miR-338-3p suppresses invasion of liver cancer cell by targeting smoothened

Understanding Gene Involvement in Hepatocellular Carcinoma: Implications for Gene Therapy and Personalized Medicine

Hepatocellular carcinoma (HCC) is the dominant type of liver cancers and is one of the deadliest health threats globally. The conventional therapeutic options for HCC are hampered by low efficiency and intolerable side effects. Gene therapy, however, now offers hope for the treatment of many disorders previously considered incurable, and gene therapy is beginning to address many of the shortcomings of conventional therapies. Herein, we summarize the involvement of genes in the pathogenesis and prognosis of HCC, with a special focus on dysregulated signaling pathways, genes involved in immune evasion, and non-coding RNAs as novel two-edged players, which collectively offer potential targets for the gene therapy of HCC. Herein, the opportunities and challenges of HCC gene therapy are discussed. These include innovative therapies such as genome editing and cell therapies. Moreover, advanced gene delivery technologies that recruit nanomedicines for use in gene therapy for HCC are highlighted. Finally, suggestions are offered for improved clinical translation and future directions in this area of endeavor.

hsa_circ_0000092 promotes hepatocellular carcinoma progression through up-regulating HN1 expression by binding to microRNA-338-3p

Circular RNAs (circRNAs) have been identified in diverse cancers for their role in regulating multiple cellular processes by antagonizing microRNAs (miRNAs or miRs). However, the role of circRNA hsa_circ_0000092 in hepatocellular carcinoma (HCC) still remains enigmatic. Therefore, we aimed to investigate the specific mechanism of hsa_circ_0000092 in HCC. Differentially expressed circRNAs associated to HCC were initially analysed. The expression of hsa_circ_0000092, miR-338-3p and HN1 in HCC tissues and cell lines was examined. Next, the interaction among hsa_circ_0000092, miR-338-3p and HN1 was determined by dual-luciferase reporter, RNA pull-down and northern blot assays. Subsequently, a series of mimic, inhibitor or siRNA plasmids were delivered into HCC cells to validate the effects of hsa_circ_0000092, miR-338-3p and HN1 in controlling cell proliferation, migration, invasion and angiogenesis in vitro. Furthermore, the role of hsa_circ_0000092 in tumour growth of HCC in vivo was assessed with hsa_circ_0000092 depleted with siRNA. The hsa_circ_0000092/miR-338-3p/HN1 axis was predicted to participate in the development of HCC. hsa_circ_0000092 and HN1 were highly expressed while miR-338-3p was poorly expressed in HCC tissues and cell lines. hsa_circ_0000092 could competitively bind to miR-338-3p to up-regulate HN1 expression. Moreover, depleted hsa_circ_0000092 or elevated miR-338-3p was shown to suppress HCC cell proliferation, migration, invasion and angiogenesis in vitro via down-regulation of HN1. Furthermore, silencing hsa_circ_0000092 was demonstrated to suppress tumour growth in HCC in vivo. The results of this study suggested that hsa_circ_0000092 impaired miR-338-3p-mediated HN1 inhibition to aggravate the development of HCC, indicating that hsa_circ_0000092 is a potential candidate marker and therapeutic target for HCC.

The estrogen/miR-338-3p/ADAM17 axis enhances the viability of breast cancer cells via suppressing NK cell's function

Natural killer (NK) cells are the critical elements of the innate immune response and implicated in rapidly recognizing and eliminating cancer cells. However, the tumor-suppressive ability of NK cells is often impaired in several cancer types. The critical roles of microRNAs have been elucidated by increasing evidences, while the regulation of miR-338-3p in anti-tumor activation of NK cells and its relationship with estrogen in breast cancer (BC) are still confusing. Here, miR-338-3p level was found to be significantly downregulated in BC tissues and estrogen receptor positive (ER+ ) cells, this difference was more obvious in ER+ patients or BC patients at advanced stage (TNM III and IV). MiR-338-3p level was shown to be downregulated by 17β-estradiol in BC cells (MDA-MB-231 cells and MCF-7) in vitro. MiR-338-3p overexpression decreased disintegrin and metalloprotease-17 (ADAM17) secretion in MDA-MB-231 (ER- ) and MCF-7 (ER+ ) cells. In addition, miR-338-3p overexpression or treatment with anti-ADAM17 antibody could down-regulate granzyme B, CD16, and NKG2D in NK cells, which was reversed by human recombinant ADAM17. Furthermore, these educated NK cells could promote the viability of MDA-MB-231 or MCF-7 cells. Taken together, our results demonstrate that miR-338-3p was negatively regulated by estrogen in BC cells, impairing NK cell's activity by the up-regulation of ADAM17, and conversely promoted the viability of BC cells. Therefore, the estrogen/miR-338-3p/ADAM17 axis is critically implicated in BC pathogenesis and may provide potential targets for BC diagnosis and treatment.

Circ_RBM23 knockdown suppresses chemoresistance, proliferation, migration and invasion of sorafenib-resistant HCC cells through miR-338-3p/RAB1B axis

BACKGROUND

Circular RNA RNA-binding motif protein 23 (circ_RBM23; ID: hsa_circ_0000524) is a novel regulator in hepatocellular carcinoma (HCC). Herein, we planned to investigate its role in sorafenib resistance in HCC.

METHOD

Levels of circ_RBM23, microRNA (miR)-338-3p, Ras-related GTPase-trafficking protein (RAB1B), Snail and E-cadherin were detected by real-time quantitative PCR and western blotting. Sorafenib resistant (SR) HCC cells (Huh7/SR and SK-HEP-1/SR) were established by acquisition of sorafenib resistance, and cell functions were measured by MTT assay, Edu assay, colony formation assay, apoptosis assay, transwell assay, and in vivo xenograft formation assay. Crosslink between miR-338-3p and circ_RBM23 or RAB1B was confirmed by bioinformatics analysis and dual-luciferase reporter assay.

RESULTS

Circ_RBM23 upregulation was discovered in the tissues of SR patients and SR cells, which was accompanied with miR-338-3p downregulation and RAB1B upregulation. The 50% inhibitory concentration (IC₅₀) of sorafenib in SR cells was greatly suppressed by interfering circ_RBM23 or reinforcing miR-338-3p, allied with this was the inhibition of EdU-positive cell rate, colony formation and migration/invasion abilities under sorafenib treatment, as well as the enhancement of apoptotic rate. Moreover, circ_RBM23 inhibition delayed tumor growth of Huh7/SR cells under sorfanib treatment in vivo.

CONCLUSION

Circ_RBM23 promoted chemoresistance, malignant proliferation, migration and invasion of SR HCC cells by modulating miR-338-3p/RAB1B axis.

Construction of a transcription factor-miRNA-mRNA interactive network elucidates underlying pathogenesis for osteosarcoma and validation by qRT-PCR

PURPOSE

Osteosarcoma is characterized by features of rapid growth and early metastasis with a poor prognosis. The aim of our research is to investigate the potential transcription factor (TF)-miRNA-mRNA regulatory mechanism in osteosarcoma utilizing bioinformatics methods and validate by qRT-PCR.

METHODS

The microRNA (miRNA) expression profiling datasets (GSE28423 and GSE65071) and mRNA expression profiling dataset GSE33382 were collected from the Gene Expression Omnibus (GEO) database. Differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) were screened using the limma package. Then, the TransmiR v2.0, miRDB, and Targetscan 7.2 database were applied for the acquisition of TF-miRNA and miRNA-mRNA interaction relationships, respectively. Finally, we built a TF-miRNA-mRNA interactive network. Furthermore, survival analysis was performed to identify sub-network with prognostic value and validate through qRT-PCR.

RESULTS

Eight overlapping DEMs and 682 DEGs were identified. Based on bioinformatics methods, 30 TF-miRNA interaction pairs and 25 miRNA-mRNA interaction pairs were screened. Finally, we constructed a TF-miRNA-mRNA regulatory network. Furthermore, laminin subunit gamma 1 (LAMC1) and thrombospondin-1 (THBS1), which involved in the network, were determined to have prognostic value and the corresponding subnetwork was identified. qRT-PCR results showed that LAMC1 mRNA expression was higher in osteosarcoma cells.

