Possible Anticancer Activity of Rosuvastatine,Doxazosin, Repaglinide and Oxcarbazepin

Background: Rosuvastatine, doxazosin, repaglinide and oxcarbazepin are therapeutic drugs available in themarket for the treatment of different diseases. Potential to display antitumor activities has also been suggested.The aim of the current study was to evaluate their in vitro effects on some human transformed cell lines. Materialsand Methods: Cytotoxicity of the four drugs was tested in MCF-7, HeLa and HepG2 cells by the neutral red assaymethod and also the effect of rosuvastatine and doxazosin against Ehrlich Ascities Carcinoma Cells (EACC) bytrypan blue assay. Results: Rosuvastatine exerted the greatest cytotoxic effect against HepG2 cells with an IC50value of 58.7±69.3; in contrast doxazosin showed least activity with IC50=104.4 ±115.7. Repaglinide inhibited thegrowth of both HepG2 and HeLa cells with IC50 values of 87.6±117.5 and 89.3±119.5, respectively. Oxcarbazepineshowed a potent cytotoxicity against both HeLa (IC50=19.4±43.9) and MCF7 cancer cells ((IC50=22±35.7).On theother hand the growth of EACC was completely inhibited by doxazosine (100% inhibition) while rosuvastatinehad weak inhibitory activity (11.6%) . Conclusions: The four tested drugs may have cytotoxic effects againsthepatic, breast and cervical carcinoma cells; also doxazosine may inhibit the growth of endometrial cancer cells.Further investigations in animals are needed to confirm these results.     

Enterocarpam-III Induces Human Liver and Breast Cancer Cell Apoptosis via Mitochondrial and Caspase-9 Activation

An aristolactam-type alkaloid, isolated from Orophea enterocarpa, is enterocarpam-III (10-amino-2,3,4,6-tetramethoxyphenanthrene-1-carboxylic acid lactam). It is cytotoxic to various human and murine cancercell lines; however, the molecular mechanisms remain unclear. The aims of this study were to investigatecytotoxic effects on and mechanism (s) of human cancer cell death in human hepatocellular carcinoma HepG2and human invasive breast cancer MDA-MB-231 cells compared to normal murine fibroblast NIH3T3 cells.Cell viability was determined by MTT assay to determine IC10, IC20 and IC50 levels, reactive oxygen species(ROS) production with 2’,7’-dichlorohydrofluorescein diacetate and the caspase-3, -8 and -9 activities usingspecific chromogenic (p-nitroaniline) tetrapeptide substrates, viz., DEVD-NA, IETD-NA and LEHD-NA andemploying a microplate reader. Mitochondrial transmembrane potential (MTP) was measured by stainingwith 3, 3’-dihexyloxacarbocyanine iodide (DiOC6) and using flow cytometry. The compound was cytotoxic toHepG2 and MDA-MB-231 cells with the IC50 levels of 26.0±4.45 and 51.3±2.05 μM, respectively. For murinenormal fibroblast NIH3T3 cells, the IC50 concentration was 81.3±10.1 μM. ROS production was reduced in adose-response manner in HepG2 cells. The caspase-9 and -3 activities increased in a concentration-dependentmanner, whereas caspase-8 activity did not alter, indicating the intrinsic pathway activation. Enterocarpam-IIIdecreased the mitochondrial transmembrane potential (MTP) dose-dependently in HepG2 cells, suggesting thatthe compound induced HepG2 cell apoptosis via the mitochondrial pathway. In conclusion, enterocarpam-IIIinhibited HepG2 and MDA-MB-231 cell proliferation and induced human HepG2 cells to undergo apoptosisvia the intrinsic (mitochondrial) pathway and induction of caspase-9 activity.     

