Overexpression of miR-1258 inhibits cell proliferation by targeting AKT3 in osteosarcoma

The Multifunctional Nature of the MicroRNA/AKT3 Regulatory Axis in Human Cancers

Serine/threonine kinase (AKT) signaling regulates diverse cellular processes and is one of the most important aberrant cell survival mechanisms associated with tumorigenesis, metastasis, and chemoresistance. Targeting AKT has become an effective therapeutic strategy for the treatment of many cancers. AKT3 (PKBγ), the least studied isoform of the AKT family, has emerged as a major contributor to malignancy. AKT3 is frequently overexpressed in human cancers, and many regulatory oncogenic or tumor suppressor small non-coding RNAs (ncRNAs), including microRNAs (miRNAs), have recently been identified to be involved in regulating AKT3 expression. Therefore, a better understanding of regulatory miRNA/AKT3 networks may reveal novel biomarkers for the diagnosis of patients with cancer and may provide invaluable information for developing more effective therapeutic strategies. The aim of this review was to summarize current research progress in the isoform-specific functions of AKT3 in human cancers and the roles of dysregulated miRNA/AKT3 in specific types of human cancers.

Drugging Hijacked Kinase Pathways in Pediatric Oncology: Opportunities and Current Scenario

Childhood cancer is considered rare, corresponding to ~3% of all malignant neoplasms in the human population. The World Health Organization (WHO) reports a universal occurrence of more than 15 cases per 100,000 inhabitants around the globe, and despite improvements in diagnosis, treatment and supportive care, one child dies of cancer every 3 min. Consequently, more efficient, selective and affordable therapeutics are still needed in order to improve outcomes and avoid long-term sequelae. Alterations in kinases' functionality is a trademark of cancer and the concept of exploiting them as drug targets has burgeoned in academia and in the pharmaceutical industry of the 21st century. Consequently, an increasing plethora of inhibitors has emerged. In the present study, the expression patterns of a selected group of kinases (including tyrosine receptors, members of the PI3K/AKT/mTOR and MAPK pathways, coordinators of cell cycle progression, and chromosome segregation) and their correlation with clinical outcomes in pediatric solid tumors were accessed through the R2: Genomics Analysis and Visualization Platform and by a thorough search of published literature. To further illustrate the importance of kinase dysregulation in the pathophysiology of pediatric cancer, we analyzed the vulnerability of different cancer cell lines against their inhibition through the Cancer Dependency Map portal, and performed a search for kinase-targeted compounds with approval and clinical applicability through the CanSAR knowledgebase. Finally, we provide a detailed literature review of a considerable set of small molecules that mitigate kinase activity under experimental testing and clinical trials for the treatment of pediatric tumors, while discuss critical challenges that must be overcome before translation into clinical options, including the absence of compounds designed specifically for childhood tumors which often show differential mutational burdens, intrinsic and acquired resistance, lack of selectivity and adverse effects on a growing organism.

The Role of MiRNA in Cancer: Pathogenesis, Diagnosis, and Treatment

Cancer is also determined by the alterations of oncogenes and tumor suppressor genes. These gene expressions can be regulated by microRNAs (miRNA). At this point, researchers focus on addressing two main questions: "How are oncogenes and/or tumor suppressor genes regulated by miRNAs?" and "Which other mechanisms in cancer cells are regulated by miRNAs?" In this work we focus on gathering the publications answering these questions. The expression of miRNAs is affected by amplification, deletion or mutation. These processes are controlled by oncogenes and tumor suppressor genes, which regulate different mechanisms of cancer initiation and progression including cell proliferation, cell growth, apoptosis, DNA repair, invasion, angiogenesis, metastasis, drug resistance, metabolic regulation, and immune response regulation in cancer cells. In addition, profiling of miRNA is an important step in developing a new therapeutic approach for cancer.

