"One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; ( DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth." (Source: MeSH)
Cancer Research UK Includes Cell death (apoptosis) news from Cancer Research UK
Introduction to Cancer Biology (Part 2): Loss of Apoptosis
mechanismsinmedicine.com Educational animation. "Apoptosis or "programmed cell death" is a mechanism by which organisms limit the growth and replication of cells. Loss of apoptosis is one of the key mechanisms behind cancer..."
This list of publications is regularly updated (Source: PubMed).
Maharath A, Fucharoen S, Tanyong DI p53 and nitric oxide are involved in cytokine-induced apoptosis in Kasumi-1 and Molt-4 Leukemics cells. Asian Pac J Allergy Immunol. 2014; 32(2):133-9 [PubMed] Related Publications
BACKGROUND: Immunotherapy has been developed to treat cancers. There are many signaling pathways involved in cytokine induced apoptosis of many cancers but their role remains unclear in some cancers such as leukemia. OBJECTIVE: To investigate the involvement of the nitric oxide (NO) and p53 tumor suppressor gene in apoptotic pathways induced by cytokines in leukemic cell lines. METHODS: Leukemic cell lines, Kasumi-1 (AML-M2) and Molt- 4 (ALL) were treated with cytokines, interleukin-1β (IL-1β), tumor necrosis factor-α (TNFα), interferon-γ (IFN-γ). The effect of cytokines on the induction cell apoptosis was analysed by flow cytometry. In addition, nitric oxide production and p53 protein levels were measured by using the Griess method and Western blot, respectively. RESULTS: Upon cytokine treatment, there was a significant increase in the percentage of cell apoptosis in both leukemic cell lines. The highest apoptosis was shown in 40 U/ml IFN-γ treated cells. In addition, nitric oxide and p53 protein increased in IFN-γ treated cells. There was a reduction of apoptosis and p53 level after adding the inducible nitric oxide synthase inhibitor, SMT. CONCLUSION: p53 and nitric oxide are involved in the mediation of apoptosis induced by cytokines in Kasumi-1 and Molt-4 leukemic cell lines.
Rupachandra S, Sarada DV Anti-proliferative and apoptotic properties of a peptide from the seeds of Polyalthia longifolia against human cancer cell lines. Indian J Biochem Biophys. 2014; 51(2):127-34 [PubMed] Related Publications
The peptides produced enzymatically from various plants have shown various biological activities including cytotoxicity. Different types of cytotoxic peptides have been reported from the seeds and leaves of Violaceae, Rubiaceae and Annonaceae families. In this study, we report purification and characterization of peptide(s) showing cytotoxic activity against A549 and HeLa cancer cell lines from the seeds of Polyalthia longifolia (Annonaceae). Seed proteins of P. longifolia were extracted and hydrolyzed using trypsin. The enzyme hydrolysate was applied on to a Sephadex G10 column and eluted using Tris-HC1 buffer (pH 7.5). Two fractions F1 and F2 were obtained, of which F2 showed significant cytotoxic activity against lung (A549) cancer cells at 10 microg/mL and cervical (HeLa) cancer cell lines at 30 microg/mL, as revealed by the MTT assay. DNA fragmentation was observed in the tested cancer cell lines treated with F2 peptide at a concentration of 10microg/mL and 30 pg/mL, respectively. Further, increased number of apoptotic cells was observed in sub-G0 phase of cell cycle of A549 and HeLa cell lines, when treated with 10 microg/mL and 30 microg/mL of F2, as revealed by the flow cytometric analyses. FTIR spectrum of F2 peptide detected the presence of stretching vibrations of carboxylic acid OH residue with peak at 3420 cm-and carbonyl (C=O) groups at 1636 cm-1, respectively. RP-HPLC analysis of F2 peptide showed a single peak at a retention time of 12.8 min detected at 280 nm, depicting the purity of F2 to be more than 90%. LC-ESI-MS/MS analysis showed the average theoretical mass of F2 to be 679.8 using m/z ratios. In conclusion, the findings suggest that F2 peptide is an effective inducer of apoptosis of cancer cells, thus offers an important strategy in the development of cancer therapeutics.
BACKGROUND: Hirano bodies are actin-rich paracrystalline inclusions found in brains of patients with Alzheimer's disease (AD), frontotemporal dementia (FTD), and in normal aged individuals. Although studies of post-mortem brain tissue provide clues of etiology, the physiological function of Hirano bodies remains unknown. A cell culture model was utilized to study the interactions of mutant tau proteins, model Hirano bodies, and GSK3β in human astrocytoma cells. RESULTS: Most tau variants showed co-localization with model Hirano bodies. Cosedimentation assays revealed this interaction may be direct, as recombinant purified forms of tau are all capable of binding F-actin. Model Hirano bodies had no effect or enhanced cell death induced by tau in the absence of amyloid precursor protein intracellular domain (AICD). In the presence of AICD and tau, synergistic cell death was observed in most cases, and model Hirano bodies decreased this synergistic cell death, except for forms of tau that caused significant cell death in the presence of Hirano bodies only. A role for the kinase GSK3β is suggested by the finding that a dominant negative form of GSK3β reduces this synergistic cell death. A subset of Hirano bodies in brain tissue of both Alzheimer's disease and normal aged individuals was found to contain tau, with some Hirano bodies in Alzheimer's disease brains containing hyperphosphorylated tau. CONCLUSION: The results demonstrate a complex interaction between tau and AICD involving activation of GSK3β in promoting cell death, and the ability of Hirano bodies to modulate this process.
