Downregulation of miRNA-638 promotes angiogenesis and growth of hepatocellular carcinoma by targeting VEGF

Vitamin D3/VDR alleviates double-stranded RNA virus -induced biliary epithelial cell damage by inhibiting autophagy

BACKGROUND

The increased apoptosis of bile duct epithelial cells (BECs) due to some damage factors is considered the initiating factor in the occurrence and progression of biliary atresia (BA). Vitamin D receptor (VDR) is thought to play a crucial role in maintaining the intrinsic immune balance and integrity of bile duct epithelial cells (BECs). To investigate the role of VDRs in the pathogenesis and progression of BA using in vitro and in vivo models.

MATERIALS AND METHODS

The VDR expression levels in intrahepatic bile duct epithelial cells (IBDECs) in pediatric patients with BA were examined using immunohistochemical analysis. The correlation of the VDR levels with the incidence of refractory cholangitis after Kasai portoenterostomy (KPE) and the autologous liver survival time was analyzed. The levels of genes and proteins involved in related pathways were examined using quantitative real-time polymerase chain reaction and western blotting, respectively. The secretory levels of inflammatory factors were analyzed using enzyme-linked immunosorbent assay. A BA mouse model was established through the intraperitoneal sequential injection of rhesus rotavirus (RRV). The role of VDR in the pathogenesis and progression of BA was examined using in vitro and in vivo models. Retrospective analysis of patients with BA to examine the therapeutic efficacy of VDR activators on BA.

RESULTS

15 pediatric BA patients exhibiting VDR downregulation in IBDECs showed a higher incidence of refractory cholangitis after Kasai portoenterostomy (p = 0.037) and a lower native liver survival time compare to 23 BA patients without VDR downregulation (p = 0.032). 1,25-VD3 inhibited the degree of autophagy induction in HIBECs by poly(I: C) (p < 0.05), mitigated poly(I: C)-induced BEC damage and apoptosis by inhibiting autophagy (p < 0.05). 1,25-VD3 significantly suppressed the poly(I: C)-induced downregulation of SRC (p < 0.05) and ERK1/2 phosphorylation (p < 0.05). 1,25-VD3 exert a protective effect against RRV-induced BEC damage by inhibiting autophagy in BA mouse model. The incidence of cholangitis and the native liver survival time after surgery in the calcitriol-treated group was significantly lower than that in the control group. (p = 0.033, p = 0.035, respectively).

CONCLUSIONS

VDR activator mitigated dsRNA-induced BEC damage and apoptosis by inhibiting autophagy in vitro and in vivo. The 1,25-VD3/VDR/Src axis alleviated poly(I: C)-induced HIBEC damage and apoptosis through the PLA2/PKC/ERK pathway.

Association of miRNA and Bone Tumors: Future Therapeutic Inroads

Small endogenous non-coding RNA molecules known as micro-ribonucleic acids (miRNAs) control post-transcriptional gene regulation. A change in miRNA expression is related to various diseases, including bone tumors. Benign bone tumors are categorized based on matrix production and predominant cell type. Osteochondromas and giant cell tumors are among the most common bone tumors. Interestingly, miRNAs can function as either tumor suppressor genes or oncogenes, thereby determining the fate of a tumor. In the present review, we discuss various bone tumors with regard to their prognosis, pathogenesis, and diagnosis. The association between miRNAs and bone tumors, such as osteosarcoma, Ewing's sarcoma, chondrosarcoma, and giant-cell tumors, is also discussed. Moreover, miRNA may play an important role in tumor proliferation, growth, and metastasis. Knowledge of the dysregulation, amplification, and deletion of miRNA can be beneficial for the treatment of various bone cancers. The miRNAs could be beneficial for prognosis, treatment, future drug design, and treatment of resistant cases of bone cancer.

microRNAs: critical targets for treating rheumatoid arthritis angiogenesis

Vascular neogenesis, an early event in the development of rheumatoid arthritis (RA) inflammation, is critical for the formation of synovial vascular networks and plays a key role in the progression and persistence of chronic RA inflammation. microRNAs (miRNAs), a class of single-stranded, non-coding RNAs with approximately 21-23 nucleotides in length, regulate gene expression by binding to the 3' untranslated region (3'-UTR) of specific mRNAs. Increasing evidence suggests that miRNAs are differently expressed in diseases associated with vascular neogenesis and play a crucial role in disease-related vascular neogenesis. However, current studies are not sufficient and further experimental studies are needed to validate and establish the relationship between miRNAs and diseases associated with vascular neogenesis, and to determine the specific role of miRNAs in vascular development pathways. To better treat vascular neogenesis in diseases such as RA, we need additional studies on the role of miRNAs and their target genes in vascular development, and to provide more strategic references. In addition, future studies can use modern biotechnological methods such as proteomics and transcriptomics to investigate the expression and regulatory mechanisms of miRNAs, providing a more comprehensive and in-depth research basis for the treatment of related diseases such as RA.

miRNAs in HCC, pathogenesis, and targets

Liver cancer is the third leading cause of cancer-related mortality worldwide. HCC, the most common type of primary liver cancer, is driven by complex genetic, epigenetic, and environmental factors. MicroRNAs, a class of naturally occurring small noncoding RNAs, play crucial roles in HCC by simultaneously modulating the expression of multiple genes in a fine-tuning manner. Significant progress has been made in understanding how miRNAs influence key oncogenic pathways, including cell proliferation, apoptosis, angiogenesis, and epithelial-mesenchymal transition (EMT), as well as their role in modulating the immune microenvironment in HCC. Due to the unexpected stability of miRNAs in the blood and fixed HCC tumors, recent advancements also highlight their potential as noninvasive diagnostic tools. Restoring or inhibiting specific miRNAs has offered promising strategies for targeted HCC treatment by suppressing malignant hepatocyte growth and enhancing antitumor immunity. In this comprehensive review, we consolidate previous research and provide the latest insights into how miRNAs regulate HCC and their therapeutic and diagnostic potential. We delve into the dysregulation of miRNA biogenesis in HCC, the roles of miRNAs in the proliferation and apoptosis of malignant hepatocytes, angiogenesis and metastasis of HCC, the immune microenvironment in HCC, and drug resistance. We also discuss the therapeutic and diagnostic potential of miRNAs and delivery approaches of miRNA drugs to overcome the limitations of current HCC treatment options. By thoroughly summarizing the roles of miRNAs in HCC, our goal is to advance the development of effective therapeutic drugs with minimal adverse effects and to establish precise tools for early diagnosis of HCC.

Overview of hepatocarcinogenesis focusing on cellular origins of liver cancer stem cells: a narrative review

Hepatocellular carcinoma (HCC) accounts for 85% to 90% of primary liver cancers and generally has a poor prognosis. The hierarchical model, which posits that HCC originates from liver cancer stem cells (CSCs), is now widely accepted, as it is for other cancer types. As CSCs typically reside in the G0 phase of the cell cycle, they are resistant to conventional chemotherapy. Therefore, to effectively treat HCC, developing therapeutic strategies that target liver CSCs is essential. Clinically, HCCs exhibit a broad spectrum of pathological and clinical characteristics, ranging from well-differentiated to poorly differentiated forms, and from slow-growing tumors to aggressive ones with significant metastatic potential. Some patients with HCC also show features of cholangiocarcinoma. This HCC heterogeneity may arise from the diverse cellular origins of liver CSCs. This review explores the normal physiology of liver regeneration and provides a comprehensive overview of hepatocarcinogenesis, including cancer initiation, isolation of liver CSCs, molecular signaling pathways, and microRNAs. Additionally, the cellular origins of liver CSCs are reviewed, emphasizing hematopoietic and mesenchymal stem cells, along with the well-known hepatocytes and hepatic progenitor cells.

