MicroRNA miR-30 family regulates non-attachment growth of breast cancer cells

AVEN: a novel oncogenic biomarker with prognostic significance and implications of AVEN-associated immunophenotypes in lung adenocarcinoma

Introduction: AVEN, an apoptosis and caspase activation inhibitor, has been associated with adverse clinical outcomes and poor prognosis in Acute myeloid leukemia (AML). Targeting AVEN in AML improves apoptosis sensitivity and chemotherapy efficacy, making it a promising therapeutic target. However, AVEN's role has not been studied in solid tumors. Therefore, our study investigated AVEN as a prognostic biomarker in a more comprehensive manner and developed an AVEN-derived prognostic model in Lung adenocarcinoma (LUAD). Method: Pan-cancer analysis was performed to examine AVEN expression in 33 cancer types obtained from the TCGA database. GEPIA analysis was used to determine the predictive value of AVEN in each cancer type with cancer-specific AVEN expression. Lung Adenocarcinomas (LUAD) patients were grouped into AVENhigh and AVENlow based on AVEN expression level. Differentially expressed genes (DEGs) and pathway enrichment analysis were performed to gain insight into the biological function of AVEN in LUAD. In addition, several deconvolution tools, including Timer, CIBERSORT, EPIC, xCell, Quanti-seq and MCP-counter were used to explore immune infiltration. AVEN-relevant prognostic genes were identified by Random Survival Forest analysis via univariate Cox regression. The AVEN-derived genomic model was established using a multivariate-Cox regression model and GEO datasets (GSE31210, GSE50081) were used to validate its prognostic effect. Results: AVEN expression was increased in several cancer types compared to normal tissue, but its impact on survival was only significant in LUAD in the TCGA cohort. High AVEN expression was significantly correlated with tumor progression and shorter life span in LUAD patients. Pathway analysis was performed with 838 genes associated with AVEN expression and several oncogenic pathways were altered such as the Cell cycle, VEGFA-VEGFR2 pathway, and epithelial-mesenchymal-transition pathway. Immune infiltration was also analyzed, and less infiltrated B cells was observed in AVENhigh patients. Furthermore, an AVEN-derived genomic model was established, demonstrating a reliable and improved prognostic value in TCGA and GEO databases. Conclusion: This study provided evidence that AVEN is accumulated in LUAD compared to adjacent tissue and is associated with poor survival, high tumor progression, and immune infiltration alteration. Moreover, the study introduced the AVEN-derived prognostic model as a promising prognosis tool for LUAD.

Rhinoceros Serum microRNAs: Identification, Characterization, and Evaluation of Potential Iron Overload Biomarkers

Iron overload disorder (IOD) in critically endangered Sumatran (Dicerorhinus sumatrensis) and black (Diceros bicornis) rhinoceros is an over-accumulation of iron in organs which may exacerbate other diseases and indicate metabolic disturbances. IOD in rhinos is not well understood and diagnostics and therapeutics are limited in effectiveness. MicroRNAs (miRNAs) are small non-coding RNAs capable of altering protein synthesis. miRNA expression responds to physiological states and could serve as the basis for development of diagnostics and therapeutics. This study aimed to identify miRNAs differentially expressed among healthy rhinos and those afflicted with IOD or other diseases ("unhealthy"), and assess expression of select miRNAs to evaluate their potential as biomarkers of IOD. miRNAs in serum of black (n = 11 samples; five individuals) and Sumatran (n = 7 samples; four individuals) rhinos, representing individuals categorized as healthy (n = 9), unhealthy (n = 5), and afflicted by IOD (n = 3) were sequenced. In total, 715 miRNAs were identified, of which 160 were novel, 131 were specific to black rhinos, and 108 were specific to Sumatran rhinos. Additionally, 95 miRNAs were specific to healthy individuals, 31 specific to unhealthy, and 63 were specific to IOD individuals. Among healthy, unhealthy, and IOD states, 21 miRNAs were differentially expressed (P ≤ 0.01). Five known miRNAs (let-7g, miR-16b, miR-30e, miR-143, and miR-146a) were selected for further assessment via RT-qPCR in serum from black (n = 61 samples; seven individuals) and Sumatran (n = 38 samples; five individuals) rhinos. let-7g, miR-30e, and miR-143 all showed significant increased expression (P ≤ 0.05) during IOD (between 1 and 2 years prior to death) and late IOD (within 1 year of death) compared to healthy and unhealthy individuals. miR-16b expression increased (P ≤ 0.05) in late IOD, but was not different among IOD, healthy, and unhealthy states (P > 0.05). Expression of miR-146a increased in IOD and late IOD as compared to unhealthy samples (P ≤ 0.05) but was not different from the healthy state (P > 0.05). Selected serum miRNAs of black and Sumatran rhinos, in particular let-7g, miR-30e, and miR-143, could therefore provide a tool for advancing rhino IOD diagnostics that should be further investigated.

miR-30a attenuates drug sensitivity to 5-FU by modulating cell proliferation possibly by downregulating cyclin E2 in oral squamous cell carcinoma

We aimed to determine the functional role of the miRNA, which affects drug sensitivity to 5-FU in oral squamous cell carcinoma (OSCC), using two types of 5-FU-resistant and parental OSCC cell lines. MiRNA microarray data showed that miR-30a was significantly upregulated in two resistant cell lines. Therefore, we investigated the effects and molecular mechanism of miR-30a on 5-FU sensitivity. Stable overexpression of miR-30a in parental OSCC cells decreased cell proliferation and attenuated drug sensitivity to 5-FU. Cell cycle analysis indicated that miR-30a overexpression increased the proportion of G1 phase cells and decreased the proportion of S phase cells. MiR-30a knockdown using siRNA reversed the effects of miR-30a overexpression. DNA microarray analysis using miR-30a-overexpressing cell lines and a TargetScan database search showed that cyclin E2 (CCNE2) is a target of miR-30a. A luciferase reporter assay confirmed that a miR-30a mimic interacted with the specific binding site in the 3' UTR of CCNE2. CCNE2 knockdown with siRNA in OSCC cells yielded decreased drug sensitivity to 5-FU, similar to miR-30a overexpressing cells. These findings suggest that miR-30a in OSCC may be a novel biomarker of 5-FU-resistant tumors, as well as a therapeutic target for combating resistance.

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miR-30a overexpression increased the proportion of G1 phase cells.

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miR-30a knockdown using si-RNA reversed the effects of miR-30a overexpression.

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CCNE2 knockdown with si-RNA in OSCC cells decreased drug sensitivity to 5-FU.

The Role of microRNAs in Pulp Inflammation

The dental pulp can be affected by thermal, physical, chemical, and bacterial phenomena that stimulate the inflammatory response. The pulp tissue produces an immunological, cellular, and vascular reaction in an attempt to defend itself and resolve the affected tissue. The expression of different microRNAs during pulp inflammation has been previously documented. MicroRNAs (miRNAs) are endogenous small molecules involved in the transcription of genes that regulate the immune system and the inflammatory response. They are present in cellular and physiological functions, as well as in the pathogenesis of human diseases, becoming potential biomarkers for diagnosis, prognosis, monitoring, and safety. Previous studies have evidenced the different roles played by miRNAs in proinflammatory, anti-inflammatory, and immunological phenomena in the dental pulp, highlighting specific key functions of pulp pathology. This systematized review aims to provide an understanding of the role of the different microRNAs detected in the pulp and their effects on the expression of the different target genes that are involved during pulp inflammation.