Hotnog D, Mihăilă M, Lancu IV, et al. Resveratrol modulates apoptosis in 5-fluorouracyl treated colon cancer cell lines. Roum Arch Microbiol Immunol. 2013 Oct-Dec; 72(4):255-64 [PubMed] Related Publications
Since cancer is a cellular disease, it is essential to identify the development stages and use the information in the prediction, prevention, early detection and design of drug targets. Colon cancer represents a malignancy with high incidence and mortality throughout the world, its etiology involving many genetic, immunological and biochemical factors. 5-fluorouracyl (5-FU) is one of the most effective anti-cancer agents used in the treatment of colorectal cancers, but tumor chemoresistance is a major limiting factor of its use. In order to choose the most effective chemotherapeutic doses of 5-FU, and thereby diminish the side-effects, we tried to modulate the anticancer properties of 5-FU by adding dietary natural compounds. The study focused on the role of natural compounds as resveratrol (RSV) in sensitization of LoVo human colon adenocarcinoma cell line to 5-FU action. Real-time cell analysis (RTCA) by xCELLigence System was used to continuously monitor the cytotoxic effects of drug treatments on LoVo cells. RTCA allowed us to choose the proper concentrations for further end-point assays, such as flow-cytometry techniques used for the evaluation of apoptotic events, progression through cell cycle phases or nuclear antigen expression of compound-treated LoVo cells. Data obtained showed additional effects of RSV to 5-FU treatments on the increase ofapoptotic events, and suggested alternative approaches to obtain a stronger antitumor response, and diminished side-effects when low concentrations of anti-cancer drugs are used. Modulation of the mechanisms of programmed cell death process seem to be of great importance for malignant transformation, and therefore for anti-cancer therapeutic approaches.
Kato T, Fujii T, Ide M, et al. Effect of long interval between hyperthermochemoradiation therapy and surgery for rectal cancer on apoptosis, proliferation and tumor response. Anticancer Res. 2014; 34(6):3141-6 [PubMed] Related Publications
Neoadjuvant chemoradiotherapy is commonly used to improve the local control and resectability of locally advanced rectal cancer, with surgery performed after an interval of a number of weeks. We have been conducting a clinical trial of preoperative chemoradiotherapy in combination with regional hyperthermia (hyperthermo-chemoradiation therapy; HCRT) for locally advanced rectal cancer. In the current study we assessed the effect of a longer (>10 weeks) interval after neoadjuvant HCRT on pathological response, oncological outcome and especially on apoptosis, proliferation and p53 expression in patients with rectal cancer. Forty-eight patients with proven rectal adenocarcinoma who underwent HCRT followed by surgery were identified for inclusion in this study. Patients were divided into two groups according to the interval between HCRT and surgery, ≤ 10 weeks (short-interval group) and >10 weeks (long-interval group). Patients in the long-interval group had a significantly higher rate of pathological complete response (pCR) (43.5% vs. 16.0%) than patients of the short-interval group. Patients of the long-interval group had a significantly higher rate of down-staging of T-stage (78.3% vs. 36.0%) and relatively higher rate of that of N-stage (52.2% vs. 36.0%) than patients of the short-interval group. Furthermore, apoptosis in the long-interval group was relatively higher compared to that of the short-interval group, without a significant difference in the Ki-67 proliferative index and expression of p53 in the primary tumor. In conclusion, we demonstrated that a longer interval after HCRT (>10 weeks) seemed to result in a better chance of a pCR, a result confirmed by the trends in tumor response markers, including apoptosis, proliferation and p53 expression.
Alkahtani SH The steroidal Na+/K+ ATPase inhibitor 3-[(R)-3-pyrrolidinyl]oxime derivative (3-R-POD) induces potent pro-apoptotic responses in colonic tumor cells. Anticancer Res. 2014; 34(6):2967-71 [PubMed] Related Publications
Recently, potent anticancer actions of the steroidal Na(+)/K(+) ATPase inhibitor 3-[(R)-3-pyrrolidinyl]oxime derivative 3 (3-R-POD) have been reported for multiple cell lines, including prostate and lung cancer cells. In the present study, the anticancer action of 3-R-POD was addressed in colonic tumor cells. Treatment of Caco2 colonic tumor cells with increasing concentrations of 3-R-POD induced potent, dose-dependent inhibition of cell growth as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, the APOpercentage apoptosis assay revealed significant pro-apoptotic responses, suggesting that the anticancer activity of this steroidal Na(+)/K(+) ATPase inhibitor in colonic tumors takes places mainly through the induction of strong pro-apoptotic effects. Focussing on the molecular mechanism that may regulate these interactions, 3-R-POD was shown to induce significant early actin re-organization and late Protein Kinase B (AKT) de-phosphorylation. Finally, the 3-R-POD-induced inhibition of cell growth and early actin reorganization in colonic cancer cells remained unchanged when cells were pre-treated with pertussis toxin, thus excluding possible interactions of this inhibitor with G-coupled receptors. These results indicate that 3-R-POD induces potent pro-apoptotic responses in colonic tumor cells governed by actin re-organization and inhibition of AKT pro-survival signaling.
Seo HS, Ku JM, Choi HS, et al. Induction of caspase-dependent apoptosis by apigenin by inhibiting STAT3 signaling in HER2-overexpressing MDA-MB-453 breast cancer cells. Anticancer Res. 2014; 34(6):2869-82 [PubMed] Related Publications
BACKGROUND: This study aimed to examine the effect of apigenin on proliferation and apoptosis in HER2-overexpressing MDA-MB-453 breast cancer cells. MATERIALS AND METHODS: The antiproliferative effects of apigenin were examined by proliferation and MTT assays. The effect of apigenin on apoptotic molecules was determined by western blotting. RT-PCR was performed to measure mRNA levels of HIF-1α and VEGF. ELISA assay was performed to measure intracellular VEGF levels. Immunocytochemistry was performed to evaluate nuclear STAT3 level. RESULTS: Apigenin inhibited the proliferation of MDA-MB-453 cells. Apigenin up-regulated the levels of cleaved caspase-8 and caspase-3, and induced the cleavage of PARP. Apigenin induced extrinsic apoptosis and blocked the activation (phosphorylation) of JAK2 and STAT3. Apigenin inhibited CoCl2-induced VEGF secretion and decreased the nuclear staining of STAT3. CONCLUSION: Apigenin exerts its antiproliferative activity by inhibiting STAT3 signaling. Apigenin could serve as a useful compound to prevent or treat HER2-overexpressing breast cancer.
