Poor prognosis osteosarcoma: new therapeutic approach

Cu-Tremella fuciformis polysaccharide-based tumor microenvironment-responsive injectable gels for cuproptosis-based synergistic osteosarcoma therapy

Cuproptosis affects osteosarcoma locally, and the exploitation of cuproptosis-related biomaterials for osteosarcoma treatment is still in its infancy. We designed and synthesized a novel injectable gel of Cu ion-coordinated Tremella fuciformis polysaccharide (TFP-Cu) for antiosteosarcoma therapy. This material has antitumor effects, the ability to stimulate immunity and promote bone formation, and a controlled Cu2+ release profile in smart response to tumor microenvironment stimulation. TFP-Cu can selectively inhibit the proliferation of K7M2 tumor cells by arresting the cell cycle and promoting cell apoptosis and cuproptosis. TFP-Cu also promoted the M1 polarization of RAW264.7 cells and regulated the immune microenvironment. These effects increased osteogenic gene and protein expression in MC3T3-E1 cells. TFP-Cu could significantly limit tumor growth in tumor-bearing mice by inducing tumor cell apoptosis and improving the activation of anti-CD8 T cell-mediated immune responses. Therefore, TFP-Cu could be a potential candidate for treating osteosarcoma and bioactive drug carrier for further cancer-related applications.

Bone tumor necrosis rate detection in few-shot X-rays based on deep learning

Although biopsy-based necrosis rate is a golden standard for reflecting the sensitivity of bone tumor and guiding postoperative chemotherapy, it requires biopsy which is invasive and time-consuming. In this paper, we develop a new necrosis rate detection method using time series X-ray images instead of biopsy. To overcome the limitations of few-shot samples, the proposed method utilizes a Generative Adversarial Network with Long Short-term Memory to generate time series X-ray images. For further data expansion, an image-to-image translation network is applied for producing the initial images. These augmented data are treated as the training set of a 3D-Convolutional Neural Network classification model. Our method expands the few-shot bone tumor X-rays by 10 times, and approaches the necrotic rate classification result of biopsy, which is the state-of-the-art technique in the detection of few-shot bone tumor necrosis rate. Furthermore, it provides an efficient method to investigate the bone tumor necrosis rate in few-shot samples.

Tannic acid enhances cisplatin effect on cell proliferation and apoptosis of human osteosarcoma cell line (U2OS)

BACKGROUND

The increase in cases of chemoresistance of cisplatin for osteosarcoma treatment has called for the need to establish a new treatment regime. Tannic acid (TA) possesses a potent antiproliferative effect against various cancers. Therefore, this study investigated the effect of TA combined with cisplatin on human osteosarcoma cell lines (U2OS).

METHODS

MTT assay was used to determine the half-maximal inhibitory concentration (IC₅₀), while the combination index (CI) value was utilized to analyze the interaction within each combination. The antiproliferative effect of the treatment was evaluated by trypan blue exclusion assay. The morphological changes of cells were observed under a phase-contrast inverted microscope. The nuclear morphology and percentage of apoptosis cells were evaluated by using the Hoechst 33258 staining and annexin V/PI assay, respectively.

RESULTS

The U2OS cells showed cytotoxic effect when treated with TA and cisplatin, with IC₅₀ at 4.47 µg/mL and 16.25 µg/mL, respectively. The TA demonstrated no significant inhibition effect on the normal human fetal osteoblast cells (hFOB 1.19); yet, interestingly, a potent proliferative effect was indicated. Synergistic interaction was triggered when TA was combined with cisplatin at percentage ratios of 90:10 and 85:15. Meanwhile, antagonistic interaction was induced in the combination at percentage ratios of 75:25 and 50:50. On the other hand, a significant antiproliferative effect with prominent morphological alteration was detected in the cells treated with a combination of TA and cisplatin at the percentage ratio of 90:10. Additionally, combination-treated cells demonstrated the highest percentage of apoptosis cells, with distinct chromosomal condensation, nuclear fragmentation, reduction of nuclear volume, and notable apoptotic body.

CONCLUSION

Therefore, there is a high potential for the inclusion of TA in the cisplatin-based chemotherapeutic regimen of osteosarcoma.

