miR-206 functions as a novel cell cycle regulator and tumor suppressor in clear-cell renal cell carcinoma

KLF4 Suppresses the Progression of Hepatocellular Carcinoma by Reducing Tumor ATP Synthesis through Targeting the Mir-206/RICTOR Axis

To address the increased energy demand, tumor cells undergo metabolic reprogramming, including oxidative phosphorylation (OXPHOS) and aerobic glycolysis. This study investigates the role of Kruppel-like factor 4 (KLF4), a transcription factor, as a tumor suppressor in hepatocellular carcinoma (HCC) by regulating ATP synthesis. Immunohistochemistry was performed to assess KLF4 expression in HCC tissues. Functional assays, such as CCK-8, EdU, and colony formation, as well as in vivo assays, including subcutaneous tumor formation and liver orthotopic xenograft mouse models, were conducted to determine the impact of KLF4 on HCC proliferation. Luciferase reporter assay and chromatin immunoprecipitation assay were utilized to evaluate the interaction between KLF4, miR-206, and RICTOR. The findings reveal low KLF4 expression in HCC, which is associated with poor prognosis. Both in vitro and in vivo functional assays demonstrate that KLF4 inhibits HCC cell proliferation. Mechanistically, it was demonstrated that KLF4 reduces ATP synthesis in HCC by suppressing the expression of RICTOR, a core component of mTORC2. This suppression promotes glutaminolysis to replenish the TCA cycle and increase ATP levels, facilitated by the promotion of miR-206 transcription. In conclusion, this study enhances the understanding of KLF4's role in HCC ATP synthesis and suggests that targeting the KLF4/miR-206/RICTOR axis could be a promising therapeutic approach for anti-HCC therapeutics.

Targeting apoptosis in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cancer, accounting for approximately 80% of all renal cell cancers. Due to its exceptional inter- and intratumor heterogeneity, it is highly resistant to conventional systemic therapies. Targeting the evasion of cell death, one of cancer's hallmarks, is currently emerging as an alternative strategy for ccRCC. In this article, we review the current state of apoptosis-inducing therapies against ccRCC, including antisense oligonucleotides, BH3 mimetics, histone deacetylase inhibitors, cyclin-kinase inhibitors, inhibitors of apoptosis protein antagonists, and monoclonal antibodies. Although preclinical studies have shown encouraging results, these compounds fail to improve patients' outcomes significantly. Current evidence suggests that inducing apoptosis in ccRCC may promote tumor progression through apoptosis-induced proliferation, anastasis, and apoptosis-induced nuclear expulsion. Therefore, re-evaluating this approach is expected to enable successful preclinical-to-clinical translation.

Interaction between miR‑206 and lncRNA MALAT1 in regulating viability and invasion in hepatocellular carcinoma

MicroRNAs (miRNAs) are strongly associated to the progression of hepatocellular carcinoma (HCC), which presents a high potential for diagnosis and treatment; however, the role of miRNAs is still largely unknown. The aim of the present study was to examine the expression and the biological role of miRNA (miR)-206 in the development of HCC, and to identify the underlying molecular mechanism. Results from this study show that miR-206 was significantly downregulated in HCC tissues and cell lines. It was observed that low expression of miR-206 was linked to advanced TNM stage, tumor nodularity and venous infiltration in patients with HCC; low miR-206 expression was associated with shorter survival times. miR-206 overexpression using miR-206 mimics notably decreased the proliferative ability and increased apoptosis of MHCC97-H and HCCLM3 HCC cell lines. Overexpression of miR-206 suppressed invasiveness associated with reduced epithelial-mesenchymal transition. Moreover, the c-Met oncogene, which is upregulated in HCC tissues, was negatively associated with the expression of miR-206. Notably, it was shown that miR-206 may exert its antitumor effect through suppressing c-Met/Akt/mTOR signaling. Low expression of miR-206 was shown to be regulated by lncRNA MALAT1 in HCC. Collectively, this study presented evidence that miR-206 was controlled by lncRNA MALAT1 and partially suppressed the proliferation and invasion of HCC through the c-Met/Akt/mTOR signaling pathway. According to these results, understanding MALAT1/miR-206-dependent regulation may lead to potential approaches for diagnosis and prospective treatment of HCC.

The novel CDK9 inhibitor, XPW1, alone and in combination with BRD4 inhibitor JQ1, for the treatment of clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is a highly lethal malignancy with few therapeutic options. Cyclin‑dependent kinase 9 (CDK9), a potential therapeutic target of many cancers, has been recently observed to be upregulated in ccRCC patients. Therefore, we aimed to investigate the therapeutic potential of CDK9 in ccRCC and develop a novel CDK9 inhibitor with low toxicity for ccRCC treatment.

METHODS

The expression of CDK9 in ccRCC was checked using the online database and tissue microarray analysis. shRNA-mediated CDK9 knockdown and CDK inhibitor were applied to evaluate the effect of CDK9 on ccRCC. Medicinal chemistry methods were used to develop a new CDK9 inhibitor with drugability. RNA-seq and ChIP-seq experiments were conducted to explore the mechanism of action. MTS, western blotting, and colony formation assays were performed to evaluate the anti-ccRCC effects of CDK9 knockdown and inhibition in vitro. The in vivo anti-tumour efficacy was evaluated in a xenograft model.

RESULTS

CDK9 is overexpressed and associated with poor survival in ccRCC. Knockdown or inhibition of CDK9 significantly suppressed ccRCC cells. XPW1 was identified as a new potent and selective CDK9 inhibitor with excellent anti-ccRCC activity and low toxicity. In mechanism, XPW1 transcriptionally inhibited DNA repair programmes in ccRCC cells, resulting in an excellent anti-tumour effect. CDK9 and BRD4 were two highly correlated transcriptional regulators in ccRCC patients, and the BRD4 inhibitor JQ1 enhanced XPW1's anti-ccRCC effects in vitro and in vivo.

CONCLUSIONS

This work provides valuable insights into the therapeutic potential of CDK9 in ccRCC. The CDK9 inhibitor XPW1 would be a novel therapeutic agent for targeting ccRCC, alone or in rational combinations.

Epigenetically-regulated miR-30a/c-5p directly target TWF1 and hamper ccRCC cell aggressiveness

Clear cell renal cell carcinoma (ccRCC) is highly prone to metastasize and displays an extremely low 5-year survival rate. Not only miRNAs (miRs) are key gene expression regulators but can also be epigenetically modified. Abnormal miR expression has been linked with epithelial-mesenchymal transition (EMT)-driven ccRCC progression. MiR-30a/c-5p were found downregulated in ccRCC and associated with aggressiveness. Herein, we sought to unravel miR-30a/c-5p mechanistic role in ccRCC. RNA sequencing and genome-wide methylome data of ccRCC and normal tissue samples from The Cancer Genome Atlas database were integrated to identify candidate miRs cytosine-phosphate-guanine (CpG) loci deregulated in ccRCC. TargetScan was searched to identify miR putative targets. MiR-30a/c-5p expression and promoter methylation was evaluated in vitro, by PCR. Western blot, functional and luciferase assays were performed after cell transfection with either pre-miR, antimiR, or siRNA against twinfilin-1 (TWF1). Immunohistochemistry (IHC) was performed in ccRCC tissues. We found miR-30c-5p downregulation and aberrant promoter methylation in ccRCC tissues. In vitro studies revealed concomitant miR-30a/c-5p downregulation and increased promoter methylation, as well as a significant re-expression following decitabine treatment. Functional assays demonstrated that both miRs significantly decreased cell aggressiveness and the protein levels of EMT-promoting players, while upregulating epithelial markers, namely Claudin-1 and ZO-1. Importantly, we confirmed TWF1 as a direct target of both miRs, and its potential involvement in epithelial-mesenchymal transition/mesenchymal-epithelial transition regulation. IHC analysis revealed higher TWF1 expression in primary tissues from patients that developed metastases, after surgical treatment. Our results implicate miR-30a/c-5p in ccRCC cells' aggressiveness attenuation by directly targeting TWF1 and hampering EMT.

A review on the role of cyclin dependent kinases in cancers

The Cyclin-dependent kinase (CDK) class of serine/threonine kinases has crucial roles in the regulation of cell cycle transition and is mainly involved in the pathogenesis of cancers. The expression of CDKs is controlled by a complex regulatory network comprised of genetic and epigenetic mechanisms, which are dysregulated during the progression of cancer. The abnormal activation of CDKs results in uncontrolled cancer cell proliferation and the induction of cancer stem cell characteristics. The levels of CDKs can be utilized to predict the prognosis and treatment response of cancer patients, and further understanding of the function and underlying mechanisms of CDKs in human tumors would pave the way for future cancer therapies that effectively target CDKs. Defects in the regulation of cell cycle and mutations in the genes coding cell-cycle regulatory proteins lead to unrestrained proliferation of cells leading to formation of tumors. A number of treatment modalities have been designed to combat dysregulation of cell cycle through affecting expression or activity of CDKs. However, effective application of these methods in the clinical settings requires recognition of the role of CDKs in the progression of each type of cancer, their partners, their interactions with signaling pathways and the effects of suppression of these kinases on malignant features. Thus, we designed this literature search to summarize these findings at cellular level, as well as in vivo and clinical levels.

