Current research progress in targeted anti-angiogenesis therapy for osteosarcoma

Inhibitory effect of Endostar on HIF-1 with upregulation of MHC-I in lung cancer cells

Endostar is a human recombinant endostatin which is an attractive anti-angiogenesis protein. Because inefficient antigen presenting MHC class I expression (which can be downregulated by HIF-1) is an important strategy for cancer immune evasion, besides its anti-angiogenesis effect, it remains unclear whether Endostar has an inhibitory effect on HIF-1 expression by upregulating MHC class I expression in cancer cells to facilitate immunotherapies, including PD-1/PD-L1 inhibitors. In this study, A549 and NCI-H1299 lung cancer cells were treated with Endostar (6.25 μg/ml, 12.5 μg/ml, and 25 μg/ml, respectively). HIF-1 expression was detected by Immunocytochemistry and Western blot. Proteins of the MHC class I α-heavy chain and β2 m light chain, STAT3 and pSTAT3 were detected by Western blot. The mRNAs of MHC class I α-heavy chain and β2 m light chain were detected by RT-qPCR. It was shown that decreased expression of HIF-1 and promotion of β2-microglobulin were observed after Endostar treatment. In addition, elevated levels of MHC class I α-heavy chain mRNA and protein, as well as downregulation of STAT3 and pSTAT3, were also observed following Endostar treatment. Endostar inhibited HIF-1 expression in A549 and NCI-H1299 lung cancer cells, upregulated expression of MHC class I α-heavy chain and β2 m light chain, with the upregulation of STAT3 and pSTAT3, suggesting involvement of STAT3 pathway. It is important because only in combination with MHC class I on target cells can tumor antigenic peptides be recognized by CD8+ CTLs which destroy target cells. However, MHC class I is frequently deficient in cancer cells.

Lactate metabolism and lactylation in breast cancer: mechanisms and implications

As the end-product of glycolysis, lactate serves as a regulator of protein lactylation in addition to being an energy substrate, metabolite, and signaling molecule in cancer. The reprogramming of glucose metabolism and the Warburg effect in breast cancer results in extensive lactate production and accumulation, making it likely that lactylation in tumor tissue is also abnormal. This review summarizes evidence on lactylation derived from studies of lactate metabolism and disease, highlighting the role of lactate in the tumor microenvironment of breast cancer and detailing the levels of lactylation and cancer-promoting mechanisms across various tumors. The roles of lactate and lactylation, along with potential intervention mechanisms, are presented and discussed, offering valuable insights for future research on the role of lactylation in tumors.

Efficacy and safety analysis of vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) in the treatment of osteosarcoma: a systematic review and meta-analysis

BACKGROUND

Osteosarcoma is a rare and aggressive bone cancer, with targeted therapy using VEGFR-TKIs (Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitors) emerging as a promising treatment option.

RESEARCH DESIGN AND METHODS

This meta-analysis evaluated the efficacy and safety of VEGFR-TKIs in osteosarcoma treatment, analyzing studies from PubMed, Embase, Web of Science, and Cochrane databases until 18 September 2023, involving 14 trials with 447 patients.

RESULTS

Results indicated that monotherapy with VEGFR-TKIs had an objective response rate(ORR) of 16% (95% CI = 9-24%) and a disease control rate(DCR) of 65% (95% CI = 57-73%). The average progression-free survival(PFS) was 4.27 months(95% CI = 3.21-5.34), with overall survival(OS) at 9.26 months(95% CI = 7.75-10.77). Combined treatments led to an ORR of 7% (95% CI = 2-12%) and a DCR of 71% (95% CI = 54-88%), with PFS of 5.62 months(95% CI = 3.57-7.74) and OS of 11.84 months(95% CI = 9.26-14.43). Treatment-related adverse events occurred in 83% (95% CI = 74-92%), with severe events in 32% (95% CI = 3-61%).

CONCLUSIONS

In conclusion, VEGFR-TKIs demonstrate effectiveness and tolerability in osteosarcoma treatment, providing significant disease control and survival advantages despite notable adverse event risks.

REGISTRATION

PROSPERO (CRD42024579648).

Prognostic Significance of Microvessel Density and Hypoxic Markers in Canine Osteosarcoma: Insights into Angiogenesis and Tumor Aggressiveness

Canine osteosarcoma (OSA) is an aggressive and highly malignant tumor of bone with a poor prognosis and it mirrors the disease in humans. Angiogenesis, the formation of new blood vessels, is driven by hypoxia-induced factors such as HIF-1α and VEGF, both of which play a crucial role in tumor growth and metastasis. However, the role of angiogenesis in OSA remains a topic of ongoing debate. This study aimed to investigate the relationship between angiogenesis, measured by intratumoral microvessel density (MVD), hypoxic markers, and clinical outcomes in 28 dogs diagnosed with appendicular OSA. Clinicopathological data such as age, breed distribution, tumor localization, histopathological subtypes, and metastatic behavior were consistent with reported epidemiologic characteristics of canine OSA, though no significant correlation was found among these variables. The results indicated a significant association between higher MVD and high-grade OSA (p = 0.029), suggesting that increased tumor vascularization is linked to more aggressive tumor behavior. Additionally, elevated VEGF expression was strongly correlated with disease-free interval DFI), with a p-value of 0.045. Although HIF-1α positivity showed a trend towards poorer survival, the results did not reach statistical significance (p = 0.07). These findings highlight the potential role of VEGF as a valuable prognostic marker in canine OSA, which could have potentially important implications for therapeutic targeting and clinical management of the disease. This study advances the understanding of angiogenesis in canine OSA, while emphasizing the need for continued research into the complex mechanisms regulating the interplay between hypoxia, angiogenesis and tumor progression.

Lactylation in cancer: Mechanisms in tumour biology and therapeutic potentials

Lactylation, a recently identified form of protein post-translational modification (PTM), has emerged as a key player in cancer biology. The Warburg effect, a hallmark of tumour metabolism, underscores the significance of lactylation in cancer progression. By regulating gene transcription and protein function, lactylation facilitates metabolic reprogramming, enabling tumours to adapt to nutrient limitations and sustain rapid growth. Over the past decade, extensive research has revealed the intricate regulatory network underlying lactylation in tumours. Large-scale sequencing and machine learning have confirmed the widespread occurrence of lactylation sites across the tumour proteome. Targeting lactylation enzymes or metabolic pathways has demonstrated promising anti-tumour effects, highlighting the therapeutic potential of this modification. This review comprehensively explores the mechanisms of lactylation in cancer cells and the tumour microenvironment. We expound on the application of advanced omics technologies for target identification and data modelling within the lactylation field. Additionally, we summarise existing anti-lactylation drugs and discuss their clinical implications. By providing a comprehensive overview of recent advancements, this review aims to stimulate innovative research and accelerate the translation of lactylation-based therapies into clinical practice. KEY POINTS: Lactylation significantly influences tumour metabolism and gene regulation, contributing to cancer progression. Advanced sequencing and machine learning reveal widespread lactylation sites in tumours. Targeting lactylation enzymes shows promise in enhancing anti-tumour drug efficacy and overcoming chemotherapy resistance. This review outlines the clinical implications and future research directions of lactylation in oncology.

Exosome-mediated delivery of siRNA molecules in cancer therapy: triumphs and challenges

The discovery of novel and innovative therapeutic strategies for cancer treatment and management remains a major global challenge. Exosomes are endogenous nanoscale extracellular vesicles that have garnered increasing attention as innovative vehicles for advanced drug delivery and targeted therapy. The attractive physicochemical and biological properties of exosomes, including increased permeability, biocompatibility, extended half-life in circulation, reduced toxicity and immunogenicity, and multiple functionalization strategies, have made them preferred drug delivery vehicles in cancer and other diseases. Small interfering RNAs (siRNAs) are remarkably able to target any known gene: an attribute harnessed to knock down cancer-associated genes as a viable strategy in cancer management. Extensive research on exosome-mediated delivery of siRNAs for targeting diverse types of cancer has yielded promising results for anticancer therapy, with some formulations progressing through clinical trials. This review catalogs recent advances in exosome-mediated siRNA delivery in several types of cancer, including the manifold benefits and minimal drawbacks of such innovative delivery systems. Additionally, we have highlighted the potential of plant-derived exosomes as innovative drug delivery systems for cancer treatment, offering numerous advantages such as biocompatibility, scalability, and reduced toxicity compared to traditional methods. These exosomes, with their unique characteristics and potential for effective siRNA delivery, represent a significant advancement in nanomedicine and cancer therapeutics. Further exploration of their manufacturing processes and biological mechanisms could significantly advance natural medicine and enhance the efficacy of exosome-based therapies.

