SLIT2 promoter hypermethylation-mediated SLIT2-IT1/miR-218 repression drives leukemogenesis and predicts adverse prognosis in myelodysplastic neoplasm

MiR-218 Exhibits Anti-Leukemia Effects by Targeting CTNND2 in Primary Acute Erythroid Leukemia HEL Cells

Acute erythroid leukemia (AEL) is a rare acute myeloid leukemia (AML) subtype that is highly aggressive and is associated with a poor prognosis. Notably, the blockage of erythroid differentiation represents a significant factor in the pathogenesis of erythroleukemia. Prior studies indicated that miR-218 inhibited the erythroid differentiation in a chronic myeloid leukemia (CML)-derived erythroleukemia cell line K562. However, functions of miR-218 in primary AEL remains to be elucidated. To address this gap, functions of miR-218 in HEL cells were evaluated through cell differentiation, cell proliferation, colony formation, cell cycle and cell apoptosis experiments. Subsequently, the targeted downstream genes of miR-218 were identified by the transcriptome sequencing and bioinformatic research, of which demonstrated by the dual-luciferase reporter experiment. Finally, the underlying mechanism of miR-218 in leukemogenesis was identified by enrichment analysis and was validated by western blot (WB) assays. Intriguingly, enhanced miR-218 showed no effect on the erythroid differentiation in HEL cells by determination of the expression of erythroid markers including GATA1, KLF1, TFRC and GYPA. However, miR-218 overexpression in HEL cells presented a markedly anti-proliferative and pro-apoptotic effects, inhibited colony formation and G0/G1 arrest. Transcriptome sequencing and bioinformatics analysis revealed that CTNND2 as the candidate gene of miR-218 within its 3'-untranslated region (3'-UTR) could be bonded by it. Reduced expression level of CTNND2 was further demonstrated by quantitative-PCR and WB after miR-218 overexpression in HEL cells. Furthermore, the luciferase report assay revealed that the CTNND2 production was reduced with its 3'-UTR region was bonded by miR-218. In addition, MAPK signaling pathway was identified and validated as the potential functional pathway involved in leukemogenesis caused by miR-218 overexpression in HEL cells. In summary, miR-218 exhibits anti-proliferative and pro-apoptotic functions by targeting CTNND2 and modulating MAPK signaling in HEL cells, yet it has no impact on the erythroid differentiation process.

Overexpression and oncogenic role of RIPK3 in acute myeloid leukemia associated with specific subtypes and treatment outcome

BACKGROUND

Receptor-interacting protein kinase 3 (RIPK3) has been implicated in the pathogenesis of diverse human cancers. However, the role of RIPK3 in acute myeloid leukemia (AML) is not fully understood, which needs further research and clarification.

METHODS

We first identified the expression and clinical prognostic value of RIPK3 in AML through a public database and further validated in our research cohort. In addition, the biological function of RIPK3 in leukemic development was further verified through in vitro experiments.

RESULTS

Based on the GEPIA database, we screened that RIPK3 overexpression among RIPK family was associated with poor prognosis in AML. Afterwards, another independent cohort from our research center further confirmed the expression pattern of RIPK3 in AML patients. Clinically, increased RIPK3 expression was closely related to specific subtypes of AML, such as FAB-M4/M5, normal karyotype and NPM1 mutation. The significant association of RIPK3 overexpression with FAB-M4/M5 was further validated in AML cell lines. Notably, AML patients with RIPK3 overexpression received transplantation presented a markedly longer survival than those just receiving chemotherapy, whereas those with RIPK3 underexpression showed similar survival between transplantation and chemotherapy group. Bioinformatics analysis showed the significant association of RIPK3 expression with diverse oncogenes/tumor suppressor genes and tumor-related biological processes in AML. Subsequently, we further performed functional experiments in vitro confirmed the potential oncogenic role of RIPK3 in AML.

CONCLUSIONS

Overexpression of RIPK3 was associated with specific subtypes of AML, such as FAB-M4/M5, normal karyotype and NPM1 mutation, and may facilitate the leukemic development. Moreover, RIPK3 overexpression was associated poor prognosis, and may guide treatment choice in AML.

Identification of HOXA9 methylation as an epigenetic biomarker predicting prognosis and guiding treatment choice in acute myeloid leukemia

BACKGROUND

The homeobox (HOX) genes especially for HOXA cluster play crucial roles in leukemogenesis. HOXA overexpression caused by genetic alterations, such as KMT2A rearrangements, NUP98- fusions and FLT3-ITD mutations, is frequently identified in AML. However, very few studies determined the DNA methylation-mediated epigenetic regulation of the HOXA cluster genes in AML.

METHODS

We systematically first screened the prognostic value of HOXA cluster genes methylation in AML from The Cancer Genome Atlas (TCGA) datasets. Afterwards, the candidate prognosis-related gene HOXA9 were selected for clinical relevance analysis and were further validated in another independent cohort from our research center.

