Apoptosis Of Osteosarcoma Cells Research Articles

Tongguanteng injection exerts anti-osteosarcoma effects through the ER stress-associated IRE1/CHOP pathway.

In China, Tongguanteng injection (TGT) is widely used in the treatment or adjuvant treatment of various types of cancer. However, the effect and mechanism of TGT in osteosarcoma is not clear. The 143B and MG-63 cells were treated with different concentrations of TGT. Cell proliferation, migration, invasion and apoptosis were detected using CCK8 assay, transwell assay and flow cytometry. Differentially expressed genes (DEGs) were screened using RNA sequencing (RNA-seq). The identified mRNA and protein expression associated with the IRE1/CHOP pathway was validated by RT-PCR and western blot assay. To explore the underlying mechanisms, 4-phenylbutyric acid (4-PBA) was selected as a specific endoplasmic reticulum (ER) stress inhibitor. Small interfering RNA (siRNA) or pEX-3-ERN1 plasmid was transfected into 143B cells to silence or overexpress IRE1, respectively. The potential downstream proteins, including CHOP, and apoptosis associated proteins, caspase-3 and PARP1 were determined. Furthermore, the effect of TGT was demonstrated in 143B cell tumor-bearing mice in vivo. H&E staining, TUNEL staining and immunohistochemistry were conducted in tumor tissues obtained from the xenograft mouse model. TGT was shown to dramatically suppress the proliferation, migration and invasion, and induce apoptosis of osteosarcoma 143B and MG-63 cells in vitro. The identified DEGs included HSPA5 (encoding BiP) and ERN1 (encoding the IRE1 protein), as well as apoptosis-associated gene DDIT3 (encoding the CHOP protein). The term "IRE1-mediated unfolded protein response" was screened to be the most enriched biological process GO term. The expression of ER stress-associated proteins including ATF6, BiP, p-IRE1, XBP1s and CHOP, as well as apoptosis-associated cleaved caspase-3 and cleaved PARP1 proteins, was significantly upregulated by TGT treatment in osteosarcoma 143B cells, suggesting that TGT might promote the apoptosis of osteosarcoma 143B cells through the IRE1/CHOP pathway. Furthermore, knocking down IRE1 with si-IRE1 or inhibiting of ER stress with 4-PBA suppressed the expression of ATF6, BiP, XBP1s and CHOP induced by TGT, as well as the expression of cleaved caspase-3 and cleaved PARP1. On the contrary, overexpressing IRE1 promoted CHOP expression and induced osteosarcoma cell apoptosis. Consistent with in vitro results, TGT dramatically inhibited the tumor growth and promoted the expression of p-IRE1 and CHOP in tumor-bearing mice. The findings suggest that TGT exerts an anti-osteosarcoma effect in vitro and in vivo. The underlying mechanism might be associated with the activation of IRE1/CHOP pathway in ER stress. Our findings suggest that targeting IRE1/CHOP pathway might be a potential novel approach for osteosarcoma treatment.

CD47 in Osteosarcoma: Correlation with Metastasis and Macrophage-Mediated Phagocytosis

CD47 is expressed on cell surfaces and acts as a “don’t eat me” signal by interacting with signal-regulatory protein-α on the macrophage surface. Some cancer cells express CD47 protein and can evade macrophage phagocytosis. Herein, we evaluated the feasibility of targeting CD47 for osteosarcoma by analyzing its expression patterns, clinicopathological correlations, and immunotherapeutic potential. We performed a retrospective analysis on 24 biopsy samples from patients with osteosarcoma to investigate correlations between CD47 protein positivity and clinicopathological characteristics. CD47 protein expression was detected in 20.8% of the biopsy samples. CD47 positivity correlated with metastasis at diagnosis. Patients with CD47-positive tumors were older than those with CD47-negative tumors. However, CD47 protein expression was not associated with sex, tumor size, or histologic response to preoperative chemotherapy. In vitro, CD47 antibody (B6H12) did not affect osteosarcoma cell viability or apoptosis. In a wound-healing assay, CD47 inhibited the migration of osteosarcoma cells. Differentiated macrophages exhibited higher phagocytic activity against osteosarcoma cells when pretreated with B6H12 compared with the isotype control. Our preliminary data suggest a possible interaction between CD47 protein and macrophage phagocytosis in osteosarcoma metastasis. A better understanding of the role of CD47 is necessary to develop an innovative immunotherapeutic approach against osteosarcoma.