CONCLUSION

Based on the survival analysis, a TF-miRNA-mRNA sub-network, that is TFs (SPI1, HEY1, and CEBPB)-hsa-miR-338-3p-target genes (LAMC1 and THBS1) was established. In conclusion, the construction of a potential TF-related regulatory network will help elucidate the underlying pathological mechanisms of osteosarcoma, and may provide novel insights for the diagnosis and treatment of osteosarcoma.

The emerging role of noncoding RNAs in the Hedgehog signaling pathway in cancer

Hedgehog (HH), a conserved signaling pathway, is involved in embryo development, organogenesis, and other biological functions. Dysregulation and abnormal activation of HH are involved in tumorigenesis and tumor progression. With the emergence of interest in noncoding RNAs, studies on their involvement in abnormal regulation of biological processes in tumors have been published one after another. In this review, we focus on the crosstalk between noncoding RNAs and the HH pathway in tumors and elaborate the mechanisms by which long noncoding RNAs and microRNAs regulate or are regulated by HH signaling in cancer. We also discuss the interaction between noncoding RNAs and the HH pathway from the perspective of cancer hallmarks, presenting this complex network as concisely as possible and organizing ideas for cancer diagnosis and treatment.

Noncoding RNAs related to the hedgehog pathway in cancer: clinical implications and future perspectives

Cancer is a type of malignant affliction threatening human health worldwide; however, the molecular mechanism of cancer pathogenesis remains to be elusive. The oncogenic hedgehog (Hh) pathway is a highly evolutionarily conserved signaling pathway in which the hedgehog-Patched complex is internalized to cellular lysosomes for degradation, resulting in the release of Smoothened inhibition and producing downstream intracellular signals. Noncoding RNAs (ncRNAs) with diversified regulatory functions have the potency of controlling cellular processes. Compelling evidence reveals that Hh pathway, ncRNAs, or their crosstalk play complicated roles in the initiation, metastasis, apoptosis and drug resistance of cancer, allowing ncRNAs related to the Hh pathway to serve as clinical biomarkers for targeted cancer therapy. In this review, we attempt to depict the multiple patterns of ncRNAs in the progression of malignant tumors via interactions with the Hh crucial elements in order to better understand the complex regulatory mechanism, and focus on Hh associated ncRNA therapeutics aimed at boosting their application in the clinical setting.

High Expression of RRM1 Mediated by ncRNAs Correlates with Poor Prognosis and Tumor Immune Infiltration of Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) is one of several tumors with poor prognosis and causes a significant social burden. A growing number of studies have shown that RRM1 plays a crucial role in the development and progression of multiple human cancers. However, the specific role and mechanism of RRM1 have not been fully defined in HCC.

Methods

TCGA and GTEx data were used for the first time to conduct a pan-cancer analysis of RRM1 expression and prognosis, and identified RRM1 as a possible potential oncogene in HCC. At the same time, a combination of analyses (including expression analysis, correlation analysis or survival analysis) identified non-coding RNAs (ncRNAs) that contribute to RRM1 overexpression.

Results

MIR4435-2HG/miR-22-3p and SNHG6/miR-101-3p were identified as the most promising RRM1 upstream ncRNA-related pathways in HCC. In addition, RRM1 levels were significantly and positively correlated with tumor immune cell infiltration, immune cell biomarker or immune checkpoint expression.

Conclusion

These results suggest that high expression of RRM1 mediated by ncRNAs is associated with poor prognosis and tumor immune infiltration in HCC.

Hepatocellular carcinoma cell line-microenvironment induced cancer-associated phenotype, genotype and functionality in mesenchymal stem cells

Mesenchymal stromal cells (MSCs) have shown promise in liver cancer treatment. However, when MSCs are recruited to hepatic site of injury, they acquire cancerous promoting phenotype.

AIMS

To assess the influence of Hepatocellular carcinoma (HCC) microenvironment on human adipose MSCs (hA-MSCs) and predict hA-MSCs intracellular miRNAs role.

MATERIALS AND METHODS

After indirect co-culturing with Huh-7 cells, hA-MSCs were characterized via cell cycle profile, proliferation and migration potentials by MTT and scratch assays respectively. Functional enrichment analysis of deregulated proteins and miRNA targets was also analyzed.

KEY FINDINGS

Co-cultured hA-MSCs could acquire a cancer-associated phenotype as shown by upregulation of CAF, cancer markers, and downregulation of differentiation markers. Migration of these cancer-associated cells was increased concomitantly with upregulation of adhesion molecules, but not epithelial to mesenchymal transition markers. Co-cultured cells showed increased proliferation confirmed by downregulation in cell percentage in G0/G1, G2/M and upregulation in S phases of cell cycle. Upregulation of miR-17-5p and 615-5p in co-cultured hA-MSCs was also observed. Functional enrichment analysis of dysregulated proteins in co-cultured hA-MSCs, including our selected miRNAs targets, showed their involvement in development of cancer-associated characteristics.

SIGNIFICANCE

This study suggests an interaction between tumor cells and surrounding stromal components to generate cancer associated phenotype of some CAF-like characteristics, known to favor cancer progression. This sheds the light on the use of hA-MSCs in HCC therapy. hA-MSCs modulation may be partially achieved via dysregulation of intracellular miR17-5P and 615-5p expression, suggesting an important role for miRNAs in HCC pathogenesis, and as a possible therapeutic candidate.

LncRNA SNHG17 regulates cell proliferation and invasion by targeting miR-338-3p/SOX4 axis in esophageal squamous cell carcinoma

Small nucleolar RNA host gene 17 (SNHG17), a novel functional long noncoding RNA, has been demonstrated to play an essential role in the oncogenesis of several tumors. However, for esophageal squamous cell carcinoma (ESCC) the expression pattern and detailed function of SNHG17 are largely unknown. Hence, we conducted this study to explore potential roles and underlying oncogenic mechanisms for SNHG17 in ESCC progression. Results demonstrated SNHG17 to be markedly upregulated in ESCC. Knockdown of SNHG17 significantly suppressed ESCC cell proliferation, invasion, and epithelial-mesenchymal transition in vitro and tumor growth in vivo. Online database software analysis found miR-338-3p to interact with SNHG17 with the level of miR-338-3p negatively correlated with SNHG17 levels in ESCC samples. Further, miR-338-3p was found to directly target SRY-box transcription factor 4 (SOX4) in ESCC cells. Mechanistic analysis suggested that SNHG17 acts as an endogenous "sponge" competing with miR-338-3p to regulate SOX4, thereby promoting tumor progression. These results suggest that these molecular interactions may be potential therapeutic targets for ESCC.

circRNA hsa_circ_104566 Sponged miR-338-3p to Promote Hepatocellular Carcinoma Progression

Circular RNAs (circRNAs) could sponge micro-RNAs (miRNAs) to regulate tumor progression of hepatocellular carcinoma (HCC). Hsa_circ_104566 contributes to papillary thyroid carcinoma progression. However, the tumorigenic mechanism of hsa_circ_104566 on HCC remains enigmatic. The role of hsa_circ_104566 on HCC was therefore evaluated in this study. First, the high expression of hsa_circ_104566 was found in HCC tissues, which was significantly associated with poor prognosis in HCC patients. Second, Hsa_circ_104566 promoted HCC progression by decreasing apoptosis and E-cadherin, while increasing cell viability, proliferation, migration, invasion, and N-cadherin. On the other hand, HCC progression was suppressed by knockdown of hsa_circ_104566. Hsa_circ_104566 could target miR-338-3p, and its expression was negatively correlated with miR-338-3p in HCC patients. Moreover, miR-338-3p suppressed protein expression of Forkhead box protein 1 (FOXP1) and had a negative correlation with FOXP1 in HCC patients. Functional assay further indicated that the promotion of HCC progression by hsa_circ_104566 was reversed by miR-338-3p, and miR-338-3p inhibitor could counteract the effect of hsa_circ_104566 knockdown on the suppression of HCC progression. In vivo assay indicated that hsa_circ_104566 knockdown suppressed HCC tumor growth and metastasis. In conclusion, hsa_circ_104566 sponged miR-338-3p to promote HCC progression, providing a potential therapeutic target for cancer intervention.

