MicroRNA-455 inhibits proliferation and invasion of colorectal cancer by targeting RAF proto-oncogene serine/threonine-protein kinase. Tumour Biol. 2015;36:1313-1321. [PMID: 25355599 DOI: 10.1007/s13277-014-2766-3]

MicroRNA-605-3p Inhibited the Growth and Chemoresistance of Osteosarcoma Cells via Negatively Modulating RAF1

BACKGROUND

Osteosarcoma (OS) is the leading cancer-associated mortality in childhood and adolescence. Increasing evidence has demonstrated the key function of microRNAs (miRNAs) in OS development and chemoresistance. Among them, miRNA-605-3p acted as an important tumor suppressor and was frequently down-regulated in multiple cancers. However, the function of miR-650-3p in OS has not been reported.

OBJECTIVE

The aim of this work is to explore the novel role of miR-605-3p in osteosarcoma and its possible involvement in OS chemotherapy resistance.

METHODS

The expression levels of miR-605-3p in OS tissues and cells were assessed by reverse transcription quantitative PCR (RT-qPCR). The relevance of miR-605-3p with the prognosis of OS patients was determined by the Kaplan-Meier analysis. Additionally, the influence of miR-605-3p on OS cell growth was analyzed using the cell counting kit-8, colony formation assay, and flow cytometry. The mRNA and protein expression of RAF1 were detected by RT-qPCR and western blot. The binding of miR-605-3p with the 3'-UTR of RAF1 was confirmed by dual-luciferase reporter assay.

RESULTS

Our results showed that miR-605-3p was markedly decreased in OS tissues and cells. A lower level of miR-605-3p was strongly correlated with lymph node metastasis and poor 5-year overall survival rate of OS patients. In vitro assay found that miR-605-3p suppressed OS cell proliferation and promoted cell apoptosis. Mechanistically, the proto-oncogene RAF1 was seen as a target of miR-605-3p and strongly suppressed by miR-605-3p in OS cells. Restoration of RAF1 markedly eliminated the inhibitory effect of miR-605-3p on OS progression, suggesting RAF1 as a key mediator of miR-605-3p. Consistent with the decreased level of RAF1, miR-605-3p suppressed the activation of both MEK and ERK in OS cells, which are the targets of RAF1. Moreover, lower levels of miR-605-3p were found in chemoresistant OS patients, and downregulated miR-605-3p increased the resistance of OS cells to therapeutic agents.

CONCLUSION

Our data revealed that miR-605-3p serves as a tumor suppressor gene by regulating RAF1 and increasing the chemosensitivity of OS cells, which provided the novel working mechanism of miR-605-3p in OS. Engineering stable nanovesicles that could efficiently deliver miR-605-3p with therapeutic activity into tumors could be a promising therapeutic approach for the treatment of OS.

Multiple Roles of the RUNX Gene Family in Hepatocellular Carcinoma and Their Potential Clinical Implications

Hepatocellular carcinoma (HCC) is one of the most frequent cancers in humans, characterised by a high resistance to conventional chemotherapy, late diagnosis, and a high mortality rate. It is necessary to elucidate the molecular mechanisms involved in hepatocarcinogenesis to improve diagnosis and treatment outcomes. The Runt-related (RUNX) family of transcription factors (RUNX1, RUNX2, and RUNX3) participates in cardinal biological processes and plays paramount roles in the pathogenesis of numerous human malignancies. Their role is often controversial as they can act as oncogenes or tumour suppressors and depends on cellular context. Evidence shows that deregulated RUNX genes may be involved in hepatocarcinogenesis from the earliest to the latest stages. In this review, we summarise the topical evidence on the roles of RUNX gene family members in HCC. We discuss their possible application as non-invasive molecular markers for early diagnosis, prognosis, and development of novel treatment strategies in HCC patients.

Novel insights on perils and promises of miRNA in understanding colon cancer metastasis and progression

Colorectal cancer (CRC) is the third highest frequent malignancy and ultimate critical source of cancer-associated mortality around the world. Regardless of latest advances in molecular and surgical targeted medicines that have increased remedial effects in CRC patients, the 5-year mortality rate for CRC patients remains dismally low. Evidence suggests that microRNAs (miRNAs) execute an essential part in the development and spread of CRC. The miRNAs are a type of short non-coding RNA that exhibited to control the appearance of tumor suppressor genes and oncogenes. miRNA expression profiling is already being utilized in clinical practice as analytical and prognostic biomarkers to evaluate cancer patients' tumor genesis, advancement, and counteraction to drugs. By modulating their target genes, dysregulated miRNAs are linked to malignant characteristics (e.g., improved proliferative and invasive capabilities, cell cycle aberration, evasion of apoptosis, and promotion of angiogenesis). This review presents an updated summary of circulatory miRNAs, tumor-suppressive and oncogenic miRNAs, and the potential reasons for dysregulated miRNAs in CRC. Further we will explore the critical role of miRNAs in CRC drug resistance.

Identification of LncPVT1 and CircPVT1 as prognostic biomarkers in human colorectal polyps

LncPVT1 and CircPVT1 are isoforms for the PVT1 gene and are associated with cancer progression and carcinogenesis. Our study investigated the expression of LncPVT1 and CircPVT1 in colon adenoma polyps. 40 tissues of colorectal polyps and 40 normal-adjacent tissues (NATs) were taken. The expression of LncPVT1 and CircPVT1 was evaluated through qRael-Time PCR. The relation between expression and features of clinicopathological was explored. The ceRNA network was constructed by LncPVT1 and CircPVT1 and predicted miRNAs and miRNAs targets. Further, hub nodes in this network were determined using the cytoHubba package. Over-expressed LncPVT1 and CircPVT1 were differentiated in polyp and NATs. The expression level of LncPVT1 and CircPVT1 were significantly higher in adenoma polyps than in hyperplastic polyps. The area under the curve of the ROC estimate for the LncPVT1 and CircPVT1 was 0.74 and 0.77, respectively. A positive correlation was observed between the LncPVT1 expression and CircPVT1. Three miRNAs, including hsa-miR-484, hsa-miR-24-3p, hsa-miR-423-5p, and CircPVT1, were detected as ceRNA hub nodes. In this study, expression profiles of LncPVT1 and CircPVT1 were significantly higher in precancerous polyps. In addition, based on our in silico analysis, LncPVT1, CircPVT1/miR-484, miR-24-3p, miR-423-5p/PLAGL2 axis might be involved in colon cancer development. LncPVT1 and CircPVT1 can be prescribed as warning problems as potential prognostic biomarkers in patients with pre-CRC colon polyps.

MicroRNA-455-3p functions as a tumor suppressor by targeting HDAC2 to regulate cell cycle in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers. MicroRNA has been studied more and more deeply and may become a new target for the treatment of HCC. Here, we investigated the role of miR-455-3p in HCC progression. Compared with non-tumor tissues and normal human hepatic cells, miR-455-3p expression was significantly downregulated in HCC tissues and cell lines. And overexpression of miR-455-3p inhibited cell proliferation and migration but promoted cell apoptosis in HCC cell lines HepG2 and Huh7. Mechanism studies displayed that miR-455-3p targeted HDAC2 and negatively regulated HDAC2 expression. Moreover, HDAC2 was highly expressed in HCC tissues and cell lines. Overexpression of HDAC2 reversed the inhibitory effects of miR-455-3p on cell proliferation, migration and cell cycle protein (CDK6 and cyclin D1) expression, and neutralized the promotion effects of miR-455-3p on cell apoptosis and the activation of p53 pathway. Furthermore, a p53 inhibitor Pifithrin-α (PFT-α) effectively abolished the effects of miR-455-3p on HCC cell behaviors. Additionally, the role of miR-455-3p in tumorigenesis was evaluated by using a mouse xenograft model, and the data showed that miR-455-3p suppressed tumor growth in vivo. In summary, our results suggested that miR-455-3p targeted HDAC2 to inhibit cell proliferation, migration and promote cell apoptosis via the activation of p53 pathway.

miR-484: A Potential Biomarker in Health and Disease

Disorders of miR-484 expression are observed in cancer, different diseases or pathological states. There is accumulating evidence that miR-484 plays an essential role in the development as well as the regression of different diseases, and miR-484 has been reported as a key regulator of common cancer and non-cancer diseases. The miR-484 targets that have effects on inflammation, apoptosis and mitochondrial function include SMAD7, Fis1, YAP1 and BCL2L13. For cancer, identified targets include VEGFB, VEGFR2, MAP2, MMP14, HNF1A, TUSC5 and KLF12. The effects of miR-484 on these targets have been documented separately. Moreover, miR-484 is typically described as an oncosuppressor, but this claim is simplistic and one-sided. This review will combine relevant basic and clinical studies to find that miR-484 promotes tumorigenesis and metastasis in liver, prostate and lung tissues. It will provide a basis for the possible mechanisms of miR-484 in early tumor diagnosis, prognosis determination, disease assessment, and as a potential therapeutic target for tumors.

