MicroRNA-618 modulates cell growth via targeting PI3K/Akt pathway in human thyroid carcinomas

Correlation between the miR-618 rs2682818 C>A polymorphism and venous malformation susceptibility

Venous malformations are the most common congenital vascular malformations, and the incidence rate is high. Previous studies have confirmed that a variety of polymorphisms within the miRNA functional region are associated with tumor susceptibility. We examined the correlation between miR-618 rs2682818 C>A and risk of developing venous malformation in a southern Chinese population (1113 patients and 1158 controls). TaqMan genotyping of miR-618 rs2682818 C>A was conducted utilizing real-time fluorescent quantitative PCR. The miR-618 rs2682818 polymorphism was not correlated with susceptibility to venous malformation (CA/AA vs. CC: adjusted odds ratio [AOR] = 1.00, 95% confidence interval [CI] = 0.81-1.25, p = 0.994; AA vs. CC/CA: AOR = 1.10, 95% CI = 0.73-1.65, p = 0.646). Stratified analysis of different subtypes of venous malformation revealed that there was no significant difference in the rs2682818 C>A polymorphism genotypes across these subtypes. Our results indicate that miR-618 rs2682818 C>A polymorphism is not correlated with the susceptibility to venous malformation.

NGS-based profiling identifies miRNAs and pathways dysregulated in cisplatin-resistant esophageal cancer cells

Esophageal cancer (EC) incidence remains to be on a global rise supported by an unchanged recurrence and 5-year survival rate owing to the development of chemoresistance. Resistance to cisplatin, one of the majorly used chemotherapeutic drugs in EC, is a major nuisance. This study sheds light on miRNA dysregulation and its inverse relation with dysregulated mRNAs to guide pathways into the manifestation of cisplatin resistance in EC. A cisplatin-resistant version of an EC cell line was established and comparative profiling by NGS with the parental cell line was employed to identify dysregulation in miRNA and mRNA levels. Protein-protein interaction network analysis was done using Cytoscape, followed by Funrich pathway analysis. Furthermore, selective significant miRNAs were validated using qRT-PCR. miRNA-mRNA integrated analysis was carried out using the Ingenuity Pathway Analysis (IPA) tool. Expression of various established resistance markers supported the successful establishment of cisplatin-resistant cell line. Whole-cell small RNA sequencing and transcriptome sequencing identified 261 miRNAs and 1892 genes to be significantly differentially expressed (DE), respectively. Pathway analysis indicated enrichment of EMT signaling, supported by NOTCH, mTOR, TNF receptor, and PI3K-mediated AKT signaling pathways, in chemoresistant cells. Validation by qRT-PCR confirmed upregulation of miR-10a-5p, miR-618, miR-99a-5p, and miR-935 and downregulation of miR-335-3p, miR-205-5p, miR-944, miR-130a-3p, and miR-429 in resistant cells. Pathway analysis that followed IPA analysis indicated that the dysregulation of these miRNAs and their target genes may be instrumental in the development and regulation of chemoresistance via p53 signaling, xenobiotic metabolism, and NRF2-mediated oxidative stress. This study concludes the interplay between miRNA and mRNA as an important aspect and occurrence in guiding the regulation, acquisition, and maintenance of chemoresistance in esophageal cancer in vitro.

Polymorphism rs2682818 participates in the progression of colorectal carcinoma via miR-618-TIMP1 regulatory axis

Colorectal carcinoma (CRC) has a high morbidity and mortality. Current studies have confirmed a variety of microRNA polymorphisms were associated with tumor susceptibility, however, the mechanisms are still unknown. In this study, we were aimed to clarify how polymorphism rs2682818 participated in the progression of CRC. First of all, the differential expression of miR-618 was assessed by quantitative real-time polymerase chain reaction in CRC patients with different genotypes of polymorphism rs2682818, including homozygous (TT) genotype, homozygous (GG) genotype and heterozygous (TG) genotype. Secondly, plasmids carried miR-168 precursor sequences harboring rs2682818 (SNP type) or without rs2682818 (wild type) were transfected into 293T cells to verify that polymorphism rs2682818 affected miR-618 expression. Thirdly, CCK-8 assay, flow cytometry assay, transwell assay and mouse xenograft assay were performed to measure the biological functions of miR-618 in CRC. Fourthly, the candidate target genes of miR-618 which were predicted by bioinformatics tools were verified by luciferase reporter assay. Finally, in order to explain the potential molecular mechanisms, western blotting was performed to demonstrate the differential expression and phosphorylation of pathway related proteins. The results showed that miR-618 was down-regulated in colon cancer, especially in CRC patients with rs2682818 GG homozygous genotype. Higher expression of mature miR-618 occurred in patients with TT homozygous genotype, and these patients usually had a longer survival time. Moreover, miR-618 mimic obviously impaired the growth and invasion ability of CRC cells, and miR-618 mimic also remarkably promoted CRC cell apoptosis. Our luciferase experiments confirmed that TIMP1 was a target of miR-618 in CRC cells. Knockdown of TIMP1 also significantly inhibited the malignant cytological features of CRC, including malignant growth and invasion as well as apoptosis resistance. In summary, polymorphism rs2682818 participated in the progression of CRC via affecting the expression of mature miR-618 in CRC cells, and miR-618 inhibited the progression of CRC via targeting TIMP1expression.

