miR-34a Inhibits Cell Proliferation by Targeting SATB2 in Hepatocellular Carcinoma. Biomed Res Int. 2018;2018:2863902. [PMID: 30627547 PMCID: PMC6304654 DOI: 10.1155/2018/2863902]

Prognostic Value of Tumor Tissue Up-regulated microRNAs in Clear Cell Renal Cell Carcinoma (ccRCC)

BACKGROUND/AIM

The management of patients with clear cell renal cell carcinoma (ccRCC) includes prognosis assessment based on TNM classification and biochemical markers. This approach stratifies patients with advanced ccRCC into groups of favorable, intermediate, and poor prognosis. The aim of the study was to improve prognosis estimation using microRNAs involved in the pathogenesis of ccRCC.

PATIENTS AND METHODS

The study was based on a histologically-verified set of matched ccRCC FFPE tissue samples (normal renal tissue, primary tumor, metastasis, n=20+20+20). The expression of 2,549 microRNAs was analyzed using the SurePrint G3 Human miRNA microarray kit (Agilent Technologies). Prognostic value of significantly deregulated microRNAs was further evaluated on microRNA expression and clinical data of 475 patients obtained from TCGA Kidney Clear Cell Carcinoma (KIRC) database.

RESULTS

There were 13 up-regulated and 6 down-regulated microRNAs in tumor tissues compared to control tissues. Among them, survival analysis revealed those with prognostic significance. Patients with high expression of miR-21, miR-27a, miR-34a, miR-106b, miR-210, and miR-342 showed significantly unfavorable outcome. The opposite was observed for miR-30e, patients with low expression had significantly shorter survival.

CONCLUSION

The inclusion of these microRNAs in a prognostic panel holds the potential to enhance stratification scoring systems, on which the treatment of ccRCC patients is based.

MiR-34a-5p suppresses cutaneous squamous cell carcinoma progression by targeting SIRT6

Cutaneous squamous cell carcinoma (cSCC) is a malignant tumor originating from epidermal or appendageal keratinocytes, with a rising incidence in recent years. Understanding the molecular mechanism driving its development is crucial. This study aims to investigate whether miR-34a-5p is involved in the pathogenesis of cSCC by targeting Sirtuin 6 (SIRT6).The expression levels of miR-34a-5p and SIRT6 were determined in 15 cSCC tissue specimens, 15 normal tissue specimens and cultured cells via real-time polymerase chain reaction (RT-qPCR). Pearson's correlation analysis was conducted to evaluate the relationship between miR-34a-5p and SIRT6 expression levels in cSCC tissues. A431 and SCL-1 cells were transfected with miR-34a-5p mimic, negative control or miR-34a-5p mimic together with recombinant plasmids containing SIRT6 gene. Cell counting kit-8, clone formation assay, wound healing assay, and flow cytometry were employed to assess the effects of these transfections on proliferation, migration, and apoptosis, respectively. The interaction between miR-34a-5p and SIRT6 was characterized using a dual-luciferase reporter assay.MiR-34a-5p expression was down-regulated in cSCC tissues significantly, while the SIRT6 expression was the opposite. A negative correlation was observed between the expression of miR-34a-5p and SIRT6 in cSCC tissues. Furthermore, overexpression of miR-34a-5p led to a significant reduction in the proliferation and migration abilities of A431 and SCL-1 cells, accompanied by an increase in apoptosis levels and a decrease in SIRT6 expression levels. MiR-34a-5p was identified as a direct target of SIRT6. Importantly, overexpression of SIRT6 effectively counteracted the inhibitory effect mediated by miR-34a-5p in cSCC cells.Our findings suggest that miR-34a-5p functions as a tumor suppressor in cSCC cells by targeting SIRT6.

microRNA-660 Enhances Cisplatin Sensitivity via Decreasing SATB2 Expression in Lung Adenocarcinoma