The Value of Immune-Related Genes Signature in Osteosarcoma Based on Weighted Gene Co-expression Network Analysis

Background. Osteosarcoma (OS) is a serious malignant tumor that is more common in adolescents or children under 20 years of age. This study is aimed at obtaining immune-related genes (IRGs) associated with the progression and prognosis of OS. Method. Expression profiling data and clinical data for OS were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. ESTIMATE calculates immune scores and stromal scores of samples and performs the prognostic analysis. Weighted gene coexpression network analysis (WGCNA) was used to find modules correlated with immune and stromal scores. Cox regression analysis and least absolute shrinkage and selection operator (LASSO) analysis were used to explore IRGs associated with OS prognosis and construct and validate a hazard score model. Finally, we verified the expression and function of EVI2B in OS. Results. WGCNA selected twenty-eight IRGs, 10 of which were associated with OS prognosis, and LASSO further obtained three key prognostic genes. A prognostic model of EVI2B was constructed, and according to the risk score model, patients in the high-risk group had a worse prognosis than those in the low-risk group, and the prognosis was statistically significant in the high- and low-risk groups. Receiver operating characteristic (ROC) curves were used to assess the prognostic model’s accuracy and externally validate the independent GSE21257 cohort. The results of immunohistochemical staining and qPCR showed that EVI2B was a tumor suppressor gene. The differential genes in the high- and low-risk groups were analyzed by enrichment analysis of GO and KEGG, indicating that the EVI2B model is associated with immune response. Conclusion. In this study, IRG EVI2B is closely related to OS’s prognosis and can be used as a potential biomarker for prognosis and treatment of OS.

A multicentric randomized phase II clinical trial evaluating high-dose thiotepa as adjuvant treatment to standard chemotherapy in patients with resectable relapsed osteosarcoma

BACKGROUND

The role of high-dose chemotherapy in relapsing osteosarcomas has not been established. We evaluated the efficacy and tolerance of high-dose thiotepa (HDTp) after standard chemotherapy (SCT) in patients with relapsed osteosarcoma.

PATIENTS AND METHODS

This randomised open-label phase II study enrolled patients 1-50 years, with local or metastatic relapse of a high-grade osteosarcoma, not progressive after two cycles of SCT, for whom a complete surgery can be achievable following treatment. The trial assigned enrolled patients in a 1:1 ratio to receive two additional courses of SCT + HDTp and autologous transplantation (Arm A), or SCT alone (Arm B). Surgery for complete resection was scheduled as soon as feasible. Primary endpoint was overall survival (OS). Secondary objectives included progression-free survival (PFS) and safety.

RESULTS

From September 2009 to November 2016, 44 patients were randomised (A:22; B:22). In total, 54.5% were males, and the median age was 16 years (9-32years). The two-year OS rate was 66.7% (95% CI 42.5-82.5) (SCT + HDTp, Arm A) versus 50.0% (95% CI 28.2-68.4) for SCT alone (Arm B). Median OS was 27.4 and 24.8 months, respectively (hazard ratio [HR] 0.826, 95% CI 0.393-1.734; p = 0.6123). Median PFS was 15.6 (8.9-24.9) months in Arm A versus 7.2 (4.8-33.3) months in Arm B, p = 0.3845. Among the 22 patients treated with SCT + HDTp, 16 (72.7%) experienced at least one grade ≥3 adverse events versus 18/22 (81.8%) patients treated with SCT. No toxic death occurred.

CONCLUSION

Adjuvant HDTp failed to significantly improve OS and PFS in resectable relapsed osteosarcomas. Despite a trend of prolonged survival and an acceptable toxicity, thiotepa cannot be recommended.

KEY MESSAGE

HDTp and autologous transplantation added to SCT did not improve OS and PFS in patients with resectable relapsed osteosarcomas. Despite a trend of prolonged survival, thiotepa cannot be recommended.