Haghighitalab A, Matin MM, Bahrami AR, et al. In vitro investigation of anticancer, cell-cycle-inhibitory, and apoptosis-inducing effects of diversin, a natural prenylated coumarin, on bladder carcinoma cells. Z Naturforsch C. 2014 Mar-Apr; 69(3-4):99-109 [PubMed] Related Publications
Chemotherapy is one of the main strategies for reducing the rate of cancer progression or, in some cases, curing the tumour. Since a great number of chemotherapeutic agents are cytotoxic compounds, i. e. similarly affect normal and neoplastic cells, application of antitumour drugs is preferred in cancer management and therapy. In this study, the cytotoxicity of diversin was evaluated in 5637 cells, a transitional cell carcinoma (TCC) subline (bladder carcinoma), and normal human fibroblast cells using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Chromatin condensation and DNA damage induced by diversin were also determined by means of 4',6-diamidino-2-phenylindole (DAPI) staining and the comet assay, respectively. In addition, the mechanism of action of diversin was studied in more detail by the caspase 3 colourimetric assay and flow cytometry-based cell-cycle analyses (PI staining). Our results revealed that diversin has considerable cytotoxic effects in 5637 cells, but not on HFF3 (human foreskin fibroblast) and HDF1 (human dermal fibroblast) cells. Further studies showed that diversin exerts its cytotoxicity via induction of chromatin condensation, DNA damage, and activation of caspase 3 in 5637 cells. In addition, flow cytometric analyses revealed that 5637 cells are mostly arrested at the G2 phase of the cell cycle in the presence of diversin.
Yun HS, Baek JH, Yim JH, et al. Knockdown of hepatoma-derived growth factor-related protein-3 induces apoptosis of H1299 cells via ROS-dependent and p53-independent NF-κB activation. Biochem Biophys Res Commun. 2014; 449(4):471-6 [PubMed] Related Publications
We previously identified hepatoma-derived growth factor-related protein-3 (HRP-3) as a radioresistant biomarker in p53 wild-type A549 cells and found that p53-dependent induction of the PUMA pathway was a critical event in regulating the radioresistant phenotype. Here, we found that HRP-3 knockdown regulates the radioresistance of p53-null H1299 cells through a distinctly different molecular mechanism. HRP-3 depletion was sufficient to cause apoptosis of H1299 cells by generating substantial levels of reactive oxygen species (ROS) through inhibition of the Nrf2/HO-1 antioxidant pathway. Subsequent, ROS-dependent and p53-independent NF-κB activation stimulated expression of c-Myc and Noxa proteins, thereby inducing the apoptotic machinery. Our results thus extend the range of targets for the development of new drugs to treat both p53 wild-type or p53-null radioresistant lung cancer cells.
Gao B, Shi HL, Li X, et al. p38 MAPK and ERK1/2 pathways are involved in the pro-apoptotic effect of notoginsenoside Ft1 on human neuroblastoma SH-SY5Y cells. Life Sci. 2014; 108(2):63-70 [PubMed] Related Publications
AIMS: This study aims to investigate the effect and the mechanisms of notoginsenoside Ft1, a natural compound exclusively found in P. notoginseng, on the proliferation and apoptosis of human neuroblastoma SH-SY5Y cells. MAIN METHODS: CCK-8 assay was used to assess the cell proliferation. Flow cytometry was performed to measure the cell cycle distribution and cell apoptosis. Hoechst 33258 staining was conducted to confirm the morphological changes of apoptotic cells. Protein expression was detected by western blot analysis and caspase 3 activity was measured by colorimetric assay kit. KEY FINDINGS: Among the saponins examined, Ft1 showed the best inhibitory effect on cell proliferation of SH-SY5Y cells with IC50 of 45μM. Ft1 not only arrested the cell cycle at S, G2/M stages, but also promoted cell apoptosis, which was confirmed by Hoechst 33258 staining. Further studies demonstrated that Ft1 up-regulated the protein expressions of cleaved caspase 3, phospho-p53, p21, and cyclin B1, but down-regulated that of Bcl-2. Moreover, Ft1 enhanced the phosphorylation of ERK1/2, JNK and p38 MAPK. However, the phosphorylation of Jak2 and p85 PI3K was reduced by Ft1. Inhibitors of p38 MAPK and ERK1/2 but not JNK abrogated the up-regulated protein expressions of cleaved caspase 3, p21 and down-regulated protein expression of Bcl-2 as well as elevated caspase 3 activity induced by Ft1. SIGNIFICANCE: Ft1 arrested the proliferation and elicited the apoptosis of SH-SY5Y cells possibly via p38 MAPK and ERK1/2 pathways, which indicates the potential therapeutic effect of it on human neuroblastoma.
Colis LC, Woo CM, Hegan DC, et al. The cytotoxicity of (-)-lomaiviticin A arises from induction of double-strand breaks in DNA. Nat Chem. 2014; 6(6):504-10 [PubMed] Article available free on PMC after 01/12/2014 Related Publications
The metabolite (-)-lomaiviticin A, which contains two diazotetrahydrobenzo[b]fluorene (diazofluorene) functional groups, inhibits the growth of cultured human cancer cells at nanomolar-picomolar concentrations; however, the mechanism responsible for the potent cytotoxicity of this natural product is not known. Here we report that (-)-lomaiviticin A nicks and cleaves plasmid DNA by a pathway that is independent of reactive oxygen species and iron, and that the potent cytotoxicity of (-)-lomaiviticin A arises from the induction of DNA double-strand breaks (dsbs). In a plasmid cleavage assay, the ratio of single-strand breaks (ssbs) to dsbs is 5.3 ± 0.6:1. Labelling studies suggest that this cleavage occurs via a radical pathway. The structurally related isolates (-)-lomaiviticin C and (-)-kinamycin C, which contain one diazofluorene, are demonstrated to be much less effective DNA cleavage agents, thereby providing an explanation for the enhanced cytotoxicity of (-)-lomaiviticin A compared to that of other members of this family.
