Poor prognosis and high mortality rate are frequently observed in patients with relapsed/refractory acute myeloid leukemia (R/R AML), and there is no standard salvage therapy for these patients. As a method to evade apoptosis, cancer cells often upregulate anti-apoptotic proteins BCL-2 and MCL-1. Recently, venetoclax-based combination therapies have demonstrated promising prospects in treating R/R AML. However, the prevalent use of venetoclax comes with a new challenge of resistance. Upregulation of BCL-1 and/or MCL-1 is the main cause of venetoclax resistance and preemptively targeting BCL-2/BCL-XL/MCL-1 can be used to delay or forestall drug resistance. Thus, selective targeting of BCL-2 and MCL-1 is a viable treatment strategy. This review reports the latest clinical progress on targeting BCL-2 and MCL-1 in R/R AML.
Humans ; Leukemia, Myeloid, Acute/drug therapy* ; Myeloid Cell Leukemia Sequence 1 Protein ; Proto-Oncogene Proteins c-bcl-2 ; Drug Resistance, Neoplasm ; Bridged Bicyclo Compounds, Heterocyclic/therapeutic use* ; Sulfonamides/therapeutic use* ; Recurrence

Glutamine provides carbon and nitrogen to support the proliferation of cancer cells. However, the precise reason why cancer cells are particularly dependent on glutamine remains unclear. In this study, we report that glutamine modulates the tumor suppressor F-box and WD repeat domain-containing 7 (FBW7) to promote cancer cell proliferation and survival. Specifically, lysine 604 (K604) in the sixth of the 7 substrate-recruiting WD repeats of FBW7 undergoes glutaminylation (Gln-K604) by glutaminyl tRNA synthetase. Gln-K604 inhibits SCFFBW7-mediated degradation of c-Myc and Mcl-1, enhances glutamine utilization, and stimulates nucleotide and DNA biosynthesis through the activation of c-Myc. Additionally, Gln-K604 promotes resistance to apoptosis by activating Mcl-1. In contrast, SIRT1 deglutaminylates Gln-K604, thereby reversing its effects. Cancer cells lacking Gln-K604 exhibit overexpression of c-Myc and Mcl-1 and display resistance to chemotherapy-induced apoptosis. Silencing both c-MYC and MCL-1 in these cells sensitizes them to chemotherapy. These findings indicate that the glutamine-mediated signal via Gln-K604 is a key driver of cancer progression and suggest potential strategies for targeted cancer therapies based on varying Gln-K604 status.
Glutamine/metabolism* ; Myeloid Cell Leukemia Sequence 1 Protein/genetics* ; Humans ; Proto-Oncogene Proteins c-myc/genetics* ; Cell Proliferation ; Signal Transduction ; Neoplasms/pathology* ; F-Box-WD Repeat-Containing Protein 7/genetics* ; Cell Survival ; Cell Line, Tumor ; Apoptosis

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

OBJECTIVE: To investigate the effect of dihydroartemisinin (DHA) combined with arsenic trioxide (ATO) on the viability and apoptosis of acute myeloid leukemia (AML) FLT3-ITD mutant cell line MOLM13 and its mechanism. METHODS: MOLM13 cells were treated with DHA or ATO alone or in combination. The viability of MOLM13 cells was detected by CCK-8 assay, cell proliferation was observed by colony formation assay, cell apoptosis and reactive oxygen species (ROS) level were measured by flow cytometry, and the expression levels of proteins related to apoptosis were detected by Western blot. RESULTS: Compared with the control group, treatment with DHA and ATO alone or in combination could inhibit cell proliferation, activate ROS formation, and finally induce cell apoptosis. DHA in combination with ATO produced a synergistic effect. Western blot analysis showed that DHA combined with ATO could significantly upregulate the level of c-PARP and activate apoptosis via inhibition of Mcl-1 and FLT3-ITD. CONCLUSION DHA combined with ATO induces the apoptosis of FLT3-ITD AML cell line MOLM13 by inhibiting Mcl-1 pathway and activating FLT3-ITD protein degradation.
Apoptosis ; Arsenic Trioxide/therapeutic use* ; Artemisinins/therapeutic use* ; Cell Line, Tumor ; Humans ; Leukemia, Myeloid, Acute/drug therapy* ; Myeloid Cell Leukemia Sequence 1 Protein ; Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use* ; Reactive Oxygen Species/therapeutic use* ; Sincalide/therapeutic use* ; fms-Like Tyrosine Kinase 3