Trifluoperazine exerts anti-osteosarcoma effect by inducing mitochondria-dependent apoptosis via AKT/TXNIP signaling pathway

The survival rates for patients with osteosarcoma (OS) have stagnated over the past few decades. It is essential to find new therapies and drugs. A licensed antipsychotic medication called trifluoperazine (TFP) significantly reduces the growth of several cancers. However, the exact molecular pathways of TFP in OS remain to be discovered. Our research revealed that TFP greatly reduced OS cell migration and growth and caused the arrest of G0/G1 cell cycle. Combined with RNA-Seq data and further research, we confirmed that TFP promoted reactive oxygen species (ROS) production by elevating thioredoxin binding protein (TXNIP) expression to induce mitochondria-dependent apoptosis. Interestingly, we first demonstrated that AKT was an upstream regulatory target of TXNIP in OS cells. Dephosphorylation of AKT led to an increase in TXNIP expression, further elucidating the anticancer mechanism of TFP. In vivo, TFP inhibited subcutaneous OS cell proliferation and induced OS cell apoptosis without noticeable side effects. In conclusion, our findings imply that TFP is a potential treatment for OS.

Green Synthesis and Characterization of Hydroxyapatite Nanorods with Enhanced Antibacterial and Anticancer Properties

This study reports the microwave synthesis of hydroxyapatite nanorods using Lantana camara L. flower extract (LCF-HA) and characterized by FTIR, XRD, TEM and SEM-EDX techniques. The extract coating on the hydroxyapatite nanorods improves the antibacterial efficacy against Gram-positive bacteria. The study also evaluates the mitochondrial membrane potential (MMP), generation of reactive oxygen species (ROS) and capacity to induce apoptosis of LCF-HA. It shows that LCF-HA efficiently inhibits the growth of osteosarcoma cells (MG-63) in a dose-dependent manner. The efficacy of LCF-HA in inducing apoptosis in osteosarcoma cells is established by dual acridine orange/ethidium bromide (AO/EB) fluorescence labelling. Additionally, LCF-HA induces an increase in reactive oxygen species (ROS) generation and a reduction in mitochondrial membrane potential (MMP) levels. The findings indicate that derived LCF-HA has significant anticancer efficacy by inducing apoptosis in osteosarcoma cells through enhanced ROS generation, suggesting that derived LCF-HA may serve as a promising therapeutic target for bone cancer cell lines. Furthermore, the study demostrates excellent compatibility with osteoblast cells, highlighting its potential for bone regeneration applications.

Arnicolide D Inhibits Proliferation and Induces Apoptosis of Osteosarcoma Cells through PI3K/Akt/mTOR Pathway.

Osteosarcoma is considered as the most prevalent form of primary malignant bone cancer, prompting a pressing need for novel therapeutic options. Arnicolide D, a sesquiterpene lactone derived from the traditional Chinese herbal medicine Centipeda minima (known as E Bu Shi Cao in Chinese), showed anticancer efficacy against several kinds of cancers. However, its effect on osteosarcoma remains unclear. This study aimed to investigate the anticancer activity of arnicolide D and the underlying molecular mechanism of its action in osteosarcoma cells, MG63 and U2OS. Cell viability and proliferation were evaluated through MTT assay and colony formation assay following 24 h and 48 h treatment with different concentrations of arnicolide D. Flow cytometry was employed to examine cell cycle progression and apoptosis after 24 h treatment of arnicolide D. Western blotting was performed to determine the expression of the PI3k, Akt and m-TOR and their phosphorylated forms. Our findings revealed that arnicolide D treatment resulted in a significant reduction in cell viability, the inhibition of proliferation, and the induction of apoptosis and cell cycle arrest in the G2/M phase. Furthermore, arnicolide D could inhibit the activation of PI3K/Akt/mTOR pathway in osteosarcoma cells. Based on our results, arnicolide D demonstrated significant anti-osteosarcoma activity and held the potential to be considered as a therapeutic candidate for osteosarcoma in the future.

