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Objective To investigate the effects of gemcitabine and ABT-199 on proliferation inhibition and apoptosis induction of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) cell line SUP-B15, and to explore its synergistic mechanism. Methods SUP-B15 cells in logarithmic growth phase were treated with gemcitabine (0.025 and 0.050 μmol/L), ABT-199 (0, 0.5, 1.0, 2.0, 4.0, 8.0 μmol/L) or two drugs for 24 h. Cell proliferation was detected by CCK-8 method, apoptosis was detected by flow cytometry (FCM), mitochondrial membrane potential was detected by JC-1 method, and expression of mitochondrial apoptosis pathway-related protein was analyzed by Western blot. Results The 50 ％ inhibitory concentration (IC50) of SBT-B15 cells treated with ABT-199 for 24 h was (4.13±0.89) μmol/L. However, gemcitabine (0.025, 0.050 μmol/L) significantly enhanced the inhibitory effect of ABT-199 on proliferation of SUP-B15 cells, the IC50 values were (2.23 ±0.73) and (1.15 ±0.45) μmol/L, respectively. The results of FCM assay showed that compared with the monotherapy group [(7.33±1.54)％], 0.025 umol/L gemcitabine combined with ABT-199 (1.0 and 2.0 μmol/L) acted on SUP-B15 cells for 24 h, the proportions of apoptotic cells were (32.42±1.45) ％and (44.33±1.86) ％, the difference was statistically significant (F=70.78, P<0.001);compared with the monotherapy group [(9.60 ±2.76) ％], 0.05 μmol/L gemcitabine combined with ABT-199 (1.0 and 2.0 μmol/L) acted on SUP-B15 cells for 24 h, the proportion of apoptotic cells increased to (47.63 ± 3.81) ％ and (58.73 ±4.33) ％, respectively, and the difference was statistically significant (F= 79.21, P<0.001). The JC-1 experiment showed that treated with ABT-199 and gemcitabine for 12 h, the percentage of depolarizing cell was significantly higher than that in single agent group, and the difference was statistical significant (P<0.001). Western blot showed that the anti-apoptotic proteins bcl-2, bcl-xL and Mcl-1 decreased after treated by gemcitabine combined with ABT-199 for 12 h. Conclusion Gemcitabine could enhance the proliferation inhibition and induce apoptosis of Ph+ALL cells by ABT-199, and its mechanism may be related to down-regulation of anti-apoptosis-related proteins.
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[Objective] To investigate the effects of platycodin D(PD) on the proliferation and apoptosis of human stomach cancer SGC7901 and the related mechanism.[Methods] SGC7901 was cultured in virto and was treated with 5～20μm·L-1 concentrations of PD.Cell proliferation was examined by MTT assay.Cell apoptosis was detected by Annexin V FITC/PI double staining.The change of mitochondrial trans-membrane potential was measured by JC-1 staining.The potein expression of cleaved caspase-3,cleaved caspase-9,cleaved PARP,bcl-2,bax,p-ERK,ERK,p-JNK,JNK,p-p38 and p38 detected by Western blot.[Results] MTT results showed that PD inhibited the growth of SGC7901 cells in a dose-dependent manner at 24h and 48h.SGC7901 cells treated with PD for 24h showed significantly enhanced apoptosis and weakened mitochondrial membrane potential compared with the control cells.Western blot results showed that PD could up-regulate expression of cleaved PARP,cleaved caspase-3,cleaved caspase-9,bax,p-JNK,p-p38 protein,decreased bcl-2,p-ERK protein,the expression of ERK,JNK,p38 protein did not change significantly.[Conclusion] PD may inhibit the proliferation and induce the apoptosis of SGC7901 cells.These findings indicated that PD inhibited cell proliferation by inhibiting the ERK signaling.PD effect on bax and bcl-2 by activation of JNK and p38 signaling pathway resulted in the decrease of mitochondrial membrane potential and activation of caspase,which induced the apoptosis of cancer cells.
