Sox-4 is a positive regulator of Hep3B and HepG2 cells' apoptosis induced by prostaglandin (PG)A(2) and delta(12)-PGJ(2)

We reported earlier that expression of Sox-4 was found to be elevated during prostaglandin (PG) A(2) and delta(12)-PGJ(2) induced apoptosis in human hepatocarcinoma Hep3B cells. In this study, the role of Sox-4 was examined using human Hep3B and HepG2 cell lines. Sox-4 induction by several apoptotic inducer such as A23187 (Ca(2+) ionophore) and etoposide (topoisomerase II inhibitor) and Sox-4 transfection into the cells were able to induce apoptosis as observed by the cellular DNA fragmentation. Antisense oligonucleotide of Sox-4 inhibited the induction of Sox-4 expression and blocked the formation of DNA fragmentation by PGA(2) and delta(12)-PGJ(2) in Hep3B and HepG2 cells. Sox-4-induced apoptosis was accompanied with caspase-1 activation indicating that caspase cascade was involved in this apoptotic pathway. These results indicate that Sox-4 is involved in Hep3B and HepG2 cells apoptosis as an important apoptotic mediator.     

纳米TiO2-Cu2O复合材料可见光催化杀伤人宫颈肿瘤细胞研究

以人宫颈肿瘤细胞(Hela细胞)为研究对象, 研究了可见光催化(光强为50 mW/cm2)条件下, 该复合材料Fenton作用对细胞的凋亡诱导作用和细胞周期的影响, 并对抗肿瘤作用机理进行探讨. 结果表明, 该复合材料对肿瘤细胞具有明显的杀伤作用, 抑制Hela细胞增殖, 降低细胞存活率, 诱导Hela细胞产生细胞凋亡. 此外, 还能够引起细胞周期各时相改变, 使细胞生长阻滞于G2/M期. 并引发细胞氧化应激反应的发生, 最终破坏胞内抗氧化酶体系的平衡. 由此可见, 纳米TiO2-Cu2O复合材料在抗肿瘤的可见光疗应用中具有一定的应用价值.     

纳米TiO2光催化氧化对胃癌细胞周期的影响

以胃癌细胞系BGC-823为研究对象,采用倒置相差显微镜观察纳米TiO2光催化氧化前后BGC-823细胞形态的变化,通过流式细胞仪考察其对BGC-823细胞凋亡率及细胞周期的影响。结果表明,纳米TiO2光催化氧化使BGC-823细胞呈受激坏死或凋亡晚期继发性坏死状态;导致BGC-823细胞周期阻滞于G2/M期并诱导细胞凋亡,从而抑制其DNA合成及增殖分化进程。当TiO2比负载量为9.8×10-7g/cm2、光照时间为40 min时,G2/M期阻滞较为显著,细胞凋亡率达24.34%。     

Luteolin induces mitochondria-dependent apoptosis in human lung adenocarcinoma cell

The effects of luteolin on the proliferation of A549 cells were evaluated by MTT and clone formation assays. DNA ploidy and apoptotic cell percentage were calculated by flow cytometry. The expression of Bax, Bcl-xl, Bcl-2, Mcl-1, caspase-9, caspase-3, and PARP was analyzed by Western blotting. The membrane potential of mitochondria was detected by JC-1 fluorescence microscopy assay. Our results demonstrated that luteolin could inhibit the proliferation of A549 cells via induction of apoptosis, with the evidence of characteristic morphological changes of apoptosis in the nucleus. Furthermore, DNA flow cytometric analysis indicated that luteolin induced a S phase arrest of the cell cycle. The membrane potential of mitochondria was decreased. The protein levels of Bax, Bcl-xl, Bcl-2, Mcl-1, caspase-9, caspase-3, and PARP were activated after treatment with luteolin. Luteolin can inhibit the proliferation of A549 cells and trigger mitochondria- dependent apoptosis in them.     