BMP-2 and miR-29c in osteosarcoma tissues on proliferation and invasion of osteosarcoma cells

Expression of bone morphogenetic protein (BMP)-2 and microRNA (miR)-29c in osteosarcoma tissues and effects on proliferation and invasion of osteosarcoma cells were investigated. A retrospective analysis of 75 patients with osteosarcoma who underwent surgery in Tianjin Baodi Hospital from May 2013 to June 2017 was conducted. A total of 75 osteosarcoma tissues and 51 normal paraneoplastic tissues were collected. RT-PCR was used to compare the expression difference of BMP-2 and miR-29c. miR-29c mimics (experimental group A) and BMP-2 siRNA plasmid (experimental group B) were transfected into human osteosarcoma cells MG-63, respectively. The transfected cells were divided into miRNA negative control (miR-NC) group (cells transfected with miR-negative control), siRNA negative control group (cells transfected with non-silent siRNA) and blank group (cells without any transfection). MTT assay was used to detect cell proliferation in each group at different time periods. Transwell insert was used to detect invasion of cells in vitro. The relative expression of BMP-2 in osteosarcoma tissue was significantly higher than that in paraneoplastic tissue (P<0.05). Τhe relative expression of miR-29c in osteosarcoma tissue was significantly lower than that in paraneoplastic tissue (P<0.05). The cell survival rates in experimental groups A and B were significantly lower than those in the blank, miR-NC negative control and siRNA negative control groups on day 5 (P<0.05). The number of cell transmembranes in experimental groups A and B was significantly lower than those in the blank, miR-NC negative control and siRNA negative control groups (P<0.05). BMP-2 is over-expressed in osteosarcoma tissues, and miR-29c is under-expressed in osteosarcoma tissues. Interfering with the expression of BMP-2 and overexpression of miR-29c can inhibit the proliferation and invasion of osteosarcoma cells, indicating that BMP-2 and miR-29c may be involved in the regulation of proliferation and metastasis of osteosarcoma cells and could be used as new molecular target markers for the diagnosis and treatment of osteosarcoma.

Expression of microRNA-150 and its Target Gene IGF2BP1 in Human Osteosarcoma and their Clinical Implications

Previous study revealed that microRNA (miR)-150 might function as a tumor suppressor in osteosarcoma partially by targeting Insulin-Like Growth Factor 2 mRNA-Binding Protein 1 (IGF2BP1). The aim of this study was to investigate the clinical significance of miR-150-IGF2BP1 axis in human osteosarcoma which remains unclear. At first, expression levels of miR-150, and IGF2BP1 mRNA and protein in 20 osteosarcoma and matched adjacent noncancerous tissues were respectively detected by quantitative real-time PCR and western blot analyses. Then, subcellular localization and expression pattern of IGF2BP1 protein in 100 osteosarcoma tissues were examined by immunohistochemistry. Associations of miR-150/IGF2BP1 expression with various clinicopathological features and patients’ prognosis were also statistically evaluated. As a result, miR-150 expression was significantly decreased, while IGF2BP1 mRNA and protein expression were dramatically increased in osteosarcoma tissues compared to matched adjacent noncancerous tissues (all P < 0.001). Immunostaining of IGF2BP1 protein was localized in cytoplasm of tumor cells in osteosarcoma tissues. Statistically, low miR-150 expression and/or high IGF2BP1 protein immunoreactive score were all significantly associated with high tumor grade, presence of metastasis and recurrence, as well as poor response to chemotherapy (all P < 0.05). Moreover, miR-150, IGF2BP1 and combined miR-150/IGF2BP1 expressions were all identified as independent prognostic factors for overall and disease-free survivals of osteosarcoma patients (all P < 0.05). In conclusion, our data suggest that miR-150 and its downstream target IGF2BP1 may be a crucial axis for the development, progression and patients’ prognosis of ostesarcoma. The newly identified miR-150/IGF2BP1 axis might be a novel potential therapeutic target for osteosarcoma treatment.

Increased Six1 expression is associated with poor prognosis in patients with osteosarcoma

Sine oculis homeobox homolog 1 (Six1) is an evolutionarily conserved transcription factor that acts as master regulator of development and is frequently dysregulated in various types of cancer. Six1 has been demonstrated to be upregulated in human osteosarcoma cell lines compared with osteoblastic cell lines. However, the association of Six1 expression with the progression and prognosis of osteosarcoma patients remains unclear. The purpose of the present study was to investigate the association between Six1 expression and the clinicopathological characteristics and prognosis of osteosarcoma. Six1 protein was detected by immunohistochemistry in a series of 100 osteosarcoma patients, and Kaplan-Meier survival analysis was performed to assess prognosis. The results revealed that increased Six1 protein expression was prevalent in osteosarcoma and was significantly associated with Enneking stage (P=0.002) and tumor size (P=0.010). Additionally, according to the log-rank test and Cox regression model, expression of Six1 is indicated to be an independent prognostic factor in osteosarcoma patients. In summary, positive expression of Six1 protein is closely associated with the tumor progression and poor survival of osteosarcoma patients. The results suggest that Six1 is a overexpressed in individuals with poor prognosis, and may thus be used as a prognostic biomarker in patients with osteosarcoma.

