane bound co-receptor for vascular endothelial growth factor, to be highly downregulated in response to romidepsin; (<70% compared to vehicle in multiple OS cell lines). NRP1 knockdown (siRNA) led to reduced cell proliferation and interestingly, increased cell migration. Further, a phosphokinase array revealed increased phosphorylation in eNOS, ERK 1/2 and β-catenin in NRP1 knockdown cells that is consistent with a role for NRP1 in regulating OS migration. Based on this data, we hypothesize that NRP1 is a significant regulator of OS proliferation and migration. Our next steps will be to dissect the role of NRP1 silencing in OS invasion and metastasisin vivo and the potential role of NRP1 in OS differentiation. Conclusions: HDAC1/2 contributes to OS growth potentially via the upregulation of NRP1, a therapeutically actionable target. Citation Format: Niveditha Nerlakanti, Jeremy Mcguire, Diana Yu, Damon Reed, Conor C. Lynch. Epigenetic upregulation of neuropilin-1 promotes osteosarcoma progression and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 988.

Expression of Concern: Exosomes function as nanoparticles to transfer miR-199a-3p to reverse chemoresistance to cisplatin in hepatocellular carcinoma.

The Editorial Office has been made aware of potential issues surrounding the scientific validity of this paper, including identical image panels that appear across multiple publications. Figure panels 3C and 3D contains identical images with the following papers: ‘The Long Non-coding RNA LINC01705 Regulates the Development of Breast Cancer by Sponging miR-186-5p to Mediate TPR Expression as a Competitive Endogenous RNA’ (Figure panels 7C and 7D respectively; https://doi.org/10.3389/fgene.2020.00779), ‘Circular RNA circ-0016068 Promotes the Growth, Migration, and Invasion of Prostate Cancer Cells by Regulating the miR-330-3p/BMI-1 Axis as a Competing Endogenous RNA’ (Figure 2C and 2D respectively; https://doi.org/10.3389/fcell.2020.00827), and ‘LncRNA SNHG4 promotes osteosarcoma proliferation and migration by sponging miR‐377‐3p’ (Figure 2D; https://doi.org/10.1002%2Fmgg3.1349). Figure panels 3E and 3F share identical images with those of article ‘Long Non-Coding RNA ELFN1-AS1 Promoted Colon Cancer Cell Growth and Migration via the miR-191-5p/Special AT-Rich Sequence-Binding Protein 1 Axis’ Figure panel 3C (https://doi.org/10.3389%2Ffonc.2020.588360). The authors have been contacted with regards to these concerns.

Retraction: Up-Regulation of MiR-300 Promotes Proliferation and Invasion of Osteosarcoma by Targeting BRD7.

Retraction: Up-Regulation of MiR-300 Promotes Proliferation and Invasion of Osteosarcoma by Targeting BRD7.

Polydatin Incorporated in Polycaprolactone Nanofibers Improves Osteogenic Differentiation.

Polycaprolactone nanofibers are used as scaffolds in the field of tissue engineering for tissue regeneration or drug delivery. Polycaprolactone (PCL) is a biodegradable hydrophobic polyester used to obtain implantable nanostructures, which are clinically applicable due to their biological safety. Polydatin (PD), a glycosidic precursor of resveratrol, is known for its antioxidant, antitumor, antiosteoporotic, and bone regeneration activities. We aimed to use the osteogenic capacity of polydatin to create a biomimetic innovative and patented scaffold consisting of PCL-PD for bone tissue engineering. Both osteosarcoma cells (Saos-2) and mesenchymal stem cells (MSCs) were used to test the in vitro cytocompatibility of the PD-PCL scaffold. Reverse-phase (RP) HPLC was used to evaluate the timing release of PD from the PCL-PD nanofibers and the MTT assay, scanning electron microscopy, and alkaline phosphatase (ALP) activity were used to evaluate the proliferation, adhesion, and cellular differentiation in both osteosarcoma and human mesenchymal stem cells (MSCs) seeded on PD-PCL nanofibers. The proliferation of osteosarcoma cells (Saos-2) on the PD-PCL scaffold decreased when compared to cells grown on PLC nanofibers, whereas the proliferation of MSCs was comparable in both PCL and PD-PCL nanofibers. Noteworthy, after 14 days, the ALP activity was higher in both Saos-2 cells and MSCs cultivated on PD-PCL than on empty scaffolds. Moreover, the same cells showed a spindle-shaped morphology after 14 days when grown on PD-PCL as shown by SEM. In conclusion, we provide evidence that nanofibers appropriately coated with PD support the adhesion and promote the osteogenic differentiation of both human osteosarcoma cells and MSCs.

Quercetin encapsulated in folic acid-modified liposomes is therapeutic against osteosarcoma by non-covalent binding to the JH2 domain of JAK2 Via the JAK2-STAT3-PDL1

Osteosarcoma (OS) is a malignant solid tumor prone to lung metastasis that occurs in adolescents aged 15–19 years. Neoadjuvant chemotherapy and surgical treatment aimed at curing OS have gained limited progress over the last 30 years. Exploring new effective second-line therapies for OS patients is a serious challenge for researchers. Quercetin, a multiple biologically active polyphenolic flavonoid, has been used in tumor therapy. However, the exact mechanism of quercetin is still unknown, which limits the application of quercetin. In the current study, we found that quercetin could inhibit JAK2 through the JH2 domain in a non-covalent manner, resulting in the inhibition of OS proliferation and immune escape via the JAK2-STAT3-PD-L1 signaling axis. More importantly, to overcome the shortcomings of quercetin, including low water solubility and low oral availability, we encapsulated it with folic acid-modified liposomes. The transportation of quercetin by folic acid-modified liposomes may provide a feasible strategy to cure OS.

