Role of microRNAs in translation regulation and cancer

Establishment of the Prognosis Predicting Signature for Endometrial Cancer Patient

BACKGROUND Novel biomarkers provide clinicians more critical information on tumor genetic features and patients' prognosis. Here, we aimed to establish prognosis-predicting signatures for endometrial carcinoma (EC) patients based on the miRNA information. MATERIAL AND METHODS The Cancer Genome Atlas (TCGA) website was available for dataset extraction. Prognosis-associated miRNAs were generated by univariate Cox regression test. Online websites were used to predict the targeted genes of these enrolled miRNAs. The miRNA-mRNA network was described by Cytoscape software, while the relevant signaling pathways of these targeted genes were enriched by Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. RESULTS The miRNA-based overall survival (OS) and recurrence-free survival (RFS) predicting signatures were constructed by LASSO Cox regression analyses, respectively, by which, the endometrial carcinoma patients were separated into high- and low-risk groups in both the discovery and validation sets. Univariate Cox regression analyses suggested that these high-risk patients had elevated death and recurrence risk compared to low-risk patients. In addition, multivariate Cox regression analysis confirmed that our signatures were independent prognosticate factors with or without clinicopathological features for endometrial carcinoma patients. Moreover, the miRNA-mRNA network was displayed by Cytoscape software, and the pathway enrichment analyses found that the targeted genes of these enrolled miRNAs were enriched in tumor progression and drug resistance-related pathways. CONCLUSIONS The OS and RFS predicting classifiers serve as independent prognosis-associated determiners for EC patients.

MicroRNAs - novel biomarkers for malignant pleural effusions

Lung cancer is one of the most common causes of cancer death. Its poor prognosis can be attributed to the patients’ advanced or metastatic presentation at the time of diagnosis. To improve and accelerate the diagnosis, better therapeutic and diagnostic methods are constantly being sought. MicroRNAs (miRNAs) are short nucleotide sequences of single-stranded, non-coding RNA that function as critical post-transcriptional regulators of gene expression. They are identified not only intracellularly, but also in physiological and pathological body fluids. These molecules are responsible for the regulation of approximately 33% of human genes, either regulating the expression of both oncogenes and suppressor genes or acting directly as an oncogene or suppressor gene itself. MiRNAs can contribute to the formation of cancer. The high specificity and sensitivity of miRNAs have been demonstrated with various malignant diseases, and for this reason, they raise particular interest as new and perspective biomarkers of tumours. Our work summarises the available information from recent years regarding the possibility of using miRNAs as biomarkers in the diagnosis of neoplasms. In this review, we focused on malignant pleural effusions with an emphasis on non-small cell lung cancer (NSCLC).

Analysis of Differential Expression of microRNAs and Their Target Genes in Prostate Cancer: A Bioinformatics Study on Microarray Gene Expression Data

Early diagnosis of prostate cancer (PCa) as the second most common cancer in men is not associated with precise and specific results. Thus, alternate methods with high specificity and sensitivity are needed for accurate and timely detection of PCa. MicroRNAs regulate the molecular pathways involved in cancer by targeting multiple genes. The aberrant expression of the microRNAs has been reported in different cancer types including PCa. In this bioinformatics study, we studied differential expression profiles of microRNAs and their target genes in four PCa gene expression omnibus (GEO) databases. PCa diagnostic biomarker candidates were investigated using bioinformatics tools for analysis of gene expression data, microRNA target prediction, pathway and GO annotation, as well as ROC curves. The results of this study revealed significant changes in the expression of 14 microRNAs and 40 relevant target genes, which ultimately composed four combination panels (miR- 375+96+663/ miR- 133b+143- 3p + 205/ C2ORF72 + ENTPD5 + GLYAT11/LAMB3 + NTNG2+TSLP) as candidate biomarkers capable to distinguish between PCa tumor samples and normal prostate tissue samples. These biomarkers may be suggested for a more accurate early diagnosis of PCa patients along with current diagnostic tests.

The Role of MicroRNA in Paediatric Acute Lymphoblastic Leukaemia: Challenges for Diagnosis and Therapy

Acute lymphoblastic leukaemia (ALL) is the most common cancer of childhood. Although the overall survival of children with ALL is now more than 90%, leukaemia remains one of the leading causes of death from disease. In developed countries, the overall survival of patients with ALL has increased to more than 80%; however, those children cured from ALL still show a significant risk of short- and long-term complications as a consequence of their treatment. Accordingly, there is a need not only to develop new methods of diagnosis and prognosis but also to provide patients with less toxic therapies. MicroRNAs (miRNAs) are small ribonucleic acids (RNA), usually without coding potential, that regulate gene expression by directing their target messenger RNAs (mRNAs) for degradation or translational suppression. In paediatric ALL, several miRNAs have been observed to be overexpressed or underexpressed in patient cohorts compared to healthy individuals, while numerous studies have identified specific miRNAs that can be used as biomarkers to diagnose ALL, classify it into subgroups, and predict prognosis. Likewise, a variety of miRNAs identify as candidate targets for treatment, although there are numerous obstacles to overcome before their clinical use in patients. Here, we summarise the roles played by different miRNAs in childhood leukaemia, focussing primarily on their use as diagnostic tools and potential therapeutic targets, as well as a role in predicting treatment outcome. Finally, we discuss the potential roles of miRNA in immunotherapy and the novel contributions made by gut miRNAs to regulation of the host microbiome.

The Regulatory Role of MicroRNAs in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNA molecules which function as critical post-transcriptional gene regulators of various biological functions. Generally, miRNAs negatively regulate gene expression by binding to their selective messenger RNAs (mRNAs), thereby leading to either mRNA degradation or translational repression, depending on the degree of complementarity with target mRNA sequences. Aberrant expression of these miRNAs has been linked etiologically with various human diseases including breast cancer. Different cellular pathways of breast cancer development such as cell proliferation, apoptotic response, metastasis, cancer recurrence and chemoresistance are regulated by either the oncogenic miRNA (oncomiR) or tumor suppressor miRNA (tsmiR). In this review, we highlight the current state of research into miRNA involved in breast cancer, with particular attention to articles published between the years 2000 to 2019, using detailed searches of the databases PubMed, Google Scholar, and Scopus. The post-transcriptional gene regulatory roles of various dysregulated miRNAs in breast cancer and their potential as therapeutic targets are also discussed.

Nanotechnological based miRNA intervention in the therapeutic management of neuroblastoma

Neuroblastoma (NB) is a widely diagnosed cancer in children, characterized by amplification of the gene encoding the MYCN transcription factor, which is highly predictive of poor clinical outcome and metastatic disease. microRNAs (a class of small non-coding RNAs) are regulated by MYCN transcription factor in neuroblastoma cells. The current research is focussed on identifying differential role of miRNAs and their interactions with signalling proteins, which are intricately linked with cellular processes like apoptosis, proliferation or metastasis. However, the therapeutic success of miRNAs is limited by pharmaco-technical issues which are well counteracted by nanotechnological advancements. The nanoformulated miRNAs unload anti-cancer drugs in a controlled and prespecified manner at target sites, to influence the activity of target protein in amelioration of NB. Recent advances and developments in the field of miRNAs-based systems for clinical management of NBs and the role of nanotechnology to overcome challenges with drug delivery of miRNAs have been reviewed in this paper.

Functions and mechanisms of miR-186 in human cancer

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the post-transcriptional level. Mounting evidence suggests the involvement of miRNAs in carcinogenesis and the development of human cancer. Among the miRNAs, miR-186 has been extensively studied in various cancers. The expression of miR-186 in tissues varies depending on the type of cancer and miR-186 in tissues and body fluids may serve as a marker for the diagnosis and prognosis of cancers. Various biological processes in human cancer are affected by miR-186. Additionally, miR-186 itself is regulated by several factors. Thus, this evidence highlights the potential value of miR-186 in the diagnosis, prognosis and treatment of human cancer.