: AbstractObjective: To explore the effect and mechanism of curcumin on human T-cell acute lymphoblastic leukemia (T-ALL) cell apoptosis induced by Mcl-1 small molecule inhibitors UMI-77. METHODS: T-ALL cell line Molt-4 was cultured, and the cells were treated with different concentrations of curcumin and Mcl-1 small molecule inhibitor UMI-77 for 24 h. The MTT method was used to detect the cell survival rate after different treatment; According to the results of curcumin and UMI-77, the experimental settings were divided into control group, curcumin group (20 μmol/L curcumin treated cells), UMI-77 group (15 μmol/L Mcl-1 small molecule inhibitor UMI-77 treated cells) and curcumin+ UMI-77 group (20 μmol/L curcumin and 15 μmol/L Mcl-1 small molecule inhibitor UMI-77 treated cells), MTT method was used to detect cell proliferation inhibition rate, Annexin V-FITC/PI double staining method and TUNEL staining were used to detect cell apoptosis, DCFH-DA probe was used to detect cell reactive oxygen species, JC-1 fluorescent probe was used to detect mitochondrial membrane potential, Western blot was used to detect the expression levels of apoptosis-related proteins and Notch1 signaling pathway-related proteins. RESULTS: After the treatment of Molt-4 cells with different concentrations of curcumin and Mcl-1 small molecule inhibitor UMI-77, the cell survival rate was decreased (P<0.05); Compared with the control group, the cell proliferation inhibition rate of the curcumin group and the UMI-77 group were increased, the apoptosis rate of cell was increased, the level of ROS was increased, the protein expression of Bax, Caspase-3 and Caspase-9 in the cells were all increased, and the protein expression of Bcl-2 was reduced (P<0.05); Compared with the curcumin group or UMI-77 group, the cell proliferation inhibition rate and apoptosis rate of the curcumin+UMI-77 group were further increased, and the level of ROS was increased. At the same time, the protein expression of Bax, Caspase-3 and Caspase-9 in the cells were all increased, the protein expression of Bcl-2 was reduced (P<0.05); In addition, the mitochondrial membrane potential of the cells after curcumin treatment was decreased, and the proteins expression of Notch1 and HES1 were reduced (P<0.05). CONCLUSION Curcumin can enhance the apoptosis of T-ALL cells induced by Mcl-1 small molecule inhibitor UMI-77 by reducing the mitochondrial membrane potential, the mechanism may be related to the inhibition of Notch1 signaling pathway.
Apoptosis ; Apoptosis Regulatory Proteins ; Caspase 3/metabolism* ; Caspase 9/pharmacology* ; Cell Line, Tumor ; Curcumin/pharmacology* ; Humans ; Myeloid Cell Leukemia Sequence 1 Protein/metabolism* ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Reactive Oxygen Species/pharmacology* ; Sulfonamides ; Thioglycolates ; bcl-2-Associated X Protein/pharmacology*

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

Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality in part due to its high resistance to chemotherapeutic drugs. The anti-apoptotic Mcl-1 expression has been reported as a resistance factor in various types of tumors. Here, we investigated the expression of Mcl-1 in hepatoma cells and HCC tissues and its relationship with p53, and analyzed the possibility of the gene as a molecular target for HCC therapy. HCC specimens of 30 patients were examined by immunohistochemistry for Mcl-1 and p53 expression. Mcl-1 expression in hepatoma cell lines was measured by RT-PCR and Western blotting. The suppression of Mcl-1 by RNA interference or specific phosphatidylinositol-3 kinase (PI3K) inhibitor, LY294002, was evaluated as monotherapy, and it was combined with mitomycin C (MMC) in treating hepatoma cell line HepG2. Cell viability and apoptosis were assessed by MTT and FACS analysis. Finally, changes of Mcl-1 or p53 expression in various hepatoma cell lines were examined after transfection with Mcl-1 siRNA, the Mcl-1 expression plasmid, or the wide-type p53 expression plasmid, respectively. Mcl-1 protein was remarkably enhanced in HCC tissues as compared with adjacent non-tumor liver tissues. In addition, Mcl-1 was prominently expressed in HepG2 and Hep3B cells, weakly in SMMC7721 cells, and not in L02 cells. P53 protein was also overexpressed in HCC tissues and there was a significant correlation between the expression of p53 and Mcl-1. Silencing Mcl-1 by RNAi or LY294002 downregulated Mcl-1 expression and led to decreased cell viability and increased apoptosis. Combination of MMC and Mcl-1 RNAi or LY294002 exhibited a significant chemosensitizing effect. The expression of p53 was not influenced by Mcl-1 siRNA in HepG2 cells or transfection with the Mcl-1 expression plasmid in L02 cells. Furthermore, the expression of Mcl-1 in Hep3B cells was also not significantly changed after transfection with the wild-type p53 expression plasmid. It is concluded that Mcl-1 is overexpressed in HCC tissues. The mechanisms by which silencing Mcl-1 sensitizes hepatoma cells towards chemotherapy may be not attributed to the upregulated expression of p53 but the dysfunction of p53 through Mcl-1/p53 interaction. Mcl-1 may be a potential target of gene therapy for HCC.
Adenoma, Liver Cell ; drug therapy ; genetics ; pathology ; Apoptosis ; drug effects ; Biomarkers, Tumor ; biosynthesis ; genetics ; Chromones ; administration & dosage ; Gene Expression Regulation, Neoplastic ; drug effects ; Hep G2 Cells ; Humans ; Liver Neoplasms ; drug therapy ; genetics ; pathology ; Morpholines ; administration & dosage ; Myeloid Cell Leukemia Sequence 1 Protein ; biosynthesis ; genetics ; RNA, Small Interfering ; genetics ; Transfection ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

