Search Results (404)

Background/Objectives: Tamoxifen, a selective estrogen receptor modulator widely used as an adjunct in the treatment of breast cancer, has known effects on bone metabolism, although its impact on osseointegration and cellular responses during early bone healing remains unclear. Understanding these effects is essential given the increasing use of dental implants in cancer survivors. The study aimed to observe the influence of tamoxifen on human osteosarcoma (SAOS-2) cells lines, as well on the osseointegration of titanium implants in ovariectomized female rats. Methods: SAOS-2 cells were incubated with Dulbecco’s modified growth medium. Six titanium (Ti) disks were used at each time point. The samples were divided into groups with the presence (TAM, n = 36) or not (CTR, n = 36) of tamoxifen in a concentration of 2 μM. In vivo, 72 animals were divided in groups with bilateral ovariectomy or SHAM and tamoxifen administration or not (15 mg/kg). Cell viability, mineralization rate, and collagen synthesis were assessed, as well as bone/implant contact (BIC) and bone ingrowth (BIN). Results: Tamoxifen caused a decrease in SAOS-2 viability, although an increase in the mineralization rate was observed. In vivo, the TAM groups presented higher BIC and BIN when compared to their control, but a lower percentage of mature collagen cells. Conclusions: Based on our findings, in vitro, the therapy with TAM slightly reduced the viability of SAOS-2 cells while significantly increasing the mineralization rate. In vivo, the therapy positively influenced BIC and BIN during the osseointegration phase. Full article

Stress granule formation is a type of liquid–liquid phase separation in the cytoplasm, leading to RNA–protein condensates that are associated with various cellular stress responses and implicated in numerous pathologies, including cancer, neurodegeneration, inflammation, and cellular senescence. One of the key components of mammalian stress granules is the DEAD-box RNA helicase DDX3, which unwinds RNA in an ATP-dependent manner. DDX3 is involved in multiple steps of RNA metabolism, facilitating gene transcription, splicing, and nuclear export and regulating cytoplasmic translation. In this study, we investigate the role of the RNA helicase DDX3’s enzymatic activity in shaping the RNA content of ribonucleoprotein (RNP) condensates formed during arsenite-induced stress by inhibiting DDX3 activity with RK-33, a small molecule previously shown to be effective in cancer clinical studies. Using the human osteosarcoma U2OS cell line, we purified the RNP granule fraction and performed RNA sequencing to assess changes in the RNA pool. Our results reveal that RK-33 treatment alters the composition of non-coding RNAs within the RNP granule fraction. We observed a DDX3-dependent increase in circular RNA (circRNA) content and alterations in the granule-associated intronic RNAs, suggesting a novel role for DDX3 in regulating the cytoplasmic redistribution of non-coding RNAs. Full article

Bioactive glass materials have been used for decades in orthopedic surgery, traumatology, and oral and maxillofacial surgery to repair bone defects. This study aimed to evaluate in vitro the survival and proliferation of MG63 human osteosarcoma-derived cells on S53P4 bioactive glass (BonAlive^® granules). Microscopic visualization was performed to directly observe the interactions between the cells and the material. Osteoblast-like cells were examined on non-adherent test plates, on tissue culture (TC)-treated plates and on the surface of the bioglass to assess the differences. Cell survival and proliferation were monitored using a CCK-8 optical density assay. Comparing the mean OD of MG63 cells in MEM on TC-treated plates with cells on BG, we detected a significant difference (p < 0.05), over each time of observation. The sustained cell proliferation confirmed the non-cytotoxic property of the bioglass, as the cell number increased continuously at 48, 72, 96, and 168 h and even did not plateau after 168 h. Since the properties of bioglasses can vary significantly depending on their composition and environment, a thorough characterization of their biocompatibility is crucial to ensure their effective and appropriate application—for example, during hip and knee prosthesis insertion. Full article

