MicroRNA-100 inhibits osteosarcoma cell proliferation by targeting Cyr61

CCN proteins in the musculoskeletal system: current understanding and challenges in physiology and pathology

The acronym for the CCN family was recently revised to represent “cellular communication network”. These six, small, cysteine-enriched and evolutionarily conserved proteins are secreted matricellular proteins, that convey and modulate intercellular communication by interacting with structural proteins, signalling factors and cell surface receptors. Their role in the development and physiology of musculoskeletal system, constituted by connective tissues where cells are interspersed in the cellular matrix, has been broadly studied. Previous research has highlighted a crucial balance of CCN proteins in mesenchymal stem cell commitment and a pivotal role for CCN1, CCN2 and their alter ego CCN3 in chondrogenesis and osteogenesis; CCN4 plays a minor role and the role of CCN5 and CCN6 is still unclear. CCN proteins also participate in osteoclastogenesis and myogenesis. In adult life, CCN proteins serve as mechanosensory proteins in the musculoskeletal system providing a steady response to environmental stimuli and participating in fracture healing. Substantial evidence also supports the involvement of CCN proteins in inflammatory pathologies, such as osteoarthritis and rheumatoid arthritis, as well as in cancers affecting the musculoskeletal system and bone metastasis. These matricellular proteins indeed show involvement in inflammation and cancer, thus representing intriguing therapeutic targets. This review discusses the current understanding of CCN proteins in the musculoskeletal system as well as the controversies and challenges associated with their multiple and complex roles, and it aims to link the dispersed knowledge in an effort to stimulate and guide readers to an area that the writers consider to have significant impact and relevant potentialities.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

Tumor necrosis factor-alpha suppresses the invasion of HTR-8/SVneo trophoblast cells through microRNA-145-5p-mediated downregulation of Cyr61

Deficiency in trophoblast invasion is causally linked to the pathogenesis of preeclampsia. Tumor necrosis factor-alpha (TNF-α) shows the ability to suppress the invasiveness of trophoblasts, while cysteine-rich 61 (Cyr61) exerts an opposite function in trophoblast invasion. This study was designed to check the hypothesis that cysteine-rich 61 (Cyr61) may be involved in the anti-invasive activity of TNF-α in trophoblasts. To this end, we examined the effect of TNF-α treatment on Cyr61 expression in HTR-8/SVneo trophoblast cells and investigated the mechanism for the regulation of Cyr61 by TNF-α. Gain-of-function experiments were performed to clarify the role of Cyr61 in TNF-α-dependent suppression of trophoblast invasion. It was found that TNF-α at 1 and 10 ng/mL reduced Cyr61 protein levels by 30 and 80%, respectively, in HTR-8/SVneo cells, but did not affect the mRNA expression of Cyr61. Mechanistically, microRNA (miR)-145-5p was stimulated by TNF-α and negatively regulated the expression of Cyr61 via interaction with its 3'-untranslated region. Functionally, overexpression of miR-145-5p significantly impaired the migration and invasion of HTR-8/SVneo cells. Depletion of miR-145-5p rescued HTR-8/SVneo cells from TNF-α-mediated invasion suppression, which coincided with prevention of Cyr61 downregulation by TNF-α. In addition, overexpression of Cyr61 partially restored the invasion of HTR8/SVneo cells co-transfected with miR-145-5p mimic or exposed to TNF-α. Taken together, miR-145-5p-mediated downregulation of Cyr61 is required for the anti-invasive effect of TNF-α on trophoblasts.

MicroRNA-100 suppresses human osteosarcoma cell proliferation and chemo-resistance via ZNRF2

Osteosarcoma (OS) is a prevalent cancer worldwide. MicroRNAs (miRNAs) play critical roles in the growth, invasion and carcinogenesis of OS, whereas the underlying mechanisms remain ill-defined. Here, we addressed these questions. We detected significantly higher levels of ZNRF2, a ubiquitin ligase of the RING superfamily, and significantly lower levels of miR-100 in the OS specimens, compared to the paired normal bone tissues. The levels of ZNRF2 and miR-100 inversely correlated in the OS specimens. In addition, low miR-100 levels are associated with poor prognosis of the OS patients. Either ZNRF2 overexpression or miR-100 depletion increased in vitro OS cell growth and improved cell survival at the presence of Doxorubicin. Mechanistically, with the help of bioinformatics analysis and luciferase-reporter assay, we found that miR-100 might bind to the 3’-UTR of ZNRF2 mRNA to prevent its protein translation. Thus, our data suggest that re-expression of miR-100 may inhibit OS cell growth and decrease OS cell chemo-resistance.

