Hsa-let-7b-5p Inhibits Proliferation of Human Leukemia THP-1 Cells via FTO/m / 中国实验血液学杂志

OBJECTIVE@#To investigate the down-regulation effect of let-7b-5p on the expression of FTO in acute myeloid leukemia cell line THP-1 and inhibitory effect on THP-1 proliferation via m@*METHODS@#The acute myeloid leukemia cell line THP-1 and the normal human peripheral blood mononuclear cells (PBMNC) were selected as subjects. The expression of let-7b-5p and FTO mRNA in those cells was detected by qPCR, further the expression of FTO protein in those cells was detected by Western blot. And, the luciferase reporter gene assay was used to verify the targeting effect of let-7b-5p on FTO. Finally, THP-1 cells were transfected respectively with let-7b-5p mimic, and PBMNC with let-7b-5p inhibitor, there after the C-MYC mRNA m@*RESULTS@#Compared with PBMNC, the expression of let-7b-5p in THP-1 significantly decreased, while the expression of FTO was significantly increased (P<0.05). After transfection with let-7b-5p mimic combined with FTO 3'-UTR, the luciferase activity of transfected THP-1 cells significantly decreased, but the luciferase activity significantly increased after transfection with mutant 3'-UTR, which was significantly different from the negative control group(blank vector) (P<0.05). Let-7b-5p inhibitor down-regulated c-MYC mRNA m@*CONCLUSION@#Human acute myeloid leukemia cell line THP-1 low expresses the let-7b-5p, which regulates c-MYC expression through let-7b-5p-/FTO-/m

Expression of Hippo signaling pathway core element MST1 in acute leukemia patients and its significance / 中国实验血液学杂志

This study was aimed to investigate the expression of Hippo signaling pathway core element MST1 gene in acute leukemia (AL) patients, and explore its relation with AL pathogenesis and prognosis. 50 newly diagnosed patients with AL, 33 normal people, 23 patients with AL in complete remission, 12 refractory or relapsed patients were tested for the expression of MST1 gene by real-time quantitative PCR, Western blot was used to further validate the level of MST1 protein expression. And combined with clinical data, prognostic factors of the patients were analyzed. The results indicated that compared with the normal people, the expression level of MST1 in newly diagnosed patients with AL significantly decreased (P < 0.05), but significantly increased in AL patients with complete remission (CR), the difference of expression was statistically significant before CR and after CR (P < 0.05). Compared with refractory or relapsed patients, the expression level of MST1 gene in newly diagnosed patients was not significantly different (P > 0.05). Besides, the expression level of MST1 between the patients with CR and the normal people was not significantly different (P > 0.05). It is concluded that the low expression of MST1 may be related with the pathogenesis and prognosis of AL.

Differential expression of miR-143 in bone marrow cells between acute leukemia patients and normal people and its significance / 中国实验血液学杂志

MicroRNA abnormality is closely related to the development of acute leukemia. This study was aimed to investigate the differential expression of miR-143 in bone marrow cells between patients with acute leukemia and normal people. Bone marrow cells from 50 AL patients and 20 normal people were collected respectively and the total RNA was isolated routinely. The quantitative real-time PCR (Q-PCR) method was used to detect the expression levels of miR-143 in these specimens. The results showed that compared with the normal people, the expression of miR-143 in AL patients was significantly decreased (p < 0.05), which significantly increased after complete remission; besides, the expression of miR-143 was negatively correlated with the expression of DNMT3A mRNA, a known target gene of miR-143. It is concluded that the expression of miR-143 in bone marrow cells of AL patients is down-regulated which may be related with the development of acute leukemia.

