miR-181b as a key regulator of the oncogenic process and its clinical implications in cancer (Review)

HES1 in cancer: a key player in tumorigenesis and its prognostic significance

The dysregulation of transcriptional regulators is a critical feature in the progression of many malignancies. Hairy and enhancer of split homolog-1 (HES1), a member of the basic helix-loop-helix (bHLH) gene family, has emerged as a key player in tumorigenesis due to its regulatory roles in multiple cellular pathways. This review aims to systematically explore the relevance of HES1 in cancer development, emphasizing its activation through major signaling pathways such as Notch, Hedgehog, hypoxia, and Wnt, and its contribution to advanced tumor progression. Numerous studies have demonstrated that HES1 upregulates genes associated with stemness, proliferation, and metastasis, and its expression correlates with poor clinicopathological features, including enhanced tumor proliferation, self-renewal, migration, metastasis, and drug resistance. Furthermore, HES1 has been frequently identified as a downstream effector of critical oncogenic pathways, further consolidating its role in aggressive cancers. Based on current evidence, HES1 holds promise as both a prognostic biomarker and a potential therapeutic target in various lethal malignancies. A deeper understanding of HES1's molecular mechanisms could pave the way for the development of targeted interventions aimed at improving cancer outcomes.

Exploring recent advances in signaling pathways and hallmarks of uveal melanoma: a comprehensive review

The purpose of this review was to provide a comprehensive review of the latest insights on the pathogenesis of uveal melanoma (UM) and its intracellular pathways. This article covers the epidemiology of UM, racial predispositions, cytogenetic and chromosomal alterations, gene mutations, key defective pathways, and their underlying mechanisms, as well as the application of hallmarks of cancer to UM. A key knowledge gap remains in identifying the most effective targeted therapy and determining the central pathway linking multiple signaling networks. UM is a malignant tumor arising from uveal melanocytes, predominantly affecting the choroid, with both genetic and epigenetic contributors. Key cytogenetic alterations include monosomy 3, chromosome 6p gain, chromosome 1p loss, and chromosome 8q gain. The most important UM-related signaling pathways are RAS/MAPK, PI3K/Akt/mTOR, Hippo-YAP, retinoblastoma (Rb), and p53 pathways. In the RAS/MAPK pathway, GNAQ/GNA11 mutations occur which account for more than 80% of UM cases. The PI3K/Akt/mTOR pathway promotes cyclin D1 overexpression and MDM2 upregulation, leading to p53 pathway inhibition. GNAQ/GNA11 mutations activate YAP via the Trio-RhoGTPase/RhoA/Rac1 signaling circuit in the Hippo-YAP pathway. Rb pathway dysregulation results from cyclin D1 overexpression or cyclin-dependent kinase inhibitor (CDKI) inactivation. In the p53 pathway, UM is characterized by p53 mutations, MDM2 overexpression, and Bcl-2 deregulation. Eventually, the ARF-MDM2 axis serves as a critical link between the RAS and p53 pathways. Hallmarks of cancer, such as evasion of growth suppression and self-sufficiency in growth signals, are also evident in UM. Genetic and epigenetic alterations, including NSB1, MDM2 and CCND1 amplification, and BAP1 mutations, play pivotal roles in UM pathobiology. Thus, UM exhibits a multifactorial pathology. By consolidating key mechanisms underlying UM pathogenesis, this review provides a comprehensive perspective on the involved pathways, offering insights that may facilitate the development of effective therapeutic strategies.

Could let-7f, miR-10b, miR-34a, miR-181b, and miR-181d Be Useful Tools as a Target Therapy for Uterine Leiomyosarcoma?

Background/Objectives: We have previously identified let-7f-5p, miR-10b-5p, miR-34a-5p, miR-181b-5p, and miR-181d-5p as differentially expressed between uterine leiomyoma (LM) and leiomyosarcoma (LMS) tissue samples. The present study aimed to characterize these miRNA expression profiles and to assess the functional role of miR-34a and miR-181b in uterine LM and LMS cells. Methods: All the selected miRNAs showed downregulation in LMS cells compared to LM cells, but only miR-34a and miR-181b expression patterns matched those of patient samples. Therefore, these two miRs were selected for further analyses. Results: Loss of function analysis demonstrated that miR-34a and miR-181b silencing inhibited LM cell proliferation and migration. MiR-34a silencing induced CCND1 and MDM4 expression and inhibited KMT2D, BCL2, and NOTCH2 in LM. Silencing of miR-181b promotes TIMP3 and FGFR1 expression in LM and diminishes BCL2, NOTCH2, ATM, IRS1, and PRLR. Gain of function analysis revealed that the introduction of miR-34a and miR-181b mimics suppressed proliferation and migration in malignant LMS cells. Additionally, transfection with a miR-34a mimic downregulated NOTCH2 and BCL2 expression and enhanced the expression of CCND1, KMT2D, and TP53 in LMS cells. Moreover, miR-181b overexpression decreased TIMP3, NOTCH2, ATM, and IRS1 expression and increased the expression of FGFR1 in this cell. Importantly, the single introduction of either a miR-34a or miR-181b mimic was able to decrease the invasion capacity of LMS cells. Conclusions: Our studies demonstrated that miR-34a or miR-181b may play an anti-oncogenic role in uterine tumors; further studies are needed to better understand the role and regulatory mechanism of these miRNAs in LMS cancer development, which will help provide prognostic and therapeutic options for patients with LMS.

Plasma-derived exosomes of Edwardsiella piscicida challenged olive flounder (Paralichthys olivaceus): Characterization and miRNA profiling for potential biomarkers screening

Exosomes are released from multiple cell types as part of their normal physiology as well as during acquired abnormalities. In this study, we investigated the effect of pathogenic Edwardsiella piscicida infection on olive flounder (Paralichthys olivaceus) exosomes at morphometric, physicochemical, and molecular levels. Unique cup-shaped exosomes were isolated from the plasma of non-infected (PBS-Exo) and E. piscicida experimentally challenged (Ep-Exo) olive flounder using ultracentrifugation. The average particle size, concentration, and zeta potential were 150.9 ± 6.9 nm, 5.67 × 1010 particles/mL, and -25.6 ± 1.36 mV for PBS-Exo while 138.7 ± 1.9 nm, 1.22 × 1011 particles/mL, and -35 ± 1.82 mV for Ep-Exo, respectively. Expression of tetraspanin markers (CD81, CD9, and CD63) confirmed the presence of olive flounder exosomes. Differentially expressed (DE) known (9) and novel (29) miRNAs (log2 fold change ≥1; p < 0.05) were identified in the Ep-Exo that could be potential as diagnostic biomarkers for the infection. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the predicted target genes of the DE miRNAs were highly enriched in metabolic and immune roles. Both PBS-Exo and Ep-Exo were non-toxic in vitro (up to 100 μg/mL) and in vivo (up to 400 μg/mL). Compared to the vehicle, PBS-Exo at 50 μg/mL induced Nf-kB (>1.50-fold) while at 100 μg/mL, Il8, Il10, Nf-kB, P53, and Inf were induced (>1.50-fold) in fathead minnow cells (FHMs). This suggests that the PBS-Exo contains molecules that moderately stimulate gene expression. In the future, validating the exact olive flounder immune response target genes that interact with DE miRNAs in Ep-Exo will be crucial for investigating the host-pathogen interactions, immune defense mechanisms, and therapeutic targets for olive flounder against E. piscicida infection.