The Role of MicroRNAs in Early Chondrogenesis of Human Induced Pluripotent Stem Cells (hiPSCs)

Human induced pluripotent stem cells (hiPSCs) play an important role in research regarding regenerative medicine. Particularly, chondrocytes differentiated from hiPSCs seems to be a promising solution for patients suffering from osteoarthritis. We decided to perform chondrogenesis in a three-week monolayer culture. Based on transcriptome analysis, hiPSC-derived chondrocytes (ChiPS) demonstrate the gene expression profile of cells from early chondrogenesis. Chondrogenic progenitors obtained by our group are characterized by significantly high expression of Hox genes, strongly upregulated during limb formation and morphogenesis. There are scanty literature data concerning the role of microRNAs in early chondrogenesis, especially in chondrogenic differentiation of hiPSCs. The main aim of this study was to investigate the microRNA expression profile and to select microRNAs (miRNAs) taking part in early chondrogenesis. Our findings allowed for selection crucial miRNAs engaged in both diminishing pluripotency state and chondrogenic process (inter alia hsa-miR-525-5p, hsa-miR-520c-3p, hsa-miR-628-3p, hsa-miR-196b-star, hsa-miR-629-star, hsa-miR-517b, has-miR-187). These miRNAs regulate early chondrogenic genes such as: HOXD10, HOXA11, RARB, SEMA3C. These results were confirmed by RT-qPCR analysis. This work contributes to a better understanding of the role of miRNAs directly involved in chondrogenic differentiation of hiPSCs. These data may result in the establishment of a more efficient protocol of obtaining chondrocyte-like cells from hiPSCs.

Exosomal miR-16-5p as a target for malignant mesothelioma

Malignant mesothelioma (MM) is an asbestos-induced cancer arising on the mesothelial surface of organ cavities. MM is essentially incurable without a means of early diagnosis and no successful standard of care. These facts indicate a deep chasm of knowledge that needs to be filled. Our group recently delved into MM tumor biology from the perspective of exosome-contained microRNAs (miRNAs). We discovered that the most abundant miRNAs in MM cancer exosomes were tumor suppressors, particularly miR-16-5p. This observation lead us to hypothesize that MM cells preferentially secreted tumor-suppressor miRNAs via exosomes. Through separate avenues of potential therapeutic advance, we embarked on an innovative strategy to kill MM tumor cells. We employed small molecule inhibitors to block exosome secretion, thereby reducing miR-16-5p exosome loss and replenishing cellular miR-16-5p leading to reduced tumorigenic capacity and miR-16-5p target oncoproteins CCND1 and BCL2. Additionally, we force-fed MM tumor exosomes back to MM tumor cells, which led to cell death, and a reduction in the same oncoproteins. We recapitulated these results with direct transfection of miR-16-5p, confirmed that this is a cancer-cell specific effect, and elucidated a part of the miR-16-5p mechanism of exosome loading.

MiR-361-5p inhibits cell proliferation and induces cell apoptosis in retinoblastoma by negatively regulating CLDN8

PURPOSE

MiR-361-5p has been reported to act as tumor suppressor in several types of cancers. Retinoblastoma (RB) is the most common ocular tumor in childhood. The current study aimed to investigate the expression pattern and biological function of miR-361-5p in RB.

METHODS

Quantitative real time was utilized to determine and compare the expression of miR-361-5p in RB cells and normal retinal pigment epithelial cell line ARPE-19. CCK-8 and Edu assay were performed to assess cell proliferation. Cell apoptosis was evaluated using flow cytometry assay. Bioinformatics databases and luciferase reporter assay were applied to predict and confirm the target gene of miR-361-5p in RB cells.

RESULTS

Here, we found miR-361-5p was significantly downregulated in RB cells compared with normal retinal pigment epithelial cell line ARPE-19. MiR-361-5p overexpression significantly inhibited or silencing promoted cell proliferation in Y79 and SO-RB50 cells, respectively. Flow cytometry assay showed a significantly decreased cell apoptosis in miR-361-5p silencing Y79 cells and increased cell apoptosis in miR-361-5p overexpressing SO-RB50 cells. Moreover, miR-361-5p directly bound to the 3' untranslated region of claudin 8 (CLDN8) and inhibited the expression of CLDN8. Furthermore, we found knockdown of CLDN8 photocopied the effect of miR-361-5p on cell proliferation and apoptosis in RB cells.

CONCLUSION

These results indicated that overexpression of miR-361-5p might act as a suppressor in RB by targeting CLDN8 to inhibit the cellular function.

Dual-strand tumor suppressor miR-193b-3p and -5p inhibit malignant phenotypes of lung cancer by suppressing their common targets

Emerging studies suggest that microRNAs (miRNAs) play multiple roles in cancer malignancy, including proliferation and acquisition of metastatic potential. Differentially expressed miRNAs responsible for the malignancy of lung cancer were searched by miRNA microarray using a previously established brain metastatic lung cancer model. Twenty-five miRNAs were down-regulated in brain metastatic lung cancer cells. Among those, miR-193b-3p and -5p were chosen for further studies. Their function in metastatic potential and proliferation was examined using Transwell invasion, wound healing, and colony forming assays. The underlying mechanism of tumor-suppressor miR-193b-3p and -5p was explored using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), Western blot, Argonaute 2-RNA immunoprecipitation (Ago2-RIP), and reporter assays. Both strands of miR-193b were down-regulated in brain metastatic lung cancer cells and in tissues from lung cancer patients. Overexpression of miR-193b-3p and -5p inhibited invasive and migratory activities and diminished clonogenic ability. Conversely, inhibition of miR-193b-3p or -5p increased the metastatic potential and colony forming ability. Cyclin D1 (CCND1), Ajuba LIM Protein (AJUBA), and heart development protein with EGF like domains 1 (HEG1) were identified as common target genes of miR-193b-3p and -5p. A reporter assay and an Ago2-RIP experiment showed that both miRNAs directly bind to the 3′ untranslated region (3′UTR) of the target mRNA. Knockdown of target gene reduced the proliferative and metastatic potential of primary and metastatic lung cancer cells. Our results demonstrate miR-193b is a dual-strand tumor suppressor and a novel therapeutic target for lung cancer.

On the evolutionary origins of insect seminal fluid proteins

In most cases, proteins affect the phenotype of the individual in which they are produced. However, in some cases, proteins have evolved in such a way that they are able to influence the phenotype of another individual of the same or of a different species ("influential proteins"). Examples of interspecific influential proteins include venom proteins and proteins produced by parasites that influence their hosts' physiology or behavior. Examples of intraspecific influential proteins include those produced by both mothers and fetuses that mitigate maternal resource allocation and proteins transferred to females in the seminal fluid during mating that change female physiology and behavior. Although there has been much interest in the functions and evolutionary dynamics of these influential proteins, less is known about the origin of these proteins. Where does the DNA that encodes the proteins that can impact another individual's phenotype come from and how do the proteins acquire their influential abilities? In this mini-review, I use insect seminal fluid proteins as a case study to consider the origin of intraspecific influential proteins. The existing data suggest that influential insect seminal fluid proteins arise both through co-option of existing genes (both single copy genes and gene duplicates) and de novo evolution. Other mechanisms for the origin of new insect seminal fluid proteins (e.g., retrotransoposition and horizontal gene transfer) are plausible but have not yet been demonstrated. Additional gaps in our understanding of the origin of insect seminal fluid proteins include an understanding of the cis-regulatory elements that designate expression in the male reproductive tract and of the evolutionary steps by which individual proteins come to depend on other seminal fluid proteins for their activity within the mated female.

