LINC00968 functions as an oncogene in osteosarcoma by activating the PI3K/AKT/mTOR signaling.

Osteosarcoma is recognized as a malignant tumor in the skeletal system. Long non-coding RNAs (lncRNAs) have been exhibited to play crucial roles in osteosarcoma development. Our current study focused on the biological effects and mechanism of LINC00968 in osteosarcoma pathogenesis. We observed that LINC00968 was dramatically elevated in osteosarcoma cells including U2OS, MG63, Saos-2, SW1353, and 143-B cells compared to human osteoblast cell line hFOB. Silence of LINC00968 inhibited osteosarcoma cell growth and proliferation in vitro. Reversely, overexpression of LINC00968 promoted osteosarcoma cell survival and cell colony formation ability in Saos-2 and 143-B cells. In addition, LINC00968 was able to induce osteosarcoma cell migration and invasion through up-regulating MMP-2 and MMP-9 protein levels. The phosphoinosmde-3-kinase/Protein Kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway has been reported to participate in several cancer types. Here, in our study, we found that PI3K/AKT/mTOR pathway was involved in osteosarcoma progression. Knockdown of LINC00968 inactivated PI3K/AKT/mTOR signaling pathway in vitro. Subsequently, in vivo tumor xenografts were established using 143-B cells to investigate whether LINC00968 can induce osteosarcoma development in vivo. Consistently, it was indicated that inhibition of LINC00968 significantly inhibited osteosarcoma progression in vivo. Taken these together, in our research, LINC00968 could be provided as a novel prognostic biomarker and therapeutic target in osteosarcoma diagnosis and treatment.

CRISPR-Cas9 systems: versatile cancer modelling platforms and promising therapeutic strategies.

The RNA-guided nuclease CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR associated nuclease 9) and its variants such as nickase Cas9, dead Cas9, guide RNA scaffolds and RNA-targeting Cas9 are convenient and versatile platforms for site-specific genome editing and epigenome modulation. They are easy-to-use, simple-to-design and capable of targeting multiple loci simultaneously. Given that cancer develops from cumulative genetic and epigenetic alterations, CRISPR-Cas9 and its variants (hereafter referred to as CRISPR-Cas9 systems) hold extensive application potentials in cancer modeling and therapy. To date, they have already been applied to model oncogenic mutations in cell lines (e.g., Choi and Meyerson, Nat Commun 2014;5:3728) and in adult animals (e.g., Xue et al., Nature 2014;514:380-4), as well as to combat cancer by disabling oncogenic viruses (e.g., Hu et al., Biomed Res Int 2014;2014:612823) or by manipulating cancer genome (e.g., Liu et al., Nat Commun 2014;5:5393). Given the importance of epigenome and transcriptome in tumourigenesis, manipulation of cancer epigenome and transcriptome for cancer modeling and therapy is a promising area in the future. Whereas (epi)genetic modifications of cancer microenvironment with CRISPR-Cas9 systems for therapeutic purposes represent another promising area in cancer research. Herein, we introduce the functions and mechanisms of CRISPR-Cas9 systems in genome editing and epigenome modulation, retrospect their applications in cancer modelling and therapy, discuss limitations and possible solutions and propose future directions, in hope of providing concise and enlightening information for readers interested in this area.

Competitive assessments of pulmonary embolism: Noninvasiveness versus the golden standard.

