MicroRNA-3064-5p sponged by MALAT1 suppresses angiogenesis in human hepatocellular carcinoma by targeting the FOXA1/CD24/Src pathway

Long non-coding RNAs with essential roles in neurodegenerative disorders

ABSTRACT

Recently, with the advent of high-resolution and high-throughput sequencing technologies, an increasing number of long non-coding RNAs (lncRNAs) have been found to be involved in the regulation of neuronal function in the central nervous system with specific spatiotemporal patterns, across different neurodegenerative diseases. However, the underlying mechanisms of lncRNAs during neurodegeneration remain poorly understood. This review provides an overview of the current knowledge of the biology of lncRNAs and focuses on introducing the latest identified roles, regulatory mechanisms, and research status of lncRNAs in Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Finally, this review discusses the potential values of lncRNAs as diagnostic biomarkers and therapeutic targets for neurodegenerative diseases, hoping to provide broader implications for developing effective treatments.

Clinical Application of Different Liquid Biopsy Components in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer, usually occurring in the background of chronic liver disease. HCC lethality rate is in the third highest place in the world. Patients with HCC have concealed early symptoms and possess a high-level of heterogeneity. Once diagnosed, most of the tumors are in advanced stages and have a poor prognosis. The sensitivity and specificity of existing detection modalities and protocols are suboptimal. HCC calls for more sophisticated and individualized therapeutic regimens. Liquid biopsy is non-invasive, repeatable, unaffected by location, and can be monitored dynamically. It has emerged as a useable aid in achieving precision malignant tumor treatment. Circulating tumor cells (CTCs), circulating nucleic acids, exosomes and tumor-educated platelets are the commonest components of a liquid biopsy. It possesses the theoretical ability to conquer the high heterogeneity and the difficulty of early detection for HCC patients. In this review, we summarize the common enrichment techniques and the clinical applications in HCC for different liquid biopsy components. Tumor recurrence after HCC-related liver transplantation is more insidious and difficult to treat. The clinical use of liquid biopsy in HCC-related liver transplantation is also summarized in this review.

Analysis of the expression level and predictive value of CLEC16A|miR-654-5p|RARA regulatory axis in the peripheral blood of patients with ischemic stroke based on biosignature analysis

Introduction

Ischemic stroke (IS) is a cerebrovascular disease that can be disabling and fatal, and there are limitations in the clinical treatment and prognosis of IS. It has been reported that changes in the expression profile of circRNAs have been found during injury in ischemic stroke, and circRNAs play an important role in the IS cascade response. However, the specific mechanisms involved in the pathogenesis of IS are not yet fully understood, and thus in-depth studies are needed.

Methods

In this study, one circRNA dataset (GSE161913), one miRNA dataset (GSE60319) and one mRNA dataset (GSE180470) were retrieved from the Gene Expression Omnibus (GEO) database and included, and the datasets were differentially expressed analyzed by GEO2R and easyGEO to get the DEcircRNA, DEmiRNA and DEmRNA, and DEmRNA was enriched using ImageGP, binding sites were predicted in the ENCORI database, respectively, and the competitive endogenous RNA (ceRNA) regulatory network was visualized by the cytoscape software, and then selected by MCC scoring in the cytoHubba plugin Hub genes. In addition, this study conducted a case-control study in which blood samples were collected from stroke patients and healthy medical examiners to validate the core network of ceRNAs constructed by biosignature analysis by real-time fluorescence quantitative qRT-PCR experiments.

Results

A total of 233 DEcircRNAs, 132 DEmiRNAs and 72 DEmRNAs were screened by bioinformatics analysis. circRNA-mediated ceRNA regulatory network was constructed, including 148 circRNAs, 43 miRNAs and 44 mRNAs. Finally, CLEC16A|miR-654-5p|RARA competitive endogenous regulatory axis was selected for validation by qRT-PCR, and the validation results were consistent with the bioinformatics analysis.

Discussion

In conclusion, the present study establishes a new axis of regulation associated with IS, providing new insights into the pathogenesis of IS.

FOXA1 and FOXA2: the regulatory mechanisms and therapeutic implications in cancer

FOXA1 (Forkhead Box A1) and FOXA2 (Forkhead Box A2) serve as pioneering transcription factors that build gene expression capacity and play a central role in biological processes, including organogenesis and differentiation, glycolipid metabolism, proliferation, migration and invasion, and drug resistance. Notably, FOXA1 and FOXA2 may exert antagonistic, synergistic, or complementary effects in the aforementioned biological processes. This article focuses on the molecular mechanisms and clinical relevance of FOXA1 and FOXA2 in steroid hormone-induced malignancies and highlights potential strategies for targeting FOXA1 and FOXA2 for cancer therapy. Furthermore, the article describes the prospect of targeting upstream regulators of FOXA1/FOXA2 to regulate its expression for cancer therapy because of the drug untargetability of FOXA1/FOXA2.

Staufen1 Represses the FOXA1-Regulated Transcriptome by Destabilizing FOXA1 mRNA in Colorectal Cancer Cells

Transcription factors play key roles in development and disease by controlling gene expression. Forkhead box A1 (FOXA1), is a pioneer transcription factor essential for mouse development and functions as an oncogene in prostate and breast cancer. In colorectal cancer (CRC), FOXA1 is significantly downregulated and high FOXA1 expression is associated with better prognosis, suggesting potential tumor suppressive functions. We therefore investigated the regulation of FOXA1 expression in CRC, focusing on well-differentiated CRC cells, where FOXA1 is robustly expressed. Genome-wide RNA stability assays identified FOXA1 as an unstable mRNA in CRC cells. We validated FOXA1 mRNA instability in multiple CRC cell lines and in patient-derived CRC organoids, and found that the FOXA1 3'UTR confers instability to the FOXA1 transcript. RNA pulldowns and mass spectrometry identified Staufen1 (STAU1) as a potential regulator of FOXA1 mRNA. Indeed, STAU1 knockdown resulted in increased FOXA1 mRNA and protein expression due to increased FOXA1 mRNA stability. Consistent with these data, RNA-seq following STAU1 knockdown in CRC cells revealed that FOXA1 targets were upregulated upon STAU1 knockdown. Collectively, this study uncovers a molecular mechanism by which FOXA1 is regulated in CRC cells and provides insights into our understanding of the complex mechanisms of gene regulation in cancer.

The role of competing endogenous RNA network in the development of hepatocellular carcinoma: potential therapeutic targets

The current situation of hepatocellular carcinoma (HCC) management is challenging due to its high incidence, mortality, recurrence and metastasis. Recent advances in gene genetic and expression regulation have unveiled the significant role of non-coding RNA (ncRNA) in various cancers. This led to the formulation of the competing endogenous RNA (ceRNA) hypothesis, which posits that both coding RNA and ncRNA, containing miRNA response elements (MRE), can share the same miRNA sequence. This results in a competitive network between ncRNAs, such as lncRNA and mRNA, allowing them to regulate each other. Extensive research has highlighted the crucial role of the ceRNA network in HCC development, impacting various cellular processes including proliferation, metastasis, cell death, angiogenesis, tumor microenvironment, organismal immunity, and chemotherapy resistance. Additionally, the ceRNA network, mediated by lncRNA or circRNA, offers potential in early diagnosis and prevention of HCC. Consequently, ceRNAs are emerging as therapeutic targets for HCC. The complexity of these gene networks aligns with the multi-target approach of traditional Chinese medicine (TCM), presenting a novel perspective for TCM in combating HCC. Research is beginning to show that TCM compounds and prescriptions can affect HCC progression through the ceRNA network, inhibiting proliferation and metastasis, and inducing apoptosis. Currently, the lncRNAs TUG1, NEAT1, and CCAT1, along with their associated ceRNA networks, are among the most promising ncRNAs for HCC research. However, this field is still in its infancy, necessitating advanced technology and extensive basic research to fully understand the ceRNA network mechanisms of TCM in HCC treatment.

