MicroRNA-613 inhibits cell growth, migration and invasion of papillary thyroid carcinoma by regulating SphK2

miR‑137 is a diagnostic tumor‑suppressive miRNA that targets SPHK2 to promote M1‑type tumor‑associated macrophage polarization

The present study investigated the expression level of microRNA (miR)-137 in glioma tissues and cell lines and explored its potential diagnostic significance as well as its function effects on glioma cells. miR-137 expression level was detected in glioma tissues using in situ hybridization, and in glioma cell lines using reverse transcription-quantitative PCR (RT-qPCR). The diagnostic significance of miR-137 in glioma was assessed using receiver operating characteristic curve analyses. Quantibody® Human Inflammation Array 1 was used to evaluate the impact of ectopic miR-137 expression on release of cytokines in glioma cell lines. IL-13, TNF-α and IFN-γ levels were detected using ELISA. To confirm that sphingosine kinase 2 (SPHK2) is a target of miR-137, RT-qPCR, western blot analysis and dual-luciferase assay were adopted. The results demonstrated that miR-137 expression was downregulated in both glioma tissues and cell lines. Downregulation of miR-137 was significantly associated with high grade gliomas. Additionally, it was found that overexpression of miR-137 reduced IL-13, but promoted TNFα and IFN-γ production. SPHK2 knockdown inhibited IL-13 release, promoted TNF-α and IFN-γ production. SPHK2 was a direct target of miR-137. Collectively, the results of the present study indicated that miR-137 expression plays a tumor-suppressive role in glioma. It is downregulated in glioma and may promote M1-type TAMs polarization, and may be a diagnostic biomarker and potential therapeutic strategy for glioma treatment in the future.

TBK1 promotes thyroid cancer progress by activating the PI3K/Akt/mTOR signaling pathway

Introduction

Thyroid cancer has received increasing attention; however, its detailed pathogenesis and pathological processes remain unclear. We investigated the role of TANK‐binding kinase 1 (TBK1) in the progression of thyroid cancer.

Methods

The expression of TBK1 in thyroid cancer and normal control tissues was analyzed using real‐time quantitative polymerase chain reaction. The function of TBK1 on thyroid cancer cells was detected using MTT, colony formation, wound healing, and Transwell assays. The xenograft assay was carried out to check on the role of TBK1 in thyroid cancer.

Results

TBK1 was highly expressed in thyroid tumors. High expression of TBK1 raised viability, proliferation, migration, and invasion of thyroid cancer cells. Gene set enrichment analysis revealed that TBK1 activated the phosphatidylinositol‐3‐kinase/protein kinase B/mammalian target of rapamycin pathway. In addition, Myc‐associated zinc finger protein (MAZ) was overexpressed in thyroid cancer and transcriptionally activated BK1. MAZ silence reversed the effects of TBK1 overexpression on thyroid cancer progression. Cotransfection with MAZ small‐interfering RNA(siRNA) and TBK1 siRNA did not strengthen the inhibitory effect of TBK1 silencing on the thyroid cancer cells. The xenograft tumor assay showed that TBK1 short hairpinRNA inhibited tumor growth.

Conclusion

MAZ silencing inhibited tumor progress of thyroid cancer cells, whereas this inhibitory effect was reversed by TBK1 overexpression.

The Crosstalk between FcεRI and Sphingosine Signaling in Allergic Inflammation

Sphingolipid molecules have recently attracted attention as signaling molecules in allergic inflammation diseases. Sphingosine-1-phosphate (S1P) is synthesized by two isoforms of sphingosine kinases (SPHK 1 and SPHK2) and is known to be involved in various cellular processes. S1P levels reportedly increase in allergic inflammatory diseases, such as asthma and anaphylaxis. FcεRI signaling is necessary for allergic inflammation as it can activate the SPHKs and increase the S1P level; once S1P is secreted, it can bind to the S1P receptors (S1PRs). The role of S1P signaling in various allergic diseases is discussed. Increased levels of S1P are positively associated with asthma and anaphylaxis. S1P can either induce or suppress allergic skin diseases in a context-dependent manner. The crosstalk between FcεRI and S1P/SPHK/S1PRs is discussed. The roles of the microRNAs that regulate the expression of the components of S1P signaling in allergic inflammatory diseases are also discussed. Various reports suggest the role of S1P in FcεRI-mediated mast cell (MC) activation. Thus, S1P/SPHK/S1PRs signaling can be the target for developing anti-allergy drugs.

MicroRNAs as the critical regulators of cell migration and invasion in thyroid cancer

Thyroid cancer (TC) is one of the most frequent endocrine malignancies that is more common among females. Tumor recurrence is one of the most important clinical manifestations in differentiated TC which is associated with different factors including age, tumor size, and histological features. Various molecular processes such as genetic or epigenetic modifications and non-coding RNAs are also involved in TC progression and metastasis. The epithelial-to-mesenchymal transition (EMT) is an important biological process during tumor invasion and migration that affects the initiation and transformation of early-stage tumors into invasive malignancies. A combination of transcription factors, growth factors, signaling pathways, and epigenetic regulations affect the thyroid cell migration and EMT process. MicroRNAs (miRNAs) are important molecular factors involved in tumor metastasis by regulation of EMT-activating signaling pathways. Various miRNAs are involved in the signaling pathways associated with TC metastasis which can be used as diagnostic and therapeutic biomarkers. Since, the miRNAs are sensitive, specific, and non-invasive, they can be suggested as efficient and optimal biomarkers of tumor invasion and metastasis. In the present review, we have summarized all of the miRNAs which have been significantly involved in thyroid tumor cells migration and invasion. We also categorized all of the reported miRNAs based on their cellular processes to clarify the molecular role of miRNAs during thyroid tumor cell migration and invasion. This review paves the way of introducing a non-invasive diagnostic and prognostic panel of miRNAs in aggressive and metastatic TC patients.

MicroRNAs in Papillary Thyroid Cancer: What Is New in Diagnosis and Treatment

Introduction

Papillary thyroid cancer (PTC) accounts for up to 80% of thyroid malignancies. New diagnostic and therapeutic options are suggested including innovative molecular methods. MicroRNAs (miRNAs) are nonprotein coding single-stranded RNAs that regulate many cell processes. The aim of the present study is to review the deregulated miRNAs associated with PTCs.

Methods

A bibliographic research was conducted, resulting in 272 articles referred to miRNAs and PTC. Regarding our exclusion criteria, 183 articles were finally included in our review.

Results

A remarkably large number of miRNAs have been found to be deregulated during PTC manifestation in the literature. The deregulated miRNAs are detected in tissue samples, serum/plasma, and FNA samples of patients with PTC. These miRNAs are related to several molecular pathways, involving genes and proteins responsible for important biological processes. MiRNA deregulation is associated with tumor aggressiveness, including larger tumor size, multifocality, extrathyroidal extension, lymphovascular invasion, lymph node and distant metastasis, and advanced tumor node metastasis stage.

Conclusion

MiRNAs are proposed as new diagnostic and therapeutic tools regarding PTC. They could be essential biomarkers for PTC diagnosis applied in serum and FNA samples, while their contribution to prognosis is of great importance.

Interaction of microRNAs with sphingosine kinases, sphingosine-1 phosphate, and sphingosine-1 phosphate receptors in cancer

Sphingosine-1-phosphate (S1P), a pleiotropic lipid mediator, participates in various cellular processes during tumorigenesis, including cell proliferation, survival, drug resistance, metastasis, and angiogenesis. S1P is formed by two sphingosine kinases (SphKs), SphK1 and SphK2. The intracellularly produced S1P is delivered to the extracellular space by ATP-binding cassette (ABC) transporters and spinster homolog 2 (SPNS2), where it binds to five transmembrane G protein-coupled receptors to mediate its oncogenic functions (S1PR1-S1PR5). MicroRNAs (miRNAs) are small non-coding RNAs, 21-25 nucleotides in length, that play numerous crucial roles in cancer, such as tumor initiation, progression, apoptosis, metastasis, and angiogenesis via binding to the 3'-untranslated region (3'-UTR) of the target mRNA. There is growing evidence that various miRNAs modulate tumorigenesis by regulating the expression of SphKs, and S1P receptors. We have reviewed various roles of miRNAs, SphKs, S1P, and S1P receptors (S1PRs) in malignancies and how notable miRNAs like miR-101, miR-125b, miR-128, and miR-506, miR-1246, miR-21, miR-126, miR499a, miR20a-5p, miR-140-5p, miR-224, miR-137, miR-183-5p, miR-194, miR181b, miR136, and miR-675-3p, modulate S1P signaling. These tumorigenesis modulating miRNAs are involved in different cancers including breast, gastric, hepatocellular carcinoma, prostate, colorectal, cervical, ovarian, and lung cancer via cell proliferation, invasion, angiogenesis, apoptosis, metastasis, immune evasion, chemoresistance, and chemosensitivity. Therefore, understanding the interaction of SphKs, S1P, and S1P receptors with miRNAs in human malignancies will lead to better insights for miRNA-based cancer therapy.