Development and experimental verification of novel angiogenesis related prognostic model and immune infiltration characterization in osteosarcoma

BACKGROUND

As the most common primary bone cancer, osteosarcoma (OS) still lacks satisfactory therapeutic outcomes. Therefore, it is crucial to further evaluate OS at different risk levels and identify new intervention targets. Many evidences suggest the important role of angiogenesis in OS, but further exploration is needed.

METHODS

We utilized public databases TARGET and GEO and employed bioinformatics algorithms such as LASSO, univariate and multivariate Cox regression analyses, and unsupervised consensus clustering to explore the role of angiogenesis-related genes (AGRGs) in OS. By calculating AGRG scores, we further analyzed OS molecular subtypes based on AGRGs. The correlation between AGRG scores and immune infiltration was subsequently examined. In vitro experiments, including WB, PCR, siRNA, migration, and invasion assays, were used to determine the value of the selected targets for OS.

RESULTS

Ultimately, we established an OS prognosis model based on five AGRGs (COL5A2, CXCL6, FSTL1, NRP1, and TNFRSF21) that can independently validate prognosis levels. In vitro experiments confirmed the aberrant expression of CXCL6 in OS and its potential role in migration and invasion.

CONCLUSION

Our study reveals the impact of angiogenesis on OS from a novel perspective and provides potential intervention targets.

WTAP-mediated m6A modification of circ_0032463 promotes osteosarcoma progression by sponging miR-145-5p and regulating GFRA1 expression

Osteosarcoma (OS) is the most frequent bone malignancy in humans. Previous evidence suggest that circ_0032463 is an oncogenic circular RNA (circRNA) in various cancers, including OS. However, the molecular mechanism of circ_0032463 involved in OS is still unclear. Circ_0032463, microRNA-145-5p (miR-145-5p), GDNF receptor alpha 1 (GFRA1), and Wilms tumor 1-associated protein (WTAP) levels were determined using real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, apoptosis, migration, invasion, and angiogenesis were analyzed using 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, and tube formation assays. Western blot analysis was performed to measure matrix metalloproteinase 2 (MMP2), MMP9, GFRA1, and WTAP protein levels. Binding between miR-145-5p and circ_0032463 or GFRA1 was confirmed using a dual-luciferase reporter and pull-down assay. The biological role of circ_0032463 on OS cell growth was also analyzed using a xenograft tumor model in vivo. Methylated RNA immunoprecipitation assay validated the interaction between WTAP and circ_0032463. Circ_0032463, GFRA1, and WTAP levels were increased, and miR-145-5p was decreased in OS tissues and cells. Circ_0032463 deficiency might hinder OS cell proliferation, migration, invasion, angiogenesis, and promote apoptosis in vitro. Mechanically, circ_0032463 worked as a miR-145-5p sponge to increase GFRA1 expression. Repression of circ_0032463 knockdown on tumor cell growth was proved in vivo. Besides, N6-methyladenosine (m6A) modification facilitates the biogenesis of circ_0032463. Taken together, m6A-mediated biogenesis of circ_0032463 facilitates OS cell malignant biological behavior partly via regulating the miR-145-5p/GFRA1 axis, suggesting a promising molecular marker for OS treatment.

Targeted anti-angiogenesis therapy for advanced osteosarcoma

To date, despite extensive research, the prognosis of advanced osteosarcoma has not improved significantly. Thus, patients experience a reduced survival rate, suggesting that a reevaluation of current treatment strategies is required. Recently, in addition to routine surgery, chemotherapy and radiotherapy, researchers have explored more effective and safer treatments, including targeted therapy, immunotherapy, anti-angiogenesis therapy, metabolic targets therapy, and nanomedicine therapy. The tumorigenesis and development of osteosarcoma is closely related to angiogenesis. Thus, anti-angiogenesis therapy is crucial to treat osteosarcoma; however, recent clinical trials found that it has insufficient efficacy. To solve this problem, the causes of treatment failure and improve treatment strategies should be investigated. This review focuses on summarizing the pathophysiological mechanisms of angiogenesis in osteosarcoma and recent advances in anti-angiogenesis treatment of osteosarcoma. We also discuss some clinical studies, with the aim of providing new ideas to improve treatment strategies for osteosarcoma and the prognosis of patients.

EYA4 reduces chemosensitivity of osteosarcoma to doxorubicin through DNA damage repair

Previous studies have demonstrated that Eyes Absent 4 (EYA4) influences the proliferation and migration of tumor cells. Notably, studies have established that EYA4 can also limit tumor sensitivity to chemotherapeutic agents. The objective of this study was to investigate the effect of EYA4 in conferring drug resistance in osteosarcoma (OS). Bioinformatics, histological, and cellular analyses revealed that the expression level of EYA4 was higher in OS tissues than in healthy tissues/cells and in resistant tissues/cells compared with sensitive tissues/cells. In vitro and in vivo experiments demonstrated that EYA4 knockdown increased the sensitivity of OS to doxorubicin (DOX). Conversely, overexpression of EYA4 decreased the sensitivity of OS to DOX. Exploration of the resistance mechanism exposed that EYA4 facilitates DNA double-strand break (DSB) repair, a typical mode of DNA damage repair (DDR). Subsequently, our findings indicated that EYA4 could directly interact with histone H2AX to activate the DDR pathway. Taken together, our observations indicated that EYA4 may serve as a target molecule for reversing drug resistance in OS patients.

Exploring the effects of taurolidine on tumor weight and microvessel density in a murine model of osteosarcoma

Background

Osteosarcoma is the most common malignant primary bone tumor. The prognosis for patients with disseminated disease remains very poor despite recent advancements in chemotherapy. Moreover, current treatment regimens bear a significant risk of serious side effects. Thus, there is an unmet clinical need for effective therapies with improved safety profiles. Taurolidine is an antibacterial agent that has been shown to induce cell death in different types of cancer cell lines.

Methods

In this study, we examined both the antineoplastic and antiangiogenic effects of taurolidine in animal models of osteosarcoma. K7M2 murine osteosarcoma cells were injected, both intramuscular and intraperitoneal, into 60 BALB/c mice on day zero. Animals were then randomized to receive treatment with taurolidine 2% (800 mg/kg), taurolidine 1% (400 mg/kg), or NaCl 0.9% control for seven days by intravenous or intraperitoneal administration.

Results

After 35 days, mice were euthanized, and the tumors were harvested for analysis. Eighteen mice were excluded from the analysis due to complications. Body weight was significantly lower in the 2% taurolidine intraperitoneal treatment group from day 9 to 21, consistent with elevated mortality in this group. Intraperitoneal tumor weight was significantly lower in the 1% (p = 0.003) and 2% (p = 0.006) intraperitoneal taurolidine treatment groups compared to the control. No antineoplastic effects were observed on intramuscular tumors or for intravenous administration of taurolidine. There were no significant differences in microvessel density or mitotic rate between treatment groups. Reduced body weight and elevated mortality in the 2% taurolidine intraperitoneal group suggest that the lower 1% dose is preferable.

Conclusions

In conclusion, there is no evidence of antiangiogenic activity, and the antitumor effects of taurolidine on osteosarcoma observed in this study are limited. Moreover, its toxic profile grants further evaluation. Given these observations, further research is necessary to refine the use of taurolidine in osteosarcoma treatment.

