Effect of MiR-96 on Cell Invasion and Apoptosis in Pediatric Acute Myeloid Leukemia via Regulating MYB / 中国实验血液学杂志

OBJECTIVE@#To analyze the relationship of the expression of transcription factor MYB targeted regulation by miR-96 to cell invasion and apoptosis in pediatric acute myeloid leukemia (AML).@*METHODS@#A total of 65 children with AML in The 928 Hospital of PLA Joint Logistics Support Forces from January 2017 to November 2019 were selected, including 35 cases diagnosed as primary AML and 30 cases as complete remission AML. Thirty children with immune thrombocytopenia were selected as control group. The clinical characteristics were analyzed and compared between the two groups. The levels of miR-96 and MYB in peripheral blood samples were detected by qRT-PCR and compared between the two groups. The miR-96 mimics and its negative control (NC), inhibitor-miR-96 and its NC transfected HL60 cells induced by liposome (Lipofectamine 2000), respectively, Then the expression levels of MYB were detected with Western blot and compared among four HL60 cell groups. The invasion ability of four HL60 cell groups were detected with Transwell assay. The cell proliferation ability of four HL60 cell groups were detected with MTT at 24 h, 48 h, and 72 h, respectively. The apoptosis rates of four HL60 cell groups were detected with flow cytometry.@*RESULTS@#Compared with control group, the level of miR-96 in AML children were higher, but MYB lower (P0.05). The promotion of over-expression level of miR-96 on the invasion ability of HL 60 cells was confirmed by Transwell assay. MTT assay showed that miR-96 could promote the proliferation of HL60 cells, inhibit the apoptosis of HL60 cells, and the effect was time-dependent manner (r=0.804). The inhibition of miR-96 on HL60 cells apoptosis was also confirmed with flow cytometry.@*CONCLUSION@#MiR-96 has significant negative effect on invasion and apoptosis of AML cells by targeting regulation MYB, and it might be a potential novel strategy for pediatric AML treatment.

Diagnostic value of MYB protein expression in adenoid cystic carcinoma and status of MYB gene copy number / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore the diagnostic value of MYB protein expression for adenoid cystic carcinoma and its differential diagnosis from other salivary gland tumors, and to further investigate the status of MYB gene copy number.</p><p><b>METHODS</b>MYB expression was studied by immunohistochemistry in 34 adenoid cystic carcinomas, 55 non-adenoid cystic carcinomas (other salivary gland tumors) including 10 pleomorphic adenomas, 10 basal cell adenomas, 10 epithelial-myoepithelial carcinomas, 9 basal cell adenocarcinomas, 8 mucoepidermoid carcinomas, 4 carcinoma in pleomorphic adenomas, and 4 polymorphous low-grade adenocarcinoma. MYB gene copy number status was detected by FISH in MYB protein-positive cases.</p><p><b>RESULTS</b>82.4% (28/34) of adenoid cystic carcinomas were MYB protein-positive, compared with 9.1% (5/55) of non-adenoid cystic carcinomas, and the difference between the two groups was statistically significant (P < 0.01). 2/18 of adenoid cystic carcinomas had duplication of MYB gene by FISH, and all non-adenoid cystic carcinomas were negative although the difference was not statistically significant (P = 0.435).</p><p><b>CONCLUSIONS</b>MYB protein expression is a useful diagnostic marker for adenoid cystic carcinomas in its separation from other salivary gland tumors. In addition, duplication of MYB gene is no a major mechanism for the MYB protein overexpression.</p>

Bioinformatics analysis and identification of transcriptional regulation of human UCA1 gene / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the transcription factor binding sites and methylation in the promoter region of UCA1 gene.</p><p><b>METHODS</b>UCA1 gene promoter was analyzed using CpG software to predict the CpG island. MatrixCatch and TFSEARCH were used to predict the potential transcription factor binding sites in UCA1 gene core promoter. ChIP assay was used to identify the transcription factors binding to UCA1 gene core promoter.</p><p><b>RESULTS</b>UCA1 gene promoter contained no CpG island and was therefore a typical tissue-specific gene. There were 4 transcription factors associated with human cancers in UCA1 gene core promoter, but only one of them interacted with UCA1 gene core promoter.</p><p><b>CONCLUSION</b>There is no CpG island in UCA1 gene promoter region, and the transcription factor c-Myb can specifically bind to the core promoter.</p>