Methylation status of IEX-1 gene promotor CpG island in malignant hematopoietic cell lines / 中国实验血液学杂志

This study was to purposed to explore the methylation status changes of IEX-1 gene promoter CpG island and its relevance with occurrence of hematologic malignancies. The methylation status of IEX-1 gene promoter CpG island in 9 NB4, HL-60 U937, Raji, CA46, Jurkat, K562, CEM and Molt4 hematologic malignant cell lines was detected by using methylation-specific PCR, the methylation status of IEX-1 gene promoter CpG island in normal peripheral blood mononuclear cells treated by M. sssI enzyme and the methylation status of IEX-1 gene promoter CpG island in normal peripheral blood mononuclear cells untreated were used as positive and negative controls respectively. The results showed that the hypermethylation of IEX-1 gene promoter CpG islands was detected in NB4, Molt4 and Raji cell lines, as well as in normal peripheral blood mononuclear cells treated by M. sssl enzyme; the partial methylation status was found in CA46, CEM, U937, K562, HL-60 and Jurkat cell lines; the unmethylation status was observed in untreated normal peripheral blood mononuclear cells. It is concluded that the changes of methylation status of gene IEX-1 promoter CpG island correlates with hematologic malignancies to a certain extent.

Mechanism of As(2)O(3) on hdpr1 gene demethylation in Jurkat cell line / 中国实验血液学杂志

This study was purposed to investigate the effect of As(2)O(3) on the demethylation of anti-oncogene-hdpr1 gene of acute lymphoblastic leukemia cell line Jurkat in vitro and its mechanism. The inhibitory effect of As(2)O(3) on the proliferation of Jurkat cells was assayed by CCK-8; the change of Jurkat cell cycle was detected by flow cytometry before and after using As(2)O(3); the effect of As(2)O(3) on the methylation model of hdpr1 gene was analyzed by methylation-specific PCR, and the effect of As(2)O(3) on the expression of hdpr1 mRNA was analyzed by semiquantitative RT-PCR. The results showed that the proliferation rate of Jurkat cells was decreased significantly after being treated with As(2)O(3), and in dose-and time-dependent manner; As(2)O(3) blocked Jurkat cell cycle in G(0)/G(1) phase in dose-dependent manner. As(2)O(3) could reverse hypermethylation of hdpr1 gene and induce its mRNA reexpression, and down-regulate the dnmt1, dnmt3a, dnmt3b mRNA expression level also in dose-dependent manner. It is concluded that the As(2)O(3) suppresses the proliferation of Jurkat cells and blocks cell cycle is G(0)/G(1), its possible mechanism may be down-regulating mRNA expression level of dnmt1, dnmt3a and dnmt3b, induce demethylation of hdpr1 gene from abnormal hypermethylation status and activates its reexpression.

Detection of APC gene promoter methylation in hematological malignant cell lines by nested-methylation specific polymerase chain reaction / 中国实验血液学杂志

This study was aimed to investigate the efficiency of nested methylation specific polymerase chain reaction (nMS-PCR) for detecting the APC gene promoter methylation and to clarify the roles of methylation in genesis and development of hematologic malignancies, as well as to screen the hematologic malignant cell lines with hypermethylation of APC gene promoter to use as an ideal cell model for exploring the relationship between gen methylation and gene expression. The genome DNA of 10 cell lines modified with bisulfide was amplified and the methylation status of APC gene promoter was detected by using nMS-PCR. The results showed that the methylation of APC gene promoter was detected in Jurkat cells, while could not be detected in CA46, U266, Molt4, K562, HL-60, CEM, AKR, U937 and Raji cell lines. In conclusion, APC gene methylation in hematological malignant cell lines can be accurately detected by nMS-PCP method, which is simple method for detecting methylation status of various hematological malignant cell lines.

Methylation status of CpG islands in secreted frizzled-related protein gene promoter region of malignant hematopoietic cell lines / 中国实验血液学杂志

To investigate the methylation status of CpG islands of the secreted frizzled-related protein (SFRP) gene promoter region in malignant hematopoietic cell lines, and to explore the possible relationship of CpG abnormal methylation status with pathogenic mechanism of hematologic malignancies. Methylation-specific PCR was used to detect the status of SFRP gene promoter region in nine malignant hematopoietic cell lines and peripheral blood mononuclear cells from healthy people. The results indicated that hypermethylation of 2 genes coding for SFRP1 and 2 were present in nine malignant hematopoietic cell lines, however, methylation and unmethylation of SFRP4 were both detected in CA46, HL60 and U937 cell lines, and SFRP5 in U266 as well. None of the normal mononuclear cells showed methylation of SFRP 1-5 genes. It is concluded that the hypermethylation of SFRP genes is related to the evolution of malignant hematopoiesis. Methylation of SFRP genes may serve as potential independent biomarkers for early detection of hematologic malignancies.