Polyphenol-Enriched Blueberry Preparation Controls Breast Cancer Stem Cells by Targeting FOXO1 and miR-145

Scientific evidence supports the early deregulation of epigenetic profiles during breast carcinogenesis. Research shows that cellular transformation, carcinogenesis, and stemness maintenance are regulated by epigenetic-specific changes that involve microRNAs (miRNAs). Dietary bioactive compounds such as blueberry polyphenols may modulate susceptibility to breast cancer by the modulation of CSC survival and self-renewal pathways through the epigenetic mechanism, including the regulation of miRNA expression. Therefore, the current study aimed to assay the effect of polyphenol enriched blueberry preparation (PEBP) or non-fermented blueberry juice (NBJ) on the modulation of miRNA signature and the target proteins associated with different clinical-pathological characteristics of breast cancer such as stemness, invasion, and chemoresistance using breast cancer cell lines. To this end, 4T1 and MB-MDM-231 cell lines were exposed to NBJ or PEBP for 24 h. miRNA profiling was performed in breast cancer cell cultures, and RT-qPCR was undertaken to assay the expression of target miRNA. The expression of target proteins was examined by Western blotting. Profiling of miRNA revealed that several miRNAs associated with different clinical-pathological characteristics were differentially expressed in cells treated with PEBP. The validation study showed significant downregulation of oncogenic miR-210 expression in both 4T1 and MDA-MB-231 cells exposed to PEBP. In addition, expression of tumor suppressor miR-145 was significantly increased in both cell lines treated with PEBP. Western blot analysis showed a significant increase in the relative expression of FOXO1 in 4T1 and MDA-MB-231 cells exposed to PEBP and in MDA-MB-231 cells exposed to NBJ. Furthermore, a significant decrease was observed in the relative expression of N-RAS in 4T1 and MDA-MB-231 cells exposed to PEBP and in MDA-MB-231 cells exposed to NBJ. Our data indicate a potential chemoprevention role of PEBP through the modulation of miRNA expression, particularly miR-210 and miR-145, and protection against breast cancer development and progression. Thus, PEBP may represent a source for novel chemopreventative agents against breast cancer.

miR-30a-5p suppresses lung squamous cell carcinoma via ATG5 - mediated autophagy

Propose: Autophagy plays a complicated role in cancer progression. This study aims at assessing the function of ATG5-induced autophagy in progression of lung squamous cell carcinoma and its upstream mechanism.

METHOD

TCGA database of lung squamous cell carcinoma was analyzed to explore the differentially expressed miRNAs and mRNAs and relative prognosis. RT-PCR and Western blot were performed to evaluate autophagy relative gene expression level in human lung squamous cell carcinoma cell Lines. Autophagy flux was observed using transmission electron microscopy and immunofluorescence. Meanwhile, binding relationship of potential target miRNA and mRNAs were also confirmed using Dual-luciferase reporter gene assay. Lung metastatic model was established to evaluated the effect of targeting protein and miRNA.

RESULT

High level expression of ATG5 was detected in LUSC patients. Relative experiments confirmed that ATG5 silencing could decrease the autophagy flux in LUSC. In addition, our research revealed that there is a binding sites between hsa-mir-30a-5p and 3'-UTR of ATG5. Mimic miR-30a-5p suppresses ATG5-mediated autophagy in lung squamous cell carcinoma cells. The in vivo experiments confirmed that miR-30a-5p could attenuate lung squamous cell carcinoma progression through the autophagy pathway.

CONCLUSION

Accordingly, the in vivo and in vitro study in our research have demonstrated that miR-30a-5p inhibits lung squamous cell carcinoma progression via ATG5-mediated autophagy.

Non-coding RNA in cancer

Majority of the human genome is transcribed to RNAs that do not encode proteins. These non-coding RNAs (ncRNAs) play crucial roles in regulating the initiation and progression of various cancers. Given the importance of the ncRNAs, the roles of ncRNAs in cancers have been reviewed elsewhere. Thus, in this review, we mainly focus on the recent studies of the function, regulatory mechanism and therapeutic potential of the ncRNAs including microRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA) and PIWI interacting RNA (piRNA), in different type of cancers.

Reciprocal Changes in miRNA Expression with Pigmentation and Decreased Proliferation Induced in Mouse B16F1 Melanoma Cells by L-Tyrosine and 5-Bromo-2'-Deoxyuridine

Background: Many microRNAs have been identified as critical mediators in the progression of melanoma through its regulation of genes involved in different cellular processes such as melanogenesis, cell cycle control, and senescence. However, microRNAs’ concurrent participation in syngeneic mouse B16F1 melanoma cells simultaneously induced decreased proliferation and differential pigmentation by exposure to 5-Brd-2′-dU (5’Bromo-2-deoxyuridine) and L-Tyr (L-Tyrosine) respectively, is poorly understood. Aim: To evaluate changes in the expression of microRNAs and identify which miRNAs in-network may contribute to the functional bases of phenotypes of differential pigmentation and reduction of proliferation in B16F1 melanoma cells exposed to 5-Brd-2′-dU and L-Tyr. Methods: Small RNAseq evaluation of the expression profiles of miRNAs in B16F1 melanoma cells exposed to 5-Brd-2′-dU (2.5 μg/mL) and L-Tyr (5 mM), as well as the expression by qRT-PCR of some molecular targets related to melanogenesis, cell cycle, and senescence. By bioinformatic analysis, we constructed network models of regulation and co-expression of microRNAs. Results: We confirmed that stimulation or repression of melanogenesis with L-Tyr or 5-Brd-2′-dU, respectively, generated changes in melanin concentration, reduction in proliferation, and changes in expression of microRNAs 470-3p, 470-5p, 30d-5p, 129-5p, 148b-3p, 27b-3p, and 211-5p, which presented patterns of coordinated and reciprocal co-expression, related to changes in melanogenesis through their putative targets Mitf, Tyr and Tyrp1, and control of cell cycle and senescence: Cyclin D1, Cdk2, Cdk4, p21, and p27. Conclusions: These findings provide insights into the molecular biology of melanoma of the way miRNAs are coordinated and reciprocal expression that may operate in a network as molecular bases for understanding changes in pigmentation and decreased proliferation induced in B16F1 melanoma cells exposed to L-Tyr and 5-Brd-2′-dU.

MicroRNA regulation of cancer stem cells in the pathogenesis of breast cancer

Breast cancer is the most common cancer among women and accounts for 30% of all female malignancies worldwide. Breast cancer stem cells (BCSCs) are a small population of breast cancer cells that exhibit multiple characteristics including differentiation capacity, self-renewal and therapeutic resistance. Recently, BCSCs have attracted attention due to their modulation of breast tumor behaviors and drug resistance. miRNAs are small noncoding mRNAs involved in virtually all biological processes, including stem cell development, maintenance and differentiation. In breast cancer, miRNAs appear to be multi-faceted since they can act as either suppressors or oncogenes to regulate breast cancer progression. This review summarizes the critical roles of miRNAs in regulating multiple signaling pathways such as Wnt/β-catenin, Notch, PI3K/AKT/mTOR, BMI-1 and STAT3 that are important for the BCSC maintenance.

Thymoquinone alleviates liver fibrosis via miR-30a-mediated epithelial-mesenchymal transition

Thymoquinone (TQ), the main active constituent of Nigella sativa seeds, has been shown to play a role in antioxidation, anti-inflammation, and antitumor. Recent studies have demonstrated that TQ contributes to the suppression of liver fibrosis. Abnormal activated epithelial-mesenchymal transition (EMT) promotes the activation of hepatic stellate cells (HSCs). However, whether the antifibrotic effects of TQ occur through inhibiting EMT is largely unknown. In this study, it was found that TQ ameliorated liver fibrosis and collagen accumulation in carbon tetrachloride (CCl4) mice. In vitro, TQ inhibited HSC activation including reduced proliferation, α-smooth muscle actin, and collagen. In addition, TQ markedly suppressed the EMT process, with enhanced E-cadherin and reduced desmin. Notably, snail family transcriptional repressor 1 (Snai1), the EMT master transcription factor, was obviously inhibited by TQ in vivo and in vitro. Further studies demonstrated that Snai1 was a target of microRNA-30a (miR-30a), which was upregulated by TQ. Interestingly, the effects of TQ on HSC activation and EMT were almost inhibited by miR-30a inhibitor. Collectively, we demonstrate that TQ inhibits HSC activation, at least in part, via regulation of miR-30a and Snai1. TQ upregulates miR-30a expression, resulting in a reduced Snai1 level as well as EMT process inactivation, which contributes to the inhibition of HSC activation. TQ may be a potential therapeutic agent for liver fibrosis.

