Expression and prognostic relevance of long noncoding RNAs CRNDE and AOX2P in adult acute myeloid leukemia

The role of long noncoding RNAs in the diagnosis, prognosis and therapeutic biomarkers of acute myeloid leukemia

Acute myeloid leukemia (AML) is the abnormal proliferation of immature myeloid blast cells in the bone marrow. Currently, there are no universally recognized biomarkers for the early diagnosis, prognosis and effective treatment of AML to improve the overall survival of patients. Recent studies, however, have demonstrated that long noncoding RNAs (lncRNAs) are promising targets for the early diagnosis, prognosis and treatment of AML. A critical review of available data would be important to identify study gaps and provide perspectives. In this review, we explored comprehensive information on the potential use of lncRNAs as targets for the diagnosis, prognosis, and treatment of AML. LncRNAs are nonprotein-coding RNAs that are approximately 200 nucleotides long and play important roles in the regulation, metabolism and differentiation of tissues. In addition, they play important roles in the diagnosis, prognosis and treatment of different cancers, including AML. LncRNAs play multifaceted roles as oncogenes or tumor suppressor genes. Recently, deregulated lncRNAs were identified as novel players in the development of AML, making them promising prognostic indicators. Given that lncRNAs could have potential diagnostic marker roles, the lack of sufficient evidence identifying specific lncRNAs expressed in specific cancers hampers the use of lncRNAs as diagnostic markers of AML. The complex roles of lncRNAs in the pathophysiology of AML require further scrutiny to identify specific lncRNAs. This review, despite the lack of sufficient literature, discusses the therapeutic, diagnostic and prognostic roles of lncRNAs in AML and provides future insights that will contribute to studies targeting lncRNAs in the diagnosis, treatment, and management of AML.

lncRNA Biomarkers of Glioblastoma Multiforme

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.

Development and validation of a promising 5-gene prognostic model for pediatric acute myeloid leukemia

Risk classification in pediatric acute myeloid leukemia (P-AML) is crucial for personalizing treatments. Thus, we aimed to establish a risk-stratification tool for P-AML patients and eventually guide individual treatment. A total of 256 P-AML patients with accredited mRNA-seq data from the TARGET database were divided into training and internal validation datasets. A gene-expression-based prognostic score was constructed for overall survival (OS), by using univariate Cox analysis, LASSO regression analysis, Kaplan-Meier (K-M) survival, and multivariate Cox analysis. A P-AML-5G prognostic score bioinformatically derived from expression levels of 5 genes (ZNF775, RNFT1, CRNDE, COL23A1, and TTC38), clustered P-AML patients in training dataset into high-risk group (above optimal cut-off) with shorter OS, and low-risk group (below optimal cut-off) with longer OS (p < 0.0001). Meanwhile, similar results were obtained in internal validation dataset (p = 0.005), combination dataset (p < 0.001), two treatment sub-groups (p < 0.05), intermediate-risk group defined with the Children's Oncology Group (COG) (p < 0.05) and an external Japanese P-AML dataset (p = 0.005). The model was further validated in the COG study AAML1031(p = 0.001), and based on transcriptomic analysis of 943 pediatric patients and 70 normal bone marrow samples from this dataset, two genes in the model demonstrated significant differential expression between the groups [all log2(foldchange) > 3, p < 0.001]. Independent of other prognostic factors, the P-AML-5G groups presented the highest concordance-index values in training dataset, chemo-therapy only treatment subgroups of the training and internal validation datasets, and whole genome-sequencing subgroup of the combined dataset, outperforming two Children's Oncology Group (COG) risk stratification systems, 2022 European LeukemiaNet (ELN) risk classification tool and two leukemic stem cell expression-based models. The 5-gene prognostic model generated by a single assay can further refine the current COG risk stratification system that relies on numerous tests and may have the potential for the risk judgment and identification of the high-risk pediatric AML patients receiving chemo-therapy only treatment.

Contribution of CRNDE lncRNA in the development of cancer and the underlying mechanisms

Colorectal Neoplasia Differentially Expressed (CRNDE) is an lncRNA with crucial roles in cancer development. It is located on chromosome 16 on the opposite strand to the adjacent IRX5 gene, implying the presence of a shared bidirectional promoter for these two genes. Expression of CRNDE has been assessed in a diverse array of hematological malignancies and solid tumors, representing its potential as a therapeutic target in these conditions. This lncRNA has a regulatory effect on activity of several pathways and axes that are involved in the regulation of cell apoptosis, immune responses and tumorigenesis. The current review is an updated review about the role of CRNDE in the development of cancers.

Downregulation of IRAIN long non-coding RNA predicts unfavourable clinical outcome in acute myeloid leukaemia patients

BACKGROUND

Although it has been shown that the long non-coding RNA (lncRNA) insulin-like growth factor type 1 receptor (IGF1R) antisense imprinted non-protein coding RNA (IRAIN) is downregulated in leukaemia cell lines, its usefulness as a prognostic marker in acute myeloid leukaemia (AML) has not yet been thoroughly investigated. Here, we sought to determine whether the expression of IRAIN is associated with clinical outcome of AML patients.