Tumor mitochondrial oxidative phosphorylation stimulated by the nuclear receptor RORγ represents an effective therapeutic opportunity in osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor with a poor prognosis. Here, we show that the nuclear receptor RORγ may serve as a potential therapeutic target in OS. OS exhibits a hyperactivated oxidative phosphorylation (OXPHOS) program, which fuels the carbon source to promote tumor progression. We found that RORγ is overexpressed in OS tumors and is linked to hyperactivated OXPHOS. RORγ induces the expression of PGC-1β and physically interacts with it to activate the OXPHOS program by upregulating the expression of respiratory chain component genes. Inhibition of RORγ strongly inhibits OXPHOS activation, downregulates mitochondrial functions, and increases ROS production, which results in OS cell apoptosis and ferroptosis. RORγ inverse agonists strongly suppressed OS tumor growth and progression and sensitized OS tumors to chemotherapy. Taken together, our results indicate that RORγ is a critical regulator of the OXPHOS program in OS and provides an effective therapeutic strategy for this deadly disease.

A Reconfigurable DNA Framework Nanotube-Assisted Antiangiogenic Therapy

A major limitation of tumor antiangiogenic therapy is the pronounced off-target effect, which can lead to unavoidable injury in multiple organs. Ensuring sufficient delivery and controlled release of these antiangiogenic agents at tumor sites is crucial for realizing their clinical application. Here, we develop a smart DNA-based nanodrug, termed Endo-rDFN, by precisely assembling the antiangiogenic agent, endostar (Endo), into a reconfigurable DNA framework nanotube (rDFN) that could recognize tumor-overexpressed nucleolin to achieve the targeted delivery and controllable release of Endo. Endo-rDFN can not only effectively enhance the tumor-targeting capability of Endo and maintain its efficient accumulation in tumor tissues but also achieve on-demand release of Endo at tumor sites via the specific DNA aptamer for tumor-overexpressed nucleolin, named AS1411. We also found that Endo-rDFN exhibited significant inhibition of angiogenesis and tumor growth, while also providing effective protection against multiorgan injury (heart, liver, spleen, kidney, lung, etc.) to some extent, without compromising the function of these organs. Our study demonstrates that rDFN represents a promising vector for reducing antiangiogenic therapy-induced multiorgan injury, highlighting its potential for promoting the clinical application of antiangiogenic agents.

Investigating the synergy of Shikonin and Valproic acid in inducing apoptosis of osteosarcoma cells via ROS-mediated EGR1 expression

BACKGROUND

Osteosarcoma is the most prevalent malignant bone tumour with a poor prognosis. Shikonin (SHK) is derived from the traditional Chinese medicine Lithospermum that has been extensively studied for its notable anti-tumour effects, including for osteosarcoma. However, its application has certain limitations. Valproic acid (VPA) is a histone deacetylase inhibitor (HDACI) that has recently been employed as an adjunctive therapeutic agent that allows chromatin to assume a more relaxed state, thereby enhancing anti-tumour efficacy.

PURPOSE

This study was aimed to investigate the synergistic anti-tumour efficacy of SHK in combination with VPA and elucidate its underlying mechanism.

METHODS/STUDY DESIGN

CCK-8 assays were utilized to calculate the combination index. Additional assays, including colony formation, acridine orange/ethidium bromide double fluorescent staining, and flow cytometry, were employed to evaluate the effects on osteosarcoma cells. Wound healing and transwell assays were utilized to assess cell mobility. RNA sequencing, PCR, and Western blot analyses were conducted to uncover the underlying mechanism. Rescue experiments were performed to validate the mechanism of apoptotic induction. The impact of SHK and VPA combination treatment on primary osteosarcoma cells was also assessed. Finally, in vivo experiments were conducted to validate its anti-tumour effects and mechanism.

RESULTS

The combination of SHK and VPA synergistically inhibited the proliferation and migration of osteosarcoma cells in vitro and induced apoptosis in these cells. Through a comprehensive analysis involving RNA sequencing, PCR, Western blot, and rescue experiments, we have substantiated our hypothesis that the combination of SHK and VPA induced apoptosis via the ROS-EGR1-Bax axis. Importantly, our in vivo experiments corroborated these findings, demonstrating the potential of the SHK and VPA combination as a promising therapeutic approach for osteosarcoma.

CONCLUSION

The combination of SHK and VPA exerted an anti-tumour effect by inducing apoptosis through the ROS-EGR1-Bax pathway. Repurposing the old drug VPA demonstrated its effectiveness as an adjunctive therapeutic agent for SHK, enhancing its anti-tumour efficacy and revealing its potential value. Furthermore, our study expanded the application of natural compounds in the anti-tumour field and overcame some of their limitations through combination therapy. Finally, we enhanced the understanding of the mechanistic pathways linking reactive oxygen species (ROS) accumulation and apoptosis in osteosarcoma cells. Additionally, we elucidated the role of EGR1 in osteosarcoma cells, offering novel strategies and concepts for the treatment of osteosarcoma.

FRS2 regulated by miR-429 and miR-206 promotes angiogenesis in osteosarcoma

FRS2 has demonstrated oncogenic roles in various malignancies, including liposarcoma and giant cell tumor of bone. However, its role in osteosarcoma remains less understood, and the upstream regulatory molecules influencing FRS2 remain unclear. This study aims to explore the clinical implications and biological function of FRS2 in osteosarcoma, and the potential regulatory microRNAs (miRNAs) governing its expression. Our study indicated significant upregulation of FRS2 in osteosarcoma cells and tissues by Western blotting and immunohistochemical staining. Elevated FRS2 expression correlated positively with increased angiogenesis and poor prognosis, possibly serving as an independent prognostic indicator for osteosarcoma patients. Functional assays revealed that attenuating FRS2 in osteosarcoma cells could mitigate proliferation, migration, and angiogenesis of vascular endothelial cells. Further investigations revealed that miR-429 and miR-206 directly targeted FRS2, exerting a negative regulation on its expression. Furthermore, FRS2 played a role in repressing osteosarcoma advancement influenced by miR-429 or miR-206. In summary, FRS2, influenced by miR-429 and miR-206, emerges as a promising therapeutic candidate for antiangiogenic osteosarcoma treatments.

Hypoxia inducible factor-1ɑ as a potential therapeutic target for osteosarcoma metastasis

Osteosarcoma (OS) is a malignant tumor originating from mesenchymal tissue. Pulmonary metastasis is usually present upon initial diagnosis, and metastasis is the primary factor affecting the poor prognosis of patients with OS. Current research shows that the ability to regulate the cellular microenvironment is essential for preventing the distant metastasis of OS, and anoxic microenvironments are important features of solid tumors. During hypoxia, hypoxia-inducible factor-1α (HIF-1α) expression levels and stability increase. Increased HIF-1α promotes tumor vascular remodeling, epithelial-mesenchymal transformation (EMT), and OS cells invasiveness; this leads to distant metastasis of OS cells. HIF-1α plays an essential role in the mechanisms of OS metastasis. In order to develop precise prognostic indicators and potential therapeutic targets for OS treatment, this review examines the molecular mechanisms of HIF-1α in the distant metastasis of OS cells; the signal transduction pathways mediated by HIF-1α are also discussed.

Nano-Based Drug Delivery Systems: Potential Developments in the Therapy of Metastatic Osteosarcoma-A Narrative Review

Osteosarcoma, a predominant malignant bone tumor, poses significant challenges due to its high metastatic and recurrent nature. Although various therapeutic strategies are currently in use, they often inadequately target osteosarcoma metastasis. This review focuses on the potential of nanoscale drug delivery systems to bridge this clinical gap. It begins with an overview of the molecular mechanisms underlying metastatic osteosarcoma, highlighting the limitations of existing treatments. The review then transitions to an in-depth examination of nanoscale drug delivery technologies, emphasizing their potential to enhance drug bioavailability and reduce systemic toxicity. Central to this review is a discussion of recent advancements in utilizing nanotechnology for the potential intervention of metastatic osteosarcoma, with a critical analysis of several preclinical studies. This review aims to provide insights into the potential applications of nanotechnology in metastatic osteosarcoma therapy, setting the stage for future clinical breakthroughs and innovative cancer treatments.

