A novel miR-375-HOXB3-CDCA3/DNMT3B regulatory circuitry contributes to leukemogenesis in acute myeloid leukemia

Identifying CDCA3 as a pivotal biomarker for predicting outcomes and immunotherapy efficacy in pan-renal cell carcinoma

Background

Renal cell carcinoma (RCC) is a heterogeneous disease. Identifying effective biomarkers is crucial for improving prognostic accuracy and therapy outcomes. This study investigates cell division cycle-associated 3 (CDCA3) as a novel biomarker for prognostic assessment and immunotherapy response in RCC.

Methods

This study analyzed multi-omics data from The Cancer Genome Atlas (TCGA) for kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), and kidney chromophobe (KICH) subtypes to evaluate CDCA3 expression and its clinical implications. Functional enrichment and immune infiltration analyses were performed using bioinformatics tools gene set enrichment analysis (GSEA) and xCell. The prognostic value of CDCA3 was assessed through Cox regression and Kaplan-Meier survival analysis. Immunohistochemistry (IHC) was employed to confirm CDCA3 expression at the protein level in RCC samples.

Results

Higher CDCA3 expression correlated with poor survival outcomes and reduced response to programmed cell death protein 1 (PD-1) blockade therapies. Statistical analysis indicated that CDCA3 was an independent prognostic factor for poor survival in RCC. CDCA3 was consistently overexpressed in RCC tissues compared to normal tissues and was associated with adverse clinical features, including high Th2 cell infiltration and suppression of immune pathways.

Conclusions

CDCA3 is a promising biomarker for RCC, offering insights into the tumor's prognosis and potential response to immunotherapy. The strong association between CDCA3 expression and poor therapeutic outcomes suggests that CDCA3 could be targeted in future therapeutic strategies.

Role of HOX genes in cancer progression and their therapeutical aspects

HOX genes constitute a family of evolutionarily conserved transcription factors that play pivotal roles in embryonic development, tissue patterning, and cell differentiation. These genes are essential for the precise spatial and temporal control of body axis formation in vertebrates. In addition to their developmental functions, HOX genes have garnered significant attention for their involvement in various diseases, including cancer. Deregulation of HOX gene expression has been observed in numerous malignancies, where they can influence tumorigenesis, progression, and therapeutic responses. This review provides an overview of the diverse roles of HOX genes in development, disease, and potential therapeutic targets, highlighting their significance in understanding biological processes and their potential clinical implications.

Combined ultrasound endoscopy-guided fine-needle aspiration with DNA methylation of SHOX2 and RASSF1A genes to enhance the auxiliary diagnostic precision of pancreatic cancer

The purpose of this study was to assess the influence and the clinical effectiveness of the short stature homeobox 2 (SHOX2) and ras association domain family 1A (RASSF1A) genes by tissue sampling through ultrasound endoscopy-guided fine-needle aspiration (EUS-FNA) as auxiliary diagnostic tools for pancreatic cancer (PC). Methylation markers were detected in 96 patients using real-time fluorescence quantitative PCR (qPCR), and the performance of this diagnostic assay was compared with CA19-9, CEA, and puncture fluid-based exfoliative cytology using receiver operating characteristic curve (ROC) analysis. The PC group exhibited higher methylation rates for SHOX2, RASSF1A, and the combined assay of both genes compared to the control group (95.7 % vs. 54.0 %, 78.3 % vs. 36.0 %, and 73.9 % vs. 16.0 %, P < 0.05). The areas under the ROC curve (AUC) for CA19-9, CEA, liquid-based exfoliative cytology, SHOX2, RASSF1A, the combination of SHOX2 and RASSF1A, the combination assay with CEA, CA19-9, and liquid-based exfoliative cytology were 0.827, 0.692, 0.767, 0.770, 0.732, 0.870, 0.870, 0.933, and 0.900, respectively. Therefore, the methylation assay based on the combined SHOX2 and RASSF1A genes in EUS-FNA puncture fluid is more effective than using a single gene, liquid-based exfoliative cytology, or intravenous tumor markers for diagnosing PC. Combining the conventional marker CA19-9 enhances the diagnostic value, making it a promising approach to complement histology and cytology.

Sequential gene expression analysis of myelodysplastic syndrome transformation identifies HOXB3 and HOXB7 as the novel targets for mesenchymal cells in disease

BACKGROUND

Myelodysplastic syndrome (MDS) is known to arise through the pathogenic bone marrow mesenchymal stem cells (MSC) by interacting with hematopoietic stem cells (HSC). However, due to the strong heterogeneity of MDS patients, it is difficult to find common targets in studies with limited sample sizes. This study aimed to describe sequential molecular changes and identify biomarkers in MSC of MDS transformation.

METHODS

Multidimensional data from three publicly available microarray and TCGA datasets were analyzed. MDS-MSC was further isolated and cultured in vitro to determine the potential diagnostic and prognostic value of the identified biomarkers.

RESULTS

We demonstrated that normal MSCs presented greater molecular homogeneity than MDS-MSC. Biological process (embryonic skeletal system morphogenesis and angiogenesis) and pathways (p53 and MAPK) were enriched according to the differential gene expression. Furthermore, we identified HOXB3 and HOXB7 as potential causative genes gradually upregulated during the normal-MDS-AML transition. Blocking the HOXB3 and HOXB7 in MSCs could enhance the cell proliferation and differentiation, inhibit cell apoptosis and restore the function that supports hematopoietic differentiation in HSCs.

CONCLUSION

Our comprehensive study of gene expression profiling has identified dysregulated genes and biological processes in MSCs during MDS. HOXB3 and HOXB7 are proposed as novel surrogate targets for therapeutic and diagnostic applications in MDS.

Non-coding RNAs/DNMT3B axis in human cancers: from pathogenesis to clinical significance

Cancer is a complex disease with many contributing factors, and researchers have gained extensive knowledge that has helped them understand the diverse and varied nature of cancer. The altered patterns of DNA methylation found in numerous types of cancer imply that they may play a part in the disease's progression. The human cancer condition involves dysregulation of the DNA methyltransferase 3 beta (DNMT3B) gene, a prominent de novo DNA methyltransferase, and its abnormal behavior serves as an indicator for tumor prognosis and staging. The expression of non-coding RNAs (ncRNAs), which include microRNAs (miRNA), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), is critical in controlling targeted gene expression and protein translation and their dysregulation correlates with the onset of tumors. NcRNAs dysregulation of is a critical factor that influences the modulation of several cellular characteristics in cancerous cells. These characteristics include but are not limited to, drug responsiveness, angiogenesis, metastasis, apoptosis, proliferation, and properties of tumor stem cell. The reciprocal regulation of ncRNAs and DNMT3B can act in synergy to influence the destiny of tumor cells. Thus, a critical avenue for advancing cancer prevention and treatment is an inquiry into the interplay between DNMT3B and ncRNAs. In this review, we present a comprehensive overview of the ncRNAs/DNMT3B axis in cancer pathogenesis. This brings about valuable insights into the intricate mechanisms of tumorigenesis and provides a foundation for developing effective therapeutic interventions.

