Atypical role of sprouty in colorectal cancer: sprouty repression inhibits epithelial-mesenchymal transition. Oncogene. 2016;35:3151-3162. [PMID: 26434583 PMCID: PMC4850112 DOI: 10.1038/onc.2015.365]

Inhibiting mechanotransduction prevents scarring and yields regeneration in a large animal model

Modulating mechanotransduction by inhibiting yes-associated protein (YAP) in mice yields wound regeneration without scarring. However, rodents are loose-skinned and fail to recapitulate key aspects of human wound repair. We sought to elucidate the effects of YAP inhibition in red Duroc pig wounds, the most human-like model of scarring. We show that one-time treatment with verteporfin, a YAP inhibitor, immediately after wounding is sufficient to prevent scarring and to drive wound regeneration in pigs. By performing single-cell RNA sequencing (scRNA-seq) on porcine wounds in conjunction with spatial proteomic analysis, we found perturbations in fibroblast dynamics with verteporfin treatment and the presence of putative pro-regenerative/profibrotic fibroblasts enriched in regenerating/scarring pig wounds, respectively. We also identified differences in enriched myeloid cell subpopulations after treatment and linked this observation to increased elaboration of interleukin-33 (IL-33) in regenerating wounds. Finally, we validated our findings in a xenograft wound model containing human neonatal foreskin engrafted onto nude mice and used scRNA-seq of human wound cells to draw parallels with fibroblast subpopulation dynamics in porcine wounds. Collectively, our findings provide support for the clinical translation of local mechanotransduction inhibitors to prevent human skin scarring, and they clarify a YAP/IL-33 signaling axis in large animal wound regeneration.

BTB protein family and human breast cancer: signaling pathways and clinical progress

BACKGROUND

Breast cancer is considered the number one killer of women both in China and abroad, and the leading cause of cancer death. It severely affects female health-related quality of life. Broad-complex, tramtrack, bric à brac (BTB) protein family was first discovered in drosophila as early as in 1993 by Godt D and peers, since then, more family members and their critical biological functions were uncovered. Moreover, researchers around the world have recently demonstrated that numerous signaling pathways connect BTB family members and human breast cancer.

PURPOSE

In this review, we critically discuss these findings regarding the essential mechanisms and functions of the BTB protein family in mediating the organic processes of human breast cancer. Meanwhile, we summarize the signaling pathways the BTB protein family participates in. And we address that BTB proteins regulate the growth, apoptosis, and other behaviors of breast cancer cells. We also point out the future directions for further studies in this field.

METHODS

The relevant online literatures have been reviewed for this article.

CONCLUSION

This review could offer an update on novel molecular targets for treating human breast cancer and new insights into BTB protein family research.

Identification of Novel Biomarkers for Response to Preoperative Chemoradiation in Locally Advanced Rectal Cancer with Genetic Algorithm-Based Gene Selection

BACKGROUND

The conventional treatment for patients with locally advanced colorectal tumors is preoperative chemo-radiotherapy (PCRT) preceding surgery. This treatment strategy has some long-term side effects, and some patients do not respond to it. Therefore, an evaluation of biomarkers that may help predict patients' response to PCRT is essential.

METHODS

We took advantage of genetic algorithm to search the space of possible combinations of features to choose subsets of genes that would yield convenient performance in differentiating PCRT responders from non-responders using a logistic regression model as our classifier.

RESULTS

We developed two gene signatures; first, to achieve the maximum prediction accuracy, the algorithm yielded 39 genes, and then, aiming to reduce the feature numbers as much as possible (while maintaining acceptable performance), a 5-gene signature was chosen. The performance of the two gene signatures was (accuracy = 0.97 and 0.81, sensitivity = 0.96 and 0.83, and specificity = 86 and 0.77) using a logistic regression classifier. Through analyzing bias and variance decomposition of the model error, we further investigated the involved genes by discovering and validating another 28-gene signature which possibly points towards two different sub-systems involved in the response of the patients to treatment.

CONCLUSIONS

Using genetic algorithm as our gene selection method, we have identified two groups of genes that can differentiate PCRT responders from non-responders in patients of the studied dataset with considerable performance.

IMPACT

After passing standard requirements, our gene signatures may be applicable as a robust and effective PCRT response prediction tool for colorectal cancer patients in clinical settings and may also help future studies aiming to further investigate involved pathways gain a clearer picture for the course of their research.

Increased SPRY1 expression activates NF-κB signaling and promotes pancreatic cancer progression by recruiting neutrophils and macrophages through CXCL12-CXCR4 axis

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high mortality rate, in which about 90% of patients harbor somatic oncogenic point mutations in KRAS. SPRY family genes have been recognized as crucial negative regulators of Ras/Raf/ERK signaling. Here, we investigate the expression and role of SPRY proteins in PDAC.

METHODS

Expression of SPRY genes in human and mice PDAC was analyzed using The Cancer Genome Atlas and Gene Expression Omnibus datasets, and by immunohistochemistry analysis. Gain-of-function, loss-of-function of Spry1 and orthotopic xenograft model were adopted to investigate the function of Spry1 in mice PDAC. Bioinformatics analysis, transwell and flowcytometry analysis were used to identify the effects of SPRY1 on immune cells. Co-immunoprecipitation and K-ras4B G12V overexpression were used to identify molecular mechanism.

