miR-143, miR-222, and miR-452 are useful as tumor stratification and noninvasive diagnostic biomarkers for bladder cancer

MicroRNAs with prognostic significance in bladder cancer: a systematic review and meta-analysis

The aim of this study was to systematically review articles that investigated the prognostic significance of different microRNAs in bladder cancer (BC). We systematically searched PubMed, Web of Science, and Embase to identify relevant studies until March 2016. After screening, 26 studies that involved 2753 patients were included. Results suggested that many miRs expression aberration may predict prognosis in patients with BC. There are six miRs (miR-21, miR-143, miR-155, miR-200, miR-214, and miR-222) were reported by at least two studies, and we performed meta-analysis in the corresponding studies. Accordingly, we found that high miR-21 expression was associated with poor overall survival [OS; hazard ratio (HR) = 3.94, 95% CI 2.08–7.44]. High miR-143 expression was associated with poor progression-free survival (PFS; HR = 3.78, 95% CI 1.61–8.89). High miR-155 expression was associated with poor PFS (HR = 8.10, 95% CI 2.92–22.48). High miR-222 expression was associated with poor OS (HR = 3.39, 95% CI 1.10–10.41). Meanwhile, low miR-214 expression was correlated with poor RFS(HR = 0.34, 95% CI 0.22–0.53). Our comprehensive systematic review concluded that microRNAs, particularly miR-21, miR-143, miR-155, miR-214, and miR-222, could serve as meticulous follow-up markers for early detection of progression or recurrence and even useful therapeutic targets for the treatment in patients with BC.

MicroRNA-452 suppresses pancreatic cancer migration and invasion by directly targeting B-cell-specific Moloney murine leukemia virus insertion site 1

Pancreatic cancer, one of the most common cancers globally, is the fourth most common cause of cancer-associated mortality in the USA. The 5-year relative survival rate for patients with pancreatic cancer is ~5% and the median survival time is only 6 months. The poor prognosis is mainly due to early and aggressive local invasion and metastasis, as well as dissemination of the pancreatic cancer cells. The present study demonstrated that microRNA-452 (miR-452) was markedly downregulated in pancreatic cancer tissues, particularly in metastatic tumors and pancreatic cancer cell lines. Overexpression of miR-452 significantly inhibited migration and invasion in pancreatic cancer cells. In addition, the molecular mechanism underlying the inhibitory functions of miR-452 in pancreatic cancer was also investigated. The results indicated that B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI1) was a direct target gene of miR-452 in pancreatic cancer. Overexpression of miR-452 inhibited the migration and invasion of pancreatic cancer, at least partially by knockdown of BMI1 expression. The results provided novel insight with potential therapeutic applications for the treatment of metastatic pancreatic cancer.

MicroRNAs in biofluids are novel tools for bladder cancer screening

MicroRNAs (miRNAs) are short non-coding RNAs that play important roles in basic cellular processes, including differentiation, proliferation, apoptosis and autophagy. They are also involved in various stages of tumorigenesis and play key roles in bladder cancer initiation and progression. Notably, the altered expression of miRNAs in the tumors is reflected in body fluids, including blood and urine, which opens avenues for non-invasive diagnosis and prognosis. Many studies have demonstrated that epigenetic changes extensively alter tumoral microRNA expression. The high reproducibility, specificity and sensitivity of miRNA levels in body fluids suggest their potential use as biomarkers for cancer screening and diagnosis. For example, recent technological advances have made it possible to detect miRNAs in urine for bladder cancer screening. In this review, we focus mainly on the current knowledge and future challenges for incorporating miRNAs in body fluids, like urine and blood, for making clinical diagnoses and assessing prognoses in bladder cancer.

Recent Advances in the Diagnosis and Management of Bladder Cancer

The most common malignancy of urinary tract is bladder cancer. It is one of the most widespread cancers of the world and ranks nine among frequent malignancies existing in world. The only solution to above burning problem is timely diagnosis at earlier stage, and the cancer research is being forwarded in this direction. There are various prominent gene modifications responsible for growth of bladder cancer. The present review is focused on recent advances in the field of cancer makers involving, genetic, urinary, pathological, etc., approaches to contain the deadly process of carcinogenesis. The present review provides an insight on the emerging biomarkers that could be developed to boost current bladder cancer detection strategies. This shall help timely diagnosis of this deadly disease at early stage, thereby, helping bladder cancer patients to fight against this iniquity of life.

A Polycomb-mir200 loop regulates clinical outcome in bladder cancer

Bladder cancer (BC) is a highly prevalent disease, ranking fifth in the most common cancers worldwide. Various miRNAs have recently emerged as potential prognostic biomarkers in cancer. The miR-200 family, which repressed the epithelial-to-mesenchymal transition (EMT), is repressed in multiple advanced cancers. However, its expression and function in BC is still poorly understood. Here we show that miR-200 family displays increased expression, probably due to the activation of specific oncogenic signaling pathways, and reduced promoter methylation, in BC compared to normal bladder samples. Furthermore, we show that the expression of these miRNAs is decreased in high grade and stage tumors, and the down-regulation is associated with patient's poor clinical outcome. Our data indicate that the miR-200 family plays distinct roles in Non-Muscle (NMIBC) and Muscle-Invasive BC (MIBC). In MIBC, miR-200 expression post transcriptionally regulates EMT-promoting transcription factors ZEB1 and ZEB2, whereas suppresses BMI1 expression in NMIBC. Interestingly, we show that increased EZH2 and/or BMI1 expression repress the expression of miR-200 family members. Collectively, these findings support a model of BC progression through a coordinated action between the Polycomb Repression Complex (PRC) members repressing the miR-200 expression, which ultimately favors invasive BC development. Since pharmacological inhibition of EZH2 in BC cell lines lead to increased miR-200 expression, our findings may support new therapeutic strategies for BC clinical management.

MicroRNA-106a suppresses proliferation, migration, and invasion of bladder cancer cells by modulating MAPK signaling, cell cycle regulators, and Ets-1-mediated MMP-2 expression

Despite the clinical significance of tumorigenesis, little is known about the cellular signaling networks of microRNAs (miRs). Here we report a new finding that mir‑106a regulates the proliferation, migration, and invasion of bladder cancer cells. Basal expression levels of mir‑106a were significantly lower in bladder cancer cells than in normal urothelial cells. Overexpression of mir‑106a suppressed the proliferation of bladder cancer cell line EJ. Transient transfection of mir‑106a into EJ cells led to downregulation of ERK phosphorylation and upregulation of p38 and JNK phosphorylation over their levels in the control. Flow cytometry analysis revealed that mir‑106a-transfected cells accumulated in the G1-phase of the cell cycle, and cyclin D1 and CDK6 were significantly downregulated. This G1-phase cell cycle arrest was due in part to the upregulation of p21CIP1/WAF1. In addition, mir‑106a overexpression blocked the wound-healing migration and invasion of EJ cells. Furthermore, mir‑106a transfection resulted in decreased expression of MMP-2 and diminished binding activity of transcription factor Ets-1 in EJ cells. Collectively, we report the novel mir‑106a-mediated molecular signaling networks that regulate the proliferation, migration, and invasion of bladder cancer cells, suggesting that mir‑106a may be a therapeutic target for treating advanced bladder tumors.

