Detection of NPM1 Mutations in Acute Myeloid Leukemia by using Drop-Off Droplet Digital PCR and its Clinical Application.

BACKGROUND: Nucleophosmin 1 (NPM1) mutations, which occur in 25 - 30% of acute myeloid leukemia (AML) and 50 - 60% of AML with normal karyotype, have been identified as an important marker for stratification of prog-nosis in AML. This study aimed to establish a new quantitative polymerase chain reaction (PCR) technique, the drop-off droplet digital PCR (ddPCR), for rapid and sensitive detection of NPM1 mutations in AML. METHODS: We established the drop-off ddPCR system and verified its performance. NPM1 mutations were screened in 130 AML patients by drop-off ddPCR and were validated by Sanger sequencing and next-generation sequencing (NGS). Then, the NPM1 mutation burden was dynamically monitored in five patients. RESULTS: The limit of blank (LOB) of drop-off ddPCR established for NPM1 mutation was 3.36 copies/µL, and the limit of detection (LOD) was 5.00 - 5.37 copies/µL in 50 ng DNA, and the sensitivity was about 0.05%, which had good linearity. Drop-off ddPCR identified 33/130 (25.4%) NPM1 mutated cases, consistent with Sanger sequencing. In 18 NPM1 positive cases selected randomly, NGS identified fourteen with type A mutation, two with type D mutation, and two with rare type mutations. The mutation burden of NPM1 mutation analyzed by NGS was consistent with the drop-off ddPCR. The sequential samples were detected for measurable residual disease (MRD) monitoring in 5 patients showed that the NPM1 mutation burden was consistent with clinical remission and recurrence. Compared with traditional ddPCR, drop-off ddPCR was also suitable for MRD monitoring. CONCLUSIONS: In this study, we established a drop-off ddPCR method for detecting three common mutations in AML with good sensitivity and repeatability, which can be used to screen mutations in newly diagnosed AML patients and for MRD monitoring after remission to guide treatment.

DNA methylation-mediated differential expression of DLX4 isoforms has opposing roles in leukemogenesis.

BACKGROUND: Previously, we reported the expression of DLX4 isoforms (BP1 and DLX7) in myeloid leukemia, but the functional role of DLX4 isoforms remains poorly understood. In the work described herein, we further determined the underlying role of DLX4 isoforms in chronic myeloid leukemia (CML) leukemogenesis. METHODS: The expression and methylation of DLX4 isoforms were detected by real-time quantitative PCR (RT-qPCR) and real-time quantitative methylation-specific PCR (RT-qMSP) in patients with CML. The functional role of DLX4 isoforms was determined in vitro and in vivo. The molecular mechanism of DLX4 isoforms in leukemogenesis was identified based on chromatin immunoprecipitation with high-throughput sequencing (ChIP-Seq)/assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-Seq) and RNA sequencing (RNA-Seq). RESULTS: BP1 expression was increased in patients with CML with unmethylated promoter, but DLX7 expression was decreased with hypermethylated promoter. Functionally, overexpression of BP1 increased the proliferation rate of K562 cells with S/G2 promotion, whereas DLX7 overexpression reduced the proliferation rate of K562 cells with G1 arrest. Moreover, K562 cells with BP1 overexpression increased the tumorigenicity in NCG mice, whereas K562 cells with DLX7 overexpression decreased the tumorigenicity. Mechanistically, a total of 91 genes including 79 messenger RNAs (mRNAs) and 12 long noncoding RNAs (lncRNAs) were discovered by ChIP-Seq and RNA-Seq as direct downstream targets of BP1. Among the downstream genes, knockdown of RREB1 and SGMS1-AS1 partially revived the proliferation caused by BP1 overexpression in K562 cells. Similarly, using ATAC-Seq and RNA-Seq, a total of 282 genes including 151 mRNA and 131 lncRNAs were identified as direct downstream targets of DLX7. Knockdown of downstream genes PTPRB and NEAT1 partially revived the proliferation caused by DLX7 overexpression in K562 cells. Finally, we also identified and validated a SGMS1-AS1/miR-181d-5p/SRPK2 competing endogenous RNA (ceRNA) network caused by BP1 overexpression in K562 cells. CONCLUSIONS: The current findings reveal that DNA methylation-mediated differential expression of DLX4 isoforms BP1 and DLX7 plays opposite functions in leukemogenesis. BP1 plays an oncogenic role in leukemia development, whereas DLX7 acts as a tumor suppressor gene. These results suggest DLX4 as a therapeutic target for antileukemia therapy.