Hypomethylation-driven AKT Serine/Threonine Kinase 3 promotes testicular germ cell tumors proliferation and negatively correlates to immune infiltration

AKT Serine/Threonine Kinase 3 (AKT3) has been reported to play an important role in different tumors. However, its clinical value, biological function, and molecular mechanism in testicular germ cell tumors (TGCT) remains unclear. In the current study, we applied the Gene Set Cancer Analysis (GSCA), UCSC XENA, Gene Expression Omnibus (GEO), the Human Protein Atlas (HPA), LinkedOmics, DiseaseMeth version 2.0, TISIDB, and other databases for TGCT data mining. Then, we investigated AKT3’s mechanism of action and clinical survival significance via bioinformatics followed by in vitro experiments. We found that AKT3 was upregulated and had frequent copy number amplifications in TGCT, which were associated with poor survival outcomes of patients. On the other hand, mutations that led to AKT3 loss-of-function were correlated to a better prognosis in patients. Moreover, AKT3 silencing significantly inhibited the proliferation, DNA synthesis and colony formation of NCCIT cells (a TGCT cell line). AKT3 might participate in TGCT progression through multiple signaling pathways, such as ErbB, oxidative phosphorylation, and affecting tumor immune infiltration. Also, the upregulation of AKT3 mRNA expression might be driven by the hypomethylation of its promoter region. Overall, AKT3 is a potential TGCT oncogene and can be further used as a therapeutic target.

CircNRIP1 Encapsulated by Bone Marrow Mesenchymal Stem Cell-Derived Extracellular Vesicles Aggravates Osteosarcoma by Modulating the miR-532-3p/AKT3/PI3K/AKT Axis

Emerging evidence indicates that extracellular vesicle (EV)-encapsulated circRNAs have the potential diagnostic and prognostic values for malignancies. However, the role of circNRIP1 in osteosarcoma remains unclear. We herein investigated the therapeutic potential of circNRIP1 delivered by bone marrow mesenchymal stem cell–derived EVs (BMSC-EVs) in osteosarcoma. The expression of circNRIP1 was examined in the clinical tissue samples of osteosarcoma patients, after which the downstream genes of circNRIP1 were bioinformatically predicted. Gain- and loss-of function assays were then performed in osteosarcoma cells with manipulation of circNRIP1 and miR-532-3p expression. EVs isolated from BMSCs were characterized and co-cultured with osteosarcoma cells to examine their effects on cell phenotypes, as reflected by CCK-8 and Transwell assays. Further, a mouse model of tumor xenografts was established for in vivo substantiation. circNRIP1 was upregulated in osteosarcoma tissues and cells. Overexpression of circNRIP1 promoted the proliferative, migratory, and invasive potential of osteosarcoma cells. Co-culture data showed that BMSC-EVs could transfer circNRIP1 into osteosarcoma cells where it competitively bound to miR-532-3p and weakened miR-532-3p’s binding ability to AKT3. By this mechanism, the PI3K/AKT signaling pathway was activated and the malignant characteristics of osteosarcoma cells were stimulated. In vivo experimental results unveiled that circNRIP1-overexpressing BMSC-EVs in nude mice resulted in enhanced tumor growth. In conclusion, the BMSC-EV-enclosed circNRIP1 revealed a new molecular mechanism in the pathogenesis of osteosarcoma, which might provide a novel therapeutic target for osteosarcoma.

MicroRNA-802 promotes the progression of osteosarcoma through targeting p27 and activating PI3K/AKT pathway

PURPOSE

Increasing evidences suggest dysfunctions of microRNAs (miRNAs) are playing important part in tumors. Therefore, the role of miR-802 in osteosarcoma (OS) was exploited. The object was to evaluate the effect of miR-802 and verify its influence on p27 Kip1 (p27) in OS.

METHODS

RT-qPCR experiment was used to detect miR-802 and p27 expression in OS tissues and cells. We explored the function of miR-802 through Transwell assays. The phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase pathway and epithelial-mesenchymal transition (EMT) was detected by Western blot assays. Luciferase assay was used to testify the target of miR-802.

