MicroRNAs: novel players in cancer diagnosis and therapies

The evaluation of miR-1181 and miR-4314 as serum microRNA biomarkers for epithelial ovarian cancer diagnosis and prognosis

AIM

Epithelial ovarian cancer (EOC) is the most ominous tumor of gynecological cancers due to its poor early detection rate and unfavorable prognosis. To date, there is no reliable screening method for the diagnosis of ovarian cancer at an early stage. MiRNAs are small non-coding RNA molecules, and their main function is to regulate gene expression. The present study compared the serum miR-1181 and miR-4314 levels in patients with EOC and healthy controls to measure the diagnostic and prognostic value as candidate biomarkers.

MATERIALS AND METHODS

We collected serum samples from a total of 135 participants (69 patients with EOC and 66 healthy controls). Relative expressions of miR-1181 and miR-4314 were measured by quantitative real-time polymerase chain reaction assay (qPCR).

RESULTS

The present study revealed that both serum miR-1181 and miR-4314 levels in patients with EOC were significantly increased compared to healthy controls for each marker. In addition, there was a significant relationship between miR-1181 and miR-4314 overexpressions and the stage and prognosis of the disease. Finally, patients with high expression levels of miR-1181 and miR-4314 had significantly shorter survival rates than those with low expression levels.

CONCLUSION

The current study proposed that serum miR-1181 and miR-4314 could discriminate the EOC patients from healthy controls. In addition, both miR-1181 and miR-4314 may be predictive biomarkers for ovarian cancer prognosis. Further studies are needed to confirm the findings of the present study.

MicroRNA-142-5p promotes the proliferation and metastasis of nasopharyngeal carcinoma

Growing pieces of evidence reported abnormal expression of microRNA in various cancer. Our research aimed to ascertain the miR-142-5p expression and its potential function in the growth and metastasis of human nasopharyngeal carcinoma (NPC). In human NPC tissues and cell lines, miR-142-5p expression was quantified via the real-time qPCR assay. Functionally, the potential effect of miR-142-5p in human CNE-1 and SUNE-1 cells through MTT assay, colony formation assay, Transwell assay, and cell cycle assay. In addition, the potential target gene of miR-142-5p was determined by the dual-luciferase reporter assay. MiR-142-5p expression was remarkably elevated in human NPC tissues, CNE-1 and SUNE-1 cells. MiR-142-5p overexpression obviously enhanced the ability of cell proliferative and colony formation, and prevented G1 phase arrest in CNE-1 and SUNE-1 cells. Further, the migration number of NPC cells was increased compared to NP69 cells. BTG3 was identified as the direct target gene of miR-142-5p. Inhibition of BTG3 expression could reverse the cell proliferation by miR-142-5p-induced. Overall, miR-142-5p could strengthen the NPC cell's proliferation and migration by directly targeting BTG3. Hence, miR-142-5p may provide a new strategy and program for future clinical treatment of NPC.

Multi-Drug Resistance against Second-Line Medication and MicroRNA Plasma Level in Metastatic Breast Cancer Patients

Background

Circulating microRNAs (miRNAs) can help to predict the chemotherapy response in breast cancer with promising results. The aim of the present study was to investigate the relationships between the miR-199a, miR-663a, and miR-663b expression and chemotherapy response in metastatic breast cancer patients.

Methods

This study is a case-control study performed at Yasuj University of Medical Sciences (2018-2021). The expression levels of miR-663a, miR-663b, and miR-199a in the serum of 25 patients with metastatic breast cancer versus 15 healthy individuals were determined by the real-time polymerase chain reaction method. The response to treatment was followed up in a 24-month period. All patients were treated with second-line medications. Two or more combinations of these drugs were used: gemcitabine, Navelbine^®, Diphereline^®, Xeloda^®, letrozole, Aromasin^®, and Zolena^®. Statistical analyses were performed in SPSS 21.0 and GraphPad Prism 6 software. The expression levels were presented as mean±SD and analyzed by Student's t test.

Results

The results and clinicopathological features of patients were analyzed by t test. The statistical analysis showed that miR-663a expression was related to human epidermal growth factor receptor 2 (HER2) status and was significantly lower in the HER2⁺ than HER2^- group (P=0.027). Moreover, the expression of miR-199a and miR-663b was significantly correlated with the response to treatment, in which the expression of miR-199a was higher in the poor-response group (P=0.049), while the higher expression of miR-663b was seen in the good-response group (P=0.009).

Conclusion

These findings state that the high plasma level of miR-199a and the low plasma level of miR-663b may be related to chemoresistance in patients with metastatic breast cancer.

Molecular Landscape of Small Bowel Adenocarcinoma

Small bowel adenocarcinoma (SBA) is a rare malignancy, with lower incidence, later stage at diagnosis, and poor overall prognosis compared to other cancers of the gastrointestinal tract. Owing to the rarity of the disease along with the paucity of high-quality tissue samples and preclinical models, little is known about the molecular alterations characteristic of SBA. This is reflected by the fact that the clinical management of SBA is primarily extrapolated from colorectal cancer (CRC). Recent advances in genomic profiling have highlighted key differences between these tumors, establishing SBA as a molecularly unique intestinal cancer. Moreover, comprehensive molecular analysis has identified a relatively high incidence of potentially targetable genomic alterations in SBA, predictive of response to targeted and immunotherapies. Further advances in our knowledge of the mutational and transcriptomic landscape of SBA, guided by an increased understanding of the molecular drivers of SBA, will provide opportunities to develop novel diagnostic tools and personalized therapeutic strategies.

miR-3132 upregulates surface TRAIL to induce apoptotic cell death in cancer cells

TRAIL-based therapies are of significant clinical interest because of its unique ability to induce apoptosis in cancer cells while sparing normal and untransformed cells. This selective antitumor potential of the TRAIL pathway has been harnessed by development of therapeutics including recombinant (rh)TRAIL and TRAIL-receptor agonist antibodies such as mapatumumab and lexatumumab. While these TRAIL-based therapies have proven successful in preclinical studies and safe in early phase clinical trials, the limited serum half-life has been a hurdle for further clinical development. Here we characterize miR-3132, a novel and first-in class TRAIL-inducing miRNA with potent anti-proliferative and pro-apoptotic effects in cancer cell lines. Initial mechanistic studies indicate that miR-3132 engages the interferon signaling pathway to induce TRAIL and subsequent TRAIL-dependent apoptosis in cancer cell lines. Our data further suggests that the binding of miR-3132 to toll-like receptors could be the upstream pathway for the interferon response. The current study the first report to demonstrate miR-3132's in vitro efficacy and preliminary mechanism of action in cancer cell lines.

Prediction methods for microRNA targets in bilaterian animals: Toward a better understanding by biologists

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the posttranscriptional level. Because of their wide network of interactions, miRNAs have become the focus of many studies over the past decade, particularly in animal species. To streamline the number of potential wet lab experiments, the use of miRNA target prediction tools is currently the first step undertaken. However, the predictions made may vary considerably depending on the tool used, which is mostly due to the complex and still not fully understood mechanism of action of miRNAs. The discrepancies complicate the choice of the tool for miRNA target prediction. To provide a comprehensive view of this issue, we highlight in this review the main characteristics of miRNA-target interactions in bilaterian animals, describe the prediction models currently used, and provide some insights for the evaluation of predictor performance.