Treatment of traumatic cerebrospinal fluid rhinorrhea via extended extradural anterior skull base approach.

OBJECTIVE: To describe and assess the repair technique and perioperative management for cerebrospinal fluid (CSF) leak resulting from extensive anterior skull base fracture via extradural anterior skull base approach. METHODS: This was a retrospective review conducted at the Department of Neurosurgery of the Shanghai Tenth People's Hospital from January 2015 to April 2020. Patients with traumatic CSF rhinorrhea resulting from extensive anterior skull base fracture treated surgically via extended extradural anterior skull base approach were included in this study. The data of medical and radiological records, surgical approaches, repair techniques, peritoperative management, surgical outcome and postoperative follow-up were analyzed. Surgical repair techniques were tailored to the condition of associated injuries of the scalp, bony and dura injuries and associated intracranial lesions. Patients were followed up for the outcome of CSF leak and surgical complications. Data were presented as frequency and percent. RESULTS: Thirty-five patients were included in this series. The patients' mean age was 33 years (range 11-71 years). Eight patients were treated surgically within 2 weeks; while the other 27 patients, with prolonged or recurrent CSF rhinorrhea, received the repair surgery at 17 days to 10 years after the initial trauma. The mean overall length of follow-up was 23 months (range 3-65 months). All the patients suffered from frontobasal multiple fractures. The basic repair tenet was to achieve watertight seal of the dura. The frontal pericranial flap alone was used in 20 patients, combined with temporalis muscle and/or its facia in 10 patients. Free fascia lata graft was used instead in the rest 5 patients. No CSF leak was found in all the patients at discharge. There was no surgical mortality in this series. Bilateral anosmia was the most common complication. At follow-up, no recurrent CSF leak or meningitis occurred. No patients developed mucoceles, epidural abscess or osteomyelitis. One patient ultimately required ventriculoperitoneal shunt because of progressive hydrocephalus. CONCLUSION: Traumatic CSF rhinorrhea associated with extensive anterior skull base fractures often requires aggressive treatment via extended intracranial extradural approach. Vascularized tissue flaps are ideal grafts for cranial base reconstruction, either alone or in combination with temporalis muscle and its fascia---fascia lata sometimes can be opted as free autologous graft. The approach is usually reserved for patients with traumatic CSF rhinorrhea in complex frontobasal injuries.

EZH2 dysregulation: Potential biomarkers predicting prognosis and guiding treatment choice in acute myeloid leukaemia.

Accumulating studies have proved EZH2 dysregulation mediated by mutation and expression in diverse human cancers including AML. However, the expression pattern of EZH2 remains controversial in acute myeloid leukaemia (AML). EZH1/2 expression and mutation were analysed in 200 patients with AML. EZH2 expression was significantly decreased in AML patients compared with normal controls but not for EZH1 expression. EZH2 mutation was identified three of the 200 AML patients (1.5%, 3/200), whereas none of the patients harboured EZH1 mutation (0%, 0/200). EZH2 expression and mutation were significantly associated with -7/del(7) karyotypes. Moreover, lower EZH2 expression was associated with older age, higher white blood cells, NPM1 mutation, CEBPA wild-type and WT1 wild-type. Patients with EZH2 mutation showed shorter overall survival (OS) and leukaemia-free survival (LFS) than patients without EHZ2 mutation after receiving autologous or allogeneic haematopoietic stem cell transplantation (HSCT). However, EZH2 expression has no effect on OS and LFS of AML patients. Notably, in EZH2 low group, patients undergone HSCT had significantly better OS and LFS compared with patients only received chemotherapy, whereas no significant difference was found in OS and LFS between chemotherapy and HSCT patients in EZH2 high group. Collectively, EZH2 dysregulation caused by mutation and under-expression identifies specific subtypes of AML EZH2 dysregulation may be acted as potential biomarkers predicting prognosis and guiding the treatment choice between transplantation and chemotherapy.

Establishment and molecular characterization of decitabine-resistant K562 cells.