Clinical significance of exosomal noncoding RNAs in hepatocellular carcinoma: a narrative review

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies worldwide, with poor prognosis owing to its high frequency of recurrence and metastasis. Moreover, most patients are diagnosed at an advanced stage owing to a lack of early detection markers. Exosomes, which are characterized by their cargos of stable intracellular messengers, such as DNA, RNA, proteins, and lipids, play a crucial role in regulating cell differentiation and HCC development. Recently, exosomal noncoding RNAs (ncRNAs), including microRNAs, long ncRNAs, and circular RNAs, have become increasingly important diagnostic, prognostic, and predictive markers of HCC. Herein, we discuss the clinical implications of exosomal ncRNAs, specifically those within the HCC regulatory network.

Role of Angiogenesis and Its Biomarkers in Development of Targeted Tumor Therapies

Angiogenesis plays a significant role in the human body, from wound healing to tumor progression. "Angiogenic switch" indicates a time-restricted event where the imbalance between pro- and antiangiogenic factors results in the transition from prevascular hyperplasia to outgrowing vascularized tumor, which eventually leads to the malignant cancer progression. In the last decade, molecular players, i.e., angiogenic biomarkers and underlying molecular pathways involved in tumorigenesis, have been intensely investigated. Disrupting the initiation and halting the progression of angiogenesis by targeting these biomarkers and molecular pathways has been considered as a potential treatment approach for tumor angiogenesis. This review discusses the currently known biomarkers and available antiangiogenic therapies in cancer, i.e., monoclonal antibodies, aptamers, small molecular inhibitors, miRNAs, siRNAs, angiostatin, endostatin, and melatonin analogues, either approved by the U.S. Food and Drug Administration or currently under clinical and preclinical investigations.

MicroRNAs as the critical regulators of tumor angiogenesis in liver cancer

Liver cancer is one of the most common malignancies in human digestive system. Despite the recent therapeutic methods, there is a high rate of mortality among liver cancer patients. Late diagnosis in the advanced tumor stages can be one of the main reasons for the poor prognosis in these patients. Therefore, investigating the molecular mechanisms of liver cancer can be helpful for the early stage tumor detection and treatment. Vascular expansion in liver tumors can be one of the important reasons for poor prognosis and aggressiveness. Therefore, anti-angiogenic drugs are widely used in liver cancer patients. MicroRNAs (miRNAs) have key roles in the regulation of angiogenesis in liver tumors. Due to the high stability of miRNAs in body fluids, these factors are widely used as the non-invasive diagnostic and prognostic markers in cancer patients. Regarding, the importance of angiogenesis during liver tumor growth and invasion, in the present review, we discussed the role of miRNAs in regulation of angiogenesis in these tumors. It has been reported that miRNAs mainly exert an anti-angiogenic function by regulation of tumor microenvironment, transcription factors, and signaling pathways in liver tumors. This review can be an effective step to suggest the miRNAs for the non-invasive early detection of malignant and invasive liver tumors.

Comparative analysis of miRNA expression in dedifferentiated and well-differentiated components of dedifferentiated chondrosarcoma

Dedifferentiated chondrosarcoma (DDCS) is a rare malignant cartilage tumor arising out of a low-grade chondrosarcoma, whereby the well-differentiated and the dedifferentiated components coexist in the same localization. DDCS has a massively increased metastatic potential in comparison to low-grade chondrosarcoma. So far, the underlying mechanisms of DDCS development and the increased malignancy are widely unknown. Targeted DNA sequencing revealed no genetic differences between both tissue components. Besides genetic events, alterations in epigenetic control may play a role in DDCS development. In this preliminary study, we have analyzed the differential miRNA expression in paired samples of both components of four primary DDCS cases and a rare lung metastasis with both components using the nCounter MAX analysis system from NanoString technologies. We identified 21 upregulated and two downregulated miRNAs in the dedifferentiated components of the primary cases. Moreover, three miRNAs were also significantly deregulated in the dedifferentiated component of the lung metastasis, supporting their possible role in DDCS development. Additionally, validated targets of the 23 deregulated miRNAs are involved in signaling pathways, like PI3K/Akt, Wnt/β-catenin, and TGF-β, as well as in cellular processes, like cell cycle regulation, apoptosis, and dedifferentiation. Further investigations are necessary to confirm and understand the role of the identified miRNAs in DDCS development.

Empagliflozin Improves the MicroRNA Signature of Endothelial Dysfunction in Patients with Heart Failure with Preserved Ejection Fraction and Diabetes

Endothelial dysfunction represents a key mechanism underlying heart failure with preserved ejection fraction (HFpEF), diabetes mellitus (DM), and frailty. However, reliable biomarkers to monitor endothelial dysfunction in these patients are lacking. In this study, we evaluated the expression of a panel of circulating microRNAs (miRs) involved in the regulation of endothelial function in a population of frail older adults with HFpEF and DM treated for 3 months with empagliflozin, metformin, or insulin. We identified a distinctive pattern of miRs that were significantly regulated in HFpEF patients compared to healthy controls and to HFpEF patients treated with the sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin. Three miRs were significantly downregulated (miR-126, miR-342-3p, and miR-638) and two were significantly upregulated (miR-21 and miR-92) in HFpEF patients compared to healthy controls. Strikingly, two of these miRs (miR-21 and miR-92) were significantly reduced in HFpEF patients after the 3-month treatment with empagliflozin, whereas no significant differences in the profile of endothelial miRs were detected in patients treated with metformin or insulin. Taken together, our findings demonstrate for the first time that specific circulating miRs involved in the regulation of endothelial function are significantly regulated in frail HFpEF patients with DM and in response to SGLT2 inhibition. SIGNIFICANCE STATEMENT: We have identified a novel microRNA signature functionally involved in the regulation of endothelial function that is significantly regulated in frail patients with HFpEF and diabetes. Moreover, the treatment with the SGLT2 inhibitor empagliflozin caused a modification of some of these microRNAs in a direction that was opposite to what observed in HFpEF patients, indicating a rescue of endothelial function. Our findings are relevant for clinical practice inasmuch as we were able to establish novel biomarkers of disease and response to therapy.

miR-638: A Promising Cancer Biomarker with Therapeutic Potential

BACKGROUND

There is an unmet need to improve the diagnosis of cancer with precise treatment strategies. Therefore, more powerful diagnostic, prognostic, and therapeutic biomarkers are needed to overcome tumor cells. microRNAs (miRNAs, miRs), as a class of small non-coding RNAs, play essential roles in cancer through the tumor-suppressive or oncogenic effects by post-transcriptional regulation of their targets. Many studies have provided shreds of evidence on aberrantly expressed miRNAs in numerous cancers and have shown that miRNAs could play potential roles as diagnostic, prognostic, and even therapeutic biomarkers in patients with cancers. Findings have revealed that miR-638 over or underexpression might play a critical role in cancer initiation, development, and progression. However, the mechanistic effects of miR-638 on cancer cells are still controversial.

CONCLUSION

In the present review, we have focused on the diagnostic, prognostic, and therapeutic potentials of miR-638 and discussed its mechanistic roles in various types of cancers.