Research progress of proto-oncogene c-myb in megakaryocyte-erythroid hematopoiesis / 中国实验血液学杂志

The nuclear proto-oncogene c-myb is an essential regulator of hematopoiesis, it involves in the growth, survival, proliferation and differentiation of hematopoietic cells. More recently, different cell lines and transgenic mouse studies have suggested that c-myb plays a pivotal role in the megakaryocyte-erythroid progenitor cell lineage commitment. The deletion of the proto-oncogene c-myb would lead to profoundly impaired definitive erythropoiesis, but little influence in definitive megakaryopoiesis. Moreover, transient transfection and immunoprecipitation studies have demonstrated that c-myb exerts its physiological function in normal hematopoiesis by influencing a network of regulator molecules. Now therefore, insight into the structure, function and related molecular regulation mechanism of c-myb gene can help to further clarify its function in megakaryocyte-erythroid hematopoiesis and can provide new ideas for molecular target therapy of the platelet diseases and red blood cell diseases. In this article, c-myb structure, function and related effects involved in megakaryocyte-erythroid hematopoiesis as well as related molecular mechanisms are reviewed.

Expression of c-myc and c-myb gene in leukemic bone marrow stromal cells and their correlation / 中国实验血液学杂志

This study was purposed to investigate the expression level of oncogene c-myc and c-myb in leukemic cells and leukemic bone marrow stromal cells (BMSC) and the correlation with each other. The expression levels of c-myc and c-myb in those cells were examined semi-quantitatively by reverse transcription polymerase chain reaction (RT-PCR). Flow cytometry analysis was used to detect the membrane surface antigens of leukemic cells and BMSC. The karyotype was analyzed by G-banding techniques. The results showed that (1) c-myc and c-myb gene were expressed in the normal control group, the leukemic cells and BMSC of patients group. The mean expression levels of c-myb mRNA and c-myc mRNA in abnormal chromosomal leukemic cells were 1.03 ± 0.48 and 1.15 ± 0.38 respectively, which were significantly higher than those in control group (P < 0.05). In the abnormal karyotype stromal cells, the mean expression level of c-myb mRNA and c-myc mRNA were 2.08 ± 0.82 and 1.46 ± 0.29 respectively (P < 0.05). (2) The expression level of c-myc and c-myb mRNA were closely associated with patients' platelet counts (P < 0.05). (3) The expression of c-myc mRNA linearly correlated with the expression of c-myb mRNA in different prognostic groups. (4) In acute leukemic cells and BMSC, c-myc expression positively correlated with c-myb expression. (5) The expression level of c-myc in leukemic cells correlated with the expression levels of c-myc and c-myb in BMSC, respectively. It is concluded that the reduction of c-myc or c-myb expression levels may be a therapeutic regimen for leukemia.

Targeting c-Myc on cell growth and vascular endothelial growth factor expression in IN500 glioblastoma cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The level of c-Myc is closely associated with high pathological grade and the poor prognosis of gliomas. Vascular endothelial growth factor (VEGF) is the most important angiogenic factor that potently stimulates the proliferation and migration of vascular endothelial cells. This study aimed to address the biological importance of c-Myc in the development of gliomas, we downregulated the expression of c-Myc in the human glioblastoma cell line IN500 and studied the in vitro effect on cellular growth, proliferation, and apoptosis and the expression of VEGF and the in vivo effect on tumor formation in a xenograft mouse model.</p><p><b>METHODS</b>IN500Δ cells were stably transfected with shRNA-expressing plasmids for either c-Myc (pCMYC-shRNA) or as a control (pCtrl-shRNA). Following establishment of stable cells, the mRNA expressions of c-Myc and VEGF were examined by reverse transcription (RT)-PCR, and c-Myc and VEGF proteins by Western blotting and immunohistochemistry. Cell-cycle progression and apoptosis were determined by flow cytometry. The in vivo effect of targeting c-Myc was determined by subcutaneous injection of stable cells into immunodeficient nude mice.</p><p><b>RESULTS</b>The stable transfection of pCMYC-shRNA successfully knocked down the steady-state mRNA and protein levels of c-Myc in IN500, which positively correlated with the downregulation of VEGF. Downregulating c-Myc in vitro also led to G1-S arrest and enhanced apoptosis. In vivo, targeting c-Myc reduced xenograft tumor formation and resulted in significantly smaller tumors.</p><p><b>CONCLUSIONS</b>c-Myc has multiple functions in glioblastoma development that include regulating cell-cycle, apoptosis, and VEGF expression. Targeting c-Myc expression may be a promising therapy for malignant glioma.</p>