High level of αB-crystallin contributes to the progression of osteosarcoma

Accumulating evidences indicate the elevated expression of αB-Crystallin (Cryab) is implicated in tumorigenesis. However, the expression and biologic role of Cryab in osteosarcoma (OS) are still unknown. In this study, we showed that Cryab expression was elevated in OS tissues and cell lines, and down-regulation of Cryab in MG-63 and U-2OS cells led to a decline in the cells' aggressiveness, and reduced secretion of matrix metalloproteinase-9 (MMP-9) in vitro, and lower metastasis potential in vivo. Further study indicated that the Cryab expression was positively associated with the activity of ERK1/2 which is responsible for the cells' aggressiveness and MMP-9 secretion. Clinically, our data confirmed that the high level of Cryab was associated with shorten survival and tumor recurrence for the postoperative OS patients. Together, our results indicate that high level of Cryab is a new adverse outcomes marker for OS patients and may be used as a new therapeutic target.

Identification of CD20, ECM, and ITGA as Biomarkers for Osteosarcoma by Integrating Transcriptome Analysis

Background

Osteosarcoma is the most frequent primary bone cancer derived from primitive mesenchymal cells. The aim of this study was to explore the molecular mechanism of the development and progression of osteosarcoma.

Material/Methods

The gene expression profiles of osteosarcoma from 17 specimens (3 normal and 14 osteosarcoma) were downloaded from the GEO database. The differentially expressed genes were identified by use of the Limma package. DAVID and Enrichment Map were used to perform GO and KEGG pathways enrichment analysis and to integrate enrichment results of differentially expressed genes (DEGs). Protein-protein interaction network was constructed and analyzed to screen out the potential regulatory proteins using the STRING online tools.

Results

A total of 417 DEGs were screened, including 215 up-regulated and 202 down-regulated ones, accounting for 51.56% and 48.4%, respectively. In GO term, a total of 12 up-regulated expression genes were enriched in Cellular Component. The up-regulated DEGs were enriched in 6 KEGG pathways while the down-regulated expression genes were enriched in 2 KEGG pathways. The constructed PPI network was aggregated with 1006 PPI relationships and 238 nodes, accounting for 57.07% of DEGs. We found that CD20, MCM, and CCNB1 (down-regulated) in cell cycle and ECM, ITGA, RTKin (up-regulated) in focal adhesion had important roles in the progression of osteosarcoma.

Conclusions

The identified DEGs and their enriched pathways provide references for the exploration of the molecular mechanism of the development and progression of osteosarcoma. Moreover, the key genes (CD20, ECM, and ITGA) may be useful in treatment and diagnosis of osteosarcoma.

The impact of COX-2 on invasion of osteosarcoma cell and its mechanism of regulation

Background

Recently, cyclooxygenase-2 (COX-2) has become an important new target in the field of tumor metastasis. However, the relationship between COX-2 gene expression and the behavior of osteosarcoma metastasis is largely unknown. The study is to investigate how antisense oligonucleotides (ODNs) of COX-2 inhibit the invasion of human osteosarcoma cell line OS-732 and their mechanism of regulation.

Methods

A COX-2 antisense oligonucleotide was designed, synthesized, and transfected into OS-732 human osteosarcoma cells. RT-PCR and western blotting were performed to determine the transfection efficiency. A modified Boyden-transwell assay was used to measure the inhibition rate of tumor cell invasion. In OS-732 cells transfected with COX-2 antisense ODNs, RT-PCR was used to examine the mRNA expression of urokinase-type plasminogen activator (uPA) and that of its receptor, uPAR.

Results

Both the mRNA and protein expression levels of COX-2 were significantly reduced when cells were transfected with COX-2 antisense ODNs, which significantly reduced the invasive ability of OS-732 cells in a dose-dependent manner. The expression levels of uPA and uPAR were also significantly reduced (p < 0.01).

Conclusion

COX-2 antisense ODNs significantly inhibited the invasion of OS-732 cells, primarily by decreasing the mRNA expression of uPA and uPAR.

