MiR-1254 suppresses HO-1 expression through seed region-dependent silencing and non-seed interaction with TFAP2A transcript to attenuate NSCLC growth

[Research Progress of Engineered Exosomes in the Treatment of Lung Cancer]

The best treatment for non-small cell lung cancer is early surgical treatment, but most lung cancer is diagnosed at an advanced stage. The main treatment methods are drug and radiotherapy. However, drug resistance or no signifi cant effect of the above treatment methods is inevitable. Therefore, more methods are urgently needed for the treatment of lung cancer. Studies have confirmed that engineered exosomes have good clinical application potential in cardiovascular diseases, tumors, tissue regeneration and repair. This paper summarizes the application of engineered exosomes in the treatment of lung cancer at home and abroad.
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Potential prognosis and immunotherapy predictor TFAP2A in pan-cancer

BACKGROUND

TFAP2A is critical in regulating the expression of various genes, affecting various biological processes and driving tumorigenesis and tumor development. However, the significance of TFAP2A in carcinogenesis processes remains obscure.

METHODS

In our study, we explored multiple databases including TCGA, GTEx, HPA, cBioPortal, TCIA, and other well-established databases for further analysis to expound TFAP2A expression, genetic alternations, and their relationship with the prognosis and cellular signaling network alternations. GO term and KEGG pathway enrichment analysis as well as GSEA were conducted to examine the common functions of TFAP2A. RT-qPCR, Western Blot and Dual Luciferase Reporter assay were employed to perform experimental validation.

RESULTS

TFAP2A mRNA expression level was upregulated and its genetic alternations were frequently present in most cancer types. The enrichment analysis results prompted us to investigate the changes in the tumor immune microenvironment further. We discovered that the expression of TFAP2A was significantly associated with the expression of immune checkpoint genes, immune subtypes, ESTIMATE scores, tumor-infiltrating immune cells, and the possible role of TFAP2A in predicting immunotherapy efficacy. In addition, high TFAP2A expression significantly correlated with several ICP genes, and promoted the expression of PD-L1 on mRNA and protein levels through regulating its expression at the transcriptional level. TFAP2A protein level was upregulated in fresh colon tumor tissue samples compared to that in the adjacent normal tissues, which essentially positively correlated with the expression of PD-L1.

CONCLUSIONS

Our study suggests that targeting TFAP2A may provide a novel and effective strategy for cancer treatment.

Plasma miR-1254 as a predictive biomarker of chemosensitivity and a target of nucleic acid therapy in esophageal cancer

This study investigated novel tumor suppressor microRNAs (miRNAs) that decrease in plasma and predict chemosensitivity to neoadjuvant chemotherapy (NAC) for esophageal squamous cell carcinoma (ESCC) and revealed their usefulness as novel therapeutic agents. We selected four miRNA candidates (miR-323, 345, 409, and 1254) based on the microRNA microarray comparing pre-treatment plasma levels in ESCC patients with high and low histopathological responses to NAC and an NCBI database review. Among these miRNA candidates, miR-1254 was more highly elevated in pre-treatment plasma of ESCC patients with a high histopathological response than in those with a low histopathological response (P = 0.0021, area under the receiver-operating characteristic curve 0.7621). High plasma miR-1254 levels tended to correlate with the absence of venous invasion (P = 0.0710) and were an independent factor predicting a higher response to chemotherapy (P = 0.0022, odds ratio 7.86) and better prognosis (P = 0.0235, hazard ratio 0.23). Overexpressing miR-1254 in ESCC cells significantly enhanced chemosensitivity to cisplatin through the transcriptional regulation of ABCC1 in vitro. Moreover, increased plasma miR-1254 levels by subcutaneous injection significantly improved responses to cisplatin in mice. Plasma miR-1254 might be a useful biomarker for predicting responses to NAC, and the restoration of plasma miR-1254 levels might improve chemosensitivity in ESCC.

Cytoprotective Role of Heme Oxygenase-1 in Cancer Chemoresistance: Focus on Antioxidant, Antiapoptotic, and Pro-Autophagy Properties

Chemoresistance remains the foremost challenge in cancer therapy. Targeting reactive oxygen species (ROS) manipulation is a promising strategy in cancer treatment since tumor cells present high levels of intracellular ROS, which makes them more vulnerable to further ROS elevation than normal cells. Nevertheless, dynamic redox evolution and adaptation of tumor cells are capable of counteracting therapy-induced oxidative stress, which leads to chemoresistance. Hence, exploring the cytoprotective mechanisms of tumor cells is urgently needed to overcome chemoresistance. Heme oxygenase-1 (HO-1), a rate-limiting enzyme of heme degradation, acts as a crucial antioxidant defense and cytoprotective molecule in response to cellular stress. Recently, emerging evidence indicated that ROS detoxification and oxidative stress tolerance owing to the antioxidant function of HO-1 contribute to chemoresistance in various cancers. Enhanced HO-1 expression or enzymatic activity was revealed to promote apoptosis resistance and activate protective autophagy, which also involved in the development of chemoresistance. Moreover, inhibition of HO-1 in multiple cancers was identified to reversing chemoresistance or improving chemosensitivity. Here, we summarize the most recent advances regarding the antioxidant, antiapoptotic, and pro-autophagy properties of HO-1 in mediating chemoresistance, highlighting HO-1 as a novel target for overcoming chemoresistance and improving the prognosis of cancer patients.

Heme oxygenase 1 in erythropoiesis: an important regulator beyond catalyzing heme catabolism

Heme oxygenase 1 (HO-1), encoded by the HMOX-1 gene, is the main heme oxygenase that catalyzes the degradation of heme into iron, carbon monoxide, and biliverdin. HMOX-1 gene expression is stimulated by oxidative stress and regulated at transcriptional and post-transcriptional levels. After translation, subcellular location and protein stability of HO-1 are also altered by different extracellular and intracellular stimuli. HO-1 plays a key role in regulating iron homeostasis and cell protection and has become a new target for disease treatment. Erythropoiesis is a tightly controlled, iron-dependent process that begins with hematopoietic stem cells and maturates to red blood cells. HO-1 is expressed in hematopoietic stem/progenitor cells, hematopoietic niche cells, erythroblasts, and especially erythroblastic island and phagocytic macrophages. HO-1 functions importantly in the entire erythroid development process by influencing hematopoietic stem cell proliferation, erythroid lineage engagement, terminal erythroid differentiation, and even senescent RBC erythrophagocytosis. HO-1 is also related to stress erythropoiesis and certain red blood cell diseases. Elucidation of HO-1 regulation and function in erythropoiesis will be of great significance for the treatment of related diseases.