23-hydroxybetulinic acid-induced HL-60 cell autophagic apoptosis and its molecular mechanism

This study investigates the effects of 23-hydroxybetulinic acid (23-HBA) in inducing HL-60 autophagic apoptosis and explores its potential molecular mechanism. The generation depression effects of HL-60 cells cultured in?vitro were detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method (p?相似文献   

Photoactivation of pheophorbide a induces a mitochondrial-mediated apoptosis in Jurkat leukaemia cells

The mechanism of cell death by pheophorbide a (Pba) which has been established to be a potential photosensitizer was examined in experimental photodynamic therapy (PDT) on Jurkat cells, a human lymphoid tumor cell line. In 30-60 min after irradiation, Pba treated cells exhibited apoptotic features including membrane blebbing and DNA fragmentation. Pba/PDT caused a rapid release of cytochrome c from mitochondria into the cytosol. Sequentially, activation of caspase-3 and the cleavage of poly ADP-ribose polymerase (PARP) were followed. Meanwhile, no evidence of activation of caspase-8 was indicated in the cells. In experiments with caspase inhibitors, it was found that caspase-3 alone was sufficient initiator for the Pba-induced apoptosis of the cells. Pba specific emission spectra were confirmed in the mitochondrial fraction and the light irradiation caused a rapid change in its membrane potential. Thus, mitochondria were entailed as the crucial targets for Pba as well as a responsible component for the cytochrome c release to initiate apoptotic pathways. Taken together, it was concluded that the mode of Jurkat cell death by Pba/PDT is an apoptosis, which is initiated by mitochondrial cytochrome c release and caspase-3-pathways.     

Apoptosis of Human Gastric Carcinoma SGC-7901 Induced by Deoxycholic Acid via the Mitochondrial-Dependent Pathway

The study aimed to evaluate the effects of deoxycholic acid (DCA) on human gastric carcinoma cell lines and to explore its mechanisms. In the present study, effects of DCA on SGC-7901 cell growth, cell cycle, and apoptosis were investigated by MTT assay, inverted microscopy, fluorescence microscopy, PI single- and FITC/PI double-staining flow cytometry, and western blotting. The study have revealed that DCA significantly inhibited the growth of SGC-7901 cells in a dose- and time-dependent manner and arrested cell cycle at G0/G1 phase. SGC-7901 cells showed typical apoptotic morphological changes after treated with DCA for 48 h. The intensity of typical apoptosis pattern- “ladders” formed by DNA in fragments of multiples of 200 base pairs was also observed. Apoptosis of SGC-7901 cells induced by DCA were associated with collapse of the mitochondrial membrane potential. DCA treatment could also increase the ratio of Bax to Bcl-2 in SGC-7901 cells. Meanwhile, the expression of p53, cyclinD1, and c-Myc were changed after DCA treatment. These results suggest that DCA induces apoptosis of gastric carcinoma cells through an intrinsic mitochondrial-dependent pathway, and the increase in the Bax/Bcl-2 ratio and collapse of the mitochondrial membrane potential may play important roles in DCA-induced apoptosis of gastric carcinoma cells.     

Cytotoxicity and DNA Damage Effect of TGA-capped CdTe Quantum Dots

The cytotoxicity and DNA damage caused by thioglycolic acid(TGA)-capped cadmium telluride(CdTe)quantum dots(QDs)to hepatocyte line HL-7702 were investigated.Cell viability was measured by 3-(4,5-dimeth...     

The apoptotic effect of 1's-1'-acetoxychavicol acetate from Alpinia conchigera on human cancer cells

1'-(S)-1'-Acetoxychavicol acetate (ACA) isolated from the Malaysian ethno-medicinal plant Alpinia conchigera Griff. was investigated for its potential as an anticancer drug. In this communication, we describe the cytotoxic and apoptotic properties of ACA on five human tumour cell lines. Data from MTT cell viability assays indicated that ACA induced both time- and dose-dependent cytotoxicity on all tumour cell lines tested and had no adverse cytotoxic effects on normal cells. Total mortality of the entire tumour cell population was achieved within 30 hrs when treated with ACA at 40.0 μM concentration. Flow cytometric analysis for annexin-V and PI dual staining demonstrated that cell death occurred via apoptosis, followed by secondary necrosis. The apoptotic effects of ACA were confirmed via the DNA fragmentation assay, in which consistent laddering of genomic DNA was observed for all tumour cell lines after a 24 hrs post-treatment period at the IC(50) concentration of ACA. A cell cycle analysis using PI staining also demonstrated that ACA induced cell cycle arrest at the G(0)/G(1) phase, corresponding to oral tumour cell lines. In conclusion, ACA exhibits enormous potential for future development as a chemotherapeutic drug against various malignancies.     