Red Blood Cell Membrane-coated Functionalized Au Nanocage as a Biomimetic Platform for Improved MicroRNA Delivery in Hepatocellular Carcinoma

Dysregulation of microRNAs (miRNAs) expression is closely related to cancers and managing miRNA expression holds great promise for cancer therapy. However, their wide clinical application has been hampered by their poor stability, short half-life and non-specific biodistribution in vivo. Herein, a novel biomimetic platform designated as RHAuNCs-miRNA for improved miRNA delivery was prepared through wrapping miRNA-loaded functionalized Au nanocages (AuNCs) with red blood cell (RBC) membrane. RHAuNCs-miRNA not only successfully loaded miRNAs but also effectively protected them from enzymatic degradation. With good stability, RHAuNCs-miRNA had the characteristics of photothermal conversion and sustained release. Cellular uptake of RHAuNCs-miRNA by SMMC-7721 cells was in a time-dependent manner via clathrin- and caveolin-mediated endocytosis. The uptake of RHAuNCs-miRNAs was affected by cell types and improved by mild near infrared (NIR) laser irradiation. More importantly, RHAuNCs-miRNA exhibited a prolonged circulation time without the occurrence of accelerated blood clearance (ABC) in vivo, resulting in efficient delivery to tumor tissues. This study may demonstrate the great potential of RHAuNCs-miRNA for improved miRNAs delivery.

The expression of miR-181b, CYLD, CBX-7, BCL2, and p53 in osteosarcoma patients and correlation with clinicopathological factors

Osteosarcoma is a common human malignancy with a high mortality rate worldwide. Recent studies have been focused on understanding the involvement of microRNA (miRNAs) in the pathogenesis of osteosarcoma. Therefore, the present study aimed to measure the expression levels of miR-181a, cylindromatosis (CYLD), chromo box homolog 7 (CBX7), B-cell lymphoma 2 (BCL2), and tumor protein p53 in tumor tissue and adjacent normal tissues in patients with osteosarcoma and its relationship with clinicopathological factors. The expression levels of miR-181a, CYLD, CBX7, BCL2, and p53 were measured in 60 patients with osteosarcoma using quantitative real-time polymerase chain reaction. Finally, we compared the relationship between these gene levels and clinicopathological factors in tumor and healthy tissues. Our results showed that the expression levels of miR-181a, BCL2, and p53 were significantly higher in osteosarcoma tissue in comparison with normal tissues (p < .05). On the contrary, CYLD and CBX7 were downregulated in osteosarcoma tumor tissues compared to adjacent healthy tissues (p < .05). In addition, the expression levels of miR-181a in tumor tissues were strongly correlated with patients' age, tumor size, clinical stage, cancer grade, and lymph node metastasis (p < .05). Our findings highlight new insights into understanding the role of miR-181a in the pathogenesis of osteosarcoma. However, further studies are needed to elucidate miRNA as therapeutic targets for osteosarcoma.

Development of dynamical network biomarkers for regulation in Epstein-Barr virus positive peripheral T cell lymphoma unspecified type

Background: This study was performed to identify key regulatory network biomarkers including transcription factors (TFs), miRNAs and lncRNAs that may affect the oncogenesis of EBV positive PTCL-U. Methods: GSE34143 dataset was downloaded and analyzed to identify differentially expressed genes (DEGs) between EBV positive PTCL-U and normal samples. Gene ontology and pathway enrichment analyses were performed to illustrate the potential function of the DEGs. Then, key regulators including TFs, miRNAs and lncRNAs involved in EBV positive PTCL-U were identified by constructing TF-mRNA, lncRNA-miRNA-mRNA, and EBV encoded miRNA-mRNA regulatory networks. Results: A total of 96 DEGs were identified between EBV positive PTCL-U and normal tissues, which were related to immune responses, B cell receptor signaling pathway, chemokine activity. Pathway analysis indicated that the DEGs were mainly enriched in cytokine-cytokine receptor interaction and chemokine signaling pathway. Based on the TF network, hub TFs were identified regulate the target DEGs. Afterwards, a ceRNA network was constructed, in which miR-181(a/b/c/d) and lncRNA LINC01744 were found. According to the EBV-related miRNA regulatory network, CXCL10 and CXCL11 were found to be regulated by EBV-miR-BART1-3p and EBV-miR-BHRF1-3, respectively. By integrating the three networks, some key regulators were found and may serve as potential network biomarkers in the regulation of EBV positive PTCL-U. Conclusion: The network-based approach of the present study identified potential biomarkers including transcription factors, miRNAs, lncRNAs and EBV-related miRNAs involved in EBV positive PTCL-U, assisting us in understanding the molecular mechanisms that underlie the carcinogenesis and progression of EBV positive PTCL-U.

Liver-specific deletion of miR-181ab1 reduces liver tumour progression via upregulation of CBX7

MiR-181 expression levels increased in hepatocellular carcinoma (HCC) compared to non-cancerous tissues. MiR-181 has been widely reported as a possible driver of tumourigenesis but also acts as a tumour suppressor. In addition, the miR-181 family regulates the development and function of immune and vascular cells, which play vital roles in the progression of tumours. More complicatedly, many genes have been identified as miR-181 targets to mediate the effects of miR-181. However, the role of miR-181 in the development of primary tumours remains largely unexplored. We aimed to examine the function of miR-181 and its vital mediators in the progression of diethylnitrosamine-induced primary liver cancers in mice. The size of liver tumours was significantly reduced by 90% in global (GKO) or liver-specific (LKO) 181ab1 knockout mice but not in hematopoietic and endothelial lineage-specific knockout mice, compared to WT mice. In addition, the number of tumours was significantly reduced by 50% in GKO mice. Whole-genome RNA-seq analysis and immunohistochemistry showed that epithelial-mesenchymal transition was partially reversed in GKO tumours compared to WT tumours. The expression of CBX7, a confirmed miR-181 target, was up-regulated in GKO compared to WT tumours. Stable CBX7 expression was achieved with an AAV/Transposase Hybrid-Vector System and up-regulated CBX7 expression inhibited liver tumour progression in WT mice. Hepatic CBX7 deletion restored the progression of LKO liver tumours. MiR-181a expression was the lowest and CBX7 expression the highest in iClust2 and 3 subclasses of human HCC compared to iClust1. Gene expression profiles of GKO tumours overlapped with low-proliferative peri-portal-type HCCs. Liver-specific loss of miR-181ab1 inhibited primary liver tumour progression via up-regulating CBX7 expression, but tumour induction requires both hepatic and non-hepatic miR-181. Also, miR-181ab1-deficient liver tumours may resemble low-proliferative periportal-type human HCC.