The Therapeutic Potential of a Strategy to Prevent Acute Myeloid Leukemia Stem Cell Reprogramming in Older Patients

Acute myeloid leukemia (AML) is the most common and incurable leukemia subtype. Despite extensive research into the disease's intricate molecular mechanisms, effective treatments or expanded diagnostic or prognostic markers for AML have not yet been identified. The morphological, immunophenotypic, cytogenetic, biomolecular, and clinical characteristics of AML patients are extensive and complex. Leukemia stem cells (LSCs) consist of hematopoietic stem cells (HSCs) and cancer cells transformed by a complex, finely-tuned interaction that causes the complexity of AML. Microenvironmental regulation of LSCs dormancy and the diagnostic and therapeutic implications for identifying and targeting LSCs due to their significance in the pathogenesis of AML are discussed in this review. It is essential to perceive the relationship between the niche for LSCs and HSCs, which together cause the progression of AML. Notably, methylation is a well-known epigenetic change that is significant in AML, and our data also reveal that microRNAs are a unique factor for LSCs. Multiple-targeted approaches to reduce the risk of epigenetic factors, such as the administration of natural compounds for the elimination of local LSCs, may prevent potentially fatal relapses. Furthermore, the survival analysis of overlapping genes revealed that specific targets had significant effects on the survival and prognosis of patients. We predict that the multiple-targeted effects of herbal products on epigenetic modification are governed by different mechanisms in AML and could prevent potentially fatal relapses. Thus, these strategies can facilitate the incorporation of herbal medicine and natural compounds into the advanced drug discovery and development processes achievable with Network Pharmacology research.

Targeting AXL in Mesothelioma: from functional characterization to clinical implication

Malignant pleural mesothelioma (MM) is a highly aggressive and lethal cancer with a poor survival rate. Current treatment approaches primarily rely on chemotherapy and radiation, but their effectiveness is limited. Consequently, there is an urgent need for alternative treatment strategies, a comprehensive understanding of the molecular mechanisms underlying MM, and the identification of potential therapeutic targets. Extensive studies over the past decade have emphasized the role of Axl in driving tumor development and metastasis, while high levels of Axl expression have been associated with immune evasion, drug resistance, and reduced patient survival in various cancer types. Ongoing clinical trials are investigating the efficacy of Axl inhibitors for different cancers. However, the precise role of Axl in MM progression, development, and metastasis, as well as its regulatory mechanisms within MM, remain inadequately understood. This review aims to comprehensively investigate the involvement of Axl in MM. We discuss Axl role in MM progression, development, and metastasis, along with its specific regulatory mechanisms. Additionally, we examined the Axl associated signaling pathways, the relationship between Axl and immune evasion, and the clinical implications of Axl for MM treatment. Furthermore, we discussed the potential utility of liquid biopsy as a non-invasive diagnostic technique for early detection of Axl in MM. Lastly, we evaluated the potential of a microRNA signature that targets Axl. By consolidating existing knowledge and identifying research gaps, this review contributes to a better understanding of Axl's role in MM and sets the stage for future investigations and the development of effective therapeutic interventions.

Crosstalk between Noncoding RNAs and the Epigenetics Machinery in Pediatric Tumors and Their Microenvironment

According to the World Health Organization, every year, an estimated 400,000+ new cancer cases affect children under the age of 20 worldwide. Unlike adult cancers, pediatric cancers develop very early in life due to alterations in signaling pathways that regulate embryonic development, and environmental factors do not contribute much to cancer development. The highly organized complex microenvironment controlled by synchronized gene expression patterns plays an essential role in the embryonic stages of development. Dysregulated development can lead to tumor initiation and growth. The low mutational burden in pediatric tumors suggests the predominant role of epigenetic changes in driving the cancer phenotype. However, one more upstream layer of regulation driven by ncRNAs regulates gene expression and signaling pathways involved in the development. Deregulation of ncRNAs can alter the epigenetic machinery of a cell, affecting the transcription and translation profiles of gene regulatory networks required for cellular proliferation and differentiation during embryonic development. Therefore, it is essential to understand the role of ncRNAs in pediatric tumor development to accelerate translational research to discover new treatments for childhood cancers. This review focuses on the role of ncRNA in regulating the epigenetics of pediatric tumors and their tumor microenvironment, the impact of their deregulation on driving pediatric tumor progress, and their potential as effective therapeutic targets.

Bioinformatics analysis of prognosis and immune microenvironment of immunological cell death-related gemcitabine-resistance genes in bladder cancer

Background

Bladder cancer (BC) is the most common malignant tumor of the urinary system. Gemcitabine resistance partly accounts for treatment failure and recurrence in BC. Immunological cell death (ICD) is correlated with chemoresistance. The prognosis of patients with similar tumor stage still varies in response to chemotherapy, recurrence, and disease progression. Therefore, our study aimed to provide a prognostic model based on ICD-related and gemcitabine-resistance genes for BC.

Methods

The data of BC patients were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs), and differentially expressed gemcitabine resistance-related genes (DEGRRGs) were identified using the edgeR package. The survival-associated DEGRRGs were identified by univariate Cox analysis. A prognostic model was established by univariate Cox regression analysis and validated by GEO dataset. The outcome of low-risk group and high-risk group was analyzed by the Kaplan-Meier curve. The relationship between risk score and immune cell infiltration was investigated using the TIMER online database.

Results

The prognosis of patients in the ICD-high group was significantly better than ICD-low group. A prognostic model containing 5 gemcitabine resistance-related ICD-associated genes, including PTPRR, HOXB3, SIGLEC15, UNC5CL, and CASQ1, was established. In both TCGA prognostic model and GEO validation model, patients in the low-risk group had better outcomes than high-risk group. According to the receiver operating characteristic (ROC) curves, the risk score area under ROC curve (AUC) of the TCGA prognostic model were calculated to be 0.705, while the risk score of the GEO validation model were calculated to be 0.716. Patients in the high-risk group had a significantly higher immune score, stromal score, and infiltration of M0 macrophages, M1 macrophages, M2 macrophages, and activated CD4⁺ T cells. Patients in the high-risk group had significantly lower infiltration of the regulatory T cells, resting dendritic cell (DCs), and activated DCs.

Conclusions

The present study highlighted the functional role of gemcitabine resistance-related ICD-associated genes, constructed a prognostic score for the outcome evaluation and searched for potential targets to overcome gemcitabine chemoresistance in BC.

Advancements on the Multifaceted Roles of Sphingolipids in Hematological Malignancies

Dysregulation of sphingolipid metabolism plays a complex role in hematological malignancies, beginning with the first historical link between sphingolipids and apoptosis discovered in HL-60 leukemic cells. Numerous manuscripts have reviewed the field including the early discoveries that jumpstarted the studies. Many studies discussed here support a role for sphingolipids, such as ceramide, in combinatorial therapeutic regimens to enhance anti-leukemic effects and reduce resistance to standard therapies. Additionally, inhibitors of specific nodes of the sphingolipid pathway, such as sphingosine kinase inhibitors, significantly reduce leukemic cell survival in various types of leukemias. Acid ceramidase inhibitors have also shown promising results in acute myeloid leukemia. As the field moves rapidly, here we aim to expand the body of literature discussed in previously published reviews by focusing on advances reported in the latter part of the last decade.

Cell Division Cycle-Associated Protein 3 (CDCA3) Is a Potential Biomarker for Clinical Prognosis and Immunotherapy in Pan-Cancer

CDCA3 is an essential regulator in cell mitosis and can regulate many physiological and pathological processes in the human body by stimulating certain proteins such as cell cycle regulatory proteins, transcription factors, and signal transduction molecules. Although several studies have shown that dysregulation of CDCA3 is a common phenomenon in human cancers, no systematic pan-cancer analysis has been performed. In this study, we comprehensively investigated the role of CDCA3 in 33 human cancer types by utilizing multiple cancer-related databases and bioinformatics analysis tools, including TCGA, GTEx, GEPIA, TIMER, STRING, Metascape, and Cytoscape. Evidence from bioinformatics databases shows that CDCA3 is overexpressed in almost all human cancer types, and its overexpression is significantly associated with survival in patients with more than ten cancer types. CDCA3 expression positively correlates with immune cell infiltration levels in multiple human cancer types. Furthermore, the results of the GSEA analysis revealed that overexpression of CDCA3 may promote the malignant progression of cancer by activating various oncogenic signaling pathways in human cancers. In conclusion, our pan-cancer analysis provides a comprehensive overview of the oncogenic role of CDCA3 in multiple human cancer types, suggesting that CDCA3 may serve as a potential therapeutic target and prognostic biomarker in multiple human cancer types.

