Human γδ T cells induce CD8+ T cell antitumor responses via antigen-presenting effect through HSP90-MyD88-mediated activation of JNK.

Human Vγ9Vδ2 T cells have attracted considerable attention as novel alternative antigen-presenting cells (APCs) with the potential to replace dendritic cells in antitumor immunotherapy owing to their high proliferative capacity and low cost. However, the utility of γδ T cells as APCs to induce CD8+ T cell-mediated antitumor immune response, as well as the mechanism by which they perform APC functions, remains unexplored. In this study, we found that activated Vγ9Vδ2 T cells were capable of inducing robust CD8+ T cell responses in osteosarcoma cells. Activated γδ T cells also effectively suppressed osteosarcoma growth by priming CD8+ T cells in xenograft animal models. Mechanistically, we further revealed that activated γδ T cells exhibited increased HSP90 production, which fed back to upregulate MyD88, followed by JNK activation and a subsequent improvement in CCL5 secretion, leading to enhanced CD8+ T cell cross-priming. Thus, our study suggests that Vγ9Vδ2 T cells represent a promising alternative APC for the development of γδ T cell-based tumor immunotherapy.

An oriented-collagen scaffold including Wnt5a promotes osteochondral regeneration and cartilage interface integration in a rabbit model.

Articular cartilage regeneration remains a major challenge in orthopedics. Noncanonical Wnt5a is a particularly attractive growth factor in this context; Wnt5a inhibits chondrocyte hypertrophy but maintains chondrogenesis. We designed a novel, vertically oriented-collagen scaffold. The effect of Wnt5a on MSCs and chondrocytes and the therapeutic effects of the Wnt5a/oriented-collagen scaffold in terms of osteochondral repair and cartilage integration were evaluated. In vitro, the proliferation, migration, and differentiation of MSCs and chondrocytes treated with Wnt5a, and the mechanisms thereof, were assessed. mRNA microarray analysis was performed to compare the expression profiles of MSCs before and after Wnt5a treatment. In vivo, full-thickness cylindrical osteochondral defects (4 mm in diameter, 3 mm in depth) were created in the patellar grooves of 24 New Zealand white rabbits and implanted with oriented-collagen scaffolds (n = 8), Wnt5a/oriented-collagen scaffolds (n = 8), or nothing (n = 8). After 6 and 12 weeks, integration and tissue responses were evaluated. The proliferation, migration, chondrogenic differentiation, and extracellular matrix formation of/by MSCs and chondrocytes improved greatly after treatment with Wnt5a. Western blotting showed that the PI3K/AKT/JNK signaling pathway was activated. Microarray analysis revealed that the Wnt5a group exhibited a significant upregulation of the PI3K pathway. Reactome GSEA pathway interaction analysis revealed that such upregulation was associated with collagen and extracellular matrix formation. In vivo, the Wnt5a/oriented-collagen scaffold group exhibited optimal interface integration, cartilage regeneration, and collagenous fiber arrangement, accompanied by significantly increased glycosaminoglycan and collagen accumulations in the zones of regeneration and integration, compared to the other groups. Gene expression analysis showed that the levels of mRNAs encoding genes involved in cartilage formation were significantly increased in the Wnt5a/oriented, collagen scaffold group (all P < .05). Wnt5a promoted the proliferation, migration, and chondrogenic differentiation of MSCs and chondrocytes via the activation of the PI3K/AKT/JNK signaling pathway. The Wnt5a/oriented-collagen constructs enhanced the structure-specific regeneration of hyaline cartilage in a rabbit model and may be a promising treatment for the repair of human cartilage defects.

Stachydrine prevents LPS-induced bone loss by inhibiting osteoclastogenesis via NF-κB and Akt signalling.