Mutually distinguishing microRNA signatures of breast, ovarian and endometrial cancers in vitro

Early diagnosis and therapy in the first stages of a malignant disease is the most crucial factor for successful cancer treatment and recovery. Currently, there is a high demand for novel diagnostic tools that indicate neoplasms in the first or pre‑malignant stages. MicroRNAs (miRNA or miR) are small non‑coding RNAs that may act as oncogenes and downregulate tumor‑suppressor genes. The detection and mutual discrimination of the three common female malignant neoplasia types breast (BC), ovarian (OC) and endometrial cancer (EC) could be enabled by identification of tumor entity‑specific miRNA expression differences. In the present study, the relative expression levels of 25 BC, EC and OC‑related miRNAs were assessed by reverse transcription‑quantitative PCR and determined using the 2‑ΔΔCq method for normalization against the mean of four housekeeping genes. Expression levels of all miRNAs were analyzed by regression against cell line as a factor. An expression level‑based discrimination between BC and OC cell types was obtained for a subgroup of ten different miRNA types. miR‑30 family genes, as well as three other miRNAs, were found to be uniformly upregulated in OC cells compared with BC cells. BC and EC cells could be distinguished by the expression profiles of six specific miRNAs. In addition, four miRNAs were differentially expressed between EC and OC cells. In conclusion, miRNAs were identified as a potential novel tool to detect and mutually discriminate between BC, OC and EC. Based on a subset of 25 clinically relevant human miRNA types, the present study could significantly discriminate between these three female cancer types by means of their expression levels. For further verification and validation of miRNA‑based biomarker expression signatures that enable valuable tumor detection and characterization in routine screening or potential therapy monitoring, additional and extended in vitro analyses, followed by translational studies utilizing patients' tissue and liquid biopsy materials, are required.

Adenosine and adenosine receptors in colorectal cancer

CD39 (nucleoside triphosphate diphosphohydrolase) and Ecto-5-nucleotidase (CD73) have been recognized as important factors mediating various pathological and physiological responses in the tumor microenvironment. Elevated expression of CD73 and CD39 is correlated with the over-production of adenosine in the tumor region. This increase is associated with an immunosuppressive state in the tumor site that enhances various tumor hallmarks such as metastasis, angiogenesis, and cell proliferation. Adenosine promotes these behaviors through interaction with four adenosine receptors, including A3R, A2BR, A2AR, and A1R. Signaling of these receptors reduces the function of immune effector cells and enhances the expansion and function of tumor-associated immune cells. Several studies have been shown the important role of adenosine/CD73/CD39/ARs axis in the immunopathogenesis of colorectal cancer. These findings imply that components of this axis can be considered as a worthy target for colorectal cancer immunotherapy. In this review, we summarized the role of CD73/CD39/adenosine/ARs in the immunopathogenesis of colorectal cancer.

Potential miRNAs for miRNA-Based Therapeutics in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNAs that can post-transcriptionally regulate the genes involved in critical cellular processes. The aberrant expressions of oncogenic or tumor suppressor miRNAs have been associated with cancer progression and malignancies. This resulted in the dysregulation of signaling pathways involved in cell proliferation, apoptosis and survival, metastasis, cancer recurrence and chemoresistance. In this review, we will first (i) provide an overview of the miRNA biogenesis pathways, and in vitro and in vivo models for research, (ii) summarize the most recent findings on the roles of microRNAs (miRNAs) that could potentially be used for miRNA-based therapy in the treatment of breast cancer and (iii) discuss the various therapeutic applications.

MicroRNA-30b participates in the pathological process of hyperuricemia by regulating interleukin-6 receptor

The present study aimed to examine the expression of hyperuricemia (HUA)-related factors in the body fluids of HUA patients and in renal tissues and body fluids of HUA mice to elucidate the underlying mechanism of HUA and provide theoretical basis for the diagnosis, prevention and treatment of this disease. A total of 51 HUA patients (HUA group), and 36 healthy subjects (control group) were included in the present study. The peripheral blood and urine were collected from all patients and healthy subjects. A total of 20 male Kunming mice were used to construct HUA model, and another 20 mice were used as controls. The kidney tissues, peripheral blood and urine were collected from all mice. ELISA was performed to determine the levels of interleukin-6 receptor (IL-6R) proteins in the serum and urine of human or mice, while western blotting was employed to determine the protein expression in the kidney tissues of mice. Quantitative real-time polymerase chain reaction was used to measure the expression of mRNA and miR-30b in all sample types. Dual luciferase reporter assay was performed to identify the direct interaction between 3'-untranslated region of IL-6R mRNA and miR-30b. The expression of IL-6R mRNA and protein was increased in serum and urine of HUA patients, while the expression of miR-30b was reduced in HUA patients when compared with healthy subjects. The contents of uric acid, urea nitrogen and creatinine in the blood of HUA mice model were significantly elevated. Similarly, the expression of IL-6R mRNA and protein was increased in kidney, serum and urine of HUA mice model, while the expression of miR-30b was reduced in kidney tissues, serum and urine of HUA mice model. Dual luciferase reporter assay showed that miR-30b was able to bind with 3'-UTR seed region of IL-6R mRNA to regulate its expression. These findings demonstrated that the expression of IL-6R in patients and mouse with HUA is elevated, which is related with the down-regulation of miR-30b. Therefore, miR-30b might participate in the pathological process of HUA by regulating IL-6R.

Secreted breast tumor interstitial fluid microRNAs and their target genes are associated with triple-negative breast cancer, tumor grade, and immune infiltration

Background

Studies on tumor-secreted microRNAs point to a functional role of these in cellular communication and reprogramming of the tumor microenvironment. Uptake of tumor-secreted microRNAs by neighboring cells may result in the silencing of mRNA targets and, in turn, modulation of the transcriptome. Studying miRNAs externalized from tumors could improve cancer patient diagnosis and disease monitoring and help to pinpoint which miRNA-gene interactions are central for tumor properties such as invasiveness and metastasis.

Methods

Using a bioinformatics approach, we analyzed the profiles of secreted tumor and normal interstitial fluid (IF) microRNAs, from women with breast cancer (BC). We carried out differential abundance analysis (DAA), to obtain miRNAs, which were enriched or depleted in IFs, from patients with different clinical traits. Subsequently, miRNA family enrichment analysis was performed to assess whether any families were over-represented in the specific sets. We identified dysregulated genes in tumor tissues from the same cohort of patients and constructed weighted gene co-expression networks, to extract sets of co-expressed genes and co-abundant miRNAs. Lastly, we integrated miRNAs and mRNAs to obtain interaction networks and supported our findings using prediction tools and cancer gene databases.

Results

Network analysis showed co-expressed genes and miRNA regulators, associated with tumor lymphocyte infiltration. All of the genes were involved in immune system processes, and many had previously been associated with cancer immunity. A subset of these, BTLA, CXCL13, IL7R, LAMP3, and LTB, was linked to the presence of tertiary lymphoid structures and high endothelial venules within tumors. Co-abundant tumor interstitial fluid miRNAs within this network, including miR-146a and miR-494, were annotated as negative regulators of immune-stimulatory responses. One co-expression network encompassed differences between BC subtypes. Genes differentially co-expressed between luminal B and triple-negative breast cancer (TNBC) were connected with sphingolipid metabolism and predicted to be co-regulated by miR-23a. Co-expressed genes and TIF miRNAs associated with tumor grade were BTRC, CHST1, miR-10a/b, miR-107, miR-301a, and miR-454.

Conclusion

Integration of IF miRNAs and mRNAs unveiled networks associated with patient clinicopathological traits, and underlined molecular mechanisms, specific to BC sub-groups. Our results highlight the benefits of an integrative approach to biomarker discovery, placing secreted miRNAs within a biological context.

miR-30a-5p Inhibits Proliferation and Migration of Lung Squamous Cell Carcinoma Cells by Targeting FOXD1

OBJECTIVE

To investigate the mechanism of miR-30a-5p inhibiting proliferation and migration of lung squamous cell carcinoma (LSCC) cells by targeting FOXD1.

