MiR-590-3p promotes proliferation and metastasis of colorectal cancer via Hippo pathway

Impaired Expression of the Salvador Homolog-1 Gene Is Associated with the Development and Progression of Colorectal Cancer

Salvador homolog-1 (SAV1) is a component of the Hippo pathway that regulates tissue growth and homeostasis by affecting diverse cell processes, including apoptosis, cell division, and differentiation. The aberrant expression of Hippo pathway components has been observed in various human cancers. This study aimed to examine the expression level of the SAV1 gene in colorectal cancer (CRC) and its prognostic value and associations with tumor progression. We obtained matched pairs of tumor tissue and non-cancerous mucosa of the large intestine from 94 CRC patients as well as 40 colon biopsies of healthy subjects collected during screening colonoscopy. The tissue samples and CRC cell lines were quantified for SAV1 mRNA levels using the quantitative polymerase chain reaction method, while SAV1 protein expression was estimated in the paired tissues of CRC patients using immunohistochemistry. The average level of SAV1 mRNA was decreased in 93.6% of the tumor tissues compared to the corresponding non-cancerous tissues and biopsies of healthy colon mucosa. A downregulated expression of SAV1 mRNA was also noted in the CRC cell lines. Although the average SAV1 immunoreactivity was increased in the CRC samples compared to the non-cancerous tissues, a decreased immunoreactivity of the SAV1 protein in the tumor specimens was associated with lymph node involvement and higher TNM disease stage and histological grade. The results of our study suggest that the impaired expression of SAV1 is involved in CRC progression.

Deciphering Promoter Hypermethylation of Genes Encoding for RASSF/Hippo Pathway Reveals the Poor Prognostic Factor of RASSF2 Gene Silencing in Colon Cancers

Simple Summary

Colorectal cancer (CRC) is a major public health issue due to its incidence and mortality. Thus, the development of molecular biomarkers is essential to optimize its therapeutic management. Such markers could be identified among the members of the RASSF/Hippo pathway. Indeed, epigenetic alterations are strongly implicated in colorectal carcinogenesis and this pathway is altered in many cancers, mainly by hypermethylation of the promoter of the gene coding for its members. The objectives of the study were to map the hypermethylation of the RASSF/Hippo pathway promoters in a morphologically, clinically, and prognostically well-characterized population of colon cancers. This first report of a whole systematic analysis of the Hippo pathway in colon cancer highlights RASSF2 gene promoter hypermethylation as a worst prognostic factor and a tool to be sought in clinical practice to improve therapeutic management.

Abstract

The aims of this study were to assess the frequency of promoter hypermethylation of the genes encoding the Ras associated domain family (RASSF)/Hippo pathway, as well as the impact on overall (OS) and progression-free survival (PFS) in a single-center retrospective cohort of 229 patients operated on for colon cancers. Hypermethylation status was investigated by methylation-specific PCR on the promoters of the RASSF1/2, STK4/3 (encoding Mammalian Ste20-like protein 1 and 2 (MST1 and 2), respectively), and LATS1/2 genes. Clinicopathological characteristics, recurrence-free survival, and overall survival were analysed. We found the RASSF/Hippo pathway to be highly silenced in colon cancer, and particularly RASSF2 (86%). The other promoters were hypermethylated with a lesser frequency of 16, 3, 1, 10 and 6%, respectively for RASSF1, STK4, STK3, LATS1, and LATS2 genes. As the hypermethylation of one RASSF/Hippo family member was by no means exclusive from the others, 27% of colon cancers displayed the hypermethylation of at least two RASSF/Hippo member promotors. The median overall survival of the cohort was 60.2 months, and the median recurrence-free survival was 46.9 months. Survival analyses showed a significantly poorer overall survival of patients when the RASSF2 promoter was hypermethylated (p = 0.03). The median OS was 53.5 months for patients with colon cancer with a hypermethylated RASSF2 promoter versus still not reached after 80 months follow-up for other patients, upon univariate analysis (HR = 1.86, [95% CI: 1.05–3.3], p < 0.03). Such difference was not significant for relapse-free survival as in multivariate analysis. A logistic regression model showed that RASSF2 hypermethylation was an independent factor. In conclusion, RASSF2 hypermethylation is a frequent event and an independent poor prognostic factor in colon cancer. This biomarker could be investigated in clinical practice.