MicroRNA-17-5p inhibits thyroid cancer progression by suppressing Early growth response 2 (EGR2)

miR-17-5p has been proved that play important roles in many kinds of tumors progression. This study aimed at explore the function and mechanism of miR-17-5p in thyroid cancer (TC). RT-qPCR was used to detect miR-17-5p and Early growth response 2 (EGR2) expression in TC tissues and cells. CCK8 and colony formation assay were used to analyze cell proliferation. Cell migration and cell invasion was detected by Wound-healing assay and Transwell assay. Detection of protein expression using Western blot analysis. Dual-Luciferase assay was used to analyze the relationship between miR-17-5p and EGR2. In vivo experiment was performed by establishing Xenograft animal model to observe the function of miR-17-5p. We found that miR-17-5p is significantly increased in thyroid cancer tissues and cells. miR-17-5p inhibition repressed cell proliferation, clonal formation, cell migration, and cell invasion in thyroid carcinoma. Moreover, miR-17-5p inhibition suppressed tumorigenesis in vivo. Dual-Luciferase assay and Western blotting assay further proved that miR-17-5p has a negative regulation to EGR2. EGR2 was decreased in TC tissues and cells. Overexpressed EGR2 inhibited the development of thyroid carcinoma both vivo and in vivo. EGR2 knockdown remarkably decreased the anti-cancer effect of miR-17-5p inhibition. miR-17-5p is a thyroid cancer oncomir by modulation of the EGR2.

SphK2/S1P Promotes Metastasis of Triple-Negative Breast Cancer Through the PAK1/LIMK1/Cofilin1 Signaling Pathway

Background

Triple-negative breast cancer (TNBC) features a poor prognosis, which is partially attributed to its high metastatic rate. However, there is no effective target for systemic TNBC therapy due to the absence of estrogen, progesterone, and human epidermal growth factor 2 receptors (ER, PR, and HER-2, respectively) in cancer. In the present study, we evaluated the role of sphingosine kinase 2 (SphK2) and its catalyst sphingosine-1-phosphate (S1P) in TNBC metastasis and the effect of the SphK2-specific inhibitor ABC294640 on TNBC metastasis.

Methods

The function of SphK2 and S1P in TNBC cell metastasis was evaluated using transwell migration and wound-healing assays. The molecular mechanism of SphK2/S1P mediating TNBC metastasis was investigated using Western blot, histological examination, and immunohistochemistry assays. The antitumor activity of ABC294640 was examined in an in vivo TNBC lung metastatic model.

Results

Sphingosine kinase 2 promoted TNBC cell migration through the generation of S1P. Targeting SphK2 with ABC294640 inhibited TNBC lung metastasis in vivo. p21-activated kinase 1 (PAK1), p-Lin-11/Isl-1/Mec-3 kinase 1 (LIMK1), and Cofilin1 were the downstream signaling molecules of SphK2/S1P. Inhibition of PAK1 suppressed SphK2/S1P-induced TNBC cell migration.

Conclusion

Sphingosine kinase 2/sphingosine-1-phosphate promotes TNBC metastasis through the activation of the PAK1/LIMK1/Cofilin1 signaling pathway. ABC294640 inhibits TNBC metastasis in vivo and could be developed as a novel agent for the clinical treatment of TNBC.

METTL3-mediated m6A methylation of SPHK2 promotes gastric cancer progression by targeting KLF2

N6-methyladenosine (m⁶A) RNA methylation is profoundly involved in epigenetic regulation, especially for carcinogenesis and tumor progression. Mounting evidence suggests that methyltransferase METTL3 regulates malignant behaviors of gastric cancer (GC). However, the clinical significance and biological implication of SPHK2 and its related m⁶A modification in GC remain unclear. In this study, quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry were utilized to detect the expression profiles and prognostic significance of SPHK2 in GC. Here, we showed that increased SPHK2 was signified a poor prognosis of GC patients. Phosphorylation and ubiquitination assays were used to investigate the possible mechanisms of SPHK2-mediated KLF2 expression. SPHK2 can promote the phosphorylation of KLF2, which triggers the ubiquitination and degradation of KLF2 protein in GC. Methylated RNA immunoprecipitation (MeRIP) was performed to uncover the m⁶A modification of SPHK2 mRNA. METTL3 promotes translation of SPHK2 mRNA via an m⁶A-YTHDF1-dependent manner. Functionally, SPHK2 facilitates GC cell proliferation, migration and invasion by inhibiting KLF2 expression. SPHK2/KLF2 regulates the cell proliferation, migration, and invasion induced by METTL3 in GC. Overall, our findings reveal that METTL3-mediated m⁶A modification of SPHK2 contributes to GC progression, which extends the understanding of the importance m⁶A methylation in GC and represents a potential target for GC therapy.

Epigenetic signature associated with thyroid cancer progression and metastasis

Thyroid cancer is not among the top cancers in terms of diagnosis or mortality but it still ranks fifth among the cancers diagnosed in women. Infact, women are more likely to be diagnosed with thyroid cancer than the males. The burden of thyroid cancer has dramatically increased in last two decades in China and, in the United States, it is the most diagnosed cancer in young adults under the age of twenty-nine. All these factors make it worthwhile to fully understand the pathogenesis of thyroid cancer. Towards this end, microRNAs (miRNAs) have constantly emerged as the non-coding RNAs of interest in various thyroid cancer subtypes on which there have been numerous investigations over the last decade and half. This comprehensive review takes a look at the current knowledge on the topic with cataloging of miRNAs known so far, particularly related to their utility as epigenetic signatures of thyroid cancer progression and metastasis. Such information could be of immense use for the eventual development of miRNAs as therapeutic targets or even therapeutic agents for thyroid cancer therapy.

Hsa_circ_0000199 facilitates chemo-tolerance of triple-negative breast cancer by interfering with miR-206/613-led PI3K/Akt/mTOR signaling

Increasing attentions have been paid to the role of circRNAs in the etiology of triple-negative breast cancer (TNBC), and we strived to figure out the association of circRNA AKT3/miRNA axis with TNBC chemo-resistance. Altogether 207 BC patients were divided into TNBC group (n=83) and non-TNBC group (n=124), and MCF-10A, MDA-MB-231, MDA-MB-468, SK-BR-3 and MCF-7 cell lines were prepared in advance. Expressions of AKT3-derived circRNAs and relevant miRNAs in the TNBC tissues and cell lines were determined by employing real-time polymerase chain reaction (PCR). It was indicated that hsa_circ_0000199 expression was higher in TNBC tissues than in non-TNBC tissues, and high hsa_circ_0000199 expression was predictive of large tumor size, advanced TNM grade, high Ki-67 level and poor 3-year survival of TNBC patients (all P<0.05). Furthermore, miR-613 and miR-206 were sponged and negatively regulated by hsa_circ_0000199 (P<0.001), and PI3K/Akt/mTOR signaling was depressed by si-hsa_circ_0000199 in TNBC cell lines (P<0.01). Ultimately, miR-206/miR-613 inhibitor reversed impacts of si-hsa_circ_0000199 on PI3K/Akt/mTOR signaling, proliferation, migration, invasion, chemo-sensitivity and autophagy of TNBC cells (all P<0.01). Conclusively, silencing of hsa_circ_0000199 enhanced TNBC chemo-sensitivity by promoting miR-206/miR-613 expression and deactivating PI3K/Akt/mTOR signaling, which was conducive to improving chemotherapeutic efficacy of TNBC patients.

The Tumorigenic Effect of Sphingosine Kinase 1 and Its Potential Therapeutic Target

Sphingosine kinase 1 (SPHK1) regulates cell proliferation and survival by converting sphingosine to the signaling mediator sphingosine 1-phosphate (S1P). SPHK1 is widely overexpressed in most cancers, promoting tumor progression and is associated with clinical prognosis. Numerous studies have explored SPHK1 as a promising target for cancer therapy. However, due to insufficient knowledge of SPHK1 oncogenic mechanisms, its inhibitors’ therapeutic potential in preventing and treating cancer still needs further investigation. In this review, we summarized the metabolic balance regulated by the SPHK1/S1P signaling pathway and highlighted the oncogenic mechanisms of SPHK1 via the upregulation of autophagy, proliferation, and survival, migration, angiogenesis and inflammation, and inhibition of apoptosis. Drug candidates targeting SPHK1 were also discussed at the end. This review provides new insights into the oncogenic effect of SPHK1 and sheds light on the future direction for targeting SPHK1 as cancer therapy.

