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Fulltext Antioxidant and cytotoxic activities of three species of tropical seaweeds

Chia YY, Kanthimathi MS, Khoo KS, Rajarajeswaran J, Cheng HM, Yap WS

BMC Complement Altern Med, 2015;15:339.
PMID: 26415532 DOI: 10.1186/s12906-015-0867-1

Three species of seaweeds (Padina tetrastromatica, Caulerpa racemosa and Turbinaria ornata) are widely consumed by Asians as nutraceutical food due to their antioxidant properties. Studies have shown that these seaweeds exhibit bioactivities which include antimicrobial, antiviral, anti-hypertensive and anticoagulant activities. However, investigations into the mechanisms of action pertaining to the cytotoxic activity of the seaweeds are limited. The aim of this study was to determine the antioxidant and cytotoxic activities of whole extracts of P. tetrastromatica, C. racemosa and T. ornata, including the cellular events leading to the apoptotic cell death of the extract treated-MCF-7 cells. Bioassay guided fractionation was carried out and the compounds identified.

Matched MeSH terms: Apoptosis/drug effects
Fulltext Antiproliferative and Proapoptotic Effects of Labisia pumila Ethanol Extract and Its Active Fraction in Human Melanoma HM3KO Cells

Lope Pihie AH, Zakaria ZA, Othman F

Evid Based Complement Alternat Med, 2012;2012:123470.
PMID: 22474490 DOI: 10.1155/2012/123470

The present study was to determine the anticancer potential of Labisia pumila in in vitro models. Results from the study revealed that ethanol extract of L. pumila was more cytotoxic against HM3KO cells while having reduced effects on nonmalignant cells as compared to aqueous and hexane extracts. Thus, ethanol extract was selected to be further separated by using the bioassay-guided fractionation method to give an active fraction, SF2Lp. Results obtained from the flow cytometry analysis showed that SF2Lp was able to arrest the HM3KO cell cycle at the G1 phase, while morphological findings from AO-EB nuclear staining assays along with the Apoptotic Index confirmed the induction of apoptosis by SF2Lp in HM3KO cells. Results from the mechanistic study further revealed that SF2Lp treatment was able to concurrently increase the expression level of p53 and pro-apoptotic protein Bax and also reduce the expression level of anti-apoptotic protein BCl-2 in HM3KO cells, directly contributing to the increase in Bax/Bcl-2 ratio. These findings, therefore, suggested that L. pumila was able to inhibit HM3KO cell growth possibly by arresting the cell cycle at G1 phase and inducing apoptosis in HM3KO cells via the up- and down-regulation of Bax/Bcl-2 protein, mediated through a p53-dependent pathway.

Matched MeSH terms: Apoptosis; Apoptosis Regulatory Proteins
Fulltext Pharmacological Effects of Grifolin: Focusing on Anticancer Mechanisms

Bouyahya A, El Allam A, Zeouk I, Taha D, Zengin G, Goh BH, et al.

Molecules, 2022 Jan 03;27(1).
PMID: 35011516 DOI: 10.3390/molecules27010284

Grifolin is a volatile compound contained in essential oils of several medicinal plants. Several studies show that this substance has been the subject of numerous pharmacological investigations, which have yielded interesting results. Grifolin demonstrated beneficial effects for health via its multiple pharmacological activities. It has anti-microbial properties against bacteria, fungi, and parasites. In addition, grifolin exhibited remarkable anti-cancer effects on different human cancer cells. The anticancer action of this molecule is related to its ability to act at cellular and molecular levels on different checkpoints controlling the signaling pathways of human cancer cell lines. Grifolin can induce apoptosis, cell cycle arrest, autophagy, and senescence in these cells. Despite its major pharmacological properties, grifolin has only been investigated in vitro and in vivo. Therefore, further investigations concerning pharmacodynamic and pharmacokinetic tests are required for any possible pharmaceutical application of this substance. Moreover, toxicological tests and other investigations involving humans as a study model are required to validate the safety and clinical applications of grifolin.