Role of miRNA in pathogenesis, diagnosis, and prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers and is responsible for the second cancer-related death globally. Many treatment regimens have been developed to cure the disease; however, life expectancy is still low. Therefore, there is an urgent need to explore new selective, specific, and robust diagnosis markers for efficient early recognition of the ailment. Along with the diagnosis, the treatment's effectiveness can be determined by prognostic markers, and miRNAs are excellent tools for the diagnosis and prognosis of HCC. In addition, the altered expression profile of a few miRNAs promotes HCC cell migration and invasion, and selective up- or downregulation of these responsible genes may help mitigate the disorder. On one hand, few of the miRNAs have been found to enhance angiogenesis, a crucial step of tumor growth; on the other hand, upregulation of specific miRNAs is reported to suppress angiogenesis and resulting tumor growth of HCC cells. Exosomal miRNAs have significant implications in promoting angiogenesis, increased endothelial cell permeability, tube formation, and metastasis to hepatic and pulmonary tissues. miRNA also attributes to drug resistance toward chemotherapy and the prevention of autophagy also. Identifying novel miRNA and determining their differential expression in HCC tissue may serve as a potential tool for diagnosis, prognosis, and therapy to enhance the life expectancy and quality of life of HCC patients. In the present review, we have summarized the recent advances in HCC-related research.

Forkhead box A1 induces angiogenesis through activation of the S100A8/p38 MAPK axis in cutaneous wound healing

BACKGROUND

The association between S100 calcium-binding protein A8 (S100A8) and angiogenesis has been reported in previous reports. This study focuses on the roles of S100A8 in the angiogenesis of human dermal microvascular endothelial cells (HDMECs) and in cutaneous wound healing in mice.

METHODS

Candidate genes related to angiogenesis activity were screened using a GSE83582 dataset. The overexpression DNA plasmid of S100A8 was transfected into HDMECs to analyze its effect on cell proliferation, migration, and angiogenesis. Full-thickness skin wounds were induced on mice, followed by adenovirus treatments to analyze the function of gene alteration in wound healing and pathological changes. The upstream regulator of S100A8 was predicted by bioinformatics analysis and verified by luciferase and immunoprecipitation assays. The role of the forkhead box A1 (FOXA1)-S100A8 interaction in p38 MAPK activation and angiogenesis were validated by rescue experiments.

RESULTS

S100A8 was identified as a gene significantly correlated with angiogenesis. The S100A8 upregulation promoted the proliferation, migration, and angiogenesis of HDMECs, and it promoted p38 MAPK phosphorylation. Treatment of SB203580, a p38 MAPK inhibitor, blocked the promoting effect of S100A8. FOXA1 was identified as an upstream factor of S100A8 promoting its transcription. FOXA1 overexpression in HDMECs increased p38 MAPK phosphorylation and enhanced the activity of cells, which were blocked by the S100A8 inhibition. Similar results were reproduced in vivo where FOXA1 overexpression accelerated whereas the S100A8 knockdown retarded the cutaneous wound healing in mice.

CONCLUSION

FOXA1 mediates the phosphorylation of p38 MAPK through transcription activation of S100A8, thereby inducing angiogenesis and promoting cutaneous wound healing.

The role of noncoding RNAs in the tumor microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading fatal malignancy worldwide. The tumor microenvironment (TME) can affect the survival, proliferation, migration, and even dormancy of cancer cells. Hypoxia is an important component of the TME, and hypoxia-inducible factor-1α (HIF-1α) is the most important transcriptional regulator. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), comprise a large part of the human transcriptome and play an important role in regulating the tumorigenesis of HCC. This review discusses the role of ncRNAs in hepatocarcinogenesis, epithelial-mesenchymal transition (EMT), and angiogenesis in a hypoxic microenvironment, as well as the interactions between ncRNAs and key components of the TME. It further discusses their use as biomarkers and the potential clinical value of drugs, as well as the challenges faced in the future.

Targeting CD24 as a novel immunotherapy for solid cancers

Cluster of differentiation 24 (CD24), a mucin-like highly glycosylated molecule has been extensively studied as a cancer stem cell marker in a variety of solid cancers. The functional role of CD24 is either fulfilled by combining with ligands or participating in signal transduction, which mediate the initiation and progression of neoplasms. Recently, CD24 was also described as an innate immune checkpoint with apparent significance in several types of solid cancers. Herein, we review the current understanding of the molecular fundamentals of CD24, the role of CD24 in tumorigenesis and cancer progression, the possibility as a promising therapeutic target and summarized different therapeutic agents or strategies targeting CD24 in solid cancers. Video Abstract.

MALAT1/ mir-1-3p mediated BRF2 expression promotes HCC progression via inhibiting the LKB1/AMPK signaling pathway

BACKGROUND

The long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been reported to play a vital role in the occurrence and development of various tumors. However, the underlying mechanism of MALAT1 in hepatocellular carcinoma (HCC) has not been thoroughly elucidated.

METHODS

The expression levels of MALAT1 in HCC tissues and different cell lines were detected by qRT-PCR. Antisense oligonucleotides (ASO)-MALAT1 transfected cells were used to explore the biological effects of MALAT1 in HCC cells by cell counting kit 8 (CCK-8), colony formation, transwell, wound healing, and flow cytometry analysis. Western blotting was performed to measure AMPK and apoptosis-related protein levels. Dual-luciferase reporter assay was performed to verify the relationship between MALAT1 and its specific targets.

RESULTS

We found that MALAT1 was upregulated in HCC, and MALAT1 knockdown in HCC cells inhibited cell proliferation, migration, and invasion and inhibited apoptosis in vitro. Further studies demonstrated that MALAT1 positively regulated the expression of transcription factor II B‑related factor 2 (BRF2), which was associated with tumor recurrence, large tumor size, and poor prognosis in HCC. Mechanistically, MALAT1 was found to act as a competitive endogenous RNA to sponge has-miR-1-3p, which upregulated BRF2 expression. Knockdown of BRF2 inhibited the progression of HCC by activating the LKB1/AMPK signaling pathway. Overexpression of BRF2 reversed the inhibitory effect of MALAT1 knockdown on HCC cell viability. Moreover, ASO targeting MALAT1 inhibited the growth of xenograft tumors.

CONCLUSIONS

Our results demonstrate a novel MALAT1/miR-1-3p/BRF2/LKB1/AMPK regulatory axis in HCC, which may provide new molecular therapeutic targets for HCC in the future.

