Expression analysis of genes associated with human osteosarcoma tumors shows correlation of RUNX2 overexpression with poor response to chemotherapy

Hsa_circ_0001480 affects osteosarcoma progression by regulating the miR-363-3p/IBSP pathway

Osteosarcoma (OS) is a malignant bone tumor that commonly affects young individuals. Circular RNAs (circRNAs) are associated with OS progression. In this study, we aimed to determine the role of hsa_circ_0001480 (circ_0001480) in OS development. OS cell invasion, viability, and colony numbers were assessed via transwell, cell counting kit-8, and colony formation assays, respectively. Tumor growth in vivo was also assessed using an OS mouse model. Additionally, targeted associations among the integrin-binding sialoprotein (IBSP), microRNA (miR)-363-3p, and circ_0001480 were evaluated via RNA immunoprecipitation and dual luciferase reporter assays, whereas their expression levels in OS cells and tissues were determined via quantitative reverse transcription-polymerase chain reaction and western blotting. Loss of circ_0001480 or IBSP significantly inhibited the proliferation and invasion of OS cells, but this effect was reversed by miR-363-3p downregulation. Moreover, circ_0001480 knockdown inhibited neoplasm growth in vivo. circ_0001480 directly bound to miR-363-3p, which further modulated IBSP. Both circ_0001480 and IBSP levels were high, whereas miR-363-3p levels were low in OS cells. Furthermore, low miR-363-3p levels attenuated the suppressive effects of circ_0001480 silencing on the proliferation and invasion of OS cells; however, loss of IBSP partially reversed these effects. Overall, our findings revealed circ_0001480 an oncogenic circRNA stimulating OS progression by modulating the miR-363-3p/IBSP pathway, suggesting its potential for OS treatment.

Chb-M', an Inhibitor of the RUNX Family Binding to DNA, Induces Apoptosis in p53-Mutated Non-Small Cell Lung Cancer and Inhibits Tumor Growth and Repopulation In Vivo

Runt-related transcription factor (RUNX) proteins are considered to play various roles in cancer. Here, we evaluated the anticancer activity of Chb-M', a compound that specifically and covalently binds to the consensus sequence for RUNX family proteins, in p53-mutated non-small cell lung cancer cells. Chb-M' killed the cancer cells by inducing apoptosis. The compound showed an anticancer effect comparable to that of the clinically used drugs alectinib and ceritinib in vivo. Notably, Chb-M' extended the cancer-free survival of mice after ending treatment more effectively than did the other two drugs. The results presented here suggest that Chb-M' is an attractive candidate as an anticancer drug applicable to the treatment of non-small cell lung cancer and various other types of cancers.

RUNX transcription factors: biological functions and implications in cancer

Runt-related transcription factors (RUNX) are a family of transcription factors that are essential for normal and malignant hematopoietic processes. Their most widely recognized role in malignancy is to promote the occurrence and development of acute myeloid leukemia. However, it is worth noting that during the last decade, studies of RUNX proteins in solid tumors have made considerable progress, suggesting that these proteins are directly involved in different stages of tumor development, including tumor initiation, progression, and invasion. RUNX proteins also play a role in tumor angiogenesis, the maintenance of tumor cell stemness, and resistance to antitumor drugs. These findings have led to the consideration of RUNX as a tumor biomarker. All RUNX proteins are involved in the occurrence and development of solid tumors, but the role of each RUNX protein in different tumors and the major signaling pathways involved are complicated by tumor heterogeneity and the interacting tumor microenvironment. Understanding how the dysregulation of RUNX in tumors affects normal biological processes is important to elucidate the molecular mechanisms by which RUNX affects malignant tumors.

Clinical Significance and Potential Mechanisms of the RNA Methyltransferase KIAA1429 in Osteosarcoma

Background: KIAA1429, a member of the RNA methyltransferase complex, is involved in cancer progression; however, the clinical significance and underlying mechanism of KIAA1429 in osteosarcoma (OS) remains to be reported. Methods: We evaluated the clinical significance of KIAA1429 in OS by performing RT-qPCR, microarray, and RNA sequencing and using published data as a reference. Two KIAA1429-targeting siRNA constructs were transfected into SW1353 cells. CCK-8 assay, colony formation assays, flow cytometry and the xenograft mouse model were conducted to investigate the biological function of KIAA1429 in OS. Results: The mRNA expression of KIAA1429 was markedly upregulated in 250 OS samples as compared to that in 71 non-cancer samples (standardized mean difference = 0.67). Summary receiver operating characteristic curve analysis revealed that KIAA1429 exhibited reliable diagnostic capacity to differentiate OS samples from non-cancer samples (area under the curve = 0.83). Further, survival analysis indicated that KIAA1429 overexpression was associated with shorter overall survival time. Knocking down KIAA1429 reduced m6A methylation levels, inhibited proliferation, prevented the growth of tumors in vivo and accelerated apoptosis of OS cells. In total, 395 KIAA1429-related genes were identified among co-expressed genes and differentially expressed genes, which were enriched in the cell cycle pathway. Protein-protein interaction network analysis showed that CDK1, CCNA2, and CCNB1 were KIAA1429-related genes, serving as major network hubs in OS. Conclusions: Our findings indicate that KIAA1429 plays an oncogenic role in OS and potentially facilitates OS progression via a mechanism that involves regulating CDK1, CCNA2, and CCNB1.

A novel CircRNA Circ_0001722 regulates proliferation and invasion of osteosarcoma cells through targeting miR-204-5p/RUNX2 axis

BACKGROUND

Osteosarcoma (OS) is the most prevalent primary fatal bone neoplasm in adolescents and children owing to limited therapeutic methods. Circular RNAs (circRNAs) are identified as vital regulators in a variety of cancers. However, the roles of circRNAs in OS are still unclear.

METHODS

Firstly, we evaluate the differentially expressed circRNAs in 3 paired OS and corresponding adjacent nontumor tissue samples by circRNA microarray assay, finding a novel circRNA, circ_001722, significantly upregulated in OS tissues and cells. The circular structure of candidate circRNA was confirmed through Sanger sequencing, divergent primer PCR, and RNase R treatments. Proliferation of OS cells was evaluated in vitro and in vivo. The microRNA (miRNA) sponge mechanism of circRNAs was verified by dual-luciferase assay and RNA immunoprecipitation assay.

RESULTS

A novel circRNA, circ_001722, is significantly upregulated in OS tissues and cells. Downregulation of circ_0001722 can suppress proliferation and invasion of human OS cells in vitro and in vivo. Computational algorithms predict miR-204-5p can bind with circ_0001722 and RUNX2 mRNA 3'UTR, which is verified by Dual-luciferase assay and RNA immunoprecipitation assay. Further functional experiments show that circ_0001722 competitively binds to miR-204-5p and prevents it to decrease the level of RUNX2, which upregulates proliferation and invasion of human OS cells.

CONCLUSION

Circ_001722 is a novel tumor promotor in OS, and promotes the progression of OS via miR-204-5p/RUNX2 axis.

The OSR9 Regimen: A New Augmentation Strategy for Osteosarcoma Treatment Using Nine Older Drugs from General Medicine to Inhibit Growth Drive

As things stand in 2023, metastatic osteosarcoma commonly results in death. There has been little treatment progress in recent decades. To redress the poor prognosis of metastatic osteosarcoma, the present regimen, OSR9, uses nine already marketed drugs as adjuncts to current treatments. The nine drugs in OSR9 are: (1) the antinausea drug aprepitant, (2) the analgesic drug celecoxib, (3) the anti-malaria drug chloroquine, (4) the antibiotic dapsone, (5) the alcoholism treatment drug disulfiram, (6) the antifungal drug itraconazole, (7) the diabetes treatment drug linagliptin, (8) the hypertension drug propranolol, and (9) the psychiatric drug quetiapine. Although none are traditionally used to treat cancer, all nine have attributes that have been shown to inhibit growth-promoting physiological systems active in osteosarcoma. In their general medicinal uses, all nine drugs in OSR9 have low side-effect risks. The current paper reviews the collected data supporting the role of OSR9.