Increasing evidence suggests that microRNAs' (miRNAs) abnormal expression is one of the main factors of chemotherapy resistance in various cancers. However, the role of miRNAs in lung adenocarcinoma (LUAD) resistance to cisplatin is still unclear. In this study, we analyzed a microarray dataset to investigate miRNAs related to cisplatin resistance in LUAD. The expression of miRNAs in LUAD tissues and cell lines was detected using real-time quantitative polymerase chain reaction (RT-qPCR). Special AT-Rich Sequence-Binding Protein 2 (SATB2) in LUAD cell lines was detected using RT-qPCR and Western blot. Cell proliferation was measured by CCK8 and colony formation assays, while cell cycle and apoptosis were measured by flow cytometry. A dual-luciferase reporter assay was performed to confirm that SATB2 is a target gene of microRNA-660 (miR-660). We showed that the expression of miR-660 was not only decreased in LUAD cells and tissues but also further decreased in the cisplatin-resistant A549 cell line. The overexpression of miR-660 increased cisplatin sensitivity in LUAD cells. In addition, we identified SATB2 as a direct target gene of miR-660. We also revealed that miR-660 increased cisplatin sensitivity in LUAD cells via targeting SATB2. In conclusion, miR-660/SATB2 axis is a key regulator of cisplatin resistance in LUAD.

Immune-related biomarkers shared by inflammatory bowel disease and liver cancer

It has been indicated that there is an association between inflammatory bowel disease (IBD) and hepatocellular carcinoma (HCC). However, the molecular mechanism underlying the risk of developing HCC among patients with IBD is not well understood. The current study aimed to identify shared genes and potential pathways and regulators between IBD and HCC using a system biology approach. By performing the different gene expression analyses, we identified 871 common differentially expressed genes (DEGs) between IBD and HCC. Of these, 112 genes overlapped with immune genes were subjected to subsequent bioinformatics analyses. The results revealed four hub genes (CXCL2, MMP9, SPP1 and SRC) and several other key regulators including six transcription factors (FOXC1, FOXL1, GATA2, YY1, ZNF354C and TP53) and five microRNAs (miR-124-3p, miR-34a-5p, miR-1-3p, miR-7-5p and miR-99b-5p) for these disease networks. Protein-drug interaction analysis discovered the interaction of the hub genes with 46 SRC-related and 11 MMP9- related drugs that may have a therapeutic effect on IBD and HCC. In conclusion, this study sheds light on the potential connecting mechanisms of HCC and IBD.

SATB2: A versatile transcriptional regulator of craniofacial and skeleton development, neurogenesis and tumorigenesis, and its applications in regenerative medicine

SATB2 (special AT-rich sequence-binding protein 2) is a member of the special AT-rich binding protein family. As a transcription regulator, SATB2 mainly integrates higher-order chromatin organization. SATB2 expression appears to be tissue- and stage-specific, and is governed by several cellular signaling molecules and mediators. Expressed in branchial arches and osteoblast-lineage cells, SATB2 plays a significant role in craniofacial pattern and skeleton development. In addition to regulating osteogenic differentiation, SATB2 also displays versatile functions in neural development and cancer progression. As an osteoinductive factor, SATB2 holds great promise in improving bone regeneration toward bone defect repair. In this review, we have summarized our current understanding of the physiological and pathological functions of SATB2 in craniofacial and skeleton development, neurogenesis, tumorigenesis and regenerative medicine.