miR-181b regulates vascular endothelial aging by modulating an MAP3K3 signaling pathway

Endothelial cell (EC) aging plays a vital role in the pathogenesis of cardiovascular disease (CVD). MicroRNAs have emerged as crucial regulators of target gene expression by inhibiting mRNA translation and/or promoting mRNA degradation. We identify an aging-related and oxidative stress-responsive microRNA, miR-181b, that inhibits endothelial cell apoptosis and senescence. In gain- or loss-of-function studies, miR-181b regulated the expression of key apoptosis markers (Bcl2, Bax, cleaved-Caspase3) and senescence markers (p16, p21, γH2AX) and the ratio of apoptotic cells (TUNEL-positive) and senescent cells (SA-βgal-positive) in H2 O2 -induced ECs. Mechanistically, miR-181b targets MAP3K3 and modulates a MAP3K3/MKK/MAPK signaling pathway. MAP3K3 knockdown recapitulated the phenotype of miR-181b overexpression and miR-181b was dependent on MAP3K3 for regulating EC apoptosis and senescence. In vivo, miR-181b expression showed a negative correlation with increasing age in the mouse aorta. Endothelial-specific deficiency of miR-181a2b2 increased the target MAP3K3, markers of vascular senescence (p16, p21), and DNA double-strand breaks (γH2AX) in the aorta of aged mice. Collectively, this study unveils an important role of miR-181b in regulating vascular endothelial aging via an MAP3K3-MAPK signaling pathway, providing new potential therapeutic targets for antiaging therapy in CVD.

Melatonin Increases the Sensitivity of Osteosarcoma Cells to Chemotherapy Drug Cisplatin

Chemotherapy, which is one of the common treatments for osteosarcoma (OS), has many side effects and in some cases has low effectiveness due to chemoresistance, hence it is vital to study new therapies for OS. In this regard, we combined melatonin with cisplatin and evaluate their effect on MG63 OS cells. Since melatonin has anti-cancer properties, we hypothesized that its combination with cisplatin could increase the effectiveness of cisplatin. Firstly, MTT assay was used to evaluate the cell viability and cytotoxicity of cisplatin on MG63 cells and the results showed that melatonin in combination with cisplatin increases the sensitivity of MG63 cells to cisplatin. In addition, qRT-PCR results showed that the expressions of miR-181 and P53, CYLD, CBX7 and BCL2 genes change in MG63 cells after treatment with the combination of cisplatin and melatonin, so that the expression of P53, CYLD and CBX7 increased and the expression of BCL2 and miR-181b decreases significantly. Furthermore, analysis of Annexin V/FITC assay data revealed that the rate of apoptosis in MG63 OS cell line remarkably promoted after treated with cisplatin and melatonin combination. As a result, our findings show that melatonin in combination with cisplatin increases the effectiveness of cisplatin in osteosarcoma cells and this study provides a new therapeutic approach for OS.

Modulation of MicroRNAs by Euphorbia Microsciadia Boiss in MDA-MB-231 Cell Line: New Possibilities in Breast Cancer Therapy

BACKGROUND

A large number of Euphorbia species have been evaluated for anticancer effects; however, their anticancer mechanisms have not been established up to now.

OBJECTIVE

The present study aimed to evaluate the effects of Euphorbia microsciadia (E. microsciadia) Boiss on the modulation of micro (mi) RNAs in MDA-MB-231 cell line.

METHODS

As the first step, the inhibitory concentration of hydroalcoholic extract of E. microsciadia on MDA-MB-231 cells was examined using the MTT assay, bypassing 24 and 48h from seeding. The real-time quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) was also utilized to determine Let-7, miR-15, miR-16, miR-29, miR-151, miR-155, miR-21, miR-146b, miR-181b, miR-221, miR-222, miR-21, and miR-146b expressions in MDA-MB-231 cells, by passing 24 and 48h from treating with the extract of E. microsciadia.

RESULTS

The results reveal the cytotoxic effects of E. microsciadia on MDA-MB-231 cell line in a dose-dependent manner. The half maximal Inhibitory Concentrations (IC50) were also equal to 275 and 240μg/ml for E. microsciadia, by passing 24 and 48h from the treatment, respectively. Furthermore, it was confirmed that, E. microsciadia had augmented the expression levels of Let-7, miR-15, miR-16, miR-29, and miR-34a, which lead to an increase in apoptosis.

CONCLUSION

E. microsciadia could modulate some miRNAs involved in cell cycle arrest and apoptosis in MDA-MB-231 cell line. Accordingly, targeting miRNAs by E. microsciadia can open some newer avenues for breast cancer therapy.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

Proangiogenic signature in advanced laryngeal carcinoma after microRNA expression profiling

The aim of this study is to evaluate which dysregulated angiomiRs compose the specific proangiogenic microRNA signature of advanced laryngeal cancer and review the literature. Thirty-six samples from twelve patients with advanced laryngeal carcinoma were collected. Total RNA was extracted and microRNA global profiling was performed using Agilent Technologies Microarray Kit. Fifty-nine microRNAs were found to have significantly different expression levels. Eleven microRNAs from the whole group were sorted as regulators of tumor angiogenesis (angiomiRs): seven were up-regulated-miR-1246, miR-181b 5p, miR-18a 5p, miR-21 3p, miR-210 3p, miR-503 5p, miR-93 5p and four were down-regulated-miR148a 5p, miR-145 5p, miR-204 5p, miR-125b 5p. For none of those microRNAs we found heterogeneity in tumor tissue. We are the first to report the specific proangiogenic microRNA signature in advanced laryngeal carcinoma and we confirm and amplify findings from previous studies that expand our perception of a specific "molecular state" of angiogenesis that is distinctive only for laryngeal cancer.

The Upregulation of hsa-mir-181b-1 and Downregulation of Its Target CYLD in the Late-Stage of Tumor Progression of Breast Cancer

Some microRNAs are usually dysregulated in the cancers and influencing tumor behavior and progression. Hsa-miR-181b-1 and its target CYLD are involved in regulating the inflammatory pathways. This study aimed to investigate the expression levels of hsa-mir-181b-1 and CYLD in a cohort of breast tumor tissues and normal adjacent tissues to assess their association with breast cancer stages. A total number of 60 breast samples including cancerous and normal adjacent tissue specimens were collected. After pathological study, the expression of hsa-mir-181b-1 and CYLD were measured by qRT-PCR method. The hsa-mir-181b-1 expression level was significantly increased in breast tumor tissues compared to the controls. This increase was associated with the disease progression. Conversely, CYLD expression level was decreased in tumor samples compared to normal samples, significantly. ROC curve data added other prestigious information of hsa-mir-181b-1 and CYLD by defining cancer and healthy tissues with high specificity and sensitivity at a proposed cutoff point. Also, bioinformatic enrichment for the possible targets of mature sequence of "hsa-mir-181b-5p" was performed. Computational analysis showed the five most significant pathways including metabolic, cancer, calcium signaling, PI3K-Akt signaling and focal adhesion pathways which may be influenced by hsa-mir-181b-1. Thus, we suggested hsa-mir-181b-1 and CYLD might be involved in the pathogenesis of breast cancer and could be considered as two biomarkers for prediction, prognosis and diagnosis of the stages of the breast cancer.

