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PurposeThe transcription factor Fra-2 affects the invasive potential of breast cancer cells by dysregulating adhesion molecules in vitro. Previous results suggested that it upregulates the expression of E- and P-selectin ligands. Such selectin ligands are important members of the leukocyte adhesion cascade, which govern the adhesion and transmigration of cancer cells into the stroma of the host organ of metastasis. As so far, no in vivo data are available, this study was designed to elucidate the role of Fra-2 expression in a spontaneous breast cancer metastasis xenograft model.MethodsThe effect of Fra-2 overexpression in two stable Fra-2 overexpressing clones of the human breast cancer cell line MDA MB231 on survival and metastatic load was studied after subcutaneous injection into scid and E- and P-selectin-deficient scid mice.ResultsFra-2 overexpression leads to a significantly shorter overall survival and a higher amount of spontaneous lung metastases not only in scid mice, but also in E- and P-deficient mice, indicating that it regulates not only selectin ligands, but also selectin-independent adhesion processes.ConclusionThus, Fra-2 expression influences the metastatic potential of breast cancer cells by changing the expression of adhesion molecules, resulting in increased adherence to endothelial cells in a breast cancer xenograft model.

Background Distant metastasis formation is the major clinical problem in prostate cancer (PCa) and the underlying mechanisms remain poorly understood. Our aim was to identify novel molecules that functionally contribute to human PCa systemic dissemination based on unbiased approaches. Methods We compared mRNA, microRNA (miR) and protein expression levels in established human PCa xenograft tumours with high (PC-3), moderate (VCaP) or weak (DU-145) spontaneous micrometastatic potential. By focussing on those mRNAs, miRs and proteins that were differentially regulated among the xenograft groups and known to interact with each other we constructed dissemination-related mRNA/miR and protein/miR networks. Next, we clinically and functionally validated our findings. Results Besides known determinants of PCa progression and/or metastasis, our interaction networks include several novel candidates. We observed a clear role of epithelial-to-mesenchymal transition (EMT) pathways for PCa dissemination, which was additionally confirmed by an independent human PCa model (ARCAP-E/-M). Two converging nodes, CD46 (decreasing with metastatic potential) and DDX21 (increasing with metastatic potential), were used to test the clinical relevance of the networks. Intriguingly, both network nodes consistently added prognostic information for patients with PCa whereas CD46 loss predicted poor outcome independent of established parameters. Accordingly, depletion of CD46 in weakly metastatic PCa cells induced EMT-like properties in vitro and spontaneous micrometastasis formation in vivo. Conclusions The clinical and functional relevance of the dissemination-related interaction networks shown here could be successfully validated by proof-of-principle experiments. Therefore, we suggest a direct pro-metastatic, clinically relevant role for the multiple novel candidates included in this study; these should be further exploited by future studies.

MicroRNAs (miRNAs) are a family of short noncoding RNAs that posttranscriptionally regulate gene expression and play an important role in multiple cellular processes. A significant percentage of miRNAs are intragenic, which is often functionally related to their host genes playing either antagonistic or synergistic roles. In this study, we constructed and analyzed the entire network of intergenic interactions induced by intragenic miRNAs. We further focused on the core of this network, which was defined as a union of nontrivial strongly connected components, i.e., sets of nodes (genes) mutually connected via directed paths. Both the entire network and its core possessed statistically significant non-random properties. Specifically, genes forming the core had high expression levels and low expression variance. Furthermore, the network core did not split into separate components corresponding to individual signalling or metabolic pathways, but integrated genes involved in key cellular processes, including DNA replication, transcription, protein homeostasis and cell metabolism. We suggest that the network core, consisting of genes mutually regulated by their intragenic miRNAs, could coordinate adjacent pathways or homeostatic control circuits, serving as a horizontal inter-circuit link. Notably, expression patterns of these genes had an efficient prognostic potential for breast and colorectal cancer patients.

