The Identification of Long Non-coding RNA H19 Target and Its Function in Chronic Myeloid Leukemia

The Role of Long Noncoding RNAs in Progression of Leukemia: Based on Chromosomal Location

Long non-coding RNA [LncRNA] dysregulation has been seen in many human cancers, including several kinds of leukemia, which is still a fatal disease with a poor prognosis. LncRNAs have been demonstrated to function as tumor suppressors or oncogenes in leukemia. This study covers current research findings on the role of lncRNAs in the prognosis and diagnosis of leukemia. Based on recent results, several lncRNAs are emerging as biomarkers for the prognosis, diagnosis, and even treatment outcome prediction of leukemia and have been shown to play critical roles in controlling leukemia cell activities, such as proliferation, cell death, metastasis, and drug resistance. As a result, lncRNA profiles may have superior predictive and diagnostic potential in leukemia. Accordingly, this review concentrates on the significance of lncRNAs in leukemia progression based on their chromosomal position.

Altered expression of imprinted genes in patients with cytogenetically normal‑acute myeloid leukemia: Implications for leukemogenesis and survival outcomes

Genomic imprinting, an epigenetic mechanism that regulates gene expression from parental chromosomes, holds substantial relevance in multiple cancers, including hematopoietic malignancies. In the present study, the expression of a panel of 16 human imprinted genes in bone marrow samples from 64 patients newly diagnosed with cytogenetically normal-acute myeloid leukemia (CN-AML) were examined alongside peripheral blood samples from 85 healthy subjects. The validated findings of the present study revealed significant upregulation of seven genes [COPI coat complex subunit gamma 2 (COPG2), H19 imprinted maternally expressed transcript (H19), insulin like growth factor 2 (IGF2), PEG3 antisense RNA 1 (PEG3-AS1), DNA primase subunit 2 (PRIM2), solute carrier family 22 member 3 SLC22A3 and Zinc finger protein 215 (ZNF215)] in patients with CN-AML (P<0.001). Notably, the expression level of H19 exhibited an inverse association with the survival duration of the patients (P=0.018), establishing it as a predictive marker for two- and five-year survival in patients with CN-AML. Kaplan-Meier analysis demonstrated that patients with lower H19 expression had superior two- and five-year survival rates compared with those with higher H19 expression. The results of the present study highlighted the association between loss of imprinting and leukemogenesis in CN-AML, underscoring the significance of H19 imprinting loss as a prognostic indicator for unfavorable two- and five-year survival in CN-AML patients.

Epigenetic regulation in hematopoiesis and its implications in the targeted therapy of hematologic malignancies

Hematologic malignancies are one of the most common cancers, and the incidence has been rising in recent decades. The clinical and molecular features of hematologic malignancies are highly heterogenous, and some hematologic malignancies are incurable, challenging the treatment, and prognosis of the patients. However, hematopoiesis and oncogenesis of hematologic malignancies are profoundly affected by epigenetic regulation. Studies have found that methylation-related mutations, abnormal methylation profiles of DNA, and abnormal histone deacetylase expression are recurrent in leukemia and lymphoma. Furthermore, the hypomethylating agents and histone deacetylase inhibitors are effective to treat acute myeloid leukemia and T-cell lymphomas, indicating that epigenetic regulation is indispensable to hematologic oncogenesis. Epigenetic regulation mainly includes DNA modifications, histone modifications, and noncoding RNA-mediated targeting, and regulates various DNA-based processes. This review presents the role of writers, readers, and erasers of DNA methylation and histone methylation, and acetylation in hematologic malignancies. In addition, this review provides the influence of microRNAs and long noncoding RNAs on hematologic malignancies. Furthermore, the implication of epigenetic regulation in targeted treatment is discussed. This review comprehensively presents the change and function of each epigenetic regulator in normal and oncogenic hematopoiesis and provides innovative epigenetic-targeted treatment in clinical practice.

Leonurus japonicus Houttuyn induces reactive oxygen species-mediated apoptosis via regulation of miR-19a-3p/PTEN/PI3K/AKT in U937 and THP-1 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurus japonicus Houttuyn is a medicinal ingredient in more than 300 prescriptions in traditional Korean medicine. It is especially important for women's health and blood-related diseases. Recent research revealed that Leonurus japonicus Houttuyn extracts have antioxidative, anticancer, analgesic, anti-inflammatory, and neuroprotective properties.

AIM OF THE STUDY

However, its underlying anti-cancerous mechanisms remain unclear. This study elucidated the anticancer mechanism of Leonurus japonicus Houttuyn in U937 and THP-1 cancer cells.

MATERIALS AND METHODS

High-performance liquid chromatography (HPLC) was used for detecting main compound of Leonurus japonicus Houttuyn, rutin. EZ-Cytox cell viability assay, Western blot analysis, live and dead cell assay, 2', 7' dichlorofluorescin diacetate (DCFDA) assay, quantitative real-time PCR (qRT-PCR) analysis, and microRNA (miR) mimic transfection assay were applied to further investigate anti-cancer efficacies and underlying mechanism in U937 and THP-1 cells.