Matched MeSH terms: Apoptosis/drug effects*
Fulltext Hepatic histopathological and ultrastructural alterations induced by 10 nm silver nanoparticles

Al-Doaiss A, Jarrar Q, Moshawih S

IET Nanobiotechnol, 2020 Jul;14(5):405-411.
PMID: 32691743 DOI: 10.1049/iet-nbt.2020.0039

Silver nanoparticles (Ag NPs) are invested in various sectors and are becoming more persistent in our ambient environment with potential risk on our health and the ecosystems. The current study aims to investigate the histological, histochemical and ultrastructural hepatic changes that might be induced by 10 nm silver nanomaterials. Male mice (BALB/C) were exposed for 35 injections of daily dose of 10 nm Ag NPs (2 mg/kg). Liver tissues were subjected to examination by light and electron microscopy for histological, histochemical and ultrastructural alterations. Exposure to Ag NPs induced Kupffer cells hyperplasia, sinusoidal dilatation, apoptosis, ground glass hepatocytes appearance, nuclear changes, inflammatory cells infiltration, hepatocytes degeneration and necrosis. In addition, 10 nm Ag NPs induced histochemical alterations mainly glycogen depletion with no hemosiderin precipitation. Moreover, these nanomaterials exhibited ultrastructure alterations including mitochondrial swelling and cristolysis, cytoplasmic vacuolation, apoptosis, multilammellar myelin figures formation and endoplasmic destruction and reduction. The findings revealed that Ag NPs can induce alterations in the hepatic tissues, the chemical components of the hepatocytes and in the ultrastructure of the liver. One may also conclude that small size Ag NPs, which are increasingly used in human products could cause various toxigenic responses to all hepatic tissue components.

Matched MeSH terms: Apoptosis/drug effects
Fulltext Anti-proliferative effect and induction of apoptosis in androgen-independent human prostate cancer cells by 1,5-bis(2-hydroxyphenyl)-1,4-pentadiene-3-one

Citalingam K, Abas F, Lajis NH, Othman I, Naidu R

Molecules, 2015 Feb 17;20(2):3406-30.
PMID: 25690296 DOI: 10.3390/molecules20023406

Curcumin has poor in vivo absorption and bioavailability, highlighting a need for new curcumin analogues with better characteristics in these aspects. The aim of this study is to determine the anti-cancer properties of four selected curcumin analogues, on the cytotoxicity, proliferative and apoptotic effects on androgen-independent human prostate cancer cells (PC-3 and DU 145). Initial cytotoxicity screening showed MS17 has the highest cell inhibitory effect, with EC50 values of 4.4 ± 0.3 and 4.1 ± 0.8 µM, followed by MS13 (7.5 ± 0.1 and 7.4 ± 2.6 µM), MS49 (14.5 ± 1.2 and 12.3 ± 2.3 µM) and MS40E (28.0 ± 7.8 and 30.3 ± 1.9 µM) for PC-3 and DU 145 cells, respectively. Time-dependent analysis also revealed that MS13 and MS17 displayed a greater anti-proliferative effect than the other compounds. MS17 was chosen based on the high selectivity index value for further analysis on the morphological and biochemical hallmarks of apoptosis. Fluorescence microscopy analysis revealed apoptotic changes in both treated prostate cancer cells. Relative caspase-3 activity increased significantly at 48 h in PC-3 and 12 h in DU 145 cells. Highest enrichment of free nucleosomes was noted at 48 h after treatment with MS17. In conclusion, MS17 demonstrated anti-proliferative effect and induces apoptosis in a time and dose-dependent manner suggesting its potential for development as an anti-cancer agent for androgen-independent prostate cancer.

Matched MeSH terms: Apoptosis/drug effects*
Fulltext Apoptotic Activity of New Oxisterigmatocystin Derivatives from the Marine-Derived Fungus Aspergillus nomius NC06

Artasasta MA, Yanwirasti Y, Taher M, Djamaan A, Ariantari NP, Edrada-Ebel RA, et al.

Mar Drugs, 2021 Nov 11;19(11).
PMID: 34822502 DOI: 10.3390/md19110631

Sponge-derived fungi have recently attracted attention as an important source of interesting bioactive compounds. Aspergillus nomius NC06 was isolated from the marine sponge Neopetrosia chaliniformis. This fungus was cultured on rice medium and yielded four compounds including three new oxisterigmatocystins, namely, J, K, and L (1, 2, and 3), and one known compound, aspergillicin A (4). Structures of the compounds were elucidated by 1D and 2D NMR spectroscopy and by high-resolution mass spectrometry. The isolated compounds were tested for cytotoxic activity against HT 29 colon cancer cells, where compounds 1, 2, and 4 exhibited IC50 values of 6.28, 15.14, and 1.63 µM, respectively. Under the fluorescence microscope by using a double staining method, HT 29 cells were observed to be viable, apoptotic, and necrotic after treatment with the cytotoxic compounds 1, 2, and 4. The result shows that compounds 1 and 2 were able to induce apoptosis and cell death in HT 29 cells.