Suppression of CDCA3 inhibits prostate cancer progression via NF‑κB/cyclin D1 signaling inactivation and p21 accumulation

Dysregulation of the cell cycle contributes to tumor progression. Cell division cycle‑associated 3 (CDCA3) is a known trigger of mitotic entry and has been demonstrated to be constitutively upregulated in tumors. It is therefore associated with carcinogenic properties reported in various cancers. However, the role of CDCA3 in prostate cancer is unclear. In the present study, western blotting and analysis of gene expression profiling datasets determined that CDCA3 expression was upregulated in prostate cancer and was associated with a poor prognosis. CDCA3 knockdown in DU145 and PC‑3 cells led to decreased cell proliferation and increased apoptosis, with increased protein expression levels of cleaved‑caspase3. Further experiments demonstrated that downregulated CDCA3 expression levels induced G0/G1 phase arrest, which was attributed to increased p21 protein expression levels and decreased cyclin D1 expression levels via the regulation of NF‑κB signaling proteins (NFκB‑p105/p50, IKKα/β, and pho‑NFκB‑p65). In conclusion, these results indicated that CDCA3 may serve a crucial role in prostate cancer and consequently, CDCA3 knockdown may be used as a potential therapeutic target.

Extracellular Vesicle-Encapsulated MicroRNA-375 from Bone Marrow-Derived Mesenchymal Stem Cells Inhibits Hepatocellular Carcinoma Progression through Regulating HOXB3-Mediated Wnt/β-Catenin Pathway

Nowadays, microRNA-375 (miR-375) has been implicated in many types of cancers, including hepatocellular carcinoma (HCC), and the functions of miRNAs encapsulated by extracellular vesicles (EV) in HCC progression have also been extensively investigated. In this research, we aimed to probe into the mechanism of EV-encapsulated miR-375 from bone marrow-derived mesenchymal stem cells (BM-MSCs) in HCC progression. At first, miR-375 expression in HCC tissues and cells was detected using RT-qPCR, and miR-375 was overexpressed to specify the effects of miR-375 on the malignant phenotype of HCC cells. miR-375 was downregulated in HCC, and overexpression of miR-375 suppressed HCC cell growth. Then, BM-MSCs and EV were isolated and identified, and, EV were cocultured with HCC cells for further functional assays. It was found that miR-375 encapsulated by EV could restrict the malignant phenotypes of HCC cells. Furthermore, the downstream genes and signaling cascades involved in HCC growth were investigated. HOXB3 was determined to be a downstream target of miR-375, and upregulation of miR-375 decreased Wnt1 and β-catenin protein expression. Furthermore, HOXB3 blocked the repressive effects of miR-375 on HCC cells and Wnt1 and β-catenin expression. This study highlights that miR-375 encapsulated by EV inhibits HCC development via modulating the HOXB3/Wnt/β-catenin axis.

miR-370 is better than miR-375 as a non-invasive diagnostic biomarker for pediatric acute myeloid leukemia patients

BACKGROUND: Acute myeloid leukemia (AML) is characterized by heterogeneity in phenotypic, genotypic, and clinical traits. miRNAs play an important role in pathogenesis and diagnosis of adult AML. Such information is not available about miRNA expression role in pediatric AML. OBJECTIVE: We aimed to investigate the expression of miR-370 and miR-375 as new diagnostic biomarkers to discriminate pediatric AML patients and to predict their roles in the disease molecular basis. METHODS: The expression of both miR-370 and miR-375 in peripheral blood (PB) of pediatric AML patients was assessed by QPCR; their impact for diagnosis was evaluated by ROC curve and their roles in pediatric AML development were predicted by bioinformatics analysis. RESULTS: The expression of miR-370 and miR-375 levels were significantly decreased in pediatric AML patients, suggesting them as tumor suppressor miRNAs as supported by bioinformatics analysis. MiR-370 showed better potential and sensitivity toscreen pediatric AML patients and more significant correlation with AML risk than miR-375. This is the first study to report the positive correlation between both miR-370 and miR-375. CONCLUSION: miR-370 level in peripheral blood can serve as a potential non-invasive diagnostic biomarker and was significantly correlated with AML risk. We strongly recommend PB miRNAs as diagnostic biomarkers for pediatric AML.

Comparative Gene Expression Analysis Reveals Similarities and Differences of Chronic Myeloid Leukemia Phases

Chronic myeloid leukemia (CML) is a slowly progressing blood cancer that primarily affects elderly people. Without successful treatment, CML progressively develops from the chronic phase through the accelerated phase to the blast crisis, and ultimately to death. Nowadays, the availability of targeted tyrosine kinase inhibitor (TKI) therapies has led to long-term disease control for the vast majority of patients. Nevertheless, there are still patients that do not respond well enough to TKI therapies and available targeted therapies are also less efficient for patients in accelerated phase or blast crises. Thus, a more detailed characterization of molecular alterations that distinguish the different CML phases is still very important. We performed an in-depth bioinformatics analysis of publicly available gene expression profiles of the three CML phases. Pairwise comparisons revealed many differentially expressed genes that formed a characteristic gene expression signature, which clearly distinguished the three CML phases. Signaling pathway expression patterns were very similar between the three phases but differed strongly in the number of affected genes, which increased with the phase. Still, significant alterations of MAPK, VEGF, PI3K-Akt, adherens junction and cytokine receptor interaction signaling distinguished specific phases. Our study also suggests that one can consider the phase-wise CML development as a three rather than a two-step process. This is in accordance with the phase-specific expression behavior of 24 potential major regulators that we predicted by a network-based approach. Several of these genes are known to be involved in the accumulation of additional mutations, alterations of immune responses, deregulation of signaling pathways or may have an impact on treatment response and survival. Importantly, some of these genes have already been reported in relation to CML (e.g., AURKB, AZU1, HLA-B, HLA-DMB, PF4) and others have been found to play important roles in different leukemias (e.g., CDCA3, RPL18A, PRG3, TLX3). In addition, increased expression of BCL2 in the accelerated and blast phase indicates that venetoclax could be a potential treatment option. Moreover, a characteristic signaling pathway signature with increased expression of cytokine and ECM receptor interaction pathway genes distinguished imatinib-resistant patients from each individual CML phase. Overall, our comparative analysis contributes to an in-depth molecular characterization of similarities and differences of the CML phases and provides hints for the identification of patients that may not profit from an imatinib therapy, which could support the development of additional treatment strategies.

Homeobox Genes in Cancers: From Carcinogenesis to Recent Therapeutic Intervention

The homeobox (HOX) genes encoding an evolutionarily highly conserved family of homeodomain-containing transcriptional factors are essential for embryogenesis and tumorigenesis. HOX genes are involved in cell identity determination during early embryonic development and postnatal processes. The deregulation of HOX genes is closely associated with numerous human malignancies, highlighting the indispensable involvement in mortal cancer development. Since most HOX genes behave as oncogenes or tumor suppressors in human cancer, a better comprehension of their upstream regulators and downstream targets contributes to elucidating the function of HOX genes in cancer development. In addition, targeting HOX genes may imply therapeutic potential. Recently, novel therapies such as monoclonal antibodies targeting tyrosine receptor kinases, small molecular chemical inhibitors, and small interfering RNA strategies, are difficult to implement for targeting transcriptional factors on account of the dual function and pleiotropic nature of HOX genes-related molecular networks. This paper summarizes the current state of knowledge on the roles of HOX genes in human cancer and emphasizes the emerging importance of HOX genes as potential therapeutic targets to overcome the limitations of present cancer therapy.