Osteoclast overactivation-induced imbalance in bone remodelling leads to pathological bone destruction, which is a characteristic of many osteolytic diseases such as rheumatoid arthritis, osteoporosis, periprosthetic osteolysis and periodontitis. Natural compounds that suppress osteoclast formation and function have therapeutic potential for treating these diseases. Stachydrine (STA) is a bioactive alkaloid isolated from Leonurus heterophyllus Sweet and possesses antioxidant, anti-inflammatory, anticancer and cardioprotective properties. However, its effects on osteoclast formation and function have been rarely described. In the present study, we found that STA suppressed receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclast formation and bone resorption, and reduced osteoclast-related gene expression in vitro. Mechanistically, STA inhibited RANKL-induced activation of NF-κB and Akt signalling, thus suppressing nuclear factor of activated T cells c1 induction and nuclear translocation. In addition, STA alleviated bone loss and reduced osteoclast number in a murine model of LPS-induced inflammatory bone loss. STA also inhibited the activities of NF-κB and NFATc1 in vivo. Together, these results suggest that STA effectively inhibits osteoclastogenesis both in vitro and in vivo and therefore is a potential option for treating osteoclast-related diseases.

An On-Demand Collaborative Innate-Adaptive Immune Response to Infection Treatment.

Deep tissue infection is a common clinical issue and therapeutic difficulty caused by the disruption of the host antibacterial immune function, resulting in treatment failure and infection relapse. Intracellular pathogens are refractory to elimination and can manipulate host cell biology even after appropriate treatment, resulting in a locoregional immunosuppressive state that leads to an inadequate response to conventional anti-infective therapies. Here, a novel antibacterial strategy involving autogenous immunity using a biomimetic nanoparticle (NP)-based regulating system is reported to induce in situ collaborative innate-adaptive immune responses. It is observed that a macrophage membrane coating facilitates NP enrichment at the infection site, followed by active NP accumulation in macrophages in a mannose-dependent manner. These NP-armed macrophages exhibit considerably improved innate capabilities, including more efficient intracellular ROS generation and pro-inflammatory factor secretion, M1 phenotype promotion, and effective eradication of invasive bacteria. Furthermore, the reprogrammed macrophages direct T cell activation at infectious sites, resulting in a robust adaptive antimicrobial immune response to ultimately achieve bacterial clearance and prevent infection relapse. Overall, these results provide a conceptual framework for a novel macrophage-based strategy for infection treatment via the regulation of autogenous immunity.

Multiple influence of immune cells in the bone metastatic cancer microenvironment on tumors.

Bone is a common organ for solid tumor metastasis. Malignant bone tumor becomes insensitive to systemic therapy after colonization, followed by poor prognosis and high relapse rate. Immune and bone cells in situ constitute a unique immune microenvironment, which plays a crucial role in the context of bone metastasis. This review firstly focuses on lymphatic cells in bone metastatic cancer, including their function in tumor dissemination, invasion, growth and possible cytotoxicity-induced eradication. Subsequently, we examine myeloid cells, namely macrophages, myeloid-derived suppressor cells, dendritic cells, and megakaryocytes, evaluating their interaction with cytotoxic T lymphocytes and contribution to bone metastasis. As important components of skeletal tissue, osteoclasts and osteoblasts derived from bone marrow stromal cells, engaging in 'vicious cycle' accelerate osteolytic bone metastasis. We also explain the concept tumor dormancy and investigate underlying role of immune microenvironment on it. Additionally, a thorough review of emerging treatments for bone metastatic malignancy in clinical research, especially immunotherapy, is presented, indicating current challenges and opportunities in research and development of bone metastasis therapies.

Osteocyte mitochondria inhibit tumor development via STING-dependent antitumor immunity.

Bone is one of the most common sites of tumor metastases. During the last step of bone metastasis, cancer cells colonize and disrupt the bone matrix, which is maintained mainly by osteocytes, the most abundant cells in the bone microenvironment. However, the role of osteocytes in bone metastasis is still unclear. Here, we demonstrated that osteocytes transfer mitochondria to metastatic cancer cells and trigger the cGAS/STING-mediated antitumor response. Blocking the transfer of mitochondria by specifically knocking out mitochondrial Rho GTPase 1 (Rhot1) or mitochondrial mitofusin 2 (Mfn2) in osteocytes impaired tumor immunogenicity and consequently resulted in the progression of metastatic cancer toward the bone matrix. These findings reveal the protective role of osteocytes against cancer metastasis by transferring mitochondria to cancer cells and potentially offer a valuable therapeutic strategy for preventing bone metastasis.

Osteocyte mitochondria regulate angiogenesis of transcortical vessels.