Indoloquinazoline alkaloids suppress angiogenesis and inhibit metastasis of melanoma cells

Metastasis is the leading cause of cancer-related mortality, targeting angiogenesis emerges as a therapeutic strategy for the treatment of melanoma metastasis. Discovery of new antiangiogenic compounds with specific mechanism of action is still desired. In present study, a bioassay-guidance uncovers the EtOAc extract of a marine-derived fungus Aspergillus clavutus LZD32-24 with significant inhibitory activity against the angiogenesis in Tg (fli1a: EGFP) zebrafish model. Extensive chromatographic fractionation led to the isolation of 48 indoloquinazoline alkaloids, including 21 new analogues namely clavutoines A-U (1-21). Their structures were determined by the spectroscopic data, including the ECD, single crystal X-ray diffraction and quantum chemical calculation for the configurational assignments. Among the bioactive analogues, quinadoline B (QB) showed the most efficacy to suppress the zebrafish vascular outgrowth in zebrafish embryos. QB markedly inhibited the migration, invasion and tube formation with weak cytotoxicity in human umbilical vein endothelial cells (HUVECs). Investigation of the mode of action revealed QB suppressed the ROCK/MYPT1/MLC2/coffin and FAK /Src signaling pathways, and subsequently disrupted actin cytoskeletal organization. In addition, QB reduced the number of new vessels sprouting from the ex vivo chick chorioallantoic membrane (CAM), and inhibited the metastasis of B16F10 melanoma cells in lung of C57BL/6 mice through suppressing angiogenesis. These findings suggest that QB is a potential lead for the development of new antiangiogenic agent to inhibit melanoma metastasis.

Vascular normalization: reshaping the tumor microenvironment and augmenting antitumor immunity for ovarian cancer

Ovarian cancer remains a challenging disease with limited treatment options and poor prognosis. The tumor microenvironment (TME) plays a crucial role in tumor growth, progression, and therapy response. One characteristic feature of the TME is the abnormal tumor vasculature, which is associated with inadequate blood perfusion, hypoxia, and immune evasion. Vascular normalization, a therapeutic strategy aiming to rectify the abnormal tumor vasculature, has emerged as a promising approach to reshape the TME, enhance antitumor immunity, and synergize with immunotherapy in ovarian cancer. This review paper provides a comprehensive overview of vascular normalization and its potential implications in ovarian cancer. In this review, we summarize the intricate interplay between anti-angiogenesis and immune modulation, as well as ICI combined with anti-angiogenesis therapy in ovarian cancer. The compelling evidence discussed in this review contributes to the growing body of knowledge supporting the utilization of combination therapy as a promising treatment paradigm for ovarian cancer, paving the way for further clinical development and optimization of this therapeutic approach.

Research progress in the mechanism and treatment of osteosarcoma

ABSTRACT

Osteosarcoma (OS) is the most common primary malignant bone tumor that more commonly occurs in children and adolescents. The most commonly used treatment for OS is surgery combined with chemotherapy, but the treatment outcomes are typically unsatisfactory. High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS. This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities. Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS. In this review, we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS. We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.

In vivo self-assembly and delivery of VEGFR2 siRNA-encapsulated small extracellular vesicles for lung metastatic osteosarcoma therapy

The prognosis of lung metastatic osteosarcoma (OS) remains disappointing. siRNA-based gene silencing of VEGFR2 is a promising treatment strategy for lung metastatic OS, but there is a lack of safe and efficient delivery systems to encapsulate siRNAs for in vivo administration. This study presented a synthetic biological strategy that remolds the host liver with synthesized genetic circuits for efficient in vivo VEGFR2 siRNA delivery. After being taken-up by hepatocytes, the genetic circuit (in the form of a DNA plasmid) reprogrammed the liver to drive the autonomous intrahepatic assembly and encapsulation of VEGFR2 siRNAs into secretory small extracellular vesicles (sEVs), thus allowing for the transport of self-assembled VEGFR2 siRNAs towards the lung. The results showed that our strategy was superior to the positive medicine (Apatinib) for OS lung metastasis in terms of therapeutic efficacy and toxic adverse effects and may provide a feasible and viable therapeutic solution for lung metastatic OS.

Tocilizumab (monoclonal anti-IL-6R antibody) reverses anlotinib resistance in osteosarcoma

Purpose

Anlotinib, a tyrosine kinase inhibitor (TKI) has been in clinical application to inhibit malignant cell growth and lung metastasis in osteosarcoma (OS). However, a variety of drug resistance phenomena have been observed in the treatment. We aim to explore the new target to reverse anlotinib resistance in OS.

Materials and Methods

In this study, we established four OS anlotinib-resistant cell lines, and RNA-sequence was performed to evaluate differentially expressed genes. We verified the results of RNA-sequence by PCR, western blot and ELISA assay. We further explored the effects of tocilizumab (anti- IL-6 receptor), either alone or in combined with anlotinib, on the inhibition of anlotinib-resistant OS cells malignant viability by CCK8, EDU, colony formation, apoptosis, transwell, wound healing, Cytoskeletal stain assays, and xenograft nude mouse model. The expression of IL-6 in 104 osteosarcoma samples was tested by IHC.

Results

We found IL-6 and its downstream pathway STAT3 were activated in anlotinib-resistant osteosarcoma. Tocilizumab impaired the tumor progression of anlotinib-resistant OS cells, and combined treatment with anlotinib augmented these effects by inhibiting STAT3 expressions. IL-6 was highly expressed in patients with OS and correlated with poor prognosis.

Conclusion

Tocilizumab could reverse anlotinib resistance in OS by IL-6/STAT3 pathway and the combination treatment with anlotinib rationalized further studies and clinical treatment of OS.

METTL1/WDR4-mediated tRNA m7G modification and mRNA translation control promote oncogenesis and doxorubicin resistance

Osteosarcoma is the most common bone tumor that leads to high mortality in adolescents and children. The tRNA N⁷-methylguanosine methyltransferase METTL1 is located in chromosome 12q14.1, a region that is frequently amplified in osteosarcoma patients, while its functions and underlying mechanisms in regulation of osteosarcoma remain unknown. Herein we show that METTL1 and WDR4 are overexpressed in osteosarcoma and associated with poor patient prognosis. Knockdown of METTL1 or WDR4 causes decreased tRNA m⁷G modification level and impairs osteosarcoma progression in vitro and in vivo. Conversely, METTL1/WDR4 overexpression promotes osteosarcoma proliferation, migration and invasion capacities. tRNA methylation and mRNA translation profiling indicate that METTL1/WDR4 modified tRNAs enhance translation of mRNAs with more m⁷G tRNA-decoded codons, including extracellular matrix (ECM) remodeling effectors, which facilitates osteosarcoma progression and chemoresistance to doxorubicin. Our study demonstrates METTL1/WDR4 mediated tRNA m⁷G modification plays crucial oncogenic functions to enhance osteosarcoma progression and chemoresistance to doxorubicin via alteration of oncogenic mRNA translation, suggesting METTL1 inhibition combined with chemotherapy is a promising strategy for treatment of osteosarcoma patients.

The Roles of Exosomes in Metastasis of Sarcoma: From Biomarkers to Therapeutic Targets

Sarcoma is a heterogeneous group of mesenchymal neoplasms with a high rate of lung metastasis. The cellular mechanisms responsible for sarcoma metastasis remain poorly understood. Furthermore, there are limited efficacious therapeutic strategies for treating metastatic sarcoma. Improved diagnostic and therapeutic modalities are of increasing importance for the treatment of sarcoma due to their high mortality in the advanced stages of the disease. Recent evidence demonstrates that the exosome, a type of extracellular vesicle released by virtually all cells in the body, is an important facilitator of intercellular communication between the cells and the surrounding environment. The exosome is gaining significant attention among the medical research community, but there is little knowledge about how the exosome affects sarcoma metastasis. In this review, we summarize the multifaceted roles of sarcoma-derived exosomes in promoting the process of metastasis via the formation of pre-metastatic niche (PMN), the regulation of immunity, angiogenesis, vascular permeability, and the migration of sarcoma cells. We also highlight the potential of exosomes as innovative diagnostic and prognostic biomarkers as well as therapeutic targets in sarcoma metastasis.