MicroRNA-375: potential cancer suppressor and therapeutic drug

MiR-375 is a conserved noncoding RNA that is known to be involved in tumor cell proliferation, migration, and drug resistance. Previous studies have shown that miR-375 affects the epithelial-mesenchymal transition (EMT) of human tumor cells via some key transcription factors, such as Yes-associated protein 1 (YAP1), Specificity protein 1 (SP1) and signaling pathways (Wnt signaling pathway, nuclear factor κB (NF-κB) pathway and transforming growth factor β (TGF-β) signaling pathway) and is vital for the development of cancer. Additionally, recent studies have identified microRNA (miRNA) delivery system carriers for improved in vivo transportation of miR-375 to specific sites. Here, we discussed the role of miR-375 in different types of cancers, as well as molecular mechanisms, and analyzed the potential of miR-375 as a molecular biomarker and therapeutic target to improve the efficiency of clinical diagnosis of cancer.

Identification of 5-methylcytosine-related signature for predicting prognosis in ovarian cancer

BACKGROUND

Ovarian cancer is one of the most common malignancies often resulting in a poor prognosis. 5-methylcytosine (m5C) is a common epigenetic modification with roles in eukaryotes. However, the expression and function of m5C regulatory factors in ovarian cancer remained unclear.

RESULTS

Two molecular subtypes with different prognostic and clinicopathological features were identified based on m5C regulatory factors. Meanwhile, functional annotation showed that in the two subtypes, 452 differentially expressed genes were significantly related to the malignant progression of ovarian cancer. Subsequently, four m5C genes were screened to construct a risk marker predictive of overall survival and indicative of clinicopathological features of ovarian cancer, also the robustness of the risk marker was verified in external dataset and internal validation set. multifactorial cox regression analysis and nomogram demonstrated that risk score was an independent prognostic factor for ovarian cancer prognosis.

CONCLUSION

In conclusion, our results revealed that m5C-related genes play a critical role in tumor progression in ovarian cancer. Further detection of m5C methylation could provide a novel targeted therapy for treating ovarian cancer.

LncRNA VPS9D1-AS1 promotes cell proliferation in acute lymphoblastic leukemia through modulating GPX1 expression by miR-491-5p and miR-214-3p evasion

Alterations in messenger RNAs (mRNAs) of protein-coding genes can influence the malignant behaviors of acute lymphoblastic leukemia (ALL) cells. According to the prediction from The Cancer Genome Atlas (TCGA) database, we discovered that glutathione peroxidase 1 (GPX1) was up-regulated in acute myeloid leukemia (LAML) tissues, which pushed us to explore the feasible role and its related modulatory mechanism of GPX1 in ALL. In this research, we first proved the high expression of GPX1 in ALL cells compared with normal cells. Functional assays further revealed that the proliferation was obstructed and the apoptosis was facilitated in ALL cells with silenced GPX1. Then, both miR-491-5p and miR-214-3p that were down-regulated in ALL cells were affirmed to target GPX1. Subsequently, VPS9D1 antisense RNA 1 (VPS9D1-AS1) was recognized as the upstream regulator of miR-491-5p-miR-214-3p/GPX1 axis in a competing endogenous RNA (ceRNA) model. Importantly, we proved that VPS9D1-AS1 served as a tumor promoter in ALL through elevating GPX1. In conclusion, VPS9D1-AS1 contributed to ALL cell proliferation through miR-491-5p-miR-214-3p/GPX1 axis, hinting an optional choice for the treatment of ALL.

MiR-375: A novel multifunctional regulator

MiR-375, a primitively described beta cell-specific miRNA, is confirmed to function as multi-functional regulator in diverse typical cellular pathways according to the follow-up researches. Based on the existing studies, miR-375 can regulate many functional genes and ectopic expressions of miR-375 are usually associated with pathological changes, and its expression regulation mechanism is mainly related to promoter methylation or circRNA. In this review, the regulatory functions of miR-375 in immunity, such as its relevance with macrophages, T helper cells and autoimmune diseases were briefly discussed. Also, the functions of miR-375 involved in inflammation, development and virus replication were reviewed. Finally, the mechanisms and application prospects of miR-375 in cancers were analyzed. Studies show that the application of miR-375 as therapeutic target and biomarker has a broad developing space in future. We hope this paper can provide reference for its further study.

LncRNA SNHG5 upregulation induced by YY1 contributes to angiogenesis via miR-26b/CTGF/VEGFA axis in acute myelogenous leukemia

Acute myelogenous leukemia (AML) is the most common acute leukemia in adults. Despite great progress has been made in this field, the pathogenesis of AML is still not fully understood. We report here the biological role of lncRNA small nucleolar RNA host gene 5 (SNHG5) in the pathogenesis of AML and the underlying mechanisms. The results showed that lncRNA SNHG5 was highly expressed in AML cancer cell lines. In vitro studies displayed that inhibition of SNHG5 with shRNA resulted in suppression of survival, cell cycle progression, migration/invasion of AML and capacity of adhesion and angiogenesis in human umbilical vein endothelial cells. Mechanistic studies revealed a SNHG5/miR-26b/connective tissue growth factor (CTGF)/vascular endothelial growth factor A (VEGFA) axis in the regulation of AML angiogenesis. Finally, Yin Yang 1 (YY1) was found to transactivate and interact with SNHG5 promoter, leading to the upregulation of SNHG5 in AML. Collectively, upregulation of lncRNA SNHG5 mediated by YY1, activates CTGF/VEGFA via targeting miR-26b to regulate angiogenesis of AML. Our work provides new insights into the molecular mechanisms of AML.

CDCA3 Is a Novel Prognostic Biomarker Associated with Immune Infiltration in Hepatocellular Carcinoma

Cell division cycle-associated protein-3 (CDCA3) contributes to the regulation of the cell cycle. CDCA3 plays an important role in the carcinogenesis of various cancers; however, the association between CDCA3 expression, prognosis of patients, and immune infiltration in the tumor microenvironment is still unknown. Here, we demonstrated that CDCA3 was differentially expressed between the tumor tissues and corresponding normal tissues using in silico analysis in the ONCOMINE and Tumor Immune Estimation Resource (TIMER) databases. We analyzed the relationship between the expression of CDCA3 and prognosis of patients with hepatocellular carcinoma (HCC) using the Kaplan-Meier plotter database and Gene Expression Profiling Interactive Analysis (GEPIA). Furthermore, we determined the prognostic value of CDCA3 expression using univariate and multivariate analyses. We observed that CDCA3 expression closely correlated with immune infiltration and gene markers of infiltrating immune cells in the TIMER database. CDCA3 was highly expressed in the tumor tissues than in the adjacent normal tissues in various cancers, including HCC. Increased expression of CDCA3 was accompanied by poorer overall survival (OS), relapse-free survival (RFS), progression-free survival (PFS), and disease-specific survival (DSS). The correlation between CDCA3 expression and OS and disease-free survival (DFS) was also studied using GEPIA. CDCA3 expression was associated with the levels of immune cell infiltration and was positively correlated with tumor purity. Moreover, CDCA3 expression was associated with gene markers such as PD-1, CTLA4, LAG3, and TIM-3 from exhausted T cells, CD3D, CD3E, and CD2 from T cells, and TGFB1 and CCR8 located on the surface of Tregs. Thus, we demonstrated that CDCA3 may be a potential target and biomarker for the management and diagnosis of HCC.