Exosomal long non-coding RNA UCA1 functions as growth inhibitor in esophageal cancer

PURPOSE

Esophageal cancer is a highly lethal and broad-spreading malignant tumor worldwide. Exosome-carrying lncRNAs play an essential role in the pathogenesis of various cancers.

RESULTS

The results revealed that the expression of UCA1 was decreased in esophageal cancer tissues and plasma exosomes. UCA1 was enriched in exosomes, and exosomal UCA1 was a promising biomarker for the diagnosis of esophageal cancer with 86.7% sensitivity and 70.2% specificity. Overexpression of UCA1 played anticancer roles in esophageal cancer cells through inhibiting cell proliferation, invasion and migration, and colony formation. Also, exosomal UCA1 was taken up by esophageal cancer cells and inhibited the progression of esophageal cancer in vitro and tumor growth in vivo. Furthermore, exosomal UCA1 could directly target miRNA-613 in esophageal cancer cells.

CONCLUSIONS

The results suggested that exosomal UCA1 inhibits tumorigenesis and progression of esophageal cancer in vitro and in vivo, and might be a promising biomarker for esophageal cancer.

PATIENT AND METHODS

In this study, we determined the expression of UCA1 in esophageal cancer tissues, plasma exosomes of patients with esophageal cancer. We determined the potential of exosomal UCA1 as a biomarker and its effect on the pathogenesis and progression of esophageal cancer in vitro and in vivo.

The Long Intergenic Noncoding RNA 00707 Sponges MicroRNA-613 (miR-613) to Promote Proliferation and Invasion of Gliomas

Background:

Glioma is one of the most deadly malignant tumors in humans. Long non-coding RNA (lncRNA) plays a key role in the occurrence, development and invasion of tumors by regulating oncogenic and tumor suppressor pathways. However, the role and action mechanism of long intergenic non-coding RNA 00707 (LINC00707) in gliomas have not been elucidated. This study aimed to investigate the interaction between LINC00707 and miR-613 as well as its role in gliomas.

Materials and Methods:

The expression levels of LINC00707 and miR-613 were detected by qRT-PCR. The chi-square test was used to analyze the correlation between LINC00707 expression and clinicopathological parameters. CCK-8 and colony formation assays were used to detect glioma cell proliferation; and wound healing and transwell assays were used to detect glioma cell migration and invasion. The relationship between LINC00707 and miR-613 was predicted by Starbase, and verified by qRT-PCR and dual luciferase reporter gene assay.

Results:

LINC00707 was up-regulated in gliomas. Up-regulated LINC00707 increased the proliferation, migration and invasion of glioma cells, and silenced LINC00707 reduced these abilities. The increase of the expression level of LINC00707 down-regulated miR-613 in glioma cells, while the inhibition of the expression level of LINC00707 up-regulated miR-613 in glioma cells. The high expression of LINC00707 was related to the Karnofsky performance status (KPS) score and WHO staging. LINC00707 could offset the ability of miR-613 to inhibit glioma proliferation and invasion.

Conclusion:

LINC00707 promotes proliferation and invasion of glioma cells by sponging miR-613. The regulatory axis of LINC00707/miR-613 provides new insights into the mechanism and treatment of gliomas.

Recent advances in the role of sphingosine 1-phosphate in cancer

Sphingosine 1-phosphate (S1P) is a bioactive lipid that binds to a family of G protein-coupled receptors (S1P_1-5 ) and intracellular targets, such as HDAC1/2, that are functional in normal and pathophysiologic cell biology. There is a significant role for sphingosine 1-phosphate in cancer underpinning the so-called hallmarks, such as transformation and replicative immortality. In this review, we survey the most recent developments concerning the role of sphingosine 1-phosphate receptors, sphingosine kinase and S1P lyase in cancer and the prognostic indications of these receptors and enzymes in terms of disease-specific survival and recurrence. We also provide evidence for identification of new therapeutic approaches targeting sphingosine 1-phosphate to prevent neovascularisation, to revert aggressive and drug-resistant cancers to more amenable forms sensitive to chemotherapy, and to induce cytotoxicity in cancer cells. Finally, we briefly describe current advances in the development of isoform-specific inhibitors of sphingosine kinases for potential use in the treatment of various cancers, where these enzymes have a predominant role. This review will therefore highlight sphingosine 1-phosphate signalling as a promising translational target for precision medicine in stratified cancer patients.

hsa-miR-195-5p inhibits cell proliferation of human thyroid carcinoma cells via modulation of p21/cyclin D1 axis

Background

Based on existing evidence, microRNAs (miRs) are gene regulators that undertake key functions in the oncogenesis and tumor progression of every single human malignant disease, such as thyroid carcinoma (TC). Previous clinical findings showed that expression of miR-195 is down-regulated in TC, which implies that miR-195 may be practically involved in TC pathogenesis. Nevertheless, the function of hsa-miR-195-5p in TC is still largely unclear. Herein, we detected the conceivable involvement of hsa-miR-195-5p in TC cell proliferation.

Methods

Real time PCR examination was performed to assess the expression level of hsa-miR-195-5p in TC cell lines TPC-1 and B-CPAP. TPC-1 cells were transfected with either hsa-miR-195-5p mimics or hsa-miR-195-5p inhibitor. After confirmation of transfection efficiency, the effect of hsa-miR-195-5p on proliferation and cell cycle of TPC-1 cells was assessed. The expression of cyclin D1 and p21 was simultaneously detected by western blotting. Moreover, targetScan 6.2 was used to predict hsa-miR-195-5p target genes. Subsequently, luciferase reporter was performed to examine whether there is a possible binding of hsa-miR-195-5p to 3’-UTR of cyclin D1 mRNA. Furthermore, cyclin D1 mRNA and protein levels were measured to check whether hsa-miR-195-5p exerts its function at the post-transcriptional level. In addition, to explore the function of cyclin D1 in TPC-1 cells overexpressing hsa-miR-195-5p, cyclin D1 siRNA was used to silence the expression of cyclin D1 in TPC-1 cells overexpressing hsa-miR-195-5p.

Results

We quantified the expression of hsa-miR-195-5p in TC cells and normal thyroid cells and found a remarkable decrease in hsa-miR-195-5p expression in TC cells. Over-expression of hsa-miR-195-5p obviously resulted in downgraded proliferation of TC cells. Moreover, hsa-miR-195-5p caused cell arrest at the GO/G1 phase. Further in silico analyses and the dual-luciferase reporter assay confirmed that 3’-UTR of cyclin D1 is a direct target of hsa-miR-195-5p. Western blot analysis uncovered that hsa-miR-195-5p over-expression led to decreased levels of cyclin D1 and p21. In mechanistic analyses, we found that silencing of cyclin D1 reversed the inhibitory effect of hsa-miR-195-5p on the proliferation of TC cells, which indicates that hsa-miR-195-5p suppresses TC cell proliferation by adversely regulating cyclin D1.

Conclusions

We concluded that hsa-miR-195-5p is a candidate tumor-suppressor miRNA in TC and that the hsa-miR-195-5p/p21/cyclin D1 pathway could be a potential therapeutic target for TC.