The clinical activity of decitabine (5-aza-2-deoxycytidine, DAC), a hypomethylating agent, has been demonstrated in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients. However, secondary resistance to this agent often occurs during treatment and leads to treatment failure. It is important to clarify the mechanisms underlying the resistance for improving the efficacy. In this study, by gradually increasing concentration after a continuous induction of DAC, we established the DAC-resistant K562 cell line (K562/DAC) from its parental cell line K562. The proliferation and survival rate of K562/DAC was significantly increased, whereas the apoptosis rate was remarkably decreased than that of K562 after DAC treatment. In K562/DAC, a total of 108 genes were upregulated and 118 genes were downregulated by RNA-Seq. In addition, we also observed aberrant expression of DDX43/H19/miR-186 axis (increased DDX43/H19 and decreased miR-186) in K562/DAC cells. Ectopic expression of DDX43 in parental K562 cells rendered cells resistant to the DAC. Taken together, we successfully established DAC-resistant K562 cell line which can serve as a good model for investigating DAC resistance mechanisms, and DDX43/H19/miR-186 may be involved in DAC resistance in K562.

Reduced protocadherin17 expression in leukemia stem cells: the clinical and biological effect in acute myeloid leukemia.

BACKGROUND: Leukemia stem cell (LSC)-enriched genes have been shown to be highly prognostic in acute myeloid leukemia (AML). However, the prognostic value of tumor suppressor genes (TSGs) that are repressed early in LSC remains largely unknown. METHODS: We compared the public available expression/methylation profiling data of LSCs with that of hematopoietic stem cells (HSCs), in order to identify potential tumor suppressor genes in LSC. The prognostic relevance of PCDH17 was analyzed on a cohort of 173 AML patients from The Cancer Genome Atlas (TCGA), and further validated in three independent cohorts (n = 339). RESULTS: We identified protocadherin17 (PCDH17) and demonstrated that it was significantly down-regulated and hypermethylated in LSCs compared with HSCs. Our analyses of primary AML patient samples also confirmed these deregulations. Clinically, low PCDH17 expression was associated with female sex (P = 0.01), higher WBC (P < 0.0001), higher percentages of blasts in bone marrow (BM) and peripheral blood (PB) (P = 0.04 and < 0.001, respectively), presence of FLT3-internal tandem duplications (P = 0.002), mutated NPM1 (P = 0.02), and wild-type TP53 (P = 0.005). Moreover, low PCDH17 expression predicted worse overall survival (OS) in four independent cohorts as well as in the molecularly defined subgroups of AML patients. In multivariable analyses, low PCDH17 expression retained independent prognostic value for OS. Biologically, PCDH17 expression-associated gene signatures were characterized by deregulations of EMT- and Wnt pathway-related genes. CONCLUSIONS: PCDH17 gene was silenced by DNA methylation in AML. Low PCDH17 expression is associated with distinct clinical and biological features and improves risk stratification in patients with AML.

Down-regulation of miR-29c is a prognostic biomarker in acute myeloid leukemia and can reduce the sensitivity of leukemic cells to decitabine.

BACKGROUND: MicroRNA-29c (miR-29c) is abnormally expressed in several cancers and serves as an important predictor of tumor prognosis. Herein, we investigate the effects of abnormal miR-29c expression and analyze its clinical significance in acute myeloid leukemia (AML) patients. In addition, decitabine (DAC) has made great progress in the treatment of AML in recent years, but DAC resistance is still common phenomenon and the mechanism of resistance is still unclear. We further analyze the influences of miR-29c to leukemic cells treated with DAC. METHODS: Real-time quantitative PCR (RQ-PCR) was carried out to detect miR-29c transcript level in 102 de novo AML patients and 25 normal controls. miR-29c/shRNA-29c were respectively transfected into K562 cells and HEL cells. Cell viability after transfection was detected by cell counting Kit-8 assays. Flow cytometry was used to detect apoptosis. RESULTS: MiR-29c was significantly down-regulated in AML (P < 0.001). Low miR-29c expression was frequently observed in patients with poor karyotype and high risk (P = 0.006 and 0.013, respectively). Patients with low miR-29c expression had a markedly shorter overall survival (OS) than those with high miR-29c expression (P < 0.001). Multivariate analysis confirmed the independent prognostic value of low miR-29c expression in both the whole cohort as well as the cytogenetically normal AML (CN-AML) subset. Over-expression of miR-29c in K562 treated with DAC inhibited growth, while silencing of miR-29c in HEL promoted growth and inhibited apoptosis. MiR-29c overexpression decreased the half maximal inhibitory concentration (IC50) of DAC in K562, while miR-29c silencing increased the IC50 of DAC in HEL. The demethylation of the miR-29c promoter was associated with its up-regulated expression. Although miR-29c demethylation was also observed in DAC-resistant K562 (K562/DAC), miR-29c expression was down-regulated. MiR-29c transfection also promoted apoptosis and decreased the IC50 of DAC in K562/DAC cells. CONCLUSIONS: Our results suggest that miR-29c down-regulation may act as an independent prognostic biomarker in AML patients, and miR-29c over-expression can increase the sensitivity of both non-resistant and resistant of leukemic cells to DAC.