MiR-181c-5p Mitigates Tumorigenesis in Cervical Squamous Cell Carcinoma via Targeting Glycogen Synthase Kinase 3β Interaction Protein (GSKIP)

BACKGROUND

Cervical cancer (CC) is a highly prevalent cancer and one of the main causes of death among women worldwide. The miR-181 family has turned out to be associated with tumorigenesis in a variety of tumors by regulating the expression of tumor-related genes. However, the mechanisms and biological function of miR-181c-5p in cervical squamous cell carcinoma (SCC) have not been well elucidated.

MATERIALS AND METHODS

SiHa cell lines with specific gene overexpression vectors were constructed. Targetscan was used to predict the binding site of miR-181c-5p and GSKIP. MTT assay was used to detect the clone formation rate. Flow cytometry was used to detect the apoptosis rate and to separate the cell markers. The Transwell test was used to detect cell invasion. Immunohistochemistry was used to detect protein expression in tumor tissues. Western Blotting was used to detect the expression levels of related proteins.

RESULTS

GSKIP was predicted to be the target gene of miR-181c-5p in cervical SCC. MiR-181c-5p overexpression suppressed SiHa cells proliferation and promoted apoptosis; the protein expressions of Ki67 and PCNA were decreased, but the expressions of Caspase-3 and Bax/Bcl-2 were increased. The overexpression of miR-181c-5p inhibited the stem-like properties of SiHa cells; the expressions of SOX2, OCT4 and CD44 were decreased. Furthermore, miR-181c-5p upregulation limited the invasion of SiHa cells; the expression of E-cadherin was higher, but the expressions of N-cadherin and Vimentin were lower. MiR-181c-5p overexpression inhibited tumorigenesis in cervical SCC tissues; the expressions of Ki67, Caspase-3, CD44 and Vimentin in vivo were consistent with those in vitro.

CONCLUSION

Taken together, miR-181c-5p was able to mitigate the cancer cell characteristic and invasive properties of cervical SCC through targeting GSKIP gene.

Association of MicroRNA Expression and BRAFV600E Mutation with Recurrence of Thyroid Cancer

Many miRNAs and cancer-related mutations have been proposed as promising molecular markers of papillary thyroid carcinoma (PTC). However, there are limited data on the correlation between miRNA expression, BRAFV600E mutation, and PTC recurrence. Therefore, to evaluate the potential of BRAFV600E mutation and five selected miRNAs (-146b, -222, -21, -221, -181b) in predicting PTC recurrence, these molecular markers were analyzed in 400 formalin-fixed, paraffin-embedded PTC tissue specimens. The expression levels of miRNAs were measured using qRT-PCR. It was demonstrated that expression levels of all analyzed miRNAs are significantly higher in recurrent PTC than in non-recurrent PTC (p < 0.05). Moreover, higher expression levels of miR-146b, miR-222, miR-21, and miR-221 were associated with other clinicopathologic features of PTC, such as tumor size and lymph node metastases at initial surgery (p < 0.05). No significant differences in the frequency of BRAFV600E mutation in recurrent PTC and non-recurrent PTC were determined. Our results suggest that miRNA expression profile differs in PTC that is prone to recurrence when compared to PTC that does not reoccur after the initial surgery while BRAFV600E mutation frequency does not reflect the PTC recurrence status. However, the prognostic value of the analyzed miRNAs is rather limited in individual cases as the pattern of miRNA expression is highly overlapping between recurrent and non-recurrent PTC.

Liquiritigenin suppresses the activation of hepatic stellate cells via targeting miR-181b/PTEN axis

BACKGROUND

Liquiritigenin (LQ), an aglycone of liquiritin in licorice, has demonstrated antioxidant, anti-inflammatory and anti-tumor activities. Previously, LQ was found to inhibit liver fibrosis progression.

PURPOSE

Phosphatase and tensin homolog (PTEN) has been reported to act as a negative regulator of hepatic stellate cell (HSC) activation. However, the roles of PTEN in the effects of LQ on liver fibrosis have not been identified to date.

METHODS

The effects of LQ on liver fibrosis in carbon tetrachloride (CCl₄) mice as well as primary HSCs were examined. Moreover, the roles of PTEN and microRNA-181b (miR-181b) in the effects of LQ on liver fibrosis were examined.

RESULTS

LQ markedly ameliorated CCl₄-induced liver fibrosis, with a reduction in collagen deposition as well as α-SMA level. Moreover, LQ induced an increase in PTEN and effectively inhibited HSC activation including cell proliferation, α-SMA and collagen expression, which was similar with curcumin (a positive control). Notably, loss of PTEN blocked down the effects of LQ on HSC activation. PTEN was confirmed as a target of miR-181b and miR-181b-mediated PTEN was involved in the effects of LQ on liver fibrosis. LQ led to a significant reduction in miR-181b expression. LQ-inhibited HSC activation could be restored by over-expression of miR-181b. Further studies demonstrated that LQ down-regulated miR-181b level via Sp1. Collectively, we demonstrate that LQ inhibits liver fibrosis, at least in part, via regulation of miR-181b and PTEN.

CONCLUSION

LQ down-regulates miR-181b level, leading to the restoration of PTEN expression, which contributes to the suppression of HSC activation. LQ may be a potential candidate drug against liver fibrosis.

Inflammation related miRNAs as an important player between obesity and cancers

The growing trend in addition to their burden, prevalence, and death has made obesity and cancer two of the most concerning diseases worldwide. Obesity is an important risk factor for common types of cancers where the risk of some cancers is directly related to the obesity. Various inflammatory mechanisms and increased level of pro-inflammatory cytokines have been investigated in many previous studies, which play key roles in the pathophysiology and development of both of these conditions. On the other hand, in the recent years, many studies have individually focused on the biomarker's role and therapeutic targeting of microRNAs (miRNAs) in different types of cancers and obesity including newly discovered small noncoding RNAs (sncRNAs) which regulate gene expression and RNA silencing. This study is a comprehensive review of the main inflammation related miRNAs in obesity/obesity related traits. For the first time, the main roles of miRNAs in obesity related cancers have been discussed in response to the question raised in the following hypothesis; do the main inflammatory miRNAs link obesity with obesity-related cancers regarding their role as biomarkers? Graphical abstractConceptual design of inflammatory miRNAs which provide link between obesity and cancers.