Long non-coding RNAs in hepatocellular carcinoma

Long noncoding RNAs (lncRNAs) refer to a class of RNAs greater than 200 nucleotides in length, most of which are considered unable to encode proteins, thus deemed to be junk genes formerly. But with emerging studies about lncRNAs coming out in recent years, it is much more clearly depicted that they can regulate gene expression at different levels, with various mechanisms, thus participating in diverse biological or pathological processes, including complicated tumor-associated pathways. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, the third leading cause of cancer-related mortality worldwide, which has been found to tightly associate with aberrant expression of a variety of lncRNAs regulating tumor proliferation, invasion, drug resistance, and so on, making it a potential novel tumor marker and therapeutic target. In this review, we highlight a few lncRNAs that are closely related to the occurrence and progression of HCC and try to cover their multifarious roles from different layers.

CD24-associated ceRNA network reveals prognostic biomarkers in breast carcinoma

Breast cancer is one of the most common cancer types which is described as the leading cause of cancer death in women. After competitive endogenous RNA (ceRNA) hypothesis was proposed, this triple regulatory network has been observed in various cancers, and increasing evidences reveal that ceRNA network plays a significant role in the migration, invasion, proliferation of cancer cells. In the current study, our target is to construct a CD24-associated ceRNA network, and to further identify key prognostic biomarkers in breast cancer. Using the transcriptom profiles from TCGA database, we performed a comprehensive analysis between CD24^high tumor samples and CD24^low tumor samples, and identified 132 DElncRNAs, 602 DEmRNAs and 26 DEmiRNAs. Through comprehensive analysis, RP1-228H13.5/miR-135a-5p/BEND3 and SIM2 were identified as key CD24-associated biomarkers, which exhibited highly significance with overall survival, immune microenvironment as well as clinical features. To sum up the above, the current study constructed a CD24-associated ceRNA network, and RP1-228H13.5/miR-135a-5p/BEND3 and SIM2 axis worked as a potential therapeutic target and a predictor for BRCA diagnosis and prognosis.

Prognostic value of long non-coding RNA MALAT1 in hepatocellular carcinoma: A study based on multi-omics analysis and RT-PCR validation

Background: This study aimed to explore the relationship between MALAT1 and the prognosis of patients with hepatocellular carcinoma (HCC). Methods: We constructed a MALAT1 protein-protein interaction network using the STRING database and a network of competing endogenous RNAs (ceRNAs) using the StarBase database. Using data from the GEPIA2 database, we studied the association between genes in these networks and survival of patients with HCC. The potential mechanisms underlying the relationship between MALAT1 and HCC prognosis were studied using combined data from RNA sequencing, DNA methylation, and somatic mutation data from The Cancer Genome Atlas (TCGA) liver cancer cohort. Tumor tissues and 19 paired adjacent non-tumor tissues (PANTs) from HCC patients who underwent radical resection were analyzed for MALAT1 mRNA levels using real-time PCR, and associations of MALAT1 expression with clinicopathological features or prognosis of patients were analyzed using log-rank test and Gehan-Breslow-Wilcoxon test. Results: Five interacting proteins and five target genes of MALAT1 in the ceRNA network significantly correlated with poor survival of patients with HCC (p < 0.05). High MALAT1 expression was associated with mutations in two genes leading to poor prognosis and may upregulate some prognostic risk genes through methylation. MALAT1 was significantly co-expressed with various signatures of genes involved in HCC progression, including the cell cycle, DNA damage repair, mismatch repair, homologous recombination, molecular cancer m6A, exosome, ferroptosis, infiltration of lymphocyte (p < 0.05). The expression of MALAT1 was markedly upregulated in HCC tissues compared with PANTs. In Kaplan-Meier analysis, patients with high MALAT1 expression had significantly shorter progression-free survival (PFS) (p = 0.033) and overall survival (OS) (p = 0.023) than those with low MALAT1 expression. Median PFS was 19.2 months for patients with high MALAT1 expression and 52.8 months for patients with low expression, while the corresponding median OS was 40.5 and 78.3 months. In subgroup analysis of patients with vascular invasion, cirrhosis, and HBsAg positive or AFP positive, MALAT1 overexpression was significantly associated with shorter PFS and OS. Models for predicting PFS and OS constructed based on MALAT1 expression and clinicopathological features had moderate predictive power, with areas under the receiver operating characteristic curves of 0.661-0.731. Additionally, MALAT1 expression level was significantly associated with liver cirrhosis, vascular invasion, and tumor capsular infiltration (p < 0.05 for all). Conclusion: MALAT1 is overexpressed in HCC, and higher expression is associated with worse prognosis. MALAT1 mRNA level may serve as a prognostic marker for patients with HCC after hepatectomy.

FOXA1/2 depletion drives global reprogramming of differentiation state and metabolism in a human liver cell line and inhibits differentiation of human stem cell-derived hepatic progenitor cells

FOXA factors are critical members of the developmental gene regulatory network (GRN) composed of master transcription factors (TF) which regulate murine cell fate and metabolism in the gut and liver. How FOXA factors dictate human liver cell fate, differentiation, and simultaneously regulate metabolic pathways is poorly understood. Here, we aimed to determine the role of FOXA2 (and FOXA1 which is believed to compensate for FOXA2) in controlling hepatic differentiation and cell metabolism in a human hepatic cell line (HepG2). siRNA mediated knockdown of FOXA1/2 in HepG2 cells significantly downregulated albumin (p < .05) and GRN TF gene expression (HNF4α, HEX, HNF1ß, TBX3) (p < .05) and significantly upregulated endoderm/gut/hepatic endoderm markers (goosecoid [GSC], FOXA3, and GATA4), gut TF (CDX2), pluripotent TF (NANOG), and neuroectodermal TF (PAX6) (p < .05), all consistent with partial/transient reprograming. shFOXA1/2 targeting resulted in similar findings and demonstrated evidence of reversibility of phenotype. RNA-seq followed by bioinformatic analysis of shFOXA1/2 knockdown HepG2 cells demonstrated 235 significant downregulated genes and 448 upregulated genes, including upregulation of markers for alternate germ layers lineages (cardiac, endothelial, muscle) and neurectoderm (eye, neural). We found widespread downregulation of glycolysis, citric acid cycle, mitochondrial genes, and alterations in lipid metabolism, pentose phosphate pathway, and ketogenesis. Functional metabolic analysis agreed with these findings, demonstrating significantly diminished glycolysis and mitochondrial respiration, with concomitant accumulation of lipid droplets. We hypothesized that FOXA1/2 inhibit the initiation of human liver differentiation in vitro. During human pluripotent stem cells (hPSC)-hepatic differentiation, siRNA knockdown demonstrated de-differentiation and unexpectedly, activation of pluripotency factors and neuroectoderm. shRNA knockdown demonstrated similar results and activation of SOX9 (hepatobiliary). These results demonstrate that FOXA1/2 controls hepatic and developmental GRN, and their knockdown leads to reprogramming of both differentiation and metabolism, with applications in studies of cancer, differentiation, and organogenesis.