Therapeutic potential of CDK4/6 inhibitors in renal cell carcinoma

The treatment of advanced and metastatic kidney cancer has entered a golden era with the addition of more therapeutic options, improved survival and new targeted therapies. Tyrosine kinase inhibitors, mammalian target of rapamycin (mTOR) inhibitors and immune checkpoint blockade have all been shown to be promising strategies in the treatment of renal cell carcinoma (RCC). However, little is known about the best therapeutic approach for individual patients with RCC and how to combat therapeutic resistance. Cancers, including RCC, rely on sustained replicative potential. The cyclin-dependent kinases CDK4 and CDK6 are involved in cell-cycle regulation with additional roles in metabolism, immunogenicity and antitumour immune response. Inhibitors of CDK4 and CDK6 are now commonly used as approved and investigative treatments in breast cancer, as well as several other tumours. Furthermore, CDK4/6 inhibitors have been shown to work synergistically with other kinase inhibitors, including mTOR inhibitors, as well as with immune checkpoint inhibitors in preclinical cancer models. The effect of CDK4/6 inhibitors in kidney cancer is relatively understudied compared with other cancers, but the preclinical studies available are promising. Collectively, growing evidence suggests that targeting CDK4 and CDK6 in kidney cancer, alone and in combination with current therapeutics including mTOR and immune checkpoint inhibitors, might have therapeutic benefit and should be further explored.

Synthetic lethality of cyclin-dependent kinase inhibitor Dinaciclib with VHL-deficiency allows for selective targeting of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (CC-RCC) remains one of the most deadly forms of kidney cancer despite recent advancements in targeted therapeutics, including tyrosine kinase and immune checkpoint inhibitors. Unfortunately, these therapies have not been able to show better than a 16% complete response rate. In this study we evaluated a cyclin-dependent kinase inhibitor, Dinaciclib, as a potential new targeted therapeutic for CC-RCC. In vitro, Dinaciclib showed anti-proliferative and pro-apoptotic effects on CC-RCC cell lines in Cell Titer Glo, Crystal Violet, FACS-based cell cycle analysis, and TUNEL assays. Additionally, these responses were accompanied by a reduction in phospho-Rb and pro-survival MCL-1 cell signaling responses, as well as the induction of caspase 3 and PARP cleavage. In vivo, Dinaciclib efficiently inhibited primary tumor growth in an orthotopic, patient-derived xenograft-based CC-RCC mouse model. Importantly, Dinaciclib targeted both CD105⁺ cancer stem cells (CSCs) and CD105⁻ non-CSCs in vivo. Moreover, normal cell lines, as well as a CC-RCC cell line with re-expressed von-Hippel Lindau (VHL) tumor suppressor gene, were protected from Dinaciclib-induced cytotoxicity when not actively dividing, indicating an effective therapeutic window due to synthetic lethality of Dinaciclib treatment with VHL loss. Thus, Dinaciclib represents a novel potential therapeutic for CC-RCC.

MIMRDA: A Method Incorporating the miRNA and mRNA Expression Profiles for Predicting miRNA-Disease Associations to Identify Key miRNAs (microRNAs)

Identifying cancer-related miRNAs (or microRNAs) that precisely target mRNAs is important for diagnosis and treatment of cancer. Creating novel methods to identify candidate miRNAs becomes an imminent Frontier of researches in the field. One major obstacle lies in the integration of the state-of-the-art databases. Here, we introduce a novel method, MIMRDA, which incorporates the miRNA and mRNA expression profiles for predicting miRNA-disease associations to identify key miRNAs. As a proof-of-principle study, we use the MIMRDA method to analyze TCGA datasets of 20 types (BLCA, BRCA, CESE, CHOL, COAD, ESCA, HNSC, KICH, KIRC, KIRP, LIHC, LUAD, LUSC, PAAD, PRAD, READ, SKCM, STAD, THCA and UCEC) of cancer, which identified hundreds of top-ranked miRNAs. Some (as Category 1) of them are endorsed by public databases including TCGA, miRTarBase, miR2Disease, HMDD, MISIM, ncDR and mTD; others (as Category 2) are supported by literature evidences. miR-21 (representing Category 1) and miR-1258 (representing Category 2) display the excellent characteristics of biomarkers in multi-dimensional assessments focusing on the function similarity analysis, overall survival analysis, and anti-cancer drugs’ sensitivity or resistance analysis. We compare the performance of the MIMRDA method over the Limma and SPIA packages, and estimate the accuracy of the MIMRDA method in classifying top-ranked miRNAs via the Random Forest simulation test. Our results indicate the superiority and effectiveness of the MIMRDA method, and recommend some top-ranked key miRNAs be potential biomarkers that warrant experimental validations.

MicroRNA as a Biomarker for Diagnostic, Prognostic, and Therapeutic Purpose in Urinary Tract Cancer

The incidence of urologic cancers, including kidney, upper tract urothelial, and bladder malignancies, is increasing globally, with a high percentage of cases showing metastasis upon diagnosis and low five-year survival rates. MicroRNA (miRNA), a small non-coding RNA, was found to regulate the expression of oncogenes and tumor suppressor genes in several tumors, including cancers of the urinary system. In the current review, we comprehensively discuss the recently reported up-or down-regulated miRNAs as well as their possible targets and regulated pathways involved in the development, progression, and metastasis of urinary tract cancers. These miRNAs represent potential therapeutic targets and diagnostic/prognostic biomarkers that may help in efficient and early diagnosis in addition to better treatment outcomes.

MiR-1-3p and MiR-124-3p Synergistically Damage the Intestinal Barrier in the Ageing Colon

BACKGROUND AND AIMS

Disruption of the intestinal barrier of the digestive tract is a common pathophysiological change in the elderly, which may partly contribute to gut dysfunction and inflammatory bowel disease [IBD]. This study aimed to discover new interactive epigenetic regulation patterns involved in intestinal barrier dysfunction and colitis in elderly populations.

METHODS

Intestinal barrier function and structure were evaluated in naturally ageing mice and elderly people. High-throughput analysis was performed on colonic tissues from humans and mice. The synergistic roles of miR-1-3p and miR-124-3p were identified using microRNA mimic/agomirs. Related genes were examined in biopsies of old IBD patients.

RESULTS

A defective mucus barrier was observed before mucosal microstructural damage during ageing. Elevated miR-1-3p expression in the colons of older individuals impaired the mucus barrier by directly targeting T-synthase, similarly to the mechanism of miR-124-3p, which we reported previously. Importantly, the synergistic effect of a half dose of each microRNA supplement on T-synthase and CDK4/6 was stronger than that of a full dose of miR-1-3p or miR-124-3p alone, and mice co-treated with two microRNAs showed greater susceptibility to chemical-induced colitis than mice treated with either microRNA alone. These two microRNAs were up-expressed in old IBD patients.

CONCLUSIONS

The slight increases in miR-1-3p and miR-124-3p expression with ageing may be important contributors to the breakdown of intestinal homeostasis by targeting divergent genes in different cells. These data reveal the potential ability of multiple microRNAs to exert synergistic effects to damage the intestinal barrier and promote inflammatory bowel disease development in elderly populations.

MicroRNA-206 has a bright application prospect in the diagnosis of cases with oral cancer

Previous studies have shown that microRNA‐206 (miR‐206) exhibits anti‐tumour properties in various tumours. Nevertheless, diagnostic significance of miR‐206 in oral cancer is still poorly known. Our research was carried out to explore the performance of miR‐206 in the diagnosis of oral cancer. Quantitative real‐time polymerase chain reaction (qRT‐PCR) method was adopted to measure the level of miR‐206 in serum specimens from oral cancer cases and control individuals. Chi‐square test was performed to analyse the correlation between miR‐206 level and clinicopathological parameters of the cases. Receiver operating characteristic (ROC) curve was constituted to assess diagnostic accuracy of miR‐206 in oral cancer. Serum miR‐206 level in oral cancer patients was significantly lower than that in control individuals (P < .001). miR‐206 expression was obviously related to T classification (P = .033), TNM stage (P = .008) and lymph node metastasis (P = .028). The area under the curve (AUC) of the ROC curve was 0.846 (95% CI = 0.797‐0.896, P < .001) with a specificity of 72.7% and a sensitivity of 81.2%. It revealed that miR‐206 might be a non‐invasive indicator in differentiating oral cancer cases from control individuals. Down‐regulation of miR‐206 is related to the development of oral cancer. Serum miR‐206 might be an effective indicator for early detection of oral cancer.