Hypomethylation-mediated H19 overexpression increases the risk of disease evolution through the association with BCR-ABL transcript in chronic myeloid leukemia.

Previous study has revealed that H19 expression is required for efficient tumor growth induced by BCR-ABL in chronic myeloid leukemia (CML). Herein, we further determined H19 expression and its clinical implication in patients with CML. H19 expression and methylation were detected by real-time quantitative PCR and real-time quantitative methylation-specific PCR, and then clinical implication of H19 expression was further analyzed. H19 expression was significantly up-regulated in CML patients (p < 0.001). H19 expression with an area under receiver operating characteristic curve value of 0.824 might serve as a promising biomarker in distinguishing CML patients from controls. The patients with high H19 expression had a tendency of higher white blood cells and BCR-ABL transcript than those with low H19 expression. H19 overexpression occurred with the higher frequency in blast crisis stage (11/11, 100%), lower in accelerated phase (3/5, 60%), and chronic phase (42/62, 66%) stages. Moreover, paired patients during disease progression with increased BCR-ABL transcript also showed a significant upregulation of H19 expression. Meanwhile, H19 expression was decreased in follow-up patients who achieved complete molecular remission after tyrosine kinase inhibitors-based therapy. Epigenetic studies showed that H19 differentially methylated region/imprinting control region (DMR/ICR) was hypomethylated and associated with H19 expression in CML patients. Moreover, demethylation of H19 DMR/ICR reactivated H19 expression in K562 cells. Collectively, H19 overexpression, a frequent event in CML, was associated with higher BCR-ABL transcript involving in disease progression. Moreover, H19 DMR/ICR hypomethylation in CML may be one of the mechanisms mediating H19 overexpression.

Methylation-independent ITGA2 overexpression is associated with poor prognosis in de novo acute myeloid leukemia.

Previous studies have been indicated that integrin α2 (ITGA2) may be important in cell migration, invasion, survival, and angiogenesis. However, the correlation between ITGA2 expression and acute myeloid leukemia (AML) is still unclear. Real-time quantitative polymerase chain reaction was carried out to analyze ITGA2 messenger RNA level. Methylation-specific polymerase chain reaction (PCR) and bisulfite sequencing PCR were performed to detect the methylation of ITGA2 promoter. ITGA2 expression was significantly upregulated in 134 de novo AML patients compared with 33 controls (p = 0.007). ITGA2high group had markedly lower complete remission (CR) rate than ITGA2low group (p = 0.011). Furthermore, the overall survival in ITGA2high patients was significantly shorter than ITGA2low patients throughout AML cohort, non-acute promyelocytic leukemia (APL) and cytogenetic normal-AML (p = 0.001, 0.002, and 0.044, respectively). Multivariate analysis confirmed that ITGA2 overexpression served as an independent prognostic factor in both whole-cohort AML patients (p = 0.018) and non-APL AML patients (p = 0.021). Besides, ITGA2 expression level was significantly decreased in AML patients after CR (p = 0.011), and was returned at the time of relapse phase (p = 0.021). Moreover, unmethylated ITGA2 promoter was identified in normal controls, leukemia cell lines, and primary leukemia cells with low or high ITGA2 expression. In conclusions, methylation-independent ITGA2 overexpression is associated with poor prognosis in AML.

Methylation-associated DOK1 and DOK2 down-regulation: Potential biomarkers for predicting adverse prognosis in acute myeloid leukemia.