Function of Deptor and its roles in hematological malignancies

Deptor is a protein that interacts with mTOR and that belongs to the mTORC1 and mTORC2 complexes. Deptor is capable of inhibiting the kinase activity of mTOR. It is well known that the mTOR pathway is involved in various signaling pathways that are involved with various biological processes such as cell growth, apoptosis, autophagy, and the ER stress response. Therefore, Deptor, being a natural inhibitor of mTOR, has become very important in its study. Because of this, it is important to research its role regarding the development and progression of human malignancies, especially in hematologic malignancies. Due to its variation in expression in cancer, it has been suggested that Deptor can act as an oncogene or tumor suppressor depending on the cellular or tissue context. This review discusses recent advances in its transcriptional and post-transcriptional regulation of Deptor. As well as the advances regarding the activities of Deptor in hematological malignancies, its possible role as a biomarker, and its possible clinical relevance in these malignancies.

Loss of HOXB3 correlates with the development of hormone receptor negative breast cancer

Background

The homeobox gene family, encoding a specific nuclear protein, is essential for embryonic development, differentiation, and homeostasis. The role of the HOXB3 protein varies in different tumors. This study aims to explore the role of the HOXB3 gene in breast cancer.

Method

Differentially expressed genes were screened by analyzing metastatic breast cancer gene chip data from TCGA and GEO databases. The function of the selected HOXB3 gene was also analyzed in different databases and through molecular biology methods, such as qRT-PCR, western blot and IF to verify bioinformatics findings.

Results

Both bioinformatics analyses and western blot showed that HOXB3 was lost in breast cancer compared to normal breast tissue. Survival analysis also showed that lower expression of HOXB3 was associated with poor prognosis. Bioinformatics analyses further showed that HOXB3 was positively correlated with hormone receptors. Metascape for GO analysis of GEO data provided possible mechanisms that HOXB3 could positively regulate cell adhesion, inhibit cell proliferation and activate immune response in breast cancer; moreover, GSEA included several cancer-associated pathways.

Conclusion

In summary, HOXB3 expression was decreased in breast cancer, and it was associated with poor prognosis. It might become a new biomarker to predict prognosis of breast cancer.

Circ_0001421 facilitates glycolysis and lung cancer development by regulating miR-4677-3p/CDCA3

BACKGROUND

Lung cancer (LC) is a malignant tumor originating in the bronchial mucosa or gland of the lung. Circular RNAs (circRNAs) are proved to be key regulators of tumor progression. However, the regulatory effect of circ_0001421 on lung cancer tumorigenesis remains unclear.

METHODS

The expression levels of circ_0001421, microRNA-4677-3p (miR-4677-3p) and cell division cycle associated 3 (CDCA3) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Methyl thiazolyl tetrazolium (MTT), Transwell and Tumor formation assays were performed to explore the role of circ_0001421 in LC. Glucose consumption and lactate production were examined by a Glucose assay kit and a Lactic Acid assay kit. Western blot was utilized to examine the protein levels of Hexokinase 2 (HK2) and CDCA3. The interaction between miR-4677-3p and circ_0001421 or CDCA3 was confirmed by dual-luciferase reporter assay.

RESULTS

Circ_0001421 was increased in LC tissues and cells, and knockdown of circ_0001421 repressed cell proliferation, migration, invasion and glycolysis in vitro. Meanwhile, circ_0001421 knockdown inhibited LC tumor growth in vivo. Mechanistically, circ_0001421 could bind to miR-4677-3p, and CDCA3 was a target of miR-4677-3p. Rescue assays manifested that silencing miR-4677-3p or CDCA3 overexpression reversed circ_0001421 knockdown-mediated suppression on cell proliferation, migration, invasion and glycolysis in LC cells.

CONCLUSION

Circ_0001421 promoted cell proliferation, migration, invasion and glycolysis in LC by regulating the miR-4677-3p/CDCA3 axis, which providing a new mechanism for LC tumor progression.

Identification of Acute Myeloid Leukemia Bone Marrow Circulating MicroRNAs

BACKGROUND

In addition to their roles in different biological processes, microRNAs in the tumor microenvironment appear to be potential diagnostic and prognostic biomarkers for various malignant diseases, including acute myeloid leukemia (AML). To date, no screening of circulating miRNAs has been carried out in the bone marrow compartment of AML. Accordingly, we investigated the circulating miRNA profile in AML bone marrow at diagnosis (AMLD) and first complete remission post treatment (AMLPT) in comparison to healthy donors (HD).

METHODS

Circulating miRNAs were isolated from AML bone marrow aspirations, and a low-density TaqMan miRNA array was performed to identify deregulated miRNAs followed by quantitative RT-PCR to validate the results. Bioinformatic analysis was conducted to evaluate the diagnostic and prognostic accuracy of the highly and significantly identified deregulated miRNA(s) as potential candidate biomarker(s).

RESULTS

We found several deregulated miRNAs between the AMLD vs. HD vs. AMLPT groups, which were involved in tumor progression and immune suppression pathways. We also identified significant diagnostic and prognostic signatures with the ability to predict AML patient treatment response.

CONCLUSIONS

This study provides a possible role of enriched circulating bone marrow miRNAs in the initiation and progression of AML and highlights new markers for prognosis and treatment monitoring.

miR-550-1 functions as a tumor suppressor in acute myeloid leukemia via the hippo signaling pathway

MicroRNAs (miRNAs) and N⁶-methyladenosine (m⁶A) are known to serve as key regulators of acute myeloid leukemia (AML). Our previous microarray analysis indicated miR-550-1 was significantly downregulated in AML. The specific biological roles of miR-550-1 and its indirect interactions and regulation of m⁶A in AML, however, remain poorly understood. At the present study, we found that miR-550-1 was significantly down-regulated in primary AML samples from human patients, likely owing to hypermethylation of the associated CpG islands. When miR-550-1 expression was induced, it impaired AML cell proliferation both in vitro and in vivo, thus suppressing tumor development. When ectopically expressed, miR-550-1 drove the G0/1 cell cycle phase arrest, differentiation, and apoptotic death of affected cells. We confirmed mechanistically that WW-domain containing transcription regulator-1 (WWTR1) gene was a downstream target of miR-550-1. Moreover, we also identified Wilms tumor 1-associated protein (WTAP), a vital component of the m⁶A methyltransferase complex, as a target of miR-550-1. These data indicated that miR-550-1 might mediate a decrease in m⁶A levels via targeting WTAP, which led to a further reduction in WWTR1 stability. Using gain- and loss-of-function approaches, we were able to determine that miR-550-1 disrupted the proliferation and tumorigenesis of AML cells at least in part via the direct targeting of WWTR1. Taken together, our results provide direct evidence that miR-550-1 acts as a tumor suppressor in the context of AML pathogenesis, suggesting that efforts to bolster miR-550-1 expression in AML patients may thus be a viable clinical strategy to improve patient outcomes.

Levels of serum Hoxb3 and sFlt-1 in pre-eclamptic patients and their effects on pregnancy outcomes

AIM

We aimed to explore a new approach and theoretical basis for the diagnosis, treatment and prognosis of pre-eclampsia.

METHODS

In total, 103 pre-eclamptic patients (study group: SG) and 100 healthy pregnant women (control group: CG) were enrolled. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression level of serum Hoxb3. Enzyme-linked immunosorbent assay was used to detect the content of serum sFlt-1. Pregnancy outcomes in the two groups were recorded, and the correlations of the levels of Hoxb3 and sFlt-1 with the pregnancy outcomes were analyzed.

RESULTS

The relative expression of serum Hoxb3 mRNA in the CG was significantly higher than that in the SG, whereas the content of serum sFlt-1 in the CG was significantly lower than that in the SG. Compared with the CG, the SG had a significantly lower number of spontaneous deliveries, higher number of cesarean deliveries and significantly higher number of uneventful perinatal births. The incidences of intrauterine growth restriction, intrauterine distress, premature infants and neonatal deaths in perinatal infants in the SG were significantly higher than those in the CG. According to the analysis of receiver operating characteristic curves, the areas under the curves of Hoxb3, sFlt-1 and their combined detection for diagnosing pre-eclampsia were 0.799, 0.856 and 0.930, respectively. The areas under the curves for predicting poor perinatal outcomes were 0.724, 0.828 and 0.871, respectively.