Matched MeSH terms: Apoptosis/drug effects
Fulltext Granular Formation during Apoptosis in Blastocystis sp. Exposed to Metronidazole (MTZ)

Dhurga DB, Suresh K, Tan TC

PLoS One, 2016;11(7):e0155390.
PMID: 27471855 DOI: 10.1371/journal.pone.0155390

The role and function of the granular life cycle stage in Blastocystis sp, remains uncertain despite suggestions being made that the granules are metabolic, reproductive and lipid in nature. This present study aims to understand granular formation by triggering apoptosis in Blastocystis sp. by treating them with metronidazole (MTZ). Blastocystis sp.cultures of 4 sub-types namely 1, 2, 3 and 5 when treated with 0.01 and 0.0001 mg/ml of metronidazole (MTZ) respectively showed many of the parasites to be both viable and apoptotic (VA). Treated subtype 3 isolates exhibited the highest number of granular forms i.e. 88% (p<0.001) (0.0001 mg/ml) and 69% (p<0.01) (0.01 mg/ml) respectively at the 72 h in in vitro culture compared to other subtypes. These VA forms showed distinct granules using acridine orange (AO) and 4',6-diamino-2-phenylindole (DAPI) staining with a mean per cell ranging from 5 in ST 5 to as high as 16 in ST 3. These forms showed intact mitochondria in both viable apoptotic (VA) and viable non-apoptotic (VNA) cells with a pattern of accumulation of lipid droplets corresponding to viable cells. Granular VA forms looked ultra-structurally different with prominent presence of mitochondria-like organelle (MLO) and a changed mitochondrial trans-membrane potential with thicker membrane and a highly convoluted inner membrane than the less dense non-viable apoptotic (NVA) cells. This suggests that granular formation during apoptosis is a self-regulatory mechanism to produce higher number of viable cells in response to treatment. This study directs the need to search novel chemotherapeutic approaches by incorporating these findings when developing drugs against the emerging Blastocystis sp. infections.

Matched MeSH terms: Apoptosis/drug effects*
BomMDH1 regulates malate-mediated oxidative stress in tobacco BY-2 suspension cells

Chen H, Cao S, Chen J, Wang H, Wei Y, Chen Y, et al.

J Plant Physiol, 2024 Sep;300:154297.
PMID: 38945071 DOI: 10.1016/j.jplph.2024.154297

Programmed cell death (PCD) is a genetically regulated process of cell suicide essential for plant development. The 'malate valve' is a mechanism that ensures redox balance across different subcellular compartments. In broccoli, the BomMDH1 gene encodes malate dehydrogenase in mitochondria, a critical enzyme in the 'malate circulation' pathway. This study investigates the functional role of BomMDH1 in malate (MA)-induced apoptosis in bright yellow-2 (BY-2) suspension cells. Findings revealed that transgenic cells overexpressing BomMDH1 showed enhanced viability under MA-induced oxidative stress compared to wild-type (WT) cells. Overexpression of BomMDH1 also reduced levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), and malondialdehyde (MDA), while increasing the expression of antioxidant enzyme genes such as NtAPX, NtAOX1a, NtSOD, and NtMDHAR. Additionally, treatment with salicylhydroxamic acid (SHAM), a characteristic inhibitor of mitochondrial respiration, further improved the anti-apoptotic activity of BY-2 cells. Overall, these results highlighted the function of the BomMDH1 gene and the potential of SHAM treatment in mitigating oxidative stress in BY-2 suspension cells.

Matched MeSH terms: Apoptosis/drug effects
Fulltext Adenovirus-mediated expression of MOAP-1, Bax and RASSF1A antagonizes chemo-drug resistance of human breast cancer cells expressing cancer stem cell markers

Tan EW, Abdullah ADI, Ming LC, Poh CL, Goh BH, Lau TP, et al.

Biomed Pharmacother, 2024 Jul;176:116744.
PMID: 38810399 DOI: 10.1016/j.biopha.2024.116744

