miR-326 associates with biochemical markers of bone turnover in lung cancer bone metastasis

Exosomal hsa-miR-151a-3p and hsa-miR-877-5p are potential novel biomarkers for predicting bone metastasis in lung cancer

Exosomal miRNAs (exo-miRNAs) have arisen as novel diagnostic biomarkers for various cancers. However, few reports on exo-miRNAs related to bone metastasis (BM) in lung cancer exist. This study aims to screen out key exo-miRNAs and estimate their prognostic values for predicting BM in lung cancer. The differentially expressed exo-miRNAs between the highly-metastatic (95D) and lowly-metastatic (A549) human lung cancer cell lines were comprehensively analyzed using high-throughput sequencing followed by bioinformatic analyses. 29 candidate exo-miRNAs were identified, and 101 BM-related target genes were predicted. Enrichment analysis revealed that these target genes were mainly involved in regulating transcription and pathways in cancer. An exosomal miRNA-mRNA regulatory network consisting of 7 key miRNAs and 10 hub genes was constructed. Further function analysis indicated that these 10 hub genes were mainly enriched in regulating cancer's apoptosis and central carbon metabolism. The survival analysis indicated that 7 of 10 hub genes were closely related to prognosis. Mutation analysis showed that lung cancer patients presented certain genetic alterations in the 7 real hub genes. GSEA for a single hub gene suggested that 6 of 7 real hub genes had close associations with lung cancer development. Finally, ROC analysis revealed that hsa-miR-151a-3p and hsa-miR-877-5p provided high diagnostic accuracy in discriminating patients with bone metastasis (BM+) from patients without bone metastasis (BM-). These findings provided a comprehensive analysis of exo-miRNAs and target genes in the regulatory network of BM in lung cancer. In particular, hsa-miR-151a-3p and hsa-miR-877-5p may be novel biomarkers for predicting BM in lung cancer.

Circulating and extracellular vesicle-derived microRNAs as biomarkers in bone-related diseases

MicroRNAs (miRNA) are small non-coding RNA molecules that regulate posttranscriptional gene expression by repressing messengerRNA-targets. MiRNAs are abundant in many cell types and are secreted into extracellular fluids, protected from degradation by packaging in extracellular vesicles. These circulating miRNAs are easily accessible, disease-specific and sensitive to small changes, which makes them ideal biomarkers for diagnostic, prognostic, predictive or monitoring purposes. Specific miRNA signatures can be reflective of disease status and development or indicators of poor treatment response. This is especially important in malignant diseases, as the ease of accessibility of circulating miRNAs circumvents the need for invasive tissue biopsy. In osteogenesis, miRNAs can act either osteo-enhancing or osteo-repressing by targeting key transcription factors and signaling pathways. This review highlights the role of circulating and extracellular vesicle-derived miRNAs as biomarkers in bone-related diseases, with a specific focus on osteoporosis and osteosarcoma. To this end, a comprehensive literature search has been performed. The first part of the review discusses the history and biology of miRNAs, followed by a description of different types of biomarkers and an update of the current knowledge of miRNAs as biomarkers in bone related diseases. Finally, limitations of miRNAs biomarker research and future perspectives will be presented.

Comprehensive circular RNA expression profile of lung adenocarcinoma with bone metastasis: Identification of potential biomarkers

Background: Lung adenocarcinoma (LUAD) has a significant tendency to metastasize to the bone, with severe comorbidities. Recent studies have reported that circular RNAs (circRNAs) are involved in various cancer metastasis-related physiological cellular processes. However, their role in LUAD with bone metastasis (LUAD-BM) remains unknown.

Methods: Bone metastasis (BM) circRNAs were identified using high-throughput sequencing and validated by quantitative reverse transcription-PCR (qRT-PCR). Bioinformatic analyses were used to predict the potential functions of the differentially expressed circRNAs. The effects of circ_0096442 on the growth and metastasis of A549 cells were detected in a co-culture system of A549 and bone marrow-derived cells.

Results: There were 598 (238 upregulated and 360 downregulated) 390 (187 upregulated and 203 downregulated) and 644 (336 upregulated and 308 downregulated) differentially expressed circRNAs between LUAD-BM and LUAD, LUAD-BM and healthy individuals, and LUAD and healthy individuals, respectively. These differentially expressed circRNAs play important roles in cellular components, biological processes, and molecular functions. Moreover, they map several pathways related to BM, including DNA repair, DNA damage, and osteoclast differentiation. The results validated by qRT-PCR for the five most dysregulated circRNAs are consistent with the sequencing data. Additionally, circ_0096442 was found to promote the growth and metastasis of LUAD in a bone microenvironment.

Conclusion: Our findings provide a novel and important circRNA expression profile of LUAD-BM and suggest that circ_0096442 may be a biomarker for LUAD-BM.

The Imbalance of Cytokines and Lower Levels of Tregs in Elderly Male Primary Osteoporosis

INTRODUCTION

Osteoporosis (OP) is a debilitating disease that brings a heavy burden to individuals and society with reduced quality of life and lifespan. However, it's frequently overlooked and poorly studied in elderly male patients. Worse still, few anti-osteoporosis drugs are effective at the prevention and treatment of osteoporosis in men. It has been reported that the cells of bone and the immune system share common progenitors, cytokines and growth factors, and that reciprocal interactions occur during health and disease. Nevertheless, the role of immune system in OP is not fully understood, especially in male patients. Therefore, this study aimed to investigate molecular alterations in immune cells in men with OP and to identify immunomodulatory strategies with potential therapeutic value.

MATERIALS AND METHODS

A population of 121 men aged between 51 and 80 years old was recruited. Bone mineral density (BMD) was measured at the lumbar spine L1-4 and femoral neck using dual-energy X-ray absorptiometry (DXA). Twenty people were healthy, 66 people had osteopenia and 35 people had OP. Bone metabolic markers, Th1, Th2, Tregs and immune molecules were evaluated at the time of enrollment.

RESULTS

Smoking was a risk factor for OP. C-terminal crosslinking of type I collagen (β-CTX) and the ratio of receptor activator of nuclear factor-κB ligand (RANKL) to osteoprotegerin (OPG) were higher in OP group, which had lower 25-hydroxyvitamin D [25(OH)D] levels. OP had the higher levels of IL-6 and TNF-α and lower levels of IFN-γ and IL-10. CD4⁺CD25⁺CD127^-/low Tregs were significantly lower in the OP group. The imbalance of Th1/Th2 cells may play an important role in the development of OP. 25(OH)D may play essential roles in maintaining bone health. The low level of Tregs is also one of the underlying immune mechanism that leads to male primary OP.

CONCLUSION

The active function of osteoclasts and the decline in osteoblasts were characteristics of OP, and the imbalance in cytokines and lower levels of Tregs were observed in elderly male patients with primary OP.

