Mutations in ASH1L confer susceptibility to Tourette syndrome.

Tourette syndrome (TS) is a childhood-onset neuropsychiatric disorder characterized by repetitive motor movements and vocal tics. The clinical manifestations of TS are complex and often overlap with other neuropsychiatric disorders. TS is highly heritable; however, the underlying genetic basis and molecular and neuronal mechanisms of TS remain largely unknown. We performed whole-exome sequencing of a hundred trios (probands and their parents) with detailed records of their clinical presentations and identified a risk gene, ASH1L, that was both de novo mutated and associated with TS based on a transmission disequilibrium test. As a replication, we performed follow-up targeted sequencing of ASH1L in additional 524 unrelated TS samples and replicated the association (P value = 0.001). The point mutations in ASH1L cause defects in its enzymatic activity. Therefore, we established a transgenic mouse line and performed an array of anatomical, behavioral, and functional assays to investigate ASH1L function. The Ash1l+/- mice manifested tic-like behaviors and compulsive behaviors that could be rescued by the tic-relieving drug haloperidol. We also found that Ash1l disruption leads to hyper-activation and elevated dopamine-releasing events in the dorsal striatum, all of which could explain the neural mechanisms for the behavioral abnormalities in mice. Taken together, our results provide compelling evidence that ASH1L is a TS risk gene.

MicroRNAs: pivotal regulators in acute myeloid leukemia.

MicroRNAs are a class of small non-coding RNAs that are 19-22 nucleotides in length and regulate a variety of biological processes at the post-transcriptional level. MicroRNA dysregulation disrupts normal biological processes, resulting in tumorigenesis. Acute myeloid leukemia is an invasive hematological malignancy characterized by the abnormal proliferation and differentiation of immature myeloid cells. Due to the low 5-year survival rate, there is an urgent need to discover novel diagnostic markers and therapeutic targets. In recent years, microRNAs have been shown to play important roles in hematological malignancies by acting as tumor suppressors and oncogenes. MicroRNAs have the potential to be a breakthrough in the diagnosis and treatment of acute myeloid leukemia. In this review, we summarize the biology of microRNAs and discuss the relationships between microRNA dysregulation and acute myeloid leukemia in the following aspects: signaling pathways, the abnormal biological behavior of acute myeloid leukemia cells, the clinical application of microRNAs and competing endogenous RNA regulatory networks.

The Expression and Clinical Significance of MicroRNA-409-3p in Acute Myeloid Leukemia.

BACKGROUND: MicroRNA-409-3p, is down-regulated in a variety of malignant diseases. However, the expression level and clinical value of microRNA-409-3p in acute myeloid leukemia has not yet been systematically studied. METHODS: We collected 88 bone marrow samples derived from 73 patients with acute myeloid leukemia and 15 healthy controls. Then we evaluated the expression of microRNA-409-3p by quantitative real-time PCR. RESULTS: The results revealed that compared with the healthy controls, microRNA-409-3p expression in a newly diagnosed group was significantly lower (p < 0.001). In addition, the microRNA-409-3p expression in the complete remission group was strikingly higher compared to that of the newly diagnosed group (p < 0.001). There was a correlation between microRNA-409-3p expression and white blood cells (p = 0.021). Most importantly, the micro-RNA-409-3p low expression group indicated a shorter event-free survival compared with microRNA-409-3p high expression group by using Kaplan-Meier analysis (p < 0.0438). CONCLUSIONS: The microRNA-409-3p expression level could be a novel potential biomarker for acute myeloid leukemia diagnosis and prognosis, providing a new therapeutic strategy for acute myeloid leukemia treatment.

Next-generation sequencing identifies a novel frameshift variant in FRMD7 in a Chinese family with idiopathic infantile nystagmus.

BACKGROUND: Idiopathic infantile nystagmus (IIN) is a high genetically heterogeneous ophthalmic disease and is often associated with pathogenic mutations in FRMD7 and GPR143, respectively. Idiopathic infantile nystagmus manifests as involuntary periodic rhythmic oscillation of the eyes in the very early life, which decreases visual acuity and affects the quality of life. OBJECTIVE AND METHODS: The aim of our study was to reveal a possible pathogenic variant through the investigation of a Chinese Han family with IIN with an implementation of a next-generation sequencing method. Isolated DNA analysis was followed by Sanger sequencing validation. We also performed the detailed ophthalmological examination of family members. RESULTS: We identified a novel frameshift variant in FRMD7 (NM_194277.2: c.1419_1422dup, p.Tyr475fs), which leads to a frameshift mutation since tyrosine (Tyr) at 475 codon of FRMD7 protein (p.Tyr475fs) and co-segregates with IIN phenotype in this family. CONCLUSIONS: We found a novel frameshift FRMD7 variant in a Chinese Han family, which may be causative variant for IIN and can further enrich the mutation spectrum and uncover the etiology of IIN.