Transcription factor AP-2α activates RNA polymerase III-directed transcription and tumor cell proliferation by controlling expression of c-MYC and p53

Deregulation of transcription factor AP2 alpha (TFAP2A) and RNA polymerase III (Pol III) products is associated with tumorigenesis. However, the mechanism underlying this event is not fully understood and the connection between TFAP2A and Pol III-directed transcription has not been investigated. Here, we report that TFAP2A functions as a positive factor in the regulation of Pol III-directed transcription and cell proliferation. We found TFAP2A is also required for the activation of Pol III transcription induced by the silencing of filamin A, a well-known cytoskeletal protein and an inhibitor in Pol III-dependent transcription identified previously. Using a chromatin immunoprecipitation technique, we showed TFAP2A positively modulates the assembly of Pol III transcription machinery factors at Pol III-transcribed gene loci. We found TFAP2A can activate the expression of Pol III transcription-related factors, including BRF1, GTF3C2, and c-MYC. Furthermore, we demonstrate TFAP2A enhances expression of MDM2, a negative regulator of tumor suppressor p53, and also inhibits p53 expression. Finally, we found MDM2 overexpression can rescue the inhibition of Pol III-directed transcription and cell proliferation caused by TFAP2A silencing. In summary, we identified that TFAP2A can activate Pol III-directed transcription by controlling multiple pathways, including general transcription factors, c-MYC and MDM2/p53. The findings from this study provide novel insights into the regulatory mechanisms of Pol III-dependent transcription and cancer cell proliferation.

Non-coding RNAs: New players in mitophagy and neurodegeneration

Mitophagy controls mitochondrial quality to maintain cellular homeostasis, while aberrations in this process are responsible for neurodegenerative diseases. Mitophagy is initiated through the recruitment of autophagosomes in a ubiquitin-dependent or ubiquitin-independent manner under different stress conditions. Although the detailed molecular mechanisms of how mitophagy processes influence neurodegeneration remain largely uncharacterized, there is mounting evidence indicating that non-coding RNAs (ncRNAs), a variety of endogenous regulators, including microRNAs and long non-coding RNAs, extensively participate in mitophagy processes and play pivotal roles in the aging process and neurodegenerative diseases. Here, we reviewed the major mitophagy pathways modulated by some classical and newly found ncRNAs and summarized the diverse mechanisms in a regulatory network. We also discussed the generalizability of ncRNAs in the development of common neurodegenerative diseases related to proteotoxicity and the importance of mitophagy in the pathogenesis of these diseases. In summary, we propose that ncRNAs act as linkers between mitophagy and neurodegeneration, showing the potential therapeutic application of mitophagy regulation mediated by ncRNAs in neurodegenerative diseases.

The non-canonical effects of heme oxygenase-1, a classical fighter against oxidative stress

The role of heme oxygenase-1 in resisting oxidative stress and cell protection has always been a hot research topic. With the continuous deepening of research, in addition to directly regulating redox by catalyzing the degradation of heme, HO-1 protein also participates in the gene expression level in a great diversity of methods, thereby initiating cell defense. Particularly the non-canonical nuclear-localized HO-1 and HO-1 protein interactions play the role of a warrior against oxidative stress. Besides, HO-1 may be a promising marker for disease prediction and detection in many clinical trials. Especially for malignant diseases, there may be new advances in the treatment of HO-1 by regulating abnormal ROS and metabolic signaling. The purpose of this review is to systematically sort out and describe several aspects of research to facilitate further detailed mechanism research and clinical application promotion in the future.

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The different subcellular localizations ofHO-1 implies that it has special functions.

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Nuclear HO-1 plays an indispensable role in gene regulation and other aspects.

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The interactions between HO-1 and others provide the possibility to participate in vital physiological processes.

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HO-1 may become a potential disease assessment marker.

Engineered exosomes loaded with miR-449a selectively inhibit the growth of homologous non-small cell lung cancer

As an efficient drug carrier, exosome has been widely used in the delivery of genetic drugs, chemotherapeutic drugs, and anti-inflammatory drugs. As a genetic drug carrier, exosomes are beneficial to improve transfection efficiency and weaken side effects at the same time. Here, we use genetic engineering to prepare engineered exosomes (miR-449a Exo) that can actively deliver miR-449a. It was verified that miR-449a Exo had good homology targeting capacity and was specifically taken up by A549 cells. Moreover, miR-449a Exo had high delivery efficiency of miR-449a in vitro and in vivo. We demonstrated that miR-449a Exo effectively inhibited the proliferation of A549 cells and promoted their apoptosis. In addition, miR-449a Exo was found to control the progression of mouse tumors and prolong their survival in vivo. Our research provides new ideas for exosomes to efficiently and actively load gene drugs, and finds promising methods for the treatment of non-small cell lung cancer.

MicroRNAs involved in drug resistance of breast cancer by regulating autophagy

Autophagy is a conserved catabolic process characterized by degradation and recycling of cytosolic components or organelles through a lysosome-dependent pathway. It has a complex and close relationship to drug resistance in breast cancer. MicroRNAs (miRNAs) are small noncoding molecules that can influence numerous cellular processes including autophagy, through the posttranscriptional regulation of gene expression. Autophagy is regulated by many proteins and pathways, some of which in turn have been found to be regulated by miRNAs. These miRNAs may affect the drug resistance of breast cancer. Drug resistance is the main cause of distant recurrence, metastasis and death in breast cancer patients. In this review, we summarize the causative relationship between autophagy and drug resistance of breast cancer. The roles of autophagy-related proteins and pathways and their associated miRNAs in drug resistance of breast cancer are also discussed.