RESULTS

SPRY1 expression was remarkably increased in PDAC tissues and positively associated with poor prognosis of PDAC patients. SPRY1 knockdown suppressed tumor growth in mice. SPRY1 was found to promote CXCL12 expression and facilitate neutrophil and macrophage infiltration via CXCL12-CXCR4 axis. Pharmacological inhibition of CXCL12-CXCR4 largely abrogated the oncogenic functions of SPRY1 by suppressing neutrophil and macrophage infiltration. Mechanistically, SPRY1 interacted with ubiquitin carboxy-terminal hydrolase L1 to induce activation of nuclear factor κB signaling and ultimately increase CXCL12 expression. Moreover, SPRY1 transcription was dependent on KRAS mutation and was mediated by MAPK-ERK signaling.

CONCLUSION

High expression of SPRY1 can function as an oncogene in PDAC by promoting cancer-associated inflammation. Targeting SPRY1 might be an important approach for designing new strategy of tumor therapy.

Loss of SPRY2 contributes to cancer-associated fibroblasts activation and promotes breast cancer development

The communication between tumor cells and tumor microenvironment plays a critical role in cancer development. Cancer-associated fibroblasts (CAFs) are the major components of the tumor microenvironment and take part in breast cancer formation and progression. Here, by comparing the gene expression patterns in CAFs and normal fibroblasts, we found SPRY2 expression was significantly decreased in CAFs and decreased SPRY2 expression was correlated with worse prognosis in breast cancer patients. SPRY2 knockdown in fibroblasts promoted tumor growth and distant metastasis of breast cancer in mice. Loss of stromal SPRY2 expression promoted CAF activation dependent on glycolytic metabolism. Mechanically, SPRY2 suppressed Y10 phosphorylation of LDHA and LDHA activity by interfering with the interaction between LDHA and SRC. Functionally, SPRY2 knockdown in fibroblasts enhanced the stemness of tumor cell dependent on glycolysis in fibroblasts. Collectively, this work identified SPRY2 as a negative regulator of CAF activation, and SPRY2 in CAFs may potentially be therapeutically targeted in breast cancer treatment.

Improved Delineation of Colorectal Cancer Molecular Subtypes and Functional Profiles with a 62-Gene Panel

Since its establishment in 2015, the transcriptomics-based consensus molecular subtype (CMS) classification has unified our understanding of colorectal cancer. Each of the four CMS exhibited distinctive high-level molecular signatures that correlated well with prognosis and treatment response. Nonetheless, many key aspects of colorectal cancer progression and intra-subtype heterogeneity remain unresolved. This is partly because the bulk transcriptomic data used to define CMS contain substantial interference from non-tumor cells. Here, we propose a concise panel of 62 genes that not only accurately recapitulates all key characteristics of the four original CMS but also identifies three additional subpopulations with unique molecular signatures. Validation on independent cohorts confirms that the new CMS4 intra-subtypes coincide with single-cell-derived intrinsic subtypes and that the panel consists of many immune cell-type markers that can capture the status of tumor microenvironment. Furthermore, a 2D embedding of CMS structure based on the proposed gene panel provides a high-resolution view of the functional pathways and cell-type markers that underlie each CMS intra-subtype and the continuous progression from CMS2 to CMS4 subtypes. Our gene panel and 2D visualization refined the delineation of colorectal cancer subtypes and could aid further discovery of molecular mechanisms in colorectal cancer.

IMPLICATIONS

: Well-selected gene panel and representation can capture both the continuum of cancer cell states and tumor microenvironment status.

Identification of stage-associated exosome miRNAs in colorectal cancer by improved robust and corroborative approach embedded miRNA-target network

Background

Colorectal cancer (CRC) is a common gastrointestinal tumor with high morbidity and mortality. At the molecular level, patients at different stages present considerable heterogeneity. Although the miRNA in exosome is an effective biomarker to reveal tumor progression, studies based on stage-associated exosome miRNA regulatory network analysis still lacking. This study aims to identify CRC stage-associated exosome miRNAs and reveal their potential function in tumor progression.

Methods

In this study, serum and cellular exosome miRNA expression microarrays associated with CRC were downloaded from GEO database. Stage-common (SC) and stage-specific (SS) differentially expressed miRNAs were extracted and their targets were identified based on 11 databases. Furthermore, miRNA SC and SS regulatory function networks were built based on the CRC phenotypic relevance of miRNA targets, and the corresponding transcription factors were identified. Concurrently, the potential stage-associated miRNAs were identified by receiver-operating characteristic (ROC) curve analysis, survival analysis, drug response analysis, ceRNA analysis, pathway analysis and a comprehensive investigation of 159 publications.

Results

Ten candidate stage-associated miRNAs were identified, with three SC (miR-146a-5p, miR-22-3p, miR-23b-3p) and seven SS (I: miR-301a-3p, miR-548i; IIIA: miR-23a-3p; IV: miR-194-3p, miR-33a-3p, miR-485-3p, miR-194-5p) miRNAs. Additionally, their targets were enriched in several vital cancer-associated pathways such as TGF-beta, p53, and hippo signaling pathways. Moreover, five key hotspot target genes (CCNA2, MAPK1, PTPRD, MET, and CDKN1A) were demonstrated to associated with better overall survival in CRC patients. Finally, miR-23b-3p, miR-301a-3p and miR-194-3p were validated being the most stably expressed stage-associated miRNAs in CRC serum exosomes, cell exosomes and tissues.