Prognostic significance of HLA EMR8-5 immunohistochemically analyzed expression in osteosarcoma

Background

Defects in Human Leukocyte Antigen (HLA) class I antigen expression and/or function in tumor cells have been extensively investigated, because of their potential role in the escape of tumor cells from T cell recognition and destruction. The researchers evaluated HLA class I expression in tumor tissue as a prognostic factor in osteosarcoma patients and as a predictor of their survival. This retrospective cohort study was conducted at the pathology laboratory of Ain Shams University Hospital, and Ain Shams University Specialized Hospital during the period between January 2009 and January 2012.

Methods

The researchers investigated HLA class I expression in primary osteosarcoma by immunohistochemistry using EMR8-5 mAbs. Furthermore, researchers evaluated the correlation between HLA class I expression and the clinicopathological status and outcome in formalin fixed paraffin embedded tissues from thirty six (36) patients with osteosarcoma.

Results

A high expression of HLA class I was detected in 18 (50) % of tumor samples examined; while tumors with low or negative expression represented 9 (25%) cases each. Data indicate that the overall survival rate of patients with tumors highly expressing HLA class I was significantly higher than those with low or negative expression.

Conclusion

Down-regulation of class I antigen expression is associated with features of aggressive disease and a poorer prognosis. Therefore, it is imperative to identify HLA as a prognostic factor at the time of diagnosis to detect chemotherapy-resistant tumors and to generate a modified treatment regimen.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1159334857109547.

Expression and clinical significance of extracellular matrix metalloproteinase inducer, EMMPRIN/CD147, in human osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. Recent studies have shown that extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) promotes adhesion, invasion and metastasis of malignant tumor cells. The aim of this study was to investigate the impact of EMMPRIN/CD147 expression on prognosis and its correlation with clinicopathological characteristics in patients with osteosarcoma. The expression of EMMPRIN/CD147 in 55 surgical specimens from patients with osteosarcoma at stage IIA or above, 15 non-tumor rib bone tissues, three human osteosarcoma cell lines (Saos-2, U-2OS and MG-63), the human osteoblast cell line HOB and the malignant melanoma cell line A375 were examined by immunohistochemistry, western blot analysis and ELISA, respectively. The potential association of the levels of EMMPRIN/CD147 expression in osteosarcoma specimens with the overall survival of patients was statistically analyzed. We found that the EMMPRIN/CD147 was expressed in 45 out of 55 osteosarcomas, with immunoreactivity primarily within the membrane and cytoplasm of tumor cells, but not in the non-tumor bone tissues. We also observed that EMMPRIN/CD147 was expressed in Saos-2, U-2OS, MG-63 and A375, but not in HOB cells. The levels of EMMPRIN/CD147 expression correlated positively with the pathological degree of osteosarcoma and negatively with the survival period of patients with osteosarcoma. The expression of EMMPRIN/CD147 is a potential factor in the development and prognosis of osteosarcoma and may be a novel therapeutic target of human osteosarcoma.

Potential of human γδ T cells for immunotherapy of osteosarcoma

Recurrent or metastatic osteosarcomas remain a challenging malignancy to treat. Therefore, development and testing of novel therapeutic strategies to target these patients are needed. Adoptive cellular therapy strategies are being evaluated intensively as a novel therapeutic strategy for cancer. Unlike αβ T cells requiring antigen processing and MHC-restricted peptide displayed by antigen-presenting cells, γδ T cells exhibit the potent MHC-unrestricted lytic activity against various tumors in vitro and in vivo. The recent considerable success of γδ T cell-based immunotherapy in lung metastasis of renal cell carcinoma warrants further efforts to apply this treatment to other cancers including osteosarcoma, especially recurrent and metastatic osteosarcomas. In this review, we summarize the available evidence on γδ T cell-based immunotherapy for osteosarcoma that has been achieved to date. More importantly, we discuss potential strategies of the combination of expanded γδ T cells and bisphosphonates, and modification and expansion of αβ TCR modified γδ T cells for improving its efficacy for the treatment of osteosarcoma.

