MiR-20a-5p functions as a potent tumor suppressor by targeting PPP6C in acute myeloid leukemia

ALKBH5 promotes T-cell acute lymphoblastic leukemia growth via m6A-guided epigenetic inhibition of miR-20a-5p

This study investigates the role of ALKBH5-mediated m6A demethylation in T-cell acute lymphoblastic leukemia (T-ALL). T-ALL cell lines (HPB-ALL, MOLT4, Jurkat, CCRF-CEM) and human T cells were analyzed. CCRF-CEM and Jurkat cells were transfected with si-ALKBH5, miR-20a-5p-inhibitor, and pcDNA3.1-DDX5. The expression levels of ALKBH5, miR-20a-5p, and DDX5 in these cells were determined using qRT-PCR and Western blotting. Cell viability, proliferation, colony formation, and apoptosis were assessed using CCK-8, EdU staining, colony formation assay, and flow cytometry. mRNA m6A levels were quantified with an m6A RNA methylation detection reagent, and RNA immunoprecipitation was employed to measure the enrichment of DGCR8 and m6A on the primary transcript pri-miR-20a of miR-20a-5p. Dual-luciferase assay confirmed the binding relationship between miR-20a-5p and DDX5. Results showed that ALKBH5 and DDX5 were upregulated in T-ALL tissues and cells, whereas miR-20a-5p was downregulated. Silencing ALKBH5 inhibited T-ALL cell viability, colony formation, and proliferation, while promoting apoptosis. These effects were reversed by miR-20a-5p inhibition or DDX5 overexpression. ALKBH5 reduced the relative m6A level in T-ALL cells and decreased miR-20a-5p expression by reducing DGCR8 binding to pri-miR-20a-5p. miR-20a-5p suppressed DDX5 transcription. In conclusion, ALKBH5-mediated m6A demethylation decreases DGCR8 binding to pri-miR-20a, thereby repressing miR-20a-5p expression and enhancing DDX5 expression, ultimately inhibiting T-ALL cell apoptosis and promoting proliferation.

M6A-induced transcription factor IRF5 contributes to the progression of cervical cancer by upregulating PPP6C

Cervical cancer (CC) is a gynaecological malignancy tumour that seriously threatens women's health. Recent evidence has identified that interferon regulatory factor 5 (IRF5), a nucleoplasm shuttling protein, is a pivotal transcription factor regulating the growth and metastasis of various human tumours. This study aimed to investigate the function and molecular basis of IRF5 in CC development. IRF5, protein phosphatase 6 catalytic subunit (PPP6C) and methyltransferase-like 3 (METTL3) mRNA levels were evaluated by quantitative real-time (qRT)-polymerase chain reaction (PCR). IRF5, PPP6C, METTL3, B-cell lymphoma 2 and Bax protein levels were detected using western blot. Cell proliferation, migration, invasion, angiogenesis and apoptosis were determined by using colony formation, 5-ethynyl-2'-deoxyuridine (EdU), transwell, tube formation assay and flow cytometry assay, respectively. Glucose uptake and lactate production were measured using commercial kits. Xenograft tumour assay in vivo was used to explore the role of IRF5. After JASPAR predication, binding between IRF5 and PPP6C promoter was verified using chromatin immunoprecipitation and dual-luciferase reporter assays. Moreover, the interaction between METTL3 and IRF5 was verified using methylated RNA immunoprecipitation (MeRIP). IRF5, PPP6C and METTL3 were highly expressed in CC tissues and cells. IRF5 silencing significantly inhibited cell proliferation, migration, invasion, angiogenesis and glycolytic metabolism in CC cells, while induced cell apoptosis. Furthermore, the absence of IRF5 hindered tumour growth in vivo. At the molecular level, IRF5 might bind with PPP6C to positively regulate the expression of PPP6C mRNA. Meanwhile, IRF5 was identified as a downstream target of METTL3-mediated m6A modification. METTL3-mediated m6A modification of mRNA might promote CC malignant progression by regulating PPP6C, which might provide a promising therapeutic target for CC treatment.