Biological functions and role of CCN1/Cyr61 in embryogenesis and tumorigenesis in the female reproductive system (Review)

Cysteine-rich angiogenic inducer 61 (CCN1/Cyr61) is a prompt response transcription product activated by growth factors. As a member of the CCN family, it mediates cell survival, proliferation, differentiation, migration, adhesion and synthesis of the extracellular matrix by binding directly to the integrins and heparin sulfate proteoglycans or activating multiple signaling transduction pathways. It has previously been demonstrated that CCN1/Cyr61 exhibits an important role in the female reproductive system during embryogenesis and tumorigenesis. However, the functions of CCN1/Cyr61 in the female reproductive system have not been systematically investigated, therefore, the primary aim of the present review is to introduce the role and function of CCN1/Cyr61 in the female reproductive system. The current review presents the molecular structure and biological function of CCN1/Cyr61 and provides detailed data on its expression pattern and contribution to the female reproductive system, including the role in embryogenesis and tumorigenesis.

Down-regulation of microRNA-182 and microRNA-183 predicts progression of osteosarcoma

INTRODUCTION

The aim of this study was to investigate the expression levels of microRNA-182 and microRNA-183 and their association with clinicopathological features in patients with osteosarcoma.

MATERIAL AND METHODS

Total RNA was purified from samples and noncancerous bone tissues and then quantitative real-time polymerase chain reaction was applied to evaluate the expression levels of microRNAs, and their relationship with clinicopathological features and survival in osteosarcoma patients.

RESULTS

Our findings showed that expression of MiR-182 was clearly lower in osteosarcoma bone tissue (mean ± SD: 2.84 ±.07) compared with noncancerous bone tissues (6.23 ±1.72, p = 0.004). On the other hand, lower expression of MiR-183 was seen in osteosarcoma bone tissue (1.43 ±0.59) when compared with normal tissues (4.36 ±2.47, p = 0.036). Decreased expression of MiR-182 was clearly correlated with advanced clinical stage (p = 0.001), metastasis or recurrence (p = 0.024), and large tumor size (p = 0.032). Decreased expression of MiR-183 was associated with advanced TNM stage (p = 0.004), and metastasis or recurrence (p = 0.002). A multivariate Cox proportional hazards model revealed that low expression of MiR-182 and MiR-183 (p = 0.02; p = 0.016), TNM stage (p = 0.04), and metastasis or recurrence (p = 0.03) were significantly associated with poor survival as independent prognostic factors.

CONCLUSIONS

These findings suggest that MiR-182 and MiR-183 may be associated with progression and metastasis of osteosarcoma.

MicroRNA-100 is involved in shrimp immune response to white spot syndrome virus (WSSV) and Vibrio alginolyticus infection

In this study, we discovered that shrimp miR-100 was up-regulated at 24 h after WSSV or Vibrio alginolyticus infection, confirming its participation in the innate immune system of shrimp. The anti-miRNA oligonucleotide (AMO-miR-100) was applied to inhibit the expression of miR-100. After AMO-miR-100 treatment, the shrimp was challenged with WSSV or V. alginolyticus. The knockdown of miR-100 expression decreased the mortality of WSSV-infected shrimp from 24 h to 72 h post-infection and enhanced the mortality of V. alginolyticus-infected shrimp significantly. The knockdown of miR-100 affected phenoloxidase (PO) activity, superoxide dismutase (SOD) activity and total hemocyte count (THC) after the infection with WSSV or V. alginolyticus, indicating a regulative role of miR-100 in the immune potential of shrimp in the response to WSSV or V. alginolyticus infection. The knockdown of miR-100 induced the apoptosis of shrimp hemocytes, and V. alginolyticus + AMO-miR-100 treatment caused more hemocyte apoptosis than V. alginolyticus treatment. The miR-100 influenced also the morphology of shrimp hemocytes and regulated the phagocytosis of WSSV or V. alginolyticus. Thus, we concluded that miR-100 may promote the anti-Vibrio immune response of shrimp through regulating apoptosis, phagocytosis and PO activity and affects the progression of WSSV infection at a certain level.