Weighted Gene Coexpression Network Analysis to Construct Competitive Endogenous RNA Network in Chromogenic Renal Cell Carcinoma

Aim

This study is aimed at constructing the competing endogenous RNA (ceRNA) network in chromophobe renal cell carcinoma (ChRCC).

Methods

Clinical and RNA sequence profiles of patients with ChRCC, including messenger RNAs (mRNAs), microRNAs (miRNAs), and long noncoding RNAs (lncRNAs), were obtained from The Cancer Genome Atlas (TCGA) database. “edgeR” and “clusterProfiler” packages were utilized to obtain the expression matrices of differential RNAs (DERNAs) and to conduct gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Weighted gene coexpression network analysis (WGCNA) was performed to screen the highly related RNAs, and miRcode, StarBase, miRTarBase, miRDB, and TargetScan datasets were used to predict the connections between them. Univariate and multivariate Cox proportional hazards regressions were performed in turn to elucidate prognosis-related mRNAs in order to construct the ceRNA regulatory network.

Results

A total of 1628 DElncRNAs, 104 DEmiRNAs, and 2619 DEmRNAs were identified. WGCNA showed significant correlation in 1534 DElncRNAs, 98 DEmiRNAs, and 2543 DEmRNAs, which were related to ChRCC. Fourteen DEmiRNAs, 113 DElncRNAs, and 43 DEmRNAs were screened. Nine mRNAs (ALPL, ARHGAP29, CADM2, KIT, KLRD1, MYBL1, PSD3, SFRP1, and SLC7A11) significantly contributed to the overall survival (OS) of patients with ChRCC (P < 0.05). Furthermore, two mRNAs (CADM2 and SFRP1) appeared to be independent risk factors for ChRCC.

Conclusion

The findings revealed the molecular mechanism of ChRCC and potential therapeutic targets for the disease.

miR-34c inhibits PDGF-BB-induced HAVSMCs phenotypic transformation and proliferation via PDGFR-β/SIRT1 pathway

The purpose of this study was to explore the effect of miR-34c on PDGF-BB-induced HAVSMCs phenotypic transformation and proliferation via PDGFR-β/SIRT1 pathway, so as to find a new method for early diagnosis and treatment of cardiovascular disease. HA-VSMCs were treated with platelet-derived growth factor-BB (PDGF-BB) at 0 h, 12 h, 24 h, 48 h or 36 h to explore the optimal time for phenotypic transformation of VSMCs. And then, PDGF-BB-induced HA-VSMCs were transfected with miR-34c mimics/mimics NC and pcDNA3.1-PDGFR-β/pcDNA3.1-NC to observe cell biological behaviour. CCK8 was used to detect cell proliferation activity. Transwell chamber assay was used to detect cell invasion. Early apoptosis was analyzed by flow cytometry. The expression of α-SMA and Smemb was detected by immunofluorescence staining. The expressions of PDGFR-β, IRF9, Acetyl-NF-κB/p65, Acetyl-p53 and CyclinD1 were analyzed by Western blot analysis. The expression of miR-34a, miR-34b and miR-34c was detected by RT-PCR, and the targeting relationship between miR-34c and PDGFR-β was detected by luciferase reporting assay. The results indicated the proliferation and migration of PDGF-BB-induced HA-VSMCs significantly increased, and apoptosis significantly decreased. Besides, α-SMA decreased significantly, while Smemb increased significantly. Furthermore, expressions of PDGFR-β, IRF9, Acetyl-NF-κB/p65, Acetyl-p53 and CyclinD1 increased significantly, and SIRT1 decreased significantly. Experimental results showed that, miR-34c mimics significantly inhibited cell proliferation and migration, and promoted cell apoptosis, and miR-34c inhibitor had the opposite effects. MiR-34c mimics significantly increased α-SMA expression and decreased Smemb expression, while the opposite effects were reflected after transfection with miR-34c inhibitor. Moreover, miR-34c mimics significantly decreased the expressions of PDGFR-β, IRF9, Acetyl-NF-κB/p65, Acetyl-p53 and CyclinD1, and significantly increased the expression of SIRT1, while miR-34c inhibitor had the opposite effects. Luciferase assay confirmed that PDGFR-β was a potential target of miR-34c. Subsequently, PDGF-BB-induced HA-VSMCs were co-transfected with miR-34c mimics and pcDNA3.1-PDGFR-β. The results indicated that PDGFR-β reversed the biological function of miR-34c mimic. The results revealed the potential application value of miR-34c as a marker molecule of phenotypic transformation, providing a potential target for improving phenotypic transformation.

What we can learn from embryos to understand the mesenchymal-to-epithelial transition in tumor progression

Epithelial plasticity involved the terminal and transitional stages that occur during epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET), both are essential at different stages of early embryonic development that have been co-opted by cancer cells to undergo tumor metastasis. These processes are regulated at multiple instances, whereas the post-transcriptional regulation of key genes mediated by microRNAs is gaining major attention as a common and conserved pathway. In this review, we focus on discussing the latest findings of the cellular and molecular basis of the less characterized process of MET during embryonic development, with special attention to the role of microRNAs. Although we take in consideration the necessity of being cautious when extrapolating the obtained evidence, we propose some commonalities between early embryonic development and cancer progression that can shed light into our current understanding of this complex event and might aid in the design of specific therapeutic approaches.

Clear Cell Renal Carcinoma: MicroRNAs With Efficacy in Preclinical In Vivo Models

In order to identify new targets and treatment modalities for clear cell renal carcinoma, we surveyed the literature with respect to microRNAs involved in this disease. In this review, we have focused on up- and down-regulated miRs which mediate efficacy in preclinical clear-cell renal carcinoma-related in vivo models. We have identified 10 up-regulated and 33 down-regulated micro-RNAs according to this criterion. As proof-of-concept, micro-RNAs interfering with VEGF (miR-205p) and mTOR (mir-99a) pathways, which are modulated by approved drugs for this disease, have been identified. miRs targeting hypoxia induced factor-2α (HIF-2α) (miR-145), E3 ubiquitinylases speckle-type POZ protein (SPOP) (miR 520/372/373) and casitas B-lineage lymphoma (CBL) (miR-200a-3p), interfere with druggable targets. Further identified miRs interfere with cell-cycle dependent kinases, such as CDK2 (miR-200c), CDK4, 6 (miR-1) and CDK4, 9 (206c). Transmembrane receptor Ral interacting protein of 76 kD (RLIP76), targeted by mir-137, has emerged as another important target for ccRCC. Additional miRs and their targets merrying further preclinical validation are discussed.

Long Non-Coding RNA ZNF667-AS1 Knockdown Curbs Liver Metastasis in Acute Myeloid Leukemia by Regulating the microRNA-206/AKAP13 Axis

BACKGROUND

Zinc finger protein 667-antisense RNA 1 (ZNF667-AS1), a long non-coding RNA (lncRNA), plays important parts in tumorigenesis and development of esophageal squamous cell carcinoma, but its function in acute myeloid leukemia (AML) is unknown. Our goal here was to probe the functional mechanism of ZNF667-AS1 in AML by mediating microRNA-206 (miR-206)/A-kinase anchoring protein 13 (AKAP13) axis.

MATERIALS AND METHODS

The bone marrow samples from AML patients and controls were selected for microarray analysis to select significantly upregulated lncRNAs. Next, effects of ZNF667-AS1 on cell aggressiveness of AML were assessed after delivery of cells with siRNA against ZNF667-AS1. Subcellular fractionation location assay and FISH experiments were used to determine ZNF667-AS1 localization in cells. Dual-luciferase experiments detect the targeting relationships among ZNF667-AS1, miR-206 and AKAP13. Finally, tumor growth and metastasis were evaluated in vivo to determine the relevance of ZNF667-AS1/miR-206/AKAP13 axis.

RESULTS

The expression of ZNF667-AS1 was upregulated in AML patients, which predicted poor prognosis. Downregulation of ZNF667-AS1 reduced cell proliferation, invasion, tumorigenesis and metastasis. miR-206 inhibitor reversed the repressive role of ZNF667-AS1 knockdown in cell proliferation, invasion and tumorigenesis, while AKAP13 silencing flattened the stimulative role of miR-206 inhibitor in AML malignant aggressiveness. Mechanistically, we demonstrated that ZNF667-AS1 functioned as a molecular sponge for miR-206. In addition, we observed that Wnt/β-catenin pathway was suppressed by ZNF667-AS1 knockdown.