SNHG12 promotes carcinogenesis of human renal cell cancer via functioning as a competing endogenous RNA and sponging miR-30a-3p

Small nucleolar RNA host gene 12 (SNHG12) has been indicated in the tumorigenesis of various human cancers, including clear cell renal cell carcinoma (ccRCC). However, the underlying mechanisms of SNHG12 driving progression of ccRCC remain incompletely understood. In the present study, we discovered that SNHG12 is up-regulated in ccRCC and that overexpression of SNHG12 predicted poor clinical outcome of ccRCC patients. SNHG12 knockdown notably inhibited proliferation and migration of RCC cells. Furthermore, we discovered that miR-30a-3p, a putative ccRCC inhibitor, was competitively sponged by SNHG12. Via the crosstalk network, SNHG12 was capable of up-regulating multiple target genes of miR-30a-3p, namely, RUNX2, WNT2 and IGF-1R, which have been identified to facilitate tumorigenesis of ccRCC. Taken together, our present study suggested a novel ceRNA network, in which SNHG12 could promote the malignancy of ccRCC although competitively binding with miR-30a-3p and consequently release the expression of its downstream cancer-related genes.

Knockdown of LINC02471 Inhibits Papillary Thyroid Carcinoma Cell Invasion and Metastasis by Targeting miR-375

Background

LncRNAs play important roles in papillary thyroid carcinoma (PTC). LINC02471 has been reported to be related to PTC prognosis. The current study aimed to investigate the effects of LINC02471 on human PTC cells.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to examine LINC02471 expression in PTC tissues and cells and miR-375 expression in PTC cells. SiLINC02471, miR-375 mimic and miR-375 inhibitor were used for cell transfection. Cell proliferation, apoptosis, migration, and invasion were detected by performing Cell Counting Kit-8 (CCK-8), clone formation assay, flow cytometry, scratch assay, and transwell assay. Western blot was carried out to detect protein levels of E-cadherin, N-cadherin and Snail. The target gene for LINC02471 was verified by dual-luciferase reporter assay.

Results

LINC02471 was highly expressed in PTC tissues and cells. After silencing LINC02471, cell proliferation, migration and invasion were reduced, but cell apoptosis was increased. SiLINC02471 increased the expressions of E-cadherin and miR-375, and inhibited the expressions of N-Cadherin and Snail. LINC02471 directly targeted miR-375 in PTC cells. Overexpression of miR-375 inhibited the proliferation, migration, invasion of PTC cells and reduced the expressions of N-Cadherin and Snail but promoted the cell apoptosis and increased E-cadherin expression, while miR-375 inhibitor produced opposite effects to overexpressed miR-375. After inhibiting miR-375 expression, siLINC02471 reversed the effect of miR-375 inhibitor.

Conclusion

LINC02471 could promote the development of PTC. Knocking down LINC02471 could inhibit invasion and metastasis and promote PTC cell apoptosis through directly targeting miR-375.

Limonoid compounds from Xylocarpus granatum and their anticancer activity against esophageal cancer cells

Background

To investigate the anticancer effects of limonoid compounds that were isolated and purified from Xylocarpus granatum fruits on human esophageal cancer (EC) cells. A structure‐activity relationship experiment was designed to identify the functional moiety of limonoid compounds identified as being critical for its anticancer activity.

Methods

Eca109 cells were cultured in RPMI1640 medium and treated with limonoid compounds. Cell proliferation was determined by the MTT assay in vitro. Eca109 cells apoptosis was analyzed by by flow cytometry after being treated with xylogranatin C. The expression of p53, Bax, bcl‐2, caspase‐3 and GRP78 in Eca109 cells after xylogranatin C treatment was examined by western blot assay.

Results

Four linonoid compounds strongly inhibited the cellular proliferation of Eca109 cells. Xylogranatin C was the strongest inhibitor, whose inhibitory effect was comparable to that of the well‐known chemotherapeutic agent, cisplatin. Furthermore, xylogranatin C might induce Eca109 cell apoptosis through joint effects on multiple pathways, including the death receptor and endoplasmic reticulum pathways. Additionally, xylogranatin C suppressed tumor cell proliferation by upregulating miR‐203a expression in Eca109 cells.

Conclusions

Xylogranatin C induced Eca109 cellular apoptosis and exerted antitumor activity. Xylogranatin C suppressed tumor cell proliferation by upregulating miR‐203a expression in Eca109 cells.

Chemoresistance-Associated Silencing of miR-4454 Promotes Colorectal Cancer Aggression through the GNL3L and NF-κB Pathway

Guanine nucleotide-binding protein-like-3-like (GNL3L) is a crucial regulator of NF-κB signaling that is aberrantly activated during diverse chemoresistance-associated cellular processes. However, the molecular mechanisms of GNL3L tumor initiation and resistant state are largely unknown. Moreover, the identification of predictive biomarkers is necessary to effectively generate therapeutic strategies for metastatic human colorectal cancer (CRC). This study aims to identify how cells acquire resistance to anticancer drugs and whether the downregulation of miR-4454 is associated with the progression of CRC. Here, we have shown that the overexpression of miR-4454 in resistant tumors is a crucial precursor for the posttranscriptional repression of GNL3L in human chemoresistant CRC progression, and we used doxycycline induced miR-4454 overexpression that significantly reduced tumor volume in a subcutaneous injection nude mice model. Together, these observations highlight that the downregulation of miR-4454 in resistant clones is prominently responsible for maintaining their resistance against anticancer drug therapy. Our study indicates that the development of miR-4454 as a microRNA-based therapeutic approach to silence GNL3L may remarkably reduce oncogenic cell survival that depends on GNL3L/NF-κB signaling, making miR-4454 a candidate for treating metastatic human CRC.

microRNA-214 Prevents Traits of Cutaneous Squamous Cell Carcinoma via VEGFA and Bcl-2

BACKGROUND

Dysregulation of microRNA-214 (miR-214) has been indicated in different tumors. The function of miR-214 in cutaneous squamous cell carcinoma (CSCC) is yet to be deciphered. The current study aimed to investigate the specific mechanism underpinning CSCC development with the involvement of miR-214 and its putative targets.

METHODS

Microarray analysis of CSCC and adjacent tissues was carried out to filter the most significant downregulated miRNA. Survival analysis of patients was subsequently implemented, followed by miRNA expression determination in CSCC cells. Gain-of-function assays were performed to evaluate its function on cellular level. The targets of the determined miRNA were predicted and their expression in CSCC and adjacent tissues was evaluated. The targeting relationship was analyzed by dual-luciferase assays. Finally, rescue experiments were conducted.

RESULTS

miR-214 was reduced in CSCC tissues and cells, and the survival of patients harboring overexpression of miR-214 was higher. miR-214 restoration increased CSCC cell apoptosis, while decreased proliferative, invasive and migratory activities. miR-214 interacted with vascular endothelial growth factor A (VEGFA) and B-cell CLL/lymphoma 2 (Bcl-2). VEGFA and Bcl-2, overexpressed in CSCC tissues and cells, were negatively correlated with miR-214. Moreover, VEGFA and Bcl-2 overexpression reversed the anti-tumor phenotypes of miR-214 on CSCC cells. miR-214 disrupted the Wnt/β-catenin pathway through VEGFA and Bcl-2 in the CSCC cells.

CONCLUSION

Our data demonstrates that miR-214 exerts a suppressing role in CSCC. The discovery of novel targets such as miR-214 and VEGFA/Bcl-2 may facilitate the development of therapeutic options.

