Counterbalance between RB inactivation and miR-17-92 overexpression in reactive oxygen species and DNA damage induction in lung cancers

Prognostic microRNA signature for estimating survival in patients with hepatocellular carcinoma

OBJECTIVE

Hepatocellular carcinoma (HCC) is one of the leading cancer types with increasing annual incidence and high mortality in the USA. MicroRNAs (miRNAs) have emerged as valuable prognostic indicators in cancer patients. To identify a miRNA signature predictive of survival in patients with HCC, we developed a machine learning-based HCC survival estimation method, HCCse, using the miRNA expression profiles of 122 patients with HCC.

METHODS

The HCCse method was designed using an optimal feature selection algorithm incorporated with support vector regression.

RESULTS

HCCse identified a robust miRNA signature consisting of 32 miRNAs and obtained a mean correlation coefficient (R) and mean absolute error (MAE) of 0.87 ± 0.02 and 0.73 years between the actual and estimated survival times of patients with HCC; and the jackknife test achieved an R and MAE of 0.73 and 0.97 years between actual and estimated survival times, respectively. The identified signature has seven prognostic miRNAs (hsa-miR-146a-3p, hsa-miR-200a-3p, hsa-miR-652-3p, hsa-miR-34a-3p, hsa-miR-132-5p, hsa-miR-1301-3p and hsa-miR-374b-3p) and four diagnostic miRNAs (hsa-miR-1301-3p, hsa-miR-17-5p, hsa-miR-34a-3p and hsa-miR-200a-3p). Notably, three of these miRNAs, hsa-miR-200a-3p, hsa-miR-1301-3p and hsa-miR-17-5p, also displayed association with tumor stage, further emphasizing their clinical relevance. Furthermore, we performed pathway enrichment analysis and found that the target genes of the identified miRNA signature were significantly enriched in the hepatitis B pathway, suggesting its potential involvement in HCC pathogenesis.

CONCLUSIONS

Our study developed HCCse, a machine learning-based method, to predict survival in HCC patients using miRNA expression profiles. We identified a robust miRNA signature of 32 miRNAs with prognostic and diagnostic value, highlighting their clinical relevance in HCC management and potential involvement in HCC pathogenesis.

Noncoding RNAs in cancer ferroptosis: From biology to clinical opportunity

Ferroptosis is a recently discovered pattern of programmed cell death that is nonapoptotic and irondependent. It is involved in lipid peroxidation dependent on reactive oxygen species. Ferroptosis has been verified to play a crucial regulatory role in a variety of pathological courses of disease, in particularly cancer. Emerging research has highlighted the potential of ferroptosis in tumorigenesis, cancer development and resistance to chemotherapy. However, the regulatory mechanism of ferroptosis remains unclear, which limits the application of ferroptosis in cancer treatment. Noncoding RNAs (ncRNAs) are noncoding transcripts that regulate gene expression in various ways to affect the malignant phenotypes of cancer cells. At present, the biological function and underlying regulatory mechanism of ncRNAs in cancer ferroptosis have been partially elucidated. Herein, we summarize the current knowledge of the central regulatory network of ferroptosis, with a focus on the regulatory functions of ncRNAs in cancer ferroptosis. The clinical application and prospects of ferroptosis-related ncRNAs in cancer diagnosis, prognosis and anticancer therapies are also discussed. Elucidating the function and mechanism of ncRNAs in ferroptosis, along with assessing the clinical significance of ferroptosis-related ncRNAs, provides new perspectives for understanding cancer biology and treatment approaches, which may benefit numerous cancer patients in the future.

Evaluation of Plasma miR-17-5p, miR-24-3p and miRNA-223-3p Profile of Hepatitis C Virus-Infected Patients after Treatment with Direct-Acting Antivirals

The expression of miR-223-3p, miR-17-5p, and miR-24-3p was evaluated in hepatitis C virus (HCV) patient serum samples, collected before DAA treatment and after a sustained virological response (SVR). Fifty HCV patients were stratified based on their liver damage stages into three different subgroups (21 with chronic hepatitis-CH, 15 with cirrhosis, and 14 with hepatocellular carcinoma-HCC). Considering the entire HCV population, the miRNA expression levels were significantly downregulated after the SVR compared to pre-treatment ones (p < 0.05). Stratifying the patients based on liver damage, the post-SVR values of the three miRNAs were significantly downregulated compared to the pre-treatment levels for both cirrhosis and HCC patients. No significant differences emerged from the analysis of the CH group. To our knowledge, this is the first study to detail the behavior of miR-223-3p, miR-17-5p, and miR-24-3p levels in patients with HCV-related CH, cirrhosis, and HCC after DAA therapy. Our findings show that HCV-infected patients have different miRNA profiles before and after treatment with DAAs, strongly suggesting that miRNAs may be involved in the pathogenesis of HCV-related damage. In this respect, the correlation observed among the three studied miRNAs could imply that they share common pathways by which they contribute the progression of HCV-induced chronic liver damage.

A systematic review and meta-analysis of the diagnostic value of circulating microRNA-17-5p in patients with non-small cell lung cancer

BACKGROUND

nonSmall Cell Lung Cancer (NSCLC) is the most common type of lung cancer with high morbidity and mortality rates. Studies have shown that miR-17-5p levels are significantly increased in the circulating blood of NSCLC patients. This meta-analysis aimed to investigate the diagnostic value of miR-17-5p in NSCLC in China.

METHODS

A literature search was conducted for studies on the correlation between miR-25 and the diagnosis of NSCLC until October 2022 using English and Chinese databases. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was adopted to evaluate the quality of studies in the literature. Numerical values for sensitivity and specificity were obtained from false negative (FN), false positive (FP), true negative (TN), and true positive (TP) rates, presented alongside graphical representations with boxes marking the values and horizontal lines showing the confidence intervals. Summary Receiver Operating Characteristic (SROC) curves were applied to assess the performance of the diagnostic tests. The data were processed using RevMan 5.3.

RESULTS

Three studies (208 cases of NSCLC patients and 198 healthy controls) met our evaluation criteria. The sensitivity was 0.70 to 0.75, and the specificity value was 0.82 to 0.83. The Area Under the Curve (AUC) from the SROC curves was > 80%; therefore, it was classified as a good category.

CONCLUSION

Our meta-analysis shows that miR-17-5p can be used for the diagnosis of NSCLC and may serve as a biomarker for the detection of early NSCLC in the Chinese population.