Inhibition of sphingosine kinase 2 attenuates hypertrophic scar formation via upregulation of Smad7 in human hypertrophic scar fibroblasts

The aims of the present study were to investigate the role of sphingosine kinase 2 (Sphk2) in hypertrophic scar (HS) formation and its underlying mechanisms. The expression levels of Sphk2 and Smad7 in HS tissues and healthy skin tissues of patients undergoing plastic surgery were determined using immunohistochemical staining. Subsequently, the expression levels of Sphk2 and collagen I in human embryonic skin fibroblasts (control) and human HS fibroblasts (HSF) were detected using western blot analysis and immunofluorescence assay, respectively. Following Sphk2 silencing, Smad7 overexpression or both Sphk2 and Smad7 silencing, HSF proliferative ability was assessed using Cell Counting Kit‑8 assay and proliferation‑associated proteins were evaluated using western blot analysis. In addition, the level of apoptosis in HSF was assessed using flow cytometry and expression levels of apoptotic‑associated proteins were determined using western blotting. Furthermore, the expression levels of collagen I and proteins in the TGF‑β1/Smad signaling pathway were detected using western blot analysis. The results indicated that the expression of Sphk2 was significantly increased, while Smad7 expression was decreased in HS tissue. Moreover, the upregulation of Sphk2 and collagen I expression levels was identified in HSF. The present results also indicated that Sphk2 silencing or Smad7 overexpression inhibited proliferation, but promoted apoptosis of HSF, coupled with changes in the expression levels of proliferation‑associated proteins, with an increase in p21 and a decrease in cyclin D1 expression levels, and apoptosis‑associated proteins, with an increase in Bax and cleaved caspase‑3, and a decrease in Bcl‑2, which were reversed following transfection with both Sphk2 and Smad7 using small interfering RNA in HSF. In addition, the expression levels of transforming growth factor‑β1, phosphorylated (p)‑Smad2, p‑Smad3 and collagen I were reduced following Sphk2 silencing or Smad7 overexpression, which were abolished by silencing both Sphk2 and Smad7. Collectively, the present results indicated that inhibition of Sphk2 attenuated HS formation via upregulation of Smad7 expression, thus Sphk2 may serve as a potential therapeutic target for the treatment of HS.

Clinical Potentials of miR-576-3p, miR-613, NDRG2 and YKL40 in Colorectal Cancer Patients

Introduction:

Colorectal cancer (CRC) is the most common type of gastrointestinal tract cancers. This investigation aim was to assess the expression of miR-576-3p and miR-613 in CRC patients in addition to NDRG2 and YKL40 serum levels determination to decide their diagnostic and prognostic significance.

Methods:

Sixty early diagnosed CRC patients prior to any treatment in addition to twelve healthy subjects were enrolled in this study. Blood samples were taken from subjects and allowed for clotting and centrifugation, then the collected sera were stored at -80ºC till it were used for detection of our molecular biomarkers. The mature miRNAs expressions (miR-576-3p and miR-613) were detected in serum by qRT-PCR, while NDRG2 and YKL40 serum levels were determined by ELISA. In addition, the correlation of the measured parameters with the clinicopathological data of the patients was investigated.

Results:

The study results showed that both miRNA-576-3p and miRNA-613 were down-regulated in CRC patients with fold change 0.33, 0.36; respectively. A significant positive correlation was observed between miR-576-3p and miR-613 (r = 0.75, p < 0.001). NDRG2 serum levels were decreased in patients compared to the control group but the decrease wasn’t statistically significant. On the other hand, it was observed that YKL40 serum level was significantly increased in CRC patients compared to control (p-value < 0.001). Furthermore, YKL40 showed a very high diagnostic value (AUC = 0.97, specificity = 91.7%, sensitivity = 96%, p-value = 0.0001).

Conclusion:

The observations of this investigation concluded that, the expressions of miR-576-3p and miR-613 in addition to YKL40 serum levels determinations may help in the diagnosis of CRC.

Long noncoding RNA LINC00520 accelerates progression of papillary thyroid carcinoma by serving as a competing endogenous RNA of microRNA-577 to increase Sphk2 expression

The long noncoding RNA (lncRNA) LINC00520 is an important modulator of the oncogenicity of multiple human cancers. However, whether LINC00520 is involved in the malignancy of papillary thyroid carcinoma (PTC) has not been extensively studied until recently. Therefore, the present study aimed to detect LINC00520 expression and evaluate its clinical significance in PTC. Functional experiments were conducted to test the biological role(s) and underlying mechanisms of LINC00520 in PTC progression. Reverse transcription quantitative polymerase chain reaction was performed to detect LINC00520 expression in PTC. A series of functional experiments, including Cell Counting Kit-8 assay, flow cytometry, Transwell migration assay, and tumor xenograft assay, was employed to investigate the biological roles of LINC00520 in PTC cells. High LINC00520 expression was verified in PTC tissues and cell lines, and this high expression was associated with the unfavorable clinicopathological parameters and short overall survival of patients. Functionally, LINC00520 interference resulted in a significant decrease in PTC cell proliferation, migration, and in vitro invasion and an increase in cell apoptosis. Further, its downregulation impaired tumor growth in vivo. Mechanistically, LINC00520 functioned as a competing endogenous RNA by sponging microRNA-577 (miR-577) and thereby increasing sphingosine kinase 2 (Sphk2) expression. Rescue experiments revealed that inhibiting miR-577 or restoring Sphk2 could abrogate the effects of LINC00520 silencing on the malignant phenotypes of PTC. LINC00520 functioned as an oncogenic lncRNA in PTC, and it facilitated PTC progression by regulating the miR-577/Sphk2 axis, suggesting that the LINC00520/miR-577/Sphk2 axis is an effective target in anticancer management.

Regulation of hypoxia-inducible factor functions in the nucleus by sphingosine-1-phosphate

Sphingosine kinase 2 (SphK2) is known to phosphorylate the nuclear sphingolipid metabolite to generate sphingosine-1-phosphate (S1P). Nuclear S1P is involved in epigenetic regulation of gene expression; however, the underlying mechanisms are not well understood. In this work, we have identified the role of nuclear S1P and SphK2 in regulating hypoxia-responsive master transcription factors hypoxia-inducible factor (HIF)-1α/2α, and their functions in breast cancer, with a focus on triple-negative breast cancer (TNBC). We have shown SphK2 is associated with HIF-1α in protein complexes, and is enriched at the promoters of HIF target genes, including vascular endothelial growth factor (VEGF), where it enhances local histone H3 acetylation and transcription. S1P specifically binds to the PAS domains of HIF-1α. SphK2, and HIF-1α expression levels are elevated in metastatic estrogen receptor-positive (ER+) and TNBC clinical tissue specimens compared to healthy breast tissue samples. To determine if S1P formation in the nucleus by SphK2 is a key regulator of HIF functions, we found using a preclinical TNBC xenograft mouse model, and an existing selective SphK2 inhibitor K-145, that nuclear S1P, histone acetylation, HIF-1α expression, and TNBC tumor growth were all reduced in vivo. Our results suggest that S1P and SphK2 in the nucleus are linked to the regulation of HIF-1α/2α functions associated with breast cancer progression, and may provide potential therapeutic targets.

LDOC1 is differentially expressed in thyroid cancer and display tumor-suppressive function in papillary thyroid carcinoma

The leucine zipper downregulated in cancer 1 (LDOC1) has been proposed as a regulator of transcription and cell signaling. We have previously demonstrated that LDOC1 is differentially expressed in papillary thyroid carcinoma (PTC), this study was designed to characterize LDOC1 expression in thyroid follicle originated cancer tissues and to specifically evaluate its function in thyroid carcinogenesis. LDOC1 expression was performed in human normal thyroid and thyroid cancer. LDOC1 function was characterized, in two PTC cell lines (TPC1 and BCPAP), through the analysis of in vitro cell proliferation, apoptosis, migration, and invasion along with in vivo tumor xenograft growth. Transduced BCPAP cells were stimulated with tumor necrosis factor α, and the levels of nuclear P65, Bax, Bcl-2, c-Myc, and XIAP were assessed. A luciferase reporter assay was used to measure nuclear factor-κB (NF-κB) activity, and the functional connection between LDOC1 effect and NF-κB activity was determined using a specific NF-κB inhibitor. Our results revealed that LDOC1 was translocated from the nucleus to the cytoplasm in human thyroid cancer, and was significantly downregulated in PTC compared with normal thyroid. LDOC1 overexpression in TPC1 resulted in a significant suppression of the malignant phenotype, whereas LDOC1 ablation in BCPAP promoted this phenotype. Additional studies demonstrated that LDOC1 ablation facilitated nuclear P65 expression and NF-κB activity. NF-κB inhibition reversed the effects of LDOC1 ablation on proliferation, apoptosis, migration, and invasion. Our findings confirmed that LDOC1 is a novel therapeutic target in PTC and provides new insight into the role of LDOC1 in PTC progression, through NF-κΒ signaling suppression.

S1P Signaling in the Tumor Microenvironment

Sphingosine-1-phosphate (S1P), together with other phosphosphingolipids, has been found to regulate complex cellular function in the tumor microenvironment (TME) where it acts as a signaling molecule that participates in cell-cell communication. S1P, through intracellular and extracellular signaling, was found to promote tumor growth, angiogenesis, chemoresistance, and metastasis; it also regulates anticancer immune response, modulates inflammation, and promotes angiogenesis. Interestingly, cancer cells are capable of releasing S1P and thus modifying the behavior of the TME components in a way that contributes to tumor growth and progression. Therefore, S1P is considered an important therapeutic target, and several anticancer therapies targeting S1P signaling are being developed and tested in clinics.