Crosstalk between miRNA and PI3K/AKT/mTOR signaling pathway in cancer

Phosphoinositide-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway is one of the most important proliferative signaling pathways with critical undeniable function in various aspects of cancer initiation/progression, including proliferation, apoptosis, metastasis, angiogenesis, and drug resistance. On the other hand, numerous genetic alterations in the key genes involved in the PI3K/AKT/mTOR signaling pathway have been identified in multiple solid and hematological tumors. In addition, accumulating recent evidences have demonstrated a reciprocal interaction between this signaling pathway and microRNAs, a large group of small non-coding RNAs. Therefore, in this review, it was attempted to discuss about the interaction between key components of PI3K/AKT/mTOR signaling pathway with various miRNAs and their importance in cancer biology.

Circulating miR-618 Has Prognostic Significance in Patients with Metastatic Colon Cancer

The present study evaluated the prognostic role of circulating miRNA-618 in patients with metastatic colon cancer (mCC) and whether miR-618 gene rs2682818 single nucleotide polymorphisms (SNP) are associated with colon cancer susceptibility and expression levels of mature miR-618. In total, 104 patients with mCC before starting the chemotherapy were investigated. The expression status of circulating miR-618 in mCC was evaluated by quantitative PCR. TaqMan PCR assay was used for rs2682818 SNP genotyping. miR-618 was overexpressed in serum of mCC patients. Patients with high and intermediate expression of miR-618 had a significantly longer mean overall survival (OS) of 21 months than patients with low expression—16 months. In addition, multivariate Cox regression analysis confirmed the association between high/intermediate levels of miRNA-618 and longer OS, HR = 0.51, 95% CI: 0.30–0.86, p = 0.012. miR-618 rs2682818 SNP significantly decreased the risk of colon cancer susceptibility in both heterozygous codominant (AC vs. CC, OR = 0.39, 95% CI: 0.17–0.88, p = 0.024) and overdominant (AC vs. CC + AA, OR = 0.37, 95% CI: 0.16–0.85, p = 0.018) genetic models. Our data suggest that circulating miRNA-618 could be useful as a prognostic biomarker in mCC. Patients harboring AC rs2682818 genotype have a decreased risk for colon cancer in comparison with patients with CC and AA genotypes.

MicroRNA Analysis of ATM-Deficient Cells Indicate PTEN and CCDN1 as Potential Biomarkers of Radiation Response

Genetic and epigenetic profile changes associated with individual radiation sensitivity are well documented and have led to enhanced understanding of the mechanisms of the radiation-induced DNA damage response. However, the search continues to identify reliable biomarkers of individual radiation sensitivity. Herein, we report on a multi-biomarker approach using traditional cytogenetic biomarkers, DNA damage biomarkers and transcriptional microRNA (miR) biomarkers coupled with their potential gene targets to identify radiosensitivity in ataxia-telangiectasia mutated (ATM)-deficient lymphoblastoid cell lines (LCL); ATM-proficient cell lines were used as controls. Cells were 0.05 and 0.5 Gy irradiated, using a linear accelerator, with sham-irradiated cells as controls. At 1 h postirradiation, cells were fixed for γ-H2AX analysis as a measurement of DNA damage, and cytogenetic analysis using the G2 chromosomal sensitivity assay, G-banding and FISH techniques. RNA was also isolated for genetic profiling by microRNA (miR) and RT-PCR analysis. A panel of 752 miR were analyzed, and potential target genes, phosphatase and tensin homolog (PTEN) and cyclin D1 (CCND1), were measured. The cytogenetic assays revealed that although the control cell line had functional cell cycle checkpoints, the radiosensitivity of the control and AT cell lines were similar. Analysis of DNA damage in all cell lines, including an additional control cell line, showed elevated γ-H2AX levels for only one AT cell line. Of the 752 miR analyzed, eight miR were upregulated, and six miR were downregulated in the AT cells compared to the control. Upregulated miR-152-3p, miR-24-5p and miR-92-15p and all downregulated miR were indicated as modulators of PTEN and CCDN1. Further measurement of both genes validated their potential role as radiation-response biomarkers. The multi-biomarker approach not only revealed potential candidates for radiation response, but provided additional mechanistic insights into the response in AT-deficient cells.

