MicroRNA-610 suppresses osteosarcoma oncogenicity via targeting TWIST1 expression

Decoding the Impact of Tumor Microenvironment in Osteosarcoma Progression and Metastasis

Osteosarcoma (OS) is a heterogeneous, highly metastatic bone malignancy in children and adolescents. Despite advancements in multimodal treatment strategies, the prognosis for patients with metastatic or recurrent disease has not improved significantly in the last four decades. OS is a highly heterogeneous tumor; its genetic background and the mechanism of oncogenesis are not well defined. Unfortunately, no effective molecular targeted therapy is currently available for this disease. Understanding osteosarcoma's tumor microenvironment (TME) has recently gained much interest among scientists hoping to provide valuable insights into tumor heterogeneity, progression, metastasis, and the identification of novel therapeutic avenues. Here, we review the current understanding of the TME of OS, including different cellular and noncellular components, their crosstalk with OS tumor cells, and their involvement in tumor progression and metastasis. We also highlight past/current clinical trials targeting the TME of OS for effective therapies and potential future therapeutic strategies with negligible adverse effects.

The interplay between non-coding RNAs and Twist1 signaling contribute to human disorders

Twist-related protein 1 (Twist1) is a basic helix-loop-helix (bHLH) transcription factor (TF) being coded by the TWIST1 gene. This TF has a fundamental effect on the normal development and in the pathogenesis of various diseases especially cancer. Twist1 has interactions with some long non-coding RNAs and miRNAs. The interactions between this TF and various miRNAs such as miR-16, miR-26b-5p, miR-1271, miR-539, miR-214, miR-200b/c, miR-335, miR-10b, and miR-381 are implicated in the carcinogenic processes. TP73-AS1, LINC01638, ATB, NONHSAT101069, CASC15, H19, PVT1, LINC00339, LINC01385, TANAR, SNHG5, DANCR, CHRF, and TUG1 are among long non-coding RNAs which interact with Twist1 and participate in the carcinogenesis. This review aims at depicting the interaction between these non-coding transcripts and Twist1 and the consequence of these interactions in human neoplasms.

The role of microRNA in cisplatin resistance or sensitivity

INTRODUCTION

Cisplatin is a chemotherapy drug that has been used to treat a number of cancers for decades, and is still one of the most commonly used anti-cancer agents. However, some patients do not respond to cisplatin while other patients who were originally sensitive to cisplatin eventually develop chemoresistance, leading to treatment failure or/and tumor recurrence.

AREAS COVERED

Different mechanisms contribute to cisplatin resistance or sensitivity, involving multiple pathways or/and processes such as DNA repair, DNA damage response, drug transport, and apoptosis. Among the various mechanisms, it appears that microRNAs play an important role in determining the resistance or sensitivity. In this article, we analyzed and summarized recent findings in this area, with the aim that these data can aid further research and understanding, leading to the eventual reduction of cisplatin resistance.

EXPERT COMMENTARY

microRNAs can positively or negatively regulate cisplatin resistance by acting on molecules or/and pathways related to apoptosis, autophagy, hypoxia, cancer stem cells, NF-κB, and Notch1. It appears that the modulation of relevant microRNAs can effectively re-sensitize cancer cells to cisplatin regimen in certain types of cancers including breast, colorectal, gastric, liver, lung, ovarian, prostate, testicular, and thyroid cancers.

Activation of CXCL6/CXCR1/2 Axis Promotes the Growth and Metastasis of Osteosarcoma Cells in vitro and in vivo

Osteosarcoma (OS) is a malignant primary bone tumor with high metastatic rate. C-X-C motif chemokine ligand 6 (CXCL6) and its receptor C-X-C motif chemokine receptor 1/2 (CXCR1/2) have been found to participate in the process of carcinogenesis. In this study, we evaluated the role of CXCL6/CXCR1/2 axis in proliferation and metastasis of OS cells. According to our results, the mRNA and protein expressions of CXCL6, CXCR1, and CXCR2 in multiple OS cell lines were determined. Treatment with exogenous CXCL6 for more than 72 h significantly promoted the proliferation of OS cells. Blocking the effect of endogenous CXCL6 restrained the migration, invasion and epithelial-mesenchymal transition (EMT) as evidenced by increased E-cadherin level, decreased N-cadherin and Snail levels in OS cells. On the contrary, exogenous CXCL6 administration enhanced the migration and invasive abilities of OS cells. Moreover, silencing of CXCR1/2 suppressed migration, invasion and EMT of OS cells with or without treatment with exogenous CXCL6. In addition, exogenous CXCL6 promoted the activation of PI3K/AKT and β-catenin signaling pathways, which could be repressed by CXCR2 knockdown. Inactivation of PI3K/AKT or β-catenin pathway by specific inhibitors effectively suppressed CXCL6-induced migration, invasion and EMT of OS cells. Finally, overexpression of CXCL6 significantly contributed to tumor growth, pulmonary metastasis and activation of PI3K/AKT and β-catenin pathways in nude mice in vivo, which were repressed by treatment with CXCR2 antagonist. Our results suggest that CXCL6/CXCR1/2 axis promotes the proliferation and metastasis of OS cells.