Improvement of hyperlipidemia by aerobic exercise in mice through a regulatory effect of miR-21a-5p on its target genes

Hyperlipidemia is a risk factor for cardiovascular disease, and miR-21a-5p plays an important role in the occurrence and progression of hyperlipidemia. Here, we aimed to investigate the mechanism of aerobic exercise improved hyperlipidemia through enhancing miR-21a-5p expression. In this study, high-fat/high-cholesterol diet mice received 8 weeks of aerobic exercise intervention, then we collected plasma and liver samples, we found that there had a notable improvement in weight gain, blood lipid level, and liver steatosis in hyperlipidemia mice after 8 weeks of aerobic exercise intervention. Besides, aerobic exercise significantly up-regulated the expression of miR-21a-5p and provoked favorable changes in the expression of target genes. Knockdown of miR-21a-5p resulted in dysregulation of lipid metabolism and increased expression of FABP7, HMGCR, ACAT1, and OLR1. While aerobic exercise could alleviate miR-21a-5p knock-down induced lipid metabolism disorder. Taken together, these results demonstrated that aerobic exercise improved hyperlipidemia through miR-21a-5p-induced inhibition of target genes FABP7, HMGCR, ACAT1, and OLR1.

MiR-337-3p lowers serum LDL-C level through targeting PCSK9 in hyperlipidemic mice

BACKGROUND

Reducing serum low-density lipoprotein cholesterol (LDL-C) in hyperlipemia is recognized as an effective strategy to minimize the risk of atherosclerotic cardiovascular disease (ASCVD). MiR-337-3p has already been discovered to play regulatory roles in tumor proliferation and metastasis, adipocyte browning and ischemic brain injury, etc. However, the association between miR-337-3p and LDL-C is unknown.

METHODS

Gene Expression Omnibus (GEO) dataset and two hyperlipidemic murine models were used to analyze the potential relationship between miR-337-3p and LDL-C. AAV-mediated liver-directed miRNA overexpression in high fat diet (HFD)-fed mouse model was used to examine the effect of miR-337-3p on LDL-C and WB/RT-PCR/ELISA/luciferase assays were used to investigate the underlying mechanism.

RESULTS

The expressions of miR-337-3p were obviously lower in multiple hyperlipidemic mouse models and had a negative correlation with serum LDL-C levels. After confirming the effect of miR-337-3p on the improvement of serum LDL-C in vivo, we discovered PCSK9 might be a possible target of miR-337-3p, which was further proved by in vitro experiments. MiR-337-3p could directly interact with both the PCSK9 3'UTR and promoter to inhibit PCSK9 translation and transcription. Furthermore, the result from DiI-LDL uptake assay under the knockdown of PCSK9 demonstrated that miR-337-3p promoting the absorption of LDL-C in HepG2 cells was dependent on PCSK9, and the result from LDLR-/- mouse model indicated that miR-337-3p regulating LDL-C was dependent on PCSK9/LDLR pathway.

CONCLUSION

We discovered a new function of miR-337-3p in regulating PCSK9 expression and LDL-C absorption, suggesting miR-337-3p might be a new therapeutic target for the development of antihyperlipidemic drug.

Clinical Significance of Heme Oxygenase 1 in Tumor Progression

Heme oxygenase 1 (HO-1) plays a key role in cell adaptation to stressors through the antioxidant, antiapoptotic, and anti-inflammatory properties of its metabolic products. For these reasons, in cancer cells, HO-1 can favor aggressiveness and resistance to therapies, leading to poor prognosis/outcome. Genetic polymorphisms of HO-1 promoter have been associated with an increased risk of cancer progression and a high degree of therapy failure. Moreover, evidence from cancer biopsies highlights the possible correlation between HO-1 expression, pathological features, and clinical outcome. Indeed, high levels of HO-1 in tumor specimens often correlate with reduced survival rates. Furthermore, HO-1 modulation has been proposed in order to improve the efficacy of antitumor therapies. However, contrasting evidence on the role of HO-1 in tumor biology has been reported. This review focuses on the role of HO-1 as a promising biomarker of cancer progression; understanding the correlation between HO-1 and clinical data might guide the therapeutic choice and improve the outcome of patients in terms of prognosis and life quality.

TFAP2A potentiates lung adenocarcinoma metastasis by a novel miR-16 family/TFAP2A/PSG9/TGF-β signaling pathway

Transcription factor AP-2α (TFAP2A) was previously regarded as a critical regulator during embryonic development, and its mediation in carcinogenesis has received intensive attention recently. However, its role in lung adenocarcinoma (LUAD) has not been fully elucidated. Here, we tried to investigate TFAP2A expression profiling, clinical significance, biological function and molecular underpinnings in LUAD. We proved LUAD possessed universal TFAP2A high expression, indicating a pervasively poorer prognosis in multiple independent datasets. Then we found TFAP2A was not indispensable for LUAD proliferation, and exogenous overexpression even caused repression. However, we found TFAP2A could potently promote LUAD metastasis possibly by triggering epithelial-mesenchymal transition (EMT) in vitro and in vivo. Furthermore, we demonstrated TFAP2A could transactivate Pregnancy-specific glycoprotein 9 (PSG9) to enhance transforming growth factor β (TGF-β)-triggering EMT in LUAD. Meanwhile, we discovered suppressed post-transcriptional silencing of miR-16 family upon TFAP2A partly contributed to TFAP2A upregulation in LUAD. In clinical specimens, we also validated cancer-regulating effect of miR-16 family/TFAP2A/PSG9 axis, especially for lymph node metastasis of LUAD. In conclusion, we demonstrated that TFAP2A could pivotally facilitate LUAD progression, possibly through a novel pro-metastasis signaling pathway (miR-16 family/TFAP2A/PSG9/ TGF-β).