SFTPA1 is a potential prognostic biomarker correlated with immune cell infiltration and response to immunotherapy in lung adenocarcinoma

Pulmonary surfactant protein A1 (SFTPA1) is a member of the C-type lectin subfamily that plays a critical role in maintaining lung tissue homeostasis and the innate immune response. SFTPA1 disruption can cause several acute or chronic lung diseases, including lung cancer. However, little research has been performed to associate SFTPA1 with immune cell infiltration and the response to immunotherapy in lung cancer. The findings of our study describe the SFTPA1 expression profile in multiple databases and was validated in BALB/c mice, human tumor tissues, and paired normal tissues using an immunohistochemistry assay. High SFTPA1 mRNA expression was associated with a favorable prognosis through a survival analysis in lung adenocarcinoma (LUAD) samples from TCGA. Further GeneOntology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that SFTPA1 was involved in the toll-like receptor signaling pathway. An immune infiltration analysis clarified that high SFTPA1 expression was associated with an increased number of M1 macrophages, CD8⁺ T cells, memory activated CD4⁺ T cells, regulatory T cells, as well as a reduced number of M2 macrophages. Our clinical data suggest that SFTPA1 may serve as a biomarker for predicting a favorable response to immunotherapy for patients with LUAD. Collectively, our study extends the expression profile and potential regulatory pathways of SFTPA1 and may provide a potential biomarker for establishing novel preventive and therapeutic strategies for lung adenocarcinoma.

Curcumol inhibits the viability and invasion of colorectal cancer cells via miR-30a-5p and Hippo signaling pathway

MicroRNA-30a-5p (miR-30a-5p), which functions as a tumor suppressor, has been reported to be downregulated in colorectal cancer (CRC) tissues and to be associated with cancer invasion. However, the detailed regulatory mechanism of curcumol in the malignant progression of CRC remains unknown. MTT, Transwell, scratch, western blotting and reverse transcription-quantitative PCR assays were performed to examine how curcumol inhibited CRC cell viability, invasion and migration, and to detect the role of miR-30a-5p and curcumol in the invasion and Hippo signaling pathways of CRC cells. The present study revealed that miR-30a-5p expression was downregulated in human CRC tissues and cells. The results demonstrated that miR-30a-5p downregulation was accompanied by the inactivation of the Hippo signaling pathway, which was demonstrated to promote CRC cell viability, invasion and migration. Curcumol treatment was identified to increase miR-30a-5p expression and to activate the Hippo signaling pathway, which in turn inhibited the invasion and migration of CRC cells. Overexpression of miR-30a-5p enhanced the effects of curcumol on cell invasion and migration, and the Hippo signaling pathway in CRC cells. Furthermore, downregulation of miR-30a-5p reversed the effects of curcumol on cell invasion and migration, and the Hippo signaling pathway in CRC cells. These findings identified novel signaling pathways associated with miR-30a-5p and revealed the effects of curcumol on miR-30a-5p expression. Therefore, curcumol may serve as a potential therapeutic strategy to delay CRC progression.

The tumor suppressor role of salvador family WW domain-containing protein 1 (SAV1): one of the key pieces of the tumor puzzle

PURPOSE

In the complex tumor scenario, understanding the function of proteins with protumor or antitumor roles is essential to support advances in the cancer clinical area. Among them, the salvador family WW domain-containing protein 1 (SAV1) is highlighted. This protein plays a fundamental role in the tumor suppressor face of the Hippo pathway, which are responsible for controlling cell proliferation, organ size, development and tissue homeostasis. However, the functional dysregulation of this pathway may contribute to tumorigenesis and tumor progression. As SAV1 is a tumor suppressor scaffold protein, we explored the functions performed by SAV1 with its partners, the regulation of its expression, and its antitumor role in various types of cancer.

METHODS

We selected and analyzed 80 original articles and reviews from Pubmed that focuses on the study of SAV1 in cancer.

RESULTS

SAV1 interacts with several proteins, has different functions and acts as tumor suppressor by other mechanisms besides Hippo pathway. SAV1 expression regulation seems to occur by microRNAs and rarely by mutation or promoter methylation. It is downregulated in different types of cancer, which leads to cancer promotion and progression and is associated with poor prognosis. In vivo models have shown that the loss of SAV1 contributes to tumorigenesis.

CONCLUSION

SAV1 plays a relevant role as tumor suppressor in several types of cancer, highlighting SAV1 and the Hippo pathway's importance to cancer. Thus, encouraging further studies to include the SAV1 as a molecular key piece in cancer biology and in clinical approaches to cancer.