RESULTS

MiR-802 expression was elevated in OS, which was related to poor clinical outcome in OS patients. MiR-802 overexpression promoted OS migration, invasion and EMT. Further, p27 is a direct target of miR-802. P27 elevation counteracted the promotion effect of OS on EMT, migration and invasion induced by miR-802. In addition, miR-802 overexpression inactivated PI3K/AKT pathway via targeting p27 in OS.

CONCLUSION

MiR-802 promoted the progress of EMT, migration and invasion in OS via targeting p27. This newly identified miR-802/p27/PI3K/AKT axis may represent potential targets for OS.

miRNA Let-7a-5p targets RNA KCNQ1OT1 and Participates in Osteoblast Differentiation to Improve the Development of Osteoporosis

It is known that miRNA mediates the formation of osteogenesis, but the mechanism by which miRNA let-7a-5p regulates osteogenesis in osteoporosis (OP) is not yet understood. This paper aims to probe into the regulatory mechanism of miRNA let-7a-5p in the development of OP. Fresh femoral trabecular bones of patients with osteoporotic fracture (OP group, n = 25) and non-OP osteoarthritis (Non-OP group, n = 23) who underwent hip replacement in our hospital from December 2016 to December 2019 were collected. The expression and protein levels of miRNA let-7a-5p and V-AKT murine thymoma viral oncogene homolog 3 (RNA KCNQ1OT1) were detected. C2C12 cells were purchased and osteogenic differentiation model was constructed by BMP2 induction. After miRNA let-7a-5p up-regulation or down-regulation by transfection of corresponding mimics and inhibitors, the impacts of miRNA let-7a-5p and RNA KCNQ1OT1 on osteogenic differentiation-related factors (OC, ALP, COL1A1) in C2C12 cells were analyzed. The determination of targeting correlation of miRNA let-7a-5p with RNA KCNQ1OT1 was performed by dual-luciferase reporter (DLR). In OP samples, miRNA let-7a-5p was notably declined while RNA KCNQ1OT1 were remarkably up-regulated. MiRNA let-7a-5p reduced in C2C12 cells as BMP2 treatment proceeded. MiRNA let-7a-5p up-regulation or RNA KCNQ1OT1 down-regulation increased OC, ALP, COL1A1 levels and ALP activity. RNA KCNQ1OT1 was directly targeted to miR-497-5p. RNA KCNQ1OT1 up-regulation weakened the promoting effect of miRNA let-7a-5p up-regulation on osteoblast differentiation. MiRNA let-7a-5p up-regulation can target to reduce RNA KCNQ1OT1 and promote osteoblast differentiation, thereby improving the development of osteoporosis.

Radiopacity endowed magnetic nanocomposite with hyperthermia andin vitromineralization potential: a combinatorial therapeutic system for osteosarcoma

The development of clinically advanced multifaceted therapeutic materials for osteosarcoma is at the forefront of cancer research. Accordingly, this work presents the design of a multifunctional magnetic nanocomposite composed of maghemite, strontium doped hydroxyapatite and silica nanoparticles prospectively holding indispensable therapeutic features such as magnetic hyperthermia,in vitrobiomineralization, sustained drug release and intrinsic radiopacity for the treatment of osteosarcoma. The optimal composition has been identified by sequentially modulating the ratio of precursors of the magnetic nanocomposite synthesized by sol-gel technique. Structural and morphological characterization by x-ray diffraction, fourier transform infrared spectrum, Brunauer-Emmet-Teller and transmission electron microscopy analyses followed by VSM, hyperthermia and micro-CT analyses essentially assisted in the selective configuration of biofunctional properties. Results exemplify that MSHSr1 has a saturation magnetization of 47.4 emu g^-1and attained hyperthermia temperature (42 °C) at a very low exposure time of 4 min. MSHSr1 is further unique with respect to its exceptional x-ray attenuation ability (contrast enhancement 154.5% in digital radiography; CT number 3100 HU), early biomimetic mineralization (in vitro) evident by the formation of spheroidal apatite layer (Ca/P ratio 1.33) harvested from FESEM-EDX analysis and controlled release of Doxorubicin, the clinically used chemotherapeutic drug: 87.7% at 120 h in tumour analogous pH (6.5) when compared to physiological pH (71.3% at 7.4). MTT assay complemented with cytoskeleton (F-actin) staining of human osteosarcoma (HOS) cells affirm biocompatibility of MSHSr1.In vitrobiomineralization authenticated by Alizarin red S and von Kossa staining has been further corroborated by semi-quantitative calcium estimation of HOS cells cultured with MSHSr1 for two weeks. The results therefore validate the multifunctionality of MSHSr1, and hence could be proposed as a combinatorial therapeutic nanocomposite for osteosarcoma treatment.

