Mcl-1 (myeloid cell leukemia-1) is a member of Bcl-2 (B cell leukemia-2) family, which may play an important role in cell apoptosis regulation, occurrence and development of tumors. This paper reviews advance of studies on the function of the mcl-1 gene and MCL-1 protein, the signal transduction pathways (JAK/STAT, MAPK, PI-3K) regulating the expression of mcl-1 gene, and the relationship between mcl-1 gene and hematologic malignancies.
Apoptosis ; Gene Expression Regulation, Neoplastic ; Humans ; Leukemia ; genetics ; Lymphoma ; genetics ; Multiple Myeloma ; genetics ; Myeloid Cell Leukemia Sequence 1 Protein ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; Signal Transduction

This study was aimed to investigate the relation of MCL-1 and BAK proteins with incidence and development of nutritional anemia (NA) and their clinical significance. The MCL-1 and BAK protein levels in serum of 66 patients with NA were determined by using ELISA. Eighteen healthy people were randomly selected as normal controls. The results indicated that: (1) as compared with normal control group, the expression level of MCL-1 protein in 3 NA groups (iron-deficiency anemia, macrocytic anemia, mixed anemia) significantly decreased (P < 0.001), while the expression level of BAK protein obviously increased (P < 0.001), but the expression level of MCL-1 and BAK proteins among 3 NA groups showed no obvious differences; (2) the MCL-1 protein expression level increased and BAK protein expression level decreased in 3 NA groups after treatment (P < 0.05). (3) there was negative correlation of expression levels of MCL-1 protein with BAK protein in NA group (r = -0.858 P < 0.05). It is concluded that the MCL-1 and BAK proteins may play an important role in the incidence and development of NA, and can be used as the assist index for defining diagnosis and evaluate prognosis of NA.
Anemia ; metabolism ; pathology ; Apoptosis ; Case-Control Studies ; Humans ; Malnutrition ; metabolism ; pathology ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; bcl-2 Homologous Antagonist-Killer Protein ; metabolism

Resistance to chemotherapy is a major obstacle for the effective treatment of advanced ovarian cancer. The mechanism of chemoresistance is still poorly understood. Recently, more and more evidence showed microRNAs (miRNAs) modulated many key molecules and pathways involved in chemotherapy. microRNA-106a (miR-106a) has been implicated in many cancers, but its role in ovarian cancer and drug resistance still remains unexplored. This study was to investigate whether miR-106a mediated resistance of the ovarian cancer cell line A2780 to the chemotherapeutic agent cisplatin (DDP). The different levels of miR-106a in A2780 cells and their resistant variant A2780/DDP cells were identified by using real-time PCR. MTT assay and flow cytometry were used to analyze the effect of miR-106a on cisplatin resistance of these paired cells. Real-time PCR, Western blotting and luciferase reporter assay were applied to explore whether Mcl-1 was a target of miR-106a. As compared to A2780 cells, the expression of miR-106a was down-regulated in the cisplatin resistant cell line A2780/DDP. Moreover, knockdown of miR-106a dramatically decreased antiproliferative effects and apoptosis induced by cisplatin in A2780 cells, while overexpression of miR-106a significantly increased antiproliferative effects and apoptosis induced by cisplatin in A2780/DDP cells. Furthermore, miR-106a inhibited cell survival and cisplatin resistance through downregulating the expression of Mcl-1. Mcl-1 was a direct target of miR-106a. These results suggest that miR-106a may provide a novel mechanism for understanding cisplatin resistance in ovarian cancer by modulating Mcl-1.
Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Drug Resistance, Neoplasm ; genetics ; Female ; Humans ; MicroRNAs ; genetics ; Myeloid Cell Leukemia Sequence 1 Protein ; genetics ; Ovarian Neoplasms ; drug therapy ; genetics

OBJECTIVETo investigate the expression and significance of miR-125a and anti-apoptotic protein Mcl-1 in intestinal tissue after massive small bowel resection in intestinal adaptation.