Zhang S, Yu M, Deng H, et al. Polyclonal rabbit anti-human ovarian cancer globulins inhibit tumor growth through apoptosis involving the caspase signaling. Sci Rep. 2014; 4:4984 [PubMed] Article available free on PMC after 01/12/2014 Related Publications
Most women with ovarian cancer are diagnosed at an advanced stage and there are few therapeutic options. Recently, monoclonal antibody therapies have had limited success, thus more effective antibodies are needed to improve long-term survival. In this report, we prepared polyclonal rabbit anti-ovarian cancer antibody (Poly Ab) by immunizing rabbits with the human ovarian cancer cell line SKOV3. The Poly Ab bound to SKOV3 and inhibited the cancer cells proliferation. Western blot analysis was conducted, which indicated that Poly Ab inhibited cancer cells through apoptosis involving the caspase signaling pathway including caspase-3 and caspase-9. Finally, compared with the control antibody, administration of Poly Ab reached 64% and 72% tumor inhibition in the subcutaneous and intraperitoneal xenograft mouse model, respectively. Our findings suggest that Poly Ab is an effective agent for apoptosis induction and may be useful as a safe anticancer agent for ovarian cancer therapy.
Wiener Z, Band AM, Kallio P, et al. Oncogenic mutations in intestinal adenomas regulate Bim-mediated apoptosis induced by TGF-β. Proc Natl Acad Sci U S A. 2014; 111(21):E2229-36 [PubMed] Article available free on PMC after 01/12/2014 Related Publications
In the majority of microsatellite-stable colorectal cancers (CRCs), an initiating mutation occurs in the adenomatous polyposis coli (APC) or β-catenin gene, activating the β-catenin/TCF pathway. The progression of resulting adenomas is associated with oncogenic activation of KRas and inactivation of the p53 and TGF-β/Smad functions. Most established CRC cell lines contain mutations in the TGF-β/Smad pathway, but little is known about the function of TGF-β in the early phases of intestinal tumorigenesis. We used mouse and human ex vivo 3D intestinal organoid cultures and in vivo mouse models to study the effect of TGF-β on the Lgr5(+) intestinal stem cells and their progeny in intestinal adenomas. We found that the TGF-β-induced apoptosis in Apc-mutant organoids, including the Lgr5(+) stem cells, was mediated by up-regulation of the BH3-only proapoptotic protein Bcl-2-like protein 11 (Bim). BH3-mimetic compounds recapitulated the effect of Bim not only in the adenomas but also in human CRC organoids that had lost responsiveness to TGF-β-induced apoptosis. However, wild-type intestinal crypts were markedly less sensitive to TGF-β than Apc-mutant adenomas, whereas the KRas oncogene increased resistance to TGF-β via the activation of the Erk1/2 kinase pathway, leading to Bim down-regulation. Our studies identify Bim as a critical mediator of TGF-β-induced apoptosis in intestinal adenomas and show that the common progression mutations modify Bim levels and sensitivity to TGF-β during intestinal adenoma development.
Li X, Wang FS, Wu ZY, et al. MicroRNA-19b targets Mfn1 to inhibit Mfn1-induced apoptosis in osteosarcoma cells. Neoplasma. 2014; 61(3):265-73 [PubMed] Related Publications
Accumulative evidence has confirmed that, miR-17-92, a typical polycistronic mRNA cluster, was up-regulated in various solid tumors, and play an important role in the occurrence and development progress of tumors. In our study, we detected the six members of miR-17-92 cluster in osteosarcoma cell line, finding that the expression of miR-17 and miR-19b was up-regulated significantly. Further studies have found that Mfn1 was one of the target genes of miR-19b and the transcription and expression level of Mfn1 were down-regulated by miR-19b. MTS, flow cytometry, TUNEL-DAPI, Annexin V-FITC and transwell assay demonstrated that Mfn1 significantly blocked the cell cycle, promoted apoptosis and inhibited proliferation and invasion of osteosarcoma cells. Whereas, miR-19b targets 3'UTR sequences of Mfn1 genes inhibit the expression of Mfn1, thus inhibited Mfn1 triggered anti-cancer effect. Taken together, miR-19b functions by targeting Mfn1 reduce the protein expression level, thus provides a novel target to understand the molecular biology and genetics mechanisms of occurrence and development of osteosarcoma, contributing to the diagnosis and therapy of osteosarcoma.
Liou JS, Wu YC, Yen WY, et al. Inhibition of autophagy enhances DNA damage-induced apoptosis by disrupting CHK1-dependent S phase arrest. Toxicol Appl Pharmacol. 2014; 278(3):249-58 [PubMed] Related Publications
DNA damage has been shown to induce autophagy, but the role of autophagy in the DNA damage response and cell fate is not fully understood. BO-1012, a bifunctional alkylating derivative of 3a-aza-cyclopenta[a]indene, is a potent DNA interstrand cross-linking agent with anticancer activity. In this study, BO-1012 was found to reduce DNA synthesis, inhibit S phase progression, and induce phosphorylation of histone H2AX on serine 139 (γH2AX) exclusively in S phase cells. Both CHK1 and CHK2 were phosphorylated in response to BO-1012 treatment, but only depletion of CHK1, but not CHK2, impaired BO-1012-induced S phase arrest and facilitated the entry of γH2AX-positive cells into G2 phase. CHK1 depletion also significantly enhanced BO-1012-induced cell death and apoptosis. These results indicate that BO-1012-induced S phase arrest is a CHK1-dependent pro-survival response. BO-1012 also resulted in marked induction of acidic vesicular organelle (AVO) formation and microtubule-associated protein 1 light chain 3 (LC3) processing and redistribution, features characteristic of autophagy. Depletion of ATG7 or co-treatment of cells with BO-1012 and either 3-methyladenine or bafilomycin A1, two inhibitors of autophagy, not only reduced CHK1 phosphorylation and disrupted S phase arrest, but also increased cleavage of caspase-9 and PARP, and cell death. These results suggest that cells initiate S phase arrest and autophagy as pro-survival responses to BO-1012-induced DNA damage, and that suppression of autophagy enhances BO-1012-induced apoptosis via disruption of CHK1-dependent S phase arrest.