Altered expression of miR-181 affects cell fate and targets drug resistance-related mechanisms

MicroRNAs (miRNAs) are non-coding transcripts which regulate genetic and epigenetic events by interfering with mRNA translation. miRNAs are involved in regulation of cell fate due to their ability of interfering with physiological or pathological processes. In this review paper, we evaluate the role of miR-181 family members as prognostic or diagnostic markers or therapeutic targets in malignant pathologies in connection with the main hallmarks of cancer that are modulated by the family. Also, we take over the dual role of this family in dependency with the tumour suppressor and oncogenic features presented in cell and cancer type specific manner. Restoration of the altered expression levels contributes to the activation of cell death pathways or to a reduction in the invasion and migration mechanism; moreover, the mechanism of drug resistance is also modulated by miR-181 sequences with important applications in therapeutic strategies for malignant cells sensitisation. Overall, the main miR-181 family regulatory mechanisms are presented in a cancer specific context, emphasizing the possible clinical application of this family in terms of novel diagnosis and therapy approaches.

Differential expression of miRNAs regulating NF-κB and STAT3 crosstalk during colitis-associated tumorigenesis

Inflammatory bowel disease (IBD) is mostly responsible for the development of colitis-associated colon cancer. Of the several signaling pathways involved in colonic inflammation, the activation and crosstalk between NF-κB and STAT3 serve as the pivotal regulatory hubs that regulate epithelial tumorigenesis by linking inflammation with cancer development. Understanding the molecular mechanisms regulating the crosstalk between NF-κB and STAT3 will help in targeting these signaling pathways and halt epithelial tumorigenesis. MicroRNAs (miRNAs) play important role in the regulation of NF-κB and STAT3 and function in a positive- or negative feedback loop to regulate the crosstalk of these transcription factor. In the present study we evaluated the aberrant expression of a selected panel of miRNAs (miR-181b, miR-31, miR-34a, miR-146b, miR-221, and miR-155) that regulate the crosstalk between NF-κB and STAT3 during colitis-associated tumorigenesis. We used the stepwise colorectal carcinogenesis murine model known as Azoxymethane (AOM)/Dextran sodium sulphate (DSS) to recapitulate the different stages of tumorigenesis. Our results revealed that the expression of the selected miRNAs changed dynamically in a stepwise pattern as colonic tissue transforms from normal to actively inflamed to neoplastic state, in accordance with the gradual activation of NF-κB and STAT3, suggesting that the aberrant expression of these miRNAs could function as the epigenetic switch between inflammation and colorectal tumorigenesis. We were able to elucidate the contribution of miRNAs in the NF-κB - STAT3 crosstalk during the stepwise development of colitis-associated carcinoma, and this could improve our understanding of the molecular pathology of colorectal tumorigenesis and even suggesting a therapeutic strategy by modulating the expression of these regulating miRNAs.

Non-Coding RNAs in Breast Cancer: Intracellular and Intercellular Communication

Non-coding RNAs (ncRNAs) are regulators of intracellular and intercellular signaling in breast cancer. ncRNAs modulate intracellular signaling to control diverse cellular processes, including levels and activity of estrogen receptor α (ERα), proliferation, invasion, migration, apoptosis, and stemness. In addition, ncRNAs can be packaged into exosomes to provide intercellular communication by the transmission of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) to cells locally or systemically. This review provides an overview of the biogenesis and roles of ncRNAs: small nucleolar RNA (snRNA), circular RNAs (circRNAs), PIWI-interacting RNAs (piRNAs), miRNAs, and lncRNAs in breast cancer. Since more is known about the miRNAs and lncRNAs that are expressed in breast tumors, their established targets as oncogenic drivers and tumor suppressors will be reviewed. The focus is on miRNAs and lncRNAs identified in breast tumors, since a number of ncRNAs identified in breast cancer cells are not dysregulated in breast tumors. The identity and putative function of selected lncRNAs increased: nuclear paraspeckle assembly transcript 1 (NEAT1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), steroid receptor RNA activator 1 (SRA1), colon cancer associated transcript 2 (CCAT2), colorectal neoplasia differentially expressed (CRNDE), myocardial infarction associated transcript (MIAT), and long intergenic non-protein coding RNA, Regulator of Reprogramming (LINC-ROR); and decreased levels of maternally-expressed 3 (MEG3) in breast tumors have been observed as well. miRNAs and lncRNAs are considered targets of therapeutic intervention in breast cancer, but further work is needed to bring the promise of regulating their activities to clinical use.

Extracellular vesicles from human liver stem cells inhibit tumor angiogenesis

Human liver stem-like cells (HLSC) and derived extracellular vesicles (EVs) were previously shown to exhibit anti-tumor activity. In our study, we investigated whether HLSC-derived EVs (HLSC-EVs) were able to inhibit tumor angiogenesis in vitro and in vivo, in comparison with EVs derived from mesenchymal stem cells (MSC-EVs). The results obtained indicated that HLSC-EVs, but not MSC-EVs, inhibited the angiogenic properties of tumor-derived endothelial cells (TEC) both in vitro and in vivo in a model of subcutaneous implantation in Matrigel. Treatment of TEC with HLSC-EVs led to the down-regulation of pro-angiogenic genes. Since HLSC-EVs carry a specific set of microRNAs (miRNAs) that could target these genes, we investigated their potential role by transfecting TEC with HLSC-EV specific miRNAs. We observed that four miRNAs, namely miR-15a, miR-181b, miR-320c and miR-874, significantly inhibited the angiogenic properties of TEC in vitro, and decreased the expression of some predicted target genes (ITGB3, FGF1, EPHB4 and PLAU). In parallel, TEC treated with HLSC-EVs significantly enhanced expression of miR-15a, miR-181b, miR-320c and miR-874 associated with the down-regulation of FGF1 and PLAU. In summary, HLSC-EVs possess an anti-tumorigenic effect, based on their ability to inhibit tumor angiogenesis.

The interplay of LncRNA ANRIL and miR-181b on the inflammation-relevant coronary artery disease through mediating NF-κB signalling pathway

This study was designed to investigate whether ANRIL affected the aetiology of coronary artery disease (CAD) by acting on downstream miR-181b and NF-κB signalling. Altogether 327 CAD patients diagnosed by angiography were included, and mice models of CAD were established. Human coronary endothelial cells (HCAECs) and human umbilical vein endothelial cells (HUVECs) were also purchased. In addition, shRNA-ANRIL, shRNA-NC, pcDNA3.1-ANRIL, miR-181b mimic, miR-181b inhibitor and miR-NC were transfected into the cells. The lipopolysaccharides (LPS) and pyrrolidine dithiocarbamate (PDTC) were also added to activate or deactivate NF-κB signalling. Both highly expressed ANRIL and lowly expressed miR-181b were associated with CAD population aged over 60 years old, with smoking history, with hypertension and hyperlipidemia, with CHOL H 4.34 mmol/L, TG ≥ 1.93 mmol/L and Hcy ≥ 16.8 μmol/L (all P < 0.05). Besides, IL-6, IL-8, NF-κB, TNF-α, iNOS, ICAM-1, VCAM-1 and COX-2 expressions observed within AD mice models were all beyond those within NC and sham-operated groups (P < 0.05). Also VEGF and HSP 70 were highly expressed within AD mice models than within NC and sham-operated mice (P < 0.05). Transfection of either pcDNA-ANRIL or miR-181b inhibitor could significantly fortify HCAECs' viability and put on their survival rate. At the meantime, the inflammatory factors and vascular-protective parameters were released to a greater level (P < 0.05). Finally, highly expressed ANRIL also notably bring down miR-181b expression and raise p50/p65 expressions within HCAECs (P < 0.05). The joint role of ANRIL, miR-181b and NF-κB signalling could aid in further treating and diagnosing CAD.