Cross-regulation between microRNAs and key proteins of signaling pathways in hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a subtype of primary liver cancer and a major cause of death. Although miRNA plays an important role in hepatocellular carcinoma, the specific regulatory network remains unclear. Therefore, this paper comprehensively describes the miRNA-related signaling pathways in HCC and the possible interactions among different signaling pathways. The aim is to lay the foundation for the discovery of new molecular targets and multi-target therapy.

AREAS COVERED

Based on miRNA, HCC, and signaling pathways, the literature was searched on Web of Science and PubMed. Then, common targets between different signaling pathways were found from KEGG database, and possible cross-regulation mechanisms were further studied. In this review, we elaborated from two aspects, respectively, laying a foundation for studying the regulatory mechanism and potential targets of miRNA in HCC.

EXPERT OPINION

Non-coding RNAs have become notable molecules in cancer research in recent years, and many types of targeted drugs have emerged. From the outset, molecular targets and signal pathways are interlinked, which suggests that signal pathways and regulatory networks should be concerned in basic research, which also provides a strong direction for future mechanism research.

MicroRNAs: Novel players in the diagnosis and treatment of cancer cachexia (Review)

Cachexia denotes a complex metabolic syndrome featuring severe loss of weight, fatigue and anorexia. In total, 50-80% of patients suffering from advanced cancer are diagnosed with cancer cachexia, which contributes to 40% of cancer-associated mortalities. MicroRNAs (miRNAs) are non-coding RNAs capable of regulating gene expression. Dysregulated miRNA expression has been observed in muscle tissue, adipose tissue and blood samples from patients with cancer cachexia compared with that of samples from patients with cancer without cachexia or healthy controls. In addition, miRNAs promote and maintain the malignant state of systemic inflammation, while inflammation contributes to cancer cachexia. The present review discusses the role of miRNAs in the progression of cancer cachexia, and assess their diagnostic value and potential therapeutic value.

Transcriptome analysis of lncRNA expression patterns in human congenital lung malformations

Objectives

To explore the long non-coding RNA (lncRNA) expression pattern of congenital lung malformations on a genome-wide scale and investigate their potential biological function in four subtypes of congenital lung malformations.

Methods

We obtained both lesions and normal lung control tissues from the patients diagnosed with CPAM-I, CPAM-II, ILS, and ILS-CPAM, and underwent lobectomy (i.e., surgical removal of the whole lobe which contains the localized lesion as well as normal lung tissue). Then, we performed lncRNA transcriptome profiling in these tissues by RNA sequencing (RNA-seq). A comprehensive bioinformatics analysis was conducted to characterize the expression profiles and relevant biological functions and for multiple comparisons of lncRNA expression in the different subtypes of congenital lung malformation tissues. Furthermore, the lncRNA-mRNA co-expression network was constructed, and dysregulated mRNAs were functionally analyzed. Finally, gene set enrichment analysis (GSEA) was used to predict the potential molecular mechanism of the identified lncRNAs.

Results

A total of 5921 lncRNA transcripts were identified between congenital lung malformations tissues and normal lung control tissues. Compared with normal lung control, 481of these expressed lncRNAs were upregulated and 142 were downregulated in CPAM-I, 91 were upregulated and 14 were downregulated in CPAM-II, 39 were upregulated and 38 were downregulated in ILS, and 201 were upregulated and 38 were downregulated in ILS-CPAM. Unsupervised clustering and principal component analysis of the expressed lncRNAs visualized the differences between normal lung control and different subtypes of congenital lung malformations samples. We also confirmed significant differences in the composition of differentially expressed genes (DEGs) and the differentially expressed lncRNAs (DE lncRNAs) between CPAM-I and other subtypes of congenital lung malformations, as well as in normal lung control tissues, and observed enrichment of DEGs in the regulation of the immune system, cell projection organization, and inflammatory pathways. Finally, we identified the lncRNA FLJ26850 might be related to congenital lung malformations via ZNF473.

Conclusions

Significant differences in lncRNAs expression patterns were observed between different subtypes of congenital lung malformations and normal control. The lncRNA FLJ26850 might be related to congenital lung malformations via ZNF473.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-08204-x.

MicroRNAs as Diagnostic Tools in Hepatocellular Carcinoma

Liver cancer is the fourth leading cause of cancer-related deaths worldwide, with hepatocellular carcinoma (HCC) accounting for approximately 80% of all liver cancers. The serum concentration of alpha-fetoprotein (AFP) is the only validated biomarker for HCC diagnosis. MicroRNAs (miRNAs) are small non-coding RNAs of 21–30 nucleotides playing a critical role in human carcinogenesis, with types of miRNAs with oncogenic (oncomiRs) or tumor suppressor features. The altered expression of miRNAs in HCC is associated with many pathological processes, such as cancer initiation, tumor growth, apoptosis escape, promotion of migration and invasion. Moreover, circulating miRNAs have been increasingly investigated as non-invasive biomarkers for HCC diagnosis. MiRNAs’ expression patterns are altered in HCC and several single miRNAs or miRNAs panels have been found significantly up or downregulated in HCC with respect to healthy controls or non-oncological patients (cirrhotic or with viral hepatitis). However, any of the investigated miRNAs or miRNAs panels has entered clinical practice so far. This has mostly to do with lack of protocols standardization, small sample size and discrepancies in the measurement techniques. This review summarizes the major findings regarding the diagnostic role of miRNAs in HCC and their possible use together with standard biomarkers in order to obtain an early diagnosis and easier differential diagnosis from non-cancerous liver disease.

miR-638 suppresses proliferation by negatively regulating high mobility group A1 in ovarian cancer cells

Ovarian cancer is one of the most common gynecological diseases with high mortality rates. Previous studies have shown that microRNA (miR)-638 is associated with tumorigenesis. The present study aimed to assess the role and underlying mechanisms of miR-638 in ovarian cancer. miR-638 expression was detected in ovarian cancer tissues and miR-638 was overexpressed or knocked down in ovarian cancer OVCAR-3 and Caov-3 cells. The clinical results revealed that miR-638 expression was downregulated in ovarian cancer tissues compared with in adjacent normal tissues. miR-638 expression was also found to be relatively low in OVCAR-3 cells whilst being relatively high in Caov-3 cells among the five ovarian cancer cell lines tested. miR-638 overexpression inhibited cell viability, arrested the cell cycle at the G₁ phase and promoted apoptosis in OVCAR-3 cells. By contrast, miR-638 knockdown increased Caov-3 cell viability, facilitated cell cycle progression and inhibited apoptosis. miR-638 reduced the expression of high mobility group A1 (HMGA1) by directly targeting its 3' untranslated region. HMGA1 overexpression reversed the inhibition of proliferation induced by miR-638 overexpression in OVCAR-3 cells. These results suggest that miR-638 may serve to be a suppressor of ovarian cancer by regulating HMGA1, which may provide a potential therapeutic target for ovarian cancer.

microRNAs and bone tumours: Role of tiny molecules in the development and progression of chondrosarcoma, of giant cell tumour of bone and of Ewing's sarcoma

The increasing interest on microRNAs (miRNAs), small non-coding RNA molecules containing about 22 nucleotides, about their biological functions led researchers to discover that they are actively involved in several biological processes. In the last decades, miRNAs become one of the most topic of cancer research. miRNAs, thanks to their function, are the perfect molecules to modulate multiple signaling pathways and gene expression in cancer, with the consequent capacity to modulate cancerous processes, such as cellular proliferation, invasion, metastasis and chemoresistance in various tumours. In the last years, several studies have demonstrated the role of miRNAs in their pathophysiology, but little we know about the underlying mechanism that lead to bone tumours like chondrosarcoma (COS), giant cell tumour of bone (GCTB) and Ewing sarcoma (EWS) to still be highly aggressive and resistant tumours. An exploration of the role of miRNAs in the biology of them will permit to researchers to find new molecular mechanisms that can be used to develop new and more effective therapies against these bone tumours. Here we present a comprehensive study of the latest discoveries which have been performed in relation to the role of miRNAs in the neoplastic processes which characterize COS, EWS and GCTB, demonstrating how these tiny molecules can act as tumour promoters or as tumour suppressors and how they can be used for improving therapeutic approaches.