Background: Osteosarcoma (OS) is the most common primary malignant bone tumor. Doxorubicin (DOX) is extensively used in OS chemotherapy, yet improving patient outcomes remains challenging. This study investigated the effect of free DOX combined with inductive moderate hyperthermia (IMH) on Saos-2 human OS cells. Methods: Cell viability was assessed by trypan blue exclusion. Flow cytometry analyzed apoptosis, necrosis, and reactive oxygen species (ROS) in cells exposed to control (no treatment), IMH (42 MHz frequency, 500 μT magnetic field induction, 564 V/m electric field strength, 15 W output power, and 30 min duration) alone, DOX (0.06 μg/mL) alone, or DOX combined with IMH. The expression of p14^ARF tumor suppressor and epidermal growth factor receptor (EGFR) was evaluated by immunocytochemistry. Spatial autocorrelation analysis quantified the heterogeneity of p14^ARF and EGFR distributions in acquired images. Results: The half maximal inhibitory concentration (IC₅₀) of DOX in Saos-2 cells had minimal variation between 48 h (0.060 ± 0.01 μg/mL) and 72 h (0.055 ± 0.003 μg/mL). DOX + IMH resulted in a 15% increase in early apoptosis and a 20% elevation in ROS levels compared with DOX alone. Immunocytochemical analysis revealed a 37% increase in p14^ARF and a 32% reduction in EGFR expression following combined treatment in comparison to DOX alone. Image analysis showed that DOX + IMH treatment caused the highest Moran’s index values for p14^ARF and EGFR, reflecting less heterogeneous spatial distributions (p < 0.05). Conclusions: IMH enhanced DOX-induced cytotoxicity in Saos-2 cells by initiating ROS-mediated apoptosis and reducing heterogeneity of cellular responses. Full article

STRAP (serine-threonine kinase receptor-associated protein), a WD domain-containing 38.5 kDa protein, was first identified in TGF-ß signaling and participates in scaffold formation in numerous cellular multiprotein complexes. It is involved in the regulation of several oncogenic biological processes, including cell proliferation, apoptosis, migration/invasion, tumor initiation and progression, and metastasis. STRAP upregulation in epithelial tumors regulates several signaling pathways, such as TGF-ß, MEK/ERK, Wnt/β-Catenin, Notch, PI3K, NF-κB, and ASK-1 in human cancers, including colon, breast, lung, osteosarcoma, and neuroblastoma. The upregulation of STRAP expression is correlated with worse survival in colorectal cancer following post-adjuvant therapy. Strap knockout sensitizes colon tumors to chemotherapy, delays APC-induced tumor progression, and reduces cancer cell stemness. The loss of Strap disrupts lineage differentiation, delays neural tube closure, and alters exon skipping, resulting in early embryonic lethality in mice. Collectively, the purpose of this review is to update and describe the diversity of targets functionally interacting with STRAP and to rationalize the involvement of STRAP in a variety of signaling pathways and biological processes. Therefore, these in vitro and in vivo studies provide a proof of concept that lowering STRAP expression in solid tumors decreases tumorigenicity and metastasis, and targeting STRAP provides strong translational potential to develop pre-therapeutic leads. Full article

A histological evaluation remains the cornerstone of diagnosing highly malignant osteosarcoma, having demonstrated its efficacy and reliability over several decades. However, despite these advancements, misdiagnoses with severe consequences, including inadequate surgical procedures, continue to occur. Consequently, there is a pressing need to further enhance diagnostic security. Adjunct immunohistochemical approaches have demonstrated significant effectiveness in regard to cancer diagnostics, generally. However, their utility for identifying highly malignant osteosarcoma is limited. Molecular genetic findings have significantly improved the diagnosis of Ewing’s sarcoma by identifying specific translocations and have been used to detect specific IDH gene mutations in chondrosarcoma. Nevertheless, molecular genetic alterations in highly malignant osteosarcoma exhibit a high degree of complexity, thereby limiting their diagnostic utility. Given that only 1–2% of the human genome comprises protein-coding sequences, the growing number of non-coding regulatory RNAs, which are increasingly being elucidated, has garnered substantial attention in the field of clinical cancer diagnostics. Over the past several years, patterns of altered non-coding RNA expression have been identified that facilitate the distinction between benign and malignant tumors in various organs. In the field of bone tumors, the experience of this approach has been limited thus far. The divergent expression of microRNAs has demonstrated utility for differentiating osteosarcoma from osteoblastoma and discriminating between osteosarcoma and giant-cell tumors of bone and fibrous dysplasia. However, the application of non-coding RNA expression patterns for the differential diagnosis of osteosarcoma is still in its preliminary stages. This review provides an overview of the current status of non-coding RNAs in osteosarcoma diagnostics, in conjunction with a histological evaluation. The potential of this approach is discussed comprehensively. Full article