Circular RNA, hsa_circRNA_102049, promotes colorectal cancer cell migration and invasion via binding and suppressing miRNA-455-3p

Colorectal cancer (CRC) is the second most prevalent malignant gastrointestinal tumor type worldwide, displaying poor prognosis. Accumulating studies have reported the significance of circular RNAs (circRNAs) and microRNAs (miRNAs) in CRC carcinogenesis and development. At present, the functions and mechanisms of action underlying the circular RNA, hsa_circRNA_102049, in CRC are not completely understood. The present study aimed to establish the involvement of hsa_circRNA_102049 in CRC, as well as the associated mechanisms. The expression levels of hsa_circRNA_102049 and miRNA-455-3p were measured in CRC cell lines and tissues via reverse transcription-quantitative PCR. CRC progression was evaluated by performing Cell Counting Kit-8, flow cytometry, wound healing and Transwell invasion assays. The results demonstrated that hsa_circRNA_102049 was highly expressed in both CRC tissues and cell lines, which was associated with enhanced CRC cell proliferation, migration and invasion. Furthermore, miR-455-3p expression was downregulated in CRC cells and served as a target of has_circRNA_102049, which was validated by performing the dual luciferase reporter assay. hsa_circRNA_102049 knockdown significantly increased miR-455-3p expression, which was significantly reversed by co-transfection with the miR-455-3p inhibitor. Notably, miRNA-455-3p overexpression alleviated hsa_circRNA_102049-mediated induction of CRC cell proliferation, migration and invasion. The present study clearly demonstrated that miRNA-455-3p was a target of hsa_circRNA_102049. Moreover, the results indicated that the circular RNA, hsa_circRNA_102049, may function as a tumor promoter in CRC via directly sponging miRNA-455-3p.

Expression, Interaction, and Role of Pseudogene Adh6-ps1 in Cancer Phenotypes

Pseudogenes have been classified as functionless and their annotation is an ongoing problem. The Adh6-ps1-a mouse pseudogene belonging to the alcohol dehydrogenase gene complex (Adh) was analyzed to review the conservation, homology, expression, and interactions and identify any role it plays in disease phenotypes using bioinformatics databases. Results showed that Adh6-ps1 have 2 transcripts (processed and unprocessed) which may have emerged from a transposition and duplication event, respectively, and that induced inversions (Uox gene, In(3)11Rk) involving gene complexes associated with Adh6-ps1 have been implicated in a diverse range of diseases. Adh6-ps1 is highly conserved in vertebrates particularly rodents and expressed in the liver. The top 5 MirRNA targets were Mir455, Mir511, Mir1903, Mir361, and Mir669o markers. While much is unknown about Mir1903 and Mir669o, the silencing of Mir455 and Mir511 is linked with hepatocellular carcinoma (HCC), and Mir361 is implicated in endometrial cancers. Given the identified MirRNA interactions with Adh6-ps1 and its expression in HCC and reproductive systems, it may well have a role in tumorigenesis and disease phenotypes. Nonetheless, further studies are required to establish these facts to add to the growing efforts to understand pseudogenes and their potential involvement in disease conditions.

Both microRNA-455-5p and -3p repress hypoxia-inducible factor-2α expression and coordinately regulate cartilage homeostasis

Osteoarthritis (OA), the most common aging-related joint disease, is caused by an imbalance between extracellular matrix synthesis and degradation. Here, we discover that both strands of microRNA-455 (miR-455), -5p and -3p, are up-regulated by Sox9, an essential transcription factor for cartilage differentiation and function. Both miR-455-5p and -3p are highly expressed in human chondrocytes from normal articular cartilage and in mouse primary chondrocytes. We generate miR-455 knockout mice, and find that cartilage degeneration mimicking OA and elevated expression of cartilage degeneration-related genes are observed at 6-months-old. Using a cell-based miRNA target screening system, we identify hypoxia-inducible factor-2α (HIF-2α), a catabolic factor for cartilage homeostasis, as a direct target of both miR-455-5p and -3p. In addition, overexpression of both miR-455-5p and -3p protect cartilage degeneration in a mouse OA model, demonstrating their potential therapeutic value. Furthermore, knockdown of HIF-2α in 6-month-old miR-455 knockout cartilage rescues the elevated expression of cartilage degeneration-related genes. These data demonstrate that both strands of a miRNA target the same gene to regulate articular cartilage homeostasis.

miR-455 Inhibits the Viability and Invasion by Targeting RAB18 in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) has been regarded as the fifth most common cancer worldwide with a low prognosis. miR-455 usually played the role of a tumor suppressor in multiple cancers. The aim of this study was to investigate the roles of miR-455 in HCC.

Materials and Methods

Cell viability and invasion were measured by CCK8 and Transwell assays. Luciferase reporter assay was performed to verify that miR-455 directly binds to the 3′-noncoding region (UTR) of RAB18 mRNA in Huh7 cells.

Results

The expression of miR-455 was lower in HCC tissues and cell lines than in nontumor tissues and normal cell line, and downregulation of miR-455 was connected with worse outcome of HCC patients. miR-455 suppressed cell proliferation in vitro and in vivo, and it inhibited the abilities of cell invasion and EMT in HCC. RAB18 was upregulated in HCC tissues and cell lines, and the expression of RAB18 was regulated by miR-455. RAB18 reversed partial roles of miR-455 on cell viability and invasion in HCC.

Conclusion

miR-455 inhibited cell viability and invasion by directly targeting the 3′-UTR of RAB18 mRNA of hepatocellular carcinoma.

Interplay between MAPK/ERK signaling pathway and MicroRNAs: A crucial mechanism regulating cancer cell metabolism and tumor progression

Mitogen-activated protein kinase (MAPK) signal transduction, as a highly conserved signaling pathway, is reported to be involved in various biological events, including metabolic reprogramming, cell proliferation, survival, and differentiation. Mutations in key molecules involved in MAPK/ERK signaling and dysregulation of this pathway are very common events in various human malignancies, which make the MAPK signaling a crucial signaling pathway participating in the regulation of glucose uptake by malignant cells and tumorigenesis. MicroRNAs (miRNAs), as small non-coding RNAs, are critical regulators of gene expression that play key roles in cancer initiation and progression. On the other hand, these small RNAs mutually regulate the MAPK signaling which is often overexpressed in the case of cancer progression; suggesting that crosstalk between miRNAs and this signaling pathway plays a pivotal role in the development of human cancers. Some miRNAs such as miR-20b, miR-34c-3p, miR-152, miR-181a, and miR-302b through inhibiting MAPK signaling, and miR-193a-3p, miR-330-3p, and miR-592 by activating this signaling pathway, play imperative roles in tumorigenesis. Therefore, in this review, we aimed to focus on the interplay between miRNAs and MAPK signaling in the various steps of tumorigenesis, including metabolic regulation, cell proliferation, apoptosis, metastasis, angiogenesis, and drug resistance.

RUNX2 as a promising therapeutic target for malignant tumors

The transcription factor runt-related protein 2 (RUNX2) has an important impact on the transformation of bone marrow mesenchymal stem cells to osteoblasts. Further studies have shown that RUNX2 plays a key role in the invasion and metastasis of cancers. RUNX2 is a "key" molecule in the regulatory network comprised of multiple signaling pathways upstream and its target downstream molecules. Due to the complex regulatory mechanisms of RUNX2, the specific mechanism underlying the occurrence, development and prognosis of malignant tumors has not been fully understood. Currently, RUNX2 as a promising therapeutic target for cancers has become a research hotspot. Herein, we reviewed the current literature on the modulatory functions and mechanisms of RUNX2 in the development of malignant tumors, aiming to explore its potential clinical application in the diagnosis, prognosis and treatment of tumors.