Artesunate inhibits growth and induces apoptosis in human osteosarcoma HOS cell line in vitro and in vivo

This paper aims to investigate the effects of artesunate (ART) on growth and apoptosis in human osteosarcoma HOS cell line in vitro and in vivo and to explore the possible underlying mechanisms. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The induction of apoptosis was detected by light and transmission electron microscopy and flow cytometry. Western blot analysis was used to investigate the related mechanisms. Nude mice were further employed to investigate the antitumour activity of ART in vivo. MTT assay results demonstrated that ART selectively inhibits the growth of HOS cells in a dose- and time-dependent manner. Based on the findings of light and transmission electron microscopy, Hoechst 33258 staining, and fluorescein isothiocyanate (FITC)-annexin V staining, the cytotoxicity of ART in HOS cells occurs through apoptosis. With ART treatment, cytosolic cytochrome c was increased, Bax expression was gradually upregulated, Bcl-2 expression was downregulated, and caspase-9 and caspase-3 were activated. Thus, the intrinsic apoptotic pathway may be involved in ART-induced apoptosis. Cell cycle analysis by flow cytometry indicated that ART may induce cell cycle arrest at G(2)/M phase. In nude mice bearing HOS xenograft tumours, ART inhibited tumour growth and regulated the expressions of cleaved caspase-3 and survivin, in agreement with in vitro observations. ART has a selective antitumour activity against human osteosarcoma HOS cells, which may be related to its effects on induction of apoptosis via the intrinsic pathway. The results suggest that ART is a promising candidate for the treatment of osteosarcoma.

Corosolic acid triggers mitochondria and caspase-dependent apoptotic cell death in osteosarcoma MG-63 cells

The response of osteosarcoma MG-63 cells to corosolic acid treatment has been investigated. The results showed that corosolic acid significantly inhibited cell viability in both a dose and a time dependent manner. It was found that corosolic acid increased the Bax/Bcl-2 ratio by up-regulating Bax expression, disrupted mitochondrial membrane potential and triggered the release of cytochrome c from mitochondria into the cytoplasm. Corosolic acid treatment triggered the activation of caspase-8, 9 and 3. The apoptosis was obviously inhibited by pretreatment with a general caspase inhibitor, z-VAD-FMK. Moreover, pretreatment of CsA, a cyclophilin D ligand that inhibits mitochondria potential uncoupling, prevented the activation of caspase-9 and caspase-3, but not caspase-8, and the apoptosis of MG-63 cells, triggered by corosolic acid. All these results indicated that corosolic acid-induced apoptosis was associated with the activation of caspases via a mitochondrial pathway.

Celecoxib inhibits β-catenin-dependent survival of the human osteosarcoma MG-63 cell line

Cyclo-oxygenase (COX)-2 inhibitors may exert antitumour effects through COX-2-independent mechanisms. This study investigated the effects of the COX-2 inhibitor celecoxib on the viability of the human osteosarcoma MG-63 cell line and its β-catenin signalling pathway. Cell viability and apoptosis were examined in celecoxib-treated cells or after β-catenin knockdown in vitro. Analyses were performed to detect glycogen synthase kinase (GSK)-3β, phosphorylated GSK-3β, β-catenin, c-Myc and cyclin D1 proteins, and mRNA levels of β-catenin, c-Myc and CCND1 (encoding cyclin D1). β-Catenin was shown to be required for MG63 cell survival and celecoxib exerted an inhibitory effect on the viability of cultured MG-63 cells in a time- and dose-dependent manner. β-Catenin protein decreased in the cytosol and nucleus following celecoxib treatment (from 6 h after initiation of treatment onwards; lowest protein levels were reached at > 72 h). Significant reductions in β-catenin, c-Myc and CCND1 mRNA were observed. Celecoxib inhibited MG-63 cell viability, possibly by activating GSK-3β and inhibiting β-catenin-dependent gene transcription, suggesting a role for celecoxib in osteosarcoma treatment.

Cryoimmunologic antitumor effects enhanced by dendritic cells in osteosarcoma

BACKGROUND

We previously reported a limb-salvage technique by treating tumor-bearing bone with liquid nitrogen. We also reported systemic antitumor immunity was enhanced by cryotreatment in a murine osteosarcoma (LM8) model. We therefore combined the cryotreatment of tumor with dendritic cells to promote tumor-specific immune responses.

QUESTIONS/PURPOSES

We determined whether our technique could enhance systemic immune response and inhibit metastatic tumor growth in a murine osteosarcoma model.