In vitro Evaluation of Cytotoxic Activities of Essential Oil from Moringa oleifera Seeds on HeLa,HepG2, MCF-7, CACO-2 and L929 Cell Lines

Moringa oleifera Lam. (Moringaceae) is widely consumed in tropical and subtropical regions for their valuablenutritional and medicinal characteristics. Recently, extensive research has been conducted on leaf extracts of M.oleifera to evaluate their potential cytotoxic effects. However, with the exception of antimicrobial and antioxidantactivities, little information is present on the cytotoxic activity of the essential oil obtained from M. oleifera seeds.Therefore, the present investigation was designed to investigate the potential cytotoxic activity of seed essentialoil obtained from M. oleifera on HeLa, HepG2, MCF-7, CACO-2 and L929 cell lines. The different cell lineswere subjected to increasing oil concentrations ranging from 0.15 to 1 mg/mL for 24h, and the cytotoxicity wasassessed using MTT assay. All treated cell lines showed a significant reduction in cell viability in response to theincreasing oil concentration. Moreover, the reduction depended on the cell line as well as the oil concentrationapplied. Additionally, HeLa cells were the most affected cells followed by HepG2, MCF-7, L929 and CACO-2,where the percentages of cell toxicity recorded were 76.1, 65.1, 59.5, 57.0 and 49.7%, respectively. Furthermore,the IC50 values obtained for MCF-7, HeLa and HepG2 cells were 226.1, 422.8 and 751.9 μg/mL, respectively.Conclusively, the present investigation provides preliminary results which suggest that seed essential oil fromM. oleifera has potent cytotoxic activities against cancer cell lines.     

Apoptosis Induction,Cell Cycle Arrest and in Vitro Anticancer Activity of Gonothalamin in a Cancer Cell Lines

Cancer is one of the major health problems worldwide and its current treatments have a number of undesiredadverse side effects. Natural compounds may reduce these. Currently, a few plant products are being used totreat cancer. In this study, goniothalamin, a natural occurring styryl-lactone extracted from Goniothalamusmacrophyllus, was investigated for cytotoxic properties against cervical cancer (HeLa), breast carcinoma(MCF-7) and colon cancer (HT29) cells as well as normal mouse fibroblast (3T3) using MTT assay. Fluorescencemicroscopy showed that GTN is able to induce apoptosis in HeLa cells in a time dependent manner. Flow cytometryfurther revealed HeLa cells treated with GTN to be arrested in the S phase. Phosphatidyl serine propertiespresent during apoptosis enable early detection of the apoptosis in the cells. Using annexin V/PI double stainingit could be shown that GTN induces early apoptosis on HeLa cells after 24, 48 and 72 h. It could be concludedthat goniothalamin showing a promising cytotoxicity effect against several cancer cell lines including cervicalcancer cells (HeLa) with apoptosis as the mode of cell death induced on HeLa cells by Goniothalamin was.     

15d-PGJ2 Induces Apoptosis of MCF-7 and MDA-MB-231 Cells via Increased Intracellular Calcium and Activation of Caspases,Independent of ER and ER

Reports indicate that 15deoxydelta12,14prostaglandinJ2 (15dPGJ2) has anticancer activities, but its mechanisms of action have yet to be fully elucidated We therefore investigated the effects of 15dPGJ2 on the human breast cancer cell lines, MCF7 (estrogen receptor ERER) and MDAMB231 (ERER) Cellular proliferation and cytotoxicity were determined using the 3(4,5dimethylthiazol2yl)2,5diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays while apoptosis was determined by fluorescence microscopy and flow cytometry using annexin Vpropidium iodide (PI) staining ER expression was determined by Western blotting Intracellular calcium was stained with Fluo4 AM while intracellular caspase activities were detected with CaspaseFLICA and measured by flow cytometry We showed that 15dPGJ2 caused a significant increase in apoptosis in MCF7 and MDAMB231 cells ER protein expression was reduced in treated MCF7 cells but preincubation with the ER inhibitor ICI 182 780 did not affect the percentage of apoptotic cells The expression of ER was unchanged in both cell lines In addition, 15dPGJ2 increased intracellular calcium (Ca) staining and caspase 8, 9 and37 activities We therefore conclude that 15dPGJ2 induces caspasedependent apoptosis that is associated with an influx of intracellular Ca with no involvement of ER signaling     

Stigmalactam from Orophea Enterocarpa Induces Human Cancer Cell Apoptosis Via a Mitochondrial Pathway