Reduction of Bladder Cancer Chemosensitivity Induced by the Effect of HOXA-AS3 as a ceRNA for miR-455-5p That Upregulates Notch1

Chemoresistance is one of the main causes of recurrence in bladder cancer patients and leads to poor prognosis. Recently, long non-coding RNAs, like HOXA-AS3, have been reported to regulate chemoresistance in several types of cancer. In this study, we aimed to determine whether HOXA-AS3 can mediate cisplatin resistance in bladder cancer, and its potential mechanism of action. We determined the viability, proliferation, and apoptosis of bladder cancer cells using a CCK-8 assay, EdU staining, and flow cytometry, respectively. We used western blot analysis to assess the expression of markers of epithelial-mesenchymal transition (EMT) and Notch1. We then confirmed expression of these EMT-related markers by immunofluorescence analysis. We found that hypoxia promoted resistance to cisplatin and upregulated the level of HOXA-AS3 in BC cells. Inhibition of HOXA-AS3 enhanced hypoxia-induced cisplatin sensitivity by regulating EMT and Notch1 in BC cells. A dual-luciferase reporter assay confirmed that HOXA-AS3 directly targets miR-455-5p and that Notch1 was a potential target of miRNA-455-5p. We also found that the positive effect of HOXA-AS3 inhibition on cisplatin resistance and tumorigenesis was alleviated when BC cells were transfected with miR-455-5p. Finally, we showed combining HOXA-AS3 small interfering RNA (siRNA) with cisplatin treatment inhibited tumorigenesis in a BALB/c nu/nu mouse model. Our findings indicate that HOXA-AS3 may function as a competing endogenous RNA (ceRNA) of miR-455-5p to regulate Notch1 and play an important role in regulating chemotherapeutic drug sensitivity in BC cells. Therefore, HOXA-AS3 may be a novel therapeutic target for treating bladder cancer.

LncRNA RNF144A-AS1 Promotes Bladder Cancer Progression via RNF144A-AS1/miR-455-5p/SOX11 Axis

Background

Bladder cancer (BC) is the most commonly occurring malignant tumor of the urinary system worldwide. Long non-coding RNAs (lncRNAs), including lncRNA RNF144A-AS1 (RNF144A-AS1), perform an oncogenic role in BC progression. However, how RNF144A-AS1 is regulated in BC has not been fully investigated, and its role in BC is mostly obscure. In this study, we explore its role in BC progression.

Materials and Methods

The expression level of RNF144A-AS1 in BC tissues was explored via bioinformatics analysis and quantitative real-time PCR (qRT-PCR). We used RNF144A-AS1 siRNA (si-RNF144A-AS1) to inhibit the RNF144A-AS1 level in BC cell lines (J82 and 5637 cells). A series of experimental studies in vitro (CCK-8 assay, colony formation assay and Transwell assay) was performed to explore the role of si-RNF144A-AS1 on the proliferation, migration and invasion of J82 and 5637 cells. A BC xenograft model was established, and the effect of si-RNF144A-AS1 on xenograft growth was explored in vivo. The interactions among RNF144A-AS1, miR-455-5p and SOX11 were predicted by bioinformatics miRanda and Targetscan database, and verified by the luciferase reporter assay and RNA pull-down assay. Finally, miR-455-5p inhibitor and si-RNF144A-AS1 were cotransfected into J82 and 5637 cells.

Results

RNF144A-AS1 is overexpressed in BC tumors and cells, and its overexpression is correlated with poor prognosis. Knockdown of RNF144A-AS1 markedly suppressed the proliferation, migration and invasion of J82 and 5637 cells and significantly inhibited xenograft growth in nude mice, compared to si-NC. We found that RNF144A-AS1 serves as a sponge for miR-455-5p. Furthermore, a binding site of miR-455-5p was found in 3ʹ UTR of SOX11 gene, and overexpression of miR-455-5p suppressed SOX11 levels. RNF144A-AS1 knockdown markedly decreased SOX11 expression levels, while miR-455-5p inhibitor restored this repressive effect. Restoration of SOX11 could reverse this repressive effect of RNF144A-AS1 on cell proliferation, migration and invasion abilities.

Conclusion

Overall, our findings underline the critical role of RNF144A-AS1 in BC development, and our study reveals for the first time that RNF144A-AS1 promotes BC progression via the RNF144A-AS1/miR-455-5p/SOX11 axis.

miRNAs expression signature potentially associated with lymphatic dissemination in locally advanced prostate cancer

Background

Prostate cancer is one of the most common and socially significant cancers among men. The aim of our study was to reveal changes in miRNA expression profiles associated with lymphatic dissemination in prostate cancer and to identify the most prominent miRNAs as potential prognostic markers for future studies.

Methods

High-throughput miRNA sequencing was performed for 44 prostate cancer specimens taken from Russian patients, with and without lymphatic dissemination (N1 – 20 samples; N0 – 24 samples).

Results

We found at least 18 microRNAs with differential expression between N0 and N1 sample groups: miR-182-5p, miR-183-5p, miR-96-5p, miR-25-3p, miR-93-5p, miR-7-5p, miR-615-3p, miR-10b, miR-1248 (N1-miRs; elevated expression in N1 cohort; p < 0.05); miR-1271-5p, miR-184, miR-222-3p, miR-221-5p, miR-221-3p, miR-455-3p, miR-143-5p, miR-181c-3p and miR-455-5p (N0-miRs; elevated expression in N0; p < 0.05). The expression levels of N1-miRs were highly correlated between each other (the same is applied for N0-miRs) and the expression levels of N0-miRs and N1-miRs were anti-correlated. The tumor samples can be divided into two groups depending on the expression ratio between N0-miRs and N1-miRs.

Conclusions

We found the miRNA expression signature associated with lymphatic dissemination, in particular on the Russian patient cohort. Many of these miRNAs are well-known players in either oncogenic transformation or tumor suppression. Further experimental studies with extended sampling are required to validate these results.

Functional analysis of miRNAs combined with TGF-β1/Smad3 inhibitor in an intrauterine rat adhesion cell model

In this study, we aimed to study the role of miRNAs in intrauterine adhesion (IUA) disease. An IUA cell model was constructed by TGF-β1. Smad3 inhibitor (SIS3) can inhibit the Smad3 signaling pathway and affect the role of TGF-β1; thus, it was used to identify the role of Smad3 and related miRNAs in IUA. Cell number significantly increased in the TGF-β1 group after 72 h and 96 h, respectively, compared with that in the control group (P < 0.05). However, cell proliferation was significantly decreased in the TGF-β1 + SIS3 group (P < 0.0001). Cell apoptosis was increased in the TGF-β1 + SIS3 group compared with that in the TGF-β1 group. Western Blot (WB) analysis suggested that TGF-β1 treatment could effectively increase the expression of α-SMA, COL1, Smad3, and p-Smad3, which could be inhibited by SIS3 treatment. A total of 235 and 530 differentially expressed miRNAs in the TGF-β1 + SIS3 group were significantly up- and downregulated compared with those in the TGF-β1 group, respectively. These differentially expressed miRNAs were enriched in the MAPK and PI3K-AKT pathways. The ten most differentially expressed miRNAs were selected to verify their expressions using quantitative real-time polymerase chain reaction (qPCR). Furthermore, overexpression of rno-miR-3586-3p and rno-miR-455-5p can promote cell proliferation and exacerbate the IUA pathogenic process. However, overexpression of rno-miR-204-3p and rno-miR-3578 can inhibit cell behavior and IUA progression. The above results can provide detailed information for the understanding of IUA molecular mechanisms.

MicroRNA-455-5p exerts inhibitory effect in cervical carcinoma through targeting S1PR1 and blocking mTOR pathway

BACKGROUND

MicroRNAs (miRNAs) have been increasingly exploited in human malignancies. The regulation of microRNA-455-5p (miR-455-5p) has been shown in several cancers, except for cervical carcinoma. Therefore, the role of miR-455-5p was exploited in cervical carcinoma.

METHODS

The qRT-PCR experiment was used to assess miR-455-5p and S1PR1 expression levels. We explored the function of miR-455-5p through MTT and Transwell assays. The mTOR pathway and cell apoptosis were detected by Western blot assays. The relationship between miR-455-5p and S1PR1 was testified by dual-luciferase reporter assay.

RESULTS

MiR-455-5p expression was decreased in cervical carcinoma, which was related to poor clinical outcome in cervical carcinoma patients. MiR-455-5p inhibited cell viability and metastasis in cervical carcinoma. Further, S1PR1 is a direct target of miR-455-5p. S1PR1 recovered the inhibition of cell viability and metastasis induced by miR-455-5p in cervical carcinoma. In addition, miR-455-5p induced cell apoptosis and inactivated the mTOR pathway in cervical carcinoma.