Disulfiram Upgrades the Radiosensitivity of Osteosarcoma by Enhancing Apoptosis and P53-Induced Cell Cycle Arrest.

The prognosis of osteosarcoma has not been improved for decades. As radioresistance is one of the major reasons, effective radiotherapy sensitization drugs need to be discovered. HOS and K7M2 osteosarcoma cell lines were treated with disulfiram (DSF) and radiation to assess cell viability, proliferation, migration ability, apoptosis level, ROS and Ca2+ level, and cell cycle in vitro. A HOS-derived subcutaneous tumor mouse model was constructed to evaluate tumor growth after DSF combined with radiation, and the Tunel assay and immunohistochemistry of Ki67 were conducted. Western blot was used to evaluate the protein expression level. The IC50 and working concentration of DSF in osteosarcoma cell lines were ascertained. When combined with radiation, DSF effectively suppressed cell viability, proliferation, and migration, while enhancing apoptosis in osteosarcoma cells. The cell cycle postirradiation exhibited a downward shift in the G1 phase, but the addition of DSF counteracted this trend. The combination of DSF and radiation exhibited inhibitory effects on tumor growth invivo, which was corroborated by Ki67 staining and Tunel assay. Western blot analysis revealed that DSF upregulated the expression of P53, P21, CDKN2C, BAX, and cleaved Caspase-3 while downregulating BCL2, CDK4/6, and CyclinD1 after irradiation. Our results document that DSF exerts its radiosensitization effects invivo and in vitro, and is a valuable radiosensitizing drug option for osteosarcoma. The radiosensitization effect is mainly achieved by activating the apoptotic pathway and promoting cell cycle arrest induced by P53/P21 and CDKN2C after irradiation.

RETRACTION: Zebularine Enhances Apoptosis of Human Osteosarcoma Cells by Suppressing Methylation of ARHI.

K. Ye, S. Wang, J. Wang, H. Han, B. Ma and Y. Yang, "Zebularine Enhances Apoptosis of Human Osteosarcoma Cells by Suppressing Methylation of ARHI," Cancer Science 107, no. 12 (2016): 1851-1857, https://doi.org/10.1111/cas.13088. The above article, published online on 29 September 2016 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Masanori Hatakeyama; the Japanese Cancer Association; and John Wiley & Sons Australia, Ltd. The retraction has been agreed following an investigation into concerns raised by a third party, which revealed that the western blots presented in figure4a and 4d contain duplicated bands. Furthermore, duplications were found between bands within figure4d itself, some of which appear to have been horizontally flipped. The authors did not respond to the concerns raised and did not provide their original data. The editors consider the results and conclusion reported in this article unreliable.

GNAS, not a Highly Mutated Gene, Has Prognostic Significance and Carcinogenic Effects in Osteosarcoma.

Osteosarcoma is a prevalent and aggressive primary malignant bone tumor affecting children and adolescents. Despite advancements in sequencing technologies, there remains a lack of reliable prognostic biomarkers and effective targeted therapies for osteosarcoma. This study focuses on identifying key prognostic genes, particularly the role of GNAS, in osteosarcoma progression. Bioinformatics analyses were performed on osteosarcoma datasets from the Gene Expression Omnibus (GEO). Differential gene expression analysis, weighted correlation network analysis (WGCNA), and survival analysis identified potential prognostic hub genes. The expression and function of these genes were validated through immunohistochemistry and animal experiments. Specifically, the role of GNAS was investigated through siRNA-mediated knockdown in osteosarcoma cell lines and nude mice models. Five hub genes (PROP1, GNAS, CYP4F2, LHX3, CNGB1) were identified as significantly related to osteosarcoma prognosis. Among these, GNAS was found to be highly expressed in osteosarcoma tissues compared to normal tissues. Immunohistochemical analysis confirmed the elevated expression of GNAS in osteosarcoma samples. GNAS mutation analysis revealed a low mutation rate in osteosarcoma, suggesting its oncogenic role is independent of mutational status. Animal experiments demonstrated that knocking down GNAS significantly inhibited tumor growth and induced apoptosis in osteosarcoma cells. GNAS is highly expressed in osteosarcoma and associated with poor prognosis, acting as an oncogene in osteosarcoma progression. Targeting GNAS could be a potential therapeutic strategy for osteosarcoma. Further studies on GNAS-related signaling pathways may provide deeper insights into the molecular mechanisms driving osteosarcoma malignancy.