Correlations between Epstein-Barr virus and acute leukemia.

Infection with Epstein-Barr virus (EBV) may be correlated to the onset of acute leukemia (AL). Studies were performed to investigate the relationship between EBV infection and immunophenotyping of acute lymphoblastic leukemia (ALL) and chromosome aberrations. Additionally, the effects of EBV on clinical prognosis were described. Fluorescence quantitative polymerase chain reaction (FQ-PCR) was used to detect EBV-DNA copy numbers from bone marrow in 110 cases of patients with ALL, 75 cases of patients with acute myeloid leukemia (AML), and 37 cases of hematologically healthy control subjects. EBV-DNA copies were found in 64 of 185 (34.6%) patients with AL and 2 of 37 healthy control subjects (P < 0.001). The EBV infection rate of ALL patients, AML patients, and healthy controls was 40.9% (45/110), 25.3% (19/75), and 5.4% (2/37), respectively. The positive rate of EBV in the ALL and AML groups was higher than in healthy subjects (P < 0.05). EBV-DNA copies were found in 1 of 12 (8.3%) T-ALLs and 44 of 98 (44.9%) B-ALLs, the positive rate of EBV in B-ALLs increased significantly compared to the rate of T-ALLs (P < 0.05). Chromosome karyotype analysis showed that EBV infection rates in B-ALL, T-ALL, and AML patients with chromosome abnormalities were 46.3% (25/54), 33.3% (1/3), and 30% (9/30), respectively. There was no statistical significance between chromosome abnormality and EBV infection (P > 0.05). In addition, EBV+ -ALLs had higher relapse and mortality rates than that of EBV- -ALLs. Together, we conclude that EBV infection may be correlated with the incidence of AL, and the infection rate of EBV in B-ALL was higher than that of T-ALL. EBV-positive patients showed an unfavorable prognosis.

Ubiquitination is absolutely required for the degradation of hypoxia-inducible factor--1 alpha protein in hypoxic conditions.

The hypoxia-inducible factor (HIF) is recognized as the master regulator of hypoxia response. HIF-α subunits expression are tightly regulated. In this study, our data show that ts20 cells still expressed detectable E1 protein even at 39.5° C for 12 h, and complete depletion of E1 protein expression at 39.5° C by siRNA enhanced HIF-1α and P53 protein expression. Further inhibition of E1 at 39.5 °C by siRNA, or E1 inhibitor Ube1-41 completely blocked HIF-1α degradation. Moreover, immunoprecipitations of co-transfection of HA-ubiquitin and FLAG-HIF-1α plasmids directly confirmed the involvement of ubiquitin in the hypoxic degradation of HIF-1α. Additionally, hypoxic HIF-1 α degradation is independent of HAF, RACK1, sumoylation or nuclear/cytoplasmic localization. Taken together, our data suggest that constitutive HIF-1α protein degradation in hypoxia is absolutely ubiquitination-dependent, and unidentified E3 ligase may exist for this degradation pathway.

microRNA-106b-5p and Rab10: Potential Markers of Acute Myeloid Leukemia.