Two alternative cell line models for the study of multiorganic metastasis and immunotherapy in Lung Squamous Cell Carcinoma

There is a paucity of adequate mouse models and cell lines available to study lung squamous cell carcinoma (LUSC). We have generated and characterized two models of phenotypically different transplantable LUSC cell lines (UN-SCC679 and UN-SCC680) derived from an N-nitroso-tris-chloroethylurea (NTCU) chemically-induced mouse model in A/J mice. Furthermore, we genetically characterized and compared both LUSC cell lines by performing whole exome and RNA sequencing. These experiments revealed similar genetic and transcriptomic patterns that may correspond to the classical LUSC human subtype. In addition, we compared the immune landscape generated by both tumor cells lines in vivo and assessed their response to immune checkpoint inhibition. The differences between the two cell lines are a good model for the remarkable heterogeneity of human squamous cell carcinoma. Study of the metastatic potential of these models revealed that both cell lines represent the human LUSC organotropism to the brain, bones, liver and adrenal glands. In summary, we have generated a very valuable cell line tools for LUSC research that recapitulates the complexity of the human disease.

The construction and analysis of ceRNA network and patterns of immune infiltration in lung adenocarcinoma

BACKGROUND

Competitive Endogenous RNA (ceRNA) may be closely associated with tumor progression. However, studies on ceRNAs and immune cells in LUAD are scarce.

METHOD

The profiles of gene expression and clinical data of LUAD patients were extracted from the TCGA database. Bioinformatics methods were used to evaluate differentially-expressed genes (DEGs) and to form a ceRNA network. Preliminary verification of clinical specimens was utilized to detect the expressions of key biomarkers at the tissues. Cox and Lasso regressions were used to identify key genes, and prognosis prediction nomograms were formed. The mRNA levels of 9 genes in the risk score model in independent clinical LUAD samples were detected by qRT-PCR. The interconnection between the risk of cancer and immune cells was evaluated using the CIBERSORT algorithm, while the conformation of notable tumor-infiltrating immune cells (TIICs) in the LUAD tissues of the high and low risk groups was assessed using the RNA transcript subgroup in order to identify tissue types. Finally, co-expression study was used to examine the interconnection between the key genes in the ceRNA networks and the immune cells.

RESULT

A ceRNA network of 115 RNAs was established, and nine key genes were identified to construct a Cox proportional-hazard model and create a prognostic nomogram. This risk-assessment model might serve as an independent factor to forecast the prognosis of LUAD, and it was consistent with the preliminary verification of clinical specimens. Survival analysis of clinical samples further validated the potential value of high risk groups in predicting LUAD prognosis. Five immune cells were identified with significant differences in the LUAD tissues of the high and low risk groups. Besides, two pairs of biomarkers associated with the growth of LUAD were found, i.e., E2F7 and macrophage M1 (R = 0.419, p = 1.4e- 08) and DBF4 and macrophage M1 (R = 0.282, p < 2.2 e- 16).

CONCLUSION

This study identified several important ceRNAs, i.e. (E2F7 and BNF4) and TIICs (macrophage M1), which might be related to the development and prognosis of LUAD. The established risk-assessment model might be a potential tool in predicting LUAD of prognosis.

Non-coding RNAs in necroptosis, pyroptosis and ferroptosis in cancer metastasis

Distant metastasis is the main cause of death for cancer patients. Recently, the newly discovered programmed cell death includes necroptosis, pyroptosis, and ferroptosis, which possesses an important role in the process of tumor metastasis. At the same time, it is widely reported that non-coding RNA precisely regulates programmed death and tumor metastasis. In the present review, we summarize the function and role of necroptosis, pyrolysis, and ferroptosis involving in cancer metastasis, as well as the regulatory factors, including non-coding RNAs, of necroptosis, pyroptosis, and ferroptosis in the process of tumor metastasis.

LncRNA SNHG3 Promotes Gastric Cancer Cells Proliferation, Migration, and Invasion by Targeting miR-326

The function and possible mechanism of lncRNA Small Nucleolar RNA Host Gene 3 (SNHG3) in GC have not been fully studied. The aim of our study was to investigate the role of SNHG3 in the proliferation, migration, and invasion of GC cell lines. The expressions of SNHG3, miR-326, and TWIST in GC9811-P GC cell lines were detected by RT-qPCR. Western blotting was performed to detect the protein levels of TWIST and EMT-related genes. Luciferase reporter gene analysis and RNA immunoprecipitation (RIP) analysis confirmed the interaction between lncRNA SNHG3, miR-326, and TWIST. CCK-8 and Transwell assays were performed to detect cell proliferation, invasion, and migration abilities. The results showed that lncRNA SNHG3 and TWIST were highly expressed in GC cell lines, while miR-326 was expressed to a low degree. Moreover, lncRNA SNHG3 knockdown or miR-326 overexpression significantly inhibited cell proliferation, migration, and invasion of GC cell lines. In addition, TWIST overexpression can reverse the inhibition of lncRNA SNHG3 knockdown or miR-326 overexpression on cell proliferation, migration, and invasion. In conclusion, lncRNA SNHG3 may promote GC progression through the miR-326/TWIST axis, which may provide a new diagnostic and prognostic biomarker for GC.

MicroRNAs Possibly Involved in the Development of Bone Metastasis in Clear-Cell Renal Cell Carcinoma

Simple Summary

Bone metastases cause substantial morbidity and implicate worse clinical outcomes for clear-cell renal cell carcinoma patients. MicroRNAs are small RNA molecules that modulate gene translation and are involved in the development of cancer and metastasis. We identified six microRNAs that are potentially specifically involved in metastasis to bone, of which two seem protective and four implicate a higher risk. This aids further understanding of the process of metastasizing to bone. Furthermore, these microRNA hold potential for biomarkers or therapeutic targets.

Abstract

Bone metastasis in clear-cell renal cell carcinoma (ccRCC) leads to substantial morbidity through skeletal related adverse events and implicates worse clinical outcomes. MicroRNAs (miRNA) are small non-protein coding RNA molecules with important regulatory functions in cancer development and metastasis. In this retrospective analysis we present dysregulated miRNA in ccRCC, which are associated with bone metastasis. In particular, miR-23a-3p, miR-27a-3p, miR-20a-5p, and miR-335-3p specifically correlated with the earlier appearance of bone metastasis, compared to metastasis in other organs. In contrast, miR-30b-3p and miR-139-3p were correlated with less occurrence of bone metastasis. These miRNAs are potential biomarkers and attractive targets for miRNA inhibitors or mimics, which could lead to novel therapeutic possibilities for bone targeted treatment in metastatic ccRCC.