miR-1258 Attenuates Tumorigenesis Through Targeting E2F1 to Inhibit PCNA and MMP2 Transcription in Glioblastoma

MicroRNAs are a group of endogenous small non-coding RNAs commonly dysregulated in tumorigenesis, including glioblastoma (GBM), the most malignant brain tumor with rapid proliferation, diffuse invasion, and therapeutic resistance. Accumulating evidence has manifested that miR-1258 exerts an inhibitory role in many human cancers. However, the expression pattern of miR-1258 and its potential function in GBM tumorigenesis remain unclear. In this study, we reported that miR-1258 expression decreased with the ascending pathological grade of glioma, which indicated an unfavorable prognosis of patients. Functional assays revealed an inhibitory effect of miR-1258 on malignant proliferation, therapeutic resistance, migration, and invasion of GBM in vitro. Moreover, xenograft models also suggested a repression effect of miR-1258 on gliomagenesis. Mechanistically, miR-1258 directly targeted E2F1 in 3’-untranslated regions and attenuated E2F1-mediated downstream gene PCNA and MMP2 transcriptions. Furthermore, restoration of E2F1 expression in GBM cells effectively rescued the tumor-suppressive effect of miR-1258. Our studies illustrated that miR-1258 functioned as a tumor suppressor in GBM by directly targeting E2F1, subsequently inhibiting PCNA and MMP2 transcriptions, which contributed to new potential targets for GBM therapy and other E2F1-driven cancers.

circ_SMAD2 regulate colorectal cancer cells proliferation through targeting miR-1258/RPN2 signaling pathway

Circular RNAs (circRNAs) are associated with various diseases, including cancers. However, their roles in colorectal cancer (CRC) have not been established. Hsa_circ_0000847 (circ_SMAD2) is a novel circRNA that was found to be elevated in CRC cell lines and tissues. High circ_SMAD2 levels were positively correlated with CRC clinicopathological features. Functional assays revealed that circ_SMAD2 enhanced CRC cell invasion, proliferation, and tumor growth. Mechanistically, circ_SMAD2 elevated Ribophorin II (RPN2) levels by inhibiting miR-1258. Therefore, circ_SMAD2 is a potential indicator for CRC progression.

miR-1258 Regulates Cell Proliferation and Cell Cycle to Inhibit the Progression of Breast Cancer by Targeting E2F1

Objective

This study is designed to clarify that miR-1258 targets E2F1 to regulate the proliferation and cell cycle of breast cancer (BC) cells and consequently suppress the progression of BC.

Methods

Bioinformatics analysis was used to analyze the differentially expressed genes in BC. The expression of miR-1258 and E2F1 mRNA in BC cell lines and immortalized breast epithelial cell lines were detected by qRT-PCR. The proliferation and growth activity of BC cells were detected by MTT and colony formation assays. The apoptosis and cell cycle of BC cells were detected by flow cytometry and the targeting relationship between miR-1258 and E2F1 was identified by dual-luciferase assay.