This study focuses on acute myeloid leukemia (AML), a condition with a 5-year survival rate below 30% despite various treatment options. Recent strides in targeted therapies have shown promise, leading to better outcomes with minimal toxicity. These advances underscore the importance of discovering new diagnostic and prognostic targets for AML. In this context, the authors investigated the expression of microRNA-106b-5p (miR-106b-5p), Rab10 mRNA, and Rab10 proteins in peripheral blood and bone marrow (BM) samples from both healthy individuals and AML patients at different stages of the disease (initial diagnosis, recurrence, and complete remission). This examination aimed to identify potential biomarkers for AML diagnosis, treatment, and prognosis. From June 2021 to December 2022, they collected 100 BM and peripheral blood samples. The relative expression of miR-106b-5p and Rab10 mRNA in the BM of AML patients was measured using Real-time polymerase chain reaction (qRT-PCR), while the relative expression of Rab10 protein in serum was determined using the ELISA method. The chromosomal karyotype of initially diagnosed patients was analyzed using the R tape. The qRT-PCR results revealed that the expression of miR-106b-5p and Rab10 mRNA were significantly higher in patients at initial diagnosis and recurrence compared with healthy individuals and those in complete remission (p < 0.001). They observed a significant reduction in the expression of miR-106b-5p, Rab10 mRNA, and Rab10 protein in the BM and peripheral blood of patients during complete remission (p < 0.05), as demonstrated by dynamic monitoring of five patients in the initial group. Furthermore, they found a close association between the expression of miR-106b-5p and the number of white blood cells at the initial diagnosis in AML patients (p < 0.05). Spearman correlation analysis revealed a positive correlation among miR-106b-5p, Rab10 mRNA, and Rab10 proteins (p < 0.05). The diagnostic potential of miR-106b-5p and Rab10 proteins was underscored by Receiver Operating Characteristic (ROC) curve analysis, which demonstrated their high accuracy in AML diagnosis (AUC: 0.944 and 0.853, respectively; p < 0.0001). Additionally, Kaplan-Meier survival analysis suggested that lower expression of these markers was associated with better prognoses (p < 0.05). In summary, their findings propose miR-106b-5p and Rab10 proteins as promising biomarkers for AML, offering insights for diagnosis, treatment, and prognosis.

Investigating the molecular mechanisms of microRNA­409­3p in tumor progression: Towards targeted therapeutics (Review).

MicroRNAs (miRNAs) are a group of non­coding RNAs that exert master regulatory functions in post­-transcriptional gene expression. Accumulating evidence shows that miRNAs can either promote or suppress tumorigenesis by regulating different target genes or pathways and may be involved in the occurrence of carcinoma. miR­409­3p is dysregulated in a variety of malignant cancers. It plays a fundamental role in numerous cellular biological processes, such as cell proliferation, apoptosis, migration, invasion, autophagy, angiogenesis and glycolysis. In addition, studies have shown that miR­409­3p is expected to become a non­invasive biomarker. Identifying the molecular mechanisms underlying miR­409­3p­mediated tumor progression will help investigate miR­409­3p­based targeted therapy for human cancers. The present review comprehensively summarized the recently published literature on miR­409­3p, with a focus on the regulation and function of miR­409­3p in various types of cancer, and discussed the clinical implications of miR­409­3p, providing new insight for the diagnosis and treatment of cancers.

The diagnostic, prognostic role and molecular mechanism of miR-328 in human cancer.

MicroRNA are non-coding small RNAs that bind to their target mRNA and cause mRNA degradation or translation inhibition. MiRNA dysregulation is linked to a variety of human cancers and has a role in the genesis and development of cancer pathology. MiR-328 has been reported to be involved in various human cancers. And miR-328 is considered a key regulator in human cancer. It participates in biological processes such as proliferation, apoptosis, invasion, migration, and EMT. The present review will combine the basic and clinical studies to find that miR-328 promotes tumorigenesis and metastasis in human cancer. And we will describe the diagnostic, prognostic, and therapeutic value of miR-328 in various human cancers.

Diverse Functions of MiR-425 in Human Cancer.

miRNAs are a type of small endogenous noncoding RNA composed of 20-22 nucleotides that can regulate gene expression by targeting the 3' untranslated region of mRNA. Many investigations have discovered that miRNAs have a role in the development and progression of human cancer. Several aspects of tumor development are affected by miR-425, including growth, apoptosis, invasion, migration, epithelial-mesenchymal transition, and drug resistance. In this article, we discuss the properties and research development of miR-425, focusing on the regulation and function of miR-425 in various cancers. Furthermore, we discuss the clinical implications of miR-425. This review may broaden our horizon for better understanding the role of miR-425 as biomarkers and therapeutic targets in human cancer.

MiR-409-3p regulates the proliferation and apoptosis of THP-1 through targeting Rab10.