Groenlandicine enhances cisplatin sensitivity in cisplatin-resistant osteosarcoma cells through the BAX/Bcl-2/Caspase-9/Caspase-3 pathway

Groenlandicine is a protoberberine alkaloid isolated from Coptidis Rhizoma, a widely used traditional Chinese medicine known for its various biological activities. This study aims to validate groenlandicine’s effect on both cisplatin-sensitive and cisplatin-resistant osteosarcoma (OS) cells, along with exploring its potential molecular mechanism.The ligand-based virtual screening (LBVS) method and molecular docking were employed to screen drugs. CCK-8 and FCM were used to measure the effect of groenlandicine on the OS cells transfected by lentivirus with over-expression or low-expression of TOP1. Cell scratch assay, CCK-8, FCM, and the EdU assay were utilized to evaluate the effect of groenlandicine on cisplatin-resistant cells. WB, immunofluorescence, and PCR were conducted to measure the levels of TOP1, Bcl-2, BAX, Caspase-9, and Caspase-3. Additionally, a subcutaneous tumor model was established in nude mice to verify the efficacy of groenlandicine.Groenlandicine reduced the migration and proliferation while promoting apoptosis in OS cells, effectively damaging them. Meanwhile, groenlandicine exhibited weak cytotoxicity in 293T cells. Combination with cisplatin enhanced tumor-killing activity, markedly activating BAX, cleaved-Caspase-3, and cleaved-Caspase-9, while inhibiting the Bcl2 pathway in cisplatin-resistant OS cells. Moreover, the level of TOP1, elevated in cisplatin-resistant OS cells, was down-regulated by groenlandicine both in vitro and in vivo. Animal experiments confirmed that groenlandicine combined with cisplatin suppressed OS growth with lower nephrotoxicity.Groenlandicine induces apoptosis and enhances the sensitivity of drug-resistant OS cells to cisplatin via the BAX/Bcl-2/Caspase-9/Caspase-3 pathway. Groenlandicine inhibits OS cells growth by down-regulating TOP1 level.Therefore, groenlandicine holds promise as a potential agent for reversing cisplatin resistance in OS treatment.

Ezetimibe Inhibits Cell Viability and Invasion by Suppressing PI3K/AKT Signaling Pathway in Human Osteosarcoma Cells

Introduction: Osteosarcoma is one of the most prevalent malignant bone tumors with a poor overall prognosis and mainly happens in children and adolescents. Current therapy strategies still possess a lot of limitations, and new and efficient strategies are required. Ezetimibe was previously reported to have its anti-tumor effect in various tumors, but the investigation of Ezetimibe on osteosarcoma is still limited. Aims: This study explores whether ezetimibe could exert an anti-tumor effect on human osteosarcoma cell lines, U2OS, and Saos-2. Methods: The effect of ezetimibe on the proliferation of osteosarcoma was explored by CCK-8 and colony formation assay. The role of ezetimibe on osteosarcoma cell migration and invasion was explored by wound healing assay and transwell assay. The role of ezetimibe on osteosarcoma cell apoptosis was explored by PI/Annexin V analysis. In addition, a western blot was performed to verify the phenotype. Results: The flow cytometry assay indicated that ezetimibe could promote osteosarcoma apoptosis. Western blot assay further demonstrated the effect of ezetimibe on proliferation, migration, invasion and apoptosis- related proteins. Finally, the deep anti-tumor effect of ezetimibe contributed to suppressing the PI3K/AKT signaling pathway. Conclusion: Present data indicated that ezetimibe has an antitumor effect on osteosarcoma and could be considered a future osteosarcoma treatment.

