MicroRNAs -the next generation therapeutic targets in human diseases

Circulating MiR-16-5p and MiR-19b-3p as Two Novel Potential Biomarkers to Indicate Progression of Gastric Cancer

Gastric cancer (GC) is the second most common cancer in China and the second leading cause of cancer-related death in the world. Identifying circulating biomarkers is helpful to improve theranostics of gastric cancer. Herein, we are for the first time to report miR-16-5p and miR-19b-3p were identified to be the novel potential plasma biomarkers to detect gastric cancer. Differentially expressed miRNAs were initially screened out by genome-wide miRNA profiling microarrays between 16 plasma samples of gastric cancer and 18 matched normal controls, and then were quantified and validated by quantitative reverse transcription-PCR method between 155 gastric cancer cases and 111 normal controls. Additionally, 30 plasma samples from precancerous lesions and 18 paired samples from gastric cancer patients with gastrectomy were further detected. Results showed that based on two normalization methods, miR-16-5p and miR-19b-3p in plasma were found to be capable of distinguishing normal population from GC cases with different TNM stages and differentiation grades, particularly including the early cancer cases (P<0.05). And the two miRNAs were down-regulated in GC cases (FC<0.5). Especially, the down-regulation degree was correlated with the progression of the GC cases from the early stage to the advanced stage (0.2< r_s<0.3, P<0.01). And the same weak down-regulation of the two biomarkers as the early GC occurred initially in the precancerous diseases (P<0.05). The corresponding performance of the two miRNAs to detect GC in ROC analysis gradually performed better with the disease progression from the earlier stages or lower grades to the advanced stages (TNM Ⅳ stage: AUC=0.832 for miR-16-5p; TNM Ⅲ stage: AUC=0.822 for miR-19b-3p) or high grade (Poorly differentiated: AUC=0.801, 0.791 respectively for miR-16-5p and miR-19b-3p). Additionally, miR-19b-3p remained down-regulated in patient plasma within 9 days after gastrectomy. In conclusion, miR-19b-3p and miR-16-5p maybe prospective biomarkers to detect gastric cancer and indicate its progression, and thus may own great potential in applications such as early screening and progression evaluation of gastric cancer in the near future.

Increased expression of microRNA-196a predicts poor prognosis in human ovarian carcinoma

OBJECTIVE

Overexpression of MicroRNA-196a (miR-196a) has recently been reported in different types of human cancers. However, the prognostic value of miR-196a in ovarian carcinoma remains unknown. In this study, we investigated the expression of miR-196a in ovarian carcinoma and its relationship with tumor progression and clinical prognosis.

METHODS

The expression level of miR-196a was examined by quantitative Real-time PCR (qRT-PCR) in surgically removed ovarian cancer tissues and ovarian cancer cell lines. The correlation between miR-196a expression and clinical features and prognosis were statistically analyzed.

RESULTS

The results showed that the miR-196a expression was significantly upregulated in tumor tissues and ovarian cancer cell lines compared with that in normal ovarian surface tissues and normal ovarian epithelial cells. Moreover, miR-196a expression was positively correlated with FIGO stage (P<0.001), tumor size (P=0.020), and lymph nodes metastasis (P=0.019). Kaplan-Meier analysis demonstrated that high levels of miR-196a expression was associated with poorer overall survival (P<0.001) and recurrent-free survival (P=0.003), especially in patients with advanced disease (P=0.002). Multivariate analysis suggested that miR-196a expression was an independent prognostic factor for overall survival of patients with ovarian carcinoma.

CONCLUSIONS

In conclusion, miR-196a may play an important role in the progression of ovarian carcinoma, and could be used as an independent prognostic biomarker for patients with ovarian carcinoma.

Biomarker-based MicroRNA Therapeutic Strategies for Hepatocellular Carcinoma

Recently, microRNAs (miRNAs) have emerged as key factors involved in a series of biological processes, ranging from embryogenesis to programmed cell death. Its link to aberrant expression profiles has rendered it a potentially attractive tool for the diagnosis, prognosis, or treatment of various diseases. Accumulating evidence has indicated that miRNAs act as tumor suppressors in hepatocyte malignant transformation by regulating development, differentiation, proliferation, and tumorigenesis. Here, we summarize recent progress in the development of novel biomarker-based miRNA therapeutic strategies for hepatocellular carcinoma (HCC).