CONCLUSION

ZNF667-AS1 potentiated AML progression by targeting the miR-206/AKAP13 axis. This indicates ZNF667-AS 1 inhibition may act as a prospective therapeutic option for the treatment of AML.

A novel miR-206/hnRNPA1/PKM2 axis reshapes the Warburg effect to suppress colon cancer growth

Alternative splicing of pyruvate kinase gene (PKM) results in a higher PKM2/PKM1 ratio that contributes to the Warburg effect and reversing the Warburg effect has opened novel avenues for cancer treatment. miR-206 functions as a tumor suppressor in several types of cancer. However, the effect and underlying mechanisms of miR-206 on the Warburg effect are not yet elucidated. Here, we showed that miR-206 expression was obviously decreased in CRC tissues based on LinkedOmics. A significant decrease in miR-206 expression was negatively correlated with advanced tumor stage, while inversely correlated with overall survival in CRC patients. Ectopic overexpression of miR-206 has dramatically restricted the cell proliferation, glucose consumption and lactate production in CRC cells, whereas transfection of miR-206 inhibitor exhibited the opposite results. Furthermore, miR-206 overexpression induced switching from PKM2 to PKM1 via modulating alternative splicing of PKM gene. The alternative splicing factor hnRNPA1 is identified as the direct functional target of miR-206. Mechanistically, miR-206 overexpression directly targeted hnRNPA1 to suppress PKM2 expression to attenuate Warburg effect and cell proliferation of CRC. Importantly, the restoration of hnRNPA1 expression mostly abrogated the miR-206-meditated Warburg effect. Collectively, these results revealed that the novel miR-206/hnRNPA1/PKM2 axis plays a pivotal role in the Warburg effect to modulate CRC progression.

Bone marrow mesenchymal stem cell-derived exosomal miR-206 inhibits osteosarcoma progression by targeting TRA2B

Osteosarcoma is the most common primary malignant bone tumor in young people. Recently, extracellular vesicles, especially exosomes, have been reported to play an increasingly important role in the development of many types of tumors. In this research, we found that overexpression of transformer 2β (TRA2B) was associated with tumor progression in osteosarcoma, and TRA2B was the target gene of miR-206, which was downregulated in osteosarcoma tissues. Furthermore, we observed that bone marrow mesenchymal stem cell (BMSC)-derived exosomes could carry and transport miR-206 to osteosarcoma cells. Both in vitro and in vivo results showed that BMSC-derived exosomal miR-206 could inhibit the proliferation, migration and invasion of osteosarcoma cells and induce their apoptosis. Taken together, our study demonstrates that BMSC-derived exosomal miR-206 can be transferred into osteosarcoma cells and inhibit tumor progression by targeting TRA2B, which provides new insight into the molecular mechanism of osteosarcoma and highlights the potential of miR-206 and TRA2B as new therapeutic targets.

CDK9 as an Appealing Target for Therapeutic Interventions

Cyclin Dependent Kinase 9 (CDK9) as a serine/threonine kinase belongs to a great number of CDKs. CDK9 is the main core of PTEF-b complex and phosphorylates RNA polymerase (RNAP) II besides other transcription factors which regulate gene transcription elongation in numerous physiological processes. Multi-functional nature of CDK9 in diverse cellular pathways proposes that it is as an appealing target. In this review, we summarized the recent findings on the molecular interaction of CDK9 with critical participant molecules to modulate their activity in various diseases. Furthermore, the presented review provides a rationale supporting the use of CDK9 as a therapeutic target in clinical developments for crucial diseases; particularly cancers will be reviewed.

Long non-coding RNA HOTAIR as a competitive endogenous RNA to sponge miR-206 to promote colorectal cancer progression by activating CCL2

Colorectal cancer (CRC) is one of the common malignant tumors, the incidence of which is on rise. LncHOTAIR, considered as an oncogene, contributed to the progression of a lot of cancers. However, the molecular mechanism and biological functions of the HOTAIR/miR-206/CCL2 axis have not been reported before. Here, our research aimed to explore HOTAIR/miR-206/CCL2 axis in CRC to demonstrate its role in predicting the poor prognosis of CRC. LncHOTAIR, miR-206 and CCL2 mRNA were detected in CRC tissues and cells by RT-PCR. The interactions among LncHOTAIR, miR-206 and CCL2 were explored by luciferase reporter assay, qRT-PCR, western blot and RNA interfere. Flow Cytometry Cell Analysis was performed to detect cell cycle and apoptosis as well as colony assay was prepared to test the cell proliferation. Immunohistochemical analysis was used to detect the CCL2 protein in CRC tissues. In our study, silence of LncHOTAIR by RNA interference could suppress the proliferation, migration and invasion of CRC cells. Mechanistically, LncHOTAIR downregulated miR-206 abundance which indicated that LncHOTAIR was considered as a competing endogenous RNA (ceRNA) by directly sponging miR-206 in CRC cells. In addition, further exploration suggested that miR-206 could inhibit the function of the downstream CCL2, the expression of which was repressed by LncHOTAIR/miR-206 signaling. Furthermore, we verified that the overexpression of CCL2 attenuated CRC cell proliferation, migration, invasion. Overall, this study firstly elucidated that LncHOTAIR played as oncogene in CRC via directly sponging miR-206 to activate the downstream CCL2, which would be considered as the novel therapeutic target in CRC.

MiR-206 may suppress non-small lung cancer metastasis by targeting CORO1C

Object

Non-small lung cancer (NSCLC), with a poor 5-year survival rate (16%), is the major type of lung cancer. Metastasis has been identified as the main factor that leads to NSCLC therapy failure. MiR-206 is a metastasis suppressor in many cancers, including colorectal cancer, renal cell carcinoma and breast cancer. However, the role of miR-206 in NSCLC metastasis and the underlying mechanism are still obscure.

Methods

Quantitative reverse-transcription PCR (q-RT-PCR) assay was used to detect miR-206 mRNA of NSCLC tissues and lung cancer lines. The MTT assay, scratch wound healing assay, transwell migration assay and transwell invasion assay were conducted to illuminate the effect of miR-206 on A549 cells’ proliferation, migration and invasion. Gaussia luciferase reporter assay, q-RT-PCR and western blotting assay were used to explore the underlying mechanism. Also, the A549 xenograft model was conducted to evaluate the anti-tumor effect of miR-206 in vivo.

Results

The results showed that miR-206 expression was decreased in NSCLC tissues and lung cancer cells. Further research demonstrated that miR-206 inhibited the proliferation, migration and invasion of A549 cells via negatively regulating Coronin-1C (CORO1C), and CORO1C deletion significantly rescues the miR-206 mediated inhibitory effect on A549 cells. Moreover, miR-206 exhibited a perfect anti-tumor effect in the A549 xenograft model.

Conclusion

Our study reveals that miR-206 functions as a tumor metastasis suppressor and sheds new light on the clinical significance of miR-206 in NSCLC therapy.

Effects of photoelectric therapy on proliferation and apoptosis of scar cells by regulating the expression of microRNA-206 and its related mechanisms

Human skin fibroblast (HSF) cells were irradiated with different energy lasers to detect cell proliferation, apoptosis, and expression of microRNA-206 and protein, and to further summarise the therapeutic effect of laser on scar cells. Human scar cell line HSF cells were cultured in three groups. The control group was not irradiated by laser, the low-energy group was irradiated by 10 J/cm² laser, and the high-energy group was irradiated by 20 J/cm² laser. After irradiation, HSF cells were cultured for 20 hours. Cell proliferation was detected by MTT assay. Cell cycle and apoptosis were detected by flow cytometry. Transwell migration assay was used to detect cell migratory ability. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect miR-206 and mTOR gene levels. The levels of MMP-9, Bax, Bcl-2, cyclin D1, and mTOR signalling pathway proteins were detected by Western blotting assays. The results showed that after laser irradiation, the proliferation of cells decreased, and the difference between the control group and the experimental group was significant (P < .05). The higher the energy was, the greater the upregulation of apoptosis was. Apoptosis and cell migration increased (P < .05). The expressions of microRNA-206, MMP-9, and Bax were upregulated, while the expressions of mTOR, Bcl-2, and cyclin D1 were downregulated. To sum up, laser irradiation can significantly inhibit the proliferation of HSF cells, affect cell cycle, and increase cell apoptosis and migratory ability.