Regulation of Hippo signaling pathway in cancer: A MicroRNA perspective

Recent studies have suggested that Hippo signaling is not only involved in controlling organ size in Drosophila but can also regulate cell proliferation, tissue homeostasis, differentiation, apoptosis and regeneration. Any dysregulation of Hippo signaling, especially the hyper activation of its downstream effectors YAP/TAZ, can lead to uncontrolled cell proliferation and malignant transformation. In majority of cancers, expression of YAP/TAZ is extremely high and this increased expression of YAP/TAZ has been shown to be an independent predictor of prognosis and indicator of increased cell proliferation, metastasis and poor survival. In this review, we have summarized the most recent findings about the cross talk of Hippo signaling pathway with other signaling pathways and its regulation by different miRNAs in various cancer types. Recent evidence has suggested that Hippo pathway is also involved in mediating the resistance of different cancer cells to chemotherapeutic drugs and in a few cancer types, this is brought about by regulating miRNAs. Therefore, the delineation of the underlying mechanisms regulating the chemotherapeutic resistance might help in developing better treatment options. This review has attempted to provide an overview of different drugs/options which can be utilized to target oncogenic YAP/TAZ proteins for therapeutic interventions.

miR-590-5p may regulate colorectal cancer cell viability and migration by targeting PDCD4

Recent studies have revealed that microRNAs (miRs) are involved in the pathogenesis of colorectal cancer (CRC); however, the roles of miR-590-5p in CRC are not completely understood. Therefore, the present study investigated the expression of miR-590-5p and programmed cell death 4 (PDCD4) in CRC tissues and healthy adjacent tissues via reverse transcription-quantitative PCR. Furthermore, human CRC cells were cultured in vitro and transfected with miR-590-5p inhibitor. CRC cell viability, migration and invasion were evaluated by conducting MTT, wound healing and Transwell assays, respectively. Additionally, the relative expression of PDCD4 and phosphorylated-Smad2/3 was analyzed via western blotting. miR-590-5p was significantly upregulated and PDCD4 was significantly downregulated in CRC tissues compared with healthy adjacent tissues. Moreover, the results indicated that miR-590-5p knockdown inhibited cell viability and migration by altering the expression of PDCD4, transforming growth factor-β and phosphorylated-Smad2/3. PDCD4 was identified as a direct target of miR-590-5p. In conclusion, the results of the present study suggested that miR-590-5p may regulate CRC cell viability and migration, indicating that miR-590-5p may serve as a potential therapeutic target for CRC.

Hsa-MiR-590-3p Promotes the Malignancy Progression of Pancreatic Ductal Carcinoma by Inhibiting the Expression of p27 and PPP2R2A via G1/S Cell Cycle Pathway

Objective

To investigate the effect of miR-590-3p on the malignant biological behavior of pancreatic cancer, and to explore the target genes and pathways directly affected by miR-590-3p, to provide new therapeutic ideas and targets for the study of the diagnosis and treatment of pancreatic cancer.

Methods

We used qRT-PCR to measure miR-590-3p expression quantities. We used cell cycle, CCK-8, clonal formation to verify the change of proliferation capacity of PC cells. We used transwell assay to detect the migration and invasion of PC cells. We used the bioinformatics tool TargetScan (http://www.targetscan.org) to identify the possible target genes of miR-590-3p. Immunohistochemistry revealed the clinicopathological significance of PPP2R2A, p27 and miR-590-3p in the expression of pancreatic cancer. Western blot was used to detect the expression changes of PPP2R2A, p27 and G1/S cell cycle pathway-related proteins CDK2, cyclinE2 and p21 after transfection of mimics and inhibitors of miR-590-3p.

Results

According to our study, hsa-miR-590-3p expression was significantly higher in PC tissues than that in paired normal pancreas, which was associated with PC tumor size (P=0.042) and preoperative CA19-9 level (P=0.046) of PC patients. Its overexpression promoted PC cell proliferation, invasion and migration following with the p27 and PPP2R2A protein downregulation in Capan-2, PANC-1 and BxPC-3 cells, and vice versa. Bioinformatics analysis and dual-luciferase reporter assay further confirmed that p27 and PPP2R2A were direct target genes of miR-590-3p. The negative relationship of miR-590-3p with p27 and PPP2R2A was also observed in PC tissues.

Conclusion

MiR-590-3p promotes the proliferation, migration and invasion of pancreatic cancer cells. MiR-590-3p directly downregulated p27 and PPP2R2A and via the G1/S cell cycle pathway to promote the development of pancreatic cancer.

Identification of miRNA Master Regulators in Breast Cancer

Breast cancer is the neoplasm with the highest number of deaths in women. Although the molecular mechanisms associated with the development of this tumor have been widely described, metastatic disease has a high mortality rate. In recent years, several studies show that microRNAs or miRNAs regulate complex processes in different biological systems including cancer. In the present work, we describe a group of 61 miRNAs consistently over-expressed in breast cancer (BC) samples that regulate the breast cancer transcriptome. By means of data mining from TCGA, miRNA and mRNA sequencing data corresponding to 1091 BC patients and 110 normal adjacent tissues were downloaded and a miRNA-mRNA network was inferred. Calculations of their oncogenic activity demonstrated that they were involved in the regulation of classical cancer pathways such as cell cycle, PI3K-AKT, DNA repair, and k-Ras signaling. Using univariate and multivariate analysis, we found that five of these miRNAs could be used as biomarkers for the prognosis of overall survival. Furthermore, we confirmed the over-expression of two of them in 56 locally advanced BC samples obtained from the histopathological archive of the National Cancer Institute of Mexico, showing concordance with our previous bioinformatic analysis.