MicroRNA-30a-3p functions as a tumor suppressor in renal cell carcinoma by targeting WNT2

The expression and function of microRNA (miR)-30a-3p in several types of human cancer have been explored. However, the biological function of miR-30a-3p in renal cell carcinoma (RCC) remains largely unknown. In this study, we demonstrate that expression of miR-30a-3p is down-regulated in RCC tissues compared to adjacent normal tissues. Furthermore, ectopic expression of miR-30a-3p significantly suppressed the proliferation, migration, and invasion of a human RCC cell line in vitro, while miR-30a-3p inhibited tumor growth in vivo as well. TargetScan software identified Wnt2 as a potential direct target of miR-30a-3p. To confirm this relationship, Wnt2 was ectopically expressed. The effects of miR-30a-3p on RCC cell proliferation and invasion were subsequently restored. Therefore, the results of this study support an anti-tumor role for miR-30a-3p in RCC progression which is potentially mediated via Wnt2.

MicroRNA-664 functions as an oncogene in cutaneous squamous cell carcinomas (cSCC) via suppressing interferon regulatory factor 2

BACKGROUND

Aberrant expression of microRNA-664 was involved in tumor growth and metastasis of various cancers. The specific role of miR-664 in cutaneous squamous cell carcinoma (cSCC) is yet to be elucidated.

OBJECTIVE

The present study aimed to investigate the molecular mechanisms underpinning of cSCC development and provide translational insights for future therapeutics.

METHODS

Human cSCC specimens were used to determine the miR-664 by in situhybridization and IRF2 by immunohistochemistry. To study the potential mechanisms in tumorigenesis, three cSCC cell lines including HSC-5, HSC-1 and A431 as well as BALB/C mouse tumor model was utilized.

RESULTS

We found that miR-664 was remarkably high in cSCC patient specimens and cSCC cell lines. Overexpression of miR-664 promotes tumorigenic behaviors such as increased cell proliferation, migration and invasion capacities in vitro and enhanced tumorigenicity in xenograft mouse model. Our data further identified IRF2 as a direct downstream target of miR-664. Knockdown of IRF2 reverses pro-tumorigenesis phenotype of miR-664; whereas IRF2 over-expression inhibits miR-664 tumorigenesis in cSCC. Together, it revealed miR-664 functions as an oncogene in cSCC via suppression of IRF2.

CONCLUSION

Our data demonstrates that aberrant expression of miR-664 plays a critical role in carcinogenesis of cSCC. The discovery of novel targets such as miR-664 and IRF2 will facilitate future development of therapeutic interventions.

Small non-coding RNA and colorectal cancer

Colorectal cancer (CRC) is the third most common malignance. Although great efforts have been made to understand the pathogenesis of CRC, the underlying mechanisms are still unclear. It is now clear that more than 90% of the total genome is actively transcribed, but lack of protein‐coding potential. The massive amount of RNA can be classified as housekeeping RNAs (such as ribosomal RNAs, transfer RNAs) and regulatory RNAs (such as microRNAs [miRNAs], PIWI‐interacting RNA [piRNAs], tRNA‐derived stress‐induced RNA, tRNA‐derived small RNA [tRFs] and long non‐coding RNAs [lncRNAs]). Small non‐coding RNAs are a group of ncRNAs with the length no more than 200 nt and they have been found to exert important regulatory functions under many pathological conditions. In this review, we summarize the biogenesis and functions of regulatory sncRNAs, such as miRNAs, piRNA and tRFs, and highlight their involvements in cancers, particularly in CRC.

Preliminary study on the effect of nucleolin specific aptamer-miRNA let-7d chimera on Janus kinase-2 expression level and activity in gastric cancer (MKN-45) cells

Recently, much attention has been focused on the use of miRNAs in cancer treatment. The role of proto-oncogene Janus kinase-2 (JAK-2) in proliferation and survival of gastric cancer has been previously documented. The aim of this study was to evaluate the effect of a chimera consisted of nucleolin specific aptamer (NCL-Apt) and miRNA let-7d on JAK2 expression level and activity in gastric cancer cells. NCL-Apt-miRNA let-7d chimera was prepared by two methods. Gastric cancer (MKN-45) cell line and control cell line of human dermal fibroblast (HDF) were treated with the chimera and the changes in JAK2 expression and activity were determined using real-time PCR and ELISA techniques, respectively. In MKN-45 cells, the chimera caused significant decrease in JAK2 expression level and activity compared to the aptamer alone and miRNA mimic negative control. Nevertheless, transfected miRNA let-7d showed remarkable reduction in the expression level of JAK2 in comparison with control state in both MKN-45 and HDF, confirmed unspecific effect of let-7d on normal and cancerous cells. With regard to the synergic effect of this chimera on JAK2 activity, it might be viewed as a therapeutic candidate in gastric cancer. However, further studies are warranted to prove it.

MicroRNA-145 performs as a tumor suppressor in human esophageal squamous cell carcinoma by targeting phospholipase C epsilon 1

Esophageal squamous cell carcinoma (ESCC) is the leading pathologic type in China. miR-145 has been reported to be downregulated in multiple tumors. This study was aimed to investigate the role of miR-145 in ESCC. miR-145 expression was investigated in 65 ESCC samples as well as four ESCC cell lines by quantitative real-time polymerase chain reaction (qRT-PCR). Targetscan 6.2 website (http://www.targetscan.org/) was used to predict the targets of miR-145. Expression of phospholipase C epsilon 1 (PLCE1) messenger RNA and protein was detected by qRT-PCR or Western blot. MTT and wound healing assay were conducted to explore the effects of miR-145 on the proliferation and migration of ESCC cell lines, respectively. miR-145 was significantly decreased in ESCC tissues. An inverse correlation between miR-145 and invasion depth and TNM stage were observed. PLCE1 was a direct target of miR-145, and the expression of PLCE1 was inversely correlated with miR-145 expression in ESCC tissues. In addition, overexpression of miR-145 suppressed cell proliferation and migration in ESCC cells. The enforced expression of PLCE1 partially reversed the suppressive effect of miR-145. These results prove that miR-145 may perform as a tumor suppressor in ESCC by targeting PLCE1.

Modulation in the microRNA repertoire is responsible for the stage-specific effects of Akt suppression on murine neuroendocrine prostate cancer

Recent studies indicate a stage-specific, differential role for the oncogene Akt on various cancers. In prostate cancer (PCa), suppression of Akt activity in the advanced stages promoted transforming growth factor-β (TGFβ) pathway-mediated epithelial-to-mesenchymal transition (EMT) and metastasis to the lungs. In the current study, we performed Affymetrix analysis to compare the expression profile of microRNAs in the mouse prostate tissues collected at the prostatic inter-epithelial neoplasia (PIN) stage from Transgenic adenocarcinoma of the mouse (TRAMP)/Akt1^+/+ versus TRAMP/Akt1^–/– mice, and at the advanced stage from TRAMP/Akt1^+/+ mice treated with triciribine (Akt inhibitor) versus DMSO-treated control. Our analysis demonstrates that in the early stage, Akt1 in the TRAMP prostate tumors express a set of miRNAs responsible for regulating cancer cell survival, proliferation, and tumor growth, whereas, in the advanced stages, a different set of miRNAs that promote EMT and cancer metastasis is expressed. Our study has identified novel Akt-regulated signature microRNAs in the early and advanced PCa and demonstrates their differential effects on PCa growth and metastasis.

Identification of miR-379/miR-656 (C14MC) cluster downregulation and associated epigenetic and transcription regulatory mechanism in oligodendrogliomas

INTRODUCTION

Although role of individual microRNAs (miRNAs) in the pathogenesis of gliomas has been well studied, their role as a clustered remains unexplored in gliomas.

