Promote Apoptosis Of Osteosarcoma Cells Research Articles

Mometasone furoate inhibits tumor progression and promotes apoptosis through activation of the AMPK/mTOR signaling pathway in osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor in adolescents. While treatments for osteosarcoma have improved, the overall survival has not changed for three decades, and thus, new targets for therapeutic development are needed. Recently, glucocorticoids have been reported to have antitumor effects. Mometasone furoate (MF), a synthetic glucocorticoid, is of great value in clinical application, but there are few reports on its antitumor effect. Here, we verified the effect of MF on osteosarcoma in vitro and in vivo. In vitro, cell proliferation, cell cycle progression, apoptosis and cell metastasis were detected using Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, wound-healing and transwell assays, respectively. In vivo, we generated a xenograft mouse model. To examine the potential role of the AMPK pathway, an AMPK-specific inhibitor (dorsomorphin) was used. The expression levels of factors related to the cell cycle, apoptosis and activation of the AMPK/mTOR pathway were assessed by immunohistochemistry and Western blotting. MF inhibited proliferation and metastasis and induced S phase arrest and apoptosis in osteosarcoma cells in a dose-dependent manner. In vivo, MF effectively inhibited osteosarcoma cell growth and pulmonary metastasis; however, it had no negative effect on the internal organs. Additionally, MF could activate the AMPK/mTOR pathway in osteosarcoma. Dorsomorphin significantly attenuated MF-induced antitumor activities. In summary, MF can inhibit osteosarcoma proliferation and metastasis and promote osteosarcoma cell apoptosis through the AMPK/mTOR signaling pathway in vitro and in vivo, which can provide a new rationale for subsequent academic and clinical research on osteosarcoma treatment.

3D-Printed Magnesium Peroxide-Incorporated Scaffolds with Sustained Oxygen Release and Enhanced Photothermal Performance for Osteosarcoma Multimodal Treatments.

The hypoxic microenvironment in osteosarcoma inevitably compromises the antitumor effect and local bone defect repair, suggesting an urgent need for sustained oxygenation in the tumor. The currently reported oxygen-releasing materials have short oxygen-releasing cycles, harmful products, and limited antitumor effects simply by improving hypoxia. Therefore, the PCL/nHA/MgO2/PDA-integrated oxygen-releasing scaffold with a good photothermal therapy effect was innovatively constructed in this work to achieve tumor cell killing and bone regeneration functions simultaneously. The material distributes MgO2 powder evenly on the scaffold material through 3D printing technology and achieves the effect of continuous oxygen release (more than 3 weeks) through its slow reaction with water. The in vitro and in vivo results also indicate that the scaffold has good biocompatibility and sustained-release oxygen properties, which can effectively induce the proliferation and osteogenic differentiation of bone mesenchymal stem cells, achieving excellent bone defect repair. At the same time, in vitro cell experiments and subcutaneous tumorigenesis experiments also confirmed that local oxygen supply can promote osteosarcoma cell apoptosis, inhibit proliferation, and reduce the expression of heat shock protein 60, thereby enhancing the photothermal therapy effect of polydopamine and efficiently eliminating osteosarcoma. Taken together, this integrated functional scaffold provides a unique and efficient approach for antitumor and tumor-based bone defect repair for osteosarcoma treatment.

Network pharmacology-based research on the effect of angelicin on osteosarcoma and the underlying mechanism.