FOXE1 inhibits cell proliferation, migration and invasion of papillary thyroid cancer by regulating PDGFA

PURPOSE

Forkhead box E1 (FOXE1) plays an important role in the development, proliferation and differentiation of thyroid cells. However, the biological functions of FOXE1 in papillary thyroid cancer (PTC) remain unclear.

MATERIALS AND METHODS

In this study, the level of FOXE1 expression was examined in human PTC tissues and cells. Then, the high expression of FOXE1 was specifically silenced by RNA interference in vitro. Subsequently, FOXE1-shRNA was transfected into PTC cells (TPC-1 and K1). The effects on cell proliferation, migration and invasion were evaluated. In addition, FOXE1 targets were screened by cDNA microarray assays. The correlation between the expression of target gene platelet-derived growth factor A (PDGFA) and clinicopathological features of PTC patients was analysed.

RESULTS

FOXE1 is highly expressed in PTC tissues and PTC cell lines. The silencing of FOXE1 significantly promotes PTC cell proliferation, migration and invasion in vitro. The cDNA microarray analyses show that PDGFA is a critical downstream target gene of FOXE1 in PTC cells. It was also observed that PDGFA is negatively regulated by FOXE1 in PTC. The clinical data indicate that the low expression level of PDGFA is correlated with the small size of PTC.

CONCLUSION

Collectively, the results indicate for the first time that high expression of FOXE1 may function as a tumour suppressor in the early stage of PTC and restrain the proliferation, migration and invasion of PTC by negatively regulating PDGFA expression. Thus, FOXE1 could serve as a prognostic biomarker for PTC.

MicroRNA-101 Targets CXCL12-Mediated Akt and Snail Signaling Pathways to Inhibit Cellular Proliferation and Invasion in Papillary Thyroid Carcinoma

Escalating evidence suggests that microRNA-101 (miR-101) is implicated in the development and progression of various cancers, including papillary thyroid carcinoma (PTC). However, the biological function and molecular mechanisms of miR-101 in PTC are still unclear. In this study, we demonstrated that miR-101 expression was significantly decreased in PTC tissues and cell lines. Clinically, a low level of miR-101 was positively associated with advanced histological stages and lymph node and distant metastases. The expression of CXCL12 was negatively correlated with miR-101 level in PTC. CXCL12 was validated as a direct target of miR-101 in PTC cells. Functional experiments proved that miR-101 markedly reduced the proliferation, apoptosis escape, migration, and invasion of PTC cells. Moreover, CXCL12 restoration rescued the suppressive effects of miR-101 on PTC cells by activating Akt- and EMT-associated signaling pathways. Overall, miR-101 exerts oncostatic effects on PTC by downregulating CXCL12 and repressing its downstream Akt and Snail signaling pathways, suggesting that miR-101/CXCL12/Akt or Snail axis may serve as a potential therapeutic target for PTC.

MicroRNA-613 induces the sensitivity of gastric cancer cells to cisplatin through targeting SOX9 expression

Increasing evidences have suggested that deregulated miRNAs may involve in drug chemoresistance in a lot of human cancers. However, the role of miR-613 in drug chemoresistance of GC cell is still unknown. The expression of miR-613 and Sex-determining region Y (SRY)-box 9 (SOX9) in GC tissues and cell lines was detected by using qRT-PCR. Cell migration and viability were measured by the wound healing assay and CCK-8 assays. Western blot and dual-luciferase reporter were done to identify the target gene of miR-613. We showed that miR-613 expression was downregulated in GC tissues and cell lines. Ectopic expression of miR-613 increased the sensitivity of GC cells to cisplatin. Overexpression of miR-613 suppressed GC cell proliferation, cycle and migration. In addition, we identified SOX9 was a direct target gene of miR-613 in GC cell. We showed that SOX9 expression was upregulated in gastric cancer samples. Moreover, the expression of SOX9 was negatively correlated with miR-613 expression in GC tissues. Furthermore, elevated expression of miR-613 increased the sensitivity of GC cells to cisplatin and suppressed GC cell proliferation and migration by targeting SOX9. These data suggested that miR-613 might function as a chemoresistant suppressor in GC.

miR-29a-3p inhibits growth, proliferation, and invasion of papillary thyroid carcinoma by suppressing NF-κB signaling via direct targeting of OTUB2

Background

Aberrant expression of microRNAs (miRNAs) is closely involved in cancer development. Downregulation of miR-29a-3p and its tumor suppressive roles in cancer have been revealed by multiple reporters. However, study of its expression pattern and function in papillary thyroid carcinoma (PTC) is rare.

Materials and methods

The expression of miR-29a-3p in PTC tissues and cells was detected by qPCR. CCK-8, plate clone formation, transwell invasion, Western blot, immunohistochem-istry, and luciferase reporter assays were carried out to identify the target of miR-29a-3p and explore its roles and mechanisms in PTC.

Results

Deregulated miR-29a-3p in PTC tissues and cell lines were revealed by qPCR. Restoring miR-29a-3p expression significantly inhibited growth, proliferation, and invasion of PTC cells demonstrated by CCK-8, plate clone formation, and transwell assays. Luciferase reporter assays showed miR-29a-3p can directly target OTUB2 in PTC cells. Ectopic expression of OTUB2 can antagonize the effects of miR-29a-3p on cell growth, proliferation, and invasion of PTC. Mechanistically, OTUB2 overexpression can activate NF-κB signaling mostly by stabilizing TRAF6. Upregulated OTUB2 expression was observed in PTC tissues via immunohistochemistry analysis. Moreover, OTUB2 showed a positive correlation to metastatic status and showed a negative correlation to the overall survival rate in PTC patients.

Conclusion

Deregulated miR-29a-3p can promote cell growth, proliferation, and invasion in PTC. OTUB2 is a direct downstream target of miR-29a-3p in PTC, and it mediates the effects of deregulated miR-29a-3p by activating TRAF6-associated NF-κB signaling in PTC.

MicroRNA-146b-5p as an oncomiR promotes papillary thyroid carcinoma development by targeting CCDC6

The microRNA-146b-5p (miR-146b-5p) is known to be involved in the development of papillary thyroid cancer (PTC); however, the underlying mechanism is unclear. Here we have investigated the biological functions and underlying molecular mechanisms of miR-146b-5p in PTC. The expression of miR-146b-5p was assessed in 92 pairs of PTC and adjacent normal tissues and showed correlation with the clinicopathological status such as the tumour size. Effects of miR-146b-5p and its direct target, coiled-coil domain containing 6 (CCDC6), on cell proliferation, migration, invasion, and cell cycle were evaluated through gain- and loss-of-function studies in vitro and in vivo. The expression of CCDC6 was further examined in 187 PTC cases and was found to be correlated with the clinicopathological status. Overexpression of miR-146b-5p was observed in PTC tissues that correlated with advanced PTC. miR-146b-5p promoted cell proliferation, migration, invasion, and cell cycle progression in vitro, whereas CCDC6 reversed this effect. miR-146b-5p promoted PTC growth in a subcutaneous mouse model in vivo, whereas overexpression of CCDC6 exerted the opposite effect. In conclusion, miR-146b-5p expression correlated with advanced PTC and promoted PTC development by targeting CCDC6 in vitro and in vivo; it could, therefore, serve as a promising target for PTC treatment.

MiR-129 regulates growth and invasion by targeting MAL2 in papillary thyroid carcinoma

MAL2, a member of the MAL proteolipid family, is essential for raft-mediated transport. In this study, we investigated the roles and underlying mechanism of MAL2 in the development of papillary thyroid carcinoma (PTC). Up-regulation of MAL2 was found in human PTC tissues and significantly correlated with poor overall survival (OS). Knockdown of MAL2 dramatically suppressed PTC cell proliferation and invasion in vitro and inhibited tumor growth in vivo. We further found that miR-129 suppressed the expression of MLA through directly binding to the 3' untranslated region (3' UTR). While forced miR-129 expression suppressed growth and invasion of PTC cells, re-expression of MAL2 rescued these effects. Taken together, our data indicated that MAL2 acted as an oncogene and was negatively regulated by miR-129, supporting the potential therapeutic strategy against PTC by targeting miR-129-MAL2 axis.