Non-canonical Hedgehog Signaling Pathway in Cancer: Activation of GLI Transcription Factors Beyond Smoothened

The Hedgehog-GLI (HH-GLI) pathway is a highly conserved signaling that plays a critical role in controlling cell specification, cell–cell interaction and tissue patterning during embryonic development. Canonical activation of HH-GLI signaling occurs through binding of HH ligands to the twelve-pass transmembrane receptor Patched 1 (PTCH1), which derepresses the seven-pass transmembrane G protein-coupled receptor Smoothened (SMO). Thus, active SMO initiates a complex intracellular cascade that leads to the activation of the three GLI transcription factors, the final effectors of the HH-GLI pathway. Aberrant activation of this signaling has been implicated in a wide variety of tumors, such as those of the brain, skin, breast, gastrointestinal, lung, pancreas, prostate and ovary. In several of these cases, activation of HH-GLI signaling is mediated by overproduction of HH ligands (e.g., prostate cancer), loss-of-function mutations in PTCH1 or gain-of-function mutations in SMO, which occur in the majority of basal cell carcinoma (BCC), SHH-subtype medulloblastoma and rhabdomyosarcoma. Besides the classical canonical ligand-PTCH1-SMO route, mounting evidence points toward additional, non-canonical ways of GLI activation in cancer. By non-canonical we refer to all those mechanisms of activation of the GLI transcription factors occurring independently of SMO. Often, in a given cancer type canonical and non-canonical activation of HH-GLI signaling co-exist, and in some cancer types, more than one mechanism of non-canonical activation may occur. Tumors harboring non-canonical HH-GLI signaling are less sensitive to SMO inhibition, posing a threat for therapeutic efficacy of these antagonists. Here we will review the most recent findings on the involvement of alternative signaling pathways in inducing GLI activity in cancer and stem cells. We will also discuss the rationale of targeting these oncogenic pathways in combination with HH-GLI inhibitors as a promising anti-cancer therapies.

The biomarker features of miR-145-3p determined via meta-analysis validated by qRT-PCR in metastatic cancer cell lines

MicroRNAs (miRNAs) play important roles in the cancer biology such as proliferation, differentiation, and apoptosis. The pivotal roles that miRNA expression plays, make them ideal candidates for detection of cancer progression as well as cancer metastasis. Especially for breast, lung and prostate cancer which are originated from soft tissues and prone to metastasis. Thus, the aim of this study is to evaluate the expression level of miR-145-3p which is a shared potential biomarker identified by meta-analysis of breast, prostate and lung cancer data sets. Six different data sets representative of three different cancer types were analyzed. These data sets are pooled together to have a master metamiRNA list while getting rid of the platform differentiations between them. As a result, 24 common differentially expressed miRNAs are determined in which miR-145-3p has the topmost rank. To mimic in vivo cancer microenvironment, hypoxia and serum deprivation were used to induce metastasis in breast (MCF-7, MDA-MB-231, MDA-MB-453), prostate (PC3, LNCaP, DU145), lung (A549, NCIH82,) cancer cell lines and noncancerous cell lines of the coresponding tissues (MCF10A, RWPE-1, MRC-5). miR-145-3p expression levels were determined by qRT-PCR. It has been shown that it is down regulated by the induction of metastasis in cancer cell lines while it is up regulated in normal cell lines to suppress the tumor formation. As a conclusion, as representing the same results in three different cancer cell types, miR-145-3p will be a promising biomarker to follow up its expression to detect cancer metastasis.

Long intergenic noncoding RNA 00707 promotes colorectal cancer cell proliferation and metastasis by sponging miR-206

Background: The incidence and mortality of colorectal cancer (CRC) are rising worldwide. Long-noncoding RNAs (lncRNAs) are known to play key roles in the development of human cancers, including CRC. However, the function and underlying mechanism of long intergenic noncoding RNA 00707 (LINC00707) in the development of CRC are unknown.

Materials and methods: The expression of LINC00707 and miR-206 in tissue samples or cell lines was measured by quantitative reverse transcription PCR (qRT-PCR). The protein expression of neurogenic locus notch homolog protein 3 (NOTCH3) and transmembrane 4 L6 family member 1 (TM4SF1) was assessed by Western blotting. Cell proliferation, migration, and invasion were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and transwell assays. Luciferase reporter assay and biotin-coupled miRNA capture assay were used to explore the relationship between LINC00707 and miR-206 expression.

Results: The expression of LINC00707 was significantly upregulated in CRC tissues as compared with the adjacent non-CRC tissues. LINC00707 expression was significantly correlated with tumor size, lymphatic metastasis, and distant metastasis, but not significantly correlated with age and gender. Knockdown of LINC00707 expression significantly inhibited LoVo and HCT116 cell proliferation, migration, and invasion. LINC00707 acted as a molecular sponge by competing for miR-206 and indirectly modulating the expression of its targets, NOTCH3 and TM4SF1.

Conclusion: LINC00707 promotes CRC cell proliferation and metastasis by sponging miR-206, suggestive of its potential application for CRC treatment.

The role of dietary phytochemicals in the carcinogenesis via the modulation of miRNA expression

PURPOSE

Phytochemicals are naturally occurring plant-derived compounds and some of them have the potential to serve as anticancer drugs. Based on recent evidence, aberrantly regulated expression of microRNAs (miRNAs) is closely associated with malignancy. MicroRNAs are characterized as small non-coding RNAs functioning as posttranscriptional regulators of gene expression. Accordingly, miRNAs regulate various target genes, some of which are involved in the process of carcinogenesis.

RESULTS

This comprehensive review emphasizes the anticancer potential of phytochemicals, either isolated or in combination, mediated by miRNAs. The ability to modulate the expression of miRNAs demonstrates their importance as regulators of tumorigenesis. Phytochemicals as anticancer agents targeting miRNAs are widely studied in preclinical in vitro and in vivo research. Unfortunately, their anticancer efficacy in targeting miRNAs is less investigated in clinical research.

CONCLUSIONS

Significant anticancer properties of phytochemicals as regulators of miRNA expression have been proven, but more studies investigating their clinical relevance are needed.

miR-1915-3p inhibits Bcl-2 expression in the development of gastric cancer

Many gene expressions changed during the development of gastric cancer, and non-coding RNAs including microRNAs (miRNAs) have been found to regulate cancer progression by participating in the process of tumor cell growth, migration, invasion and apoptosis. Our previous study has identified 29 miRNAs that are highly expressed in gastric cancer stem cells. One of these miRNAs, miR-1915-3p, has shown great potential as a diagnostic and prognostic biomarker for the cancers in liver, colon and thyroid, as well as in immune and kidney diseases. Herein, we found that miR-1915-3p exhibited low expression level in differentiated gastric cancer cell lines and gastric cancer tissues. It was found that the miR-1915-3p inhibited the growth of gastric cancer cells and thus promoted cell apoptosis. We discovered that the expressions of miR-1915-3p were significantly correlated to the lymph node metastasis and overall survival of patients with gastric cancer. Further study showed that there was a negative correlation between miR-1915-3p and Bcl-2 (B cell lymphoma/leukemia-2) expression, suggesting that Bcl-2 was a target gene of miR-1915-3p. Hence, miR-1915-3p possibly contributes to the development and progression of gastric cancer by inhibiting the anti-apoptotic protein Bcl-2. The finding provides a potential therapeutic strategy for gastric cancer.

MicroRNA Dysregulation in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and it can be locally invasive and metastatic to distant sites. MicroRNAs (miRNAs or miRs) are endogenous, small, non-coding RNAs of 19–25 nucleotides in length, that are involved in regulating gene expression at a post-transcriptional level. MicroRNAs have been implicated in diverse biological functions and diseases. In cancer, miRNAs can proceed either as oncogenic miRNAs (onco-miRs) or as tumor suppressor miRNAs (oncosuppressor-miRs), depending on the pathway in which they are involved. Dysregulation of miRNA expression has been shown in most of the tumors evaluated. MiRNA dysregulation is known to be involved in the development of cutaneous squamous cell carcinoma (CSCC). In this review, we focus on the recent evidence about the role of miRNAs in the development of CSCC and in the prognosis of this form of skin cancer.