Changes in cell adhesion molecule (CAM) expression and miRNAs regulating them are known to be involved in malignant progression in colon cancer. We investigated expression profiles of CAM genes and non-coding RNAs in CaCo2 colon cancer cells in static culture and under dynamic flow conditions perfused in microfluidic chip emulating physiological microenvironment. We incubated monolayers of CaCo2 cells in Transwell® units either under static conditions or under flow in a microfluidic chip. We identified 7 up-regulated CAM genes (CD44, CDH7, CEACAM5, CEACAM6, CYR61, L1CAM and VCAN), 7 down-regulated genes (COL12A1, FGA, FGB, FGG, GJA1, ITGA5 and LAMA1) and 69 miRNAs targeting them under the influence of microcirculation. The revealed network comprised CAM genes known to interact with each other and 13 miRNAs simultaneously regulating more than one of them. The discovered regulatory network comprising CAM genes and miRNAs is likely involved in normal functioning of intestine epithelium as well as in cancer progression.

MicroRNA (miRNA) is a class of small non-coding RNAs which mediate post-transcriptional gene silencing (PTGS) by sequence-specific inhibition of target mRNAs translation and/or lowering their half-lives in the cytoplasm. Together with their binding partners, Argonaute (AGO) proteins, miRNAs form cores of RNA-induced silencing complexes (RISC). Despite a substantial progress in understanding RISC structure, until recently little was known about its localization in the cell. This review is aimed to provide an overview of the emerging picture of miRNA and RISC localization and function both in the intracellular space and outside of the cell. In contrast to the common assumption that PTGS occurs in the cytoplasm, it was found to operate mainly on the membranes of the endoplasmic reticulum (ER). Besides ER membranes miRNAs were found in all main cellular compartments including nucleus, nucleolus and mitochondria where they regulate various processes including transcription, translation, alternative splicing and DNA repair. Moreover, a certain pool of miRNAs may not be associated with RISC and carry completely different functions. Finally, the discovery of cell-free miRNAs in all biological fluids suggests that miRNAs might also act as signaling molecules outside the cell, and may be utilized as biomarkers for a variety of diseases. In this review we discuss miRNA secretion mechanisms and possible pathways of cell-cell communication via miRNA-containing exosomes in vivo.

L1CAM is a cell adhesion molecule of the immunoglobulin superfamily which was originally discovered as a major player in the development of the nervous system. L1CAM was demonstrated to have prognostic value in different cancers and to be a promising target for anti-cancer therapy. Here we overview the present data on L1CAM structure and function, regulation of its expression, role in cancer and therapeutic potential.

The human-on-chip technology provides an efficient basis for preclinical studies and has potentially a greater predictive power for human drug response than classical 2D cell culture. Here we report the expression profile of druggable genes in the human colon cancer cells CaCo2 in static culture and within a microfluidic chip. We identified gene expression pattern under flow to be closer to the one of CaCo2 primary xenograft tumours as compared to those cells grown without circulation. The obtained results indicate that a microenvironment connected to a circulation within a chip brings the cells closer to in vivo situation. Hence the human-on-chip technology is a more powerful tool for drug development than conventional 2D cell culture.

Peripheral blood plasma profiles of circulating microRNA expression were analyzed in patients with prostatic cancer and benign hyperplasia. In prostatic cancer, significant increase in hsa-miR-619-5p and hsa-miR-1184 microRNA expression and significant decrease in hsalet-7b-5p and hsa-let-7c-5p microRNA expression were observed. The role of the relationship between the microRNA expression and the activities and functions of host genes with introns encoding these microRNA is discussed.

Molecule L1CAM is specific for nerve cells and tumors of various localizations. The expression of L1CAM is significantly higher in melanoma in comparison with benign nevi and correlates with the progress of melanoma and transition from radial to vertical growth. Monoclonal antibodies to L1CAM effectively and specifically attenuate melanoma growth, though stimulates the epithelial-mesenchymal transition. shRNA-mediated knock-down of L1CAM showed the involvement of L1CAM in regulation of activity of the canonical Wnt pathway and expression of genes of class I melanoma-associated antigens (MAGE).