METHODS

Bioinformatics was used to analyze differentially expressed genes in the TCGA_LUSC database. qRT-PCR was used to detect the expression levels of miR-30a-5p and FOXD1 in human normal lung epithelial cell line and human LSCC cell lines. The protein expression of FOXD1 was detected by western blot. The cell viability and colony formation abilities were examined by CCK-8 and colony formation assays, respectively. Wound healing and Transwell assays were performed to examine the migration and invasion abilities of cells. The targeted binding sites of miR-30a-5p and FOXD1 were predicted by bioinformatics, and dual luciferase assay was used to verify the targeted binding relationship between miR-30a-5p and FOXD1.

RESULT

miR-30a-5p was downregulated in LSCC tissues and cells, while FOXD1 was highly expressed. Overexpression of miR-30a-5p or silencing FOXD1 inhibited cell viability, colony formation ability, migration, and invasion of LSCC cells. miR-30a-5p inhibited the proliferation and migration of LSCC cells by downregulating the expression of FOXD1.

CONCLUSION

miR-30a-5p can downregulate the expression of FOXD1 and inhibit the proliferation and migration of LSCC.

Nicotine-upregulated miR-30a arrests cell cycle in G1 phase by directly targeting CCNE2 in human periodontal ligament cells

The consumption of nicotine via smoking tobacco has been reported to stimulate the occurrence and progression of periodontitis. Many studies have demonstrated that nicotine prevents the regeneration of periodontal tissues primarily by inhibiting the proliferation of human periodontal ligament (PDL) cells. However, the mechanisms underlying this process are still unclear. Therefore, we investigated whether nicotine-upregulated miR-30a inhibited the proliferation of human PDL cells by downregulating cyclin E2 (CCNE2), in vitro. Quantitative real-time PCR analysis revealed that nicotine upregulated the expression of miR-30a in human PDL cells. In addition, nicotine inhibited the proliferation of human PDL cells by inducing cell cycle arrest. To support this hypothesis, we showed that nicotine downregulated the expression of CCNE2 in human PDL cells, whereas inhibition of miR-30a restored CCNE2 expression that had been downregulated by nicotine. Furthermore, using luciferase reporter assays, we found that miR-30a directly interacts with the CCNE2 3'UTR. In conclusion, these findings indicate that nicotine-upregulated miR-30a inhibits the proliferation of human PDL cells by downregulating the expression of CCNE2.

Generation of microRNA-30e-producing recombinant viral hemorrhagic septicemia virus (VHSV) and its effect on in vitro immune responses

MicroRNAs (miRNAs) are non-coding small RNAs involved in the regulation of gene expression. In the present study, we firstly reported the use of a fish RNA virus, viral hemorrhagic septicemia virus (VHSV), as a delivery vehicle of a miRNA-30e, and the effect of miR-30e produced by the recombinant VHSV on the immune responses of Epithelioma papulosum cyprini (EPC) cells was investigated. The expression of functional miR-30e using a CMV promoter-driven vector was verified by the significantly lower eGFP expression in cells transfected with a vector containing miR-30e sponge sequence than that in cells transfected with a control vector that had mutated miR-30e sponge sequence. Furthermore, the down-regulation of reporter gene containing 3'-UTR of NF-κb inhibitor α-like protein B (NFκbiαb) by miR-30e was demonstrated, suggesting that miR-30e overexpression can increase immune responses related to NF-κB activation through inhibition of IκB. A miR-30e-expressing recombinant VHSV (rVHSV-A-miR30e) that had primary microRNA-30e sequence between N and P genes was rescued using the reverse genetic method, and the successful expression of miR-30e in the cells infected with rVHSV-A-miR30e was demonstrated using Northern blot and qRT-PCR. Cells infected with rVHSV-A-miR30e showed the increase of NF-κB activation and type I interferon induced genes expression, suggesting that rVHSV-A-miR30e can produce functional miR-30e in fish cells, and VHSV can be used as a vehicle to deliver functional microRNAs in fish.

Plasma miR-30a-5p as an early novel noninvasive diagnostic and prognostic biomarker for lung cancer

Aim: Circulation miRNAs have become increasingly appreciated in the diagnosis and prognosis of lung cancer. This study aims to identify and evaluate plasma miRNA-30a-5p as an early noninvasive biomarker for the diagnosis and prognosis of lung cancer. Pateints & methods: Expression levels of plasma miRNA 30a-5p were measured by quantitative real-time PCR. Receiver operating characteristic analysis and area under the curve were used to differentiate malignant from benign tumors and from healthy controls. Kaplan-Meier curves and Cox regression were used to determine survival and prognosis. Results: Our results suggest that the level of miRNA-30a-5p in plasma might be a considerable early novel noninvasive diagnostic and prognostic biomarker for lung cancer. Conclusion: Prospective studies must be performed to confirm this new early novel noninvasive diagnostic and prognostic biomarker for lung cancer.

The Role of MicroRNAs in the Regulation of Gastric Cancer Stem Cells: A Meta-Analysis of the Current Status

Gastric cancer (GC) remains one of the major causes of cancer-related mortality worldwide. As for other types of cancers, several limitations to the success of current therapeutic GC treatments may be due to cancer drug resistance that leads to tumor recurrence and metastasis. Increasing evidence suggests that cancer stem cells (CSCs) are among the major causative factors of cancer treatment failure. The research of molecular CSC mechanisms and the regulation of their properties have been intensively studied. To date, molecular gastric cancer stem cell (GCSC) characterization remains largely incomplete. Among the GCSC-targeting approaches to overcome tumor progression, recent studies have focused their attention on microRNA (miRNA). The miRNAs are short non-coding RNAs which play an important role in the regulation of numerous cellular processes through the modulation of their target gene expression. In this review, we summarize and discuss recent findings on the role of miRNAs in GCSC regulation. In addition, we perform a meta-analysis aimed to identify novel miRNAs involved in GCSC homeostasis.

MiR-30a-5p frequently downregulated in prostate cancer inhibits cell proliferation via targeting PCLAF

MicroRNAs (miRNAs) have vastly expanded our view of RNA world in intracellular signal regulating networks. Here, we functionally characterized a normally highly expressed miRNA, miR-30a-5p (MIMAT0000087), which exhibits downregulated expression profiles in prostate cancer samples. MiR-30a-5p knockdown and overexpression in PC-3 cell line alters cell proliferation supporting a tumour suppressor role. We also discovered that PCLAF is the direct target of miR-30a-5p. Notably, PC-3 cell proliferation is inhibited by miR-30a-5p/PCLAF axis. miR-30a-5p represents a novel molecule of functionally important miRNAs which may shed light on the novel therapeutic targets for prostate cancer.

Comparative analysis of milk microRNA in the therian lineage highlights the evolution of lactation

Milk is a complex secretion that has an important role in mammalian reproduction. It is only recently that sequencing technologies have allowed the identification and quantification of microRNA (miRNA) in milk of a growing number of mammalian species. This provides a novel window on the study of the evolution and functionality of milk through the comparative analysis of milk miRNA content. Here, milk miRNA sequencing data from five species (one marsupial (tammar wallaby) and four eutherians (human, mouse, cow and pig)) have been retrieved from public depositories and integrated in order to perform a comparison of milk miRNA profiles. The study shows that milk miRNA composition varies widely between species, except for a few miRNAs that are ubiquitously expressed in the milk of all mammals and indicates that milk miRNA secretion has broadly evolved during mammalian evolution. The putative functions of the most abundant milk miRNAs are also discussed.