MicroRNAs Associated with a Bad Prognosis in Acute Myeloid Leukemia and Their Impact on Macrophage Polarization

MicroRNAs (miRNAs) are short, non-coding ribonucleic acids (RNAs) associated with gene expression regulation. Since the discovery of the first miRNA in 1993, thousands of miRNAs have been studied and they have been associated not only with physiological processes, but also with various diseases such as cancer and inflammatory conditions. MiRNAs have proven to be not only significant biomarkers but also an interesting therapeutic target in various diseases, including cancer. In acute myeloid leukemia (AML), miRNAs have been regarded as a welcome addition to the limited therapeutic armamentarium, and there is a vast amount of data on miRNAs and their dysregulation. Macrophages are innate immune cells, present in various tissues involved in both tissue repair and phagocytosis. Based on their polarization, macrophages can be classified into two groups: M1 macrophages with pro-inflammatory functions and M2 macrophages with an anti-inflammatory action. In cancer, M2 macrophages are associated with tumor evasion, metastasis, and a poor outcome. Several miRNAs have been associated with a poor prognosis in AML and with either the M1 or M2 macrophage phenotype. In the present paper, we review miRNAs with a reported negative prognostic significance in cancer with a focus on AML and analyze their potential impact on macrophage polarization.

Comprehensive analysis of cuproptosis-associated LncRNAs predictive value and related CeRNA network in acute myeloid leukemia

Background

Acute myeloid leukemia (AML) is characterized by a high recurrence and mortality rate. Cuproptosis is involved in cell death regulation in in a variety of solid tumors. Long non-coding RNAs that regulate cuproptosis genes in the pathogenesis of acute leukemia have yet to be explored.

Methods

First, cuproptosis genes with distinct expression levels were discovered by contrasting AML with normal samples from the TCGA and GTEx cohorts. Pearson correlation and univariate Cox-regression analysis were performed to identify cuproptosis-associated lncRNAs with significant prognostic values. Then the least absolute shrinkage and selection operator (LASSO) Cox regression was utilized to establish a multi-gene signature to predict AML prognosis. Next, Kaplan-Meier estimator, receiver operating characteristic curve, and a nomogram were performed to evaluate the predictive capacity of the risk signature. Functional enrichment analyses were employed to assess their function. Moreover, qRT-PCR testing of lncRNA expression in AML samples was conducted. The competing endogenous RNA (ceRNA) network was constructed to find the target genes.

Results

A risk model based on the signature of three cuproptosis-associated lncRNAs was developed. The results showed that the model possessed excellent prognostic potential. The nomogram raised the accuracy in predicting AML survival. In addition, functional enrichment analyses demonstrated an enrichment of inflammatory and immune-related pathways. Moreover, correlations between the risk signature and clinicopathological variables, tumor mutational burden, RNA stemness score, immune profile, and drug sensitivity were observed. Furthermore, we discovered that TRAF3IP2-AS1 may function as a ceRNA to regulate cuproptosis and ferroptosis gene expression.

Conclusion

The risk signature established in this study could serve as a reliable biosignature for AML prognosis. And the findings presented here may facilitate research on cuproptosis in AML.

High expression of miR-107 and miR-17 predicts poor prognosis and guides treatment selection in acute myeloid leukemia

Background

The prognostic significance of miR-107 and miR-17 in patients with acute myeloid leukemia (AML) remains unclear.

Methods

A total of 173 patients with de novo AML from the Cancer Genome Atlas database were enrolled in this study and further divided into a chemotherapy group (98 cases) and an allogeneic hematopoietic stem cell transplantation (allo-HSCT) group (75 cases) according to their therapy regimen.

Results

In the chemotherapy cohort, high miR-107 or miR-17 expression was associated with poorer overall survival (OS) and event-free survival (EFS). On the other hand, there were no significant differences in OS and EFS between the high- and low-expression subgroups in the allo-HSCT group. Next, we stratified the total number of patients with AML into high- and low-expression groups according to the median expression levels of miR-107 or miR-17. In the high miR-107 or miR-17 expression group, patients treated with allo-HSCT had longer OS than those treated with chemotherapy. In the low miR-107 or miR-17 expression group, no significant differences in OS and EFS were observed between the two therapy subgroups. When patients were further clustered into three groups (both low miR-107 and low miR-17, either high miR-107 or high miR-17, and both high miR-107 and high miR-17), patients with both high miR-107 and high miR-17 expression had the worst OS and EFS of the entire group and of the chemotherapy group. On the other hand, there were no significant differences in OS and EFS among the three subgroups in the allo-HSCT group. Cox regression confirmed the concurrence of high expression of miR-107 and miR-17 might act as an independent prognostic factor for EFS and OS in the entire group and the chemotherapy group. Bioinformatics analysis showed differentially expressed genes (DEGs) associated with miR-107 and miR-17 expression were mainly enriched in multiple metabolic processes.

Conclusions

The combination of miR-107 and miR-17 provides prognostic significance for patients with AML and should be considered in the clinical selection of the optimal treatment regimen when deciding between chemotherapy and allo-HSCT.