MATERIALS AND METHODS

To evaluate activation of the immune response, we prepared six groups of C3H mice (80 mice total): (1) excision only, (2) dendritic cells without reimplantation of the cryotreated primary tumor, (3) reimplantation of the cryotreated primary tumor alone, (4) dendritic cells combined with reimplantation of the cryotreated primary tumor, (5) dendritic cells exposed to cryotreated tumor lysates without reimplantation of the cryotreated primary tumor, and (6) dendritic cells exposed to cryotreated tumor lysates with reimplantation of the cryotreated primary tumor. We then compared and verified the activation state of each group's antitumor immunity.

RESULTS

Mice that received dendritic cells exposed to cryotreated tumor lysates with reimplantation of the cryotreated primary tumor group had high serum interferon gamma, reduced pulmonary metastases, and increased numbers of CD8(+) T lymphocytes in the metastatic areas.

CONCLUSIONS

Combining tumor cryotreatment with dendritic cells enhanced systemic immune responses and inhibited metastatic tumor growth.

CLINICAL RELEVANCE

We suggest immunotherapy could be developed further to improve the treatment of osteosarcoma.

The kinase Mirk is a potential therapeutic target in osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor affecting children and adolescents. The majority of patients are treated by surgery and chemotherapy but have limited alternative therapeutic options. Kinases play an important role in the growth and survival of tumor cells. We aim to identify specific kinases to be vital in the survival of osteosarcoma cells and thus may be a key target in creating novel anticancer therapies. A lentiviral short hairpin RNA kinase library, screened osteosarcoma cells, identified kinase minibrain-related kinase (Mirk) (Dyrk1B) as a potential target. Knockdown Mirk expression could inhibit cell growth and induce apoptosis. Chemically synthetic small interfering RNA knockdown and complementary DNA rescue assay further confirmed the results from the decrease of Mirk gene expression. The relationship between Mirk gene expression and the clinical characteristics of patients with osteosarcoma was investigated using tissue microarray and immunohistochemistry analysis. The data indicate that the overall survival rate of patients with Mirk high staining (high levels of Mirk protein expression) is significantly shorter than those with Mirk low staining and moderate staining. This highlights Mirk's potential to serve as a promising target for molecular therapy in the treatment of osteosarcoma.

Safety and pharmacokinetics of a solid lipid curcumin particle formulation in osteosarcoma patients and healthy volunteers

Curcumin is the lipid-soluble antioxidant compound obtained from the rhizome of Curcuma longa Linn, also known as turmeric. Curcumin targets multiple chemotherapeutic and inflammatory pathways and has demonstrated safety and tolerability in humans, supporting its potential as a therapeutic agent; however, the clinical literature lacks conclusive evidence supporting its use as a therapeutic agent due to its low bioavailability in humans. The purpose of this study was to quantify plasma levels of free curcumin after dosing of a solid lipid curcumin particle (SLCP) formulation versus unformulated curcumin in healthy volunteers and to determine its tolerability and dose-plasma concentration relationship in late-stage osteosarcoma patients. Doses of 2, 3, and 4 g of SLCP were evaluated in 11 patients with osteosarcoma. Plasma curcumin levels were measured using a validated high-performance liquid chromatography method. The limit of detection of the assay was 1 ng/mL of curcumin. In healthy subjects, the mean peak concentration of curcumin achieved from dosing 650 mg of SLCP was 22.43 ng/mL, whereas plasma curcumin from dosing an equal quantity of unformulated 95% curcuminoids extract was not detected. In both healthy individuals and osteosarcoma patients, high interindividual variability in pharmacokinetics and nonlinear dose dependency was observed, suggesting potentially complex absorption kinetics. Overall, good tolerability was noted in both healthy and osteosarcoma groups.

Novel therapeutic agents for osteosarcoma

Osteosarcoma is the most common malignant primary bone tumor in childhood. Despite multiagent chemotherapy and aggressive surgical resection, 30% of patients with localized disease and 80% of patients with metastatic disease at diagnosis will relapse. Survival for these patients has remained unchanged over the past 20 years. A number of novel agents in various stages of development hold promise for improving therapy for patients with osteosarcoma. This article will focus on novel therapeutic approaches, including agents targeting signal-transduction pathways, inhibitors of the tumor microenvironment and immunomodulatory agents, as well as overcoming resistance mechanisms and the use of novel delivery mechanisms.