METHODS

In this study, we performed the expression analysis of miR-379/miR-656 miRNA-cluster (C14MC) in oligodendrogliomas (ODGs) and also investigated the mechanism underlying modulation of this cluster.

RESULTS

We identified significant downregulation of majority of the miRNAs from this cluster in ODGs. Further data from The Cancer Genome Atlas (TCGA) also confirmed the global downregulation of C14MC. Furthermore, we observed that its regulation is maintained by transcription factor MEF2. In addition, epigenetic machinery involving DNA and histone-methylation are also involved in its regulation, which is acting independently or in synergy. The post- transcriptionally regulatory network of this cluster showed enrichment of key cancer-related biological processes such as cell adhesion and migration. Also, there was enrichment of several cancer related pathways viz PIK3 signaling pathway and glioma pathways. Survival analysis demonstrated association of C14MC (miR-487b and miR-409-3p) with poor progression free survival in ODGs.

CONCLUSION

Our work demonstrates tumor-suppressive role of C14MC and its role in pathogenesis of ODGs and therefore could be relevant for the development of new therapeutic strategies.

miR-486-5p inhibits cell proliferation and invasion through repressing GAB2 in non-small cell lung cancer

Previous studies have reported that cell metastasis is the main reason for the high mortality of non-small cell lung cancer (NSCLC). Many miRNAs have been identified to be involved in the development of NSCLC. In this study, we explored the effect of miR-486-5p and GAB2 on cell proliferation and invasion in NSCLC. First, miR-486-5p and GAB2 expression levels were detected in NSCLC through quantitative RT-qPCR, and downregulation of miR-486-5p and upregulation of GAB2 were both identified in NSCLC. Then MTT and Transwell analysis were performed to confirm the functions of miR-486-5p and GAB2 for cell proliferation and invasion in NSCLC. Moreover, miR-486-5p overexpression was found to inhibit proliferation and invasion by suppressing GAB2 in NSCLC cells. Besides, miR-486-5p overexpression lessened GAB2 expression level in NSCLC, while miR-486-5p knockout enhanced GAB2 expression level. Additionally, miR-486-5p was identified to directly target GAB2 through dual luciferase reporter assay. The silence of GAB2 was found to inhibit proliferation and invasion of NSCLC cells. Collectively, miR-486-5p contributed to inhibiting proliferation and invasion of NSCLC cells through regulating GAB2, and miR-486-5p/GAB2 axis may provide a breakthrough for diagnosing NSCLC.

Cationic liquid crystalline nanoparticles for the delivery of synthetic RNAi-based therapeutics

RNA interference (RNAi)-based therapeutics have been used to silence the expression of targeted pathological genes. Small interfering RNA (siRNAs) and microRNA (miRNAs) inhibitor have performed this function. However, short half-life, poor cellular uptake, and nonspecific distribution of small RNAs call for the development of novel delivery systems to facilitate the use of RNAi. We developed a novel cationic liquid crystalline nanoparticle (CLCN) to efficiently deliver synthetic siRNAs and miRNAs. CLCNs were prepared by using high-speed homogenization and assembled with synthetic siRNA or miRNA molecules in nuclease-free water to create CLCN/siRNA or miRNA complexes. The homogeneous and stable CLCNs and CLCN-siRNA complexes were about 100 nm in diameter, with positively charged surfaces. CLCNs are nontoxic and are taken up by human cells though endocytosis. Significant inhibition of gene expression was detected in transiently transfected lung cancer H1299 cells treated with CLCNs/anti-GFP complexes 24 hours after transfection. Biodistribution analysis showed that the CLCNs and CLCNs-RNAi complexes were successfully delivered to various organs and into the subcutaneous human lung cancer H1299 tumor xenografts in mice 24 hours after systemic administration. These results suggest that CLCNs are a unique and advanced delivery system capable of protecting RNAi from degradation and of efficiently delivering RNAi in vitro and in vivo.

Effects of Yangzheng Sanjie Decoction-containing serum mediated by microRNA-7 on cell proliferation and apoptosis in gastric cancer

Gastric cancer (GC) is one of the most common types of cancer and a leading cause of cancer-associated mortality. MicroRNAs (miRNAs/miRs) are demonstrated to function as oncomiRs or tumor-suppressor-miRs in GC. miR-7 has been identified to be a tumor suppressor of GC by targeting epidermal growth factor receptor (EGFR). In our previous study, Yangzheng Sanjie Decoction (YZSJD), a traditional Chinese formula, was identified to be effective in alleviating the symptoms and even postponing turnover of precancerous lesions. To elucidate the mechanism of YZSJD, the present study evaluated the effects of YZSJD of the GC MKN-45 cell line and investigated the underlying molecular mechanisms using YZSJD-containing serum (YCS). The expression of miR-7 in GC, normal and adjacent tissue samples was examined. The results demonstrated that YCS inhibited proliferation by inducing cell cycle arrest at the S phase, and significantly induced apoptosis compared with the control group. miR-7 was significantly downregulated in GC tissues compared with the matched ones. Using reverse transcription-quantitative polymerase chain reaction and western blot analysis, the expression of miR-7 was inversely associated with EGFR. This indicates that YCS inhibits proliferation and induces apoptosis of GC cells mediated by miR-7 targeting EGFR, which may be one of the mechanisms whereby YZSJD exerts its effects on GC.

Grapefruit-derived nanovectors deliver miR-18a for treatment of liver metastasis of colon cancer by induction of M1 macrophages

Liver metastasis accounts for many of the cancer deaths in patients. Effective treatment for metastatic liver tumors is not available. Here, we provide evidence for the role of miR-18a in the induction of liver M1 (F4/80⁺interferon gamma (IFNγ)⁺IL-12⁺) macrophages. We found that miR-18a encapsulated in grapefruit-derived nanovector (GNV) mediated inhibition of liver metastasis that is dependent upon the induction of M1 (F4/80⁺IFNγ⁺IL-12⁺) macrophages; depletion of macrophages eliminated its anti-metastasis effect. Furthermore, the miR-18a mediated induction of macrophage IFNγ by targeting IRF2 is required for subsequent induction of IL-12. IL-12 then activates natural killer (NK) and natural killer T (NKT) cells for inhibition of liver metastasis of colon cancer. This conclusion is supported by the fact that knockout of IFNγ eliminates miR-18a mediated induction of IL-12, miR-18a treatment has an anti-metastatic effects in T cell deficient mice but there is no anti-metastatic effect on NK and NKT deficient mice. Co-delivery of miR-18a and siRNA IL-12 to macrophages did not result in activation of co-cultured NK and NKT cells. Taken together our results indicate that miR-18a can act as an inhibitor for liver metastasis through induction of M1 macrophages.

Aptamer-based Targeted Delivery of miRNA let-7d to Gastric Cancer Cells as a Novel Anti-Tumor Therapeutic Agent

miRNAs as one of the potential therapeutic agents have been recently considered for cancer treatment. AS1411 (aptNCL) is a DNA aptamer specifically binding to nucleolin protein on the cancer cell surface with antiproliferative effect. The aim of the study was to develop a conjugate consisting of aptNCL (as targeted delivery of therapeutic agent) and miRNA let-7d (as a tumor suppressor) using two different linking methods and also to evaluate the potential effect of the conjugates on the proliferation of gastric cancer (MKN-45) cell line compared to negative control cell line of human dermal fibroblast (HDF). Conjugation was performed covalently by SM (PEG)₂ as a bifunctional crosslinker (conjugate-1) and noncovalently, using 19bp complementary sticky end sequences (conjugate-2). Nucleolin positive MKN-45 and nucleolin negative HDF cells were cultured and treated with the conjugates. Then, the changes in let-7d expression and cell proliferation were determined using Real-time PCR and MTT methods, respectively. In MKN-45 cells, the conjugates caused significant increase in let7-d uptake compared with HDF cells (P = 0.0001). The conjugate-1, likely due to its higher stability compared with the conjugate-2, led to significantly more increase in intracellular let-7d in MKN-45 cells (30 fold versus 15 fold, respectively, P = 0.0001). The conjugates revealed more potent antiproliferative effect against gastric cancer cells compared with aptNCL alone (P = 0.0001). It was found that the aptNCL-let-7d conjugate efficiently carried let-7d into the cancer cells. Also, it appears that in the setting of aptNCL-let-7d conjugate, let-7d and aptNCL moieties could cooperate and synergistically exhibit the antiproliferative effect on cancer cells.