The Accelerated Progression of Atherosclerosis Correlates with Decreased miR-33a and miR-21 and Increased miR-122 and miR-3064-5p in Circulation and the Liver of ApoE-/- Mice with Streptozocin (STZ)-Induced Type 2 Diabetes

Atherosclerosis is a major risk factor for type 2 diabetes (T2D) mortality. We aim to investigate the changes in miR-21, miR-122, miR-33a and miR-3064-5p in circulation and the liver of ApoE-/- mice with streptozocin (STZ)-induced T2D. Twenty 5-week-old male ApoE-/- mice were randomly assigned to the control (n = 10) and T2D group (n = 10) and intraperitoneally injected with a citrate buffer and streptozotocin (STZ) (40 mg/kg BW) once a day for three consecutive days. The successfully STZ-induced T2D mice (n = 5) and control mice (n = 5) were then fed with a high-fat diet (HFD) for 34 weeks. Compared to the control mice, ApoE-/- mice with STZ-induced T2D had slower (p < 0.05) growth, increased (p < 0.05) total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), decreased (p < 0.05) high-density lipoprotein cholesterol (HDL-C) in serum, reduced (p < 0.05) TC and sterol regulatory element-binding protein-2 (Srebp-2), elevated (p < 0.05) ATP-binding-cassette-transporter-A1 (Abca1) in the liver, aggravated (p < 0.05) atherosclerotic lesions in the aorta, downregulated (p < 0.05) miR-21 and miR-33a, and upregulated (p < 0.05) miR-122 and miR-3064-5p in serum and the liver. In addition, the aortic lesions showed a positive correlation with miR-122 (r = 1.000, p = 0.001) and a negative correlation with miR-21 (r = −1.000, p = 0.001) in ApoE-/- mice with T2D. In conclusion, T2D-accelerated atherosclerosis correlates with a reduction in miR-21 and miR-33a and an elevation in miR-122 and miR-3064-5p in circulation and the liver of ApoE-/- mice.

Involvement of microRNAs and their potential diagnostic, therapeutic, and prognostic role in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) accounts for 85%-90% of primary liver cancer. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by targeting the 3'UTR of mRNA. Abnormal expression and regulation of miRNAs are involved in the occurrence and progression of HCC, and miRNAs can also play a role in the diagnosis and treatment of HCC as oncogenes or tumor suppressors.

METHODS

In the past decades, a large number of studies have shown that miRNAs play an essential regulatory role in HCC and have potential as biomarkers for HCC. We reviewed the literature to summarize these studies.

RESULTS

By reviewing the literature, we retrospected the roles of miRNAs in the development, diagnosis, treatment, and prognosis of HCC, and put forward prospects for the further research on miRNAs in the precision treatment of HCC.

CONCLUSION

MicroRNAs are important regulators and biomarkers in the occurrence, progression, outcome, and treatment of HCC, and can provide new targets and strategies for improving the therapeutic effect of HCC.

Downregulation of estrogen receptor-α36 expression attenuates metastasis of hepatocellular carcinoma cells

This study aimed to examine the role of estrogen receptor (ER)-α36 in the metastasis of hepatocellular carcinoma (HCC) and in the epithelial-mesenchymal transition (EMT). HCC HepG2 and Huh7 cells with the knocked-down level of ER-α36 expression were established. Cell growth and migration of the HepG2 and Huh7 cell variants were studied using MTS, transwell, and wound-healing assays, and the metastatic abilities of HepG2 cell variants were examined using a tail-vein injection model in nude mice. Levels of EMT markers, Src phosphorylation in HepG2 and Huh7 cell variants, and tumors formed by HepG2 cell variants in the nude mice were examined using Western blot and immunohistochemistry. We found that the growth and metastatic abilities of HepG2 and Huh7 cells with the knocked-down level of ER-α36 expression (HepG2/Si36 and Huh7/Si36) were significantly reduced, with increased levels of cytokeratin and E-Cadherin expression, and decreased levels of Vimentin, Snail, Slug and the Src phosphorylation, compared to the HCC cells transfected with an empty vector (HepG2/Vector and Huh7/Vector). We also found ER-α36 knockdown suppressed the lung metastasis of HepG2 cells with the involvement of EMT and the Src pathway in vivo. The Src inhibitor PP2 suppressed the growth and migration of HepG2/Vector and Huh7/Vector cells with decreased Vimentin, Snail, and Slug and increased cytokeratin and E-Cadherin expressions, but failed to induce the migration and the EMT markers in HepG2/Si36 and Huh7/Si36 cells. ER-α36 is involved in the metastasis of HCC cells through the regulation of EMT and the Src signaling pathway.

Analysis of Genomic Alternative Splicing Patterns in Rat under Heat Stress Based on RNA-Seq Data

Heat stress is one of the most severe challenges faced in livestock production in summer. Alternative splicing as an important post-transcriptional regulation is rarely studied in heat-stressed animals. Here, we performed and analyzed RNA-sequencing assays on the liver of Sprague-Dawley rats in control (22 °C, n = 5) and heat stress (4 °C for 120 min, H120; n = 5) groups, resulting in the identification of 636 differentially expressed genes. Identification analysis of the alternative splicing events revealed that heat stress-induced alternative splicing events increased by 20.18%. Compared with other types of alternative splicing events, the alternative start increased the most (43.40%) after heat stress. Twenty-eight genes were differentially alternatively spliced (DAS) between the control and H120 groups, among which Acly, Hnrnpd and mir3064 were also differentially expressed. For DAS genes, Srebf1, Shc1, Srsf5 and Ensa were associated with insulin, while Cast, Srebf1, Tmem33, Tor1aip2, Slc39a7 and Sqstm1 were enriched in the composition of the endoplasmic reticulum. In summary, our study conducts a comprehensive profile of alternative splicing in heat-stressed rats, indicating that alternative splicing is one of the molecular mechanisms of heat stress response in mammals and providing reference data for research on heat tolerance in mammalian livestock.

Long Non-coding RNA MALAT1: A Key Player in Liver Diseases

Long non-coding RNAs (lncRNAs) exceed 200 nucleotides in length are considered to be involved in both developmental processes and various diseases. Here, we focus on lncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), which was one of the most important lncRNAs in proliferation, apoptosis, and migration. MALAT1 plays a regulatory role in liver diseases, including hepatic fibrosis, liver regeneration, liver cancer, and fatty liver diseases. In the current review, we summarize the latest literature about the function roles of MALAT1 in liver disorders. Probing the regulatory mechanism and cross talk of MALAT1 with other signaling pathways of pathological processes would improve the prognosis, diagnosis of liver diseases, and offer a promising candidate target for therapeutic interventions.

The Multiple Function of lncRNA MALAT1 in Cancer Occurrence and Progression

Long non-coding RNAs (lncRNAs) have received particular attention in the last decade due to its engaging in carcinogenesis and tumorigenesis. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a lncRNA that plays physiological and pathological roles in many aspects of genome function as well as biological processes involved in cell development, differentiation, proliferation, invasion, and migration. In this article, we will review the effects of lncRNA MALAT1 on the progression of six prevalent human cancers by focusing on MALAT1 ability to regulate post-transcriptional modification and signaling pathways.