A minor review of microRNA-338 exploring the insights of its function in tumorigenesis

MicroRNAs(miRNAs) are small non-coding RNAs which have a critical role in various biological processes via direct binding and post-transcriptionally regulating targeted genes expression. More than one-half of human genes were regulated by miRNAs and their aberrant expression was detected in various human diseases, including cancers. miRNA-338 is a new identified miRNA and increasing evidence show that miRNA-338 participates in the progression of lots of cancers, such as lung cancer, hepatocellular cancer, breast cancer, glioma, and so on. Although a range of targets and signaling pathways such as MACC1 and Wnt/β-catenin signaling pathway were illustrated to be regulated by miRNA-338, which functions in tumor progression are still ambiguous and the underlying molecular mechanisms are also unclear. Herein, we reviewed the latest studies in miRNA-338 and summarized its roles in different type of human tumors, which might provide us new idea for further investigations and potential targeted therapy.

Gene Ontology Curation of Neuroinflammation Biology Improves the Interpretation of Alzheimer's Disease Gene Expression Data

BACKGROUND

Gene Ontology (GO) is a major bioinformatic resource used for analysis of large biomedical datasets, for example from genome-wide association studies, applied universally across biological fields, including Alzheimer's disease (AD) research.

OBJECTIVE

We aim to demonstrate the applicability of GO for interpretation of AD datasets to improve the understanding of the underlying molecular disease mechanisms, including the involvement of inflammatory pathways and dysregulated microRNAs (miRs).

METHODS

We have undertaken a systematic full article GO annotation approach focused on microglial proteins implicated in AD and the miRs regulating their expression. PANTHER was used for enrichment analysis of previously published AD data. Cytoscape was used for visualizing and analyzing miR-target interactions captured from published experimental evidence.

RESULTS

We contributed 3,084 new annotations for 494 entities, i.e., on average six new annotations per entity. This included a total of 1,352 annotations for 40 prioritized microglial proteins implicated in AD and 66 miRs regulating their expression, yielding an average of twelve annotations per prioritized entity. The updated GO resource was then used to re-analyze previously published data. The re-analysis showed novel processes associated with AD-related genes, not identified in the original study, such as 'gliogenesis', 'regulation of neuron projection development', or 'response to cytokine', demonstrating enhanced applicability of GO for neuroscience research.

CONCLUSIONS

This study highlights ongoing development of the neurobiological aspects of GO and demonstrates the value of biocuration activities in the area, thus helping to delineate the molecular bases of AD to aid the development of diagnostic tools and treatments.

miRNA expression profiles in liver grafts of HCV and HIV/HCV-infected recipients, 6 months after liver transplantation

In hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co‐infected patients, HIV enhances HCV replication and liver damage. Several microRNAs (miRNAs), active in pro‐fibrotic and inflammatory pathways, have been implicated in the pathogenesis of this phenomenon. However, these miRNAs have been tested only in explanted cirrhotic livers, when the liver damage has become chronic and irreversible. No data are available on the early phase of viral infection, such as early after liver transplantation (LT). In the present study, the expression of miR‐101, miR‐122, miR‐155, miR‐192, miR‐200c, miR‐338, and miR‐532 was determined by quantitative real‐time polymerase chain reaction in liver biopsies of HCV (n = 19) and HCV/HIV‐infected (n = 20) LT recipients, as well as in a control group (n = 18) of noninfected patients, transplanted for alcoholic cirrhosis. The timing of liver biopsy was 6 months post‐LT. None of the patients was treated with direct‐acting anti‐HCV drugs. All co‐infected recipients had suppressed HIV viral load. Grading and staging were assessed according to the Ishak Classification. HCV and HIV viral load were measured in the sera. miR‐101 (p = .03), miR‐122 (p = .012), and miR‐192 (p = .038) were significantly downregulated in HCV/HIV co‐infected and HCV mono‐infected recipients when compared with noninfected recipients, and such downregulation was more pronounced in co‐infected ones. Moreover, in co‐infected recipients but not in mono‐infected ones, miR‐101 inversely correlated with the peripheral HCV‐RNA levels (r = .41, p = .04) and miR‐122 inversely correlated with peripheral HCV‐RNA levels (r = .49, p = .03) and with the histological grading (r = .51, p = .02).  In conclusion, as early as 6 months after LT, the presence of HIV‐HCV co‐infection enhanced a significant downregulation of certain miRNAs that showed a direct correlation with HCV viral load and liver inflammation.

Molecular interactions of miR-338 during tumor progression and metastasis

Background

Cancer, as one of the main causes of human deaths, is currently a significant global health challenge. Since the majority of cancer-related deaths are associated with late diagnosis, it is necessary to develop minimally invasive early detection markers to manage and reduce mortality rates. MicroRNAs (miRNAs), as highly conserved non-coding RNAs, target the specific mRNAs which are involved in regulation of various fundamental cellular processes such as cell proliferation, death, and signaling pathways. MiRNAs can also be regulated by long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). They are highly stable in body fluids and have tumor-specific expression profiles, which suggest their suitability as efficient non-invasive diagnostic and prognostic tumor markers. Aberrant expression of miR-338 has been widely reported in different cancers. It regulates cell proliferation, migration, angiogenesis, and apoptosis in tumor cells.

Main body

In the present review, we have summarized all miR-338 interactions with other non-coding RNAs (ncRNAs) and associated signaling pathways to clarify the role of miR-338 during tumor progression.

Conclusions

It was concluded that miR-338 mainly functions as a tumor suppressor in different cancers. There were also significant associations between miR-338 and other ncRNAs in tumor cells. Moreover, miR-338 has a pivotal role during tumor progression using the regulation of WNT, MAPK, and PI3K/AKT signaling pathways. This review highlights miR-338 as a pivotal ncRNA in biology of tumor cells.

miR-338-3p inhibits autophagy in a rat model of allergic rhinitis after PM2.5 exposure through AKT/mTOR signaling by targeting UBE2Q1

Exposure to fine particulate matter (PM2.5) increases the incidence of allergic rhinitis (AR). microRNA (miRNA) can regulate cell proliferation, invasion and apoptosis. However, the mechanism of miR-338-3p in mediating PM2.5-induced autophagy in AR animal models remains unknown. To explore the mechanism of miR-338-3p in PM2.5-induced autophagy in AR, the human nasal epithelium cells and AR model exposed to PM2.5 were deployed. The results showed that miR-338-3p was down-regulated in both nasal mucosa of PM2.5-exacerbated AR rat models and PM2.5-treated RPMI-2650 cells. Forced expression of miR-338-3p could inhibit autophagy in vitro. miR-338-3p specifically bound to UBE2Q1 3'-untranslated region (3' UTR) and negatively regulated its expression. Overexpression of UBE2Q1 attenuated the inhibitory effects of miR-338-3p on PM2.5-induced autophagy of RPMI-2650 cells through AKT/mTOR pathway. Moreover, our in vivo study found that after administration of agomiR-338-3p in AR rats model, the expression of autophagy-related proteins decreased and nasal symptoms alleviated. In conclusion, this study revealed that miR-338-3p acts as an autophagy suppressor in PM2.5-exacerbated AR by directly targeting UBE2Q1 and affecting AKT/mTOR pathway.

hsa_circ_0001018 promotes papillary thyroid cancer by facilitating cell survival, invasion, G1/S cell cycle progression, and repressing cell apoptosis via crosstalk with miR-338-3p and SOX4

We identified a novel interactome, circ_0001018/miR-338-3p/SOX4, in papillary thyroid cancer (PTC), and we intended to confirm the regulatory relationship between the three and to study the effects of the three in PTC. The bioinformatics method was used to screen out the circular RNA and mRNA of interest. A cellular fractionation assay and fluorescence in situ hybridization (FISH) assay were conducted to prove that circ_0001018 and CCT4 (the host gene of circ_0001018) mRNA primarily localized in the cytoplasm of PTC cell lines. By qRT-PCR analysis, the expression of circ_0001018 and SOX4 mRNA was found upregulated while the expression of miR-338-3p was found downregulated in PTC tissues and cells. circ_0001018 silence significantly inhibited the tumor growth in xenografted nude mice. A series of cytological experiments such as a Cell Counting Kit-8 (CCK-8) assay, a 5-ethynyl-2′-deoxyuridine (EdU) assay, cell cycle profiling, wound healing, a transwell assay, and cell apoptosis were conducted and showed that circ_0001018 and SOX4 promoted cell proliferation, migration, and invasion, inhibited cell apoptosis, and reduced the cell cycle arrest at the G₁ phase in PTC cells. Compared with circ_0001018 and SOX4, miR-338-3p held the opposite function. The regulatory relationship between circ_0001018 and miR-338-3p, and between miR-338-3p and SOX4 mRNA, was validated using a luciferase reporter gene assay and/or RNA immunoprecipitation (RIP assay). Our findings showed that circ_0001018 acted as the tumor promoter via sponging miR-338-3p to elevate SOX4 expression level in PTC. Importantly, this novel circ_0001018/miR-338-3p/SOX4 axis has the potential to be considered as a therapy target for PTC.