Transcortical vessels (TCVs) provide effective communication between bone marrow vascular system and external circulation. Although osteocytes are in close contact with them, it is not clear whether osteocytes regulate the homeostasis of TCVs. Here, we show that osteocytes maintain the normal network of TCVs by transferring mitochondria to the endothelial cells of TCV. Partial ablation of osteocytes causes TCV regression. Inhibition of mitochondrial transfer by conditional knockout of Rhot1 in osteocytes also leads to regression of the TCV network. By contrast, acquisition of osteocyte mitochondria by endothelial cells efficiently restores endothelial dysfunction. Administration of osteocyte mitochondria resultes in acceleration of the angiogenesis and healing of the cortical bone defect. Our results provide new insights into osteocyte-TCV interactions and inspire the potential application of mitochondrial therapy for bone-related diseases.

Enhancement of T cell infiltration via tumor-targeted Th9 cell delivery improves the efficacy of antitumor immunotherapy of solid tumors.

Insufficient infiltration of T cells severely compromises the antitumor efficacy of adoptive cell therapy (ACT) against solid tumors. Here, we present a facile immune cell surface engineering strategy aiming to substantially enhance the anti-tumor efficacy of Th9-mediated ACT by rapidly identifying tumor-specific binding ligands and improving the infiltration of infused cells into solid tumors. Non-genetic decoration of Th9 cells with tumor-targeting peptide screened from phage display not only allowed precise targeted ACT against highly heterogeneous solid tumors but also substantially enhanced infiltration of CD8+ T cells, which led to improved antitumor outcomes. Mechanistically, infusion of Th9 cells modified with tumor-specific binding ligands facilitated the enhanced distribution of tumor-killing cells and remodeled the immunosuppressive microenvironment of solid tumors via IL-9 mediated immunomodulation. Overall, we presented a simple, cost-effective, and cell-friendly strategy to enhance the efficacy of ACT against solid tumors with the potential to complement the current ACT.

Cancer cells reprogram to metastatic state through the acquisition of platelet mitochondria.

Metastasis is the major cause of cancer deaths, and cancer cells evolve to adapt to various tumor microenvironments, which hinders the treatment of tumor metastasis. Platelets play critical roles in tumor development, especially during metastasis. Here, we elucidate the role of platelet mitochondria in tumor metastasis. Cancer cells are reprogrammed to a metastatic state through the acquisition of platelet mitochondria via the PINK1/Parkin-Mfn2 pathway. Furthermore, platelet mitochondria regulate the GSH/GSSG ratio and reactive oxygen species (ROS) in cancer cells to promote lung metastasis of osteosarcoma. Impairing platelet mitochondrial function has proven to be an efficient approach to impair metastasis, providing a direction for osteosarcoma therapy. Our findings demonstrate mitochondrial transfer between platelets and cancer cells and suggest a role for platelet mitochondria in tumor metastasis.

α-Mangostin inhibits LPS-induced bone resorption by restricting osteoclastogenesis via NF-κB and MAPK signaling.

BACKGROUND: Excessive osteoclast activation is an important cause of imbalanced bone remodeling that leads to pathological bone destruction. This is a clear feature of many osteolytic diseases such as rheumatoid arthritis, osteoporosis, and osteolysis around prostheses. Because many natural compounds have therapeutic potential for treating these diseases by suppressing osteoclast formation and function, we hypothesized that α-mangostin, a natural compound isolated from mangosteen, might be a promising treatment as it exhibits anti-inflammatory, anticancer, and cardioprotective effects. METHODS: We evaluated the therapeutic effect of α-mangostin on the processes of osteoclast formation and bone resorption. The receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL) induces osteoclast formation in vitro, and potential pathways of α-mangostin to inhibit osteoclast differentiation and function were explored. A mouse model of lipopolysaccharide-induced calvarial osteolysis was established. Subsequently, micro-computed tomography and histological assays were used to evaluate the effect of α-mangostin in preventing inflammatory osteolysis. RESULTS: We found that α-mangostin could inhibit RANKL-induced osteoclastogenesis and reduced osteoclast-related gene expression in vitro. F-actin ring immunofluorescence and resorption pit assays indicated that α-mangostin also inhibited osteoclast functions. It achieved these effects by disrupting the activation of NF-κB/mitogen-activated protein kinase signaling pathways. Our in vivo data revealed that α-mangostin could protect mouse calvarial bone from osteolysis. CONCLUSIONS: Our findings demonstrate that α-mangostin can inhibit osteoclastogenesis both in vitro and in vivo and may be a potential option for treating osteoclast-related diseases.