MicroRNA-18a targeting of the STK4/MST1 tumour suppressor is necessary for transformation in HPV positive cervical cancer

Human papillomaviruses (HPV) are a major cause of malignancy worldwide. They are the aetiological agents of almost all cervical cancers as well as a sub-set of other anogenital and head and neck cancers. Hijacking of host cellular pathways is essential for virus pathogenesis; however, a major challenge remains to identify key host targets and to define their contribution to HPV-driven malignancy. The Hippo pathway regulates epithelial homeostasis by down-regulating the function of the transcription factor YAP. Increased YAP expression has been observed in cervical cancer but the mechanisms driving this increase remain unclear. We found significant down-regulation of the master Hippo regulatory kinase STK4 (also termed MST1) in cervical disease samples and cervical cancer cell lines compared with healthy controls. Re-introduction of STK4 inhibited the proliferation of HPV positive cervical cells and this corresponded with decreased YAP nuclear localization and decreased YAP-dependent gene expression. The HPV E6 and E7 oncoproteins maintained low STK4 expression in cervical cancer cells by upregulating the oncomiR miR-18a, which directly targeted the STK4 mRNA 3’UTR. Interestingly, miR-18a knockdown increased STK4 expression and activated the Hippo pathway, significantly reducing cervical cancer cell proliferation. Our results identify STK4 as a key cervical cancer tumour suppressor, which is targeted via miR-18a in HPV positive tumours. Our study indicates that activation of the Hippo pathway may offer a therapeutically beneficial option for cervical cancer treatment.

HPVs are the causative agents of ~5% of human cancers. Better understanding of the mechanisms by which these viruses deregulate cellular signalling pathways may offer therapeutic options for HPV-associated malignancies. The transcription factor YAP is active in cervical cancer but the mechanisms controlling its activation remain unclear. YAP is negatively regulated and sequestered in the cytoplasm through activation of the Hippo pathway. We discovered that expression of the master Hippo kinase, STK4 (also termed MST1), is reduced in HPV positive cervical cell lines and cervical disease samples. Low STK4 levels were maintained by the HPV oncogenes through up-regulation of miR-18a, which targeted the STK4 mRNA 3’UTR. Re-introduction of STK4 or bypassing miR-18a-dependent regulation de-activated YAP-driven transcription and reduced cell proliferation. Thus, our study identifies a novel interplay between HPV oncogenes and the STK4 tumour suppressor and identifies the Hippo pathway as a target for therapeutic intervention in HPV-associated malignancies.

Effect of LINC00657 on Apoptosis of Breast Cancer Cells by Regulating miR-590-3p

Objective

To investigate the effect of LINC00657 on breast carcinoma by regulating miR-590-3p.

Methods

Ninety-seven cases with breast carcinoma who were admitted to Qingdao Chengyang People’s Hospital were collected. The breast carcinoma (n=97) and tumor-adjacent tissues (n=97) of patients were collected during the operation with the permission of the patients. The expressions of LINC00657 and miR-590-3p were detected in breast carcinoma cells and tissues. The breast carcinoma cells were transfected and their proliferation, migration, invasion and apoptosis were detected.

Results

LINC00657 was highly expressed in breast carcinoma tissues, while miR-590-3p was reduced (P<0.05). The proliferation, invasion and migration of cells transfected with si-LINC00657 or miR-590-3p-mimics were significantly inhibited, and the apoptosis rate increased, resulting in the up-regulation of the expressions of apoptosis-related proteins Bax and Caspase-3 and the reduction of Bcl-2 (P<0.05). After si-LINC00657 or miR-590-3p-mimics, the level of GOLPH3 decreased. Through double luciferase report and RIP experiment, it was confirmed that LINC00657 could act as a sponge of miR-590-3p to negatively regulate its expression. After correlation analysis, it was concluded that there was a negative correlation between LINC00657 and miR-590-3p. Rescue experiments concluded that co-transfection of si-LINC00657+miR-590-3P-inhibitor could reverse the inhibitory action of si-LINC00657 on breast carcinoma cells.

Conclusion

LINC00657 can participate in the biological behavior process of breast carcinoma by regulating miR-590-3p/GOLPH3 signal.