Results

The expression of miR-1258 was decreased while that of E2F1 was increased in BC cells. Overexpression of miR-1258 and silencing E2F1 could inhibit the cell proliferation and growth, block cells in the G0/G1 phase, and promote cell apoptosis. Besides, miR-1258 inhibited cell proliferation and growth, block cells in the G0/G1 phase, and promote cell apoptosis by downregulating E2F1.

Conclusion

miR-1258 regulates the proliferation and cell cycle to inhibit the progression of BC by targeting and downregulating E2F1.

RHPN1-AS1 promotes cell proliferation and migration via miR-665/Akt3 in ovarian cancer

Recent efforts have revealed that long non-coding RNAs exert crucial roles in cancer initiation and progression. RHPN1-AS1 is a 2030 bp transcript from human chromosome 8q24, and involved in tumorigenesis in uveal melanoma and non-small cell lung cancer, but it remains unknown in ovarian cancer. This study focused on the role of RHPN1-AS1 in ovarian cancer and found that RHPN1-AS1 was up-regulated in ovarian cancer tissues and cell lines. Overexpression of RHPN1-AS1 promoted ovarian cancer cell proliferation, migration, and invasion. Mechanistically, overexpression of RHPN1-AS1 decreased the expression of miR-665 and subsequently promoted the expression of Akt3 at posttranscriptional level. Taken together, RHPN1-AS1 positively regulated the expression of Akt3 through sponging miR-665, and exerted an oncogenic role in ovarian cancer progression, and indicates that RHPN1-AS1 may be a potential therapeutic target in ovarian cancer.

The β-catenin/TCF-4-LINC01278-miR-1258-Smad2/3 axis promotes hepatocellular carcinoma metastasis

Hepatocellular carcinoma (HCC) metastasis is largely responsible for HCC-associated recurrence and mortality. We aimed to identify metastasis-related long non-coding RNAs (lncRNAs) to understand the molecular mechanism of HCC metastasis. We first identified that miR-1258 was downregulated in HCC tissues both in The Cancer Genome Atlas (TCGA) and Sun Yat-sen University Cancer Center (SYSUCC) dataset. MiR-1258 expression negatively correlated with recurrence-free survival and overall survival of HCC patients. MiR-1258 overexpression inhibited migration and invasion of HCC cells both in vitro and in vivo, whereas miR-1258 downregulation promoted cell metastasis. Luciferase assays verified direct binding of miR-1258 to Smad2 and Smad3, thereby attenuating TGF-β/Smad signaling. We further established that lncRNA LINC01278 was a negative regulator of miR-1258. In vivo and in vitro assays demonstrated that LINC01278-mediated HCC metastasis was dependent on miR-1258 expression. Furthermore, miR-1258 downregulation in turn increased LINC01278 expression. We also observed that TCF-4 could bind to the LINC01278 promoter site. In addition, LINC01278 downregulation decreased migration and invasion of HCC cells induced by β-catenin and TGF-β1 both in vitro and in vivo. We uncovered a novel mechanism for β-catenin/TCF-4-LINC01278-miR-1258-Smad2/3 feedback loop activation in HCC metastasis, and the study indicated that LINC01278 could serve as a therapeutic target for HCC metastasis.

miR-485-5p/HSP90 axis blocks Akt1 phosphorylation to suppress osteosarcoma cell proliferation and migration via PI3K/AKT pathway