The role of microRNA-338-3p in cancer: growth, invasion, chemoresistance, and mediators

Cancer still remains as one of the leading causes of death worldwide. Metastasis and proliferation are abnormally increased in cancer cells that subsequently, mediate resistance of cancer cells to different therapies such as radio-, chemo- and immune-therapy. MicroRNAs (miRNAs) are endogenous short non-coding RNAs that can regulate expression of target genes at post-transcriptional level and capable of interaction with mRNA-coding genes. Vital biological mechanisms including apoptosis, migration and differentiation are modulated by these small molecules. MiRNAs are key players in regulating cancer proliferation and metastasis as well as cancer therapy response. MiRNAs can function as both tumor-suppressing and tumor-promoting factors. In the present review, regulatory impact of miRNA-338-3p on cancer growth and migration is discussed. This new emerging miRNA can regulate response of cancer cells to chemotherapy and radiotherapy. It seems that miRNA-338-3p has dual role in cancer chemotherapy, acting as tumor-promoting or tumor-suppressor factor. Experiments reveal anti-tumor activity of miRNA-338-3p in cancer. Hence, increasing miRNA-338-3p expression is of importance in effective cancer therapy. Long non-coding RNAs, circular RNAs and hypoxia are potential upstream mediators of miRNA-338-3p in cancer. Anti-tumor agents including baicalin and arbutin can promote expression of miRNA-338-3p in suppressing cancer progression. These topics are discussed to shed some light on function of miRNA-338-3p in cancer cells.

Therapeutically actionable PAK4 is amplified, overexpressed, and involved in bladder cancer progression

Muscle-invasive bladder carcinomas (MIBCs) are aggressive genitourinary malignancies. Metastatic urothelial carcinoma of the bladder is generally incurable by current chemotherapy and leads to early mortality. Recent studies have identified molecular subtypes of MIBCs with different sensitivities to frontline therapy, suggesting tumor heterogeneity. We have performed multi-omic profiling of the kinome in bladder cancer patients with the goal of identify therapeutic targets. Our analyses revealed amplification, overexpression, and elevated kinase activity of P21 (RAC1) activated kinase 4 (PAK4) in a subset of Bladder cancer (BLCA). Using bladder cancer cells, we confirmed the role of PAK4 in BLCA cell proliferation and invasion. Furthermore, we observed that a PAK4 inhibitor was effective in curtailing growth of BLCA cells. Transcriptomic analyses identified elevated expression of another kinase, protein tyrosine kinase 6 (PTK6), upon treatment with a PAK4 inhibitor and RNA interference of PAK4. Treatment with a combination of kinase inhibitors (vandetanib and dasatinib) showed enhanced sensitivity compared with either drug alone. Thus, PAK4 may be therapeutically actionable for a subset of MIBC patients with amplified and/or overexpressed PAK4 in their tumors. Our results also indicate that combined inhibition of PAK4 and PTK6 may overcome resistance to PAK4. These observations warrant clinical investigations with selected BLCA patients.

Hepatocellular carcinoma-derived exosomes in organotropic metastasis, recurrence and early diagnosis application

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, despite improvements in the clinical trial and diagnosis, HCC still remains high mortality due to the 70% recurrence and lung metastasis after surgical resection. Exosomes are small membrane vesicles, which are shuttled from donor cells to recipient cells, contributing to the recruitment and reprogramming of constituents via an autocrine or paracrine fashion. HCC derived exosomes could redirect metastasis of tumor cells which lack the capacity to metastasize to a specific organ via generating pre-metastatic niche. These findings emphasize a practical and potentially feasible role of exosomes in the treatment of patients with HCC, both as a target and a vehicle for drug design. We herein summarize recent findings that implicate oncogenes and non-canonical signaling of HCC exosomes, as well as the impact of exosomal bioactive molecules in high recurrence induced by organ-specific metastasis. The aim of review is to illustrate the underlying mechanism of exosomes in tumor metastasis, immune evasion, and the potential application of prognostic biomarker in HCC process.

Circular RNA SMO sponges miR-338-3p to promote the growth of glioma by enhancing the expression of SMO

Glioma is one of the most common tumors in the brain and complete cure still a challenge. The present research aimed to investigate the molecular mechanism of circular RNA SMO (circSMO742) in glioma, via targeting miR-338-3p and regulating SMO expression. QRT-PCR was utilized to examine the expression profiles of circSMO742 and microRNA-338-3p (miR-338-3p) in glioma. SMO protein in glioma was tested via western blot. RNA pulldown assay and dual luciferase reporter assays were used to explore the targeting correlation between RNAs. MTT assay, transwell assays and flow cytometry were used to investigate cell proliferation, migration and invasion, and apoptosis, respectively. Tumor xenograft was done to ascertain the effect of circSMO742 knocking down on tumor growth. CircSMO742 and SMO were highly expressed in glioma tissues, while miR-338-3p expression was reduced. CircSMO742 together with SMO could promote cells proliferation, migration and invasion while inhibit cells apoptosis, whereas miR-338-3p showed negative impacts on the cell activity. Knocking down of circSMO742 suppressed glioma growing in vivo. CircSMO742 promoted glioma growth by sponging miR-338-3p to regulate SMO expression. Our research revealed a new molecular mechanism of glioma growth and provide a fresh perspective on circRNAs in glioma progression.

MiR-338-5p ameliorates pathological cardiac hypertrophy by targeting CAMKIIδ

Pathological cardiac hypertrophy (PCH) is characterized by an increase in cardiomyocyte size and thickening of the ventricular walls during the adaptive response to maintain cardiac function, which often progresses to a maladaptive response and, ultimately, to heart failure. Previous studies have demonstrated that miRNAs play roles in the pathogenesis of PCH. In this study, we first found that the regulation of miR-338-5p was aberrant in cardiac tissues of heart failure patients and transverse aortic constriction (TAC)-induced PCH mice. Overexpression of miR-338-5p in the heart using recombinant adeno-associated virus serotype 9 (rAAV9) ameliorated TAC-induced PCH, as indicated by a decreased heart weight/body weight (HW/BW) ratio. Furthermore, miR-338-5p mitigated the TAC-induced damage in heart contraction and relaxation function, as measured by echocardiography and a cardio hemodynamic measurement, respectively. We also identified CAMKIIδ as a direct target of miR-338-5p using bioinformatics tools and the luciferase reporter assay. Finally, we observed that the miR-338-5p-mediated downregulation of CAMKIIδ reversed the cell surface area enlargement induced by the Ang-II treatment in H9c2 cells. Therefore, we highlight a novel molecular mechanism of the miR-338-5p/CAMKIIδ axis that contributes to the pathogenesis of PCH.

MicroRNA-338-3p suppresses cell proliferation, migration and invasion in human malignant melanoma by targeting MACC1

Malignant melanoma (MM) is the most aggressive form of skin cancer originating from melanocytes with increased proliferative and metastatic ability. Previous studies have revealed that microRNA-338-3p (miR-338-3p) functions as a tumor suppressor in several types of cancer, including cervical cancer, renal cell carcinoma and thyroid cancer. However, the function and mechanism underlying the action of miR-383-3p in MM remain unclear. In the study, aberrant downregulation of miR-338-3p was observed in 60 pairs of MM and adjacent non-tumor tissue using quantitative polymerase chain reaction assay. Decreased miR-383-3p expression was associated with advanced clinical stage (P<0.05) and lymph node metastasis (P<0.001). The overexpression of miR-338-3p in A375 and G361 cells suppressed cell proliferation and migration using MTT, colony formation, wound healing and transwell assays. Mechanistically, MACC1 was identified as a direct target for miR-338-3p using bioinformatics prediction and dual-luciferase assays. Furthermore, MACC1 expression was significantly increased and inversely correlated with the levels of miR-338-3p in MM tissues. More importantly, restoration of MACC1 resulted in reversed the inhibitory effects of miR-338-3p overexpression on MM cells by altering the expression levels of PCNA and epithelial-mesenchymal transition (EMT)-associated proteins. These results suggest that miR-338-3p functions as a novel tumor suppressor, at least in part, via targeting MACC1 and suggest that miR-338-3p may serve as a potential target for treatment of MM patients.