MiR-204-5p/TFAP2A feedback loop positively regulates the proliferation, migration, invasion and EMT process in cervical cancer

MicroRNAs (MiRNAs) have been clarified as crucial regulators of the pathological processes in various carcinomas in the past years. Interestingly, existing evidence has manifested that microRNA-204-5p (miR-204-5p) is engaged in the initiation and progression of multiple carcinomas. However, the potential of miR-204-5p in cervical cancer remains to be disentombed. This study focused on unraveling the detailed role of miR-204-5p in cervical cancer. MiR-204-5p exhibited a low level in cervical cancer cells. The functional assays demonstrated that miR-204-5p upregulation exerted suppressive impact on the functions of cervical cancer cells, including proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) process. Moreover, transcription factor AP-2 alpha (TFAP2A) was screened to be the most affected target gene by miR-204-5p, and TFAP2A was discovered to transcriptionally repress miR-204-5p in cervical cancer. The mutual regulation between TFAP2A and miR-204-5p was testified through molecular mechanism assays. Final rescued-function assays demonstrated that overexpression of TFAP2A could recover the suppressed cellular process caused by miR-204-5p upregulation. In conclusion, miR-204-5p/TFAP2A feedback loop promoted the proliferative and motorial capacities of cervical cancer cells. This finding suggested a novel modulatory loop of miR-204-5p/TFAP2A in cervical cancer, offering promising biomarkers for cervical cancer therapy.

MiR-1254 and MEGF6 regulates oxaliplatin resistance in human colorectal cancer cells

Colorectal cancer (CRC) remains one of the deadliest diseases in the whole world. Cancer recurrence and chemotherapeutic drug resistance limit the overall survival rate of patients with CRC. This study aimed to discover the latent miRNAs and genes associated with oxaliplatin resistance in CRC cells. The study found that miR-1254 is upregulated in oxaliplatin-resistant CRC cell line HCT116-R compared with its parental cell line HCT116 by transcriptome sequencing and small RNA sequencing. Meanwhile, MEGF6 (multiple EGF-like domains 6) was downregulated in HCT116-R cells. Transient transfection of miR-1254 mimics significantly reduced cell apoptosis, increased HCT116 tolerance to oxaliplatin, and enhanced MEGF6 expression. Furthermore, transfection of miR-1254 inhibitor increased apoptosis, decreased HCT116-R tolerance to oxaliplatin, and reduced MEGF6 expression. In addition, transient transfection of SiMEGF6 enhanced HCT116 cell resistance to oxaliplatin and reduced cell apoptosis. In summary, MEGF6 is a latent functional target of miR-1254 in regulating oxaliplatin resistance and apoptosis in human CRC cells, suggesting a potential therapeutic target for CRC.

Upregulation of miR-1254 promotes Hepatocellular Carcinoma Cell Proliferation, Migration, and Invasion via Inactivation of the Hippo-YAP signaling pathway by decreasing PAX5

Increasing evidence suggests that microRNAs (miRNAs) affect the progression of hepatocellular carcinoma (HCC). However, the exact function and mechanism of miR-1254 in HCC remains unclear. This study explored the effects of miR-1254 on the biological behavior of HCC cells and determined the underlying mechanism. RT-qPCR was used to detect the expression of miR-1254. Gain- or loss-of-function assays determined if miR-1254 affected the biological function of HCC cells in vitro. Dual luciferase reporter assays confirmed the target gene of miR-1254. Tumor xenografts in mice were used to explore the effects of miR-1254 on tumorigenesis and metastasis of HCC. miR-1254 was upregulated in HCC tissues and cell lines and linked to larger tumor size, aggressive vascular invasion and higher Edmondson grade. Lentiviral-based overexpression and knockdown experiments indicated that miR-1254 promoted proliferation, migration, invasion, and the epithelial-mesenchymal transition of HCC cells. The paired box gene 5 (PAX5) was downregulated in HCC tissues, negatively correlated with miR-1254 expression, and confirmed to be a direct target of miR-1254. Restoration of PAX5 reversed the effects of miR-1254 on the biological behavior of HCC cells. Advanced mechanism studies suggested that PAX5 might mediate miR-1254 by regulating the Hippo signaling pathway. Tumor xenografts in mice confirmed that miR-1254 promoted tumorigenesis and metastasis, and led to poor survival. In conclusion, miR-1254 promoted proliferation, migration, and invasion of HCC cells via decreasing Hippo signaling through targeting PAX5 in vitro and in vivo. This miRNA might be a therapeutic target for HCC.

Natural Antioxidant and Anti-Inflammatory Compounds in Foodstuff or Medicinal Herbs Inducing Heme Oxygenase-1 Expression

Heme oxygenase-1 (HO-1) is an inducible antioxidant enzyme that catalyzes heme group degradation. Decreased level of HO-1 is correlated with disease progression, and HO-1 induction suppresses development of metabolic and neurological disorders. Natural compounds with antioxidant activities have emerged as a rich source of HO-1 inducers with marginal toxicity. Here we discuss the therapeutic role of HO-1 in obesity, hypertension, atherosclerosis, Parkinson's disease and hepatic fibrosis, and present important signaling pathway components that lead to HO-1 expression. We provide an updated, comprehensive list of natural HO-1 inducers in foodstuff and medicinal herbs categorized by their chemical structures. Based on the continued research in HO-1 signaling pathways and rapid development of their natural inducers, HO-1 may serve as a preventive and therapeutic target for metabolic and neurological disorders.

Silencing of lncRNA DLEU1 inhibits tumorigenesis of ovarian cancer via regulating miR-429/TFAP2A axis

Long non-coding RNAs (lncRNAs) are known as crucial regulators in the development of OC. In the current study, we aim to explore the function and molecular mechanism of lncRNA DLEU1 in OC. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to determine the expression of DLEU1, miR-429, and TFAP2A in OC cells and tissues. The relationship among DLEU1, miR-429, and TFAP2A was tested by dual-luciferase reporter (DLR) assay. Besides, the proliferative, migratory and invasive abilities of OC cells were analyzed by MTT, wound healing, and transwell assays, respectively. Western blot was performed to determine the protein expression of TFAP2A. The expression of lncRNA DLEU1 and TFAP2A were upregulated, and miR-429 was downregulated in OC tissues. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells. Bioinformation and DLR assay showed that DLEU1 acted as the sponge for miR-429. Moreover, miR-429 could directly target TFAP2A and inhibit the proliferation, migration, and invasion of OC cells. Moreover, we observed a negative correlation between miR-429 and DLEU1, and between miR-429 and TFAP2A in OC tissues. The transfection of miR-429 inhibitor or pcDNA-TFAP2A reversed the inhibitory effects of si-DLEU1 on the proliferation, migration, and invasion of OC cells. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells by regulating miR-429/TFAP2A axis, indicating a potential therapeutic target for OC.