Osteosarcoma Multi-Omics Landscape and Subtypes

Osteosarcoma (OS) is the most common primary bone malignancy that exhibits remarkable histologic diversity and genetic heterogeneity. The complex nature of osteosarcoma has confounded precise molecular categorization, prognosis, and prediction for this disease. In this study, we performed a comprehensive multiplatform analysis on 86 osteosarcoma tumors, including somatic copy-number alteration, gene expression and methylation, and identified three molecularly distinct and clinically relevant subtypes of osteosarcoma. The subgrouping criteria was validated on another cohort of osteosarcoma tumors. Previously unappreciated osteosarcoma-type-specific changes in specific genes' copy number, expression and methylation were revealed based on the subgrouping. The subgrouping and novel gene signatures provide insights into refining osteosarcoma therapy and relationships to other types of cancer.

Regulation and Function of FOXC1 in Osteoblasts

Estrogens, which bind to estrogen receptor alpha (ERα), are important for proper bone mineral density. When women go through menopause, estrogen levels decrease, and there is a decrease in bone quality, along with an increased risk for fractures. We previously identified an enhancer near FOXC1 as the most significantly enriched binding site for estrogen receptor alpha (ERα) in osteoblasts. FOXC1 is a transcription factor belonging to a large group of proteins known as forkhead box genes and is an important regulator of bone formation. Here, we demonstrate that 17β-estradiol (E2) increases the mRNA and protein levels of FOXC1 in primary mouse and human osteoblasts. GATA4 is a pioneer factor for ERα and it is also recruited to enhancers near Foxc1. Knockdown of Gata4 in mouse osteoblasts in vitro decreases Foxc1 expression as does knockout of Gata4 in vivo. Functionally, GATA4 and FOXC1 interact and regulate osteoblast proteins such as RUNX2, as demonstrated by ChIP-reChIP and luciferase assays. The most enriched motif in GATA4 binding sites from ChIP-seq is for FOXC1, supporting the notion that GATA4 and FOXC1 cooperate in regulating osteoblast differentiation. Together, these data demonstrate the interactions of the transcription factors ERα, GATA4, and FOXC1 to regulate each other's expression and other osteoblast differentiation genes.

RUNX Family as a Promising Biomarker and a Therapeutic Target in Bone Cancers: A Review on Its Molecular Mechanism(s) behind Tumorigenesis

The transcription factor runt-related protein (RUNX) family is the major transcription factor responsible for the formation of osteoblasts from bone marrow mesenchymal stem cells, which are involved in bone formation. Accumulating evidence implicates the RUNX family for its role in tumor biology and cancer progression. The RUNX family has been linked to osteosarcoma via its regulation of many tumorigenicity-related factors. In the regulatory network of cancers, with numerous upstream signaling pathways and its potential target molecules downstream, RUNX is a vital molecule. Hence, a pressing need exists to understand the precise process underpinning the occurrence and prognosis of several malignant tumors. Until recently, RUNX has been regarded as one of the therapeutic targets for bone cancer. Therefore, in this review, we have provided insights into various molecular mechanisms behind the tumorigenic role of RUNX in various important cancers. RUNX is anticipated to grow into a novel therapeutic target with the in-depth study of RUNX family-related regulatory processes, aid in the creation of new medications, and enhance clinical efficacy.

Role of RUNX2 in breast cancer development and drug resistance (Review)

Breast cancer is the most common malignancy and ranks second among the causes of tumor-associated death in females. The recurrence and drug resistance of breast cancer are intractable due to the presence of breast cancer stem cells (BCSCs), which are adequate to initiate tumor formation and refractory to conventional remedies. Runt-related transcription factor 2 (RUNX2), a pivotal transcription factor in mammary gland and bone development, has also been related to metastatic cancer and BCSCs. State-of-the-art research has indicated the retention of RUNX2 expression in a more invasive subtype of breast cancer, and in particular, triple-negative breast cancer development and drug resistance are associated with estrogen receptor signaling pathways. The present review mainly focused on the latest updates on RUNX2 in BCSCs and their roles in breast cancer progression and drug resistance, providing insight that may aid the development of RUNX2-based diagnostics and treatments for breast cancer in clinical practice.

Runt-related transcription factors in human carcinogenesis: a friend or foe?

PURPOSE

Cancer is one of the deadliest pathologies with more than 19 million new cases and 10 million cancer-related deaths across the globe. Despite development of advanced therapeutic interventions, cancer remains as a fatal pathology due to lack of early prognostic biomarkers, therapy resistance and requires identification of novel drug targets.

METHODS

Runt-related transcription factors (Runx) family controls several cellular and physiological functions including osteogenesis. Recent literatures from PubMed was mined and the review was written in comprehensive manner RESULTS: Recent literature suggests that aberrant expression of Runx contributes to tumorigenesis of many organs. Conversely, cell- and tissue-specific tumor suppressor roles of Runx are also reported. In this review, we have provided the structural/functional properties of Runx isoforms and its regulation in context of human cancer. Moreover, in an urgent need to discover novel therapeutic interventions against cancer, we comprehensively discussed the reported oncogenic and tumor suppressive roles of Runx isoforms in several tumor types and discussed the discrepancies that may have risen on Runx as a driver of malignant transformation.

CONCLUSION

Runx may be a novel therapeutic target against a battery of deadly human cancers.

RUNX2 promotes the suppression of osteoblast function and enhancement of osteoclast activity by multiple myeloma cells

RUNX2 is a transcription factor that participates in osteoblast differentiation and chondrocyte maturation and plays an important role in the invasion and metastasis of cancers. With the deepening of research, evidence has indicated the correlation between RUNX2 and bone destruction in cancers. However, the mechanisms underlying its role in multiple myeloma remain unclear. By observing the induction effects of conditioned medium from myeloma cells on preosteoblasts (MC3T3-E1) and preosteoclasts (RAW264.7) and constructing myeloma-bearing mice, we found that RUNX2 promotes bone destruction in multiple myeloma. In vitro, conditioned medium from RUNX2-overexpressing myeloma cells reduced osteoblast activity and increased osteoclast activity. In vivo, RUNX2 expression was positively correlated with bone loss in myeloma-bearing mice. These results suggest that therapeutic inhibition of RUNX2 may protect against bone destruction by maintaining the balance between osteoblast and osteoclast activity in multiple myeloma.

RUNX2 Reverses p53-Induced Chemotherapy Resistance in Gastric Cancer

Objective

Gastric cancer is one of the most common malignancies worldwide; however, its overall mortality has not improved significantly over the last decade. Chemoresistance plays a critical role in this issue. This study aimed to clarify the role and mechanism of runt-related transcription factor 2 (RUNX2) in platinum-based chemotherapy resistance.

Methods

First, a drug-resistant model of gastric cancer cells was established to evaluate the relative expression level of the RUNX2 as a potential biomarker of chemotherapy resistance. Next, exogenous silencing was conducted to study whether RUNX2 could reverse drug resistance and understand the underlying mechanisms. Simultaneously, the correlation between the clinical outcomes of 40 patients after chemotherapy and the RUNX2 expression levels in tumor samples was analyzed.

Results

We discovered that RUNX2 was significantly expressed in drug-resistant gastric cancer cells and tissues; it was also reversibly resistant to transformation treatment by exogenous RUNX2 silencing. It is confirmed that RUNX2 negatively regulates the apoptosis pathway of the p53 to reduce the chemotherapeutic effects of gastric cancer.

Conclusion

RUNX2 is a possible target for platinum-based chemotherapy resistance.

The RUNX Family Defines Trk Phenotype and Aggressiveness of Human Neuroblastoma through Regulation of p53 and MYCN

The Runt-related transcription factor (RUNX) family, which is essential for the differentiation of cells of neural crest origin, also plays a potential role in neuroblastoma tumorigenesis. Consecutive studies in various tumor types have demonstrated that the RUNX family can play either pro-tumorigenic or anti-tumorigenic roles in a context-dependent manner, including in response to chemotherapeutic agents. However, in primary neuroblastomas, RUNX3 acts as a tumor-suppressor, whereas RUNX1 bifunctionally regulates cell proliferation according to the characterized genetic and epigenetic backgrounds, including MYCN oncogenesis. In this review, we first highlight the current knowledge regarding the mechanism through which the RUNX family regulates the neurotrophin receptors known as the tropomyosin-related kinase (Trk) family, which are significantly associated with neuroblastoma aggressiveness. We then focus on the possible involvement of the RUNX family in functional alterations of the p53 family members that execute either tumor-suppressive or dominant-negative functions in neuroblastoma tumorigenesis. By examining the tripartite relationship between the RUNX, Trk, and p53 families, in addition to the oncogene MYCN, we endeavor to elucidate the possible contribution of the RUNX family to neuroblastoma tumorigenesis for a better understanding of potential future molecular-based therapies.