METHODSSprague-Dawley rats (54 male rats, 8-week old) were divided into 3 groups randomly, including two control groups. Rats in the experiment group were subjected to 70% massive small bowel resection. Rats in the resection group underwent simple intestinal resection and anastomosis. Rats in the control group underwent laparotomy alone. A 5 cm intestine approximately 1 cm distal to the anastomosis was harvested a week after operation. Expression of Mcl-1 was assessed by immunohistochemistry and real-time PCR was used to detect the expression of miR-125a in intestinal tissue.

RESULTSThe positive expression of Mcl-1 in the experiment group was 18.8%(3/16), significantly lower than that in the control group(76.5%, 13/17) and the resection group (83.33%, 15/18)(both P<0.01). The expression of miR-125a in the experiment group was 1.92, significantly higher than that in the control group (1.01) and the resection group (1.05)(both P<0.01).

CONCLUSIONmiR-125a and anti-apoptotic protein Mcl-1 may play an important role in intestinal adaptation process and they may regulate each other through a certain pathway.

Anastomosis, Surgical ; Animals ; Disease Models, Animal ; Intestine, Small ; metabolism ; surgery ; Male ; MicroRNAs ; metabolism ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Rats ; Rats, Sprague-Dawley ; Short Bowel Syndrome ; metabolism

MCL-1 is encoded by myeloid cell leukemia-1 gene (mcl-1), which is one of the anti-apoptotic members of bcl-2 cell apoptotic gene superfamily. ChanSu is made of dorsal secretions of several Bufo species, commonly used in the prescriptions of traditional Chinese medicine for treating many diseases including cancer. To clarify if mcl-1 is expressed in the dorsal skin of B. gargarizans, the PCR (polymerase chain reaction) was performed with its dorsal skin first strand cDNA as the template and a pair of specific primers of mcl-1, and PCR products were cloned into the pGM-T vector. DNA sequencing indicated that the ORF length was 639 bp encoding 212 amino acid residues, and the homology of 44%-95% with the MCL-1 of several other animals. For the further studies on MCL-1 biological functions during the oncogenesis and preparation of its antibody, the prokaryotic expression construct of pET-28b-mcl-1 was prepared which was confirmed by DNA sequencing, and its recombinant protein expression (0.02% wet weight) in E. coli BL21 (DE3) strain was confirmed by SDS-PAGE and Western blotting.
Amino Acid Sequence ; Animals ; Bufonidae ; classification ; genetics ; Cloning, Molecular ; DNA, Complementary ; genetics ; Escherichia coli ; metabolism ; Myeloid Cell Leukemia Sequence 1 Protein ; genetics ; metabolism ; Open Reading Frames ; genetics ; Phylogeny ; Recombinant Proteins ; genetics ; metabolism ; Sequence Alignment ; Sequence Homology ; Skin ; metabolism

OBJECTIVETo investigate the inducing effect of down-regulation of MCL-1 by diallyl disulfide(DADS) on the G/M arrest of human leukemia K562 cells and its mechanisms.

METHODSCCK-8 was used to detect the effect of DADS on proliferation of K562 cells, flow cytometry was employed to observe the effect of cycle arrest by DADS and RNAi silencing MCL-1 gene in K562 cells. The expressions of MCL-1, PCNA and CDK1 in K562 cells treated with DADS were detected by Western blot. The amphigamy of MCL-1 with PCNA and CDK1 was detected by Coimmunoprecipitation.

RESULTSCCK-8 detection showed that the inhibition rates of K562 cells treated with 15, 30, 60, 120, 240 µmol/L DADS were 32.48%, 59.34%, 66.42%, 77.06%, 81.05% respectively (P<0.05). Flow cytometry analysis revealed that the perecentages of G/M cells were increased to 18.6% and 34.4%, 17.5% and 28.5%, respectively at 24 and 48 h after treating K562 cells with 60 and 120 µmol/L DADS (P<0.05). And the perecentage of G/M cells of silencing MCL-1 was significantly increased (P<0.05). Silencing effects of MCL-1+DADS on the cells were enhanced more significantly as compared with DADS or MCL-1 alone (P<0.05). Western blot exhibited that DADS could markedly downregulate the expression of MCL-1, PCNA and CDK1(P<0.05). Coimmunoprecipitation revealed that MCL-1 bound with PCNA and CDK1, then forming heterodimers, which were downregulated respectively more significantly than that in the control group after treating K562 cells with DADS for 8 h (P<0.05).