To explore the antitumor effects of angelicin on osteosarcoma and the underlying mechanism. We aimed to elucidate the mechanism by network pharmacology, molecular docking, and in vitro experiments. We analyzed a PPI network of potential angelicin targets in the treatment of osteosarcoma and identified hub targets. We systematically performed GO and KEGG enrichment analyses of the potential targets of angelicin, and we predicted it function in osteosarcoma treatment and the underlying molecular mechanism. Through molecular docking, the interactions between hub targets and angelicin were simulated, and then, the hub targets of angelicin were identified. Based on these results, we validated the effects of angelicin on osteosarcoma cells by conducting in vitro experiments. The PPI network analysis of potential therapeutic targets identified four apoptosis-related hub targets, namely, BCL-2, Casp9, BAX and BIRC 2. GO and KEGG enrichment analyses demonstrated that angelicin regulates osteosarcoma cell apoptosis. Molecular docking results indicated that angelicin can freely bind to the hub targets listed above. In vitro experiments showed that angelicin promoted osteosarcoma cell apoptosis in a dose-dependent manner and inhibited osteosarcoma cell migration and proliferation in a time- and dose-dependent manner. The RT-PCR results showed that angelicin simultaneously promoted the mRNA expression of Bcl-2 and Casp9 and inhibited the mRNA expression of BAX and BIRC 2. Angelicin promotes osteosarcoma cell apoptosis and inhibits osteosarcoma cell proliferation and migration by activating a signaling network that is composed of hub targets that link multiple signaling pathways. Angelicin could become an alternative drug for the treatment of osteosarcoma.

Comprehensive analysis of hypoxia-related genes for prognosis value, immune status, and therapy in osteosarcoma patients.

Osteosarcoma is a common malignant bone tumor in children and adolescents. The overall survival of osteosarcoma patients is remarkably poor. Herein, we sought to establish a reliable risk prognostic model to predict the prognosis of osteosarcoma patients. Patients ' RNA expression and corresponding clinical data were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Gene Expression Omnibus databases. A consensus clustering was conducted to uncover novel molecular subgroups based on 200 hypoxia-linked genes. A hypoxia-risk models were established by Cox regression analysis coupled with LASSO regression. Functional enrichment analysis, including Gene Ontology annotation and KEGG pathway analysis, were conducted to determine the associated mechanisms. Moreover, we explored relationships between the risk scores and age, gender, tumor microenvironment, and drug sensitivity by correlation analysis. We identified two molecular subgroups with significantly different survival rates and developed a risk model based on 12 genes. Survival analysis indicated that the high-risk osteosarcoma patients likely have a poor prognosis. The area under the curve (AUC) value showed the validity of our risk scoring model, and the nomogram indicates the model's reliability. High-risk patients had lower Tfh cell infiltration and a lower stromal score. We determined the abnormal expression of three prognostic genes in osteosarcoma cells. Sunitinib can promote osteosarcoma cell apoptosis with down-regulation of KCNJ3 expression. In summary, the constructed hypoxia-related risk score model can assist clinicians during clinical practice for osteosarcoma prognosis management. Immune and drug sensitivity analysis can provide essential insights into subsequent mechanisms. KCNJ3 may be a valuable prognostic marker for osteosarcoma development.

Carvacrol Suppresses Human Osteosarcoma Cells via the Wnt/β-Catenin Signaling Pathway.

Carvacrol is a monoterpenic phenol extracted from traditional Chinese herbs, including oregano and thyme. Currently, carvacrol has been widely studied for its therapeutic role in central nervous system diseases, liver diseases and digestive system cancer. However, the role of carvacrol in osteosarcoma and its underlying molecular mechanism remain elusive. Here, we aimed to examine the anticancer effects of carvacrol on osteosarcoma. The effects of carvacrol on the osteosarcoma proliferation capacity were revealed by CCK-8 and colony formation assays. Flow cytometry and Hoechst assays were used to determine the effects of carvacrol on osteosarcoma cell apoptosis. The effect of carvacrol on migration and invasion of osteosarcoma cells was determined by wound healing and transwell tests. Protein expression was evaluated by WB assays. The suppressive effects of carvacrol on osteosarcoma in vivo were examined by a xenograft animal model, immunohistochemistry and HE staining. We demonstrated that carvacrol treatment reduced viability and inhibited the colony formation of U2OS and 143B cells in a concentration-dependent manner. Apoptotic cell number increased after exposure to carvacrol. Meanwhile, the expression of Bax increased, and that of Bcl-2 decreased by carvacrol treatment. In addition, the MMP-9 expression and migration and invasion of 143B and U2OS cells were inhibited by carvacrol. We also found that these carvacrol-induced effects on osteosarcoma are associated with the regulation of the Wnt/β-catenin signaling pathway. Our findings suggest that carvacrol suppresses proliferation, migration, invasion and promotes apoptosis in osteosarcoma cells, in part by regulating the Wnt/β-catenin signaling pathway.