Circular RNA circMRPS35 represses malignant progression in osteosarcoma cells via targeting miR-105-5p/FOXO1.

Osteosarcoma is a highly metastatic, aggressive bone cancer that occurs in children and young adults worldwide. Circular RNAs (circRNAs) are crucial molecules for osteosarcoma progression. In this study, we aimed to investigate the impact of circMRPS35 overexpression and its interaction with FOXO1 via evaluating apoptosis, cell cycle, and bioinformatic analyses on the malignant development of osteosarcoma in MG63 and MNNG/HOS cells. We found that circMRPS35 overexpression reduced osteosarcoma cell viability and inhibited tumor growth in vivo. It increased the apoptosis rate and induced cell cycle arrest in osteosarcoma cells. We identified a potential interaction between circMRPS35 and FOXO1 with miR-105-5p using bioinformatics analysis. Overexpression of circMRPS35 decreased miR-105-5p expression, whereas miR-105-5p mimic treatment increased its expression. This mimic also suppressed the luciferase activity of circMRPS35 and FOXO1 and reduced FOXO1 expression. Overexpression of circMRPS35 elevated FOXO1 protein levels, but this effect was reversed by co-treatment with the miR-105-5p mimic. We demonstrated that inhibiting miR-105-5p decreased viability and induced apoptosis. Overexpression of FOXO1 or treatment with a miR-105-5p inhibitor could counteract the effects of circMRPS35 on viability and apoptosis in osteosarcoma cells. Therefore, we concluded that circMRPS35 suppressed the malignant progression of osteosarcoma via targeting the miR-105-5p/FOXO1 axis.

MiR-488-3p Represses Malignant Behaviors and Facilitates Autophagy of Osteosarcoma Cells by Targeting Neurensin-2.

Osteosarcoma (OS) is a primary bone sarcoma that primarily affects children and adolescents and poses significant challenges in terms of treatment. microRNAs (miRNAs) have been implicated in OS cell growth and regulation. This study sought to investigate the role of hsa-miR-488-3p in autophagy and apoptosis of OS cells. The expression of miR-488-3p was examined in normal human osteoblasts and OS cell lines (U2OS, Saos2, and OS 99-1) using RT-qPCR. U2OS cells were transfected with miR-488- 3p-mimic, and cell viability, apoptosis, migration, and invasion were assessed using CCK-8, flow cytometry, and Transwell assays, respectively. Western blotting and immunofluorescence were employed to measure apoptosis- and autophagy-related protein levels, as well as the autophagosome marker LC3. The binding sites between miR-488-3p and neurensin-2 (NRSN2) were predicted using online bioinformatics tools and confirmed by a dual-luciferase assay. Functional rescue experiments were conducted by co-transfecting miR-488-3p-mimic and pcDNA3.1-NRSN2 into U2OS cells to validate the effects of the miR-488-3p/NRSN2 axis on OS cell behaviors. Additionally, 3-MA, an autophagy inhibitor, was used to investigate the relationship between miR- 488-3p/NRSN2 and cell apoptosis and autophagy. miR-488-3p was found to be downregulated in OS cell lines, and its over-expression inhibited the viability, migration, and invasion while promoting apoptosis of U2OS cells. NRSN2 was identified as a direct target of miR-488-3p. Over-expression of NRSN2 partially counteracted the inhibitory effects of miR-488-3p on malignant behaviors of U2OS cells. Furthermore, miR- 488-3p induced autophagy in U2OS cells through NRSN2-mediated mechanisms. The autophagy inhibitor 3-MA partially reversed the effects of the miR-488-3p/NRSN2 axis in U2OS cells. Our findings demonstrate that miR-488-3p suppresses malignant behaviors and promotes autophagy in OS cells by targeting NRSN2. This study provides insights into the role of miR-488-3p in OS pathogenesis and suggests its potential as a therapeutic target for OS treatment.