RESULTS

The methylation of HOXA9, among HOXA cluster genes, negatively correlated with adverse prognosis and expression were screened and identified in AML among TCGA datasets. Clinically, HOXA9 hypomethylation was positively correlated with specific subtypes of AML, such as French-American-British (FAB)-M5/M7, normal karyotype and FLT3, NPM1 and DNMT3A mutation, whereas negatively associated with FAB-M3, t(15;17), t(8;21) and t(16;16). Importantly, AML patients with HOXA9 hypomethylation may profit from transplantation, whereas AML patients with HOXA9 hypermethylation could not, suggesting that HOXA9 methylation may be used to guide therapeutic selection between transplantation and chemotherapy. Bioinformatics analysis demonstrated the association of HOXA9 expression with diverse leukemia-related genes (HOXAs, SOSTDC1, MEG3, miR-10a, miR-381 and miR-193b) and signaling pathways (PI3K-Akt signaling) in AML. Subsequently, we further validate the hypomethylation pattern of HOXA9 in AML patients and the epigenetic regulation of HOXA9 methylation in AML cell-lines.

CONCLUSIONS

HOXA9 methylation linked to HOXA9 expression correlates with diverse genetic abnormalities of AML, such as normal karyotype, t(15;17), t(8;21), t(16;16) and FLT3, NPM1 and DNMT3A mutations. Moreover, HOXA9 hypomethylation may be associated with adverse prognosis, and may guide treatment choice in AML.

Crosstalk between circBMI1 and miR-338-5p/ID4 inhibits acute myeloid leukemia progression

BMI1 polycomb ring finger proto-oncogene (BMI1) is involved in the pathogenesis of different cancers, including acute myeloid leukemia (AML). However, the role of the circular RNA of BMI1 (circBMI1) has not been studied. Our study aimed to investigate the role and mechanism of circBMI1 in AML. circBMI1 was significantly decreased in bone marrow mononuclear cells aspirated from patients with AML. Receiver operating characteristic curve analysis showed that circBMI1 could distinguish patients with AML from controls. By overexpressing and knocking down circBMI1 in HL-60 cells, we found that circBMI1 inhibited cell proliferation, promoted apoptosis, and increased chemotherapeutic drug sensitivity in AML. Experiments using severe combined immune-deficient mice and circBMI1 transgenic mice showed that mice with circBMI1 overexpression had lower white blood cell counts, which suggested less severe AML invasion. RNA immunoprecipitation and dual-luciferase reporter assay revealed binding sites among circBMI1, miR-338-5p, and inhibitor of DNA-binding protein 4 (ID4). Rescue experiments proved that circBMI1 inhibited AML progression by binding to miR-338-5p, which affected the expression of ID4. By coculturing exosomes extracted from circBMI1-HL-60 and small interfering circBMI1-HL-60 cells with HL-60 cells, we found that exosomes from circBMI1-HL-60 cells showed tumor-suppressive effects, namely inhibiting HL-60 proliferation, promoting apoptosis, and increasing chemotherapeutic drug sensitivity. Exosomes from small interfering circBMI1-HL-60 cells showed the opposite effects. circBMI1 may act as an exosome-dependent tumor inhibitor. circBMI1, a potential biomarker for clinical diagnosis, acts as a tumor suppressor in AML by regulating miR-338-5p/ID4 and might affect the pathogenesis of AML by exosome secretion.

Research on the expression of Mir-218-2 in the serum of patients with papillary thyroid cancer and its clinical significance

Papillary thyroid carcinoma is an epithelial malignancy with follicular cell differentiation and sets of defined nuclear features and appearance of an irregular solid mass. The main objective of our study is to research on the expression of miR-218-2 in the serum of patients with papillary thyroid cancer and its clinical significance. Our study involved patients with thyroid nodules were divided into a capitate cancer group (N = 100) and a benign nodule group (N =100). Lastly, 50 cases of healthy individuals were used as controls. The total sample size was 250. All cases were clinically diagnosed and underwent histopathological examinations at the Tonglu County Hospital of Traditional Chinese Medicine between January 2023 and January 2024. Quantitative RT-PCR was used to assess the expression levels of miR-218-2 and its host gene SLIT3 in normal and cancer thyroid tissues. We found that 45% of tumour sizes were less than 1 cm with 90% of tumours did not infiltrate the glandular capsule, implying a favourable prognosis. Lastly, 85% of tumours were well differentiated with about 75% showing no metastasis while 60% of TNM stage were classified as stage I. Also, miR-218-2 and its host gene SLIT3 are significantly down-regulated in papillary thyroid carcinoma. The inhibitory effects of miR-218-2 act in synergy with its host gene SLIT3 to alter the rates of cell invasion, cell migration and cell proliferation. Our findings have clinical significance on the involvement of miR-218-2 and SLIT3. There exists a functional relationship between host genes and intronic miRNAs in the tumorigenesis of thyroid cancers.