SATB2 is a novel biomarker and therapeutic target for cancer

Several studies have confirmed the involvement of cancer stem cells (CSC) in tumour progression, metastasis, drug resistance and cancer relapse. SATB2 (special AT-rich binding protein-2) acts as a transcriptional co-factor and modulates chromatin architecture to regulate gene expression. The purpose of this review was to discuss the pathophysiological roles of SATB2 and assess whether it could be used as a therapeutic target for cancer. SATB2 modulated the expression of those genes which regulated pluripotency and self-renewal. Overexpression of SATB2 gene in normal epithelial cells was shown to induce transformation, as a result transformed cells gained CSC's characteristics by expressing stem cell markers and pluripotency maintaining factors, suggesting its role as an oncogene. In addition, SATB2 induced epithelial-mesenchymal transition (EMT) and metastasis. Interestingly, the expression of SATB2 was positively correlated with the activation of β-catenin/TCF-LEF pathway. Furthermore, SATB2 silencing inhibited EMT and their positive regulators, and tumour growth, and suppressed the expression of stem cell markers, pluripotency maintaining factors, cell cycle and cell survival genes, and TCF/LEF targets. Based on the cancer genome atlas (TCGA) expression data and published papers, SATB2 alone or in combination with other proteins could be used a diagnostic biomarker for cancer. Although there is no pharmacological inhibitor of SATB2, studies using genetic approaches suggest that SATB2 could be a potential target for cancer treatment and prevention.

Circulating microRNAs associated with liver fibrosis in chronic hepatitis C patients

A major challenge in hepatitis C research is the detection of early potential for progressive liver disease. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and can be biomarkers of pathological processes. In this study, we compared circulating miRNAs identified in hepatitis C virus (HCV)-infected patients presenting two extremes of liver disease: mild/moderate fibrosis and cirrhosis. The patients in the cirrhosis group subsequently developed hepatocellular carcinoma (HCC). We identified 163 mature miRNAs in the mild/moderate fibrosis group and 171 in the cirrhosis group, with 144 in common to both groups. Differential expression analysis revealed 5 upregulated miRNAs and 2 downregulated miRNAs in the cirrhosis group relative to the mild/moderate fibrosis group. Functional analyses of regulatory networks (target gene and miRNA) identified gene categories involved in cell cycle biological processes and metabolic pathways related to cell cycle, cancer, and apoptosis. These results suggest that the differentially expressed circulating miRNAs observed in this work (miR-215-5p, miR-483-5p, miR-193b-3p, miR-34a-5p, miR-885-5p, miR-26b-5p and miR -197-3p) may be candidates for biomarkers in the prognosis of liver disease.

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Circulating miRNome was performed in patients infected with HCV-1a or 1b.

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Mature miRNAs were identified in patients with mild/moderate fibrosis and cirrhosis.

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Five upregulated and two downregulated miRNAs were observed in the cirrhosis group.

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Regulatory networks identified gene categories involved in cell cycle.

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A routine baseline circulating biomarkers detection can have a prognostic value.

Effects of miR-103 by negatively regulating SATB2 on proliferation and osteogenic differentiation of human bone marrow mesenchymal stem cells

Background

The proliferation and osteogenic differentiation of human bone marrow mesenchymal stem cells (HBMScs) are modulated by a variety of microRNAs (miRNAs). SATB homeobox 2 (SATB2) is a critical transcription factor that contributes to maintain the balance of bone metabolism. However, it remains unclear how the regulatory relationship between miR-103 and SATB2 on HBMScs proliferation and osteogenic differentiation.

Methods

HBMScs were obtained from Cyagen Biosciences and successful induced osteogenic differentiation. The proliferation abilities of HBMScs after treatment with agomiR-103 and antagomiR-103 were assessed using a cell counting Kit-8 (CCK-8) assay, and osteogenic differentiation was determined using alizarin red S staining and alkaline phosphatase (ALP) activity assay. The expression levels of miR-103, SATB2, and associated osteogenic differentiation biomarkers, including RUNX family transcription factor 2 (RUNX2), bone gamma-carboxyglutamate protein (BGLAP), and secreted phosphoprotein 1 (SPP1), were evaluated using real-time qPCR and Western blot. The regulatory sites of miR-103 on SATB2 were predicted using bioinformatics software and validated using a dual luciferase reporter assay. The underlying mechanism of miR-103 on SATB2-medicated HBMScs proliferation and osteogenic differentiation were confirmed by co-transfection of antagomiR-103 and SATB2 siRNA.