Cancer is one of the major leading causes of mortality globally and chemo-drug-resistant cancers pose significant challenges to cancer treatment by reducing patient survival rates and increasing treatment costs. Although the mechanisms of chemoresistance vary among different types of cancer, cancer cells are known to share several hallmarks, such as their resistance to apoptosis as well as the ability of cancer stem cells to produce metastatic daughter cells that are resistant to chemotherapy. To address the issue of chemo-drug resistance in cancer cells, a tetracistronic expression construct, Ad-MBR-GFP, encoding adenovirus-mediated expression of MOAP-1, Bax, RASSSF1A, and GFP, was generated to investigate its potential activity in reducing or inhibiting the chemo-drug resistant activity of the human breast cancer cells, MCF-7-CR and MDA-MB-231. When infected by Ad-MBR-GFP, the cancer cells exhibited round cell morphology and nuclei condensation with positive staining for annexin-V. Furthermore, our results showed that both MCF-7-CR and MDA-MB-231 cells stained positively for CD 44 and negatively for CD 24 (CD44+/CD24-) with high levels of endogenous ALDH activity whereas SNU-1581 breast cancer cells were identified as CD 44-/CD 24- cells with relatively low levels of endogenous ALDH activity and high sensitivity toward chemo-drugs, suggesting that both CD 44 and ALDH activity contribute to chemo-drug resistance. Moreover, both MCF-7-CR and MDA-MB-231 cells showed strong chemo-drug sensitivity to cisplatin when the cells were infected by Ad-MBR-GFP, leading to 9-fold and 2-fold reduction in the IC 50 values when compared to cisplatin treatment alone, respectively. The data were further supported by 3D (soft agar) and spheroid cell models of MCF-7-CR and MDA-MB-231 cells which showed a 2-fold reduction of a number of cell colonies and spheroid size when treated with both Ad-MBR-GFP and cisplatin, and compared to control. Other than chemo-sensitivity, Ad-MBR-GFP-infected cancer cells retarded cell migration. Flow cytometry analysis showed that the mechanism of action of Ad-MBR-GFP involved cell cycle arrest at the G1 phase and inhibition of cellular DNA synthesis. Taken together, our investigation showed that Ad-MBR-GFP mediated chemo-drug sensitization in the infected cancer cells involved the activation of apoptosis signaling, cell cycle arrest, and inhibition of DNA synthesis, suggesting that Ad-MBR-GFP is potentially efficacious for the treatment of chemo-drug resistant cancers.

Matched MeSH terms: Apoptosis/drug effects
Inhibition of angiogenesis and metastasis in colorectal cancer cell lines through KRAS-associated signaling pathways by 2-methoxy-6-undecyl-1,4-benzoquinone

Abd Rahman NI, Tham CL, Abd Hamid R

Chem Biol Interact, 2024 Aug 25;399:111151.
PMID: 39025287 DOI: 10.1016/j.cbi.2024.111151

Colorectal cancer (CRC), the third most prevalent cancer globally, presents formidable hurdles in treatment owing to factors such as therapeutic resistance and genetic mutations affecting primary drug targets. 2-methoxy-6-undecyl-1,4-benzoquinone (BQ), derived from Ardisia crispa roots, has emerged as a potent anti-inflammatory and anti-angiogenic compound with substantial potential, as evidenced by previous studies. This study aimed to explore the potential of BQ in suppressing angiogenesis and metastasis in the human CRC cell lines LoVo and HCT116. Various in vitro and in silico studies have been conducted to elucidate the potential pathway(s) of BQ. BQ was highly cytotoxic, with an IC50 of 7.01 ± 0.6 μM in HCT116 and 9.58 ± 0.8 μM in LoVo cells. Moreover, BQ induced notable apoptotic activity and suppressed migration, invasion, and adhesion in both cell lines. The inhibition of MMP-2 suggests the potential of BQ to impede extracellular matrix degradation and CRC cell metastasis. BQ inhibits the expression of key proteins involved in angiogenesis and metastasis, including VEGF-A, VEGF-C, BRAF, ERK, KRAS, PI3K, and AKT. Molecular docking simulations illustrated the robust binding of BQ to CRC protein receptors. BQ holds promise in impeding CRC progression by targeting angiogenesis and metastasis, particularly through inhibition of the KRAS/BRAF/ERK and KRAS/PI3K/AKT signaling pathways.

Matched MeSH terms: Apoptosis/drug effects
Metal Oxide Nanoparticles Exhibit Anti-Acanthamoeba castellanii Properties by Inducing Necrotic Cell Death

Ahmed U, Gew LT, Siddiqui R, Khan NA, Alharbi AM, Alhazmi A, et al.