Progress of research on Proto-oncogene c-myc, c-myb in platelet diseases / 中国实验血液学杂志

The Proto-oncogene c-myc and c-myb has been shown to be crucial in the development of the hematopoietic system. The changes in the expression of c-myc are concerned the cell proliferation and differentiation, the expression products of which play an important regulatory role in cell growth, differentiation or malignant transformation. The c-myb involves in transcription and affects cell proliferation, differentiation, apoptosis. More recently, the researches on proto-oncogene c-myc, c-myb in hematopoietic regulation have gradually increased along with development of molecular biology, molecular immunology and cell biology. Scientists point out that the directive differentiation of erythroid and megakaryocytic progenitors, and platelet abnormalities all relate to the level of their expressions. The most common thrombocytopathy includes thrombocytopenia, thrombocytosis and so on. The etiology and the mechanism of these diseases are unknown. This article reviews the structure, function and the expression of c-myc and c-myb in platelet diseases and their significance.

Silencing of the annexin II gene down- regulates the levels of S100A10, c-Myc, and plasmin and inhibits breast cancer cell proliferation and invasion

To explore the roles of annexin II in breast cancer progression, and to study the effect of annexin II on breast cancer cell proliferation and invasion. This study was conducted in the Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China from December 2006 to January 2009. First, we employed Western blot and reverse transcriptase polymerase chain reaction to detect the expression of annexin II and S100A10 in a panel of well-characterized human breast cancer cell lines, and investigated the localization of annexin II and S100A10 by use of immunofluorescence. We then silenced the expression of annexin II in MDA-MB-435s, which was found to over express annexin II, using the chemically-synthetic annexin II small interfering RNA [siRNA] duplexes [including 3 groups: blank MDA-MB-435s cells, cells transfected with negative control siRNA, and cells transfected with annexin II-siRNA]. Finally, the cell proliferation, invasion, and plasmin generation were assayed, and the cellular levels of S100A10 and c-Myc were also detected. All the tests were repeated 3 times. Annexin II and S100A10 were over expressed in invasive human breast cancer cell lines. The siRNA targeting annexin II of MDS-MB 435s cells did not only decrease annexin II messenger RNA and protein levels, but also down-regulated the levels of S100A10, and c-Myc. The treated cells were remarkably blocked in the G0/G1 phase, and cells in the S/G2+M phase decreased. Additionally, the treatment with siRNA resulted in reduction of plasmin generation as well as a loss of the invasive capacity of breast cancer cells. Annexin II might be a key contributor to breast cancer proliferation and invasion

Expression of c-myb in reflux esophagitis, Barrett esophagus and esophageal adenocarcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of c-myb in reflux esophagitis, Barrett esophagus and esophageal adenocarcinoma.</p><p><b>METHODS</b>The expression levels of c-myb in the esophageal mucosa tissue of patients with reflux esophagitis, Barrett esophagus and esophageal adenocarcinoma were detected by real-time fluorescent quantitative RT-PCR.</p><p><b>RESULTS</b>The expression levels of c-myb mRNA in Barrett esophagus and esophageal adenocarcinoma tissues was significantly higher than that in normal and reflux esophagitis esophageal tissue (P<0.05 or 0.01), and increased progressively with the development of reflux esophagitis into Barrett esophagus and esophageal adenocarcinoma.</p><p><b>CONCLUSIONS</b>The expression level of c-myb mRNA is closely related with the development of Barrett esophagus and esophageal adenocarcinoma, and may be used as a valuable index for monitoring the early onset and intervention of Barrett esophagus and esophageal adenocarcinoma.</p>

Cloning and molecular characteristics analysis of a MYB gene from Fagopyrum dibotrys / 中国中药杂志

Using RACE with a Fagopyrum dibotrys callus cDNA library, one clone, named FdMYBP1, encoding a putative R2R3 MYB protein was identified. FdMYBP1 appeared to be a full-length cDNA of 1159 bp encoding a protein of 265 amino acids. Through structure and property analysis of FdMYBPI with bioinformational methods, it was found that the amino acid sequence of FdMYBP1 showed great homology to other MYBP with the R2R3 repeat region in the N-terminus. Southern blot analysis indicated that FdMYBP1 belongs to a single copy gene in F. dibotrys genomes. The FdMYBP1 gene has the same classic characters with other MYBP and probably involved in the pathway of flavonoid metabolisms.

The effects of protooncogene on oocyte maturation mediated by cytokines / 中国应用生理学杂志

<p><b>AIM</b>The mechanisms of cytokines in regulating oocyte maturation is still little known. The present study attempt to investigate whether the protooncogene of c-erbB2, c-myb are involved in introducing of cytokines to regulate oocyte maturation.</p><p><b>METHODS</b>This research used mouse GV stage oocyte culture model in vitro and RT-PCR, Western blotting method to explore the effect of EGF, TNFalpha, ET-1 and NO on oocyte maturation; to analyze the c-erbB2 mRNA and c-myb mRNA expression and the phosphorylation of MAPK and cyclinB1 expression in oocytes affected by above cytokines.</p><p><b>RESULTS</b>EGF(10 microg/L) stimulated meiosis of oocytes significantly, the level of c-erbB2 mRNA, c-myb mRNA were increased, and promoted the phosphorylation of MAPK and cyclinB1 expression; TNFalpha (1 microg/L) and ET-1 ((10(-1) mol/L) had the results to EGF. Low dose of SNP (10(-5)mol/L) had no effect on oocyte maturation, but could significantly reverse the suppression of dbcAMP on oocyte maturation.</p><p><b>CONCLUSION</b>c-erbB2 and c-myb were involved in introducing of cytokines to regulate oocyte maturation, might be the middle link in connection of the cytokines with MAPK and MPF in regulation oocyte maturation.</p>

Expression and function of Ahi-1 gene in Jurkat cells / 中国实验血液学杂志

This study was aimed to investigate the expression, protein localization and function of Ahi-1 gene and its encoding protein in Jurkat cells. The expression of Ahi-1 mRNA and protein were measured by Northern and Western blot respectively. The plasmid containing prototype Ahi-1 was constructed and transfected into Jurkat cells. The Jurkat-A and Jurkat-C cells which either over-expressed the prototype Ahi-1 or not were obtained by selection with G418. The proliferation of the cells was assayed by XTT. The colony formation potential of the leukemia cells was checked by semisolid agarose culture. The results showed that three different transcripts of Ahi-1 (6.5,4.2 and 2 kb) were expressed in peripheral blood lymphocytes (PBLs), Jurkat and HUT78 cells. Ahi-1 protein with 140 kD localized in the cytoplasm majorly while traceless in the nucleus of Jurkat cells and PBLs from normal donor. Ahi-1 protein with 120 kD could be detected in the nucleus fraction of PBLs. Very low level of Ahi-1 protein with 120 kD was expressed in Jurkat cells. Up-regulating expression of Ahi-1 protein with 140 kD in the nucleus was found in Jurkat cells after exposure to meisoindigo, cytarabine, homoharringtonine, methotrexate and etoposide, down-regulating expression of Ahi-1 with 140 kD in the cytoplasm was observed after treatment with meisoindigo. The growth and colony formation potential were inhibited in the Jurkat-A cells, as compared to Jurkat-C cells. Total c-myb and phosphorylated AKT protein were continuously expressed in the Jurkat-C and Jurkat-A cells at similar level, but more phosphorylated c-myb was observed in Jurkat-A cells. It is concluded that three different transcripts of Ahi-1 at 6.5, 4.2 and 2 kb are detected in Jurkat cells; the Ahi-1 protein with 140 kD majorly expresses in the cytoplasm fraction and exposure to multiple chemotherapeutic compounds increased its expression in nucleus fraction. Over-expression of exogenous Ahi-1 can not only inhibit the growth and colony formation potential of Jurkat cells, but also induce the phosphorylation of c-myb in Jurkat cells.