Finding additional functional targets for combination therapy could improve the outcome for melanoma patients. In a spontaneous metastasis xenograft model of human melanoma a shRNA mediated knockdown of L1CAM more than sevenfold reduced the number of lung metastases after the induction of subcutaneous tumors for two human melanoma cell lines (MeWo, MV3). Whole genome expression arrays of the initially L1CAM high MeWo subcutaneous tumors revealed unchanged or downregulated genes involved in epithelial to mesenchymal transition (EMT) except an upregulation of Jagged 1, indicating a compensatory change in Notch signaling especially as Jagged 1 expression showed an increase in MeWo L1CAM metastases and Jagged 1 was expressed in metastases of the initially L1CAM low MV3 cells as well. Expression of 17 genes showed concordant regulation for L1CAM knockdown tumors of both cell lines. The changes in gene expression indicated changes in the EMT network of the melanoma cells and an increase in p53/p21 and p38 activity contributing to the reduced metastatic potential of the L1CAM knockdowns. Taken together, these data make L1CAM a highly interesting therapeutic target to prevent further metastatic spread in melanoma patients.

We studied the effect of transfection of PC-3 prostate cancer cells with a plasmid encoding shRNA complimentary to a fragment of integrin β4 (ITGB4). The results attest to considerable changes in the transcriptome of transfected cells. For instance, compensatory changes in the expression of integrin family genes were found.

The metastatic cascade comprises the following steps in sequential manner: the future metastatic cell has to leave the primary tumor mass, degrade the surrounding extracellular matrix, extravasate and circulate within in the bloodstream. Thereafter it has to attach to the endothelium of a target organ, intravasate into the connective tissue and has to proliferate to form a clinically detectable metastasis. We overview the in vitro microfluidic platforms modelling the metastatic cascade and the evolution towards systems capable of recapitulating all the steps by a single comprehensive model.

Small molecule inhibitors of pre-mRNA splicing are important tools for identifying new spliceosome assembly intermediates, allowing a finer dissection of spliceosome dynamics and function. Here, we identified a small molecule that inhibits human pre-mRNA splicing at an intermediate stage during conversion of pre-catalytic spliceosomal B complexes into activated Bact complexes. Characterization of the stalled complexes (designated B028) revealed that U4/U6 snRNP proteins are released during activation before the U6 Lsm and B-specific proteins, and before recruitment and/or stable incorporation of Prp19/CDC5L complex and other Bact complex proteins. The U2/U6 RNA network in B028 complexes differs from that of the Bact complex, consistent with the idea that the catalytic RNA core forms stepwise during the B to Bact transition and is likely stabilized by the Prp19/CDC5L complex and related proteins. Taken together, our data provide new insights into the RNP rearrangements and extensive exchange of proteins that occurs during spliceosome activation. DOI: http://dx.doi.org/10.7554/eLife.23533.001

Aberrant glycosylation of cell surface glycoproteins acquired during malignant progression is a common characteristic of human cancer cells. Several biological processes and molecular mechanisms relevant for tumour progression are accompanied by altered mRNA expression levels of certain glycosyltransferases resulting in unusual ratios of common glycoconjugates present in a cancer cell's glycocalyx or even in the development of unusual, cancer-characterizing carbohydrates. This mini-review aims to give a concise overview on the current knowledge of the functional relevance of altered O- and N-glycans during two critical steps of tumour progression: (I) epithelial-to-mesenchymal transition of primary tumour cells during intravasation and (II) adhesion of circulating tumour cells towards the vascular wall during extravasation at a distant metastatic site. Characteristic lectin binding patterns reflecting these glycosylation changes and the resulting prognostic impact of certain lectin binding sites in different neoplasias are reviewed as well.