Chromatin accessibility analysis reveals that TFAP2A promotes angiogenesis in acquired resistance to anlotinib in lung cancer cells

Anlotinib, a multitarget tyrosine kinase inhibitor, is effective as a third-line treatment against non-small cell lung cancer (NSCLC). However, acquired resistance occurs during its administration. To understand the molecular mechanisms of anlotinib resistance, we characterized chromatin accessibility in both the parental and anlotinib-resistant lung cancer cell line NCI-H1975 through ATAC-seq. Compared with the parental cells, we identified 2666 genomic regions with greater accessibility in anlotinib-resistant cells, in which angiogenesis-related processes and the motifs of 21 transcription factors were enriched. Among these transcription factors, TFAP2A was upregulated. TFAP2A knockdown robustly diminished tumor-induced angiogenesis and partially rescued the anti-angiogenic activity of anlotinib. Furthermore, transcriptome analysis indicated that 2280 genes were downregulated in anlotinib-resistant cells with TFAP2A knocked down, among which the PDGFR, TGF-β, and VEGFR signaling pathways were enriched. Meanwhile, we demonstrated that TFAP2A binds to accessible sites within BMP4 and HSPG2. Collectively, this study suggests that TFAP2A accelerates anlotinib resistance by promoting tumor-induced angiogenesis.

[Research Progress of Epigenetics in Pathogenesis and Treatment of Malignant Tumors]

表观遗传学修饰与肿瘤的发生发展密切相关，其主要通过DNA甲基化、组蛋白修饰、非编码RNA调控和染色质结构重构等方式对基因功能和表达水平进行调控，从而影响肿瘤的进展。目前针对表观遗传学的药物已经逐渐应用于恶性肿瘤的治疗，常见的药物类型包括DNA甲基转移酶抑制剂和组蛋白去乙酰化酶抑制剂，但此类药物仍存在诸多不足之处广泛的临床应用仍需要进一步的研究，令人鼓舞的是表观遗传药物与多种抗肿瘤药物联合应用已表现出巨大的应用潜力。本文就表观遗传学在恶性肿瘤的发生发展机制和相关药物的新进展进行了综述。

Regulation of Organic Anion Transporting Polypeptide 2B1 Expression by MicroRNA in the Human Liver

Organic anion transporting polypeptide 2B1 (OATP2B1, SLCO2B1) is an uptake transporter expressed in several tissues, including the liver, intestine, brain, kidney, and skeletal muscle. Hepatocyte nuclear factor 4 alpha (HNF4α) is known as an important transcriptional factor of OATP2B1 in the liver. It has been reported that there are large interindividual differences in OATP2B1 mRNA and protein expressions in human livers. The mechanism causing the interindividual differences in OATP2B1 expression is still unclear. MicroRNAs (miRNAs) control gene expression by leading translational repression and/or degradation of the target mRNA. There is no significant correlation between OATP2B1 mRNA and protein expression, suggesting that post-transcriptional regulating mechanisms, such as miRNAs, play an important role in the interindividual differences in OATP2B1 expression. In this study, we hypothesized that certain miRNAs cause the interindividual differences in OATP2B1 expression in the human liver. In silico analysis showed that miR-24 was a candidate miRNA regulating OATP2B1 expression. It has been reported that miR-24 degrades HNF4α mRNA expression. We revealed that the miR-24 expression level was negatively correlated with OATP2B1 mRNA, protein, and HNF4α mRNA expression levels in human livers. Transfection by the miR-24 precursor decreased the luciferase activity in the transfected cells with the vector containing the OATP2B1 3' untranslated region (3'UTR) or SLCO2B1 promoter region. In HepaRG cells, miR-24 decreased the OATP2B1 and HNF4α expression levels. These results suggest that miR-24 represses not only the translation of OATP2B1 but also the transcription of OATP2B1 by HNF4α mRNA degradation.

MiR-629-5p promotes the invasion of lung adenocarcinoma via increasing both tumor cell invasion and endothelial cell permeability

Tumor invasion underlies further metastasis, the leading cause for cancer-related deaths. Deregulation of microRNAs has been identified associated with the malignant behavior of various cancers, including lung adenocarcinoma (LUAD), the major subtype of lung cancer. Here, we showed the significantly positive correlation between miR-629-5p level and tumor invasion in LUAD specimens (n = 49). In a human LUAD metastasis mouse model, H1650 cells (high level of miR-629-5p) were more aggressive than A549 cells (low level of miR-629-5p) in vivo, including higher incidence of vascular invasion and pulmonary colonization. Ectopic expression of miR-629-5p in A549 cells also increased their invasive capability. Then we identified that miR-629-5p promotes LUAD invasion in a mode of dual regulation via tumor cells invasion and endothelial cells permeability, respectively. In tumor cells, miR-629-5p enhanced motility and invasiveness of tumor cells by directly targeting PPWD1 (a cyclophilin), which clinically related to tumor invasion in LUAD specimens. Restoring PPWD1 protein significantly attenuated the invasion-promoting effects of miR-629-5p. Besides, exosomal-miR-629-5p secreted from tumor cells could be transferred to endothelial cells and increased endothelial monolayers permeability by suppressing CELSR1 (a nonclassic-type cadherin), which had a low level in the endothelial cells of invasive LUAD specimens. Activating the expression of CELSR1 in endothelial cells markedly blocked the effect of miR-629-5p. Our study suggests the dual roles of miR-629-5p in tumor cells and endothelial cells for LUAD invasion, implying a therapeutic option to targeting miR-629-5p using the "one stone, two birds" strategy in LUAD.