Conclusions

These CRC stage-associated exosome miRNAs aid to further mechanism research of tumor progression and provide support for better clinical management in patients with different stages.

High Levels of Tumor miR-187-3p—A Potential Tumor-Suppressor microRNA—Are Correlated with Poor Prognosis in Colorectal Cancer

Background: The microRNA miR-187-3p plays antitumor roles in a variety of cancers. We and others have previously identified miR-187-3p as a potential tumor suppressor in colorectal cancer (CRC), but there are also reports revealing that high miR-187-3p levels are associated with poor prognosis among CRC patients. This study further investigated the clinicopathological significance of miR-187-3p in CRC. Methods: MiR-187-3p levels in paired polyp/CRC/normal specimens or primary CRC/liver metastasis specimens were determined by qPCR, and correlated with the patient’s clinicopathological and postoperative survival data. The clinical findings were validated using our validation cohort and data obtained from the TCGA or GEO databases. The functional effects of miR-187-3p were investigated through its overexpression in CRC cell lines. Results: MiR-187-3p was significantly repressed in colorectal polyps and CRC when compared to adjacent normal tissue. Overexpression of miR-187-3p in CRC cell lines impaired colony formation, cell migration, and invasion, and induced chemosensitivity. Clinical analysis revealed that despite miR-187-3p being repressed in CRC, high tumor miR-187-3p levels were positively correlated with tumor stage and disease recurrence. Further analysis showed that miR-187-3p levels were lower in metastatic specimens when compared to paired primary CRC, suggesting that high tumor miR-187-3p levels resulted from the dissemination of metastatic tumor cells. Tumor miR-187-3p levels were positively correlated with peripheral inflammation-related blood markers. Finally, SPRY1 was identified as a novel target gene of miR-187-3p, and was involved in miR-187-3p-impaired CRC metastasis. Conclusions: This study demonstrated that in spite of its repression and role as a tumor suppressor in CRC, high levels of miR-187-3p in tumors were correlated with poor prognosis and higher levels of peripheral inflammation-related blood markers.

Synergistic Antitumoral Effect of Epigenetic Inhibitors and Gemcitabine in Pancreatic Cancer Cells

Epigenetic modifications could drive some of the molecular events implicated in proliferation, drug resistance and metastasis of pancreatic ductal adenocarcinoma (PDAC). Thus, epigenetic enzyme inhibitors could be the key to revert those events and transform PDAC into a drug-sensitive tumor. We performed a systematic study with five different epigenetic enzyme inhibitors (1, UVI5008, MS275, psammaplin A, and BIX01294) targeting either Histone Deacetylase (HDAC) 1 or 1/4, DNA methyltransferase 3a (DNMT3a), Euchromatic histone lysine methyltransferase 2 (EHMT2), or Sirtuin 1 (SIRT1), as well as one drug that restores the p53 function (P53R3), in three different human PDAC cell lines (SKPC-1, MIA PaCa-2, and BxPC-3) using 2D and 3D cell cultures. The synergistic effect of these antitumoral drugs with gemcitabine was tested and the most efficient combinations were characterized by RNA-seq. The inhibition of HDAC1/4 (MS275), HDAC1/4/SIRT1/DNMT3a (UVI5008) or EHMT2 (BIX01294) induced a significant reduction on the cell viability, even in gemcitabine-resistance cells. The combination of UVI5008 or MS275 with gemcitabine induced a synergistic effect at low concentration and the RNA-Seq analysis revealed some synergy candidate genes as potential biomarkers. Reverting aberrant epigenetic modifications in combination with gemcitabine offers an alternative treatment for PDAC patients, with an important reduction of the therapeutic dose.

Epigenetic DNA Modifications Upregulate SPRY2 in Human Colorectal Cancers

Conventional wisdom is that Sprouty2 (SPRY2), a suppressor of Receptor Tyrosine Kinase (RTK) signaling, functions as a tumor suppressor and is downregulated in many solid tumors. We reported, for the first time, that increased expression of SPRY2 augments cancer phenotype and Epithelial-Mesenchymal-Transition (EMT) in colorectal cancer (CRC). In this report, we assessed epigenetic DNA modifications that regulate SPRY2 expression in CRC. A total of 4 loci within SPRY2 were evaluated for 5mC using Combined Bisulfite Restriction Analysis (COBRA). Previously sequenced 5hmC nano-hmC seal data within SPRY2 promoter and gene body were evaluated in CRC. Combined bioinformatics analyses of SPRY2 CRC transcripts by RNA-seq/microarray and 450K methyl-array data archived in The Cancer Genome Atlas (TCGA) and GEO database were performed. SPRY2 protein in CRC tumors and cells was measured by Western blotting. Increased SPRY2 mRNA was observed across several CRC datasets and increased protein expression was observed among CRC patient samples. For the first time, SPRY2 hypomethylation was identified in adenocarcinomas in the promoter and gene body. We also revealed, for the first time, increases of 5hmC deposition in the promoter region of SPRY2 in CRC. SPRY2 promoter hypomethylation and increased 5hmC may play an influential role in upregulating SPRY2 in CRC.