The role of microRNAs in bladder cancer

Bladder cancer (BC) is the fifth most common cancer worldwide and is associated with significant morbidity and mortality. The prognosis of muscle invasive BC is poor, and recurrence is common after radical surgery or chemotherapy. Therefore, new diagnostic methods and treatment modalities are critical. MicroRNAs (miRNAs), a class of small noncoding RNAs, regulate the expression of protein-coding genes by repressing translation or cleaving RNA transcripts in a sequence-specific manner. miRNAs have important roles in the regulation of genes involved in cancer development, progression, and metastasis. The availability of genomewide miRNA expression profiles by deep sequencing technology has facilitated rapid and precise identification of aberrant miRNA expression in BC. Indeed, several miRNAs that are either upregulated or downregulated have been shown to have associations with significant cancer pathways. Furthermore, many miRNAs, including those that can be detected in urine and blood, have been studied as potential noninvasive tumor markers for diagnostic and prognostic purposes. Here, we searched PubMed for publications describing the role of miRNAs in BC by using the keywords "bladder cancer" and "microRNA" on March 1, 2016. We found 374 papers and selected articles written in English in which the level of scientific detail and reporting were sufficient and in which novel findings were demonstrated. In this review, we summarize these studies from the point of view of miRNA-related molecular networks (specific miRNAs and their targets) and miRNAs as tumor markers in BC. We also discuss future directions of miRNA studies in the context of therapeutic modalities.

E3 ubiquitin ligase isolated by differential display regulates cervical cancer growth in vitro and in vivo via microRNA-143

Cervical cancer is one of the most common gynecological cancers worldwide. Aberrant expression of E3 ubiquitin ligase isolated by differential display (EDD) has been detected in various types of tumor and has been demonstrated to have an important role in carcinogenesis, tumor growth and drug resistance. However, the role of EDD in cervical cancer and its underlying molecular mechanisms remains unknown. The present study aimed to investigate the role of EDD in the tumorigenicity of cervical cancer. EDD expression levels were measured using reverse transcription-quantitative polymerase chain reaction and western blotting in SiHa, HeLa, CaSki, c-41 and c-33A cervical cancer cell lines and cervical cancer tissue specimens. A functional study was performed using cell proliferation, colony formation, cell apoptosis assays in vitro and tumor growth assays in vivo with EDD either overexpressed or silenced. In the present study, EDD expression levels were significantly upregulated in cervical cancer cell lines and tissue samples. EDD knockdown significantly inhibited colony formation, cell proliferation and tumor growth and accelerated cell apoptosis in the cervical cancer cell lines and tissue samples. Furthermore, microRNA (miR)-143 expression levels were low in cervical cancer tissue samples and were negatively correlated with EDD expression. miR-143 silencing eliminated the effect of EDD on cell proliferation, colony formation and cell apoptosis in the cervical cancer cells, which suggested that miR-143 is critical for EDD-mediated regulation of cervical cancer cell growth. The results of the present study indicated that EDD may promote cervical cancer growth in vivo and in vitro by targeting miR-143. In conclusion, EDD may have an oncogenic role in cervical cancer and may serve as a potential therapeutic target for the treatment of patients with cervical cancer.

Decreased microRNA-452 expression and its prognostic significance in human osteosarcoma

BACKGROUND

MicroRNA-452 (miR-452) was previously reported to be dysregulated in several types of human cancers and involved in tumor progression. The aim of this study was to investigate the clinical significance and prognostic value of miR-452 expression in human osteosarcoma.

METHODS

The expression of miR-452 was detected in 95 pairs of osteosarcoma specimens and adjacent noncancerous bone tissues using quantitative RT-PCR (qRT-PCR) assay. Then, the association of miR-452 levels with clinicopathological features and prognosis was analyzed. The roles of miR-452 in regulating osteosarcoma cell proliferation, apoptosis, and invasion were evaluated in vitro.

RESULTS

miR-452 expression was significantly downregulated in osteosarcoma tissues than those in corresponding noncancerous bone tissues (P < 0.001). Decreased miR-452 expression was linked to larger tumor size, high tumor grade, advanced clinical stage, distant metastasis, and shorter overall survival. Multivariate Cox regression analysis confirmed that low level of miR-452 expression predicted poor prognosis independently. miR-452 overexpression in MG-63 cells suppressed cell proliferation, promoted cell apoptosis, inhibited cell invasion, and led to decreased BMI1 protein levels.

CONCLUSIONS

These findings suggest that miR-452 downregulation may be involved in osteosarcoma formation and progression and that miR-452 would serve as a novel prognostic biomarker for patients with this disease.

miR-222 attenuates cisplatin-induced cell death by targeting the PPP2R2A/Akt/mTOR Axis in bladder cancer cells

Increased miR-222 levels are associated with a poor prognosis in patients with bladder cancer. However, the role of miR-222 remains unclear. In the present study, we found that miR-222 enhanced the proliferation of both the T24 and the 5637 bladder cancer cell lines. Overexpression of miR-222 attenuated cisplatin-induced cell death in bladder cancer cells. miR-222 activated the Akt/mTOR pathway and inhibited cisplatin-induced autophagy in bladder cancer cells by directly targeting protein phosphatase 2A subunit B (PPP2R2A). Blocking the activation of Akt with LY294002 or mTOR with rapamycin significantly prevented miR-222-induced proliferation and restored the sensitivity of bladder cancer cells to cisplatin. These findings demonstrate that miR-222 modulates the PPP2R2A/Akt/mTOR axis and thus plays a critical role in regulating proliferation and chemotherapeutic drug resistance. Therefore, miR-222 may be a novel therapeutic target for bladder cancer.

Alterations of prefrontal cortical microRNAs in methamphetamine self-administering rats: From controlled drug intake to escalated drug intake

Drug addiction is a process that transits from recreative and regular drug use into compulsive drug use. The two patterns of drug use, controlled drug intake and escalated drug intake, represent different stages in the development of drug addiction; and escalation of drug use is a hallmark of addiction. Accumulating studies indicate that microRNAs (miRNAs) play key regulatory roles in drug addiction. However, the molecular adaptations in escalation of drug use, as well as the difference in the adaptations between escalated and controlled drug use, remain unclear. In the present study, 28 altered miRNAs in the prefrontal cortex (PFC) were found in the groups of controlled methamphetamine self-administration (1h/session) and escalated self-administration (6h/session), and some of them were validated. Compared with saline control group, miR-186 was verified to be up-regulated while miR-195 and miR-329 were down-regulated in the rats with controlled methamphetamine use. In the rats with escalated drug use, miR-127, miR-186, miR-222 and miR-24 were verified to be up-regulated while miR-329 was down-regulated compared with controls. Furthermore, bioinformatic analysis indicated that the predicted targets of these verified miRNAs involved in the processes of neuronal apoptosis and synaptic plasticity. However, the putative regulated molecules may be different between controlled and escalated drug use groups. Taken together, we detected the altered miRNAs in rat PFC under the conditions of controlled methamphetamine use and escalated use respectively, which may extend our understanding of the molecular adaptations underlying the transition from controlled drug use to addiction.