RUNX Proteins as Epigenetic Modulators in Cancer

RUNX proteins are highly conserved in metazoans and perform critical functions during development. Dysregulation of RUNX proteins through various molecular mechanisms facilitates the development and progression of various cancers, where different RUNX proteins show tumor type-specific functions and regulate different aspects of tumorigenesis by cross-talking with different signaling pathways such as Wnt, TGF-β, and Hippo. Molecularly, they could serve as transcription factors (TFs) to activate their direct target genes or interact with many other TFs to modulate chromatin architecture globally. Here, we review the current knowledge on the functions and regulations of RUNX proteins in different cancer types and highlight their potential role as epigenetic modulators in cancer.

RUNX Family in Hypoxic Microenvironment and Angiogenesis in Cancers

The tumor microenvironment (TME) is broadly implicated in tumorigenesis, as tumor cells interact with surrounding cells to influence the development and progression of the tumor. Blood vessels are a major component of the TME and are attributed to the creation of a hypoxic microenvironment, which is a common feature of advanced cancers and inflamed premalignant tissues. Runt-related transcription factor (RUNX) proteins, a transcription factor family of developmental master regulators, are involved in vital cellular processes such as differentiation, proliferation, cell lineage specification, and apoptosis. Furthermore, the RUNX family is involved in the regulation of various oncogenic processes and signaling pathways as well as tumor suppressive functions, suggesting that the RUNX family plays a strategic role in tumorigenesis. In this review, we have discussed the relevant findings that describe the crosstalk of the RUNX family with the hypoxic TME and tumor angiogenesis or with their signaling molecules in cancer development and progression.

Origin and Therapies of Osteosarcoma

Simple Summary

Osteosarcoma is the most common malignant bone tumor in children, with a 5-year survival rate ranging from 70% to 20% depending on the aggressiveness of the disease. The current treatments have not evolved over the past four decades due in part to the genetic complexity of the disease and its heterogeneity. This review will summarize the current knowledge of OS origin, diagnosis and therapies.

Abstract

Osteosarcoma (OS) is the most frequent primary bone tumor, mainly affecting children and young adults. Despite therapeutic advances, the 5-year survival rate is 70% but drastically decreases to 20–30% for poor responders to therapies or for patients with metastasis. No real evolution of the survival rates has been observed for four decades, explained by poor knowledge of the origin, difficulties related to diagnosis and the lack of targeted therapies for this pediatric tumor. This review will describe a non-exhaustive overview of osteosarcoma disease from a clinical and biological point of view, describing the origin, diagnosis and therapies.

MicroRNAs and osteosarcoma: Potential targets for inhibiting metastasis and increasing chemosensitivity

Osteosarcoma (OS) is the third most common cancer in young adults after lymphoma and brain cancer. Metastasis, like other cellular events, is dependent on signaling pathways; a series of changes in some proteins and signaling pathways pave the way for OS cells to invade and migrate. Ezrin, TGF-β, Notch, RUNX2, matrix metalloproteinases (MMPs), Wnt/β-catenin, and phosphoinositide 3-kinase (PI3K)/AKT are among the most important of these proteins and signaling pathways. Despite the improvements in treating OS, the overall survival of patients suffering from the metastatic disease has not experienced any significant change after surgical treatments and chemotherapy and 5-years overall survival in patients with metastatic OS is about 20%. Studies have shown that overexpression or inhibition of some microRNAs (miRNAs) has significant effects in limiting the invasion and migration of OS cells. The results of these studies highlight the potential of the clinical application of some miRNA mimics and miRNA inhibitors (antagomiRs) to inhibit OS metastasis in the future. In addition, some studies have shown that miRNAs are associated with the most important drug resistance mechanisms in OS, and some miRNAs are highly effective targets to increase chemosensitivity. The results of these studies suggest that miRNA mimics and antagomiRs may be helpful to increase the efficacy of conventional chemotherapy drugs in the treatment of metastatic OS. In this article, we discussed the role of various signaling pathways and the involved miRNAs in the metastasis of OS, attempting to provide a comprehensive review of the literature on OS metastasis and chemosensitivity.

A Spheroid Model of Early and Late-Stage Osteosarcoma Mimicking the Divergent Relationship between Tumor Elimination and Bone Regeneration

Osteosarcoma is the most diagnosed bone tumor in children. The use of tissue engineering strategies after malignant tumor resection remains a subject of scientific controversy. As a result, there is limited research that focuses on bone regeneration postresection, which is further compromised following chemotherapy. This study aims to develop the first co-culture spheroid model for osteosarcoma, to understand the divergent relationship between tumor elimination and bone regeneration. By manipulating the ratio of stromal to osteosarcoma cells the modelled cancer state (early/late) is modified, as is evident by the increased tumor growth rates and an upregulation of a panel of well-established osteosarcoma prognostic genes. Validation of the authors' model is conducted by analyzing its ability to mimic the cytotoxic effects of the FDA-approved chemotherapeutic Doxorubicin. Next, the model is used to investigate what effect osteogenic supplements have, if any, on tumor growth. When their model is treated with osteogenic supplements, there is a stimulatory effect on the surrounding stromal cells. However, when treated with chemotherapeutics this stimulatory effect is significantly diminished. Together, the results of this study present a novel multicellular model of osteosarcoma and provide a unique platform for screening potential therapeutic options for osteosarcoma before conducting in vivo experiments.

A Cell Culture Chip with Transparent, Micropillar-Decorated Bottom for Live Cell Imaging and Screening of Breast Cancer Cells

In the recent years, microfabrication technologies have been widely used in cell biology, tissue engineering, and regenerative medicine studies. Today, the implementation of microfabricated devices in cancer research is frequent and advantageous because it enables the study of cancer cells in controlled microenvironments provided by the microchips. Breast cancer is one of the most common cancers in women, and the way breast cancer cells interact with their physical microenvironment is still under investigation. In this study, we developed a transparent cell culture chip (Ch-Pattern) with a micropillar-decorated bottom that makes live imaging and monitoring of the metabolic, proliferative, apoptotic, and morphological behavior of breast cancer cells possible. The reason for the use of micropatterned surfaces is because cancer cells deform and lose their shape and acto-myosin integrity on micropatterned substrates, and this allows the quantification of the changes in morphology and through that identification of the cancerous cells. In the last decade, cancer cells were studied on micropatterned substrates of varying sizes and with a variety of biomaterials. These studies were conducted using conventional cell culture plates carrying patterned films. In the present study, cell culture protocols were conducted in the clear-bottom micropatterned chip. This approach adds significantly to the current knowledge and applications by enabling low-volume and high-throughput processing of the cell behavior, especially the cell–micropattern interactions. In this study, two different breast cancer cell lines, MDA-MB-231 and MCF-7, were used. MDA-MB-231 cells are invasive and metastatic, while MCF-7 cells are not metastatic. The nuclei of these two cell types deformed to distinctly different levels on the micropatterns, had different metabolic and proliferation rates, and their cell cycles were affected. The Ch-Pattern chips developed in this study proved to have significant advantages when used in the biological analysis of live cells and highly beneficial in the study of screening breast cancer cell–substrate interactions in vitro.

To B (Bone Morphogenic Protein-2) or Not to B (Bone Morphogenic Protein-2): Mesenchymal Stem Cells May Explain the Protein's Role in Osteosarcomagenesis

Osteosarcoma (OS), a primary malignant bone tumor, stems from bone marrow-derived mesenchymal stem cells (BMSCs) and/or committed osteoblast precursors. Distant metastases, in particular pulmonary and skeletal metastases, are common in patients with OS. Moreover, extensive resection of the primary tumor and bone metastases usually leads to bone defects in these patients. Bone morphogenic protein-2 (BMP-2) has been widely applied in bone regeneration with the rationale that BMP-2 promotes osteoblastic differentiation of BMSCs. Thus, BMP-2 might be useful after OS resection to repair bone defects. However, the potential tumorigenicity of BMP-2 remains a concern that has impeded the administration of BMP-2 in patients with OS and in populations susceptible to OS with severe bone deficiency (e.g., in patients with genetic mutation diseases and aberrant activities of bone metabolism). In fact, some studies have drawn the opposite conclusion about the effect of BMP-2 on OS progression. Given the roles of BMSCs in the origination of OS and osteogenesis, we hypothesized that the responses of BMSCs to BMP-2 in the tumor milieu may be responsible for OS development. This review focuses on the relationship among BMSCs, BMP-2, and OS cells; a better understanding of this relationship may elucidate the accurate mechanisms of actions of BMP-2 in osteosarcomagenesis and thereby pave the way for clinically safer and broader administration of BMP-2 in the future. For example, a low dosage of and a slow-release delivery strategy for BMP-2 are potential topics for exploration to treat OS.