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.

Long Non-Coding RNA HOTAIR Modulates KLF12 to Regulate Gastric Cancer Progression via PI3K/ATK Signaling Pathway by Sponging miR-618

Purpose

Long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) has been reported to dysregulate in many tumors. However, the mechanism of HOTAIR was rarely reported in GC.

Methods

The levels of HOTAIR, microRNA-618 (miR-618) and Krueppel-like factor 12 (KLF12) in GC tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The cell viability and apoptotic rate were assessed via cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The migrating and invading abilities were tested by Transwell assay. The protein levels of KLF12, p-PI3K, PI3K, p-ATK and ATK were measured by Western blot assay. These interactions between miR-618 and HOTAIR or KLF12 were predicted by DIANA tools, and then, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to validate these interactions. Besides, the xenograft tumor experiment was performed to further verify the roles of HOTAIR in GC.

Results

The levels of HOTAIR and KLF12 were significantly upregulated and the level of miR-618 was strikingly downregulated in GC tissues and cells. miR-618 was verified as a direct target of HOTAIR or KLF12. HOTAIR silencing blocked GC progression and PI3K/ATK signaling pathway by sponging miR-618 and also restrained xenograft tumor growth in vivo. miR-618 inhibited GC progression and PI3K/ATK signaling pathway by targeting KLF12. Mechanistically, HOTAIR modulated KLF12 expression by sponging miR-618 in GC cells.

Conclusion

These data unraveled that HOTAIR promoted GC progression through PI3K/ATK signaling pathway via miR-618/KLF12 axis.

MicroRNA-618 Directly Targets Metadherin mRNA To Suppress The Malignant Phenotype Of Osteosarcoma Cells By Reducing PTEN-AKT Pathway Output

Purpose

Dysregulation of microRNA-618 (miR-618) has been observed in multiple types of human cancer. However, whether miR-618 is implicated in osteosarcoma (OS) initiation and progression is still unclear. Hence, we measured the expression of miR-618 in OS tissues and cell lines. In addition, the roles of miR-618 and the mechanisms underlying its activities in OS cells were examined.

Methods

The expression status of miR-618 in OS was analyzed by reverse-transcription quantitative PCR. The regulatory roles of miR-618 overexpression in OS were explored by the Cell Counting Kit-8 assay, flow-cytometric analysis, Transwell cell migration and invasion assays, and a tumor xenograft experiment.

Results

The results revealed that the expression of miR-618 was notably lower in OS tissues and cell lines, and that the low miR-618 expression significantly correlated with the clinical stage and distant metastasis among patients with OS. Exogenous miR-618 expression significantly suppressed OS cell proliferation, migration, and invasion and induced apoptosis in vitro as well as slowed tumor growth in vivo. Mechanism investigation indicated that metadherin (MTDH) is a direct target gene of miR-618 in OS cells. A knockdown of MTDH mimicked the tumor-suppressive effects of miR-618 upregulation on OS cells. Notably, resumption of MTDH expression attenuated the miR-618–mediated reduction in OS cell growth and metastasis in vitro. In addition, miR-618 overexpression reduced the PTEN–AKT pathway output in OS cells both in vitro and in vivo through downregulation of MTDH.

Conclusion

To the best of our knowledge, this is the first study to show that miR-618 exerts crucial tumor-suppressive actions in OS pathogenesis by directly targeting MTDH mRNA and reducing PTEN–AKT pathway output. These results will help to elucidate the functions of miR-618 in OS and suggest that this miRNA may be investigated as a therapeutic target in this disease.

Long intergenic non-protein coding RNA 511 promotes the progression of osteosarcoma cells through sponging microRNA 618 to upregulate the expression of maelstrom

Osteosarcoma is a tumor disease that commonly exists among young populations. Our research explored the role of the LINC00511/microRNA-618/MAEL axis in osteosarcoma.Expression profiles of long non-coding RNAs (lncRNAs) in osteosarcoma (OS) tissues were constructed, and LINC00511 expression levels were verified with qRT-PCR. LncRNA-miRNA and miRNA-mRNA interactions were predicted. Validation was performed using a dual-luciferase reporter assay. Protein expression levels of MAEL were evaluated by Western blot assays. The effects of LINC00511, miR-618 and MAEL on the proliferation, viability, and metastasis of OS cells were detected using colony formation, cell counting kit-8 (CCK-8) and transwell assays, respectively. The apoptosis rates of OS cells were investigated using flow cytometry. The tumor-suppressing effect of LINC00511 silencing was also analyzed using a xenograft model in nude mice.LINC00511 overexpression was observed in OS tissues and cell lines. Knockdown of LINC00511 in nude mice inhibited the tumorigenic ability of OS cells. Transfection-induced overexpression of LINC00511 and MAEL, as well as downregulation, highlighted the features of tumor cells, and LINC00511 overexpression reduced apoptosis in vitro.LINC00511 was confirmed to be beneficial for osteosarcoma development via sponging miR-618 and increasing MAEL expression and may thus be considered a potential target for osteosarcoma therapy.

