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.
Blood Platelet Disorders ; genetics ; metabolism ; Humans ; Proto-Oncogene Proteins c-myb ; genetics ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism

Synthetic lethal screening, which exploits the combination of mutations that result in cell death, is a promising method for identifying novel drug targets. This method provides a new avenue for targeting "undruggable" proteins, such as c-Myc. Here, we revisit current methods used to target c-Myc and discuss the important functional nodes related to c-Myc in non-oncogene addicted network, whose inhibition may cause a catastrophe for tumor cell destiny but not for normal cells. We further discuss strategies to identify these functional nodes in the context of synthetic lethality. We review the progress and shortcomings of this research field and look forward to opportunities offered by synthetic lethal screening to treat tumors potently.
Humans ; Mutation ; Neoplasms/genetics* ; Proteins ; Proto-Oncogene Proteins c-myc/genetics* ; Synthetic Lethal Mutations

Objective: To investigate the strong expression (S+) of P53 and BCL2 proteins in MYC/BCL2 double-expression DLBCL (DEL) and whether they can be used for the prognostic evaluation and stratified diagnosis of DELs. Methods: Tissue microarray were made by filed FFPE blocks of 174 DLBCL cases. The translocation of MYC, BCL2 and BCL6 genes were detected by FISH, and the proteins were detected by IHC. Data of clinicopathologic features and follow up of patients were collected and OS (overall survival) and PFS (progression free survival) were analyzed by statistics. Results: Eight double-hit lymphomas (DHLs) were identified in all cases, and 45 DELs were selected from 166 remaining cases, which have no significant difference in OS and PFS compared with non-DEL cases (P=0.668 and P=0.790) . Of 42 DEL-cases with follow up data, 24 cases with P53+ or/and BCL2 (S+) are significantly shorter OS and PFS than others (P=0.003 and P=0.000) , in which the cases with P53+/BCL2 (S+) co-expression were the worst prognosis, and P53/BCL2 co-weaker positive DEL cases even have superior OS and PFS than those non-DELs. Although statistics showed that the cases of P53+ or/and BCL2 (S+) have a lower OS and PFS in total cases (P=0.063 and P=0.024) , it is not the case when the DEL-cases take out from total cases, that is the cases with P53+ or/and BCL2 (S+) are as similar OS and PFS as others in non-DEL group (P=0.590 and P=0.550) . Conclusion: The strong expression of P53 and BCL2 proteins can be used as indicators of stratified diagnosis and poor prognosis of DEL.
Humans ; Lymphoma, Large B-Cell, Diffuse/genetics* ; Prognosis ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Proto-Oncogene Proteins c-myc/genetics* ; Tumor Suppressor Protein p53/genetics*

OBJECTIVE: To investigate the effect of P53 expression on prognosis of patients with double expressor lymphoma(DEL) and the interaction between the expression of MYC, BCL2 and P53 in diffuse large B-cell lymphoma(DLBCL). METHODS: Eighty-eight patients with newly diagnosed DLBCL from 1st September 2012 to 31th May 2018 in Shanxi Dayi Hospital affiliated to Shanxi Medical University were selected. The expressions of MYC、BCL2、P53、CD10、BCL6、MUM and Ki-67 were tested by immunohistochemistry method. The overall survival of patients was analyzed by the Kaplan-Meier method and compared by the log-rank test. The prognostic effect of MYC, BCL2 and P53 expression was analyzed by univariate and multivariate analysis. RESULTS: Compared with patients without P53 expression, the patients with P53 expression had higher LDH level, higher NCCN-IPI scores, lower response to chemotherapy，poorer overall survival(OS) and a higher rate of death(P<0.05). In patients who had diffuse large B-cell lymphoma associated with MYC, BCL2 expression or MYC/BCL2 double expression， compared with the patients whom without P53 expression, P53 expression associated with a significant worse OS (P<0.05). The patients with concurrent MYC and P53 expression had a worse OS, compared with patients with either P53 or MYC expression(P<0.05). In patients with MYC/P53 co-expression, BCL2 expression did not correlate with poorer survival significantly(P>0.05). Among lymphoma patients with MYC/P53, MYC/BCL2 and BCL2/P53 co-expression, the patients with MYC/P53 co-expression had the worse OS (3 year OS rate：31.6%), followed by the subgroup of patients with MYC/BCL2/P53(3 year OS rate：46.2%), patients with MYC/BCL2/P53 expression(3 year OS rate： 636%) showed a longer OS compared with the other two subgroups（P<0.05）. Multivariate analysis demonstrated that P53 expression and NCCN-IPI were independent prognostic factors in this patient cohort. CONCLUSION P53 and MYC expressions have a synergistically negative prognostic effect in DLBCL patients. P53 expression augments the negative prognostic effect of MYC/BCL2 double expression. Patients with MYC/P53 co-expression have a worse prognosis in comparison with the patients with MYC/BCL2 double expression.
Humans ; Lymphoma, Large B-Cell, Diffuse ; genetics ; Prognosis ; Proto-Oncogene Proteins c-bcl-2 ; Proto-Oncogene Proteins c-myc ; Tumor Suppressor Protein p53 ; genetics