Metabolic control of CD47 expression through LAT2-mediated amino acid uptake promotes tumor immune evasion.

Chemotherapy elicits tumor immune evasion with poorly characterized mechanisms. Here, we demonstrate that chemotherapy markedly enhances the expression levels of CD47 in osteosarcoma tissues, which are positively associated with patient mortality. We reveal that macrophages in response to chemotherapy secrete interleukin-18, which in turn upregulates expression of L-amino acid transporter 2 (LAT2) in tumor cells for substantially enhanced uptakes of leucine and glutamine, two potent stimulators of mTORC1. The increased levels of leucine and enhanced glutaminolysis activate mTORC1 and subsequent c-Myc-mediated transcription of CD47. Depletion of LAT2 or treatment of tumor cells with a LAT inhibitor downregulates CD47 with enhanced macrophage infiltration and phagocytosis of tumor cells, and sensitizes osteosarcoma to doxorubicin treatment in mice. These findings unveil a mutual regulation between macrophage and tumor cells that plays a critical role in tumor immune evasion and underscore the potential to intervene with the LAT2-mediated amino acid uptake for improving cancer therapies.

Can "domino" therapy effectively treat the infection around the prosthesis after the limb salvage surgery of bone tumor? - A study of sequential therapy.

BACKGROUND: Tumor resection and prosthetic replacement have become the treatments of choice for malignant bone tumors. Infections are the leading cause of failure of limb salvage surgeries. Therefore, treating infections around prostheses after limb salvage is essential and challenging. Our research team designed a "domino" sequential treatment plan to treat postoperative infections around tumor prostheses and evaluated its efficacy. PURPOSE: To introduce the new domino sequential treatment plan for postoperative infections of tumor prostheses, and evaluate the technical points of the plan and prognosis in medium- and long-term follow-ups. METHODS: Between January 2015 and August 2021, 14 patients were treated with prosthesis-preserving domino sequential therapy for peripheral prosthesis infections after bone-tumor limb salvage. The sample included eight cases of distal femur tumor, two of proximal tibia tumor, three of pelvic tumor, and one of middle femur tumor. We evaluated routine blood test results, C-reactive protein level, the erythrocyte sedimentation rate, and other indicators. X-rays and CT scans of the surgical site were obtained and the Musculoskeletal Tumor Society (MSTS) score was calculated. Treatment involved debridement and lavage of the prosthesis, and systemic and local antibiotics. RESULTS: The positivity rate of microbial culture was 78.6%. There were three cases of Staphylococcus aureus, one of Staphylococcus epidermidis, two of methicillin-resistant Staphylococcus epidermidis, one of methicillin-resistant Staphylococcus aureus, two of Acinetobacter baumannii, one of Streptococcus lactis (group C), one of Streptococcus mitis, and three with negative cultures. In three cases, sequential treatment failed to control the infection. The operation success rate was 78.6% (11/14). One case eventually required amputation, and another required long-term wound dressings. To control the infection, a third had to be treated using antibiotic bone cement combined with the "intramedullary nail reverse double insertion" technique. The MSTS scores of patients before infection debridement and at the last follow-up showed statistically significant differences (t = 5.312, p = 0.02). CONCLUSIONS: The prosthesis-preserving domino sequential method has certain advantages for treating bone-tumor limb salvage infections around the prosthesis. LEVEL OF EVIDENCE: Level IV, therapeutic.

Fraxinellone Has Anticancer Activity by Inducing Osteosarcoma Cell Apoptosis via Promoting Excessive Autophagy Flux.

Osteosarcoma is a malignant bone tumor that is easy to metastasize in the early stage and has a very poor prognosis. Fraxinellone (FRA) is one of the main components isolated from the D. dasycarpus plant. Its anti-inflammatory and neuroprotective effects have been confirmed, but the research on the anti-cancer effect of FRA and its potential mechanism is relatively scarce. In this study, we found that FRA inhibited the proliferation and migration of osteosarcoma cells HOS and MG63 in a dose-dependent manner. Immunofluorescence, fluorescence staining and western blotting analysis showed that FRA could simultaneously induce osteosarcoma cell apoptosis and increase autophagy flux. Subsequent turnaround experiments suggested that the pro-apoptotic effect of FRA was achieved through excessive autophagy flux. The results of the xenograft orthotopic model further supported the anti-cancer effects of FRA, indicating that FRA treatment inhibited the growth of osteosarcoma, and the pro-apoptotic and autophagy effects of FRA were also proved in vivo. These studies provide new ideas for the future treatment of osteosarcoma and offer theoretical support for the anti-cancer mechanism of FRA.