Toxoplasma gondii: CD8 T Cells Cry for CD4 Help

Toxoplasma gondii, an apicomplexan parasite, is a pathogenic protozoan that can infect the central nervous system. In pregnant women, infection can result in congenital problems of the fetus, while in immunocompromised individual it can lead to severe neurological consequences. Although CD8 T cells play an important effector role in controlling the chronic infection, their maintenance is dependent on the critical help provided by CD4 T cells. In a recent study, we demonstrated that reactivation of the infection in chronically infected host is a consequence of CD8 T dysfunction caused by CD4 T cell exhaustion. Furthermore, treatment of chronically infected host with antigen-specific non-exhausted CD4 T cells can restore CD8 T cell functionality and prevent reactivation of the latent infection. The exhaustion status of CD4 T cells is mediated by the increased expression of the transcription factor BLIMP-1, and deletion of this molecule led to the restoration of CD4 T cell function, reversal of CD8 exhaustion and prevention of reactivation of the latent infection. In a recent study from our laboratory, we also observed an increased expression of miR146a levels by CD4 T cells from the chronically infected animals. Recent reports have demonstrated that microRNAs (especially miR146a) has a strong impact on the immune system of T. gondii infected host. Whether these molecules have any role in the BLIMP-1 up-regulation and dysfunctionality of these cells needs to be investigated.

MicroRNAs contribute to ATP-binding cassette transporter- and autophagy-mediated chemoresistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has an elevated mortality rate, largely because of high recurrence and metastasis. Additionally, the main obstacle during treatment of HCC is that patients usually develop resistance to chemotherapy. Cancer drug resistance involves many different mechanisms, including alterations in drug metabolism and processing, impairment of the apoptotic machine, activation of cell survival signaling, decreased drug sensitivity and autophagy, among others. Nowadays, miRNAs are emerging as master regulators of normal physiology- and tumor-related gene expression. In HCC, aberrant expression of many miRNAs leads to chemoresistance. Herein, we particularly analyzed miRNA impact on HCC resistance to drug therapy. Certain miRNAs target ABC (ATP-binding cassette) transporter genes. As most of these miRNAs are downregulated in HCC, transporter levels increase and intracellular drug accumulation decrease, turning cells less sensitive to death. Others miRNAs target autophagy-related gene expression, inhibiting autophagy and acting as tumor suppressors. Nevertheless, due to its downregulation in HCC, these miRNAs do not inhibit autophagy or tumor growth and, resistance is favored. Concluding, modulation of ABC transporter and/or autophagy-related gene expression or function by miRNAs could be determinant for HCC cell survival under chemotherapeutic drug treatment. Undoubtedly, more insights on the biological processes, signaling pathways and/or molecular mechanisms regulated by miRNAs are needed. Anyway, miRNA-based therapy together with conventional chemotherapeutic drugs has a great future in cancer therapy.

Diagnostic utility of epigenetics in breast cancer - A review

Epigenetic alterations are clearly involved in cancer initiation and progression as recent epigenetic studies of genomic DNA, histone modifications and micro-RNA alterations suggest that these are playing an important role in the incidence of breast cancer. Epigenetic information has recently gained the attention of researchers because epigenetic modification of the genome in breast cancer is still an evolving area for researchers. Several active compounds present in foods, poisons, drugs, and industrial chemicals may as a result of epigenetic mechanisms increase or decrease the risk of breast cancer. Epigenetic regulation is critical in normal growth and development and closely conditions the transcriptional potential of genes. Epigenetic mechanisms convey genomic adaption to an environment thereby ultimately contributing towards given phenotype. In addition to the use of epigenetic alterations as a means of screening, epigenetic alterations in a tumor or adjacent tissues or peripheral blood may also help clinicians in determining prognosis and treatment of breast cancer. As we understand specific epigenetic alterations contributing to breast tumorigenesis and prognosis, these discoveries will lead to significant advances for breast cancer treatment, like in therapeutics that target methylation and histone modifications in breast cancer and the newer versions of the drugs are likely to play an important role in future clinical treatment.

Roles of MicroRNA-34a in Epithelial to Mesenchymal Transition, Competing Endogenous RNA Sponging and Its Therapeutic Potential

MicroRNA-34a (miR-34a), a tumor suppressor, has been reported to be dysregulated in various human cancers. MiR-34a is involves in certain epithelial-mesenchymal transition (EMT)-associated signal pathways to repress tumorigenesis, cancer progression, and metastasis. Due to the particularity of miR-34 family in tumor-associated EMT, the significance of miR-34a is being increasingly recognized. Competing endogenous RNA (ceRNA) is a novel concept involving mRNA, circular RNA, pseudogene transcript, and long noncoding RNA regulating each other’s expressions using microRNA response elements to compete for the binding of microRNAs. Studies showed that miR-34a is efficient for cancer therapy. Here, we provide an overview of the function of miR-34a in tumor-associated EMT. ceRNA hypothesis plays an important role in miR-34a regulation in EMT, cancer progression, and metastasis. Its potential roles and challenges as a microRNA therapeutic candidate are discussed. As the negative effect on cancer progression, miR-34a should play crucial roles in clinical diagnosis and cancer therapy.

THz vibrational spectroscopy for RNA basepair cocrystals and oligonucleotide sequences

Fourier infrared spectrometer and X-ray diffractometer were used to detect the spectra of lab-made U:A (uracil and adenine hydrate dried at room temperature), lab-made C:G (cytosine and guanine hydrate dried at room temperature), U + A (mixture of uracil and adenine), and C + G (mixture of cytosine and guanine). The results of our testing showed that U:A did not form a eutectic, but C:G did. In order to further characterize the vibrational modes of RNA base pair crystals, the absorption spectra of 1‑methyl‑5‑bromouracil‑9‑methyladenine (abbreviated as 1M5BU:9MA) and 1‑methylcytosine‑9‑ethylguanine (abbreviated as 1MC:9EG) were calculated based on the PBC-GEBF (generalized energy-based fragmentation approach under periodic boundary conditions) method. To further study the effect of substituents on the vibrational mode of the crystal structure, the substituents of 1M5BU:9MA and 1MC:9EG were artificially removed. The results of calculation brought out that methyl and ethyl as substituents have little effect on the vibrational spectrum, but halogen atoms such as Br atom in 1M5BU:9MA has a certain influence on the spectrum. Furthermore, THz (terahertz) spectra of the RNA nucleotide sequence 5'-AUCG-3' was analyzed. In the perspective of the spectra with DNA signatures, their spectra show a great deal of similarity regardless of RNA or DNA, or the base sequence difference. This study will provide a very important information for revealing the role of RNA in the formation of biological macromolecules and its mechanism.

Endometriosis-associated ovarian cancer: What have we learned so far?

Endometriosis is defined as the presence of ectopic endometrial tissue outside of the uterine cavity, most commonly in the ovaries and peritoneum. It is a complex disease that is influenced by multiple factors. It is also a common gynecological disorder and affects approximately 10-15% of all women of reproductive age. Recent molecular and pathological studies indicate that endometriosis may serve as a precursor of ovarian cancer (endometriosis-associated ovarian cancer, EAOC), particularly endometrioid and clear cell ovarian cancers. Although histological and epidemiological studies have demonstrated that endometriosis has a malignant potential, the molecular mechanism that underlies the malignant transformation of endometriosis is still controversial, and the precise mechanism of carcinogenesis must be fully elucidated. Currently, the development and improvement of a new sequencing technology, next-generation sequencing (NGS), has been increasingly relevant in cancer genomics research. Recently, NGS has also been utilized in clinical oncology to advance the personalized treatment of cancer. In addition, the sensitivity, speed, and cost make NGS a highly attractive platform compared to other sequencing modalities. For this reason, NGS may lead to the identification of driver mutations and underlying pathways associated with EAOC. Here, we present an overview of the molecular pathways that have led to the current opinions on the relationship between endometriosis and ovarian cancer.

MiR-219-5p suppresses cell proliferation and cell cycle progression in esophageal squamous cell carcinoma by targeting CCNA2

Background

We investigated the potential regulatory role of miR-219-5p in esophageal squamous cell carcinoma (ESCC) and looked at the underlying mechanisms in ESCC.