Targeted therapy for osteosarcoma: a review

BACKGROUND

Osteosarcoma is a common primary malignant tumour of the bone that usually occurs in children and adolescents. It is characterised by difficult treatment, recurrence and metastasis, and poor prognosis. Currently, the treatment of osteosarcoma is mainly based on surgery and auxiliary chemotherapy. However, for recurrent and some primary osteosarcoma cases, owing to the rapid progression of disease and chemotherapy resistance, the effects of chemotherapy are poor. With the rapid development of tumour-targeted therapy, molecular-targeted therapy for osteosarcoma has shown promise.

PURPOSE

In this paper, we review the molecular mechanisms, related targets, and clinical applications of targeted osteosarcoma therapy. In doing this, we provide a summary of recent literature on the characteristics of targeted osteosarcoma therapy, the advantages of its clinical application, and development of targeted therapy in future. We aim to provide new insights into the treatment of osteosarcoma.

CONCLUSION

Targeted therapy shows potential in the treatment of osteosarcoma and may offer an important means of precise and personalised treatment in the future, but drug resistance and adverse effects may limit its application.

Identification and validation of an anoikis-related lncRNA signature to predict prognosis and immune landscape in osteosarcoma

Background

Anoikis is a specialized form of programmed apoptosis that occurs in two model epithelial cell lines and plays an important role in tumors. However, the prognostic value of anoikis-related lncRNA (ARLncs) in osteosarcoma (OS) has not been reported.

Methods

Based on GTEx and TARGET RNA sequencing data, we carried out a thorough bioinformatics analysis. The 27 anoikis-related genes were obtained from the Gene Set Enrichment Analysis (GSEA). Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) analysis were successively used to screen for prognostic-related ARLncs. To create the prognostic signature of ARLncs, we performed multivariate Cox regression analysis. We calculated the risk score based on the risk coefficient, dividing OS patients into high- and low-risk subgroups. Additionally, the relationship between the OS immune microenvironment and risk prognostic models was investigated using function enrichment, including Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), single-sample gene set enrichment analysis (ssGSEA), and GSEA analysis. Finally, the potential effective drugs in OS were found by immune checkpoint and drug sensitivity screening.

Results

A prognostic signature consisting of four ARLncs (AC079612.1, MEF2C-AS1, SNHG6, and TBX2-AS1) was constructed. To assess the regulation patterns of anoikis-related lncRNA genes, we created a risk score model. According to a survival analysis, high-risk patients have a poor prognosis as they progress. By using immune functional analysis, the lower-risk group demonstrated the opposite effects compared with the higher-risk group. GO and KEGG analysis showed that the ARLncs pathways and immune-related pathways were enriched. Immune checkpoints and drug sensitivity analysis might be used to determine the better effects of the higher group.

Conclusion

We identified a novel prognostic model based on a four-ARLncs signature that might serve as potential prognostic indicators that can be used to predict the prognosis of OS patients, and immunotherapy and drugs that may contribute to improving the overall survival of OS patients and advance our understanding of OS.

The interaction between osteosarcoma and other cells in the bone microenvironment: From mechanism to clinical applications

Osteosarcoma is a primary bone tumor with a high mortality rate. The event-free survival rate has not improved significantly in the past 30 years, which brings a heavy burden to patients and society. The high heterogeneity of osteosarcoma leads to the lack of specific targets and poor therapeutic effect. Tumor microenvironment is the focus of current research, and osteosarcoma is closely related to bone microenvironment. Many soluble factors and extracellular matrix secreted by many cells in the bone microenvironment have been shown to affect the occurrence, proliferation, invasion and metastasis of osteosarcoma through a variety of signaling pathways. Therefore, targeting other cells in the bone microenvironment may improve the prognosis of osteosarcoma. The mechanism by which osteosarcoma interacts with other cells in the bone microenvironment has been extensively investigated, but currently developed drugs targeting the bone microenvironment have poor efficacy. Therefore, we review the regulatory effects of major cells and physical and chemical properties in the bone microenvironment on osteosarcoma, focusing on their complex interactions, potential therapeutic strategies and clinical applications, to deepen our understanding of osteosarcoma and the bone microenvironment and provide reference for future treatment. Targeting other cells in the bone microenvironment may provide potential targets for the development of clinical drugs for osteosarcoma and may improve the prognosis of osteosarcoma.

RNA-seq and Single-Cell Transcriptome Analyses of TRAIL Receptors Gene Expression in Human Osteosarcoma Cells and Tissues

Osteosarcoma (OS) is the most common primary cancer in the skeletal system, characterized by a high incidence of lung metastasis, local recurrence and death. Systemic treatment of this aggressive cancer has not improved significantly since the introduction of chemotherapy regimens, underscoring a critical need for new treatment strategies. TRAIL receptors have long been proposed to be therapeutic targets for cancer treatment, but their role in osteosarcoma remains unclear. In this study, we investigated the expression profile of four TRAIL receptors in human OS cells using total RNA-seq and single-cell RNA-seq (scRNA-seq). The results revealed that TNFRSF10B and TNFRSF10D but not TNFRSF10A and TNFRSF10C are differentially expressed in human OS cells as compared to normal cells. At the single cell level by scRNA-seq analyses, TNFRSF10B, TNFRSF10D, TNFRSF10A and TNFRSF10C are most abundantly expressed in endothelial cells of OS tissues among nine distinct cell clusters. Notably, in osteoblastic OS cells, TNFRSF10B is most abundantly expressed, followed by TNFRSF10D, TNFRSF10A and TNFRSF10C. Similarly, in an OS cell line U2-OS using RNA-seq, TNFRSF10B is most abundantly expressed, followed by TNFRSF10D, TNFRSF10A and TNFRSF10C. According to the TARGET online database, poor patient outcomes were associated with low expression of TNFRSF10C. These results could provide a new perspective to design novel therapeutic targets of TRAIL receptors for the diagnosis, prognosis and treatment of OS and other cancers.

The role of angiogenesis in melanoma: Clinical treatments and future expectations

The incidence of melanoma has increased rapidly over the past few decades, with mortality accounting for more than 75% of all skin cancers. The high metastatic potential of Melanoma is an essential factor in its high mortality. Vascular angiogenic system has been proved to be crucial for the metastasis of melanoma. An in-depth understanding of angiogenesis will be of great benefit to melanoma treatment and may promote the development of melanoma therapies. This review summarizes the recent advances and challenges of anti-angiogenic agents, including monoclonal antibodies, tyrosine kinase inhibitors, human recombinant Endostatin, and traditional Chinese herbal medicine. We hope to provide a better understanding of the mechanisms, clinical research progress, and future research directions of melanoma.

Current progress and open challenges for applying tyrosine kinase inhibitors in osteosarcoma

Osteosarcoma (OS) is a mesenchymal-origin tumor that constitutes the most common primary malignant bone tumor. The survival rate of the patients has significantly improved since the introduction of neoadjuvant chemotherapy and extensive resection, but it has stagnated in recent 40 years. Tyrosine kinase inhibitors (TKIs) have played a key part in the treatment of malignant tumors. In advanced OS, TKIs including anlotinib, apatinib, sorafenib, etc. have significantly improved the progression-free survival of patients, while the overall survival remains unchanged. The main reason is the rapid and inevitable progress of acquired drug resistance of OS. However, as the application of TKIs in OS and other tumors is still in the exploratory phase, its drug resistance mechanism and corresponding solutions are rarely reported. Hence, in this review, we summarize knowledge of the applications of TKIs, the mechanism of TKIs resistance, and the attempts to overcome TKIs resistance in OS, which are the three potentially novel insights of TKIs in OS. Because most evidence is derived from studies using animal and cell models, we also reviewed clinical trials and related bioinformatics data available in public databases, which partially improved our understanding of TKIs applications.