Animals ; Gene Amplification ; Genes, myc ; Humans ; Lymphoma, B-Cell ; genetics ; metabolism ; pathology ; Mutagenesis, Insertional ; Proto-Oncogene Proteins c-myc ; metabolism ; Translocation, Genetic

OBJECTIVETo study the clinical significance of P53, C-MYC and BCL-6 abnormality in the patients with diffuse large B cell lymphoma (DLBCL).

METHODSFrom July 2011 to January 2013, 80 patients with DLBCL were admitted in our hospital and were chosen as study objects, their clinical data were collected. The abnormality of P53, C-MYC and BCL-6 was examined by using I-FISH for all the patients. The correlation of abnormality of P53, C-MYC and BCL-6 with clinical staging, curative efficacy and prognosis of the patients were analyzed.

RESULTSOut of 80 patients 27 patients (33.75%) had P53 deletion, 24 patients (30.00%) had C-MYC rearrangement/amplification, and 46 patients (57.50%) had BCL-6 rearrangement. The P53 deletion, C-MYC rearrangement/amplification and BCL-6 rearrangement significantly correlated with staging, curative effect and prognosis of the patients (P < 0.05).

CONCLUSIONThe curative efficacy and prognosis of the DLBCL patients with abnormality of P53, C-MYC and BCL-6 have been confirmed to be unsatisfactory.

DNA-Binding Proteins ; genetics ; metabolism ; Humans ; In Situ Hybridization, Fluorescence ; Lymphoma, Large B-Cell, Diffuse ; diagnosis ; genetics ; metabolism ; Prognosis ; Proto-Oncogene Proteins c-bcl-6 ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; genetics ; metabolism

This study was aimed to investigate the effects of SUV39H1 siRNA on proliferation and apoptosis of acute myelogenous leukemia KG-1 cell line. The small interfering RNA (siRNA) targeting SUV39H1 gene was designed and transfected into KG-1 cells by Lipofectamine(TM) 2000. Cell growth affected by SUV39H1 siRNA was determined by MTS method. Cell apoptosis was measured by flow cytometry. The expressions of P15 and anti-apoptosis protein such as BCL-2, procaspase-9, procaspase-3 and C-MYC were detected by Western blot. The results indicated that siRNA targeting SUV39H1 inhibited proliferation of KG-1 cells. Proliferated rates were (76.43 ± 1.98)%, (51.31 ± 1.84)%, (37.31 ± 1.61)%, (18.94 ± 3.22)% respectively after transfection with SUV39H1 siRNA at 30, 60, 120, 240 nmol/L for 48 h, while P15 expression was upregulated. Apoptotic cells significantly increased, apoptotic rates were (40.2 ± 5.1)%, (56.8 ± 4.8)%, (71.6 ± 5.6)% respectively after transfection with siRNA targeting SUV39H1 at 30, 60, 120 nmol/L (P < 0.05). The protein expression of BCL-2, procaspase-9, procaspase-3, C-MYC was downregulated after transfection. It is concluded that the siRNA targeting SUV39H1 inhibits cell growth and induces cell apoptosis of KG-1 cell line, which may be a new therapeutic target in human leukemia.
Apoptosis ; genetics ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Methyltransferases ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; RNA Interference ; RNA, Small Interfering ; genetics ; Repressor Proteins ; genetics

OBJECTIVETo investigate BCL-6, MYC and p53 genes abnormalities in diffuse large B-cell lymphoma (DLBCL) and correlate the result with immunosubtypes and prognosis.

METHODSInterphase fluorescence in situ hybridization (I-FISH) was performed to detect the BCL-6, MYC and p53 genes. Immunohistochemistry (Envision method) was used to measure the expressions of CD3, CD10, CD20, BCL-6, MUM -1, BCL-2 and Ki-67 genes in DLBCL. The patients were classified into germinal center B cell-like (GCB) and non-GCB subtypes according to Hans' algorithm.

RESULTSBCL-6 rearrangement was detected in 10 of 46 DLBCL cases. The presence of gene rearrangement had no correlation with BCL-6 protein expression (P= 0.245). Overall survival (OS, P= 0.138) and progression-free survival (PFS, P= 0.095) were not influenced by BCL-6 rearrangement. All MYC rearrangements were detected in GCB type DLBCL. Deletion of p53 gene was detected in 14 cases and was significantly associated with shorter OS (P= 0.046) and PFS (P= 0.043).

