LATS1 Promotes B-ALL Tumorigenesis by Regulating YAP1 Phosphorylation and Subcellular Localization.

OBJECTIVE: YAP1 plays a dual role as an oncogene and tumor suppressor gene in several tumors; differentiating between these roles may depend on the YAP1 phosphorylation pattern. The specific function of YAP1 in B cell acute lymphoblastic leukemia (B-ALL), however, is currently unclear. Thus, in the present study, the role of YAP1 in B-ALL was investigated using relevant cell lines and patient datasets. METHODS: The effects of shRNA-mediated knockdown on YAP1 and LATS1 levels in the NALM6 and MOLT-4 cell lines were examined using Western blotting, quantitative real-time polymerase chain reaction, flow cytometry, immunostaining, and nude mouse subcutaneous tumorigenesis experiments. Gene expression levels of Hippo pathway-related molecules before and after verteporfin (VP) treatment were compared using RNA-Seq to identify significant Hippo pathway-related genes in NALM6 cells. RESULTS: Patients with ALL showing high YAP1 expression and low YAP1-Ser127 phosphorylation levels had worse prognoses than those with low YAP1 protein expression and high YAP1-Ser127 phosphorylation levels. YAP1-Ser127 phosphorylation levels were lower in NALM6 cells than in MOLT-4 and control cells; YAP1 was distributed in the nuclei in NALM6 cells. Knockdown of YAP1 inhibited MOLT-4 and NALM6 cell proliferation and arrested the NALM6 cell cycle in the G0/G1 phase. Before and after VP treatment, the expression of the upstream gene LATS1 was upregulated; its overexpression promoted YAP1-Ser127 phosphorylation. Further, YAP1 was distributed in the plasma. CONCLUSION: LATS1 may downregulate YAP1-Ser127 phosphorylation and maintain B-ALL cell function; thus, VP, which targets this axis, may serve as a new therapeutic method for improving the outcomes for B-ALL patients.

Expression profiling of N6-methyladenosine modified circRNAs in acute myeloid leukemia.

Acute myeloid leukemia (AML) is the most common acute leukemia in adults, associated with poor prognosis and easy relapse of disease. Circular RNAs (circRNAs) were detected to be m6A modified and the role of m6A circRNAs has been reported in other diseases including cancers, however, their role has not been elucidated in AML yet. In the present study, we aimed to investigate the expression profiling of m6A circRNAs in AML. We performed m6A circRNAs microarray analysis to identify differentially expressed m6A circRNAs in bone marrow samples from AML patients and healthy individuals (control). Furthermore, bioinformatics analysis predicted the potential functions and relevant pathways that may be associated with the m6A circRNAs. The circRNA m6A methylation levels were found to be positively associated with the circRNAs expression, suggesting circRNA m6A modification could contribute to circRNA regulation in AML. Further analysis demonstrated that circRNA m6A modification might influence the circRNA-miRNA-mRNA co-expression network that may contribute to the circRNA regulatory network in AML. Our findings provide evidence of the differential expression profile of m6A circRNAs in AML, and circRNA m6A modification may contribute to circRNA regulatory function in AML.

A miR-129-5P/ARID3A Negative Feedback Loop Modulates Diffuse Large B Cell Lymphoma Progression and Immune Evasion Through Regulating the PD-1/PD-L1 Checkpoint.

The activated B cell (ABC) and germinal center B cell (GCB) subtypes of diffuse large B cell lymphoma (DLBCL) have different gene expression profiles and clinical outcomes, and miRNAs have been reported to play important roles in tumorigenesis, progression, and metastasis. This study aimed to explore the differentially expressed miRNAs and target genes in the two main subtypes of DLBCL. Hub miRNAs were identified by constructing a regulatory network, and in vitro experiments and peripheral blood samples of DLBCL were used to explore the functions and mechanisms of differential miRNAs and mRNAs. Differentially expressed miRNAs and genes associated with the two DLBCL subtypes were identified using GEO datasets. Weighted gene co-expression network analysis shows that one gene module was associated with a better prognosis of patients with the GCB subtype. Through the construction of a regulatory network and qPCR verification of clinical samples and cell lines, miR-129-5p was identified as an important differential miRNA between the ABC and GCB subtypes. The negative relationship between miR-129-5p and ARID3A in DLBCL was confirmed using luciferase reporter assays. Overexpression of miR-129-5p and knockdown of ARID3A inhibited the proliferation of SU-DHL-2 (ABC-type) cells and promoted their apoptosis through the JAK and STAT6 signaling pathways. In addition, inhibition of miR-129-5p and overexpression of ARID3A promoted the proliferation and reduced apoptosis of DB and SU-DHL-6 (GCB-type) cells. Inhibition of miR-129-5p and overexpression of ARID3A in DB and SU-DHL-6 promoted immune escape by increasing PD-L1 expression, which was transcriptionally activated by ARID3A. In conclusion, we showed for the first time that the mir-129-5P/ARID3A negative feedback loop modulates DLBCL progression and immune evasion by regulating PD-1/PD-L1.

Epigenetic modifications in acute myeloid leukemia: The emerging role of circular RNAs (Review).