Osteosarcoma (OS) is closely related to the dysregulation of various intracellular signaling pathways, especially the PI3K/Akt signaling pathway. Reportedly, HSP90 was responsible for phospho-Akt stabilization, and both AKT1 and HSP90 were upregulated within osteosarcoma. Herein, we demonstrated that AKT1 and HSP90 mRNA and protein expression were upregulated within osteosarcoma tissues and cells; AKT1 knockdown significantly inhibited OS cell viability. HSP90 knockdown suppressed the phosphorylation of AKT1, decreased ki-67 and Vimentin protein levels, enhanced p21 and E-cadherin protein levels, and inhibited OS cell proliferation and migration; AKT1 overexpression exerted opposing effects and significantly attenuated the effects of HSP90 knockdown. miR-485-5p targeted AKT1 and HSP90 3'-UTR to inhibit AKT1 and HSP90 expression. miR-485-5p overexpression dramatically reduced AKT1, HSP90, and ki-67 proteins, increased E-cadherin protein levels, and inhibited OS cell proliferation and migration. In conclusion, HSP90 knockdown blocked the phosphorylation of AKT1 suppressing the proliferation and migration capacity of OS cells via the PI3K/AKT pathway; miR-485-5p binds to HSP90 and AKT1 in their 3'-UTR to inhibit HSP90 and AKT1 expression, therefore exerting a tumor suppressor function within osteosarcoma.

miR-451a Inhibits the Growth and Invasion of Osteosarcoma via Targeting TRIM66

The importance of microRNAs in regulating osteosarcoma development has been studied in recent years. However, the function of microRNA-451a in osteosarcoma growth is rarely investigated. Here, we explored the expression of microRNA-451a in osteosarcoma cell lines. Bioinformatic software, luciferase activity reporter assay, and Western blot were conducted to determine the association between microRNA-451a and tripartite motif-containing 66. Cell Counting Kit-8 assay and transwell assay were used to explore the regulatory effects of microRNA-451a on osteosarcoma cells. Moreover, we explored whether microRNA-451a modulates osteosarcoma cell biological activity by regulating tripartite motif-containing 66. The expression of microRNA-451a was found to be downregulated in osteosarcoma and negatively regulated the expression of tripartite motif-containing 66. Tripartite motif-containing 66 was further validated as a target of microRNA-451a. MicroRNA-451a inhibits the growth and invasion of osteosarcoma cell lines through targeting tripartite motif-containing 66. The miR-451a targets tripartite motif-containing 66 may provide novel therapeutic targets for the treatment of osteosarcoma.

miR-210-5p promotes epithelial-mesenchymal transition by inhibiting PIK3R5 thereby activating oncogenic autophagy in osteosarcoma cells

Osteosarcoma (OS) is a malignant bone tumor which occurs mainly in adolescents with frequent pulmonary metastasis and a high mortality rate. Accumulating evidence has indicated that microRNAs (miRNAs) play a vital role in various tumors by modulating target genes as well as signal pathways, and aberrant expression of miRNAs may contribute to OS progression. This study aimed to determine the association between miR-210-5p expression and OS progression and to investigate its potential underlying mechanism. Using reverse transcription-polymerase chain reaction (RT-PCR), miR-210-5p was found to be upregulated in clinical OS specimens and cell lines. Further functional analysis demonstrated that miR-210-5p promoted epithelial–mesenchymal transition (EMT) and induced oncogenic autophagy. Luciferase reporter assay, RNA-ChIP, and western blot analysis confirmed that PIK3R5, an essential regulator in the AKT/mTOR signaling pathway, is a target downstream gene of miR-210-5p. Overexpression or knockdown of PIK3R5 reversed the functional role of overexpression or knockdown of miR-210-5p, respectively. Silencing autophagy-related gene 5 (ATG5) abolished the functional effects of miR-210-5p upregulation or PIK3R5 knockdown in OS cells. In vivo, miR-210-5p overexpression promoted OS tumor growth and pulmonary metastasis. Taken together, our results demonstrated that miR-210-5p promoted EMT and oncogenic autophagy by suppressing the expression of PIK3R5 and regulating the AKT/mTOR signaling pathway. Therefore, inhibition of miR-210-5p may represent a promising treatment for OS.

Exosomes derived from bone marrow mesenchymal stem cells promote osteosarcoma development by activating oncogenic autophagy

•

BMSC-Exos promote malignant tumorigenesis and metastasis in OS cells.

•

BMSC-Exos promotes oncogenic autophagy in OS cells.