Wnt pathway targeting reduces triple-negative breast cancer aggressiveness through miRNA regulation in vitro and in vivo

Triple-negative breast cancer, devoid of estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER-2) expression, is deprived of commonly used targeted therapies. MicroRNAs (miRNAs) are undergoing a revolution in terms of potentially diagnostic or therapeutic elements. Combining computational approaches, we enriched miRNA binding motifs of Wnt pathway-associated upregulated genes. Our in-depth bioinformatics, in vitro and in vivo analyses indicated that miR-381 targets main genes of the Wnt signaling pathway including CTNNB1, RhoA, ROCK1, and c-MYC genes. The expression level of miR-381 and target genes was assessed by quantitative real-time polymerase chain reaction (RT-qPCR) in MCF-7, MDA-MB-231, and MCF-10A as well as 20 breast cancer samples and normal tissues. Luciferase reporter assay was performed. Lentiviral particles containing miR-381 were used to evaluate the effect of miR-381 restoration on cell proliferation, migration, and invasion of the invasive triple-negative MDA-MB-231 cell line and also in a mouse model of breast cancer. The expression of miR-381 was lower than that of normal cells, especially in TNBC cell line and breast tissues. Luciferase assay results confirmed that miR-381 targets all the predicted 3'-untranslated regions (3'-UTRs). Upon miR-381 overexpression, the expression of target genes declined, and the migration and invasion potential of miR-381-receiving MDA-MB-231 cells decreased. In a mouse model of triple-negative breast cancer, miR-381 re-expression inhibited the invasion of cancer cells to lung and liver and prolonged the survival time of cancer cell-bearing mice. Therefore, miR-381 is a regulator of Wnt signaling and its re-expression provides a potentially effective strategy for inhibition of TNBC.

Decreased expression of microRNA-30b promotes the development of pulpitis by upregulating the expression of interleukin-6 receptor

The present study aimed to examine the expression of interleukin-6 receptor (IL-6R) mRNA and protein in pulp tissues, blood and saliva from patients with pulpitis. It also investigated the association between IL-6R and microRNA (miR)-30b, as well as their effects on pulpitis. A total of 28 patients with pulpitis were recruited into the experimental group and 16 subjects with no pulpitis who also underwent tooth extraction were recruited into the control group. Pulp tissues, plasma and saliva were collected from all participants. Reverse transcription-quantitative polymerase chain reaction was used to determine the expression of IL-6R mRNA and miR-30b in all sample types. Western blot analysis was performed to examine the protein expression of IL-6R in pulp tissues, while ELISA was used to determine the contents of IL-6R protein in the plasma and saliva samples. A dual luciferase reporter assay was performed to verify the interactions between IL-6R and miR-30b. The expression of IL-6R mRNA in the pulp tissues, plasma and saliva was significantly increased in patients with pulpitis compared with the control group. Similarly, the IL-6R protein expression in the samples from patients with pulpitis were also significantly increased compared with the control group. Conversely, the expression of miR-30b was significantly reduced in the samples from patients with pulpitis compared with the control group. The dual luciferase reporter assay revealed that miR-30b may bind with the 3'-untranslated seed region of IL-6R mRNA to regulate its expression. The present study demonstrated that the upregulated expression of IL-6R in pulp tissues, plasma and saliva from patients with pulpitis was associated with the downregulation of miR-30b expression. In addition, miR-30b may affect the progression of pulpitis via IL-6R and may be a potential genetic marker for the diagnosis of pulpitis.

Integrated Genomic and Functional microRNA Analysis Identifies miR-30-5p as a Tumor Suppressor and Potential Therapeutic Nanomedicine in Head and Neck Cancer

PURPOSE

To identify deregulated and inhibitory miRNAs and generate novel mimics for replacement nanomedicine for head and neck squamous cell carcinomas (HNSCC).

EXPERIMENTAL DESIGN

We integrated miRNA and mRNA expression, copy number variation, and DNA methylation results from The Cancer Genome Atlas (TCGA), with a functional genome-wide screen.

RESULTS

We reveal that the miR-30 family is commonly repressed, and all 5 members sharing these seed sequence similarly inhibit HNSCC proliferation in vitro. We uncover a previously unrecognized inverse relationship with overexpression of a network of important predicted target mRNAs deregulated in HNSCC, that includes key molecules involved in proliferation (EGFR, MET, IGF1R, IRS1, E2F7), differentiation (WNT7B, FZD2), adhesion, and invasion (ITGA6, SERPINE1). Reexpression of the most differentially repressed family member, miR-30a-5p, suppressed this mRNA program, selected signaling proteins and pathways, and inhibited cell proliferation, migration, and invasion in vitro. Furthermore, a novel miR-30a-5p mimic formulated into a targeted nanomedicine significantly inhibited HNSCC xenograft tumor growth and target growth receptors EGFR and MET in vivo. Significantly decreased miR-30a/e family expression was related to DNA promoter hypermethylation and/or copy loss in TCGA data, and clinically with decreased disease-specific survival in a validation dataset. Strikingly, decreased miR-30e-5p distinguished oropharyngeal HNSCC with poor prognosis in TCGA (P = 0.002) and validation (P = 0.007) datasets, identifying a novel candidate biomarker and target for this HNSCC subset.

CONCLUSIONS

We identify the miR-30 family as an important regulator of signal networks and tumor suppressor in a subset of HNSCC patients, which may benefit from miRNA replacement nanomedicine therapy.

An integrated analysis to predict micro-RNAs targeting both stemness and metastasis in breast cancer stem cells

Several evidences support the idea that a small population of tumour cells representing self‐renewal potential are involved in initiation, maintenance, metastasis, and outcomes of cancer therapy. Elucidation of microRNAs/genes regulatory networks activated in cancer stem cells (CSCs) is necessary for the identification of new targets for cancer therapy. The aim of the present study was to predict the miRNAs pattern, which can target both metastasis and self‐renewal pathways using integration of literature and data mining. For this purpose, mammospheres derived from MCF‐7, MDA‐MB231, and MDA‐MB468 were used as breast CSCs model. They had higher migration, invasion, and colony formation potential, with increasing in stemness‐ and EMT‐related genes expression. Our results determined that miR‐204, ‐200c, ‐34a, and ‐10b contemporarily could target both self‐renewal and EMT pathways. This core regulatory of miRNAs could increase the survival rate of breast invasive carcinoma via up‐regulation of OCT4, SOX2, KLF4, c‐MYC, NOTCH1, SNAI1, ZEB1, and CDH2 and down‐regulation of CDH1. The majority of those target genes were involved in the regulation of pluripotency, MAPK, WNT, Hedgehog, p53, and transforming growth factor β pathways. Hence, this study provides novel insights for targeting core regulatory of miRNAs in breast CSCs to target both self‐renewal and metastasis potential and eradication of breast cancer.

LncRNA MALAT1 potentiates autophagy‑associated cisplatin resistance by regulating the microRNA‑30b/autophagy‑related gene 5 axis in gastric cancer

Gastric cancer (GC) is the fourth most common type of cancer worldwide and chemoresistance is a major obstacle to successful GC treatment. In the present study, reverse transcription‑quantitative polymerase chain reaction analysis was used to measure the expression of metastasis‑associated lung adenocarcinoma transcript 1 (MALAT1) and microRNA (miR)‑30b. Western blot analysis was conducted to detect the protein expression of autophagy‑related gene 5 (ATG5), p62 and LC3 (LC3‑I and LC3‑II). Cell viability and half maximal inhibitory concentration were determined by the Cell Counting Kit‑8 assay. The green fluorescent protein (GFP)‑LC3‑positive cell percentage was determined by the GFP‑LC3 puncta experiment. Luciferase reporter and RNA immunoprecipitation assays were used to explore the molecular associations among MALAT1, miR‑30b and ATG5. MALAT1 was found to be highly expressed in CDDP‑resistant AGS(AGS/CDDP) cells and CDDP‑resistant HGC‑27 (HGC‑27/CDDP) cells. Cell viability was markedly increased in MALAT1‑overexpressing AGS/CDDP cells, but was notably reduced in MALAT1‑depleted HGC‑27/CDDP cells. Moreover, MALAT1 potentiated CDDP resistance by facilitating autophagy in AGS/CDDP and HGC‑27/CDDP cells. Further investigations demonstrated that MALAT1 inhibited miR‑30b expression by direct interaction. Moreover, miR‑30b abolished MALAT1‑induced CDDP resistance by inhibiting autophagy in AGS/CDDP and HGC‑27/CDDP cells. Furthermore, ATG5 was found to be a target of miR‑30b. miR‑30b weakened resistance to CDDP by inhibiting autophagy in AGS/CDDP and HGC‑27/CDDP cells, while this effect was abrogated by increased ATG5 expression. Additionally, MALAT1 sequestered miR‑30b from ATG5 to increase ATG5 expression in AGS/CDDP and HGC‑27/CDDP cells. Therefore, MALAT1 potentiated autophagy‑related CDDP resistance through suppressing the miR‑30b/ATG5 axis in AGS/CDDP and HGC‑27/CDDP cells, indicating that it may represent a promising target for the reversal of chemoresistance in GC.