CONCLUSION

MiR-455-5p exerts inhibitory effect in cervical carcinoma through targeting S1PR1 and blocking the mTOR pathway.

Focused screening reveals functional effects of microRNAs differentially expressed in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is still a leading cause of death worldwide. Recent studies have pointed to an important role of microRNAs in carcinogenesis. Several microRNAs are described as aberrantly expressed in CRC tissues and in the serum of patients. However, functional outcomes of microRNA aberrant expression still need to be explored at the cellular level. Here, we aimed to investigate the effects of microRNAs aberrantly expressed in CRC samples in the proliferation and cell death of a CRC cell line.

METHODS

We transfected 31 microRNA mimics into HCT116 cells. Total number of live propidium iodide negative (PI-) and dead (PI+) cells were measured 4 days post-transfection by using a high content screening (HCS) approach. HCS was further used to evaluate apoptosis (via Annexin V and PI staining), and to discern between intrinsic and extrinsic apoptotic pathways, by detecting cleaved Caspase 9 and 8, respectively. To reveal mRNA targets and potentially involved mechanisms, we performed microarray gene expression and functional pathway enrichment analysis. Quantitative PCR and western blot were used to validate potential mRNA targets.

RESULTS

Twenty microRNAs altered the proliferation of HCT116 cells in comparison to control. miR-22-3p, miR-24-3p, and miR-101-3p significantly repressed cell proliferation and induced cell death. Interestingly, all anti-proliferative microRNAs in our study had been previously described as poorly expressed in the CRC samples. Predicted miR-101-3p targets that were also downregulated by in our microarray were enriched for genes associated with Wnt and cancer pathways, including MCL-1, a member of the BCL-2 family, involved in apoptosis. Interestingly, miR-101-3p preferentially downregulated the long anti-apoptotic MCL-1 L isoform, and reduced cell survival specifically by activating the intrinsic apoptosis pathway. Moreover, miR-101-3p also downregulated IL6ST, STAT3A/B, and MYC mRNA levels, genes associated with stemness properties of CRC cells.

CONCLUSIONS

microRNAs upregulated in CRC tend to induce proliferation in vitro, whereas microRNAs poorly expressed in CRC halt proliferation and induce cell death. We provide novel evidence linking preferential inhibition of the anti-apoptotic MCL-1 L isoform by miR-101-3p and consequent activation of the intrinsic apoptotic pathway as potential mechanisms for its antitumoral activity, likely due to the inhibition of the IL-6/JAK/STAT signaling pathway.

The potential role of regulatory microRNAs of RAS/MAPK signaling pathway in the pathogenesis of colorectal cancer

Colorectal cancer (CRC) is the leading cause of cancer death worldwide. Dysregulation of RAS/MAPK signaling axis is frequently found in CRC patients. The RAS/MAPK axis regulates cancer cell proliferation, apoptosis, inflammation, migration, and metastasis. Oncogenic or tumor-suppressor microRNAs (miRNAs) for RAS/MAPK signaling play a key role in the pathogenesis of CRC and are considered as novel potential biomarkers for diagnosis and prognosis of human malignancies. This review summarizes the current knowledge of mechanisms of action of RAS/MAPK miRNAs in the development and progression of CRC for a better understanding and hence a better management of this disease.

Measurement of Conditional Relatedness Between Genes Using Fully Convolutional Neural Network

Measuring conditional relatedness, the degree of relation between a pair of genes in a certain condition, is a basic but difficult task in bioinformatics, as traditional co-expression analysis methods rely on co-expression similarities, well known with high false positive rate. Complement with prior-knowledge similarities is a feasible way to tackle the problem. However, classical combination machine learning algorithms fail in detection and application of the complex mapping relations between similarities and conditional relatedness, so a powerful predictive model will have enormous benefit for measuring this kind of complex mapping relations. To this need, we propose a novel deep learning model of convolutional neural network with a fully connected first layer, named fully convolutional neural network (FCNN), to measure conditional relatedness between genes using both co-expression and prior-knowledge similarities. The results on validation and test datasets show FCNN model yields an average 3.0% and 2.7% higher accuracy values for identifying gene–gene interactions collected from the COXPRESdb, KEGG, and TRRUST databases, and a benchmark dataset of Xiao-Yong et al. research, by grid-search 10-fold cross validation, respectively. In order to estimate the FCNN model, we conduct a further verification on the GeneFriends and DIP datasets, and the FCNN model obtains an average of 1.8% and 7.6% higher accuracy, respectively. Then the FCNN model is applied to construct cancer gene networks, and also calls more practical results than other compared models and methods. A website of the FCNN model and relevant datasets can be accessed from https://bmbl.bmi.osumc.edu/FCNN.

MicroRNA gga-miR-455-5p suppresses Newcastle disease virus replication via targeting cellular suppressors of cytokine signaling 3

Newcastle disease (ND) is an acute and contagious avian disease caused by Newcastle disease virus (NDV). MicroRNAs (miRNAs) play a significant role in host-pathogen interactions and the innate immune response. However, the role of miRNAs in the host response to NDV infection is not clearly understood. In this study, we showed that expression of the cellular miRNA gga-miR-455-5p was downregulated in vivo and in vitro in response to NDV infection. Next, we found that the transfection of chicken embryonic fibroblasts (CEFs) with gga-miR-455-5p suppressed NDV replication, while the blockade of endogenous gga-miR-455-5p expression with inhibitors enhanced NDV replication. In addition, gga-miR-455-5p enhanced the expression of type I interferon and the interferon-inducible genes (ISGs) OASL and Mx1 by targeting SOCS3, a negative regulator of type I IFN signaling. Altogether, these findings highlight the crucial role of gga-miR-455-5p in host defense against NDV by targeting the SOCS3 gene to inhibit NDV replication.

Comprehensive analysis of an lncRNA-miRNA-mRNA competing endogenous RNA network in pulpitis

Background

Pulpitis is a common inflammatory disease that affects dental pulp. It is important to understand the molecular signals of inflammation and repair associated with this process. Increasing evidence has revealed that long noncoding RNAs (lncRNAs), via competitively sponging microRNAs (miRNAs), can act as competing endogenous RNAs (ceRNAs) to regulate inflammation and reparative responses. The aim of this study was to elucidate the potential roles of lncRNA, miRNA and messenger RNA (mRNA) ceRNA networks in pulpitis tissues compared to normal control tissues.

Methods

The oligo and limma packages were used to identify differentially expressed lncRNAs and mRNAs (DElncRNAs and DEmRNAs, respectively) based on expression profiles in two datasets, GSE92681 and GSE77459, from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were further analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Protein–protein interaction (PPI) networks and modules were established to screen hub genes using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and the Molecular Complex Detection (MCODE) plugin for Cytoscape, respectively. Furthermore, an lncRNA-miRNA-mRNA-hub genes regulatory network was constructed to investigate mechanisms related to the progression and prognosis of pulpitis. Then, quantitative real-time polymerase chain reaction (qRT-PCR) was applied to verify critical lncRNAs that may significantly affect the pathogenesis in inflamed and normal human dental pulp.

Results

A total of 644 upregulated and 264 downregulated differentially expressed genes (DEGs) in pulpitis samples were identified from the GSE77459 dataset, while 8 up- and 19 downregulated probes associated with lncRNA were identified from the GSE92681 dataset. Protein–protein interaction (PPI) based on STRING analysis revealed a network of DEGs containing 4,929 edges and 623 nodes. Upon combined analysis of the constructed PPI network and the MCODE results, 10 hub genes, including IL6, IL8, PTPRC, IL1B, TLR2, ITGAM, CCL2, PIK3CG, ICAM1, and PIK3CD, were detected in the network. Next, a ceRNA regulatory relationship consisting of one lncRNA (PVT1), one miRNA (hsa-miR-455-5p) and two mRNAs (SOCS3 and PLXNC1) was established. Then, we constructed the network in which the regulatory relationship between ceRNA and hub genes was summarized. Finally, our qRT-PCR results confirmed significantly higher levels of PVT1 transcript in inflamed pulp than in normal pulp tissues (p = 0.03).

Conclusion

Our study identified a novel lncRNA-mediated ceRNA regulatory mechanisms in the pathogenesis of pulpitis.