Antileukemic Activity of hsa-miR-203a-5p by Limiting Glutathione Metabolism in Imatinib-Resistant K562 Cells

Imatinib has been the first and most successful tyrosine kinase inhibitor (TKI) for chronic myeloid leukemia (CML), but many patients develop resistance to it after a satisfactory response. Glutathione (GSH) metabolism is thought to be one of the factors causing the emergence of imatinib resistance. Since hsa-miR-203a-5p was found to downregulate Bcr-Abl1 oncogene and also a link between this oncogene and GSH metabolism is reported, the present study aimed to investigate whether hsa-miR-203a-5p could overcome imatinib resistance by targeting GSH metabolism in imatinib-resistant CML cells. After the development of imatinib-resistant K562 (IR-K562) cells by gradually exposing K562 (C) cells to increasing doses of imatinib, resistant cells were transfected with hsa-miR-203a-5p (R+203). Thereafter, cell lysates from various K562 cell sets (imatinib-sensitive, imatinib-resistant, and miR-transfected imatinib-resistant K562 cells) were used for GC-MS-based metabolic profiling. L-alanine, 5-oxoproline (also known as pyroglutamic acid), L-glutamic acid, glycine, and phosphoric acid (Pi)-five metabolites from our data, matched with the enumerated 28 metabolites of the MetaboAnalyst 5.0 for the GSH metabolism. All of these metabolites were present in higher concentrations in IR-K562 cells, but intriguingly, they were all reduced in R+203 and equated to imatinib-sensitive K562 cells (C). Concludingly, the identified metabolites associated with GSH metabolism could be used as diagnostic markers.

SLU7: A New Hub of Gene Expression Regulation—From Epigenetics to Protein Stability in Health and Disease

SLU7 (Splicing factor synergistic lethal with U5 snRNA 7) was first identified as a splicing factor necessary for the correct selection of 3′ splice sites, strongly impacting on the diversity of gene transcripts in a cell. More recent studies have uncovered new and non-redundant roles of SLU7 as an integrative hub of different levels of gene expression regulation, including epigenetic DNA remodeling, modulation of transcription and protein stability. Here we review those findings, the multiple factors and mechanisms implicated as well as the cellular functions affected. For instance, SLU7 is essential to secure liver differentiation, genome integrity acting at different levels and a correct cell cycle progression. Accordingly, the aberrant expression of SLU7 could be associated with human diseases including cancer, although strikingly, it is an essential survival factor for cancer cells. Finally, we discuss the implications of SLU7 in pathophysiology, with particular emphasis on the progression of liver disease and its possible role as a therapeutic target in human cancer.

Effects of Cadmium on Physiochemistry and Bioactive Substances of Muskmelon (Cucumis melo L.)

Muskmelon pedicel is the fruit stalk of muskmelon and one of the traditional Chinese medicines, which can be used to treat jaundice, diabetes and neuropathy. However, in recent years, agricultural soil heavy metal cadmium (Cd) pollution has become serious, coupled with the imperfect sales management of herbal medicine, increasing the potential health risk of contaminated herbal medicine in the human body. In this paper, the comprehensive quality of contaminated muskmelon was tested. The results showed that Cd stress significantly inhibited the growth of muskmelon plants, reduced the anthocyanin and chlorophyll contents, and increased the fruit size and sweetness of muskmelon. In addition, heavy metal Cd can also cause oxidative stress in plants, resulting in a series of changes in antioxidant enzyme activities. In the experimental group, the content of polyphenols and saponins increased by 27.02% and 23.92%, respectively, after high-concentration Cd treatment, which may be a mechanism of plant resistance to stress. This paper reveals that the content of bioactive substances in Chinese herbal medicine is high, but the harm in heavy metals cannot be underestimated, which should be paid attention to by relevant departments.

Regulation of Metabolic Reprogramming by Long Non-Coding RNAs in Cancer

Metabolic reprogramming is a well described hallmark of cancer. Oncogenic stimuli and the microenvironment shape the metabolic phenotype of cancer cells, causing pathological modifications of carbohydrate, amino acid and lipid metabolism that support the uncontrolled growth and proliferation of cancer cells. Conversely, metabolic alterations in cancer can drive changes in genetic programs affecting cell proliferation and differentiation. In recent years, the role of non-coding RNAs in metabolic reprogramming in cancer has been extensively studied. Here, we review this topic, with a focus on glucose, glutamine, and lipid metabolism and point to some evidence that metabolic alterations occurring in cancer can drive changes in non-coding RNA expression, thus adding an additional level of complexity in the relationship between metabolism and genetic programs in cancer cells.

Endothelial-Derived miR-17∼92 Promotes Angiogenesis to Protect against Renal Ischemia-Reperfusion Injury

BACKGROUND

Damage to the renal microvasculature is a hallmark of renal ischemia-reperfusion injury (IRI)-mediated AKI. The miR-17∼92 miRNA cluster (encoding miR-17, -18a, -19a, -20a, -19b-1, and -92a-1) regulates angiogenesis in multiple settings, but no definitive role in renal endothelium during AKI pathogenesis has been established.

METHODS

Antibodies bound to magnetic beads were utilized to selectively enrich for renal endothelial cells from mice. Endothelial-specific miR-17∼92 knockout (miR-17∼92endo-/- ) mice were generated and given renal IRI. Mice were monitored for the development of AKI using serum chemistries and histology and for renal blood flow using magnetic resonance imaging (MRI) and laser Doppler imaging. Mice were treated with miRNA mimics during renal IRI, and therapeutic efficacies were evaluated.

RESULTS

miR-17, -18a, -20a, -19b, and pri-miR-17∼92 are dynamically regulated in renal endothelial cells after renal IRI. miR-17∼92endo-/- exacerbates renal IRI in male and female mice. Specifically, miR-17∼92endo-/- promotes renal tubular injury, reduces renal blood flow, promotes microvascular rarefaction, increases renal oxidative stress, and promotes macrophage infiltration to injured kidneys. The potent antiangiogenic factor thrombospondin 1 (TSP1) is highly expressed in renal endothelium in miR-17∼92endo-/- after renal IRI and is a target of miR-18a and miR-19a/b. miR-17∼92 is critical in the angiogenic response after renal IRI, which treatment with miR-18a and miR-19b mimics can mitigate.

CONCLUSIONS

These data suggest that endothelial-derived miR-17∼92 stimulates a reparative response in damaged renal vasculature during renal IRI by regulating angiogenic pathways.