Establishment of Rapid and Accurate Screening System for Molecular Target Therapy of Osteosarcoma

Introduction Comprehensive analyses using clinical sequences subcategorized osteosarcoma (OS) into several groups according to the activated signaling pathways. Mutually exclusive co-occurrences of gene amplification (PDGFRA/KIT/KDR, VEGFA/CCND3, and MDM2/CDK4) have been identified in approximately 40% of OS, representing candidate subsets for clinical evaluation of additional therapeutic options. Thus, it would be desirable to evaluate the specific gene amplification before starting therapy in patients with OS. Materials and Methods This is a retrospective study. We examined 13 cases of clinical OS samples using NanoString-based copy number variation (CNV) analysis. Decalcification and chemotherapeutic effects on this analysis were also assessed. Results First, the accuracy of this system was validated by showing that amplification/deletion data obtained from this system using various types of cancer cell lines almost perfectly matched to that from the Cancer Cell Line Encyclopedia (CCLE). We identified potentially actionable alterations in CDK4/MDM2 amplification in 10% of samples and potential additional therapeutic targets (PDGFRA/KIT/KDR and VEGFA/CCND3) in 20% of samples, which is consistent with the reported frequencies. Furthermore, this assay could identify these potential therapeutic targets regardless of the sample status (frozen vs formalin-fixed paraffin-embedded [FFPE] tissues). Conclusion We established a NanoString-based rapid and cost-effective method with a short turnaround time (TAT) to examine gene amplification status in OS. This CNV analysis using FFPE samples is recommended where the histological evaluation of viable tumor cells is possible, especially for tumors after chemotherapy with higher chemotherapeutic effects.

Effects of microenvironment in osteosarcoma on chemoresistance and the promise of immunotherapy as an osteosarcoma therapeutic modality

Osteosarcoma (OS) is one of the most common primary malignant tumors originating in bones. Its high malignancy typically manifests in lung metastasis leading to high mortality. Although remarkable advances in surgical resection and neoadjuvant chemotherapy have lengthened life expectancy and greatly improved the survival rate among OS patients, no further breakthroughs have been achieved. It is challenging to treat patients with chemoresistant tumors and distant metastases. Recent studies have identified a compelling set of links between hypoxia and chemotherapy failure. Here, we review the evidence supporting the positive effects of hypoxia in the tumor microenvironment (TME). In addition, certain anticancer effects of immune checkpoint inhibitors have been demonstrated in OS preclinical models. Continued long-term observation in clinical trials is required. In the present review, we discuss the mutualistic effects of the TME in OS treatment and summarize the mechanisms of immunotherapy and their interaction with TME when used to treat OS. We also suggest that immunotherapy, a new comprehensive and potential antitumor approach that stimulates an immune response to eliminate tumor cells, may represent an innovative approach for the development of a novel treatment regimen for OS patients.

Progress of phototherapy for osteosarcoma and application prospect of blue light photobiomodulation therapy

Osteosarcoma (OS) is the most common primary malignant bone tumor that mainly affects the pediatric and adolescent population; limb salvage treatment has become one of the most concerned and expected outcomes of OS patients recently. Phototherapy (PT), as a novel, non-invasive, and efficient antitumor therapeutic approach including photodynamic therapy (PDT), photothermal therapy (PTT), and photobiomodulation therapy (PBMT), has been widely applied in superficial skin tumor research and clinical treatment. OS is the typical deep tumor, and its phototherapy research faces great limitations and challenges. Surprisingly, pulse mode LED light can effectively improve tissue penetration and reduce skin damage caused by high light intensity and has great application potential in deep tumor research. In this review, we discussed the research progress and related molecular mechanisms of phototherapy in the treatment of OS, mainly summarized the status quo of blue light PBMT in the scientific research and clinical applications of tumor treatment, and outlooked the application prospect of pulsed blue LED light in the treatment of OS, so as to further improve clinical survival rate and prognosis of OS treatment and explore corresponding cellular mechanisms.

Circular RNA circDOCK1 contributes to osteosarcoma progression by acting as a ceRNA for miR-936 to regulate LEF1

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CircDOCK1 knockdown relieved osteosarcoma cell malignant behaviors.

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CircDOCK1 functioned as a molecular sponge of miR-936.

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miR-936 directly targeted LEF1.

Background

Osteosarcoma (OS) is a serious bone malignancy that commonly occurred in humans. Recent research suggested that circular RNA (circRNA) Dedicator of cytokinesis 1 (circDOCK1, also called hsa_circ_0020378) enrolled in the tumorigenesis of osteogenic sarcoma. This subject aimed to explore the precise role and mechanism of circDOCK1 on OS progression.

Methods

CircDOCK1, microRNA-936 (miR-936), and Lymphoid enhancer binding factor 1 (LEF1) levels were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8), colony formation, 5-ethynyl-2′-deoxyuridine (EdU), transwell, wound healing, and tube formation assays were used to assess OS cell proliferation, migration, invasion, and angiogenesis. Western blot analysis of protein levels of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP2), MMP9, and LEF1. According to bioinformatics software (circular RNA Interactome and TargetScan) analysis, the binding between miR-936 and circDOCK1 or LEF1 was predicted, followed by verification by a dual-luciferase reporter and RNA Immunoprecipitation (RIP) assays.

Results

Increased circDOCK1 and LEF1, and decreased miR-936 were found in OS tissues and cell lines. Furthermore, circDOCK1 silencing might suppress OS cell proliferation, migration, invasion, and angiogenesis in vitro. Bioinformatics analysis exhibited that circDOCK1 acted as a sponge for miR-936 and LEF1 was a downstream target of miR-936. Moreover, circDOCK1 functions through modulation of the miR-936/LEF1 axis.

Conclusion

CircDOCK1 knockdown might attenuate OS cell malignant biological behaviors by regulating the miR-936/GFRA1 axis, which may highlight the diagnostic and therapeutic potential of these molecules for OS treatment.

Extracellular vesicles: A new diagnostic biomarker and targeted drug in osteosarcoma

Osteosarcoma (OS) is a primary bone cancer that is highly prevalent among adolescents and adults below the age of 20 years. The prognostic outcome of metastatic OS or relapse is extremely poor; thus, developing new diagnostic and therapeutic strategies for treating OS is necessary. Extracellular vesicles (EVs) ranging from 30–150 nm in diameter are commonly produced in different cells and are found in various types of body fluids. EVs are rich in biologically active components like proteins, lipids, and nucleic acids. They also strongly affect pathophysiological processes by modulating the intercellular signaling pathways and the exchange of biomolecules. Many studies have found that EVs influence the occurrence, development, and metastasis of osteosarcoma. The regulation of inflammatory communication pathways by EVs affects OS and other bone-related pathological conditions, such as osteoarthritis and rheumatoid arthritis. In this study, we reviewed the latest findings related to diagnosis, prognosis prediction, and the development of treatment strategies for OS from the perspective of EVs.

Circular RNA circFIRRE drives osteosarcoma progression and metastasis through tumorigenic-angiogenic coupling

Background

Disappointing clinical efficacy of standard treatment has been proven in refractory metastatic osteosarcoma, and the emerging anti-angiogenic regimens are still in the infantile stage. Thus, there is an urgent need to develop novel therapeutic approach for osteosarcoma lung metastasis.

Methods

circFIRRE was selected from RNA-sequencing of 4 matched osteosarcoma and adjacent samples. The expression of circFIRRE was verified in clinical osteosarcoma samples and cell lines via quantitative real-time polymerase chain reaction (RT-qPCR). The effect of circFIRRE was investigated in cell lines in vitro models, ex vivo models and in vivo xenograft tumor models, including proliferation, invasion, migration, metastasis and angiogenesis. Signaling regulatory mechanism was evaluated by RT-qPCR, Western blot, RNA pull-down and dual-luciferase reporter assays.

Results

In this article, a novel circular RNA, circFIRRE (hsa_circ_0001944) was screened out and identified from RNA-sequencing, and was upregulated in both osteosarcoma cell lines and tissues. Clinically, aberrantly upregulated circFIRRE portended higher metastatic risk and worse prognosis in osteosarcoma patients. Functionally, in vitro, ex vivo and in vivo experiments demonstrated that circFIRRE could drive primary osteosarcoma progression and lung metastasis by inducing both tumor cells and blood vessels, we call as “tumorigenic-angiogenic coupling”. Mechanistically, upregulated circFIRRE was induced by transcription factor YY1, and partially boosted the mRNA and protein level of LUZP1 by sponging miR-486-3p and miR-1225-5p.