Acute myeloid leukemia cytogenetics and molecular subtypes are connected with microRNAs, although it is unclear how miRNAs affect AML pathogenesis. miR-409-3p expression is downregulated in bone marrows, as we have previously demonstrated in our team. Nevertheless, the tumor-suppressing activities and molecular mechanisms of miR-409-3p remain unknown. Hence, in this study, we investigate at the functional significance of miR-409-3p in the development of AML. We found that a significant decrease in miR-409-3p expression was observed in THP-1 cell. The expression of miR-409-3p was altered in THP-1 by transfecting with agomiR-409-3p and agomiR-409-3p NC. A series of experiments showed that overexpression of miR-409-3p expression significantly suppressed proliferation and increased the apoptosis of THP-1. Moreover, Rab10 was confirmed as a direct target gene of miR-409-3p and was negatively modulated by miR-409-3p. Rab10 downregulation imitated the suppressed proliferation and increased the apoptosis of THP-1. Furthermore, miR-409-3p overexpression or Rab10 knockdown obviously down-regulated the expression levels of Bcl-2, but up-regulated Bax expression. In a xenograft mouse model, miR-409-3p-overexpressed THP-1 cells resulted in much less tumor weight and size in the mice bearing the cells as compared to the mock-transfected mice. Collectively, our findings demonstrated that miR-409-3p exerted tumor suppressor gene effects in AML by directly targeting Rab10, which might provide a promising therapeutic target for AML.

Serious consequences of Epstein-Barr virus infection: Hemophagocytic lymphohistocytosis.

Human is the host of the Epstein-Barr virus (EBV) especially in childhood and adolescence. Most of them are asymptomatic infection and self-limiting. However, for those patients who suffer from immune dysfunction, EBV infection will be life-threatening. Epstein-Barr virus-associated hemophagocytic lymphohistocytosis (EBV-HLH) is one of the severe effects. The diagnosis and differential diagnosis of EBV-HLH and other EBV infectious diseases are mentioned in this paper. The molecular biology mechanism and complications of EBV-HLH are equally briefly presented. It also provides a practical method for the genetic diagnosis of such diseases and the differential diagnosis with other human immunodeficiency diseases for medical scientists in routine clinical practice.

KIF21A mutations in two Chinese families with congenital fibrosis of the extraocular muscles (CFEOM).

PURPOSE: Two Chinese families (XT and YT) with congenital fibrosis of the extraocular muscles (CFEOM) were identified. The purpose of this study was to determine if previously described Homo sapiens kinesin family member 21A (KIF21A) mutations were responsible for CFEOM in these two Chinese pedigrees. METHODS: Clinical characterization and genetic studies were performed. Microsatellite genotyping for linkage to the CFEOM1 and CFEOM3 loci was performed. The probands were screened for KIF21A mutations by bidirectional direct sequencing. Once a mutation was detected in the proband, all other participating family members and 100 unrelated control normal individuals were screened for the mutation. RESULTS: All affected individuals in family XT shared the common manifestations of CFEOM1. Family YT had two affected individuals, a mother and a daughter. The daughter had CFEOM1, while her mother never had congential ptosis but did have limited extraocular movements status post strabismus surgery. Haplotype analysis revealed that pedigree XT was linked to the 12q CFEOM1 locus and the affected memberes harbored the second most common missense mutation in KIF21A (2,861G>A, R954Q). Family YT harbored the most common missense de novo mutation in KIF21A (2,860C>T, R954W). Both of these mutations have been previously described. CONCLUSIONS: The observation of these two KIF21A mutations in a Chinese pedigree underscores the homogeneity of these mutations as a cause of CFEOM1 and CFEOM3 across ethnic divisions.

Ghrelin acts on rat dorsal vagal complex to stimulate feeding via arcuate neuropeptide Y/agouti-related peptide neurons activation.

Ghrelin, an endogenous ligand for the growth hormone secretagogue (GHS) receptor, stimulates feeding and increases body weight. The primary action site of ghrelin has been reported to be the neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons in the hypothalamic arcuate nucleus (ARC). In addition to the hypothalamus, the caudal brainstem also appears to be an important mediator for the orexigenic activity of ghrelin. However, it is not clear whether ghrelin applied directly to the caudal brainstem activates forebrain structures. The aim of this study was to determine whether recruitment of forebrain structures was required for hyperphagic responses stimulated by ghrelin delivery within the caudal brainstem. In our experiment, all rats were surgically implanted with indwelling cannulas in the dorsal vagal complex (DVC), and ghrelin (20 pmol in 0.5 µL) was delivered to the DVC. After the injection, the orexigenic response to ghrelin was recorded by Feeding and Activity Analyser, and NPY/AgRP mRNA expressions in rat hypothalamus were detected by real-time PCR. In addition, the NPY immunoreactive neurons in the ARC were assayed by immunohistochemistry. The results showed that ghrelin significantly increased cumulative food intake at 1, 2 and 3 h after ghrelin injection, maximal response occurring at 2 h after injection. NPY/AgRP mRNA levels in ARC treated with ghrelin increased significantly compared with those in control group (injected with saline). The highest levels of NPY and AgRP mRNA were detected at 2 h after injection. The total number and mean optical density of NPY-positive neurons increased in ghrelin treated rats compared with those in control group. Consistently, ghrelin's effect was most pronounced at 2 h after injection. Taken together, we conclude that the activation of NPY/AgRP neurons in the ARC is involved in the mediation of the hyperphagic response to brainstem ghrelin administration in neurologically intact rats.