Small Nuclear Ribonucleoprotein Polypeptides B and B1 Promote Osteosarcoma Progression via Activating the Ataxia-Telangiectasia Mutated Signaling Pathway through Ribonucleotide Reductase Subunit M2

Osteosarcoma is a malignant bone tumor characterized by high metastatic potential and recurrence rates post-therapy. The small nuclear ribonucleoprotein polypeptides B and B1 (SNRPB), a core component of spliceosome, have been reported to exhibit upregulation across several cancer types. However, the precise role of SNRPB in osteosarcoma progression remains poorly elucidated. Herein, we explored SNRPB expression in human osteosarcoma tissues and normal bone tissues by immunohistochemical staining (IHC) staining, revealing a notable upregulation of SNRPB in osteosarcoma, correlating with diminished survival rates. Moreover, the in vitro loss-of-function experiments showed that SNRPB knockdown significantly suppressed the osteosarcoma cell proliferation and migration, as well as tubule formation of HUVECs, while enhancing osteosarcoma cell apoptosis. Mechanistically, we revealed that SNRPB promoted the transcription of ribonucleotide reductase subunit M2 (RRM2) via E2F transcription factor 1 (E2F1). Further rescue experiments indicated that RRM2 was required for SNRPB-induced malignant behaviors in osteosarcoma. Additionally, we confirmed that the function of SNRPB in osteosarcoma cell growth and apoptosis was associated with ATM signaling pathway activation. In conclusion, our findings provide initial insights into the underlying mechanisms governing SNRPB-induced osteosarcoma progression and proposed for SNRPB as a novel therapeutic target in osteosarcoma management.

RNF135 Promotes Human Osteosarcoma Cell Growth and Inhibits Apoptosis by Upregulating the PI3K/AKT Pathway.

Ring finger protein 135 (RNF135) is an E3 ubiquitin ligase that has been implicated in the tumorigenesis of multiple human malignancies. However, whether RNF135 plays a role in the development of human osteosarcoma (OS) remains unknown. RNF135 expression in 20 human OS and 20 human osteochondroma specimens were evaluated by means of immunohistochemistry staining. The effects of shRNA-mediated RNF135 knockdown on human OS cell growth and apoptosis were evaluated through a panel of in vitro studies on cell proliferation, colony formation, exposure of phosphatidylserine on the cell surface, and caspase 3/7 activation. The protein levels of PI3K, AKT, and p-AKT were determined by western blot analysis. We detected significantly higher RNF135 levels in human OS tissues than human osteochondroma tissues. In in vitro studies, shRNA-mediated RNF135 knockdown in human OS cells inhibited proliferation and induced apoptosis. In addition, RNF135 knockdown reduced PI3K and p-AKT protein levels and activated caspase 3 and 7. These results supported that RNF135 contributes to human OS development through PI3K/AKT-dependent mechanisms. Targeting RNF135 may provide a new therapeutic approach for treating this human malignancy.

Modulating tumor-associated macrophage polarization by anti-maRCO mAb exerts anti-osteosarcoma effects through regulating osteosarcoma cell proliferation, migration and apoptosis