MiR-1254 Functions as a Tumor Suppressor in Oral Squamous Cell Carcinoma by Targeting CD36

Oral squamous cell carcinoma is one of the most common cancers around the world. The patients with oral squamous cell carcinoma are often diagnosed at late stages, leading to unfavorable prognosis. MicroRNAs might function as oncogenes or tumor suppressor genes in the tumorigenesis of cancer. This study aimed to explore the role of miR-1254 in oral squamous cell carcinoma. We examined the expression levels of miR-1254 in oral squamous cell carcinoma tissue samples and cell line.Proliferation and invasion assays were performed in oral squamous cell carcinoma cells with miR-1254 overexpression or underexpression. The potential regulatory mechanisms were also explored. We found that miR-1254 was significantly reduced in oral squamous cell carcinoma tissues and cell lines. In addition, downregulation of miR-1254 in oral squamous cell carcinoma tumor tissues was closely associated with cancer staging and lymph node metastasis. Enforced expression of miR-1254 significantly inhibited proliferation and invasion in oral cancer cells, and downregulation of miR-1254 promoted the oncogenic activities of oral cancer cells. CD36 was identified as a direct downstream target of miR-1254 by the luciferase reporter assay. Overexpression of CD36 partially restored the proliferation and invasion capacity inhibited by miR-1254. CD36 expression was inversely correlated with miR-1254 expression in the oral squamous cell carcinoma tissues. Taken together, our study provided the compelling evidence that miR-1254 might inhibit the progression of OSCC by partially downregulating CD36, and restoration of miR-1254 may represent an effective strategy for treating oral squamous cell carcinoma.

The seasonal changes of the heme oxygenase in the retina pig

The eye is a very important organ in the human body which is affected by various external factors. One of these factors is the sunlight which can cause the visual impairment and as well as the increase in the oxidative stress. The heme oxygenase I (HO-1) plays a very important role in the fight against the oxidative stress. The HO enzyme catalyses the degradation of the heme to the ferrous iron, the biliverdin and the carbon monoxide (CO). The HO-2 is the isoform HO-1 and is mainly constitutively expressed. We have studied the changes in the HO-1 and the HO-2 in the retina on the level of the RNA and the protein in the summer and in the winter season (the biggest difference is in the length of the day light). The retina of the eye was obtained from the breeding pigs in concern (Sus scrofa f. domestica) posthumously. The expression of the HO-1 genes in the retina cells is higher in the winter and the amount of protein decreases. However, the HO enzyme concentration definitely increases in the summer, when the production of the free radicals (the oxidative stress) related to the exposition to the sunlight is greater. The obtained results suggest that various factors have the influence on the protein synthesis. One of the factors, can be the miRNA which blocks the synthesis of the HO. Another factors, influencing the HO are the biological clock, the sunlight and the UV radiation associated with it.

Highly Sensitive in Vitro Diagnostic System of Pandemic Influenza A (H1N1) Virus Infection with Specific MicroRNA as a Biomarker

Several microRNAs (miRNAs) have been reported to be closely related to influenza A virus infection, replication, and immune response. Therefore, the development of the infectious-disease detection system using miRNAs as biomarkers is actively underway. Herein, we identified two miRNAs (miR-181c-5p and miR-1254) as biomarkers for detection of pandemic influenza A H1N1 virus infection and proposed the catalytic hairpin assembly-based in vitro diagnostic (CIVD) system for a highly sensitive diagnosis; this system is composed of two sets of cascade hairpin probes enabling to detect miR-181c-5p and miR-1254. We demonstrated that CIVD kits could not only detect subnanomolar levels of target miRNAs but also distinguish even single-base mismatches. Moreover, this CIVD kit has shown excellent detection performance in real intracellular RNA samples and confirmed results similar to those of conventional methods (microarray and quantitative real-time polymerase chain reaction).

[Plasma miRNA-23a and miRNA-451 as candidate biomarkers for early diagnosis of nonsmall cell lung cancer: a case-control study]

OBJECTIVE

To study the value of plasma miRNA23-a and miRNA-451 as potential biomarkers for early diagnosis of non-small cell lung cancer (NSCLC).

METHODS

Fifty patients with NSCLC and 50 healthy control subjects were recruited for testing the plasma levels of miRNA23-a and miRNA-451 and their expression levels in the tumor tissues using qRT-PCR. The correlations of the plasma levels of miRNA23-a and miRNA-451 with their expressions in the tumor tissues were analyzed. The diagnostic power of CEA, miRNA23-a and miRNA-451 for NSCLC was evaluated using the receiver-operating characteristics (ROC) curves and the area under the ROC curves (AUC). In the NSCLC cell line A549, we tested the effect of inhibition of miRNA-23a and miRNA-451 on the expression levels of SPRY2 and MIF mRNA using qRT-PCR.

RESULTS

The expression levels of miRNA-23a and miRNA-451 in NSCLC tissues was significantly associated with smoking, tumor size, lymph node metastasis and TNM stage (P < 0.05). Compared with those in the control group, miRNA-23a level was significantly increased while miRNA-451 was significantly down-regulated in the tumor tissues and plasma of NSCLC patients. The plasma levels of miRNA-23a and miRNA-45 were strongly correlated with their expression levels in the tumor tissues. ROC analysis showed that for the diagnosis of NSCLC, the AUC, sensitivity and specificity of either miRNA-23a or miRNA-451 were significantly higher than those of CEA (P < 0.05). The combination of miRNA23-a and miRNA-451 markedly improved the AUC (0.900), sensitivity (78%) and specificity (86%) for the diagnosis. In A549 cells, inhibition of miRNA23-a and miRNA-451 resulted in significantly increased expression levels of SPRY2 mRNA and MIF mRNA, respectively.

CONCLUSIONS

miRNA-23a and miRNA-451 can be used as potential biomarkers for early diagnosis of NSCLC, and their combined detection can be more effective for the diagnosis.