MicroRNAs: Emerging oncogenic and tumor-suppressive regulators, biomarkers and therapeutic targets in lung cancer

Lung cancer is one of the most common solid tumors worldwide and the leading cause of cancer-related deaths, causing a devastating impact on human health. The clinical prognosis of lung cancer is usually restricted by delayed diagnosis and resistance to anticancer therapies. MicroRNAs, a range of small endogenous noncoding RNAs 22 nucleotides in length, have emerged as one of the most important players in cancer initiation and progression in recent decades. Current evidence reveals pivotal roles of microRNAs in regulating cell proliferation, migration, invasion and metastasis in lung cancer. An increasing number of preclinical and clinical studies have also explored the potential of microRNAs as promising biomarkers and new therapeutic targets for lung cancer. The current review summarizes the most recent progress on the functional mechanisms of microRNAs involved in lung cancer development and progression and further discusses the clinical application of miRNAs as putative therapeutic targets for molecular diagnosis and prognostic prediction in lung cancer.

miR-132 improves the cognitive function of rats with Alzheimer's disease by inhibiting the MAPK1 signal pathway

Alzheimer's disease (AD) is a common worldwide progressive neurodegenerative disease. The dysregulation of miRNA is crucial in neurodegenerative diseases and neuron apoptosis during AD and is closely associated with the MAPK pathway. By bioinformatic website, we found that there was target inhibiting relationship between microRNA (miR)-132 and MAPK1. Therefore, the current study speculated that miR-132 could improve the cognitive function of rats with AD by inhibiting MAPK1 expression. To verify our hypothesis, 10 normal rats and 60 rats with AD were selected and divided into model, Ad-miR-132 negative control (NC), Ad-miR-132, Ad-small interfering (si)MAPK1 NC, Ad-siMAPK1 and Ad-miR-132 + Ad-MAPK1 groups. Rats were evaluated for learning by performing morris water maze tests and pathological changes of the hippocampus were assessed via HE staining. Additionally, hippocampus cell apoptosis was determined using a TUNEL assay and levels of acetylcholinesterase (AChE), reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were evaluated in sera via ELISA. The mRNA and protein expression of miR-132, iNOS, MAPK1 and phosphorylated (p)-MAPK1 was determined in hippocampus tissues via reverse transcription-quantitative PCR and western blotting, respectively. Compared with normal mice, rats with AD had significantly decreased learning abilities, increased cell apoptosis rates, increased levels of AChE, iNOS, ROS, MDA, MAPK1 and p-MAPK1 and decreased levels of SOD, GSH-Px and miR-132. Upregulation of miR-132 group improved the above indictors and silencing MAKP1 worsened the condition of rats. miR-132 upregulation therefore reversed the negative effects caused by MAPK1 silencing in rats with AD. In conclusion, miR-132 inhibited hippocampal iNOS expression and oxidative stress by inhibiting MAPK1expression to improve the cognitive function of rats with AD.

Prenatal particulate air pollution exposure and expression of the miR-17/92 cluster in cord blood: Findings from the ENVIRONAGE birth cohort

BACKGROUND

Air pollution exposure during pregnancy is an important environmental health issue. Epigenetics mediate the effects of prenatal exposure and could increase disease predisposition in later life. The oncogenic miR-17/92 cluster is involved in normal development and disease.

OBJECTIVES

Here, for the first time the potential prenatal effects of particulate matter with a diameter<2.5 μm (PM_2.5) exposure on expression of the miR-17/92 cluster in cord blood are explored.

METHODS

In 370 mother-newborn pairs from the ENVIRONAGE birth cohort, expression of three members of the miR-17/92 cluster was measured in cord blood by qRT-PCR. Expression of C-MYC and CDKN1A, a cluster activator and a target gene, respectively, was also analyzed. Multivariable linear regression models were used to associate the relative m(i)RNA expression with prenatal PM_2.5 exposure.

RESULTS

PM_2.5 exposure averaged (10^th-90^th percentile) 11.7 (9.0-14.4) µg/m³ over the entire pregnancy. In cord blood, miR-17 and miR-20a showed a -45.0% (95%CI: -55.9 to -31.4, p < 0.0001) and a -33.7% (95%CI: -46.9 to -17.2, p = 0.0003), decrease in expression in association with first trimester PM_2.5 exposure, and a -32.5% (95%CI: -45.6 to -16.3, p = 0.0004) and -23.3% (95%CI: -38.1 to -4.8, p = 0.02), respectively, decrease in expression in association with PM_2.5 exposure during the entire pregnancy. In association with third trimester PM_2.5 exposure, a reduction of -25.8% (95%CI: -40.2 to -8.0, p = 0.007) and -14.2% (95%CI: -27.7 to 1.9, p = 0.08), for miR-20a and miR-92a expression, respectively, was identified. Only miR-92a expression (-15.7%, 95%CI: -27.3 to -2.4, p = 0.02) was associated with PM_2.5 exposure during the last month of pregnancy. C-MYC expression was downregulated in cord blood in association with prenatal PM_2.5 exposure during the first trimester and the entire pregnancy, in the adjusted model.

DISCUSSION

Lower expression levels of the miR-17/92 cluster in cord blood in association with increased prenatal PM_2.5 exposure were observed. Whether this oncogenic microRNA cluster plays a role in trans-placental carcinogenesis remains to be elucidated.

Revisiting cancer hallmarks: insights from the interplay between oxidative stress and non-coding RNAs

Cancer is one of the most common disease worldwide, with complex changes and certain traits which have been described as “The Hallmarks of Cancer.” Despite increasing studies on in-depth investigation of these hallmarks, the molecular mechanisms associated with tumorigenesis have still not yet been fully defined. Recently, accumulating evidence supports the observation that microRNAs and long noncoding RNAs (lncRNAs), two main classes of noncoding RNAs (ncRNAs), regulate most cancer hallmarks through their binding with DNA, RNA or proteins, or encoding small peptides. Reactive oxygen species (ROS), the byproducts generated during metabolic processes, are known to regulate every step of tumorigenesis by acting as second messengers in cancer cells. The disturbance in ROS homeostasis leads to a specific pathological state termed “oxidative stress”, which plays essential roles in regulation of cancer progression. In addition, the interplay between oxidative stress and ncRNAs is found to regulate the expression of multiple genes and the activation of several signaling pathways involved in cancer hallmarks, revealing a potential mechanistic relationship involving ncRNAs, oxidative stress and cancer. In this review, we provide evidence that shows the essential role of ncRNAs and the interplay between oxidative stress and ncRNAs in regulating cancer hallmarks, which may expand our understanding of ncRNAs in the cancer development from the new perspective.