•

BMSC-Exos-mediated autophagy contributes to the BMSC-Exos-induced malignant tumorigenesis metastasis in OS cells.

Osteosarcoma (OS) is a malignant bone tumor that frequently occurs in adolescents. It has a high rate of pulmonary metastasis and mortality. Previous studies have demonstrated that human bone marrow mesenchymal stem cells (hBMSCs) can promote the malignant progression in various tumors, including OS. Also, it is recognized that exosomes derived from hBMSCs (hBMSC-Exos) mediate cell-to-cell communication and exhibit similar effects on the development of various tumors. However, the role of hBMSC-Exos in the development of OS is still unclear and the underlying mechanism needs to be elucidated. Our results show that hBMSC-derived exosomes promote OS cell proliferation, migration, and invasion. Meanwhile, silencing autophagy-related gene 5 (ATG5) in OS cells abolishes the pro-tumor effects of hBMSC-Exos in vitro and in vivo. Our present study demonstrates that hBMSC-Exos promotes tumorigenesis and metastasis by promoting oncogenic autophagy in OS.

MiR-1258 promotes the apoptosis of cervical cancer cells by regulating the E2F1/P53 signaling pathway

OBJECTIVE

Cervical cancer is the most common malignant tumor in gynaecology with high mortality. MiRNA has been reported to regulate cell biological processes in cervical cancer. This study aimed to explore the expression of miR-1258 and role of miR-1258 by targeting E2F1 in cervical cancer cells.

METHODS

The expression of miR-1258 and E2F1 in cervical cancer cells and transfection effects was determined by RT-qPCR analysis. The expression of E2F1, MMP2, MMP7, MMP9, Bcl2, Bax, cleaved caspase3, caspase3, KI67, p-AKT, cyclinD1, CDK2, P53 and AKT in cervical cancer cells was detected by western blot analysis. The proliferation, invasion, migration and apoptosis were respectively analyzed by CCK-8 assay, transwell assay, wound healing assay and flow cytometry analysis. E2F1 was a potential target of miR-1258, which demonstrated by a dual-luciferase reporter assay.

RESULTS

miR-1258 expression was decreased while E2F1 expression was increased in cervical cancer cells. MiR-1258 overexpression could down-regulate the E2F1 expression. Overexpression of miR-1258 inhibited the proliferation, invasion and migration and promoted the apoptosis of cervical cancer cells by AKT and P53 signal pathway. And, Overexpression of miR-1258 also suppressed the tumor growth by AKT and P53 signal pathway. Overexpression of E2F1 reduced the inhibition effects of miR-1258 in cervical cancer.

CONCLUSION

Taken together, miR-1258 overexpression exerts its inhibition effects on the proliferation, invasion and migration and promotion effects on the apoptosis of cervical cancer cells by targeting the E2F1, which might provide new ideas for clinical treatment of cervical cancer.

miR-624-5p promoted tumorigenesis and metastasis by suppressing hippo signaling through targeting PTPRB in osteosarcoma cells

Background

Accumulating evidence indicates that aberrant microRNA (miRNA) expression contributes to osteosarcoma progression. This study aimed to elucidate the association between miR-624-5p expression and osteosarcoma (OS) development and to investigate its underlying mechanism.

Methods

We analyzed GSE65071 from the GEO database and found miR-624-5p was the most upregulated miRNA. The expression of miR-624-5p and its specific target gene were determined in human OS specimens and cell lines by RT-PCR and western blot. The effects of miR-624-5p depletion or ectopic expression on OS proliferation, migration and invasion were evaluated in vitro using CCK-8 proliferation assay, colony formation assay, transwell assay, would-healing assay and 3D spheroid BME cell invasion assay respectively. We investigated in vivo effects of miR-624-5p using a mouse tumorigenicity model. Besides, luciferase reporter assays were employed to identify interactions between miR-624-5p and its specific target gene.