Diagnosis of suspected pulmonary embolism (PE) is crucial as undiagnosed and over-diagnosis can both lead to serious consequences. Contemporary diagnostic approach of PE is a sequential combination assessment beginning with clinical assessment, validated with D-dimer measurement and confirmed with pulmonary angiography or imaging. Since the invasive pulmonary angiography is risky and costly, imaging is a warranted tool in the diagnosis procedure. CT pulmonary angiography is a less-invasive method with general availability, studies provide favorable evidences for CT pulmonary angiography as a stand-alone test for excluding PE, and it has become the first choice of tests in emergency department for suspected PE in most centers. Ventilation/perfusion single-photon emission CT signifies a new era in nuclear medicine. It has excellent sensitivity and specificity, fast procedure, low radiation exposure, few complications and contradictions. Besides, MR angiography is another possible and promising approach for diagnosis of suspected PE with much safer contrast agents than CT and no ionizing radiation. With wide availability and less invasive effects, imaging becomes a firsthand tool to obtain optimal accuracy in the diagnosis work up in clinic nowadays. This review summarizes the current methods in diagnosing PE and the update of imaging assessments of the disease.

Overexpression of fibroblast activation protein and its clinical implications in patients with osteosarcoma.

BACKGROUND AND OBJECTIVES: Fibroblast activation protein (FAP) expression has been detected in fibroblastic component of osteosarcomas. The aim of this study was to analyze the correlation of FAP expression with the clinicopathological features of osteosarcoma. METHODS: FAP mRNA and protein expression levels in human osteosarcoma tissues were, respectively detected by RT-PCR, Western blot, and immunohistochemistry assays. RESULTS: FAP mRNA and protein expression were both higher in osteosarcoma than in corresponding noncancerous bone tissues (both P < 0.001). In addition, the immunohistochemistry assay found that all patients showed positive FAP expression. Higher FAP expression was significantly correlated with advanced clinical stage (P = 0.006), high histological grade (P = 0.02), positive metastatic status (P = 0.01), shorter overall (P < 0.001), and disease-free (P < 0.001) survival in osteosarcoma patients. Furthermore, Cox multivariate analysis showed that FAP overexpression was an independent prognostic factor for predicting both overall and disease-free survival of osteosarcoma patients. CONCLUSION: Expression of FAP in osteosarcoma could be adopted as a candidate biomarker for the diagnosis of clinical stage, histological grade and metastasis, and for assessing prognosis, indicating for the first time that FAP may play an important role in tumor development and progression in osteosarcoma. FAP might be considered as a novel therapeutic target against this cancer.

Long non-coding RNA ANRIL is associated with a poor prognosis of osteosarcoma and promotes tumorigenesis via PI3K/Akt pathway.

AIM: Increasing evidence has shown that long noncoding RNAs (lncRNAs) ANRIL may function as oncogenes in various types of malignancies. However, there is still a lack of knowledge concerning its role in osteosarcoma (OS). In this study, we aimed to investigate the influence of ANRIL on cell proliferation and invasion of OS and to determine its association with clinicopathological features of the patients. METHODS: The tumor specimens and the adjacent normal tissues were collected from 57 OS patients and the expression level of ANRIL was quantified by RT-qPCR. High expression of ANRIL was defined as a relative mRNA expression of > 1.5 fold (tumor/normal). Knockdown of ANRIL was performed in human OS cell lines to investigate its influence on cell proliferation, apoptosis and invasion. In addition, expression of downstream genes in the transfected cells were determined by Western blot. RESULTS: The expression level of ANRIL was significantly increased in OS tissues than in the adjacent normal tissues. 33 patients were included in the high expression group and the other 24 patients were included in the normal expression group. ANRIL expression was significantly associated with tumor size (5.7 cm ±â€¯2.4 cm vs. 4.3 cm ±â€¯1.7 cm, p = 0.02) and the 5-year survival rate (51.5% vs. 79.1%, p = 0.03). Knockdown of ANRIL could significantly induce cell apoptosis and inhibit cell proliferation and invasion. Moreover, knockdown of ANRIL could significantly decrease the expression level of phosphorylated PI3K and AKT in OS cells. CONCLUSIONS: Upregulated expression of ANRIL is associated with the tumor development and prognosis of OS. ANRIL may regulate the function of OS cells through the AKT pathway.

MicroRNA-34a promotes cell cycle arrest and apoptosis and suppresses cell adhesion by targeting DUSP1 in osteosarcoma.