MiR-135a-5p modulates biological functions of thyroid carcinoma cells via targeting VCAN 3'-UTR

Thyroid carcinoma is one of the most frequent malignant tumors of the endocrine system, which accounts for nearly 1% population in newly diagnosed carcinoma worldwide and the incidence has an increasing tendency in recent years. To explore whether miR-135a-5p could affect the proliferation, invasion and migration of thyroid carcinoma cells by targeting VCAN. The expression levels of miR-135a-5p and VCAN were detected in human thyroid carcinoma tissues and cells, para-carcinoma tissues, as well as human normal thyroid cells using RT-qPCR and Western blot. In addition, dual-luciferase reporter gene assay, MTT assay, colony formation assay, wound healing assay, Transwell assay, flow cytometry analysis and in vivo tumorigenesis assay were also conducted. The results demonstrated that miR-135a-5p was down-regulated while VCAN was up-regulated both in thyroid carcinoma tissues and cells. Furthermore, the up-regulation of miR-135a-5p inhibited cell proliferation, invasion and migration of thyroid carcinoma. Dual-luciferase reporter gene assay provided evidence indicating that miR-135a-5p targeted VCAN in thyroid carcinoma. MiR-135a-5p could inhibit cell proliferation, invasion and migration of thyroid carcinoma by targeting VCAN. MiR-135a-5p and VCAN might emerge as a target for the treatment of thyroid carcinoma.

Role of miR-613 as a tumor suppressor in glioma cells by targeting SOX9

Background and objectives

MicroRNA-613 (miR-613), a novel cancer-related microRNA, has been shown to be responsible for the inhibition of tumor development and progression in various cancers. We aimed to investigate the biological function and regulatory mechanisms of miR-613 in gliomas.

Materials and methods

miR-613 expression were detected by qRT-PCR assays in glioma tissues and cell lines. Cell Counting Kit-8 (CCK-8) assay, colony formation analysis, wound healing and transwell invasion assays were performed to evaluate cell proliferation, colony formation, migration and invasion abilities. Luciferase reporter assays, qRT-PCR and Western blot were performed to explore the potential targets of miR-613. Xenograft mice model was established to evaluate the effect of miR-613 in vivo.

Result

The expression levels of miR-613 were significantly downregulated in the glioma tissues and cell lines, and the decreased level was significantly negatively associated with the overall disease-free survival of the patients. Functionally, ectopic expression of miR-613 in glioma cells suppressed the proliferation, colony formation, and migration and invasion of the cells. The sex-determining region Y-box 9 (SOX9) was identified as a direct functional target of miR-613, and its expression was inversely correlated with miR-613 expression in glioma tissues. Moreover, rescue of SOX9 could partially reverse the inhibitory effects of miR-613 on glioma cell proliferation, colony formation, migration, and invasion. Importantly, miR-613 also suppressed tumor growth in vivo by targeting SOX9.

Conclusion

Taken together, these findings demonstrate that miR-613 functions as a tumor suppressor in glioma cells by directly targeting SOX9.

MiR-613 suppressed the laryngeal squamous cell carcinoma progression through regulating PDK1

MicroRNAs (miRNAs) are aberrantly expressed in several tumors and play important role in tumorigenesis. However, little is known about the role of miR-613 in laryngeal squamous cell carcinoma (LSCC). We determined the expression of miR-613 in a panel of 30 LSCC specimens. Compared with the adjacent normal samples, 20 cases of LSCC tissues exhibited decreased expression of miR-613. The average expression of miR-613 in LSCC tissues was lower than in normal samples. Moreover, we demonstrated that exogenous expression of miR-613 suppressed LSCC cell proliferation, invasion, and blocked G1/S phase transition. We identified that 3-phosphoinositide-dependent protein kinase-1 (PDK1) was a direct target gene of miR-613 in LSCC cell. Overexpression of miR-613 suppressed PDK1 expression in LSCC cell. Furthermore, we demonstrated that PDK1 was upregulated in LSCC tissues. MiR-613 expression was inversely correlated with the expression of PDK1 in LSCC tissues. Moreover, we showed that PDK1 was involved in the miR-613-mediated cancer suppression of LSCC cell. These results suggested that miR-613 played as a tumor suppressor gene in LSCC partly by inhibiting PDK1 expression.

LncRNA HOTAIR acts a competing endogenous RNA to control the expression of notch3 via sponging miR-613 in pancreatic cancer

Pancreatic cancer is one of the most deadly cancers with a poor prognosis. Though studies have implicated the roles of microRNAs in pancreatic cancer progression, little is known about the role of miR-613 in pancreatic cancer. In the present study, the expression of miR-613 was down-regulated in pancreatic cancer tissues and cancer cell lines. Down-regulation of miR-613 was positively correlated with tumor differentiation, advanced TNM stage, nodal metastasis and shorter overall survival in patients with pancreatic cancer. Overexpression of miR-613 suppressed cell proliferation, invasion and migration, and induced cell apoptosis and cell cycle arrest at G0/G1 phase in pancreatic cancer cells. Bioinformatics analysis, luciferase reporter assay and rescue experiments showed that notch3 was a direct target of miR-613. MiR-613 was inversely correlated with notch3 expression in pancreatic cancer tissues. The long non-coding RNA, HOX transcript antisense RNA (HOTAIR) was up-regulated in both pancreatic cancer tissues and cancer cell lines, and HOTAIR suppressed the expression of miR-613 via functioning as a competing endogenous RNA. In vivo studies showed that stable overexpression of miR-613 or knock-down of HOTAIR suppressed tumor growth and also reduced the expression of notch3. In conclusion, these results suggest that HOTAIR functions as a competing endogenous RNA to regulate notch3 expression via sponging miR-613 in pancreatic cancer.

Targeting sphingosine kinase 2 by ABC294640 inhibits human skin squamous cell carcinoma cell growth

The activity of ABC294640, a small-molecular sphingosine kinase 2 (SphK2) inhibitor, in human skin squamous cell carcinoma (SCC) cells was tested in this study. SphK2 mRNA and protein are expressed in established (A431 cheilocarcinoma cell line) and primary human skin SCC cells. ABC294640 dose-dependently inhibited survival, cell cycle progression and proliferation of skin SCC cells. Furthermore, ABC294640 induced caspase-3/-9 and apoptosis activation in skin SCC cells. The SphK2 inhibitor was however non-cytotoxic to SphK2-null skin melanocytes, keratinocytes and fibroblasts. ABC294640 induced ceramide accumulation, sphingosine-1-phosphate (S1P) reduction, Akt-S6K1 inhibition and JNK activation in skin SCC cells. Conversely, its cytotoxicity against SCC cells was largely attenuated by co-treatment of S1P, the Akt activator SC79, and the JNK inhibitor SP600125. In vivo, ABC294640 oral administration inhibited A431 xenograft tumor growth in nude mice. Akt-S6K1 inhibition and JNK activation were observed in ABC294640-treated tumors. Collectively, ABC294640 efficiently inhibits human skin SCC cell growth in vitro and in vivo.

MicroRNA-613 impedes the proliferation and invasion of glioma cells by targeting cyclin-dependent kinase 14

Increasing evidence has suggested that microRNAs (miRNAs) are critical regulators of tumorigenesis. MicroRNA-613 (miR-613) has recently been reported as a novel tumor-related miRNA that plays an important role in multiple cancers. However, the expression and functional significance of miR-613 in glioma remains unclear. In this study, we aimed to investigate the biological function of miR-613 in glioma. We found that miR-613 expression was frequently downregulated in glioma tissues and cell lines compared with normal controls. Overexpression of miR-613 impeded proliferation and colony formation and induced cell cycle arrest in G0/G1 phase, and also inhibited the invasive ability of glioma cells. By contrast, miR-613 inhibition had the opposite effects. Bioinformatic analysis and dual-luciferase reporter assays showed that miR-613 directly targets the 3'-untranslated region of cyclin-dependent kinase 14 (CDK14). Real-time quantitative PCR and Western blot analysis showed that CDK14 expression is negatively regulated by miR-613. In addition, miR-613 expression was inversely correlated with CDK14 expression in clinical glioma tissues. Moreover, overexpression of miR-613 decreased the protein expression of β-catenin and inhibited the activation of Wnt signaling. Importantly, the antitumor effects of miR-613 were significantly reversed by CDK14 overexpression. Overall, our results show that miR-613 inhibits glioma cell proliferation and invasion by downregulating CDK14, suggesting that miR-613 and CDK14 may serve as potential therapeutic targets for the treatment of glioma.