Crosstalk between noncoding RNAs and ferroptosis: new dawn for overcoming cancer progression

Cancer progression including proliferation, metastasis, and chemoresistance has become a serious hindrance to cancer therapy. This phenomenon mainly derives from the innate insensitive or acquired resistance of cancer cells to apoptosis. Ferroptosis is a newly discovered mechanism of programmed cell death characterized by peroxidation of the lipid membrane induced by reactive oxygen species. Ferroptosis has been confirmed to eliminate cancer cells in an apoptosis-independent manner, however, the specific regulatory mechanism of ferroptosis is still unknown. The use of ferroptosis for overcoming cancer progression is limited. Noncoding RNAs have been found to play an important roles in cancer. They regulate gene expression to affect biological processes of cancer cells such as proliferation, cell cycle, and cell death. Thus far, the functions of ncRNAs in ferroptosis of cancer cells have been examined, and the specific mechanisms by which noncoding RNAs regulate ferroptosis have been partially discovered. However, there is no summary of ferroptosis associated noncoding RNAs and their functions in different cancer types. In this review, we discuss the roles of ferroptosis-associated noncoding RNAs in detail. Moreover, future work regarding the interaction between noncoding RNAs and ferroptosis is proposed, the possible obstacles are predicted and associated solutions are put forward. This review will deepen our understanding of the relationship between noncoding RNAs and ferroptosis, and provide new insights in targeting noncoding RNAs in ferroptosis associated therapeutic strategies.

MicroRNA and ROS Crosstalk in Cardiac and Pulmonary Diseases

Reactive oxygen species (ROS) affect many cellular functions and the proper redox balance between ROS and antioxidants contributes substantially to the physiological welfare of the cell. During pathological conditions, an altered redox equilibrium leads to increased production of ROS that in turn may cause oxidative damage. MicroRNAs (miRNAs) regulate gene expression at the post-transcriptional level contributing to all major cellular processes, including oxidative stress and cell death. Several miRNAs are expressed in response to ROS to mediate oxidative stress. Conversely, oxidative stress may lead to the upregulation of miRNAs that control mechanisms to buffer the damage induced by ROS. This review focuses on the complex crosstalk between miRNAs and ROS in diseases of the cardiac (i.e., cardiac hypertrophy, heart failure, myocardial infarction, ischemia/reperfusion injury, diabetic cardiomyopathy) and pulmonary (i.e., idiopathic pulmonary fibrosis, acute lung injury/acute respiratory distress syndrome, asthma, chronic obstructive pulmonary disease, lung cancer) compartments. Of note, miR-34a, miR-144, miR-421, miR-129, miR-181c, miR-16, miR-31, miR-155, miR-21, and miR-1/206 were found to play a role during oxidative stress in both heart and lung pathologies. This review comprehensively summarizes current knowledge in the field.

microRNAs Tune Oxidative Stress in Cancer Therapeutic Tolerance and Resistance

Relapsed disease following first-line therapy remains one of the central problems in cancer management, including chemotherapy, radiotherapy, growth factor receptor-based targeted therapy, and immune checkpoint-based immunotherapy. Cancer cells develop therapeutic resistance through both intrinsic and extrinsic mechanisms including cellular heterogeneity, drug tolerance, bypassing alternative signaling pathways, as well as the acquisition of new genetic mutations. Reactive oxygen species (ROSs) are byproducts originated from cellular oxidative metabolism. Recent discoveries have shown that a disabled antioxidant program leads to therapeutic resistance in several types of cancers. ROSs are finely tuned by dysregulated microRNAs, and vice versa. However, mechanisms of a crosstalk between ROSs and microRNAs in regulating therapeutic resistance are not clear. Here, we summarize how the microRNA-ROS network modulates cancer therapeutic tolerance and resistance and direct new vulnerable targets against drug tolerance and resistance for future applications.

Mitochondrial miR-762 regulates apoptosis and myocardial infarction by impairing ND2

Mitochondrial dysfunction plays a major role in the pathogenesis of cardiovascular diseases. MicroRNAs (miRNAs) are small RNAs that act as negative regulators of gene expression, but how miRNAs affect mitochondrial function in the heart is unclear. Using a miRNA microarray assay, we found that miR-762 predominantly translocated in the mitochondria and was significantly upregulated upon anoxia/reoxygenation (A/R) treatment. Knockdown of endogenous miR-762 significantly attenuated the decrease in intracellular ATP levels, the increase in ROS levels, the decrease in mitochondrial complex I enzyme activity and the increase in apoptotic cell death in cardiomyocytes, which was induced by A/R treatment. In addition, knockdown of miR-762 ameliorated myocardial ischemia/reperfusion (I/R) injury in mice. Mechanistically, we showed that enforced expression of miR-762 dramatically decreased the protein levels of endogenous NADH dehydrogenase subunit 2 (ND2) but had no effect on the transcript levels of ND2. The luciferase reporter assay showed that miR-762 bound to the coding sequence of ND2. In addition, knockdown of endogenous ND2 significantly decreased intracellular ATP levels, increased ROS levels, reduced mitochondrial complex I enzyme activity and increased apoptotic cell death in cardiomyocytes, which was induced by A/R treatment. Furthermore, we found that the inhibitory effect of miR-762 downregulation was attenuated by ND2 knockdown. Thus, our findings suggest that miR-762 participates in the regulation of mitochondrial function and cardiomyocyte apoptosis by ND2, a core assembly subunit of mitochondrial complex I. Our results revealed that mitochondrial miR-762, as a new player in mitochondrial dysfunction, may provide a new therapeutic target for myocardial infarction.

Predicting microRNA-disease associations using bipartite local models and hubness-aware regression

The development and progression of numerous complex human diseases have been confirmed to be associated with microRNAs (miRNAs) by various experimental and clinical studies. Predicting potential miRNA-disease associations can help us understand the underlying molecular and cellular mechanisms of diseases and promote the development of disease treatment and diagnosis. Due to the high cost of conventional experimental verification, proposing a new computational method for miRNA-disease association prediction is an efficient and economical way. Since previous computational models ignored the hubness phenomenon, we presented a novel computational model of Bipartite Local models and Hubness-Aware Regression for MiRNA-Disease Association prediction (BLHARMDA). In this method, we first used known miRNA-disease associations to calculate the Jaccard similarity between miRNAs and between diseases, then utilized a modified kNNs model in the bipartite local model method. As a result, we effectively alleviated the detriments from 'bad' hubs. BLHARMDA obtained AUCs of 0.9141 and 0.8390 in the global and local leave-one-out cross validation, respectively, which outperformed most of the previous models and proved high prediction performance of BLHARMDA. Besides, the standard deviation of 0.0006 in 5-fold cross validation confirmed our model's prediction stability and the averaged prediction accuracy of 0.9120 showed the high precision of our model. In addition, to further evaluate our model's accuracy, we implemented BLHARMDA on three typical human diseases in three different types of case studies. As a result, 49 (Esophageal Neoplasms), 50 (Lung Neoplasms) and 50 (Carcinoma Hepatocellular) out of the top 50 related miRNAs were validated by recent experimental discoveries.