Regulation of bcl-2 family in hydrogen peroxide-induced apoptosis in human leukemia HL-60 cells

Numerous types of cells have been shown to undergo apoptosis when exposed to oxidant agent such as hydrogen peroxide. In order to understand the functional relationship between the anti- and pro-apoptotic regulatory proteins in the cells under oxidant stress, we have studied the level of expression of apoptosis regulatory proteins, bcl-2 and bax, in human leukemia HL-60 cells. The exposure of HL-60 cells to different concentrations of H2O2 for 6 h resulted in a typical apoptosis of the cells as characterized by flow cytometry, cell cycle analysis, and DNA fragmantation. There was a block in G1 to S transition and apoptotic cells were mainly derived from S and G2 cells. Kinetic study demonstrated that the levels of both bcl-2-mRNA and -protein expression were decreased with the progression of cellular apoptosis whereas the level of bax-mRNA was unchanged but the expressed bax-protein was not detectable. Cycloheximide, a nonspecific translation inhibitor, did not prevent the hydrogen peroxide-mediated apoptosis in HL-60 cells. These results suggest that the regulation of bcl-2, but not of bax are important factor in the oxidative stress-induced apoptosis in HL-60 cells.     

Calotropis procera extract induces apoptosis and cell cycle arrest at G2/M phase in human skin melanoma (SK-MEL-2) cells

Calotropis procera (family: Asclepiadaceae) contains cardiac glycosides which are cytotoxic to cancer cells. The extracts of C. procera have been reported to be cytotoxic to many cancer cell lines and this is the first report against the human skin melanoma cells (SK-MEL-2). The SK-MEL-2 cells treated with C. procera methanolic extract (CPME) were analysed for growth inhibition and apoptosis. The exposure of phosphatidylserine in apoptotic SK-MEL-2 was analysed by using the Annexin-V FITC flow cytometry method. In CPME-treated SK-MEL-2 cells, 19.6% of apoptotic and 58.3% dead cells were observed. The 15.97% and 15.85% of early apoptotic cells were found at 20 μg/mL of the ouabain and paclitaxel, respectively. Active caspases, nuclear degradation confirmed apoptotic SK-MEL-2 cells in time- and dose-dependent manner. The cell cycle analysis shows that CPME treated cells halt at G2/M phase. Significant cytotoxic activity of CPME against SK-MEL-2 may be attributed to its high cardenolide content.     

Induction of Apoptosis and Regulation of MicroRNA Expression by (2E,6E)-2,6-bis-(4-hydroxy-3-methoxybenzylidene)-cyclohexanone (BHMC) Treatment on MCF-7 Breast Cancer Cells

(2E,6E)-2,6-bis-(4-hydroxy-3-methoxybenzylidene)-cyclohexanone (BHMC) is a synthetic curcumin analogue, which has been reported to possess anti-tumor, anti-metastatic, and anti-invasion properties on estrogen receptor (ER) negative breast cancer cells in vitro and in vivo. However, the cytotoxic effects of BHMC on ER positive breast cancer cells were not widely reported. This study was aimed to investigate the cytotoxic potential of BHMC on MCF-7 cells using cell viability, cell cycle, and apoptotic assays. Besides, microarray and quantitative polymerase chain reaction (qPCR) were performed to identify the list of miRNAs and genes, which could be dysregulated following BHMC treatment. The current study discovered that BHMC exhibits selective cytotoxic effects on ER positive MCF-7 cells as compared to ER negative MDA-MB-231 cells and normal breast cells, MCF-10A. BHMC was shown to promote G2/M cell cycle arrest and apoptosis in MCF-7 cells. Microarray and qPCR analysis demonstrated that BHMC treatment would upregulate several miRNAs like miR-3195 and miR-30a-3p and downregulate miRNAs such as miR-6813-5p and miR-6132 in MCF-7 cells. Besides, BHMC administration was also found to downregulate few tumor-promoting genes like VEGF and SNAIL in MCF-7. In conclusion, BHMC induced apoptosis in the MCF-7 cells by altering the expressions of apoptotic-regulating miRNAs and associated genes.     

CRISPR-Cas13a mediated nanosystem for attomolar detection of canine parvovirus type 2

The CPV-2 DNA extracted from dog's intestine was amplified using RPA and transcribed into an RNA copy. The RNA copy was incubated with Cas13a and crRNA, upon activation collateral cleavage activity of Cas13a cleaves all the target RNA and nonspecific RNA in the vicinity producing fluorescent signals within 30 min.     