Sonodynamic Therapy Combined to 2-Deoxyglucose Potentiate Cell Metastasis Inhibition of Breast Cancer

Metastasis is a major dilemma of cancer therapy. It frequently occurs in breast cancer, which is the leading form of malignant tumor among females worldwide. Although there are therapies that provide a possible method for this challenge, such as chemotherapy, the tumoral metabolic pathway is unconventional and favors metastasis and proliferation. This magnifies the difficulty of treating breast cancer. In this study, we identified 2-deoxyglucose (2 DG) as an important glycolysis suppressor that can potentiate sonodynamic therapy (SDT) to inhibit migration and invasion. In addition, disruptions of the cell membrane microstructure were captured by a scanning electron microscope in cells treated with the co-therapy. Similarly, we detected blockages of the cell cycle process, using flow cytometry. Of note, we observed that hexokinase II (HK2), the rate-limiting enzyme of glycolysis, was notably uncoupled from the mitochondria in SDT + 2 DG co-therapy group. Furthermore, there was altered expression of HK2 and Glut1, which control glycolysis. Simultaneously, the in vivo results revealed that pulmonary metastasis was also seriously suppressed by SDT + 2 DG co-therapy. These results demonstrate this co-therapy is a promising strategy for breast cancer inhibition through metastasis and proliferation.

Suppression of MALAT1 ameliorates chronic constriction injury-induced neuropathic pain in rats via modulating miR-206 and ZEB2

Long noncoding RNAs (lncRNAs) are involved in multiple nervous system diseases, including neuropathic pain. Previous studies have demonstrated that lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified as a diagnostic biomarker in many diseases. Nevertheless, the function of MALAT1 in neuropathic pain progression is still unclear. Here, we established a chronic constriction injury (CCI) rat model. We found that MALAT1 was remarkably upregulated in CCI rats. In addition, neuropathic pain behaviors such as mechanical and thermal hyperalgesia were reduced by the inhibition of MALAT1. Meanwhile, the loss of MALAT1 was able to depress the neuroinflammation process via the inhibition of COX-2, interleukin-1β, and interleukin-6. A previous study has indicated that miR-206 upregulation can restrain the CCI-induced neuropathic pain. Furthermore, we exhibited that miR-206 was significantly downregulated and silence of MALAT1 restrained its expression in CCI rats. For another, ZEB2 was a target of miR-206 and it was shown that ZEB2 was elevated in CCI rats in a time-dependent manner. Overexpression of miR-206 obviously suppressed ZEB2 levels in rat microglial cells. Subsequently, it was demonstrated that upregulation of miR-206 rescued the neuropathic pain triggered by ZEB2 overexpression in vivo through neuroinflammation inhibition. Overall, we indicated that suppression of MALAT1 ameliorated neuropathic pain progression via miR-206/ZEB2 axis.

Identification of a lncRNA‑associated competing endogenous RNA‑regulated network in clear cell renal cell carcinoma

Long noncoding RNAs (lncRNAs) act as competing endogenous RNAs (ceRNAs) in the regulation of gene expression in various physiological and pathological processes. The present study aimed to explore the lncRNA-miRNA-mRNA interactions in clear cell renal cell carcinoma (ccRCC) using comprehensive bioinformatics analysis. RNA-seq data were downloaded from the TCGA Data Portal, and the differentially expressed lncRNAs (DElncRs), miRNAs (DEmiRs), and mRNAs (DEGs) between tumoral and control samples were identified using the edgeR package. The correlations between the DemiR/DElncR expression levels and clinical features were evaluated using nonparametric regression analysis. The Kaplan-Meier method was used to identify DElncRs associated with overall survival time. Then, the DElncR-DEmiR interaction pairs were predicted using miRcode and the starBase v2.0 database, and DEmiR-DEG pairs were predicted using the miRTarBase database. Then, a ceRNA-regulated network of ccRCC was constructed based on these interactions. Genes in the network were also assigned to functional categories in the KEGG pathway database. A total of 1,573 DEGs, 37 DelncRs, and 62 DEmiRs were identified. Moreover, several DElncRs were significantly associated with patient clinical variables; for example, TCL6 was significantly associated with tumor grade and AJCC pathological stage. Next, 38 pairs of DElncR-DEmiR interactions (13 DElncRs and 8 DEmiRs) were identified. Among the 8 DEmiRs that target DElncRs, six were found to target DEGs. Based on the identified DElncR-DEmiR interactions and DEmiR-DEG interactions, a ceRNA-regulated network comprising 203 nodes and 221 edges was constructed (with MIC >0.15 and MIC-p² >0.15). The novel lncRNAs, DGCR5, MYCNOS, and PART1 may participate in the progression of ccRCC through cytochrome P450-mediated drug metabolism.

Expression of microRNA-3133 correlates with the prognosis in patients with clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) represents a prevalent urological malignancy among men worldwide. MicroRNAs (miRNAs) are involved in the progression of diverse human cancers. The aim of this study was to explore the expression profile and prognostic value of microRNA-3133 (miR-3133) in ccRCC.The expression of miR-3133 in ccRCC tissues and non-cancerous tissues was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Chi-square test was applied to evaluate the relationship between miR-3133 expression and clinical characteristics. Overall survival curve was constructed by Kaplan-Meier with log-rank test. The prognostic value of miR-3133 in ccRCC was estimated by Cox regression analysis.MiR-3133 was downregulated in ccRCC samples compared to the matched noncancerous samples (P <.01). Moreover, its expression level was correlated with T stage, vascular invasion and lymph node metastasis (all P <.05). Survival curves demonstrated that patients with low level of miR-3133 underwent lower overall survival than those with high level (log rank test, P = .002). MiR-3133 might be an independent prognostic biomarker in ccRCC patients (HR = 2.802, 95% CI = 1.391-5.646, P = .004).MiR-3133 is downregulated, and plays inhibitory roles in aggressive progression of ccRCC. MiR-3133 may be an independent prognostic biomarker for ccRCC.

MicroRNA signature predicts survival in papillary thyroid carcinoma

Papillary thyroid cancer (PTC) accounts for the majority of malignant thyroid tumors. Recently, several microRNA (miRNA) expression profiling studies have used bioinformatics to suggest miRNA signatures as potential prognostic biomarkers in various malignancies. However, a prognostic miRNA biomarker has not yet been established for PTC. The aim of the present study was to identify miRNAs with prognostic value for the overall survival (OS) of patients with PTC by analyzing high-throughput miRNA data and their associated clinical characteristics downloaded from The Cancer Genome Atlas database. From our dataset, 150 differentially expressed miRNAs were identified between tumor and nontumor samples; of these miRNAs, 118 were upregulated and 32 were downregulated. Among the 150 differentially expressed miRNAs, a four miRNA signature was identified that reliably predicts OS in patients with PTC. This miRNA signature was able to classify patients into a high-risk group and a low-risk group with a significant difference in OS (P < .01). The prognostic value of the signature was validated in a testing set ( P < .01). The four miRNA signature was an independent prognostic predictor according to the multivariate analysis and demonstrated good performance in predicting 5-year disease survival with an area under the receiver operating characteristic curve area under the curve (AUC) score of 0.886. Thus, this signature may serve as a novel biomarker for predicting the survival of patients with PTC.

Identification of prognostic biomarkers in colorectal cancer using a long non-coding RNA-mediated competitive endogenous RNA network

Colorectal cancer (CRC) is a highly malignant gastrointestinal tumor accompanied by poor prognosis. Long non-coding RNA (lncRNA) plays an important role in the progression and physiology of tumors as it competes with endogenous RNAs, including miRNA and mRNA. In the present study, a multi-step computational method was used to build a CRC-related functional lncRNA-mediated competitive endogenous RNA (ceRNA) network (LMCN). lncRNAs with more degrees and betweenness centrality (BC) were screened out as hub lncRNAs. Then functional enrichment analyses of lncRNAs were carried out from the Gene Ontology (GO) and Reactome pathway databases based on the 'guilt by association' principle. As a result, lncRNAs in the LMCN displayed specific topological characteristics in accordance with the regulatory correlation of coding mRNAs in CRC pathology. HCP5, EPB41L4A-AS1, SNHG12, and LINC00649 were screened out as hub lncRNAs which were more significantly related to the development and prognosis of CRC. The hub lncRNAs in CRC were obviously involved in functions of cell cycle arrest, vacuolar transport, histone modification, and in pathways of GPCR, signaling by Rho GTPases, axon guidance pathways, meaning that they might be potential biomarkers for diagnosis, evaluation and gene-targeted therapy of CRC. Thus, the LMCN construction method could accelerate lncRNA discovery and therapeutic development in CRC.

Spatio-Temporal Expression and Functional Analysis of miR-206 in Developing Orofacial Tissue

BACKGROUND

Development of the mammalian palate is dependent on precise, spatiotemporal expression of a panoply of genes. MicroRNAs (miRNAs), the largest family of noncoding RNAs, function as crucial modulators of cell and tissue differentiation, regulating expression of key downstream genes.