Wu T, Chen W, Liu S, et al. Huaier suppresses proliferation and induces apoptosis in human pulmonary cancer cells via upregulation of miR-26b-5p. FEBS Lett. 2014; 588(12):2107-14 [PubMed] Related Publications
Various studies have reported that Huaier possesses anti-tumor effects. However, the mechanisms are not completely elucidated. Here, we found 66 differentially expressed miRNAs in Huaier-treated pulmonary adenocarcinoma A549 cells, with upregulation of miR-26b-5p. Transfection of A549 cells with miR-26b-5p mimic inhibited proliferation and induced apoptosis, while transfection of Huaier-treated A549 cells with a miR-26b-5p inhibitor reversed the effects of Huaier. EZH2 was verified as the target of miR-26b-5p. Thus, our findings indicate that Huaier might suppress proliferation and induce apoptosis in lung cancer cells via a miR-26b-5p-EZH2-mediated approach, which provides a new perspective for understanding the anti-tumor effects of Huaier.
Zhang S, Wang Y, Li SJ Lansoprazole induces apoptosis of breast cancer cells through inhibition of intracellular proton extrusion. Biochem Biophys Res Commun. 2014; 448(4):424-9 [PubMed] Related Publications
The increased glycolysis and proton secretion in tumors is proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. Here, treatment of human breast cancer cells with proton pump inhibitor (PPI) lansoprazole (LPZ) induces cell apoptosis in a dose-dependent manner. In the implantation of the MDA-MB-231 xenografts in nude mice, administration of LPZ significantly inhibits tumorigenesis and induces large-scale apopotosis of tumor cells. LPZ markedly inhibits intracellular proton extrusion, induces an increase in intracellular ATP level, lysosomal alkalinization and accumulation of reactive oxygen species (ROS) in breast cancer cells. The ROS scavenger N-acetyl-l-cysteine (NAC) and diphenyleneiodonium (DPI), a specific pharmacological inhibitor of NADPH oxidases (NOX), significantly abolish LPZ-induced ROS accumulation in breast cancer cells. Our results suggested that LPZ may be used as a new therapeutic drug for breast tumor.
Alves ID, Carré M, Montero MP, et al. A proapoptotic peptide conjugated to penetratin selectively inhibits tumor cell growth. Biochim Biophys Acta. 2014; 1838(8):2087-98 [PubMed] Related Publications
The peptide KLA (acetyl-(KLAKLAK)2-NH2), which is rather non toxic for eukaryotic cell lines, becomes active when coupled to the cell penetrating peptide, penetratin (Pen), by a disulfide bridge. Remarkably, the conjugate KLA-Pen is cytotoxic, at low micromolar concentrations, against a panel of seven human tumor cell lines of various tissue origins, including cells resistant to conventional chemotherapy agents but not to normal human cell lines. Live microscopy on cells possessing fluorescent labeled mitochondria shows that in tumor cells, KLA-Pen had a strong impact on mitochondria tubular organization instantly resulting in their aggregation, while the unconjugated KLA and pen peptides had no effect. But, mitochondria in various normal cells were not affected by KLA-Pen. The interaction with membrane models of KLA-Pen, KLA and penetratin were studied using dynamic light scattering, calorimetry, plasmon resonance, circular dichroism and ATR-FTIR to unveil the mode of action of the conjugate. To understand the selectivity of the conjugate towards tumor cell lines and its action on mitochondria, lipid model systems composed of zwitterionic lipids were used as mimics of normal cell membranes and anionic lipids as mimics of tumor cell and mitochondria membrane. A very distinct mode of interaction with the two model systems was observed. KLA-Pen may exert its deleterious and selective action on cancer cells by the formation of pores with an oblique membrane orientation and establishment of important hydrophobic interactions. These results suggest that KLA-Pen could be a lead compound for the design of cancer therapeutics.
Kim YJ, Choi WI, Jeon BN, et al. Stereospecific effects of ginsenoside 20-Rg3 inhibits TGF-β1-induced epithelial-mesenchymal transition and suppresses lung cancer migration, invasion and anoikis resistance. Toxicology. 2014; 322:23-33 [PubMed] Related Publications
The epithelial-mesenchymal transition (EMT) is a pivotal cellular process during which epithelial polarized cells become motile mesenchymal-appearing cells, which, in turn, promotes the metastatic potential of cancer. Ginseng is a perennial plant belonging to the genus Panax that exhibits a wide range of pharmacological and physiological activities. Ginsenosides 20-Rg3, which is the active component of ginseng, has various medical effects, such as anti-tumorigenic, anti-angiogenesis, and anti-fatiguing activities. In addition, ginsenosides 20(S)-Rg3 and 20(R)-Rg3 are epimers, and this epimerization is produced by steaming. However, the possible role of 20(S)-Rg3 and 20(R)-Rg3 in the EMT is unclear. We investigated the effect of 20(S)-Rg3 and 20(R)-Rg3 on the EMT. Transforming growth factor-beta 1 (TGF-β1) induces the EMT to promote lung adenocarcinoma migration, invasion, and anoikis resistance. To understand the repressive role of 20(S)-Rg3 and 20(R)-Rg3 in lung cancer migration, invasion, and anoikis resistance, we investigated the potential use of 20(S)-Rg3 and 20(R)-Rg3 as inhibitors of TGF-β1-induced EMT development in A549 lung cancer cells in vitro. Here, we show that 20(R)-Rg3, but not 20(S)-Rg3, markedly increased expression of the epithelial marker E-cadherin and repressed Snail upregulation and expression of the mesenchymal marker vimentin during initiation of the TGF-β1-induced EMT. 20(R)-Rg3 also inhibited the TGF-β1-induced increase in cell migration, invasion, and anoikis resistance of A549 lung cancer cells. Additionally, 20(R)-Rg3 markedly inhibited TGF-β1-regulated matrix metalloproteinase-2 and activation of Smad2 and p38 mitogen activated protein kinase. Taken together, our findings provide new evidence that 20(R)-Rg3 suppresses lung cancer migration, invasion, and anoikis resistance in vitro by inhibiting the TGF-β1-induced EMT.