Discovery of 2-Amino-3-cyanothiophene Derivatives as Potent STAT3 Inhibitors for the Treatment of Osteosarcoma Growth and Metastasis.

Osteosarcoma is one of the most common malignant bone tumors. However, the treatment and clinical outcomes of osteosarcoma have hardly changed over the past three decades due to the comprehensive heterogeneity and higher rate of mutation of osteosarcoma. Recent studies have shown that STAT3 has the potential to suppress the proliferation and metastasis of osteosarcoma. In this study, a novel class of 2-amino-3-cyanothiophene derivatives were designed and synthesized to inhibit osteosarcoma by targeting STAT3. Representative compound 6f showed potent antiproliferative effects against osteosarcoma cells, directly bound to the STAT3 SH2 domain with a KD of 0.46 μM, and inhibited the phosphorylation of STAT3 Y705 in a dose-dependent manner. Furthermore, compound 6f promoted osteosarcoma cell apoptosis in vitro and significantly suppressed the growth and metastasis of osteosarcoma in vivo. These findings demonstrate that targeting STAT3 may be a feasible therapeutic strategy for the treatment of metastatic osteosarcoma.

Epigallocatechin-3-gallate suppresses the growth of human osteosarcoma by inhibiting the Wnt/β-catenin signalling pathway

ABSTRACT Osteosarcoma (OS) is one of the most common malignant tumors in adolescents. Due to local invasion, distant metastasis and drug resistance, the clinical treatment efficacy and prognosis of OS have remained almost unchanged for decades. Epigallocatechin-3-gallate (EGCG) is a unique catechin from tea leaves, and some studies have confirmed its antitumour effects on various tumors. Here, cellular experiments showed that EGCG significantly promoted OS cell apoptosis and inhibited proliferation, migration and invasion, and cell and animal experiments demonstrated that the Wnt/β-catenin pathway played an indispensable role in the antitumour effects of EGCG. Moreover, EGCG inhibited the growth of OS cells in vitro while suppressing tumor cell damage to the bone in situ and distant lung metastasis. The results indicate that the antitumour effect of EGCG on human OS may be mediated by regulating the Wnt/β-catenin pathway and that EGCG can be used alone or in combination with other regimens as a potentially effective anticancer treatment.

Cordycepin augments the chemosensitivity of osteosarcoma to cisplatin by activating AMPK and suppressing the AKT signaling pathway

BackgroundOsteosarcoma is the most common primary bone tumor in children and adolescents. However, some patients with osteosarcoma develop resistance to chemotherapy, leading to a poor clinical prognosis. Hence, effective therapeutic agents that can improve the response to chemotherapy drugs to improve the prognosis of patients with osteosarcoma are urgently needed. Cordycepin has recently emerged as a promising antitumor drug candidate. This study aims to explore the effect of cordycepin in suppressing osteosarcoma in vivo and in vitro and the synergistic effect of cordycepin combined with cisplatin and to demonstrate the underlying molecular mechanism.MethodsCCK-8 assay was performed to investigate the inhibition effect of cordycepin combined with cisplatin in osteosarcoma cell lines. The colony formation and invasion abilities were measured by colony formation assay and Transwell assay. Osteosarcoma cells apoptosis was detected by flow cytometry. Western blot analysis were used to detect the expression of cell apoptosis-related proteins and AMPK and AKT/mTOR signaling pathway-related proteins. Finally, we performed the in vivo animal model to further explore whether cordycepin and cisplatin exert synergistic antitumor effects.ResultsNotably, we found that treatment with cordycepin inhibited cell proliferation, invasion, and induced apoptosis in osteosarcoma cells in vitro and in vivo. Moreover, the combination of cordycepin and cisplatin led to marked inhibition of osteosarcoma cell proliferation and invasion and promoted osteosarcoma cell apoptosis in vitro and in vivo. Mechanistically, we demonstrated that cordycepin enhanced the sensitivity of osteosarcoma cells to cisplatin by activating AMPK and inhibiting the AKT/mTOR signaling pathway.ConclusionsIn brief, this study provides comprehensive evidence that cordycepin inhibits osteosarcoma cell growth and invasion and induces osteosarcoma cell apoptosis by activating AMPK and inhibiting the AKT/mTOR signaling pathway and enhances the sensitivity of osteosarcoma cells to cisplatin, suggesting that cordycepin is a promising treatment for osteosarcoma.