Elucidating the Molecular Basis of Sorafenib Resistance in HCC: Current Findings and Future Directions

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. Sorafenib is the first multi-tyrosine kinase inhibitor approved for HCC and it has represented the standard of care for advanced HCC for almost 10 years, offering a survival benefit when compared to placebo. However, this benefit is limited, showing rare objective responses and a disease control rate approaching 50–60%, with most patients experiencing disease progression at 6 months. These scant results dictate the urgent need for strategies to overcome both primary and acquired resistance. Herein we report several mechanisms supporting resistance to sorafenib in HCC patients, including activation of oncogenic pathways. Among these, the AKT/mTOR pathway plays a crucial role being at the crossroad of multiple driving events. Autophagy, multidrug-resistant phenotype, hypoxia-related mechanisms and endoplasmic reticulum stress are gaining more and more relevance as crucial events driving the response to anticancer drugs, including sorafenib. Several HCC-specific miRNAs take part to the regulation of these cellular processes. Remarkably, molecularly targeted strategies able to overcome resistance in these settings have also been reported. So far, the vast majority of data has been derived from laboratory studies, which means the need for an extensive validation. Indeed, most of the possible drug associations displaying promising effects in improving sorafenib efficacy herein described derive from preclinical explorations. Notably, data obtained in animal models can be inconsistent with regard to the human disease for efficacy, safety, side effects, best formulation and pharmacokinetics. However, they represent the necessary preliminary step to improve the management of advanced HCC.

Angiogenesis-related non-coding RNAs and gastrointestinal cancer

Gastrointestinal (GI) cancers are among the main reasons for cancer death globally. The deadliest types of GI cancer include colon, stomach, and liver cancers. Multiple lines of evidence have shown that angiogenesis has a key role in the growth and metastasis of all GI tumors. Abnormal angiogenesis also has a critical role in many non-malignant diseases. Therefore, angiogenesis is considered to be an important target for improved cancer treatment. Despite much research, the mechanisms governing angiogenesis are not completely understood. Recently, it has been shown that angiogenesis-related non-coding RNAs (ncRNAs) could affect the development of angiogenesis in cancer cells and tumors. The broad family of ncRNAs, which include long non-coding RNAs, microRNAs, and circular RNAs, are related to the development, promotion, and metastasis of GI cancers, especially in angiogenesis. This review discusses the role of ncRNAs in mediating angiogenesis in various types of GI cancers and looks forward to the introduction of mimetics and antagonists as possible therapeutic agents.

Prognostic and clinicopathological significance of miR-638 in cancer patients: A meta-analysis

INTRODUCTION

MiR-638 is believed to be involved in human cancers. However, the prognostic value of miR-638 in human carcinomas is controversial and inconclusive. Therefore, we conducted this meta-analysis to investigate the association between miR-638 expression and clinical outcomes in the patients with various cancers.

METHODS

We searched Pubmed, Embase, Wanfang, and the China National Knowledge Infrastructure (CNKI) up to September 1, 2020 to identify relevant studies. Hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were used to correlate expression of miR-638 with prognosis and clinicopathological features.

RESULTS

A total of 18 studies involving 1886 patients were included in the meta-analysis. The results revealed that low miR-638 expression was significantly correlated with poor overall survival (OS) (HR = 2.09, 95% CI: 1.46-2.98, P < .001), but not with disease-free survival (DFS) (HR = 1.71, 95% CI: 0.31-9.56, P = .540). Subgroup analysis found that low miR-638 expression was associated with worse OS in patients with digestive system cancer (HR = 2.47, 95% CI: 1.85-3.30, P < .001), the reported directly from articles group (HR = 2.12, 95% CI: 1.34-3.33, P < .001), survival curves group (HR = 2.02, 95% CI: 1.07-3.80, P = .029), in studies with sample size ≥100 (HR = 2.12, 95% CI: 1.34-3.35, P = .001), and in studies with sample size <100 (HR = 2.02, 95%CI: 1.09-3.75, P = .025). Moreover, cancer patients with low miR-638 expression were prone to tumor size (OR = 1.47, 95% CI: 1.03-2.09, P = .035), earlier lymph node metastasis (present vs absent, OR = 2.26, 95% CI: 1.63-3.14, P < .001), earlier distant metastasis (present vs absent, OR = 2.60, 95% CI: 1.45-4.67, P < .001), TNM stage (III-IV vs I-II, OR = 2.01, 95% CI: 1.35-2.99, P = .001), and portal vein invasion (present vs absent, OR = 4.39, 95% CI:2.23-8.64, P < .001), but not associated with age, gender, tumor differentiation, and vascular invasion.

CONCLUSIONS

MiR-638 may serve as a promising indicator in the prediction of prognosis and clinicopathological features in patients with different kinds of cancers.

The Role and Expression of Angiogenesis-Related miRNAs in Gastric Cancer

Gastric cancer (GC) is the fifth most frequently diagnosed malignant tumor and the third highest cause of cancer mortality worldwide. For advanced GC, many novel drugs and combinations have been tested, but results are still disappointing, and the disease is incurable in the majority of cases. In this regard, it is critical to investigate the molecular mechanisms underlying GC development. Angiogenesis is one of the hallmarks of cancer with a fundamental role in GC growth and progression. Ramucirumab, a monoclonal antibody that binds to vascular endothelial growth factor-2 (VEGFR-2), is approved in the treatment of advanced and pretreated GC. However, no predictive biomarkers for ramucirumab have been identified so far. Micro RNAs (miRNAs) are a class of evolutionarily-conserved single-stranded non-coding RNAs that play an important role (via post-transcriptional regulation) in essentially all biologic processes, such as cell proliferation, differentiation, apoptosis, survival, invasion, and migration. In our review, we aimed to analyze the available data on the role of angiogenesis-related miRNAs in GC.

MicroRNA-638 induces apoptosis and autophagy in human liver cancer cells by targeting enhancer of zeste homolog 2 (EZH2)

Liver cancer is of the devastating human cancers and its incidence is increasing at an alarming rate. The clinical outcomes are far from descent due to lack of efficient therapeutic targets and chemotherapeutic agents. Studies have revealed the therapeutic implications of microRNAs in the management of different human cancers. This study was designed to explore the role and therapeutic potential of miR-638 in liver cancer via modulation of zeste homolog 2 (EZH2). The results revealed significant (P < 0.05) downregulation of miR-638 in human liver cancer tissues and cell lines. Overexpression of miR-638 led to a significant (P < 0.05) decline in liver cancer cell proliferation. Nonetheless, inhibition of miR-638 could promote the proliferation of the human liver cancer cells. The DAPI and annexin V/PI staining assays revealed that miR-638 induces apoptosis in human liver cancer cells which was accompanied by enhancement of Bax and depletion of Bcl-2 expression. Furthermore, miR-638 overexpression also leads to a significant (P < 0.05) increase of autophagosomes and autolysosomes in liver cancer cells suggestive of autophagy. The induction of autophagy was further confirmed by increase and decrease in expression of LC3B-II and Beclin-1 proteins, respectively. In contrary, inhibition of miR-638 prevented both apoptosis and autophagy of the liver cancer cells. In silico analysis and the dual luciferase assay revealed EZH2 as the molecular target of miR-638 at post-transcriptional level. The qRT-PCR showed that EZH2 to be significantly (P < 0.05) upregulated in the human liver cancer tissues and cell lines. However, the expression of EZH2 was considerably suppressed upon miR-638 overexpression in SNU-423 cells. Taken together, these findings suggest the tumor-suppressive role of miR-638/EZH2 axis liver cancer and point towards the potential of miR-638 as therapeutic target in the treatment of liver cancer.