Direct repression of the oncogene CDK4 by the tumor suppressor miR-486-5p in non-small cell lung cancer

MicroRNAs are a class of non-coding single-stranded RNA, 20-23 nucleotide in length, which can be involved in the regulation of gene expression. Through binding with 3′-untranslated regions (3′-UTR), microRNAs can cause degradation of target mRNAs or inhibition of translation, and thus regulating the expression of genes at the post-transcriptional level. In this study, we found that miR-486-5p was significantly downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines, suggesting that miR-486-5p might function as a tumor suppressor in lung cancer. Additionally, we showed that CDK4, an oncogene that plays an important role in cell cycle G1/S phase progression, was directly targeted by miR-486-5p. Furthermore, our data reveals that knockdown of CDK4 by siRNA can inhibit cell proliferation, promote apoptosis, and impede cell-cycle progression. In epigenetics, the upstream promoter of miR-486-5p was strongly regulated by methylation in NSCLC. Collectively, our results suggest that miR-486-5p could not only inhibit NSCLC by downregulating the expression of CDK4, but also be as a promising and potent therapy in the near future.

MicroRNA regulation of K-Ras in pancreatic cancer and opportunities for therapeutic intervention

The Ras family of GTPases is involved in cell proliferation, cell survival, and angiogenesis. It is upregulated in several cancers, including pancreatic cancer (PC) and leads to uncontrolled growth and aggressiveness. PC is well known to be a lethal disease with poor prognosis, plagued by limited therapeutic modalities. MicroRNAs (miRNAs), which are short non-coding RNA molecules, have recently emerged as regulators of signaling networks and have shown potential to target pathway components for therapeutic use in several malignancies. K-Ras mutations are widespread in PC cases (90%), with mutations detectable as early as pancreatic intraepithelial neoplasias and in later metastatic stages alike; therefore, these mutations in K-Ras are obvious drivers and potential targets for PC therapy. Several K-Ras targeting miRNAs have lately been discovered, and many of them have shown promise in combating pancreatic tumor growth in vitro and in mouse models. However, the field of miRNA therapy is still in its infancy, and miRNA mimics or anti-miRNA oligonucleotides that target Ras pathway have thus far not been evaluated in PC patients. In this review, we summarize the role of several miRNAs that regulate oncogenic K-Ras signaling in PC, with their prospective roles as therapeutic agents for targeting K-Ras pathway.

miR-6883 Family miRNAs Target CDK4/6 to Induce G1 Phase Cell-Cycle Arrest in Colon Cancer Cells

CDK4/6 targeting is a promising therapeutic strategy under development for various tumor types. In this study, we used computational methods and The Cancer Genome Atlas dataset analysis to identify novel miRNAs that target CDK4/6 and exhibit potential for therapeutic development in colorectal cancer. The 3'UTR of CDK4/6 mRNAs are targeted by a family of miRNAs, which includes miR-6883-5p, miR-149*, miR-6785-5p, and miR-4728-5p. Ectopic expression of miR-6883-5p or miR-149* downregulated CDK4 and CDK6 levels in human colorectal cancer cells. RNA-seq analysis revealed an inverse relationship between the expression of CDK4/6 and miR-149* and intronic miRNA-6883-5p encoding the clock gene PER1 in colorectal cancer patient samples. Restoring expression of miR-6883-5p and miR-149* blocked cell growth leading to G₀-G₁ phase cell-cycle arrest and apoptosis in colorectal cancer cells. CDK4/6 targeting by miR-6883-5p and miR-149* could only partially explain the observed antiproliferative effects. Notably, both miRNAs synergized with the frontline colorectal cancer chemotherapy drug irinotecan. Further, they resensitized mutant p53-expressing cell lines resistant to 5-fluorouracil. Taken together, our results established the foundations of a candidate miRNA-based theranostic strategy to improve colorectal cancer management. Cancer Res; 77(24); 6902-13. ©2017 AACR.

MiR-200a Regulates CDK4/6 Inhibitor Effect by Targeting CDK6 in Metastatic Melanoma

The CDK4/6 pathway is frequently dysregulated in cutaneous melanoma. Recently, CDK4/6 inhibitors have shown promising clinical activity against several cancer types, including melanoma. Here, we show that microRNA-200a decreases CDK6 expression and thus reduces the response of CDK4/6 inhibitor in highly proliferative metastatic melanoma. Down-regulation of microRNA-200a expression in melanoma cells is associated with disease progression and a higher number of lymph node metastases. Furthermore, microRNA-200a expression is epigenetically modulated by both DNA methylation at the promoter region and chromatin accessibility of an upstream genomic region with enhancer activity. Mechanistically, overexpression of miR-200a in metastatic melanoma cells induces cell cycle arrest by targeting CDK6 and decreases the levels of phosphorylated-Rb1 and E2F-downstream targets, diminishing cell proliferation; these effects are recovered by CDK6 overexpression. Conversely, low microRNA-200a expression in metastatic melanoma cells results in higher levels of CDK6 and a more significant response to CDK4/6 inhibitors. We propose that microRNA-200a functions as a "cell cycle brake" that is lost during melanoma progression to metastasis and provides the ability to identify melanomas that are highly proliferative and more prompted to respond to CDK4/6 inhibitors.

MicroRNA‑336 directly targets Sox‑2 in osteosarcoma to inhibit tumorigenesis

Previous evidence has suggested that microRNAs (miRNAs or miRs), which belong to a class of non‑coding RNAs, shape cellular processes by regulating gene expression. Abnormal expression of miRNAs has been associated with tumorigenesis in multiple cancers. However, the function of miR‑336 in osteosarcoma (OS) remains unknown. The experimental procedures used in the present study included flow cytometry, reverse transcription‑quantitative polymerase chain reaction, luciferase reporter assay, invasion assay, western blot analysis and in vivo implantation. The results of the present study demonstrated that miR‑336 may serve as a tumor suppressor in OS. Downregulation of miR‑336 was observed in human OS specimens as well as OS cell lines. In addition, a significant negative correlation between sex determining region Y‑box 2 (Sox‑2) expression and miR‑336 was demonstrated. miR‑336 was confirmed to target the 3'‑untranslated region of Sox‑2 to inhibit proliferation, migration and invasion of OS cells. Consistently, restoration of Sox‑2 expression counteracted the effect of miR‑336, and recovered the tumorigenic potential of OS cells. The present study established a novel association between miR‑336 and Sox‑2 in OS. This relationship between miR‑336 and Sox‑2 may lead to improved knowledge concerning OS progression and sheds light on potential novel therapeutic interventions for OS treatment.