PBX1: a key character of the hallmarks of cancer

Pre-B-cell leukemia homeobox transcription factor 1 (PBX1) was first identified as part of a fusion protein resulting from the chromosomal translocation t(1;19) in pre-B cell acute lymphoblastic leukemias. Since then, PBX1 has been associated with important developmental programs, and its expression dysregulation has been related to multifactorial disorders, including cancer. As PBX1 overexpression in many cancers is correlated to poor prognosis, we sought to understand how this transcription factor contributes to carcinogenesis, and to organize PBX1's roles in the hallmarks of cancer. There is enough evidence to associate PBX1 with at least five hallmarks: sustaining proliferative signaling, activating invasion and metastasis, inducing angiogenesis, resisting cell death, and deregulating cellular energetics. The lack of studies investigating a possible role for PBX1 on the remaining hallmarks made it impossible to defend or refute its contribution on them. However, the functions of some of the PBX1's transcription targets indicate a potential engagement of PBX1 in the avoidance of immune destruction and in the tumor-promoting inflammation hallmarks. Interestingly, PBX1 might be a player in tumor suppression by activating the transcription of some DNA damage response genes. This is the first review organizing PBX1 roles into the hallmarks of cancer. Thus, we encourage future studies to uncover the PBX1's underlying mechanisms to promote carcinogenesis, for it is a promising diagnostic and prognostic biomarker, as well as a potential target in cancer treatment.

Cypermethrin triggers YY1-mediated testosterone biosynthesis suppression

Cypermethrin (CYP), an extensively-used broad-spectrum pyrethroid pesticide, is regarded as a potential environmental endocrine disruptor with the anti-androgenic characteristic. To explore underlying roles of non-coding RNAs and the Jak/Stat pathway in CYP-mediated testosterone biosynthesis suppression, SD rats and Leydig cells were employed in this work. Results displayed that β-CYP decreased plasma testosterone levels and led to abnormal alterations of testicular histomorphology and ultrastructures. LncRNA XIST and miR-142-5p were co-localized in the cytoplasm of Leydig cells, but the expression of XIST was inhibited by β-CYP while that of miR-142-5p was induced. Then overexpressed miR-142-5p dampened the Jak1/Stat1 pathway by directly targeting Jak1. Transcription factors NFκB and YY1 impeded by β-CYP were positively regulated by the Jak1/Stat1 pathway. Bidirectional Co-IP and ChIP assays demonstrated that NFκB interacted with and modulated YY1 by directly binding to the promoter region of YY1. ChIP, qPCR, and YY1 knockdown/overexpression assays indicated that YY1 acted as a transcriptional activator to directly modulate steroidogenic StAR and 3β-HSD in Leydig cells. Taken together, miR-142-5p sponged by lncRNA XIST directly targets the Jak1/Stat1 pathway, which regulates steroidogenic StAR and 3β-HSD via NFκB and YY1, and ultimately dampens testosterone production in Leydig cells.

Emerging role of long noncoding RNAs in recurrent hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the most frequent types of liver cancer and is characterized by a high recurrence rate. Recent studies have proposed that long non-coding RNAs (lncRNAs) are potential biomarkers in several recurrent tumor types. It is now well understood that invasion, migration, and metastasis are important factors for tumor recurrence. Moreover, some of the known risk factors for HCC may affect the expression levels of several types of lncRNAs and thus affect the recurrence of liver cancer through lncRNA regulation. In this paper, we review the biological functions, molecular mechanisms, and roles of lncRNAs in HCC and summarize current knowledge about lncRNAs as potential biomarkers in recurrent HCC.

Extracellular Vesicles Long Non-Coding RNA AGAP2-AS1 Contributes to Cervical Cancer Cell Proliferation Through Regulating the miR-3064-5p/SIRT1 Axis

Cervical cancer is one of the most severe and prevalent female malignancies and a global health issue. The molecular mechanisms underlying cervical cancer development are poorly investigated. As a type of extracellular membrane vesicles, EVs from cancer cells are involved in cancer progression by delivering regulatory factors, such as proteins, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). In this study, we identified an innovative function of extracellular vesicle (EV) lncRNA AGAP2-AS1 in regulating cervical cancer cell proliferation. The EVs were isolated from the cervical cancer cells and were observed by transmission electron microscopy (TEM) and were confirmed by analyzing exosome markers. The depletion of AGAP2-AS1 by siRNA significantly reduced its expression in the exosomes from cervical cancer and in the cervical cancer treated with AGAP2-AS1-knockdown exosomes. The expression of AGAP2-AS1 was elevated in the clinical cervical cancer tissues compared with the adjacent normal tissues. The depletion of EV AGAP2-AS1 reduced cell viabilities and Edu-positive cervical cancer cells, while it enhanced cervical cancer cell apoptosis. Tumorigenicity analysis in nude mice showed that the silencing of EV AGAP2-AS1 attenuated cervical cancer cell growth in vivo. Regarding the mechanism, we identified that AGAP2-AS1 increased SIRT1 expression by sponging miR-3064-5p in cervical cancer cells. The overexpression of SIRT1 or the inhibition of miR-3064-5p reversed EV AGAP2-AS1 depletion-inhibited cancer cell proliferation in vitro. Consequently, we concluded that EV lncRNA AGAP2-AS1 contributed to cervical cancer cell proliferation through regulating the miR-3064-5p/SIRT1 axis. The clinical values of EV lncRNA AGAP2-AS1 and miR-3064-5p deserve to be explored in cervical cancer diagnosis and treatments.

Non-coding RNAs as biomarkers for hepatocellular carcinoma-A systematic review

Hepatocellular carcinoma (HCC) is the sixth most common malignancy in the world and the fourth leading cause of cancer-related death, and its incidence is increasing globally. Despite significant advances in treatment strategies for HCC, the prognosis is still poor due to its high recurrence rate. Therefore, there is an urgent need to understand the pathogenesis of HCC and further develop new therapies to improve the prognosis and quality of life of HCC patients. MicroRNAs (miRNAs, miRs) are small non-coding RNAs involved in post-transcriptional regulation of gene expression that is abnormally expressed in cancer-associated genomic regions or vulnerable sites. More and more findings have shown that miRNAs are important regulatory factors of mRNA expression in HCC, and they are receiving more and more attention as a possible key biomarker of HCC. This review mainly summarizes the potential applied value on miRNAs as diagnostic, drug resistant, prognostic, and therapeutic biomarkers in the diagnosis, therapy, and prognosis of HCC. Also, we summarize the research value of long non-coding RNA (lncRNAs), circular RNAs (circRNAs), and miRNAs network in HCC as novel biomarkers, aiming at providing some references for the therapy of HCC.

Footprints of microRNAs in Cancer Biology

MicroRNAs (miRNAs) are short non-coding RNAs involved in post-transcriptional gene regulation. Over the past years, various studies have demonstrated the role of aberrant miRNA expression in the onset of cancer. The mechanisms by which miRNA exerts its cancer-promoting or inhibitory effects are apparent through the various cancer hallmarks, which include selective proliferative advantage, altered stress response, vascularization, invasion and metastasis, metabolic rewiring, the tumor microenvironment and immune modulation; therefore, this review aims to highlight the association between miRNAs and the various cancer hallmarks by dissecting the mechanisms of miRNA regulation in each hallmark separately. It is hoped that the information presented herein will provide further insights regarding the role of cancer and serve as a guideline to evaluate the potential of microRNAs to be utilized as biomarkers and therapeutic targets on a larger scale in cancer research.