Results

The expression of miR-103 in HBMScs after induction of osteogenic differentiation was reduced in a time-dependent way. Overexpression of miR-103 by transfection of agomiR-103 suppressed HBMScs proliferation and osteogenic differentiation, while silencing of miR-103 by antagomiR-103 abolished these inhibitory effects. Consistently, RUNX2, BGLAP and SPP1 mRNA and protein expression were decreased in agomiR-103 treated HBMScs compared with those in agomiR-NC group. Meanwhile, antagomiR-103 upregulated the mRNA and protein expression levels of RUNX2, BGLAP and SPP1 in HBMScs. Further studies revealed that SATB2 was a direct target gene of miR-103. BMSCs transfected with agomiR-103 exhibited significantly downregulated protein expression level of SATB2, whereas knockdown of miR-103 promoted it. Additionally, rescue assays confirmed that silencing of SATB2 partially reversed the effects of antagomiR-103 induced HBMScs proliferation and osteogenic differentiation.

Conclusions

The present results suggested that miR-103 negatively regulates SATB2 to serve an inhibitory role in the proliferation and osteogenic differentiation of HBMScs, which sheds light upon a potential therapeutic target for treating bone-related diseases.

Bio responsive self-assembly of Au-miRNAs for targeted cancer theranostics

Background

MicroRNA (miRNA) therapeutics are a promising approach to cancer treatment. However, this method faces considerable challenges to achieve tissue-specific, efficient, and safe delivery of miRNAs in vivo.

Methods

Herein, we developed a miRNA delivery system based on the in situ self-assembly of Au-miRNA nanocomplexes (Au-miRNA NCs). Within the cancer microenvironment, we constructed in situ self-assembled Au-miRNA NCs by coincubating gold salt and tumor suppressor mimics, such as let-7a, miRNA-34a, and miRNA-200a.

Findings

The in vitro experiments demonstrated that characteristic in situ self-assembled Au-miRNA NCs were present in cancer cells and can be taken up to inhibit the proliferation of cancer cells effectively. Most importantly, as proven in subcutaneous tumor treatment models, Au-miRNA NCs were especially useful for accurate target imaging and tumor suppression, with significantly enhanced antitumor effects for combination therapy.

Interpretation

These observations highlight that a new strategy for the in situ biosynthesis of Au-let-7a NCs, Au-miR-34a NCs, and Au-miR-200a NCs is feasible, and this may assist in the delivery of more miRNA to tumor cells for cancer treatment. This work opens up new opportunities for the development of miRNA tumor therapy strategies.

Funding

National Natural Science Foundation of China (91753106); Primary Research & Development Plan of Jiangsu Province (BE2019716); National Key Research and Development Program of China (2017YFA0205300).

MicroRNA signature in patients with hepatocellular carcinoma associated with type 2 diabetes

BACKGROUND

Nonalcoholic steatohepatitis-related cirrhosis is one of the liver complications in type 2 diabetes mellitus (T2DM) and reported to be a risk factor for developing hepatocellular carcinoma (HCC). A reliable screening biomarker of liver cirrhosis (LC) and HCC among T2DM patients is important to reduce the morbidity and mortality of this disease. MicroRNA (miRNA) is considered a key player in HCC and T2DM, and it might be a hidden culprit in diabetes-associated HCC, making it a promising reliable prognostic tool.

AIM

To investigate the signature of serum miRNAs as early biomarkers for the screening of HCC among diabetic patients.

METHODS

Expression profiles of miRNAs in serum samples of diabetic LC and diabetic HCC patients were assessed using Illumina sequencing; then, RT-qPCR was used to validate significantly altered miRNAs between the two groups. Candidate miRNAs were tested in serum samples of 200 T2DM patients, 270 LC patients, 200 HCC patients, and 225 healthy control subjects. Additionally, receiver operating characteristic (ROC) analysis, with area under the curve (AUC), was performed to assess the diagnostic performance of the screened miRNAs for discriminating HCC from LC and nonmalignant patients (LC + T2DM).