Mechanisms and Future of Non-Small Cell Lung Cancer Metastasis

Lung cancer, renowned for its fast progression and metastatic potency, is rising to become a leading cause of death globally. It has been long observed that lung cancer is particularly ept in spawning distant metastasis at its early stages, and it can readily colonize virtually any human organ. In recent years, cancer research has shed light on why lung cancer is endowed with its exceptional ability to metastasize. In this review, we will take a comprehensive look at the current research on lung cancer metastasis, including molecular pathways, anatomical features and genetic traits that make lung cancer intrinsically metastatic, as we go from lung cancer’s general metastatic potential to the particular metastasis mechanisms in multiple organs. We highly concerned about the advanced discovery and development of lung cancer metastasis, indicating the importance of lung cancer specific gene mutations, heterogeneity or biomarker discovery, and discussing potential opportunities and challenges. We will also introduce some current treatments that targets certain metastatic strategies of non-small cell lung cancer (NSCLC). Advances made in these regards could be critical to our current knowledge base of lung cancer metastasis.

Quercetin regulates ERα mediated differentiation of BMSCs through circular RNA

Circular RNA (circRNA) participates in regulation of gene transcription, while estrogen receptor alpha (ERα) and quercetin (QUE) positively regulate bone formation, but little is known about the correlation among circRNA, ERα and QUE. In this experiment, we created an ERα-deficient rBMSC model treated with QUE and evaluated the effects of ERα or QUE on rBMSCs, then analyzed differentially-expressed circRNAs by RNA-Seq and bioinformatics. The results showed that ERα deficiency constrained osteogenic differentiation and stimulated adipocytic differentiation of rBMSCs, while QUE abrogated those effects. We identified 136 differentially-expressed circRNAs in the Lv-shERα group and 120 differentially-expressed circRNAs in the Lv-shERα + QUE group. Thirty-two circRNAs retroregulated by ERα and QUE were involved in Rap1 and Wnt signaling, and four of them together sponged miR-326-5p, the target genes of which are osteogenic and adipogenic differentiation factors. Further study showed that over-expressed miR-326-5p could stimulate osteogenic differentiation, while attenuating adipogenic differentiation of rBMSCs. Therefore, we concluded that ERα and QUE might regulate the differentiation of rBMSCs through the circRNA-miR-326-5p-mRNA axis.

Diagnostic biomarker and therapeutic target applications of miR-326 in cancers: A systematic review

MicroRNAs (miRNAs) are endogenous mediators of RNA interference and have key roles in the modulation of gene expression under healthy, inflamed, stimulated, carcinogenic, or other cells, and tissues of a pathological state. Many studies have proved the association between miRNAs and cancer. The role of miR-326 as a tumor suppressor miRNA in much human cancer confirmed. We will explain the history and the role of miRNAs changes, especially miR-326 in cancers and other pathological conditions. Attuned with these facts, this review highlights recent preclinical and clinical research performed on miRNAs as novel promising diagnostic biomarkers of patients at early stages, prediction of prognosis, and monitoring of the patients in response to treatment. All related publications retrieved from the PubMed database, with keywords such as epigenetic, miRNA, microRNA, miR-326, cancer, diagnostic biomarker, and therapeutic target similar terms from 1899 to 2018 with limitations in the English language. Recently, researchers have focused on the impacts of miRNAs and their association in inflammatory, autoinflammatory, and cancerous conditions. Recent studies have suggested a major pathogenic role in cancers and autoinflammatory diseases. Investigations have explained the role of miRNAs in cancers, autoimmunity, and autoinflammatory diseases, and so on. The miRNA-326 expression has an important role in cancer conditions and other diseases.

MiR-326/Sp1/KLF3: A novel regulatory axis in lung cancer progression

OBJECTIVES

To investigate the function and regulatory mechanism of Krüppel-like factor 3 (KLF3) in lung cancer.

MATERIALS AND METHODS

KLF3 expression was analysed by qRT-PCR and Western blot assays. The proliferation, migration, invasion, cycle and apoptosis were measured by CCK-8 and EdU, wound-healing and Transwell, and flow cytometry assays. The tumour growth was detected by nude mouse tumorigenesis assay. In addition, the interaction between KLF3 and Sp1 was accessed by luciferase reporter, EMSA and ChIP assay. JAK2, STAT3, PI3K and p-AKT levels were evaluated by Western blot and IHC assays.

RESULTS

The results indicated that KLF3 expression was elevated in lung cancer tissues. Knockdown of KLF3 inhibited lung cancer cell proliferation, migration and invasion, and induced cell cycle arrest and apoptosis. In addition, the downregulation of KLF3 suppressed tumour growth in vivo. KLF3 was transcriptionally activated by Sp1. miR-326 could bind to 3'UTR of Sp1 but not KLF3 and decreased the accumulation of Sp1, which further indirectly reduced KLF3 expression and inactivated JAK2/STAT3 and PI3K/AKT signaling pathways in vitro and in vivo.

CONCLUSIONS

Our data demonstrate that miR-326/Sp1/KLF3 regulatory axis is involved in the development of lung cancer, which hints the potential target for the further therapeutic strategy against lung cancer.

A two-circular RNA signature as a noninvasive diagnostic biomarker for lung adenocarcinoma

BACKGROUND

Recently, circular RNAs (circRNAs) have been reported to be microRNA sponges and play essential roles in cancer development. This study aimed to evaluate whether circulating circRNAs could be used as diagnostic biomarkers for lung adenocarcinoma (LUAD).

METHODS

The Gene Expression Omnibus (GEO) dataset was used to investigate differentially expressed circRNAs (DEcircRNAs) in paired LUAD tissues and adjacent nontumor tissues. The expression levels of the host genes were analyzed in The Cancer Genome Atlas (TCGA)-LUAD dataset, and the prognostic value was assessed using the Kaplan-Meier plotter. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression of candidate circRNAs in the LUAD plasma and cells. The CCK8 assay was used to measure the function of circRNAs in cell proliferation. Competing endogenous RNA (ceRNA) network, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to predict the possible mechanisms and functions of circRNAs in LUAD.

RESULTS

Two upregulated and two downregulated circRNAs were identified as candidate circRNAs using bioinformatics analysis. qRT-PCR demonstrated that hsa_circ_0005962 was upregulated in LUAD plasma and cells, whereas hsa_circ_0086414 was downregulated. Receiver operating characteristic (ROC) curve analysis confirmed that a signature comprising the two circRNAs had good diagnostic potential, with an area under the ROC curve (AUC) of 0.81 (P < 0.0001). In addition, we observed that overexpression of plasma hsa_circ_0086414 was related to EGFR mutations (P = 0.001). Plasma hsa_circ_0005962 displayed significantly different expression before and after surgery in patients with LUAD (P < 0.0001). In vitro experiments suggested that hsa_circ_0005962 promoted LUAD cell proliferation. For future studies, we predicted the circRNA-miRNA-mRNA network for hsa_circ_0005962. Bioinformatics analysis revealed that hsa_circ_0005962 might be involved in LUAD development.