Background and Objectives: Osteosarcoma is a primary malignant bone tumor characterized by the proliferation of malignant mesenchymal cells and primarily affects children and adolescents. Hesperidin (Hes) interacts with various cellular targets and inhibits cancer cell proliferation by inducing apoptosis. However, the precise mechanisms underlying Hes-induced cell death in osteosarcoma cells remain unclear. This study aimed to investigate the effects of Hes and cisplatin (Cis) on the Bax/Bcl-2 apoptotic pathway in osteosarcoma cells. Materials and Methods: The human osteosarcoma cell line U2OS (Uppsala 2 Osteosarcoma) was treated with IC₅₀ concentrations of Hes and Cis for 48 h. Changes in the mRNA expression levels of Bax, Bcl-2, Caspase-3, and Survivin—key regulators of apoptosis—were analyzed using quantitative real-time PCR (qPCR). The synergistic and/or antagonistic interactions of the Hes and Cis combination were evaluated using Combenefit v2.021 software (Cambridge, UK). Results: The dose–response curve for Hes revealed a gradual reduction in cell viability, with an IC₅₀ value of 106 µM, while the IC₅₀ value for Cis was 4.83 µM. The levels of the inflammatory cytokines IL-1β, TNF-α, and IFN-γ were significantly decreased in the treatment groups compared to the control (p = 0.01). IL-6 levels also showed a marked decrease, particularly in the Hes and Cis groups, with high statistical significance (p = 0.002). Treatment with Hes and Cis significantly upregulated the mRNA expression of Bax and Caspase-3, while significantly downregulating Bcl-2 and Survivin mRNA levels (p < 0.05). Notably, Bax expression was highest in the Hes + Cis combination group. The combination treatment exhibited enhanced cytotoxicity, especially at higher concentrations, indicating a synergistic effect between the two compounds. Conclusions: This study is the first to demonstrate that Hes induces apoptosis in U2OS osteosarcoma cells and that its combination with Cis may enhance anticancer efficacy by activating apoptosis-related cell death pathways. Given the growing focus on combination therapies and cell death mechanisms in cancer research, these findings provide valuable insights into potential novel strategies for osteosarcoma treatment. Full article

Dysregulation of protein kinases is associated with developmental defects and various human diseases. The human kinome comprises 518 kinases, including several orphan kinases whose functions remain to be fully characterized. The NKF4 family, which includes STK35L1 and PDIK1L, is one such uncharacterized kinase family. STK35L1, also known as Clik1, was initially identified as a nuclear kinase associated with actin fibers. Subsequent studies have demonstrated that STK35L1 plays critical roles in cellular processes such as cell cycle regulation, migration, angiogenesis, the DNA damage response, and related processes such as spermatogenesis. STK35L1 has also been implicated in various developmental processes and its knockout mice exhibited defects in the testis, ovary, and eye. STK35L1 acts as a central regulator of the fundamental cellular functions, and its dysregulation leads to various diseases. Research has established that STK35L1 regulates tumor growth and proliferation in cancers such as osteosarcoma, colorectal cancer, and acute myeloid leukemia. Notably, it also affects chemosensitivity in colorectal cancer and metabolism in acute myeloid leukemia. Additionally, STK35L1 is crucial for the infection of hepatocytes by Plasmodium sporozoites during the liver stage of Malaria. This review discusses the current understanding of STK35L1, highlighting its role in various diseases. Full article