MicroRNA molecular profiling from matched tumor and bio-fluids in bladder cancer

Background

MicroRNAs have been identified as potential cancer biomarkers due to their presence and stability in many body fluids including urine and plasma, but the relationship of the pattern of expression of these messengers across various biological media has not been addressed and could provide important information in order to translate these biomarkers for epidemiologic or clinical use.

Methods

We analyzed microRNA of matched FFPE-tumor tissue, plasma, urine exosomes (n = 16) and WBCs (n = 11) from patients with bladder cancer, using Nanostring miRNA assays and droplet digital PCR for validation. Pearson correlations were used to compare expression between media.

Results

Numerous microRNAs were detected and overlapping from specific bio-specimen sources. MiR-4454 and miR-21 overexpression was found in three sources: tumor, WBCs and urine. Additionally, miR-15b-5p, miR-126-3p, miR-93-5p, and miR-150-5p were common to tumor/WBCs, while miR-720/3007a, miR-205, miR-200c-3p and miR-29b-3p common to tumor/urine. Significant associations were noted between the log-adjusted average miRNA counts in tumor vs. WBCs (r = 0.418 p < 0.001), and tumor vs. urine (r = 0.38 p < 0.001). No association was seen tumor vs. plasma exosome miRs (r = 0.07 p = 0.06).

Conclusions

MicroRNA profiling from matched samples in patients shows a significant number of microRNAs up regulated in bladder tumors are identifiable in urine exosomes and WBCs of the same patient, but not in blood plasma. This study demonstrated varying relationships between miRNA detected in biological media from the same patient, and serves to inform the potential of urine-based microRNAs as biomarkers for bladder cancer and potentially other malignancies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0466-2) contains supplementary material, which is available to authorized users.

Upregulation of microRNA-96 and its oncogenic functions by targeting CDKN1A in bladder cancer

Background

Genome-wide miRNA expression profile has identified microRNA (miR)-96 as one of upregulated miRNAs in clinical bladder cancer (BC) tissues compared to normal bladder tissues. The aim of this study was to confirm the expression pattern of miR-96 in BC tissues and to investigate its involvement in carcinogenesis.

Methods

Quantitative real-time PCR was performed to detect the expression levels of miR-96 in 60 BC and 40 normal control tissues. Bioinformatics prediction combined with luciferase reporter assay were used to verify whether the cyclin-dependent kinase inhibitor CDKN1A was a potential target gene of miR-96. Cell counting kit-8 and apoptosis assays were further performed to evaluate the effects of miR-96-CDKN1A axis on cell proliferation and apoptosis of BC cell lines.

Results

We validated that miR-96 was significantly increased in both human BC tissues and cell lines. According to the data of miRTarBase, CDKN1A might be a candidate target gene of miR-96. In addition, luciferase reporter and Western blot assays respectively demonstrated that miR-96 could bind to the putative seed region in CDKN1A mRNA 3′UTR, and significantly reduce the expression level of CDKN1A protein. Moreover, we found that the inhibition of miR-96 expression remarkably decreased cell proliferation and promoted cell apoptosis of BC cell lines, which was consistent with the findings observed following the introduction of CDKN1A cDNA without 3′UTR restored miR-96.

Conclusions

Our data reveal that miR-96 may function as an onco-miRNA in BC. Upregulation of miR-96 may contribute to aggressive malignancy partly through suppressing CDKN1A protein expression in BC cells.

microRNA-145 promotes differentiation in human urothelial carcinoma through down-regulation of syndecan-1

Background

A new molecular marker of carcinoma in the urinary bladder is needed as a diagnostic tool or as a therapeutic target. Potential markers include microRNAs (miRNAs), which are short, low molecular weight RNAs 19–24 nt long that regulate genes associated with cell proliferation, differentiation, and development in various cancers. In this study, we investigated the molecular mechanisms by which miR-145 promotes survival of urothelial carcinoma cells and differentiation into multiple lineages. We found miR-145 to regulate expression of syndecan-1, a heparin sulfate proteoglycan.

Methods

Cell proliferation in the human urothelial carcinoma cell lines T24 and KU7 was assessed by MTS assay. Cellular senescence and apoptosis were measured by senescence-associated β-galactosidase (SA-β-gal) and TUNEL assay, respectively. Quantitative RT-PCR was used to measure mRNA expression of various genes, including syndecan-1, stem cell factors, and markers of differentiation into squamous, glandular, or neuroendocrine cells.

Results

Overexpression of miR-145 induced cell senescence, and thus significantly inhibited cell proliferation in T24 and KU7 cells. Syndecan-1 expression diminished, whereas stem cell markers such as SOX2, NANOG, OCT4, and E2F3 increased. miR-145 also up-regulated markers of differentiation into squamous (p63, TP63, and CK5), glandular (MUC-1, MUC-2, and MUC-5 AC), and neuroendocrine cells (NSE and UCHL-1). Finally, expression of miR-145 was down-regulated in high-grade urothelial carcinomas, but not in low-grade tumors.

Conclusions

Results indicate that miR-145 suppresses syndecan-1 and, by this mechanism, up-regulates stem cell factors and induces cell senescence and differentiation. We propose that miR-145 may confer stem cell-like properties on urothelial carcinoma cells and thus facilitate differentiation into multiple cell types.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1846-0) contains supplementary material, which is available to authorized users.

Jumonji domain containing 2A predicts prognosis and regulates cell growth in lung cancer depending on miR-150

Lung cancer has become the most common cancer worldwide, of which non-small cell lung cancer (NSCLC) accounts for over 80%. Previous studies have shown that the Jumonji domain containing 2A (JMJD2A) was aberrantly expressed in various tumors and involved in the regulation of tumor progression, but the role of JMJD2A on the tumorigenesis in NSCLC and the underlying mechanisms are still unclear. In the present study, we first identified the expression of JMJD2A in NSCLC tissues and cell lines through quantitative RT-PCR (qRT-PCR) and western blotting. Next, the effects of JMJD2A on the progression of NSCLC were analyzed. MTT assay was performed to measure the cell numbers and fluorescence-activated cell sorting (FACS) was adopted to evaluate cell apoptosis. Finally, the relationship between JMJD2A and miR-150 involved in NSCLC was studied. Our results suggested that JMJD2A was significantly overexpressed in NSCLC samples and cell lines. Kaplan-Meier analysis showed that high level of JMJD2A predicted a poor prognosis. Knockdown of JMJD2A inhibited tumor growth and promoted cell apoptosis in NSCLC cells. Additionally, miR-150 was upregulated in NSCLC tissues and positively related with JMJD2A expression. Significant downregulation of miR-150 was observed with JMJD2A knockdown. Furthermore, JMJD2A knockdown inhibited NSCLC cell proliferation while the silencing of miR-150 attenuated the inhibition effect on cell proliferation, suggesting that the effect of JMJD2A on NSCLC cell growth was dependent on miR-150. Thus, our findings identified that JMJD2A played an oncogenic role in NSCLC via regulating miR-150. JMJD2A could possibly serve as a prognostic factor and potential target for NSCLC therapy.