MiR-30-5p suppresses cell chemoresistance and stemness in colorectal cancer through USP22/Wnt/β-catenin signaling axis

Colorectal cancer (CRC) remains both common and fatal, and its successful treatment is greatly limited by the development of stem cell‐like characteristics (stemness) and chemoresistance. MiR‐30‐5p has been shown to function as a tumor suppressor by targeting the Wnt/β‐catenin signaling pathway, but its activity in CRC has never been assessed. We hypothesized that miR‐30‐5p exerts anti‐oncogenic effects in CRC by regulating the USP22/Wnt/β‐catenin signaling axis. In the present study, we demonstrate that tissues from CRC patients and human CRC cell lines show significantly decreased miR‐30‐5p family expression. After identifying the 3’UTR of USP22 as a potential binding site of miR‐30‐5p, we constructed a luciferase reporter containing the potential miR‐30‐5p binding site and measured the effects on USP22 expression. Western blot assays showed that miR‐30‐5p decreased USP22 protein expression in HEK293 and Caco2 CRC cells. To evaluate the effects of miR‐30‐5p on CRC cell stemness, we isolated CD133 + CRC cells (Caco2 and HCT15). We then determined that, while miR‐30‐5p is normally decreased in CD133 + CRC cells, miR‐30‐5p overexpression significantly reduces expression of stem cell markers CD133 and Sox2, sphere formation, and cell proliferation. Similarly, we found that miR‐30‐5p expression is normally reduced in 5‐fluorouracil (5‐FU) resistant CRC cells, whereas miR‐30‐5p overexpression in 5‐FU resistant cells reduces sphere formation and cell viability. Inhibition of miR‐30‐5p reversed the process. Finally, we determined that miR‐30‐5p attenuates the expression of Wnt/β‐catenin signaling target genes (Axin2 and MYC), Wnt luciferase activity, and β‐catenin protein levels in CRC stem cells.

MiR-30a: A Novel Biomarker and Potential Therapeutic Target for Cancer

MicroRNAs (miRNAs) are small, highly conserved noncoding RNAs molecules, consisting of 18–25 nucleotides that regulate gene expression by binding to complementary binding sites within the 3′untranslated region (3′UTR) of target mRNAs. MiRNAs have been involved in regulating gene expression and diverse physiological and pathological processes. Several studies have reported that miR-30a, situated on chromosome 6q.13, is produced by an intronic transcriptional unit. Moreover, miR-30a has demonstrated its role in biological processes, including inhibiting proliferation and metastasis in many tumors, autophagy in chronic myelogenous leukemia, and regulating TGF-b1-induced epithelial-mesenchymal transition. However, based on the pathogenetic relationship between miR-30a and cancer in tumorigenesis, we believe that miR-30a may serve as tumor promising biomarker. Moreover, it would offer a therapeutic target for the treatment of cancer.

Effects of miRNAs on functions of breast cancer stem cells and treatment of breast cancer

Breast cancer is one of the most common malignancies for women, which accounts for 30% of all female malignancies. The formation of breast cancer stem cells (BCSCs) is attributed to the acquisition of stemness of tumor cells. With self-renewal potential, these stem cells are insensitive to either radiotherapy or chemotherapy but are significant in regulating tumor behaviors and drug resistance. MicroRNA (miRNA) is a kind of noncoding small RNA for negatively regulating gene expressions. Research findings suggest that many miRNAs specifically regulate the expression of target genes and signal pathways of BCSCs. They play an important role in self-renewal, growth, and metastasis of breast cancer cells as potential targets for treating breast cancer. These signal pathways include phosphatase and tensin homolog deleted on chromosome 10-phosphatidylinositol 3-kinase/Akt, Wnt/β-catenin, Notch, and so on. This paper reviews the progress of research about miRNAs in self-renewal, metastasis, epithelial-mesenchymal transition and metastasis, mediation of resistance to chemotherapies, and treatment of breast cancer.

MicroRNA-30 mediates cell invasion and metastasis in breast cancer

Despite the great progress in recent years, many aspects of the pathogenesis and progression of breast cancer remain unclear. A better understanding on the molecular mechanisms underlying metastasis and recurrence is crucial to improve the treatment of this lethal disease. MCF-7 cells were xenografted into mice until visible tumors developed, and the cells from tumor tissue and adjacent normal tissue were cultured with 3 passages as mass tumor (MT) cells and invasive tumor (IT) cells, respectively. Microarray analysis was performed to detect several viable microRNAs in these 2 types of cells. Further, miR-30 knockdown was used to investigate its role in tumor aggression. Relative levels of miR-30 were significantly higher in IT cells than MT cells. Knockdown of miR-30 in both MT and IT cells lowered cell proliferation and cell invasion abilities, and thus increased the survival time of mice xenografted with tumor cells. This study suggested that the knockdown of miR-30 decreased proliferation and invasion of carcinoma cells, giving rise to the potential of miR-30 as a tumor target or marker candidate for breast cancer therapy.

MicroRNA array analysis of the regulation of microRNAs in rats exhibiting hyperplasia of mammary glands

Hyperplasia of mammary glands (HMG) is also termed mammary dysplasia. In China, the number of patients suffering from breast hyperplasia is increasing annually. MicroRNAs (miRNAs; length, 19–24 nucleotides), a group of small endogenous non-coding RNAs, post-transcriptionally regulate gene expression via RNA interference and gene silencing pathways. The cause of disease of HMG because remains unclear. Thus, the aim of the present study was to establish comprehensive profile of drug treatments following at different time intervals on rat models of differentially expressed miRNAs, using miRNA microarray data. After scanning the chip, 13 up-regulated and 20 down-regulated miRNAs were identified. MiR-31 and miR-30 exhibited different expression levels between rats exhibiting mammary gland hyperplasia treated with or without Jiedu Capsule water solution once a day for 4 weeks, and the two demonstrated a strong association with HMG and breast cancer. Therefore, the functions of these miRNAs may provide the basis for further investigation of HMG.

Breast Cancer Heterogeneity: A focus on Epigenetics and In Vitro 3D Model Systems

Breast cancer (BC) is a widely prevalent form of neoplasia in women with fairly alarming mortality statistics. This aspect may be attributed, in part, to the current spatial and temporal heterogeneity-based limitations in therapies with possible recurrence of this tumour at primary and/or secondary sites. Such an extensive phenotypic heterogeneity in breast cancer is unlikely to be adequately or completely comprehended by an immuno-histopathology-based classification alone. This finding has warranted research and development in the area of microarray-based methods (i.e. transcriptomic and proteomic chips) for an improved molecular classification of this complex and heterogeneous tumour. Further, since epigenetics can also be an important determinant in terms of diagnosis, prognosis and therapy, this review provides an insight into the molecular portrait of BC in genetic and epigenetic terms. Specifically, the roles of characteristic DNA and histone-based modifications as well as mi-RNA- based alterations have been discussed with specific examples. Also, their involvement in epithelial mesenchymal transition (EMT) processes in cancer stem cells (CSCs) has been outlined. Last but not least, the salient aspects and the advantages of ex vivo/in vitro 3D model systems in recapitulating several aspects of BC tumour (particularly the architecture as well as the apico-basal polarity) are mentioned. This review hopes to provide not only an improved and updated understanding of the epigenetics of breast cancer, but to also elaborate on tumour model development/refinement, biomarker evaluation, drug resistance and test of individual drugs or drug combinations and drug delivery systems.