MicroRNA-375 represses tumor angiogenesis and reverses resistance to sorafenib in hepatocarcinoma

Sorafenib was originally identified as an inhibitor of multiple oncogenic kinases and remains the first-line systemic therapy for advanced hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) have been reported to play critical roles in the initiation, progression, and drug resistance of HCC. In this study, we aimed to identify sorafenib-induced miRNAs and demonstrate their regulatory roles. First, we identified that the expression of the tumor-suppressive miRNA miR-375 was significantly induced in hepatoma cells treated with sorafenib, and miR-375 could exert its antiangiogenic effect partially via platelet-derived growth factor C (PDGFC) inhibition. Then, we demonstrated that sorafenib inhibited PDGFC expression by inducing the expression of miR-375 and a transcription factor, achaete-scute homolog-1 (ASH1), mediated the induction of miR-375 by sorafeinb administration in hepatoma cells. Finally, we verified that the expression of miR-375 was reduced in sorafenib-resistant cells and that the restoration of miR-375 could resensitize sorafenib-resistant cells to sorafenib partially by the degradation of astrocyte elevated gene-1 (AEG-1). In conclusion, our data demonstrate that miR-375 is a critical determinant of HCC angiogenesis and sorafenib tolerance, revealing a novel miRNA-mediated mechanism underlying sorafenib treatment.

Dysregulation of miR-638 in the progression of cancers

MicroRNA (miRNA) is a form of short, single-stranded and non-coding RNA that is important in regulating the post-transcriptional modification of multiple downstream targets. Many miRNAs have been reported to involve in controlling the progression of human diseases, and one of them is miR-638, which play essential roles in regulating the development of human cancer. By targeting the 3'-ends of its targets, miR-638 can regulate cellular processes including proliferation, invasion, metastases, angiogenesis, apoptosis and inflammation. This review was aimed to summarize current findings on the roles of miR-638 in different human cancers based on the results from various in vitro, in vivo and clinical studies. The biogenesis process and tissue expression, followed by the roles of miR-638 in regulating the development of various human cancers by targeting different downstream targets were covered in this review. The potential applications and challenges of employing miR-638 as cancer biomarker and therapeutic agent were also discussed.

Regulators at Every Step-How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial-mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

Molecular and Functional Roles of MicroRNAs in the Progression of Hepatocellular Carcinoma-A Review

Liver cancer is the fourth leading cause of cancer deaths globally, of which hepatocellular carcinoma (HCC) is the major subtype. Viral hepatitis B and C infections, alcohol abuse, and metabolic disorders are multiple risk factors for liver cirrhosis and HCC development. Although great therapeutic advances have been made in recent decades, the prognosis for HCC patients remains poor due to late diagnosis, chemotherapy failure, and frequent recurrence. MicroRNAs (miRNAs) are endogenous, non-coding RNAs that regulate various molecular biological phenomena by suppressing the translation of target messenger RNAs (mRNAs). miRNAs, which often become dysregulated in malignancy, control cell proliferation, migration, invasion, and development in HCC by promoting or suppressing tumors. Exploring the detailed mechanisms underlying miRNA-mediated HCC development and progression can likely improve the outcomes of patients with HCC. This review summarizes the molecular and functional roles of miRNAs in the pathogenesis of HCC. Further, it elucidates the utility of miRNAs as novel biomarkers and therapeutic targets.

MicroRNAs as regulators of VEGFA and NFE2L2 in cancer

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in post-transcriptional regulation of various genes, and their deregulation can lead to tumorigenesis. They may play the role of oncogenes or tumor suppressors by regulating different genes involved in cellular processes. One of the genes regulated by the miRNAs is the vascular endothelial growth factor A (VEGFA), which is responsible for angiogenesis. Angiogenesis is the process of formation of new blood vessels from pre-existing ones. This process plays an important role in tumor development, since it is responsible for the transport of nutrients required for tumor growth. Several studies have shown an increased expression of VEGFA in various cancers. Another gene regulated by miRNAs, the nuclear factor erythroid 2-like-2 (NFE2L2/NRF2), has a cytoprotective function and regulates cellular defense against oxidative stress. The NFE2L2 is the major regulator of cytoprotective agents and their oxidative damage to cells, which is down-regulated by Kelch-like ECH-associated protein 1 (KEAP1) at the post-transcriptional level. Regulation of the VEGFA and NFE2L2 by miRNAs has been observed in hepatocellular carcinoma and breast, lung, esophageal, endometrial, gastric, and ovarian cancer. This review highlights the role of miRNAs in the regulation of VEGFA and NFE2L2 and their relevance as therapeutic targets in various cancers.

Exosomal miR-638 Inhibits Hepatocellular Carcinoma Progression by Targeting SP1

Purpose

Exosomal microRNAs (miRNAs) play essential roles in the development of hepatocellular carcinoma (HCC). Nevertheless, the role and mechanism of exosomal miR-638 in HCC development remain largely unknown.

Methods

Exosomes were isolated and confirmed via transmission electron microscopy and western blot. The abundances of miR-638 and specificity protein 1 (SP1) were measured via quantitative reverse transcription polymerase chain reaction or western blot. Cell proliferation was investigated by Cell Counting Kit-8, colony formation assay, apoptosis, cell cycle distribution and related protein expression. Cell migration and invasion were detected via transwell assay and western blot. Co-culture experiment was performed to assess exosome transfer from HCC cells to endothelial cells. The target correlation between miR-638 and SP1 was analyzed via dual-luciferase reporter and RNA immunoprecipitation assays. The subcutaneous xenograft experiment was conducted to test the function of miR-638 in vivo.

Results

The miR-638 level declined in exosomes from serum or HCC cell medium. miR-638 overexpression repressed HCC cell proliferation by decreasing viability and colony formation and inducing apoptosis and cell cycle arrest at G1 phase, and decreased abilities of migration and invasion. Exosomal miR-638 from HCC cells could transfer to human umbilical vein endothelial cells (HUVECs) and suppress HUVEC proliferation, migration and invasion. SP1 was a target of miR-638 and overexpression of SP1 reversed the effect of miR-638 on HCC cells. Overexpression of miR-638 reduced xenograft tumor growth via decreasing SP1.

Conclusion

Exosomal miR-638 inhibited HCC tumorigenesis by targeting SP1. This study indicated the potential clinical implications of miR-638 in HCC.