MiR-455-5p Suppresses the Progression of Prostate Cancer by Targeting CCR5

Accumulated evidence indicates that miR-455-5p functions as tumor suppressor in the progression of various cancers. However, the mechanism through which miR-455-5p influences the tumorigenesis of human prostate cancer (PCa) remains undetermined. In this study, reanalysis of data obtained from the Memorial Sloan Kettering Cancer Center showed that miR-455-5p can be used as biomarker for PCa diagnosis and predictor of poor prognosis. Functional assays indicated that miR-455-5p overexpression could suppress cellular proliferation, inhibit tumor growth, and trigger apoptosis by activating and cleaving caspase 3. We experimentally verified that miR-455-5p negatively regulated the C–C motif chemokine receptor 5 (CCR5). Overall, our data demonstrate that miR-455-5p suppressed PCa cellular proliferation and induced cell apoptosis by downregulating CCR5. Thus, miR-455-5p may be considered a new therapeutic strategy for PCa.

MicroRNA-7 Exerts Antiangiogenic Effect on Colorectal Cancer via ERK Signaling

BACKGROUND

Recent studies have suggested that microRNA-7 (miR-7) family members may play important roles in human cancer by regulating cell proliferation, apoptosis, migration, and invasion. Therefore, the present study aimed to investigate the clinical significance and biological function of miR-7 in colorectal cancer (CRC).

METHODS

Initially, cancer and adjacent tissues were collected from 76 patients with CRC. Then, microvascular density was detected using the Weidner counting method. The functional role of miR-7 in CRC was determined using ectopic expression, knockdown, and reporter assay experiments. The vasculogenic mimicry density was determined. Expression of miR-7, epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK1/2), vascular endothelial growth factor, and thrombospondin-1 was determined. 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assays, scratch tests, and Transwell assays were conducted to examine cell proliferation, migration, and invasion, respectively. Finally, flow cytometry was applied to evaluate cell apoptosis.

RESULTS

CRC tissues showed increased microvascular density and EGFR expression, activated ERK signaling, and miR-7 downregulation. EGFR was a target gene of miR-7. miR-7 overexpression and EGFR silencing decreased vasculogenic mimicry density, cell migration, and cell invasion, but increased cell apoptosis. In addition, miR-7 overexpression and EGFR silencing upregulated thrombospondin-1 and downregulated EGFR, ERK1/2, and vascular endothelial growth factor. Furthermore, we observed that the effect of miR-7 inhibition was abolished after EGFR silencing.

CONCLUSIONS

Overexpressed miR-7 suppresses angiogenesis of CRC cells through ERK signaling by downregulating EGFR. It may identify new targets for CRC treatment.

Epigenetic Regulation by lncRNAs: An Overview Focused on UCA1 in Colorectal Cancer

Colorectal cancers have become the second leading cause of cancer-related deaths. In particular, acquired chemoresistance and metastatic lesions occurring in colorectal cancer are a major challenge for chemotherapy treatment. Accumulating evidence shows that long non-coding (lncRNAs) are involved in the initiation, progression, and metastasis of cancer. We here discuss the epigenetic mechanisms through which lncRNAs regulate gene expression in cancer cells. In the second part of this review, we focus on the role of lncRNA Urothelial Cancer Associated 1 (UCA1) to integrate research in different types of cancer in order to decipher its putative function and mechanism of regulation in colorectal cancer cells. UCA1 is highly expressed in cancer cells and mediates transcriptional regulation on an epigenetic level through the interaction with chromatin modifiers, by direct regulation via chromatin looping and/or by sponging the action of a diversity of miRNAs. Furthermore, we discuss the role of UCA1 in the regulation of cell cycle progression and its relation to chemoresistance in colorectal cancer cells.

The Dual Role of MicroRNAs in Colorectal Cancer Progression

Colorectal cancer (CRC) is responsible for one of the major cancer incidence and mortality worldwide. It is well known that MicroRNAs (miRNAs) play vital roles in maintaining the cell development and other physiological processes, as well as, the aberrant expression of numerous miRNAs involved in CRC progression. MiRNAs are a class of small, endogenous, non-coding, single-stranded RNAs that bind to the 3’-untranslated region (3′-UTR) complementary sequences of their target mRNA, resulting in mRNA degradation or inhibition of its translation as a post-transcriptional regulators. Moreover, miRNAs also can target the long non-coding RNA (lncRNA) to regulate the expression of its target genes involved in proliferation and metastasis of CRC. The functions of these dysregulated miRNAs appear to be context specific, with evidence of having a dual role in both oncogenes and tumor suppression depending on the cellular environment in which they are expressed. Therefore, the unique expression profiles of miRNAs relate to the diagnosis, prognosis, and therapeutic outcome in CRC. In this review, we focused on several oncogenic and tumor-suppressive miRNAs specific to CRC, and assess their functions to uncover the molecular mechanisms of tumor initiation and progression in CRC. These data promised that miRNAs can be used as early detection biomarkers and potential therapeutic target in CRC patients.

miR-455 Functions as a Tumor Suppressor Through Targeting GATA6 in Colorectal Cancer

Emerging evidence indicates that microRNAs (miRNAs) are often aberrantly expressed in human cancers. Meanwhile, the importance of miRNAs in regulating multiple cellular biological processes has been appreciated. The aim of this study was to investigate the significance of miR-455 and identify its possible mechanism in regulating colorectal cancer (CRC) progression. We found that the expression of miR-455 was sharply reduced in CRC tissues and cell lines. Importantly, the low expression of miR-455 was associated with poor overall survival of CRC patients. Overexpression of miR-455 in CRC cell lines significantly inhibited cell proliferation and migration in vitro. Moreover, GATA-binding protein 6 (GATA6), whose expression can be inversely regulated by miR-455 in CRC cell lines, was validated as a direct target of miR-455. Overall, our results revealed that miR-455 functions as a tumor suppressor, and its downregulation may contribute to CRC progression. Our study may provide a novel therapeutic target for CRC in the future.

A Network Pharmacology Approach to Uncover the Multiple Mechanisms of Hedyotis diffusa Willd. on Colorectal Cancer

Background

As one of the most frequently diagnosed cancer diseases globally, colorectal cancer (CRC) remains an important cause of cancer-related death. Although the traditional Chinese herb Hedyotis diffusa Willd. (HDW) has been proven to be effective for treating CRC in clinical practice, its definite mechanisms have not been completely deciphered.

Objective

The aim of our research is to systematically explore the multiple mechanisms of HDW on CRC.

Methods

This study adopted the network pharmacology approach, which was mainly composed of active component gathering, target prediction, CRC gene collection, network analysis, and gene enrichment analysis.

Results

The network analysis showed that 10 targets might be the therapeutic targets of HDW on CRC, namely, HRAS, PIK3CA, KRAS, TP53, APC, BRAF, GSK3B, CDK2, AKT1, and RAF1. The gene enrichment analysis implied that HDW probably benefits patients with CRC by modulating pathways related to cancers, infectious diseases, endocrine system, immune system, nervous system, signal transduction, cellular community, and cell motility.

Conclusions

This study partially verified and predicted the pharmacological and molecular mechanism of HDW against CRC from a holistic perspective, which will also lay a foundation for the further experimental research and clinical rational application of HDW.

miR-182 and miR-135b Mediate the Tumorigenesis and Invasiveness of Colorectal Cancer Cells via Targeting ST6GALNAC2 and PI3K/AKT Pathway

BACKGROUND

Metastasis is a leading cause of cancer-related death including colorectal cancer (CRC). MicroRNAs are known to regulate cancer pathways and to be expressed aberrantly in cancer. Aberrant sialylation is closely associated with malignant phenotype of tumor cells, including invasiveness and metastasis.

AIM

This study aimed to investigate the association of miR-182 and miR-135b with proliferation and invasion by targeting sialyltransferase ST6GALNAC2 in CRC cells and explore the potential molecular mechanism.

METHODS

We measured the levels of miR-182, miR-135b, and ST6GALNAC2 in a series of CRC cell lines and tissues using real-time PCR. Bioinformatics analysis and luciferase reporter assay were performed to test the direct binding of miR-182 and miR-135b to the target gene ST6GALNAC2. We also analyzed the possible role of miR-182/-135b on colony formation, wound healing, invasion, and tube formation.