How iron is handled in the course of heme catabolism: Integration of heme oxygenase with intracellular iron transport mechanisms mediated by poly (rC)-binding protein-2

Heme and iron are essential to almost all forms of life. The strict maintenance of heme and iron homeostasis is essential to prevent cellular toxicity and the existence of systemic and intracellular regulation is fundamental. Cytosolic heme can be catabolized and detoxified by heme oxygenases (HOs). Interestingly, free heme detoxification through HOs results in the production of free ferrous iron, which can be potentially hazardous for cells. Recently, the intracellular iron chaperone, poly (rC)-binding protein 2 (PCBP2), has been identified, which can be involved in accepting iron after heme catabolism as well as intracellular iron transport. In fact, HO1, NADPH-cytochrome P450 reductase, and PCBP2 form a functional unit that integrates the catabolism of heme with the binding and transport of iron by PCBP2. In this review, we provide an overview of our understanding of the iron chaperones and discuss the mechanism how iron chaperones bind iron released during the process of heme degradation.

The biological characteristics of transcription factors AP-2α and AP-2γ and their importance in various types of cancers

The Activator Protein 2 (AP-2) transcription factor (TF) family is vital for the regulation of gene expression during early development as well as carcinogenesis process. The review focusses on the AP-2α and AP-2γ proteins and their dualistic regulation of gene expression in the process of carcinogenesis. Both AP-2α and AP-2γ influence a wide range of physiological or pathological processes by regulating different pathways and interacting with diverse molecules, i.e. other proteins, long non-coding RNAs (lncRNA) or miRNAs. This review summarizes the newest information about the biology of two, AP-2α and AP-2γ, TFs in the carcinogenesis process. We emphasize that these two proteins could have either oncogenic or suppressive characteristics depending on the type of cancer tissue or their interaction with specific molecules. They have also been found to contribute to resistance and sensitivity to chemotherapy in oncological patients. A better understanding of molecular network of AP-2 factors and other molecules may clarify the atypical molecular mechanisms occurring during carcinogenesis, and may assist in the recognition of new diagnostic biomarkers.

Regulatory network of miRNA on its target: coordination between transcriptional and post-transcriptional regulation of gene expression

MicroRNAs (miRNAs) are a class of endogenous small noncoding RNAs that participate in a majority of biological processes via regulating target gene expression. The post-transcriptional repression through miRNA seed region binding to 3' UTR of target mRNA is considered as the canonical mode of miRNA-mediated gene regulation. However, emerging evidence suggests that other regulatory modes exist beyond the canonical mechanism. In particular, the function of intranuclear miRNA in gene transcriptional regulation is gradually revealed, with evidence showing their contribution to gene silencing or activating. Therefore, miRNA-mediated regulation of gene transcription not only expands our understanding of the molecular mechanism underlying miRNA regulatory function, but also provides new evidence to explain its ability in the sophisticated regulation of many bioprocesses. In this review, mechanisms of miRNA-mediated gene transcriptional and post-transcriptional regulation are summarized, and the synergistic effects among these actions which form a regulatory network of a miRNA on its target are particularly elaborated. With these discussions, we aim to emphasize the importance of miRNA regulatory network on target gene regulation and further highlight the potential application of the network mode in the achievement of a more effective and stable modulation of the target gene expression.

LncRNA DCST1-AS1 functions as a competing endogenous RNA to regulate FAIM2 expression by sponging miR-1254 in hepatocellular carcinoma

Long non-coding RNAs (lncRNAs) play important roles in a variety of tumours; however, their biological function and clinical significance in hepatocellular carcinoma (HCC) are still unclear. In the present study, the clinical significance, biological function and regulatory mechanisms of lncRNA DCST1-AS1 in HCC were investigated. Differential lncRNAs in HCC were identified based on The Cancer Genome Atlas (TCGA) database. The biological function and mechanism of DCST1-AS1 were studied in vitro and in vivo LncRNA DCST1-AS1 was highly expressed in HCC tissues, and the high expression of DCST1-AS1 was significantly correlated with larger tumours and shorter survival time. Moreover, DCST1-AS1 knockout significantly inhibited proliferation, promoted apoptosis and cycle arrest of HCC cells, and inhibited tumour growth in vivo According to functional analysis, DCST1-AS1 competitively bound miR-1254, thus blocking the silencing effect of miR-1254 on the target gene Fas apoptosis inhibitor 2 (FAIM2). A novel lncRNA DCST1-AS1 that functions as an oncogene in HCC was discovered. DCST1-AS1 up-regulates the expression of FAIM2 by up-regulating the expression of miR-1254, ultimately promoting the proliferation of HCC cells. This research provides new therapeutic targets for HCC.

miR-1254 inhibits cell proliferation, migration, and invasion by down-regulating Smurf1 in gastric cancer

Gastric cancer (GC) is one of the most frequent malignancies, and increasing evidence supports the contribution of microRNA (miRNAs) to cancer progression. miR-1254 has been confirmed to participate in the regulation of various cancers, while the function of miR-1254 in GC remains unknown. In this study, we investigated the role of miR-1254 in GC. The expression of miR-1254 was detected in human GC specimens and cell lines by miRNA RT-PCR. The effects of miR-1254 on GC proliferation were determined by CCK-8 proliferation assays, colony formation assays, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, and cell-cycle assays. The ability of migration and invasion was examined by transwell and wound-healing assay. Dual Luciferase reporter assay was used to validate the interaction of miR-1254 with its target gene. The xenograft mouse models were conducted to investigate the effects of miR-1254 in vivo. The signaling pathways and epithelial-mesenchymal transition (EMT)-related proteins were detected with western blot. The results showed that miR-1254 inhibited the proliferation, migration and invasion in vitro and suppressed tumorigenesis in vivo. Smurf1 was shown to be the direct target of miR-1254. Overexpressing Smurf1 could partially counteract the effects caused by miR-1254. Similarly, the effects of the miR-1254-inhibitor were also rescued by Smurf1-shRNA. Furthermore, we found that miR-1254 inhibited EMT and decreased the PI3K/AKT signaling pathway through downregulating Smurf1. In summary, overexpression of miR-1254 could suppress proliferation, migration, invasion, and EMT via PI3K/AKT signaling pathways by downregulation of Smurf1 in GC, which suggests a potential therapeutic target for GC.