TRIM59 promotes osteosarcoma progression via activation of STAT3.

Osteosarcoma (OS) is a common, highly malignant bone tumor. Tripartite motif-containing protein 59 (TRIM59) has been identified as a potential oncogenic protein involved in the initiation and progression of various human carcinomas. Nonetheless, the possible roles and molecular mechanisms of action of TRIM59 in OS remain unclear. In this study, we found that TRIM59 expression levels were frequently upregulated in OS tissues and cell lines. TRIM59 knockdown significantly suppressed the proliferation, migration, and invasion of OS cells and promoted OS cell apoptosis, whereas TRIM59 overexpression had the opposite effects. In vivo experiments demonstrated that TRIM59 knockdown suppressed OS tumor growth and metastasis in vivo. Furthermore, we found that TRIM59 directly interacted with phospho-STAT3 in OS cells. The downregulation of STAT3 levels attenuated TRIM59-induced cell proliferation and invasion. Taken together, our results indicate that TRIM59 promoted OS progression via STAT3 activation. Therefore, our study may provide a novel therapeutic target for OS.

Sestrin2-Mediated Autophagy Contributes to Drug Resistance via Endoplasmic Reticulum Stress in Human Osteosarcoma.

One contributor to the high mortality of osteosarcoma is its reduced sensitivity to chemotherapy, but the mechanism involved is unclear. Improving the sensitivity of osteosarcoma to chemotherapy is urgently needed to improve patient survival. We found that chemotherapy triggered apoptosis of human osteosarcoma cells in vitro and in vivo; this was accompanied by increased Sestrin2 expression. Importantly, autophagy was also enhanced with increased Sestrin2 expression. Based on this observation, we explored the potential role of Sestrin2 in autophagy of osteosarcoma. We found that Sestrin2 inhibited osteosarcoma cell apoptosis by promoting autophagy via inhibition of endoplasmic reticulum stress, and this process is closely related to the PERK-eIF2α-CHOP pathway. In addition, our study showed that low Sestrin2 expression can effectively reduce autophagy of human osteosarcoma cells after chemotherapy, increase p-mTOR expression, decrease Bcl-2 expression, promote osteosarcoma cell apoptosis, and slow down tumour progression in NU/NU mice. Sestrin2 activates autophagy by inhibiting mTOR via the PERK-eIF2α-CHOP pathway and inhibits apoptosis via Bcl-2. Therefore, our results explain one underlying mechanism of increasing the sensitivity of osteosarcoma to chemotherapy and suggest that Sestrin2 is a promising gene target.

MicroRNA-382-5p inhibits osteosarcoma development and progression by negatively regulating VEZF1 expression.