CONCLUSIONDADS can inhibit the K562 cell proliferation and induce them arrest G/M through downregulation of MCL-1, then decreasing the expression of PCNA and CDK1 in hunan leukemia K562 cells. Moreover, silencing MCL-1 can enhance the effect of DADS.

Allyl Compounds ; Apoptosis ; Cell Line, Tumor ; Disulfides ; Down-Regulation ; G2 Phase Cell Cycle Checkpoints ; Humans ; K562 Cells ; Leukemia ; M Phase Cell Cycle Checkpoints ; Myeloid Cell Leukemia Sequence 1 Protein

OBJECTIVETo observe the effect of sodium valproate (VPA) on the proliferation and apoptosis of human lung carcinoma SPC-A1 cells and the underlying mechanism.

METHODSThe effect of VPA on the proliferation of SPC-A1 cells was evaluated by MTT assay and clone formation assay. Flow cytometry was used to analyze the apoptosis of the cells exposed to VPA. The changes in the expressions of Bcl-xl, Bcl-2, Mcl-1, caspase-9, and caspase-3 in the exposed cells were detected by Western blotting.

RESULTSIncubation with VPA for 48 h resulted in a significant inhibition of SPC-A1 cell proliferation, with a IC(50) of 1.8 mmol/L. VPA treatment also inhibited cell colony formation and induced obvious cell apoptosis. Exposure to 8 mmol/L VPA for 48 h caused a percentage of early apoptotic cells of 60.44%. VPA treatment at different concentrations for 48 h obviously lowered the protein levels of Bcl-xl, Bcl-2, and Mcl-1 and induced caspase-9 and caspase-3 activation in SPC-A1 cells.

CONCLUSIONVPA can inhibit the proliferation of SPC-A1 cells by triggering mitochondrion-dependent apoptosis.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Myeloid Cell Leukemia Sequence 1 Protein ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Valproic Acid ; pharmacology ; bcl-X Protein ; metabolism

OBJECTIVE: To investigate the effects of mTOR inhibitors everolimus (EVE) and gemcitabine (GEM) on the proliferation, apoptosis and cell cycle of diffuse large B-cell lymphoma (DLBCL) cell line U2932, and further explore the molecular mechanisms, so as to provide new ideas and experimental basis for the clinical treatment of DLBCL. METHODS: The effect of EVE and GEM on the proliferation of U2932 cells was detected by CCK-8 assay, the IC₅₀ of the two drugs was calculated, and the combination index (CI=) of the two drugs was calculated by CompuSyn software. The effect of EVE and GEM on apoptosis of U2932 cells was detected by flow cytometry with AnnexinV-FITC/PI staining. Flow cytometry with propidium iodide (PI) staining was used to detect the effect of EVE and GEM on the cell cycle of U2932 cells. Western blot assay was used to detect the effects of EVE and GEM on the channel proteins p-mTOR and p-4EBP1, the anti-apoptotic proteins MCL-1 and Survivin, and the cell cycle protein Cyclin D1. RESULTS: Both EVE and GEM could significantly inhitbit the proliferation of U2932 cells in a time- and dose-dependent manner (r=0.465, 0.848; 0.555, 0.796). According to the calculation of CompuSyn software, EVE combined with GEM inhibited the proliferation of U2932 cells at 24, 48 and 72 h with CI=<1, which had a synergistic effect. After treated U2932 cells with 10 nmol/L EVE, 250 nmol/L GEM alone and in combination for 48 h, both EVE and GEM induced apoptosis, and the difference was statistically significant compared with the control group (P<0.05). The apoptosis rate was significantly enhanced after EVE in combination with GEM compared with single-agent (P<0.05). Both EVE and GEM alone and in combination significantly increased the proportion of cells in G₁ phase compared with the control group (P<0.05). The proportion of cells in G₁ phase was significantly increased when the two drugs were combined (P<0.05). The expression of p-mTOR and effector protein p-4EBP1 was significantly downregulated in the EVE combined with GEM group, the expression of anti-apoptotic proteins MCL-1, Survivin and cell cycle protein cyclin D1 was downregulated too (P<0.05). CONCLUSION EVE combined with GEM can synergistically inhibit the proliferation of U2932 cells, and the mechanism may be that they can synergistically induce apoptosis by downregulating the expression of MCL-1 and Survivin proteins and block the cell cycle progression by downregulating the expression of Cyclin D1.
Humans ; Gemcitabine ; Everolimus/pharmacology* ; Survivin/pharmacology* ; Cyclin D1/pharmacology* ; Myeloid Cell Leukemia Sequence 1 Protein ; Cell Line, Tumor ; Cell Proliferation ; TOR Serine-Threonine Kinases ; Apoptosis ; Apoptosis Regulatory Proteins ; Cell Cycle Proteins ; Lymphoma, Large B-Cell, Diffuse