Absent expression of miR-30a promotes the growth of lung cancer cells by targeting MEF2D

The microRNA (miR)-30 family has been reported to be aberrantly expressed in several types of cancer. However, its contributions to lung cancer remain to be fully elucidated. Myocyte enhancer factor 2D (MEF2D), an oncogene in liver cancer, has been shown to be aberrantly expressed in lung cancer. In the present study, it was found that MEF2D and miR-30a were inversely correlated in lung cancer samples. Using an online database, it was predicted that miR-30a targeted the 3' untranslated region (UTR) of MEF2D mRNA. The activity of luciferase with MEF2D 3'UTR was suppressed by transfecting cells with miR-30a mimics. The results of western blot analysis showed that the miR-30a mimics also suppressed the MEF2D protein. The miR-30a mimics were able to reduce the growth and colonies of lung cancer cells by suppressing MEF2D. The results of FACS and western blot assays showed that the apoptotic rate was reduced by transfection with the miR-30a mimics. Collectively, the aberrant expression of miR-30a in lung cancer promoted the expression of MEF2D protein. miR-30a inhibited the growth and colony formation of the lung cancer cells by promoting apoptosis.

FOXD1 is targeted by miR-30a-5p and miR-200a-5p and suppresses the proliferation of human ovarian carcinoma cells by promoting p21 expression in a p53-independent manner

High-grade serous ovarian carcinoma (HGSOC) accounts for the highest number of deaths among patients with epithelial ovarian cancer. However, the molecular mechanisms underlying HGSOC tumorigenesis are currently unclear. In the present study, a lentiviral expression system was employed to manipulate forkhead box D1 (FOXD1) expression in ovarian cancer cells. Immunohistochemical staining was used to examine the expression of FOXD1 in tissue samples. Clonogenic and MTT assays were employed to evaluate cell proliferation, and flow cytometry was applied for cell cycle analysis. Dual-luciferase reporter and chromatin immunoprecipitation assays were used to determine the role of FOXD1 in regulating p21 expression. The results demonstrated that FOXD1 expression was downregulated in HGSOC, and high expression levels of FOXD1 were found to be a predictor of good prognosis. FOXD1 significantly inhibited the proliferation of human ovarian cancer cells and induced cell cycle arrest at G1 phase in vitro. In addition, exogenous FOXD1 expression inhibited ovarian cancer cell growth in vivo. Furthermore, microRNA (miR)-30a-5p and miR-200a-5p were observed to be upregulated in HGSOC, and function as direct negative regulators of FOXD1 by targeting its 3'-untranslated region. The present study also revealed that FOXD1 promotes p21 expression in a p53-independent manner. In conclusion, the results of the present study indicate a direct association between FOXD1 and p21 that may be mediated by miR-30a-5p and miR-200a-5p. The authors hypothesize that FOXD1 may serve as a biomarker or therapeutic target in HGSOC.

Comparative aspects of microRNA expression in canine and human cancers

MicroRNAs (miRNAs) have important roles in all biological pathways in multicellular organisms. Over 1,400 human miRNAs have been identified, and many are conserved among vertebrates and invertebrates. Regulation of miRNA is the most common mode of post-transcriptional gene regulation. The miRNAs that are involved in the initiation and progression of cancers are termed oncomiRs and several of them have been identified in canine and human cancers. Similarly, several miRNAs have been reported to be down-regulated in cancers of the two species. In this review, current information on the expression and roles of miRNAs in oncogenesis and progression of human and canine cancers, as well the roles miRNAs have in cancer stem cell biology, are highlighted. The potential for the use of miRNAs as therapeutic targets in personalized cancer therapy in domestic dogs and their possible application in human cancer counterparts are also discussed.

Low expression of miR-30a-5p induced the proliferation and invasion of oral cancer via promoting the expression of FAP

The study aimed at investigating the effects of miR-30a-5p on the biological functions of oral cancer cells and figuring out the potential mechanism. We first verified the low expression of miR-30a-5p and high expression of FAP (Homo sapiens fibroblast activation protein α) in oral cancerous tissues and their negative correlation. Then, the target relationship between miR-30a-5p and FAP was validated by dual luciferase reporter assay and biotin-coupled miRNA pulldown assay. After transfection in Tca-8113 cells and SCC-15 cells, MTT, colony formation, Transwell, and wound healing assays were performed to investigate how miR-30a-5p and FAP adjusted propagation, invasiveness, and migration, respectively. Mounting evidence supported that miR-30a-5p directly targetted FAP and suppressed its expression in oral cavity cancer cells (OSCCs). By suppressing FAP expression, miR-30a-5p significantly inhibited cell propagation, migration, and invasion. Therefore, miR-30a-5p might be a new therapeutic target for oral cancer treatment.

MicroRNAs and cancer: Key paradigms in molecular therapy

MicroRNAs (miRNAs) are a type of small non-coding RNA molecule that performs an important role in post-transcriptional gene regulation. Since miRNAs were first identified in 1993, a number of studies have demonstrated that they act as tumor suppressors or oncogenes in human cancer, including colorectal, lung, brain, breast and liver cancer, and leukemia. Large high-throughput studies have previously revealed that miRNA profiling is critical for the diagnosis and prognosis of patients with cancer, while certain miRNAs possess the potential to be used as diagnostic and prognostic biomarkers or therapeutic targets in cancer. The present study reviews the studies and examines the roles of miRNAs in cancer diagnosis, prognosis and treatment, and discusses the potential therapeutic modality of exploiting miRNAs.

Identification of bladder cancer prognostic biomarkers using an ageing gene-related competitive endogenous RNA network

Competitive endogenous RNAs (ceRNAs) are a newly proposed RNA interaction mechanism that has been associated with the initiation and progression of various cancers. In this study, we constructed an ageing gene related ceRNA network (AgeingCeNet) in bladder cancer. Network analysis revealed that ageing gene ceRNAs have a larger degree and closeness centrality than ageing genes themselves. Notably, the difference of betweenness centrality of ageing genes and their ceRNAs is not significant, suggesting that the ceRNAs of ageing genes and ageing genes themselves both play important communication roles in AgeingCeNet. KEGG pathway enrichment analysis for genes in AgeingCeNet revealed that AgeingCeNet genes are enriched in cancer pathways and several cancer related singaling pathways. We also identified 37 core modules from AgeingCeNet using CFinder software. Next, we identified 2 potential prognostic modules, named K11M14 and K13M4, whose prognostic ability is better than that of age and gender. Finally, we identified microRNAs (miRNAs) regulating the two modules, which include miR-15b-5p, miR-195-5p, miR-30 family members, and several other cancer-related miRNAs. Our study demonstrated that constructing an ageing gene related ceRNA network is a feasible strategy to explore the mechanism of initiation and progression of bladder cancer, which might benefit the treatment of this disease.

miR-30e controls DNA damage-induced stress responses by modulating expression of the CDK inhibitor p21WAF1/CIP1 and caspase-3

MicroRNAs (miRNAs), a class of small non-coding RNAs that usually cause gene silencing by translational repression or degradation of mRNAs, are implicated in DNA damage-induced stress responses. To identify senescence-associated miRNAs, we performed microarray analyses using wild-type and p53-deficient HCT116 colon carcinoma cells that following gamma-irradiation (γIR) are driven into senescence and apoptosis, respectively. Several miRNAs including miR-30e were found upregulated in a p53-dependent manner specifically in senescent cells, but not in apoptotic cells. Overexpression of miR-30e in HCT116 cells not only inhibited γIR-, etoposide- or miR-34a-induced caspase-3-like DEVDase activities and cell death, but greatly accelerated and augmented their senescent phenotype. Consistently, procaspase-3 protein, but not mRNA decreased in the presence of miR-30e, whereas expression of the cyclin-dependent kinase inhibitor p21 increased both at the mRNA and protein level. Performing luciferase reporter gene assays, we identified the 3′-UTR of the caspase-3 mRNA as a direct miR-30e target. In contrast, although miR-30e was unable to bind to the p21 mRNA, it increased expression of a luciferase construct containing the p21 promoter, suggesting that the miR-30e-mediated upregulation of p21 occurs indirectly at the transcriptional level. Interestingly, despite suppressing procaspase-3 expression, miR-30e was unable to protect RKO colon carcinoma cells from DNA damage-induced death or to induce senescence, as miR-30e completely fails to upregulate p21 in these cells. These data suggest that miR-30e functions in a cell type-dependent manner as an important molecular switch for DNA damage-induced stress responses and may thus represent a target of therapeutic value.