DOK-1 and DOK-2 (DOK1/2) are closely related members of downstream of tyrosine kinase (DOK) family genes, which are found to be frequently rearranged in several hematopoietic cancers. However, the clinical implications of DOK1/2 in acute myeloid leukemia (AML) remain largely unknown. To investigate the clinical significance, real-time quantitative PCR (RQ-PCR) was carried out to detect DOK1/2 expressions in 125 de novo AML patients and 28 healthy controls. Real-time quantitative methylation-specific PCR (RQ-MSP) and bisulfite sequencing PCR (BSP) were applied to detect DOK1/2 methylation level and density. DOK1/2 expressions were significantly down-regulated in AML patients. The promoters of DOK1/2 were highly hypermethylated and negatively correlated with DOK1/2 expressions in AML patients. In addition, we also confirmed that DOK1/2 expressions could be restored by DOK1/2 demethylation using 5-aza-2'-deoxycytidine in leukemia cell line THP-1. Survival analyses showed that low-expressed DOK1/2 were associated with markedly shorter overall survival and leukemia free survival in both whole-cohort AML and non-M3 AML patients. Multivariate analyses further revealed that DOK1/2 were act as independent prognostic factors in AML patients. These findings indicate that decreased DOK1/2 expressions associated with their promoter hypermethylations predict adverse prognosis in AML.

Decreased SCIN expression, associated with promoter methylation, is a valuable predictor for prognosis in acute myeloid leukemia.

The present study was aimed to investigate SCIN expression as well as promoter methylation and further explore their clinical relevance in acute myeloid leukemia (AML) patients. Real-time quantitative PCR was carried out to detect the expression level of SCIN in 119 AML patients and 37 healthy controls. Real-time quantitative methylation-specific PCR and bisulfite sequencing PCR were carried out to detect SCIN promoter methylation levels in 103 AML patients and 29 controls. As compared with controls, the level of SCIN transcript was significantly down-regulated in AML patients (P = 0.001), and the level of methylated SCIN promoter was significantly higher in AML patients (P = 0.001). Moreover, the level of promoter methylation was weakly negatively correlated with SCIN expression in AML patients (R = -0.265, P = 0.027). Demethylation of SCIN promoter by 5-aza-2'-deoxycytidine could restore its expression in leukemic cell line THP1. The age of SCINlow patients was significantly higher and C/EBPA mutation was significantly less than SCINhigh patients (P = 0.039 and 0.038, respectively). Moreover, the rate of complete remission (CR) of SCINlow patients was significantly lower than SCINhigh patients (P = 0.009). Kaplan-Meier analysis showed that low SCIN expression was associated with shorter overall survival (P = 0.036). Cox regression analysis demonstrated low SCIN expression was an independent poor prognostic factor (P = 0.047). Furthermore, SCIN expression was restored in those patients who achieved CR after induction therapy (P = 0.003). These findings indicate that decreased SCIN expression associated with its promoter methylation is a valuable biomarker for predicting adverse prognosis in AML patients.

Pan-cancer analysis identifies CD300 molecules as potential immune regulators and promising therapeutic targets in acute myeloid leukemia.

BACKGROUND: CD300s are a group of proteins playing vital roles in immune responses. However, much is yet to be elucidated regarding the expression patterns and clinical significances of CD300s in cancers. METHODS: In this study, we comprehensively investigated CD300s in a pan-cancer manner using multi-omic data from The Cancer Genome Atlas. We also studied the relationship between CD300s and the immune landscape of AML. RESULTS: We found that CD300A-CD300LF were generally overexpressed in tumors (especially AML), whereas CD300LG was more often downregulated. In AML, transactivation of CD300A was not mediated by genetic alterations but by histone modification. Survival analyses revealed that high CD300A-CD300LF expression predicted poor outcome in AML patients; the prognostic value of CD300A was validated in seven independent datasets and a meta dataset including 1115 AML patients. Furthermore, we demonstrated that CD300A expression could add prognostic value in refining existing risk models in AML. Importantly, CD300A-CD300LF expression was closely associated with T-cell dysfunction score and could predict response to AML immunotherapy. Also, CD300A was found to be positively associated with HLA genes and critical immune checkpoints in AML, such as VISTA, CD86, CD200R1, Tim-3, and the LILRB family genes. CONCLUSIONS: Our study demonstrated CD300s as potential prognostic biomarker and an ideal immunotherapy target in AML, which warrants future functional and clinical studies.

A novel methionine metabolism-related signature predicts prognosis and immunotherapy response in lung adenocarcinoma.