The purpose of this study was to explore the mechanism underlying the regulation of 2-methoxyestradiol (2-ME)-induced cell apoptosis by mcl-1 and bax gene in myelodysplastic syndrome (MDS). The MUTZ-1 cells were pretreated with 2-ME; then the activity of caspases-3 was determined by fluorescent colorimetry; the mRNA expressions of apoptosis-related genes (mcl-1) and bcl-2-related X protein (bax) were determined by RT-PCR. The results showed that as compared with control, the 2-ME enhanced the activity of caspase-3 in MUTZ-1 cells in a dose-and time-dependent manners (p<0.05); along with increasing of 2-ME concentration, the expression of intracellular mcl-1 mRNA reduced (p<0.05), meanwhile the expression level of mcl-1 mRNA negatively correlated to the activity of caspase-3 at the corresponding time points (r=-0.992, p<0.01), but the expression of bax mRNA did not show significant change (p>0.05). It is concluded that 2-ME can regulate the apoptosis of MDS cells through the pathway of down-regulating the expression of mcl-1 mRNA and activating the caspase-3.
Apoptosis ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Estradiol ; adverse effects ; analogs & derivatives ; Humans ; Myelodysplastic Syndromes ; metabolism ; pathology ; Myeloid Cell Leukemia Sequence 1 Protein ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; metabolism

Objective of this study was to detect the expression of Survivin in acute myeloid leukemia (AML) and investigate the relationship of its expression levels with clinical variates and its correlations with BCL-2 ,Bcl-xL and MCL-1. The expression of Survivin, BCL-2, Bcl-xL and MCL-1 were measured by immunohistochemistry in bone marrow biopsy of 63 newly diagnosed AML patients, and the relationship between its expression level and clinical parameters (age, sex, WBC count, diagnosis, prognosis), especially fusion protein AML1/ETO was investigated. The results showed that the expression level of Survivin in newly diagnosed AML patients was higher than that of normal controls (P < 0.01), the expression levels of Survivin did not correlate with age, sex, and WBC counts of patients and so on. There was no significant difference of Survivin expression between different NCCN prognosis groups, either between patients with AML1/ETO or FLT3-ITD mutation and the other patients. Survivin positive patients were got to have lower CR rate but higher relapse rate, however that was not significant in statistics. Indeed, the cumulative survivin rate of Survivin positive patients were lower than that of Survivin negative patients (P = 0.04). Finally, positive correlation between Survivin and MCL-1 was also observed (r = 0.639, P = 0.000). It is concluded that overexpression of Survivin are closely related with occurrence and development of acute leukemia, and may be used as an indicator of prognosis evaluation. In addition, Survivin and MCL-1 may have a relationship of cooperation or interaction.
Adolescent ; Adult ; Core Binding Factor Alpha 2 Subunit ; metabolism ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; metabolism ; Leukemia, Myeloid, Acute ; metabolism ; pathology ; Male ; Middle Aged ; Mutation ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Oncogene Proteins, Fusion ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RUNX1 Translocation Partner 1 Protein ; Young Adult ; bcl-X Protein ; metabolism ; fms-Like Tyrosine Kinase 3 ; metabolism