Stigmalactam, an aristolactam-type alkaloid extracted from Orophea enterocarpa, exerts cytotoxicityagainst several human and murine cancer cell lines, but the molecular mechanisms remain elusive. The aimsof this study were to identify the mode and mechanisms of human cancer cell death induced by stigmalactamemploying human hepatocellular carcinoma HepG2 and human invasive breast cancer MDA-MB-231 cellsas models, compared to normal murine fibroblasts. It was found that stigmalactam was toxic to HepG2 andMDA-MB-231 cells with IC50 levels of 23.0±2.67 μM and 33.2±4.54 μM, respectively, using MTT assays. At thesame time the IC50 level towards murine normal fibroblast NIH3T3 cells was 24.4±6.75 μM. Reactive oxygenspecies (ROS) production was reduced in stigmalactam-treated cells dose dependently after 4 h of incubation,indicating antioxidant activity, measured by using 2’,7’,-dichlorohydrofluorescein diacetate and flow cytometry.Caspase-3 and caspase-9 activities were increased in a dose response manner, while stigmalactam decreased themitochondrial transmembrane potential dose-dependently in HepG2 cells, using 3,3’-dihexyloxacarbocyanineiodide and flow cytometry, indicating mitochondrial pathway-mediated apoptosis. In conclusion, stigmalactamfrom O. enterocarpa was toxic to both HepG2 and MDA-MB-231 cells and induced human cancer HepG2 cellsto undergo apoptosis via the intrinsic (mitochondrial) pathway.     

自体宫颈癌-树突细胞疫苗激活的CTL杀伤效应

背景与目的:树突细胞(dendriticcells,DC)是目前已知的功能最强的抗原递呈细胞(antigen-presentingcell,APC),它可以在体内、外向T淋巴细胞递呈抗原,并诱发细胞毒T淋巴细胞(cytotoxicTlymphocyte,CTL)反应。本研究旨在探讨负载自体宫颈癌抗原的DC体外激发的CTL对自体宫颈癌细胞的杀伤效应。方法:先冻融宫颈癌细胞制备抗原,然后以GM-CSF、IL-4诱导自体外周血单个核细胞(peripheralbloodmononuclearcell,PBMC)获得DC并负载抗原,刺激自体T淋巴细胞制备宫颈癌抗原特异性CTL,观察CTL对宫颈癌细胞的杀伤活性。结果:负载自体宫颈癌抗原DC诱导的特异性CTL对自体宫颈癌细胞的体外杀伤率高达79.32%～89.27%,显著高于淋巴因子激活的杀伤细胞(lymphokine-activatedkillingcells,LAK)的杀伤率(t≥2.89,P<0.05);且对宫颈癌HeLa细胞株具有一定杀伤效应(40.35%～58.09%),但低于自体癌细胞组(t≥2.97,P<0.05);特异性CTL对HepG2、MCF7、A549、MGC803细胞无明显杀伤效应。结论:自体宫颈癌-树突细胞疫苗体外诱导的CTL具有高效而特异的抗自体宫颈癌细胞免疫活性,可望成为宫颈癌生物治疗的一个有力手段。     

Cytotoxic and Apoptotic-inducing Effects of Purple Rice Extracts and Chemotherapeutic Drugs on Human Cancer Cell Lines

Pigmented rice is mainly black, red, and dark purple, and contains a variety of flavones, tannin, polyphenols,sterols, tocopherols, γ-oryzanols, amino acids, and essential oils. The present study evaluated the cytotoxic effectsof purple rice extracts (PREs) combined with chemotherapeutic drugs on human cancer cells and mechanismsof cell death. Methanolic (MeOH) and dichloromethane (DCM) extracts of three cultivars of purple rice inThailand: Doisaket (DSK), Nan and Payao (PYO), were tested and compared with white rice (KK6). Cytotoxicitywas determined by 3-(4, 5-dimethyl)-2, 5-diphenyltetrazolium bromide (MTT) assay in human hepatocellularcarcinoma HepG2, prostate cancer LNCaP and murine normal fibroblast NIH3T3 cells. MeOH-PYO-PRE wasthe most cytotoxic and inhibited HepG2 cell growth more than that of LNCaP cells but was not toxic to NIH3T3cells. When PREs were combined with paclitaxel or vinblastine, they showed additive cytotoxic effects on HepG2and LNCaP cells, except for MeOH-PYO-PRE which showed synergistic effects on HepG2 cells when combinedwith vinblastine. MeOH-PYO-PRE plus vinblastine induced HepG2 cell apoptosis with loss of mitochondrialtransmembrane potential (MTP) but no ROS production. MeOH-PYO-PRE-treated HepG2 cells underwentapoptosis via caspase-9 and-3 activation. The level of γ-oryzanol was highest in DCM-PYO-PRE (44.17 mg/g)whereas anthocyanin content was high in MeOH-PYO-PRE (5.80 mg/g). In conclusion, methanolic Payaopurple rice extract was mostly toxic to human HepG2 cells and synergistically enhanced the cytotoxicity ofvinblastine. Human HepG2 cell apoptosis induced by MeOH-PYO-PRE and vinblastine was mediated througha mitochondrial pathway.     