CONCLUSION

In conclusion, Hoxb3 and sFlt-1 have certain reference significance for the risk evaluation of pre-eclampsia and the adverse pregnancy outcomes of pre-eclampsia women.

The DNA methylation landscape of hematological malignancies: an update

The rapid advances in high-throughput sequencing technologies have made it more evident that epigenetic modifications orchestrate a plethora of complex biological processes. During the last decade, we have gained significant knowledge about a wide range of epigenetic changes that crucially contribute to some of the most aggressive forms of leukemia, lymphoma, and myelodysplastic syndromes. DNA methylation is a key epigenetic player in the abnormal initiation, development, and progression of these malignancies, often acting in synergy with other epigenetic alterations. It also contributes to the acquisition of drug resistance. In this review, we summarize the role of DNA methylation in hematological malignancies described in the current literature. We discuss in detail the dual role of DNA methylation in normal and aberrant hematopoiesis, as well as the involvement of this type of epigenetic change in other aspects of the disease. Finally, we present a comprehensive overview of the main clinical implications, including a discussion of the therapeutic strategies that regulate or reverse aberrant DNA methylation patterns in hematological malignancies, including their combination with (chemo)immunotherapy.

Signaling pathways and clinical application of RASSF1A and SHOX2 in lung cancer

BACKGROUND

An increasing number of studies have focused on the early diagnostic value of the methylation of RASSF1A and SHOX2 in lung cancer. However, the intricate cellular events related to RASSF1A and SHOX2 in lung cancer are still a mystery. For researchers and clinicians aiming to more profoundly understand the diagnostic value of methylated RASSF1A and SHOX2 in lung cancer, this review will provide deeper insights into the molecular events of RASSF1A and SHOX2 in lung cancer.

METHODOLOGY

We searched for relevant publications in the PubMed and Google Scholar databases using the keywords "RASSF1A", "SHOX2" and "lung cancer" etc. First, we reviewed the RASSF1A and SHOX2 genes, from their family structures to the functions of their basic structural domains. Then we mainly focused on the roles of RASSF1A and SHOX2 in lung cancer, especially on their molecular events in recent decades. Finally, we compared the value of measuring RASSF1A and SHOX2 gene methylation with that of the common methods for the diagnosis of lung cancer patients.

RESULTS

The RASSF1A and SHOX2 genes were confirmed to be regulators or effectors of multiple cancer signaling pathways, driving tumorigenesis and lung cancer progression. The detection of RASSF1A and SHOX2 gene methylation has higher sensitivity and specificity than other commonly used methods for diagnosing lung cancer, especially in the early stage.

CONCLUSIONS

The RASSF1A and SHOX2 genes are critical for the processes of tumorigenesis, development, metastasis, drug resistance, and recurrence in lung cancer. The combined detection of RASSF1A and SHOX2 gene methylation was identified as an excellent method for the screening and surveillance of lung cancer that exhibits high sensitivity and specificity.

miR-4792 Inhibits Acute Myeloid Leukemia Cell Proliferation and Invasion and Promotes Cell Apoptosis by Targeting Kindlin-3

It has been reported that kindlin-3 expression is closely associated with progression of many cancers and microRNA (miRNA) processing. However, the effects and precise mechanisms of kindlin-3 in acute myeloid leukemia (AML) have not been well clarified. Our study aimed to explore the interaction between kindlin-3 and miR-4792 in AML. In our study, we found that the expression of kindlin-3 was dramatically increased in AML samples and cell lines, and the miR-4792 level was significantly downregulated. Interestingly, the low miR-4792 level was closely associated with upregulated kindlin-3 expression in AML samples. Moreover, introduction of miR-4792 dramatically suppressed proliferation and invasion and induced apoptosis of AML cells. We demonstrated that miR-4792 could directly target kindlin-3 by using both bioinformatics analysis and luciferase reporter assay. In addition, kindlin-3 silencing had similar effects with miR-4792 overexpression on AML cells. Overexpression of kindlin-3 in AML cells partially reversed the inhibitory effects of miR-4792 mimic. miR-4792 inhibited cell proliferation and invasion and induced apoptosis of AML cells by directly downregulating kindlin-3 expression, and miR-4792 targeting kindlin-3 was responsible for the regulation of the proliferation, invasion, and apoptosis of AML cells.

HOX genes function in Breast Cancer development

Breast cancer develops in the mammary glands during mammalian adulthood and is considered the second most common type of human carcinoma and the most incident and mortal in the female population. In contrast to other human structures, the female mammary glands continue to develop after birth, undergoing various modifications during pregnancy, lactation and involution under the regulation of hormones and transcription factors, including those encoded by the HOX clusters (A, B, C, and D). Interestingly, HOX gene deregulation is often associated to breast cancer development. Within the HOXB cluster, 8 out of the 10 genes present altered expression levels in breast cancer with an impact in its aggressiveness and resistance to hormone therapy, which highlights the importance of HOXB genes as potential therapeutic targets used to overcome the limitations of tamoxifen-resistant cancer treatments. Here, we review the current state of knowledge on the role of HOX genes in breast cancer, specially focus on HOXB, discussing the causes and consequences of HOXB gene deregulation and their relevance as prognostic factors and therapeutic targets.

Methyltransferase DNMT3B in leukemia

DNA methyltransferases (DNMTs) are highly conserved DNA-modifying enzymes that play important roles in epigenetic regulation and they are involved in cell proliferation, differentiation, and apoptosis. In mammalian cells, three active DNMTs have been identified: DNMT1 acts as a maintenance methyltransferase to replicate preexisting methylation patterns, whereas DNMT3A and DNMT3B primarily act as de novo methyltransferases that are responsible for establishing DNA methylation patterns by adding a methyl group to cytosine bases. The expression of DNMT3B is widespread in a variety of hematological cells and it is altered in each type of leukemia, which is associated with its pathogenesis, progression, treatment, and prognosis. Here, we review current information on DNMT3B in leukemia, including its expression, single-nucleotide polymorphisms, mutations, regulation, function, and clinical value for anti-leukemic therapy and prognosis.

MicroRNAs: pivotal regulators in acute myeloid leukemia

MicroRNAs are a class of small non-coding RNAs that are 19-22 nucleotides in length and regulate a variety of biological processes at the post-transcriptional level. MicroRNA dysregulation disrupts normal biological processes, resulting in tumorigenesis. Acute myeloid leukemia is an invasive hematological malignancy characterized by the abnormal proliferation and differentiation of immature myeloid cells. Due to the low 5-year survival rate, there is an urgent need to discover novel diagnostic markers and therapeutic targets. In recent years, microRNAs have been shown to play important roles in hematological malignancies by acting as tumor suppressors and oncogenes. MicroRNAs have the potential to be a breakthrough in the diagnosis and treatment of acute myeloid leukemia. In this review, we summarize the biology of microRNAs and discuss the relationships between microRNA dysregulation and acute myeloid leukemia in the following aspects: signaling pathways, the abnormal biological behavior of acute myeloid leukemia cells, the clinical application of microRNAs and competing endogenous RNA regulatory networks.

HOX genes as transcriptional and epigenetic regulators during tumorigenesis and their value as therapeutic targets

Several HOX genes are aberrantly expressed in a wide range of cancers interfering with their development and resistance to treatment. This seems to be often caused by alterations in the methylation profiles of their promoters. The role of HOX gene products in cancer is highly 'tissue specific', relying ultimately on their ability to regulate oncogenes or tumor-suppressor genes, directly as transcriptional regulators or indirectly interfering with the levels of epigenetic regulators. Nowadays, different strategies have been tested the use of HOX genes as therapeutic targets for cancer diagnosis and treatment. Here, we trace the history of the research concerning the involvement of HOX genes in cancer, their connection with epigenetic regulation and their potential use as therapeutic targets.