OBSERVATIONS

Our laboratory has previously identified several developmentally regulated miRNAs, including miR-206, during critical stages of palatal morphogenesis. The current study reports spatiotemporal distribution of miR-206 during development of the murine secondary palate (gestational days 12.5-14.5).

RESULT AND CONCLUSION

Potential cellular functions and downstream gene targets of miR-206 were investigated using functional assays and expression profiling, respectively. Functional analyses highlighted potential roles of miR-206 in governing TGFß- and Wnt signaling in mesenchymal cells of the developing secondary palate. In addition, altered expression of miR-206 within developing palatal tissue of TGFß3-/- fetuses reinforced the premise that crosstalk between this miRNA and TGFß3 is crucial for secondary palate development.

miR-625-3p promotes migration and invasion and reduces apoptosis of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common malignancy, yet, the mechanisms underlying tumorigenesis remain unclear. Several miRNAs have been implicated in the development of RCC previously via regulation of target gene expression. As miR-625-3p has recently been identified to play a role in development of other malignancies and is reportedly upregulated in ccRCC, we sought to investigate the role of this miRNA in the progression of ccRCC. Analysis of 30 paired fresh ccRCC tissues and adjacent normal renal tissues revealed that the expression of miR-625-3p was increased in ccRCC tissues compared to normal tissues. Subsequently, in 136 formalin-fixed paraffin-embedded ccRCC tissues, the increased miR-625-3p expression was correlated with poor prognosis for ccRCC patients. The diagnostic value of miR-625-3p was identified in 50 ccRCC patients and 74 healthy controls by ROC curve. miR-625-3p was decreased in serum of ccRCC patients compared to healthy individuals. miR-625-3p could serve as a promising serum biomarker for yielding an area under the receiver operating characteristic curve of 0.792 with 70.3% sensitivity and 80.0% specificity in discriminating ccRCC from healthy individuals. Using in vitro functional assays, we found that overexpression of miR-625-3p promoted migration and invasion of ccRCC cells but reduced ccRCC cell apoptosis. Inhibition of miR-625-3p, on the other hand, exerted the opposite effects. Bioinformatic analyses indicated that predicted gene targets of miR-625-3p are correlated with lower overall survival of ccRCC patients. Together, these findings demonstrate that miR-625-3p promotes ccRCC migration and invasion and reduces apoptosis, providing a prognostic marker for survival and a potential diagnostic and therapeutic target against ccRCC.

LncRNA RMRP silence curbs neonatal neuroblastoma progression by regulating microRNA-206/tachykinin-1 receptor axis via inactivating extracellular signal-regulated kinases

BACKGROUND

Neuroblastoma is the commonest malignancy in neonates. Long non-coding RNA (lncRNA) RNA component of mitochondrial RNA processing endoribonuclease (RMRP) has been reported to be an oncogenic factor in some malignancies. However, its roles and molecular mechanisms in neuroblastoma progression are poor defined.

METHODS

The expression of RMRP, microRNA-206 (miR-206), and tachykinin-1 receptor (TACR1) mRNA was measured by RT-qPCR assay. Protein levels of TACR1, phosphorylated extracellular signal-regulated kinases (ERK) 1/2 (p-ERK1/2) and ERK1/2 were detected by western blot assay. Cell proliferation was assessed by CCK-8 and colony formation assays. Cell migratory and invasive capacities were determined using Transwell migration and invasion assays. The interaction between miR-206 and RMRP or TACR1 was verified by luciferase assay. The roles and molecular mechanisms of RMRP knockdown on the growth of neuroblastoma xenografts were examined in vivo.

RESULTS

RMRP was highly expressed in neuroblastoma tissues. RMRP knockdown inhibited proliferation, migration and invasion in neuroblastoma cells. Moreover, TACR1 was a target of miR-206 and RMRP performed as a molecular sponge of miR-206 to sequester miR-206 from TACR1 in neuroblastoma cells. TACR1 overexpression abrogated the inhibitory effect of RMRP downregulation on neuroblastoma cell progression by activating ERK1/2 pathway. Inhibition of TACR1 and ERK1/2 pathway abated RMRP-mediated pro-proliferation effect in neuroblastoma cells. RMRP knockdown hindered neuroblastoma xenograft growth by regulating miR-206/TACR1 axis via inactivating ERK1/2 pathway in vivo.

CONCLUSION

RMRP knockdown hindered the tumorigenesis and progression of neuroblastoma by regulating miR-206/TACR1 axis via inactivating ERK1/2 pathway, hinting a potential therapeutic target for neuroblastoma.

MicroRNA‑206 exerts anti‑oncogenic functions in esophageal squamous cell carcinoma by suppressing the c‑Met/AKT/mTOR pathway

Increasing evidence suggests that the dysregulation of microRNAs (miRNAs) has an important role in the progression of human cancer, including ESCC. However, the exact functions and mechanisms of miRNAs in ESCC remain largely unclear. The aim of the present study was to investigate the expression and biological functions of miRNAs in ESCC and reveal the underlying molecular mechanisms. miRNA microarray and reverse transcription-quantitative polymerase chain reaction analyses were performed, which identified and confirmed that miR-206 was significantly downregulated in ESCC tissues and cell lines. Its low expression was associated with lymph node metastasis, advanced TNM stage and N classification, as well as poorer overall survival in patients with ESCC. CCK-8 and flow cytometry assays demonstrated that ectopic miR-206 expression inhibited ESCC cell proliferation and induced cell apoptosis. In addition, MET proto-oncogene, receptor tyrosine kinase (c-Met), a well-known oncogene, was a direct target of miR-206. An inverse correlation between the levels of miR-206 and c-Met mRNA in ESCC tissue samples was confirmed. Notably, c-Met overexpression inhibited the effects of miR-206 on the proliferation and apoptosis of ESCC cells. Additionally, it was confirmed that the tumor-suppressive functions of miR-206 may have contributed to the inactivation of the c-Met/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway. In conclusion, the findings of the present study suggested that miR-206 exerts its anti-cancer functions via the c-Met/AKT/mTOR signaling pathway, providing a novel candidate prognostic factor and a potential therapeutic target in ESCC.

The oncomir face of microRNA-206: A permanent miR-206 transfection study

MiR-206 is a remarkable miRNA because it functions as a suppressor miRNA in rhabdomyosarcoma while at the same time, as previously showed, it can act as an oncomiRNA in SMARCB1 immunonegative soft tissue sarcomas. The aim of this study was to investigate the effect of miR-206 on its several target genes in various human tumorous and normal cell lines. In the current work, we created miR-206-overexpressing cell lines (HT-1080, Caco2, iASC, and SS-iASC) using permanent transfection. mRNA expression of the target genes of miR-206 (SMARCB1, ACTL6A, CCND1, POLA1, NOTCH3, MET, and G6PD) and SMARCB1 protein expression were examined with quantitative real-time polymerase chain reaction, immunoblotting, immunocytochemistry, and flow cytometry. MiRNA inhibition was used to validate our results. We found a diverse silencing effect of miR-206 on its target genes. While an overall tendency of downregulation was noted, expression profiles of individual cell lines showed large variability. Only CCND1 and MET were consistently downregulated. MiR-206 had an antiproliferative effect on a normal human fibroblast cell line. A strong silencing effect of SMARCB1 in miR-206 transfected SS-iASC was most likely caused by the synergic influence of the SS18-SSX1 fusion protein and miR-206. In the same cell line, a moderate decrease of SMARCB1 protein expression could be observed with immunocytochemistry and flow cytometry. In the most comprehensive analysis of miR-206 effects so far, a modest but significant downregulation of miR-206 targets on the mRNA level was confirmed across all cell lines. However, the variability of the effect shows that the action of this miRNA is largely cell context-dependent. Our results also support the conception that the oncomiR effect of miR-206 on SMARCB1 plays an important but not exclusive role in SMARCB1 immunonegative soft tissue sarcomas so it can be considered important in planning the targeted therapy of these tumors in the future. Impact statement Mir-206 is a very unique microRNA because it can act as a suppressor miRNA or as an oncomiRNA depending on the tumor tissue. In SMARCB1 negative soft tissue sarcomas miR-206 is overexpressed, so thus in epithelioid and synovial sarcomas it functions as an oncomiRNA. MiR-206 has diverse silencing effects on its target genes. We found that the action of miR-206 is largely cell context dependent. The oncomiR role of miR-206 is crucial but not exclusive in SMARCB1 negative soft tissue sarcomas and miR-206 has an antiproliferative effect on a normal human fibroblast cell line. Expressions of miR-206 targets observed in tumors can only be reproduced in the corresponding tumorous cell lines. This is the first study which examined the permanent effect of miR-206 on its target genes in normal, tumor, and genetically engineered cell lines.