Prognostic implications of cell division cycle protein 45 expression in hepatocellular carcinoma

Background

The overall prognosis of hepatocellular carcinoma (HCC) is poor and novel prognostic biomarkers might better monitor the progression of HCC. Cell division cycle protein 45 (CDC45) plays a key role in DNA replication and considered to be involved in tumorigenesis. This study investigated CDC45 expression in tumour tissues and defined its prognostic value in HCC patients.

Methods

We used immunohistochemistry (IHC) staining to examine the expression of CDC45 in tumour tissue specimens and compare them with adjacent normal tissue specimens using a constructed tissue microarray (TMA) and analyzed how clinical features are related to HCC prognosis. Functional enrichment analyses were used to describe significantly involved hallmark pathways of differentially expressed genes (DEGs, which were screened out according to the high or low expression of CDC45 in tumour tissues).

Results

Our findings showed that the proteome expression of CDC45 was evidently downregulated in HCC tissues compared with matched normal tissues (P < 0.0001). Although we did not find any differences in terms of vascular invasion, metastasis, lymphatic infiltration, or Edmondson grade between patients with high and low CDC45 expression, low CDC45 expression was significantly correlated with microvascular invasion (P = 0.046). Multivariate analysis indicated that CDC45 expression (P = 0.035) was an independent prognostic factor for the overall survival (OS) rate of HCC patients. Patients with CDC45 expression was positively correlated with OS rates among HCC patients (P < 0.05). Functional annotations indicated that CDC45 is involved in the most significant pathways, including the cell cycle, DNA replication, chemical carcinogenesis and drug metabolism–cytochrome P450 pathways.

Discussion

Our findings showed that low proteomic level of CDC45 was associated with a poor prognosis in HCC patients, indicating that CDC45 might be a novel prognostic marker.

MicroRNAs and Apoptosis in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of cancer death in the world, and its incidence is rising in developing countries. Treatment with 5-Fluorouracil (5-FU) is known to improve survival in CRC patients. Most anti-cancer therapies trigger apoptosis induction to eliminate malignant cells. However, de-regulated apoptotic signaling allows cancer cells to escape this signaling, leading to therapeutic resistance. Treatment resistance is a major challenge in the development of effective therapies. The microRNAs (miRNAs) play important roles in CRC treatment resistance and CRC progression and apoptosis. This review discusses the role of miRNAs in contributing to the promotion or inhibition of apoptosis in CRC and the role of miRNAs in modulating treatment resistance in CRC cells.

Loss of Spry1 reduces growth of BRAFV600-mutant cutaneous melanoma and improves response to targeted therapy

Mitogen-activated protein kinase (MAPK) pathway activation is a central step in BRAF^V600-mutant cutaneous melanoma (CM) pathogenesis. In the last years, Spry1 has been frequently described as an upstream regulator of MAPK signaling pathway. However, its specific role in BRAF^V600-mutant CM is still poorly defined. Here, we report that Spry1 knockdown (Spry1^KO) in three BRAF^V600-mutant CM cell lines markedly induced cell cycle arrest and apoptosis, repressed cell proliferation in vitro, and impaired tumor growth in vivo. Furthermore, our findings indicated that Spry1^KO reduced the expression of several markers of epithelial–mesenchymal transition, such as MMP-2 both in vitro and in vivo. These effects were associated with a sustained and deleterious phosphorylation of ERK1/2. In addition, p38 activation along with an increase in basal ROS levels were found in Spry1^KO clones compared to parental CM cell lines, suggesting that BRAF^V600-mutant CM may restrain the activity of Spry1 to avoid oncogenic stress and to enable tumor growth. Consistent with this hypothesis, treatment with the BRAF inhibitor (BRAFi) vemurafenib down-regulated Spry1 levels in parental CM cell lines, indicating that Spry1 expression is sustained by the MAPK/ERK signaling pathway in a positive feedback loop that safeguards cells from the potentially toxic effects of ERK1/2 hyperactivation. Disruption of this feedback loop rendered Spry1^KO cells more susceptible to apoptosis and markedly improved response to BRAFi both in vitro and in vivo, as a consequence of the detrimental effect of ERK1/2 hyperactivation observed upon Spry1 abrogation. Therefore, targeting Spry1 might offer a treatment strategy for BRAF^V600-mutant CM by inducing the toxic effects of ERK-mediated signaling.

A Nine-Gene Signature for Predicting the Response to Preoperative Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer

Preoperative chemoradiotherapy (PCRT) and subsequent surgery is the standard multimodal treatment for locally advanced rectal cancer (LARC), albeit PCRT response varies among the individuals. This creates a dire necessity to identify a predictive model to forecast treatment response outcomes and identify patients who would benefit from PCRT. In this study, we performed a gene expression study using formalin-fixed paraffin-embedded (FFPE) tumor biopsy samples from 156 LARC patients (training cohort n = 60; validation cohort n = 96); we identified the nine-gene signature (FGFR3, GNA11, H3F3A, IL12A, IL1R1, IL2RB, NKD1, SGK2, and SPRY2) that distinctively differentiated responders from non-responders in the training cohort (accuracy = 86.9%, specificity = 84.8%, sensitivity = 81.5%) as well as in an independent validation cohort (accuracy = 81.0%, specificity = 79.4%, sensitivity = 82.3%). The signature was independent of all pathological and clinical features and was robust in predicting PCRT response. It is readily applicable to the clinical setting using FFPE samples and Food and Drug Administration (FDA) approved hardware and reagents. Predicting the response to PCRT may aid in tailored therapies for respective responders to PCRT and improve the oncologic outcomes for LARC patients.