Down-regulation of miR-338-3p and Up-regulation of MACC1 Indicated Poor Prognosis of Epithelial Ovarian Cancer Patients

Objective To detect the expression of microRNA-338-3p (miR-338-3p) and MET transcriptional regulator MACC1 (MACC1) gene in different ovarian tissues, to analyze their relationships, their correlations to the clinicopathologic characteristics of epithelial ovarian cancer and their significant to the progression of ovarian cancer. Methods The expression of miR-338-3p and MACC1 gene in 20 specimens of normal ovarian tissues, 20 specimens of benign epithelial ovarian tumor and 65 specimens of epithelial ovarian cancer was detected by real-time PCR method. Their interrelationships and their correlations to the clinicopathologic characteristics of epithelial ovarian cancer were analyzed. Risk factors of recurrence and death were discussed by binary Logistic regression analysis. The relations between miR-338-3p and MACC1 expression and the survival of ovarian cancer were measured by Kaplan-Meier analysis. Results The expressions of miR-338-3p and MACC1 gene in epithelial ovarian cancer tissues were (0.331±0.038) and (0.774±0.025), significant differences were noted between epithelial ovarian cancer and normal ovarian tissues, benign ovarian tumors (F=77.916, P=1.205E-18; F=77.945, P=1.187E-18). In different ovarian tissues, miR-338-3p expression was negatively correlated to MACC1 expression (r = -0.968, P<0.0001). In epithelial ovarian cancer, lower expression of miR-338-3p and higher expression of MACC1 were associated with more advanced FIGO stage, higher histological grade and developed lymph node metastasis. Down-regulation of miR-338-3p was related with the recurrence (P=0. 005, OR=12.862, 95%CI: 2.120~78.026) and death (P=0. 007, OR=12.837, 95%CI: 2.205~81.389) of ovarian cancer patients, which was showed by binary Logistic regression analysis. Compared to other patients, the overall survival rate and progression free survival rate of patients with lower miR-338-3p and higher MACC1 expression were obviously poorer (χ²=16.955, P=7.219E-5; χ²=18.929, P=2.828E-5). Conclusions Down-regulation of miR-338-3p and up-regulation of MACC1 gene were closely related with the poor prognosis of epithelial ovarian cancer patients, which could served as bio-markers of the progression and recurrence of ovarian cancer.

MicroRNA-338-3p inhibits tumor growth and metastasis in osteosarcoma cells by targeting RUNX2/CDK4 and inhibition of MAPK pathway

Osteosarcoma (OS) is one of the most aggressive bone tumors. MicroRNAs (miRNAs) have been found to implicate in the pathogenesis of different types of cancers, including OS. This study aimed to explore the roles of miR-338-3p in OS and investigate the underlying mechanism. Human OS cell lines (MG-63 and U2OS) and osteoblast (hFOB) cell line were used in the study. The expression levels of miR-338-3p, runt-related transcription factor 2 (RUNX2) and cyclin-dependent kinase 4 (CDK4) were altered by transient transfection and determined by quantitative real-time polymerase chain reaction/Western blot analysis. Cell viability, colony numbers, migration, and invasion, and apoptotic cells were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, transwell assay, and flow cytometry assay, respectively. Dual luciferase reporter assay was performed to identify the target gene of miR-338-3p. Western blot assay was carried to measure the protein expression levels involved in cell apoptosis, migration, and mitogen-activated protein kinases (MAPK) pathway. We found that the expression of miR-338-3p was downregulated in MG-63 cell and U2OS cells, compared with hFOB cells. MiR-338-3p suppression significantly increased cell viability and colony numbers, promoted cell migration, and invasion, but suppressed cell apoptosis in MG-63 and U2OS cells. Opposite results were observed in the miR-338-3p overexpression. Interestingly, RUNX2 and CDK4 were direct target genes of miR-338-3p. RUNX2 inhibition shared a similar effect of miR-338-3p mimic on MG-63 cells. Furthermore, miR-338-3p inhibited the activation of MAPK pathway in MG-63 cells. To conclude, these findings suggested that miR-338-3p functioned as a tumor suppressor in OS cells by targeting RUNX2 and CDK4, as well as inhibition of the MAPK pathway.

miR-338-3p Is Regulated by Estrogens through GPER in Breast Cancer Cells and Cancer-Associated Fibroblasts (CAFs)

Estrogens acting through the classic estrogen receptors (ERs) and the G protein estrogen receptor (GPER) regulate the expression of diverse miRNAs, small sequences of non-coding RNA involved in several pathophysiological conditions, including breast cancer. In order to provide novel insights on miRNAs regulation by estrogens in breast tumor, we evaluated the expression of 754 miRNAs by TaqMan Array in ER-negative and GPER-positive SkBr3 breast cancer cells and cancer-associated fibroblasts (CAFs) upon 17β-estradiol (E2) treatment. Various miRNAs were regulated by E2 in a peculiar manner in SkBr3 cancer cells and CAFs, while miR-338-3p displayed a similar regulation in both cell types. By METABRIC database analysis we ascertained that miR-338-3p positively correlates with overall survival in breast cancer patients, according to previous studies showing that miR-338-3p may suppress the growth and invasion of different cancer cells. Well-fitting with these data, a miR-338-3p mimic sequence decreased and a miR-338-3p inhibitor sequence rescued the expression of genes and the proliferative effects induced by E2 through GPER in SkBr3 cancer cells and CAFs. Altogether, our results provide novel evidence on the molecular mechanisms by which E2 may regulate miR-338-3p toward breast cancer progression.

LncRNA SNHG1 alleviates OGD induced injury in BMEC via miR-338/HIF-1α axis

BACKGROUND

Brain microvascular endothelial cell (BMEC) is an important therapeutic target for the inhibition of brain vascular dysfunction in ischemic stroke. Expression of long non-coding RNA SNHG1 is reportedly upregulated in BMEC after OGD. The present study aims to investigate the potential roles of SNHG1 in OGD-induced injury in BMEC.

METHODS

Mice primary brain microvascular endothelial cells (BMEC) were cultured under "normal" or "oxygen/glucose-deprived" (OGD) conditions. The expression of SNHG1 and miR-338 after OGD were examined by qPCR. shRNA against SNHG1 was used to knockdown SNHG1 in BMEC. MiR-338-3p mimic and inhibitor were used to change the expression of miR-338 in BMEC. The relationship between SNHG1 and miR-338, and the relationship between miR-338 and HIF-1α were clarified using RNA pull-down and luciferase reporter gene assays, respectively.

RESULTS

SNHG1 and miR-338 were upregulated in OGD induced BMEC. SNHG1 silence aggravated OGD-induced cell apoptosis by down-regulating Bcl-2, HIF-1α and VEGF-A, and upregulating caspase 3 activity and Bax. MiR-338 was upregulated in SNHG1-silenced BMEC. RNA pull-down assays showed that SNHG1 could be directly bound by miR-338. In addition, miR-338 overexpression reduced cell viability in OGD while miR-338 inhibition protected BMEC against OGD-induced injury. Furthermore, luciferase reporter assay showed that HIF-1α was a direct target of miR-338.

CONCLUSIONS

SNHG1 exerted protective effects against OGD induced injury via sponging miR-338, thus upregulating HIF-1α/VEGF-A in BMEC.