PurposeOsteosarcoma is a primary bone tumor lacking optimal clinical treatment options. Tumor-associated macrophages in the tumor microenvironment are closely associated with tumor development and metastasis. Studies have identified the macrophage receptor with collagenous structure (MARCO) as a specific receptor expressed in macrophages. This study aimed to investigate whether anti-MARCO mAb treatment can induce macrophage polarization in the tumor microenvironment and elicit anti-tumor effects.MethodsTHP-1 cells were treated with 20 ng/mL phorbol 12-myristate 13-acetate and 80 ng/mL interleukin-4 for 48 h to induce macrophage polarization to alternatively activated macrophages (M2). Enzyme-linked immunosorbent assay, real-time quantitative polymerase chain reaction, flow cytometry, and bioinformatic analyses were performed to evaluate macrophage polarization. The co-culture groups included a blank group, an M2 macrophage and U2OS co-culture group, and an anti-MARCO mAb-treated M2 macrophage group. Cell viability assays, cell scratch tests, apoptosis, and cell cycle analyses were performed to determine the effects of anti-MARCO mAb-treated macrophages on osteosarcoma cells.ResultsIt was demonstrated that anti-MARCO mAb can drive macrophages toward classically activated macrophage (M1) polarization. Anti-MARCO mAb promoted the secretion of pro-inflammatory factors by macrophages, including tumor necrosis factor-alpha (TNF-α), interleukin-1beta, interleukin-6 and interleukin-23. Studies on in vitro co-culture models have revealed that macrophages treated with anti-MARCO mAb can suppress the growth and migration of osteosarcoma cells, induce cell apoptosis, and inhibit cell cycle progression of osteosarcoma cells through M1 polarization of macrophages in vitro.ConclusionAnti-MARCO mAb treatment exerts anti-osteosarcoma effects by affecting macrophage polarization toward M1 macrophages, offering a potential new therapeutic approach for treating osteosarcoma.

Lycorine combined with cisplatin synergistically inhibited osteosarcoma cells growth and metastasis by suppressing Wnt/β-Catenin and STAT3 signaling pathways

Cisplatin is commonly used in treating osteosarcoma, however, chemoresistance reduces its efficacy and results in a poor prognosis. Lycorine, a Chinese herbal medicine component, possesses anti-tumor and anti-inflammatory properties. This study aims to investigate the combined impact of lycorine and cisplatin on osteosarcoma and its molecular mechanism. The combination of lycorine and cisplatin exhibited a synergistic effect evaluated by MTT and Zheng-Jun Jin’s method. Lycorine and cisplatin synergistically inhibit proliferation, migration, invasion, and induce apoptosis of osteosarcoma cells. Pharmacological analysis predicts 13 key targets, including Wnt/β-Catenin and STAT3. After treatment with this combination, key molecules in Wnt/β-Catenin and STAT3 pathways were significantly inhibited. In an orthotopic tumor model, the combination significantly reduces lung metastasis. The present work suggests that a combination of lycorine with cisplatin can effectively inhibit OS cells by suppressing the Wnt/β-Catenin and STAT3 signaling pathways synergistically. This is expected to enhance the therapeutic effect of OS.

A novel prognostic signature related to programmed cell death in osteosarcoma.

Osteosarcoma primarily affects children and adolescents, with current clinical treatments often resulting in poor prognosis. There has been growing evidence linking programmed cell death (PCD) to the occurrence and progression of tumors. This study aims to enhance the accuracy of OS prognosis assessment by identifying PCD-related prognostic risk genes, constructing a PCD-based OS prognostic risk model, and characterizing the function of genes within this model. We retrieved osteosarcoma patient samples from TARGET and GEO databases, and manually curated literature to summarize 15 forms of programmed cell death. We collated 1621 PCD genes from literature sources as well as databases such as KEGG and GSEA. To construct our model, we integrated ten machine learning methods including Enet, Ridge, RSF, CoxBoost, plsRcox, survivalSVM, Lasso, SuperPC, StepCox, and GBM. The optimal model was chosen based on the average C-index, and named Osteosarcoma Programmed Cell Death Score (OS-PCDS). To validate the predictive performance of our model across different datasets, we employed three independent GEO validation sets. Moreover, we assessed mRNA and protein expression levels of the genes included in our model, and investigated their impact on proliferation, migration, and apoptosis of osteosarcoma cells by gene knockdown experiments. In our extensive analysis, we identified 30 prognostic risk genes associated with programmed cell death (PCD) in osteosarcoma (OS). To assess the predictive power of these genes, we computed the C-index for various combinations. The model that employed the random survival forest (RSF) algorithm demonstrated superior predictive performance, significantly outperforming traditional approaches. This optimal model included five key genes: MTM1, MLH1, CLTCL1, EDIL3, and SQLE. To validate the relevance of these genes, we analyzed their mRNA and protein expression levels, revealing significant disparities between osteosarcoma cells and normal tissue cells. Specifically, the expression levels of these genes were markedly altered in OS cells, suggesting their critical role in tumor progression. Further functional validation was performed through gene knockdown experiments in U2OS cells. Knockdown of three of these genes-CLTCL1, EDIL3, and SQLE-resulted in substantial changes in proliferation rate, migration capacity, and apoptosis rate of osteosarcoma cells. These findings underscore the pivotal roles of these genes in the pathophysiology of osteosarcoma and highlight their potential as therapeutic targets. The five genes constituting the OS-PCDS model-CLTCL1, MTM1, MLH1, EDIL3, and SQLE-were found to significantly impact the proliferation, migration, and apoptosis of osteosarcoma cells, highlighting their potential as key prognostic markers and therapeutic targets. OS-PCDS enables accurate evaluation of the prognosis in patients with osteosarcoma.