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Objective: To explore the inductive effect of galangin on HPV-positive human cervical cancer cells and the possible mechanism. Methods: Two HPV-positive human cervical cancer cell lines (SiHa cell and HeLa cell) and one HPV-negative human cervical cancer cell line (C-33-A cell) were given different concentration of galangin (20, 40, and 80 μmol/L) for 24, 48, and 72 h. Three human cervical cancer cell lines and relative cell viabilities were determined by the MTT method. Apoptosis and cell cycle were analyzed by flow cytometry. Western blotting analysis was used to determine the protein expression levels of Bcl-2 family proteins. Results: Cell proliferation of two HPV-positive human cervical cancer cells was significantly inhibited by galangin in a dose- and time-dependent manner, and galangin had no effect on cell proliferation of HPV-negative human cervical cancer cells. Cell cycle detection results showed that galangin could reversibly arrest the two HPV-positive cell lines, either in G1 or in G2/M phases. Flow cytometry results showed that beyond certain galangin concentration or/and over 24 h exposure, the cells underwent apoptosis. The data of Western blotting showed that 40 μmol/L galangin up-regulated the expression levels of Bad, Bid, and Bax, but down-regulated Bcl-2 and Bcl-w. Conclusion: Galangin can inhibit the proliferation of HPV-positive cervical cancer cells and promote apoptosis, which may be associated with the regulation of Bcl-2 family proteins expression.
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Epilepsy is one of the most common episodic neurological diseases characterized by recurrent epileptic seizures. The seizures occur by synchronization of a neuronal network, which may cause disturbances in intracellular ion homeostasis, neuronal excitability, network remodeling, and neuronal death. The neuronal death following epileptic seizures results from the execution of cellular programs that are similar to those in developmentally programmed cell death. Research into cell death after seizures has identified the molecular machinery of apoptosis including the caspases and bcl-2 family proteins. The author reviews the clinical experimental evidences of programmed death pathway function in epileptic seizures. Four neuronal death pathways after epileptic seizures are proposed; non-programmed necrotic, programmed necrotic, programmed apoptotic extrinsic, and programmed apoptotic intrinsic pathways. Epileptogenesis is speculated based on the programmed pathways. Research on seizure-induced neuronal damage has developed considerably in recent years and that may open new ways to improve neuroprotective and antiepileptic treatments for patients with epilepsy.
Subject(s)
Humans , Apoptosis , Caspases , Cell Death , Epilepsy , Homeostasis , Neurons , SeizuresABSTRACT
BACKGROUND: Proteins of the Bcl-2 family are intracellular membrane-associated proteins that regulate programmed cell death either positively or negatively by as yet unknown mechanism. Bcl-2 family proteins have an antiapoptotic function, such as the Bcl-2, the long form of Bcl-x and Mcl-l, or a proapoptotic function, like the short form of Bcl-x and Bax. To investigate the potential role of Bcl-2 family proteins in thyroid tumorigenesis, the authors examined the pattern of expression of the Bel-2 family proteins in various thyroid neoplasms. METHODS: Bcl-2 family proteins, including Bcl-2, Bcl-x, Mcl-1 and Bax proteins were immunohistochemically stained in 57 cases of various thyroid neoplasms using formalin-fixed and paraffin embedded tissues; 18 cases of papillary carcinoma, 6 cases of medullary carcinoma, 4 cases of anaplastic carcinoma, 10 cases of follicular adenoma, 9 cases of adenomatous goiter, and 10 autopsy cases of fetal thyroid galnd. The intensity and frequency of the immunostaining were evaluated with the program of Image-Pro Plus Version 3.0 for image analysis. RESULT: Consistent expression of Bcl-2, Mcl-1, and Bax proteins were present in the surrounding normal thyroid tissue, however the expression of Bcl-x protein was not observed. Compare to the expression patterns of adenomatous goiter, and fetal and surrounding normal thyroid tissues, papillary and anaplastic carcinomas showed the decreased Bcl-2 and increased Bcl-x protein expressions(p (0.05). Medullary carcinoma revealed the increased Bcl-x protein expression only(p 0.05). CONCLUSION: These data suggest that combined patterns of decreased Bcl-2 and increased Bcl-x protein expressions may eontribute to the carcinogenesis of thyroid cancers originated from thyroid follicular cells, and an increased expression of Bcl-x protein may be related to the pathogenesis of medullary carcinoma from parafollicular C cells.