MiR-302a sensitizes leukemia cells to etoposide by targeting Rad52

miR-302a have been reported to participate in various physiological and pathological processes, however, a role for miR-302a in etoposide (VP-16) resistance of acute myeloid leukemia (AML) has not been reported. In this study, the aberrant expression of miR-302a was analyzed in patients with AML and in the AML HL-60 and U937 cell lines. Overexpression of miR-302a, by targeting the 3'UTR of Rad52, enhanced VP-16 sensitivity in the HL-60 and U937 cell. Accordingly, knockdown of Rad52 sensitized the HL-60 and U937 cells to VP-16-induced apoptosis and proliferation suppression. In addition, miR-302a enhanced the tumor-suppressive effect of VP-16 in a xenograft model of human HL-60 and U937 cell lines. Moreover, miR-302a repressed the AKT/Gsk3β/β-catenin pathway after Rad52 inhibition. Reintroduction of Rad52 reversed miR-302a-induced signaling suppression. The results of the present study demonstrated that miR-302a may be a target for the treatment of AML and a potential indicator of the therapeutic sensitivity of AML to VP-16.

MicroRNA-142-5p promotes cell growth and migration in renal cell carcinoma by targeting BTG3

PURPOSE

Some microRNA (miRNA) levels have been found to be dysregulated in cancer patients, suggesting the potential usefulness of miRNAs in cancer therapies. The purpose of this study was to investigate the expression of miR-142-5p in human renal cell carcinoma (RCC) and its potential role in tumor growth and metastasis.

METHODS

The expression level of miR-142-5p in human RCC tissue and cell lines was determined by quantitative reverse transcription polymerase chain reaction analysis. MTT, colony formation, Transwell, and cell cycle assays were performed to explore the potential functions of miR-142-5p in human RCC cells. The potential target gene of miR-142-5p was identified and confirmed via luciferase reporter assays.

RESULTS

miR-142-5p expression was elevated in RCC tissues and cell lines. Overexpression of miR-142-5p significantly promoted cell proliferation and colony formation and could prevent G1 phase arrest among RCC 786-O cells. Meanwhile, the migration potential of 786-O cells was greater than that of control cells. BTG3 was identified as a direct target of miR-142-5p, and re-expression of BTG3 reversed the miR-142-5p-induced cell proliferation.

CONCLUSION

miR-142-5p promoted the proliferation and migration of RCC cells by targeting BTG3. With this potential onco-miRNA role in the progression of RCC, miR-142-5p may be a therapeutic target for the treatment of RCC.

MicroRNA-18a-5p functions as an oncogene by directly targeting IRF2 in lung cancer

Lung cancer is the major form of cancer resulting in cancer-related mortality around the world. MicroRNAs are endogenous small non-coding single-stranded RNAs, which can engage in the regulation of gene expression. In this study, miR-18a-5p significantly upregulated in non-small cell lung cancer (NSCLC) tissues and NSCLC cell lines, suggesting an oncogenic function in lung cancer. Additionally, miR-18a-5p can promote carcinogenesis by directly targeting interferon regulatory factor 2 (IRF2). Further experiments indicated that IRF2 can increase cell apoptosis, inhibit cell proliferation and migration ability. Our study demonstrates that miR-18a-5p promotes autophagy in NSCLC. Collectively, these results indicate that miR-18a-5p can not only promote NSCLC by suppressing IRF2, but also will be a promising target in the near future.

A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits

A millisecond micro-RNA separation of a mixture of total RNA and genomic DNA, extracted from cultured HeLa cells, was successfully achieved using a hybrid structure of nanopillars and nanoslits contained inside a microchannel. The nanopillars, 250-nm in diameter and 100-nm in height, were fabricated with a 750-nm space inside the nanoslits, which were 100-nm in height and 25-μm in width; the nanopillars were then applied as a new sieve matrix. This ultra-fast technique for the separation of miRNA can be an effective pretreatment for semiconductor nanopore DNA sequencing, which has an optimum reading speed of 1 base/ms to obtain effective signal-to-noise ratio and discriminate each base by ion or tunneling current during the passage of nucleic acids.

Blood-Based Nucleic Acid Biomarkers as a Potential Tool to Determine Radiation Therapy Response in Non-Small Cell Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide, with smoking as the main risk factor. The use of low-dose computed tomography (LDCT) as a screening method has shown a 20% lung cancer specific mortality benefit; however, widespread implementation is estimated to add $1.3-$2.0 billion in annual national health care expenditures. Blood-based microRNAs (miRNAs) have been investigated in detail and found to be potentially useful biomarkers indicating the presence of lung cancer, especially when used as a companion test to LDCT. Testing for miRNAs and circulating tumor DNA (ct-DNA) in the blood are anticipated to become more affordable in the near future, and therefore these potentially sensitive methods could serve as first-line screening modalities prior to obtaining LDCT and definitive diagnostic tests for lung cancer. Furthermore, miRNAs may shed light not only on the tumor burden, but also perhaps on tumor aggressiveness, histology, treatment response and the patient's overall survival. In the near future, analysis of ct-DNA may reveal somatic mutations beyond EGFR, tumor burden and the presence of occult progression of disease. In theory, these biomarkers may also help oncologists to elucidate the tumor response to radiotherapy, and in the future, may assist the radiation oncologist in making data-driven treatment decisions and providing patients with quantitative information regarding their treatment response.

The role of microRNAs in metal carcinogen-induced cell malignant transformation and tumorigenesis

MicroRNAs (miRNAs), an important component of epigenetic mechanisms of carcinogenesis, have been shown to play crucial roles in cancer initiation, metastasis, prognosis and responses to drug treatment and may serve as biomarkers for early diagnosis of cancer and tools for cancer therapy. Metal carcinogens, such as arsenic, cadmium, hexavalent chromium and nickel, are well-established human carcinogens causing various cancers upon long term exposure. However, the mechanism of metal carcinogenesis has not been well understood, which limits our capability to effectively diagnose and treat human cancers resulting from chronic metal carcinogen exposure. Over recent years, the role of miRNAs in metal carcinogenesis has been actively explored and a growing body of evidence indicates the critical involvement of miRNAs in metal carcinogenesis. This review aims to discuss recent studies showing that miRNAs play important roles in metal carcinogen-induced cell malignant transformation and tumorigenesis. Some thoughts for future further studies in this field are also presented.

MicroRNA expression profiling of Chinese follicular lymphoma by microarray: A preliminary study

BACKGROUND

MicroRNAs (miRNAs) have been widely regarded as crucial regulators in various biological processes involved in carcinogenesis. However, the comprehensive miRNA profiles of Chinese follicular lymphoma (FL) remains completely unknown.

METHODS

The Exiqon miRCURY LNA™ microRNA Array (v.18.0) was used to detect the miRNA expression profiles of three Chinese FL samples, and compared to three reactive lymphatic nodes (RLN). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to confirm the selected miRNAs in different series. Three databases (miRAnda, miRBase and TargetScan) were used to predict the putative target genes. Bioinformatic analysis (gene ontology analysis and pathway analysis) was performed for further evaluation.

RESULTS

The microarray assay demonstrated that 1643 miRNAs were expressed; in which 103 miRNAs were upregulated and 68 miRNAs were downregulated, according to P-value (<0.05) and fold change (FC>2-fold). Furthermore, qRT-PCR was used to confirm that miR-17-5p, miR-20a-5p and miR-19a-3p were upregulated, and miR-3615 was downregulated (P<0.05). Bioinformatic analysis (gene ontology analysis and pathway analysis) was used for further evaluation. Pathway analysis indicated that 25 pathways corresponded to differentially expressed miRNAs (P-value cut-off is 0.05). Furthermore, miR-17-5p, miR-20a-5p and miR-19a-3p were validated by qRT-PCR in an independent series including five FL3a and five RLN cases. Data analysis revealed that the changing trend of miR-19a-3p and miR-17-5p expression in the independent series was basically identical with that of the microarray data.

CONCLUSIONS

Our results are the first to reveal the miRNA expression profiling of Chinese FL and three upregulated miRNAs. Furthermore, the expression of miR-19a-3p and miR-17-5p were found to be significantly upregulated in FL3a. Further study needs to be urgently performed to reveal its potential role in the pathogenesis of FL in the near future.

Prognostic role of miR-9 expression in various human malignant neoplasms: a meta-analysis

Emerging evidence has shown that aberrant microRNA expression has the potential to be used for predicting survival and treatment response of malignant neoplasms. In recent years, the role of miR-9 had been investigated in various types of cancers, and it was found that the results were inconsistent and inconclusive. Hence, in this study, a meta-analysis was conducted to assess the prognostic value of miR-9 in various types of tumors. Eligible studies were identified through a systematic search in PubMed and EMBASE and then were assessed by further quality evaluation. Pooled hazard ratios (HRs) with 95% confidence intervals for overall survival (OS) were calculated to investigate the association between miR-9 expression and cancer prognosis. The pooled results of eight published studies showed that elevated miR-9 was a predictor of poor survival of various carcinomas, with pooled HR of 3.04 (95% confidence interval: 1.96–4.73) for OS. Subgroup analysis on the basis of tumor type, sample size, and HR estimate also showed that high levels of miR-9 were also significantly correlated with OS. In addition, when the subgroup analyses were grouped by follow-up time, it was found that the elevated expression of miR-9 was associated with a lower long-term survival when the follow-up time was >60 months, but there was no correlation between the outcomes and those patients whose follow-up time was <60 months. Funnel plots and Egger’s tests revealed that there was no obvious publication bias risk in the meta-analysis. In conclusion, our results demonstrated that higher expression level of miR-9 significantly predicted worse OS in various carcinomas and that miR-9 may act as a novel biomarker in the prognosis of malignant neoplasms.

MicroRNA-351 Regulates Two-Types of Cell Death, Necrosis and Apoptosis, Induced by 5-fluoro-2'-deoxyuridine

Cell-death can be necrosis and apoptosis. We are investigating the mechanisms regulating the cell death that occurs on treatment of mouse cancer cell-line FM3A with antitumor 5-fluoro-2'-deoxyuridine (FUdR): necrosis occurs for the original clone F28-7, and apoptosis for its variant F28-7-A. Here we report that a microRNA (miR-351) regulates the cell death pattern. The miR-351 is expressed strongly in F28-7-A but only weakly in F28-7. Induction of a higher expression of miR-351 in F28-7 by transfecting an miRNA mimic into F28-7 resulted in a change of the death mode; necrosis to apoptosis. Furthermore, transfection of an miR-351 inhibitor into F28-7-A resulted in the morphology change, apoptosis to necrosis, in this death-by-FUdR. Possible mechanism involving lamin B1 in this miR-351's regulatory action is discussed.

Exosomal microRNA Biomarkers: Emerging Frontiers in Colorectal and Other Human Cancers

Diagnostic strategies, particularly non-invasive blood-based screening approaches, are gaining increased attention for the early detection and attenuation of mortality associated with colorectal cancer (CRC). However, the majority of current screening approaches are inadequate at replacing the conventional CRC diagnostic procedures. Yet, due to technological advances and better understanding of molecular events underlying human cancer, a new category of biomarkers are on the horizon. Recent evidence indicates that cells release a distinct class of small vesicles called 'exosomes', which contain nucleic acids and proteins that reflect and typify host-cell molecular architecture. Intriguingly, exosomes released from cancer cells have a distinct genetic and epigenetic makeup, which allows them to undertake their tumorigenic function. From a clinical standpoint, these unique cancer-specific fingerprints present in exosomes appear to be detectable in a small amount of blood, making them very attractive substrates for developing cancer biomarkers, particularly noninvasive diagnostic approaches.

Methylation-mediated repression of potential tumor suppressor miR-203a and miR-203b contributes to esophageal squamous cell carcinoma development

MiRNAs regulate gene expression and play pivotal roles in biological processes. MiRNAs can be inactivated by epigenetic mechanisms, such as DNA hypermethylation of CpG sites within CpG islands. Here, we investigated the role and methylation status of miR-203a and miR-203b in esophageal cancer cell lines and primary esophageal squamous cell carcinoma (ESCC) tumors and further elucidate the role of both miRNAs in the prognosis of ESCC. The present study revealed a strong downregulation of miR-203a and miR-203b in esophageal cancer cell lines and primary ESCC samples. Treatment of esophageal cancer cells with demethylating agent 5-Aza-dC led to increased miR-203a and miR-203b expression, confirming the epigenetic regulation of both miRNAs. The inhibition of proliferation and invasiveness in esophageal cancer cells after treated with 5-Aza-dC or transfected with miR-203a or miR-203b mimics, suggesting the tumor suppressor role of both miRNAs in esophageal cancer. Furthermore, the critical CpG sites of miR-203a and miR-203b were found to be located in proximal promoter region, and the proximal promoter hypermethylation of both miRNAs was found to influence transcriptional activity. Downregulation and hypermethylation of miR-203a and miR-203b were associated with TNM stage, pathological differentiation, and lymph node metastasis. ESCC patients in stages III and IV, with reduced expression of miR-203a or hypermethylation of miR-203a or miR-203b, demonstrated poor patient survival. In summary, our results suggest that miR-203a and miR-203b may function as tumor-suppressive miRNAs that are inactivated through proximal promoter hypermethylation and miR-203a expression and methylation may be useful prognostic marker in ESCC patients.

Profile of differentially expressed miRNAs in high-grade serous carcinoma and clear cell ovarian carcinoma, and the expression of miR-510 in ovarian carcinoma

Improved insight into the molecular and genetic profile of different types of epithelial ovarian cancer (EOC) is required for understanding the carcinogenesis of EOC and may potentially be exploited by future targeted therapies. The aim of the present study was to identify a unique microRNA (miRNA) patterns and key miRNAs, which may assist in predicting progression and prognosis in high‑grade serous carcinoma (HGSC) and clear cell carcinoma (CCC). To identify unique miRNA patterns associated with HGSC and CCC, a miRNA microarray was performed using Chinese tumor bank specimens of patients with HGSC or CCC in a retrospective analysis. The expression levels of four deregulated miRNAs were further validated using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) in an external cohort of 42 cases of HGSC and 36 cases of CCC. Kaplan‑Meier analysis was performed to analyze the correlation between the expression levels of the four miRNAs and patient prognosis. Among these validated miRNAs, miR‑510 was further examined in another cohort of normal ovarian tissues, as well as the HGSC, low‑grade serous carcinoma (LGSC) and CCC specimens using RT‑qPCR and in situ hybridization. The results revealed that, of the 768 miRNAs analyzed in the microarray, 33 and 50 miRNAs were significantly upregulated and downregulated, respectively, with at least a 2‑fold difference in HGSC, compared with CCC. The quantitative analysis demonstrated that miR‑510 and miR‑129‑3p were significantly downregulated, and that miR‑483‑5p and miR‑miR‑449a were significantly upregulated in CCC, compared with HGSC (P<0.05), which was consistent with the microarray results. Kaplan‑Meier analysis revealed low expression levels of miR‑510 and low expression levels of miR‑129‑3p, advanced International Federation of Gynecology and Obstetrics (FIGO) stage, lymphatic metastasis and that HGSC was significantly associated with the poorer overall survival rates (P<0.05). The expression of miR‑510 was significantly higher in the LGSC and CCC tissues, compared with the HGSC and normal ovarian tissues. The results of the present study suggested that different subtypes of EOC have specific miRNA signatures, and that miR‑510 may be involved differently in HGSC and CCC. Thus, miR‑510 and miR‑129‑3p may be considered as potential novel candidate clinical biomarkers for predicting the outcome of EOC.