Peiffer L, Poll-Wolbeck SJ, Flamme H, et al. Trichostatin A effectively induces apoptosis in chronic lymphocytic leukemia cells via inhibition of Wnt signaling and histone deacetylation. J Cancer Res Clin Oncol. 2014; 140(8):1283-93 [PubMed] Related Publications
BACKGROUND: The ontogenetic Wnt pathway shows almost no activity in adult tissues. In contrast, chronic lymphocytic leukemia (CLL) cells show constitutionally active Wnt signaling, which is associated with upregulated levels of pathway members such as Wnt3 and lymphoid enhancer-binding factor-1. Functionally, this results in increased resistance to apoptosis. We therefore assumed that targeting members of the pathway could reveal new therapeutic options for the treatment of CLL. METHODS: Screening a Wnt compound library with 75 Wnt modulators via ATP assay revealed Trichostatin A as an outstanding substance with strong viability decreasing effects on CLL cells and little effect on healthy peripheral blood mononuclear cells (PBMCs). Further survival analysis was performed via fluorescence-activated cell sorting analysis. RESULTS: A maximum effect was achieved after 48 h with a wide therapeutic window in contrast to PBMCs (CLL cells: 0.253 µM, PBMCs: 145.22 µM). Trichostatin A induced caspases and acted via a dual mechanism to reveal histone and non-histone targets. Histone targets were displayed in deacetylation inhibition at DNA level, and non-histone targeting was demonstrated by elevated levels of Dickkopf-related protein 1 mRNA. Primary cells of patients with critical mutations such as TP53 or those who had already undergone extensive previous treatment responded well to the treatment. Moreover, the approved histone deacetylase (HDAC) inhibitor suberoylanilidehydroxamic acid (SAHA) was not as effective as Trichostatin A (Trichostatin A: 0.253 µM, SAHA: 7.88 µM). Combining Trichostatin A with established CLL drugs fludarabine or bendamustine showed an additive effect in vitro. CONCLUSION: Taken together, Trichostatin A appears to act via a dual anti-HDAC/Wnt mechanism with a high selectivity and efficacy in CLL and therefore warrants further investigation.
Ye L, Yao XD, Wan FN, et al. MS4A8B promotes cell proliferation in prostate cancer. Prostate. 2014; 74(9):911-22 [PubMed] Related Publications
BACKGROUND: Prostate cancer cells must maintain or achieve the further ability of proliferation during the progression. The molecular mechanisms, however, remain poorly understood. We identified a novel oncogene, termed membrane-spanning 4-domains, subfamily A, member 8B (MS4A8B), over-expressed in prostate cancer. METHODS: We firstly detected MS4A8B mRNA in 13 types of paired human normal and cancer tissues by real-time polymerase chain reaction (RT-PCR). In 140 clinically localized prostate cancer samples from radical prostatectomy, immunohistochemical staining was performed to study MS4A8B and PCNA protein level as an index of proliferative activity, TUNEL staining as an index of apoptosis. As MS4A8B RNAi and cDNA transfection technologies were used, the effect of MS4A8B on cellular vitality was determined in vitro and in vivo. RESULTS: MS4A8B mRNA was over-expressed specifically in prostate cancer. Positive ratios of MS4A8B protein expression were 1.94%, 5.92%, and 62.8% in benign, HPIN and prostate cancer, respectively. Moreover, MS4A8B was positively associated with Gleason score, the proliferation index. In vitro, MS4A8B knockdown resulted in G1 -S cell cycle arrest and descended vitality, MS4A8B over-expression with accelerated S phase entry, elevated vitality in prostate cancer cells. Moreover, it was also found that expression of MS4A8B led to changes of Cyclin D1 , Cyclin E1 and PCNA. LNCaP cells transfected with sh-MS4A8B lentivirus particles grew more slowly when subcutaneously injected into the flanks of nude mice. CONCLUSIONS: We conclude that the expression of MS4A8B expression promotes cell proliferation and plays an important role in carcinogenesis and progression of prostate cancer.
Kwon HY, Kim KS, An HK, et al. Triptolide induces apoptosis through extrinsic and intrinsic pathways in human osteosarcoma U2OS cells. Indian J Biochem Biophys. 2013; 50(6):485-91 [PubMed] Related Publications
Triptolide, a diterpene derived from Tripterygium wilfordii Hook f., a Chinese medicinal herb, has been reported to inhibit cell proliferation and induce apoptosis in various human cancer cells, but its anticancer effects on human osteosarcoma cells have not yet been elucidated. In this study, we investigated whether triptolide induces apoptosis in human osteosarcoma cells and the underlying molecular mechanisms. We firstly demonstrated that triptolide inhibited cell growth and induced apoptosis in U2OS cells. Western blot analysis showed that the levels of procaspase-8, -9, Bcl-2, Bid and mitochondrial cytochrome c were downregulated in triptolide-treated U2OS cells, whereas the levels of Fas, FasL, Bax, cytosolic cytochrome c, cleaved caspase-3 and cleaved PARP were upregulated. These results suggest that triptolide induces apoptosis in U2OS cells by activating both death receptor and mitochondrial apoptotic pathways.