Conclusions

We identified circFIRRE as a master regulator in the tumorigenesis and angiogenesis of osteosarcoma, which could be purposed as a novel prognostic biomarker and therapeutic target for refractory osteosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01624-7.

The SIRT1-HMGB1 axis: Therapeutic potential to ameliorate inflammatory responses and tumor occurrence

Inflammation is a common complication of many chronic diseases. It includes inflammation of the parenchyma and vascular systems. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase, which can directly participate in the suppression of inflammation. It can also regulate the activity of other proteins. Among them, high mobility group box 1 (HMGB1) signaling can be inhibited by deacetylating four lysine residues (55, 88, 90, and 177) in quiescent endothelial cells. HMGB1 is a ubiquitous nuclear protein, once translocated outside the cell, which can interact with various target cell receptors including the receptor for advanced glycation end-products (RAGE), toll-like receptor (TLR) 2, and TLR4 and stimulates the release of pro-inflammatory cyto-/chemokines. And SIRT1 has been reported to inhibit the activity of HMGB1. Both are related to the occurrence and development of inflammation and associated diseases but show an antagonistic relationship in controlling inflammation. Therefore, in this review, we introduce how this signaling axis regulates the emergence of inflammation-related responses and tumor occurrence, providing a new experimental perspective for future inflammation research. In addition, it explores diverse upstream regulators and some natural/synthetic activators of SIRT1 as a possible treatment for inflammatory responses and tumor occurrence which may encourage the development of new anti-inflammatory drugs. Meanwhile, this review also introduces the potential molecular mechanism of the SIRT1-HMGB1 pathway to improve inflammation, suggesting that SIRT1 and HMGB1 proteins may be potential targets for treating inflammation.

Single-cell RNA sequencing reveals differential expression of EGFL7 and VEGF in giant-cell tumor of bone and osteosarcoma

Dysregulation of angiogenesis is associated with tumor development and is accompanied by altered expression of pro-angiogenic factors. EGFL7 is a newly identified antigenic factor that plays a role in various cancers such as breast cancer, lung cancer, and acute myeloid leukemia. We have recently found that EGFL7 is expressed in the bone microenvironment, but its role in giant-cell tumor of bone (GCTB) and osteosarcoma (OS) is unknown. The aims of this study are to examine the gene expression profile of EGFL7 in GCTB and OS and compare with that of VEGF-A-D and TNFSF11 using single-cell RNA sequencing data. In-depth differential expression analyses were employed to characterize their expression in the constituent cell types of GCTB and OS. Notably, EGFL7 in GCTB was expressed at highest levels in the endothelial cell (EC) cluster followed by osteoblasts, myeloid cells, and chondrocytes, respectively. In OS, EGFL7 exhibited highest expression in EC cell cluster followed by osteoblastic OS cells, myeloid cells 1, and carcinoma associated fibroblasts (CAFs), respectively. In comparison, VEGF-A is expressed at highest levels in myeloid cells followed by OCs in GCTB, and in myeloid cells, and OCs in OS. VEGF-B is expressed at highest levels in chondrocytes in GCTB and in OCs in OS. VEGF-C is strongly enriched in ECs and VEGF-D is expressed at weak levels in all cell types in both GCTB and OS. TNFSF11 (or RANKL) shows high expression in CAFs and osteoblastic OS cells in OS, and osteoblasts in GCTB. This study investigates pro-angiogenic genes in GCTB and OS and suggests that these genes and their expression patterns are cell-type specific and could provide potential prognostic biomarkers and cell type target treatment for GCTB and OS.

Single-cell RNA-seq identification of four differentially expressed survival-related genes by a TARGET: Osteosarcoma database analysis

Osteosarcoma (OS) differentially expressed genes (DEGs) have been predicted using the data portal of the Therapeutically Applicable Research to Generate Effective Treatments (TARGET). In this study, we sought to identify cell types that specially express key DEGs (MUC1, COL13A1, JAG2, and KAZALD1) in each of the nine identified cell populations derived from tissues of OS tumors with single-cell RNA-sequencing data. Gene expression levels were pairwise compared between cell clusters and a p value < 0.05 was considered differentially expressed. It was revealed that MUC1 is expressed at high levels in osteoblastic OS cells followed by carcinoma-associated fibroblasts (CAFs) and plasmocytes, respectively. COL13A1 is highly expressed in osteoblastic OS cells, CAFs, and endothelial cells (ECs), respectively. The KAZALD1 gene is expressed in CAFs and osteoblastic OS cells at high levels, but at very low levels in plasmocytes, osteoclasts, NK/T, myeloid cells 1, myeloid cells 2, ECs, and B cells. JAG2 is expressed at significantly high levels in ECs and osteoblastic OS cells, and at relatively lower levels in all other cell types. Interestingly, LSAMP, as an established gene in the development of OS shows high expression in osteoblastic OS cells and CAFs but low in other cells such as osteoclasts. Our findings here highlight the heterogeneity of OS cells and cell-type-dependent DEGs which have potential as therapeutic targets in OS.

The regulatory mechanism of LncRNA-mediated ceRNA network in osteosarcoma

Aberrantly expressed lncRNAs have been reported to be closely related to the oncogenesis and development of osteosarcoma. However, the role of a dysregulated lncRNA-miRNA-mRNA network in osteosarcoma in the same individual needs to be further investigated. Whole transcriptome sequencing was performed on the tumour tissues and matched paratumour tissues of three patients with confirmed osteosarcoma. Two divergent lncRNA-miRNA-mRNA regulatory networks were constructed in accordance with their biological significance. The GO and KEGG analysis results of the mRNAs in the two networks revealed that the aberrantly expressed lncRNAs were involved in regulating bone growth and development, epithelial cell proliferation, cell cycle arrest and the N-terminal acetylation of proteins. The survival analysis results of the two networks showed that patients with high expression of GALNT3, FAM91A1, STC2 and SLC7A1 end in poorer prognosis. Likewise, patients with low expression of IGF2, BLCAP, ZBTB47, THRB, PKIA and MITF also had poor prognosis. A subnetwork was then constructed to demonstrate the key genes regulated by aberrantly expressed lncRNAs at the posttranscriptional level via the ceRNA network. Aberrantly expressed lncRNAs in osteosarcoma tissues regulate genes involved in cellular proliferation, differentiation, angiogenesis and the cell cycle via the ceRNA network.

Screening and Analysis of Biomarkers in the miRNA-mRNA Regulatory Network of Osteosarcoma

Osteosarcoma is a malignant disease, and few effective strategies can completely overcome the prognosis of these patients. This study attempted to reveal the key factors and related molecular mechanisms of osteosarcoma via excavating public microarray datasets. The data were obtained from the Gene Expression Omnibus (GEO) database; the differentially expressed miRNAs and differentially expressed genes were obtained in GSE69470 and GSE12685l, respectively; the target of miRNAs were predicted with the miRDIP database; the functions of the factors were analyzed and visualized by the David database and R language, respectively. Moreover, the protein-protein interaction network and miRNA-mRNA network were performed with the STRING database and Cytoscape software to identify the hub nodes in GSE69470 and GSE12685. The results showed that 834 DEGs were found in GSE12685 and 37 miRNAs were found in GSE69470. Moreover, the target of 37 miRNAs were enriched in PI3K/AKT, P53, Wnt/β-catenin, and TGF-β pathways and related with skeletal system development and cell growth. Besides, the miRNAs including miR-22-3p, miR-154-5p, miR-34a-5p, miR-485-3p, miR-93-5p, and miR-9-5p and the genes including LEF1, RUNX2, CSF1R, CDKN1A, and FBN1 were identified as the hub nodes via network analysis. In conclusion, this study suggested that the miRNAs including miR-22-3p, miR-154-5p, miR-34a-5p, miR-485-3p, miR-93-5p, and miR-9-5p and the genes including LEF1, RUNX2, CSF1R, CDKN1A, and FBN1 act as key factors in the progression of osteosarcoma.