Methods

Real-time PCR was used to determine the levels of miR-219-5p in ESCC tissues and cell lines. The effects of miR-219-5p and cyclin A2 (CCNA2) on cell proliferation and cell cycle progression were evaluated using MTT, colony formation and flow cytometry assays with ESCC cell lines EC9706 and TE-9. Bioinformatics techniques and the luciferase reporter assay were applied to validate CCNA2 as the miR-219-5p target in ESCC cells. The mRNA and protein levels of CCNA2 were measured using real-time PCR and western blotting.

Results

MiR-219-5p expression was significantly lower in ESCC tissues and cells than in healthy tissues. Upregulation of miR-219-5p repressed cell proliferation and induced cell cycle arrest at the G2/M phase. CCNA2 was identified and confirmed as a direct downstream target of miR-219-5p and its expression negatively correlated with miR-219-5p profiles in ESCC tissues. Knockdown of CCNA2 potentiated the effects of miR-219-5p on cell proliferation and cell cycle distribution.

Conclusions

Our results demonstrate that miR-219-5p might function as a tumor suppressor by directly targeting CCNA2 expression. It could serve as a new therapeutic target for ESCC.

MicroRNAs and their role in environmental chemical carcinogenesis

MicroRNAs (miRNAs) are a class of small, noncoding RNA species that play crucial roles across many biological processes and in the pathogenesis of major diseases, including cancer. Recent studies suggest that the expression of miRNA is altered by certain environmental chemicals, including metals, organic pollutants, cigarette smoke, pesticides and carcinogenic drugs. In addition, extensive studies have indicated the existence and importance of miRNA in different cancers, suggesting that cancer-related miRNAs could serve as potential markers for chemically induced cancers. The altered expression of miRNA was considered to be a vital pathogenic role in xenobiotic-induced cancer development. However, the significance of miRNA in the etiology of cancer and the exact mechanisms by which environmental factors alter miRNA expression remain relatively unexplored. Hence, understanding the interaction of miRNAs with environmental chemicals will provide important information on mechanisms underlying the pathogenesis of chemically induced cancers, and effectively diagnose and treat human cancers resulting from chronic or acute carcinogen exposure. This study presents the current evidence that the miRNA deregulation induced by various chemical carcinogens, different cancers caused by environmental carcinogens and the potentially related genes in the onset or progression of cancer. For each carcinogen, the specifically expressed miRNA may be considered as the early biomarkers of the cancer process. In this review, we also summarize various target genes of the altered miRNA, oncogenes or anti-oncogenes, and the existing evidence regarding the gene regulation mechanisms of cancer caused by environmentally induced miRNA alteration. The future perspective of miRNA may become attractive targets for the diagnosis and treatment of carcinogen-induced cancer.

Sliced inverse regression for integrative multi-omics data analysis

Advancement in next-generation sequencing, transcriptomics, proteomics and other high-throughput technologies has enabled simultaneous measurement of multiple types of genomic data for cancer samples. These data together may reveal new biological insights as compared to analyzing one single genome type data. This study proposes a novel use of supervised dimension reduction method, called sliced inverse regression, to multi-omics data analysis to improve prediction over a single data type analysis. The study further proposes an integrative sliced inverse regression method (integrative SIR) for simultaneous analysis of multiple omics data types of cancer samples, including MiRNA, MRNA and proteomics, to achieve integrative dimension reduction and to further improve prediction performance. Numerical results show that integrative analysis of multi-omics data is beneficial as compared to single data source analysis, and more importantly, that supervised dimension reduction methods possess advantages in integrative data analysis in terms of classification and prediction as compared to unsupervised dimension reduction methods.

PGC-1α/SNAI1 axis regulates tumor growth and metastasis by targeting miR-128b in gastric cancer

Peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) is a transcriptional coactivator that has been characterized as master regulators of mitochondrial biogenesis. It has been reported that aberrant regulation of PGC-1α is involved in a variety of human cancers. However, whether PGC-1α is involved in the regulation of tumor growth and metastasis in gastric cancer (GC) remains unknown. In the present study, we found that the expression of PGC-1α was upregulated in GC tissues and GC cell lines. Inhibition of PGC-1α inhibited cell viability, migration, and invasion, and promoted cell apoptosis of GC cells. Furthermore, inhibition of PGC-1α downregulated the SNAI1 expression, whereas upregulated microRNA (miR)-128b expression. The expression of SNAI1 was upregulated and the expression of miR-128b was downregulated in GC tissues. We further found that there was a positive correlation between PGC-1α and SNAI1 expression, and a negative correlation between PGC-1α and miR-128b expression or between SNAI1 and miR-128b expression in GC tissues. Moreover, PGC-1α inhibition-induced increased miR-128b expression, and PGC-1α overexpression-induced decreased miR-128b expression were both markedly suppressed by SNAI1 overexpression. In addition, SNAI1 overexpression or miR-128b inhibition partly reversed the effects of PGC-1α inhibition in GC cells. Furthermore, inhibition of PGC-1α suppressed the tumor growth in a nude mouse model, which may be related with the dysregulation of SNAI1 and miR-128b. In conclusion, these data indicate that the PGC-1α/SNAI1/miR-128b axis plays a vital role in GC via regulating cell viability, migration, invasion, and apoptosis.

MicroRNA replacement therapy in cancer

Despite the recent progress in cancer management approaches, the mortality rate of cancer is still growing and there are lots of challenges in the clinics in terms of novel therapeutics. MicroRNAs (miRNA) are regulatory small noncoding RNAs and are already confirmed to have a great role in regulating gene expression level by targeting multiple molecules that affect cell physiology and disease development. Recently, miRNAs have been introduced as promising therapeutic targets for cancer treatment. Regulatory potential of tumor suppressor miRNAs, which enables regulation of entire signaling networks within the cells, makes them an interesting option for developing cancer therapeutics. In this regard, over recent decades, scientists have aimed at developing powerful and safe targeting approaches to restore these suppressive miRNAs in cancerous cells. The present review summarizes the function of miRNAs in tumor development and presents recent findings on how miRNAs have served as therapeutic agents against cancer, with a special focus on tumor suppressor miRNAs (mimics). Moreover, the latest investigations on the therapeutic strategies of miRNA delivery have been presented.

The Implication of mRNA Degradation Disorders on Human DISease: Focus on DIS3 and DIS3-Like Enzymes

RNA degradation is considered a critical posttranscriptional regulatory checkpoint, maintaining the correct functioning of organisms. When a specific RNA transcript is no longer required in the cell, it is signaled for degradation through a number of highly regulated steps. Ribonucleases (or simply RNases) are key enzymes involved in the control of RNA stability. These enzymes can perform the RNA degradation alone or cooperate with other proteins in RNA degradation complexes. Important findings over the last years have shed light into eukaryotic RNA degradation by members of the RNase II/RNB family of enzymes. DIS3 enzyme belongs to this family and represents one of the catalytic subunits of the multiprotein complex exosome. This RNase has a diverse range of functions, mainly within nuclear RNA metabolism. Humans encode two other DIS3-like enzymes: DIS3L (DIS3L1) and DIS3L2. DIS3L1 also acts in association with the exosome but is strictly cytoplasmic. In contrast, DIS3L2 acts independently of the exosome and shows a distinctive preference for uridylated RNAs. These enzymes have been shown to be involved in important cellular processes, such as mitotic control, and associated with human disorders like cancer. This review shows how the impairment of function of each of these enzymes is implicated in human disease.