The Polydimethylsiloxane (PDMS) SlipChip is a microfluidic platform enabling fluid manipulation without pumps or valves, simplifying operation and reducing reagent use. High-viscosity silicone oils (e.g., 5000–10,000 cSt) improve sealing but frequently block microfluidic channels, reducing usability. In contrast, low-viscosity oils (50–100 cSt) reduce blockages but may compromise sealing. This study addresses these challenges by optimizing the viscosity of silicone oil and the curing conditions of PDMS. Low-viscosity silicone oil (50 cSt) was identified as optimal, ensuring smooth slipping and reliable sealing without blockages. Curing conditions were also adjusted to balance adhesion and stiffness as follows: lower temperatures (50–60 °C) enhanced van der Waals adhesion, while higher temperatures (80 °C) increased stiffness. A mixed curing approach (80 °C for the top layer and 60 °C for the bottom layer) further improved performance. Biocompatibility testing using human osteosarcoma cells demonstrated minimal cytotoxicity with 50 cSt oil, supporting cell viability (95%) comparable to traditional multiwell plates. These findings provide practical guidelines for fabricating reliable and biocompatible SlipChips. Full article

Background/Objectives: Osteosarcoma (OSA) is the most common bone cancer, characterized by rapid progression and poor prognosis. The isothiocyanate sulforaphane (SFN), has gained scientific interest because of its potent anticancer properties. The aim of this study was to conduct a systematic review of research examining the effectiveness of SFN as a treatment for OSA. Methods: A literature search was conducted using MEDLINE, EMBASE, and Web of Science. Studies evaluating the therapeutic efficacy of SFN on OSA were included, while studies examining the effects of isothiocyanates other than SFN were excluded. The quality of the studies was evaluated using the OHAT risk of bias rating tool, and the meta-analysis was conducted using RevMan. Cancer-related outcomes evaluated included cell viability/migration/invasion, cell cycle arrest, apoptosis induction, antioxidant activity, colony formation, and tumour size. A protocol describing the review plan was registered to INPLASY (INPLASY202530001). Results: Ten articles were considered eligible for qualitative synthesis and meta-analysis. All articles included in vitro studies, with two also incorporating in vivo studies, utilizing a combination of human, canine, and murine OSA cell lines. This review indicates that SFN could be beneficial in the treatment of OSA, particularly by reducing cell viability, inducing apoptosis, arresting the cell cycle, and decreasing invasiveness and migration. It emphasizes dose-dependent effects, the need for human trials, and highlights limitations like study heterogeneity and SFN’s bioavailability challenges. Conclusions: This review explores SFN’s potential in OSA at the preclinical stage, focusing on cell apoptosis and proliferation. It highlights promising evidence but calls for more human trials. This research received no external funding. Full article

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents. Unfortunately, drug resistance limits the efficacy of chemotherapeutic treatment and compromises therapeutic outcomes in a substantial proportion of cases. Aberrant CpG island methylation-associated transcriptional silencing contributes to chemoresistance in pediatric solid tumors. Here, using whole-genome DNA methylation screening on 16 human primary OS specimens, we identify receptor interacting protein kinase-3 (RIPK3), a molecular regulator of the necroptosis programmed cell death pathway, as a gene target of aberrant CpG methylation and demonstrate its role in human OS chemoresistance. We validated these findings via enforced expression and DsiRNA silencing, and evaluated the role of RIPK3 in cisplatin chemosensitivity and necroptosis activation through MLKL phosphorylation. We found that CpG island methylation results in RIPK3 silencing in primary human OS samples and cell lines. Enforced RIPK3 expression significantly enhanced cisplatin cytotoxicity in OS cells and DsiRNA knockdown reversed the cisplatin-sensitive phenotype. In cells with enforced RIPK3 expression, cisplatin treatment significantly increased phosphorylation of both RIPK3 and its target, MLKL, indicative of induction of necroptosis. Here, we identify RIPK3 as an important mediator of chemoresistance in OS and a potential pharmacologic target to improve chemotherapy efficacy in drug-resistant tumors. Full article