Acta Parasitol, 2024 Sep;69(3):1717-1723.
PMID: 39153011 DOI: 10.1007/s11686-024-00891-2

PURPOSE: The treatment of amoebic infections is often problematic, largely due to delayed diagnosis, amoebae transformation into resistant cyst form, and lack of availability of effective chemotherapeutic agents. Herein, we determined anti-Acanthamoeba castellanii properties of three metal oxide nanoparticles (TiO2, ZrO2, and Al2O3).
METHODS: Amoebicidal assays were performed to determine whether metal oxide nanoparticles inhibit amoebae viability. Encystation assays were performed to test whether metal oxide nanoparticles inhibit cyst formation. By measuring lactate dehydrogenase release, cytotoxicity assays were performed to determine human cell damage. Hoechst 33342/PI staining was performed to determine programmed cell death (apoptosis) and necrosis in A. castellanii.
RESULTS: TiO2-NPs significantly inhibited amoebae viability as observed through amoebicidal assays, as well as inhibited their phenotypic transformation as evident using encystation assays, and showed limited human cell damage as observed by measuring lactate dehydrogenase assays. Furthermore, TiO2-NPs altered parasite membranes and resulted in necrotic cell death as determined using double staining cell death assays with Hoechst33342/Propidium iodide (PI) observed through chromatin condensation. These findings suggest that TiO2-NPs offers a potential viable avenue in the rationale development of therapeutic interventions against Acanthamoeba infections.

Matched MeSH terms: Apoptosis/drug effects
Vitamin D treatment ameliorates memory function through downregulation of BAX and upregulation of SOD2 mRNA expression in transient global brain ischaemic injury in rats

Zahra F, Sari DCR, Yuniartha R, Alex, Thamrin MM, Melindah T, et al.

Med J Malaysia, 2024 Aug;79(Suppl 4):31-37.
PMID: 39215412

INTRODUCTION: Ischaemic stroke induces oxidative stress with SOD2 downregulation, and BAX upregulation producing apoptosis. Vitamin D is a fat-soluble hormone that has a neuroprotective effect. The aim of this study is to elucidate the role of vitamin D in memory function, oxidative stress and apoptosis in transient global brain schaemic injury (TGBII) model.
MATERIALS AND METHODS: TGBII was performed in male Wistar rats (3 to 5 months, 150 to 300 g) which underwent bilateral common carotid artery occlusion (BCCAO) for 20 minutes, then reperfused for 10 days (BCCAO group, n = 6). Two groups of BCCAO were treated with intraperitoneal injection of calcitriol 0.125 μg/kgBW (VD1 group) and 0.5 μg/kgBW (VD2 group). The spatial memory function was tested using a probe test with Morris water maze (MWM). mRNA expression of BAX and SOD2 were assessed by the RT-PCR method. Meanwhile, immunohistochemical staining was used for identification of SOD2 protein. Statistical analysis is tested using one-way ANOVA followed by post-hoc LSD.
RESULTS: MWM showed a shorter duration in target quadrant of BCCAO group than the SO group, which is associated with BAX upregulation and SOD2 downregulation. The VDtreated groups had longer duration probe test compared to BCCAO. Furthermore, VD-treated groups had a longer duration in probe test with lower mRNA expression of BAX and higher expression of SOD2. However, there was no significant difference in VD1 and VD2. Immunostaining showed a reduced SOD2 signal in pyramidal cell of CA1 area in BCCAO group and ameliorated in VD1 and VD2 groups.
CONCLUSION: Vitamin D ameliorates memory function and attenuates oxidative stress and apoptosis in the TGBII model.

Matched MeSH terms: Apoptosis/drug effects
Hypoxia drives estrogen receptor β-mediated cell growth via transcription activation in non-small cell lung cancer

Su Q, Chen K, Ren J, Zhang Y, Han X, Leong SW, et al.

J Mol Med (Berl), 2024 Dec;102(12):1471-1484.
PMID: 39420137 DOI: 10.1007/s00109-024-02496-8

Non-small cell lung cancer (NSCLC) is a highly malignant tumor with a poor prognosis. Hypoxia conditions affect multiple cellular processes promoting the adaptation and progression of cancer cells via the activation of hypoxia-inducible factors (HIF) and subsequent transcription activation of their target genes. Preliminary studies have suggested that estrogen receptor β (ERβ) might play a promoting role in the progression of NSCLC. However, the precise mechanisms, particularly its connection to HIF-1α-mediated modulation under hypoxia, remain unclear. Our findings demonstrated that the overexpression of ERβ, not ERα, increased cell proliferation and inhibition of apoptosis in NSCLC cells and xenografts. Tissue microarray staining revealed a strong correlation between the protein expression of HIF-1α and ERβ. HIF-1α induced ERβ gene transcription and protein expression in CoCl2-induced hypoxia, 1% O2 incubation, or HIF-1α overexpressing cells. ChIP identified HIF-1α binding to a hypoxia response element in the ESR2 promoter. The suppression of HIF-1α and ERβ both in vitro and in vivo effectively reduced the tumor growth, thus emphasizing the promising prospects of targeting HIF-1α and ERβ as a therapeutic approach for the treatment of NSCLC. KEY MESSAGES: ERβ, not ERα, increases cell proliferation and inhibition of apoptosis in NSCLC cells and xenografts. A strong correlation exists between the protein expression of HIF-1α and ERβ. HIF-1α induced ERβ gene transcription and protein expression in hypoxic cells via binding to HRE in the ESR2 promoter. The suppression of HIF-1α and ERβ both in vitro and in vivo effectively reduced the NSCLC tumor growth.