The micro RNA hsa-miR-377-3p inhibits tumor growth in malignant melanoma

Background/Aims: Most recently, micro RNAs (miRNAs/miRs) have been suggested to play a key role in various physiological and pathological processes by regulating the expression of specific genes. The influence of miR-377-3p on multitudinous cancer cells has been investigated; however, its function in melanoma remains undiscovered. Armadillo repeat-containing protein 8 (ARMC8), a target of miR-377-3p, plays essential roles in proliferation, differentiation and apoptosis. Our research aimed to detect the specific roles of miR-377-3p in melanoma. Methods: The MiRNA and mRNA expressions were evaluated by a real-time quantitative polymerase chain reaction in the A375 and HEMa-LP cell lines. We predicted the possible interactions between microRNA and mRNAs by bioinformatics database and constructed them with the Cytoscape software. The proliferation and migration activities were investigated using a cell counting kit-8 (CCK8) and wound-healing assay. Validation of the correlation between miR-377-3p and ARMC8 was implemented by the luciferase reporter assay and PCR. Results: The expression of miR-377-3p was found to be lower in malignant melanoma cells. The upregulation of miR-377-3p inhibited the melanoma cell proliferation, migration, and ARMC8 expression. miR-377-3p was identified to bind to the 3′UTR region of ARMC8 directly; this indicated that miR-377-3p suppressed melanoma cell growth partly mediated via the ARMC8 expression. Conclusion: These findings show that miR-377-3p negatively regulates tumor growth in malignant melanoma, which may thus provide a potential biological target for melanoma treatment and subsequently lead to the development of potential treatments.

We have demonstrated that miR-377-3p inhibits melanoma cell growth by binding to the ARMC8 mRNA in the A375 cell line.

Total circulating cell-free miRNA in plasma as a predictive biomarker of the thyroid diseases

BACKGROUND

Thyroid cancer is a common endocrine cancer. Great progress has been made in resolving its molecular mechanisms in recent years. The molecular changes observed in thyroid cancer can be used as biomarkers for diagnostic, prognostic and therapeutic purposes. MicroRNAs (miRNAs) are important components in biological and metabolic pathways, such as developmental stages, signal transduction, cell maintenance, and differentiation. Hence, their malfunctioning can expose humans to malignancies. miRNA expressions have been shown to be dysregulated in different tumor types, like thyroid cancer, and may cause tumor initiation and progression. In previous studies, only cancer has been studied, and miRNA has been detected from the tissues in all the studies performed. In this study, we have focused on thyroid diseases such as bening nodules and Hashimoto's disease, which might be the cause of thyroid cancer, and have carried out miRNA tests in the blood samples taken from the arms thyroid patients.

MATERIAL AND METHOD

The present study was conducted on the blood samples of 100 thyroid patients. Of the 100 patients in our study, 33 consisted of patients with thyroiditis, while 37 patients were diagnosed with benign thyroid nodules and 30 patients had thyroid cancer. For the control group, 18 patients were included. The plasma samples were analyzed, and the total miRNA levels were determined.

RESULTS

We found that the ccf-miRNA amount of benign patients is significantly lower than that of the controls. Similarly, the miRNA amount in the controls is significantly higher than that of the thyroiditis (P = 0.06) and the malign groups miRNA (P = 0.084). Although the present study has a low number of patients, the plasma samples could be used as a source of circulating miRNAs. In addition, the total miRNA of thyroid diseases could be used as a biomarker for different types of thyroid diseases. We could suggest, for future study, that specific miRNAs in bodily fluid might show specific properties to be used as biomarkers of thyroid diseases.

MicroRNA-20a-5p inhibits epithelial to mesenchymal transition and invasion of endometrial cancer cells by targeting STAT3

BACKGROUND

Endometrial cancer (EC) is the fourth most common malignancy among women. Epithelial to mesenchymal transition (EMT) and invasion have been identified as central cellular processes in tumor progression and malignant transformation. The function and molecular basis of microRNA-20a-5p (miR-20a-5p) in the development of EC are poorly defined.

METHODS

RT-qPCR assay was used to detect the levels of miR-20a-5p and signal transducer and activator of transcription 3 (STAT3) mRNA. Western blot assay was conducted to determine protein expression of STAT3, N-cadherin, Vimentin and E-cadherin. Cell invasive capacity was examined by transwell invasion assay. Bioinformatics analysis, luciferase reporter assay and RIP assay were performed to investigate the interaction between miR-20a-5p and STAT3 3'UTR.

RESULTS

miR-20a-5p expression was strikingly reduced in EC tissues and cells. Functional analysis revealed that miR-20a-5p overexpression inhibited EMT and invasion of EC cells. Further exploration showed that miR-20a-5p inhibited STAT3 expression by direct interaction. Moreover, the knockdown of STAT3 suppressed EMT and invasion of EC cells. Additionally, the depletion of STAT3 weakened miR-20a-5p downregulation-induced cell EMT and invasion in EC.

CONCLUSION

miR-20a-5p inhibited EMT and invasion of EC cells by targeting STAT3, highlighting the vital roles of miR-20a-5p and STAT3 in the metastasis and malignant transformation of EC.

In Situ Detection of Plasma Exosomal MicroRNA-1246 for Breast Cancer Diagnostics by a Au Nanoflare Probe

Breast cancer is the second cause of cancer mortality in women globally. Early detection, treatment, and metastasis monitoring are of great importance to favorable prognosis. Although conventional diagnostic methods, such as breast X-ray mammography and image positioning biopsy, are accurate, they could cause radioactive or invasive damage to patients. Liquid biopsy as a noninvasive method is convenient for repeated sampling in clinical cancer prognostic, metastatic evaluation, and relapse monitoring. MicroRNAs encased in exosomes circulating in biofluids are promising candidate cancer biomarkers because of their cancer-specific expression profiles. Here, we report an in situ detection of microRNA-1246 (miR-1246) in human plasma exosomes as breast cancer biomarker by a nucleic acid functionalized Au nanoflare probe. Needing neither time-consuming and costly isolation of exosomes from the plasma sample nor transfection means, the Au nanoflare probe can directly enter the plasma exosomes to generate fluorescent signal quantitatively by specifically targeting miR-1246. Only 40 μL of plasma is needed to incubate 4 h with the probe, giving signal sensitive enough to distinguish samples of breast cancer to normal control. Using plasma miR-1246 level detected by our assay as a marker, we differentiated 46 breast cancer patients from 28 healthy controls with 100% sensitivity and 92.9% specificity at the best cutoff. This simple, accurate, sensitive, and cost-effective liquid biopsy by the Au nanoflare probe is potent to be developed as a noninvasive breast cancer diagnostic assay for clinical adaption.

FADD at the Crossroads between Cancer and Inflammation

Initially described as an adaptor molecule for death receptor (DR)-mediated apoptosis, Fas-associated death domain (FADD) was later implicated in nonapoptotic cellular processes. During the last decade, FADD has been shown to participate and regulate most of the signalosome complexes, including necrosome, FADDosome, innateosome, and inflammasome. Given the role of these signaling complexes, FADD has emerged as a new actor in innate immunity, inflammation, and cancer development. Concomitant to these new roles, a surprising number of mechanisms deemed to regulate FADD functions have been identified, including post-translational modifications of FADD protein and FADD secretion. This review focuses on recent knowledge of the biological roles of FADD, a pleiotropic molecule having multiple partners, and its impact in cancer, innate immunity, and inflammation.

LncRNA and mRNA signatures associated with neoadjuvant chemoradiotherapy downstaging effects in rectal cancer

Radiotherapy plays a crucial role in combined treatment modality in local advanced rectal cancer (LARC). While neoadjuvant chemoradiotherapy responses were variable in LARC patients, so, it is important to identify genes that closely associated with short-term and long-term responses to radiotherapy. In this study, we profiled long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) expression values of LARC patients with different neoadjuvant chemoradiotherapy downstaging depth score based on Agilent Arraystar Human LncRNA V3.0 Array(Agilent, CA). LncRNAs and mRNAs with aberrant expression values between the two groups of LARC patients were identified and lncRNA-miRNA-mRNA regulation network was also obtained through the combination of miRcode and miRTarBase database. Gene interaction network and module analysis of differential expression mRNAs contained in the lncRNA-miRNA-mRNA network identified five hub genes, including KRAS, PDPK1, PPP2R5C, PPP2R1B, and YES1, that should be closely associated with LARC's response to chemoradiotherapy. Besides, Kaplan-Meier analysis based on the Cyber Research Center (CRC) data set from The Cancer Genome Atlas indicated that aberrant expression of the five hub genes is significantly associated with CRC overall survival. In conclusion, we obtained several biomarkers that should be associated with neoadjuvant chemoradiotherapy response in LARC, which should be helpful for individual treatment and prognosis improvement.