Long non‑coding RNA Unigene56159 promotes glioblastoma multiforme cell proliferation and invasion through negatively regulating microRNA‑194‑5p

Long non-coding RNAs (lncRNA) serve a vital role in tumor progression. The present study identified a fundamental role for a novel lincRNA, Unigene56159, in the progression of glioblastoma (GBM). Unigene56159 gene expression was found to be significantly upregulated in tissue samples from patients with GBM as well as in GBM cell lines by reverse transcription-quantitative PCR, while microRNA (miR)-194-5p expression levels were decreased. This higher expression level of Unigene56159 was positively correlated with poor overall survival in patients with GBM. However, the mechanism by which this occurs remains to be elucidated. lncRNAs may act as endogenous miRNA sponges for binding to miRNAs or participating in the competitive endogenous RNAs (ceRNA) regulatory network. Small interfering RNA (siRNA) was used to silence the expression of Unigene56159 and inhibit the proliferation and invasion of GBM cell lines by MTT and Transwell assay. Unigene56159 was found to directly interact with miR-194-5p, and rescue assay was performed to further confirm that Unigene56159 contributed to glioma progression by regulating miR-194-5p. Thus, Unigene56159 may function as a competing endogenous RNA by sequestering miR-194-5p in GBM cells. These findings suggested that Unigene56159 may serve an oncogenic role in GBM and may promote disease progression through interacting with miR-194-5p. This could be a potential therapeutic target for the treatment of GBM.

Identification of a five-mRNA signature as a novel potential prognostic biomarker in pediatric Wilms tumor

Background

The aim of this study was to generate a prognostic model to predict survival outcome in pediatric Wilms tumor (WT).

Methods

The data including mRNA expression and clinical information of pediatric WT patients were downloaded from the Therapeutically Available Research to Generate Effective Treatments (TARGET) database. The differentially expressed genes were identified and a prognostic signature of pediatric WT was generated according to the results of univariate and multivariate Cox analysis. Receiver operating characteristic (ROC) curve was used to evaluate the five‐mRNA signature in pediatric Wilms tumor patients. Bootstrap test with 500 times was used to perform the internal validation.

Results

We identified 6,964 differentially expressed mRNAs associated with pediatric WT, including 3,190 downregulated mRNAs and 3,774 up‐regulated mRNAs. Univariate and multivariate Cox analysis identified five mRNAs (SPRY1, SPIN4, MAP7D3, C10orf71, and SPAG11A) to establish a predictive model. The risk score formula is as follows: Risk score = 0.3036*SPIN4 + 0.8576*MAP7D3 −0.1548*C10orf71 −0.7335*SPRY1 −0.2654*SPAG11A. The pediatric WT patients were divided into low‐risk group and high‐risk group based on the median risk score (value = 1.1503). The receiver operating characteristic (ROC) curve analysis revealed good performance of the 5‐mRNA prognostic model (the area under the curve [AUC] was 0.821). Bootstrap test (Bootstrap resampling times = 500) was used to perform the internal validation and revealed that the AUC was 0.822. REACTOME, KEGG, and BIOCARTA pathway analyses demonstrated that these survival‐related genes were mainly enriched in ErbB2 and ErbB3 signaling pathways, and calcium signaling pathway.

Conclusion

The five‐mRNA signature can predict the prognosis of patients with pediatric WT. It has significant implication in the understanding of therapeutic targets for pediatric WT patients. However, further study is needed to validate this five‐mRNA signature and uncover more novel diagnostic or prognostic mRNAs candidates in pediatric WT patients.

AGR2 is controlled by DNMT3a-centered signaling module and mediates tumor resistance to 5-Aza in colorectal cancer

Human anterior gradient-2 (AGR2), a member of protein disulfide isomerase (PDI) family, is upregulated in various human cancers and reportedly has oncogenic activities. However, the functional roles of AGR2 and its regulation in colorectal cancer (CRC) remain unclear. Here, we showed that AGR2 promoted CRC tumorigenesis and progression in vitro and in vivo and acted as an independent prognostic factor of poor outcome. AGR2 was negatively regulated by DNA methyltransferase 3a (DNMT3a) through directly methylating AGR2 promoter and by a DNMT3a-SPRY2-miR-194 axis. Moreover, AGR2 mediated the resistance to 5-Aza-2'-deoxycytidine (5-Aza) treatment. Knockdown of AGR2 improved the therapeutic effect of 5-Aza in human CRC xenograft tumor model. Thus, our work supports AGR2's oncogenic role in CRC, reveals DNMT3a-mediated epigenetic modulation on AGR2 promoter, and uncovers a new DNMT3a signaling module controlling expression of AGR2. Upregulated AGR2 offset 5-Aza mediated epigenetic therapy. This work might provide potential targets for clinical anti-cancer therapy.

lncRNA UCA1 Predicts a Poor Prognosis and Regulates Cell Proliferation and Migration by Repressing p21 and SPRY1 Expression in GC

Dysregulated expression of long non-coding RNAs (lncRNAs) has been reported in many types of cancers, indicating that it has important regulatory roles in human cancer biology. Recently, lncRNA urothelial cancer-associated 1 (UCA1) was shown to be dysregulated in many cancer types, but the detailed mechanisms remain largely unknown. In our study, we found that upregulated UCA1 is associated with poor prognosis in gastric cancer patients. Further experiments revealed that UCA1 knockdown significantly repressed the proliferation and migration both in vitro and in vivo. Moreover, RNA sequencing (RNA-seq) analysis revealed that UCA1 knockdown preferentially affected genes that are linked to cell proliferation, cell cycle, and cell migration. Mechanistically, UCA1 promotes cell proliferation progression through repressing p21 and Sprouty RTK signaling antagonist 1 (SPRY1) expression by binding to EZH2. We found that UCA1 could mediate the trimethylation of H3K27 in promoters of p21 and SPRY1. To our knowledge, this is the first report showing the global gene profile of downstream targets of UCA1 in the progression of gastric cancer. Collectively, our data reveal the important roles of UCA1 in gastric cancer (GC) oncogenesis.