Diagnostic Value of MicroRNAs for Urologic Cancers: A Systematic Review and Meta-Analysis

MicroRNAs (miRNAs), particularly those extracted from the blood or tissues, have become the focus of urologic cancers research. However, the literature reviews on the accuracy of miRNA detection in urologic cancers have been inconsistent, leading us to perform this meta-analysis. Eligible studies were searched in PubMed and other databases. To calculate the pooled detection accuracy estimates, we used a bivariate random-effects meta-analysis model. According to the exclusion and inclusion criteria, 41 studies were included. Overall, the results showed sensitivity of 0.77 (95% CI: 0.74-0.80) and specificity of 0.76 (95% CI: 0.72-0.79), with an area under the SROC curve (AUC) of 0.83 (95% CI: 0.80-0.86). In addition, further subgroup analyses were also conducted. Firstly, the multiple miRNAs subgroup has significantly better diagnostic specificity than single miRNA subgroup among all these cancer types, while only bladder cancer (BC) and prostate cancer (PC) group with significantly greater diagnostic sensitivity with their multiple miRNA detection. Secondly, none of these cancer types showed significant differences on diagnostic sensitivity and specificity in their specimen and sample size subgroups. Thirdly, the diagnostic sensitivity between Asian (0.791, 95% CI: 0.748-0.827) and Caucasian (0.713, 95% CI: 0.666-0.756) in BC type was shown significant different with the P-value of 0.011. The results of our study suggested that miRNAs, particularly the multiple miRNAs, may play an important role in diagnosis and monitoring of the urologic cancers as superior biomarkers.

Molecular markers in bladder cancer: Novel research frontiers

Bladder cancer (BC) is a heterogeneous disease encompassing distinct biologic features that lead to extremely different clinical behaviors. In the last 20 years, great efforts have been made to predict disease outcome and response to treatment by developing risk assessment calculators based on multiple standard clinical-pathological factors, as well as by testing several molecular markers. Unfortunately, risk assessment calculators alone fail to accurately assess a single patient's prognosis and response to different treatment options. Several molecular markers easily assessable by routine immunohistochemical techniques hold promise for becoming widely available and cost-effective tools for a more reliable risk assessment, but none have yet entered routine clinical practice. Current research is therefore moving towards (i) identifying novel molecular markers; (ii) testing old and new markers in homogeneous patients' populations receiving homogeneous treatments; (iii) generating a multimarker panel that could be easily, and thus routinely, used in clinical practice; (iv) developing novel risk assessment tools, possibly combining standard clinical-pathological factors with molecular markers. This review analyses the emerging body of literature concerning novel biomarkers, ranging from genetic changes to altered expression of a huge variety of molecules, potentially involved in BC outcome and response to treatment. Findings suggest that some of these indicators, such as serum circulating tumor cells and tissue mitochondrial DNA, seem to be easily assessable and provide reliable information. Other markers, such as the phosphoinositide-3-kinase (PI3K)/AKT (serine-threonine kinase)/mTOR (mammalian target of rapamycin) pathway and epigenetic changes in DNA methylation seem to not only have prognostic/predictive value but also, most importantly, represent valuable therapeutic targets. Finally, there is increasing evidence that the development of novel risk assessment tools combining standard clinical-pathological factors with molecular markers represents a major quest in managing this poorly predictable disease.

Evaluation of urinary microRNA panel in bladder cancer diagnosis: relation to bilharziasis

We assessed the differential expression of a urinary panel of microRNAs (miRs) in terms of potential application as diagnostic markers of bladder cancer (BC) and relationship to bilharziasis. We investigated voided urine samples and blood from patients with BC (n = 188), benign bladder lesions (n = 88), and age-matched controls (n = 92). Five miRs (miR-210, miR-10b, miR-29c, miR-221, and miR-23a) were selected from previous microarray signature profiling (released by miR2Disease). Afterward, they were validated using polymerase chain reaction array. The expression levels of miR-210, miR-10b, and miR-29c in the urine samples were significantly higher in BC (P < 0.001). The receiver-operating characteristic curve analyses demonstrated that each miR had good sensitivity and specificity for distinguishing patients with BC from patients without BC (miR-210, 71.3% and 91.1%; miR-10b, 80.9% and 91.1%; and miR-183, 71.3% and 88.9%). On combining the 3 miR detection data with the urinary cytology, the results sensitivity increased to 95.2%. Relative quantity mean rank of the miR-29c was significantly higher in the bilharzial-positive patients compared with bilharzial-negative patients. To conclude, urine miR-210, miR-10b, and miR-29c are promising tumor markers for BC: bilharzial and nonbilharzial.

1α,25(OH)2D3 differentially regulates miRNA expression in human bladder cancer cells

Bladder cancer is the fourth most commonly diagnosed cancer in men and eighth leading cause of cancer-related death in the US. Epidemiological and experimental studies strongly suggest a role for 1α,25(OH)2D3 in cancer prevention and treatment. The antitumor activities of 1α,25(OH)2D3 are mediated by the induction of cell cycle arrest, apoptosis, differentiation and the inhibition of angiogenesis and metastasis. miRNAs play important regulatory roles in cancer development and progression. However, the role of 1α,25(OH)2D3 in the regulation of miRNA expression and the potential impact in bladder cancer has not been investigated. Therefore, we studied 1α,25(OH)2D3-regulated miRNA expression profiles in human bladder cancer cell line 253J and the highly tumorigenic and metastatic derivative line 253J-BV by miRNA qPCR panels. 253J and 253J-BV cells express endogenous vitamin D receptor (VDR), which can be further induced by 1α,25(OH)2D3. VDR target gene 24-hydroxylase was induced by 1α,25(OH)2D3 in both cell lines, indicating functional 1α,25(OH)2D3 signaling. The miRNA qPCR panel assay results showed that 253J and 253J-BV cells have distinct miRNA expression profiles. Further, 1α,25(OH)2D3 differentially regulated miRNA expression profiles in 253J and 253J-BV cells in a dynamic manner. Pathway analysis of the miRNA target genes revealed distinct patterns of contribution to the molecular functions and biological processes in the two cell lines. In conclusion, 1α,25(OH)2D3 differentially regulates the expression of miRNAs, which may contribute to distinct biological functions, in human bladder 253J and 253J-BV cells. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

Uncovering the clinical utility of miR-143, miR-145 and miR-224 for predicting the survival of bladder cancer patients following treatment

Accurate prognosis is a key factor in establishing optimal therapeutic decisions; yet in the case of bladder cancer (BlCa) current prognostic indicators cannot ensure optimal disease management. Here, we aimed to evaluate the previously unexplored clinical potential of the urological cancer-related miR-145, miR-143 and miR-224 in BlCa. A total of 279 bladder tissue specimens were included in this study (133 BlCa, 107 adjacent normal and 39 healthy samples). Total RNA was extracted from tissues, it was polyadenylated and reverse transcribed to cDNA. The expression of target molecules was measured via quantitative real-time PCR. The expression levels of both miR-143 and miR-145 were significantly decreased, whereas those of miR-224 were increased in BlCa. Receiver operating characteristic curve analysis indicated a significant discriminatory capacity for miR-143/miR-145 levels. Important associations with disease aggressiveness were observed for all three microRNAs; elevated levels were observed in tumors of higher stage and grade, as well as in 'high-risk' TaT1 patients. More importantly, high miR-143/145 levels could effectively prognose inferior overall survival for muscle-invasive patients and could independently predict the progression of superficial tumors. Finally, the combination of miR-143/145 overexpression with the widely used prognostic markers of European Organization for Research and Treatment of Cancer-risk groups or recurrence at the first follow-up cystoscopy resulted to a superior positive prediction of non-muscle-invasive bladder cancer short-term progression compared with the use of the abovementioned markers alone. The cancer-related miR-143, miR-145 and miR-224 were investigated for the first time in the clinical setting of BlCa, and miR-143/145 cluster constitutes a novel marker helpful for providing an enhanced prediction of oncologic outcome for BlCa patients.