Regulation of apoptosis through arachidonate cascade in mammalian cells

The arachidonate cascade includes the cyclooxygenase (COX) pathway to form prostanoids and the lipoxygenase (LOX) pathway to generate several oxygenated fatty acids, collectively called eicosanoids. Eicosanoids are suggested to play a dual role in regulating cell survival and apoptosis in various types of cells through an unknown mechanism. We found apoptosis in cultured Madin-Darby canine kidney (MDCK) cells treated with 12-O-tetradecanoylphorbol β-acetate (TPA), a potent tumor promoter, and nordihydroguaiaretic acid (NDGA), a LOX inhibitor. The effect of TPA was synergistically stimulated along with NDGA. Aspirin, a COX inhibitor, was not effective. The target of NDGA might be different from the mechanism involving a LOX activity in some kinds of carcinoma cells because the increased expression of 12-LOX was not detected in MDCK cells treated with TPA. Caspase and poly(ADP-ribose) metabolites were found to be involved in the signal transduction pathway of the TPA- and NDGA-induced apoptosis in MDCK cells. Alternatively, hydrogen peroxide-induced apoptosis was not affected by NDGA. Thus, the TPA-induced response involved the mechanism independent of the oxidative stress. Obesity is a risk factor for severe diseases including noninsulin-dependent diabetes and atherosclerosis characterized by the changes of cell properties of adipocytes. We found that conjugated linolenic acid from bitter gourd was able to induce apoptosis in mouse preadipogenic 3T3-L1 cells. The findings provide the potential use of conjugated fatty acids to regulate obesity.     

Synthesis,characterization and biological evaluation of a cobalt(II) complex with 5‐chloro‐8‐hydroxyquinoline as anticancer agent

A new cobalt(II) complex ( 1 ) of 5‐chloro‐8‐hydroxyquinoline was prepared and structurally characterized using infrared spectroscopy, electrospray ionization mass spectrometry, elemental analysis, single‐crystal X‐ray diffraction as well as powder X‐ray diffraction. Its biological activities including DNA binding and anticancer activity were investigated. The DNA binding study of complex 1 suggested that it interacted with calf thymus DNA mainly via an intercalative binding mode. The in vitro anticancer activity of complex 1 was screened against a series of tumor cell lines as well as the normal liver cell line HL‐7702 using MTT assay. complex 1 showed much higher cytotoxicity than corresponding metal salt and ligand towards the five tested tumor cell lines, in which T‐24 was the most sensitive tumor cell line towards 1, with IC₅₀ value of 7.04 ± 0.06 μM. complex 1 was found to greatly induce cell cycle arrest in T‐24 cells at S phase, and consequently to induce cell apoptosis in a dose‐dependent mode suggested by cell apoptosis analysis via Hoechst 33258 and acridine orange/ethidium bromide staining assays. The cell apoptosis mechanism of 1 was studied targeting the mitochondrion‐mediated pathway, since the apoptotic mechanism in the T‐24 cells treated by 1 was investigated by reactive oxygen species (ROS) detection, intracellular calcium concentration measurement and caspase‐9/3 activity assay. The results suggested that the cell apoptosis induced by 1 was closely related to the loss of mitochondrial membrane potential, ROS production and enhancement of intracellular [Ca²⁺], which would trigger the caspase‐9/3 activation via a mitochondrial dysfunction pathway. Copyright © 2016 John Wiley & Sons, Ltd.     

Cytochrome C-dependent Fas-independent apoptotic pathway in HeLa cells induced by delta12-prostaglandin J2

Cyclopentenone prostaglandins (PGs) have antiproliferative activity on various tumor cell growth in vitro. Particularly, 9-deoxy-delta(9,12)-13,14-dihydro PGD(2) (delta(12)-PGJ(2)) was reported for its antineoplastic and apoptotic effects on various cancer cells, but its mechanism inducing apoptosis is still not clear. In this study, we have characterized apoptosis induced by delta(12)-PGJ(2) in HeLa cells. Treatment of delta(12)-PGJ(2) induced apoptosis as indicated by DNA fragmentation, chromatin condensation, and formation of apoptotic body. We also observed release of cytochrome c from mitochondria and activation of caspase cascade including caspase-3, -8, and -9. And the pan-caspase inhibitor z-Val-Ala-Asp (OMe) fluoromethyl-ketone (z-VAD-fmk) and Q-Val-Asp (OMe)-CH(2)-OPH (Q-VD (OMe)-OPH) prevented cell death induced by delta(12)-PGJ(2) showing participation of caspases in this process. However, protein expression level of Bcl-2 family was not altered by delta(12)-PGJ(2), seems to have no effect on HeLa cell apoptosis. And ZB4, an antagonistic Fas-antibody, exerted no effect on the activation of caspase 8 indicating that Fas receptor-ligand interaction was not involved in this pathway. Treatment of delta(12)-PGJ(2) also leads to suppression of nuclear factor kappaB (NF-kappaB) as indicated by nuclear translocation of p65/RelA and c-Rel and its DNA binding ability analyzed by EMSA. Taken together, our results suggest that delta(12)-PGJ(2)-induced apoptosis in HeLa cell utilized caspase cascade without Fas receptor-ligand interaction and accompanied with NF-kappaB inactivation.     