Human osteosarcoma is the most frequent malignant primary bone tumor that mainly occurs in young adults and children. MicroRNAs (miRNAs/miRs) are abnormally expressed in human osteosarcoma and contribute to osteosarcoma initiation and development. The present study aimed to investigate the role of miR-382-5p in the nosogenesis of osteosarcoma and to identify a novel target for osteosarcoma treatment. miR-382-5p expression was detected in human osteosarcoma clinical tissues and cell lines, including 143B, U2OS and MG63, via reverse transcription-quantitative PCR analysis. Multiple bioinformatic prediction toowe used to identify the potential target genes of miR-382-5p and vascular endothelial zinc finger 1 (VEZF1), which were validated via the dual-luciferase reporter assay. MG63 and U2OS cells were transfected with miR-382-5p mimics. The Cell Counting Kit-8 assay was performed to assess cell proliferation, while the Transwell assay was performed to assess migration and invasion. Cell colony formation was measured via crystal violet staining, and apoptosis was assessed via Annexin V/propidium iodide staining. The wound healing assay was performed to assess the migratory ability of U2OS and MG63 cells. Antitumor effects of miR-382-5p were evaluated in nude mice xenografts using U2OS cells. The results demonstrated that miR-382-5p expression was markedly downregulated in human osteosarcoma tissues and cell lines compared with adjacent normal tissues. Transfection of miR-382-5p mimics into MG63 and U2OS cells significantly inhibited the malignant behaviors of cells, including decreased proliferation, migration, diminished colony formation and invasion, and promoted osteosarcoma cell apoptosis. Bioinformatics prediction indicated that VEZF1 is a direct target gene of miR-382-5p. Overexpression of VEZF1 restored osteosarcoma tumor development inhibited by miR-382-5p in vivo. In addition, overexpression of miR-382-5p restrained the growth of xenograft osteosarcoma in nude mice following co-transfection, and overexpression of VEZF1 attenuated the inhibitory effect of miR-382-5p in nude mice. miR-382-5p acted as a tumor suppressor gene and inhibited the malignant biological behaviors of human osteosarcoma cells and functions associated with directly targeting VEZF1. Taken together, these results suggest that the miR-382-5p/VEZF1 interaction has an important role in osteosarcoma development and progression, and thus may be used as a diagnostic and therapeutic target for osteosarcoma.

PolyphyllinVII induces apoptosis and autophagy via mediating H2O2 levels and the JNK pathway in human osteosarcoma U2OS cells.

Polyphyllin VII, a compound extracted from the rhizomes of Paris polyphylla, has strong antitumor effects on various human tumor cell lines. However, few studies have reported the possible effect of Polyphyllin VII on human osteosarcoma (OS) cell lines. The present study revealed that Polyphyllin VII promoted OS cell apoptosis and inhibited cell proliferation via upregulating the expression of LC3II, Atg5, Atg7 and the Atg12-Atg5 complex. By contrast, treatment of OS cells with Polyphyllin VII downregulated Atg12 and p62 expression. Following treatment with class III PI 3-kinase inhibitor (3-MA; an autophagy inhibitor), the Polyphyllin VII-mediated apoptotic effect was reversed. These findings indicated that the inhibition of autophagy could attenuate U2OS cell apoptosis in cells treated with high concentrations of Polyphyllin VII. The present study also demonstrated that Polyphyllin VII upregulated the intracellular hydrogen peroxide (H2O2) levels in U2OS cells. However, treatment of U2OS cells with N-acetyl-L cysteine (NAC) effectively reversed this effect. The western blot analysis results indicated that the c-Jun N-terminal kinase (JNK) signaling pathway was closely associated with Polyphyllin VII-induced apoptosis and autophagy. In conclusion, the results of the present study demonstrated that Polyphyllin VII could effectively inhibit cell viability and promote autophagy and apoptosis in U2OS cells. In addition, the mechanism underlying these effects could be associated with the intracellular H2O2 levels and the JNK signaling pathway.

Mechanisms of microRNA-19b on osteosarcoma cell proliferation and apoptosis by Targeting Krueppel-like factor 13

Objective To investigate the mechanisms of microRNA-19b on osteosarcoma cell proliferation and apoptosis by Targeting Krueppel-like factor 13 (KLF13). Methods The expression of miR-19b and KLF13 was detected by quantitative Real-time polymerase chain reaction in three human osteosarcoma cell lines (MG-63, US-OS and Saos-2) and one normal human osteoblast cell line (hFOB 1.19). KLF13 as a potential target of miR-19b was predicted by sequence analysis. The viability and apoptosis effects of miR-19 inhibitor on MG-63 cell was assessed by Cell Proliferation Assay and flow cytometry. Luciferase assay and Western blotting were used to examine the regulatory effect. Results The relative expression of miR-19b and KLF13 in osteosarcoma cells (665.66±39.74, 517.75±26.82, 564.88±41.20) were significantly higher than that in normal human osteoblast cell (16.09±4.80) (both P<0.05). Luciferase reporter vector system confirmed that KLF13 was one of the target genes of miR-19b. The absorbance (A) of experiment groups and control group was 0.424±0.021, 0.265±0.016 and 0.783±0.053 respectively by Western blotting. 3-(4, 5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and flow cytometry demonstrated that miR-19b inhibitor significantly inhibited proliferation and promoted apoptosis of MG-63 cell (both P<0.01). Moreover, the anti-proliferation and pro-apoptotic effect by miR-19b inhibitor could be consolidate d by KLF13 knock down. Conclusion Suppression the expression of miR-19b can effectively inhibit the proliferation and promote apoptosis of osteosarcoma cells. miR-19b may become a new target for the regulation of gene expression in osteosarcoma. Key words: Osteosarcoma; MicroRNA-19b; Krueppel-like factor 13; Cell proliferation; Apoptosis