Integrative analysis of the inter-tumoral heterogeneity of triple-negative breast cancer

Triple-negative breast cancers (TNBC) lack estrogen and progesterone receptors and HER2 amplification, and are resistant to therapies that target these receptors. Tumors from TNBC patients are heterogeneous based on genetic variations, tumor histology, and clinical outcomes. We used high throughput genomic data for TNBC patients (n = 137) from TCGA to characterize inter-tumor heterogeneity. Similarity network fusion (SNF)-based integrative clustering combining gene expression, miRNA expression, and copy number variation, revealed three distinct patient clusters. Integrating multiple types of data resulted in more distinct clusters than analyses with a single datatype. Whereas most TNBCs are classified by PAM50 as basal subtype, one of the clusters was enriched in the non-basal PAM50 subtypes, exhibited more aggressive clinical features and had a distinctive signature of oncogenic mutations, miRNAs and expressed genes. Our analyses provide a new classification scheme for TNBC based on multiple omics datasets and provide insight into molecular features that underlie TNBC heterogeneity.

MALAT1 induces osteosarcoma progression by targeting miR-206/CDK9 axis

Long noncoding RNAs (LncRNAs) have been reported to participate in cancer development, including osteosarcoma. Here, in our study, we observed that lncRNA metastasis-associated lung adenocarcinoma transcription 1 (MALAT1) was remarkably overexpressed in osteosarcoma. However, the role it plays in osteosarcoma proliferation mediated by miR-206/cyclin-dependent kinase 9 (CDK9) axis remains uninvestigated. It was found that miR-206 was decreased and CDK9 was elevated in human osteosarcoma cells including MG63, Saos-2, U2OS, and KHOS compared with human osteoblast cell line hFOB 1.19. In addition, it was exhibited that knockdown of MALAT1 was able to inhibit osteosarcoma cell proliferation, which suggested that MALAT1 played an oncogenic role in osteosarcoma development. Bioinformatics analysis indicated that MALAT1 can function as a competing endogenous RNA by sponging miR-206. Because miR-206 has been identified as a significant tumor suppressive gene in multiple cancers, we validated that mimics of miR-206 can restrain osteosarcoma progression. Furthermore, dual-luciferase reporter assay, RNA binding protein immunoprecipitation, and RNA pull-down assay demonstrated the correlation between miR-206 and MALAT1. Besides these, CDK9 was predicted as a downstream gene of miR-206, and we observed that MALAT1 can regulate osteosarcoma progress by modulating CDK9 expression via sponging miR-206. In conclusion, our study implied that MALAT1/miR-206/CDK9 axis can provide novel insights into the biological mechanism of osteosarcoma progression.

RETRACTED: Down-regulation of miR-373 increases the radiosensitivity of lung cancer cells by targeting TIMP2

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. The image analysis run on the Western blots in Figures 4 and 6 revealed that the images have been manipulated. Manipulating images in any part of a publication is ethically not acceptable.

Long noncoding RNA gastric cancer-related lncRNA1 mediates gastric malignancy through miRNA-885-3p and cyclin-dependent kinase 4

Gastric cancer (GC) is one of the most common malignancy and the third leading cancer-related death in China. Long noncoding RNAs (lncRNAs) have been implicated in numerous tumors, including GC, however, the mechanism of many functional lncRNAs is still unclear. In this study, we identified the abundantly expressed lncRNA, RP11-290F20.3, in GC cells and patient tumor tissues. We named this lncRNA as GC-related lncRNA1 (GCRL1), which could regulate gastric cell proliferation and metastasis, both in vitro and in vivo. Mechanistically, miRNA-885-3p (miR-885-3p) could inhibit the cell proliferation and metastasis in GC by negatively regulating the expression of cyclin-dependent kinase 4 (CDK4) at the post-transcriptional level. Further, GCRL1 promoted the cell proliferation and metastasis by sponging miR-885-3p and hence, positively regulating CDK4 in GC cells. Taken together, our results demonstrate a novel regulatory axis of malignant cell proliferation and invasion in GC, comprising GCRL1, miR-885-3p, and CDK4, which may serve as a potential therapeutic target in GC.

Tumor suppressor microRNA-136-5p regulates the cellular function of renal cell carcinoma

MicroRNAs (miRs) are involved in diverse physiological and developmental processes at the post-transcriptional level in cells. Previous studies have demonstrated that miR-136-5p is involved in certain types of cancer. However, the function of miR-136-5p in renal cell carcinoma (RCC) remains to be fully elucidated. In present study, miR-136-5p expression levels were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and MTT assays, CCK-8 assays, Transwell assays, wound healing assays and flow cytometry were performed to investigate the function of miR-136-5p in RCC. RT-qPCR revealed that the expression of miR-136 was significantly lower in RCC tissues and cells compared with adjacent non-tumor tissues and cells in vitro. miR-136-5pwas also demonstrated to be associated with RCC cell proliferation, viability, migration, invasion and apoptosis. miR-136-5p may therefore function as a tumor suppressor in RCC. Further studies are required to elucidate the molecular mechanisms and signaling pathways underlying these functions of miR-136-5p, to investigate the potential function of miR-136-5p as a biomarker for the early detection and prognosis of RCC, and its potential as a therapeutic target for the treatment of RCC.

MicroRNA-206 regulates the epithelial-mesenchymal transition and inhibits the invasion and metastasis of prostate cancer cells by targeting Annexin A2

The present study investigated the molecular mechanism by which microRNA-206 (miR-206) targets Annexin A2 (ANXA2) expression and inhibits the invasion and metastasis of prostatic cancer cells through regulation of the epithelial-mesenchymal transition (EMT). Using bioinformatics analysis, miR-206 was identified as the most promising candidate miRNA that targeted ANXA2. Prostate tissue specimens from 60 patients with prostate cancer, 30 patients with metastatic prostate cancer and 20 patients with benign prostatic hyperplasia (BPH) were examined for ANXA2 protein expression by immunohistochemistry and western blotting and for miR-206 expression by reverse transcription-quantitative polymerase chain reaction. Additionally, human prostate cancer PC-3 cells were transfected with miR-206 mimics, miR-206 inhibitors or a negative control sequence, and expression of ANXA2, E-cadherin and N-cadherin was detected by western blotting. Transwell assays were performed to determine the effect of altered miR-206 expression on the invasive behavior of PC-3 cells. Bioinformatics analysis predicted complementary binding between miR-206 and ANXA2 mRNA. ANXA2 protein expression was detected in a significantly higher proportion of BPH tissues (95%, 19/20) when compared with prostate cancer tissues (51.7%, 31/60; P<0.05). Similarly, ANXA2 was expressed in a significantly higher proportion of metastatic prostate cancer samples than that of prostate cancer samples (P<0.05). Expression of miR-206 was higher than that of ANXA2 in prostate cancer samples, but lower in BPH samples. Inhibition of miR-206 expression in PC-3 cells upregulated ANXA2 and E-cadherin protein expression levels, downregulated N-cadherin and vimentin, and promoted cell invasion in vitro. These data suggested that binding between miRNA-206 and ANXA2 mRNA may regulate EMT signaling, thereby suppressing the invasion and metastasis of prostatic cancer cells.

MicroRNA-1 suppresses proliferation, migration and invasion by targeting Notch2 in esophageal squamous cell carcinoma

MicroRNAs play an important role in the migration and invasion of tumors, and lower expression of microRNA-1 (miR-1) has been proven in a variety of malignant tumors, including esophageal squamous cell carcinoma (ESCC). In this study, we found that miR-1 expression levels in tumor tissues and preoperative serum from esophageal carcinoma patients were lower than those in non-tumorous tissues and healthy volunteers. miR-1 expression in tissues and plasma was closely related to invasion, lymph node metastasis and TNM staging. Additionally, miR-1 expression levels in tissues and plasma were positively correlated. miR-1 inhibited cell proliferation, migration and invasion. Overexpression of miR-1 in ESCC cells reduced Notch2 protein but not mRNA levels, whereas suppression of miR-1 led to an increase in Notch2 protein but not mRNA levels. A dual-luciferase experiment validated that Notch2 was a direct target of miR-1. Introducing Notch2 mRNA into cells over-expressing miR-1 partially abrogated the effects of miR-1 on migration and invasion. Further studies verified that miR-1 regulates EMT signalling pathways directly through Notch2. Therefore, these results confirm that, as a tumor suppressor gene, miR-1 may be a potential tumor marker for the early diagnosis of ESCC and a new drug target.