Noncoding RNAs: the shot callers in tumor immune escape

Immunotherapy, designed to exploit the functions of the host immune system against tumors, has shown considerable potential against several malignancies. However, the utility of immunotherapy is heavily limited due to the low response rate and various side effects in the clinical setting. Immune escape of tumor cells may be a critical reason for such low response rates. Noncoding RNAs (ncRNAs) have been identified as key regulatory factors in tumors and the immune system. Consequently, ncRNAs show promise as targets to improve the efficacy of immunotherapy in tumors. However, the relationship between ncRNAs and tumor immune escape (TIE) has not yet been comprehensively summarized. In this review, we provide a detailed account of the current knowledge on ncRNAs associated with TIE and their potential roles in tumor growth and survival mechanisms. This review bridges the gap between ncRNAs and TIE and broadens our understanding of their relationship, providing new insights and strategies to improve immunotherapy response rates by specifically targeting the ncRNAs involved in TIE.

Regulatory Role of microRNAs in Tumor Angiogenesis

The process of neoangiogenesis is one of the classic hallmarks of a cancer. Its intricate mechanisms have long been one of the major domains in cancer research and a hope for a therapeutic breakthrough. Last decade a new subgroup of non-coding RNA molecules was reported called microRNAs. Literally hundreds of new molecules in this class are being uncovered as pivotal regulators in virtually all intracellular processes. The aim of this study is to classify and review those microRNA molecules that have a role in the processes of tumor angiogenesis and map their places in the regulatory framework of the classical proangiogenic genes and their canonical cascades.

Role of microRNAs in remodeling the tumor microenvironment (Review)

MicroRNAs (miRNAs) are short non‑coding RNAs that are known to regulate gene expression at the post‑transcriptional level. miRNA expression is often deregulated in several human cancers, affecting the communication between tumor stroma and tumor cells, among other functions. Understanding the role of miRNAs in the tumor microenvironment is crucial for fully elucidating the molecular mechanisms underlying tumor progression and exploring novel diagnostic biomarkers and therapeutic targets. The present review focused on the role of miRNAs in remodeling the tumor microenvironment, with an emphasis on their impact on tumor growth, metastasis and resistance to treatment, as well as their potential clinical applications.

MicroRNA-638 expression change in osteosarcoma patients via PLD1 and VEGF expression

The present study aimed to investigate the function and mechanism of microRNA-638 (miR-638) in osteosarcoma. MiR-638 expression change in patients with osteosarcoma was detected by reverse transcription-quantitative polymerase chain reaction. Expression of miR-638 was observed to be downregulated in patients with osteosarcoma compared with the control group. In vitro, overexpression of miR-638 induced apoptosis, and inhibited cell proliferation and invasion of osteosarcoma cells. Overexpression of miR-638 induced Bcl-2 associated X and caspase-3 protein expression, and suppressed cyclin D1, phospholipase D1 (PLD1) and vascular endothelial growth factor (VEGF) protein expression in osteosarcoma. The promotion of PLD1 decreased the effects of miR-638 on osteosarcoma cell proliferation. In summary, it was demonstrated that miRNA-638 expression change in patients with osteosarcoma and an in vitro model via PLD1 and VEGF expression and miRNA-638 may be potential clinical indicators of osteosarcoma.

Prognostic value of microRNAs in lung cancer: A systematic review and meta-analysis

Lung cancer is one of the leading causes of cancer-associated mortality throughout the world. The prognosis of the disease depends on many factors including the stage and type of cancer. Many studies have identified various microRNAs (miRNAs) that affect the prognosis of lung cancer. In order to systemically analyze the available clinical data, the present study performed a meta-analysis to examine all evidence on the potential role of miRNAs as novel predictors of survival in lung cancer. Literature published in English prior to February 1st, 2018 was searched through PubMed to review all of the associations between individual miRNAs and groups of miRNAs with the prognosis of lung cancer. Data was extracted using standard forms and pooled odds ratios with 95% confidence intervals (CIs) were calculated. A total of 15 eligible studies were included in the meta-analysis. These represented 1,753 lung cancer patients and 20 miRNAs. A total of 8 downregulated miRNAs were associated with poorer overall survival (OS) [hazard ratio (HR)=0.59, 95% CI: 0.47–0.75, P<1×10⁻⁴], while 10 upregulated miRNAs were associated with poorer OS (HR=1.76, 95% CI: 1.31–2.35, P<1×10⁻⁴). Additionally, low miRNA expression was associated with lymph node metastasis [LNM; relative risk (RR)=0.53, 95% CI: 0.46–0.61, P<1×10⁻⁴]. The expression of miRNAs was not associated with lung cancer stage (RR=1.07, 95% CI: 0.94–1.22, P=0.23). Expression levels of different miRNAs were associated with the OS and LNM of patients with lung cancer. These miRNAs may be applied as potential prognostic markers in lung cancer.

The Role of MicroRNAs in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers, leading to the second cancer-related death in the global. Although the treatment of HCC has greatly improved over the past few decades, the survival rate of patients is still quite low. Thus, it is urgent to explore new therapies, especially seek for more accurate biomarkers for early diagnosis, treatment and prognosis in HCC. MicroRNAs (miRNAs), small noncoding RNAs, are pivotal participants and regulators in the development and progression of HCC. Great progress has been made in the studies of miRNAs in HCC. The key regulatory mechanisms of miRNAs include proliferation, apoptosis, invasion, metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, drug resistance and autophagy in HCC. And exosomal miRNAs also play important roles in proliferation, invasion, metastasis, and drug resistance in HCC by regulating gene expression in the target cells. In addition, some miRNAs, including exosomal miRNAs, can be as potential diagnostic and prediction markers in HCC. This review summarizes the latest researches development of miRNAs in HCC in recent years.

Steviol, a natural product inhibits proliferation of the gastrointestinal cancer cells intensively

New anticancer agents with lower toxicity have been always urged because of drug resistance associated with overused chemotherapy agents. In this study, steviol, a colonic metabolite of natural sweetener and also a component in leaves of stevia rebaudiana bertoni, was found to possess intensive anticancer activity on the human gastrointestinal cancer cells. Steviol inhibited six human gastrointestinal cancer cells intensively as 5-fluorouracil did at 100 μg/mL. The inhibition mechanism follows mitochondrial apoptotic pathway that was evidenced by increase of Bax/Bcl-2 ratio, activation of p21 and p53; and caspase 3-independent mechanism was also involved. These results are consistent with the miRNA expression analysis. The most regulated miRNAs in the steviol treated gastrointestinal cancer cells were miR-203a-3p (log2 =1.32) and miR-6088 (log2 =-2.54) in HCT-116, miR-1268b (log2 =19.85) and miR-23c (log2 =-2.05) in MKN-45. In view of the metabolic characteristics of steviol and its cytotoxicity on the cancer cells, steviol could be a chemotherapy agent potentially for cancer treatment.