Canonical epigenetic modifications, which include histone modification, chromatin remodeling and DNA methylation, play key roles in numerous cellular processes. Epigenetics underlies how cells that posses DNA with similar sequences develop into different cell types with different functions in an organism. Earlier epigenetic research has primarily been focused at the chromatin level. However, the number of studies on epigenetic modifications of RNA, such as N1­methyladenosine, 2'­O­ribosemethylation, inosine, 5­methylcytidine, N6­methyladenosine (m6A) and pseudouridine, has seen an increase. Circular RNAs (circRNAs), a type of RNA species that lacks a 5' cap or 3' poly(A) tail, are abundantly expressed in acute myeloid leukemia (AML) and may regulate disease progression. circRNAs possess various functions, including microRNA sponging, gene transcription regulation and RNA­binding protein interaction. Furthermore, circRNAs are m6A methylated in other types of cancer, such as colorectal and hypopharyngeal squamous cell cancers. Therefore, the critical roles of circRNA epigenetic modifications, particularly m6A, and their possible involvement in AML are discussed in the present review. Epigenetic modification of circRNAs may become a diagnostic and therapeutic target for AML in the future.

Identification of PLA2G7 as a novel biomarker of diffuse large B cell lymphoma.

BACKGROUND: Diffuse large B-cell lymphoma is the most common form of non-Hodgkin lymphoma globally, and patients with relapsed or refractory DLBCL typically experience poor long-term outcomes. METHODS: Differentially expressed genes associated with DLBCL were identified using two GEO datasets in an effort to detect novel diagnostic or prognostic biomarkers of this cancer type, after which receiver operating characteristic curve analyses were conducted. Genes associated with DLBCL patient prognosis were additionally identified via WCGNA analyses of the TCGA database. The expression of PLA2G7 in DLBCL patient clinical samples was further assessed, and the functional role of this gene in DLBCL was assessed through in vitro and bioinformatics analyses. RESULTS: DLBCL-related DEGs were found to be most closely associated with immune responses, cell proliferation, and angiogenesis. WCGNA analyses revealed that PLA2G7 exhibited prognostic value in DLBCL patients, and the upregulation of this gene in DLBCL patient samples was subsequently validated. PLA2G7 was also found to be closely linked to tumor microenvironmental composition such that DLBCL patients expressing higher levels of this gene exhibited high local monocyte and gamma delta T cell levels. In vitro experiments also revealed that knocking down PLA2G7 expression was sufficient to impair the migration and proliferation of DLBCL cells while promoting their apoptotic death. Furthmore, the specific inhibitor of PLA2G7, darapladib, could noticeably restrained the DLBCL cell viability and induced apoptosis. CONCLUSIONS: PLA2G7 may represent an important diagnostic, prognostic, or therapeutic biomarker in patients with DLBCL.

Fatal hyperleukocytic T lymphoblastic lymphoma/leukemia complicated with multi-gene fusion and mutation: clinical revelation and perception.

T lymphoblastic lymphoma/leukemia (T-LBL/ALL) is a highly malignant hematological tumor common in young males. Most T-LBL/ALL patients usually initially seek medical treatment for clinical manifestations of non-hematological diseases. Presently, T-ALL chemotherapy is often used for the treatment of T-LBL/ALL internationally. With the application of high-intensity standard chemotherapy, the efficacy and prognosis of T-LBL/ALL are still not optimistic. The authors present a young male patient with facial and neck edema as the initial symptoms. This young patient of T-LBL/ALL was found to have a mediastinal mass after CT examination and he was finally diagnosed as highly malignant T-LBL/ALL. Unfortunately, after undergoing three standard courses of high-intensity chemotherapy, the young male patient eventually died of white blood cell stasis and severe infection caused by hyperleukocytosis. To this end, we find that the prognosis of T-LBL/ALL with multiple gene mutations or fusions and hyperleukocytosis, is extremely poor, and probably becomes a medical problem worthy of continuing resolution in the field of hematology and oncology.

Study of the Relationship between HPA-1 and HPA-5 Gene Polymorphisms and Refractory to Platelet Therapy and Recombinant Factor VII in Glanzmann Thrombasthenia Patients in Southeast of Iran.

Background: Glanzmann Thrombasthenia (GT) is a rare autosomal disease. HPA (Human Platelet Alloantigen) is a surface polymorphic alloantigen of platelets. This study was intended to investigate and compare the polymorphism of HPA-1 and HPA-5 genes in two groups of GT patients, with and without resistance to platelet and recombinant factor VII therapy. Materials and Methods: This case control study was performed on GT patients (n=16) with resistance to platelet therapy and recombinant factor VII and control group of GT patients (n=16) without resistance to platelet therapy and recombinant factor VII. The consent form was completed by each patient. Gene polymorphisms of HPA-1 and HPA-5 were investigated using SSP-PCR, and the obtained data were analyzed using statistical software SPSS16.0. Results: The results indicated no significant relationship between the studied genes and their resistance to platelet therapy and recombinant factor VII. The frequencies of HPA-1 genotype a/a were 98% and 94% in patient and control groups, respectively. The frequency of allele b was found to be less than allele a. The value of this allele was 4% in patient group and 1% in control group. In addition, the HPA-5a/a (98%) was the most frequent alloantigen?? (check it) in both groups. Seven percent (7%) of the patients had the HPA-5a/b genotype, and the HPA-5b/b was found to be absent in these individuals. Conclusion: According to the results obtained, it could be concluded that these genes play no role in resistance to platelet therapy.