Recent research revealed methionine metabolism as a key mediator of tumor initiation and immune evasion. However, the relationship between methionine metabolism and tumor microenvironment (TME) in lung adenocarcinoma (LUAD) remains unknown. Here, we comprehensively analyzed the genomic alterations, expression patterns, and prognostic values of 68 methionine-related regulators (MRGs) in LUAD. We found that most MRGs were highly prognostic based on 30 datasets including 5024 LUAD patients. Three distinct MRG modification patterns were identified, which showed significant differences in clinical outcomes and TME characteristics: The C2 subtype was characterized by higher immune score, while the C3 subtype had more malignant cells and worse survival. We developed a MethScore to measure the level of methionine metabolism in LUAD. MethScore was positively correlated with T-cell dysfunction and tumor-associated macrophages (TAMs), indicating a dysfunctional TME phenotype in the high MethScore group. In addition, two immunotherapy cohorts confirmed that patients with a lower MethScore exhibited significant clinical benefits. Our study highlights the important role of methionine metabolism in modeling the TME. Evaluating methionine modification patterns will enhance our understanding of TME characteristics and can guide more effective immunotherapy strategies.

Identification and validation of necroptosis-related gene signatures to predict clinical outcomes and therapeutic responses in acute myeloid leukemia.

BACKGROUND: Necroptosis is a tightly regulated form of necrotic cell death that promotes inflammation and contributes to disease development. However, the potential roles of necroptosis-related genes (NRGs) in acute myeloid leukemia (AML) have not been elucidated fully. METHODS: We conducted a study to identify a robust biomarker signature for predicting the prognosis and immunotherapy efficacy based on NRGs in AML. We analyzed the genetic and transcriptional alterations of NRGs in 151 patients with AML. Then, we identified three necroptosis clusters. Moreover, a necroptosis score was constructed and assessed based on the differentially expressed genes (DEGs) between the three necroptosis clusters. RESULTS: Three necroptosis clusters were correlated with clinical characteristics, prognosis, the tumor microenvironment, and infiltration of immune cells. A high necroptosis score was positively associated with a poor prognosis, immune-cell infiltration, expression of programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1), immune score, stromal score, interferon-gamma (IFNG), merck18, T-cell dysfunction-score signatures, and cluster of differentiation-86, but negatively correlated with tumor immune dysfunction and exclusion score, myeloid-derived suppressor cells, and M2-type tumor-associated macrophages. Our observations indicated that a high necroptosis score might contribute to immune evasion. More interestingly, AML patients with a high necroptosis score may benefit from treatment based on immune checkpoint blockade. CONCLUSIONS: Consequently, our findings may contribute to deeper understanding of NRGs in AML, and facilitate assessment of the prognosis and treatment strategies.

Comprehensive characterization of TGFB1 across hematological malignancies.

TGFB1, which encodes TGF-ß1, a potent cytokine regulating varies cellular processes including immune responses. TGF-ß1 plays context-dependent roles in cancers and is increasingly recognized as a therapeutic target to enhance immunotherapy responses. We comprehensively evaluated expression of TGFB1 and its clinical and biological effects across hematological malignancies. TGFB1 expression was first explored using data from the GTEx, CCLE, and TCGA databases. The expression and clinical significances of TGFB1 in hematological malignancies were analyzed using Hemap and our In Silico curated datasets. We also analyzed the relationship between TGFB1 with immune scores and immune cell infiltrations in Hemap. We further assessed the value of TGFB1 in predicting immunotherapy response using TIDE and real-world immunotherapy datasets. TGFB1 showed a hematologic-tissue-specific expression pattern both across normal tissues and cancer types. TGFB1 expression were broadly dysregulated in blood cancers and generally associated with adverse prognosis. TGFB1 expression were associated with distinct TME properties among different blood cancer types. In addition, TGFB1 expression was found to be a useful marker in predicting immunotherapy responses. Our results suggest that TGFB1 is broadly dysregulated in hematological malignancies. TGFB1 might regulate the immune microenvironment in a cancer-type-specific manner, which could be applied in the development of new targeted drugs for immunotherapy.

ALOX5AP is a new prognostic indicator in acute myeloid leukemia.