Background: C-Fos was initially described as oncogene, but was associated with favourable prognosis in ovarian cancer (OvCa) patients. The molecular and functional aspects underlying this effect are still unknown. Methods: Using stable transfectants of SKOV3 and OVCAR8 cells, proliferation, migration, invasion and apoptotic potential of c-FOS-overexpressing clones and controls were compared. Adherence to components of the extracellular matrix was analysed in static assays, and adhesion to E-selectin, endothelial and mesothelial cells in dynamic flow assays. The effect of c-FOS in vivo was studied after intraperitoneal injection of SKOV3 clones into SCID mice, and changes in gene expression were determined by microarray analysis. Results: Tumour growth after injection into SCID mice was strongly delayed by c-FOS overexpression, with reduction of lung metastases and circulating tumour cells. In vitro, c-FOS had only weak influence on proliferation and migration, but was strongly pro-apoptotic. Adhesion to components of the extracellular matrix (collagen I, IV) and to E-selectin, endothelial and mesothelial cells was significantly reduced in c-FOS-overexpressing OvCa cells. This corresponds to deregulation of adhesion proteins and glycosylation enzymes in microarray analysis. Conclusion: In addition to its known pro-apoptotic effect, c-FOS might influence OvCa progression by changing the adhesion of OvCa cells to peritoneal surfaces.

We studied the profile of miRNA secreted into culture medium by DU145 prostate cancer cells and identified a subset of miRNAs characterized by the absence of correlation of their content in the cell and medium, which is likely a result of specific secretion. Three of these miRNA, hsa-miR-4417, hsa-miR-3175, and hsa-miR-6782-5p, exhibit the highest expression and are candidate circulating biomarkers for metastatic activity of prostate cancer. Two of these miRNA are coded by introns of genes linked with genome stability maintenance and chromatin remodeling regulation.