MicroRNA-200c and microRNA-141 as potential diagnostic and prognostic biomarkers for ovarian cancer

Ovarian cancer is the fifth leading cause of female death globally due to its low survival rates. Thus, improved approaches for ovarian cancer detection are urgently needed. MicroRNAs as a new class of biomarkers have been explored in recent studies. This study was trying to identify and validate the two kinds of serum microRNA (miR-200c and miR-141) as biomarkers for ovarian cancer. We extracted serum samples from 74 epithelial ovarian cancer patients, 19 borderline ovarian cancer, and 50 healthy controls. Relative expression of these miRNA markers were measured by quantificational real-time polymerase chain reaction assay (qRT-PCR). Receiver operating characteristics (ROC) and area under the ROC curve (AUC) were used to validate the diagnostic value of miR-200c and miR-141. Kaplan-Meier curve and the log-rank test were conducted to detect the prognostic value of miR-200c and miR-141. miR-200c and miR-141 were significantly elevated in the epithelial ovarian cancer patients compared to healthy controls. The relative expression level of miR-200c showed a descending trend from early stages to advanced stages, while the level of miR-141 displayed an escalating trend. Patients with high miR-200c level achieved significantly a higher 2-year survival rate compared with the other group (P < 0.001), while low miR-141 group showed a significantly higher survival rate. The results of the current study suggested that serum miR-200c and miR-141 were able to discriminate the ovarian cancer patients from healthy controls. In addition, miR-200c and miR-141 may be predictive biomarkers for ovarian cancer prognosis. Further large-scale studies are still needed to confirm our findings.

Clinical and pathological implications of miRNA in bladder cancer

MicroRNAs (miRNAs) are small, noncoding RNA species with a length of 20–22 nucleotides that are recognized as essential regulators of relevant molecular mechanisms, including carcinogenesis. Current investigations show that miRNAs are detectable not only in different tissue types but also in a wide range of biological fluids, either free or trapped in circulating microvesicles. miRNAs were proven to be involved in cell communication, both in pathological and physiological processes. Evaluation of the global expression patterns of miRNAs provides key opportunities with important practical applications, taking into account that they modulate essential biological processes such as epithelial to mesenchymal transition, which is a mechanism relevant in bladder cancer. miRNAs collected from biological specimens can furnish valuable evidence with regard to bladder cancer oncogenesis, as they also have been linked to clinical outcomes in urothelial carcinoma. Therefore, a single miRNA or a signature of multiple miRNAs may improve risk stratification of patients and may supplement the histological diagnosis of urological tumors, particularly for bladder cancer.

Serum microRNA expression patterns that predict early treatment failure in prostate cancer patients

We aimed to identify microRNA (miRNA) expression patterns in the serum of prostate cancer (CaP) patients that predict the risk of early treatment failure following radical prostatectomy (RP). Microarray and Q-RT-PCR analyses identified 43 miRNAs as differentiating disease stages within 14 prostate cell lines and reflectedpublically available patient data. 34 of these miRNA were detectable in the serum of CaP patients. Association with time to biochemical progression was examined in a cohort of CaP patients following RP. A greater than two-fold increase in hazard of biochemical progression associated with altered expression of miR-103, miR-125b and miR-222 (p <.0008) in the serum of CaP patients. Prediction models based on penalized regression analyses showed that the levels of the miRNAs and PSA together were better at detecting false positives than models without miRNAs, for similar level of sensitivity. Analyses of publically available data revealed significant and reciprocal relationships between changes in CpG methylation and miRNA expression patterns suggesting a role for CpG methylation to regulate miRNA. Exploratory validation supported roles for miR-222 and miR-125b to predict progression risk in CaP. The current study established that expression patterns of serum-detectable miRNAs taken at the time of RP are prognostic for men who are at risk of experiencing subsequent early biochemical progression. These non-invasive approaches could be used to augment treatment decisions.

MicroRNA-34a functions as an anti-metastatic microRNA and suppresses angiogenesis in bladder cancer by directly targeting CD44

BACKGROUND

Metastasis have considered as an important clinical obstacle in the treatment of human cancer including bladder cancer. Post-transcriptional regulation has emerged as robust effectors of metastasis. MiRNAs are involved in cancer development and progression, acting as tumor suppressors or oncogenes. In this study, we focus on it that microRNA-34a functions as an anti-metastatic microRNA and suppress angiogenesis in bladder cancer by directly targeting CD44.

METHODS

The expression of mir-34a was detected by quantitative real-time PCR. Oligonucleotide and lentivirus were used to overexpress miR-34a. Tube formation assay and transwell assay were used to examine the effect on bladder cancer tube formation, migration and invasion in vitro. Animal models were used to examine the effect on metastasis and angiogenesis in vivo. Luciferase assay was carried out to verify the precise target of miR-34a.

RESULTS

We not only proved that mir-34a was significantly downregulated in bladder cancer tissues and cell lines but also that circulating miR-34a levels are reduced in bladder cancer, and their levels were positively relevance. Gain-of-function experiments investigated that increased mir-34a expression suppressed tube formation and reduced cell migration and invasion. In vivo metastasis, assays also demonstrated that overexpression of mir34a markedly inhibited bladder cancer metastasis. CD31, an endothelial cell-specific marker which stained in T24 tumors to evaluate for blood vessel density, the immunohistochemistry results showed that blood vessel quantification reduced dramatically in the T24 tumors over-expressing mir-34a. Combining with our previous studies and bioinformatics analysis, we expected that CD44 gene was a direct target of mir-34a, siRNA-mediated knockdown of CD44 partially phenocopied mir-34a overexpression suggesting that the pro-apoptotic role of mir-34a may be mediated primarily through CD44 regulation, whereas restoring the expression of CD44 attenuated the function of mir-34a in bladder cancer cells. Additionally, we identified that EMT (epithelial-mesenchymal transition) related proteins could be regulated by mir-34a which indicated that mir-34a could partially reserve EMT.

CONCLUSION

Our study defines a major metastasis and angiogenesis suppressive role for mir-34a, a microRNA functions as a tumor suppressor in bladder cancer by directly targeting CD44, which would be helpful as a therapeutic approach to block bladder cancer metastasis.