Induction of Human Hepatocellular Carcinoma HepG2 Cell Apoptosis by Naringin

Naringin, a bioflavonoid found in Citrus seeds, inhibits proliferation of cancer cells. The objectives of this study were to investigate the mode and mechanism(s) of hepatocellular carcinoma HepG2 cell death induced by naringin. The cytotoxicity of naringin towards HepG2 cells proved dosedependent, measured by MTT assay. Naringintreated HepG2 cells underwent apoptosis also in a concentration related manner, determined by annexin Vfluorescein isothiocyanate (FITC) and propidium iodide (PI) employing flow cytometry. Mitochondrial transmembrane potential (MTP) measured using 3,3dihexyloxacarbocyanine iodide (DiOC6) and flow cytometer was reduced concentrationdependently, which indicated influence on the mitochondrial signaling pathway. Caspase3, 8 and 9 activities were enhanced as evidenced by colorimetric detection of paranitroaniline tagged with a substrate for each caspase. Thus, the extrinsic and intrinsic pathways were linked in human naringintreated HepG2 cell apoptosis. The expression levels of proapoptotic Bax and Bak proteins were increased whereas that of the antiapoptotic BclxL protein was decreased, confirming the involvement of the mitochondrial pathway by immunoblotting. There was an increased expression of truncated Bid (tBid), which indicated caspase8 proteolysis activity in Bid cleavage as its substrate in the extrinsic pathway. In conclusion, naringin induces human hepatocellular carcinoma HepG2 cell apoptosis via mitochondriamediated activation of caspase9 and caspase8mediated proteolysis of Bid. Naringin anticancer activity warrants further investigation for application in medical treatment.     

6,8-Dihydroxy-7-methoxy-1-methyl-azafluorenone Induces Caspase-8- and -9-mediated Apoptosis in Human Cancer Cells

6,8-Dihydroxy-7-methoxy-1-methyl-azafluorenone (DMMA), a purified compound from Polyalthia cerasoidesroots, is cytotoxic to various cancer cell lines. The aims of this study were to demonstrate the type of cancercell death and the mechanism(s) involved. DMMA inhibited cell growth and induced apoptotic death in humanleukemic cells (HL-60, U937, MOLT-4), human breast cancer MDA-MB231 cells and human hepatocellularcarcinoma HepG2 cells in a dose dependent manner, with IC50 values ranging between 20-55 μM. DMMA alsodecreased cell viability of human peripheral blood mononuclear cells. The morphology of cancer cells inducedby the compound after staining with propidium iodide and examined under a fluorescence microscope wascondensed nuclei and apoptotic bodies. Mitochondrial transmembrane potential (MTP) was decreased after 24hexposure in all five types of cancer cells. DMMA-induced caspase-3, -8, and -9 activity was strongly induced inhuman leukemic HL-60 and MOLT-4 cells, while in U937-, MDA-MB231- and HepG2-treated cells there waspartial induction of caspase. In conclusion, DMMA-induced activation of caspase-8 and -9 resulted in executionof apoptotic cell death in human leukemic HL-60 and MOLT-4 cell lines via extrinsic and intrinsic pathways.     