CONCLUSION

A circRNA signature was identified as a potential noninvasive biomarker for LUAD diagnosis.

Engineered exosomes: A new promise for the management of musculoskeletal diseases

BACKGROUND

Exosomes are nanovesicles actively secreted by potentially all cell types, including tumour cells, with the primary role of extracellular systemic communication mediators, both at autocrine and paracrine levels, at short and long distances. Recently, different studies have used exosomes as a delivery system for a plethora of different molecules, such as drugs, microRNAs and proteins. This has been made possible thanks to the simplicity in exosomes engineering, their great stability and versatility for applications in oncology as well as in regenerative medicine.

SCOPE OF REVIEW

The aim of this review is to provide information on the state-of-the-art and possible applications of engineered exosomes, both for cargo and specific cell-targeting, in different pathologies related to the musculoskeletal system.

MAJOR CONCLUSIONS

The use of exosomes as therapeutic agents is rapidly evolving, different studies explore drug delivery with exosomes using different molecules, showing an enormous potential in various research fields such as oncology and regenerative medicine.

GENERAL SIGNIFICANCE

However, despite the significant progress made by the different studies carried out, currently, the use of exosomes is not a therapeutic reality for the considerable difficulties to overcome.

MicroRNA-326 aggravates acute lung injury in septic shock by mediating the NF-κB signaling pathway

Our previous studies have demonstrated that the activation of the nuclear factor-kappa B (NF-κB) signaling pathway contributes to the development of lipopolysaccharide (LPS)-induced acute lung injury (ALI) as well as an inflammatory reaction, and its inhibition may provide future therapeutic values. Thereby, this study aims to explore the effects of miR-326 on inflammatory response and ALI in mice with septic shock via the NF-κB signaling pathway. The study included normal mice and LPS-induced mouse models of septic shock with ALI. Modeled mice were transfected with the blank plasmid, miR-326 mimic, miR-326 inhibitor, si-BCL2A1 and miR-326 inhibitor + si-BCL2A1. Mean arterial pressure (MAP), airway pressure (AP), heart rate (HR) and lung wet dry (W/D) ratio were determined. Serum levels of interleukin (IL)-6, IL-10, IL-1β, and tumor necrosis factor-α (TNF-α) were detected using ELISA. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were performed to detect the miR-326 expression and expression levels of BCL2A1, related genes of inflammatory response and the NF-κB signaling pathway in lung tissues. Cell viability and apoptosis were measured using the CCK-8 assay and flow cytometry, respectively. Compared to the ALI models and those transfected with blank plasmid, the up-regulated miR-326 expression and silenced BCL2A1 lead to decreased levels of MAP, increased AP, HR and lung W/D, increased serum levels of IL-6, IL-10, IL-1β and TNF-α, increased expressions of IL-6, IL-1β, TNF-α, NF-κB p65 (p-NF-κB p65), and iNOS with decreased expressions of BCL2A1s as well as inhibition of cell viability and enhanced cell apoptosis; the down-regulated miR-326 expression reversed the aforementioned situation. MiR-326 targeting the BCL2A1 gene activated the NF-κB signaling pathway, resulting in aggravated inflammatory response and lung injury of septic shock with ALI in mice.

Identification of a seven-miRNA signature as prognostic biomarker for lung squamous cell carcinoma

BACKGROUND

Specific biomarkers for outcome prediction of lung squamous cell carcinoma (LUSC) are still lacking. This study assessed the prognostic value of differentially expressed miRNAs of LUSC patients.

RESULTS

Twelve of the 133 most significantly altered miRNAs were associated with overall survival (OS) across different clinical subclasses of the Cancer Genome Atlas (TCGA) LUSC cohort. A linear prognostic model of seven miRNAs was developed to divide patients into high- and low-risk groups. Patients assigned to the high-risk group exhibited poor OS compared with patients in the low-risk group, which was further validated in the validation cohort and entire LUSC cohort.

METHODS

MiRNA expression profiles with clinical information of 447 LUSC patients were obtained from TCGA. Most significantly altered miRNAs were identified between tumor and normal samples. Using survival analysis and supervised principal components method, a seven-miRNA signature for prediction of OS of LUSC patients was established. Survival receiver operating characteristic (ROC) analysis was used to assess the performance of survival prediction. The biological relevance of predicted miRNA targets was also analyzed using bioinformatics method.

CONCLUSIONS

The current study suggests that seven-miRNA signature may have clinical implications in the outcome prediction of LUSC.

Circulating biomarkers in osteosarcoma: new translational tools for diagnosis and treatment

Osteosarcoma (OS) is a rare primary malignant bone tumour arising from primitive bone-forming mesenchymal cells, with high incidence in children and young adults, accounting for approximately 60% of all malignant bone tumours. Currently, long-term disease-free survival can be achieved by surgical treatment plus chemotherapy in approximately 60% of patients with localized extremity disease, and in 20-30% of patients with metastatic lung or bone disease. Diagnosis of primary lesions and recurrences is achieved by using radiological investigations and standard tissue biopsy, the latter being costly, painful and hardly repeatable for patients. Therefore, despite some recent advances, novel biomarkers for OS diagnosis, prediction of response to therapy, disease progression and chemoresistance, are urgently needed. Biological fluids such as blood represent a rich source of non-invasive cancer biomarkers, which allow to understand what is really happening inside the tumour, either at diagnosis or during disease progression. In this regard, liquid biopsy potentially represents an alternative and non-invasive method to detect tumour onset, progression and response to therapy. In this review, we will summarize the state of the art in this novel area, illustrating recent studies on OS. Although the data reported in literature seem preliminary, liquid biopsy represents a promising tool with the potential to be rapidly translated in the clinical practice.