MiR-3064 in Epicardial Adipose-Derived Exosomes Targets Neuronatin to Regulate Adipogenic Differentiation of Epicardial Adipose Stem Cells

Backgroud: The metabolism of epicardial adipose tissue (EAT) is closely related to coronary atherosclerotic heart disease (CAHD), but the specific mechanism is not fully understood. In this study, we investigated the effects of EAT microenvironment on adipose metabolism from the viewpoint of EAT-derived exosomes and epicardial adipose stem cells (EASCs).

Methods: EAT samples from CAHD patients and non-CAHD patients were collected to obtain exosomes via tissue culture. MiRNA sequencing was performed to analyze differences in miRNA expression in exosomes between groups. Luciferase reporter assay was then performed to verify the miRNA target gene. EAT was digested by collagenase to obtain EASCs, which were induced to mature adipocytes in vitro. Immunochemical staining and western blotting were performed to detect protein expression levels.

Results: The results showed that CAHD patients had higher levels of EASCs in EAT, and no significant difference in the adipogenic differentiation ability of EASCs was observed between CAHD and non-CAHD patients in vitro. This indicates that the EAT microenvironment is a key factor affecting the adipogenic differentiation of EASCs. The EAT-derived exosomes from CAHD patients inhibited adipogenic differentiation of EASCs in vitro. Sequencing analysis showed that miR-3064-5p was highly expressed in EAT-derived exosomes in CAHD patients, and its inhibitor could improve the adipogenic differentiation of EASCs. Luciferase reporter assay results showed that the target gene of miR-3064-5p is neuronatin (Nnat). Nnat remained silent in EASCs and was less expressed in EAT of CAHD patients.

Conclusion: Abovementioned results suggest that Nnat is the key to regulating the adipogenic differentiation of EASCs, and miR-3064-5p in EAT-derived exosomes can inhibit the expression of Nnat by targeting its mRNA, thereby affecting the adipogenic differentiation of EASCs.

LncRNA LINC00858 enhances cervical cancer cell growth through miR-3064-5p/ VMA21 axis

BACKGROUND

Cervical cancer (CC) is the most common form of gynecological malignancy. Long intergenic non-protein coding RNA 858 (LINC00858) has been identified to participate in multiple cancers. However, the role and mechanism of LINC00858 in CC cells are still elusive.

AIM

The aim of this study is to explore the biological functions and mechanisms of LINC00858 in CC cells.

METHODS

RT-qPCR analysis was used to examine the expression of LINC00858 in CC cells. EdU and colony formation assay were utilized to assess cell proliferation. TUNEL assay and flow cytometry assay were conducted to assess cell apoptosis. The mechanism regarding LINC00858 was certified through RNA pull down, RIP and luciferase reporter assays.

RESULTS

The up-regulated LINC00858 was detected in CC cells. Reduction of LINC00858 effectively subdued CC cells proliferation and stimulated cell apoptosis. LINC00858 was determined to bind with miR-3064-5p and up-regulate VMA21 in CC cells. In rescue assays, miR-3064-5p down-regulation and VMA21 up-regulation were able to counteract the effect caused by LINC00858 decrease on CC cell proliferation and apoptosis.

CONCLUSION

LINC00858 enhances cell proliferation, while restraining cell apoptosis in CC through targeting miR-3064-5p/VMA21 axis, implying that LINC00858 may serve as a promising therapeutic target for CC.

Hypoxia-Induced MALAT1 Promotes the Proliferation and Migration of Breast Cancer Cells by Sponging MiR-3064-5p

Hypoxia, a common process during tumor growth, can lead to tumor aggressiveness and is tightly associated with poor prognosis. Long noncoding RNAs (lncRNAs) are long ribonucleotides (>200 bases) with limited ability to translate proteins, and are known to affect many aspects of cellular function. One of their regulatory mechanisms is to function as a sponge for microRNA (miRNA) to modulate its biological functions. Previously, MALAT1 was identified as a hypoxia-induced lncRNA. However, the regulatory mechanism and functions of MALAT1 in breast cancer are still unclear. Therefore, we explored whether MALAT1 can regulate the functions of breast cancer cells through miRNAs. Our results showed the expression levels of MALAT1 were significantly up-regulated under hypoxia and regulated by HIF-1α and HIF-2α. Next, in contrast to previous reports, nuclear and cytoplasmic fractionation assays and fluorescence in situ hybridization indicated that MALAT1 was mainly located in the cytoplasm. Therefore, the labeling of MALAT1 as a nuclear marker should be done with the caveat. Furthermore, expression levels of miRNAs and RNA immunoprecipitation using antibody against AGO2 showed that MALAT1 functioned as a sponge of miRNA miR-3064-5p. Lastly, functional assays revealed that MALAT1 could promote cellular migration and proliferation of breast cancer cells. Our findings provide evidence that hypoxia-responsive long non-coding MALAT1 could be transcriptionally activated by HIF-1α and HIF-2α, act as a miRNA sponge of miR-3064-5p, and promote tumor growth and migration in breast cancer cells. These data suggest that MALAT1 may be a candidate for therapeutic targeting of breast cancer progression.

Hepatitis B Virus preS2 Domain Promotes Angiogenesis in Hepatocellular Carcinoma via Transcriptional Activation of VEGFA Promoter

: Angiogenesis is closely related to the development and progression of hepatocellular carcinoma (HCC). Angiogenic factors have been confirmed to be overexpressed in HCC. The hepatitis B virus preS2 domain is a transactivator that plays an important role in hepatitis B virus (HBV)-related HCC. Here, we aimed to investigate the potential of the preS2 domain in inducing angiogenesis in HCC. A total of 25 cases of pathologically confirmed HCC were screened. The levels of preS2, CD34, and vascular endothelial growth factor A (VEGFA) in HCC samples were evaluated by immunohistochemistry (IHC). The proliferation of vascular endothelial cells was detected by CCK-8. Besides, VEGFA was analyzed by Western blot in HCC cells. The effect of preS2 on the VEGFA promoter was measured by dual-luciferase reporter assays. We found that preS2 domain-positive HCCs had significantly higher microvessel density (MVD) and VEGFA expression than preS2 domain-negative HCCs. Overexpression of preS2 upregulated VEGFA expression in HepG2 and activated vascular endothelial cell proliferation. However, blocking preS2 expression reduced VEGFA expression in HepG2.2.15 and inhibited the proliferation of vascular endothelial cells. In addition, a dual-luciferase assay indicated that the preS2 domain could activate VEGFA promoter activity. In conclusion, we showed that the expression of the preS2 domain promotes angiogenesis by transactivating the VEGFA promoter in HCC.