Induction of apoptosis in human cancer cell lines by diospyrin,a plant-derived bisnaphthoquinonoid,and its synthetic derivatives

Diospyrin, a bisnaphthoquinonoid natural product, and three synthetic derivatives have been tested for their action in four human cancer cell lines: acute myeloblastic leukemia (HL-60), chronic myelogenic leukemia (K-562), breast adenocarcinoma (MCF-7) and cervical epithelial carcinoma (HeLa). In cells grown in appropriate media several derivatives elicited cytotoxicity as assessed by Trypan Blue dye exclusion, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide reduction and DNA synthesis. Diethyl ether derivative (D7) was most effective in this regard while the parent compound diospyrin (D1) was least active (D7>D3>D2>D1). D7 was not cytotoxic toward normal human lymphocytes, suggesting its action is specific for tumor cells. On microscopic examination D7-treated cells exhibited characteristic morphological features of apoptosis, such as cell shrinkage and formation of apoptotic bodies. Fluorescent staining with propidium iodide revealed distinct chromatin condensation and nuclear fragmentation. The apoptotic index paralleled cytotoxic parameters, and fragmented DNA extracted free of genomic DNA displayed on gel electrophoresis a typical ladder pattern. D7-induced apoptosis was mediated via activation of caspase 3 and caspase 8.     

补骨脂素逆转人乳腺癌细胞多药耐药性的研究

目的研究中药补骨脂素对人乳腺癌细胞多耐药性的逆转作用.方法用MTT法测定药物的细胞毒性和IC50用流式细胞仪测定耐药细胞P170糖蛋白表达,并选异搏定作阳性对照,观察具有钙拮抗作用的补骨脂素对MCF-7/ADR多药耐药性的逆转作用.结果补骨脂素在非细胞毒性剂量下能使MCF-7/ADR对阿霉素的浓度升高,但对细胞表面的糖蛋白P-170却没有影响.结论补骨脂素具有逆转人乳腺癌MCF-7/ADR多药耐药性的作用.     

Dentatin from Clausena excavata Induces Apoptosis in HepG2 Cells via Mitochondrial Mediated Signaling

Hepatocellular carcinoma (HCC) is a primary liver cancer with high global incidence and mortality rates.Current candidate drugs to treat HCC remain lacking and those in use possess undesirable side effects. In thisinvestigation, the antiproliferative effects of dentatin (DTN), a natural coumarin, were evaluated on HepG2 cellsand DTN’s probable preliminary molecular mechanisms in apoptosis induction were further investigated. DTNsignificantly (p<0.05) suppressed proliferation of HepG2 cells with an IC50 value of 12.0 μg/mL, without affectinghuman normal liver cells, WRL-68 (IC50> 50 μg/mL) causing G0/G1 cell cycle arrest via apoptosis induction.Caspase colorimetric assays showed markedly increased levels of caspase-3 and caspase-9 activities throughoutthe treatment period. Western blotting of treated HepG2 cells revealed inhibition of NF-κB that triggers themitochondrial-mediated apoptotic signaling pathway by up-regulating cytoplasmic cytochrome c and Bax, anddown-regulating Bcl-2 and Bcl-xL. The current findings suggest DTN has the potential to be developed furtheras an anticancer compound targeting human HCC.     

Betulin induces mitochondrial cytochrome c release associated apoptosis in human cancer cells

We examined whether betulin, a naturally abundant compound, has anticancer functions in human cancer cells. The results showed that betulin significantly inhibited cell viability in cervix carcinoma HeLa cells, hepatoma HepG2 cells, lung adenocarcinoma A549 cells, and breast cancer MCF‐7 cells with IC₅₀ values ranging from 10 to 15 µg/mL. While betulin exhibited only moderate anticancer activity in other human cancer cells such as hepatoma SK‐HEP‐1 cells, prostate carcinoma PC‐3, and lung carcinoma NCI‐H460, with IC₅₀ values ranging from 20 to 60 µg/mL, it showed minor growth inhibition in human erythroleukemia K562 cells (IC₅₀ > 100 µg/mL). We further investigated the mechanism of anticancer activity by betulin, using HeLa cells as an experimental model. Betulin (10 µg/mL) induces apoptotic cell death, as evidenced by morphological characteristics such as membrane phosphatidylserine translocation, nuclear condensation/fragmentation, and apoptotic body formation. A kinetics analysis showed that the depolarization of mitochondrial membrane potential and the release of mitochondrial cytochrome c occurred as early as 30 min after treatment with betulin. Betulin, unlike its chemical derivative betulinic acid, did not directly trigger mitochondrial cytochrome c release in isolated mitochondria. Importantly, Bax and Bak were rapidly translocated to the mitochondria 30 min after betulin treatment. The sequential activation of caspase‐9 and caspase‐3/‐7 and the cleavage of poly(ADP‐ribose) polymerase (PARP) were observed behind those mitochondrial events. Furthermore, specific downregulation of either caspase‐9, Bax, or Bak by siRNA effectively reduced PARP cleavage and caspase‐3 activation. Taken together, the lines of evidence demonstrate that betulin triggers apoptosis of human cancer cells through the intrinsic apoptotic pathway. © 2010 Wiley‐Liss, Inc.     