The Usefulness of Bone Biomarkers for Monitoring Treatment Disease: A Comparative Study in Osteolytic and Osteosclerotic Bone Metastasis Models

BACKGROUND: The skeleton is the most common site of colonization by metastatic cancers. Zoledronic acid (ZA) has been shown to be effective for the treatment of bone metastases regardless of whether the bone lesions are osteolytic or osteoblastic. Biochemical markers of bone turnover may be useful tools to quantify the degree of bone remodeling in the presence of bone metastases. The aim of this work was to establish the correlation between tumor dispersion (bioluminescence) and biochemical markers of bone turnover in two osteolytic and osteoblastic metastasis models in mice. METHODS: The A549M1 cell line that produces osteolytic metastases and the LADOB cell line extracted from a patient with a lung carcinoma and osteoblastic metastases cells were retrovirally transduced with a luciferase reporter gene for in vivo image analysis. Forty-four-week–old mice were inoculated in the left cardiac ventricle with A549M1 or LADOB cells. Twenty mouse of each group were treated with a single dose of ZA (70 μg/kg) 5 days after i.c. Ten animals of each group were sacrificed at 21 and 28 days postinoculation in A549M1 and 60 and 75 days in the LADOB assay. Bioluminescence analysis was quantified 7, 14, 21 ,and 28 days postinoculation in A549M1 mice and 33, 45, 60, and 75 days after inoculation in LADOB mice. Osteocalcin (BGP), aminoterminal propeptide of procollagen I (PINP), carboxiterminal telopeptide of type I collagen (CTX), and 5b isoenzyme of tartrate-resistant acid phosphatase were measured by ELISA (IDS, UK). RESULTS: Bioluminescence imaging revealed a significant increase of tumor burden on time in both osteolytic and osteoblastic mice models. ZA administration resulted in a significant decrease in tumor burden at 21 and 28 days in the A549M1 animals and 60 and 70 days postinoculation in the LADOB line. Biomarkers levels were significantly increased in the untreated group at every point in the osteolytic model. In the osteoblastic model, 2 months after inoculation, all biomarkers were significantly increased. However, 2.5 months postinoculation, only PINP and CTX were significantly increased. Serum bone remodeling markers decreased in ZA-treated mice as compared with tumor groups in both models. With respect to the correlation between bone turnover markers and tumor burden, in the osteolytic model, PINP and BGP demonstrate a strong correlation with bioluminescence in both tumoral and ZA animals, and only CTX was significantly associated with bioluminescence in the group of animals that were not treated with ZA. CONCLUSIONS: We found that the best biomarkers for the diagnosis of both osteolytic and osteoblastic metastasis are formation markers, especially BGP. Moreover, these markers can be useful in the follow-up of the treatment with ZA in both types of metastasis.

Hsa-miR-326 targets CCND1 and inhibits non-small cell lung cancer development

Hsa-miRNA-326 (miR-326) has recently been discovered having anticancer efficacy in different organs. However, the role of miR-326 on non-small cell lung cancer (NSCLC) is still ambiguous. In this study, we investigated the role of miR-326 on the development of NSCLC. The results indicated that miR-326 was significantly down-regulated in primary tumor tissues and very low levels were found in NSCLC cell lines. Ectopic expression of miR-326 in NSCLC cell lines significantly suppressed cell growth as evidenced by cell viability assay, colony formation assay and BrdU staining, through inhibition of cyclin D1, cyclin D2, CDK4 and up-regulation of p57(Kip2) and p21(Waf1/Cip1). In addition, miR-326 induced apoptosis, as indicated by concomitantly with up-regulation of key apoptosis protein cleaved caspase-3, and down-regulation of anti-apoptosis protein Bcl2. Moreover, miR-326 inhibited cellular migration and invasiveness through inhibition of matrix metalloproteinases (MMP)-7 and MMP-9. Further, oncogene CCND1 was revealed to be a putative target of miR-326, which was inversely correlated with miR-326 expression in NSCLC. Taken together, our results demonstrated that miR-326 played a pivotal role on NSCLC through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic CCND1.

SEOM Clinical Guideline for bone metastases from solid tumours (2016)

Bone metastases are common in many advanced solid tumours, being breast, prostate, thyroid, lung, and renal cancer the most prevalent. Bone metastases can produce skeletal-related events (SREs), defined as pathological fracture, spinal cord compression, need of bone irradiation or need of bone surgery, and hypercalcaemia. Patients with bone metastases experience pain, functional impairment and have a negative impact on their quality of life. Several imaging techniques are available for diagnosis of this disease. Bone-targeted therapies include zoledronic acid, a potent biphosfonate, and denosumab, an anti-RANKL monoclonal antibody. Both reduce the risk and/or delay the development of SREs in several types of tumours. Radium 233, an alpha-particle emitter, increases overall survival in patients with bone metastases from resistant castration prostate cancer. Multidisciplinary approach is essential and bone surgery and radiotherapy should be integrated in the treatment of bone metastases when necessary. This SEOM Guideline reviews bone metastases pathogenesis, clinical presentations, lab tests, imaging techniques for diagnosis and response assessment, bone-targeted agents, and local therapies, as radiation and surgery, and establishes recommendations for the management of patients with metastases to bone.

Evaluation of plasma microRNA levels to predict insensitivity of patients with advanced lung adenocarcinomas to pemetrexed and platinum

Pemetrexed combined with platinum is a first-line therapy used to treat patients with advanced non-small cell lung cancer (NSCLC) that exhibit negative or unknown epidermal growth factor receptor (EGFR) mutational status or anaplastic lymphoma kinase (ALK) rearrangements. Lung adenocarcinoma (LAC) is the primary type of NSCLC. In order to prevent overtreatment, it is necessary to identify patients with LAC who may not benefit from certain chemotherapies. Patients recruited in the present study (n=129) were diagnosed with advanced LAC and received first-line pemetrexed and platinum-based chemotherapy. A microRNA (miR) microarray was used to screen the plasma miR expression profiles in a screening set of eight patients prior to and following treatment. Specifically, plasma miR-25, miR-21, miR-27b, miR-326, miR-483-5p and miR-920 were selected for reverse transcription-quantitative polymerase chain reaction analysis in a training set (n=44) prior to treatment. The screening and training set patients were all non-smokers with no prior history of serious or chronic disease. The ∆∆Cq values of these miRs were compared between the group that showed benefit from pemetrexed and platinum treatment and the group that did not. Consequently, the ∆∆Cq values of miR-25, miR-21, miR-27b and miR-326 were further determined in a validation set (n=77). The results of the present study demonstrate that plasma expression levels of miR-25, miR-21, miR-27b and miR-326, in the training and validation sets prior to treatment, were significantly different between the benefit and non-benefit groups (P≤0.001). The expression of miR-25, miR-21, miR-27b and miR-326 was upregulated in the non-benefit group and this elevation was positively correlated with decreased progression-free survival (PFS; P≤0.001). In addition, the predictive power of each miR was evaluated through receiver operating characteristic curves, in which miR-25 exhibited the highest degree of accuracy (area under the curve, 0.926; 95% confidence interval, 0.881-0.971). These results indicate that overexpression of plasma miR-25, miR-21, miR-27b and miR-326, prior to treatment, in patients with advanced LAC is predictive of non-benefit from first-line pemetrexed and platinum-based chemotherapy, and is associated with decreased PFS. Among these four miRs, miR-25 exhibited the highest degree of accuracy in predicting insensitivity, suggesting it is the most promising biomarker.