Runt related transcription factor-1 plays a central role in vessel co-option of colorectal cancer liver metastases

Colorectal cancer liver metastasis (CRCLM) has two major histopathological growth patterns: angiogenic desmoplastic and non-angiogenic replacement. The replacement lesions obtain their blood supply through vessel co-option, wherein the cancer cells hijack pre-existing blood vessels of the surrounding liver tissue. Consequentially, anti-angiogenic therapies are less efficacious in CRCLM patients with replacement lesions. However, the mechanisms which drive vessel co-option in the replacement lesions are unknown. Here, we show that Runt Related Transcription Factor-1 (RUNX1) overexpression in the cancer cells of the replacement lesions drives cancer cell motility via ARP2/3 to achieve vessel co-option. Furthermore, overexpression of RUNX1 in the cancer cells is mediated by Transforming Growth Factor Beta-1 (TGFβ1) and thrombospondin 1 (TSP1). Importantly, RUNX1 knockdown impaired the metastatic capability of colorectal cancer cells in vivo and induced the development of angiogenic lesions in liver. Our results confirm that RUNX1 may be a potential target to overcome vessel co-option in CRCLM.

Decarboxylated osteocalcin, a possible drug for type 2 diabetes, triggers glucose uptake in MG63 cells

BACKGROUND

Uncarboxylated osteocalcin (GluOC) has been reported to improve glucose metabolism, prevent type 2 diabetes, and decrease the severity of obesity in mice with type 2 diabetes. GluOC can increase glucose uptake in a variety of cells. Glucose metabolism is the main source of energy for osteoblast proliferation and differentiation. We hypothesized that decarboxylated osteocalcin (dcOC), a kind of GluOC, can increase glucose uptake in MG63 cells (osteoblast-like osteosarcoma cells) and influence their proliferation and differentiation.

AIM

To investigate the effects of dcOC on glucose uptake in human osteoblast-like osteosarcoma cells and the possible signaling pathways involved.

METHODS

MG63 cells (human osteoblast-like osteosarcoma cells) were treated with dcOC (0, 0.3, 3, 10, or 30 ng/mL) for 1 and 72 h, and glucose uptake was measured by flow cytometry. The effect of dcOC on cell proliferation was measured with a CCK-8 assay, and alkaline phosphatase (ALP) enzyme activity was measured. PI3K was inhibited with LY294002, and hypoxia-inducible factor 1 alpha (HIF-1α) was silenced with siRNA. Then, GPRC6A (G protein-coupled receptor family C group 6 subtype A), total Akt, phosphorylated Akt, HIF-1α, and glucose transporter 1 (GLUT1) levels were measured by Western blot to elucidate the possible pathways by which dcOC modulates glucose uptake.

RESULTS

The glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after short-term (1 h) treatment with dcOC at different concentrations (0.3, 3, and 10 ng/mL groups, P < 0.01; 30 ng/mL group, P < 0.05). Glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after long-term (72 h) treatment with dcOC at different concentrations (0.3, 3, and 10 ng/mL groups, P < 0.01; 30 ng/mL group, P < 0.05). DcOC triggered Akt phosphorylation in a dose-dependent manner, and the most effective stimulatory concentration of dcOC for short-term (1 h) was 3 ng/mL (P < 0.01). LY294002 abolished the dcOC-mediated (1 h) promotion of Akt phosphorylation and glucose uptake without affecting GLUT1 protein expression. Long-term dcOC stimulation triggered Akt phosphorylation and increased the protein levels of HIF-1α, GLUT1, and Runx2 in a dose-dependent manner. Inhibition of HIF-1α with siRNA abolished the dcOC-mediated glucose uptake and substantially decreased GLUT1 protein expression. DcOC intervention promoted cell proliferation in a time- and dose-dependent manner as determined by the CCK-8 assay. Treatment with both 3 ng/mL and 10 ng/mL dcOC affected the ALP activity in MG63 cells after 72 h (P < 0.01).

CONCLUSION

Short- and long-term dcOC treatment can increase glucose uptake and affect proliferation and ALP activity in MG63 cells. This effect may occur through the PI3K/Akt, HIF-1α, and GLUT1 signaling factors.

Knockdown of microRNA-203 reduces cisplatin chemo-sensitivity to osteosarcoma cell lines MG63 and U2OS in vitro by targeting RUNX2

Clinical studies have reported that miRNAs abnormal expression are associated with the generation of cisplatin-resistant to osteosarcoma. Our previous research found that miR-203 is downregulated in osteosarcoma cells and overexpressed miR-203 exerts antitumor properties on osteosarcoma cells. However, the role and mechanism of miR-203 in regulating the sensitivity of cisplatin in osteosarcoma cells remains unclear. This study aimed to investigate the effects of miR-203 in cisplatin therapy for osteosarcoma cells in vitro and determined the underlying mechanism. In this study, we found that miR-203 was significantly upregulated in osteosarcoma cells after exposure to cisplatin. miR-203 knockdown reduced the sensitivity of osteosarcoma cells to cisplatin by suppressing cell apoptosis, cell cycle arrest, and inducing invasion. Meanwhile, we found that miR-203 knockdown reduces the therapeutic sensitivity of osteosarcoma cells by upregulating RUNX2. Moreover, we found that RUNX2 silencing sensitizes osteosarcoma cells to chemotherapy treatment of cisplatin. In summary, our findings demonstrated that miR-203 knockdown reduces cisplatin chemo-sensitivity to osteosarcoma cells in vitro by targeting RUNX2, and speculated that miR-203 may be a target for drug resistance of osteosarcoma to cisplatin.

Wrong place, wrong time: Runt-related transcription factor 2/SATB2 pathway in bone development and carcinogenesis

Upregulation or aberrant expression of genes such as special AT-rich sequence-binding protein 2 (SATB2) is necessary for normal cell differentiation and tissue development and is often associated with carcinogenesis and metastatic progression. SATB2 is a critical transcription factor for biological development of various specialized cell lineages, such as osteoblasts and neurons. The dysregulation of SATB2 expression has recently been associated with various types of cancer, while the mechanisms and pathways by which it mediates tumorigenesis are not well elucidated. Runt-related transcription factor 2 (RUNX2) is a master regulator for osteogenesis, and it shares common pathways with SATB2 to regulate bone development. Interestingly, these two transcription factors co-occur in several epithelial and mesenchymal cancers and are linked by multiple cancer-related proteins and microRNAs. This review examines the interactions between RUNX2 and SATB2 in a network necessary for normal bone development and the circumstances in which the expression of RUNX2 and SATB2 in the wrong place and time leads to carcinogenesis.

RUNX2 as a promising therapeutic target for malignant tumors

The transcription factor runt-related protein 2 (RUNX2) has an important impact on the transformation of bone marrow mesenchymal stem cells to osteoblasts. Further studies have shown that RUNX2 plays a key role in the invasion and metastasis of cancers. RUNX2 is a "key" molecule in the regulatory network comprised of multiple signaling pathways upstream and its target downstream molecules. Due to the complex regulatory mechanisms of RUNX2, the specific mechanism underlying the occurrence, development and prognosis of malignant tumors has not been fully understood. Currently, RUNX2 as a promising therapeutic target for cancers has become a research hotspot. Herein, we reviewed the current literature on the modulatory functions and mechanisms of RUNX2 in the development of malignant tumors, aiming to explore its potential clinical application in the diagnosis, prognosis and treatment of tumors.