Involvement of H19/miR-326 axis in hepatocellular carcinoma development through modulating TWIST1

Overexpression of long noncoding RNA (lncRNA) H19 has been observed in various cancers, which indicates that H19 exert important roles in the progression of carcinogenesis. MiR-326 has been reported to play tumor suppressive roles in multiple tumors. Recently, the competing endogenous RNA (ceRNA) hypothesis has implied that lncRNAs might function as molecular sponges for microRNAs in various cancers. However, the roles of H19/miR-326 in human hepatocellular carcinoma (HCC) still remain unclear. The aim of our study was to determine H19/miR-326 expression in HCC cells and investigate their roles in HCC development. We found that H19 was significantly elevated and miR-326 was decreased in HCC cells including Hep3B, HepG2, MHCC-97L, SK-hep1, Hun7, SMCC-7721 compared with LO2 cells, respectively. In the subsequent experiments, we observed that inhibition of H19 can repress HCC cell growth, migration, and invasion in vitro. H19 downregulation can increase miR-326 expression in HCC cells. Meanwhile, miR-326 mimics can also inhibit HCC progression, whereas miR-326 inhibitors exhibited a reverse phenomenon by modulating H19 expression. In addition, a negative association between H19 and miR-326 was predicted and confirmed. Furthermore, the transcription factor TWIST1 has been recognized as a significant regulator in tumor progression. Here, by performing bioinformatics analysis, TWIST1 was identified as a downstream target of miR-326. The findings of our study implied that lncRNA H19 can serve as a ceRNA to sponge miR-326 and modulate TWIST1 levels in HCC pathogenesis. Taken these together, these findings indicated that H19/miR-326/TWIST1 axis was involved in HCC development and can indicate a novel HCC target.

CXCR4-mediated osteosarcoma growth and pulmonary metastasis is suppressed by MicroRNA-613

Osteosarcoma is the most common primary bone malignancy. Recently, studies showed chemokine receptor 4 (CXCR4) played a critical role in osteosarcoma. However, the regulation of CXCR4 is not fully understood. microRNAs are short, non‐coding RNAs that play an important roles in post‐transcriptional regulation of gene expression in a variety of diseases including osteosarcoma. miR‐613 is a newly discovered miRNA and has been reported to function as a tumor suppressor in many cancers. In this study, we confirmed that both Stromal Cell‐Derived Factor (SDF‐1) and CXCR4 could be prognostic markers for osteosarcoma. Meanwhile this study found that SDF‐1/CXCR4 pathway regulated osteosarcoma cells proliferation, migration and reduced apoptosis. Besides, we demonstrated that miR‐613 was significantly downregulated in osteosarcoma patients. Elevated expression of miR‐613 directly suppressed CXCR4 expression and then decreased the proliferation, migration and induced apoptosis of osteosarcoma cells. Moreover, our study found that CXCR4 promoted the development of lung metastases and inhibition of CXCR4 by miR‐613 reduced lung metastases. These data indicated that CXCR4 mediated osteosarcoma cell growth and lung metastases and this effect can be suppressed by miR‐613 through directly downregulating CXCR4.

MicroRNA-610 inhibits tumor growth of melanoma by targeting LRP6

Accumulating evidence showed that aberrant miRNAs expression was involved in initiation and progression of melanoma. However, the investigation of different miRNAs in melanoma remain attractive. In this research, we demonstrated that miR-610 expression was decreased in melanoma tissues and cell lines. The clinical data showed that the reduced miR-610 expression was obviously associated with adverse prognostic characteristics. Furthermore, our results suggested that miR-610 had a function of prognostic indicator for 5-year predicted-survival of melanoma patients. The ectopic overexpression of miR-610 suppressed cell proliferation, cell cycle progression and promoted apoptosis while miR-610 knockdown reversed the effect in vitro and in vivo. Additionally, miR-610 could modulate LRP6 by directly interacting to its 3’-UTR. In clinical samples of melanoma, miR-610 inversely correlated with LRP6. The biological function of miR-610 on melanoma cells was abrogated by alternation of LRP6 expression. In summary, our research indexed that miR-610 had a function of tumor suppressor in regulating the proliferation, cell cycle and apoptosis of melanoma via targeting LRP6. Hence, it may represent a novel potential therapeutic target and prognostic marker for melanoma.

miRNA-221 of exosomes originating from bone marrow mesenchymal stem cells promotes oncogenic activity in gastric cancer

Worldwide, gastric cancer (GC) is one of the deadliest malignant tumors of the digestive system. Moreover, microRNAs (miRNAs) of exosomes harbored within cancer cells have been determined to induce inflammatory conditions that accelerate tumor growth and metastasis. Interestingly, the oncogenic role of bone marrow mesenchymal stem cells (BM-MSCs) in the modulation of immunosuppression, tumor invasion, and metastasis was discovered to be partly mediated through the secretion of exosomes. In this article, high expression of miRNA-221 (miR-221) in exosomes of the peripheral blood was determined to be positively correlated with the poor clinical prognosis of GC, especially with respect to tumor, node, and metastases stage. Therefore, the expression of miR-221 in exosomes of the peripheral blood may be an important detection index for GC. Proliferation, migration, invasion, and adhesion to the matrix of GC BGC-823 and SGC-7901 cells were significantly enhanced by exosomes that originated from BM-MSCs that were transfected with miR-221 mimics. In conclusion, extracted exosomes from BM-MSCs transfected with miR-221 oligonucleotides can act as high-efficiency nanocarriers, which can provide sufficient miR-221 oligonucleotides to influence the tumor microenvironment and tumor aggressiveness effectively. Notably, the use of a miR-221 inhibitor with an excellent restraining effect in exosomes provides therapeutic potential for GC in future clinical medicine.