The long noncoding RNA MALAT-1 functions as a competing endogenous RNA to regulate MSL2 expression by sponging miR-338-3p in myasthenia gravis

Myasthenia gravis (MG) is a cell-dependent autoimmune disease commonly associated with thymic pathology. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) has been associated with gene regulation and alternative splicing. It has shown relationship with proliferation, apoptosis, migration, and invasion. In this study, we found that MALAT-1 expression was downregulated in MG. The level of the miR-338-3p was increased in peripheral blood mononuclear cells from MG patients compared with those from control subjects. MALAT-1 competed for binding to miR-338-3p with male-specific lethal 2 (MSL2) in luciferase reporter assays. We confirmed the MALAT-1-miR-338-3p-MSL2 interaction network in MG in vitro. Thus, MALAT-1 directly induced MSL2 expression in MG by acting as a competing endogenous RNA for miR-338-3p, suggesting that it may serve as a therapeutic target for MG treatment.

Micro-RNAs as critical regulators of matrix metalloproteinases in cancer

Metastasis is known to be one of the important factors associated with cancer-related deaths worldwide. Several cellular and molecular targets are involved in the metastasis process. Among these targets, matrix metalloproteinases (MMPs) play central roles in promoting cancer metastasis. MMPs could contribute toward tumor growth, angiogenesis, migration, and invasion via degradation of the extracellular matrix and activation of pre-pro-growth factors. Therefore, identification of various cellular and molecular pathways that affect MMPs could contribute toward a better understanding of the metastatic pathways involved in various tumors. Micro-RNAs are important targets that could affect MMPs. Multiple lines of evidence have indicated that deregulation of various micro-RNAs, including miR-9, Let-7, miR-10b, and miR-15b, affects metastasis of tumor cells via targeting MMPs.

Coagulation Factor X Regulated by CASC2c Recruited Macrophages and Induced M2 Polarization in Glioblastoma Multiforme

Tumor-associated macrophages (TAMs) constitute a major component of inflammatory cells in the glioblastoma multiforme (GBM) tumor microenvironment. TAMs have been implicated in GBM angiogenesis, invasion, local tumor recurrence, and immunosuppression. Coagulation factor X (FX) is a vitamin K-dependent plasma protein that plays a role in the regulation of blood coagulation. In this study, we first found that FX was highly expressed and positively correlated with TAM density in human GBM. FX exhibited a potent chemotactic capacity to recruit macrophages and promoted macrophages toward M2 subtype polarization, accelerating GBM growth. FX bound to extracellular signal-related kinase (ERK)1/2 and inhibited p-ERK1/2 in GBM cells. FX was secreted in the tumor microenvironment and increased the phosphorylation and activation of ERK1/2 and AKT in macrophages, which may have been responsible for the M2 subtype macrophage polarization. Moreover, although the lncRNA CASC2c has been verified to function as a miR-101 competing endogenous RNA (ceRNA) to promote miR-101 target genes in GBM cells, we first confirmed that CASC2c did not function as a miR-338-3p ceRNA to promote FX expression, and that FX was a target gene of miR-338-3p. CASC2c interacted with and reciprocally repressed miR-338-3p. Both CASC2c and miR-388-3p bound to FX and commonly inhibited its expression and secretion. CASC2c repressed M2 subtype macrophage polarization. Taken together, our findings revealed a novel mechanism highlighting CASC2c and FX as potential therapeutic targets to improve GBM patients by altering the GBM microenvironment.

Emerging Roles of G Protein-Coupled Receptors in Hepatocellular Carcinoma

Among a great variety of cell surface receptors, the largest superfamily is G protein-coupled receptors (GPCRs), also known as seven-transmembrane domain receptors. GPCRs can modulate diverse signal-transduction pathways through G protein-dependent or independent pathways which involve &beta;-arrestins, G protein receptor kinases (GRKs), ion channels, or Src kinases under physiological and pathological conditions. Recent studies have revealed the crucial role of GPCRs in the tumorigenesis and the development of cancer metastasis. We will sum up the functions of GPCRs&mdash;particularly those coupled to chemokines, prostaglandin, lysophosphatidic acid, endothelin, catecholamine, and angiotensin&mdash;in the proliferation, invasion, metastasis, and angiogenesis of hepatoma cells and the development of hepatocellular carcinoma (HCC) in this review. We also highlight the potential avenues of GPCR-based therapeutics for HCC.

miR-338-3p functions as a tumor suppressor in gastric cancer by targeting PTP1B

Gastric cancer (GC) is one of the most common malignant tumors and peritoneal metastasis is the primary cause for advanced GC’s mortality. Protein-tyrosine phosphatase 1B (PTP1B) functions as an oncogene and involves in carcinogenesis and cancer dissemination. However, the function and regulation of PTP1B in GC remain poorly understood. In this study, we found that PTP1B was upregulated in GC tissues and overexpression of PTP1B in vitro promoted cell migration and prevented apoptosis. Then, we predicted that PTP1B was a target of miR-338-3p and we revealed an inverse correlation between miR-338-3p levels and PTP1B protein levels in GC tissues. Next, we verified that PTP1B was inhibited by miR-338-3p via direct targeting to its 3′-untranslated regions. Moreover, overexpression of miR-338-3p in vitro attenuated GC cell migration and promoted apoptosis, and these effects could be partially reversed by reintroduction of PTP1B. Finally, we established an orthotopic xenograft model and a peritoneal dissemination model of GC to demonstrate that miR-338-3p restrained tumor growth and dissemination in vivo by targeting PTP1B. Taken together, our results highlight that PTP1B is an oncogene and is negatively regulated by miR-338-3p in GC, which may provide new insights into novel molecular therapeutic targets for GC.

LncRNA Snhg1, a non-degradable sponge for miR-338, promotes expression of proto-oncogene CST3 in primary esophageal cancer cells

Competing endogenous RNA (ceRNA) is a newly proposed mechanism that describes a crosstalk among lncRNAs, mRNAs and their shared miRNAs. In this study, the role of miR-338-3p (miR-338) in the progression of esophageal cancer and its involve in the ceRNA regulatory circuit lncRNA-Snhg1/CST3 were explored. MiR-338 displayed a 30% decreased expression in esophageal squamous cell carcinoma tissues compared with the adjacent. Then, proto-oncogene CST3 was predicted and validated as a target gene of miR-338. Gain-and-loss-function experiments indicated that miR-338 suppressed expression of CST3 protein (also Cystatin C, CysC), promoted expression of apoptotic proteins caspase-8/3, attenuated esophageal carcinoma cell growth and induced its apoptosis. In addition, lncRNA-Snhg1 was significantly upregulated in esophageal carcinoma tissues and promoted esophageal carcinoma cell growth. Furthermore, our results from bioinformatics, luciferase reporter gene and RNA pull-down assays indicated that Snhg1 could be directly bound by miR-338. Snhg1 acted as a non-degradable sponge to relieve the suppression on CST3 caused by miR-338. In conclusion, lncRNA-Snhg1 promoted cell proliferation by acting as a non-degradable sponge for the tumor suppressor miR-338 in esophageal cancer cells.

Resistance a major hindrance to chemotherapy in hepatocellular carcinoma: an insight

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality, accounting for almost 90% of total liver cancer burden. Surgical resection followed by adjuvant and systemic chemotherapy are the most meticulously followed treatment procedures but the complex etiology and high metastatic potential of the disease renders surgical treatment futile in majority of the cases. Another hindrance to the scenario is the acquired resistance to drugs resulting in relapse of the disease. Hence, to provide insights into development of novel therapeutic targets and diagnostic biomarkers, this review focuses on the various molecular mechanisms underlying chemoresistance in HCC. We have provided a comprehensive summary of the various strategies adopted by HCC cells, extending from apoptosis evasion, autophagy activation, drug expulsion to epigenetic transformation as modes of therapy resistance. The role of stem cells in imparting chemoresistance is also discussed. Furthermore, the review also focuses on how this knowledge might be exploited for the development of an effective, prospective therapy against HCC.