Expression of microRNA 638 and sex-determining region Y-box 2 in hepatocellular carcinoma: Association between clinicopathological features and prognosis

The aim of the present study was to determine the expression profile of microRNA 638 (miR-638) and sex-determining region Y-box 2 (SOX2) in hepatocellular carcinoma (HCC), and to investigate their association with clinicopathological features and survival. Reverse transcription-quantitative polymerase chain reaction analysis was used to investigate miR-638 and SOX2 expression in 78 patients with HCC. Western blot and immunohistochemical analyses were performed in order to determine SOX2 protein expression in HCC samples. Combined with the clinical postoperative follow-up data, the expression of miR-638 and SOX2 and the association between this and the prognostic values of patients with HCC were statistically analyzed. The results of the present study confirmed that miR-638 expression in tumor tissues was significantly downregulated (P<0.001), while SOX2 expression was significantly increased, compared with healthy control tissues (P<0.05). In addition, a significant inverse correlation between miR-638 and SOX2 expression was also observed in the HCC tissues (r=-0.675; P<0.05). Clinicopathological correlation analysis demonstrated that reduced miR-638 and elevated SOX2 expression was significantly associated with the Tumor-Node-Metastasis stage and portal vascular invasion (P<0.05). However, no significant differences were observed in other clinicopathological features, including age, sex, tumor size, tumor differentiation and hepatitis status (P>0.05). Notably, follow-up analysis revealed that patients with HCC with low miR-638 expression and high SOX2 expression tended to have a significantly shorter postoperative survival time (P<0.001). It was concluded that miR-638 may serve a vital role in the occurrence and progression of HCC by regulating SOX2 expression and thus, that miR-638 and SOX2 may be critical as novel diagnostic and prognostic biomarkers for HCC.

Decreased levels of serum exosomal miR-638 predict poor prognosis in hepatocellular carcinoma

Currently available studies have implicated that exosome-delivered microRNAs (miRNAs) play crucial roles in human cancer. However, the association of serum exosomal miR-638 and hepatocellular carcinoma (HCC) remains largely unknown. We aim to investigate the expression of exosomal miR-638 in serum of HCC patients and its prognostic role in this deadly disease. Kaplan-Meier and Cox regression analyses were used to determine the survival of patients histologically diagnosed with HCC. Reduced levels of exosomal miR-638 in serum samples from patients with HCC were identified by real-time PCR. Negative association of serum exosomal miR-638 with tumor size, vascular infiltration, and TNM stage was observed in HCC patients. Besides, the proliferation of Huh7 and SMCC7721 HCC cells were significantly inhibited when miR-638 was over-expressed in these cells. In addition, HCC patients with lower levels of serum exosomal miR-638 had poor overall survival than those with higher levels of exosomal miR-638 in serum. Our study strongly suggests that serum exosome-delivered miR-638 may serve as a novel circulating biomarker for HCC. Downregulation of miR-638 predicts poor prognosis for patients with HCC.

New insights into the regulatory role of microRNA in tumor angiogenesis and clinical implications

Angiogenesis is essential for tumor growth and metastasis. Understanding the regulation of tumor angiogenesis has become increasingly important. MicroRNAs (miRNAs) are small noncoding RNAs that function in diverse biological processes via post-transcriptional regulation. Extensive studies have revealed two important regulatory roles of miRNAs in tumor angiogenesis: miRNAs in tumor cells affect the activity of endothelial cells via non-cell-autonomous mechanisms, and miRNAs in endothelial cells regulate the cell-autonomous behavior. Recent advances have further highlighted the role of tumor-derived extracellular vesicles in the regulation of tumor angiogenesis via transferring miRNAs to endothelial cells. In this review, we summarize the regulatory role of miRNA in tumor angiogenesis, with a highlight on clinical implications of miRNAs as biomarkers for anti-angiogenic therapy response, and as therapeutic interventions against tumor angiogenesis in vivo.

MicroRNA-638 inhibits cell growth and tubule formation by suppressing VEGFA expression in human Ewing sarcoma cells

Ewing sarcoma (EWS) is a kind of aggressive tumor of bone and soft tissues, which most occurring in children and adolescents. MicroRNAs (miRNAs) perform essential function in the progression and development of EWS, while the putative role of miR-638 in EWS remains uncertain. Accordingly, we detected the expression of miR-638 and explored its putative biological effects on the malignant phenotype of EWS cells. As expected, miR-638 was significantly down-regulated in EWS cells. Moreover, overexpression of miR-638 suppressed cell growth, induced cell apoptosis, and inhibited tubule formation of EWS cells in vitro Among the putative target genes of miR-638 predicted by the miRNA target prediction tools, vascular endothelial cell growth factor A (VEGFA) attracted out attention most. The luciferase reporter assays reaffirmed that VEGFA was a targeted gene of miR-638 in EWS cells. Furthermore, miR-638 suppressed the mRNA and protein level of VEGFA, and restored the expression of VEGFA reversed the suppressed effects of miR-638 in EWS cells. Taken together, the results suggested that miR-638 might perform tumor suppressive effects in EWS, which might be mediated, at least partially, through suppressing the activity of VEGFA.

RNA-binding protein AUF1 suppresses miR-122 biogenesis by down-regulating Dicer1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the common cancers worldwide, especially in developing countries. Although the chronic infections of hepatitis B and C viruses have been established as the etiological factors of HCC, the mechanism for the tumorigenesis and development of HCC is still unclear. The liver-specific microRNA-122 (miR-122), an established tumor-suppressor miRNA, is often down-regulated in HCC, while the underlying mechanism is not well understood. Here we report that the AU-rich element-binding factor AUF1 suppresses the expression of Dicer1, the type III RNase that is required for microRNA maturation, leading to the inhibited biogenesis of miR-122. Overexpression of AUF1 led to the decreased expression of Dicer1 and miR-122, while the level of the miR-122 precursor (pre-miR-122) was increased. On the other hand, siRNA of AUF1 (siAUF1) increased the levels of Dicer1 mRNA and miR-122, but it reduced the abundance of pre-miR-122. Consistent with the reported data, this study demonstrated that AUF1 and Dicer1 showed opposite expression pattern in both human HCC tissues and cell lines. In addition, AUF1 inhibited the expression of Dicer1 by interacting with the 3′ untranslated region (3′UTR) and coding region of DICER1 mRNA. Moreover, the knockdown of AUF1 by siRNA altered the expression of other miRNAs and promoted HCC cell death. In conclusion, AUF1 down-regulates the expression miR-122 by interacting with the 3′UTR and coding region of DICER1 mRNA and suppressing Dicer1 expression. The AUF1/Dicer1/miR-122 pathway might play a critical role in the development of HCC.

INPP4B overexpression suppresses migration, invasion and angiogenesis of human prostate cancer cells

Inositol polyphosphate 4-phosphatase B (INPP4B) has been identified as a tumour suppressor in different human cancers. However, the role of INPP4B in the angiogenesis of human prostate cancer cells remains unclear. In this study, we first compared the expression of INPP4B between prostate cancer tissues and tumour-adjacent normal prostate tissues using immunohistochemistry. Then, we explored the role of INPP4B in prostate cancer progression via transfection of a Flag-INPP4B plasmid into PC3 and DU145 cells in vitro and in vivo. Our results showed that reduced INPP4B staining was significantly correlated with the tumour-node-metastasis stage. Moreover, transfection with Flag-INPP4B plasmid suppressed the migration and invasion of prostate cancer cells through inactivating the PI3K/Akt signalling pathway, at the same time decreased vascular endothelial growth factor secretion and suppressed human umbilical vein endothelial cells proliferation and tube formation. Futhermore, it was also found that INPP4B could inhibit tumour growth and angiogenesis in vivo. Altogether, our results supported that INPP4B acted as a tumour suppressor in human prostate cancer, and provided insights into development of a targeted therapy for this disease.