SUBJECTS & METHODS

Using quantitative real-time polymerase chain reaction (qRT-PCR), IRAIN expression levels were assessed in peripheral blood leukocyte samples from 150 patients with AML and 50 healthy controls. Analysis was done on the relationship between IRAIN expression and clinical outcomes in AML patients.

RESULTS

When compared to healthy controls, IRAIN expression was markedly reduced in AML patients (P = 0.019). IRAIN expression could distinguish French-American-British (FAB) subtypes of AML (P = 0.024). Low IRAIN expression status was associated with shorter event-free survival (EFS) in the non-t(15;17) cytogenetically abnormal AML subset (P = 0.004). IRAIN downregulation was identified as an independent adverse prognostic marker for complete remission (CR) not only in the in the non-t(15;17) cytogenetically abnormal AML subset (P = 0.006) but also in the AML-M4/M5 subgroup (P = 0.033).

CONCLUSION

Aberrantly low IRAIN expression is closely associated with lower CR rates in AML patients, particularly in non-t(15;17) cytogenetically abnormal AML and M4/M5 AML, suggesting that the determination of IRAIN expression level at diagnosis provides valuable prognostic information, serves as a promising biomarker for evaluating treatment response, and helps predicting clinical outcome of AML patients.

LncRNA HOTAIR promotes myocardial fibrosis in atrial fibrillation through binding with PTBP1 to increase the stability of Wnt5a

BACKGROUND

Atrial fibrillation (AF) is one of the most common arrhythmia in clinical practice, and atrial fibrosis is the important mediator in AF. LncRNA HOTAIR was reported to be up-regulated in AF, while the underlying mechanism of HOTAIR in AF remains unclear.

METHODS

In vitro and in vivo AF model was established. qRT-PCR and Western blotting were used to assess the mRNA expression (HOTAIR, Wnt5a and PTBP1) and protein levels (Wnt5a, collagen I/III, α-SMA, CTGF, p-ERK, ERK, p-JNK, and JNK), respectively. MTT, CCK8, transwell assay was used to test cell viability, proliferation and migration, respectively. RIP assay assessed the correlation among HOTAIR, PTBP1 and Wnt5a. The level of α-SMA was detected by immunofluorescence. HE and Masson staining detected the histological changes and fibrosis in mouse heart tissues.

RESULTS

Ang II significantly increased the viability of atrial fibroblasts. The levels of HOTAIR and Wnt5a in fibroblasts were up-regulated by Ang II. HOTAIR silencing or Wnt5a significantly inhibited Ang II-induced proliferation, migration and fibrosis in fibroblasts. HOTAIR silencing repressed Wnt5a-mediated ERK and JNK signaling pathway, and Wnt5a partially abolished the effect of HOTAIR silencing on cell proliferation, migration and fibrosis. Meanwhile, HOTAIR could increase the mRNA stability of Wnt5a via recruiting PTBP1. Furthermore, HOTAIR knockdown notably inhibited the fibrosis in heart tissues of AF mice via regulation of Wnt signaling.

CONCLUSION

HOTAIR could promote atrial fibrosis in AF through binding with PTBP1 to increase Wnt5a stability. Our study might shed new insights on exploring new strategies against AF.

Diagnostic and Therapeutic Implications of Long Non-Coding RNAs in Leukemia

Leukemia is a heterogenous group of hematological malignancies categorized in four main types (acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML) and chronic lymphocytic leukemia (CLL). Several cytogenetic and molecular markers have become a part of routine analysis for leukemia patients. These markers have been used in diagnosis, risk-stratification and targeted therapy application. Recent studies have indicated that numerous regulatory RNAs, such as long non-coding RNAs (lncRNAs), have a role in tumor initiation and progression. When it comes to leukemia, data for lncRNA involvement in its etiology, progression, diagnosis, treatment and prognosis is limited. The aim of this review is to summarize research data on lncRNAs in different types of leukemia, on their expression pattern, their role in leukemic transformation and disease progression. The usefulness of this information in the clinical setting, i.e., for diagnostic and prognostic purposes, will be emphasized. Finally, how particular lncRNAs could be used as potential targets for the application of targeted therapy will be considered.

Diverse functions of long noncoding RNAs in acute myeloid leukemia: emerging roles in pathophysiology, prognosis, and treatment resistance

PURPOSE OF REVIEW

Advancements in the next-generation sequencing technologies have identified rare transcripts of long noncoding RNAs (lncRNAs) in the genome of cancers, including in acute myeloid leukemia (AML). The purpose of this review is to highlight the contribution of lncRNAs in AML pathogenesis, prognosis, and chemoresistance.

RECENT FINDINGS

Several studies have recently reported that deregulated lncRNAs are novel key players in the development of AML and are associated with AML pathophysiology and may serve as prognostic indicators. A few aberrantly expressed lncRNAs that correlated with the recurrent genetic mutations in AML such as NPM1 and RUNX1 have recently been characterized. Moreover, a few lncRNAs in MLL-rearranged leukemia have been described. Additionally, the involvement of lncRNAs in AML chemoresistance has been postulated.

SUMMARY

Investigating the functional roles of the noncoding regions including lncRNAs, may provide novel insights into the pathophysiology, refine the prognostic schema, and provide novel therapeutic treatment strategies in AML.