BCL2 overexpression: clinical implication and biological insights in acute myeloid leukemia

Background

BCL2 protein inhibitor venetoclax (ABT-199) has been authorized by Food and Drug Administration for relapsed/refractory chronic lymphoid leukemia with 17p deletion. Although venetoclax/ABT-199 also caused cell death in acute myeloid leukemia (AML), whether it could be applied to clinical treatment needs further studies. Here, we revealed clinical implication of BCL2 overexpression in de novo adult AML, and may provide theoretical basis for targeted therapy using venetoclax.

Methods

BCL2 expression was analyzed in adult AML patients from public datasets The Cancer Genome Atlas (TCGA) and confirmed by another independent cohort from our own data.

Results

BCL2 expression showed up-regulated in AML patients among TCGA data and confirmed by our own data. BCL2 overexpression was correlated with FAB-M0/M1, whereas BCL2 under-expression was related to FAB-M5. However, BCL2 expression has no effect on overall survival (OS) and leukemia-free survival (LFS) of AML patients (determined in BCL2^low and BCL2^high groups). Interestingly, in the BCL2^low group, patients undergoing autologous or allogeneic hematopoietic stem cell transplantation (auto/allo-HSCT) had significantly better OS and LFS compared with patients only received chemotherapy, whereas, no significant difference was found in OS and LFS between chemotherapy and auto/allo-HSCT patients in the BCL2^high group. BCL2 expression was found positively correlated with HOX family gene, and negatively correlated with tumor suppressor microRNA such as miR-195, miR-497, and miR-193b.

Conclusions

BCL2 overexpression identified specific FAB subtypes of AML, but it did not affect prognosis. Patients with BCL2 overexpression did not benefit from auto/allo-HSCT among whole-cohort-AML and cytogenetically normal AML.

Electronic supplementary material

The online version of this article (10.1186/s13000-019-0841-1) contains supplementary material, which is available to authorized users.

Role of microRNAs, circRNAs and long noncoding RNAs in acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant tumor of the immature myeloid hematopoietic cells in the bone marrow (BM). It is a highly heterogeneous disease, with rising morbidity and mortality in older patients. Although researches over the past decades have improved our understanding of AML, its pathogenesis has not yet been fully elucidated. Long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are three noncoding RNA (ncRNA) molecules that regulate DNA transcription and translation. With the development of RNA-Seq technology, more and more ncRNAs that are closely related to AML leukemogenesis have been discovered. Numerous studies have found that these ncRNAs play an important role in leukemia cell proliferation, differentiation, and apoptosis. Some may potentially be used as prognostic biomarkers. In this systematic review, we briefly described the characteristics and molecular functions of three groups of ncRNAs, including lncRNAs, miRNAs, and circRNAs, and discussed their relationships with AML in detail.

Targeting miR-193a-AML1-ETO-β-catenin axis by melatonin suppresses the self-renewal of leukaemia stem cells in leukaemia with t (8;21) translocation

AML1‐ETO, the most common fusion oncoprotein by t (8;21) in acute myeloid leukaemia (AML), enhances hematopoietic self‐renewal and leukemogenesis. However, currently no specific therapies have been reported for t (8;21) AML patients as AML1‐ETO is still intractable as a pharmacological target. For this purpose, leukaemia cells and AML1‐ETO‐induced murine leukaemia model were used to investigate the degradation of AML1‐ETO by melatonin (MLT), synthesized and secreted by the pineal gland. MLT remarkedly decreased AML1‐ETO protein in leukemic cells. Meanwhile, MLT induced apoptosis, decreased proliferation and reduced colony formation. Furthermore, MLT reduced the expansion of human leukemic cells and extended the overall survival in U937T‐AML1‐ETO‐xenografted NSG mice. Most importantly, MLT reduced the infiltration of leukaemia blasts, decreased the frequency of leukaemia stem cells (LSCs) and prolonged the overall survival in AML1‐ETO‐induced murine leukaemia. Mechanistically, MLT increased the expression of miR‐193a, which inhibited AML1‐ETO expression via targeting its putative binding sites. Furthermore, MLT decreased the expression of β‐catenin, which is required for the self‐renewal of LSC and is the downstream of AML1‐ETO. Thus, MLT presents anti‐self‐renewal of LSC through miR‐193a‐AML1‐ETO‐β‐catenin axis. In conclusion, MLT might be a potential treatment for t (8;21) leukaemia by targeting AML1‐ETO oncoprotein.

Oncogenic Roles and Inhibitors of DNMT1, DNMT3A, and DNMT3B in Acute Myeloid Leukaemia

Epigenetic alteration has been proposed to give rise to numerous classic hallmarks of cancer. Impaired DNA methylation plays a central role in the onset and progression of several types of malignancies, and DNA methylation is mediated by DNA methyltransferases (DNMTs) consisting of DNMT1, DNMT3A, and DNMT3B. DNMTs are frequently implicated in the pathogenesis and aggressiveness of acute myeloid leukaemia (AML) patients. In this review, we describe and discuss the oncogenic roles of DNMT1, DNMT3A, and DNMT3B in AML. The clinical response predictive roles of DNMTs in clinical trials utilising hypomethylating agents (azacitidine and decitabine) in AML patients are presented. Novel hypomethylating agent (guadecitabine) and experimental DNMT inhibitors in AML are also discussed. In summary, hypermethylation of tumour suppressors mediated by DNMT1 or DNMT3B contributes to the progression and severity of AML (except MLL-AF9 and inv(16)(p13;q22) AML for DNMT3B), while mutation affecting DNMT3A represents an early genetic lesion in the pathogenesis of AML. In clinical trials of AML patients, expression of DNMTs is downregulated by hypomethylating agents while the clinical response predictive roles of DNMT biomarkers remain unresolved. Finally, nucleoside hypomethylating agents have continued to show enhanced responses in clinical trials of AML patients, and novel non-nucleoside DNMT inhibitors have demonstrated cytotoxicity against AML cells in pre-clinical settings.

Silencing long non-coding RNA HOTAIR exerts anti-oncogenic effect on human acute myeloid leukemia via demethylation of HOXA5 by inhibiting Dnmt3b

Background

As an aggressive hematological malignancy, acute myeloid leukemia (AML) remains a dismal disease with poor prognosis. Long non-coding RNAs (lncRNAs) have been widely reported to be involved in tumorigenesis of AML. Here, we define an important role of lncRNA HOTAIR in AML in relation to HOXA5 methylation.

Methods

Firstly, the expression of HOTAIR was examined in AML samples and cells collected. Next, gain- or loss-of function experiments were conducted in AML cells to explore the effect of HOTAIR on AML. Then, relationship among HOXA5 promoter methylation, HOTAIR and Dnmt3b was measured. Expression of HOXA5 and cell proliferation/apoptosis-related genes was also detected. A last, in vivo assay was performed to assess the tumor formation in nude mice in order to explore the roles of HOTAIR and HOXA5 in cell apoptosis and proliferation.

Results

LncRNA HOTAIR was found to be upregulated in AML cells and tissues. With silencing of HOTAIR and overexpression of HOXA5, AML cell proliferation was decreased while the apoptosis was induced. Furthermore, HOTAIR was observed to recruit Dnmt3b and to increase HOXA5 promoter methylation. Moreover, silencing HOTAIR and upregulating HOXA5 were found to induce apoptosis and reduce proliferation of AML cells in vivo.

Conclusion

Our findings highlight the anti-tumor ability of HOTAIR silencing in AML, suggesting that silencing HOTAIR was able to inhibit AML progression through HOXA5 promoter demethylation by decreasing Dnmt3b.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0808-z) contains supplementary material, which is available to authorized users.