The biflavonoid isochamaejasmin is mainly distributed in the root of Stellera chamaejasme L. (Thymelaeaceae) that is used in traditional Chinese medicine (TCM) to treat tumors, tuberculosis, and psoriasis. Herein, isochamaejasmin was found to show similar bioactivity against Bcl-2 family proteins to the reference Bcl-2 ligand (-)-gossypol through 3D similarity search. It selectively bound to Bcl-xl and Mcl-1 with Ki values being 1.93 ± 0.13 μmol·L(-1) and 9.98 ± 0.21 μmol·L(-1), respectively. In addition, isochamaejasmin showed slight growth inhibitory activity against HL-60 with IC50 value being 50.40 ± 1.21 μmol·L(-1) and moderate growth inhibitory activity against K562 cells with IC50 value being 24.51 ± 1.62 μmol·L(-1). Furthermore, isochamaejasmin induced apoptosis of K562 cells by increasing the intracellular expression levels of proteins of the cleavage of caspase-9, caspase-3, and PARP which involved in the Bcl-2-induced apoptosis pathway. These results indicated that isochamaejasmin induces apoptosis in leukemia cells by inhibiting the activity of Bcl-2 family proteins, providing evidence for further studying the underlying anti-cancer mechanism of S. chamaejasme L.
Antineoplastic Agents, Phytogenic ; pharmacology ; therapeutic use ; Apoptosis ; drug effects ; Biflavonoids ; pharmacology ; therapeutic use ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Gossypol ; pharmacology ; HL-60 Cells ; Humans ; Inhibitory Concentration 50 ; K562 Cells ; Leukemia ; drug therapy ; metabolism ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Poly(ADP-ribose) Polymerases ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; antagonists & inhibitors ; metabolism ; Signal Transduction ; Thymelaeaceae ; chemistry ; bcl-2-Associated X Protein ; metabolism

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

OBJECTIVETo investigate the impact of ethanol extracts from Sedum sarmentosum (ESB) on STAT-3 signaling and its probable molecular mechanism in inducing apoptosis.

METHODMTT assay was used to detect the impact of ESB on HepG2 cell proliferation. FITC-Annexin V-FITC /PI double-labeling were used to investigate the impact on hepatoma carcinoma cell apoptosis. Western blot analysis was used to test the expression levels of cell apoptosis-related proteins Caspase-3, Caspase-9, PARP, P-STAT-3 (Tyr705) , STAT-3, Bcl-2, Mcl-1.

RESULTESB could notably inhibit proliferation of HepG2 cells, and induce HepG2 cell apoptosis, with the dose-dependent inhibitory effect. In addition, ESB could inhibit STAT-3 signaling, down-regulate Mcl-1 and Bcl-2 expressions, and induce degradation/activation of apoptosis-related proteins Caspase-3 and Caspase-9 and PARP degradation in a dose-dependent manner.

CONCLUSIONESB inhibits HepG2 cell proliferation and induces apoptosis by inhibiting STAT-3 signaling and Mcl-1 and Bcl-2 expressions.

Apoptosis ; drug effects ; Blotting, Western ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Ethanol ; chemistry ; Flow Cytometry ; Hep G2 Cells ; Humans ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Plant Extracts ; chemistry ; pharmacology ; Poly(ADP-ribose) Polymerases ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; STAT3 Transcription Factor ; metabolism ; Sedum ; chemistry ; Signal Transduction ; drug effects ; Time Factors