Long Non-Coding RNA HAND2-AS1 Inhibits Growth and Migration of Gastric Cancer Cells Through Regulating the miR-590-3p/KCNT2 Axis

Introduction

Long non-coding RNAs (lncRNAs) are regarded as crucial regulators for cancer initiation and progression. Heart and Neural Crest Derivatives Expressed 2 antisense RNA 1 (HAND2-AS1) was recently proposed to function as tumor suppressor in several human cancers. However, its role in gastric cancer (GC) remains unclear.

Methods

HAND2-AS1 expression in GC tissues and normal tissues was analyzed at GEPIA (a web server for gene expression profiling analysis). Moreover, RT-qPCR method was utilized to explore HAND2-AS1 expression in GC cells and normal cell. In vitro experiments were carried out using cell counting kit-8 assay, colony formation assay, and flow cytometry assay, respectively. Bioinformatic analysis and luciferase activity reporter assay were performed to identify the downstream targets of HAND2-AS1.

Results

We found HAND2-AS1 has decreased expression in both GC tissues and cells. Overexpression of HAND2-AS1 was able to inhibit GC cell proliferation, colony formation, but promote apoptosis. On the contrary, knockdown of HAND2-AS1 could cause the opposite effects on GC cells. Furthermore, HAND2-AS1 was shown to function as a competitive RNA that binds with microRNA-590-3p (miR-590-3p) to affect the expression of potassium sodium-activated channel subfamily T member 2 (KCNT2).

Discussion

Our results indicated the tumor suppressive role of HAND2-AS1 in GC. Also, the newly identified HAND2-AS1/miR-590-3p/KCNT2 axis will help us to understand the role of HAND2-AS1 in cancer.

NOL6, a new founding oncogene in human prostate cancer and targeted by miR-590-3p

We identified a new human prostate cancer oncogene, nucleolar protein 6 (NOL6), and screened for microRNAs that interfere with its expression in prostate cancer cells. A NOL6 shRNA plasmid was constructed and packaged into lentivirus to infect PC-3 cells. The ability of cell proliferation was evaluated by cell counting and colony formation. Cell cycle progression and apoptosis of PC-3 cells were detected by flow cytometry. A retrieval database was used to screen possible target microRNAs, and the effect of target miRNA overexpression on PC-3 cells was observed. The results showed that after NOL6 gene knockdown, PC-3 cell mitosis was blocked, proliferation was decreased, and the number of apoptotic cells were increased. The microRNA, hsa-miR-590-3p, that can regulate the NOL6 gene expression was identified. Overexpression of miR-590-3p in PC-3 cells by synthetic mimics resulted in abnormal mitosis, decreased cell proliferation, and an increase in apoptosis. In summary, we identified NOL6 as a novel oncogene in the human prostate cancer PC-3 cell line. The miRNA miR-590-3p interferes with NOL6 expression making it a potential treatment for prostate cancer.

Contributions of Gene Modules Regulated by Essential Noncoding RNA in Colon Adenocarcinoma Progression

Noncoding RNAs (ncRNAs), especially microRNA (miRNA) and long noncoding RNA (lncRNA), have an impact on a variety of important biological processes during colon adenocarcinoma (COAD) progression. This includes chromatin organization, transcriptional and posttranscriptional regulation, and cell-cell signaling. The aim of this study is to identify the ncRNA-regulated modules that accompany the progression of COAD and to analyze their mechanisms, in order to screen the potential prognostic biomarkers for COAD. An integrative molecular analysis was carried out to identify the crosstalks of gene modules between different COAD stages, as well as the essential ncRNAs in the posttranscriptional regulation of these modules. 31 ncRNA regulatory modules were found to be significantly associated with overall survival in COAD patients. 17 out of the 31 modules (in which ncRNAs played essential roles) had improved the predictive ability for COAD patient survival compared to only the mRNAs of those modules, which were enriched in the core cancer hallmark pathways with closer interactions. These suggest that the ncRNAs' regulatory modules not only exhibit close relation to COAD progression but also reflect the dynamic significant crosstalk of genes in the modules to the different malignant extent of COAD.