RESULTS

The expression of miR-182 and miR-135b was higher in tumor tissues compared to adjacent noncancerous tissues of CRC patients, as well as up-regulated in SW620 cells than in SW480 cells with different metastatic potential. By applying bioinformatics analysis and luciferase reporter assay, we identified ST6GALNAC2 as the direct target of miR-182/-135b. Furthermore, miR-182/-135b inhibited significantly ST6GALNAC2 expression, and consistently, ST6GALNAC2 mediated migration, adhesion, invasion, proliferation, and tumor angiogenesis in CRC cell lines. Additionally, PI3K/AKT signaling pathway was regulated by miR-182/135b, which was partially blocked by altered level of ST6GALNAC2 in CRC.

CONCLUSIONS

The miR-182/-135b/ST6GALNAC2/PI3K/AKT axis may serve as a predictive biomarker and a potential therapeutic target in CRC treatment.

Potential roles of microRNAs and ROS in colorectal cancer: diagnostic biomarkers and therapeutic targets

As one of the most commonly diagnosed cancers worldwide, colorectal adenocarcinoma often occurs sporadically in individuals aged 50 or above and there is an increase among younger patients under 50. Routine screenings are recommended for this age group to improve early detection. The multifactorial etiology of colorectal cancer consists of both genetic and epigenetic factors. Recently, studies have shown that the development and progression of colorectal cancer can be attributed to aberrant expression of microRNA. Reactive oxygen species (ROS) that play a key role in cancer cell survival, can also lead to carcinogenesis and cancer exacerbations. Given the rapid accumulating knowledge in the field, an updated review regarding microRNA and ROS in colorectal cancer is necessary. An extensive literature search has been conducted in PubMed/Medline databases to review the roles of microRNAs and ROS in colorectal cancer. Unique microRNA expression in tumor tissue, peripheral blood, and fecal samples from patients with colorectal cancer is outlined. Therapeutic approaches focusing on microRNA and ROS in colorectal cancer treatment is also delineated. This review aims to summarize the newest knowledge on the pathogenesis of colorectal cancer in the hopes of discovering novel diagnostic biomarkers and therapeutic techniques.

MicroRNA-455 suppresses the oncogenic function of HDAC2 in human colorectal cancer

Colorectal cancer (CRC) is the fourth leading cause of cancer-induced mortality. Histone deacetylase 2 (HDAC2) is involved in prognosis and therapy of CRC. This study aimed to explore novel therapeutic targets for CRC. The alteration of HDAC2 expression in CRC tissues was estimated by qRT-PCR. After lentivirus transfection, HDAC2 knockdown was confirmed by western blot analysis. The effect of HDAC2 knockdown on cell proliferation was then assessed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Screened by TargetScan, microRNA (miR)-455 was predicted to bind to 3′UTR of HDAC2 and the prediction was verified by luciferase assay. Finally, cells were transfected, respectively, with miR-455 mimics or miR-455 negative control (miR-NC) and the expression of HDAC2, cell proliferation and apoptosis of transfected cells were respectively evaluated by western blot analysis, MTT assay and flow cytometry. Results showed that the HDAC2 expression was up-regulated in CRC tissues (P<0.05). HDAC2 knockdown significantly decreased cell viability at day 3 (P<0.05), day 4 (P<0.01), and day 5 (P<0.001) after infection. Then, miR-455 was verified to directly target HDAC2, resulting in a significant difference in luciferase activity (P<0.01). Moreover, miR-455 decreased the expression of HDAC2 (P<0.01). miR-455 remarkably decreased cell viability at day 3 (P<0.05), day 4 (P<0.01), and day 5 (P<0.001) after transfection while inducing cell apoptosis (P<0.001). In conclusion, miR-455 inhibited cell proliferation while inducing cell apoptosis by targeting HDAC2 in CRC cells.

Colorectal Cancer: From the Genetic Model to Posttranscriptional Regulation by Noncoding RNAs

Colorectal cancer is the third most common form of cancer in developed countries and, despite the improvements achieved in its treatment options, remains as one of the main causes of cancer-related death. In this review, we first focus on colorectal carcinogenesis and on the genetic and epigenetic alterations involved. In addition, noncoding RNAs have been shown to be important regulators of gene expression. We present a general overview of what is known about these molecules and their role and dysregulation in cancer, with a special focus on the biogenesis, characteristics, and function of microRNAs. These molecules are important regulators of carcinogenesis, progression, invasion, angiogenesis, and metastases in cancer, including colorectal cancer. For this reason, miRNAs can be used as potential biomarkers for diagnosis, prognosis, and efficacy of chemotherapeutic treatments, or even as therapeutic agents, or as targets by themselves. Thus, this review highlights the importance of miRNAs in the development, progression, diagnosis, and therapy of colorectal cancer and summarizes current therapeutic approaches for the treatment of colorectal cancer.

Expression levels of microRNA‑455 and its potential functions by targeting IGF‑1R in melanoma

Melanoma has the highest fatality and malignancy of all skin cancers. In cancer, microRNAs (miRNAs) act as tumor suppressors or oncogenes, and inactivation of oncogenic miRNAs or restoration of tumor suppressor miRNAs has potential for cancer treatment. In the present study, miR‑455 expression levels were examined in melanoma tissues and cell lines, and miR‑455 was significantly downregulated in melanoma compared with matched normal tissues or normal epidermal melanocytes. In addition, increasing miR‑455 expression in melanoma cells reduced cell proliferation and invasion. Bioinformatic analysis revealed that insulin‑like growth factor 1 receptor (IGF‑1R) was a putative target of miR‑455. Luciferase reporter assays, reverse transcription‑quantitative polymerase chain reaction and western blot confirmed that miR‑455 targeted the 3'‑untranslated region of IGF‑1R and thus regulated the biological processes of melanoma cells. IGF‑1R knockdown resulted in similar effects as miR‑455 overexpression in melanoma cells. In summary, these findings indicated that miR‑455 was downregulated in melanoma, and inhibited proliferation and invasion of melanoma cells through directly targeting IGF‑1R. This also suggested that the restoration of miR‑455 may be worth investigation as a therapeutic treatment for patients with melanoma.

Proof-of-concept study: profile of circulating microRNAs in Bovine serum harvested during acute and persistent FMDV infection

Background

Changes in the levels of circulating microRNAs (miRNAs) in the serum of humans and animals have been detected as a result of infection with a variety of viruses. However, to date, such a miRNA profiling study has not been conducted for foot-and-mouth disease virus (FMDV) infection.

Methods

The relative abundance of 169 miRNAs was measured in bovine serum collected at three different phases of FMDV infection in a proof-of-concept study using miRNA PCR array plates.

Results

Alterations in specific miRNA levels were detected in serum during acute, persistent, and convalescent phases of FMDV infection. Subclinical FMDV persistence produced a circulating miRNA profile distinct from cattle that had cleared infection. bta-miR-17-5p was highest expressed during acute infection, whereas bta-miR-31 was the highest during FMDV persistence. Interestingly, miR-1281was significantly down-regulated during both acute and persistent infection. Cattle that cleared infection resembled the baseline profile, adding support to applying serum miRNA profiling for identification of sub-clinically infected FMDV carriers. Significantly regulated miRNAs during acute or persistent infection were associated with cellular proliferation, apoptosis, modulation of the immune response, and lipid metabolism.

Conclusions

These findings suggest a role for non-coding regulatory RNAs in FMDV infection of cattle. Future studies will delineate the individual contributions of the reported miRNAs to FMDV replication, determine if this miRNA signature is applicable across all FMDV serotypes, and may facilitate development of novel diagnostic applications.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-017-0743-3) contains supplementary material, which is available to authorized users.

miR-455 inhibits breast cancer cell proliferation through targeting CDK14

Breast cancer is the most frequently occurring cancer in women worldwide, microRNAs (miRNAs) play critical role in the initiation and progression of breast cancer. Here, we studied the effect of miR-455 on cell proliferation of breast cancer, and found that miR-455 was downregulated in breast cancer tissues and cells. Its overexpression inhibited cell proliferation, whereas its knockdown promoted cell proliferation of breast cancer. We found a Cdc2-related protein kinase CDK14 was the target of miR-455, when the 3^'UTR of CDK14 was cloned into luciferase reporter vector and transfected into cells, miR-455 mimic could inhibit the luciferase activity in a dose-dependent manner, miR-455 inhibitor increased the luciferase activity, but the mutant miR-455 mimic couldn't change the luciferase activity, suggesting miR-455 directly bound to the 3^'UTR of CDK14. Meanwhile, we also found miR-455 inhibited Cyclin D1 expression and promoted p21 expression, confirming miR-455 inhibited cell proliferation. Double knockdown of miR-455 and CDK14 inhibited the proliferation of breast cancer cell, confirming miR-455 inhibiting cell proliferation by targeting CDK14. Moreover, miR-455 levels were negatively correlated with CDK14 levels in breast cancer tissues. Our finding revealed miR-455 inhibits breast cancer cell proliferation through targeting CDK14, it might be a target for breast cancer therapy.

miRNA-320a inhibits tumor proliferation and invasion by targeting c-Myc in human hepatocellular carcinoma

BACKGROUND

Downregulated expression levels of microRNA-320a (miR-320a) were found in primary breast cancers and colorectal cancer. Previous findings indicated that miRNA-320a may involve in the cancer development. In this study, we explored the roles of miR-320a by targeting c-Myc in the tumor growth of hepatocellular carcinoma (HCC).