GATA1 activated lncRNA (Galont) promotes anoxia/reoxygenation-induced autophagy and cell death in cardiomyocytes by sponging miR-338

The hypernomic autophagy is associated with various cardiovascular diseases. Long noncoding RNAs (lncRNAs) are emerging as important regulators in gene expression, which have been involved in multiple physiological and pathological processes. However, the function of lncRNAs and how they functioned in the autophagy in cardiomyocytes were rarely reported. In this study, we report that a lncRNA, named GATA1 activated lncRNA (Galont), can directly interact with miR-338 and promote ATG5-mediated autophagic cell death in murine cardiomyocytes. First, we found that Galont was upregulated by anoxia/reoxygenation (A/R) stimulus, and it was able to promote autophagy and cell death in cardiomyocytes exposure to A/R. Then, miR-338 was identified as a novel suppressor in autophagy and autophagic cell death. Our results from bioinformatic analysis and luciferase reporter gene assay indicated that ATG5 is a target gene of miR-338. Furthermore, RNA pull-down assays demonstrated that Galont directly interacted with miR-338, and thus promoted ATG5 expression and autophagic cell death. Our findings reveal a novel regulatory circuit in the autophagy in cardiomyocytes, which consists of Galont, miR-338 and ATG5.

MicroRNA-338-3p Suppresses Proliferation of Human Liver Cancer Cells by Targeting SphK2

Recent studies have revealed abnormal expression of miRNAs in various tumors. Although microRNA-338-3p (miR-338-3p) plays an important role in many types of tumors, its influence on liver cancer (LC) is unknown. In this study, we found that expression of miR-338-3p was decreased in LC cells and tissues. Colony formation and cell proliferation were suppressed by enhanced expression of miR-338-3p in LC cells. Moreover, miR-338-3p targeted sphingosine kinase 2 (SphK2). Silencing of SphK2 had an identical influence as overexpression of miR-338-3p in LC cells. Overexpression of SphK2 without the 3′-untranslated region remarkably enhanced the growth suppression triggered by miR-338-3p in LC cells. These findings indicate that miR-338-3p influences the development of LC by targeting SphK2, suggesting that miR-338-3p can be targeted as an innovative therapeutic strategy for LC.

Role of canonical Hedgehog signaling pathway in liver

Hedgehog (Hh) signaling pathway plays an important role in embryonic development. It becomes reactivated in many types of acute and chronic liver injuries. Hh signaling is required for liver regeneration, regulates capillarisation, controls the fates of hepatic stellate cells, promotes liver fibrosis and liver cancers. In this review, we summarize the current knowledge of the role of canonical Hh signaling pathway in adult liver. This help to understand the pathogenesis of liver diseases and find out the new effective targeted therapeutic strategies for liver diseases treatments.

MicroRNA-124a inhibits cell proliferation and migration in liver cancer by regulating interleukin-11

Liver cancer is the sixth most common malignant tumour and ranks in the top three cancers with regard to mortality due to metastasis and postsurgical recurrence. It is significant to understand the mechanisms underlying liver cancer for diagnosis and treatment. Cumulative evidence suggests that the abnormal regulation of microRNAs (miRNAs/miRs) may contribute to the development and metastasis of cancer. miR‑124a acts as a tumour suppressor in osteosarcoma, endometrial carcinoma, prostate cancer, and glioblastoma. However, the effects of miR‑124a in liver cancer and its biological mechanism are not fully understood. It has been demonstrated that miR‑124a is downregulated and interleukin (IL)‑11 is upregulated in the liver cancer tissues. In the present study, miR‑124a upregulation inhibited cell proliferation, migration and promoted cell apoptosis. Through a dual‑luciferase reporter assay, it was verified that IL‑11 is a direct target of miR‑124a. Furthermore, the overexpression of miR‑124a repressed the secretion of IL‑11 from hepatoma cells. Finally, it was identified that mimics of miR‑124a increased the expression of tissue inhibitor of matrix metalloproteinase‑2 (TIMP‑2) and Caspase‑3 and decreased the expression levels of matrix metalloproteinase 2 (MMP2), MMP9, B‑cell lymphoma 2, signal transducer and activator of transcription 3 (STAT3), and phosphorylated‑STAT3. In conclusion, the results indicated that miR‑124a has an important role as a tumour suppressor gene by targeting IL‑11. These findings may provide novel insights for clinical treatments to prevent the development of liver cancer.

Stem Cell-Derived Exosomes, Autophagy, Extracellular Matrix Turnover, and miRNAs in Cardiac Regeneration during Stem Cell Therapy

Stem cell therapy (SCT) raises the hope for cardiac regeneration in ischemic hearts. However, underlying molecular mechanisms for repair of dead myocardium by SCT in the ischemic heart is poorly understood. Growing evidences suggest that cardiac matrix stiffness and differential expressions of miRNAs play a crucial role in stem cell survival and differentiation. However, their roles on transplanted stem cells, for myocardial repair of the ischemic heart, remain unclear. Transplanted stem cells may act in an autocrine and/or paracrine manner to regenerate the dead myocardium. Paracrine mediators such as stem cell-derived exosomes are emerging as a novel therapeutic strategy to overcome some of the limitations of SCT. These exosomes carry microRNAs (miRNAs) that may regulate stem cell differentiation into a specific lineage. MicroRNAs may also contribute to stiffness of surrounding matrix by regulating extracellular matrix (ECM) turnover. The survival of transplanted stem cell depends on its autophagic process that maintains cellular homeostasis. Therefore, exosomes, miRNAs, extracellular matrix turnover, and autophagy may have an integral role in improving the efficacy of SCT. This review elaborates the specific roles of these regulatory components on cardiac regeneration in the ischemic heart during SCT.

CCL2/CCR2 axis induces hepatocellular carcinoma invasion and epithelial-mesenchymal transition in vitro through activation of the Hedgehog pathway

Chemokine (C-C motif) ligand 2 (CCL2) has been shown to play an important role in the regulation of tumor cell growth, metastasis and host immune response. CCL2 preferentially binds to the C-C chemokine receptor type 2 (CCR2), which is expressed in various tissues. However, the role of the CCL2/CCR2 axis in hepatocellular carcinoma (HCC) invasion and its molecular mechanisms remain unclear. The aim of this study was to elucidate this issue. The human HCC cell line MHCC-97H was treated with CCL2. Cyclopamine, a smoothened (SMO) antagonist, was used to inhibit SMO activity. CCR2 siRNA and Gli-1 siRNA were used to inhibit CCR2 and Gli-1 expression respectively. The effect of CCL2 and Hedgehog (Hh) signaling on cancer cell epithelial-mesenchymal transition (EMT) and invasion was evaluated by quantitative real-time PCR analysis, western blotting and Transwell invasion assay. Our results revealed that CCL2 induced HCC cell invasion and EMT. This effect was accompanied by the activation of Hh signaling, the upregulation of Snail and vimentin and the reduction of E-cadherin. Notably, prior silencing of CCR2 with siRNA abolished CCL2-induced Hh signaling activation, Snail and vimentin upregulation, E-cadherin reduction, as well as HCC cell invasion and EMT. Furthermore, pretreatment with cyclopamine or predepletion of Gli-1 by siRNA also eliminated the changes of Snail, vimentin and E-cadherin, and HCC invasion and EMT caused by CCL2. Collectively, our results revealed that the link between the CCL2/CCR2 axis and the Hh pathway plays an important role in HCC progression. Therefore, the CCL2/CCR2 axis may represent a promising therapeutic target to prevent HCC progression.

Transcription Factor NFAT5 Promotes Glioblastoma Cell-driven Angiogenesis via SBF2-AS1/miR-338-3p-Mediated EGFL7 Expression Change

Glioblastoma (GBM) is the most aggressive primary intracranial tumor of adults and confers a poor prognosis due to high vascularization. Hence anti-angiogenic therapy has become a promising strategy for GBM treatment. In this study, the transcription factor nuclear factor of activated T-cells 5 (NFAT5) was significantly elevated in glioma samples and GBM cell lines, and positively correlated with glioma WHO grades. Knockdown of NFAT5 inhibited GBM cell-driven angiogenesis. Furthermore, long non-coding RNA SBF2 antisense RNA 1 (SBF2-AS1) was upregulated in glioma samples and knockdown of SBF2-AS1 impaired GBM-induced angiogenesis. Downregulation of NFAT5 decreased SBF2-AS1 expression at transcriptional level. In addition, knockdown of SBF2-AS1 repressed GBM cell-driven angiogenesis via enhancing the inhibitory effect of miR-338-3p on EGF like domain multiple 7 (EGFL7). In vivo study demonstrated that the combination of NFAT5 knockdown and SBF2-AS1 knockdown produced the smallest xenograft volume and the lowest microvessel density. NFAT5/SBF2-AS1/miR-338-3p/EGFL7 pathway may provide novel targets for glioma anti-angiogenic treatment.