Role of miRNAs in lung cancer

Lung cancer (LC) is the leading cause of cancer-related deaths all over the world, among both men and women, with an incidence of over 200,000 new cases per year coupled with a very high mortality rate. LC comprises of two major clinicopathological categories: small-cell (SCLC) and nonsmall-cell lung carcinoma (NSCLC). The microRNAs (miRNAs) are small noncoding RNAs, usually 18-25 nucleotides long, which repress protein translation through binding to complementary target mRNAs. The miRNAs regulate many biological processes including cell cycle regulation, cellular growth, proliferation, differentiation, apoptosis, metabolism, neuronal patterning, and aging. This review summarizes the role of miRNAs expression in LC. It also provides information about the miRNAs as biomarker and therapeutic target for lung cancer. Understanding the role of miRNAs in LC may provide insights into the diagnosis and treatment strategy for LC.

Friend leukemia virus integration 1 promotes tumorigenesis of small cell lung cancer cells by activating the miR-17-92 pathway

Small cell lung cancer (SCLC) is regarded as the most devastative type of human lung malignancies. The rapid and disseminated growth pattern remains the primary cause of poor clinical prognosis in patients with SCLC. However, the molecular factors that drive rapid progression of SCLC remain unclear. Friend leukemia virus integration 1 (FLI1), an Ets transcription factor family member, has been previously reported to act as a major driver of hematological malignancies. In this study, we explored the potential role of FLI1 in SCLC. Using immunohistochemical staining, we found that FLI1 was significantly upregulated in SCLC tissues, compared to that in non-small cell lung cancer (NSCLC) and normal lung tissues (p < 0.01). The expression score of FLI1 oncoprotein was associated with the extensive stage of SCLC and the overexpressed Ki67. Knockdown of FLI1 with small interfering RNA (siRNA) or short hairpin RNA (shRNA) promoted apoptosis and induced repression of cell proliferation, tumor colony formation and in vivo tumorigenicity in highly aggressive SCLC cell lines. Importantly, we discovered that FLI1 promoted tumorigenesis by activating the miR-17-92 cluster family. This study uncovers FLI1 as an important driving factor that promotes tumor growth in SCLC through the miR-17-92 pathway. FLI1 may serve as an attractive target for therapeutic intervention of SCLC.

MicroRNA, epigenetic machinery and lung cancer

Lung cancer is the leading cause of cancer deaths worldwide and over 80% of lung cancer patients are classified as having non-small cell lung cancer. Although there have been technological advancements in the early detection and standard treatment of lung cancer, it is often diagnosed at an advanced stage and is chemoresistant to most available drugs. A number of studies have demonstrated that microRNA is able to modulate various tumorigenic processes, including progression and metastasis, in various mechanisms. In this review we examine the most recent achievements in microRNA and lung cancer treatment and summarize the research progress on the reciprocal regulation between microRNA and epigenetic modifications, as both have been intensively studied in lung cancer. Epigenetic modifications on the human genome regulate gene and microRNA expression at the transcriptional level; inversely, microRNA can also transcriptionally cleave and/or translationally repress the expression of several key enzymes involved in epigenetic processes such as DNA methylation and histone modification. Better understanding of reciprocal regulation between microRNA and epigenetic modifications will underlie the development of novel microRNA orientated diagnostic and therapeutic strategies relating to lung cancer in the near future.

Biology of MiR-17-92 Cluster and Its Progress in Lung Cancer

MicroRNAs, a class of short endogenous RNAs, acting as post-transcriptional regulators of gene expression, mostly silence gene expression via binding imperfectly matched sequences in the 3'UTR of target mRNA. MiR-17-92, a highly conserved gene cluster, has 6 members including miR-17, miR-18a, miR-19a, miR-20a, miR-19b-1 and miR-92a. The miR-17-92 cluster, regarded as oncogene, is overexpressed in human cancers. Lung cancer is the leading cause of death all over the world. The molecular mechanism of lung cancer has been partly known at the levels of genes and proteins in last decade. However, new prognosis biomarkers and more target drugs should be developed in future. Therefore, noncoding RNAs, especially miRNAs, make them as new potentially clinical biomarkers for diagnosis and prognosis. In this review, we focus the current progress of miR-17-92 cluster in lung cancer.

MicroRNA-17-5p inhibits proliferation and triggers apoptosis in non-small cell lung cancer by targeting transforming growth factor β receptor 2

MicroRNAs (miRs) are small non-coding RNAs that suppress gene expression by directly binding to the 3′-untranslated region of their target mRNAs. Specific miRs serve key roles in the development and progression of non-small cell lung cancer (NSCLC). The aim of the present study was to determine the mechanism of miR-17-5p in the regulation of NSCLC cell survival and proliferation. Reverse transcription-quantitative polymerase chain reaction data indicated that miR-17-5p was significantly downregulated in 28 NSCLC tissues compared with 7 non-tumorous lung tissues. Furthermore, lower miR-17-5p expression was associated with a higher pathological stage in NSCLC patients. Lower miR-17-5p expression was also observed in several common NSCLC cell lines, including SK-MES-1, A549, SPCA-1, H460, H1229 and HCC827, compared with the bronchial epithelium cell line, BEAS-2B. Additionally, overexpression of miR-17-5p significantly inhibited proliferation while inducing the apoptosis of NSCLC H460 cells. Subsequently, transforming growth factor β receptor 2 (TGFβR2) was identified as a direct target of miR-17-5p using a luciferase reporter assay. Western blot analysis confirmed that miR-17-5p negatively mediated the expression of TGFβR2 in NSCLC cells. Furthermore, small interfering RNA-induced downregulation of TGFβR2 also suppressed the proliferation of H460 cells while triggering apoptosis. Therefore, the results of the current study suggest that miR-17-5p may inhibit proliferation and trigger apoptosis in NSCLC H460 cells at least partially by targeting TGFβR2.