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.

Casticin induces ferroptosis in human osteosarcoma cells through Fe2+ overload and ROS production mediated by HMOX1 and LC3-NCOA4

Osteosarcoma is a primary solid bone malignancy, and surgery + chemotherapy is the most commonly used treatment. However, chemotherapeutic drugs can cause a range of side effects. Casticin, a polymethoxyflavonoid, has anti-tumor therapeutic effects. This study is aim to investigate the anti-osteosarcoma activity of casticin and explore the mechanism. Crystal violet staining, MTT assay, colony formation assay, wound healing assay, transwell assay, hoechst 33,258 staining, and flow cytometry analysis were used to investigate the effects of casticin on proliferation, migration, invasion, and apoptosis of osteosarcoma cells in vitro. The intracellular Fe2+, ROS, MDA, GSH/GSSG content changes were detected using the corresponding assay kits. The mRNA sequencing + bioinformatics analysis and western blot were used to detect the possible mechanism. We found that casticin caused G2/M phase cell cycle arrest in human osteosarcoma cells, inhibited the migration and invasion, and induced cell apoptosis and ferroptosis. Mechanistic studies showed the ferroptosis pathway was enriched stronger than apoptosis. Casticin up-regulated the expression of HMOX1, LC3 and NCOA4, meanwhile it activated MAPK signaling pathways. Animal experiments proved that casticin also inhibited the growth and metastasis of osteosarcoma cell xenograft tumor in vivo. In conclusion, casticin can induce ferroptosis in osteosarcoma cells through Fe2+ overload and ROS production mediated by HMOX1 and LC3-NCOA4. This provides a new strategy for osteosarcoma treatment.

System analysis based on Anoikis-related genes identifies MAPK1 as a novel therapy target for osteosarcoma with neoadjuvant chemotherapy

BackgroundOsteosarcoma (OS) is the most common bone malignant tumor in children, and its prognosis is often poor. Anoikis is a unique mode of cell death.However, the effects of Anoikis in OS remain unexplored.MethodDifferential analysis of Anoikis-related genes was performed based on the metastatic and non-metastatic groups. Then LASSO logistic regression and SVM-RFE algorithms were applied to screen out the characteristic genes. Later, Univariate and multivariate Cox regression was conducted to identify prognostic genes and further develop the Anoikis-based risk score. In addition, correlation analysis was performed to analyze the relationship between tumor microenvironment, drug sensitivity, and prognostic models.ResultsWe established novel Anoikis-related subgroups and developed a prognostic model based on three Anoikis-related genes (MAPK1, MYC, and EDIL3). The survival and ROC analysis results showed that the prognostic model was reliable. Besides, the results of single-cell sequencing analysis suggested that the three prognostic genes were closely related to immune cell infiltration. Subsequently, aberrant expression of two prognostic genes was identified in osteosarcoma cells. Nilotinib can promote the apoptosis of osteosarcoma cells and down-regulate the expression of MAPK1.ConclusionsWe developed a novel Anoikis-related risk score model, which can assist clinicians in evaluating the prognosis of osteosarcoma patients in clinical practice. Analysis of the tumor immune microenvironment and chemotherapeutic drug sensitivity can provide necessary insights into subsequent mechanisms. MAPK1 may be a valuable therapeutic target for neoadjuvant chemotherapy in osteosarcoma.