RUNX2 regulates leukemic cell metabolism and chemotaxis in high-risk T cell acute lymphoblastic leukemia

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy with inferior outcome compared with that of B cell ALL. Here, we show that Runt-related transcription factor 2 (RUNX2) was upregulated in high-risk T-ALL with KMT2A rearrangements (KMT2A-R) or an immature immunophenotype. In KMT2A-R cells, we identified RUNX2 as a direct target of the KMT2A chimeras, where it reciprocally bound the KMT2A promoter, establishing a regulatory feed-forward mechanism. Notably, RUNX2 was required for survival of immature and KMT2A-R T-ALL cells in vitro and in vivo. We report direct transcriptional regulation of CXCR4 signaling by RUNX2, thereby promoting chemotaxis, adhesion, and homing to medullary and extramedullary sites. RUNX2 enabled these energy-demanding processes by increasing metabolic activity in T-ALL cells through positive regulation of both glycolysis and oxidative phosphorylation. Concurrently, RUNX2 upregulation increased mitochondrial dynamics and biogenesis in T-ALL cells. Finally, as a proof of concept, we demonstrate that immature and KMT2A-R T-ALL cells were vulnerable to pharmacological targeting of the interaction between RUNX2 and its cofactor CBFβ. In conclusion, we show that RUNX2 acts as a dependency factor in high-risk subtypes of human T-ALL through concomitant regulation of tumor metabolism and leukemic cell migration.

Pathogenesis and Current Treatment of Osteosarcoma: Perspectives for Future Therapies

Osteosarcoma is the most common primary malignant bone tumor in children and young adults. The standard-of-care curative treatment for osteosarcoma utilizes doxorubicin, cisplatin, and high-dose methotrexate, a standard that has not changed in more than 40 years. The development of patient-specific therapies requires an in-depth understanding of the unique genetics and biology of the tumor. Here, we discuss the role of normal bone biology in osteosarcomagenesis, highlighting the factors that drive normal osteoblast production, as well as abnormal osteosarcoma development. We then describe the pathology and current standard of care of osteosarcoma. Given the complex heterogeneity of osteosarcoma tumors, we explore the development of novel therapeutics for osteosarcoma that encompass a series of molecular targets. This analysis of pathogenic mechanisms will shed light on promising avenues for future therapeutic research in osteosarcoma.

Revealing the link between macrophage in microenvironment of osteosarcoma and poor prognosis by utilizing the Integrated analysis

OBJECTIVES

Osteosarcoma (OS) is the most common type of primary malignant bone tumor, The effect of tumor microenvironment components on OS oncogenesis remains unknown.

METHODS

To investigate the function of immune cells in osteosarcoma, we provided a text-based GMT (Gene Matrix Transposed) file in which each line defines one of lm22 with their markers. We used STRING to draw DEG's PPI network and selected hub genes and modules. Then, survival analysis was conducted to hub genes. We identified 10,390 common genes, and identified 218 DEGs based on the combined t-value and Z scores.

RESULTS

The KEGG and GSEA enrichment analysis showed that macrophages are significantly activated in osteosarcoma. PPI network analysis revealed that hub gene CD163 molecule. We found that the expression of CD163 was negatively associated with the OS of osteosarcoma patients. These results suggest that macrophages are a risk factor in patients with osteosarcoma.

CONCLUSIONS

This study has systematically validated results of the studies carried out previously and filled up the gap in the field of OS on large-scaled meta-analysis. In addition, for the hub gene (CD163) and the macrophage cell capable of being used as a novel biomarker in promoting early diagnosis and development of therapeutic approaches.

Is Use of BMP-2 Associated with Tumor Growth and Osteoblastic Differentiation in Murine Models of Osteosarcoma?

BACKGROUND

The putative benefit of rhBMP-2 is in the setting of limb reconstruction using structural allografts, whether it be allograft-prosthetic composites, osteoarticular allografts, or intercalary segmental grafts. There are also potential advantages in augmenting osseointegration of uncemented endoprosthetics and in reducing infection. Recombinant human BMP-2 might mitigate nonunion in structural allograft augmented osteosarcoma limb salvage surgery; however, its use is limited because of concerns about the prooncogenic effects of the agent.

QUESTIONS/PURPOSES

(1) To assess if BMP-2 signaling influences osteosarcoma cell line growth. (2) To characterize degree of osteosarcoma cell line osteoblastic differentiation in response to BMP-2. (3) To assess if BMP-2 signaling has a consistent effect on local or systemic tumor burden in various orthotopic murine models of osteosarcoma.

METHODS

In this study, 143b, SaOS-2 and DLM8-M1 osteosarcoma cell lines were transfected with BMP-2 cDNA controlled by a constitutive promoter (experimental) or an empty vector (control) using a PiggyBac transposon system. Cellular proliferation was assessed using a quantitative MTT colorimetric assay. Osteoblastic differentiation was compared between control and experimental cell lines using quantitative real-time polymerase chain reaction of the osteoblastic markers connective tissue growth factor, Runx-2, Osterix, alkaline phosphatase and osteocalcin. Experimental and control cell lines were injected into the proximal tibia of either NOD-SCID (143b and SaOS-2 xenograft model), or C3H (DLM8-M1 syngeneic model) mice. Local tumor burden was quantitatively assessed using tumor volume caliper measurements and bioluminescence, and qualitatively assessed using post-mortem ex vivo microCT. Lung metastasis was qualitatively assessed by the presence of bioluminescence, and incidence was confirmed using histology. rhBMP-2 soaked absorbable collagen sponges (experimental) and sterile-H2O soaked absorbable collagen sponges (control) were implanted adjacent to 143b proximal tibial cell line injections to compare the effects of exogenous BMP-2 application with endogenous upregulation.

RESULTS

Constitutive expression of BMP-2 increased the in vitro proliferation of 143b cells (absorbance values 1.2 ± 0.1 versus 0.89 ± 0.1, mean difference 0.36 [95% CI 0.12 to 0.6]; p = 0.01), but had no effect on SaOS-2 and DLM8-M1 cell proliferation. In response to constitutive BMP-2 expression, 143b cells had no differences in osteoblastic differentiation, while DLM8-M1 cells downregulated the early marker connective tissue growth factor (mean ΔCt 0.2 ± 0.1 versus 0.6 ± 0.1; p = 0.002) and upregulated the early-mid range marker Runx-2 (mean ΔCt -0.8 ± 0.1 versus -1.1 ± 0.1; p = 0.002), and SaOS-2 cells upregulated the mid-range marker Osterix (mean ΔCt -2.1 ± 0.6 versus -3.9 ± 0.6; p = 0.002). Constitutive expression of BMP-2 resulted in greater 143b and DLM8-M1 local tumor volume (143b: 307.2 ± 106.8 mm versus 1316 ± 387.4 mm, mean difference 1009 mm [95% CI 674.5 to 1343]; p < 0.001, DLM8-M1 week four: 0 mm versus 326.1 ± 72.8 mm, mean difference 326.1 mm [95% CI 121.2 to 531]; p = 0.009), but modestly reduced local tumor growth in SaOS-2 (9.5 x 10 ± 8.3x10 photons/s versus 9.3 x 10 ± 1.5 x 10 photons/s, mean difference 8.6 x 10 photons/s [95% CI 5.1 x 10 to 1.2 x 10]; p < 0.001). Application of exogenous rhBMP-2 also increased 143b local tumor volume (495 ± 91.9 mm versus 1335 ± 102.7 mm, mean difference 840.3 mm [95% CI 671.7 to 1009]; p < 0.001). Incidence of lung metastases was not different between experimental or control groups for all experimental conditions.

CONCLUSIONS

As demonstrated by others, ectopic BMP-2 signaling has unpredictable effects on local tumor proliferation in murine models of osteosarcoma and does not consistently result in osteosarcoma cell line differentiation. Further investigations into other methods of safe bone and soft tissue healing augmentation and the use of differentiation therapies is warranted.

CLINICAL RELEVANCE

Our results indicate that BMP-2 has the potential to stimulate the growth of osteosarcoma cells that are poorly responsive to BMP-2 mediated osteoblastic differentiation. As this differentiation potential is unpredictable in the clinical setting, BMP-2 may promote the growth of microscopic residual tumor burden after resection. Our study provides further support for the recommendation to avoid the use of BMP-2 after limb-salvage surgery in patients with osteosarcoma.

Regulatory mechanism of tumor suppressor gene miR-302b in malignant tumors

MicroRNAs are a class of endogenous non-coding RNA molecules that regulate the translation of proteins. They play important regulatory roles in the growth, development, and aging of organisms, as well as cell proliferation, differentiation, apoptosis, and even cancer. miR-302b can participate in the regulation of the expression of a variety of genes, and functions as a tumor suppressor gene in the occurrence, development, invasion, and metastasis of malignant tumors. This article discusses the expression of miR-302b in malignant tumors and its biological functions and molecular mechanism.