Amplification and Quantification of an Antisense Oligonucleotide from Target microRNA Using Programmable DNA and a Biological Nanopore

This paper describes a strategy for autonomous diagnoses of cancers using microRNA (miRNA) and therapy for tumor cells by DNA computing techniques and nanopore measurement. Theranostics, which involves the combination of diagnosis and therapy, has emerged as an approach for personalized medicine or point-of-care cancer diagnostics. DNA computing will become a potent tool for theranostics because it functions completely autonomously without the need for external regulations. However, conventional theranostics using DNA computing involves a one-to-one reaction in which a single input molecule generates a single output molecule; the concentration of the antisense drug is insufficient for the therapy in this type of reaction. Herein we developed an amplification system involving an isothermal reaction in which a large amount of the antisense DNA drug was autonomously generated after detecting miRNA from small cell lung cancer. In addition, we successfully quantified the amount of the generated drug molecule by nanopore measurement with high accuracy, which was more accurate than conventional gel electrophoresis. This autonomous amplification strategy is a potent candidate for a broad range of theranostics using DNA computing.

MicroRNAs, DNA Damage Response, and Cancer Treatment

As a result of various stresses, lesions caused by DNA-damaging agents occur constantly in each cell of the human body. Generally, DNA damage is recognized and repaired by the DNA damage response (DDR) machinery, and the cells survive. When repair fails, the genomic integrity of the cell is disrupted—a hallmark of cancer. In addition, the DDR plays a dual role in cancer development and therapy. Cancer radiotherapy and chemotherapy are designed to eliminate cancer cells by inducing DNA damage, which in turn can promote tumorigenesis. Over the past two decades, an increasing number of microRNAs (miRNAs), small noncoding RNAs, have been identified as participating in the processes regulating tumorigenesis and responses to cancer treatment with radiation therapy or genotoxic chemotherapies, by modulating the DDR. The purpose of this review is to summarize the recent findings on how miRNAs regulate the DDR and discuss the therapeutic functions of miRNAs in cancer in the context of DDR regulation.

Insights into the Regulatory Role of Non-coding RNAs in Cancer Metabolism

Cancer represents a complex disease originated from alterations in several genes leading to disturbances in important signaling pathways in tumor biology, favoring heterogeneity that promotes adaptability and pharmacological resistance of tumor cells. Metabolic reprogramming has emerged as an important hallmark of cancer characterized by the presence of aerobic glycolysis, increased glutaminolysis and fatty acid biosynthesis, as well as an altered mitochondrial energy production. The metabolic switches that support energetic requirements of cancer cells are closely related to either activation of oncogenes or down-modulation of tumor-suppressor genes, finally leading to dysregulation of cell proliferation, metastasis and drug resistance signals. Non-coding RNAs (ncRNAs) have emerged as one important kind of molecules that can regulate altered genes contributing, to the establishment of metabolic reprogramming. Moreover, diverse metabolic signals can regulate ncRNA expression and activity at genetic, transcriptional, or epigenetic levels. The regulatory landscape of ncRNAs may provide a new approach for understanding and treatment of different types of malignancies. In this review we discuss the regulatory role exerted by ncRNAs on metabolic enzymes and pathways involved in glucose, lipid, and amino acid metabolism. We also review how metabolic stress conditions and tumoral microenvironment influence ncRNA expression and activity. Furthermore, we comment on the therapeutic potential of metabolism-related ncRNAs in cancer.

Mono-(2-ethylhexyl) Phthalate Increases Oxidative Stress Responsive miRNAs in First Trimester Placental Cell Line HTR8/SVneo

Phthalates, an endocrine disruptor group, cause oxidative stress (OS) in the placenta. However, no studies have reported OS-related miRNAs induced by phthalates. In the present study, we demonstrate that mono-(2-ethylhexyl) phthalate (MEHP) induces OS responsive miR-17-5p, miR-155-5p, and miR-126-3p in HTR8/SVneo in a dose- and time-dependent manner. Furthermore, MEHP altered the expression of phosphoinositide-3-kinase regulatory subunit 1α, phosphatase and tensin homolog, CDKN2A interacting protein, superoxide dismutase 2, and 3β-hydroxysterol-D24 reductase, which are involved in OS and predicted to be regulated by these miRNAs. Our results suggest that placental exposure to MEHP may result in aberrant miRNA expression leading to pregnancy complications.

Detection of Exosomal miRNAs in the Plasma of Melanoma Patients

MicroRNAs (miRNAs) are a class of 22–25 nucleotide RNAs that control gene expression at the post-transcriptional level. MiRNAs have potential as cancer biomarkers. Melanoma is a highly aggressive form of skin cancer accounting for almost 4% of cancers among men and women, and ~80% of skin cancer-related deaths in the US. In the present study we analyzed plasma-derived exosomal miRNAs from clinically affected and unaffected familial melanoma patients (CDKN2A/p16 gene carriers) and compared them with affected (nonfamilial melanoma) and unaffected control subjects in order to identify novel risk biomarkers for melanoma. Intact miRNAs can be isolated from the circulation because of their presence in exosomes. A number of differentially regulated miRNAs identified by NanoString human V2 miRNA array were validated by quantitative PCR. Significantly, miR-17, miR-19a, miR-21, miR-126, and miR-149 were expressed at higher levels in patients with metastatic sporadic melanoma as compared with familial melanoma patients or unaffected control subjects. Surprisingly, no substantial differences in miRNA expression were detected between familial melanoma patients (all inclusive) and unaffected control subjects. The miRNAs differentially expressed in the different patient cohorts, especially in patients with metastatic melanoma, may play important roles in tumor progression and metastasis, and may be used as predictive biomarkers to monitor remission as well as relapse following therapeutic intervention.

Non-coding RNA: a new tool for the diagnosis, prognosis, and therapy of small cell lung cancer

In recent years, novel classes of noncoding RNAs (ncRNAs) have been discovered, which are implicated in diverse functional and regulatory activities. Growing evidence indicates that deregulated ncRNAs play crucial roles in the onset and progression of cancer, including small-cell lung cancer. In this review, we highlight nearly all of the findings regarding the roles and the possible mechanisms of ncRNAs as oncogenes or tumor suppressors in small-cell lung cancer. Furthermore, we discuss the possible role of ncRNAs as diagnostic biomarkers, their significant contribution to the prognosis, and their functions in regulating the response to therapy.