Altered Epigenetic Mechanisms in Thyroid Cancer Subtypes

Thyroid carcinoma (TC) is the most frequent malignant neoplasm of the endocrine system. Molecular methods for diagnosis of invasive thyroid disease can be effectively adopted. Epigenetic factors play an important role in the diversity patterns of gene expression and the phenotypic and biological characteristics of TC subtypes. We aimed to review epigenetic changes in the main subtypes of TC, along with a presentation of the methods that have examined these changes, and active clinical trials for the treatment of advanced TCs targeting epigenetic changes. A literature analysis was performed in MEDLINE using PubMed, Elsevier, and Google Scholar for studies published up to 2016, using the keywords: "Epigenetic alterations" OR "Epigenetic changes", "thyroid cancers", "papillary thyroid cancer", "medullary thyroid cancer", "follicular thyroid cancer", and "anaplastic thyroid cancer", which resulted in 310 articles in English. All related abstracts were reviewed and studies were included that were published in English, had available full text, and determined the details of the methods and materials associated with the epigenetic patterns of TC and its subtypes (100 articles). Analysis of epigenetic alterations in TC subtypes helps to identify pathogenesis and can play an important role in the classification and diagnosis of tumors. Epigenetic mechanisms, especially aberrant methylation of DNA and microRNAs (miRs), are likely to play an important role in thyroid tumorigenesis. Further studies are required to elucidate the role of histone modification mechanisms in TC development.

A miRNA signature suggestive of nodal metastases from laryngeal carcinoma

The discovery that miRNAs are frequently deregulated in tumours offers the opportunity to identify them as prognostic and diagnostic markers. The aim of this multicentric study is to identify a miRNA expression profile specific for laryngeal cancer. The secondary endpoint was to identify specific deregulated miRNAs with potential as prognostic biomarkers for tumour spread and nodal involvement, and specifically to search for a miRNA pattern pathognomonic for N+ laryngeal cancer and for N- tissues. We identified 20 miRNAs specific for laryngeal cancer and a tissue-specific miRNA signature that is predictive of lymph node metastases in laryngeal carcinoma characterised by 11 miRNAs, seven of which are overexpressed (upregulated) and four downregulated. These results allow the identification of a group of potential specific tumour biomarkers for laryngeal carcinoma that can be used to improve its diagnosis, particularly in early stages, as well as its prognosis.

Epigenetic modifications in poorly differentiated and anaplastic thyroid cancer

Well-differentiated thyroid cancer accounts for the majority of endocrine malignancies and, in general, has an excellent prognosis. In contrast, the less common poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC) are two of the most aggressive human malignancies. Recently, there has been an increased focus on the epigenetic alterations underlying thyroid carcinogenesis, including those that drive PDTC and ATC. Dysregulated epigenetic candidates identified include the Aurora group, KMT2D, PTEN, RASSF1A, multiple non-coding RNAs (ncRNA), and the SWI/SNF chromatin-remodeling complex. A deeper understanding of the signaling pathways affected by epigenetic dysregulation may improve prognostic testing and support the advancement of thyroid-specific epigenetic therapies. This review outlines the current understanding of epigenetic alterations observed in PDTC and ATC and explores the potential for exploiting this understanding in developing novel therapeutic strategies.

Overexpression of ING5 inhibits HGF-induced proliferation, invasion and EMT in thyroid cancer cells via regulation of the c-Met/PI3K/Akt signaling pathway

The inhibitor of growth 5 (ING5), a novel member of the ING family, is involved in diverse biological processes such as cell growth, apoptosis and DNA repair. Recently, ING5 has been reported to be associated with cancer development. However, its specific role in thyroid cancer has yet to be elucidated. In this study, we found that the expression of ING5 was significantly down-regulated in human thyroid cancer tissues and cell lines. In addition, overexpression of ING5 markedly inhibited hepatocyte growth factor (HGF)-induced proliferation, invasion and epithelial-mesenchymal transition (EMT) of thyroid cancer cells as well as suppressed the tumor growth and metastasis in vivo. Furthermore, our data showed that the c-Met/PI3K/Akt signaling pathway was responsible for the inhibitory effect of ING5 on the thyroid cancer. Taken together, these findings provided an essential basis for the tumor-suppression role of ING5 in thyroid cancer.