Matched MeSH terms: Apoptosis/genetics
TRAIL-based tumor sensitizing galactoxyloglucan, a novel entity for targeting apoptotic machinery

Aravind SR, Joseph MM, George SK, Dileep KV, Varghese S, Rose-James A, et al.

Int J Biochem Cell Biol, 2015 Feb;59:153-66.
PMID: 25541375 DOI: 10.1016/j.biocel.2014.11.019

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an attractive target for cancer therapy due to its ability to selectively induce apoptosis in cancer cells, without causing significant toxicity in normal tissues. We previously reported that galactoxyloglucan (PST001) possesses significant antitumor and immunomodulatory properties. However, the exact mechanism in mediating this anticancer effect is unknown. This study, for the first time, indicated that PST001 sensitizes non-small cell lung cancer (A549) and nasopharyngeal (KB) cells to TRAIL-mediated apoptosis. In vitro studies suggested that PST001 induced apoptosis primarily via death receptors and predominantly activated caspases belonging to the extrinsic apoptotic cascade. Microarray profiling of PST001 treated A549 and KB cells showed the suppression of survivin (BIRC5) and anti-apoptotic Bcl-2, as well as increased cytochrome C. TaqMan low density array analysis of A549 cells also confirmed that the induction of apoptosis by the polysaccharide occurred through the TRAIL-DR4/DR5 pathways. This was finally confirmed by in silico analysis, which revealed that PST001 binds to TRAIL-DR4/DR5 complexes more strongly than TNF and Fas ligand-receptor complexes. In summary, our results suggest the potential of PST001 to be developed as an anticancer agent that not only preserves innate biological activity of TRAIL, but also sensitizes cancer cells to TRAIL-mediated apoptosis.

Matched MeSH terms: Apoptosis/drug effects*; Apoptosis Regulatory Proteins; TNF-Related Apoptosis-Inducing Ligand/pharmacology*
Fulltext Regulation of autophagy by polyphenolic compounds as a potential therapeutic strategy for cancer

Hasima N, Ozpolat B

Cell Death Dis, 2014;5:e1509.
PMID: 25375374 DOI: 10.1038/cddis.2014.467

Autophagy, a lysosomal degradation pathway for cellular constituents and organelles, is an adaptive and essential process required for cellular homeostasis. Although autophagy functions as a survival mechanism in response to cellular stressors such as nutrient or growth factor deprivation, it can also lead to a non-apoptotic form of programmed cell death (PCD) called autophagy-induced cell death or autophagy-associated cell death (type II PCD). Current evidence suggests that cell death through autophagy can be induced as an alternative to apoptosis (type I PCD), with therapeutic purpose in cancer cells that are resistant to apoptosis. Thus, modulating autophagy is of great interest in cancer research and therapy. Natural polyphenolic compounds that are present in our diet, such as rottlerin, genistein, quercetin, curcumin, and resveratrol, can trigger type II PCD via various mechanisms through the canonical (Beclin-1 dependent) and non-canonical (Beclin-1 independent) routes of autophagy. The capacity of these compounds to provide a means of cancer cell death that enhances the effects of standard therapies should be taken into consideration for designing novel therapeutic strategies. This review focuses on the autophagy- and cell death-inducing effects of these polyphenolic compounds in cancer.

Matched MeSH terms: Apoptosis/genetics; Apoptosis Regulatory Proteins/genetics; Apoptosis Regulatory Proteins/metabolism
siRNA-mediated inhibition of survivin gene enhances the anti-cancer effect of etoposide in U-937 acute myeloid leukemia cells

Jafarlou M, Baradaran B, Shanehbandi D, Saedi TA, Jafarlou V, Ismail P, et al.