表没食子儿茶素没食子酸酯诱导人肝癌细胞HepG2凋亡与TGF-β1-Smad通路激活有关

目的 探讨表没食子儿茶素没食子酸酯(EGCG)对人肝癌细胞HepG2细胞周期和凋亡的影响及其机制.方法 四甲基偶氮唑蓝(MTT)法检测EGCG对HepG2细胞增殖的影响,流式细胞术检测EGCG对HepG2细胞周期的影响以及细胞凋亡情况,逆转录聚合酶链反应(RT-PCR)和萤光素酶报告基因系统检测验证HepG2细胞中TGF-β1-Smad通路的完整性,实时聚合酶链反应(realtime PCR)检测EGCG对HepG2细胞中Smad2、Smad3、Smad4和Smad7 mRNA表达的影响.结果 高浓度EGCG干预时,HepG2细胞的增殖能力随着EGCG浓度和作用时间的增加而下降,呈明显的时效和量效关系,作用72 h,HepG2细胞的IC50为111.76 μmol/L.随EGCG剂量增大,HepG2细胞中G0/G1期细胞的比例逐渐增高,80、120和160 μmol/L EGCG处理组分别为44.9%、54.8%和91.3%;相反,S期细胞比例逐渐降低,80、120和160 μmol/L EGCG处理组依次为38.5%、29.2%和3.0%.随着EGCG剂量增大,HepG2细胞的早期凋亡增加,80、120和160 μmol/L EGCG处理组的早期凋亡率分别为1.82%、4.22%和6.83%;晚期凋亡也随之增加,80、120和160 μmol/L EGCG处理组的晚期凋亡率分别为7.92%、24.19%和27.92%.HepG2细胞中TGF-β1-Smad通路是完整的.EGCG对HepG2细胞中Smad2、Smad3和Smad4 mRNA的表达无明显影响,但下调Smad7 mRNA的表达.结论 EGCG能诱导人肝癌细胞HepG2的凋亡,其机制可能涉及TGF-β1-Smad通路的激活.     

Apoptosis induced by novel aldehyde calpain inhibitors in human tumor cell lines

Calpain is a class of Ca(2+)-dependent cysteine proteases and has been suggested to be involved in several important signaling cascades. A series of novel aldehyde calpain inhibitors identified in our laboratory were more potent and specific than commercially available calpain inhibitors, and were used to assess the involvement of calpain in cancer. Our inhibitors demonstrated potent anti-proliferative activity in four cancer cell lines (PC-3, HeLa, Jurkat and Daudi) with IC(50)'s ranging from 2 to >30 microM. A non-cancer cell line (CV-1) was 4-7-fold less sensitive than the cancer cell lines. Apoptotic activity was determined and appeared to be inversely correlated to calpain expression levels in the different cell types. Leukemia cell lines (i.e., Daudi and Jurkat) with undetectable m-calpain were more susceptible to the apoptotic effects in response to calpain inhibition, while apoptosis was not detected in PC-3 prostate cancer cells, which highly express m-calpain. The extent of apoptosis in HeLa cells was moderate under identical conditions. Apoptosis induced by calpain inhibition was accompanied by caspase-3 activation. Furthermore, cell cycle analysis showed that aldehyde calpain inhibitors arrested cells at the G2/M boundary in a concentration-dependent manner. These results indicate that aldehyde calpain inhibitors exhibit their cytotoxic effects via induction of G2/M arrest and apoptosis. Importantly, the compounds failed to exert any inhibitory effects toward 20S proteasome. Collectively, our results suggest that calpain is a novel target for the treatment of a variety of cancer diseases and provide leads for further discovery and development of calpain inhibitors.     