METHODS

Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed to detect the expression of miR-320a in 50 HCC tissues and four HCC cells. Luciferase reporter assay was conducted to confirm the direct downstream target of miR-320a in HEK-293 cells. The effect of miR-320a on endogenous c-Myc expression was investigated by transfecting miR-320a mimics into HepG2 and QGY-7703 cell lines. The c-Myc and miR-320a expressions were analyzed by immunohistochemistry (IHC) and qRT-PCR in the same HCC tissues. Furthermore, the biological functional correlation of miR-320a with c-Myc was determined by studying the effect of miR-320a mimics or c-Myc small interfering RNA (siRNA) on HCC cell proliferation and invasion.

RESULTS

The expression of miR-320a was downregulated in 50 HCC tissues and 4 HCC cells. Luciferase assay revealed that c-Myc is a direct target of miR-320a. IHC and Western blot analysis showed that the c-Myc expression was inhibited by miR-320a in HCC tissues and cell lines. Upregulation of miR-320a suppressed the HCC cell proliferation and invasion capacity induced by inhibiting c-Myc, and the results were consistent with the effects of c-Myc siRNA on tumor suppression. These results revealed that miRNA-320a inhibits tumor proliferation and invasion by targeting c-Myc in HCC cells.

CONCLUSION

Our results showed that miR-320a functions as a tumor suppressor in HCC. By targeting c-Myc directly, miR-320a inhibits the HCC cell growth. Our studies provide evidence of miR-320a as a potentially target for HCC treatment.

MiR-200 suppresses metastases of colorectal cancer through ZEB1

Poor prognosis of some colorectal cancer (CRC) cases largely results from early metastases of CRC to the distal organs. Thus, suppression of the invasion of CRC appears to be crucial therapy. Since microRNAs (miRNAs) play critical roles in the regulation of cancer metastases, identification of the involved miRNAs may provide novel therapeutic targets for CRC treatment. Here, we showed that the levels of miR-200 were significantly decreased and the levels of ZEB1 were significantly increased in the CRC specimens from patients, compared to the paired non-tumor tissue. Moreover, the levels of miR-200 and ZEB1 are inversely correlated. Bioinformatics analyses showed that miR-200 targeted the 3'-UTR of ZEB1 mRNA to inhibit its translation, which was confirmed by luciferase reporter assay. Moreover, miR-200 overexpression inhibited ZEB1-mediated cell invasiveness, while miR-200 depletion increased ZEB1-mediated cell invasiveness in CRC cells. Together, our data suggest that miR-200 suppression in CRC cells may promote ZEB1-mediated cancer metastasis. Our work thus highlights a novel molecular regulatory machinery that regulates metastases of CRC.

Radiation and SN38 treatments modulate the expression of microRNAs, cytokines and chemokines in colon cancer cells in a p53-directed manner

Aberrant expression of miRNAs, cytokines and chemokines are involved in pathogenesis of colon cancer. However, the expression of p53 mediated miRNAs, cyto- and chemokines after radiation and SN38 treatment in colon cancer remains elusive. Here, human colon cancer cells, HCT116 with wild-type, heterozygous and a functionally null p53, were treated by radiation and SN38. The expression of 384 miRNAs was determined by using the TaqMan® miRNA array, and the expression of cyto- and chemokines was analyzed by Meso-Scale-Discovery instrument. Up- or down-regulations of miRNAs after radiation and SN38 treatments were largely dependent on p53 status of the cells. Cytokines, IL-6, TNF-α, IL-1β, Il-4, IL-10, VEGF, and chemokines, IL-8, MIP-1α were increased, and IFN-γ expression was decreased after radiation, whereas, IL-6, IFN-γ, TNF-α, IL-1β, Il-4, IL-10, IL-8 were decreased, and VEGF and MIP-1α were increased after SN38 treatment. Bioinformatic analysis pointed out that the highly up-regulated miRNAs, let-7f-5p, miR-455-3p, miR-98, miR-155-5p and the down-regulated miRNAs, miR-1, miR-127-5p, miR-142-5p, miR-202-5p were associated with colon cancer pathways and correlated with cyto- or chemokine expression. These miRNAs have the potential for use in colon cancer therapy as they are related to p53, pro- or anti-inflammatory cyto- or chemokines after the radiation and SN38 treatment.

SR-BI: Linking Cholesterol and Lipoprotein Metabolism with Breast and Prostate Cancer

Studies have demonstrated the significant role of cholesterol and lipoprotein metabolism in the progression of cancer. The SCARB1 gene encodes the scavenger receptor class B type I (SR-BI), which is an 82-kDa glycoprotein with two transmembrane domains separated by a large extracellular loop. SR-BI plays an important role in the regulation of cholesterol exchange between cells and high-density lipoproteins. Accordingly, hepatic SR-BI has been shown to play an essential role in the regulation of the reverse cholesterol transport pathway, which promotes the removal and excretion of excess body cholesterol. In the context of atherosclerosis, SR-BI has been implicated in the regulation of intracellular signaling, lipid accumulation, foam cell formation, and cellular apoptosis. Furthermore, since lipid metabolism is a relevant target for cancer treatment, recent studies have focused on examining the role of SR-BI in this pathology. While signaling pathways have initially been explored in non-tumoral cells, studies with cancer cells have now demonstrated SR-BI's function in tumor progression. In this review, we will discuss the role of SR-BI during tumor development and malignant progression. In addition, we will provide insights into the transcriptional and post-transcriptional regulation of the SCARB1 gene. Overall, studying the role of SR-BI in tumor development and progression should allow us to gain useful information for the development of new therapeutic strategies.

MicroRNA-455 regulates migration and invasion of human hepatocellular carcinoma by targeting Runx2

MicroRNA-455 (miR-455) has been considered as a novel cancer-related miRNA and dysregulated expression frequently occurs in various human types of cancer. However, its clinical significance, its biological function and the underlying molecular signaling involved in hepatocellular carcinoma (HCC) remain to be elucidated. In the present study, we found that the expression level of miR-455 was significantly downregulated in both HCC tissues and cell lines. Low expression of miR-455 was significantly associated with poor prognostic features including multiple tumor nodes, high Edmondson‑Steiner grading, advanced tumor-node‑metastasis (TNM) stage and venous infiltration. In addition, our data revealed that miR-455 was a novel prognostic indicator for predicting the 5-year overall and disease-free survival of HCC patients. The gain- and loss-of-function studies revealed that miR-455 significantly suppressed migration and invasion of HCC cells in vitro. miR-455 was inversely correlated with runt-related transcription factor 2 (Runx2) expression in HCC samples. Moreover, we identified that miR-455 inversely regulated Runx2 expression in HCC cells. In this investigation, Runx2 was found to be a direct downstream target of miR-455. Evidently, alteration in Runx2 expression suppressed the effect of miR-455 on HCC cell migration and invasion. In conclusion, our data demonstrated that miR-455 promotes HCC growth by targeting Runx2 and can potentially be regarded as a novel prognostic indicator and valuable therapeutic strategy for HCC.

