WITHDRAWN: Inhibition of MicroRNA miR-92a Inhibits Cell Proliferation in Human Acute Promyelocytic Leukemia

Therapeutic potential of antagomiRs in haematological and oncological neoplasms

BACKGROUND

The importance of the role of MicroRNAs (or miRNAs) has been emphasised by the large number of studies in human tumour cells, underlining the high impact of post-transcriptional processes in cancer onset, progression, invasion and metastatisation. Currently known as oncomiR, real databases are collecting all the smaller fragments of RNA capable of participating in the oncogenesis.

AIMS

With the aim to collect for the first time the most important acquisitions in literature about antagomiRs in oncology, our narrative review is born with the purpose of showing that specific antisense oligonucleotides, capable to bind and antagonise single or multiple miRNAs, are effective as therapeutic compounds.

RESULTS

Peptide or locked nucleic acids, miRNA sponges or antagomiRs attached to plasmid or lentiviral vectors carrying miRNA sequences to its target are objects of our analysis, demonstrating their effectiveness in a large number and types of tumours. We have also tried how to overcome their high immunogenicity, which remains its greatest limit for clinical use.

CONCLUSIONS

They are ambitious but fascinating promise to alter the promotion of the tumour growth by binding specific molecular targets, with high precision and low toxicity, leaving the scientists the chance of development as anti-cancer drugs and not just.

Retraction Note to: Inhibition of microRNA miR-92a induces apoptosis and inhibits cell proliferation in human acute promyelocytic leukemia through modulation of p63 expression

The Editor-in-Chief has decided to retract this article [1]. The article shows significant overlap with two prior publications by the same authors [2, 3], without providing the due citation and attribution.

Retraction Note to: Inhibition of microRNA miR-92a induces apoptosis and inhibits cell proliferation in human acute promyelocytic leukemia through modulation of p63 expression

The Editor-in-Chief has decided to retract this article [1]. The article shows significant overlap with two prior publications by the same authors [2, 3], without providing the due citation and attribution.

Investigation of MiR-92a as a Prognostic Indicator in Cancer Patients: a Meta-Analysis

Background: MiR-92a has been discovered to be involved in the malignant behavior of various types of cancers. However, the particular clinical and prognostic roles of miR-92a in tumors still need to be identified more precisely. The current meta-analysis assessed the prognostic value of miR-92a in various carcinomas.

Methods: Systematic literature searches of PubMed, PMC, Web of Science (WOS), Embase in English and Wanfang, SinoMed and the China National Knowledge Infrastructure (CNKI) in Chinese up to Jan 15^th 2019 were conducted for eligible studies. Twenty studies involving a total of 2573 patients were included in the analysis. Pooled hazard ratios (HR) for overall survival (OS) and disease-free survival (DFS), progression-free survival (PFS) and recurrence-free survival (RFS) were assessed using fixed-effects and random-effects models. Meta-regression and subgroup analyses were carried out to explore the source of heterogeneity. Odds ratio (OR) and 95%CIs were applied to evaluate the relationship between miR-92a expression levels and clinicopathological characteristics.

Results: A significant association between miR-92a levels and OS (HR=2.18) was identified. The random pooling model also revealed significance of consistency (HR=2.14), indicating that the stability of the results. Subgroup analyses were performed and the corresponding significance was recognized in Chinese cancer patients (HR=2.35), studies of specimen derived from tissues (HR=2.43), non-hematological cancer (HR=2.35), osteosarcoma (HR=2.54), non-small cell lung cancer (HR=2.33), hepatocellular carcinoma (HR=2.40) and so on. There were significant relations observed of the expression level of miR-92a to tumor size (≥5 vs <5 cm) (OR=2.13), lymph node metastasis (present vs. absent) (OR=1.87), distant metastasis (present vs. absent) (OR=2.99) and so on.

Conclusions: the over expression of miR-92a is associated with unfavorable prognosis of Chinese cancer patients. In addition, patients of elevated miR-92a expression level are likely to develop the cancers of more malignant behaviors.

ΔNp63α and microRNAs: leveraging the epithelial-mesenchymal transition

The epithelial-mesenchymal transition (EMT) is a cellular reprogramming mechanism that is an underlying cause of cancer metastasis. Recent investigations have uncovered an intricate network of regulation involving the TGFβ, Wnt, and Notch signaling pathways and small regulatory RNA species called microRNAs (miRNAs). The activity of a transcription factor vital to the maintenance of epithelial stemness, ΔNp63α, has been shown to modulate the activity of these EMT pathways to either repress or promote EMT. Furthermore, ΔNp63α is a known regulator of miRNA, including those directly involved in EMT. This review discusses the evidence of ΔNp63α as a master regulator of EMT components and miRNA, highlighting the need for a deeper understanding of its role in EMT. This expanded knowledge may provide a basis for new developments in the diagnosis and treatment of metastatic cancer.

From conventional therapy toward microRNA-based therapy in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a hematopoietic malignancy that is known with its special cytogenetic feature. Several studies have surveyed expression signature of microRNAs (miRNAs) in APL patients, especially patients who are treated with conventional therapy of this disease. Using miRNAs as diagnostic or prognostic biomarkers in various cancers has been widely studied. Currently, most studies are focusing on exploiting miRNAs as therapeutic tools, and promising progress has been achieved in this field. Recently, studies in the field of miRNA-based therapy in APL have been started.