RESULTS

The main compound of Leonurus japonicus Houttuyn, rutin was detected using HPLC. The cytotoxic effect of Leonurus japonicus Houttuyn was exerted in U937 and THP-1 cancer cells but not in MDBK and IEC-6 normal cells. Leonurus japonicus Houttuyn decreased mitochondria membrane potential (ΔΨm). Consistently, Leonurus japonicus Houttuyn reduced the expression of survivin and cleaved caspase-9, caspase-3, and poly (ADP-ribose) polymerase (PARP). Cell death was increased in Leonurus japonicus Houttuyn treated groups. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and CCAAT-enhancer-binding protein homologous protein (CHOP) was increased and phosphatidylinositol-3-kinase (PI3K) and Protein kinase B (AKT) were decreased by Leonurus japonicus Houttuyn. Reactive oxygen speices generation was elevated by Leonurus japonicus Houttuyn and its cytotoxicity was reversed by N-acetyl-l-cysteine (NAC) pretreatment. Moreover, onco-microRNA (miR), miR-19a-3p was suppressed by Leonurus japonicus Houttuyn and transfection of miR-19a-3p mimic reversed the regulated PTEN, p-AKT, CHOP expression, attenuating Leonurus japonicus Houttuyn induced apoptosis.

CONCLUSIONS

These findings indicated that Leonurus japonicus Houttuyn has anti-cancer effects by regulation of PTEN/PI3K/AKT signal pathway and ROS-related ER stress-induced apoptosis via regulation of miR-19a-3p. Leonurus japonicus Houttuyn may be an effective candidate for triggering PTEN-dependent apoptosis of cancer cells related to acute myeloid leukemia.

Knockdown of ADORA2A antisense RNA 1 inhibits cell proliferation and enhances imatinib sensitivity in chronic myeloid leukemia

Long non-coding RNAs (LncRNAs) exert important regulatory roles in chronic myeloid leukemia (CML). In this study, we aimed to investigate the potential role and molecular mechanism of lncRNA ADORA2A antisense RNA 1 (ADORA2A-AS1) in CML. We found that the expression of ADORA2A-AS1 was upregulated in CML. Further, knockdown of ADORA2A-AS1 inhibited the proliferation, induced apoptosis, arrested cell cycle, and enhanced imatinib sensitivity in CML cells. Besides, ADORA2A-AS1 promoted the expression of transforming growth factor-beta receptor 1 (TGFBR1) and ATP binding cassette subfamily C member 2 (ABCC2) via sponging miR-665, thereby exerting a tumor-promoting activity. Collectively, our results confirmed the oncogenic effect of ADORA2A-AS1 in CML, indicating that ADORA2A-AS1 is a promosing therapeutic target for CML.

miR‑106b‑5p targeting SIX1 inhibits TGF‑β1‑induced pulmonary fibrosis and epithelial‑mesenchymal transition in asthma through regulation of E2F1

Asthma is an inflammatory disease of the airways, characterized by lung eosinophilia, mucus hypersecretion by goblet cells and airway hyper-responsiveness to inhaled allergens. The present study aimed to identify the function of microRNA (miR/miRNA)-106b-5p in TGF-β1-induced pulmonary fibrosis and epithelial-mesenchymal transition (EMT) via targeting sine oculis homeobox homolog 1 (SIX1) through regulation of E2F transcription factor 1 (E2F1) in asthma. Asthmatic mouse models were induced with ovalbumin. miRNA expression was evaluated using reverse transcription-quantitative PCR. Transfection experiments using bronchial epithelial cells were performed to determine the target genes. A luciferase reporter assay system was applied to identify the target gene of miR-106b-5p. The present study revealed downregulated miR-106b-5p expression and upregulated SIX1 expression in asthmatic mice and TGF-β1-induced BEAS-2B cells. Moreover, miR-106b-5p overexpression inhibited TGF-β1-induced fibrosis and EMT in BEAS-2B cells, while miR-106b-5p-knockdown produced the opposite effects. Subsequently, miR-106b-5p was found to regulate SIX1 through indirect regulation of E2F1. Additionally, E2F1- and SIX1-knockdown blocked TGF-β1-induced fibrosis and EMT in BEAS-2B cells. In addition, miR-106b-5p negatively regulated SIX1 via E2F1 in BEAS-2B cells. The present study demonstrated that the miR-106b-5p/E2F1/SIX1 signaling pathway may provide potential therapeutic targets for asthma.

Role of long non-coding RNA H19 in therapy resistance of digestive system cancers

Digestive system cancers are associated with high morbidity and mortality. Chemotherapy and radiotherapy are the main treatment modalities for these cancers. However, the development of therapy resistance leads to high rates of tumor recurrence and metastasis, resulting in dismal prognosis. Long non-coding RNA (LncRNA) H19, one of the most intriguing non-coding RNAs, has been shown to play a key role in the development and therapy resistance of various digestive system cancers (including hepatocellular carcinoma, colorectal cancer, pancreatic ductal adenocarcinoma, esophageal carcinoma, gastric cancer, and biliary system cancer) by regulating the abnormal expression of genes. In this review, we discuss the potential mechanisms of LncRNA H19 related therapy resistance in the context of digestive system cancers. LncRNA H19 is a potential novel therapeutic target for amelioration of cancer therapy resistance.