Diagnosis of HCC for patients with cirrhosis using miRNA profiles of the tumor-surrounding tissue - A statistical model based on stepwise penalized logistic regression

The presence of hepatocellular carcinoma (HCC) is a significant complication of cirrhosis because it changes the prognosis and the treatment of the patients. By now, contrast-enhanced CT and MR scans are the most reliable tools for the diagnosis of HCC; however, in some cases, a biopsy of the tumor is necessary for the final diagnosis. The aim of the study was to develop a diagnostic tool using the microRNA (miRNA) profiles of the tissue surrounding the HCC tumor combined with clinical parameters in statistical models. At a transplantation setting, 32 patients with HCC and cirrhosis (B) were compared to 22 patients suffering from cirrhosis only (A). The diagnosis and exclusion of HCC was confirmed following the histopathological examination of the explanted liver. The HCC patients were significantly older than the patients with cirrhosis only (B: 60.6 and A: 49.9, p<0.001) and showed higher levels of ALT (A: 0.76μkat/l, B: 1.02μkat/, p=0.006) and AFP (A: 5.8ng/ml, B: 70.3ng/ml, p<0.001), whereas the bilirubin levels were higher in the cirrhosis only group (p=0.002). Using age (cut-off 50.23years) and AFP (cut-off 4.2ng/ml) thresholds, the levels of expression of miR-1285-3p and miR-943 differentiated between the patients with HCC and cirrhosis from those with cirrhosis only with an accuracy of 96.3%. This is the first report about the use of stepwise penalized logistic regression and decision tree analyses of miRNA expressions in the tumor-surrounding tissue combined with clinical parameters for the diagnosis of HCC.

MiR-625-3p promotes cell migration and invasion via inhibition of SCAI in colorectal carcinoma cells

MicroRNAs (miRNAs) play a critical role in controlling tumor invasion and metastasis via regulating the expression of a variety of targets, which act as oncogenes or tumor suppressor genes. Abnormally expressed miR-625-3p has been observed in several types of human cancers. However, the molecular mechanisms of miR-625-3p-mediated tumorigenesis are largely elusive. Therefore, the aim of this study was to evaluate the biological function and molecular insight on miR-625-3p-induced oncogenesis in colorectal carcinoma (CRC). The effects of miR-625-3p in cell migration and invasion were analyzed by wound healing assay and transwell assay, respectively. In addition, the expression of miR-625-3p and its targets was detected in five human CRC cell lines. In the present study, we found that overexpression of miR-625-3p promoted migration and invasion in SW480 cells, whereas downregulation of miR-625-3p inhibited cell motility in SW620 cells. More importantly, we observed potential binding sites for miR-625-3p in the 3′-untranslated region of suppressor of cancer cell invasion (SCAI). Notably, we identified that overexpression of miR-625-3p inhibited the expression of SCAI, while depletion of miR-625-3p increased SCAI level, suggesting that SCAI could be a target of miR-625-3p. Additionally, we revealed that miR-625-3p exerts its oncogenic functions through regulation of SCAI/E-cadherin/MMP-9 pathways. Our findings indicate the pivotal role of miR-625-3p in invasion that warrants further exploration whether targeting miR-625-3p could be a promising approach for the treatment of CRC.

MiR-455-5p acts as a novel tumor suppressor in gastric cancer by down-regulating RAB18

AIM

To detect the potential regulation pathway of microRNA-455-5p (miR-455-5p) and RAB18, member RAS oncogene family (RAB18) in gastric cancer (GC) cells and tissues and discuss the clinical significance of miR-455-5p in GC genesis and progression.

METHODS

Real-time PCR was used to measure mRNA level of miR-455-5p in GC, TargetScan and dual luciferase assay were used to predict and demonstrate the candidate target gene of miR-455-5p, Western blot were utilized to detect the protein level of RAB18. Cell function assays were also performed to determine the function of miR-455-5p in GC.

RESULTS

miR-455-5p was reduced significantly in gastric cancer cells and tissues compared with the corresponding normal control, the lower expression of miR-455-5p was related to advanced clinical stage in gastric cancer, re-expression of miR-455-5p could inhibit human GC cell proliferation and invasion, overexpression of miR-455-5p could also promote GC cell apoptosis. Furthermore, we found that RAB18 was a candidate target of miR-455-5p. Re-expression of miR-455-5p could inhibit the protein level of RAB18.

CONCLUSION

MiR-455-5p might serve as a novel biomarker in gastric cancer by targeting RAB18.

Weighted gene co-expression network analysis of colorectal cancer liver metastasis genome sequencing data and screening of anti-metastasis drugs

Approximately 9% of cancer-related deaths are caused by colorectal cancer (CRC). CRC patients are prone to liver metastasis, which is the most important cause for the high CRC mortality rate. Understanding the molecular mechanism of CRC liver metastasis could help us to find novel targets for the effective treatment of this deadly disease. Using weighted gene co-expression network analysis on the sequencing data of CRC with and with metastasis, we identified 5 colorectal cancer liver metastasis related modules which were labeled as brown, blue, grey, yellow and turquoise. In the brown module, which represents the metastatic tumor in the liver, gene ontology (GO) analysis revealed functions including the G-protein coupled receptor protein signaling pathway, epithelial cell differentiation and cell surface receptor linked signal transduction. In the blue module, which represents the primary CRC that has metastasized, GO analysis showed that the genes were mainly enriched in GO terms including G-protein coupled receptor protein signaling pathway, cell surface receptor linked signal transduction, and negative regulation of cell differentiation. In the yellow and turquoise modules, which represent the primary non-metastatic CRC, 13 downregulated CRC liver metastasis-related candidate miRNAs were identified (e.g. hsa-miR-204, hsa-miR-455, etc.). Furthermore, analyzing the DrugBank database and mining the literature identified 25 and 12 candidate drugs that could potentially block the metastatic processes of the primary tumor and inhibit the progression of metastatic tumors in the liver, respectively. Data generated from this study not only furthers our understanding of the genetic alterations that drive the metastatic process, but also guides the development of molecular-targeted therapy of colorectal cancer liver metastasis.

MicroRNA in rectal cancer

In rectal cancer, one of the most common cancers worldwide, the proper staging of the disease determines the subsequent therapy. For those with locally advanced rectal cancer, a neoadjuvant chemoradiotherapy (CRT) is recommended before any surgery. However, response to CRT ranges from complete response (responders) to complete resistance (non-responders). To date we are not able to separate in advance the first group from the second, due to the absence of a valid biomarker. Therefore all patients receive the same therapy regardless of whether they reap benefits. On the other hand almost all patients receive a surgical resection after the CRT, although a watch-and-wait procedure or an endoscopic resection might be sufficient for those who responded well to the CRT. Being highly conserved regulators of gene expression, microRNAs (miRNAs) seem to be promising candidates for biomarkers. Many studies have been analyzing the miRNAs expressed in rectal cancer tissue to determine a specific miRNA profile for the ailment. Unfortunately, there is only a small overlap of identified miRNAs between different studies, posing the question as to whether different methods or differences in tissue storage may contribute to that fact or if the results simply are not reproducible, due to unknown factors with undetected influences on miRNA expression. Other studies sought to find miRNAs which correlate to clinical parameters (tumor grade, nodal stage, metastasis, survival) and therapy response. Although several miRNAs seem to have an impact on the response to CRT or might predict nodal stage, there is still only little overlap between different studies. We here aimed to summarize the current literature on rectal cancer and miRNA expression with respect to the different relevant clinical parameters.

Prognostic microRNA signatures derived from The Cancer Genome Atlas for head and neck squamous cell carcinomas

Identification of novel prognostic biomarkers typically requires a large dataset which provides sufficient statistical power for discovery research. To this end, we took advantage of the high‐throughput data from The Cancer Genome Atlas (TCGA) to identify a set of prognostic biomarkers in head and neck squamous cell carcinomas (HNSCC) including oropharyngeal squamous cell carcinoma (OPSCC) and other subtypes. In this study, we analyzed miRNA‐seq data obtained from TCGA patients to identify prognostic biomarkers for OPSCC. The identified miRNAs were further tested with an independent cohort. miRNA‐seq data from TCGA was also analyzed to identify prognostic miRNAs in oral cavity squamous cell carcinoma (OSCC) and laryngeal squamous cell carcinoma (LSCC). Our study identified that miR‐193b‐3p and miR‐455‐5p were positively associated with survival, and miR‐92a‐3p and miR‐497‐5p were negatively associated with survival in OPSCC. A combined expression signature of these four miRNAs was prognostic of overall survival in OPSCC, and more importantly, this signature was validated in an independent OPSCC cohort. Furthermore, we identified four miRNAs each in OSCC and LSCC that were prognostic of survival, and combined signatures were specific for subtypes of HNSCC. A robust 4‐miRNA prognostic signature in OPSCC, as well as prognostic signatures in other subtypes of HNSCC, was developed using sequencing data from TCGA as the primary source. This demonstrates the power of using TCGA as a potential resource to develop prognostic tools for improving individualized patient care.