RESULTS

Expression of the sequenced miRNAs in serum was different in HCC vs LC-positive T2DM patients. Two miRNAs (miR-34a, miR-221) were significantly up-regulated and five miRNAs (miR-16, miR-23-3p, miR-122-5p, miR-198, miR-199a-3p) were significantly down-regulated in HCC compared to LC patients. Analysis of ROC curve demonstrated that the combination of these seven miRNAs can be used as a reliable biomarker for detection of HCC in diabetic patients, as it could identify HCC with high diagnostic accuracy in diabetic LC patients (AUC = 0.993) and in diabetic nonmalignant patients (AUC = 0.961).

CONCLUSION

This study validates a panel of serum miRNAs that can be used as a reliable noninvasive screening biomarker of HCC among T2DM cirrhotic and noncirrhotic patients. The study recommends further research to shed light on a possible role of c-Met in T2DM-associated HCC via the miRNA regulatory pathway.

miR-34a Enhances the Susceptibility of Gastric Cancer to Platycodin D by Targeting Survivin

INTRODUCTION

Platycodin D (PD), a triterpenoid saponin isolated from Platycodon grandiflorum, has a well-known anti-tumor effect in multiple human cancers, including gastric cancer (GC). miR-34a plays an important role in the progression of GC. However, the relationship between miR-34a and the susceptibility of GC cells to PD is still unclear. The aim of our research was to investigate the functions of miR-34a in mediating the susceptibility of GC to PD.

METHODS

qPCR was performed to detect the expression level of miR-34a and survivin in GC cells. The expression of survivin, Bcl-2, Bax, and cleaved caspase-3 was analyzed using Western blot. Cell viability was detected by MTT assay, and apoptosis was analyzed via Annexin V-FITC/PI staining followed by flow cy-tometry. The colony formation and scratch-wound assays were applied to assess cell proliferation and migration. Caspase-3/7 activity was detected by a Caspase-Glo®3/7 detection kit. The relationship between miR-34a and survivin was determined by dual luciferase reporter gene assay. Finally, a GC xenograft mouse model was used to confirm our findings in vivo.

RESULTS

The expression of miR-34a decreased but survivin increased inversely in human GC cells. Survivin is a direct target of miR-34a and may be negatively regulated by miR-34a. PD could inhibit GC cell proliferation and induce apoptosis. Importantly, overexpression miR-34a or suppressing survivin was shown to enhance the susceptibility of GC to PD both in vitro and in vivo.

CONCLUSIONS

miR-34a could modulate the susceptibility of GC to PD via targeting survivin, suggesting miR-34a overexpression may serve as a novel strategy to sensitize GC to anti-cancer drugs.

Higher expression of SATB2 in hepatocellular carcinoma of African Americans determines more aggressive phenotypes than those of Caucasian Americans

In the United States, Hepatocellular Carcinoma (HCC) incidence has tripled over the past two decades. The disease has disproportionately affected minority and disadvantaged populations. The purpose of this study was to examine the expression of SATB2 gene in HCC cells derived from African Americans (AA) and Caucasian Americans (CA) and assess its oncogenic potential by measuring cell viability, spheroid formation, epithelial‐mesenchymal transition (EMT), stem cell markers and pluripotency maintaining factors in cancer stem cells (CSCs). We compared the expression of SATB2 in human primary hepatocytes, HCC cells derived from AA and CA, and HCC CSCs. Hepatocellular carcinoma cells derived from AA expressed the higher level of SATB2 than those from CA. By comparison, normal human hepatocytes did not express SATB2. Higher expression of SATB2 in HCC cells from AA was associated with greater growth rate, cell viability, colony formation and EMT characteristics than those from CA. Knockout of SATB2 in CSCs by Crispr/Cas9 technique significantly inhibited the expression of SATB2 gene, stem cell markers (CD24, CD44 and CD133), pluripotency maintaining factors (c‐Myc, KLF4, SOX2 and OCT4), and EMT compared with non‐targeting control group. The expression of SATB2 was negatively correlated with miR34a. SATB2 rescued the miR‐34a‐mediated inhibition of CSC's viability. These data suggest that SATB2 is an oncogenic factor, and its higher expression may explain the disparity in HCC outcomes among AA.