MicroRNA-338-3p Suppresses Proliferation of Human Liver Cancer Cells by Targeting SphK2

Recent studies have revealed abnormal expression of miRNAs in various tumors. Although microRNA-338-3p (miR-338-3p) plays an important role in many types of tumors, its influence on liver cancer (LC) is unknown. In this study, we found that expression of miR-338-3p was decreased in LC cells and tissues. Colony formation and cell proliferation were suppressed by enhanced expression of miR-338-3p in LC cells. Moreover, miR-338-3p targeted sphingosine kinase 2 (SphK2). Silencing of SphK2 had an identical influence as overexpression of miR-338-3p in LC cells. Overexpression of SphK2 without the 3′-untranslated region remarkably enhanced the growth suppression triggered by miR-338-3p in LC cells. These findings indicate that miR-338-3p influences the development of LC by targeting SphK2, suggesting that miR-338-3p can be targeted as an innovative therapeutic strategy for LC.

The sphingosine kinase 2 inhibitor ABC294640 inhibits cervical carcinoma cell growth

ABC294640 is a specific sphingosine kinase 2 (SphK2) inhibitor. The anti-cervical carcinoma activity by ABC294640 was tested in this study. ABC294640 inhibited in vitro growth of the established (C33A and HeLa lines) and primary human cervical carcinoma cells. The SphK2 inhibitor also induced G1-S arrest and apoptosis in cervical carcinoma cells. It was yet non-cytotoxic to SphK2-low human cervical epithelial cells. ABC294640 inhibited SphK activation, causing sphingosine-1-phosphate depletion, signal transducer and activator of transcription 3 in-activation and ceramide production. Bcl-2 is a key resistance factor of ABC294640. Pharmacological Bcl-2 inhibition or Bcl-2 shRNA potentiated ABC294640-induced C33A cell growth inhibition and apoptosis. On the other hand, exogenous over-expression of Bcl-2 attenuated ABC294640's cytotoxicity against C33A cells. In vivo, ABC294640 administration inhibited C33A xenograft tumor growth in mice. Co-administration of the Bcl-2 inhibitor GDC-0199 further potentiated ABC294640's anti-tumor activity. Together, we suggest that ABC294640 might have translational value for the treatment of human cervical carcinoma.

LncRNA CRNDE promotes cell proliferation, invasion and migration by competitively binding miR-384 in papillary thyroid cancer

Thyroid cancer is one of the most prevalent endocrine neoplasm. The present study examined the effects of Colorectal Neoplasia Differentially Expressed (CRNDE) on the progression of papillary thyroid cancer (PTC), and explored the underlying molecular mechanisms. Quantitative real-time PCR was used to detect CRNDE, miR-384 and pleiotrophin (PTN) mRNA expression. Western blot was used to measure PTN protein levels. Cell proliferation, cell growth, cell invasion and migration of PTC cells were determined by CCK-8, colony formation, transwell invasion and migration assays, respectively. CRNDE was up-regulated in PTC tissues and cell lines. Overexpression of CRNDE promoted BCPAP cell proliferation, invasion and migration, while knock-down of CRNDE suppressed K1 cell proliferation, invasion and migration. CRNDE negatively regulated the expression of miR-384 in PTC cells, which was further confirmed by luciferase reporter assay. MiR-384 was down-regulated and inversely correlated with CRNDE expression in PTC tissues. MiR-384 suppressed cell proliferation, invasion and migration in PTC cells, and enforced expression of miR-384 attenuated the oncogenic effects of CRNDE in PTC cells. PTN was predicted as a downstream target of miR-384, which was confirmed by luciferase reporter assay, and PTN was up-regulated in PTC tissues, and was negatively correlated with miR-384 expression and positively correlated with CRNDE expression in PTC tissues. In summary, our results suggested that the CRNDE/miR-384/PTN axis may play an important role in the regulation of PTC progression, which provides us with new insights into understanding the PTC.

miR-613 inhibits gastric cancer progression through repressing brain derived neurotrophic factor

MicroRNA (miR)-613 has been reported to function as a tumor suppressor in several types of cancer. However, the biological function and underlying mechanism in gastric cancer (GC) has remained elusive. Therefore, the aim of the present study was to assess the expression and biological role of miR-613 in GC tissues and cell lines. miR-613 expression was found to be downregulated in 38 GC tissue samples compared to that in their adjacent non-cancerous tissues, and low expression of miR-613 was associated with lymph node metastasis and advanced tumor-nodes-metastasis stage. A gain-of-function assay demonstrated that miR-613 overexpression reduced tumor cell proliferation, migration and invasion of SGC-7901 cells, as determined by MTT and Transwell assays. Furthermore, brain-derived neutrophic factor (BDNF) was identified as a direct target of miR-613 in GC cells by a luciferase reporter assay. BDNF expression was upregulated and inversely correlated with miR-613 levels in GC tissues. In addition, knockdown of BDNF expression mimicked the tumor suppressive effect of miR-613 in GC cells. In conclusion, these findings demonstrated that miR-613 functions as a tumor suppressor in GC by targeting BDNF. Thus, miR-613 is a potential therapeutic target for GC.

Role of microRNAs in endocrine cancer metastasis

The deregulation of transcription and processing of microRNAs (miRNAs), as well as their function, has been involved in the pathogenesis of several human diseases, including cancer. Despite advances in therapeutic approaches, cancer still represents one of the major health problems worldwide. Cancer metastasis is an aggravating factor in tumor progression, related to increased treatment complexity and a worse prognosis. After more than one decade of extensive studies of miRNAs, the fundamental role of these molecules in cancer progression and metastasis is beginning to be elucidated. Recent evidences have demonstrated a significant role of miRNAs on the metastatic cascade, acting either as pro-metastatic or anti-metastatic. They are involved in distinct steps of metastasis including epithelial-to-mesenchymal transition, migration/invasion, anoikis survival, and distant organ colonization. Studies on the roles of miRNAs in cancer have focused mainly on two fronts: the establishment of a miRNA signature for different tumors, which may aid in early diagnosis using these miRNAs as markers, and functional studies of specific miRNAs, determining their targets, function and regulation. Functional miRNA studies on endocrine cancers are still scarce and represent an important area of research, since some tumors, although not frequent, present a high mortality rate. Among the endocrine tumors, thyroid cancer is the most common and best studied. Several miRNAs show lowered expression in endocrine cancers (i.e. miR-200s, miR-126, miR-7, miR-29a, miR-30a, miR-137, miR-206, miR-101, miR-613, miR-539, miR-205, miR-9, miR-195), while others are commonly overexpressed (i.e. miR-21, miR-183, miR-31, miR-let7b, miR-584, miR-146b, miR-221, miR-222, miR-25, miR-595). Additionally, some miRNAs were found in serum exosomes (miR-151, miR-145, miR-31), potentially serving as diagnostic tools. In this review, we summarize studies concerning the discovery and functions of miRNAs and their regulatory roles in endocrine cancer metastasis, which may contribute for the finding of novel therapeutic targets. The review focus on miRNAs with at least some identified targets, with established functions and, if possible, upstream regulation.

Downregulation of cyclin-dependent kinase 8 by microRNA-148a suppresses proliferation and invasiveness of papillary thyroid carcinomas

MicroRNAs (miRNAs) are important gene regulators that play key roles in tumor genesis. In this study, we investigate the role of miR-148a in the development of papillary thyroid cancer (PTC). Data from the cancer genome atlas (TCGA) indicate that miR-148a is downregulated in PTC tissues; we also find that miR-148a is downregulated in tissue samples from PTC patients and PTC cell lines. Overexpression of miR-148a significantly suppresses PTC cell proliferation, migration and invasiveness in vitro, and inhibits tumor growth in vivo as well. We have identified the cyclin-dependent kinase 8 (CDK8) gene as a direct target of miR-148a using the online software packages TargetScan and miRanda. Overexpression of miR-148a significantly represses CDK8 expression by directly targeting the 3'-untranslated region (3'-UTR) of the CDK8 gene in PTC tissues and cell lines; overexpression of CDK8 reverses the inhibitory effects of miR-148a on PTC cell growth, migration and invasiveness. Taken together, our results indicate that miR-148a functions as a tumor suppressor in PTC by repressing CDK8 expression.