Wnt5a/Platelet-rich plasma synergistically inhibits IL-1ß-induced inflammatory activity through NF-κB signaling pathway and prevents cartilage damage and promotes meniscus regeneration.

Noncanonical Wnt5a is a particularly attractive growth factor to maintain chondrogenesis. Platelet-rich plasma (PRP) is an autologous blood-derived product and a source of bioactive growth factors involved in tissue regeneration. The present study aimed to investigate the effect and inflammation reaction of Wnt5a/PRP on meniscus cells, and evaluate meniscus regeneration and osteoarthritis (OA) prevention by the application of Wnt5a/PRP gel in a rabbit model of massive meniscal defect. In vitro, the proliferation, migration, differentiation, and interleukin-1 beta (IL-1ß) IL-1ß-induced inflammation reaction of meniscus cells treated by Wnt5a and PRP was assessed. In vivo, the anterior half of the medial meniscus of 18 New Zealand rabbits was excised and implanted with PRP gel, Wnt5a/PRP gel or untreated. After 6 and 12 weeks, the regenerated meniscus were evaluated. Wnt5a can promote the migration of meniscus cells. PRP and Wnt5a had synergistic effect in promoting the proliferation and chondrogenic differentiation of meniscus cells. The IL-1ß-induced meniscus cells study showed that PRP and Wnt5a had the anti-inflammatory actions through nuclear factor kB (NF-κB) signaling pathway. PRP and Wnt5a/PRP significantly inhibited the increase of the p-p65/p65 and p-IκB-α/IκB-α ratios. In vivo transplantation of Wnt5a/PRP gel was demonstrated to promote meniscus regeneration, while reducing OA of knee joint. Wnt5a with PRP had the anti-inflammatory activity in an IL-1ß-induced inflammatory model. They can synergistically improve the chondorgenic differentiation of meniscus cells. Wnt5a/PRP gel treatment could potentially be developed into a new method for meniscus regeneration and the prevention of OA.

Aloin induced apoptosis by enhancing autophagic flux through the PI3K/AKT axis in osteosarcoma.

BACKGROUND: Osteosarcoma is a malignant tumor of bone and soft tissue in adolescents. Due to its tumor biological behavior pattern, osteosarcoma usually generates poor prognosis. Autophagy is an important self-defense mechanism in osteosarcoma. METHODS: Cell viability in IC50 testing and reverse assays was examined by the MTT assay. Cell apoptosis conditions were examined by flow cytometry, Hoechst 33,342 staining and apoptosis-related protein immunoblotting. Autophagy conditions were tested by autophagy-related protein immunoblotting, transmission electron microscopic observation and dual fluorescence autophagy flux detection. The possible targets of aloin were screened out by network pharmacology and bioinformatic methods. Osteosarcoma xenografts in nude BALB/c mice were the model for in vivo research on tumor suppression, autophagy induction, pathway signaling and toxicity tests. In vivo bioluminescence imaging systems, immunohistochemical assays, and gross tumor volume comparisons were applied as the main research methods in vivo. RESULTS: Aloin induced osteosarcoma apoptosis in a dose-dependent manner. Its possible effects on the PI3K/AKT pathway were screened out by network pharmacology methods. Aloin increased autophagic flux in osteosarcoma by downregulating the PI3K/AKT pathway. Aloin promoted autophagic flux in the osteosarcoma cell lines HOS and MG63 in a dose-dependent manner by promoting autophagosome formation. Chloroquine reversed the apoptosis-promoting and autophagy-enhancing effects of aloin. Autophagy induced by starvation and rapamycin significantly enhanced the autophagic flux and apoptosis induced by aloin, which verified the role of the PI3K/AKT axis in the pharmacological action of aloin. Therapeutic effects, autophagy enhancement and regulatory effects on the PI3K/AKT/mTOR pathway were demonstrated in a nude mouse xenogeneic osteosarcoma transplantation model. CONCLUSIONS: Aloin inhibited the proliferation of osteosarcoma by inhibiting the PI3K/AKT/mTOR pathway, increasing autophagic flux and promoting the apoptosis of osteosarcoma cells.