MicroRNA-379 suppresses osteosarcoma progression by targeting PDK1

Osteosarcoma is the most common primary bone tumour. Increasing evidence has demonstrated the pathogenic role of microRNA (miRNAs) dysregulation in tumour development. miR-379 was previously reported to function as an oncogenic or tumour-suppressing miRNA in a tissue-dependent manner. However, its function in osteosarcoma remains unknown. In this study, we found that the expression of miR-379 was downregulated in osteosarcoma tissues and cell lines. Further functional characterization revealed that miR-379 suppressed osteosarcoma cell proliferation and invasion in vitro and retarded the growth of osteosarcoma xenografts in vivo. Mechanistically, PDK1 was identified as the direct target of miR-379 in osteosarcoma, in which PDK1 expression was up-regulated and showed inverse correlation with miR-379. Enforced expression of PDK1 promoted osteosarcoma cell proliferation and rescued the anti-proliferative effect of miR-379. These data suggest that miR-379 could function as a tumour-suppressing miRNA via targeting PDK1 in osteosarcoma.

miR-125b and miR-100 Are Predictive Biomarkers of Response to Induction Chemotherapy in Osteosarcoma

Osteosarcoma is the most common primary malignancy in bone. Patients who respond poorly to induction chemotherapy are at higher risk of adverse prognosis. The molecular basis for such poor prognosis remains unclear. We investigated miRNA expression in eight open biopsy samples to identify miRNAs predictive of response to induction chemotherapy and thus maybe used for risk stratification therapy. The samples were obtained from four patients with inferior necrosis (Huvos I/II) and four patients with superior necrosis (Huvos III/IV) following induction chemotherapy. We found six miRNAs, including miR-125b and miR-100, that were differentially expressed > 2-fold (p < 0.05) in patients who respond poorly to treatment. The association between poor prognosis and the abundance of miR-125b and miR-100 was confirmed by quantitative reverse transcriptase-polymerase chain reaction in 20 additional osteosarcoma patients. Accordingly, overexpression of miR-125b and miR-100 in three osteosarcoma cell lines enhanced cell proliferation, invasiveness, and resistance to chemotherapeutic drugs such as methotrexate, doxorubicin, and cisplatin. In addition, overexpression of miR-125b blocked the ability of these chemotherapy agents to induce apoptosis. As open biopsy is routinely performed to diagnose osteosarcoma, levels of miR-125b and miR-100 in these samples may be used as basis for risk stratification therapy.

miRNAs Related to Skeletal Diseases

miRNAs as non-coding, short, double-stranded RNA segments are important for cellular biological functions, such as proliferation, differentiation, and apoptosis. miRNAs mainly contribute to the inhibition of important protein translations through their cleavage or direct repression of target messenger RNAs expressions. In the last decade, miRNAs got in the focus of interest with new publications on miRNAs in the context of different diseases. For many types of cancer or myocardial damage, typical signatures of local or systemically circulating miRNAs have already been described. However, little is known about miRNA expressions and their molecular effect in skeletal diseases. An overview of published studies reporting miRNAs detection linked with skeletal diseases was conducted. All regulated miRNAs were summarized and their molecular interactions were illustrated. This review summarizes the involvement and interaction of miRNAs in different skeletal diseases. Thereby, 59 miRNAs were described to be deregulated in tissue, cells, or in the circulation of osteoarthritis (OA), 23 miRNAs deregulated in osteoporosis, and 107 miRNAs deregulated in osteosarcoma (OS). The molecular influences of miRNAs regarding OA, osteoporosis, and OS were illustrated. Specific miRNA signatures for skeletal diseases are described in the literature. Some overlapped, but also unique ones for each disease exist. These miRNAs may present useful targets for the development of new therapeutic approaches and are candidates for diagnostic evaluations.