Hosoi T, Inoue Y, Nakatsu K, et al. TERT attenuated ER stress-induced cell death. Biochem Biophys Res Commun. 2014; 447(2):378-82 [PubMed] Related Publications
Tumor cells are frequently encountered in nutrient-deprived areas, though the mechanisms underlying their survival are unclear. In the present study, we found that depriving cells of glucose caused endoplasmic reticulum stress (ER stress) in a breast cancer cells line, MCF-7, and that specific activation of ER stress increased telomerase reverse transcriptase (TERT) expression. TERT expression would function in counteracting against the stress because over-expression of TERT diminished ER stress-induced cell death. Therefore, the results provide evidence for the underlying mechanisms of tumor progression in stressed conditions, highlighting that ER stress induces TERT expression to withstand environmental stress, a mechanism which we termed the "ER stress-TERT axis".
Shen P, Sun J, Xu G, et al. KLF9, a transcription factor induced in flutamide-caused cell apoptosis, inhibits AKT activation and suppresses tumor growth of prostate cancer cells. Prostate. 2014; 74(9):946-58 [PubMed] Related Publications
BACKGROUND: Kruppel-like factors (KLFs) are involved in various biological processes; emerging studies have indicated that KLF9 plays a critical role in regulating tumorigenesis. The role of KLF9 in prostate cancer (PCa), however, has not yet been investigated. METHODS: The expression of KLF members, AKT- and apoptosis-related proteins were analyzed by Western blot or qRT-PCR. Tet-On inducible KLF9 expression was established for the evaluation of the effects of KLF9 on cell proliferation, apoptosis, and xenograft tumor growth in nude mice. Cell cycle and apoptosis were determined by flow cytometry. RESULTS: KLF9 was induced in a time-dependent manner in flutamide-caused apoptosis, and knockdown of KLF9 significantly decreased flutamide-induced growth inhibition and apoptosis in LNCaP cells. The levels of KLF9 were relatively lower in PCa cell lines, particularly in androgen-independent cell lines compared with those in nontumorous prostate epithelial cell lines. Overexpression of KLF9 dramatically suppressed cell proliferation and caused cell cycle arrest in the G2/M phase and cell apoptosis in the androgen-independent cell lines, PC3 and DU145. Intriguingly, KLF9 expression severely suppressed the activation of AKT and its downstream targets. AKT reactivation partially rescued the KLF9-mediated inhibitory effects on the proliferation of PCa cells. More importantly, we found that KLF9 overexpression efficiently inhibited the xenograft tumor growth of PCa cells. CONCLUSIONS: These data collectively showing that KLF9 substantially inhibits AKT activation and abrogates tumor growth of PCa cells, suggest the potential of either genetic or pharmacological activation of KLF9 in the therapeutic treatment of castration-resistant PCa.
Cárdenas C, Quesada AR, Medina MÁ Insights on the antitumor effects of kahweol on human breast cancer: decreased survival and increased production of reactive oxygen species and cytotoxicity. Biochem Biophys Res Commun. 2014; 447(3):452-8 [PubMed] Related Publications
The present study aims to identify the modulatory effects of kahweol, an antioxidant diterpene present in coffee beans, on a panel of human tumor cell lines. Kahweol inhibits tumor cell proliferation and clonogenicity and induces apoptosis in several kinds of human tumor cells. In the estrogen receptor-negative MDA-MB231 human breast cancer, the mentioned effects are accompanied by caspases 3/7 and 9 activation and cytochrome c release. On the other hand, kahweol increases the production of reactive oxygen species and their cytotoxicity in human breast cancer cells but not in normal cells. Taken together, our data suggest that kahweol is an antitumor compound with inhibitory effects on tumor cell growth and survival, especially against MDA-MB231 breast cancer cells.
Sun C, Xu S, Guo J, et al. The inhibitory and apoptotic effects of docetaxel-loaded mesoporous magnetic colloidal nanocrystal clusters on bladder cancer T24 cells in vitro. J Biomed Nanotechnol. 2014; 10(3):455-62 [PubMed] Related Publications
Mesoporous magnetic colloidal nanocrystal clusters (MCNCs) are featured with high magnetization, adequate surface area, excellent colloidal stability, good biocompatibility, and acid degradability. It is thus highly anticipated that MCNCs can serve as vehicles for target drug delivery. Herein, the mesoporous MCNCs stabilized by poly(gamma-glutamic acid) (PGA) were fabricated by the modified solvothermal route, showing a high specific surface area (126.4 m2/g), strong magnetic response (63 emu/g) and appropriate mesoporosity including a large pore volume (0.27 cm3/g) and accessible pore size (8.1 nm). Docetaxel (DOC) was then loaded in the resultant MCNCs using the nanoprecipitation method, and a high drug loading capacity was achieved up to 24 wt%. The chemotherapeutic effect and mechanism of DOC-MCNC conjugates in bladder cancer was evaluated in vitro. A series of analyses for cell uptake, cell viability, cell cycle, cell apoptosis and some cell proteins were performed by transmission electron microscopy, MTT assay, flow cytometry, cell nuclei staining, Annexin V staining assay, western blot assay and caspase-3 activity assay, respectively. The results demonstrated that DOC-MCNC conjugates enhanced the inhibitory effect by hampering mitoschisis and increased the apoptotic effect by changing the expression of apoptosis-related proteins in T24 cells, substantially proving their remarkable efficiency in treatment of bladder cancer.