Sphere-derived tumor cells exhibit impaired metastasis by a host-mediated quiescent phenotype

The spread of lung cancer cells to distant sites represents a common event associated with poor prognosis. A fraction of tumor cells named cancer stem cells (CSCs) have the ability to overcome therapeutic stress and remain quiescent. However, whether these CSCs have also the capacity to initiate and sustain metastasis remains unclear. Here, we used tumor sphere cultures (TSC) isolated from mouse and human lung cancer models to enrich for CSCs, and assessed their metastatic potential as compared to non-CSCs. As expected, TSC overexpressed a variety of stem cell markers and displayed chemoresistance. The CSC phenotype of TSC was confirmed by their higher growth ability in soft agar and tumorigenic potential in vivo, despite their reduced in vitro cell growth kinetics. Surprisingly, the appearance of spontaneous lung metastases was strongly delayed in mice injected with TSC as compared to non-TSC cells. Similarly, this finding was confirmed in several other models of metastasis, an effect associated with a retarded colonization activity. Interestingly, such delay correlated with a quiescent phenotype whose underlined mechanisms included an increase in p27 protein and lower phospho-ERK1/2 levels. Thus, these data suggest that cells enriched for CSC properties display an impaired metastatic activity, a finding with potential clinical implications.

Regulation of oncogenic genes by MicroRNAs and pseudogenes in human lung cancer

Lung cancer is one of the most common mortal cancer types both for men and women. Several different biomarkers have been analyzed to reveal lung cancer prognosis pathways for developing efficient therapeutics and diagnostic agents. microRNAs (miRNAs) and pseudogenes are critical biomarkers in lung cancer and alteration of their expression levels has been identified in each step of lung cancer tumorigenesis. miRNAs and pseudogenes are crucial gene regulators in normal cells as well as in lung cancer cells, and they have both oncogenic and tumor-suppressive roles in lung cancer tumorigenesis. In this study, we have determined the relationship between lung cancer related oncogenes and miRNAs along with pseudogenes in lung cancer, and the results indicate their potential as biological markers for diagnostic and therapeutic purposes.

Progress in the research on the mechanism of bone metastasis in lung cancer

Lung cancer is still the predominant cause of cancer-associated mortality worldwide. The bone metastasis of lung cancer brings great suffering to the patient. Previous advances have provided insights into the mechanism of bone metastasis. Previous research has investigated lung cancer stem cells and three steps were determined for the lung cancer cells to metastasize to the bone: i) Escaping from the primary tumor; ii) moving in the circulation; iii) colonizing in the bone. Key molecules are involved in each of these process. Although there is a close association and similarity, dynamic microenvironments affect these processes. The receptor activator of nuclear factor-κB (RANK)/RANKL axis serves a vital role in the regulation of the generation and activation of osteoclasts during the osteolytic lesion. However, the specific molecules for the lung cancer cells to metastasize to the bone require further research and exploration. The present study aimed to investigate the relative molecular mechanisms of bone metastasis in lung cancer in recent years, providing a general understanding about the features of lung cancer preferences to bone, and discussing other things that require investigation.

Bone metastases in lung cancer. Potential novel approaches to therapy

The skeleton is a common site of metastases in lung cancer, an event associated with significant morbidities and poor outcomes. Current antiresorptive therapies provide limited benefit, and novel strategies of prevention and treatment are urgently needed. This review summarizes the latest advances and new perspectives on emerging experimental and clinical approaches to block this deleterious process. Progress propelled by preclinical models has led to a deeper understanding on the complex interplay of tumor cells in the osseous milieu, unveiling potential new targets for drug development. Improvements in early diagnosis through the use of sophisticated imaging techniques with bone serum biomarkers are also discussed in the context of identifying patients at risk and monitoring disease progression during the course of treatment.

The best of both worlds - managing the cancer, saving the bone

In the context of breast cancer, the importance of the skeleton in the regulation of primary tumour development and as a site for subsequent metastasis is well characterized. Our understanding of the contributions made by the host bone and bone marrow cells increasingly demonstrates the extent of the interaction between tumour cells and normal host cells. As a result, the need to develop and utilize therapies that can impede the growth and/or function of tumour cells while sparing normal host bone and bone marrow cells is immense and expanding. The need for these new treatments is, however, superimposed on the orthopaedic management of patients' quality of life, where pain control and continued locomotion are paramount. Indeed, the majority of the anticancer therapies used to date often result in direct or indirect damage to bone. Thus, although the bone microenvironment regulates tumour cell growth in bone, cells within the bone marrow niche also mediate many of the orthopaedic consequences of tumour progression as well as resistance to the antitumour effects of existing therapies. In this Review, we highlight the effects of existing cancer treatments on bone and the bone marrow microenvironment as well as the mechanisms mediating these effects and the current utility of modern orthopaedic interventions.

The role of miRNAs in bone metastasis and their significance in the detection of bone metastasis: a review of the published data

The preferential metastasis of cancer cells to bone disrupts the process of bone remodeling and results in serious complications. Although bone imaging techniques are well established for bone metastasis diagnosis, they still have limits. Recently, small noncoding RNA molecules, called miRNAs, have become the subject of interest in many molecular pathways in relation to bone metastasis. Furthermore, studies have demonstrated the ability to distinguish normal from cancerous cells and metastatic bone tumor origin based on miRNA profiles. Here, we summarize the data on mechanisms of osteolytic and osteoblastic bone metastases supporting the involvement of miRNA changes in the bone metastatic evolution. We also focus on the available evidence regarding current clinical studies of miRNA expression in the detection of bone metastases.

MicroRNAs and Osteolytic Bone Metastasis: The Roles of MicroRNAs in Tumor-Induced Osteoclast Differentiation

Osteolytic bone metastasis frequently occurs in the later stages of breast, lung, and several other cancers. Osteoclasts, the only cells that resorb bone, are hijacked by tumor cells, which break down bone remodeling systems. As a result, osteolysis occurs and may cause patients to suffer bone fractures, pain, and hypercalcemia. It is important to understand the mechanism of bone metastasis to establish new cancer therapies. MicroRNAs are small, noncoding RNAs that are involved in various biological processes, including cellular differentiation, proliferation, apoptosis, and tumorigenesis. MicroRNAs have significant clinical potential, including their use as new therapeutic targets and disease-specific biomarkers. Recent studies have revealed that microRNAs are involved in osteoclast differentiation and osteolytic bone metastasis. In this review focusing on microRNAs, the author discusses the roles of microRNAs in osteoclastogenesis and osteolytic bone metastasis.

Downregulation of Plasma MiR-142-3p and MiR-26a-5p in Patients With Colorectal Carcinoma

Background:

Colorectal cancer is one of the most commonly diagnosed cancers and cancer- related death worldwide. Identification of new specific biomarkers could be helpful to detection of this malignancy. Altered plasma microRNA expression has been identified in many cancers, including colorectal cancer.