Circulating miR-1254 predicts ventricular remodeling in patients with ST-Segment-Elevation Myocardial Infarction: A cardiovascular magnetic resonance study

Reliable noninvasive prognostic biomarkers for left ventricular (LV) remodeling in ST-segment elevation myocardial infarction (STEMI) are needed. This study aimed to evaluate a panel of circulating microRNAs (miRNAs) as biomarkers of LV remodeling using cardiovascular magnetic resonance (CMR). We prospectively evaluated patients with a first STEMI treated with primary percutaneous coronary intervention who underwent CMR imaging at 1 week and 6 months after STEMI (n = 70). miRNAs were measured using PCR-based technologies in plasma samples collected at admission. The associations between miRNAs and LV diastolic and systolic volumes, and ejection fraction at 6-months were estimated in adjusted models. Median age was 60 years, 71.4% were male. miR-1254 was significantly associated in univariate analyses. Patients in the highest tertile of miR-1254 exhibited lower values of LVEDVI and LVESVI and higher values of LVEF at 1 week. After comprehensive multivariate adjustment including clinical, CMR variables, hs-troponin-T and NT-proBNP, miRNA-1254 was associated with decreasing LVESVI (P = 0.006), and borderline negative associated with LVEDVI (P = 0.063) at 6-months. miR-1254 also exhibited a significant positive association with increasing LVEF during follow-up (P < 0.001). Plasma miRNA-1254 predicted changes in LV volumes and LVEF at 6 months after STEMI. The value of miR-1254 to inform tailored treatment selection and monitor ongoing efficacy deserves further investigation.

The interplay between critical transcription factors and microRNAs in the control of normal and malignant myelopoiesis

Myelopoiesis is a complex process driven by essential transcription factors, including C/EBPα, PU.1, RUNX1, KLF4 and IRF8. Together, these factors are critical for the control of myeloid progenitor cell expansion and lineage determination in the development of granulocytes and monocytes/macrophages. MicroRNAs (miRNAs) are expressed in a cell type and lineage specific manner. There is increasing evidence that miRNAs fine-tune the expression of hematopoietic lineage-specific transcription factors and drive the lineage decisions of hematopoietic progenitor cells. In this review, we discuss recently discovered self-activating and feed-back mechanisms in which transcription factors and miRNAs interact during myeloid cell development. Furthermore, we delineate how some of these mechanisms are affected in acute myeloid leukemia (AML) and how disrupted transcription factor-miRNA interplays contribute to leukemogenesis.

miR-33a-5p enhances the sensitivity of lung adenocarcinoma cells to celastrol by regulating mTOR signaling

MicroRNAs (miRNAs or miRs) have recently become a popular focus of cancer research due to their ability to act as oncogenes or tumor suppressors. In the present study, miR‑33a‑5p expression was identified to be downregulated in lung adenocarcinoma samples compared with normal, which suggested that miR‑33a‑5p may serve as a tumor suppressor gene. Transfection with miR‑33a‑5p mimics inhibited the proliferation and migration of A549 and LTEP‑a‑2 cells and increased cellular apoptosis. A luciferase reporter assay confirmed that miR‑33a‑5p targets the 3'‑untranslated region of the mechanistic target of rapamycin (mTOR) gene. mTOR expression was decreased in A549 and LTEP‑a‑2 cells treated with miR‑33a‑5p mimics, as well as the expression of its downstream effectors phosphorylated (p)‑p70 ribosomal protein S6 kinase (p70S6K) and p‑eukaryotic translation initiation factor 4E binding protein 1 (4EBP1). Following treatment with celastrol, miR‑33a‑5p expression was upregulated, and miR‑33a‑5p could enhance cellular sensitivity to celastrol. Western blot analysis revealed that the expression of mTOR, p‑p70S6K and p‑4EBP1 decreased following celastrol treatment. These results suggested that mTOR was involved in the mechanism by which miR‑33a‑5p enhanced the sensitivity of lung adenocarcinoma cells to celastrol. Furthermore, LTEP‑a‑2 cells were xenografted subcutaneously into nude mice, to examine the effect of celastrol and miR‑33a‑5p on the growth of LTEP‑a‑2 cells in vivo. The results demonstrated that tumor growth in the celastrol‑treated or miR‑33a‑5p‑treated group was attenuated compared with the control group. Notably, tumor growth in the combination treatment group was almost arrested after 2 weeks. In addition, celastrol upregulated the expression of miR‑33a‑5p, and high expression of miR‑33a‑5p inhibited mTOR and its downstream effectors. In summary, miR‑33a‑5p inhibited the proliferation of lung adenocarcinoma cells, enhanced the antitumor effect of celastrol, and improved sensitivity to celastrol by targeting mTOR in lung adenocarcinoma in vitro and in vivo.

Circulating microRNA-339-5p and -21 in plasma as an early detection predictors of lung adenocarcinoma

BACKGROUND

Many studies have shown that differentially expressed miRs in body fluids can serve as biomarkers in non-invasive detection of the cancers. However, the clinical significance of plasma miRs in the diagnosis of lung adenocarcinoma (LA) is still not clear. Therefore, we examined the LA-specific miRs in plasma, which could be utilized to diagnosis and monitor LA in routine clinical practice.

METHODS

Twenty-eight LA cases and twenty-eight healthy controls were recruited to our study. MiRs differential expression in plasma was measured by miRNA Microarray assay and revalidated by using qRT-PCR based absolute quantification methods The diagnostic power of circulating miRs in LA was evaluated using the receiver operating characteristics (ROC) curves and the area under the ROC curves (AUC).

RESULTS

Tumor tissues and plasma levels of miR-339-5p were significantly down-regulated in LA patients compared with those in the control group, whereas the levels of miR-21 in LA patients were significantly higher than control group. ROC analysis showed that miR-339-5p and miR-21 could distinguish LA patients from healthy controls with high AUC (0.900 and 0.880, respectively), sensitivity (0.821 and 0.821, respectively) and specificity (0.929 and 0.964, respectively). Importantly, the combination of miR-339-5p and miR-21 markedly improved AUC (0.963), sensitivity (0.929) and specificity (0.929).

CONCLUSION

Plasma miR-339-5p or miR-21 could serve as a potential biomarker for diagnosis of LA, however, the combination of miR-339-5p and miR-21 was more efficient for LA detection.