c-erbB(2) and c-myb induce oocyte maturation via activation of mitogen-activated protein kinase and maturation promoting factor / 生理学报

It is important to study the mechanism of oocyte maturation because oocyte maturation is essential for the female procreation. The present study was designed to observe the effects of protooncogenes c-erbB(2) and c-myb on oocyte maturation and the upstream and downstream relationship with mitogen-activated protein kinase (MAPK) and maturation promoting factor (MPF). The investigation was designed as follows: (1) In order to explore the effects of protooncogenes on oocyte maturation, the dose- and time-dependent effects of c-erbB(2) antisense oligodeoxynucleotide (ASODN) and c-myb ASODN on oocyte maturation were examined, and the effects of oocyte microinjection with recombinant c-erbB(2) and c-myb proteins on oocyte maturation were investigated; (2) In order to study the upstream and downstream relationship among protooncogenes of c-erbB(2), c-myb and protein kinases of MAPK and MPF in regulating oocyte maturation, mouse oocytes were cultured in the medium treated with c-erbB(2) ASODN, c-myb ASODN, PD98059 (the MAPK inhibitor) or roscovitine (the MPF inhibitor) for 8 h, respectively, and the expressions of c-erbB(2) mRNA, c-myb mRNA, MAPK and MPF were examined. The results showed that both c-erbB(2) ASODN and c-myb ASODN inhibited the rate of germinal vesicle breakdown (GVBD) and the first polar (PB1) extrusion of denuded oocytes (DOs) in a dose- and time-dependent way, and delayed their maturation time significantly. When recombinant c-erbB(2) and c-myb proteins were microinjected into cytoplasm of germinal vesicle stage oocyte, we found that the GVBD rate increased by 23.1% (P<0.05) and 32.2% (P<0.05), respectively, for 6-hour culture, and the PB1 extrusion rate increased by 17.3% (P<0.05) and 23.5% (P<0.05), respectively, for 12-hour culture. RT-PCR showed that the mRNA expressions of c-erbB(2) and c-myb were detected in oocytes; c c-erbB(2) ASODN inhibited c-erbB(2) mRNA and c-myb mRNA expressions; c-myb ASODN inhibited c-myb mRNA expression but had no effect on c-erbB(2) mRNA expression. Nonsense tat ODN had no effects on the expressions of c-erbB(2) mRNA and c-myb mRNA. Neither PD98059 nor roscovitine changed the expressions of c-erbB(2) mRNA and c-myb mRNA though both of them inhibited recombinant c-erbB(2) and c-myb proteins-induced oocyte maturation. Furthermore, MAPK phosphorylation and cyclin B1 synthesis in oocytes were inhibited remarkably when oocytes were treated with c-erbB(2) ASODN, c-myb ASODN, PD98059 and roscovitine. Nonsense tat ODN had no effects on MAPK phosphorylation and cyclinB1 content. The results suggest that protooncogenes c-erbB(2) and c-myb play an important role in oocyte maturation; the effects of c-erbB(2) and c-myb depend upon the action of MAPK and MPF, and their activation is the event that occurs downstream of c-erbB(2) and c-myb in the maturation signal pathway.