SENP3-Mediated PPARγ2 DeSUMOylation in BM-MSCs Potentiates Glucocorticoid-Induced Osteoporosis by Promoting Adipogenesis and Weakening Osteogenesis.

Glucocorticoid-induced osteoporosis (GIOP) is the most common secondary osteoporosis and reduced bone formation was the main pathological change in GIOP. Our previous studies have shown that there was an imbalance between adipogenic and osteogenic differentiation in GIOP BM-MSCs and peroxisome proliferator-activated receptor γ2 (PPARγ2) played a vital role in this disorders. Here, we reported that there was an increase in ROS level and SENP3 expression in Dex-induced osteoporotic BM-MSCs, and enhanced adipogenesis and weakened osteogenesis in osteoporotic BM-MSCs might be caused by upregulated SENP3. Then we found that SENP3 de-SUMOylated PPARγ2 on K107 site to potentiate adipogenesis and weaken osteogenesis. These results may provide new strategy and target in the clinical diagnosis and treatment of GIOP.

Blockage of Extracellular Signal-Regulated Kinase Exerts an Antitumor Effect via Regulating Energy Metabolism and Enhances the Efficacy of Autophagy Inhibitors by Regulating Transcription Factor EB Nuclear Translocation in Osteosarcoma.

Accumulating evidence suggests that extracellular signal-regulated kinase (ERK) is a valuable target molecule for cancer. However, antitumor drugs targeting ERK are still in their clinical phase and no FDA-approved medications exist. In this study, we identified an ERK inhibitor (ERKi; Vx-11e) with potential antitumor activities, which was reflected by the inhibition in the survival and proliferation of Osteosarcoma (OS) cells. Mechanistically, the ERKi regulated autophagic flux by promoting the translocation of transcription factor EB (TFEB) in OS cells, thereby increasing the dependence of OS cells on autophagy and sensitivity to treatment with autophagy inhibitors in OS. Besides, we also found that the ERKi could regulate mitochondrial apoptosis through the ROS/mitochondria pathway and aerobic glycolysis in OS, which also increases the dependence of OS cells on autophagy to clear metabolites to a certain extent. These results may provide a reference for the clinically improved efficacy of ERKis in combination with autophagy inhibitors in the treatment of OS and indicate its potential as a therapeutic agent.

Clinical Features and Serological Markers Risk Model Predicts Overall Survival in Patients Undergoing Breast Cancer and Bone Metastasis Surgeries.

BACKGROUND: Surgical therapy of breast cancer and bone metastasis can effectively improve the prognosis of breast cancer. However, after the first operation, the relationship between preoperative indicators and outcomes in patients who underwent metastatic bone surgery remained to be studied. Purpose 1. Recognize clinical and laboratory prognosis factors available to clinical doctors before the operation for bone metastatic breast cancer patients. 2. Develop a risk prediction model for 3-year postoperative survival in patients with breast cancer bone metastasis. METHODS: From 2014 to 2020, patients who suffered from breast cancer bone metastasis and received therapeutic procedures in our institution were included for analyses (n=145). For patients who underwent both breast cancer radical surgery and bone metastasis surgery, comprehensive datasets of the parameters of interest (clinical features, laboratory factors, and patient prognoses) were collected (n=69). We performed Multivariate Cox regression to identify factors that were associated with postoperative outcome. 3-year survival prediction model and nomograms were established by 100 bootstrapping. Its benefit was evaluated by calibration plot, C-index, and decision curve analysis. The Surveillance, Epidemiology, and End Results database was also used for external validation. RESULTS: Radiotherapy for primary cancer, pathological type of metastatic breast cancer, lymph node metastasis, elevated serum alkaline phosphatase, lactate dehydrogenase were associated with postoperative prognosis. Pathological types of metastatic breast cancer, multiple bone metastasis, organ metastases, and elevated serum lactate dehydrogenase were associated with 3-year survival. Then those significant variables and serum alkaline phosphatase counts were integrated to construct nomograms for 3-year survival. The C-statistic of the established predictive model was 0.83. The calibration plot presents a graphical representation of calibration. In the decision curve analysis, the benefits are higher than those of the extreme curve. The receiver operating characteristic of the external validation of the model was 0.82, indicating a favored fitting degree of the two models. CONCLUSION: Our study suggests that several clinical features and serological markers can predict the overall survival among the patients who are about to receive bone metastasis surgery after breast cancer surgery. The model can guide the preoperative evaluation and clinical decision-making for patients. Level of evidence Level III, prognostic study.