LncRNA BACE1-AS promotes the progression of osteosarcoma through miR-762/SOX7 axis

BACKGROUND

Osteosarcoma (OS) is a rare malignant primary tumor of mesenchymal origin affecting bone that occurs in adolescents and children. LncRNAs are important regulators of tumorigenesis and development. This study aimed to explore the role and molecular basis of LncRNA BACE1-AS (BACE1 antisense RNA) in OS.

METHODS AND RESULTS

Through the analysis of differential expressed lncRNAs in OS tissues by GEO database, LncRNA BACE1-AS display a remarkably lower expression. This found can also be observed in both OS tissues and cell lines by qRT-PCR. Furthermore, using Cell counting kit-8 (CCK-8), transwell, wound healing and westernblot assays, overexpression LncRNA BACE1-AS remarkably reduce cell proliferation, migration and invasion abilities in OS. In addition, LncRNA BACE1-AS is validated as a sponge of miR-762 through the prediction of lncRNASNP. Further, luciferase reporter and RIP assays are conducted to confirm the binding sites between LncRNA BACE1-AS and miR-762. SRY-box transcription factor 7 (SOX7) target to miR-762 and regulated by LncRNA BACE1-AS. Moreover, inhibition of miR-762 attenuate the role of sh-LncRNA BACE1-AS in OS cells, at meanwhile reduce the expression of SOX7.

CONCLUSION

In this study, LncRNA BACE1-AS regulates proliferation, migration and invasion of osteosarcoma cells by miR-762/SOX7 axis, implying that LncRNA BACE1-AS is a potential target for osteosarcoma therapy.

A multiscale cell-based model of tumor growth for chemotherapy assessment and tumor-targeted therapy through a 3D computational approach

OBJECTIVES

Computational modeling of biological systems is a powerful tool to clarify diverse processes contributing to cancer. The aim is to clarify the complex biochemical and mechanical interactions between cells, the relevance of intracellular signaling pathways in tumor progression and related events to the cancer treatments, which are largely ignored in previous studies.

MATERIALS AND METHODS

A three-dimensional multiscale cell-based model is developed, covering multiple time and spatial scales, including intracellular, cellular, and extracellular processes. The model generates a realistic representation of the processes involved from an implementation of the signaling transduction network.

RESULTS

Considering a benign tumor development, results are in good agreement with the experimental ones, which identify three different phases in tumor growth. Simulating tumor vascular growth, results predict a highly vascularized tumor morphology in a lobulated form, a consequence of cells' motile behavior. A novel systematic study of chemotherapy intervention, in combination with targeted therapy, is presented to address the capability of the model to evaluate typical clinical protocols. The model also performs a dose comparison study in order to optimize treatment efficacy and surveys the effect of chemotherapy initiation delays and different regimens.

CONCLUSIONS

Results not only provide detailed insights into tumor progression, but also support suggestions for clinical implementation. This is a major step toward the goal of predicting the effects of not only traditional chemotherapy but also tumor-targeted therapies.

The role of toceranib phosphate in dogs with non-mast cell neoplasia: A systematic review

The use of tyrosine kinase inhibitors (TKI) has gained significant importance in veterinary cancer patients over the last decade. Toceranib phosphate has been licensed for the treatment of dogs with mast cell tumours. Its molecular similarity to sunitinib, a TKI used in human medicine, has led many veterinary oncologists to use this agent for multiple neoplastic diseases. The aim of the current study was to perform a systematic review of the evidence for the use of toceranib in dogs with non-mast cell neoplasia. Two electronic databases were searched. Publications were included if toceranib was used as a treatment option in canine patients. Studies and case reports were excluded if toceranib was used as part of a multi-modal treatment plan and response or outcome data related to toceranib therapy were not described. A total of 28 studies were included from 122 references. The most common types of neoplasias identified were neuroendocrine tumours, anal gland sac adenocarcinoma, and osteosarcoma. Multiple other neoplasias had one or two studies identified to describe the use of toceranib. Results of the study support that toceranib phosphate may have efficacy against certain types of neoplasia under certain conditions, such as neuroendocrine tumours, gastrointestinal stromal tumours and anal sac adenocarcinomas, while it is probably not effective for the management of metastatic osteosarcoma based on the findings of the review.

Osteosarcoma and Metastasis

Osteosarcoma is the most common primary bone malignancy in adolescents. Its high propensity to metastasize is the leading cause for treatment failure and poor prognosis. Although the research of osteosarcoma has greatly expanded in the past decades, the knowledge and new therapy strategies targeting metastatic progression remain sparse. The prognosis of patients with metastasis is still unsatisfactory. There is resonating urgency for a thorough and deeper understanding of molecular mechanisms underlying osteosarcoma to develop innovative therapies targeting metastasis. Toward the goal of elaborating the characteristics and biological behavior of metastatic osteosarcoma, it is essential to combine the diverse investigations that are performed at molecular, cellular, and animal levels from basic research to clinical translation spanning chemical, physical sciences, and biology. This review focuses on the metastatic process, regulatory networks involving key molecules and signaling pathways, the role of microenvironment, osteoclast, angiogenesis, metabolism, immunity, and noncoding RNAs in osteosarcoma metastasis. The aim of this review is to provide an overview of current research advances, with the hope to discovery druggable targets and promising therapy strategies for osteosarcoma metastasis and thus to overcome this clinical impasse.

Research Progress of circRNAs in Glioblastoma

Circular RNAs (circRNAs) are a class of single-stranded covalently closed non-coding RNAs without a 5' cap structure or 3' terminal poly (A) tail, which are expressed in a variety of tissues and cells with conserved, stable and specific characteristics. Glioblastoma (GBM) is the most aggressive and lethal tumor in the central nervous system, characterized by high recurrence and mortality rates. The specific expression of circRNAs in GBM has demonstrated their potential to become new biomarkers for the development of GBM. The specific expression of circRNAs in GBM has shown their potential as new biomarkers for GBM cell proliferation, apoptosis, migration and invasion, which provides new ideas for GBM treatment. In this paper, we will review the biological properties and functions of circRNAs and their biological roles and clinical applications in GBM.

Osteosarcoma from the unknown to the use of exosomes as a versatile and dynamic therapeutic approach

The most common primary malignant tumor of bone in children is osteosarcoma (OS). Nowadays, the prognosis and the introduction of chemotherapy in OS have improved survival rates of patients. Nevertheless, the results are still unsatisfactory, especially, in patients with recurrent disease or metastatic. OS chemotherapy has two main challenges related to treatment toxicity and multiple drug resistance. In this way, nanotechnology has developed nanosystems capable of releasing the drug directly at the OS cells and decreasing the drug's toxicity. Exosomes (Exo), a cell-derived nano-sized and a phospholipid vehicle, have been recognized as important drug delivery systems in several cancers. They are involved in a variety of biological processes and are an important mediator of long-distance intercellular communication. Exo can reduce inflammation and show low toxicity in healthy cells. Furthermore, the incorporation of specific proteins or peptides on the Exo surface improves their targeting capability in several clinical applications. Due to their unique structure and relevant characteristics, Exo is a promising nanocarrier for OS treatment. This review intends to describe the properties that turn Exo into an efficient, as well as safe nanovesicle for drug delivery and treatment of OS.

Extracellular Vesicles in Osteosarcoma: Antagonists or Therapeutic Agents?

Osteosarcoma (OS) is a skeletal tumor affecting mainly children and adolescents. The presence of distance metastasis is frequent and it is localized preferentially to the lung, representing the main reason for death among patients. The therapeutic approaches are based on surgery and chemotherapeutics. However, the drug resistance and the side effects associated with the chemotherapy require the identification of new therapeutic approaches. The understanding of the complex biological scenario of the osteosarcoma will open the way for the identification of new targets for its treatment. Recently, a great interest of scientific community is for extracellular vesicles (EVs), that are released in the tumor microenvironment and are important regulators of tumor proliferation and the metastatic process. At the same time, circulating extracellular vesicles can be exploited as diagnostic and prognostic biomarkers, and they can be loaded with drugs as a new therapeutic approach for osteosarcoma patients. Thus, the characterization of OS-related EVs could represent a way to convert these vesicles from antagonists for human health into therapeutic and/or diagnostic agents.