Role of Exosomal Noncoding RNAs in Lung Carcinogenesis

Lung cancer is the major cause of cancer death worldwide. Novel, recently discovered classes of noncoding RNAs (ncRNAs) have diverse functional and regulatory activities and increasing evidence suggests crucial roles for deregulated ncRNAs in the onset and progression of cancer, including lung cancer. Exosomes are small extracellular membrane vesicles of endocytic origin that are released by many cells and are found in most body fluids. Tumor-derived exosomes mediate tumorigenesis by facilitating tumor growth and metastasis. MicroRNAs (miRNAs) are a subclass of ncRNAs that are present in exosomes. miRNAs are taken up by neighboring or distant cells and modulate various functions of recipient cells. Here, we review exosome-derived ncRNAs with a focus on miRNAs and their role in lung cancer biology.

The regulatory and predictive functions of miR-17 and miR-92 families on cisplatin resistance of non-small cell lung cancer

Background

Chemotherapy is an important therapeutic approach for non-small cell lung cancer (NSCLC). However, a successful long-term treatment can be prevented by the occurring of chemotherapy resistance frequently, and the molecular mechanisms of chemotherapy resistance in NSCLC remain unclear. In this study, abnormal expressions of miR-17 and miR-92 families are observed in cisplatin-resistant cells, suggesting that miR-17 and miR-92 families are involved in the regulation of cisplatin resistance in NSCLC.

Methods

miRNA microarray shows that miR-17 and miR-92 families are all down-regulated in cisplatin-resistant A549/DDP cells compared with cisplatin-sensitive A549 cells. The aim of this study is to investigate the regulatory functions of miR-17 and miR-92 families on the formation of cisplatin resistance and the predictive functions of them as biomarkers of platinum-based chemotherapy resistance in NSCLC.

Results

The low expressions of miR-17 and miR-92 families can maintain cisplatin resistance through the regulation of CDKN1A and RAD21. As a result of high expressions of CDKN1A and RAD21, the inhibition of DNA synthesis and the repair of DNA damage are achieved and these may be two major contributing factors to cisplatin resistance. Moreover, we demonstrate that the expressions of miR-17 and miR-92 families in NSCLC tissues are significantly associated with platinum-based chemotherapy response.

Conclusion

Our study indicates that miR-17 and miR-92 families play important roles in cisplatin resistance and can be used as potential biomarkers for better predicting the clinical response to platinum-based chemotherapy in NSCLC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1713-z) contains supplementary material, which is available to authorized users.

miR-342-3p regulates MYC transcriptional activity via direct repression of E2F1 in human lung cancer

Accumulating evidence indicates that altered miRNA expression is crucially involved in lung cancer development, though scant information is available regarding how MYC, an archetypical oncogene, is regulated by miRNAs, especially via a mechanism involving MYC cofactors. In this study, we attempted to identify miRNAs involved in regulation of MYC transcriptional activity in lung cancer. To this end, we utilized an integrative approach with combinatorial usage of miRNA and mRNA expression profile datasets of patient tumor tissues, as well as those of MYC-inducible cell lines in vitro. In addition to miRNAs previously reported to be directly regulated by MYC, including let-7 and miR-17-92, our strategy also helped to identify miR-342-3p as capable of indirectly regulating MYC activity via direct repression of E2F1, a MYC-cooperating molecule. Furthermore, miR-342-3p module activity, which we defined as a gene set reflecting the experimentally substantiated influence of miR-342-3p on mRNA expression, was found to be inversely correlated with MYC activity reflected by MYC module activity in three independent datasets of lung adenocarcinoma patients obtained from the Director's Challenge Consortium of the United States (P = 1.94 × 10(-73)), the National Cancer Center of Japan (P = 9.05 × 10(-34)) and the present study (P = 1.17 × 10(-19)). Our integrative approach appears to be useful to elucidate inter-regulatory relationships between miRNAs and protein coding genes of interest, even those present in patient tumor tissues, which remains a challenge to better understand the pathogenesis of this devastating disease.

Mitochondrial miRNA (MitomiR): a new player in cardiovascular health

Cardiovascular disease is one of the major causes of human morbidity and mortality in the world. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and are known to be involved in the pathogenesis of heart diseases, but the translocation phenomenon and the mode of action in mitochondria are largely unknown. Recent mitochondrial proteome analysis unveiled at least 2000 proteins, of which only 13 are made by the mitochondrial genome. There are numerous studies demonstrating the translocation of proteins into the mitochondria and also translocation of ribosomal RNA (viz., 5S rRNA) into mitochondria. Recent studies have suggested that miRNAs contain sequence elements that affect their subcellular localization, particularly nuclear localization. If there are sequence elements that direct miRNAs to the nucleus, it is also possible that similar sequence elements exist to direct miRNAs to the mitochondria. In this review we have summarized most of the miRNAs that have been shown to play an important role in mitochondrial function, either by regulating mitochondrial genes or by regulating nuclear genes that are known to influence mitochondrial function. While the focus of this review is cardiovascular diseases, we also illustrate the role of mitochondrial miRNA (MitomiR) in the initiation and progression of various diseases, including cardiovascular diseases, metabolic diseases, and cancer. Our goal here is to summarize the miRNAs that are localized to the mitochondrial fraction of cells, and how these miRNAs modulate cardiovascular health.

Non-small-cell lung cancer and miRNAs: novel biomarkers and promising tools for treatment

Lung cancer is the leading cause of cancer-related death worldwide, with approximately 80–85% of cases being non-small-cell lung cancer (NSCLC). The miRNAs are small non-coding RNAs that regulate gene expression at a post-transcriptional level by either degradation or inhibition of the translation of target genes. Evidence is mounting that miRNAs exert pivotal effects in the development and progression of human malignancies, including NSCLC. A better understanding of the role that miRNAs play in the disease will contribute to the development of new diagnostic biomarkers and individualized therapeutic tools. In the present review, we briefly describe the role of miRNAs in NSCLC as well as the possible future of these discoveries in clinical applications.

New insights into lung development and diseases: the role of microRNAs

MicroRNAs (miRNAs) are short endogenous noncoding RNA molecules (∼ 22 nucleotides) that can regulate gene expression at the post-transcription level. Research interest in the role of miRNAs in lung biology is emerging. MiRNAs have been implicated in a range of processes such as development, homeostasis, and inflammatory diseases in lung tissues and are capable of inducing differentiation, morphogenesis, and apoptosis. In recent years, several studies have reported that miRNAs are differentially regulated in lung development and lung diseases in response to epigenetic changes, providing new insights for their versatile role in various physiological and pathological processes in the lung. In this review, we discuss the contribution of miRNAs to lung development and diseases and possible future implications in the field of lung biology.