Epigenetics and Epi-miRNAs: Potential markers/therapeutics in leukemia

Epigenetic variations can play remarkable roles in different normal and abnormal situations. Such variations have been shown to have a direct role in the pathogenesis of various diseases either through inhibition of tumor suppressor genes or increasing the expression of oncogenes. Enzymes involving in epigenetic machinery are the main actors in tuning the epigenetic-based controls on gene expressions. Aberrant expression of these enzymes can trigger a big chaos in the cellular gene expression networks and finally lead to cancer progression. This situation has been shown in different types of leukemia, where high or low levels of an epigenetic enzyme are partly or highly responsible for involvement or progression of a disease. DNA hypermethylation, different histone modifications, and aberrant miRNA expressions are three main epigenetic variations, which have been shown to play a role in leukemia progression. Epigenetic based treatments now are considered as novel and effective therapies in order to decrease the abnormal epigenetic modifications in patient cells. Different epigenetic-based approaches have been developed and tested to inhibit or reverse the unusual expression of epigenetic agents in leukemia. The reciprocal behavior of miRNAs in the regulation of epigenetic modifiers, while being regulated by them, unlocks a new opportunity in order to design some epigenetic-based miRNAs able to silence or sensitize these effectors in leukemia.

A positive feedback loop between miR-181b and STAT3 that affects Warburg effect in colon cancer via regulating PIAS3 expression

This study aimed to investigate the relationship between the expression of microRNA (miR)‐181b, protein inhibitor of activated STAT3 (PIAS3) and STAT3, and to examine the function of the miR‐181b/PIAS3/STAT3 axis on the Warburg effect and xenograft tumour growth of colon cancer. Moreover, a positive feedback loop between miR‐181b and STAT3 that regulated the Warburg effect in colon cancer was explored. A luciferase reporter assay was used to identify whether PIAS3 was a direct target of miR‐181b. The gain‐of‐function and loss‐of‐function experiments were performed on HCT 116 cells to investigate the effect of miR‐181b/PIAS3/STAT3 on the Warburg effect and xenograft tumour growth of colon cancer, as determined by commercial kits and xenograft experiments. The relationship between the expression of miR‐181b, PIAS3 and STAT3 in HCT 116 and HT‐29 cells was determined using RT‐qPCR and Western blot. We found miR‐181b was a direct regulator of PIAS3. miR‐181b promoted the Warburg effect and the growth of colon cancer xenografts; however, these effects could be reversed by PIAS3. miR‐181b expression interacted with STAT3 phosphorylation in a positive feedback loop in colon cancer cells via regulating PIAS3 expression. In conclusion, this study for the first time demonstrated that miR‐181b contributed to the Warburg effect and xenograft tumour growth of colon cancer by targeting PIAS3. Moreover, a positive feedback loop between miR‐181b and STAT3 that regulated the Warburg effect in colon cancer was also demonstrated. This study suggested miR‐181b/PIAS3/STAT3 axis as a novel target for colon cancer treatment.

Roles of microRNA in prostate cancer cell metabolism

MicroRNAs are non-coding RNA which functions as regulators of genes expression. MicroRNAs have shown their biological functions in cell proliferation, cell cycle, cell metabolism, apoptosis, invasion and metastasis. Cancer cells have the ability to grow in the absence of growth factors by increased metabolic activity. MicroRNAs regulate cell metabolic processes by targeting the key enzymes or transporters and change the metabolic activities by interfering with oncogenes/tumor suppressors, hypoxia, signalling pathways and cell adhesion. This review mainly explains the roles of microRNAs in prostate cancer cell metabolism, such as glucose uptake, glycolysis and lactate secretion, lipid metabolism and interaction with signalling pathways. The relation of microRNAs with hypoxia and cell adhesion in cell metabolism is also highlighted. Therefore, miRNAs help in regulating the metabolism of survived tumor cells, understanding such miRNA-mediated interaction could lead to new avenues in therapeutic application to treat PCa.

Comprehensive miRNA expression profiling in human T-cell acute lymphoblastic leukemia by small RNA-sequencing

T-cell acute lymphoblastic leukemia (T-ALL) is a genetically heterogeneous disease that can be classified into different molecular genetic subtypes according to their mRNA gene expression profile. In this study, we applied RNA sequencing to investigate the full spectrum of miRNA expression in primary T-ALL patient samples, T-ALL leukemia cell lines and healthy donor thymocytes. Notably, this analysis revealed that genetic subtypes of human T-ALL also display unique miRNA expression signatures, which are largely conserved in human T-ALL cell lines with corresponding genetic background. Furthermore, small RNA-sequencing also unraveled the variety of isoforms that are expressed for each miRNA in T-ALL and showed that a significant number of miRNAs are actually represented by an alternative isomiR. Finally, comparison of CD34⁺ and CD4⁺CD8⁺ healthy donor thymocytes and T-ALL miRNA profiles allowed identifying several novel miRNAs with putative oncogenic or tumor suppressor functions in T-ALL. Altogether, this study provides a comprehensive overview of miRNA expression in normal and malignant T-cells and sets the stage for functional evaluation of novel miRNAs in T-ALL disease biology.

Computational Analysis of Specific MicroRNA Biomarkers for Noninvasive Early Cancer Detection

Cancer is a complex disease residing in various tissues of human body, accompanied with many abnormalities and mutations in genomes, transcriptome, and epigenome. Early detection plays a crucial role in extending survival time of all major cancer types. Recent advances in microarray and sequencing techniques have given more support to identifying effective biomarkers for early detection of cancer. MicroRNAs (miRNAs) are more and more frequently used as candidates for biomarkers in cancer related studies due to their regulation of target gene expression. In this paper, the comparative analysis is used to discover miRNA expression patterns in cancer versus normal samples on early stage of eight prevalent cancer types. Our work focuses on the specific miRNAs biomarkers identification and function analysis. Several identified miRNA biomarkers in this paper are matched well with those reported in existing researches, and most of them could serve as potential candidate indicators for clinical early diagnosis applications.

miR-22 promotes apoptosis of osteosarcoma cells via inducing cell cycle arrest

To study the effects of miR-22 on the proliferation and the apoptosis of osteosarcoma MG-63 cell line and to explore the potential molecular mechanism that miR-22 regulates this biological process. Quantitive real-time polymerase chain reaction (RT-qPCR) was performed to explore the miRNA level of miR-22. The MG-63 cell line was infected with miR-22 mimics for establishment of miR-22 overexpression. Non-infected cells were in blank group and cells infected with empty vector were served as negative control (NC group). MTT assay was conducted to measure cell viability. The cell cycle and apoptosis were explored using flow cytometry and the apoptosis-related markers were detected by western blotting. RT-qPCR results revealed that the miR-22 miRNA level in the MG-63 cells was significantly lower than that in osteoblasts (P<0.05). MTT assay showed that the MG-63 cells infected with miR-22 mimics exhibited markedly decreased proliferation ability compared with blank and empty vector (NC) groups. Next, we found that overexpression of miR-22 remarkably increased the apoptosis of the MG-63 cells, evidenced from the flow cytometry results and elevated Bax and reduced Bcl-2. Furthermore, results revealed that percentage of the cells at G0/G1 phase in miR-22 mimic group (66.75±3.67%) was significantly higher than blank (52.9±2.58%) and NC (50.5±2.45%) groups. miR-22 attenuated the proliferation and induced the apoptosis of the MG-63 cells via promoting G0/G1 cell cycle arrest. Thus, miR-22 may have the potential to be a novel therapeutic in treatment of osteosarcoma.