Splicing of pre-mRNA is catalyzed by the spliceosome, which is composed of the U1, U2, U4/U6, and U5 small nuclear ribonucleoproteins (snRNPs) and numerous non-snRNP proteins. The spliceosome assembles in a stepwise fashion, with U1 and U2 interacting initially with the pre-mRNA (to form the A complex), followed by the U4/U6.U5 tri-snRNP (to generate the pre-catalytic B complex). The activated spliceosome (B) is subsequently formed by major rearrangements leading to the displacement of U1 and U4. After additional restructuring, step 1 of splicing occurs, during which the cleaved 5’-exon of the pre-mRNA and intron-3’-exon lariat intermediates are generated. The spliceosomal C complex is formed at this time; it catalyzes step 2 of splicing, during which the 5’and 3’-exons are ligated to form mature mRNA. Many pre-mRNAs (>88% of human genes) are alternatively spliced, in a process in which different sets of exons from the same pre-mRNA are spliced together, often in a regulated and/or tissue-/cell-specific manner. Alternative splicing is therefore a major means of generating protein diversity in an organism. Furthermore, disruption/misregulation of alternative and constitutive splicing are causes or severity modulators of many human diseases, including, among others, cancer and neurodegenerative and autoimmune diseases. The spliceosome is thus a highly attractive drug target. Small-molecule inhibitors capable of blocking discrete steps of the extremely dynamic functional cycle of the spliceosome would also be highly useful for the detailed investigation of the structure and function of the spliceosome. However, only a limited number of small-molecule inhibitors that specifically target the pre-mRNA splicing machinery have been identified. Although several cell-based high-throughput splicing assays have been developed, there is a great need for an in vitro high-throughput splicing assay that would be free of all the constraints imposed by the use of living cells. As the basis for a robust, rapid, and sensitive high-throughput in vitro splicing assay, we took advantage of the fact that some spliceosomal proteins are first recruited to the spliceosome and required at a late stage—that is, during/after step 1 of splicing. By monitoring the presence of such a protein in the spliceosome, we could search for inhibitors affecting spliceosome assembly, activation, and/or step 1 catalysis. We thus prepared nuclear extract from a HeLa cell line stably expressing a FLAG-tagged version of the DEAD box ATPase Abstrakt, which is a C-complex-specific protein. For the ultimate detection of the presence of FLAG-tagged protein in spliceosomes, tagged protein was bound with anti-FLAG antibody conjugated to horse radish peroxidase (Figure 1A). We then immobilized a preformed complex of the PM5 pre-mRNA substrate (containing three MS2 protein aptamers at its 5’-end) and the phage MS2-coat protein fused to maltose binding protein (MS2-MBP) in the wells of a microplate coated with anti-MBP antibodies. Splicing active nuclear extract was added and the microplate was incubated at 30 8C (typically 90 min) to allow spliceosome assembly and step 1 of splicing (PM5 lacks a 3’exon, preventing step 2 of splicing). After washing and addition of luminescent substrate, luminescence produced by the peroxidase was measured, reflecting the amount of protein bound and thus the extent of spliceosomal complexes formed. A splicing time course demonstrates that the signal obtained with extract containing FLAG-tagged Abstrakt, consistently with its association with the C complex, appeared much later than extract containing FLAG-tagged hSmu-1 (used as a control), which binds at an earlier stage (i.e. , in the B complex; Figure 1B). In addition, the initial appearance of the tagged hSmu-1 and Abstrakt luminescence signals corresponded to the known times of appearance of the B and C complexes, respectively, during in vitro splicing. No signal was observed with a control extract lacking FLAG-tagged protein. These results clearly indicate that the luminescence signal is proteinspecific and thus that this assay can be used to monitor the splicing reaction. [a] Dr. T. R. Samatov, Dr. P. Odenw lder, Dr. S. Bessonov, Prof. Dr. R. L hrmann Max-Planck-Institut f r biophysikalische Chemie Abt. Zellul re Biochemie Am Fasberg 11, 37077 Gcttingen (Germany) E-mail : Reinhard.Luehrmann@mpi-bpc.mpg.de [b] Dr. A. Wolf Lead Discovery Center GmbH Emil-Figge-Strasse 76a, 44227 Dortmund (Germany) [c] Dr. C. Deraeve, Dr. R. S. Bon, Prof. Dr. H. Waldmann Max-Planck-Institut f r molekulare Physiologie, Abt. Chemische Biologie Otto-Hahn-Strasse 11, 44227 Dortmund (Germany) [d] Prof. Dr. H. Waldmann TU Dortmund, Fakult t Chemie 44227 Dortmund (Germany) [e] Dr. P. Odenw lder Current address: McKinsey and Company Am Sandtorkai 77, 20457 Hamburg (Germany) [f] Dr. C. Deraeve Current address: Laboratoire de Chimie de Coordination du CNRS 205 Route de Narbonne, 31077 Toulouse, Cedex 4 (France) [g] Dr. R. S. Bon Current address: School of Chemistry and Biomedical and Health Research Centre University of Leeds Leeds, LS2 9JT (UK) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cbic.201100790.

We present a method for generating gel-based unordered 2D arrays of bacterial cells of a very high density, up to 10(5) cells per mm(2). Bacteria in a suspension are focused into a thin layer when the suspension and a dry gel matrix penetrate each other. Formation of a second gel from gel-forming components contained in the suspension results in immobilization of the cells. The immobilized cells stay alive and can repeatedly divide to produce microcolonies. The method provides for high-throughput screening and massively parallel analysis of individual cells in large populations, as well as for rapid isolation of rare clones.