Enterococcus faecalis Infection and Reactive Oxygen Species Down-Regulates the miR-17-92 Cluster in Gastric Adenocarcinoma Cell Culture

Chronic inflammation due to bacterial overgrowth of the stomach predisposes to the development of gastric cancer and is also associated with high levels of reactive oxygen species (ROS). In recent years increasing attention has been drawn to microRNAs (miRNAs) due to their role in the pathogenesis of many human diseases including gastric cancer. Here we studied the impact of infection by the gram-positive bacteria Enterococcus faecalis (E. faecalis) on global miRNA expression as well as the effect of ROS on selected miRNAs. Human gastric adenocarcinoma cell line MKN74 was infected with living E. faecalis for 24 h or for 5 days or with E. faecalis lysate for 5 days. The miRNA expression was examined by microarray analysis using Affymetrix GeneChip miRNA Arrays. To test the effect of ROS, MKN74 cells were treated with 100 mM tert-Butyl hydroperoxide (TBHP). Following 5 days of E. faecalis infection we found 91 differentially expressed miRNAs in response to living bacteria and 2 miRNAs responded to E. faecalis lysate. We verified the down-regulation of the miR-17-92 and miR-106-363 clusters and of other miRNAs involved in the oxidative stress-response by qRT-PCR. We conclude that only infection by living E. faecalis bacteria caused a significant global response in miRNA expression in the MKN74 cell culture. E. faecalis infection as well as ROS stimulation down-regulated the expression of the miR-17-92 cluster. We believe that these changes could reflect a general response of gastric epithelial cells to bacterial infections.

MicroRNAs in lung cancer

MicroRNAs have become recognized as key players in the development of cancer. They are a family of small non-coding RNAs that can negatively regulate the expression of cancer-related genes by sequence-selective targeting of mRNAs, leading to either mRNA degradation or translational repression. Lung cancer is the leading cause of cancer-related death worldwide with a substantially low survival rate. MicroRNAs have been confirmed to play roles in lung cancer development, epithelial-mesenchymal transition and response to therapy. They are also being studied for their future use as diagnostic and prognostic biomarkers and as potential therapeutic targets. In this review we focus on the role of dysregulated microRNA expression in lung tumorigenesis. We also discuss the role of microRNAs in therapeutic resistance and as biomarkers. We further look into the progress made and challenges remaining in using microRNAs for therapy in lung cancer.

The role of microRNAs in the regulation of apoptosis in lung cancer and its application in cancer treatment

Lung cancer remains to be one of the most common and serious types of cancer worldwide. While treatment is available, the survival rate of this cancer is still critically low due to late stage diagnosis and high frequency of drug resistance, thus highlighting the pressing need for a greater understanding of the molecular mechanisms involved in lung carcinogenesis. Studies in the past years have evidenced that microRNAs (miRNAs) are critical players in the regulation of various biological functions, including apoptosis, which is a process frequently evaded in cancer progression. Recently, miRNAs were demonstrated to possess proapoptotic or antiapoptotic abilities through the targeting of oncogenes or tumor suppressor genes. This review examines the involvement of miRNAs in the apoptotic process of lung cancer and will also touch on the promising evidence supporting the role of miRNAs in regulating sensitivity to anticancer treatment.

The miR-19a/b family positively regulates cardiomyocyte hypertrophy by targeting atrogin-1 and MuRF-1

Progressive cardiac hypertrophy owing to pathological stimuli, such as pressure overload, is frequently associated with the development of heart failure, a major cause of morbidity and mortality worldwide. Growing evidence has shown that miRNAs are extensively involved in the pathogenesis of cardiac hypertrophy. In the present study, we examined the hypothesis that the miR-19a/b family acts as a key regulator of cardiac hypertrophy and apoptosis. Forced overexpression of miR-19a/b was sufficient to induce hypertrophy in rat neonatal cardiomyocytes. Luciferase assays revealed that miR-19a/b directly target the anti-hypertrophic genes atrogin-1 and MuRF-1 (muscle RING-finger protein-1). The endogenous expressions of the target genes were down-regulated by miR-19a/b. Pro-hypertrophic calcineurin/NFAT (nuclear factor of activated T-cells) signalling was elevated markedly in the presence of miR-19b, and the calcineurin inhibitor CsA (cyclosporin A) and the PKC (protein kinase C) inhibitor GF10923X significantly attenuated the miR-19b-mediated increase in cell size and expression of hypertrophic markers. Furthermore, miR-19b led to increased cell survival through up-regulation of the NFAT target gene encoding α-crystallin-B and repression of the pro-apoptotic gene Bim (Bcl-2-interacting mediator of cell death) under ER (endoplasmic reticulum) stress conditions. Taken together, the results of the present study demonstrate that the miR-19a/b family regulates phenotypes of cardiomyocytes via suppression of multiple direct target genes.

miRNA expression profiles associated with diagnosis and prognosis in lung cancer

miRNAs, which are small single-stranded RNA molecules composed of 18-23 nts, act as oncogenes or tumor suppressor genes playing important roles in the processes of tumor formation, infiltration and metastasis. Lung cancer currently has the highest morbidity and mortality among all malignant tumors; yet, lack of early specific diagnostic markers and effective treatments hinders its proper management. In lung cancer, about 40-45 abnormal expression patterns of miRNAs have been discovered and are involved in lung cancer development. miRNAs have functions together with oncogenes and tumor suppressor genes of lung cancer. miRNAs-based tests can be used for early clinical diagnosis and prediction of clinical outcomes of lung cancer. Studying the role of miRNAs in lung cancer development and its relationship with diagnostic and prognostic parameters might help to improve the sensitivity of diagnosis and the efficacy of lung cancer treatment.

Selective killing of lung cancer cells by miRNA-506 molecule through inhibiting NF-κB p65 to evoke reactive oxygen species generation and p53 activation

The tumor suppressor p53, nuclear factor-κB (NF-κB) and reactive oxygen species (ROS) have crucial roles in tumorigenesis, although the mechanisms of cross talk between these factors remain largely unknown. Here we report that miR-506 upregulation occurs in 83% of lung cancer patients (156 cases), and its expression highly correlates with ROS. Ectopic expression of miR-506 inhibits NF-κB p65 expression, induces ROS accumulation and then activates p53 to suppress lung cancer cell viability, but not in normal cells. Interestingly, p53 promotes miR-506 expression level, indicating that miR-506 mediates cross talk between p53, NF-κB p65 and ROS. Furthermore, we demonstrated that miR-506 mimics inhibited tumorigenesis in vivo, implicating that miR-506 might be a potential therapeutic molecule for selective killing of lung cancer cells.