Biomarker-based MicroRNA Therapeutic Strategies for Hepatocellular Carcinoma

Recently, microRNAs (miRNAs) have emerged as key factors involved in a series of biological processes, ranging from embryogenesis to programmed cell death. Its link to aberrant expression profiles has rendered it a potentially attractive tool for the diagnosis, prognosis, or treatment of various diseases. Accumulating evidence has indicated that miRNAs act as tumor suppressors in hepatocyte malignant transformation by regulating development, differentiation, proliferation, and tumorigenesis. Here, we summarize recent progress in the development of novel biomarker-based miRNA therapeutic strategies for hepatocellular carcinoma (HCC).

MicroRNAs in Schizophrenia: Implications for Synaptic Plasticity and Dopamine-Glutamate Interaction at the Postsynaptic Density. New Avenues for Antipsychotic Treatment Under a Theranostic Perspective

Despite dopamine-glutamate aberrant interaction that has long been considered a relevant landmark of psychosis pathophysiology, several aspects of these two neurotransmitters reciprocal interaction remain to be defined. The emerging role of postsynaptic density (PSD) proteins at glutamate synapse as a molecular "lego" making a functional hub where different signals converge may add a new piece of information to understand how dopamine-glutamate interaction may work with regard to schizophrenia pathophysiology and treatment. More recently, compelling evidence suggests a relevant role for microRNA (miRNA) as a new class of dopamine and glutamate modulators with regulatory functions in the reciprocal interaction of these two neurotransmitters. Here, we aimed at addressing the following issues: (i) Do miRNAs have a role in schizophrenia pathophysiology in the context of dopamine-glutamate aberrant interaction? (ii) If miRNAs are relevant for dopamine-glutamate interaction, at what level this modulation takes place? (iii) Finally, will this knowledge open the door to innovative diagnostic and therapeutic tools? The biogenesis of miRNAs and their role in synaptic plasticity with relevance to schizophrenia will be considered in the context of dopamine-glutamate interaction, with special focus on miRNA interaction with PSD elements. From this framework, implications both for biomarkers identification and potential innovative interventions will be considered.

MicroRNA-378a-5p targets cyclin G2 to inhibit fusion and differentiation in BeWo cells

MicroRNAs are expressed abundantly in the placenta throughout pregnancy. We have previously reported that microRNA (miR)-378a-5p promoted trophoblast migration and invasion. To further understand the role of miR-378a-5p during placental development, we investigated whether it may regulate the differentiation of syncytiotrophoblast (STB). Using a choriocarcinoma cell line, BeWo, we found that miR-378a-5p was down-regulated during forskolin-induced STB differentiation. Transfection of a miR-378a-5p mimic into BeWo cells decreased the formation of multinucleated STB, increased E-cadherin, and decreased the expression level of STB marker genes. On the other hand, transfection of anti-miR-378a-5p resulted in an increase in formation of multinucleated STB and expression of STB marker genes, as well as the loss of E-cadherin. Bioinformatic analysis revealed that miR-378a-5p has four potential binding sites at the 3' untranslated region (UTR) of cyclin G2 (CCNG2). Using luciferase reporter assays, we showed that miR-378a-5p decreased the luciferase activity of reporter constructs that contain CCNG2 3' UTR. In addition, miR-378a-5p decreased, whereas anti-miR-378a-5p increased, CCNG2 mRNA levels. Overexpression of CCNG2 increased the expression of syncytin-1 and fusion index and reversed the inhibitory effects of miR-378a-5p. In contrast, silencing of CCNG2 using siRNA increased E-cadherin and decreased syncytin-1 levels. These findings provide initial evidence that CCNG2 promotes STB differentiation and suggest that miR-378a-5p exerts an inhibitory role in STB differentiation, in part, by down-regulating CCNG2 expression, in the BeWo cell model.

siRNA delivery to the lung: what's new?

RNA interference (RNAi) has been thought of as the general answer to many unmet medical needs. After the first success stories, it soon became obvious that short interfering RNA (siRNA) is not suitable for systemic administration due to its poor pharmacokinetics. Therefore local administration routes have been adopted for more successful in vivo RNAi. This paper reviews nucleic acid modifications, nanocarrier chemistry, animal models used in successful pulmonary siRNA delivery, as well as clinical translation approaches. We summarize what has been published recently and conclude with the potential problems that may still hamper the efficient clinical application of RNAi in the lung.