Value of ABCG2 Q141K and Q126X genotyping in predicting risk of preeclampsia in Chinese Han women population.

Hyperuricemia (HUA) in women with preeclampsia (PE) not only indicates a reminder of severity but also contributes directly to the pathogenesis of PE. ATP-binding cassette subfamily G member 2 (ABCG2) has a very strong effect on the serum urate concentrations. Our aim was to investigate the association between polymorphisms of ABCG2 with PE in Chinese Han female population. A cohort of 793 preeclamptic women (466 PE with HUA and 327 PE without HUA) and 744 normal pregnant women recruited in this study were genotyped for genetic distribution of Q141K (rs2231142) and Q126X (72552713) in ABCG2 by the TaqMan allelic discrimination real-time PCR. There was no statistically significant difference of genotypic and allelic frequencies between PE and the normal pregnant women in Q141K (Χ2 = 1.11, P = 0.58 by genotype; Χ2 = 0.32, P = 0.57 by allele) and Q126X (P = 0.33 by genotype; P = 0.33 by allele), and no significant difference was found in the genetic distribution of Q141K and Q126X between PE with HUA, PE without HUA and controls. Additionally, this study observed no significant difference in genotypic and allelic distribution between early/late-onset PE with/without HUA or mild/severe PE with/without HUA and control subgroups. Based on our findings, the ABCG2 Q141K and Q126X polymorphisms may not be associated with PE in Chinese Han women.

Identification of a de novo ANK1 mutation in a Chinese family with hereditary spherocytosis.

OBJECTIVES: Hereditary spherocytosis (HS) is a genetic heterogeneous disorder characterized by sphere-shaped erythrocytes on peripheral blood smear with a few clinical manifestations. As an important red cell membrane protein, ankyrin 1 can interact with transmembrane proteins and the membrane skeleton and mutations in the ankyrin 1 (ANK1) genes affect about half of all patients with HS. The purpose of this study was to investigate a Chinese Han family with HS to find out the causative gene mutation and explore the genotype-phenotype correlation which can provide the basis for the pathogenesis and prenatal diagnosis for this disease. METHODS: Whole exome sequencing (WES) followed by Sanger sequencing was performed on subjects with HS from a Chinese family in Shandong Province. RESULTS: A de novo nonsense ANK1 mutation (c.796G > T, p.Glu266X), a single-nucleotide change from G to T which caused a substitution from glutamic acid to an immature stop codon at codon 266, was identified. DISCUSSION: Our finding suggested that a de novo nonsense mutation in ANK1 may be causative to HS which plays an important role in supplementing the mutational spectrum of the ANK1 and explaining the mechanism of HS. Our study also indicated that WES can be an effective and accurate diagnostic tool in the discovery of causative mutations in genetic heterogeneous Mendelian disorders.

[Expression and Clinical Significance of Focal Adhesion Kinase in Patients with Acute Leukemia].

OBJECTIVE: To explore the expression of focal adhesion kinase (FAK) in patients with acute leukemia (AL) and its clinical significance. METHODS: The FAK mRNA levels in leukemic cells of 50 patients with AL and bone marrow mononuclear cells(BMMNC) of 10 healthy controls were measured by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The bone marrow cell chromosomes were prepared using direct and short term culture, and karyotyping was performed by R-banding technique. RESULTS: The expression positive rate of FAK mRNA in leukemic cells of 50 patients with AL was 66.0%, which was significantly higher than that in normal controls (20.0%) (P<0.05). The expression positive rates and levels of FAK mRNA in both ALL and ANLL cells were statistically significantly higher than those in normal controls (P<0.05), but the difference between ALL and ANLL cells was not significant (P>0.05). All the expression- positive rates and levels of FAK mRNA in newly diagnosed AL patients and the relapsed AL patients were significantly higher than those in normal controls (P<0.05), but the difference between the newly diagnosed AL patients and the relapsed AL patients was not significant (P>0.05). Morecover, the expression plsitive rate and levels of FAK mRNA in the remitted patients were lower than those in newly diagnosed and relapsed patients (P<0.05), but were no statistically significantly different from normal controls (P>0.05). The expression- positive rate and level of FAK mRNA in the AL patients with abnormal karyotype were significantly higher than those in the AL patients without abnormal karyotype (P<0.05). CONCLUSION: FAK mRNA over-express in the leukemia patients, which may be related with the outome of disease, possibly providing novel targeting sites for the treatment of leukemia.