Cell Mol Biol (Noisy-le-grand), 2016 May 30;62(6):44-9.
PMID: 27262801

Acute myeloid leukemia (AML) is one of the most frequent types of leukemia which mostly affects adult people. Resistance to therapeutic drugs is considered as a major clinical concern resulting in a weaker response to chemotherapy, disease relapse and decreased survival rate. Survivin, a member of Inhibitor of Apoptosis Proteins (IAPs), is associated with drug resistance and inhibition of apoptotic mechanisms in numerous hematological malignancies. In the present study, we examined the combined effect of etoposide and siRNA-mediated silencing of survivin on U-937 acute myeloid leukemia cells. The AML cells were transfected with survivin specific siRNA and gene knockdown was confirmed by quantitative real time PCR and western blotting. Subsequently, U-937 cells were assessed for response to etoposide treatment and apoptosis rate was measured with flowcytometery. The cytotoxic effects in siRNA-etoposide group were measured and compared to etoposide single therapy group. Survivin siRNA effectively knocked down the mRNA and protein levels of survivin, which led to lower cell proliferation and enhanced apoptosis. Furthermore, combined treatment of etoposide and survivin siRNA synergistically increased the cell toxic effects of etoposide and its ability to induce apoptosis.

Matched MeSH terms: Apoptosis/drug effects; Inhibitor of Apoptosis Proteins/genetics*; Inhibitor of Apoptosis Proteins/metabolism
Fulltext Flavokawain C exhibits anti-tumor effects on in vivo HCT 116 xenograft and identification of its apoptosis-linked serum biomarkers via proteomic analysis

Phang CW, Abd Malek SN, Karsani SA

Biomed Pharmacother, 2021 May;137:110846.
PMID: 33761587 DOI: 10.1016/j.biopha.2020.110846

Chalcones and their derivatives belong to the flavonoid family. They have been extensively studied for their anticancer properties and some have been approved for clinical use. In this study, the in vivo anti-tumor activity of flavokawain C (FKC), a naturally occurring chalcone found in Kava (Piper methysticum Forst) was evaluated in HCT 116 cells (colon carcinoma). We also attempted to identify potential biomarkers and/or molecular targets in serum with applicability in predicting treatment outcome. The anti-tumor effects and toxicity of FKC were assessed using the xenograft nude mice model. Cisplatin was used as positive control. The anti-proliferative and apoptotic activities were then evaluated in tumor tissues treated with FKC. Furthermore, two-dimensional electrophoresis (2-DE) followed by protein identification using MALDI-TOF/TOF-MS/MS was performed to compare the serum proteome profiles between healthy nude mice and nude mice bearing HCT 116 tumor treated with vehicle solution and FKC, respectively. Our results showed that FKC treatment significantly inhibited HCT 116 tumor growth. In vivo toxicity studies showed that administration of FKC did not cause damage to major organs and had no significant effect on body weight. FKC was found to induce apoptosis in tumor, and this was associated with increased expression of cleaved caspase-3 and decreased expression of Ki67 in tumor tissues. Our proteomic analysis identified five proteins that changed in abundance - Ig mu chain C region (secreted form), GRP78, hemopexin, kininogen-1 and apolipoprotein E. Overall, our findings demonstrated the potential of FKC as an anti-cancer agent for the treatment of colon carcinoma.

Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/genetics*; Apoptosis Regulatory Proteins/genetics*
Fulltext Curcumin Analog DK1 Induces Apoptosis in Human Osteosarcoma Cells In Vitro through Mitochondria-Dependent Signaling Pathway

Aziz MNM, Hussin Y, Che Rahim NF, Nordin N, Mohamad NE, Yeap SK, et al.

Molecules, 2018 Jan 05;23(1).
PMID: 29303982 DOI: 10.3390/molecules23010075

Osteosarcoma is one of the primary malignant bone tumors that confer low survival rates for patients even with intensive regime treatments. Therefore, discovery of novel anti-osteosarcoma drugs derived from natural products that are not harmful to the normal cells remains crucial. Curcumin is one of the natural substances that have been extensively studied due to its anti-cancer properties and is pharmacologically safe considering its ubiquitous consumption for centuries. However, curcumin suffers from a poor circulating bioavailability, which has led to the development of a chemically synthesized curcuminoid analog, namely (Z)-3-hydroxy-1-(2-hydroxyphenyl)-3-phenylprop-2-en-1-one (DK1). In this study, the cytotoxic effects of the curcumin analog DK1 was investigated in both U-2OS and MG-63 osteosarcoma cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell death was microscopically examined via acridine orange/propidium iodide (AO/PI) double staining. Flow cytometer analysis including Annexin V/Fluorescein isothiocyanate (FITC), cell cycle analysis and JC-1 were adapted to determine the mode of cell death. Subsequently in order to determine the mechanism of cell death, quantitative polymerase chain reaction (qPCR) and proteome profiling was carried out to measure the expression of several apoptotic-related genes and proteins. Results indicated that DK1 induced U-2 OS and MG-63 morphological changes and substantially reduced cell numbers through induction of apoptosis. Several apoptotic genes and proteins were steadily expressed after treatment with DK1; including caspase 3, caspase 9, and BAX, which indicated that apoptosis occurred through a mitochondria-dependent signaling pathway. In conclusion, DK1 could be considered as a potential candidate for an anti-osteosarcoma drug in the near future, contingent upon its ability to induce apoptosis in osteosarcoma cell lines.