High expression of MAP7 predicts adverse prognosis in young patients with cytogenetically normal acute myeloid leukemia

Microtubule-associated protein 7 (MAP7) plays an important role in cancer cells. In this study, we identified the prognostic significance of MAP7 expression in cytogenetically normal acute myeloid leukemia (CN-AML) patients (aged <60 years) based on several microarray datasets. In the first group (n = 129), high MAP7 expression (MAP7^high) was associated with adverse overall survival (OS; P = 0.0441) and event-free survival (EFS; P = 0.0114) compared with low MAP7 expression (MAP7^low). In addition, the prognostic significance of MAP7 was confirmed by European Leukemia Net (ELN) intermediate-I genetic categories and multivariable analysis. In the second independent group of CN-AML patients (aged <60 years), MAP7^high was also associated with adverse OS (n = 88, OS; P = 0.00811). To understand the inherent mechanisms of MAP7's prognosis, we investigated genome-wide gene/microRNA expression signatures associated with MAP7 expression. Several known oncogenic genes/microRNAs and anti-oncogenic genes/microRNAs were disordered in MAP7^high CN-AML patients. In conclusion, MAP7^high is an adverse prognostic biomarker for CN-AML, which may be attributed to the distinctive genome-wide gene/microRNA expression and related cell signaling pathways.

Onco-microRNA miR-130b promoting cell growth in children APL by targeting PTEN

OBJECTIVE

To study the expression of microRNA-130b (miR-130b) in children acute promyelocytic leukemia (APL) and its role for regulating PTEN expression.

METHODS

A total of 50 children APL marrow tissues and 15 normal marrow tissues between January and December in 2012 were collected into our study. The expression of miR-130b in APL and normal marrow tissues were detected by quantitative real-time polymerase chain reaction. MiR-130b inhibitor was transfected into HL-60 cells. Cell Counting Kit-8 assay and flow cytometry were used to measure cell proliferation and apoptosis, respectively. The expression of PTEN, a potential target of miR-130b, and its downstream genes, Bcl-2 and Bax, in transformed cells were detected by quantitative real-time polymerase chain reaction and western-blot.

RESULTS

The expression of miR-130b was significantly higher in children APL marrow tissues than in normal marrow tissues (P < 0.05). Down-regulation of miR-130b could significantly suppress cell proliferation and induce apoptosis in HL-60 cells (P < 0.05). PTEN expression was upregulated when miR-130b was knocking-down (P < 0.05). As downstream genes of PTEN, the expression of Bcl-2 and Bax were regulated as well.

CONCLUSIONS

MiR-130b is overexpressed in children APL marrow tissues and associated with cell growth. MiR-130b may promote children APL progression by inducing cell proliferation and inhibiting apoptosis.

Blockage of miR-92a-3p with locked nucleic acid induces apoptosis and prevents cell proliferation in human acute megakaryoblastic leukemia

MicroRNAs (miRNAs) are non-coding RNAs involved in post-transcriptional regulation of gene expression. In many cancers, up- or downregulation of different miRNAs is reported. In acute myeloid leukemia, upregulation of miR-92a-3p was reported in human in vitro studies. We performed blockage of miR-29a-3p in human acute megakaryoblastic leukemia cell line (M-07e) by using locked nucleic acid (LNA) and cell proliferation; apoptosis and necrosis were assessed. At different time points after LNA-anti-miR92a-3p transfection, miR-92a-3p quantitation was assessed by qRT-real-time PCR, MTT assay and annexin/propidium iodide staining were performed. The data were processed using the ANOVA test. At all three time points, the expression of miR-92a-3p was lower in the LNA-anti-miR group compared with the control groups. Cell viability between LNA-Anti-miR and the control group was statistically significant. Blockage of miR-92a-3p was associated with increment of the ratio of apoptotic cells in the LNA-anti-miR group was higher than the other group. The ratio of necrotic cells in the LNA-antimiR group was higher than the other groups. These assessments indicate that miR-92a-3p blockage can decrease the viability of M-07e cells, which is mainly due to induction of apoptosis and necrosis. Our findings could open up a path to a miRNA based therapeutic approach for treatment of acute megakaryoblastic leukemia.

Effects of miR-19b knockdown on the cardiac differentiation of P19 mouse embryonic carcinoma cells

MicroRNA-19b (miR-19b) is part of the miR-17–92 cluster which is associated with cardiac development. It has previously been reported that the overexpression of miR-19b increases proliferation, inhibits apoptosis and promotes differentiation of embryonic carcinoma cells (P19 cells). The aim of the current study was to investigate the effects of miR-19b knockdown on the proliferation, apoptosis, differentiation and regulation of the Wnt/β-catenin signaling pathway in P19 cells. P19 cells were transfected with an miR-19b knockdown plasmid or an empty vector. MiR-19b knockdown or vector control stable cell lines were selected using puromycin. Cell Counting kit-8 and flow cytometry were used to analyze the levels of cellular proliferation, cell cycle progression and the levels of apoptosis, respectively. Caspase-3 activity and mitochondrial function assays were also used to analyze apoptosis. An inverted microscope was used to observe the morphological changes of P19 cells during differentiation. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to detect P19 cell differentiation markers and Wnt/β-catenin signaling pathway-related genes and their corresponding proteins. The results demonstrated that miR-19b knockdown inhibited the proliferation and apoptosis of P19 cells. However, the levels of expression of Wnt and β-catenin increased. MiR-19b knockdown activated the Wnt/β-catenin signaling pathway, which may regulate cardiomyocyte differentiation. The results of this study indicate that miR-19b is a novel therapeutic target for cardiovascular diseases and provide insight into the mechanisms underlying congenital heart diseases.