Inhibition of long non-coding RNA-AWPPH decreases osteosarcoma cell proliferation, migration and invasion.

Long non-coding RNAs (lncRNAs) serve a crucial role in various types of cancer. The lncRNA AWPPH has been reported to promote hepatocellular carcinoma and bladder cancer progression. However, to the best of our knowledge, the biological roles of AWPPH in osteosarcoma (OS) remain unclear. In the present study, the levels of AWPPH in OS tissues and cell lines were determined by reverse transcription-quantitative polymerase chain reaction. An MTT assay was used to detect OS cell proliferation. The levels of proteins associated with the PI3K/Akt signaling pathway and apoptosis were determined by western blotting. Wound-healing and Transwell assays were conducted to determine cell migration and invasion, respectively. The results demonstrated that AWPPH was highly expressed in OS tissues and cells. Functional analyses revealed that AWPPH depletion significantly inhibited OS cell proliferation and migration, and promoted OS cell apoptosis. Furthermore, AWPPH downregulation significantly inhibited the PI3K/AKT pathway. The present study demonstrated that AWPPH was highly expressed in OS, and that AWPPH promoted OS cell proliferation and migration, and inhibited OS cell apoptosis, which may be mediated by PI3K/AKT pathway activation.

MicroRNA-377 exerts a potent suppressive role in osteosarcoma through the involvement of the histone acetyltransferase 1-mediated Wnt axis.

It has been demonstrated that microRNAs (miRNAs) may contribute to tumorigenesis and tumor growth in osteosarcoma (OS), which is a primary malignant tumor of bone frequently diagnosed in adolescents and young people. The purpose of our investigation was to evaluate the functional relevance of miR-377 in OS and to investigate whether the mechanism was related to the histone acetyltransferase 1 (HAT1)-mediated Wnt signaling pathway. By screening differentially expressed genes in microarray GSE47572, HAT1 was found to be a candidate gene of interest. Besides, the regulatory miRNA (miR-377) of HAT1 was also selected. The interaction among miR-377, HAT1, and the Wnt signaling pathway was evaluated. In addition, the miR-377 expression was altered in OS cells (U-2OS and SOSP-9607) to assess the in vitro cell apoptosis and the in vivo tumor growth. OS tissues presented elevated HAT1 expression and decreased miR-377 expression. A putative miR-377 binding site in HAT1 3'-UTR HAT1 was verified. Cells with miR-377 overexpression or HAT1 silencing were observed to exhibit reduced HAT1 expression and promoted apoptosis, accompanied by blockade of Wnt signaling. Moreover, the in vivo experiment revealed that miR-377 overexpression or HAT1 silencing inhibited tumor growth and reduced tumor size in nude mice. Taken together, our results conclude that miR-377 may promote OS cell apoptosis through inactivation of the HAT1-mediated Wnt signaling pathway, highlighting the potential therapeutic effect of miR-377 on OS treatment.