Recycling Endosomes in Mature Epithelia Restrain Tumorigenic Signaling

The effects of polarized membrane trafficking in mature epithelial tissue on cell growth and cancer progression have not been fully explored in vivo. A majority of colorectal cancers have reduced and mislocalized Rab11, a small GTPase dedicated to trafficking of recycling endosomes. Patients with low Rab11 protein expression have poor survival rates. Using genetic models across species, we show that intact recycling endosome function restrains aberrant epithelial growth elicited by APC or RAS mutations. Loss of Rab11 protein led to epithelial dysplasia in early animal development and synergized with oncogenic pathways to accelerate tumor progression initiated by carcinogen, genetic mutation, or aging. Transcriptomic analysis uncovered an immediate expansion of the intestinal stem cell pool along with cell-autonomous Yki/Yap activation following disruption of Rab11a-mediated recycling endosomes. Intestinal tumors lacking Rab11a traffic exhibited marked elevation of nuclear Yap, upd3/IL6-Stat3, and amphiregulin-MAPK signaling, whereas suppression of Yki/Yap or upd3/IL6 reduced gut epithelial dysplasia and hyperplasia. Examination of Rab11a function in enteroids or cultured cell lines suggested that this endosome unit is required for suppression of the Yap pathway by Hippo kinases. Thus, recycling endosomes in mature epithelia constitute key tumor suppressors, loss of which accelerates carcinogenesis. SIGNIFICANCE: Recycling endosome traffic in mature epithelia constitutes a novel tumor suppressing mechanism.

miR-590-5p promotes liver cancer growth and chemotherapy resistance through directly targeting FOXO1

miR-590-5p functions as an onco-miR or an anti-onco-miR in various types of cancers. However, the exact role of miR-590-5p in liver cancer remains to be elucidated. In the present study, we explored the predictive role of miR-590-5p expression in liver cancer patients. In addition, CCK-8 assay, colony formation assay, and analysis of xenograft tumors were performed to investigate the biological effects of miR-590-5p in liver cancer. A direct target of miR-590-5p was identified based on a luciferase assay and further molecular experiments. Our results demonstrated that miR-590-5p was upregulated in malignant tissues of liver cancer patients and in liver cancer cell lines. miR-590-5p expression was found to be inversely correlated with disease-free survival of liver cancer patients. Furthermore, both in vitro and in vivo experiments showed that miR-590-5p knockdown inhibited the growth of HepG2 and Bel-7404 tumor cells by promoting apoptosis and cell cycle arrest. We also demonstrated that increasing of miR-590-5p in 5-Fu resistant patients and liver cancer cells, and knockdown of miR-590-5p enhances chemosensitivity to 5-Fu in liver cancer. FOXO1 was identified as a direct and necessary target of miR-590-5p during regulating liver cancer growth. Taken together, our findings provide insights into the role of miR-590-5p in liver cancer. Moreover, it is suggested that miR-590-5p can serve as a novel therapeutic target and predictive biomarker for liver cancer.

miR-590-3p Targets Cyclin G2 and FOXO3 to Promote Ovarian Cancer Cell Proliferation, Invasion, and Spheroid Formation

Ovarian cancer is the leading cause of death from gynecological cancers. MicroRNAs (miRNAs) are small, non-coding RNAs that interact with the 3' untranslated region (3' UTR) of target genes to repress their expression. We have previously reported that miR-590-3p promoted ovarian cancer growth and metastasis, in part by targeting Forkhead box A (FOXA2). In this study, we further investigated the mechanisms by which miR-590-3p promotes ovarian cancer development. Using luciferase reporter assays, real-time PCR, and Western blot analyses, we demonstrated that miR-590-3p targets cyclin G2 (CCNG2) and Forkhead box class O3 (FOXO3) at their 3' UTRs. Silencing of CCNG2 or FOXO3 mimicked, while the overexpression of CCNG2 or FOXO3 reversed, the stimulatory effect of miR-590-3p on cell proliferation and invasion. In hanging drop cultures, the overexpression of mir-590 or the transient transfection of miR-590-3p mimics induced the formation of compact spheroids. Transfection of the CCNG2 or FOXO3 plasmid into the mir-590 cells resulted in the partial disruption of the compact spheroid formation. Since we have shown that CCNG2 suppressed β-catenin signaling, we investigated if miR-590-3p regulated β-catenin activity. In the TOPFlash luciferase reporter assays, mir-590 increased β-catenin/TCF transcriptional activity and the nuclear accumulation of β-catenin. Silencing of β-catenin attenuated the effect of mir-590 on the compact spheroid formation. Taken together, these results suggest that miR-590-3p promotes ovarian cancer development, in part by directly targeting CCNG2 and FOXO3.