Involvement and Clinical Aspects of MicroRNA in Osteosarcoma

Osteosarcoma (OS) is the most common primary bone cancer in children and adolescents, but its pathogenesis has been difficult to establish because of its well-known heterogeneous nature. OS has been associated with genetic and cytogenetic abnormalities, which include function-impairing mutations in tumor suppressors and the activation of oncogenes. OS tumorigenesis has been linked to alterations of several genes characterized by a high level of genetic instability and recurrent DNA amplifications and deletions. MicroRNAs (miRNAs), 18–25-nucleotide noncoding RNAs, are critical for various biological processes like differentiation, cell growth and cell death. Dysregulation of miRNA expression leads to phenotypic and genotypic changes in cells, which leads to cancer. Studies on miRNAs have initiated a significant effect in both diagnosis and treatment of cancer. This review focuses on the current knowledge of clinical applications of miRNAs for the better diagnosis and management of OS.

Long non-coding RNAs: emerging players in osteosarcoma

Osteosarcoma is the most common kind of primary bone tumors with high morbidity in infants and adolescents. While the molecular mechanism of osteosarcoma has gained considerable attention, the mechanisms underlying its initiation and progression remain unclear. Recent studies have discovered that long non-coding RNAs (lncRNAs) play an important role in multiply biological processes including cell development, differentiation, proliferation, invasion, and migration. Deregulated expression of lncRNAs has been found in cancers including osteosarcoma. This review summarized the deregulation and functional role of lncRNAs in osteosarcoma and their potential application for diagnosis and treatment of osteosarcoma.

MicroRNA-26a inhibits osteosarcoma cell proliferation by targeting IGF-1

There are still controversies about the roles of microRNA-26a (miR-26a) in human malignancies, as it is a tumor suppressor in breast cancer, gastric cancer, and hepatocellular carcinoma, but is an oncogene in glioma and cholangiocarcinoma. Until now, the function of miR-26a in osteosarcoma remains largely elusive. Here, we found that miR-26a was downregualted in osteosarcoma tissues. Using in vitro and in vivo assays, we confirmed that miR-26a could inhibit the abilities of in vitro proliferation and suppress in vivo tumor growth in mouse model. Furthermore, we identified insulin-like growth factor 1 (IGF-1) as a novel and direct target of miR-26a and revealed that miR-26a exerted its tumor-suppressor function, at least in part, by inhibiting IGF-1 expression. These findings contribute to our understanding of the functions of miR-26a in osteosarcoma.

MicroRNAs as biomarkers and prospective therapeutic targets in colon and pancreatic cancers

Colon and pancreatic cancers have high mortality rates due to early metastasis prior to the onset of symptoms. Screening tests for colorectal cancer are invasive and expensive. No effective screening is available for pancreatic cancer. Identification of biomarkers for early detection in both of these cancers is being extensively researched. MicroRNAs (miRNA) are small non-coding molecule biomarkers that regulate cancers. Measurement of miRNAs in pancreatic fluid or blood could be a preferred non-invasive screening method. The regulation of colon and pancreatic cancers by miRNA is complex. miRNA play a central role in inflammation, invasiveness, and tumor progression in these two cancers, as well as regulation of the NF-κB pathway. miRNA's evolving role in screening is also reviewed.

Tissue expression levels of miR-29b and miR-422a in children, adolescents, and young adults' age groups and their association with prediction of poor prognosis in human osteosarcoma

Osteosarcoma is the most common type of bone cancer in children and adolescents. MicroRNAs (miRNAs) play important roles in the development, differentiation, and function of different cell types and in the pathogenesis of various human diseases. miRNAs are differentially expressed in normal and cancer cells. The investigation of miRNA expression between healthy subjects and patients with osteosarcoma is crucial for future clinical trials. In this study, the expression levels of miRNAs were detected by qRT-PCR. Correlation between expression levels of tow miRNAs and different clinicopathological characteristics were analyzed using the χ (2) test. Survival rate was detected using the log-rank test and Kaplan-Meier method. qRT-PCR was shown that expression levels of miR-29b and miR-422a were strongly decreased in osteosarcoma bone tissue compared with noncancerous bone tissues. Our result indicated that the low expression levels of miR-29b and miR-422a showed strong correlation with large tumor size (P = 0.20; 0.029), advanced TNM stage (P = 0.001; 0.012), distant metastasis (P = 0.008; 0.019), and grade of tumor (P = 0.009; 0.016). Kaplan-Meier survival analysis showed that the low expressions of miR-29b/miR-422a were correlated with shorter time overall survival (log-rank test, P = 0.009; P = 0.013). Moreover, multivariate Cox proportional hazards model indicated that miR-29b and miR-422a (P = 0.024; P = 0.016) were independent prognostic markers of overall survival of patients. Our result indicated that downregulation of miR-29b and miR-422a may be linked to the prediction of poor prognosis, indicating that miR-29b and miR-422a may be a valuable prognostic marker for osteosarcoma patients.