Objectives:

The main objective of this study was to identify the circulating microRNAs with the most expression changes in colorectal cancer patients compared with neoplasm free healthy individuals.

Materials and Methods:

MicroRNA expression profiling was performed on plasma samples of 37 colorectal cancer patients and 8 normal subjects using microRNA microarray. Quantitative real-time reverse transcription polymerase chain reaction was used to validate the two selected altered microR NAs. Plasma samples from 61 colorectal cancer patients and 24 normal subjects were used in our validation study.

Results:

In profiling study we found a panel of six plasma microRNAs with significant downregulation. MicroRNA-142-3p and microRNA-26a-5p were selected and validated by polymerase chain reaction. Our results demonstrated that expression levels of plasma microRNA-142-3p and microRNA-26a-5p were significantly downregulated in patients with colorectal cancer when compared to control group.

Conclusions:

Our findings suggest that downregulation of plasma microRNA-142-3p and microRNA-26a-5p might serve as novel noninvasive biomarkers in the diagnosis of colorectal cancer, although more studies are needed to highlight the theoretical strengths.

Tumour-derived miRNAs and bone metastasis

Skeletal metastases are complications of epithelial cancers, among which breast, prostate and lung carcinomas are the most osteotropic. In primary tumours, a subset of cancer cells undergoes epithelial-mesenchymal transition, acquires mobility to migrate into the surrounding stroma and seeds at distant sites to grow. The specific development of bone metastasis requires the recruitment of circulating tumour cells in the bone marrow, their adaptation to survive in the surrounding microenvironment where they alter the functions of osteoclasts and osteoblasts, and hijack signals coming from the bone matrix. Each of the molecular pathways underlining these steps is regulated by multiple factors, through the tight control of genes expressed by cancer cells interacting with cells from the bone microenvironment. In this context, miRNAs can act as master regulators of gene expression to control multiple aspects of bone metastasis formation, including cancer cell escape from the primary tumour site, cancer cell dissemination to bone and invasion of the bone marrow, as well as secondary outgrowth and tumour-stroma cell interactions. In the clinic, specific miRNA signatures have been identified in osteotropic cancer cells, raising the possibility that miRNAs could be used as biomarkers of bone metastasis. The regulatory activity of miRNAs in the bone microenvironment also suggests that miRNAs could be promising therapeutic targets.

Bone marrow stroma-derived miRNAs as regulators, biomarkers and therapeutic targets of bone metastasis

MicroRNAs (miRNAs) are short, endogenous RNA molecules that have essential roles in regulating gene expression. They control numerous physiological and cellular processes, including normal bone organogenesis and homeostasis, by enhancing or inhibiting bone marrow cell growth, differentiation, functional activity and crosstalk of the multiple cell types within the bone. Hence, elucidating miRNA targets in bone marrow stromal cells has revealed novel regulations during bone development and maintenance. Moreover, recent studies have detailed the capacity for bone stromal miRNAs to influence bone metastasis from a number of primary carcinomas by interfering with bone homeostasis or by directly influencing metastatic tumor cells. Owing to the current lack of good diagnostic biomarkers of bone metastases, such changes in bone stromal miRNA expression in the presence of metastatic lesions may become useful biomarkers, and may even serve as therapeutic targets. In particular, cell-free and exosomal miRNAs shed from bone stromal cells into circulation may be developed into novel biomarkers that can be routinely measured in easily accessible samples. Taken together, these findings reveal the significant role of bone marrow stroma-derived miRNAs in the regulation of bone homeostasis and bone metastasis.

TGF-β/BMP signaling and other molecular events: regulation of osteoblastogenesis and bone formation

Transforming growth factor-beta (TGF-β)/bone morphogenetic protein (BMP) plays a fundamental role in the regulation of bone organogenesis through the activation of receptor serine/threonine kinases. Perturbations of TGF-β/BMP activity are almost invariably linked to a wide variety of clinical outcomes, i.e., skeletal, extra skeletal anomalies, autoimmune, cancer, and cardiovascular diseases. Phosphorylation of TGF-β (I/II) or BMP receptors activates intracellular downstream Smads, the transducer of TGF-β/BMP signals. This signaling is modulated by various factors and pathways, including transcription factor Runx2. The signaling network in skeletal development and bone formation is overwhelmingly complex and highly time and space specific. Additive, positive, negative, or synergistic effects are observed when TGF-β/BMP interacts with the pathways of MAPK, Wnt, Hedgehog (Hh), Notch, Akt/mTOR, and miRNA to regulate the effects of BMP-induced signaling in bone dynamics. Accumulating evidence indicates that Runx2 is the key integrator, whereas Hh is a possible modulator, miRNAs are regulators, and β-catenin is a mediator/regulator within the extensive intracellular network. This review focuses on the activation of BMP signaling and interaction with other regulatory components and pathways highlighting the molecular mechanisms regarding TGF-β/BMP function and regulation that could allow understanding the complexity of bone tissue dynamics.

Emerging lung cancer therapeutic targets based on the pathogenesis of bone metastases

Lung cancer is the second most common cancer and the leading cause of cancer related mortality in both men and women. Each year, more people die of lung cancer than of colon, breast, and prostate cancers combined. It is widely accepted that tumor metastasis is a formidable barrier to effective treatment of lung cancer. The bone is one of the frequent metastatic sites for lung cancer occurring in a large number of patients. Bone metastases can cause a wide range of symptoms that could impair quality of life of lung cancer patients and shorten their survival. We strongly believe that molecular targets (tumor-related and bone microenvironment based) that have been implicated in lung cancer bone metastases hold great promise in lung cancer therapeutics. Thus, this paper discusses some of the emerging molecular targets that have provided insights into the cascade of metastases in lung cancer with the focus on bone invasion. It is anticipated that the information gathered might be useful in future efforts of optimizing lung cancer treatment strategies.

Chinese bone turnover marker study: reference ranges for C-terminal telopeptide of type I collagen and procollagen I N-terminal peptide by age and gender

Background

Bone formation marker procollagen I N-terminal peptide (PINP) and resorption marker C-terminal telopeptide of type I collagen (β-CTX) are useful biomarkers for differential diagnosis and therapeutic evaluation of osteoporosis, but reference values are required.

Methods

The multi-center, cross-sectional Chinese Bone Turnover Marker Study included 3800 healthy volunteers in 5 Chinese cities. Serum PINP, β-CTX, parathyroid hormone (PTH) and 25OHD levels were measured by chemiluminescence assay. Lumbar spine and proximal femur BMD were measured by dual-energy X-ray absorptiometry. Serum PINP and β-CTX levels were assessed by age, gender, weight, recruitment latitude, levels of PTH and 25OHD.