MicroRNA‑2682‑3p inhibits osteosarcoma cell proliferation by targeting CCND2, MMP8 and Myd88

Osteosarcoma is the most common primary bone malignancy in children and young adults. It is associated with dysregulation of certain microRNAs (miRNAs/miRs), which provides a target for osteosarcoma therapy. miR-2682-3p expression in osteosarcoma cell lines and tissues was assayed by reverse transcription-quantitative polymerase chain reaction and was upregulated or downregulated by transfection with miRNA mimics or inhibitors. miR-2682-3p was downregulated in osteosarcoma tissues and cell lines, and overexpression of miR-2682-3p inhibited tumor growth. Further studies revealed that cyclin D1 (CCND)2, matrix metalloproteinase (MMP)8, and myeloid differentiation primary response (Myd)88 were the direct targets of miR-2682-3p in osteosarcoma cells. Overexpression of miR-2682-3p promoted osteosarcoma cell apoptosis by targeting CCND2, MMP8, and Myd88, and vice-versa. Therefore, miR-2682-3p may act as a tumor suppressor gene, the downregulation of which contributed to the progression and metastasis of osteosarcoma, to provide a potential therapy target for patients with osteosarcoma.

Inhibitory effect of icariin on osteosarcoma cell proliferation via the Wnt/β-catenin signaling pathway.

Osteosarcoma, is a kind of malignant tumor derived from malignant interstitial cells. The pathogenesis of osteosarcoma remains unclear and despite use of chemotherapy drugs, resistance to these drugs affects the success of treatment. The present study was conducted to investigate the effects of icariin (ICA) on osteosarcoma cell proliferation and to investigate the role of the Wnt/β-catenin signaling pathway in the inhibition process of ICA on osteosarcoma cell proliferation. Different concentrations of ICA were selected to treat the osteosarcoma cell line 143B for 24 h, and then the onset concentration of ICA when it inhibited the growth of osteosarcoma cancer cell line 143B was detected via an MTT assay. The effect of ICA on the apoptosis of colon cancer cell line 143B under this concentration was detected using a flow cytometer. RNA in osteosarcoma cell line 143B was extracted, followed by reverse transcription. The expression levels of related and apoptotic proteins in the Wnt/β-catenin signaling pathway using ICA were detected by semi-quantitative PCR and western blot analysis, respectively. The expression quantities of vascular endothelial growth factor (VEGF) and MMP-9 were detected by ELISA. MTT assay showed that ICA inhibited the growth of 143B when its concentration was 5 µM (p<0.01). Flow cytometry showed that the number of apoptotic cells after ICA treatment was significantly higher than that in control group (p<0.01). RNA in osteosarcoma cell line 143B was extracted, followed by reverse transcription. Semi-quantitative PCR and western blot analysis revealed that the expression levels of p-GSK3β, β-catenin, c-Myc and cyclin D1 in cells after ICA treatment were significantly downregulated (p<0.01), while the expression level of caspase-3 was significantly increased (p<0.01). ELISA showed that the expression quantities of VEGF and MMP-9 were significantly decreased (p<0.01). Thus, ICA can significantly inhibit osteosarcoma cell proliferation and promote osteosarcoma cell apoptosis, which may be realized by affecting the expression of the Wnt/β-catenin signaling pathway and blocking the expression of related proteins.

Long non-coding RNA CTA sensitizes osteosarcoma cells to doxorubicin through inhibition of autophagy.

Recently, several long non-coding RNAs (lncRNAs) have been implicated in osteosarcoma (OS). However, the regulatory roles of lncRNAs in chemotherapy resistance of OS still remain unclear. This study aimed to screen a novel lncRNA that contributes to chemotherapeutic resistance of OS, and to explore the underlying mechanisms. Our data showed that lncRNA CTA was markedly downregulated in OS tissues compared to their matched non-tumor tissues, and low expression of lncRNA CTA was significantly associated with the advanced clinical stage and tumor size. In addition, OS patients with low lncRNA CTA levels showed a worse prognosis when compared with those with high expression of lncRNA CTA. Furthermore, we report that lncRNA CTA has an inverse relationship with miR-210 expression in OS tissues. LncRNA CTA could be activated by doxorubicin (DOX), and could promote OS cell apoptosis by competitively binding miR-210, while inhibit cell autophagy. On the other hand, lncRNA CTA was downregulated in DOX-resistant OS cells. Overexpression of lncRNA CTA reduced autophagy and subsequently overcame DOX resistance of OS in vitro and in vivo. Therefore, we demonstrate that lncRNA CTA is an essential regulator in DOX-induced OS cell apoptosis, and the lncRNA CTA-miR-210 axis plays an important role in reducing OS chemoresistance.