Down-regulation of microRNA-26a and up-regulation of microRNA-27a contributes to aggressive progression of human osteosarcoma

BACKGROUND

Osteosarcoma is the most common primary bone malignancy with high local aggressiveness and rapid metastasizing potential, resulting in poor survival. Increasing reports suggest that deregulated microRNAs (miRNAs) might provide novel therapeutic targets for cancers. However, the expression of miR-26a and miR-27a in osteosarcoma need further investigation in clinical samples. In our study, we evaluate the expression of these miRNAs in osteosarcoma tissues and compared with paired adjacent non-tumor bone tissues using RT-qPCR.

METHODS

Total RNA was purified from patients with osteosarcoma and noncancerous bone tissues. Real-time PCR was applied to quantify the expression level of miR-26a and miR-27a. Moreover, the correlation of these markers with clinicopathological characteristics was also evaluated in osteosarcoma patients. A cox proportional hazards model was performed to assess multivariate analyses of prognostic values.

RESULTS

Our result suggested that miR-26aexpression level in osteosarcoma bone tissue was significantly lower than that in the paired noncancerous bone tissues. MiR-27a expression was higher in osteosarcoma bone tissue in comparison with paired noncancerous bone tissues. The results indicated that low expression level of miR-26a and high expression of miR-27a were associated with high TNM stage (P = 0.001; P = 0.012), tumor grade (P = 0.007; P = 0.016), and distant metastasis (P = 0.004; P = 0.001). Kaplan-Meier analysis and log-rank test indicated that patients with low expression of miR-26a and high expression of miR-27a had shorter overall survival (log-rank test: P < 0.001). Multivariate Cox proportional hazards model analysis showed that low expression of miR-26a and high expression of miR-27a (P = 0.021; P = 0.011), high TNM stage (P = 0.001; P = 0.003), tumor grade (P = 0.005; P = 0.01), and distant metastasis.(P = 0.002; P = 0.005) were independent prognostic factors for overall survival patients with osteosarcoma cancer.

CONCLUSIONS

In conclusion, our findings suggested that expression level of miR-26a and miR-27a contributes to aggressive progression of this malignancy. Therefore, may have clinical potentials as a non-invasive diagnostic/prognostic biomarker for osteosarcoma patients.

MiR-100 Inhibits Osteosarcoma Cell Proliferation, Migration, and Invasion and Enhances Chemosensitivity by Targeting IGFIR

MicroRNAs are highly conserved noncoding RNA that negatively modulate protein expression at a posttranscriptional and/or translational level. MicroRNAs play an important role in the development and progression of human cancers, including osteosarcoma. Recent studies have shown that miR-100 was downregulated in many cancers; however, the role of miR-100 in human osteosarcoma has not been totally elucidated. In this study, we demonstrate that the expression of miR-100 was significantly downregulated in human osteosarcoma tissues compared to the adjacent tissues. Enforced expression of miR-100 inhibited cell proliferation, migration, and invasion abilities of osteosarcoma cells, U-2OS, and MG-63. Additionally, miR-100 also sensitized osteosarcoma cells to cisplatin and promoted apoptosis. Furthermore, overexpression of miR-100 decreased the expression of insulin-like growth factor I receptor and inhibited PI3K/AKT and MAPK/ERK signaling. In human clinical specimens, insulin-like growth factor I receptor was inversely correlated with miR-100 in osteosarcoma tissues. Collectively, our results demonstrate that miR-100 is a tumor suppressor microRNA and indicate its potential application for the treatment of osteosarcoma in future.