WITHDRAWN: MicroRNA-200c and microRNA-141 as potential diagnostic and prognostic biomarkers for ovarian cancer

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

MiRNA in bladder carcinogenesis: A review

Bladder cancer (BC) is the second urological malignancy in incidence, currently being one of the most neoplasms studied with profile and biology poorly defined. In the world, BC is responsible by about 386000 new cases and 150000 deaths annually with considerable economic impact and high costs for health systems. After its discovery more than 20 years, micro RNAs (miRNAs) have been recognized as molecules that work specifically in post-transcriptional control in majority of eukaryote genomes. MiRNAs are a family of small non-coding RNAs of 19-25 nucleotides in length, expressed in a wide variety of organisms, comprising plants, worms and mammals, including humans. They have a fundamental role in physiological and pathological processes in organs and tissues in a context-dependent manner. This review brings new roles of protective and oncogenic miRNAs linked to carcinogenesis of urothelial carcinoma of the bladder, and associated with behavior of disease. Many studies have demonstrated promising roles of miRNAs working as diagnostic and prognostic biomarkers or involved in target therapies, consolidating miRNAs as crucial players in human cancer. This review allowed a reflection about the true functions of miRNAs in bladder carcinogenesis. Not only by their wide capacities of action, but also by abilities in define the cell date. The future of anti-tumor target therapies will be based not in one, but in groups of miRNAs working together in several steps of carcinogenic process, being able to identify the disease, predicting behavior and effectively treat bladder cancer.

E2F1 induces miR-224/452 expression to drive EMT through TXNIP downregulation

Malignant melanoma is highly lethal due to its aggressive invasive properties and metastatic dissemination. The transcription factor E2F1 is crucial for melanoma progression through poorly understood mechanisms. Here, we show that the miR-224/miR-452 cluster is significantly increased in advanced melanoma and invasive/metastatic cell lines that express high levels of E2F1. miR-224/miR-452 expression is directly activated by E2F1 through transactivation of the GABRE gene. Ectopic expression of miR-224/miR-452 in less aggressive cells induces EMT and cytoskeletal rearrangements and enhances migration/invasion. Conversely, miR-224/miR-452 depletion in metastatic cells induces the reversal of EMT, inhibition of motility, loss of the invasive phenotype and an absence of lung metastases in mice. We identify the metastasis suppressor TXNIP as new target of miR-224/miR-452 that induces feedback inhibition of E2F1 and show that miR-224/452-mediated downregulation of TXNIP is essential for E2F1-induced EMT and invasion. The E2F1-miR-224/452-TXNIP axis constitutes a molecular signature that predicts patient survival and may help to set novel therapies.

Investigation of key miRNAs and target genes in bladder cancer using miRNA profiling and bioinformatic tools

Despite the association of several miRNAs with bladder cancer, little is known about the miRNAs' regulatory networks. In this study, we aimed to construct potential networks of bladder-cancer-related miRNAs and their known target genes using miRNA expression profiling and bioinformatics tools and to investigate potential key molecules that might play roles in bladder cancer regulatory networks. Global miRNA expression profiles were obtained using microarray followed by RT-qPCR validation using two randomly selected miRNAs. Known targets of deregulated miRNAs were utilized using DIANA-TarBase database v6.0. The incorporation of deregulated miRNAs and target genes into KEGG pathways were utilized using DIANA-mirPath software. To construct potential miRNA regulatory networks, the overlapping parts of three selected KEGG pathways were visualized by Cytoscape software. We finally gained 19 deregulated miRNAs, including 5 ups- and 14 down regulated in 27 bladder-cancer tissue samples and 8 normal urothelial tissue samples. The enrichment results of deregulated miRNAs and known target genes showed that most pathways were related to cancer or cell signaling pathways. We determined the hub CDK6, BCL2, E2F3, PTEN, MYC, RB, and ERBB3 target genes and hub hsa-let-7c, hsa-miR-195-5p, hsa-miR-141-3p, hsa-miR-26a-5p, hsa-miR-23b-3p, and hsa-miR-125b-5p miRNAs of the constructed networks. These findings provide new insights into the bladder cancer regulatory networks and give us a hypothesis that hsa-let-7c, hsa-miR-195-5p, and hsa-miR-125b-5p, along with CDK4 and CDK6 genes might exist in the same bladder cancer pathway. Particularly, hub miRNAs and genes might be potential biomarkers for bladder cancer clinics.

MicroRNA detection in cervical exfoliated cells as a triage for human papillomavirus-positive women

Background

Papanicolaou (Pap) triage, with high specificity, has been recommended for primary Human papillomavirus (HPV) testing but is flawed by poor sensitivity and cytologist dependence. We evaluated the potential role of microRNA (miRNA) detection in cervical exfoliated cells in HPV-positive women from a clinic-based population.

Methods

Primary HPV testing as well as Pap test were performed on all eligible women. Six miRNAs (miR-424/miR-375/miR-34a/miR-218/miR-92a/miR-93) were detected by RT-qPCR in cervical exfoliated cells. All HPV-positive women underwent colposcopy and further biopsy if indicated. Mann–Whitney U test, the receiver operating characteristic curve, logistic regression, and Pearson’s Chi-square were used to assess data. All tests of statistical significance were two-sided.

Results

A total of 1021 eligible HPV-positive women were enrolled. The expression of miR-424/miR-375/miR-34a/miR-218 in high-grade cervical intraepithelial neoplasia (CIN) and abnormal cytology was statistically significantly lower than that in low-grade CIN and normal cytology, respectively (all P < .05). Compared with the Pap test, both miR-424 and miR-375 detection achieved higher sensitivity (76.0% and 74.9% vs 63.8%, P < .05), higher negative predictive value (NPV) (85.7% and 85.4% vs 79.3%, P < .05), and comparable specificity while identifying CIN2 or worse (CIN2+). Similar results were achieved while identifying CIN3+. Multi-marker panels based on miR-424, miR-375, and miR-218 further improved the performance over any single miRNA test or Pap test.

Conclusion

Single miR-424 or miR-375 detection and miR-424/miR-375/miR-218–based multimarker panels in cervical exfoliated cells show superior performance over Pap triage for high-grade CIN identification in a clinic-based population. Detection of miRNA may provide a new triage option for HPV-positive women.

MicroRNAs as Potential Biomarkers for Diagnosing Cancers of Central Nervous System: a Meta-analysis

Recent studies have shown abnormal microRNA (miRNA) expression levels in the central nervous system (CNS) of cancer patients, suggesting that miRNAs may serve as promising biomarkers for cancers of CNS. However, other studies have arrived at conflicting results. Therefore, this meta-analysis aims to systematically measure the potential diagnostic value of miRNAs for CNS cancers. Electronic databases as well as other sources were searched until to April 12, 2014 for relevant articles. Data from different studies were pooled using the random-effects model. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative LR (NLR), diagnostic odds ratio (DOR), together with the summary receiver operator characteristic (SROC) curve, and area under the SROC curve (AUC) value were used to estimate overall diagnostic performance. Twenty-three studies from 6 articles were included in the current meta-analysis with a total of 299 CNS cancer patients and 418 controls. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.85 (95% CI, 0.80-0.89), 0.83 (95% CI, 0.76-0.88), 5.1 (95% CI, 3.4-7.5), 0.18 (95% CI, 0.12-0.26), 28 (95% CI, 14-58), and 0.91 (95% CI, 0.88-0.93), respectively. Subgroup analyses showed that cerebrospinal fluid (CSF)-based miRNAs assays yielded more accurate results and seemed to be more sensitive in diagnosing of primary central nervous system lymphoma (PCNSL). In conclusion, miRNAs may be suitable for serving as noninvasive biomarkers for CNS cancers detection. However, further validation based on a larger sample of patients and controls is still required.

Increased expression of miR-222 is associated with poor prognosis in bladder cancer

BACKGROUND

MicroRNA-222 (miR-222) has been shown to play a potential oncogenic role in bladder cancer. The aim of this study was to evaluate the expression of miR-222 in bladder cancer and its potential relevance to clinicopathological characteristics and patient survival.