LncRNA influence sequential steps of hepatocellular carcinoma metastasis

As a class of new and crucial molecules involved in the regulation of biological function, long noncoding RNA (lncRNA) have obtained widespread attention in recent days. While it was thought that lncRNA would be redundant in the past, it is proved that lncRNA identify a class of molecular that regulate the homeostasis including hepatocellular carcinoma in the present. All kinds of lncRNA have been implicated in a various of diseases, particularly in tumorigenesis and metastasis. But the mechanisms how they act is still not entirely clear. Metastasis is a major factor affecting long-term survival in hepatocellular carcinoma (HCC) patients. Recently, growing numbers of experiments demonstrate that there is close connection between lncRNA and HCC metastasis. Here, we will briefly introduce a series of steps (primary tumor growth, angiogenesis, epithelial-to-mesenchymal transition, invasion, intravasation, survival in circulatory system, extravasation, dormancy and subsequent secondary tumor growth) of tumor metastasis, its classical but promising theories, the role of lncRNA in metastasis and the possible mechanisms involved. LncRNA, as potentially new and important tumor diagnostic and therapeutic molecules, has attracted much attention in recent years.

LncRNA MALAT1 Regulates miR-144-3p to Facilitate Epithelial-Mesenchymal Transition of Lens Epithelial Cells via the ROS/NRF2/Notch1/Snail Pathway

Diabetic cataract is a common complication of diabetes. The epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) is a key event in the development of diabetic cataracts. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been reported to be highly expressed in different tissues of diabetic patients. This study is aimed at investigating the function and mechanism of MALAT1 in the regulation of EMT in human LECs under high glucose conditions. MALAT1, α-smooth muscle actin (α-SMA), fibronectin (FN), and nuclear factor erythroid-derived 2-like 2 (NRF2) were highly expressed in the LECs of diabetic cataract patients and in the human LECs under high glucose conditions; meanwhile, the decreased expressions of E-cadherin and zonula occludens 1 (ZO-1) were detected. Knockdown of MALAT1 could significantly reduce ROS, prevent EMT, arrest S phase cell cycle, and suppress the expression of total NRF2 and its nucleus translocation in LECs. Furthermore, after NRF2 was knocked down, total NRF2, α-SMA, and FN in cells, and NRF2, Notch intracellular domain (NICD), and Snail were decreased in the nucleus. Using bioinformatics methods, we predicted that MALAT1 and NRF2 shared the same microRNA-144-3p (miR-144-3p) combining site. Luciferase reporter coupled with qRT-PCR assays revealed that miR-144-3p was a target of MALAT1, which was confirmed to downregulate miR-144-3p in the LECs. In addition, after transfection of miR-144-3p mimics or inhibitor, western blot assay demonstrated that miR-144-3p negatively regulated the expression of total NRF2, α-SMA, and FN in cells, and NRF2, NICD, and Snail in the nucleus without affecting Kelch-like ECH-associated protein 1 (KEAP1). Finally, we confirmed that transfection of shMALAT1 inhibited NRF2 expression, and its mediated EMT could be rescued by miR-144-3p inhibitor; transfection of pcDNA3.1-MALAT1 promoted NRF2 expression, and its mediated EMT could be reversed by miR-144-3p inhibitor. In summary, we demonstrate that MALAT1 regulates miR-144-3p to facilitate EMT of LECs via the ROS/NRF2/Notch1/Snail pathway.

Lnc-ATG9B-4 aggravates progress of hepatocellular carcinoma through cell proliferation and migration by upregulating CDK5

Long noncoding RNAs play an important role in the occurrence, invasion, as well as metastasis of various human cancers, including hepatocellular carcinoma. Long noncoding RNAs can affect the biological functions of hepatocellular carcinoma cells by regulating various genes; however, only a small fraction of molecular mechanisms of long noncoding RNAs have been elucidated. In the present study, lnc AC010973.1 (lnc-ATG9B-4) was first identified by microarray analysis from 8 patients with hepatocellular carcinoma and confirmed by quantitative PCR in 176 patients with hepatocellular carcinoma. We demonstrated that lnc-ATG9B-4 was tightly relative to the tumorous size, TNM stages, portal vein tumor thrombus (PVTT), the tumor capsule, metastasis, degree of differentiation, and poor prognosis of hepatocellular carcinoma according to long-term follow-up data. In hepatocellular carcinoma cells, overexpression of lnc-ATG9B-4 promoted proliferation, invasion, as well as migration, while inhibiting lnc-ATG9B-4 by siRNA significantly attenuated the proliferation, invasion, as well as migration. Interestingly, lnc-ATG9B-4 increased the expression of cyclin-dependent kinase 5 (CDK5), which was closely related to the development and chemotherapy sensitivity of hepatocellular carcinoma. In summary, our results revealed that lnc-ATG9B-4 suggests an unfavorable prognosis of hepatocellular carcinoma and facilitates the proliferation, invasion, as well as migration of hepatocellular carcinoma cells by upregulating CDK5. This research suggests that lnc-ATG9B-4 may be a new biomarker for predicting the prognosis of hepatocellular carcinoma; meanwhile, targeting lnc-ATG9B-4 might serve as a potential strategy for the treatment hepatocellular carcinoma.

Suppression of lncRNA MALAT1 by betulinic acid inhibits hepatocellular carcinoma progression by targeting IAPs via miR-22-3p

Betulinic acid (BA) is a natural product extracted from a broad range of medicinal and edible herbal plants. Previous studies showed that BA induces cell death in tumors derived from multiple tissues; however, the underlying mechanism remains obscure. The present study aimed to study the effects of BA on autophagy and apoptosis of hepatocellular carcinoma (HCC). Human HCC cell lines and orthotopic HCC implanted mice were employed to examine the BA-induced tumor suppression; RT2 long noncoding RNA (lncRNA) PCR array and database analysis were used to explore the possible mechanisms; validation of pathways was performed using siRNA and miRNA inhibitors. The results indicated that BA regulated autophagy and induced apoptosis in HCC. The degradation of inhibitor of apoptosis proteins (IAPs), the conversion of LC3-I to LC3-II, and p62 accumulation were enhanced by BA, thereby suggesting that the downregulation of IAPs and autophagic cell death are induced by BA. The addition of autophagy and lysosomal inhibitors indicated that BA induced autophagy-independent apoptosis via degradation of IAPs. Moreover, RT2 lncRNA PCR array and database analysis suggested that BA downregulated the levels of lncRNA MALAT1, which is considered to be an oncogene. Further investigations demonstrated that lncRNA MALAT1 functioned as a ceRNA (competing endogenous RNA) to contribute to BA-mediated degradation of IAPs by sponging miR-22-3p. Therefore, BA could be developed as a potential anticancer agent for HCC.

The role of microenvironment in tumor angiogenesis

Tumor angiogenesis is necessary for the continued survival and development of tumor cells, and plays an important role in their growth, invasion, and metastasis. The tumor microenvironment—composed of tumor cells, surrounding cells, and secreted cytokines—provides a conducive environment for the growth and survival of tumors. Different components of the tumor microenvironment can regulate tumor development. In this review, we have discussed the regulatory role of the microenvironment in tumor angiogenesis. High expression of angiogenic factors and inflammatory cytokines in the tumor microenvironment, as well as hypoxia, are presumed to be the reasons for poor therapeutic efficacy of current anti-angiogenic drugs. A combination of anti-angiogenic drugs and antitumor inflammatory drugs or hypoxia inhibitors might improve the therapeutic outcome.

Exosomal CircPRRX1 Enhances Doxorubicin Resistance in Gastric Cancer by Regulating MiR-3064-5p/PTPN14 Signaling

PURPOSE

Gastric cancer (GC) is a malignant tumor with a high mortality rate. Drug resistance is a major obstacle to GC therapy. This study aimed to investigate the role and mechanism of exosomal circPRRX1 in doxorubicin resistance in GC.