A series of 3-azabicyclo[3.1.0]hexanes and cyclopropa[a]pyrrolizidines spiro-fused to acenaphthylene-1(2H)-one and aceanthrylene-1(2H)-one frameworks have been studied for their in vitro antiproliferative activity against human erythroleukemia (K562), cervical carcinoma (HeLa), melanoma (Sk-mel-2), osteosarcoma (U2OS), as well as murine melanoma (B16) cell lines. Using confocal microscopy, it was found that cultivation with the tested spiro-fused compounds led to the disappearance of stress fibers (granular actin was distributed diffusely in the cytoplasm in up to 56% of treated cells) and decrease in filopodia-like deformations (up to 69% after cultivation), which indirectly suggests a decrease in cell motility. The human melanoma cell line scratch test showed that these cells lose their ability to move after cultivation with the tested spiro-fused compounds and do not fill the scratched strip. This was also supported by docking simulations with actin-related targets (PDB ID: 8DNH, 2Q1N). Using flow cytometry, the impact on the mitochondrial membrane potential showed that the tested compounds led to a significant increase in the number of cells with decreased mitochondrial membrane potential from 10% for the control up to 55–80% for the cyclopropa[a]pyrrolizidine adducts. The obtained results support the antitumor effect of the tested spiro-compounds and encourage the extension of the study in order to improve their anticancer activity as well as reduce their toxicological risks. Full article

Myelodysplastic syndrome (MDS) is a heterogeneous myeloid clonal disorder that represents a significant threat to human health. As₂S₂, a natural compound, has been shown to exert therapeutic effects on various malignant tumors, including acute myeloid leukemia (AML), breast cancer, and osteosarcoma, based on extensive clinical experience. In this study, we investigated the mechanism by which As₂S₂ inhibits the proliferation of the myelodysplastic syndrome (MDS) SKM-1 cell line. Our findings revealed that As₂S₂ inhibited the proliferation of SKM-1 cells in a time- and dose-dependent manner. Flow cytometry, protein immunoblotting, and real-time fluorescence quantitative PCR analyses demonstrated that As₂S₂ promotes the phosphorylation of P38 MAPK, thereby activating the MAPK signaling pathway. Additionally, it promotes apoptosis by increasing the BAX/Bcl-2 ratio and induces S-phase arrest through the downregulation of the cell cycle-related protein cyclin A2. Further studies demonstrated that As₂S₂-treated cells exhibited ROS accumulation under fluorescence microscopy, along with activation of the P38 MAPK signaling pathway, increased apoptosis, and S-phase arrest in the cell cycle. This process could be partially reversed by the ROS inhibitor N-acetylcysteine. Therefore, the results of the present study suggest that As₂S₂ induces ROS accumulation in SKM-1 cells, which contributes to the activation of the P38 MAPK signaling pathway, promoting apoptosis and S-phase arrest in the cell cycle. Additionally, As₂S₂ may serve as a potent therapeutic agent for the treatment of myelodysplastic syndromes, with ROS acting as one of the key therapeutic targets. Full article

This review summarizes the findings of veterinary clinical trials on immunogene therapy published between 2017 and 2024. Various tumor types, including melanoma (canine and feline), mastocytoma (canine), mammary adenocarcinoma (canine), osteosarcoma (canine), and sarcoid (equine), were treated using diverse strategies. Non-viral vectors were predominantly used to deliver genes encoding tumor-associated antigens, cytokines, or suicide enzymes. Among these non-viral methods, electrotransfer was the most commonly employed technique for introducing therapeutic genes into cells. Generally, these procedures resulted in minimal or no adverse side effects, and treated animals often showed significant improvements, such as enhanced quality of life, delayed or suppressed tumor recurrence or metastasis, and increased survival times. Some of these innovative approaches hold great potential as adjunct therapies to standard treatments. The promising outcomes from immunogene therapy studies in companion animals strongly support their application in veterinary oncology and provide valuable preclinical data (including safety assessments and proof-of-concept studies) for analogous human clinical trials. Full article