Long non-coding RNA FLVCR1-AS1 contributes to the proliferation and invasion of lung cancer by sponging miR-573 to upregulate the expression of E2F transcription factor 3

Lung cancer is one of the most common causes of cancer-related death all over the world. In recent years, long non-coding RNAs (lncRNAs) have been reported to play critical roles in the development and progression of human malignancies. In the present study, we aimed to study the role and mechanism of FLVCR1-AS1 in human non-small cell lung cancer (NSCLC). Results revealed that FLVCR1-AS1 was markedly upregulated in NSCLC tissues and cell lines. Knockdown of FLVCR1-AS1 significantly inhibited the proliferation, migration, invasion and promoted apoptosis of NSCLC cells, and suppressed tumor growth of NSCLC in vivo. Moreover, we explored regulatory mechanism, and found that FLVCR1-AS1 functioned as a competing endogenous RNA (ceRNA) by directly binding to miRNA-573, and E2F transcription factor 3 (E2F3) was identified as a down-stream target of miR-573. FLVCR1-AS1 positively regulated E2F3 expression through inhibiting miR-573 in NSCLC cells. Our findings suggested that FLVCR1-AS1/miR-573/E2F3 axis was an important signaling pathway in mediating tumorigenesis and progression of NSCLC, and further indicated that FLVCR1-AS1 could be a novel diagnostic biomarker and therapeutic target for NSCLC.

MiR-216b inhibits osteosarcoma cell proliferation, migration, and invasion by targeting Forkhead Box M1

Osteosarcoma (OS) is considered the most common type of primary malignant bone tumor, which has a high rate of mortality in children and adolescents. However, the current treatment methods for OS are ineffective. Therefore, there is an urgent requirement to identify the critical targets. This study aimed to identify the roles and significance of microRNA-216b (miR-216b) in OS. To explore the cellular and molecular functions of miR-216b and Forkhead Box M1 (FoxM1) in OS, the expression of miR-216b and FoxM1 at the transcriptional level was measured using quantitative real-time PCR (qRT-PCR). Wound healing assay, 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide assay (MTT) assay, flow cytometry, and transwell invasion assay were conducted to study the function of miR-216b and FoxM1 in OS cells. Dual luciferase reporter assay was performed to identify the relationships between miR-216b and FoxM1. qRT-PCR results revealed that miR-216b expression was significantly downregulated, and FoxM1 was observed to be significantly upregulated in human OS cell lines (MG-63) and tissues. MTT data showed that upregulation of miR-216b expression led to cell growth inhibition in MG-63 cells. The results of the invasion assay and wound healing assay illustrated that miR-216b upregulation or FoxM1 downregulation could inhibit the invasion and migration in MG-63 cells. In vivo, the tumor volume was significantly decreased by miR-194 mimic treatment compared with the control group. Furthermore, the results of the luciferase assay indicated that FoxM1 is a direct target of miR-216b. These findings may provide novel insights into the molecular mechanism of miR-216b and FoxM1 in the progression of OS, and suggested that miR-216b may serve as a potential tumor inhibitor of OS by targeting FoxM1.

It's complicated… m6A-dependent regulation of gene expression in cancer

Cellular function relies on multiple pathways that are coordinated to ensure the proper execution of gene expression networks. Failure to coordinate the multiple programs active in the cell can have catastrophic consequences and lead to diseases such as cancer. At the post-transcriptional level, RNA modifications play important roles in the regulation of gene expression. N6-methyladenosine (m⁶A) is the most abundant internal messenger RNA (mRNA) modification and has gained increasing interest in the last few years as a dynamic regulator of RNA metabolism. Modifications regulate all stages of the RNA life cycle, from transcription to decay. Recent studies have pointed to the role of RNA methylation in cancer initiation and progression, and aberrant modification has served as a biomarker of early-stage diagnosis in several cancers. Here, we review the regulation of m⁶A, disruptions to methylation-dependent pathways that influence carcinogenesis, and potential avenues for m⁶A-related therapeutic strategies.

LncRNA LOC728196/miR-513c axis facilitates glioma carcinogenesis by targeting TCF7

Numerous long noncoding RNAs (lncRNAs) are reported to be dysregulated in glioma. However, how lncRNA participates in the process of glioma development and progression still remains elusive. Here, we identified a novel lncRNA LOC728196 highly expressed in glioma tissues. LOC728196 high expression predicts low survival rate in patients. Our data proved that LOC728196 knockdown repressed cellular growth, migration and invasion in vitro. Silencing LOC728196 led to impaired growth of glioma in vivo. Mechanistic studies further demonstrated that LOC728196 acts as the sponge for miR-513c to upregulate TCF7 expression. We observed a reciprocal inhibition between LOC728196 and miR-513c. Rescue assay showed that either inhibition of miR-513c or TCF7 overexpression restored the abilities of proliferation, migration and invasion in LOC728196-silenced glioma cells. Taken together, our study provides a comprehensive investigation on the role of LOC728196 in glioma progression and contributes to understanding the vital role of competing endogenous RNA (ceRNA).

MicroRNA in lung cancer: role, mechanisms, pathways and therapeutic relevance

Lung cancer is the cardinal cause of cancer-related deaths with restricted recourse of therapy throughout the world. Clinical success of therapies is not very promising due to - late diagnosis, limited therapeutic tools, relapse and the development of drug resistance. Recently, small ∼20-24 nucleotides molecules called microRNAs (miRNAs) have come into the limelight as they play outstanding role in the process of tumorigenesis by regulating cell cycle, metastasis, angiogenesis, metabolism and apoptosis. miRNAs essentially regulate gene expression via post-transcriptional regulation of mRNA. Nevertheless, few studies have conceded the role of miRNAs in activation of gene expression. A large body of data generated by numerous studies is suggestive of their tumor-suppressing, oncogenic, diagnostic and prognostic biomarker roles in lung cancer. They have also been implicated in regulating cancer cell metabolism and resistance or sensitivity towards chemotherapy and radiotherapy. Further, miRNAs have also been convoluted in regulation of immune checkpoints - Programmed death 1 (PD-1) and its ligand (PD-L1). These molecules play a significant role in tumor immune escape leading to the generation of a microenvironment favouring tumor growth and progression. Therefore, it is imperative to explore the expression of miRNA and understand its relevance in lung cancer and development of anti-cancer strategies (anti - miRs, miR mimics and micro RNA sponges). In view of the above, the role of miRNA in lung cancer has been dissected and the associated mechanisms and pathways are discussed in this review.

Identification of down-regulated microRNAs in thyroid cancer and their potential functions

BACKGROUND

The mechanism of microRNAs (miRNAs) in thyroid cancer is still unclear. We identified miRNAs with differential expression in thyroid cancer versus normal tissues.

METHODS

Microarray datasets were obtained from the GEO and ArrayExpress databases, and from publications found via PubMed, EMBASE, and Web of Science. Differentially expressed miRNAs were identified using the limma package, and their targets predicted using miRWalk. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) network analyses were performed using these target genes to explore potential carcinogenic mechanisms. Correlations between target gene and miRNA expression levels were examined. Changes in target protein expression were confirmed using data from The Human Protein Atlas and the Cancer Genome Atlas.