Long intergenic noncoding RNA 00641 inhibits breast cancer cell proliferation, migration, and invasion by sponging miR-194-5p

Long noncoding RNAs have an essential role in the tumorigenesis of breast cancer (BC). Nonetheless, the consequences of long intergenic noncoding RNA 00641 (LINC00641) in BC remain unidentified. This study shows that LINC00641 expression level was decreased in BC tissues. LINC00641 expression level was negatively related to tumor size, lymph-node metastasis, as well as clinical stage. LINC00641 overexpression inhibited cell proliferation, migration, and invasion but stimulated apoptosis in BC cells. LINC00641 overexpression also remarkably reduced BC growth and metastasis in vivo. LINC00641 acts as a competitive endogenous RNA to sponge miR-194-5p. miR-194-5p level was higher in BC tissues and cells compared with normal-adjacent tissues and normal breast epithelial cell. miR-194-5p expression was negatively correlated with LINC00641 expression in BC tissues. miR-194-5p overexpression reversed the effects of LINC00641 on cell proliferation, cycle, apoptosis, migration, as well as invasion. In conclusion, LINC00641 inhibits BC cell proliferation, migration, as well as invasion by sponging miR-194-5p.

MicroRNA-194 inactivates hepatic stellate cells and alleviates liver fibrosis by inhibiting AKT2

BACKGROUND

Activation of hepatic stellate cells (HSCs) is a pivotal event in the onset and progression of liver fibrosis. Loss of microRNA-194 (miR-194) has been reported in activated HSCs, but the actual role of miR-194 in liver fibrosis remains uncertain.

AIM

To explore the role and potential mechanism of miR-194-mediated regulation of liver fibrosis in vitro and in vivo.

METHODS

The expression of miR-194 was examined in human fibrotic liver tissues, activated HSCs, and a carbon tetrachloride (CCl₄) mouse model by qPCR. The effects of AKT2 regulation by miR-194 on the activation and proliferation of HSCs were assessed in vitro. For in vivo experiments, we reintroduced miR-194 in mice using a miR-194 agomir to investigate the functions of miR-194 in liver fibrosis.

RESULTS

MiR-194 expression was notably lacking in activated HSCs from both humans and mice. Overexpression of miR-194 (OV-miR-194) inhibited α-smooth muscle actin (α-SMA) and type I collagen (Col I) expression and suppressed cell proliferation in HSCs by causing cell cycle arrest in G0/G1 phase. AKT2 was predicted to be a target of miR-194. Notably, the effects of miR-194 knockdown in HSCs were almost blocked by AKT2 deletion, indicating that miR-194 plays a role in HSCs via regulation of AKT2. Finally, miR-194 agomir treatment dramatically ameliorated liver fibrosis in CCl₄-treated mice.

CONCLUSION

We revealed that miR-194 plays a protective role by inhibiting the activation and proliferation of HSCs via AKT2 suppression. Our results further propose miR-194 as a potential therapeutic target for liver fibrosis.

Sprouty3 and Sprouty4, Two Members of a Family Known to Inhibit FGF-Mediated Signaling, Exert Opposing Roles on Proliferation and Migration of Glioblastoma-Derived Cells

Dysregulation of receptor tyrosine kinase-induced pathways is a critical step driving the oncogenic potential of brain cancer. In this study, we investigated the role of two members of the Sprouty (Spry) family in brain cancer-derived cell lines. Using immunoblot analyses we found essential differences in the pattern of endogenous Spry3 and Spry4 expression. While Spry4 expression was mitogen-dependent and repressed in a number of cells from higher malignant brain cancers, Spry3 levels neither fluctuated in response to serum withdrawal nor were repressed in glioblastoma (GBM)-derived cell lines. In accordance to the well-known inhibitory role of Spry proteins in fibroblast growth factor (FGF)-mediated signaling, both Spry proteins were able to interfere with FGF-induced activation of the MAPK pathway although to a different extent. In response to serum solely, Spry4 exerts its role as a negative regulator of MAPK activation. Ectopic expression of Spry4 inhibited proliferation and migration of GBM-originated cells, positioning it as a tumor suppressor in brain cancer. In contrast, elevated Spry3 levels accelerated both proliferation and migration of these cell lines, while repression of Spry3 levels using shRNA caused a significant diminished growth and migration velocity rate of a GBM-derived cell line. This argues for a tumor-promoting function of Spry3 in GBMs. Based on these data we conclude that Spry3 and Spry4 fulfill different if not opposing roles within the cancerogenesis of brain malignancies.

