m6A Regulator-Mediated Methylation Modification Patterns and Tumor Microenvironment Infiltration Characterization in Acute Myeloid Leukemia.

Recent studies have demonstrated epigenetic regulation of immune responses. Nevertheless, the underlying effect of RNA N6-methyladenosine (m6A) modifications on tumor microenvironment cell infiltration remains elusive. In this study, we thoroughly assessed m6A modification patterns of 255 myeloid leukemia specimens based on 23 m6A regulators. Consensus clustering of the 23 m6A regulators was performed to determine three distinct m6A modification patterns that were remarkably consistent with three immunophenotypes of tumors: immunorejection, immune activation, and immune inertness. Further evaluation and prognostic analysis of the m6A modification patterns of individual tumors revealed that low m6A score was characterized by increased mutational burden, immune activation, and survival rates, whereas high m6A score was characterized by poorer survival rates and the absence of effective immune infiltration. In addition, this study investigated the association between m6A regulators and antitumor immune responses and discovered higher expression of the immune regulators PD-L1, PD-L2, MRP1, and MRP2 in low m6A scores. Generally, the expression pattern of m6A regulators was remarkably associated with prognostic results and antitumor immune responses in acute myeloid leukemia and may be an underlying target and biological marker for immune therapies.

Bioinformatic prediction and identification of immunogenic epitopes of the antigenic 14-3-3 protein of Echinococcus multilocularis.

INTRODUCTION: Alveolar echinococcosis is a high-risk parasitic disease caused by the larval stage of Echinococcus multilocularis. The study aimed to predict and identify the dominant Th1/Th2 and B cell epitopes of the antigen protein 14-3-3 beta:alpha from Echinococcus multilocularis. METHODS: A comparison of the four amino acid sequences of 14-3-3 beta:alpha was respectively derived from Echinococcus multilocularis, Rattus norvegicus, Canis lupus familiaris, and Homo sapiens was carried out by CLUSTALW to provide a basis for excluding similar epitopes. The amino acid sequence information was analyzed by SOPMA and the homology model was established by Swiss-Model. IEDB and SYFPEITHI were used to predict T cell epitopes. According to the Bcepred and ABCpred, the B cell epitopes were comprehensively predicted and analyzed. The dominant epitopes were validated by Lymphocyte Proliferation, ELISA, ELISpot, and Flow cytometry. RESULTS: Eight potential epitopes of 14-3-3 from Echinococcus multilocularis were screened according to the results of prediction and analysis: 14-3-31-15, 14-3-36-21, 14-3-371-86, 14-3-3144-157, 14-3-3145-166, 14-3-3146-160, 14-3-3153-161, and 14-3-3164-177. The 3D structure model of the protein was constructed and the location distribution of potential epitope was ascertained. Respectively, the epitopes of the dominant antigen of B cells were validated as 14-3-3145-166 and 14-3-3164-177; the Th1 dominant antigen epitopes were 14-3-36-21, 14-3-3145-166; and the Th2 dominant epitopes was 14-3-3145-166. CONCLUSION: In this study, two dominant antigen epitopes of B cells, two Th1 dominant antigen epitopes, and one Th2 dominant antigen epitope were validated. Our work provides a basis for the subsequent development of efficient and safe vaccines targeting epitopes of Echinococcus multilocularis.

[Effect of HIF-1α on Angiogenesis-Related Factors in K562 Cells].

OBJECTIVE: To explore the mechanisms of angiogenesis in chronic myeloid leukemia (CML) through detecting the levels of angiogenesis-related factors secreted from K562 cells after overexpression and interference of HIF-1α gene in K562 cells. METHODS: The K562 cells were transfected by lentiviruses carried and interfered HIF-1α gene, then the transtected K562 cells with carried and interfered with HIF-1α gene were enrolled in overexpression and interference groups respectively, at the same time the K562 cells transfected by the empty virus were enrolled in control group. The cells were harvested after culture for 72 hours under normoxid condition. The transfection efficient in 3 groups was detected by fluorescence microscopy; the mRNA expression of HIF-1α gene and angiogenesis-related factors was detected by RT-PCR; the concentration of angiogenesis-related factors in the caltured supernatant was detected by ELISA. RESULTS: The optimal MOI of K562 cells transfected with lentivirus was 10 and the transfection efficiency was about 50%. The positive rate of transfection after screening by puromycin was more than 90%. The mRNA expression of ANG-I, ANG-II, TGF-α and VEGF in the interference group was lower than that in the over-expression group, and the TGF-ß1 mRNA expression in the interference group was higher than in the over-expression group. The mRNA expression of ANG-I and VEGF in the interference group was lower than that in the control group. TGF-αdid not could be detected, and the culture supernatant concentration of ANG-I and TNF-α in the interference group was lower than in the over-expression group, while the VEGF concentration in the interference group was higher than that in the over-expression group. All of the above-mentioned differences were statistically significant (P＜0.05). CONCLUSION: The positive K562 cells transfected with leutivirus have been harvested by screening with puromycin. The HIF-1α mRNA positively regulates the mRNA expression of ANG-1, ANG-2, TGF-α, VEGF in K562 cells, promotes the antocrine ability of ANG-1 and TNF-α, moreover not stimulates the autocrine of TGF-α, the up-regulation of HIF-1α expression can inhibit the expression TGF-ß1 in K562 cells and the autocrine of TGF-ß1.