α-MSH Influences the Excitability of Feeding-Related Neurons in the Hypothalamus and Dorsal Vagal Complex of Rats.

Alpha-melanocyte-stimulating hormone (α-MSH) is processed from proopiomelanocortin (POMC) and acts on the melanocortin receptors, MC3 and MC4. α-MSH plays a key role in energy homeostasis. In the present study, to shed light on the mechanisms by which α-MSH exerts its anorectic effects, extracellular neuronal activity was recorded in the hypothalamus and the dorsal vagal complex (DVC) of anesthetized rats. We examined the impact of α-MSH on glucose-sensing neurons and gastric distension (GD) sensitive neurons. In the lateral hypothalamus (LHA), α-MSH inhibited 75.0% of the glucose-inhibited (GI) neurons. In the ventromedial nucleus (VMN), most glucose-sensitive neurons were glucose-excited (GE) neurons, which were mainly activated by α-MSH. In the paraventricular nucleus (PVN), α-MSH suppressed the majority of GI neurons and excited most GE neurons. In the DVC, among the 20 GI neurons examined for a response to α-MSH, 1 was activated, 16 were depressed, and 3 failed to respond. Nineteen of 24 GE neurons were activated by α-MSH administration. Additionally, among the 42 DVC neurons examined for responses to GD, 23 were excited (GD-EXC) and 19 were inhibited (GD-INH). Fifteen of 20 GD-EXC neurons were excited, whereas 11 out of 14 GD-INH neurons were suppressed by α-MSH. All these responses were abolished by pretreatment with the MC3/4R antagonist, SHU9119. In conclusion, the activity of glucose-sensitive neurons and GD-sensitive neurons in the hypothalamus and DVC can be modulated by α-MSH.

Lack of association between SLC5A7 polymorphisms and Tourette syndrome in a Chinese Han population.

Although Tourette syndrome (TS) is a chronic neuropsychiatric disorder whose pathogenesis remains unclear, genetic factors play an important role in the occurrence and development. A variety of studies have been shown that the candidate genes related to cholinergic neurons may be associated with the onset of TS. To investigate the association between the SLC5A7 polymorphisms and Tourette syndrome (TS) in the Chinese Han population, the SNP rs1013940, rs2433718, and rs4676169 were genotyped in 401 TS trios and 400 controls. The transmission disequilibrium test (TDT) and haplotype relative risk (HRR) compared genetic distributions of trios, while the chi-square test compared patients and controls. However, no transmission disequilibrium was found between the three SLC5A7 SNPs and TS. Therefore, we think that this gene may not be the main risk factor on the onset of TS. However, these results should be further validated in different populations.

Overexpression of dominant-negative Ikaros 6 isoform is associated with resistance to TKIs in patients with Philadelphia chromosome positive acute lymphoblastic leukemia.

The clinical significance of the dominant-negative Ikaros 6 (DN-IK6) in the treatment of patients with Philadelphia-positive acute lymphoblastic leukemia (Ph+-ALL) with tyrosine kinase inhibitors (TKIs) remains elusive. In the present study, it was demonstrated that DN-IK6 was overexpressed in B-cell (B)-ALL cases compared with T cell-ALL cases at the mRNA and protein levels. Furthermore, nucleotide sequencing revealed that DN-IK6 was due to the deletion of IKAROS family zinc finger 1 exons 4-7. The outcome of patients with Ph+-B-ALL with DN-IK6, and treated with TKIs and hyper-cyclophosphamide/vincristine/doxorubicin/dexamethasone regimen were restrospectively evaluated in a 2 year follow-up. The results demonstrated that those with the DN isoform exhibited significantly lower incidences of remission, shorter median cumulative incidence of relapse times (P<0.05) and shorter median overall survival times (P<0.05) compared with those without the DN isoform. In conclusion, the results of the present study demonstrated that DN-IK6 is overexpressed in the majority of patients with Ph+-ALL, and is significantly associated with resistance to TKI therapy.