Licochalcone B Induced Apoptosis and Autophagy in Osteosarcoma Tumor Cells via the Inactivation of PI3K/AKT/mTOR Pathway.

Licochalcone B (LicB) is a flavonoid derived from the Chinese medicinal herb Glycyrrhiza uralensis Fisch. Several previous studies have demonstrated the wide range of pharmacological activities shown by LicB. In this study, we investigated the anticancer effects of LicB in osteosarcoma (OS) tumor cells and its underlying mechanisms. According to the Cell Counting Kit-8 (CCK8) analysis and 5-ethynil-2'-deoxyuridine (EdU) staining results, we found that LicB suppresses OS cells (MG-63 and U2OS) growth depending on its concentration. Furthermore, flow cytometry and Western blot revealed that LicB promoted autophagy and apoptosis in OS cells in a dose-dependent manner. LicB treatment not only decreased the levels of Bcl-2, p62, Caspase-3, and Ki67 protein in MG-63 and U2OS cell lines but also increased the levels of Cleaved Caspase-3, Beclin1, Bax, Atg7, and LC3B. Mechanistically, LicB induced cell apoptosis by promoting the apoptosis-related cleavage of Caspase-3, while suppressing the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway to induce autophagy. The present work is the first to illustrate that LicB can serve as a potential drug candidate for tumor treatment owing to its ability to enhance autophagy and apoptosis, and suppress OS proliferation by inactivating the PI3K/AKT/mTOR pathway.

PTBP1 as a Promising Predictor of Poor Prognosis by Regulating Cell Proliferation, Immunosuppression, and Drug Sensitivity in SARC.

Background Sarcomas (SARC) have been found as rare and heterogeneous malignancies with poor prognosis. PTBP1, belonging to the hnRNPs family, plays an essential role in some biological functions (e.g., pre-mRNA splicing, cell growth, and nervous system development). However, the role of PTBP1 in SARC remains unclear. In this study, the aim was to investigate the potential role of PTBP1 with a focus on SARC. Methods The expression, prognostic value, possible biological pathways of PTBP1, and its relationship with immune infiltration and drug sensitivity were comprehensively analyzed based on multiple databases. PTBP1 was further validated in osteosarcoma as the most prominent bone SARC. The expression of PTBP1 was investigated through IHC. The prognostic value of PTBP1 was verified in TARGET-OS databases. CRISPR/Cas9-mediated PTBP1 knockout HOS human osteosarcoma cell lines were used to assess the effect of PTBP1 on cell proliferation, migration, metastasis and cell cycle by CCK-8, Transwell migration, invasion, and FACS experiment. Result PTBP1 was highly expressed and significantly correlated with poor prognosis in several cancers, especially in SARC, which was validated in the clinical cohort and osteosarcoma cell lines. The genetic alteration of PTBP1 was found most frequently in SARC. Besides, PTBP1 played a role in oncogenesis and immunity through cell cycle, TGFB, autophagy, and WNT pathways at a pan-cancer level. Knockout of PTBP1 was observed to negatively affect proliferation, migration, metastasis, and cell cycle of osteosarcoma in vitro. Furthermore, PTBP1 was significantly correlated with tumor immune infiltration, DNA methylation, TMB, and MSI in a wide variety of cancers. Moreover, the potential of the expression level of PTBP1 in predicting drug sensitivity was assessed. Conclusions PTBP1 is highly expressed and correlated with prognosis and plays a vital pathogenic role in oncogenesis and immune infiltration of various cancers, especially for SARC, which suggests that it may be a promising prognostic marker and therapeutic target in the future.

CircKIF4A enhances osteosarcoma proliferation and metastasis by sponging MiR-515-5p and upregulating SLC7A11

BackgroundCircular RNAs (circRNAs) are forms of non-coding RNAs that have crucial roles in regulation of various biological processes of several malignant tumors. circKIF4A is closely associated with malignant progression of a variety of cancers. However, the molecular mechanisms as well as roles of circKIF4A in osteosarcoma (OS) have not yet been clearly elucidated.MethodsWe evaluated the expression of circKIF4A in OS. Colony-formation, cell counting kit-8 (CCK-8), transwell and mice metastasis model assays were done to explore the roles of circKIF4A in vitro and in vivo. TargetScan database, double luciferase, quantitative reverse transcription polymerase chain reaction analysis (RT-qPCR), and RNA immunoprecipitation (RIP) were done to investigate the associated molecular mechanisms.ResultsIn both OS cells and tissues, circKIF4A (hsa_circ_0007255) was found to be upregulated. In vitro and in vivo, circKIF4A knockdown markedly suppressed OS proliferation as well as metastasis. circKIF4A enhanced OS growth as well as metastasis by sponging miR-515-5p and by upregulating SLC7A11.ConclusionsWe identified the biological significance of the circKIF4A-miR-515-5p-SLC7A11 axis in OS cell proliferation and metastasis, which is important in OS monitoring and treatment. More studies on circKIF4A will inform on the diagnostic markers for early OS screening.Graphical abstract