MicroRNA-30a increases tight junction protein expression to suppress the epithelial-mesenchymal transition and metastasis by targeting Slug in breast cancer

The epithelial-to-mesenchymal (EMT) transition is a prerequisite for conferring metastatic potential during tumor progression. microRNA-30a (miR-30a) expression was significantly lower in aggressive breast cancer cell lines compared with non-invasive breast cancer and non-malignant mammary epithelial cell lines. In contrast, miR-30a overexpression reversed the mesenchymal appearance of cancer cells to result in a cobblestone-like epithelial phenotype. We identified Slug, one of the master regulators of EMT, as a target of miR-30a using in silico prediction. Reporter assays indicated that miR-30a could bind to the 3'-untranslted region of Slug mRNA. Furthermore, we linked miR-30a to increased expression of claudins, a family of tight junction transmembrane proteins. An interaction between Slug and E-box in the claudin promoter sequences was reduced upon miR-30a overexpression, further leading to reduction of filopodia formation and decreased invasiveness/metastasis capabilities of breast cancer cells. Consistently, delivery of miR-30a in xenografted mice decreased tumor invasion and migration. In patients with breast cancer, a significantly elevated risk of the miR-30alow/CLDN2low/FSCNhigh genotype was observed, linking to a phenotypic manifestation of larger tumor size, lymph node metastasis, and advanced tumor stage among patients. In conclusion, the miR-30a/Slug axis inhibits mesenchymal tumor development by interfering with metastatic cancer cell programming and may be a potential target for therapy in breast cancer.

MiR-30e inhibits tumor growth and chemoresistance via targeting IRS1 in Breast Cancer

MicroRNA-30e (miR-30e) is downregulated in various tumor types. However, its mechanism in inhibiting tumor growth of breast cancer remains to be elucidated. In this study, we found that miR-30e was significantly downregulated in tumor tissues of breast cancer (BC) patients and cell lines, and overexpression of miR-30e inhibited cell proliferation, migration and invasion. To understand the potential mechanism of miR-30e in inhibiting tumor growth, we showed that miR-30e blocked the activation of AKT and ERK1/2 pathways, and the expression of HIF-1α and VEGF via directly targeting IRS1. Moreover, miR-30e regulates cell proliferation, migration, invasion and increases chemosensitivity of MDA-MB-231 cells to paclitaxel by inhibiting its target IRS1. MiR-30e also inhibited tumor growth and suppressed expression of IRS1, AKT, ERK1/2 and HIF-1α in mouse xenograft tumors. To test the clinical relevance of these results, we used 40 pairs of BC tissues and adjacent normal tissues, analyzed the levels of miR-30e and IRS1 expression in these tissues, and found that miR-30e levels were significantly inversely correlated with IRS1 levels in these BC tissues, suggesting the important implication of our findings in translational application for BC diagnostics and treatment in the future.

miR-500a-5p regulates oxidative stress response genes in breast cancer and predicts cancer survival

MicroRNAs (miRNAs) are small regulatory non-coding RNAs with a diversity of cellular functions, and are frequently dysregulated in cancer. Using a novel computational method (ActMir) that we recently developed, the "activity" of miRNA hsa-miR-500a was implicated in estrogen receptor (ER) positive breast cancer; however its targets and functional impact remain poorly understood. Here, we performed an extensive gene expression analysis in ER+ breast cancer cell lines, to reveal the targets of miR-500a-5p after experimental modulation of its levels. We found that among mRNAs targeted by miR-500a-5p there was enrichment in oxidative stress response genes. Moreover, in vitro exposure to oxidative stress using H2O2 induces miR-500a-5p overexpression and downregulation of the oxidative stress targets TXNRD1 and NFE2L2. Finally, expression of several of the identified miR-500a-5p targets related to oxidative stress, including TXNRD1, was associated with ER+ breast cancer survival in multiple datasets. Overall, we identify miR-500a-5p as an oxidative stress response miRNA whose activity may define breast cancer progression and survival.

Identification of miRNAs as biomarkers for acquired endocrine resistance in breast cancer

Therapies targeting estrogen receptor α (ERα) including tamoxifen, a selective estrogen receptor modulator (SERM) and aromatase inhibitors (AI), e.g., letrozole, have proven successful in reducing the death rate for breast cancer patients whose initial tumors express ERα. However, about 40% of patients develop acquired resistance to these endocrine treatments. There is a critical need to develop sensitive circulating biomarkers that accurately identify signaling pathways altered in breast cancer patients resistant to endocrine therapies. Serum miRNAs have the potential to serve as biomarkers of the progression of endocrine-resistant breast cancer due to their cancer-specific expression and stability. Exosomal transfer of miRNAs has been implicated in metastasis and endocrine-resistance. This review focuses on miRNAs in breast tumors and in serum, including exosomes, from breast cancer patients that are associated with resistance to tamoxifen since it is best-studied.

The regulatory role of IL-6R in hepatitis B-associated fibrosis and cirrhosis

This study investigated the expression and regulation of IL-6R in hepatitis B-associated moderate hepatic fibrosis and cirrhosis. Liver tissues, peripheral blood monocytes (PBMs) and serum were collected from 26 hepatitis B patients with liver fibrosis and 35 hepatitis B patients with liver cirrhosis. The levels of Il-6r mRNA expression in these samples were examined by quantitative real-time PCR and IL-6R protein levels were analyzed by western blot and ELISA. MiRNAs that regulate IL-6R expression were predicted by bioinformatics analysis, and validated by dual luciferase reporter assay. Compared with the hepatic fibrosis group, IL-6R was significantly upregulated at both mRNA and protein levels in liver tissues, PBMs and serum samples from the hepatic cirrhosis group (P<0.05). The 3'UTR of Il-6r mRNA was predicted to contain a miR-30b binding site and IL-6R was identified as a possible target of miR-30b. MiR-30b expression was significantly downregulated in samples from hepatic cirrhosis patients compared with hepatic fibrosis patients (P<0.05). In conclusion, IL-6R was upregulated while miR-30b was decreased in patients with liver cirrhosis. The miR-30 can directly regulate the expression of IL-6R.

miR-30d is related to asbestos exposure and inhibits migration and invasion in NCI-H2452 cells

Pleural malignant mesothelioma (MM) is a highly aggressive tumor that is typically related to asbestos exposure and has a latency of 20-60 years. Several microRNA contribute to MM initiation and progression, but the mechanisms are not clear. Here, we found that miR-30d is downregulated in the pleural MM cell line NCI-H2452, in the plasma of asbestos-exposed individuals, and in asbestos-exposed mesothelial cells. Furthermore, we investigated the influence of the overexpression of miR-30d in pleural MM cells. We demonstrated that miR-30d overexpression could suppress pleural MM cell proliferation, migration, and invasion in vitro and could promote cell apoptosis but could not significantly influence cell cycle. The mRNA and protein expression of vimentin and TWIST1 decreased, and the mRNA expression of CDH1 increased in NCI-H2452 cells that overexpressed miR-30d. We therefore conclude that miR-30d is related to asbestos exposure and inhibits cell migration and invasion by regulating the epithelial-mesenchymal transition in NCI-H2452 cells.