Non-coding RNAs are correlated to TGF-β receptor type 2 in patients with colorectal cancer

BACKGROUND

Multiple molecular expression alterations, particularly in non-coding RNAs, play fundamental roles in the regulations of cellular processes and may relate to the occurrence and progression of colorectal cancer (CRC). In the present study, we investigated the associations between TGFBR2, miR20a-5p and long non-coding RNA (lncRNA) LAMTOR5-AS1 in CRC patients.

METHODS

Colorectal cancer and adjacent normal tissue samples (n = 34) were prepared from CRC patients. The associations between TGFBR2, miR20a-5p and lncRNA LAMTOR5-AS1 were predicted using bioinformatics tools. The expression levels of TGFBR2, miR20a-5p and lncRNA LAMTOR5-AS1 were measured using a quantitative real-time polymerase chain reaction technique. The TGFBR2 protein values were measured by western blotting. The clinical importance of lncRNA LAMTOR5-AS1 was assessed using receiver operating characteristic curve.

RESULTS

The up-regulated levels of TGFBR2 (p = 0.02), TGFBR2 protein (p = 0.008) and lncRNA LAMTOR5-AS1 (p = 0.02) were significantly observed in CRC tissues compared to the adjacent normal tissues. The miR20a-5p expression level (p = 0.009) was downregulated in CRC tissues. In addition, the miR20a-5p expression level was inversely correlated to the TGFBR2 gene (r²  = 0.88, p < 0.0001), protein (r²  = 0.95, p < 0.0001) and lncRNA LAMTOR5-AS1 gene (r²  = 0.93, p < 0.0001) expression levels. Based on the area under curve, the increase of lncRNA LAMTOR5-AS1 expression level with a sensitivity of 64.52% and specificity of 65.52% was considered in CRC patients.

CONCLUSIONS

We propose that miR20a-5p is inversely related to long non-coding RNA (lncRNA) LAMTOR5-AS, such that it may be involved in the regulation of TGFBR2 expression level in CRC patients.

Implication of microRNAs in Carcinogenesis with Emphasis on Hematological Malignancies and Clinical Translation

MicroRNAs (miRNAs) are evolutionarily conserved small non-coding RNAs, that are involved in the multistep process of carcinogenesis, contributing to all established hallmarks of cancer. In this review, implications of miRNAs in hematological malignancies and their clinical utilization fields are discussed. As components of the complex regulatory network of gene expression, influenced by the tissue microenvironment and epigenetic modifiers, miRNAs are “micromanagers” of all physiological processes including the regulation of hematopoiesis and metabolic pathways. Dysregulated miRNA expression levels contribute to both the initiation and progression of acute leukemias, the metabolic reprogramming of malignantly transformed hematopoietic precursors, and to the development of chemoresistance. Since they are highly stable and can be easily quantified in body fluids and tissue specimens, miRNAs are promising biomarkers for the early detection of hematological malignancies. Besides novel opportunities for differential diagnosis, miRNAs can contribute to advanced chemoresistance prediction and prognostic stratification of acute leukemias. Synthetic oligonucleotides and delivery vehicles aim the therapeutic modulation of miRNA expression levels. However, major challenges such as efficient delivery to specific locations, differences of miRNA expression patterns between pediatric and adult hematological malignancies, and potential side effects of miRNA-based therapies should be considered.

Regulatory mechanism of miR-20a-5p expression in Cancer

MicroRNAs(miRNAs) are non-coding single-stranded RNA molecules encoded by endogenous genes with a length of about 22 nucleotides. The dysregulation of miRNAs has been proven to be one of the vital causes of cancer, which makes them a biomarker for cancer diagnosis and prognosis. Compared with surgery and chemotherapy, nucleic acid therapy targeting specific miRNAs is a promising candidate for cancer treatment. miR-20a-5p plays an anticancer role in high-incidence human cancers such as cervical cancer, breast cancer and leukemia, which is of great importance in the diagnosis of cancers. The up-regulation and down-regulation of miR-20a-5p offers a possible breakthrough for the treatment of cancers. In this paper, we aim to investigate the functional significance of miR-20a-5p in different cancers, reviewing the expression differences of miR-20a-5p in cancer, while systematically summarizing the changes of circRNA-miR-20a-5p networks, and probe how it promotes messenger RNA (mRNA) degradation or inhibits mRNA translation to regulate downstream gene expression. We've also summarized the biogenesis mechanism of miRNAs, and emphasized its role in cell proliferation, cell apoptosis and cell migration. On this basis, we believe that miR-20a-5p is a promising and effective marker for cancer diagnosis, prognosis and treatment.