Expression profile and bioinformatics analysis of COMMD10 in BALB/C mice and human

COMMD10, a member of COMMD protein, has been proved to target p65 NF-kappaB (nuclear factor-kappaB) subunit and reduce its nuclear translocation, thereby leading to the inactivation of NF-kappaB pathway and suppression of colorectal cancer invasion and metastasis. The aim of this study is to explore its expression pattern and tissue distribution in human normal tissues and other tumor tissues and to investigate the relevant mechanism. We firstly provided the expression profile and histological distribution of COMMD10 in various BALB/c mice tissues and identified the biological distribution of COMMD10 in different kinds of human normal and tumor tissues. We verified the expression profile of COMMD10 using TCGA database. The interacting genes of COMMD10 were predicted by using STRING using. Finally, we performed database, and the microRNAs targeting COMMD10 were predicted using miRDB, miRWalk, TargetScan and microRNA. GO and KEGG pathway analyses were performed to predict the biological function of COMMD10 and its interacting genes. mRNA expression of COMMD10 showed the highest level in the lung and spleen, and the lowest level in the heart and brain. Immunohistochemistry detection revealed that COMMD10 was expressed in different tissues with different degrees and was was located mainly in the cytoplasm. Subsequently, we showed that COMMD10 displayed various degrees of expression in different human normal tissues that mainly located in cytoplasm, while COMMD10 of liver cells resided in both nucleus and cytoplasm. All the tumor tissues except breast small cell carcinoma, breast phyllodes tumor, lung adenocarcinoma, thymoma, cervical cancer and bladder urothelial carcinoma showed that COMMD10 was positive staining in cytoplasm. Kaplan-Meier plotter indicated that renal clear cell carcinoma patients with increased expression level of COMMD10 exhibited longer survival. STRING database revealed that COMMD10 had 41 interacting genes, and data from 4 different databases indicated that hsa-miR-590-3p may be the potential regulator of COMMD10. GO analysis demonstrated that COMMD10 and its interacting genes were mainly enriched in Cullin-RING ubiquitin ligase complexes, binding and transport of copper ions, the transport and steady-state maintenance of copper ions, transcription, translation and transport of proteins, and negatively regulate the activity of NF-kappaB transcription factors. KEGG pathway showed that COMMD10 and its interacting genes were mainly involved in renal cell carcinoma, HIF-1 signaling pathways, ubiquitination-mediated proteolysis, endocytosis and mineral absorption. COMMD10 may play a tumor suppressive role in renal clear cell carcinoma through the miR-590-3p-COMMD10-Cul2-RBX1-NF-κB/HIF/NRF2 pathway and regulate the chemotherapy resistance of various tumor cells to cisplatin.

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.

miR-590-3p is a novel microRNA which suppresses osteosarcoma progression by targeting SOX9

Osteosarcoma is the most common primary bone malignancy and arises primarily in the metaphyseal ends of long bones in children and adolescents. m iR-590 has been found to have anti-tumor effects in many other cancers. However, the role of miR-590-3p in osteosarcoma is poorly understood. In this study, we show that miR-590-3p was significantly decreased both in osteosarcoma tissues and cell lines, suggesting a potential role of miR-590-3p in osteosarcoma. Over-expression of miR-590-3p inhibited U2OS cell viability as shown by the CCK-8 assay and clonogenic assay. Ki-67 immunofluorescence staining and cell cycle analysis revealed that up-regulation of miR-590-3p inhibited U2OS cell proliferation. Transfection with miR-590-3p mimics suppressed PCNA, Cyclin D1 and CDK4 expression and increased p53 and p21 expression. In addition, U2OS cells transfected with miR-590-3p mimics exhibited reduced cell invasion and migration, characterized by the wound healing assay and transwell assay. Furthermore, bioinformatics analysis demonstrated that SOX9 was a potential target of miR-590-3p. SOX9 was up-regulated in osteosarcoma tissues. Transfection with miR-590-3p mimics markedly suppressed SOX9 expression both at the mRNA level and protein level. Dual luciferase assay validated the direct binding site of miR-590-3p on SOX9. Exogenous SOX9 expression in U2OS cells at least partially reversed the effects of miR-590-3p in U2OS cells. Enforced SOX9 expression restored cell viability in osteosarcoma cells transfected with miR-590-3p mimics. In addition, over-expression of SOX9 restored decreased cell metastasis properties caused by transfection with miR-590-3p mimics in osteosarcoma cells. In summary, these results indicated that miR-590-3p is an anti-cancer miRNA that can inhibit proliferation and metastasis in osteosarcoma cells. Our findings provide a novel insight into the biological function of miR-590-3p in osteosarcoma and SOX9 may be a potential therapeutic target for osteosarcoma.