Implication of the p53-Related miR-34c, -125b, and -203 in the Osteoblastic Differentiation and the Malignant Transformation of Bone Sarcomas

The formation of the skeleton occurs throughout the lives of vertebrates and is achieved through the balanced activities of two kinds of specialized bone cells: the bone-forming osteoblasts and the bone-resorbing osteoclasts. Impairment in the remodeling processes dramatically hampers the proper healing of fractures and can also result in malignant bone diseases such as osteosarcoma. MicroRNAs (miRNAs) are a class of small non-coding single-strand RNAs implicated in the control of various cellular activities such as proliferation, differentiation, and apoptosis. Their post-transcriptional regulatory role confers on them inhibitory functions toward specific target mRNAs. As miRNAs are involved in the differentiation program of precursor cells, it is now well established that this class of molecules also influences bone formation by affecting osteoblastic differentiation and the fate of osteoblasts. In response to various cell signals, the tumor-suppressor protein p53 activates a huge range of genes, whose miRNAs promote genomic-integrity maintenance, cell-cycle arrest, cell senescence, and apoptosis. Here, we review the role of three p53-related miRNAs, miR-34c, -125b, and -203, in the bone-remodeling context and, in particular, in osteoblastic differentiation. The second aim of this study is to deal with the potential implication of these miRNAs in osteosarcoma development and progression.

Complex Interplay between the RUNX Transcription Factors and Wnt/β-Catenin Pathway in Cancer: A Tango in the Night

Cells are designed to be sensitive to a myriad of external cues so they can fulfil their individual destiny as part of the greater whole. A number of well-characterised signalling pathways dictate the cell's response to the external environment and incoming messages. In healthy, well-ordered homeostatic systems these signals are tightly controlled and kept in balance. However, given their powerful control over cell fate, these pathways, and the transcriptional machinery they orchestrate, are frequently hijacked during the development of neoplastic disease. A prime example is the Wnt signalling pathway that can be modulated by a variety of ligands and inhibitors, ultimately exerting its effects through the β-catenin transcription factor and its downstream target genes. Here we focus on the interplay between the three-member family of RUNX transcription factors with the Wnt pathway and how together they can influence cell behaviour and contribute to cancer development. In a recurring theme with other signalling systems, the RUNX genes and the Wnt pathway appear to operate within a series of feedback loops. RUNX genes are capable of directly and indirectly regulating different elements of the Wnt pathway to either strengthen or inhibit the signal. Equally, β-catenin and its transcriptional co-factors can control RUNX gene expression and together they can collaborate to regulate a large number of third party co-target genes.

RECQ DNA Helicases and Osteosarcoma

The RECQ family of DNA helicases is a conserved group of enzymes that plays an important role in maintaining genomic stability. Humans possess five RECQ helicase genes, and mutations in three of them - BLM, WRN, and RECQL4 - are associated with the genetic disorders Bloom syndrome, Werner syndrome, and Rothmund-Thomson syndrome (RTS), respectively. These syndromes share overlapping clinical features, and importantly they are all associated with an increased risk of cancer. Patients with RTS have the highest specific risk of developing osteosarcoma compared to all other cancer predisposition syndromes; therefore, RTS serves as a relevant model to study the pathogenesis and molecular genetics of osteosarcoma. The "tumor suppressor" function of the RECQ helicases continues to be an area of active investigation. This chapter will focus primarily on the known cellular functions of RECQL4 and how these may relate to tumorigenesis, as well as ongoing efforts to understand RECQL4's functions in vivo using animal models. Understanding the RECQ pathways will provide insight into avenues for novel cancer therapies in the future.

MicroRNA-150 functions as a tumor suppressor and sensitizes osteosarcoma to doxorubicin-induced apoptosis by targeting RUNX2

Osteosarcoma (OS) is the most common form of bone malignancy in children and adolescents. MicroRNAs (miRNAs) have been associated with the development and progression of OS. In the present study, reverse transcription-quantitative PCR, western blotting, Cell Counting Kit-8, luciferase and Transwell assays were performed to investigate the biological function of microRNA-150 (miR-150) in OS. The results revealed that miR-150 was significantly downregulated in OS cell lines (HOS, SAOS2, MG-63 and U2OS) in comparison with the normal osteoblast cells (hFOB1.19). Overexpression of miR-150 significantly inhibited cell proliferation in OS cells. miR-150 could sensitize OS cells to chemotherapy treatment of doxorubicin. Runt-related transcription factor 2 (RUNX2) was identified as a target gene of miR-150. RUNX2 knockdown exhibited similar inhibitory effects on both OS cell proliferation and chemotherapy sensitivity. Restoration of RUNX2 reversed the biological function of miR-150. Finally, miR-150 overexpression and RUNX2 knockdown enhanced caspase-3 cleavage. Taken together, the present study established a novel molecular mechanism, in that miR-150 plays tumor suppressor and chemoprotective roles by targeting RUNX2 in OS, indicating that miR-150 may be a potential therapeutic target for OS therapy in the future.

RUNX2 (6p21.1) amplification in osteosarcoma

Prior cytogenetic profiling of osteosarcomas has suggested that amplifications at the 6p12-21 locus are relatively common alterations in these tumors. However, these studies have been limited by variable testing methodologies used as well as by the relatively small numbers of cases that have been analyzed. To better define the frequency of this alteration, 111 osteosarcomas were profiled using hybridization capture-based next-generation sequencing (NGS) platform (Memorial Sloan Kettering Integrated Mutation Profiling of Actionable Cancer Targets) as part of an institutional clinical cancer genomics initiative. Using this platform, amplification at the 6p12-21 locus was determined by copy number assessment of the VEGFA and CCND3 genes. In addition, fluorescence in situ hybridization was used to assess copy number status for RUNX2, a known transcriptional regulator of osteoblastic differentiation which has previously been reported to be dysregulated in osteosarcomas. 6p12-21 amplification using NGS-based copy number assessment was confirmed in more than a fifth of all cases tested (24 of 111, 21.6%). Most of these cases, when tested using fluorescence in situ hybridization, were found to include RUNX2 within the amplified locus (17 of 18, 94.4%). Whereas many laboratories lack access to large-panel NGS assays, the use of fluorescence in situ hybridization to identify 6p12-21 amplification events by targeting RUNX2 represents a widely available diagnostic modality for the identification of such cases. This could help better define the role of RUNX2 in osteoblastic differentiation and serve as a surrogate for the identification of potentially targetable alterations such as VEGFA amplification at this locus.

The interaction between RUNX2 and core binding factor beta as a potential therapeutic target in canine osteosarcoma

Osteosarcoma remains the most common primary bone tumour in dogs with half of affected dogs unable to survive 1 year beyond diagnosis. New therapeutic options are needed to improve outcomes for this disease. Recent investigations into potential therapeutic targets have focused on cell surface molecules with little clear therapeutic benefit. Transcription factors and protein interactions represent underdeveloped areas of therapeutic drug development. We have utilized allosteric inhibitors of the core binding factor transcriptional complex, comprised of core binding factor beta (CBFβ) and RUNX2, in four canine osteosarcoma cell lines Active inhibitor compounds demonstrate anti-tumour activities with concentrations demonstrated to be achievable in vivo while an inactive, structural analogue has no activity. We show that CBFβ inhibitors are capable of inducing apoptosis, inhibiting clonogenic cell growth, altering cell cycle progression and impeding migration and invasion in a cell line-dependent manner. These effects coincide with a reduced interaction between RUNX2 and CBFβ and alterations in expression of RUNX2 target genes. We also show that addition of CBFβ inhibitors to the commonly used cytotoxic chemotherapeutic drugs doxorubicin and carboplatin leads to additive and/or synergistic anti-proliferative effects in canine osteosarcoma cell lines. Taken together, we have identified the interaction between components of the core binding factor transcriptional complex, RUNX2 and CBFβ, as a potential novel therapeutic target in canine osteosarcoma and provide justification for further investigations into the anti-tumour activities we describe here.

RUNX family: Oncogenes or tumor suppressors (Review)

Runt-related transcription factor (RUNX) proteins belong to a transcription factors family known as master regulators of important embryonic developmental programs. In the last decade, the whole family has been implicated in the regulation of different oncogenic processes and signaling pathways associated with cancer. Furthermore, a suppressor tumor function has been also reported, suggesting the RUNX family serves key role in all different types of cancer. In this review, the known biological characteristics, specific regulatory abilities and experimental evidence of RUNX proteins will be analyzed to demonstrate their oncogenic potential and tumor suppressor abilities during oncogenic processes, suggesting their importance as biomarkers of cancer. Additionally, the importance of continuing with the molecular studies of RUNX proteins' and its dual functions in cancer will be underlined in order to apply it in the future development of specific diagnostic methods and therapies against different types of cancer.