The Sprouty/Spred family as tumor suppressors: Coming of age

The Ras/Raf/ERK pathway is one of the most frequently dysregulated signaling pathways in various cancers. In some such cancers, Ras and Raf are hotspots for mutations, which cause continuous activation of this pathway. However, in some other cancers, it is known that negative regulators of the Ras/Raf/ERK pathway are responsible for uncontrolled activation. The Sprouty/Spred family is broadly recognized as important negative regulators of the Ras/Raf/ERK pathway, and its expression is downregulated in many malignancies, leading to hyperactivation of the Ras/Raf/ERK pathway. After the discovery of this family, intensive research investigated the mechanism by which it suppresses the Ras/Raf/ERK pathway and its roles in developmental and pathophysiological processes. In this review, we discuss the complicated roles of the Sprouty/Spred family in tumor initiation, promotion, and progression and its future therapeutic potential.

Regulation of miRNAs by Snail during epithelial-to-mesenchymal transition in HT29 colon cancer cells

Epithelial-to-mesenchymal transition (EMT) in cancer cells, represents early stages of metastasis and is a promising target in colorectal cancer (CRC) therapy. There have been many attempts to identify markers and key pathways induced throughout EMT but the process is complex and depends on the cancer type and tumour microenvironment. Here we used the colon cancer cell line HT29, which stably overexpressed Snail, the key transcription factor in early EMT, as a model for colorectal adenocarcinoma cells with a pro-metastatic phenotype. We investigated miRNA expression regulation during that phenotypic switching. We found that overexpression of Snail in HT29 cells triggered significant changes in individual miRNA levels but did not change the global efficiency of miRNA processing. Snail abundance repressed the expression of miR-192 and miR-194 and increased miR-205, let-7i and SNORD13 levels. These identified changes correlated with the reported transcriptomic alterations in Snail-overexpressing HT29 cells. We also investigated how Snail affected the miRNA content of extracellular vesicles (EVs) released from HT29 cells. Our data suggest that the presence of Snail significantly alters the complex mRNA/miRNA interactions in the early steps of metastasis and also has an impact on the content of EVs released from HT29 cells.

LncRNA TP73-AS1 accelerates tumor progression in gastric cancer through regulating miR-194-5p/SDAD1 axis

BACKGROUND

Long noncoding RNAs (lncRNAs) have been considered as significant regulators in many cancer progression, such as proliferation, invasion and other path of evolution. Nevertheless, we have not had a grasp of the role of lncRNA TP73-AS1 in gastric cancer (GC).

METHODS

qRT-PCR analysis was first conducted to examine the TP73-AS1 level in both GC tissues and cell lines. Then gain or loss-of-function assays were carried out to detect the effect of TP73-AS1 on GC development. In mechanism, bioinformatics analysis and luciferase reporter assays were used to search and confirm the target gene of TP73-AS1. Finally, rescue assays were performed to confirm the influence of TP73-AS1-miR-194-5p-SDAD1 axis on GC development.

RESULTS

TP73-AS1 was upregulated in GC tissues and cell lines. Furthermore, TP73-AS1 exerted oncogenic role in GC through promoting cell growth and metastasis. In addition, TP73-AS1 was certified as a ceRNA by regulating miR-194-5p/SDAD1 axis.

CONCLUSIONS

TP73-AS1 accelerates tumor progression in gastric cancer through regulating miR-194-5p/SDAD1 axis.

The SOX2OT/miR-194-5p axis regulates cell proliferation and mobility of gastric cancer through suppressing epithelial-mesenchymal transition

Recent studies reported that long noncoding RNAs (LncRNAs) were involved in tumorigenesis of various human cancer types, including gastric cancer (GC) through targeting microRNAs (miRNAs/miRs). The present study investigated the biological functions of LncRNA SOX2 overlapping transcript (SOX2OT)/miR-194-5p axis and its underlying mechanism in the tumor progression of GC. The results showed that relative expression of LncRNA SOX2OT was highly upregulated while the expression of miR-194-5p was down-regulated in GC tissues and cell lines (MGC-803, SGC-7901, MKN-74). Knockdown of SOX2OT inhibited cell proliferation, invasion and migration of GC cells (MGC803, MKN-74) through reducing epithelial-mesenchymal transition (EMT). Moreover, miR-194-5p was predicted to be one of the targets of SOX2OT through bioinformatics analysis and was verified by luciferase reporter assay. miR-194-5p expression was negatively regulated by SOX2OT expression in GC cells and miR-194-5p inhibitor was found to counteract the inhibitory effects of SOX2OT short hairpin (sh)RNA on cell proliferation and mobility through enhancing EMT in GC cells. Taken together, the in vitro experiments revealed that knockdown of SOX2OT inhibited cell proliferation and mobility through suppressing EMT via targeting miR-194-5p in GC. In addition, results from in vivo experiments showed that knockdown of SOX2OT suppressed GC tumor growth and matrix metalloproteinase (MMP)-2 and MMP-9 expression through inhibiting EMT. Besides that, relative expression of miR-194-5p was increased in sh-SOX2OT group compared with sh-NC group. In summary, our study elucidated that the SOX2OT/miR-194-5p axis participated in the tumor progression of GC through regulation of EMT both in vitro and in vivo. Hence, targeting the SOX2OT/miR-194-5p axis may aid in establishing novel strategies for therapy of GC.