Downregulation of microRNA-217 and microRNA-646 acts as potential predictor biomarkers in progression, metastasis, and unfavorable prognosis of human osteosarcoma

Despite the progress in therapeutic targets, it remains dissatisfactory for most osteosarcoma patients with metastasis or recurrence osteosarcoma. Therefore, it is required to determine the involved mechanisms of osteosarcoma. The aim of this study was to investigate the expression level of MiR-217 and miR-646 and also their association with clinicopathological features in patients with osteosarcoma. Total RNA was purified from patients with osteosarcoma and noncancerous bone tissues, and then quantitative real-time PCR was applied to evaluate the expression level of microRNAs. Our result suggested that miR-217 expression was remarkably deceased in osteosarcoma bone tissue when compared with noncancerous bone tissues (mean ± SD 5.32 ± 1.231, 2.01 ± 0.78; P = 0.024) and miR-646 expression decreased in osteosarcoma bone tissue in comparison with normal tissues (mean ± SD 4.56 ± 1.45, 1.76 ± 1.24; P = 0.041). Our findings indicated that decreased expression of MiR-217 and miR-646 was strongly correlated with high tumor, node, and metastasis (TNM) stage (P = 0.015, P = 0.002) and large cancer diameter (P = 0.041, P = 0.053). Kaplan-Meier survival and log-rank analysis indicated that shorter overall survival was strongly linked to decreased expression of miR-217 and miR-646 (log-rank test P = 0.034, P = 0.026). In terms of miR-217, multivariate Cox proportional hazards model analysis has showed that reduction of miR-217 expression (P = 0.001), TNM stage (P = 0.046), and lymph node metastasis (P = 0.006) were independently linked to a short-time survival of patients. In terms of miR-646, low expression of miR-646 (P = 0.021), TNM stage (P = 0.052), and tumor size (P = 0.043) were independently associated with poor survival of patients as prognostic factors. Our findings suggested that downregulation of MiR-217 and miR-646 was associated with progression of osteosarcoma. MiR-217 and miR-646 may play a key role in suppression of tumor in osteosarcoma and would be applied as a novel therapeutic agent.

Review of microRNA in osteosarcoma and chondrosarcoma

MicroRNAs (miRNAs) are small noncoding RNAs, which play a complex role in posttranscriptional gene expression and can theoretically be used as a diagnostic or prognostic tool, or therapeutic target for neoplasia. Despite advances in the diagnosis and treatment of skeletal sarcomas, including osteosarcoma and chondrosarcoma, much remains unknown regarding their underpinning molecular mechanisms. Given the recent increasing knowledge base of miRNA roles in neoplasia, both as oncogenes and tumor suppressor genes, this review will focus on the available literature regarding the expression profiles and potential roles of miRNA in skeletal sarcomas. Although this is an emerging field, miRNA profiling may be of use in clarifying competing diagnoses of skeletal sarcomas and possibly indicate patient risk of resistance to traditional chemotherapeutic agents. While detecting and targeting miRNAs is currently limited to experimental investigations, miRNA may be utilized for future clinical management of skeletal sarcomas.

MicroRNA-153 inhibits osteosarcoma cells proliferation and invasion by targeting TGF-β2

Increasing evidence indicates that microRNAs (miRNAs), a class of small noncoding RNAs, participate in almost every step of cellular processes. MiRNAs are aberrantly expressed in human cancers and contribute to cancer development and progression. Study of miRNAs may provide a new clue for understanding the mechanism of carcinogenesis and a new tool for cancer treatment. In the present study, miR-153 was downregulated in human osteosarcoma tissues and cell lines. Introduction of miR-153 mimics into the MG-63 cells inhibited cell proliferation and invasion. Our results further revealed that transforming growth factor beta 2 (TGF-β2) was negatively regulated by miR-153. Furthermore, overexpression of miR-153 decreased p-SMAD2, p-SMAD3, epidermal growth factor receptor (EGFR) and insulin-like growth factor binding protein-3 (IGFBP-3) expressions, which were the downstream signaling molecules of TGF-β. Furthermore, miRNA-153 suppressed TGF-β-mediated MG-63 proliferation and migration. Therefore, our results suggest that miR-153 may act as a tumor suppressor in osteosarcoma through targeting TGF-β2.

MicroRNA-100 functions as a tumor suppressor by inhibiting Lgr5 expression in colon cancer cells

Previous studies have demonstrated that microRNAs (miRNAs), a class of single‑stranded RNA molecules that are 18‑27 nucleotides in length, serve a critical function in tumorigenesis, including in the development of colon cancer. In the current study, miR‑100 levels were demonstrated to be reduced in colon cancer tissues compared with the levels in matched adjacent normal tissues. Forced overexpression of miR‑100 by transfection with miR‑100 mimics substantially inhibited the proliferation, migration and invasion of SW480 and HCT116 cells, whereas reduced expression, resulting from transfection of antisense oligonucleotides, promoted these processes. At the molecular level, miR‑100 was observed to reduce the levels of leucine‑rich repeat‑containing G protein‑coupled receptor 5 (Lgr5), by binding to its 3'‑untranslated region. As a result of this, Wnt/β‑catenin signaling was affected by fluctuations in the level of miR‑100 mimics or antisense. Collectively, the results of the current study elucidate a novel regulatory pathway involving miR‑100 and Lgr5 in colon cancer cells, which may present a potential therapeutic target.