RESULTS

We ultimately included five datasets, and further analyzed the four miRNAs that were down-regulated in at least four datasets (miR-7-2-3p, miR-138-5p, miR-144-5p, miR-486-5p). Predicted targets were enriched in GO terms including extracellular matrix organization, cell surface, and receptor binding, and in KEGG cancer pathways. PPI analysis identified 10 hub genes as key potential targets of these miRNAs. The expression levels of eight target genes were negatively correlated with those of their respective miRNAs. Furthermore, eight predicted target genes in cancer-related pathways showed up-regulated protein and mRNA expression in thyroid cancer.

CONCLUSION

Low miRNA expression in thyroid cancer might influence tumorigenesis via critical pathways. The genes identified here may act as a starting point for further investigation of the carcinogenic mechanisms of these miRNAs.

MicroRNA485-3p negatively regulates the transcriptional co-repressor CtBP1 to control the oncogenic process in osteosarcoma cells

Carboxyl-terminal binding protein 1 (CtBP1), a well-known transcriptional co-repressor, is highly expressed in a number of cancer types. However, it is still absent in osteosarcoma cells. Here, we found that CtBP1, but not CtBP2, is overexpressed in invasive osteosarcoma tissues and cells. The overexpressed CtBP1 in turn represses its downstream targets, such as the pro-apoptotic regulators Bax, Bim and p53 upregulated modulator of apoptosis (PUMA), cell adhesion molecule E-cadherin, and the cell cycle regulators p16, p21 and phosphatase and tensin homolog (PTEN). To explore the molecular mechanism of CtBP1 overexpression, we subjected three independent clinical samples to miRNA microarray analysis and found that miR-485-3p could specifically bind to the 3'-untranslated region (3'-UTR) of CtBP1, thereby negatively controlling CtBP1 expression. The overexpression of miR-485-3p in osteosarcoma cells significantly repressed CtBP1 levels and inhibited cell proliferation, colony formation, cell migration and sphere formation. Further analysis indicated that DNA hypermethylation in the promoter region of miR-485-3p caused the downregulation of miR-485-3p. Treatment with the DNA methylation inhibitor 5-aza-2'-deoxycytidine (AZA) resulted in the upregulation of miR-485-3p and the downregulation of CtBP1 as well as inhibited osteosarcoma cell growth. This study provides evidence that CtBP1 is also overexpressed in osteosarcoma cells and demonstrates the underlying mechanism regarding its overexpression. Thus, therapeutically targeting CtBP1 may represent an effective strategy for osteosarcoma therapy.

A Polysome-Based microRNA Screen Identifies miR-24-3p as a Novel Promigratory miRNA in Mesothelioma

The expression of miRNAs in cancer has been widely studied and has allowed the definition of oncomirs and oncosuppressors. We note that it is often underestimated that many mRNAs are expressed, but translationally silent. In spite of this, systematic identification of miRNAs in equilibrium with their target mRNAs on polysomes has not been widely exploited. To identify biologically active oncomirs, we performed a screen for miRNAs acting on the polysomes of malignant mesothelioma (MPM) cells. Only a small percentage of expressed miRNAs physically associated with polysomes. On polysomes, we identified miRNAs already characterized in MPM, as well as novel ones like miR-24-3p, which acted as a promigratory miRNA in all cancer cells tested. miR-24-3p positively regulated Rho-GTP activity, and inhibition of miR-24-3p reduced growth in MPM cells. Analysis of miR-24-3p common targets, in two mesothelioma cell lines, identified a common subset of downregulated genes. These same genes were downregulated during the progression of multiple cancer types. Among the specific targets of miR-24-3p was cingulin, a tight junction protein that inhibits Rho-GTP activity. Overexpression of miR-24-3p only partially abrogated cingulin mRNA, but completely abrogated cingulin protein, confirming its action via translational repression. We suggest that miR-24-3p is an oncomir and speculate that identification of polysome-associated miRNAs efficiently sorts out biologically active miRNAs from inactive ones.Significance: Subcellular localization of miRNAs may predict their role in cancer and identify novel oncogenic miRNAs involved in cancer progression.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/20/5741/F1.large.jpg Cancer Res; 78(20); 5741-53. ©2018 AACR.

Interplay between miRNAs and host genes and their role in cancer

MicroRNAs (miRNAs) are small endogenous non-coding functional RNAs that post-transcriptionally regulate gene expression. They play essential roles in nearly all biological processes including cell development and differentiation, DNA damage repair, cell death as well as intercellular communication. They are highly involved in cancer, acting as tumor suppressors and/or promoters to modulate cell proliferation, epithelial-mesenchymal transition and tumor invasion and metastasis. Recent studies have shown that more than half of miRNAs are located within protein-coding or non-coding genes. Intragenic miRNAs and their host genes either share the promoter or have independent transcription. Meanwhile, miRNAs work as partners or antagonists of their host genes by fine-tuning their target genes functionally associated with host genes. This review outlined the complicated relationship between intragenic miRNAs and host genes. Focusing on miRNAs known as oncogenes or tumor suppressors in specific cancer types, it studied co-expression relationships between these miRNAs and host genes in the cancer types using TCGA data sets, which validated previous findings and revealed common, tumor-specific and even subtype-specific patterns. These observations will help understand the function of intragenic miRNAs and further develop miRNA therapeutics in cancer.

Micro-RNAs involved in cellular proliferation have altered expression profiles in granulosa of young women with diminished ovarian reserve

PURPOSE

The study aims to determine differences in micro-RNA (miRNA) expression in granulosa (GC) and cumulus cells (CC) between young women with diminished ovarian reserve (DOR) or normal ovarian reserve (NOR). Secondary objective was to identify downstream signaling pathways that could ultimately indicate causes of lower developmental competence of oocytes from young women with DOR.

METHODS

The method of the study is prospective cohort study.

RESULTS

Of the miRNA, 125 are differentially expressed in GC between DOR and NOR. Only nine miRNA were different in CC; therefore, we focused analysis on GC. In DOR GC, miR-100-5p, miR-16-5p, miR-30a-3p, and miR-193a-3p were significantly downregulated, while miR-155-5p, miR-192-5p, miR-128-3p, miR-486-5p, miR130a-3p, miR-92a-3p, miR-17-3p, miR-221-3p, and miR-175p were increased. This pattern predicted higher cell proliferation in the DOR GC. The primary pathways include MAPK, Wnt, and TGFbeta.

CONCLUSIONS

The miRNA pattern identified critical functions in cell proliferation and survival associated with DOR. GC in women with DOR seems to respond differently to the LH surge.

MicroRNA-590-5p regulates cell viability, apoptosis, migration and invasion of renal cell carcinoma cell lines through targeting ARHGAP24

Renal cell carcinoma (RCC) is the leading cause of death in renal malignancies. MicroRNA-590-5p (miR-590-5p) is of great importance in the processes of many cancers regarding regulation of cancer cell invasion and proliferation. In our study, alternation of miR-590-5p expression in RCC cell lines through transfection with pre-miR-590-5p (up-regulation) or anti-miR-590-5p (down-regulation) was performed. Apoptosis and viability of RCC cell lines were measured by flow cytometry and CCK-8 analysis, respectively. Cell invasion and migration were estimated by Transwell assay. The association of miR-590-5p with ARHGAP24 expression was evaluated using luciferase assays, real-time PCR and western blot assay. The expressions of apoptosis and migration-related protein were also measured by western blotting. We found that pre-miR-590-5p transfection in Caki-2 and 786-O cells showed significant increases in cell viability, invasion and migration, which were accompanied by decreased cell apoptosis, while anti-miR-590-5p transfection obviously inhibited the cell viability, migration and invasion of Caki-2 and 786-O cells as well as induced apoptosis, compared with the negative control group. Furthermore, bioinformatics combined with luciferase reporter assays indicated that ARHGAP24 is directly targeted by miR-590-5p. ARHGAP24 overexpression in 786-O and Caki-2 cells phenocopied the effects of anti-miR-590-5p transfection along with enhanced expression of active Caspase-3 and Bax/Bcl-2 ratio as well as decreased expression of MMP-2 and MMP-9. These findings suggested that miR-590-5p/ARHGAP24 seems to function as a potentially beneficial target for RCC treatment.