Guo Y, Shan Q, Gong Y, et al. Curcumin induces apoptosis via simultaneously targeting AKT/mTOR and RAF/MEK/ERK survival signaling pathways in human leukemia THP-1 cells. Pharmazie. 2014; 69(3):229-33 [PubMed] Related Publications
BACKGROUND: Curcumin is a multi-targeted anti-cancer agent. However, there are few studies on its anti-leukemia activity in human acute monocytic leukemia. Here, we study the effect and mechanisms of curcumin on acute monocytic leukemia. METHODS: The acute monocytic leukemia cell line THP-1 was used as in vitro cell model to explore the anti-leukemia effects and mechanisms of curcumin. Cell proliferation was measured by MTT assay, cell apoptosis bodies were observed using a light microscope, cell apoptosis rate was evaluated by flow cytometry, and the expression alterations of growth-sinaling proteins were detected by Western blotting. RESULTS: Curcumin inhibited cell proliferation and induced cell apoptosis in time- and dose- dependent manner in THP-1 cells. Curcumin significantly inhibited the activations of AKT/mTOR and RAF/MEK/ERK signaling pathways simultaneously. CONCLUSION: This study demonstrates that curcumin inhibits proliferation and induces apoptosis in THP-1 cells via inhibiting the activations of AKT/mTOR and RAF/MEK/ERK signaling pathways simultaneously. Our data suggest that curcumin is a promising anti-tumor agent in acute monocytic leukemia.
Amato KR, Wang S, Hastings AK, et al. Genetic and pharmacologic inhibition of EPHA2 promotes apoptosis in NSCLC. J Clin Invest. 2014; 124(5):2037-49 [PubMed] Article available free on PMC after 01/12/2014 Related Publications
Genome-wide analyses determined previously that the receptor tyrosine kinase (RTK) EPHA2 is commonly overexpressed in non-small cell lung cancers (NSCLCs). EPHA2 overexpression is associated with poor clinical outcomes; therefore, EPHA2 may represent a promising therapeutic target for patients with NSCLC. In support of this hypothesis, here we have shown that targeted disruption of EphA2 in a murine model of aggressive Kras-mutant NSCLC impairs tumor growth. Knockdown of EPHA2 in human NSCLC cell lines reduced cell growth and viability, confirming the epithelial cell autonomous requirements for EPHA2 in NSCLCs. Targeting EPHA2 in NSCLCs decreased S6K1-mediated phosphorylation of cell death agonist BAD and induced apoptosis. Induction of EPHA2 knockdown within established NSCLC tumors in a subcutaneous murine model reduced tumor volume and induced tumor cell death. Furthermore, an ATP-competitive EPHA2 RTK inhibitor, ALW-II-41-27, reduced the number of viable NSCLC cells in a time-dependent and dose-dependent manner in vitro and induced tumor regression in human NSCLC xenografts in vivo. Collectively, these data demonstrate a role for EPHA2 in the maintenance and progression of NSCLCs and provide evidence that ALW-II-41-27 effectively inhibits EPHA2-mediated tumor growth in preclinical models of NSCLC.
Chaotham C, Pongrakhananon V, Sritularak B, Chanvorachote P A Bibenzyl from Dendrobium ellipsophyllum inhibits epithelial-to-mesenchymal transition and sensitizes lung cancer cells to anoikis. Anticancer Res. 2014; 34(4):1931-8 [PubMed] Related Publications
BACKGROUND: Anti-metastasis therapy may become the potential means of improving survival of cancer patients. As the ability of cancer cells to change phenotype from epithelial to mesenchymal has been recognized as an important hallmark of cancer metastasis, this study provides information regarding the effect of a bibenzyl, namely 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl (TDB), isolated from Dendrobium ellipsophyllum, in inhibiting epithelial-to-mesenchymal transition (EMT) and sensitization of lung cancer cells to anoikis. MATERIALS AND METHODS: Human lung cancer H292 cells were treated with non-cytotoxic doses of TDB for 24 h prior to evaluation of anoikis and anchorage-independent growth. The proteins relevant to EMT and anoikis resistance were examined in TDB-treated H292 cells via western blot analysis. RESULTS: A significant increase in apoptosis induced by cell detachment was found in TDB-treated H292 cells. The formation of tumor in anchorage-independent growth assay was found to be dramatically reduced in response to the compound. Furthermore, western blot analysis of proteins involved in EMT revealed that treatment with TDB resulted in the increase of E-cadherin and the decrease of vimentin and transcription factor SNAIL, indicating EMT suppression. Concomitantly with EMT inhibition, the activity of pro-survival pathways, including activated protein kinase B (pAKT) and activated extracellular signal-regulated kinase (pERK), were found to be significantly reduced. CONCLUSION: Because EMT, anoikis resistance and anchorage-independent growth are among important factors facilitating cancer metastasis, TDB shows potential to be developed as an anti-metastasis agent.
Vaeteewoottacharn K, Mitchai M, Srikoon P, et al. Potent reactive oxygen species-JNK-p38 activation by sodium salicylate potentiates death of primary effusion lymphoma cells. Anticancer Res. 2014; 34(4):1865-71 [PubMed] Related Publications
BACKGROUND: Primary effusion lymphoma (PEL) is a rare but aggressive form of non-Hodgkin's B-cell lymphoma in immunodeficient patients. Resistance to conventional chemotherapeutic regimens is common in PEL and contributes to a very poor prognosis; hence, novel potent anti-PEL agents are required. Anticancer effects of non-steroidal anti-inflammatory drugs (NSAIDs) are well-established in epithelial cancer but are unclear in hematological malignancies. Therefore, the anticancer activities of selected NSAIDs, sodium salicylate (NaS), on PEL cell lines are of interest. MATERIALS AND METHODS: Anti-proliferation of NaS on PEL cell lines was shown by MTT. Apoptosis induction and caspase activations were determined by flow cytometry analysis. ROS production was accessed by DCFH-DA. Western blot was performed to determine molecular mechanisms. RESULTS: NaS effectively inhibited cell proliferation of all PEL cell lines. Caspase-dependent apoptosis was demonstrated and simultaneous induction of reactive oxygen species production and c-Jun N-terminal kinases (JNK)-p38 activation was observed prior to apoptosis induction, and these might be responsible for NaS-induced apoptosis. CONCLUSION: Significant anticancer effects of NaS on PEL cell lines were found. A novel role of NaS for PEL treatment is suggested.