Human adipose mesenchymal stem cell-derived exosomal-miRNAs are critical factors for inducing anti-proliferation signalling to A2780 and SKOV-3 ovarian cancer cells

An enigmatic question exists concerning the pro- or anti-cancer status of mesenchymal stem cells (MSCs). Despite growing interest, this question remains unanswered, and the debate became intensified with new evidences backing each side. Here, we showed that human adipose MSC (hAMSC)-derived conditioned medium (CM) exhibited inhibitory effects on A2780 human ovarian cancer cells by blocking the cell cycle, and activating mitochondria-mediated apoptosis signalling. Explicitly, we demonstrated that exosomes, an important biological component of hAMSC-CM, could restrain proliferation, wound-repair and colony formation ability of A2780 and SKOV-3 cancer cells. Furthermore, hAMSC-CM-derived exosomes induced apoptosis signalling by upregulating different pro-apoptotic signalling molecules, such as BAX, CASP9, and CASP3, as well as downregulating the anti-apoptotic protein BCL2. More specifically, cancer cells exhibited reduced viability following fresh or protease-digested exosome treatment; however, treatment with RNase-digested exosomes could not inhibit the proliferation of cancer cells. Additionally, sequencing of exosomal RNAs revealed a rich population of microRNAs (miRNAs), which exhibit anti-cancer activities by targeting different molecules associated with cancer survival. Our findings indicated that exosomal miRNAs are important players involved in the inhibitory influence of hAMSC-CM towards ovarian cancer cells. Therefore, we believe that these comprehensive results will provide advances concerning ovarian cancer research and treatment.

Upregulation of microRNA-181b inhibits CCL18-induced breast cancer cell metastasis and invasion via the NF-κB signaling pathway

The purpose of the present study was to investigate the effects of upregulating microRNA (miR)-181b expression in tumor-associated macrophages regarding breast cancer cell metastasis and to identify the target gene. Ectopic miR-181b was transfected into MDA-MB-231 and MCF-7 breast cancer cell lines with or without chemokine ligand 18 (CCL18) stimulation. Cell proliferation, migration/invasion and apoptosis rate were investigated. The binding effects of miR-181b to the 3'-untranslated region (UTR) of the nuclear factor (NF)-κB gene were detected with the dual luciferase reporter system. Immunofluorescent staining of the NF-κB key component P65 was performed. The messenger (m) RNA and protein expression of NF-κB induced by CCL18 with or without miR-181b stimulation was evaluated with reverse transcription-quantitative polymerase chain reaction and western blot analysis. When compared with the CCL18-stimulated group, miR-181b mimic-transfected cells exhibited significantly inhibited proliferation and migration, with an increased cell apoptosis percentage in a dose-dependent manner. Furthermore, the luciferase activity was reduced for cells with NF-κB 3'-UTR wild-type that were co-transfected with miR-181b mimics. Immunofluorescent staining of NF-κB demonstrably weakened the P65 signal in stimulated miR-181b mimic cells when compared with parental and CCL18-treated cells. The increased expression level of NF-κB induced by CCL18 in MDA-MB-231 and MCF-7 cells was suppressed by miR-181b mimics. Overexpression of miR-181b suppressed cell survival rate and migration. This overexpression may achieve this goal by regulating the NF-κB pathway in breast cancer cells. Our study demonstrated a potential therapeutic application of miR-181b in the treatment of breast cancer.

miR-181b functions as an oncomiR in colorectal cancer by targeting PDCD4

Programmed cell death 4 (PDCD4) is a RNA-binding protein that acts as a tumor suppressor in many cancer types, including colorectal cancer (CRC). During CRC carcinogenesis, PDCD4 protein levels remarkably decrease, but the underlying molecular mechanism for decreased PDCD4 expression is not fully understood. In this study, we performed bioinformatics analysis to identify miRNAs that potentially target PDCD4. We demonstrated miR-181b as a direct regulator of PDCD4. We further showed that activation of IL6/STAT3 signaling pathway increased miR-181b expression and consequently resulted in downregulation of PDCD4 in CRC cells. In addition, we investigated the biological effects of PDCD4 inhibition by miR-181b both in vitro and in vivo and found that miR-181b could promote cell proliferation and migration and suppress apoptosis in CRC cells and accelerate tumor growth in xenograft mice, potentially through targeting PDCD4. Taken together, this study highlights an oncomiR role for miR-181b in regulating PDCD4 in CRC and suggests that miR-181b may be a novel molecular therapeutic target for CRC.

Ultrasound-guided therapeutic modulation of hepatocellular carcinoma using complementary microRNAs

Treatment options for patients with hepatocellular carcinoma (HCC) are limited, in particular in advanced and drug resistant HCC. MicroRNAs (miRNA) are non-coding small RNAs that are emerging as novel drugs for the treatment of cancer. The aim of this study was to assess treatment effects of two complementary miRNAs (sense miRNA-122, and antisense antimiR-21) encapsulated in biodegradable poly (lactic-co-glycolic acid) nanoparticles (PLGA-NP), administered by an ultrasound-guided and microbubble-enhanced delivery approach in doxorubicin-resistant and non-resistant human HCC xenografts. Proliferation and invasiveness of human HCC cells after miRNA-122/antimiR-21 and doxorubicin treatment were assessed in vitro. Confocal microscopy and qRT-PCR were used to visualize and quantitate successful intracellular miRNA-loaded PLGA-NP delivery. Up and down-regulation of miRNA downstream targets and multidrug resistance proteins and extent of apoptosis were assessed in vivo in treated human HCC xenografts in mice. Compared to single miRNA therapy, combination therapy with the two complementary miRNAs resulted in significantly (P<0.05) stronger decrease in cell proliferation, invasion, and migration of HCC cells as well as higher resensitization to doxorubicin. Ultrasound-guided delivery significantly increased in vivo miRNA-loaded PLGA-NP delivery in human HCC xenografts compared to control conditions by 5-9 fold (P<0.001). miRNA-loaded PLGA-NP were internalized in HCC cells and anti-apoptotic proteins were down regulated with apoptosis in ~27% of the tumor volume of doxorubicin-resistant human HCC after a single treatment with complementary miRNAs and doxorubicin. Thus, ultrasound-guided delivery of complementary miRNAs is highly efficient in the treatment of doxorubicin- resistant and non-resistant HCC. Further development of this new treatment approach could aid in better treatment of patients with HCC.