CONCLUSIONI-FISH is a rapid, accurate and sensitive method for detecting BCL-6, MYC and p53 abnormalities. No correlation was found between BCL-6 gene rearrangement and BCL-6 protein expression. MYC translocation was more common in GCB type DLBCL compared with non-GCB type ones. Patients with p53 deletion had a poorer prognosis. The p53 gene may provide a useful indicator for the prognosis of DLBCL.

DNA-Binding Proteins ; genetics ; Female ; Genes, p53 ; Humans ; In Situ Hybridization, Fluorescence ; Lymphoma, Large B-Cell, Diffuse ; classification ; genetics ; immunology ; mortality ; Male ; Middle Aged ; Prognosis ; Proto-Oncogene Proteins c-bcl-6 ; Proto-Oncogene Proteins c-myc ; genetics

This study was purposed to investigate the effects of siRNA targeting c-myc on apoptosis induction, proliferation in inhibition as well as c-myc protein and mRNA expression in human myeloid leukemia cell line HL-60 cells. C-myc siRNA synthesized in vitro was transfected into HL-60 cells by liposome. Changes of cell morphology were observed. Growth inhibition was detected by MTT assay and colony formation assay, and cell apoptosis was determined by DNA ladder. The expressions of c-myc mRNA and protein were detected by RT-PCR and Western-blot respectively. The results indicated that c-myc siRNA remarkably inhibited the cell proliferation, with an IC(50) value of 150 nmol/L. Data of DNA ladder showed that HL-60 cells apoptosis could be efficiently induced by c-myc siRNA, the apoptosis rate positively correlated with the time duration of treatment with drugs. The c-myc mRNA and protein expressions on HL-60 cells decreased after treatment with c-myc siRNA, which negatively correlated with time duration of treatment. It is concluded that c-myc siRNA can efficiently induce growth inhibition, decrease the expressions of c-myc mRNA and protein, and induce apoptosis in HL-60 cells.
Apoptosis ; genetics ; Cell Proliferation ; Gene Targeting ; HL-60 Cells ; Humans ; Leukemia, Myeloid ; genetics ; Proto-Oncogene Proteins c-myc ; genetics ; RNA, Messenger ; genetics ; RNA, Small Interfering ; genetics ; Transfection

OBJECTIVETo study the effects of cadmium on hepatocellular DNA damage, expression of proto-oncogenes c-myc, c-fos, and c-jun as well as apoptosis in rats.

METHODSCadmium chloride at the doses of 5, 10, and 20 micromol/kg was given to rats by i.p. and there were 5 male SD rats in each group. Hepatocellular DNA damage was measured by single cell gel electrophoresis (or comet assay), while expression of proto-oncogenes c-myc, c-fos, and c-jun in rat hepatocytes were measured by Northern dot hybridization. C-Myc, c-Fos, and c-Jun were detected with immuno-histochemical method. Hepatocellular apoptosis was determined by TUNEL (TdT-mediated dUTP Nick End Labelling) and flow cytometry.

RESULTSAt the doses of 5, 10, and 20 micromol/kg, cadmium chloride induced DNA damage in rat hepatocytes and the rates of comet cells were 50.20%, 88.40%, and 93.80%, respectively. Results also showed an obvious dose-response relationship between the rates of comet cells and the dose of cadmium chloride (r = 0.9172, P < 0.01). Cadmium chloride at the doses of 5, 10, and 20 micromol/kg induced expression of proto-oncogenes c-myc, c-fos, and c-jun. The positive brown-yellow signal for c-myc, c-fos, and c-jun was mainly located in the cytoplasm of hepatocytes with immunohistochemical method. TUNEL-positive cells were detected in cadmium-treated rat livers. Apoptotic rates (%) of cadmium-treated liver cells at the doses of 5, 10, and 20 micromol/kg were (17.24 +/- 2.98), (20.58 +/- 1.35), and (24.06 +/- 1.77) respectively, being significantly higher than those in the control. The results also displayed an obvious dose-response relationship between apoptotic rates and the dose of cadmium chloride (r = 0.8619, P < 0.05).

CONCLUSIONCadmium at 5-20 micromol/kg can induce hepatocellular DNA damage, expression of proto-oncogenes c-myc, c-fos, and c-jun as well as apoptosis in rats.

Animals ; Apoptosis ; drug effects ; Cadmium ; toxicity ; DNA Damage ; Gene Expression Regulation ; drug effects ; Hepatocytes ; cytology ; drug effects ; metabolism ; Male ; Proto-Oncogene Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins c-fos ; genetics ; metabolism ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley