There remains a significant gap in our quantitative understanding of crosstalk between apoptosis and necroptosis pathways. By employing the SWATH-MS technique, we quantified absolute amounts of up to thousands of proteins in dynamic assembling/de-assembling of TNF signaling complexes. Combining SWATH-MS-based network modeling and experimental validation, we found that when RIP1 level is below ~1000 molecules/cell (mpc), the cell solely undergoes TRADD-dependent apoptosis. When RIP1 is above ~1000 mpc, pro-caspase-8 and RIP3 are recruited to necrosome respectively with linear and nonlinear dependence on RIP1 amount, which well explains the co-occurrence of apoptosis and necroptosis and the paradoxical observations that RIP1 is required for necroptosis but its increase down-regulates necroptosis. Higher amount of RIP1 (>~46,000 mpc) suppresses apoptosis, leading to necroptosis alone. The relation between RIP1 level and occurrence of necroptosis or total cell death is biphasic. Our study provides a resource for encoding the complexity of TNF signaling and a quantitative picture how distinct dynamic interplay among proteins function as basis sets in signaling complexes, enabling RIP1 to play diverse roles in governing cell fate decisions.
Animals ; Apoptosis ; Caspase 8/metabolism* ; GTPase-Activating Proteins/metabolism* ; HEK293 Cells ; Humans ; Mice ; Mice, Knockout ; Necroptosis ; Receptor-Interacting Protein Serine-Threonine Kinases/metabolism*

BACKGROUND: Lung cancer is one of the highest morbidity and mortality in the world and it is very important to find an effective anti-tumor method. Microwave hyperthermia, a new treatment technology, has been getting more and more attention. This study was designed to investigate the effects of microwave hyperthermia combined with gemcitabine on the proliferation and apoptosis of human lung squamous cell carcinoma (NCI-H1703 and NCI-H2170) in vitro. METHODS: The proliferation of cells treated with microwave hyperthermia, the effect of gemcitabine on cell proliferation and the proliferation of cells treated with different methods of microwave hyperthermia and gemcitabine were detected by CCK-8 assay. Colony formation assay was used to measure the colony formation of human lung squamous cell carcinoma cells. Flow cytometry assay was used to detect the total apoptosis rates of the treated cells. Caspase-3, Caspase-8 activity assay was used to detect the activity of Caspase-3, Caspase-8 enzyme in each group of cells. CCK-8 assay was used to detect the effect of control group, AC-DEVD (Caspase-3 inhibitor) group, thermalization combined group, and thermal AC-DEVD combined group on cell proliferation. The levels of p53, Caspase-3, Cleaved-Caspase-3, PARP, Bax and BCL-2 protein expression were detected using Western blot assay. RESULTS: Our results demonstrated that microwave hyperthermia inhibited the proliferation of lung squamous cell carcinoma. The IC₅₀ values of gemcitabine for the two cells were 8.89 μmol/L and 44.18 μmol/L, respectively. The first chemotherapy after microwave hyperthermia has synergistic effect on the two lung squamous cell carcinoma cells and can significantly inhibit the cell clone formation (P<0.001), promote cell apoptosis (P<0.001) and increase Caspase-3 enzyme activity (P<0.001). However, it has no effect on Caspase-8 enzyme activity (P>0.05). Furthermore, Western blot analysis showed that microwave hyperthermia combined with gemcitabine could up-regulate the p53, Caspase-3, Cleaved-Caspase-3, Cleaved-PARP and Bax protein expression. CONCLUSIONS Microwave hyperthermia combined with gemcitabine remarkably inhibit the proliferation and induce apoptosis of human lung squamous cell carcinoma in vitro. This effect may be associated with the activation of p53, cleavage of PARP protein, and induced the Caspase-3 dependent apoptosis.
Apoptosis ; drug effects ; radiation effects ; Carcinoma, Squamous Cell ; pathology ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; radiation effects ; Combined Modality Therapy ; Deoxycytidine ; analogs & derivatives ; pharmacology ; Humans ; Hyperthermia, Induced ; Lung Neoplasms ; pathology ; Microwaves

BACKGROUNDThe suillin isoform iso-suillin is a natural substance isolated from a petroleum ether extract of the fruiting bodies of the mushroom Suillus flavus. Previous studies have found its inhibition effect on some cancer cells, and we aimed to study its effects on human small cell lung cancer H446 cell line.

METHODSCell viability was measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Cellular morphological changes (apoptosis and necrosis) were evaluated using an electron microscope and Hoechst 33258 staining detected by the inverted microscope. Flow cytometry was used to detect cell apoptosis, cell cycle distribution, and mitochondrial membrane potential. Protein expression was determined by Western blotting analysis.

RESULTSHere, we describe the ability of iso-suillin to inhibit the growth of H446 cells in time- and dose-dependent way. Iso-suillin had no obvious impact on normal human lymphocyte proliferation at low concentrations (9.09, 18.17, or 36.35 μmol/L) but promoted lymphocyte proliferation at a high concentration (72.70 μmol/L). After treatment of different concentrations of iso-suillin (6.82, 13.63, or 20.45 μmol/L), the apoptosis rate of H446 cells increased with increasing concentrations of iso-suillin (16.70%, 35.54%, and 49.20%, respectively, all P < 0.05 compared with the control), and the expression of related apoptotic proteins in the mitochondrial pathway including cytochrome c and caspase-9 were up-regulated compared with the control (all P < 0.05). On the contrary, Bcl-2/Bax ratio was down-regulated compared with the control. Besides, the expression of pro-apoptotic proteins in the death receptor apoptosis pathway, including Fas-associating protein with a novel death domain and caspase-8, and the expression of caspase-3, a downstream regulatory protein of apoptosis, were also increased compared with the control (all P < 0.05). Inhibitors of caspase-9 and caspase-8 reversed the apoptosis process in H446 cells to varying degrees.

CONCLUSIONSThese results suggest that iso-suillin could induce H446 cell apoptosis through the mitochondrial pathway and the death-receptor pathway. Therefore, iso-suillin might have a potential application as a novel drug for lung cancer treatment.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Caspase 9 ; metabolism ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cytochromes c ; metabolism ; Diterpenes ; pharmacology ; Flow Cytometry ; Humans ; Mice ; Phenols ; pharmacology ; Small Cell Lung Carcinoma

OBJECTIVETo investigate the effect of tumor necrosis factor-α-induced protein 8 like-2 (TIPE2) on apoptosis of CD4T lymphocytes in a murine model of severe burn injury.

METHODSA total of 140 male mice were randomly allocated into 6 groups. Small RNA interference technique was used to construct a siTIPE2-overexpressing lentivirus, and severe burn injury models were established in the mice. CD4T cells were purified from spleen of the mice, and the expressions of TIPE2, Smad2/Smad3, P-Smad2/P-Smad3 and Bcl-2/Bimprotein in CD4Tregs were detected. The changes in mitochondrial membrane potential and cytochrome C in CD4T cells were detected, and the activities of caspase-3, caspase-8, and caspase-9 were analyzed.

RESULTSDown-regulation of TIPE2 promoted the apoptosis of CD4T lymphocytes in siTIPE2-burn group, in which the protein expressions of P-smad2/P-Smad3 decreased, Bcl-2 expression increased and Bim expression decreased significantly as compared with the other groups (P<0.01 or 0.05). The mitochondrial membrane potential and cytochrome C expression in CD4T cells were down-regulated in siTIPE2-burn group (P<0.05) with a lowered caspase-3 activity compared with TIPE2-burn group (P<0.01) and decreased caspase-8 and caspase-9 compared with the other groups (P<0.05). The apoptosis rate was the highest in TIPE2-burn group, whose Smad2/Smad3 was higher than that in the sham group (P<0.05) and the expression of P-smad2/P-Smad3 significantly increased compared with the other groups (P<0.05). In TIPE2-burn group, the mitochondrial membrane potential in CD4T cells was decreased (P<0.01), the expression of cytochrome C increased markedly (P<0.01), and the activities of caspase-3, caspase-8, and caspase-9 were all obviously higher than those in the other groups (P<0.05).

CONCLUSIONAs an important immunoregulatory molecule, TIPE2 can promote the apoptosis of CD4T lymphocyte in mice with sever burn injury.

Animals ; Apoptosis ; Burns ; immunology ; CD4-Positive T-Lymphocytes ; cytology ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Caspase 9 ; metabolism ; Down-Regulation ; Intracellular Signaling Peptides and Proteins ; metabolism ; Male ; Mice ; Smad2 Protein ; metabolism ; Smad3 Protein ; metabolism ; Spleen

OBJECTIVETo observe the expression of peripheral blood CD4+ T lymphocyte apoptosis gene in rheumatoid arthritis (RA) patients with cold dampness type (CDT), and to explore its correlation with clinical indicators of RA.

METHODSSixteen RA patients with CDT (as the RA group) and 16 healthy subjects (as the normal control group) were recruited. CD4 T cell apoptosis rate was detected in the RA group and the normal control group using FCM. mRNA expressions of fas, fasL, caspase-3, caspase-8, bcl-2, and bax were detected using RT-PCR. Correlations between the expression of apoptosis gene and clinical activity indicators of RA (ESR, CRP, RF, CCP, integrals for Chinese medial symptoms, morning stiffness time, joint tenderness number, joint swelling number, DAS28-3) were analyzed.

RESULTSThe apoptosis rate of CD4+ T was significantly lower in the RA group than in the control group [(2. 6 +/- 0.9) % vs. (7.7 +/- 1.3) %, P < 0.01]. mRNA expression levels of fas, fasL, caspase-8, caspase-3, and bax mRNA of CD4+ T significantly decreased, but bcl-2 mRNA expression increased in the RA group (P < 0.01). The apoptosis rate of CD4+ T was negatively correlated with ESR (P < 0.05). The mRNA expression of caspase-8 was negatively correlated with joint swelling number (P < 0.05). The mRNA expression of bcl-2 was negatively correlated with integrals for Chinese medial-symptoms and joint function classification (P < 0.01, P < 0.05).

CONCLUSIONApoptosis obstacle exists in peripheral blood CD4 +T lymphocyte of RA patients, and is closely related to disease activity.

Apoptosis ; Arthritis, Rheumatoid ; diagnosis ; metabolism ; pathology ; CD4-Positive T-Lymphocytes ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Fas Ligand Protein ; Humans ; RNA, Messenger

Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of gamma-glutamylcysteine synthetase (gamma-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH.
Animals ; Antioxidants/*metabolism/*pharmacology ; Apoptosis/drug effects ; Caspase 3/metabolism ; Caspase 8/metabolism ; Cell Line ; Cisplatin/*toxicity ; Cysteine/*analogs & derivatives/pharmacology ; Gene Expression Regulation/*drug effects ; Gene Knockdown Techniques ; Glutathione/*metabolism ; Heme Oxygenase-1/genetics ; Intracellular Space/metabolism ; Male ; Metabolic Detoxication, Phase II/genetics ; Mice ; NF-E2-Related Factor 2/genetics ; Nitric Oxide/biosynthesis ; Organ of Corti/*drug effects/*metabolism ; RNA Interference ; Rats ; Reactive Oxygen Species/metabolism ; Superoxide Dismutase/genetics

OBJECTIVETo investigate the anticancer effect and its mechanism of SN-38 combined with sorafenib on hepatocellular cancer cell lines HepG-2 and BEL-7402.

METHODSSRB colorimetry was employed to measure the viability of HepG-2 and BEL-7402 cells after the treatment of SN-38 with sorafenib. Propidium iodide flow cytometric assay and DAPI staining were used to evaluate the apoptosis of HCC cells. Western blotting was conducted to detect the expression level of apoptosis-related and DNA damage-related proteins.

RESULTSSRB colorimetry showed the synergistic anticancer activities of SN-38 combined with sorafenib, with a combination index of <0.9. The apoptotic rates of HepG-2 cells in control, 60 nmol/L SN-38, 2.5μmol/L sorafenib and combination groups were 4.25%±2.45%, 28.95%±10.75%, 3.49%±2.49% and 53.19%±11.21%, respectively(P<0.05). Western blotting showed that the combination of these two drugs increased the enzymolysis of PARP, Caspase-8 and Caspase-3, and promoted the expression levels of p53, p21 and γ-H2AX significantly.

CONCLUSIONSN-38 and sorafenib have synergistic anticancer activity on hepatocellular carcinoma cells in vitro with the augmentation of apoptosis.

Apoptosis ; Camptothecin ; analogs & derivatives ; pharmacology ; Carcinoma, Hepatocellular ; pathology ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Histones ; metabolism ; Humans ; Liver Neoplasms ; pathology ; Niacinamide ; analogs & derivatives ; pharmacology ; Phenylurea Compounds ; pharmacology ; Poly(ADP-ribose) Polymerases ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

Various kinds of schiff base metal complexes have been proven to induce apoptosis of tumor cells. However, it remains largely unknown whether schiff base zinc complexes induce apoptosis in human cancer cells. Here, we synthesized a novel schiff base zinc coordination compound (SBZCC) and investigated its effects on the growth, proliferation and apoptosis of human osteosarcoma MG-63 cells. A novel SBZCC was synthesized by chemical processes and used to treat MG-63 cells. The cell viability was determined by CCK-8 assay. The cell cycle progression, mitochondrial membrane potential and apoptotic cells were analyzed by flow cytometry. The apoptosis-related proteins levels were determined by immunoblotting. Treatment of MG-63 cells with SBZCC resulted in inhibition of cell proliferation and cell cycle arrest at G1 phase. Moreover, SBZCC significantly reduced the mitochondrial membrane potential and induced apoptosis, accompanied with increased Bax/Bcl-2 and FlasL/Fas expression as well as caspase-3/8/9 cleavage. Our results demonstrated that the synthesized novel SBZCC could inhibit the proliferation and induce apoptosis of MG-63 cells via activating both the mitochondrial and cell death receptor apoptosis pathways, suggesting that SBZCC is a promising agent for the development as anticancer drugs.
Antineoplastic Agents ; chemical synthesis ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; genetics ; metabolism ; Caspase 8 ; genetics ; metabolism ; Caspase 9 ; genetics ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Coordination Complexes ; chemical synthesis ; pharmacology ; Fas Ligand Protein ; genetics ; metabolism ; G1 Phase Cell Cycle Checkpoints ; drug effects ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Membrane Potential, Mitochondrial ; drug effects ; Mitochondria ; drug effects ; metabolism ; pathology ; Osteoblasts ; drug effects ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Schiff Bases ; chemistry ; Signal Transduction ; Zinc ; chemistry ; bcl-2-Associated X Protein ; genetics ; metabolism ; fas Receptor ; genetics ; metabolism

As a classic fluorescent detect technique, fluorescence resonance energy transfer (FRET) has been widely used in biological researches. Researchers have developed a series of fluorescence detect probes which were based on FRET. Caspase family plays an important role in apoptosis pathway, especially Caspase-8 which located, at the initial of death receptor mediated apoptosis pathway, whose its activation can trigger subsequent precaspases' activation and lead to apoptosis. So it is of great significance to detect the activation of Caspase-8 in apoptosis assay. In this study, a fluorescent probe based on FRET has been designed which can detect the activity change of Caspase-8 in cells. To identify the effectiveness and specificity of the probe, we measure the Caspase-8 activity under the Caspase-8 specifically activated apoptosis inducer RGD-TRAIL with the flow cytometry FRET detection platform. The results show that the probe can respond to the activity change of Caspase-8 in apoptotic cells, and the change can be quantified rapidly by flow cytometry. The study provides a more efficient and convenient detection method of Caspase-8 activity in living cells.
Apoptosis ; Caspase 8 ; metabolism ; Flow Cytometry ; Fluorescence Resonance Energy Transfer ; Fluorescent Dyes ; Humans

OBJECTIVEThe study aimed to test if Paridis Rhizoma total saponins (PRTS) could induce apoptosis of human gastric cancer cell MKN-45.

METHODBased on the previous researches, PRTS was set by different concentrations to treat human gastric cancer cell for 12 h (5, 10, 20 mg x L(-1)). Fluorescent staining methods were adopted to observe apoptotic morphological changes of MKN-45. The apoptosis rates were analyzed by flow cytometry with Annexin V-FITC/PI staining. The enzymatic activities of caspase-3 and caspase-8 were measured by ELISA. The protein levels of Fas and FasL were detected by Western blotting.

RESULTUnder a fluorescence microscope, MKN-45 treated by PRTS was seen typical apoptotic morphological features. PRTS significantly increased the rate of apoptosis. Compared with the control group, there exsited significant differences in apoptosis rate of PRTS concentration of 20 mg x L(-1) (P < 0.01); besides, the enzymatic activities of caspase-3 and caspase-8 were promoted obviously after the effect of PRTS on MKN-45 cells for 12 h (P < 0.01). The protein levels of Fas and FasL in the MKN-45 were upgraded significantly.

CONCLUSIONPRTS can induce apoptosis of human gastric cancer cell MKN-45 , which is concerned with caspase-3 and caspase-8 and upgraded Fas and FasL.

Apoptosis ; drug effects ; Caspase 3 ; genetics ; metabolism ; Caspase 8 ; genetics ; metabolism ; Cell Line, Tumor ; Drugs, Chinese Herbal ; pharmacology ; Fas Ligand Protein ; metabolism ; Humans ; Magnoliopsida ; chemistry ; Rhizome ; chemistry ; Saponins ; pharmacology ; Signal Transduction ; drug effects ; Stomach Neoplasms ; drug therapy ; genetics ; metabolism ; physiopathology ; fas Receptor ; metabolism