Mechanical Property of Hydrogels and the Presence of Adipose Stem Cells in Tumor Stroma Affect Spheroid Formation in the 3D Osteosarcoma Model

Osteosarcoma is one of the most common metastatic bone cancers, which results in significant morbidity and mortality. Unfolding of effectual therapeutic strategies against osteosarcoma is impeded because of the absence of adequate animal models, which can truly recapitulate disease biology of humans. Tissue engineering provides an opportunity to develop physiologically relevant, reproducible, and tunable in vitro platforms to investigate the interactions of osteosarcoma cells with its microenvironment. Adipose-derived stem cells (ASCs) are detected adjacent to osteosarcoma masses and are considered to have protumor effects. Hence, the present study focuses on investigating the role of reactive ASCs in formation of spheroids of osteosarcoma cells (Saos 2) within a three-dimensional (3D) niche, which is created using gellan gum (GG)-silk fibroin. By modifying the blending ratio of GG-silk, the optimum stiffness of the resultant hydrogels such as GG and GG75: S25 is obtained for cancer spheroid formation. This work indicates that the co-existence of cancer and stem cells can form a spheroid, the hallmark of cancer, only in particular microenvironment stiffness. The incorporation of fibrillar silk fibroin within the hydrophilic network of GG in GG75: S25 spongy-like hydrogels closely mimics the stiffness of commercially established cancer biomaterials (e.g., Matrigel, HyStem). The GG75: S25 hydrogel maintains the metabolically active construct for a longer time with elevated expression of osteopontin, osteocalcin, RUNX 2, and bone sialoprotein genes, the biomarkers of osteosarcoma, compared to GG. The GG75: S25 construct also exhibits intense alkaline phosphatase expression in immunohistochemistry compared to GG, indicating itspotentiality to serve as biomimetic niche to model osteosarcoma. Taken together, the GG-silk fibroin-blended spongy-like hydrogel is envisioned as an alternative low-cost platform for 3D cancer modeling.

Nicotinamide Phosphoribosyl Transferase Is Increased in Osteosarcomas and Chondrosarcomas Compared to Benign Bone and Cartilage

BACKGROUND/AIM

Primary bone neoplasms include osteosarcomas (OS), chondrosarcomas (CS), and giant cell tumors (GCT). Nicotinamide phosphoribosyl transferase (NAMPT) catalyzes the rate-limiting step of nicotinamide adenine dinucleotide synthesis and is increased in multiple tumor types. In malignancies, NAMPT expression often correlates positively with tumor grade, chemotherapy resistance, and metastatic potential.

MATERIALS AND METHODS

Tissue microarray was used to examine NAMPT expression in benign bone and cartilage, GCTs, OS, and different CS grades.

RESULTS

For the first time, we showed that NAMPT expression was increased in GCTs and OS compared to benign bone, and in CS compared to benign cartilage. Its expression also increased with higher CS grade.

CONCLUSION

Our data indicate that NAMPT plays a role in bone sarcomas and GCTs, and its higher expression may contribute to increased tumor aggressiveness.

The cancer-related transcription factor RUNX2 modulates expression and secretion of the matricellular protein osteopontin in osteosarcoma cells to promote adhesion to endothelial pulmonary cells and lung metastasis

Osteosarcomas are bone tumors that frequently metastasize to the lung. Aberrant expression of the transcription factor, runt-related transcription factor 2 (RUNX2), is a key pathological feature in osteosarcoma and associated with loss of p53 and miR-34 expression. Elevated RUNX2 may transcriptionally activate genes mediating tumor progression and metastasis, including the RUNX2 target gene osteopontin (OPN/SPP1). This gene encodes a secreted matricellular protein produced by osteoblasts to regulate bone matrix remodeling and tissue calcification. Here we investigated whether and how the RUNX2/OPN axis regulates lung metastasis of osteosarcoma. Importantly, RUNX2 depletion attenuates lung metastasis of osteosarcoma cells in vivo. Using next-generation RNA-sequencing, protein-based assays, as well as the loss- and gain-of-function approaches in selected osteosarcoma cell lines, we show that osteopontin messenger RNA levels closely correlate with RUNX2 expression and that RUNX2 controls the levels of secreted osteopontin. Elevated osteopontin levels promote heterotypic cell-cell adhesion of osteosarcoma cells to human pulmonary microvascular endothelial cells, but not in the presence of neutralizing antibodies. Collectively, these findings indicate that the RUNX2/OPN axis regulates the ability of osteosarcoma cells to attach to pulmonary endothelial cells as a key step in metastasis of osteosarcoma cells to the lung.

Genetic testing for high-grade osteosarcoma: a guide for future tailored treatments?

INTRODUCTION

Genetic characterization of osteosarcoma has evolved during the last decade, thanks to the integrated application of conventional and new candidate-driven and genome-wide technologies. Areas covered: This review provides an overview of the state of art in genetic testing applied to osteosarcoma, with particular regard to novel candidate genetic biomarkers that can be analyzed in tumor tissue and blood samples, which might be used to predict toxicity and prognosis, detect disease relapse, and improve patients' selection criteria for tailoring treatment. Expert commentary: Genetic testing based on modern technologies is expected to indicate new osteosarcoma-related prognostic markers and driver genes, which may highlight novel therapeutic targets and patients stratification biomarkers. The definition of tailored or targeted treatment approaches may improve outcome of patients with localized tumors and, even more, of those with metastatic disease, for whom progress in cure probability is highly warranted.

Systematic meta-analysis of genetic variants associated with osteosarcoma susceptibility

BACKGROUND

In the past decade, accumulated evidence has suggested that genetic variation is related to the pathogenesis of osteosarcoma. Although there are a large number of studies on the association between genetic variation and osteosarcoma, their results are inconsistent. To clarify these findings, we performed a systematic meta-analysis using allelic contrasts for each gene-specific single nucleotide variants with all available data in the field of osteosarcoma.

METHODS

The literature search for relevant studies was conducted in PubMed, Embase, and Cochrane databases. Pooled ORs and 95% CI values were calculated by the random-effects model using the Comprehensive Meta-analysis version 2.0 software package. Heterogeneity between studies was examined by the Cochran's Q-test.

RESULTS

The 32 genome-wide case-control population-based studies, involving 15,336 study subjects (6924 cases and 8412 controls), were included in this meta-analysis. We analyzed 24 single nucleotide variants (SNVs) in 14 genes. We identified 12 SNVs in CTLA-4, IL-8, MDM2, PRCKG, RECQL5, TNF-a, TP53, XRCC3, and VEGF that correlated with osteosarcoma susceptibility. The average pooled odds ratio for the 9 risk alleles was 2.082 (range: 1.585 to 3.262). These included CTLA-4 rs231775, CTLA-4 rs5742909, PRCKG rs454006, RECQL5 rs820196, TNF-α rs1800629, TP53 rs1042522, XRCC3 rs861539, VEGF rs699947, and VEGF rs3025039. The average pooled odds ratio for the 3 protective alleles, IL-8 rs4073, MDM2 rs1690916, and VEGF rs2010963, was 0.606 (range: 0.510-0.719). Publication bias was not observed among the studies reporting positively correlated SNVs. The pooled odds ratios for the SNVs that correlated with osteosarcoma risk showed homogeneity.

CONCLUSION

Our results provide powerful information for tracking the most viable gene candidates. Further studies with larger multiethnicity populations and investigations of the potential biological roles of these genetic variants in osteosarcoma should be conducted.