Results

Subjects (n = 1436, M∶F, 500∶936; mean age 50.6±19.6 years) exhibited non-normally distributed PINP and β-CTX peaking between 15–19 years, gradually declining throughout adulthood, elevating within 10 years of postmenopause, and then declining by age 70. In women between the age of 30 and menopause, median PINP and β-CTX levels were 40.42 (95% CI: 17.10–102.15) and 0.26 (95% CI: 0.08–0.72) ng/mL, respectively. β-CTX and PINP were positively linearly correlated (r = 0.599, P<0.001). β-CTX correlated positively (r = 0.054 and 0.093) and PINP correlated negatively (r = −0.012 and −0.053) with 25OHD and PTH (P<0.05).

Conclusions

We established Chinese reference ranges for PINP and CTX. Chinese individuals exhibited high serum PINP and β-CTX levels between 15 and 19 years of age and at menopause, which gradually declined after 70 years of age.

MicroRNAs and bone metastasis: a new challenge

The development of bone metastases requires multistep and multicellular machinery consisting not only of processes shared with any type of metastases (formation of a pre-metastatic niche, chemotaxis of tumor cells into the host tissue, tumor cells escape from the microvasculature), but also biological interactions that are strictly related to the particular bone microenvironment (bone marrow colonization by cancer cells, osteomimicry, deregulation of bone homeostasis). MiRNAs are highly conserved, small RNAs molecules that regulate gene expression. The functional consequence of miRNA deregulation lies in the mRNA targets whose expression is altered. MiRNA networks acting as upstream regulators of these genes interfere with the initial steps of tumor local invasion and cancer cell intravasation, mainly by regulating the epithelial-mesenchymal transition, the motility, invasiveness and survival abilities of these cells. The miRNA-mediated regulation on the steps of bone tropism, anchorage, homing and finally bone colonization is more tissue specific, being dependent on the expression pattern of target miRNAs in bone marrow sinusoids, bone cells and microenvironment. In that, miRNA specific expression signatures that can distinguish between primary tumors from their corresponding bone metastases might be determinants of clinical aggressiveness. In this review, we focus on the current advances on functions and molecular mechanisms by which miRNAs exert their biological roles in regulating bone metastases development.

miRNA cargo within exosome-like vesicle transfer influences metastatic bone colonization

Bone metastasis represents one of the most deleterious clinical consequences arising in the context of many solid tumors. Severe osteolysis results from tumor cell colonization of the bone compartment, a process which entails reciprocal exchange of soluble signals between tumor cells and their osseous microenvironment. Recent evidence indicates that tumor-intrinsic miRNAs are pleiotropic regulators of gene expression. But they are also frequently released in exosome-like vesicles (ELV). Yet the functional relevance of the transference of tumor-derived ELV and their miRNA cargo to the extracellular milieu during osseous colonization is unknown. Comparative transcriptomic profiling using an in vivo murine model of bone metastasis identified a repressed miRNA signature associated with high prometastatic activity. Forced expression of single miRNAs identified miR-192 that markedly appeased osseous metastasis in vivo, as shown by X-ray, bioluminescence imaging and microCT scans. Histological examination of metastatic lesions revealed impaired tumor-induced angiogenesis in vivo, an effect that was associated in vitro with decreased hallmarks of angiogenesis. Isolation and characterization of ELV by flow cytometry, Western blot analysis, transmission electron microscopy and nanoparticle tracking analysis revealed the ELV cargo enrichment in miR-192. Consistent with these findings, fluorescent labeled miR-192-enriched-ELV showed the in vitro transfer and release of miR-192 in target endothelial cells and abrogation of the angiogenic program by repression of proangiogenic IL-8, ICAM and CXCL1. Moreover, in vivo infusion of fluorescent labeled ELV efficiently targeted cells of the osseous compartment. Furthermore, treatment with miR-192 enriched ELV in a model of in vivo bone metastasis pre-conditioned osseous milieu and impaired tumor-induced angiogenesis, thereby reducing the metastatic burden and tumor colonization. Changes in the miRNA-cargo content within ELV represent a novel mechanism heavily influencing bone metastatic colonization, which is most likely relevant in other target organs. Mechanistic mimicry of this phenomenon by synthetic nanoparticles could eventually emerge as a novel therapeutic approach.

Procollagen assays in cancer

The synthesis rates of fibrillar collagens can be assessed in blood by measuring propeptides set free from corresponding procollagens before fiber formation. Type I collagen is the major component of the organic matrix of bone, but it is also found in other connective tissues. The serum concentration of the amino-terminal propeptide of type I procollagen, PINP, functions as a measure of type I collagen synthesis during normal bone turnover, but it is also released from bone metastases that involve an osteoblastic component. Type III collagen is a major constituent of soft tissues and the corresponding amino-terminal propeptide, PIIINP, reflects collagen synthesis. Circulating PIIINP tends to be affected by malignomas that grow in the peritoneal cavity or affect bone marrow. Many studies on procollagen markers in cancer have been cross-sectional or demonstrated treatment effects in patient groups. Markers that originate from bone turnover have wide reference intervals, but low biologic variability in individuals. Thus, they appear better suited for monitoring versus diagnostic purposes. There is still definite need for research on the use of procollagen markers in the followup of individual patients undergoing cancer treatment or being monitored after such treatment.

An integrated systems genetics screen reveals the transcriptional structure of inherited predisposition to metastatic disease

Metastasis is the result of stochastic genomic and epigenetic events leading to gene expression profiles that drive tumor dissemination. Here we exploit the principle that metastatic propensity is modified by the genetic background to generate prognostic gene expression signatures that illuminate regulators of metastasis. We also identify multiple microRNAs whose germline variation is causally linked to tumor progression and metastasis. We employ network analysis of global gene expression profiles in tumors derived from a panel of recombinant inbred mice to identify a network of co-expressed genes centered on Cnot2 that predicts metastasis-free survival. Modulating Cnot2 expression changes tumor cell metastatic potential in vivo, supporting a functional role for Cnot2 in metastasis. Small RNA sequencing of the same tumor set revealed a negative correlation between expression of the Mir216/217 cluster and tumor progression. Expression quantitative trait locus analysis (eQTL) identified cis-eQTLs at the Mir216/217 locus, indicating that differences in expression may be inherited. Ectopic expression of Mir216/217 in tumor cells suppressed metastasis in vivo. Finally, small RNA sequencing and mRNA expression profiling data were integrated to reveal that miR-3470a/b target a high proportion of network transcripts. In vivo analysis of Mir3470a/b demonstrated that both promote metastasis. Moreover, Mir3470b is a likely regulator of the Cnot2 network as its overexpression down-regulated expression of network hub genes and enhanced metastasis in vivo, phenocopying Cnot2 knockdown. The resulting data from this strategy identify Cnot2 as a novel regulator of metastasis and demonstrate the power of our systems-level approach in identifying modifiers of metastasis.