BACKGROUND: The overexpression of ALOX5AP has been observed in many types of cancer and has been identified as an oncogene. However, its role in acute myeloid leukemia (AML) has not been extensively studied. This study aimed to identify the expression and methylation patterns of ALOX5AP in bone marrow (BM) samples of AML patients, and further explore its clinical significance. METHODS: Eighty-two de novo AML patients and 20 healthy donors were included in the study. Meanwhile, seven public datasets from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were included to confirm the alteration of ALOX5AP. Receiver operating characteristic (ROC) curve analysis was applied to determine the discriminative capacity of ALOX5AP expression to discriminate AML. The prognostic value of ALOX5AP was identified by the Kaplan-Meier method and log-rank test. It was further validated in four independent cohorts (n = 1186). Significantly different genes associated with ALOX5AP expression were subsequently compared by LinkedOmics, and Metascape database. RESULTS: The level of ALOX5AP expression was significantly increased in bone marrow cells of AML patients compared with healthy donors (P < 0.05). ROC curve analysis suggested that ALOX5AP expression might be a potential biomarker to discriminate AML from controls. ALOX5AP overexpression was associated with decreased overall survival (OS) in AML according to the TCGA data (P = 0.006), which was validated by other four independent cohorts. DNA methylation levels of ALOX5AP were significantly lower in AML patients compared to normal samples (P < 0.05), as confirmed in the Diseasemeth database and the independent cohort GSE63409. ALOX5AP level was positively associated with genes with proleukemic effects such as PAX2, HOX family, SOX11, H19, and microRNAs that act as oncogenes in leukemia, such as miR125b, miR-93, miR-494, miR-193b, while anti-leukemia-related genes and tumor suppressor microRNAs such as miR-582, miR-9 family and miR-205 were negatively correlated. CONCLUSION: ALOX5AP overexpression, associated with its hypomethylation, predicts poorer prognosis in AML.

Dysregulation of LINC00324 associated with methylation facilitates leukemogenesis in de novo acute myeloid leukemia.

INTRODUCTION: LINC00324 was overexpressed and facilitated carcinogenesis in various solid malignant tumors. However, the role of LINC00324 in leukemogenesis remains to be elucidated. METHODS: The relative expression and unmethylation levels of LINC00324 were detected by real-time quantitative PCR (RT-qPCR) and real-time quantitative methylation-specific PCR (RT-qMSP). Cell proliferation experimental and flow cytometer (FCM) was used to detect the change of proliferation and apoptosis in leukemia cell lines after overexpression of LINC00324. RESULTS: The results showed that the expression of LINC00324 and the methylation level of the promoter region were significantly negatively correlated in AML patients. Moreover, patients with lower LINC00324 expression showed more prolonged overall survival (OS). Remarkably, overexpression of LINC00324 in leukemia cell lines promoted the proliferation of target cells and inhibited their apoptosis. CONCLUSION: Our findings firstly identified that the hypomethylation of LINC00324 was a common molecular event in de novo AML patients. The abnormally upregulated LINC00324 promotes proliferation and inhibits apoptosis in leukemia cells.

[Clinical Significance of Low Expression of LncRNA CASC15 in Acute Myeloid Leukemia with NPM1 Mutations].

AbstractObjective: To identify the expression and methylation patterns of lncRNA CASC15 in bone marrow (BM) samples of acute myeloid leukemia (AML) patients, and further explore its clinical significance. METHODS: Eighty-two de novo AML patients and 18 healthy donors were included in the study. Meanwhile, seven public datasets from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were included to confirm the expression and methylation data of CASC15. Receiver operating characteristic (ROC) curve analysis was applied to determine the discriminative capacity of CASC15 expression to identify AML. The patients were divided into CASC15high group and CASC15low group by X-tile method, and the prognostic value of CASC15 was identified by Kaplan-Meier method and univariate and multivariate Cox regression analysis. RESULTS: The expression level of CASC15 was significantly decreased in BM cells of AML patients compared with healthy donors (P<0.001). ROC curve analysis suggested that CASC15 expression might be a potential biomarker to discriminate AML from controls. The expression of CASC15 was high at the early stage of hematopoiesis, and reached a peak at the stage of multipotent progenitors differentiation, then decreased rapidly, and was at a range of low level fluctuations in the subsequent process. Among FAB subtypes, CASC15 expression in M0 was significantly higher than that in M1-M7. Clinically, CASC15low patients were more likely to have NPM1 mutations than CASC15high patients (P=0.048), while CASC15high patients had a significantly higher frequency of IDH1 and RUNX1 mutations (P=0.021 and 0.014, respectively). Moreover, CASC15low group had a shorter overall survival (OS) in patients with NPM1 mutations. Furthermore, multivariate analysis confirmed that CASC15 expression was a significant independent risk factor for OS in NPM1 mutated AML patients. In addition, CASC15 methylation level in BM samples of AML patients was significantly decreased compared with healthy donors. Patients with CASC15 high methylation had poor OS and disease-free survival. CONCLUSION: The expression of CASC15 is decreased in AML, and low CASC15 expression may predict adverse prognosis in AML patients with NPM1 mutations. Moreover, CASC15 methylation level in AML is significantly decreased, and high CASC15 methylation may predict poor prognosis in AML.