1,4-Diselenophene-1,4-diketone triggers caspase-dependent apoptosis in human melanoma A375 cells through induction of mitochondrial dysfunction

Epidemiological, preclinical and clinical studies have supported the role of selenocompounds as potential cancer chemopreventive and chemotherapeutic agents. In this study, a novel selenophene-based compound, 1,4-diselenophene-1,4-diketone (DSeD), has been synthesized by Double Friedel-Crafts reaction and identified as a potent antiproliferative agent against a panel of six human caner cell lines. Despite this potency, DSeD was relatively nontoxic toward human normal cells, HS68 fibroblasts and HK-2 kidney cells. These results suggest that DSeD possesses great selectivity between cancer and normal cells. Induction of apoptosis in human melanoma A375 cells by DSeD was evidenced by accumulation of sub-G1 cell population, DNA fragmentation and nuclear condensation. Activation of caspase-9 and depletion of mitochondrial membrane potential indicated the initiation of the mitochondria-mediated apoptosis pathway. Pretreatment of cells with general caspase inhibitor z-VAD-fmk and caspase-9 inhibitor z-LEHD-fmk significantly suppressed the cell apoptosis, demonstrating the important roles of caspase and mitochondria in DSeD-induced apoptotic cell death. Furthermore, DSeD-induced apoptosis was found independent of reactive oxygen species generation. Taken together, our results suggest that DSeD induces caspase-dependent apoptosis in A375 cells through activation of mitochondria-mediated apoptosis pathway.     

Camptothecin-20(s)-O-[N-(3'α,12'α-dihydroxy-24'-carbonyl-5'β-cholan)]-lysine, a novel camptothecin analogue, induces apoptosis towards hepatocellular carcinoma SMMC-7721 cells

Camptothecin-20(s)-O-[N-(3'α,12'α-dihydroxy-24'-carbonyl-5'β-cholan)]-lysine (B2) is a novel camptothecin analogue. Our previous study had shown that it displayed higher cytoxicity activity towards hepatocellular carcinoma SMMC-7721 cells than camptothecin (CPT) in vitro. In this paper, the underlying mechanism of anti-proliferation of B2 towards SMMC-7721 cells was further examined. Cell growth inhibition of B2 was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay; morphological changes were observed under Laser Scanning Confocal Microscope (LSCM); cell cycle distribution, apoptotic population, changes in mitochondrial membrane potential, intracellular calcium concentration and reactive oxygen species (ROS) production were determined by flow cytometry (FCM). Activities of caspase-3 and caspase-9 were measured, and the expression level of Bcl-2 and Bax proteins were analyzed by Western blot. The results suggested that B2 inhibited SMMC-7721 cell growth by causing cell cycle arrest at the S and G2/M phases, and induced apoptosis involving a mitochondrial pathway. B2 appears to cause a high induction of apoptosis on SMMC-7721 cells in vitro, which suggests it might be a potential drug for cancer therapy.     

Essential oil from Cryptomeria japonica induces apoptosis in human oral epidermoid carcinoma cells via mitochondrial stress and activation of caspases

Cryptomeria japonica D. Don (C. japonica) has been used in traditional medicines from Asia for a variety of indications, including liver ailments, and an antitussive, and for its antiulcer activities. We examined the cell viability and apoptosis of KB cells treated with C. japonica essential oil at several concentrations for 12 h by MTT assay, Hoechst-33258 dye staining, DNA fragmentation, flow cytometry (cell cycle), and Western blotting for mitochondria stress, activation of caspases, and poly (ADP-ribose) polymerase. The essential oil induced the apoptosis of KB cells in a dose-dependent manner, which was verified by DNA fragmentation, appearance of apoptotic bodies, and the sub-G1 ratio. The essential oil also induced rapid and transient caspase-3 activity and cleavage of PARP of the KB cells. Treating the cells with the oil also caused changes in the mitochondrial level of the Bcl-2 family proteins such as Bcl-2 and Bax, thereby inducing the release of cytochrome c into the cytosol. The essential oil of C. japonica may have potential as a cancer chemopreventive and therapeutic agent.