MicroRNA dysregulation in myelodysplastic syndromes: implications for diagnosis, prognosis, and therapeutic response

Myelodysplastic syndromes (MDS) are a group of malignant clonal hematological disorders with heterogeneous clinical course and risk of transformation to acute myeloid leukemia. Genetic and epigenetic dysregulation, including alterations in microRNA (miRNA) expression, plays a pivotal role in MDS pathogenesis influencing disease development and progression. MiRNAs, known for their regulatory roles in gene expression, have emerged as promising biomarkers in various malignant diseases. This review aims to explore the diagnostic and prognostic roles of miRNAs in MDS. We discuss research efforts aimed at understanding the clinical utility of miRNAs in MDS management. MiRNA dysregulation is linked to specific chromosomal abnormalities in MDS, providing insights into the molecular landscape of the disease. Circulating miRNAs in plasma offer a less invasive avenue for diagnostic and prognostic assessment, with distinct miRNA profiles identified in MDS patients. Additionally, we discuss investigations concerning the role of miRNAs as markers for treatment response to hypomethylating and immunomodulating agents, which could lead to improved treatment decision-making and monitoring. Despite significant progress, further research in larger patient cohorts is needed to fully elucidate the role of miRNAs in MDS pathogenesis and refine personalized approaches to patient care.

Role of HOXA1-4 in the development of genetic and malignant diseases

The HOXA genes, belonging to the HOX family, encompass 11 members (HOXA1-11) and exert critical functions in early embryonic development, as well as various adult processes. Furthermore, dysregulation of HOXA genes is implicated in genetic diseases, heart disease, and various cancers. In this comprehensive overview, we primarily focused on the HOXA1-4 genes and their associated functions and diseases. Emphasis was placed on elucidating the impact of abnormal expression of these genes and highlighting their significance in maintaining optimal health and their involvement in the development of genetic and malignant diseases. Furthermore, we delved into their regulatory mechanisms, functional roles, and underlying biology and explored the therapeutic potential of targeting HOXA1-4 genes for the treatment of malignancies. Additionally, we explored the utility of HOXA1-4 genes as biomarkers for monitoring cancer recurrence and metastasis.

SLIT2 promoter hypermethylation predicts disease progression in chronic myeloid leukemia

BACKGROUND

Aberrant DNA methylation plays a crucial role in the progression of myeloid neoplasms. Previously, our literature reported that slit guidance ligand 2 (SLIT2) promoter methylation was associated with disease progression and indicated a poor prognosis in patients with myelodysplastic syndrome. Herein, we further investigated the clinical implications and role of SLIT2 promoter methylation in patients with chronic myeloid leukemia (CML).

METHODS

The level of SLIT2 promoter methylation was determined in 104 CML patients, and its clinical significance was analyzed. Moreover, demethylation studies were performed in K562 cells to determine the epigenetic mechanism by which SLIT2 promoter methylation is regulated in CML.

RESULTS

The level of SLIT2 promoter methylation was similar between CML patients and controls. However, deeper analysis revealed that the SLIT2 promoter methylation level in the accelerated phase (AP) and blast crisis (BC) was markedly higher than that in the chronic phase (CP) and controls. Additionally, a marked difference was identified between the SLIT2 promoter hypermethylated and non-hypermethylated groups among CML patients grouped by clinical stage. The frequency of SLIT2 hypermethylation was markedly increased with the progression of clinical stage, that is, it was the lowest in CP samples (12/80, 15%), higher in AP samples (4/8, 50%) and the highest in BC samples (11/16, 69%). Importantly, the level/density of SLIT2 promoter methylation was significantly higher in the advanced stage than in the early stage among the 6 tested paired CML patients. Epigenetically, the expression of the SLIT2-embedded non-coding genes SLIT2-IT1 and miR-218 expression was decreased in patients with CML. SLIT2 promoter hypermethylated cases had a markedly lower SLIT2-IT1 expression level than SLIT2 promoter non-hypermethylated cases. Moreover, SLIT2-IT1 and miR-218 expression was remarkably upregulated in a dose-dependent manner after demethylation treatment of K562 cells.

CONCLUSIONS

Hypermethylation of the SLIT2 promoter is correlated with disease progression in CML. Furthermore, SLIT2 promoter methylation may function by regulating the expression of the SLIT2-embedded non-coding genes SLIT2-IT1 and miR-218 during CML progression.

Identification of Differentially Expressed Intronic Transcripts in Osteosarcoma

Over the past decade; the discovery and characterization of long noncoding RNAs (lncRNAs) have revealed that they play a major role in the development of various diseases; including cancer. Intronic transcripts are one of the most fascinating lncRNAs that are located within intron regions of protein-coding genes, which have the advantage of encoding micropeptides. There have been several studies looking at intronic transcript expression profiles in cancer; but almost none in osteosarcoma. To overcome this problem; we have investigated differentially expressed intronic transcripts between osteosarcoma and normal bone tissues. The results highlighted that NRG1-IT1; FGF14-IT1; and HAO2-IT1 were downregulated; whereas ER3-IT1; SND1-IT1; ANKRD44-IT1; AGAP1-IT1; DIP2A-IT1; LMO7DN-IT1; SLIT2-IT1; RNF216-IT1; and TCF7L1-IT1 were upregulated in osteosarcoma tissues compared to normal bone tissues. Furthermore, we identified if the transcripts encode micropeptides and the transcripts' locations in a cell.