miR-590-3p Promotes Ovarian Cancer Growth and Metastasis via a Novel FOXA2-Versican Pathway

miRNAs play important roles in gene regulation, and their dysregulation is associated with many diseases, including epithelial ovarian cancer (EOC). In this study, we determined the expression and function of miR-590-3p in EOC. miR-590-3p levels were higher in high-grade carcinoma when compared with low-grade or tumors with low malignant potential. Interestingly, plasma levels of miR-590-3p were significantly higher in patients with EOC than in subjects with benign gynecologic disorders. Transient transfection of miR-590-3p mimics or stable transfection of mir-590 increased cell proliferation, migration, and invasion. In vivo studies revealed that mir-590 accelerated tumor growth and metastasis. Using a cDNA microarray, we identified forkhead box A2 (FOXA2) and versican (VCAN) as top downregulated and upregulated genes by mir-590, respectively. miR-590-3p targeted FOXA2 3' UTR to suppress its expression. In addition, knockdown or knockout of FOXA2 enhanced cell proliferation, migration, and invasion. Overexpression of FOXA2 decreased, whereas knockout of FOXA2 increased VCAN mRNA and protein levels, which was due to direct binding and regulation of the VCAN gene by FOXA2. Interrogation of the TCGA ovarian cancer database revealed a negative relationship between FOXA2 and VCAN mRNA levels in EOC tumors, and high FOXA2/low VCAN mRNA levels in tumors positively correlated with patient survival. Finally, overexpression of FOXA2 or silencing of VCAN reversed the effects of mir-590. These findings demonstrate that miR-590-3p promotes EOC development via a novel FOXA2-VCAN pathway.Significance: Low FOXA2/high VCAN levels mediate the tumor-promoting effects of miR-590-3p and negatively correlate with ovarian cancer survival. Cancer Res; 78(15); 4175-90. ©2018 AACR.

Loss of PPM1F expression predicts tumour recurrence and is negatively regulated by miR-590-3p in gastric cancer

OBJECTIVES

MicroRNAs (miRNAs) as small non-coding RNA molecules act by negatively regulating their target genes. Recent studies have shown that protein phosphatase Mg2+/Mn2+-dependent 1F (PPM1F) plays a critical role in cancer metastasis. But, the regulation mechanisms of PPM1F by miRNAs in gastric cancer (GC) remain undefined.

METHODS

The correlation of PPM1F or miR-590-3p (miR-590) expression with clinicopathological features and prognosis of the patients with GC was analysed by TCGA RNA-sequencing data. The miRNAs that target PPM1F gene were identified by bioinformatics and Spearman correlation analysis, and the binding site between miR-590 and PPM1F 3'UTR was confirmed by dual luciferase assay. MTT and Transwell assays were conducted to evaluate the effects of miR-590 or (and) PPM1F on cell proliferation and invasion.

RESULTS

We found that PPM1F expression was downregulated in GC tissues and cell lines and was correlated with tumour recurrence in patients with GC. The decreased expression of PPM1F was attributed to the dysregulation of miR-590 expression rather than its genetic or epigenetic alterations. Overexpression of miR-590 promoted cell proliferation and invasion capability of GC cells, while knockdown of miR-590 reversed these effects. Moreover, PPM1F was validated as a direct target of miR-590 and counteracted the tumour-promoting effects caused by miR-590. The expression of miR-590 presented the negative correlation with PPM1F expression and acted as an independent prognostic factor for tumour recurrence in patients with GC.

CONCLUSION

PPM1F may function as a suppressive factor and is negatively regulated by miR-590 in GC.

IgY Reduces AFB1-Induced Cytotoxicity, Cellular Dysfunction, and Genotoxicity in Human L-02 Hepatocytes and Swan 71 Trophoblasts

Aflatoxin B₁ (AFB₁) causes hepatotoxic, genotoxic, and immunotoxic effects in a variety of species. Although various neutralizing agents of AFB₁ toxicity have been studied, the egg yolk immunoglobulin (IgY) detoxification of small molecular toxins and the mechanisms underlying such effects have not yet been reported. In this investigation, anti-AFB₁ IgY against AFB₁ was successfully raised, and a competitive indirect enzyme-linked immunosorbent assay was established with a sensitive half-maximal inhibitory concentration (IC_50, 2.4 ng/mL) and dynamic working range (0.13-43.0 ng/mL). The anti-AFB₁ IgY obtained reduced AFB₁-induced cytotoxicity, cellular dysfunction, and genotoxicity by protecting cells against apoptotic body formation and DNA strand breaks, preventing G2/M phase cell cycle arrest, reducing AFB₁-DNA adduct and reactive oxygen species production and maintaining cell migration and invasion and the mitochondrial membrane potential. Anti-AFB₁ IgY significantly inhibited the AFB₁-induced expression of proteins related to antioxidative, pro-apoptotic, and antiapoptotic processes in a strong dose-dependent manner. These experiments demonstrated that the anti-AFB₁ IgY-bound AFB₁ could not enter cells. This is the first time that IgY has been found to reduce the effects of small molecular toxins, which will be beneficial for the development of antibodies as detoxication agents.