METHODS

Surgical specimens of cancer tissue and adjacent normal tissue were obtained from 97 patients with bladder cancer. The relative expression levels of miR-222 in the cancer and the normal adjacent tissue were measured by quantitative reverse-transcriptase PCR. We analyzed their correlation with clinicopathological parameters and prognostic value.

RESULTS

The expression level of miR-222 was significantly higher in tumor tissues than in corresponding non-cancerous tissues (5.46 ± 1.45 versus 1.92 ± 0.65, P <  0.0001), and a high expression of miR-222 was found to be significantly associated with tumor grade (P = 0.003) and tumor stage (P = 0.005). The miR-222 expression level was classified as high or low in relation to the median value (cutoff value = 5.15). Kaplan-Meier analysis showed that patients with higher levels of miR-222 had significantly poorer survival than those with lower expression of this miRNA in patients, with a 5-year overall survival of 29.53% and 52.75%, respectively (P = 0.0034). In the multivariate Cox proportional hazards analysis, which included miR-222 level, tumor grade, tumor stage, and tumor number, high miR-222 expression was independently associated with poor survival (P < 0.001; hazard ratio 6.17; 95% CI 2.33 to 10.39).

CONCLUSION

miR-222 overexpression is involved in the poor prognosis of bladder cancer and can be used as a biomarker for selection of cases requiring special attention.

Role of microRNAs in the immunity process of the flat oyster Ostrea edulis against bonamiosis

MicroRNAs (miRNAs) are small (∼22nt) non-coding regulatory single strand RNA molecules that reduce stability and/or translation of sequence-complementary target. miRNAs are a key component of gene regulatory networks and have been involved in a wide variety of biological processes, such as signal transduction, cell proliferation and apoptosis. Many miRNAs are broadly conserved among the animal lineages and even between invertebrates and vertebrates. The European flat oyster Ostrea edulis is highly susceptible to infection with Bonamia ostreae, an intracellular parasite able to survive and proliferate within oyster haemocytes. Mollusc haemocytes play a key role in the immune response of molluscs as main cellular effectors. The roles of miRNAs in the immune response of O. edulis to bonamiosis were analysed using a commercial microarray platform (miRCURY LNA™ v2, Exiqon) for miRNAs. Expression of miRNAs in haemocytes from oysters with different bonamiosis intensity was compared. Differential expression was detected in 63 and 76 miRNAs when comparing heavily-affected with non-affected oysters and with lightly-affected ones, respectively. Among them, 19 miRNAs are known to be linked to immune response, being responsible of proliferation and activation of macrophages, inflammation, apoptosis and/or oxidative damage, which is consistent with the modulation of their expression in oyster haemocytes due to bonamiosis.

Prognostic significance of microRNA-221/222 expression in cancers: evidence from 1,204 subjects

BACKGROUND

The prognostic significance of the expression of the miR-221/222 family in cancer remains controversial. We here performed a meta-analysis of published data investigating the effects of miR-221/222 expression on both overall survival (OS) and disease-free survival (DFS) among patients with cancer.

METHODS

A systematic search of the PubMed, Embase, Cochrane, and CNKI databases was performed with the last search being updated on March 15, 2013. The hazard ratio (HR) and its 95% confidence interval (95% CI) were used to assess the strength of association.

RESULTS

A total of 17 studies involving 1,204 subjects were included in this meta-analysis. When assessing the prognostic significance of miR-221 expression, the pooled HR was 1.91 (95% CI: 1.28-2.85, p=0.002) for OS and 1.36 (95% CI: 0.88-2.09, p=0.163) for DFS. When assessing the prognostic significance of miR-222 expression, the pooled HR was 2.15 (95% CI: 1.51-3.06, p<0.0001) for OS and 1.37 (95% CI: 0.45-4.13, p=0.581) for DFS. We also found that an elevated miR-221 expression was significantly associated with poor OS when stratifying by ethnicity, cancer type, statistical methodology, sample, and quality assessment. There was no evidence of publication bias.

CONCLUSION

The meta-analysis demonstrates that the elevated expression of miR-221 and miR-222 is associated with poor OS in patients with cancer. The miR-221/222 cluster might be used as a potential therapeutic strategy in clinical practice. More work is required to fully elucidate the role of the miR-221/222 family in human tumors.

Nucleic acid-based biomarkers in body fluids of patients with urologic malignancies

This review focuses on the promising potential of nucleic acids in body fluids such as blood and urine as diagnostic, prognostic, predictive and monitoring biomarkers in urologic malignancies. The tremendous progress in the basic knowledge of molecular processes in cancer, as shown in the companion review on nucleic acid-based biomarkers in tissue of urologic tumors, provides a strong rationale for using these molecular changes as non-invasive markers in body fluids. The changes observed in body fluids are an integrative result, reflecting both tissue changes and processes occurring in the body fluids. The availability of sensitive methods has only recently made possible detailed studies of DNA- and RNA-based markers in body fluids. In addition to these biological aspects, methodological aspects of the determination of nucleic acids in body fluids, i.e. pre-analytical, analytical and post-analytical issues, are particularly emphasized. The characteristic changes of RNA (differential mRNA and miRNA expression) and DNA (concentrations, integrity index, mutations, microsatellite and methylation alterations) in serum/plasma and urine samples of patients suffering from the essential urologic cancers of the prostate, bladder, kidney and testis are summarized and critically discussed below. To translate the promising results into clinical practice, laboratory scientists and clinicians have to collaborate to resolve the challenges of harmonized and feasible pre-analytical and analytical conditions for the selected markers and to validate these markers in well-designed and sufficiently powered multi-center studies.

MicroRNA143 and tumors of the digestive system

Recent studies have found that microRNAs have functions analogous to oncogenes or tumor suppressor genes and are important molecules in tumor occurrence and development. In particular, downregulation of microRNA-143 expression in tumors of the digestive system can inhibit tumor proliferation, infiltration and metastasis via regulation of its target genes. In this paper, we review the latest research progress in understanding the role of microRNA-143 in the digestive system.

MicroRNA-222 expression and its prognostic potential in non-small cell lung cancer

Overexpression of miR-222 has been found in several types of cancers; however, the expression of miR-222 in non-small cell lung cancer (NSCLC) and its prognostic values are unclear. This study aimed to investigate whether the miR-222 expression level is related to clinicopathological factors and prognosis of NSCLC. Through a prospective study, 100 pairs of NSCLC tissues and adjacent normal tissues were examined by quantitative reverse-transcription polymerase chain reaction. The correlation between miR-222 expression and clinicopathological features was analyzed, and the significance of miR-222 as a prognostic factor and its relationship with survival were determined. Results showed that the expression levels of miR-222 were significantly elevated in the NSCLC tissue compared with that in adjacent normal tissue. In addition, Cox's proportional hazards model analysis confirmed that miR-222 high expression level was an independent predictor of poor prognosis. In conclusion, miR-222 overexpression is involved in the poor prognosis of NSCLC and can be used as a biomarker for selection of cases requiring especial attention.