Study of effect and mechanism of c-myb on the fertilization in mouse / 中国应用生理学杂志

<p><b>AIM</b>To investigate the distribution of c-myb, an oncoprotein, in mouse oocytes-cumulus cell complex and sperm immunohistochemically.</p><p><b>METHODS</b>To study the effect of c-myb on mouse fertilization in vitro, various concentration of c-myb antisense-oligodeoxynucleotides (c-myb ASODNs) were incubated with sperms and oocytes during fertilization. To explore the possible mechanism involved in fertilization, the relationship between c-myb ASODNs and GABA or dbcAMP or Verapamil or Progesterone in fertilization was also observed by immunohistochemical methods.</p><p><b>RESULTS</b>c-myb oncoprotein was observed on the nucleus of cumulus cell and head of sperm. c-myb ASODNs inhibited the rate of fertilization in vitro in a dose-dependent way. The fertilization rates of the control group, low (5 micromol/L), medium (10 micromol/L), high (20 micromol/L) concentration c-myb ASODNs groups and nonsense tat oligodeoxynucleotides (20 micromol/L) group were 34.97%, 30.89%, 20.14%, 16.68%, 34.47%, respectively. All of GABA, Progesterone and dbcAMP inversed the c-myb ASODNs inhibition effects on fertilization rate, but neither of them showed significant effect on the percentages of immunohistochemical stain of Myb on sperm and cumulus cells. By contrast, Verapamil inhibited the fertilization rate. Co-treated with c-myb ASODNs, Verapamil showed synergic inhibiting effects on the fertilization with c-myb ASODNs. Verapamil also inhibited the expression of Myb on head of sperm. The fertilization rates of the control group, medium (10 micromol/L) concentration c-myb ASODNs group, GABA group, P4 group, Verapamil group, dbcAMP group were 34.81%, 22.96%, 40.83%, 39.12%, 7.46%, 40.61%, respectively.</p><p><b>CONCLUSION</b>c-myb ASODNs is closely correlated with fertilization. Verapamil can inhibit fertilization in vitro through regulating Myb expression of sperm, while GABA, dbcAMP and Verapamil may affect the process of fertilization through the way other than Myb expression.</p>

Effect of c-myb on hCG-induced testosterone secretion in isolated rat Leydig cells / 生理学报

The present study was carried out to investigate the effect of antisense c-myb oligodeoxynucleotides (ODN) on hCG-induced testosterone secretion in isolated rat Leydig cells. The effects of cAMP, Ca(2+) and cycloheximide (CYX) on c-Myb protein expression and testosterone secretion were also observed. The results showed that antisense c-myb ODN inhibited hCG-induced testosterone secretion of isolated rat Leydig cells in a dose-dependent manner. At the same time, integral optical density immunostaining of Myb in Leydig cells was also remarkably reduced. Nonsense tat ODN had no effect on Leydig cells. Further experiments showed that dbcAMP (100 micromol/L) obviously increased hCG-induced testosterone secretion and integral optical density (IOD) immunostaining of Myb in Leydig cells. Verapamil (10 micromol/L), a Ca(2+) channel blocker, and cycloheximide (50 microg/ml), a protein synthesis inhibitor, reduced the immunostaining of c-Myb, and also lowered hCG-induced testosterone secretion in isolated rat Leydig cells. The results indicate that c-myb closely correlates with hCG-induced testosterone secretion, and that cAMP and Ca(2+)-dependent pathway participates in the expression of protooncogene.

Indomethacin-induced HL-60 cell apoptosis is associated with inhibition of beta-catenin/c-myc signal transduction pathway / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of indomethacin on HL-60 cell proliferation and apoptosis, and elucidate partly the molecular mechanism about the anti-leukemia effect of indomethacin by studying beta-catenin signal transduction pathway.</p><p><b>METHODS</b>HL-60 cells were treated with indomethacin at different concentrations (0, 25, 50, 100, 200, 400 micro mol/L). Cells viability and proliferation were determined by Trypan blue staining and cell counting respectively. DNA ladder pattern and cell morphology were used to identify cell apoptosis. The expression and cleavage of caspase-3, beta-catenin, c-myc were detected by Western blot techniques.</p><p><b>RESULTS</b>Indomethacin could significantly inhibit HL-60 cells proliferation and induce cells apoptosis with a time and dose dependent manner. An up-regulating expression and cleavage of caspase-3 were observed. Indomethacin could inhibit beta-catenin expression and induce its degradation, c-myc protein exhibited a down-regulation with a concentration dependent manner.</p><p><b>CONCLUSION</b>Indomethacin could inhibit HL-60 cell proliferation and induce cells apoptosis. Anti-leukemia effect of indomethacin was associated with the inhibition of "beta-catenin --> c-myc" signal pathway.</p>