Inhibition of exosome release by ketotifen enhances sensitivity of cancer cells to doxorubicin

Exosomes released from cancer cells support metastasis and growth of recipient cells and increase their resistance to chemotherapy. Therapeutic targeting of exosomes is a promising area in cancer research. Our aim is to test the effect of the mast cell stabilizer ketotifen on exosomes release from cancer cells and how this can modify their response to doxorubicin. Exosomes release from three cancer cell lines (MCF7, HeLa and BT549) was assessed by scan electron microscope and exosomes quantification kit. Doxorubicin export within exosomes was monitored flurometrically and cellular sensitivity to doxorubicin ± ketotifen was measured by sulphorhodamine-B and colony formation assays. The three cell lines release different amounts of exosomes with the highest quantity released from BT549 followed by MCF7 and then HeLa. Ketotifen (10 µmol L^?1) reduced exosomes release in all three cell lines with different efficiency (HeLa>MCF7>BT549). Doxorubicin export via exosomes was highest in BT549, lower in HeLa and lowest in MCF7 cells. Pretreatment with ketotifen sensitized the cells to doxorubicin (HeLa>MCF7>BT549) with a sensitization factor of 27, 8 and 1.25 respectively. Increased sensitivity of cells to doxorubicin by ketotifen was proportional to its effect on exosomes release. Our data is the first report of ketotifen modulating exosomes release from cancer cells and opens the avenue for exosomes-targeting cancer therapy. The differential effects of ketotifen on doxorubicin exosomal export in the cell lines studied, suggests an opportunity of pharmacological enhancement of doxorubicin anti-tumor activity in some but not all cancer types.     

Celecoxib,a COX-2 Selective Inhibitor,Induces Cell Cycle Arrest at the G2/M Phase in HeLa Cervical Cancer Cells

Celecoxib, a selective inhibitor of COX-2, showed cytotoxic effects in many cancer cell lines including cervical cancer cells. This study investigated the effect of celecoxib on cell cycle arrest in HeLa cervical cancer cells through p53 expression. In vitro anticancer activity was determined with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. A double staining method was applied to investigate the mechanism of cell death, cell cycling was analyzed by flow cytometryand immunocytochemistry was employed to stain p53 expression in cells. Celecoxib showed strong cytotoxic effects and induced apoptosis with an IC50 value of 40 M. It induced cell cycle arrest at G2/M phase by increasing level of p53 expression on HeLa cells.     

Induction of apoptosis by casticin in cervical cancer cells through reactive oxygen species-mediated mitochondrial signaling pathways

Casticin, one of the main components from Fructus Viticis, has been reported to inhibit the growth of various cancer cells, including the human cervical cancer cell line HeLa. The purpose of this study was to examine the apoptotic activity and molecular mechanism of casticin action on human cervical cancer cells. The apoptotic activity of casticin on human cervical cancer HeLa, CasKi, SiHa and peripheral blood mononuclear cells (PBMCs) was measured using a histone/DNA ELISA assay, flow cytometry with propidium iodide (PI) staining and DNA agarose gel electrophoresis. The mitochondrial membrane potential and reactive oxygen species (ROS) production were evaluated by flow cytometry analysis. Caspase activities were assayed using a caspase colorimetric activity assay kit. Protein expression levels of cytochrome c, Bax, Bcl-2, Bcl-xL and XIAP were analyzed by Western blotting. Casticin caused accumulation of the Sub-G1 cells and increased reactive oxygen species (ROS) production in HeLa, CasKi, SiHa cell lines, but not in PBMCs. Apoptosis of HeLa cells was induced by casticin via mitochondrial release of cytochrome c due to the reduction of mitochondrial trans-membrane potential, activation of caspase-3 and -9, and the production of reactive oxygen species. The pan caspase inhibitor zVAD-FMK, the caspase-9 inhibitor zLEHD-fmk and N-acetylcysteine suppressed casticin-induced apoptosis. Bax was upregulated, while expression levels of Bcl-xL and XIAP were downregulated. However, there was no change in the expression of Bcl-2 under the same treatment. Our results indicate that casticin-induced apoptosis of cervical cancer cells is mediated by ROS generation and mitochondrial signaling pathways.