Blood and lung microRNAs as biomarkers of pulmonary tumorigenesis in cigarette smoke-exposed mice

Cigarette smoke (CS) is known to dysregulate microRNA expression profiles in the lungs of mice, rats, and humans, thereby modulating several pathways involved in lung carcinogenesis and other CS-related diseases. We designed a study aimed at evaluating (a) the expression of 1135 microRNAs in the lung of Swiss H mice exposed to mainstream CS during the first 4 months of life and thereafter kept in filtered air for an additional 3.5 months, (b) the relationship between lung microRNA profiles and histopathological alterations in the lung, (c) intergender differences in microRNA expression, and (d) the comparison with microRNA profiles in blood serum. CS caused multiple histopathological alterations in the lung, which were almost absent in sham-exposed mice. An extensive microRNA dysregulation was detected in the lung of CS-exposed mice. Modulation of microRNA profiles was specifically related to the histopathological picture, no effect being detected in lung fragments with non-neoplastic lung diseases (emphysema or alveolar epithelial hyperplasia), whereas a close association occurred with the presence and multiplicity of preneoplastic lesions (microadenomas) and benign lung tumors (adenomas). Three microRNAs regulating estrogen and HER2-dependent mechanisms were modulated in the lung of adenoma-bearing female mice. Blood microRNAs were also modulated in mice affected by early neoplastic lesions. However, there was a poor association between lung microRNAs and circulating microRNAs, which can be ascribed to an impaired release of mature microRNAs from the damaged lung. Studies in progress are evaluating the feasibility of analyzing blood microRNAs as a molecular tool for lung cancer secondary prevention.

Serum miR-122-5p and miR-206 expression: non-invasive prognostic biomarkers for renal cell carcinoma

Background

MicroRNAs (miRNA) play a relevant role in carcinogenesis, cancer progression, invasion, and metastasis. Thus, they can serve as diagnostic/prognostic biomarkers. The knowledge on circulating miRNAs for clear cell renal cell carcinomas (ccRCC) is limited. Our study was designed to identify novel biomarkers for ccRCC patients.

Results

The serum small RNA expression profile was determined in 18 ccRCC and 8 patients with benign renal tumors (BRT) using small RNA sequencing. We detected 29 differentially expressed miRNAs (17 upregulated and 12 downregulated in ccRCC) in the expression profiling cohort. Based on the expression levels, we next validated serum miR-122-5p, miR-193a-5p, and miR-206 levels in an independent cohort (68 ccRCC, 47 BRT, and 28 healthy individuals) using quantitative real-time PCR. Serum expression levels of miR-122-5p and miR-206 were significantly decreased in ccRCC compared to healthy individuals. Both miRNAs were circulating at similar levels in ccRCC and BRT patients. miR-193a-5p expression levels were not different within the study cohort. High serum miR-122-5p and miR-206 levels were associated with adverse clinicopathological parameters: miR-122-5p levels were correlated with metastatic RCC and grade, and miR-206 with pT-stage and metastasis. Furthermore, high miR-122-5p and miR-206 serum levels were associated with a shorter period of progression-free, cancer-specific, and overall survival in patients with ccRCC.

Conclusion

We identified serum miR-122-5p and miR-206 as novel non-invasive prognostic biomarkers for patients with ccRCC.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0444-9) contains supplementary material, which is available to authorized users.

miR-206 Inhibits Cell Proliferation, Migration, and Invasion by Targeting BAG3 in Human Cervical Cancer

miR-206 and Bcl-2-associated athanogene 3 (BAG3) have been suggested as important regulators in various cancer types. However, the biological role of miR-206 and BAG3 in cervical cancer (CC) remains unclear. We investigated the expressions and mechanisms of miR-206 and BAG3 in CC using in vitro and in vivo assays. In the present study, miR-206 expression was expressed at a lower level in CC tissues and cells than adjacent normal tissues and NEECs. By contrast, BAG3 mRNA and protein were expressed at higher levels in CC tissues and cells. Furthermore, miR-206 overexpression repressed cell proliferation, migration, and invasion in vitro, and the 3′-untranslated region (3′-UTR) of BAG3 was a direct target of miR-206. miR-206 overexpression also inhibited EGFR, Bcl-2, and MMP2/9 protein expression, but promoted Bax protein expression. Besides, BAG3 overexpression partially abrogated miR-206-inhibited cell proliferation and invasion, while BAG3 silencing enhanced miR-206-mediated inhibition. In vivo assay revealed that miR-206 repressed tumor growth in nude mice xenograft model. In conclusion, miR-206 inhibits cell proliferation, migration, and invasion by targeting BAG3 in human CC. Thus, miR-206-BAG3 can be used as a useful target for CC.

miRNAs in Prediction of Prognosis in Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common type of urinary malignancy. Clear cell renal cell carcinoma (ccRCC) is the predominant RCC subtype, accounting for 70-80% of RCC. In recent years, miRNAs have been found to be closely associated with the outcome of the patients with ccRCC. In this review, we summarize recent advances in research exploring the role of miRNAs in predicting prognosis in patients with ccRCC.

Downregulation of lizard immuno-genes in the regenerating tail and myogenes in the scarring limb suggests that tail regeneration occurs in an immuno-privileged organ

Amputated tails of lizards regenerate while limbs form scars which histological structure is very different from the original organs. Lizards provide useful information for regenerative medicine and some hypotheses on the loss of regeneration in terrestrial vertebrates. Analysis of tail and limb transcriptomes shows strong downregulation in the tail blastema for immunoglobulins and surface B and T receptors, cell function, and metabolism. In contrast, in the limb blastema genes for myogenesis, muscle and cell function, and extracellular matrix deposition but not immunity are variably downregulated. The upregulated genes show that the regenerating tail is an embryonic organ driven by the Wnt pathway and non-coding RNAs. The strong inflammation following amputation, the non-activation of the Wnt pathway, and the upregulation of inflammatory genes with no downregulation of immune genes indicate that the amputated limb does not activate an embryonic program. Intense inflammation in limbs influences in particular the activity of genes coding for muscle proteins, cell functions, and stimulates the deposition of dense extracellular matrix proteins resulting in scarring limb outgrowths devoid of muscles. The present study complements that on upregulated genes, and indicates that the regenerating tail requires immune suppression to maintain this embryonic organ connected to the rest of the tail without be rejected or turned into a scar. It is hypothesized that the evolution of the adaptive immune system determined scarring instead of organ regeneration in terrestrial vertebrates and that lizards evolved the process of tail regeneration through a mechanism of immuno-evasion.

Long non-coding RNA Lucat1 is a poor prognostic factor and demonstrates malignant biological behavior in clear cell renal cell carcinoma

Background

Many long intergenic noncoding RNAs (lincRNAs) are encoded in the human genome. However, their biological functions, molecular mechanisms and prognostic values associated with clear cell renal cell carcinoma (ccRCC) have yet to be elucidated.

Methods

We screened the lncRNAs’ profile in ccRCC from The Cancer Genome Atlas (TCGA) database, and selected Lucat1 for further study. MTS, colony formation assay and transwell assay were performed to examine the effect of Lucat1 on proliferation and metastasis of ccRCC. The Chip and Rip assay was performed to verify that Lucat1 can bind to polycomb PRC2 complex and suppress p57 expression.

Results

In this study, we found that lncRNA Lucat1 expression was significantly up regulated in tumor tissues compared to matched adjacent non-tumor tissues. The Lucat1 expression level was also associated with grade, the clinical pathological stage and the survival time. Functional assays showed that Lucat1 can promote renal cancer cell proliferation in vitro and in vivo. Further analysis showed that Lucat1 can bind to polycomb PRC2 complex and suppress p57 expression.

Conclusions

Taken together, our results suggest that Lucat1, as a regulator of proliferation, may serve as a candidate prognostic biomarker and target for novel therapies in human ccRCC.

miR-206 inhibits the growth of hepatocellular carcinoma cells via targeting CDK9

miR‐206 plays an important role in regulating the growth of multiple cancer cells. Cyclin‐dependent kinase 9 (CDK9) stimulates the production of abundant prosurvival proteins, leading to impaired apoptosis of cancer cells. However, it is unknown whether CDK9 is involved in the miR‐206‐mediated growth suppression of hepatocellular carcinoma (HCC) cells. In this study, we found that the expression level of miR‐206 was significantly lower in HCC cell lines than that in normal hepatic cell line (L02). Meanwhile, CDK9 was upregulated in HCC cell lines. Moreover, miR‐206 downregulated CDK9 in HCC cells via directly binding to its mRNA 3′ UTR, which resulted in a decrease of RNA PolII Ser2 phosphorylation and Mcl‐1 level. Additionally, miR‐206 suppressed the cell proliferation, and induced cell cycle arrest and apoptosis. Similarly, silence or inhibition of CDK9 also repressed the cell proliferation, and induced cell cycle arrest and apoptosis. Taken together, the results demonstrated that miR‐206 inhibited the growth of HCC cells through targeting CDK9, suggesting that the miR‐206‐CDK9 pathway may be a novel target for the treatment of HCC.