MiRNA in bladder carcinogenesis: A review

Bladder cancer (BC) is the second urological malignancy in incidence, currently being one of the most neoplasms studied with profile and biology poorly defined. In the world, BC is responsible by about 386000 new cases and 150000 deaths annually with considerable economic impact and high costs for health systems. After its discovery more than 20 years, micro RNAs (miRNAs) have been recognized as molecules that work specifically in post-transcriptional control in majority of eukaryote genomes. MiRNAs are a family of small non-coding RNAs of 19-25 nucleotides in length, expressed in a wide variety of organisms, comprising plants, worms and mammals, including humans. They have a fundamental role in physiological and pathological processes in organs and tissues in a context-dependent manner. This review brings new roles of protective and oncogenic miRNAs linked to carcinogenesis of urothelial carcinoma of the bladder, and associated with behavior of disease. Many studies have demonstrated promising roles of miRNAs working as diagnostic and prognostic biomarkers or involved in target therapies, consolidating miRNAs as crucial players in human cancer. This review allowed a reflection about the true functions of miRNAs in bladder carcinogenesis. Not only by their wide capacities of action, but also by abilities in define the cell date. The future of anti-tumor target therapies will be based not in one, but in groups of miRNAs working together in several steps of carcinogenic process, being able to identify the disease, predicting behavior and effectively treat bladder cancer.

miRNA-646 suppresses osteosarcoma cell metastasis by downregulating fibroblast growth factor 2 (FGF2)

MicroRNAs are short regulatory RNAs that play crucial roles in cancer development and progression. MicroRNA-646 (miR-646) is downregulated in many human cancers, and increasing evidence indicates that it functions as a tumor suppressor. However, the role of miR-646 in osteosarcoma remains unclear. Expression levels of miR-646 in osteosarcoma cell lines and patient tissues were evaluated by quantitative real-time PCR (qRT-PCR), and the clinicopathological significance of the resultant data was later analyzed. Next, we investigated the role of miR-646 to determine its potential roles on osteosarcoma cell proliferation, migration, and invasion in vitro. A luciferase reporter assay was conducted to confirm the target gene of miR-646, and the results were validated in the osteosarcoma cell line. In this study, we found that miR-646 was downregulated in osteosarcoma cell lines and osteosarcoma tissues compared with normal osteoblast cell line NHOst and paired adjacent nontumor tissue. We found that a lower expression of miR-646 was associated with metastasis. In osteosarcoma cells, overexpression of miR-646 inhibited cell proliferation, migration, and invasion. In contrast, downregulation of miR-646 expression promoted osteosarcoma cell proliferation, migration, and invasion. Next, we identified that the FGF2 gene is a novel direct target of miR-646 in osteosarcoma cells. Moreover, enforced expression of FGF2 partially reversed the inhibition of cell proliferation, migration, and invasion that was caused by miR-646. Our study demonstrated that miR-646 might be a tumor suppressor in osteosarcoma via the regulation of FGF2, which provided a potential prognostic biomarker and therapeutic target.

Recent advances in osteosarcoma

Although osteosarcoma (OS) is a rare malignancy, it is ranked among the leading causes of cancer-related death in the pediatric age group. The cancer's low prevalence and its large tumor heterogeneity make it difficult to obtain meaningful progress in patient survival. In this review we present an overview of current clinical trials which largely focus on stimulation of the immune system or rely on the inhibition of kinases such as Src and mTOR. The potential efficacy of tumor-targeted TNFalpha is discussed, as well as the importance of preclinical validation of new targets. To improve the success of future clinical trials, clinicians and basic researchers need to intensify their exchange. Finally, a case is made for individualized treatment of OS patients, based on interdisciplinary cooperation in dedicated Sarcoma Centers.