Application of Immune Infiltration Signature and Machine Learning Model in the Differential Diagnosis and Prognosis of Bone-Related Malignancies.

Bone-related malignancies, such as osteosarcoma, Ewing's sarcoma, multiple myeloma, and cancer bone metastases have similar histological context, but they are distinct in origin and biological behavior. We hypothesize that a distinct immune infiltrative microenvironment exists in these four most common malignant bone-associated tumors and can be used for tumor diagnosis and patient prognosis. After sample cleaning, data integration, and batch effect removal, we used 22 publicly available datasets to draw out the tumor immune microenvironment using the ssGSEA algorithm. The diagnostic model was developed using the random forest. Further statistical analysis of the immune microenvironment and clinical data of patients with osteosarcoma and Ewing's sarcoma was carried out. The results suggested significant differences in the microenvironment of bone-related tumors, and the diagnostic accuracy of the model was higher than 97%. Also, high infiltration of multiple immune cells in Ewing's sarcoma was suggestive of poor patient prognosis. Meanwhile, increased infiltration of macrophages and B cells suggested a better prognosis for patients with osteosarcoma, and effector memory CD8 T cells and type 2 T helper cells correlated with patients' chemotherapy responsiveness and tumor metastasis. Our study revealed that the random forest diagnostic model based on immune infiltration can accurately perform the differential diagnosis of bone-related malignancies. The immune microenvironment of osteosarcoma and Ewing's sarcoma has an important impact on patient prognosis. Suppressing the highly inflammatory environment of Ewing's sarcoma and promoting macrophage and B cell infiltration may have good potential to be a novel adjuvant treatment option for osteosarcoma and Ewing's sarcoma.

Predictive and Prognostic Biomarkers for Lung Cancer Bone Metastasis and Their Therapeutic Value.

Lung cancer is the leading cause of cancer-related death worldwide. Bone metastasis, which usually accompanies severe skeletal-related events, is the most common site for tumor distant dissemination and detected in more than one-third of patients with advanced lung cancer. Biopsy and imaging play critical roles in the diagnosis of bone metastasis; however, these approaches are characterized by evident limitations. Recently, studies regarding potential biomarkers in the serum, urine, and tumor tissue, were performed to predict the bone metastases and prognosis in patients with lung cancer. In this review, we summarize the findings of recent clinical research studies on biomarkers detected in samples obtained from patients with lung cancer bone metastasis. These markers include the following: (1) bone resorption-associated markers, such as N-terminal telopeptide (NTx)/C-terminal telopeptide (CTx), C-terminal telopeptide of type I collagen (CTx-I), tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), pyridinoline (PYD), and parathyroid hormone related peptide (PTHrP); (2) bone formation-associated markers, including total serum alkaline phosphatase (ALP)/bone specific alkaline phosphatase(BAP), osteopontin (OP), osteocalcin (OS), amino-terminal extension propeptide of type I procollagen/carboxy-terminal extension propeptide of type I procollagen (PICP/PINP); (3) signaling markers, including epidermal growth factor receptor/Kirsten rat sarcoma/anaplastic lymphoma kinase (EGFR/KRAS/ALK), receptor activator of nuclear factor κB ligand/receptor activator of nuclear factor κB/osteoprotegerin (RANKL/RANK/OPG), C-X-C motif chemokine ligand 12/C-X-C motif chemokine receptor 4 (CXCL12/CXCR4), complement component 5a receptor (C5AR); and (4) other potential markers, such as calcium sensing receptor (CASR), bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2), cytokeratin 19 fragment/carcinoembryonic antigen (CYFRA/CEA), tissue factor, cell-free DNA, long non-coding RNA, and microRNA. The prognostic value of these markers is also investigated. Furthermore, we listed some clinical trials targeting hotspot biomarkers in advanced lung cancer referring for their therapeutic effects.