Laparoscopic surgery for early cervical squamous cell carcinoma and its effect on the micrometastasis of cancer cells

The aim of this study was to evaluate the effect of laparoscopic radical hysterectomy on expressions of circulating tumor cells (CTCs) of cytokeratin 19 (CK19), cytokeratin 20 (CK20), and squamous cell carcinoma antigen (SCC-Ag) mRNA.We collect 78 patients with stage IA2-IIA1 cervical cancer who underwent radical hysterectomy by laparotomy or laparoscopy in our study, and 34 uterine fibroids patients and 32 healthy subjects were recruited as the positive control group and negative control group, respectively. Blood samples were taken from early-stage primary cervical squamous cell carcinoma patients. Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to amplify peripheral blood CK19, CK20 and SCC-Ag from total RNA. We measured the expression of CK19, CK20, and SCC-Ag before laparoscopic radical hysterectomy, 24 hours and 30 days after surgery. Meanwhile, the expression of these markers was compared between laparoscopic and laparotomy groups.The expressions of CK19, CK20, and SCC-Ag in the experimental group before surgery were (0.0035 ± 0.0018), (1.06 ± 0.49), and (1.48 ± 0.46), respectively, and the positive rates were 32.1%, 33.3%, and 35.9%, respectively. The expression levels of CK19, CK20, and SCC-Ag in the experimental group before surgery was significantly higher than the positive and negative control groups, and there were no significant differences between the positive and negative control groups. The expressions and positive rates of CK19, CK20, and SCC-Ag before laparoscopic radical hysterectomy were significantly lower than the stage at 24 hours after surgery (P < .05), but higher than the stage at 30 days after surgery (P > .05). There were no significant differences in CK19, CK20, and SCC-Ag expressions before surgery, 24 hours and 30 days after surgery between laparoscopic group and laparotomy group (P > .05).Both laparotomy and laparoscopic radical mastectomy tend to increase the expression of CTCs in peripheral blood, and the expressions have no differences between these 2 groups. So, the use of CK19, CK20, and SCC-Ag expression levels from peripheral blood from early stage cervical cancer radical patients before hysterectomy can aid to overcome the lack of radiographic examination and tumor markers measurement, and provide clues for postoperative treatment and prognosis determination.

Migration-inducing gene-7 independently predicts poor prognosis of human osteosarcoma and is associated with vasculogenic mimicry

Vasculogenic mimicry (VM) is a special type of vascular channel formed by tumor cells without endothelial cell participation. Migration-inducing gene 7 (MIG-7) plays an important role in regulating VM. In this study, immunohistochemical staining was used to detect MIG-7 in tissue specimens from 141 primary osteosarcoma patients, and the relationship between MIG-7 and VM was examined. Survival analysis were performed to evaluate the prognoses. MIG-7 knockdown osteosarcoma cells were used for cell proliferation, apoptosis, migration, invasiveness and VM formation assays. A spontaneously metastasizing cell line-derived orthotopic xenograft mouse model was established to evaluate the effect of MIG-7 knockdown on tumorigenesis, VM formation and lung metastasis. MIG-7 expression was associated with VM formation. There were significant differences in overall and metastasis-free survival between the MIG-7-positive and MIG-7-negative groups. The MIG-7 expression was shown to be an independent indicator of both overall and metastasis-free survival. In vitro knockdown of MIG-7 dramatically reduced migration, invasion and VM formation in osteosarcoma cells without any significant effect on cell proliferation and apoptosis. MIG-7 knockdown also exhibited potent antitumor, antimetastasis and anti-VM effects in the orthotopic mouse model of 143B osteosarcoma. Therefore, MIG-7 serves as an independent unfavorable prognostic indicator in osteosarcoma patients and MIG-7 is an important mediator of osteosarcoma VM formation.

Exploring the molecular mechanisms of osteosarcoma by the integrated analysis of mRNAs and miRNA microarrays

Osteosarcoma (OS) is the most frequently occurring primary bone malignancy with a rapid progression and poor survival. In the present study, in order to examine the molecular mechanisms of OS, we analyzed the microarray of GSE28425. GSE28425 was downloaded from Gene Expression Omnibus, which also included the miRNA expression profile, GSE28423, and the mRNA expression profile, GSE28424. Each of the expression profiles included 19 OS cell lines and 4 normal bones. The differentially expressed genes (DEGs) and differentially expressed miRNAs (DE-miRNAs) were screened using the limma package in Bioconductor. The DEGs associated with tumors were screened and annotated. Subsequently, the potential functions of the DEGs were analyzed by Gene Ontology (GO) and pathway enrichment analyses. Furthermore, the protein-protein interaction (PPI) network was constructed using the STRING database and Cytoscape software. Furthermore, modules of the PPI network were screened using the ClusterOne plugin in Cytoscape. Additionally, the transcription factor (TF)-DEG regulatory network, DE-miRNA-DEG regulatory network and miRNA-function collaborative network were separately constructed to obtain key DEGs and DE-miRNAs. In total, 1,609 DEGs and 149 DE-miRNAs were screened. Upregulated FOS-like antigen 1 (FOSL1) also had the function of an oncogene. MAD2 mitotic arrest deficient-like 1 (MAD2L1; degree, 65) and aurora kinase A (AURKA; degree, 64) had higher degrees in the PPI network of the DEGs. In the TF-DEG regulatory network, the TF, signal transducer and activator of transcription 3 (STAT3) targeted the most DEGs. Moreover, in the DE-miRNA-DEG regulatory network, downregulated miR-1 targeted many DEGs and estrogen receptor 1 (ESR1) was targeted by several highly expressed miRNAs. Moreover, in the miRNA-function collaborative networks of upregulated miRNAs, miR-128 targeted myeloid dendritic associated functions. On the whole, our data indicate that MAD2L1, AURKA, STAT3, ESR1, FOSL1, miR-1 and miR-128 may play a role in the development and/or progressio of OS.

Impact of RUNX2 on drug-resistant human pancreatic cancer cells with p53 mutations

Background

Despite the remarkable advances in the early diagnosis and treatment, overall 5-year survival rate of patients with pancreatic cancer is less than 10%. Gemcitabine (GEM), a cytidine nucleoside analogue and ribonucleotide reductase inhibitor, is a primary option for patients with advanced pancreatic cancer; however, its clinical efficacy is extremely limited. This unfavorable clinical outcome of pancreatic cancer patients is at least in part attributable to their poor response to anti-cancer drugs such as GEM. Thus, it is urgent to understand the precise molecular basis behind the drug-resistant property of pancreatic cancer and also to develop a novel strategy to overcome this deadly disease.

Review

Accumulating evidence strongly suggests that p53 mutations contribute to the acquisition and/or maintenance of drug-resistant property of pancreatic cancer. Indeed, certain p53 mutants render pancreatic cancer cells much more resistant to GEM, implying that p53 mutation is one of the critical determinants of GEM sensitivity. Intriguingly, runt-related transcription factor 2 (RUNX2) is expressed at higher level in numerous human cancers such as pancreatic cancer and osteosarcoma, indicating that, in addition to its pro-osteogenic role, RUNX2 has a pro-oncogenic potential. Moreover, a growing body of evidence implies that a variety of miRNAs suppress malignant phenotypes of pancreatic cancer cells including drug resistance through the down-regulation of RUNX2. Recently, we have found for the first time that forced depletion of RUNX2 significantly increases GEM sensitivity of p53-null as well as p53-mutated pancreatic cancer cells through the stimulation of p53 family TAp63/TAp73-dependent cell death pathway.

Conclusions

Together, it is likely that RUNX2 is one of the promising molecular targets for the treatment of the patients with pancreatic cancer regardless of their p53 status. In this review article, we will discuss how to overcome the serious drug-resistant phenotype of pancreatic cancer.

MiR-302b Suppresses Osteosarcoma Cell Migration and Invasion by Targeting Runx2

Osteosarcoma patients with lung metastasis and local invasion remain challenging to treat despite the significant contribution of the combination of surgery and neo-adjuvant chemotherapy. Our previous microarray study demonstrated that miR-302b had significantly lower expression in osteosarcoma cell lines than in osteoblast cell lines. In the present study, we further elucidated the role of miR-302b in regulating the migration and invasiveness of osteosarcoma. MiR-302b expression was markedly down-regulated in osteosarcoma cell lines and clinical tumour tissues. Lower levels of miR-302b expression were significantly associated with metastasis and high pathological grades. A functional study demonstrated that over-expression of miR-302b suppressed tumour cell proliferation, invasion and migration in vitro and in vivo. Runx2 was identified as a direct target gene for miR-302b by bioinformatics analysis and dual-luciferase reporter gene assay. Moreover, over-expression of miR-302b induced down-regulation of Runx2, OPN, MMP-2, MMP-9, MMP-12, MMP-14, and VEGF in 143B cells. Exogenous expression of Runx2 partially rescued the inhibitory effect of miR-302b on the invasion and migration activity of 143B osteosarcoma cells. Taken together, our results indicate that miR-302b functions as a tumour repressor in the invasion and migration of osteosarcoma by directly downregulating Runx2 expression and may be a potential therapeutic target for osteosarcoma.