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

Epigenetic modifications have been found to play crucial roles in myelodysplastic neoplasm (MDS) progression. Previously, we investigated genome-wide DNA methylation alterations during MDS evolution to acute myeloid leukemia (AML) by next-generation sequencing (NGS). Herein, we further determined the role and clinical implications of an evident methylation change in CpG islands at the SLIT2 promoter identified by NGS. First, increased SLIT2 promoter methylation was validated in 11 paired MDS/AML patients during disease evolution. Additionally, SLIT2 promoter methylation was markedly increased in MDS/AML patients compared with controls and was correlated with poor clinical phenotype and outcome. Interestingly, SLIT2 expression was particularly upregulated in AML patients and was not correlated with SLIT2 promoter methylation. However, the SLIT2-embedded genes SLIT2-IT1 and miR-218 were downregulated in AML patients, which was negatively associated with SLIT2 promoter methylation and further validated by demethylation studies. Functionally, SLIT2-IT1/miR-218 overexpression exhibited antileukemic effects by affecting cell proliferation, apoptosis and colony formation in vitro and in vivo. Mechanistically, SLIT2-IT1 may function as a competing endogenous RNA by sponging miR-3156-3p to regulate BMF expression, whereas miR-218 may directly target HOXA1 in MDS progression. In summary, our findings demonstrate that SLIT2 promoter hypermethylation is associated with disease evolution in MDS and predicts poor prognoses in both MDS and AML. Epigenetic inactivation of SLIT2-IT1/miR-218 by SLIT2 promoter hypermethylation could be a promising therapeutic target in MDS.

Comprehensive analysis of SPAG1 expression as a prognostic and predictive biomarker in acute myeloid leukemia by integrative bioinformatics and clinical validation.

BACKGROUND: Recently, an increasing number of studies have reported that sperm-associated antigen (SPAG) proteins play crucial roles in solid tumorigenesis, and may serve as potentially helpful biomarkers for cancer diagnosis and prognosis. However, very few studies systematically investigated the expression of SPAG family members and their clinical significance in acute myeloid leukemia (AML). METHODS: The expression of SPAGs and their prognostic significance in AML were determined by a systematic analysis on data gathered from public databases, and the results were validated in clinical samples. RESULTS: Using public data, we identified only increased SPAG1 expression negatively associated with survival in AML by Cox regression (P < 0.001) and Kaplan-Meier analysis (P < 0.001). The prognostic value of SPAG1 expression was further confirmed in other independent cohorts. Clinically, higher SPAG1 expression was significantly correlated with white blood cell counts (P = 0.014) and French-American-British (FAB) subtypes (P = 0.024). Moreover, higher SPAG1 expression was more common in + 8 patients (P = 0.034), rarely found with t(8;21) (P = 0.014), and correlated with FLT3 (P < 0.001) and DNMT3A mutations (P = 0.001). Despite these associations, multivariate analysis confirmed the independent prognostic value of SPAG1 expression in AML (P < 0.001). Notably, AML patients with higher SPAG1 expression may benefit from hematopoietic stem cell transplantation (HSCT), whereas patients with lower SPAG1 expression appeared less likely to benefit. Finally, we further validated that SPAG1 expression was significantly increased in newly diagnosed AML patients compared with normal controls (P < 0.001) and with AML patients who achieved complete remission (P < 0.001). Additionally, SPAG1 expression could act as a potentially helpful biomarker for the diagnosis and prognosis of AML (P < 0.001 and = 0.034, respectively). CONCLUSIONS: Our findings demonstrated that SPAG1 overexpression may serve as an independent prognostic biomarker and may guide the choice between HSCT and chemotherapy in patients with AML.