Matched MeSH terms: Apoptosis/drug effects; Apoptosis Regulatory Proteins/genetics; Apoptosis Regulatory Proteins/metabolism
Molecular docking studies of bioactive compounds from Annona muricata Linn as potential inhibitors for Bcl-2, Bcl-w and Mcl-1 antiapoptotic proteins

Mohamad Rosdi MN, Mohd Arif S, Abu Bakar MH, Razali SA, Mohamed Zulkifli R, Ya'akob H

Apoptosis, 2018 01;23(1):27-40.
PMID: 29204721 DOI: 10.1007/s10495-017-1434-7

Annona muricata Linn or usually identified as soursop is a potential anticancer plant that has been widely reported to contain valuable chemopreventive agents known as annonaceous acetogenins. The antiproliferative and anticancer activities of this tropical and subtropical plant have been demonstrated in cell culture and animal studies. A. muricata L. exerts inhibition against numerous types of cancer cells, involving multiple mechanism of actions such as apoptosis, a programmed cell death that are mainly regulated by Bcl-2 family of proteins. Nonetheless, the binding mode and the molecular interactions of the plant's bioactive constituents have not yet been unveiled for most of these mechanisms. In the current study, we aim to elucidate the binding interaction of ten bioactive phytochemicals of A. muricata L. to three Bcl-2 family of antiapoptotic proteins viz. Bcl-2, Bcl-w and Mcl-1 using an in silico molecular docking analysis software, Autodock 4.2. The stability of the complex with highest affinity was evaluated using MD simulation. We compared the docking analysis of these substances with pre-clinical Bcl-2 inhibitor namely obatoclax. The study identified the potential chemopreventive agent among the bioactive compounds. We also characterized the important interacting residues of protein targets which involve in the binding interaction. Results displayed that anonaine, a benzylisoquinoline alkaloid, showed a high affinity towards the Bcl-2, thus indicating that this compound is a potent inhibitor of the Bcl-2 antiapoptotic family of proteins.

Matched MeSH terms: Apoptosis/drug effects; Apoptosis Regulatory Proteins/antagonists & inhibitors*; Apoptosis Regulatory Proteins/genetics; Apoptosis Regulatory Proteins/metabolism; Apoptosis Regulatory Proteins/chemistry
Antiproliferation and induction of caspase-8-dependent mitochondria-mediated apoptosis by β-tocotrienol in human lung and brain cancer cell lines

Lim SW, Loh HS, Ting KN, Bradshaw TD, Zeenathul NA

Biomed Pharmacother, 2014 Oct;68(8):1105-15.
PMID: 25456851 DOI: 10.1016/j.biopha.2014.10.006

The pure vitamin isomer, β-tocotrienol has the least abundance among the other vitamin E isomers that are present in numerous plants. Hence, it is very scarcely studied for its bioactivity. In this study, the antiproliferative effects and primary apoptotic mechanisms of β-tocotrienol on human lung adenocarcinoma A549 and glioblastoma U87MG cells were investigated. It was evidenced that β-tocotrienol had inhibited the growth of both A549 (GI50=1.38±0.334μM) and U87MG (GI50=2.53±0.604μM) cells at rather low concentrations. Cancer cells incubated with β-tocotrienol were also found to exhibit hallmarks of apoptotic morphologies including membrane blebbing, chromatin condensation and formation of apoptotic bodies. The apoptotic properties of β-tocotrienol in both A549 and U87MG cells were the results of its capability to induce significant (P<0.05) double-strand DNA breaks (DSBs) without involving single-strand DNA breaks (SSBs). β-Tocotrienol is said to induce activation of caspase-8 in both A549 and U87MG cells guided by no activation when caspase-8 inhibitor, z-IETD-fmk was added. Besides, disruption on the mitochondrial membrane permeability of the cells in a concentration- and time-dependent manner had occurred. The induction of apoptosis by β-tocotrienol in A549 and U87MG cells was confirmed to involve both the death-receptor mediated and mitochondria-dependent apoptotic pathways. These findings could potentiate the palm oil derived β-tocotrienol to serve as a new anticancer agent for treating human lung and brain cancers.

Matched MeSH terms: Apoptosis/drug effects; Apoptosis/physiology

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