We analyzed the effect of hemolysis on microRNA profi le of blood plasma. It was found that hemolysis of ~0.05% erythrocytes in a sample signifi cantly affected the concentration of 9 microRNA: hsa-miR-486-5p, hsa-miR-16-5p, hsa-miR-451a, hsa-miR-106a-5p, hsa-miR-17-5p, hsa-miR-93-5p, hsa-miR-20a-5p, hsa-miR-107, and hsa-miR-20b-5p. The effect of hemolysis on plasma content of miR-17 family microRNA was demonstrated.

Genes with significant differential expression are traditionally used to reveal the genetic background underlying phenotypic differences between cancer cells. We hypothesized that informative marker sets can be obtained by combining genes with a relatively low degree of individual differential expression. We developed a method for construction of highly informative gene combinations aimed at the maximization of the cumulative informative power and identified sets of 2–5 genes efficiently predicting recurrence for ER-positive breast cancer patients. The gene combinations constructed on the basis of microarray data were successfully applied to data acquired by RNA-seq. The developed method provides the basis for the generation of highly efficient prognostic and predictive gene signatures for cancer and other diseases. The identified gene sets can potentially reveal novel essential segments of gene interaction networks and pathways implied in cancer progression.

We analyzed microRNA profile in hemolysis-free blood plasma of patients with prostatic cancer. The metastatic form of prostatic cancer was found to be associated with increased levels of hsa-miR-22-3p, hsa-miR-663a, and hsa-miR-4674 in comparison with non-metastatic form. Common candidate target genes of these microRNA include JUNB, KMT2A, and XPO6.

Background Inflammatory breast cancer (IBC) is an extremely malignant form of breast cancer which can be easily misdiagnosed. Conclusive prognostic IBC molecular biomarkers which are also providing the perspectives for targeted therapy are lacking so far. The aim of this study was to reveal the IBC-specific miRNA expression profile and to evaluate its association with clinicopathological parameters. Methods miRNA expression profiles of 13 IBC and 17 non-IBC patients were characterized using comprehensive Affymetrix GeneChip miRNA 3.0 microarray platform. Bioinformatic analysis was used to reveal IBC-specific miRNAs, deregulated pathways and potential miRNA targets. Results 31 differentially expressed miRNAs characterize IBC and mRNAs regulated by them and their associated pathways can functionally be attributed to IBC progression. In addition, a minimal predictive set of 4 miRNAs characteristic for the IBC phenotype and associated with the TP53 mutational status in breast cancer patients was identified. Conclusions We have characterized the complete miRNome of inflammatory breast cancer and found differentially expressed miRNAs which reliably classify the patients to IBC and non-IBC groups. We found that the mRNAs and pathways likely regulated by these miRNAs are highly relevant to cancer progression. Furthermore a minimal IBC-related predictive set of 4 miRNAs associated with the TP53 mutational status and survival for breast cancer patients was identified. Electronic supplementary material The online version of this article (doi:10.1186/1756-0500-7-871) contains supplementary material, which is available to authorized users.

The removal of intervening sequences (introns) from a primary RNA transcript is catalyzed by the spliceosome, a large ribonucleoprotein complex. At the start of each splicing cycle, the spliceosome assembles anew in a sequentially ordered manner on the pre-mRNA intron to be removed. We describe here the identification of a series of naphthalen-2-yl hydroxamate compounds that inhibit pre-mRNA splicing in vitro with mid- to high-micromolar values of IC50. These hydroxamates stall spliceosome assembly at the A complex stage. A structure–activity analysis of lead compounds revealed three pharmacophores that are essential for splicing inhibition. Specifically, a hydroxamate as a zinc-binding group and a 6-methoxynaphthalene cap group are both critical, and a linker chain comprising eight to nine methylene groups is also important, for the specific binding to the docking site of a target protein molecule and precise positioning of the zinc binding group. As we found no correlation between the inhibition patterns of known histone deacetylases on the one hand and pre-mRNA splicing on the other, we conclude that these compounds may function through the inhibition of the activities of other, at present, unknown spliceosome-associated zinc metalloprotein(s).