MicroRNA-338-3p targets SOX4 and inhibits cell proliferation and invasion of renal cell carcinoma

MicroRNA (miR)-338-3p has been reported to be involved in tumor progression and development in various types of cancer. However, the biological function of miR-338-3p and its related molecular pathways involved in the progression of renal cell carcinoma (RCC) are unknown. The present study aimed to investigate the biological role and underlying mechanism of miR-338-3p in RCC cells. It was demonstrated that miR-338-3p expression level was significantly downregulated (P<0.05) in RCC tissues and cell lines. Clinical association analysis indicated that low expression of miR-338-3p was significantly associated with advanced TNM stage and lymph node metastasis (P<0.05). Function assays revealed that restoration of miR-338-3p in RCC cells significantly inhibited cell proliferation, colony formation, migration and invasion (P<0.05). Notably, sex-determining region Y-box 4 (SOX4) was identified as a direct target of miR-338-3p in RCC cells through a luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction and western blot analysis. Furthermore, SOX4 overexpression partially rescued miR-338-3p-mediated inhibition of cell proliferation, colony formation, migration and invasion in RCC cells. These results suggested that miR-338-3p functioned as a tumor suppressor in RCC cells by modulating SOX4, suggesting that miR-338-3p may have a potential use in the treatment of RCC.

Integrative analysis of novel hypomethylation and gene expression signatures in glioblastomas

Molecular and clinical heterogeneity critically hinders better treatment outcome for glioblastomas (GBMs); integrative analysis of genomic and epigenomic data may provide useful information for improving personalized medicine. By applying training-validation approach, we identified a novel hypomethylation signature comprising of three CpGs at non-CpG island (CGI) open sea regions for GBMs. The hypomethylation signature consistently predicted poor prognosis of GBMs in a series of discovery and validation datasets. It was demonstrated as an independent prognostic indicator, and showed interrelationships with known molecular marks such as MGMT promoter methylation status, and glioma CpG island methylator phenotype (G-CIMP) or IDH1 mutations. Bioinformatic analysis found that the hypomethylation signature was closely associated with the transcriptional status of an EGFR/VEGFA/ANXA1-centered gene network. The integrative molecular analysis finally revealed that the gene network defined two distinct clinically relevant molecular subtypes reminiscent of different immature neuroglial lineages in GBMs. The novel hypomethylation signature and relevant gene network may provide new insights into prognostic classification, molecular characterization, and treatment development for GBMs.

Implication of the Hedgehog pathway in hepatocellular carcinoma

The prognosis for patients who are diagnosed with advanced stage hepatocellular carcinoma (HCC) is poor because there are few treatment options. Recent research has focused on the identification of novel molecular entities that can be targeted to inhibit oncogenic signals that are involved in the carcinogenesis, proliferation and progression of HCC. Among all of the pathways that are involved in the development of HCC, Hedgehog (HH) signalling has demonstrated a substantial role in hepatocarcinogenesis and HCC progression. HH plays a physiological role in embryogenesis, through the induction of the differentiation of hepatocytes from endodermal progenitors. The re-activation of the HH pathway in chronic damaged liver is a mechanism of fibrotic degeneration and is implicated in various stages of HCC development. HH activation sustains the sub-population of immature liver epithelial cells that are involved in the pathogenesis of cirrhosis and HCC, and HH itself is a mediator of the alcohol-derived malignant transformation of liver cells. High levels of expression of HH protein markers in liver tumour tissues are correlated with aggressive histological and biological features and a poor clinical outcome. In vitro and in vivo inhibition models of the HH pathway confirm that HH is essential in maintaining tumour growth, metastasis and a mesenchymal phenotype.

MiR-338-3p regulates neuronal maturation and suppresses glioblastoma proliferation

Neurogenesis is a highly-regulated process occurring in the dentate gyrus that has been linked to learning, memory, and antidepressant efficacy. MicroRNAs (miRNAs) have been previously shown to play an important role in the regulation of neuronal development and neurogenesis in the dentate gyrus via modulation of gene expression. However, this mode of regulation is both incompletely described in the literature thus far and highly multifactorial. In this study, we designed sensors and detected relative levels of expression of 10 different miRNAs and found miR-338-3p was most highly expressed in the dentate gyrus. Comparison of miR-338-3p expression with neuronal markers of maturity indicates miR-338-3p is expressed most highly in the mature neuron. We also designed a viral “sponge” to knock down in vivo expression of miR-338-3p. When miR-338-3p is knocked down, neurons sprout multiple primary dendrites that branch off of the soma in a disorganized manner, cellular proliferation is upregulated, and neoplasms form spontaneously in vivo. Additionally, miR-338-3p overexpression in glioblastoma cell lines slows their proliferation in vitro. Further, low miR-338-3p expression is associated with increased mortality and disease progression in patients with glioblastoma. These data identify miR-338-3p as a clinically relevant tumor suppressor in glioblastoma.

MicroRNA-338-3p suppresses cell proliferation and induces apoptosis of non-small-cell lung cancer by targeting sphingosine kinase 2

Background

Lung cancer is the major cause of cancer-related death worldwide, and 80% patients of lung cancer are non-small-cell lung cancer (NSCLC) cases. MicroRNAs are important gene regulators with critical roles in diverse biological processes, including tumorigenesis. Studies indicate that sphingosine kinase 2 (SphK2) promotes tumor progression in NSCLC, but how this occurs is unclear. Thus, we explored the effect of miR-338-3p targeting SphK2 on proliferation and apoptosis of NSCLC cells.

Methods

Expression of miR-338-3p and SphK2 in NSCLC A549 and H1299 cell lines was measured using qRT-PCR and Western blot. CCK-8 and colony formation assays were used to assess the effect of miR-338-3p on NSCLC cell line proliferation. Flow cytometry was used to study the effect of miR-338-3p on NSCLC apoptosis. Luciferase reporter assay and Western blot were used to confirm targeting of SphK2 by miR-338-3p. Finally, in vivo tumorigenesis studies were used to demonstrate subcutaneous tumor growth.

Results

miR-338-3p expression in 34 NSCLC clinical samples was downregulated and this was correlated with TNM stage. miR-338-3p significantly suppressed proliferation and induced apoptosis of NSCLC A549 and H1299 cells in vitro. SphK2 was a direct target of miR-338-3p. Overexpression of miR-338-3p significantly inhibited SphK2 expression and reduced luciferase reporter activity containing the SphK2 3′-untranslated region (3′-UTR) through the first binding site. SphK2 lacking 3′-UTR restored the effects of miR-338-3p on cell proliferation inhibition. miR-338-3p significantly inhibited tumorigenicity of NSCLC A549 and H1299 cells in a nude mouse xenograft model.

Conclusions

Collectively, miR-338-3p inhibited cell proliferation and induced apoptosis of NSCLC cells by targeting and down-regulating SphK2, and miR-338-3p could inhibit NSCLC cells A549 and H1299 growth in vivo, suggesting a potential mechanism of NSCLC progression. Therapeutically, miR-338-3p may serve as a potential target in the treatment of human lung cancer.

Targeting Smoothened Sensitizes Gastric Cancer to Chemotherapy in Experimental Models

BACKGROUND The Hedgehog pathway receptor smoothened (SMO) has critical roles in tumor progression. However, whether SMO is a key factor regulating gastric cancer chemotherapy resistance is unknown. MATERIAL AND METHODS We investigated the potential functions of SMO in inducing gastric cancer paclitaxel resistance in clinical samples, gastric cancer cell lines (424GC and AGS), and subcutaneous syngeneic mouse models. RESULTS We found high SMO expression in paclitaxel-resistant gastric cancer clinical samples. Paclitaxel gastric cancer cells had higher SMO expression than in drug-sensitive cells. Upregulating SMO expression induced paclitaxel resistance in gastric cells lines via enhancing cell proliferation and inhibiting apoptosis. The combination of IPI-926, an inhibitor of SMO, with paclitaxel decreased cell viability of paclitaxel-resistant gastric cancer cells in vitro and controlled tumor growth in animal models. CONCLUSIONS The Hedgehog pathway receptor SMO is an important regulator of gastric cancer paclitaxel resistance and could be a target for sensitizing paclitaxel-resistant tumors.