Interplay between epigenetic abnormalities and deregulated expression of microRNAs in cancer

Epigenetic abnormalities and aberrant expression of non-coding RNAs are two emerging features of cancer cells, both of which are responsible for deregulated gene expression. In this review, we describe the interplay between the two. Specific themes include epigenetic silencing of tumor suppressor miRNAs, epigenetic activation of oncogenic miRNAs, epigenetic aberrations caused by miRNAs, and naturally occurring compounds which modulate miRNA expression through epigenetic mechanisms.

microRNA-628 inhibits the proliferation of acute myeloid leukemia cells by directly targeting IGF-1R

Background

A variety of microRNAs (miRNAs) are aberrantly expressed in acute myeloid leukemia (AML), and these dysregulated miRNAs perform crucial roles in tumorigenesis and progression of AML. miR-628-3p (miR-628), one of the miRNAs dysregulated in multiple types of human cancers, exerts antitumor roles in different cancer types. However, no specific study has explored the expression pattern and role of miR-628 in AML.

Materials and methods

In this study, RT-qPCR was performed to detect miR-628 expression in AML tissues and cell lines. CCK-8 assay, flow cytometry analysis and xenograft tumor experiment was carried out to determine the functions of miR-628 in AML cells. The possible mechanism underlying the activity of miR-628 in AML cells was also explored using a series of experiments.

Results

Our results revealed the downregulated expression of miR-628 in patients with AML and AML cell lines. Ectopic expression of miR-628 resulted in the inhibition of AML cell proliferation and induction of cell cycle arrest and apoptosis in vitro and attenuation of tumor growth in vivo. Insulin-like growth factor 1 receptor (IGF-1R) was identified as a direct target gene of miR-628 in AML cells. IGF-1R expression was upregulated in patients with AML and upregulation of IGF-1R expression inversely correlated with miR-628 level. Furthermore, IGF-1R knockdown imitated the tumor suppressive effect of miR-628 in AML cells. Restoration of IGF-1R expression abrogated the effects of miR-628 on the proliferation, cycle status, and apoptosis rate of AML cells. miR-628 inhibited the activation of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (Akt) pathway in AML cells both in vitro and in vivo through the inhibition of IGF-1R expression.

Conclusion

Our results demonstrate that miR-628 exhibits antitumor effects in AML through the direct targeting of IGF-1R and regulation of PI3K/Akt pathway, suggestive of its potential role as a therapeutic target in patients with this aggressive hematological malignant tumor.

miR‑1271‑5p inhibits cell proliferation and induces apoptosis in acute myeloid leukemia by targeting ZIC2

MicroRNAs (miRNAs) have been demonstrated to regulate the progression of numerous types of cancer, including acute myeloid leukemia (AML). Previous studies demonstrated that miR‑1271‑5p functions as a tumor suppressor; however, the roles of miR‑1271‑5p in AML remain unknown. In the present study, miR‑1271‑5p was significantly downregulated in AML tissues compared with normal tissues by reverse transcription‑quantitative polymerase chain reaction analysis. Furthermore, the expression levels of miR‑1271‑5p in patients with AML may function as a prognostic marker. In addition, overexpression of miR‑1271‑5p significantly suppressed the proliferation and induced apoptosis of AML cells by Cell Counting kit‑8 and fluorescence activated cell sorter assays; miR‑1271‑5p downregulation exhibited opposing effects. Additionally, transcription factor ZIC2 may be a direct target of miR‑1271‑5p in AML cells, which was demonstrated by a luciferase reporter assay and RNA pulldown assay. Overexpression of miR‑1271‑5p significantly reduced the mRNA and protein expression levels of ZIC2 in AML193 and OCI‑AML2 cells by reverse transcription‑quantitative polymerase chain reaction analysis and western blotting. Furthermore, an inverse correlation between miR‑1271‑5p and ZIC2 expression in AML samples was observed. In summary, ZIC2 was upregulated in AML tissues, and restoration of ZIC2 expression was able to promote the proliferation and reduce the apoptosis of AML cells transfected with miR‑1271‑5p mimics. The results of the present study demonstrated that miR‑1271‑5p inhibited the progression of AML by targeting ZIC2.

MicroRNAs in Autoimmunity and Hematological Malignancies

Autoimmunity and hematological malignancies are often concomitant in patients. A causal bidirectional relationship exists between them. Loss of immunological tolerance with inappropriate activation of the immune system, likely due to environmental and genetic factors, can represent a breeding ground for the appearance of cancer cells and, on the other hand, blood cancers are characterized by imbalanced immune cell subsets that could support the development of the autoimmune clone. Considerable effort has been made for understanding the proteins that have a relevant role in both processes; however, literature advances demonstrate that microRNAs (miRNAs) surface as the epigenetic regulators of those proteins and control networks linked to both autoimmunity and hematological malignancies. Here we review the most up-to-date findings regarding the miRNA-based molecular mechanisms that underpin autoimmunity and hematological malignancies.

Exploring the Role of Fallopian Ciliated Cells in the Pathogenesis of High-Grade Serous Ovarian Cancer

High-grade serous epithelial ovarian cancer (HGSOC) is the fifth leading cause of cancer death in women and the first among gynecological malignancies. Despite an initial response to standard chemotherapy, most HGSOC patients relapse. To improve treatment options, we must continue investigating tumor biology. Tumor characteristics (e.g., risk factors and epidemiology) are valuable clues to accomplish this task. The two most frequent risk factors for HGSOC are the lifetime number of ovulations, which is associated with increased oxidative stress in the pelvic area caused by ovulation fluid, and a positive family history due to genetic factors. In the attempt to identify novel genetic factors (i.e., genes) associated with HGSOC, we observed that several genes in linkage with HGSOC are expressed in the ciliated cells of the fallopian tube. This finding made us hypothesize that ciliated cells, despite not being the cell of origin for HGSOC, may take part in HGSOC tumor initiation. Specifically, malfunction of the ciliary beat impairs the laminar fluid flow above the fallopian tube epithelia, thus likely reducing the clearance of oxidative stress caused by follicular fluid. Herein, we review the up-to-date findings dealing with HGSOC predisposition with the hypothesis that fallopian ciliated cells take part in HGSOC onset. Finally, we review the up-to-date literature concerning genes that are located in genomic loci associated with epithelial ovarian cancer (EOC) predisposition that are expressed by the fallopian ciliated cells.

miR-375 prevents nasal mucosa cells from apoptosis and ameliorates allergic rhinitis via inhibiting JAK2/STAT3 pathway

This study aims to explore the roles, and related mechanisms of miR-375 in nasal mucosa cells apoptosis and allergic rhinitis. Here, miR-375 was found to be decreased in the epithelia of nasal mucosa of allergic rhinitis mice and TNF-α-stimulated nasal mucosa cells, while JAK2 expression exhibited an opposite effect. Mechanistically, miR-375/JAK2 regulatory axis was identified in nasal mucosa cells via luciferase reporter, qRT-PCR, western blot and RNA immune co-precipitation (RIP) assays. Pre- or post-injection of miR-375 agomir following ovalbumin (OVA) treatment attenuated OVA-induced allergic rhinitis, characterized as the downregulation of IL-6 and TNF-α secretion, and upregulation of IL-10 secretion, these effects were attenuated by infection with JAK2 adenovirus through nasal cavity inhalation. Additionally, overexpression of miR-375 reversed TNF-α-mediated nasal mucosa cells apoptosis, which was attenuated by JAK2 overexpression. Therefore, our results indicate that miR-375 prevents nasal mucosa cells from apoptosis and ameliorates allergic rhinitis via inhibiting JAK2/STAT3 pathway.