Progress in aptamer-mediated drug delivery vehicles for cancer targeting and its implications in addressing chemotherapeutic challenges

Aptamers are novel oligonucleotides with flexible three-dimensional configurations that recognize and bind to their cognate targets, including tumor surface receptors, in a high-affinity and highly specific manner. Because of their unique intrinsic properties, a variety of aptamer-mediated nanovehicles have been developed to directionally transport anti-cancer drugs to tumor sites to minimize systemic cytotoxicity and to enhance permeation by these tumoricidal agents. Despite advances in the selection and synthesis of aptamers and in the conjugation and self-assembly of nanotechnologies, current chemotherapy and drug delivery systems face great challenges. These challenges are due to the limitations of aptamers and vehicles and because of complicated tumor mechanisms, including heterogeneity, anti-cancer drug resistance, and hypoxia-induced aberrances. In this review, we will summarize current approaches utilizing tumor surface hallmarks and aptamers and their roles and mechanisms in therapeutic nanovehicles targeting tumors. Delivery forms include nanoparticles, nanotubes, nanogels, aptamer-drug conjugates, and novel molecular trains. Moreover, the obstacles posed by the aforementioned issues will be highlighted, and possible solutions will be acknowledged. Furthermore, future perspectives will be presented, including cutting-edge integration with RNA interference nanotechnology and personalized chemotherapy, which will facilitate innovative approaches to aptamer-based therapeutics.

Knockdown of miR-210 decreases hypoxic glioma stem cells stemness and radioresistance

Glioma contains abundant hypoxic regions which provide niches to promote the maintenance and expansion of glioma stem cells (GSCs), which are resistant to conventional therapies and responsible for recurrence. Given the fact that miR-210 plays a vital role in cellular adaption to hypoxia and in stem cell survival and stemness maintenance, strategies correcting the aberrantly expressed miR-210 might open up a new therapeutic avenue to hypoxia GSCs. In the present study, to explore the possibility of miR-210 as an effective therapeutic target to hypoxic GSCs, we employed a lentiviral-mediated anti-sense miR-210 gene transfer technique to knockdown miR-210 expression and analyze phenotypic changes in hypoxic U87s and SHG44s cells. We found that hypoxia led to an increased HIF-2α mRNA expression and miR-210 expression in GSCs. Knockdown of miR-210 decreased neurosphere formation capacity, stem cell marker expression and cell viability, and induced differentiation and G0/G1 arrest in hypoxic GSCs by partially rescued Myc antagonist (MNT) protein expression. Knockdown of MNT could reverse the gene expression changes and the growth inhibition resulting from knockdown of miR-210 in hypoxic GSCs. Moreover, knockdown of miR-210 led to increased apoptotic rate and Caspase-3/7 activity and decreased invasive capacity, reactive oxygen species (ROS) and lactate production and radioresistance in hypoxic GSCs. These findings suggest that miR-210 might be a potential therapeutic target to eliminate GSCs located in hypoxic niches.

MicroRNA and diseases: therapeutic potential as new generation of drugs

MicroRNA (miRNA) is a small non-coding regulatory RNA of 21-25 nucleotides (nts) in length. miRNA works as a post-transcriptional regulator of a specific mRNA by inducing degradation or translation repression resulting in gene silencing. A large number of miRNA have been reported and many more are yet to be discovered. Aberrant expression of miRNA has been linked to numerous diseases. Attempts have been made to attenuate miRNA misregulation under pathophysiological conditions. Additionally, the potential use of miRNA in the diagnosis and treatment of diseases has been studied. Several preclinical and clinical results have been obtained, and miRNA-based therapeutics are still under investigations. In this review, the role of miRNA in a variety of pathological conditions has been summarized. Recent findings from preclinical and clinical investigations examining the role of miRNA as diagnostic markers, and their potential as drug candidates, are also highlighted. The current results summarized in this review may elucidate new dimensions of miRNA therapeutic and diagnostic techniques for biomedical academic and industry research.

MicroRNAs - a new generation molecular targets for treating cellular diseases

MicroRNAs (miRNAs) are a unique class of non-coding, small RNAs, similar to mRNAs, transcribed by cells, but for entirely different reasons. While mRNAs are transcribed to code for proteins, miRNAs are produced to regulate the production of proteins from mRNAs. miRNAs are central components that tightly and temporally regulating gene expression in cells. Dysregulation of miRNAs expressions in cellular pathogenesis, including cancer, has been reported, and it clearly supports the importance of miRNAs as therapeutic targets in almost every cellular disease. This special issue compiles manuscripts from different authors in order to highlight the importance of microRNAs in cancer and other cellular diseases and how to explore them as therapeutic targets to treat patients with these genetic and metabolic disorders. This issue also covers manuscripts that highlight the obstacles associated with the delivery of therapeutic microRNAs in cells and in vivo in living animals and how to improve and noninvasively monitor the delivery in living animals through molecular imaging, including potential clinical perspectives.