MATERIALS AND METHODS

HGC-27 and AGS cells were exposed to different doses of doxorubicin to construct doxorubicin-resistant cell lines. Levels of circPRRX1, miR-3064-5p, and nonreceptor tyrosine phosphatase 14 (PTPN14) were detected by quantitative real-time PCR or Western blot assay. Then, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, transwell, and Western blot assays were used to explore the function of circPRRX1 in GC cells. Interactions among circPRRX1, miR-3064-5p, and PTPN14 were confirmed by dual-luciferase reporter assay. The in vivo function of circPRRX1 was analyzed in a xenograft tumor model.

RESULTS

CircPRRX1 was highly expressed in doxorubicin-resistant GC cell lines. Knockdown of circPRRX1 reversed doxorubicin resistance in doxorubicin-resistant GC cells. Additionally, extracellular circPRRX1 was carried by exosomes to spread doxorubicin resistance. CircPRRX1 silencing reduced doxorubicin resistance by targeting miR-3064-5p or regulating PTPN14. In GC patients, high levels of circPRRX1 in serum exosomes were associated with poor responses to doxorubicin treatment. Moreover, depletion of circPRRX1 reduced doxorubicin resistance in vivo.

CONCLUSION

CircPRRX1 strengthened doxorubicin resistance by modulating miR-3064-5p/PTPN14 signaling and might be a therapeutic target for GC patients.

Non-coding RNAs regulate angiogenic processes

Angiogenesis has critical roles in numerous physiologic processes during embryonic and adult life such as wound healing and tissue regeneration. However, aberrant angiogenic processes have also been involved in the pathogenesis of several disorders such as cancer and diabetes mellitus. Vascular endothelial growth factor (VEGF) is implicated in the regulation of this process in several physiologic and pathologic conditions. Notably, several non-coding RNAs (ncRNAs) have been shown to influence angiogenesis through modulation of expression of VEGF or other angiogenic factors. In the current review, we summarize the function and characteristics of microRNAs and long non-coding RNAs which regulate angiogenic processes. Understanding the role of these transcripts in the angiogenesis can facilitate design of therapeutic strategies to defeat the pathogenic events during this process especially in the human malignancies. Besides, angiogenesis-related mechanisms can improve tissue regeneration after conditions such as arteriosclerosis, myocardial infarction and limb ischemia. Thus, ncRNA-regulated angiogenesis can be involved in the pathogenesis of several disorders.

Role of long noncoding RNA-mediated competing endogenous RNA regulatory network in hepatocellular carcinoma

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are noncoding RNAs (ncRNAs) that occupy over 90% of the human genome, and their main function is to directly or indirectly regulate messenger RNA (mRNA) expression and participate in the tumorigenesis and progression of malignances. In particular, some lncRNAs can interact with miRNAs as competing endogenous RNAs (ceRNAs) to modulate mRNA expression. Accordingly, these RNA molecules are interrelated and coordinate to form a dynamic lncRNA-mediated ceRNA regulatory network. Mounting evidence has revealed that lncRNAs that act as ceRNAs are closely related to tumorigenesis. To date, numerous studies have established many different regulatory networks in hepatocellular carcinoma (HCC), and perturbations in these ceRNA interactions may result in the initiation and progression of HCC. Herein, we emphasize recent advances concerning the biological function of lncRNAs as ceRNAs in HCC, with the aim of elucidating the molecular mechanism underlying these HCC-related RNA molecules and providing novel insights into the diagnosis and treatment of HCC.

miR-142-5p/DAX1-dependent regulation of P450c17 contributes to triclosan-mediated testosterone suppression

Triclosan (TCS) is a potent antibacterial and antifungal compound that is extensively used in various daily products. TCS is also considered as an underlying endocrine disruptor and has anti-androgenic effects. In our previous work, we found that TCS suppressed testicular steroidogenesis via the miR-6321/JNK/Nur77 cascade, but roles of the abnormal expression of miR-142-5p and P450c17 in this molecular event were still unknown. Therefore, to verify the hypothesis that miR-142-5p and P450c17 might significantly function in other manner in testosterone decline after TCS exposure, Sprague-Dawley rats and the rat Leydig cell line were used in this study. Results showed that after TCS exposure, testicular histomorphology was abnormally changed and testosterone level was declined. Overexpressed miR-142-5p by TCS directly targeted the JAK1/STAT1 pathway. Bidirectional Co-IP assays and the use of STAT1 activator demonstrated that STAT1 could interact with and regulate Sp1. The activity, mRNA level, and protein expression of DNMT1 and DNMT3β were all decreased after TCS treatment. Sp1 silencing, ChIP, and qPCR assays showed that Sp1 regulated DNMT1 expressions by directly binding to the promoter region of DNMT1. Though the DNA methylation status of the DAX1 promoter was not affected, TCS induced the transcription and translation of DAX1 by DNMT1, in turn leading to the inhibition of steroidogenic P450c17. Taken together, TCS-induced miR-142-5p inhibits P450c17 by the JAK1/STAT1 pathway and downstream Sp1/DNMT1/DAX1 cascade, finally facilitating the decrease in testosterone levels.

FOX transcription factor family in hepatocellular carcinoma

The pathogenesis of hepatocellular carcinoma (HCC) is a multistep process, involving the progressive accumulation of molecular alterations and transcriptomic alterations. The Forkhead-box (FOX) transcription factor family is characterized by its unique DNA binding domain (FKH or winged-helix domain). Human FOX family consists of about 17 subfamilies, at least 43 members. Some of them are liver-enriched transcription factors, suggesting that they may play a crucial role in the development or/and functions of the liver. Dysregulation of FOX transcription factors may contribute to the pathogenesis of HCC because they can activate or suppress the expression of various tumor-related molecules, and pinpoint different molecular and cellular events. Here we summarized, analyzed and discussed the status and the functions of the human FOX family of transcription factors in HCC, aiming to help the further development of them as potential therapeutic targets or/and diagnostic/prognostic markers for HCC.

Functionally analyzing the important roles of hepatocyte nuclear factor 3 (FoxA) in tumorigenesis

Transcriptional factors (TFs) play a central role in governing gene expression under physiological conditions including the processes of embryonic development, metabolic homeostasis and response to extracellular stimuli. Conceivably, the aberrant dysregulations of TFs would dominantly result in various human disorders including tumorigenesis, diabetes and neurodegenerative diseases. Serving as the most evolutionarily reserved TFs, Fox family TFs have been explored to exert distinct biological functions in neoplastic development, by manipulating diverse gene expression. Recently, among the Fox family members, the pilot roles of FoxAs attract more attention due to their functions as both pioneer factor and transcriptional factor in human tumorigenesis, particularly in the sex-dimorphism tumors. Therefore, the pathological roles of FoxAs in tumorigenesis have been well-explored in modulating inflammation, immune response and metabolic homeostasis. In this review, we comprehensively summarize the impressive progression of FoxA functional annotation, clinical relevance, upstream regulators and downstream effectors, as well as valuable animal models, and highlight the potential strategies to target FoxAs for cancer therapies.