Decreased expression and frequent promoter hypermethylation of RASSF2 and RASSF6 correlate with malignant progression and poor prognosis of gastric cardia adenocarcinoma

The RAS-association domain family (RASSF) consists of 10 members, and several members act as tumor suppressor genes and epigenetically inactivated in different tumor types. The present study investigated the role and methylation status of RASSF2, RASSF3, RASSF4, and RASSF6 in the pathogenesis and prognosis of GCA. Quantitative real-time RT-PCR, Western blot, and immunohistochemistry (IHC) methods were used respectively to detect the expression of RASSF2, RASSF3, RASSF4, and RASSF6 in 135 GCA cases and BS-MSP method was used to clarify the methylation status of these four genes. Decreased mRNA and protein expression of RASSF2, RASSF3, RASSF4, and RASSF6 were detected in GCA tumor tissues. Aberrant CpG island methylation of RASSF2, RASSF4, and RASSF6 were detected in GCA tumor tissues and were inversely correlated with the expression levels of these genes. Both of RASSF2 and RASSF6 expression and methylation were associated with TNM stage, depth of invasion, LN metastasis, distant metastasis or recurrence, and UGIC family history. GCA patients with simultaneous negative protein expression of RASSF2 and RASSF6 or with simultaneous methylation of both genes demonstrated poor patient survival. These results suggest that down-regulation of RASSF2, RASSF3, RASSF4, and RASSF6 is a tumor-specific phenomenon and the inactivation of RASSF2 and RASSF6 may be associated with tumor progression. Inactivation of RASSF2, RASSF4, and RASSF6 through CpG island methylation may play important roles in GCA carcinogenesis. A combination of RASSF2 and RASSF6 expression or hypermethylation may serve as useful prognostic biomarker for GCA. © 2015 Wiley Periodicals, Inc.

MicroRNA-141 is a biomarker for progression of squamous cell carcinoma and adenocarcinoma of the lung: clinical analysis of 125 patients

Lung cancer is the most common malignant tumor worldwide. MicroRNA has become an ideal biomarker for cancer diagnosis, prognosis and therapy. The relationship between microRNA-141 and non-small cell lung cancer (NSCLC) is contradictory. Thus, in current study, we aimed to investigate the level of microRNA-141 in NSCLC tissues and to evaluate its potential clinical value. This study enrolled 125 NSCLC patients (75 males and 50 females) with a median age of 61 years (range, 23-90 years). NSCLC patients included 23 squamous cell carcinomas (SCCs), 101 adenocarcinomas (ADCs) and 1 large cell carcinoma. The expression level of microRNA-141 was significantly higher in NSCLC tissues than in adjacent lung tissues (P < 0.001), detected by real time RT-PCR. Receiver operating characteristic (ROC) exhibited a moderate diagnostic value of microRNA-141 for NSCLC with the area under curve of 0.707. The microRNA-141 expression increased with the larger tumor size (P = 0.002), lymph node metastasis (P = 0.018) and advanced stage (P = 0.022) in NSCLC patients. For subgroup analysis, microRNA-141 expression in SCC was correlated with tumor size (r = 0.490, P = 0.018), and in ADC, microRNA-141 level was positively associated with tumor size (r = 0.222, P = 0.026), lymph node metastasis (r = 0.242, P = 0.015) and TNM stage (r = 0.210, P = 0.035). Furthermore, univariate analysis revealed that the expression of microRNA-141 was an independent prognostic indicator of ADC. In conclusion, microRNA-141 is a potential biomarker for the molecular diagnosis and risk stratification of NSCLC.

Small RNA Detection by in Situ Hybridization Methods

Small noncoding RNAs perform multiple regulatory functions in cells, and their exogenous mimics are widely used in research and experimental therapies to interfere with target gene expression. MicroRNAs (miRNAs) are the most thoroughly investigated representatives of the small RNA family, which includes short interfering RNAs (siRNAs), PIWI-associated RNA (piRNAs), and others. Numerous methods have been adopted for the detection and characterization of small RNAs, which is challenging due to their short length and low level of expression. These include molecular biology methods such as real-time RT-PCR, northern blotting, hybridization to microarrays, cloning and sequencing, as well as single cell miRNA detection by microscopy with in situ hybridization (ISH). In this review, we focus on the ISH method, including its fluorescent version (FISH), and we present recent methodological advances that facilitated its successful adaptation for small RNA detection. We discuss relevant technical aspects as well as the advantages and limitations of ISH. We also refer to numerous applications of small RNA ISH in basic research and molecular diagnostics.

Expression of cancer stem cell biomarkers as a tool for a correct therapeutic approach to hepatocellular carcinoma

Liver cancer is the fifth most commonly diagnosed malignancy and the second most frequent cause of cancer death in men worldwide. Amongst liver cancers, hepatocellular carcinoma (HCC) represents the major histological subtype and it is one of the most common malignant human tumors worldwide. Research into the molecular biology of hepatocarcinogenesis has identified several biomarkers, which could provide additional informations in order to better understand the biology of HCC. A large number of biomarkers have been shown to have potential predictive significance and a wide variety of molecular markers have been proven to be excellent diagnostic tools for HCC but it is difficult to characterize HCC with a single biomarker. Thus, signatures of a combination of biomarkers may be more valuable for the diagnosis, staging and prognosis of HCC. Specifically, a correlation of HCC-CSCs phenotype to specific hepatic cancer subtypes and to specific clinical and pathological features has not yet been reported in human liver tumors. In this view we will first discuss the possible sources of liver stem cells and their relation with liver cancer development and we will secondly focus on the prognostic significance of clinical and pathological features of HCC.

MiR-133a is downregulated in non-small cell lung cancer: a study of clinical significance

Background

Despite present studies which suggested miR-133a as a promising biomarker for several cancers, there still exist no articles concerning the validated clinical significance of miR-133a in non-small cell lung cancer (NSCLC). Therefore, in this study, we targeted the correlation between miR-133a expression and clinicopathological significance in NSCLC patients.

Methods

The expression of miR-133a in 125 cases of NSCLC and their paired adjacent non-cancerous tissues was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Meanwhile, the relationship between miR-133a expression and several clinicopathological parameters and patient survival was analyzed.

Results

The relative level of miR-133a was 2.0108 ± 1.3334 in NSCLC tissues, significantly lower than that of the adjacent non-cancerous lung tissues (3.6430 ± 2.2625, P = 0.019). The area under curve (AUC) of low expression of miR-133a to diagnose NSCLC was 0.760 (95% CI: 0.702 ~ 0.819, P < 0.001). MiR-133a expression was negatively correlated to lymphatic metastasis (r = −0.182, P = 0.042), tumor size (r = −0.253, P = 0.04), clinical TNM stages (r = −0.154, P = 0.087), and EGFR protein expression (r = −0.612, P < 0.001).

Conclusions

MiR-133a serves as a tumor-suppressive miRNA in human NSCLC, and its downregulation suggests deterioration in NSCLC patients.