[Significance of Bone Marrow Microvessel Density and Vascular- Related Factors in Multiple Myeloma].

OBJECTIVE: To investigate the clinical significance of bone marrow microvessel density(MVD) and angiogenesis related factors in multipic myeloma(MM). METHODS: Twenty cases of MM and 20 cases of simple fracture were selected and enrolled in MM group and control group respectively. The clinical data and results of laboratorial tests were collected; the bone marrow MVD of patients was detected by using the modified plastic-embedded pathologic sections of bone marrow tissue and histochemistry staining, the expression levels of amgiogenesis-related factors including VEGF, TNF-α, HGF, TGF-α, TGF-ß1, bFGF, Ang-Ⅰ, Ang-Ⅱ in bone marrow supernatant were detected by ELISA; the mRNA expression levels of above-mentioned cytokines in bone marrow mononuclear cells were detected by real time-PCR; the pearson correlation analysis was used to analyze the correlation of MVD with VEGF, HGF and bFGF levels. RESULTS: The MVD in MM group was significantly higher than that in control group (P＜0.001); the mRNA expression of VEGF, TGF-α, TGF-ß1 and HGF in bone marrow mononuclear cells of MM group was higher than that of control group(P＜0.001); the levels of VEGF, HGF, bFGF and THF-α in bone marrow supernatant of MM group were higher than those in control group(P＜0.05), moreover, the MVD positively correlated with levels of VEGF, HGF and bFGF in bone marrow(r=0.488, 0.472 and 0.457). CONCLUSION: The MVD and levels vessel-related factors in bone marrow supernatant of MM patients increase, among which the levels of VEGF and HGF in bone marrow supernatant are consistant with those mRNA expression level in bone marrow mononuclear cells, moreover, the MVD possitively cerrelates with levels of VEGF, HGF and bFGF in bone marrow supernatant, suggesting that the changes of bone marrow microenvironment vassel-related factors play an important role in angiogenesis and pathogenesis of multiple myeloma.

PI3K/Akt signaling transduction pathway, erythropoiesis and glycolysis in hypoxia (Review).

The purpose of this review is to summarize the research progress of PI3K/Akt signaling pathway in erythropoiesis and glycolysis. Phosphatidylinositol­4,5­bisphosphate 3­kinase (PI3K) is activated by numerous genes and leads to protein kinase B (Akt) binding to the cell membrane, with the help of phosphoinositide­dependent kinase, in the PI3K/Akt signal transduction pathway. Threonine and serine phosphorylation contribute to Akt translocation from the cytoplasm to the nucleus and further mediates enzymatic biological effects, including those involved in cell proliferation, apoptosis inhibition, cell migration, vesicle transport and cell cancerous transformation. As a key downstream protein of the PI3K/Akt signaling pathway, hypoxia­inducible factor (HIF)­1 is closely associated with the concentration of oxygen in the environment. Maintaining stable levels of HIF­1 protein is critical under normoxic conditions; however, HIF­1 levels quickly increase under hypoxic conditions. HIF­1α is involved in the acute hypoxic response associated with erythropoietin, whereas HIF­2α is associated with the response to chronic hypoxia. Furthermore, PI3K/Akt can reduce the synthesis of glycogen and increase glycolysis. Inhibition of glycogen synthase kinase 3ß activity by phosphorylation of its N­terminal serine increases accumulation of cyclin D1, which promotes the cell cycle and improves cell proliferation through the PI3K/Akt signaling pathway. The PI3K/Akt signaling pathway is closely associated with a variety of enzymatic biological effects and glucose metabolism.

[Role of CD8(+)T cells and their secreted cytokines in the pathogenesis of aplastic anemia].

Aplastic anemia(AA) is mostly considered as an immune-mediated bone marrow failure syndrome, characterized by pancytopenia and bone marrow hypoplasia. The pathogenesis of AA is complicated, until now it is not fully understood. Further study on the pathological mechanism will be helpful for the diagnosis and treatment of AA. CD8(+) T cells and their secreted cytokines play important roles in the abnormal immunity during the process of AA. Thus, this review focuses on the role of CD8(+) T cells and their secreted cytokines in the pathogenesis of AA.