Knockdown of SOX2OT inhibits the malignant biological behaviors of glioblastoma stem cells via up-regulating the expression of miR-194-5p and miR-122

Background

Accumulating evidence has highlighted the potential role of long non-coding RNAs (lncRNAs) in the biological behaviors of glioblastoma stem cells (GSCs). Here, we elucidated the function and possible molecular mechanisms of the effect of lncRNA-SOX2OT on the biological behaviors of GSCs.

Results

Real-time PCR demonstrated that SOX2OT expression was up-regulated in glioma tissues and GSCs. Knockdown of SOX2OT inhibited the proliferation, migration and invasion of GSCs, and promoted GSCs apoptosis. MiR-194-5p and miR-122 were down-regulated in human glioma tissues and GSCs, and miR-194-5p and miR-122 respectively exerted tumor-suppressive functions by inhibiting the proliferation, migration and invasion of GSCs, while promoting GSCs apoptosis. Knockdown of SOX2OT significantly increased the expression of miR-194-5p and miR-122 in GSCs. Dual-luciferase reporter assay revealed that SOX2OT bound to both miR-194-5p and miR-122. SOX3 and TDGF-1 were up-regulated in human glioma tissues and GSCs. Knockdown of SOX3 inhibited the proliferation, migration and invasion of GSCs, promoted GSCs apoptosis, and decreased TDGF-1 mRNA and protein expression through direct binding to the TDGF-1 promoter. Over-expression of miR-194-5p and miR-122 decreased the mRNA and protein expression of SOX3 by targeting its 3’UTR. Knockdown of TDGF-1 inhibited the proliferation, migration and invasion of GSCs, promoted GSCs apoptosis, and inhibited the JAK/STAT signaling pathway. Furthermore, SOX3 knockdown also inhibited the SOX2OT expression through direct binding to the SOX2OT promoter and formed a positive feedback loop.

Conclusion

This study is the first to demonstrate that the SOX2OT-miR-194-5p/miR-122-SOX3-TDGF-1 pathway forms a positive feedback loop and regulates the biological behaviors of GSCs, and these findings might provide a novel strategy for glioma treatment.

Electronic supplementary material

The online version of this article (10.1186/s12943-017-0737-1) contains supplementary material, which is available to authorized users.

Inhibition of S-Adenosylmethionine-Dependent Methyltransferase Attenuates TGFβ1-Induced EMT and Metastasis in Pancreatic Cancer: Putative Roles of miR-663a and miR-4787-5p

The identification of epigenetic reversal agents for use in combination chemotherapies to treat human pancreatic ductal adenocarcinomas (PDAC) remains an unmet clinical need. Pharmacologic inhibitors of Enhancer of Zeste Homolog 2 (EZH2) are emerging as potential histone methylation reversal agents for the treatment of various solid tumors and leukemia; however, the surprisingly small set of mRNA targets identified with EZH2 knockdown suggests novel mechanisms contribute to their antitumorigenic effects. Here, 3-deazaneplanocin-A (DZNep), an inhibitor of S-adenosyl-L-homocysteine hydrolase and EZH2 histone lysine-N-methyltransferase, significantly reprograms noncoding microRNA (miRNA) expression and dampens TGFβ1-induced epithelial-to-mesenchymal (EMT) signals in pancreatic cancer. In particular, miR-663a and miR-4787-5p were identified as PDAC-downregulated miRNAs that were reactivated by DZNep to directly target TGFβ1 for RNA interference. Lentiviral overexpression of miR-663a and miR-4787-5p reduced TGFβ1 synthesis and secretion in PDAC cells and partially phenocopied DZNep's EMT-resisting effects, whereas locked nucleic acid (LNA) antagomiRNAs counteracted them. DZNep, miR-663a, and miR-4787-5p reduced tumor burden in vivo and metastases in an orthotopic mouse pancreatic tumor model. Taken together, these findings suggest the epigenetic reprogramming of miRNAs by synthetic histone methylation reversal agents as a viable approach to attenuate TGFβ1-induced EMT features in human PDAC and uncover putative miRNA targets involved in the process.

IMPLICATIONS

The findings support the potential for synthetic histone methylation reversal agents to be included in future epigenetic-chemotherapeutic combination therapies for pancreatic cancer. Mol Cancer Res; 14(11); 1124-35. ©2016 AACR.

Sprouty2 Suppresses Epithelial-Mesenchymal Transition of Human Lens Epithelial Cells through Blockade of Smad2 and ERK1/2 Pathways

Transforming growth factor β (TGFβ)-induced epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) plays a key role in the pathogenesis of anterior subcapsular cataract (ASC) and capsule opacification. In mouse lens, Sprouty2 (Spry2) has a negative regulatory role on TGFβ signaling. However, the regulation of Spry2 during ASC development and how Spry2 modulates TGFβ signaling pathway in human LECs have not been characterized. Here, we demonstrate that Spry2 expression level is decreased in anterior capsule LECs of ASC patients. Spry2 negatively regulates TGFβ2-induced EMT and migration of LECs through inhibition of Smad2 and ERK1/2 phosphorylation. Also, blockade of Smad2 or ERK1/2 activation suppresses EMT caused by Spry2 downregulation. Collectively, our results for the first time show in human LECs that Spry2 has an inhibitory role in TGFβ signaling pathway. Our findings in human lens tissue and epithelial cells suggest that Spry2 may become a novel therapeutic target for the prevention and treatment of ASC and capsule opacification.