MiR-638 acts as a tumor suppressor gene in gastric cancer

Gastric cancer is one of the major causes of cancer mortality. Several microRNAs play a role in the tumor growth and invasion. However, the underlying molecular mechanism remains poorly understood. We detected the miR-638 expression levels in tumor samples and adjacent noncancerous tissues from 68 patients with gastric cancer as well as in the gastric cancer cell line SGC-7901 and SC-M1. The cell cycle was analyzed by flow cytometry, cell proliferation was observed by CCK-8 assay and cell invasion was detected using Transwell assay. MiR-638 was down-regulated in human GC tissues and its expression level was negatively correlated to TNM stage and lymph metastasis. In the cell lines, aberrant expression of miR-638 was related to the cell proliferation, cell cycle and invasion. We also found that SOX2 had a negative correlation with miR-638 in GC tissues, and miR-638 overexpression could decrease SOX2 expression level by directly binding the 3’-UTR of SOX2. in vitro, down-regulating SOX2 by siRNA could counteract the effect of miR-638 inhibitor on GC cells proliferation and invasion. Our results demonstrate that miR-638 may play a pivotal role in the growth and invasion of GC.

miRNA‑34a‑5p downregulation of VEGFA in endometrial stem cells contributes to the pathogenesis of endometriosis

Endometrial-derived stem cells (EnSCs) serve an important role in the development of endometriosis via retrograde menstruation. Abnormal expression of miRNAs in EnSCs is involved in the etiology of endometriosis, however, the mechanisms remain unclear. The aim of the present study was to investigate the expression of miR‑34a‑5p and VEGFA in endometrial samples from patients with or without endometriosis, and then examine the underlying mechanism of microRNA‑34a‑5p regulation of VEGFA in EnSCs. Endometrial samples from patients with or without endometriosis were collected, and miR‑34a‑5p expression in the two groups was measured using RT‑PCR. Human endometrial‑derived stem cells (hEnSCs) were isolated from these endometrial samples, and hEnSCs were transfected with the miR‑34a‑5p mimics or control miRNAs. qPCR and western blotting were performed to assess the effects of miR‑34a‑5p on the expression of VEGFA in hEnSCs, and cell growth was assessed by an MTT assay. miR‑34a‑5p was significantly downregulated in patients with endometriosis when compared with that of those without endometriosis. VEGFA expression levels in hEnSCs with an overexpression of miR‑34a‑5p were significantly reduced when compared with those in the negative control (P<0.01). In addition, the upregulation of miR‑34a‑5p suppressed EnSCs proliferation by targeting the 3' untranslated region of VEGFA. miR‑34a‑5p provides a novel avenue for the understanding of the development of endometriosis, and may facilitate the development of potential therapeutics against endometriosis.

Prognostic value of microRNAs in hepatocellular carcinoma: a meta-analysis

Background

Numerous articles reported that dysregulated expression levels of miRNAs correlated with survival time of HCC patients. However, there has not been a comprehensive meta-analysis to evaluate the accurate prognostic value of miRNAs in HCC.

Design

Meta-analysis.

Materials and Methods

Studies, published in English, estimating expression levels of miRNAs with any survival curves in HCC were identified up until 15 April, 2017 by performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two independent authors. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

Results

54 relevant articles about 16 miRNAs, with 6464 patients, were ultimately included. HCC patients with high expression of tissue miR-9 (HR = 2.35, 95% CI = 1.46–3.76), miR-21 (HR = 1.76, 95% CI = 1.29–2.41), miR-34c (HR = 1.64, 95% CI = 1.05–2.57), miR-155 (HR = 2.84, 95% CI = 1.46–5.51), miR-221 (HR = 1.76, 95% CI = 1.02–3.04) or low expression of tissue miR-22 (HR = 2.29, 95% CI = 1.63–3.21), miR-29c (HR = 1.35, 95% CI = 1.10–1.65), miR-34a (HR = 1.84, 95% CI = 1.30–2.59), miR-199a (HR = 2.78, 95% CI = 1.89–4.08), miR-200a (HR = 2.64, 95% CI = 1.86–3.77), miR-203 (HR = 2.20, 95% CI = 1.61–3.00) have significantly poor OS (P < 0.05). Likewise, HCC patients with high expression of blood miR-21 (HR = 1.73, 95% CI = 1.07–2.80), miR-192 (HR = 2.42, 95% CI = 1.15–5.10), miR-224 (HR = 1.56, 95% CI = 1.14–2.12) or low expression of blood miR-148a (HR = 2.26, 95% CI = 1.11–4.59) have significantly short OS (P < 0.05).

Conclusions

In conclusion, tissue miR-9, miR-21, miR-22, miR-29c, miR-34a, miR-34c, miR-155, miR-199a, miR-200a, miR-203, miR-221 and blood miR-21, miR-148a, miR-192, miR-224 demonstrate significantly prognostic value. Among them, tissue miR-9, miR-22, miR-155, miR-199a, miR-200a, miR-203 and blood miR-148a, miR-192 are potential prognostic candidates for predicting OS in HCC.

MicroRNA expression in bone marrow-derived human multipotent Stromal cells

Background

Multipotent stromal cells (MSCs) are being studied in the field of regenerative medicine for their multi-lineage differentiation and immunoregulatory capacity. MicroRNAs (miRNAs) are short non-coding RNAs that are responsible for regulating gene expression by targeting transcripts, which can impact MSC functions such as cellular proliferation, differentiation, migration and cell death. miRNAs are expressed in MSCs; however, the impact of miRNAs on cellular functions and donor variability is not well understood. Eight MSC lines were expanded to passages 3, 5 and 7, and their miRNA expression was evaluated using microarray technology.

Results

Statistical analyses of our data revealed that 71 miRNAs out of 939 examined were expressed by this set of MSC lines at all passages and the expression of 11 miRNAs were significantly different between passages 3 and 7, while the expression of 7 miRNAs was significantly different between passages 3 and 5. The expression of these identified miRNAs was evaluated using RT-qPCR for both the first set of MSC lines (n = 6) and a second set of MSC lines (n = 7) expanded from passages 4 to 8. By RT-qPCR only 2 miRNAs, miR-638 and miR-572 were upregulated at passage 7 compared to passage 3 in the first set of MSC lines by 1.71 and 1.54 fold, respectively; and upregulated at passage 8 compared to passage 4 in the second set of MSC lines, 1.35 and 1.59 fold, respectively.

Conclusions

The expression of miR-638 and miR-572 can distinguish MSCs from two different passages of cell culture. These results may be useful in establishing critical quality attributes of MSCs and determining whether changes in these two miRNAs impact cellular functions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3997-7) contains supplementary material, which is available to authorized users.

Downregulation of circulating exosomal miR-638 predicts poor prognosis in colon cancer patients

Exosome-encapsulated microRNAs have been recognized as novel and stable biomarkers for cancer. However, little is known about the role of exosomal microRNAs in colon cancer. In the present study, we investigated the expression of serous exosomal microRNA-638 (miR-638) and its prognostic effect in patients with colon cancer. Serous exosomal samples were assayed by quantitative real-time PCR. Kaplan-Meier analysis was adopted to determine the overall survival (OS) and disease-free survival (DFS) of colon cancer patients. Cox regression analysis was applied to assess the potential association between serous exosomal miR-638 and clinicopathological factors of colon cancer patients. MiR-638 was significantly reduced in serum exosomes of colon cancer patients compared with healthy controls. Decreased level of serous exosomal miR-638 was more significant in colon cancer patients at later TNM stage or with liver metastasis. Kaplan-Meier analysis showed that colon cancer patients with reduced level of serous exosomal miR-638 had poor OS and DFS. In addition, the Cox regression analysis suggested serous exosomal miR-638 was a prognostic factor for colon cancer independent of TNM stage and liver metastasis. In conclusion, serous exosomal miR-638 is a useful biomarker for the prediction of colon cancer prognosis.