HIS-24 linker histone and SIR-2.1 deacetylase are involved in chromatin silencing in Caenorhabditis elegans. Depletion of SIR-2.1 results in cytoplasmic retention of HIS-24 in oocytes. However, the molecular working mechanisms of HIS-24 and SIR-2.1 are unclear. We show here a synergistic function of SIR-2.1 and HIS-24 that are together essential for maintenance of the H3K27me3 mark in the germ line of C. elegans. We demonstrate the synthetic effects of the two factors on brood size, embryogenesis, and fertility. SIR-2.1 and HIS-24 associate with the subtelomeric regions but apparently do not interact directly. We report that SIR-2.1 deacetylates H3K9 at subtelomeric regions and suggest that deacetylation of H3K9 is a prerequisite for H3K27 methylation. In turn, we found that HIS-24 specifically interacts with the histone H3 K27 region, when unmodified or in the trimethylated state. Overall, our data indicate that SIR-2.1 and HIS-24 contribute to the propagation of a specialized chromatin state at the subtelomeric regions and elsewhere in the genome.

When PCR is carried out in a polyacrylamide gel, each target molecule forms a molecular colony that comprises many copies of the original template. By counting the number of colonies, one can directly determine the target titer, with 100% of the DNA molecules and approximately 15% of the RNA molecules being detected. Furthermore, because of the spatial separation of the products in the gel, no interference is observed from another simultaneously amplified target even if it is present at a 106 higher amount or from human nucleic acids that outweigh the target by up to a factor of 1012, which is often true of clinical samples. All these features provide for an accurate and reliable assay of viruses even at very low amounts, that is, in cases most important to diagnostics.

Carrying out polymerase chain reaction in a gel layer generates a 2-D pattern of DNA colonies comprising pure genetic clones. Here we demonstrate that transcription, translation and protein folding can be performed in the same gel. The resulting nucleoprotein colonies mimic living cells by serving as compartments in which the synthesized RNAs and proteins co-localize with their templates. Yet, due to the absence of penetration barriers, such a molecular colony display allows cloned genes to be directly tested for the encoded functions. Now, the results imply that virtually any manipulations with genes and their expression products can be accomplished in vitro.

Background MiRNAs are essential mediators of many biological processes. The aim of this study was to investigate the dynamics of miRNA-mRNA regulatory networks during exercise and the subsequent recovery period. Results Here we monitored the transcriptome changes using microarray analysis of the whole blood of eight highly trained athletes before and after 30 min of moderate exercise followed by 30 min and 60 min of recovery period. We combined expression profiling and bioinformatics and analysed metabolic pathways enriched with differentially expressed mRNAs and mRNAs which are known to be validated targets of differentially expressed miRNAs. Finally we revealed four dynamically regulated networks comprising differentially expressed miRNAs and their known target mRNAs with anti-correlated expression profiles over time. The data suggest that hsa-miR-21-5p regulated TGFBR3, PDGFD and PPM1L mRNAs. Hsa-miR-24-2-5p was likely to be responsible for MYC and KCNJ2 genes and hsa-miR-27a-5p for ST3GAL6. The targets of hsa-miR-181a-5p included ROPN1L and SLC37A3. All these mRNAs are involved in processes highly relevant to exercise response, including immune function, apoptosis, membrane traffic of proteins and transcription regulation. Conclusions We have identified metabolic pathways involved in response to exercise and revealed four miRNA-mRNA networks dynamically regulated following exercise. This work is the first study to monitor miRNAs and mRNAs in parallel into the recovery period. The results provide a novel insight into the regulatory role of miRNAs in stress adaptation.

Epithelial-mesenchymal transition (EMT) is a key process in embryonic development and metastases formation during malignant progression. This review focuses on transcriptional regulation, non-coding RNAs, alternative splicing events and cell adhesion molecules regulation during EMT. Additionally, we summarize the knowledge with regard to the small potentially druggable molecules capable of modulating EMT for cancer therapy.