MicroRNAs are often deregulated in most cancer types and have important functions in carcinogenesis and cancer progression. Here, we studied the function of microRNA-34 (miR-34a) in osteosarcoma MG63 and U-2OS cells by expressed with pre-miR-34a, anti-miR-34a and corresponding negative controls, respectively. Cells proliferation, cell cycle and apoptosis was measured by MTT and flow cytometry assay. The effect of miR-34a on DUSP1 expression was evaluated by luciferase assays, real-time PCR and western blot assay. The data showed that miR-34a reduced the proliferation of MG63 cells through prompting cell cycle arrest at G0/G1 phase, cell apoptosis, and suppressed cell adhesion ability. Whereas anti-miR-34a increases U-2OS cell proliferation by preventing cell apoptosis, and promotes cell adhesion. Finally, we identified Dual-specificity phosphatase 1 (DUSP1) as the target gene of miR-34a in osteosarcoma cells and confirmed that DUSP1 enhanced the proliferation through inhibiting cell cycle arrest at G0/G1 phase and apoptosis, and inhibits the decreased cell adhesion induced by miR-34a. However, inhibition of DUSP1 resulted in substantially decreased proliferation and adhesion, and cell cycle arrest in G0/G1 phase and cell apoptosis similar to that observed with miR-34a in U-2OS cells. Our findings find out an important function of miR-34a as a novel tumor-suppressor in osteosarcoma pathogenesis through inhibition of DUSP1.

Progress and perspective of TBX6 gene in congenital vertebral malformations.

Congenital vertebral malformation is a series of significant health problems affecting a large number of populations. It may present as an isolated condition or as a part of an underlying syndromes occurring with other malformations and/or clinical features. Disruption of the genesis of paraxial mesoderm, somites or axial bones can result in spinal deformity. In the course of somitogenesis, the segmentation clock and the wavefront are the leading factors during the entire process in which TBX6 gene plays an important role. TBX6 is a member of the T-box gene family, and its important pathogenicity in spinal deformity has been confirmed. Several TBX6 gene variants and novel pathogenic mechanisms have been recently revealed, and will likely have significant impact in understanding the genetic basis for CVM. In this review, we describe the role which TBX6 plays during human spine development including its interaction with other key elements during the process of somitogenesis. We then systematically review the association between TBX6 gene variants and CVM associated phenotypes, highlighting an important and emerging role for TBX6 and human malformations.

Increased expression of microRNA-191 as a potential serum biomarker for diagnosis and prognosis in human osteosarcoma.

BACKGROUND: MicroRNA (miR)-191 has been observed to be overexpressed in osteosarcoma cell lines in comparison with osteoblasts. OBJECTIVE: To investigate the clinical significance of miR-191 in human osteosarcomas. METHODS: Quantitative PCR was performed to detect miR-191 expression in osteosarcoma tissues and patients' sera. RESULTS: miR-191 expression levels, both in osteosarcoma tissues and patients' sera, were significantly higher than those in matched adjacent normal bone tissues and healthy controls (both P< 0.001). Importantly, miR-191 could efficiently screen osteosarcoma patients from healthy controls (Area under receiver operating characteristic curve, AUC = 0.808). Then, high serum miR-191 expression was significantly associated with advanced clinical stage (P = 0.001), large tumor size (P = 0.01) and positive distant metastasis (P = 0.001). Moreover, overall and disease-free survival durations in patients with high miR-191 expression were both shorter than those with low miR-191 expression. Multivariate analysis further identified serum miR-191 level as an independent and significant prognostic factor for both overall survival (P = 0.01) and disease-free survival (P = 0.02). CONCLUSIONS: Our data provide new insights for the involvement of miR-191 in osteosarcoma and suggest that the increased expression of miR-191 may be associated with aggressive tumor progression and adverse outcome. Of note, serum miR-191 quantification may be a promising biomarker for the diagnosis and prognosis in osteosarcoma.