Results

miR-624-5p expression was upregulated in OS cells and tissues, and overexpressing miR-624-5p led to a higher malignant level of OS, including cell proliferation, migration and invasion in vitro and in vivo. Protein tyrosine phosphatase receptor type B (PTPRB) was negatively correlated with miR-624-5p expression in OS tissues. Using the luciferase reporter assay and Western blotting, PTPRB was confirmed as a downstream target of miR-624-5p. PTPRB restored the effects of miR-624-5p on OS migration and invasion. The Hippo signaling pathway was identified as being involved in the miR-624-5p/PTPRB axis.

Conclusions

In conclusion, our results suggest that miR-624-5p is a negative regulator of PTPRB and a risk factor for tumor metastasis in OS progression.

MicroRNA-761 targets FGFR1 to suppress the malignancy of osteosarcoma by deactivating PI3K/Akt pathway

Purpose

MicroRNA-761 (miR-761) has been reported to be deregulated in many types of human cancers and play important roles in cancer genesis and progression. However, the biological roles of miR-761 in osteosarcoma (OS) and the underlying mechanisms remain largely unknown.

Methods

The expression of miR-761 in OS tissues and cell lines was analyzed using RT-qPCR. A series of gain-of-function tests were performed, and status of malignancy was evaluated on basis of proliferation, migration, invasion, and apoptosis using different assays to determine the regulatory roles of miR-761 in OS cells in vivo and in vitro. Notably, the mechanisms underlying the action of miR-761 in the pathogenesis of OS were investigated using bioinformatic analysis, luciferase reporter assay, RT-qPCR and Western blotting.

Results

The results showed that miR-761 expression was decreased in OS tissues and cell lines and is closely correlated with clinical stage and distant metastasis in OS patients. Patients with OS having low miR-761 expression showed worse prognosis compared to OS patients with high miR-761 expression. Restoring the miR-761 expression level decreased OS cell proliferation, migration, and invasion in vitro; promoted cell apoptosis in vitro; and impaired tumor growth in vivo. In addition, fibroblast growth factor receptor 1 (FGFR1) was found as a direct target gene of miR-761 in OS cells. Furthermore, silencing FGFR1 expression stimulated the tumor-suppressing roles of miR-761 upregulation in OS cells, whereas the activity of miR-761 overexpression in OS cells was abolished by the restoration of FGFR1 expression. Moreover, restoration of miR-761 expression deactivated the PI3K/Akt pathway in vitro and in vivo.

Conclusion

These results suggest that miR-761 plays anti-cancer roles in OS by directly targeting FGFR1 and deactivating the PI3K/Akt pathway. The newly identified miR-761/FGFR1/PI3K/Akt pathway partially illustrates the mechanism of OS pathogenesis and presents a novel candidate therapeutic target for antitumor therapy.

RETRACTED: miR-27b Targets HOXB8 to Inhibit Malignant Behaviors of Osteosarcoma

MicroRNAs function as either tumor suppressor or oncogene in human cancers. This study aimed to explore the role of miR-27b in osteosarcoma. Expression of miR-27b or homeobox B8 in osteosarcoma cell lines was analyzed by quantitative real-time polymerase chain reaction and Western blot, respectively. Luciferase activity reporter assay and Western blot were conducted to explore the association between miR-27b and homeobox B8. Cell Counting Kit-8, colony formation assay, and wound-healing assay were performed to investigate the role of miR-27b or homeobox B8 on cell proliferation, colony formation, and cell migration. Expression of miR-27b was significantly reduced, while homeobox B8 was increased in osteosarcoma cell lines. In addition, homeobox B8 was validated as a direct target of homeobox B8. Moreover, miR-27b regulates osteosarcoma cell proliferation, colony formation, and migration through targeting homeobox B8. Taken together, our study provides novel insight into the progression of osteosarcoma, and the miR-27b–homeobox B8 axis identified may be developed as therapeutic targets against hepatocellular carcinoma in the future.