MicroRNA-452 contributes to the docetaxel resistance of breast cancer cells

MicroRNA-452 (miRNA-452) was overexpressed in docetaxel-resistant human breast cancer MCF-7 cells (MCF-7/DOC). However, its role in modulating the sensitivity of breast cancer cells to docetaxel (DOC) remains unclear. The aim of this study is to investigate the role of miRNA-452 in the sensitivity of breast cancer cells to DOC.Real-time quantitative PCR (RT-qPCR) were used to identify the differential expression of miRNA-452 between MCF-7/DOC and MCF-7 cells. MiRNA-452 mimic was transfected into MCF-7 cells and miRNA-452 inhibitor was transfected into MCF-7/DOC cells. The role of miRNA-452 in these transfected cells was evaluated using RT-qPCR, MTT assay, and flow cytometry assay. The relationship of miRNA-452 and its predictive target gene "anaphase-promoting complex 4" (APC4) was analyzed by RT-qPCR and Western blot.MiRNA-452 showed significantly higher expression (78.9-folds) in MCF-7/DOC cells compared to parental MCF-7 cells. The expression of miRNA-452 in the mimic transfected MCF-7 cells was upregulated 212.2-folds (P < 0.05) compared to its negative control (NC), and the half maximal inhibitory concentration (IC50) value of DOC (1.98 ± 0.15 μM) was significantly higher than that in its NC (0.85 ± 0.08 μM, P < 0.05) or blank control (1.01 ± 0.19 μM, P < 0.05). Furthermore, its apoptotic rate (6.3 ± 1.3 %) was distinctly decreased compared with that in its NC (23.8 ± 6.6 %, P < 0.05) or blank control (18.6 ± 4.7 %, P < 0.05). In contrast, the expression of miRNA-452 in the inhibitor-transfected MCF-7/DOC cells was downregulated 0.58-fold (P < 0.05) compared to its NC, the IC50 value of DOC (44.5 ± 3.2 μM) was significantly lower than that in its NC (107.3 ± 6.63 μM, P < 0.05) or blank control (102.22 ± 11.34 μM, P < 0.05), and the apoptotic rate (45.5 ± 10.8 %) was distinctly increased compared with its NC (9.9 ± 2.2 %, P < 0.05) and blank control (9.4 ± 2.5 %, P < 0.05). Further, there was an inverse association between miRNA-452 and APC4 expression in breast cancer cells in vitro.Dysregulation of miRNA-452 involved in the DOC resistance formation of breast cancer cells may be, in part, via targeting APC4.

Advanced urothelial carcinoma: next-generation sequencing reveals diverse genomic alterations and targets of therapy

Although urothelial carcinoma (UC) of the urinary bladder generally portends a favorable prognosis, metastatic tumors often follow an aggressive clinical course. DNA was extracted from 40 μm of formalin-fixed, paraffin-embedded (FFPE) sections from 35 stage IV UCs that had relapsed and progressed after primary surgery and conventional chemotherapy. Next-generation sequencing (NGS) was performed on hybridization-captured, adaptor ligation-based libraries for 3320 exons of 182 cancer-related genes plus 37 introns from 14 genes frequently rearranged in cancer to at an average sequencing depth of 1164 × and evaluated for all classes of genomic alterations (GAs). Actionable GAs were defined as those impacting the selection of targeted anticancer therapies on the market or in registered clinical trials. A total of 139 GAs were identified, with an average of 4.0 GAs per tumor (range 0-10), of which 78 (56%) were considered actionable, with an average of 2.2 per tumor (range 0-7). Twenty-nine (83%) cases harbored at least one actionable GA including: PIK3CA (9 cases; 26%); CDKN2A/B (8 cases; 23%); CCND1 (5 cases; 14%); FGFR1 (5 cases; 14%); CCND3 (4 cases; 11%); FGFR3 (4 cases; 11%); MCL1 (4 cases; 11%); MDM2 (4 cases; 11%); EGFR (2 cases, 6%); ERBB2 (HER2/neu) (2 cases, 6%); NF1 (2 cases, 6%) and TSC1 (2 cases, 6%). Notable additional alterations included TP53 (19 cases, 54%) and RB1 (6 cases; 17%). Genes involved in chromatin modification were altered by nonsense mutation, splice site mutation or frameshift indel in a mutually exclusive manner in nearly half of all cases including KDM6A (10 cases; 29%) and ARID1A (7 cases; 20%). Comprehensive NGS of 35 UCs of the bladder revealed a diverse spectrum of actionable GAs in 83% of cases, which has the potential to inform treatment decisions for patients with relapsed and metastatic disease.

miR-302b is a potential molecular marker of esophageal squamous cell carcinoma and functions as a tumor suppressor by targeting ErbB4

Background

ErbB4 expression has been noted in various tumors, but its regulatory mechanism in esophageal squamous cell carcinoma (ESCC) remains unclear. The aim of this study was to investigate whether miR-302b regulates the expression of ErbB4 at the post-transcriptional level and to determine its expression, significance, and function in ESCC.

Methods

We used real-time reverse transcriptase-polymerase chain reaction to quantify the expression of miR-302b in 50 ESCC tissues and analyzed its relationship with clinicopathological factors and survival. Then, we investigated the post-transcriptional regulation of ErbB4 expression using immunoblot analysis and luciferase reporter assays. Finally, the effects of miR-302b on proliferation, apoptosis, and invasion of ESCC cells was detected using MTT, flow cytometric analysis, and transwell invasion assays, respectively.

Results

miR-302b was significantly down-regulated and correlated with tumor differentiation and lymph node metastasis in ESCC. Univariate and multivariate analyses indicated that low miR-302b expression might be a poor prognostic factor. Further studies demonstrated that miR-302b post-transcriptionally down-regulated the expression of ErbB4 in vitro. Moreover, miR-302b inhibited proliferation by inducing apoptosis and repressed invasion in the ESCC cell lines.

Conclusions

miR-302b is a potential molecular marker of ESCC and functions as a tumor suppressor by post-transcriptionally regulating ErbB4.

Noninvasive micromarkers

BACKGROUND

The recent revolutionary advances made in genome-wide sequencing technology have transformed biology and molecular diagnostics, allowing new sRNA (small RNA) classes to be discovered as potential disease-specific biological indicators. Cell-free microRNAs (miRNAs) have been shown to exist stably in a wide spectrum of body fluids and their expression profiles have been shown to reflect an assortment of physiological conditions, underscoring the utility of this new class of molecules to function as noninvasive biomarkers of disease.

CONTENT

We summarize information on the known mechanisms of miRNA protection and release into extracellular space and compile the current literature on extracellular miRNAs that have been investigated as biomarkers of 20 different cancers, 11 organ damage conditions and 10 diverse disease states. We also discuss the various strategies involved in the miRNA biomarker discovery workflow and provide a critical opinion on the impediments faced by this advancing field that need to be overcome in the laboratory.

SUMMARY

The field of miRNA-centered diagnostics is still in its infancy, and basic questions with regard to the exact role of miRNAs in the pathophysiology of diseases, and the mechanisms of their release from affected cells into biological fluids are yet to be completely understood. Nevertheless, these noninvasive micromarkers have immense potential in translational medicine not only for use in monitoring the efficacy and safety of therapeutic regimens but also to guide the diagnosis of diseases, to determine the risk of developing diseases or conditions, and more importantly, to inform treatment options.