AntagomiR-613 protects neuronal cells from oxygen glucose deprivation/re-oxygenation via increasing SphK2 expression

Oxygen glucose deprivation (OGD)/re-oxygenation (OGDR) causes damages to neuronal cells. Sphingosine kinase 2 (SphK2) expression could exert neuroprotective functions. Here, we aim to induce SphK2 expression via inhibiting the anti-SphK2 microRNA: microRNA-613 ("miR-613"). In both SH-SY5Y neuronal cells and primary murine hippocampal neurons, transfection of the miR-613's specific inhibitor, antagomiR-613 ("antamiR-613"), induced miR-613 depletion and SphK2 expression. Reversely, forced over-expression of miR-613 caused SphK2 downregulation in SH-SY5Y cells. OGDR-induced cytotoxicity in neuronal cells was largely attenuated by antamiR-613. SphK2 is required for antamiR-613-induced actions in neuronal cells. SphK2 knockdown (by targeted-shRNAs) or inhibition (by its inhibitor ABC294640) almost completely abolished antamiR-613-mediated neuroprotection against OGDR. Further studies showed that OGDR-induced reactive oxygen species (ROS) production, lipid peroxidation, and DNA damages in SH-SY5Y cells were largely attenuated by antamiR-613, but were intensified by miR-613 expression. Taken together, we conclude that antamiR-613 protects neuronal cells from OGDR probably via inducing SphK2 expression.

Tumor suppressor microRNA‑613 inhibits glioma cell proliferation, invasion and angiogenesis by targeting vascular endothelial growth factor A

MicroRNAs (miRNAs) are small non‑coding RNAs which can serve as oncogenes or tumor suppressors in glioma. The present study aimed to investigate the expression of miR‑613 in glioma. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detect miR‑613 in glioma cells and tissues and the relationship between miR‑613 and vascular endothelial growth factor (VEGF) A was assessed using a luciferase reporter assay. In addition, glioma cells were transfected with miR‑613 mimics and the mRNA and protein expression of VEGFA was detected using RT‑qPCR and western blot analysis, respectively. The proliferative, invasive and tube formation capabilities of transfected cells were also assessed in vitro. Furthermore, a nude mouse tumor xenograft model was used to investigate the effects of miR‑613 on tumor growth in vivo. The results of the present study demonstrated that the expression of miR‑613 was decreased in glioma cell lines, and was associated with the grade of glioma. Ectopic expression of miR‑613 markedly suppressed glioma cell proliferation and angiogenesis. Furthermore, the upregulation of miR‑613 inhibited tumor angiogenesis and tumor growth in xenografted nude mice in vivo. VEGFA was demonstrated as a direct target of miR‑613, as detected by western blot and luciferase reporter assays, and mediated miR‑613 induced glioma cell proliferation and angiogenesis inhibition.

MicroRNA‑613 inhibits proliferation and invasion of renal cell carcinoma cells through targeting FZD7

MicroRNAs (miRNAs) have emerged as critical regulators in cancer progression. miR‑613 has been reported as a tumor suppressor gene in many types of human cancers. However, the function of miR‑613 in renal cell carcinoma (RCC) remains unclear. In the present study, the authors aimed to detect the expression of miR‑613 and its function in RCC cell lines. miR‑613 was reported to be significantly downregulated RCC cell lines. Functional analyses demonstrated that overexpression of miR‑613 significantly decreased RCC cell proliferation and invasion. Bioinformatics analysis showed that Frizzled7 (FZD7) was a predicted target of miR‑613, which was verified by dual‑luciferase reporter assay, reverse transcription quantitative‑polymerase chain reaction and western blot analysis. Restoration of FZD7 significantly reversed the suppressive effects of miR‑613 on RCC cell proliferation and invasion. Taken together, the results of the present study indicated that miR‑613 functions as a tumor suppressor that inhibits RCC cell proliferation and invasion by targeting and inhibiting FZD7, providing novel insight into RCC pathogenesis and a potential therapeutic target for RCC.

MicroRNA-613 is downregulated in HCMV-positive glioblastoma and inhibits tumour progression by targeting arginase-2

Glioblastoma is the most common and malignant tumour that occurs primarily in nervous system and has a high morbidity. Research on glioblastoma has recently focused on human cytomegalovirus, belonging to the beta subfamily of Herpesviridae that plays crucial roles in cancer development and progression. This study aimed to investigate the role of human cytomegalovirus–associated microRNA-613 in glioblastoma. In this study, we demonstrate that microRNA-613 expression was frequently reduced in human cytomegalovirus–positive glioblastoma specimens/cells compared with human cytomegalovirus–negative glioblastoma tissue/cells, and a significant correlation was observed between the reduction in microRNA-613 expression and the presence of unfavourable variables, including tumour size (p = 0.0118), World Health Organization stage (p = 0.0169), the overall survival (p = 0.0107) and disease-free (p = 0.0159) survival of patients. Overexpression of microRNA-613 in the glioblastoma cell lines U87 and U251 retarded cell growth and induced cell apoptosis. Upregulation of microRNA-613 inhibited glioblastoma cell clone formation, invasion and migration. Furthermore, we demonstrated that arginase-2 was directly regulated by microRNA-613 and played an essential role in mediating the biological effects of microRNA-613 in glioblastoma. Re-expression of arginase-2 markedly reversed the inhibitory properties of microRNA-613 in glioblastoma cells. Taken together, our data provide compelling evidence that human cytomegalovirus reduced the level of microRNA-613 which functions as an anti-onco-miRNA in glioblastoma, primarily by downregulating the expression of arginase-2.

Lowered levels of microRNA-129 and potential signaling pathways in papillary thyroid carcinoma: a determination of microRNA sequencing in 507 patients and bioinformatics analysis

Papillary thyroid carcinoma (PTC) is one of the most common endocrine system malignancies. However, the mechanism of tumor development is unclear. microRNA-129-5p is a microRNA that plays an important role in the development of tumors. The main purpose of our article is to find the potential target genes of microRNA-129 and their pathways based on gene array, sequencing and bioinformatics studies. We obtained microRNA-129 expression and clinical associations in the TCGA database. In addition, we found a microRNA-129-related chip GSE19933, which is overexpressing microR-129-5p in thyroid cancer cell lines. The down-regulated gene is considered to be a potential target gene for microRNA-129. The target genes were predicted through 12 online tools. We performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of all down-regulated and predicted target genes. Furthermore, protein-protein interactions (PPI) were also analyzed for all potential genes. Finally, with intersecting down-regulated genes by overexpressed microRNA-129 and predicted target genes, the 889 genes are mainly enriched in the calcium signaling pathway, cGMP-PKG signaling pathway, ErbB signaling pathway and Proteoglycans in cancer, etc. The role of ten hub genes is particularly prominent in PPI analysis. These genes are differentially expressed in the thyroid by immunohistochemistry. We confirmed that microRNA-129 may play a major role in PTC through the above pathways, but more experiments are still needed to prove our results.

Role of Sphingosine-1-Phosphate in Mast Cell Functions and Asthma and Its Regulation by Non-Coding RNA

Sphingolipid metabolites are emerging as important signaling molecules in allergic diseases specifically asthma. One of the sphingolipid metabolite, sphingosine-1-phosphate (S1P), is involved in cell differentiation, proliferation, survival, migration, and angiogenesis. In the allergic diseases, alteration of S1P levels influences the differentiation and responsiveness of mast cells (MCs). S1P is synthesized by two sphingosine kinases (SphKs), sphingosine kinase 1, and sphingosine kinase 2. Engagement of IgE to the FcεRI receptor induces the activation of both the SphKs and generates S1P. Furthermore, SphKs are also essential to FcεRI-mediated MC activation. Activated MCs export S1P into the extracellular space and causes inflammatory response and tissue remodeling. S1P signaling has dual role in allergic responses. Activation of SphKs and secretion of S1P are required for MC activation; however, S1P signaling plays a vital role in the recovery from anaphylaxis. Several non-coding RNAs have been shown to play a crucial role in controlling the MC-associated inflammatory and allergic responses. Thus, S1P signaling pathway and its regulation by non-coding RNA could be explored as an exciting potential therapeutic target for asthma and other MC-associated diseases.

MicroRNA-153-3p suppress cell proliferation and invasion by targeting SNAI1 in melanoma

Malignant melanoma is one of the most common malignancies of the skin cancer and increasing evidences revealed that microRNAs (miRNAs) exert significant effects in melanoma. In the present study, the underlying function of microRNA-153-3p (miR-153-3p) in melanoma was investigated from different levels, including cell level, protein level and gene level. Our results showed that expression of miR-153-3p was lower in melanoma tissues and melanoma cells compared with the para-tumor tissue and normal melanocytes. The overexpression of miR-153-3p inhibited the cell proliferation and invasion, at the same time promoted cell apoptosis. Moreover, we identified that snail family transcriptional repressor 1 (SNAI1) is the direct target of miR-153-3p, and there is a negative correlation between miR-153-3p level and SNAI1 expression. In summary, we presented the evidences that miR-153-3p may act as a tumor suppressor by down-regulating the expression of SNAI1 in melanoma and miR-153-3p might be a potential biomarker in the diagnosis and treatment of malignant melanoma.