Understanding the CREB1-miRNA feedback loop in human malignancies

cAMP response element binding protein 1 (CREB1, CREB) is a key transcription factor that mediates transcriptional responses to a variety of growth factors and stress signals. CREB1 has been shown to play a critical role in development and progression of tumors. MicroRNAs (miRNAs) are a class of non-coding RNAs. They post-transcriptionally regulate gene expression through pairing with the 3'-UTR of their target mRNAs and thus regulate initiation and progression of various types of human cancers. Recent studies have demonstrated that a number of miRNAs can be transcriptionally regulated by CREB1. Interestingly, CREB1 expression can also be modulated by miRNAs, thus forming a feedback loop. This review outlines the functional roles of CREB1, miRNA, and their interactions in human malignancies. This will help to define a relationship between CREB1 and miRNA in human cancer and develop novel therapeutic strategies.

MiR-181b regulates cisplatin chemosensitivity and metastasis by targeting TGFβR1/Smad signaling pathway in NSCLC

MicroRNAs (miRNAs) have been identified as important post-transcriptional regulators involved in various biological and pathological processes of cells, but their underlying mechanisms in chemosensitivity and metastasis have not been fully elucidated. The objective of this study was to identify miR-181b and its mechanism in the chemosensitivity and metastasis of NSCLC. We found that miR-181b expression levels were lower in A549/DDP cells compared with A549 cells. Functional assays showed that the overexpression of miR-181b inhibited proliferation, enhanced chemosensitivity to DDP, attenuated migration and metastatic ability in NSCLC cell lines in vitro and in vivo. TGFβR1 was subsequently identified as a novel functional target of miR-181b. TGFβR1 knockdown revealed similar effects as that of ectopic miR-181b expression, whereas overexpression of TGFβR1 rescued the function of miR-181b-mediated growth, chemosensitivity and metastasis in NSCLC cells. In addition, miR-181b could inactivate the TGFβR1/Smad signaling pathway. We also observed that decreased miR-181b expression and increased TGFβR1 expression were significantly associated with chemosensitivity to DDP and tumor metastasis in NSCLC patients. Consequently, miR-181b functions as a tumor suppressor and has an important role in proliferation, chemosensitivity to DDP and metastasis of NSCLC by targeting TGFβR1/Smad signaling pathway.

Integrative analysis of the microRNA-mRNA response to radiochemotherapy in primary head and neck squamous cell carcinoma cells

Background

Head and neck squamous cell carcinoma (HNSCC) is a very heterogeneous disease resulting in huge differences in the treatment response. New individualized therapy strategies including molecular targeting might help to improve treatment success. In order to identify potential targets, we developed a HNSCC radiochemotherapy cell culture model of primary HNSCC cells derived from two different patients (HN1957 and HN2092) and applied an integrative microRNA (miRNA) and mRNA analysis in order to gain information on the biological networks and processes of the cellular therapy response. We further identified potential target genes of four therapy-responsive miRNAs detected previously in the circulation of HNSCC patients by pathway enrichment analysis.

Results

The two primary cell cultures differ in global copy number alterations and P53 mutational status, thus reflecting heterogeneity of HNSCC. However, they also share many copy number alterations and chromosomal rearrangements as well as deregulated therapy-responsive miRNAs and mRNAs. Accordingly, six common therapy-responsive pathways (direct P53 effectors, apoptotic execution phase, DNA damage/telomere stress induced senescence, cholesterol biosynthesis, unfolded protein response, dissolution of fibrin clot) were identified in both cell cultures based on deregulated mRNAs. However, inflammatory pathways represented an important part of the treatment response only in HN1957, pointing to differences in the treatment responses of the two primary cultures. Focused analysis of target genes of four therapy-responsive circulating miRNAs, identified in a previous study on HNSCC patients, revealed a major impact on the pathways direct P53 effectors, the E2F transcription factor network and pathways in cancer (mainly represented by the PTEN/AKT signaling pathway).

Conclusions

The integrative analysis combining miRNA expression, mRNA expression and the related cellular pathways revealed that the majority of radiochemotherapy-responsive pathways in primary HNSCC cells are related to cell cycle, proliferation, cell death and stress response (including inflammation). Despite the heterogeneity of HNSCC, the two primary cell cultures exhibited strong similarities in the treatment response. The findings of our study suggest potential therapeutic targets in the E2F transcription factor network and the PTEN/AKT signaling pathway.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1865-x) contains supplementary material, which is available to authorized users.

Emerging molecular markers for the prognosis of differentiated thyroid cancer patients

Epithelial thyroid cancers are represented by the differentiated papillary and follicular thyroid carcinomas which, following dedifferentiation, are thought to give rise to the highly aggressive and incurable anaplastic thyroid carcinomas. Although derived from the same cell type, the different thyroid tumors show specific histological features, biological behavior and degree of differentiation as a consequence of different genetic alterations. Over the last few years, our knowledge regarding the molecular alterations underlying thyroid cell malignant transformation and cancer progression has considerably increased; however, the prognosis of differentiated thyroid cancer patients still relies on high-risk clinic-pathological variables. In particular, the actual staging systems provides only a rough prediction for cancer mortality and risk of recurrences, including in each risk group patients with highly different tumor-specific progression, disease-free interval and survival time. In order to improve DTC patient's risk stratification, both the European and the American Thyroid Associations proposed practical guidelines to integrate the actual staging systems with additional clinical features such as the tumor histological variant, the results of post-ablative whole body scan and the serum thyroglobulin levels. Despite that, patients within the same risk group still show a very heterogeneous behavior in terms of disease-free interval. As a consequence, the identification of new prognostic molecular biomarkers able to testify tumor aggressiveness is highly required. Here we'll review recently characterized new molecular markers potentially able to ameliorate the prognosis in DTC patients.

Prospective evaluation of whole genome microRNA expression profiling in childhood acute lymphoblastic leukemia

Dysregulation of microRNA (miRNA) expression contributes to the pathogenesis of several clinical conditions. The aim of this study is to evaluate the associations between miRNAs and childhood acute lymphoblastic leukemia (ALL) to discover their role in the course of the disease. Forty-three children with ALL and 14 age-matched healthy controls were included in the study. MicroRNA microarray expression profiling was used for peripheral blood and bone marrow samples. Aberrant miRNA expressions associated with the diagnosis and outcome were prospectively evaluated. Confirmation analysis was performed by real time RT-PCR. miR-128, miR-146a, miR-155, miR-181a, and miR-195 were significantly dysregulated in ALL patients at day 0. Following a six-month treatment period, the change in miRNA levels was determined by real time RT-PCR and expression of miR-146a, miR-155, miR-181a, and miR-195 significantly decreased. To conclude, these miRNAs not only may be used as biomarkers in diagnosis of ALL and monitoring the disease but also provide new insights into the potential roles of them in leukemogenesis.