Antimitotic Compound Research Articles

An anti-mitotic compound, (+)-6-tuliposide A, isolated from the Canadian glacier lily, Erythronium grandiflorum

The Canadian prairie ecosystem is subjected to abiotic and biotic conditions that induce plants to produce secondary metabolites that affect mammalian physiology. Extracts prepared from certain plant species native to Canadian prairie and montane cordillera ecosystems have previously been shown to have anti-mitotic activity on human cancer cell lines. In this study, we investigated the glacier lily, Erythronium grandiflorum (Liliaceae), in which the species was the most phylogenetically distant from Asteraceae and had anti-mitotic activity. When added to cell lines, E. grandiflorum extracts induced rounded cell morphology and arrested cells in the G2/M phase of the cell cycle. Of the cells that displayed a rounded phenotype, all were positive for phospho-histone H3 and contained a distorted mitotic spindle. This anti-mitotic activity was distinct from that of the compound colchicine, which has been previously isolated from the Liliaceae family. By biology-guided fractionation, we isolated the natural product (+)-6-tuliposide A and are the first to report its anti-mitotic activity. These results reveal a chemical motif in secondary metabolites and expand the range of Canadian prairie plants with anti-mitotic activity that can become new scientific tools or used in the development of anti-proliferative medicines.

Poiploidy induction of Indonesian Black Rice Oryza sativa L. Var. Cempo Ireng with Bio-catharantine

High demand on black rice Oryza sativa L. due to their high antioxydant content and better nutrition than the white rice. On the other hand this high price rice still less interest for the farmet to cultivate it. Therefore, improvement of plant characters was carried out through polyploid induction using the natural anti-mitotic compound bio-catharanthine. The purpose of this study was to test the effectiveness of bio-catharanthine in inducing polyploidy in Cemp ireng black rice. This study used a two-factor completely randomized design (CRD) method with three replications. The treatment factor of bio-catharanthine concentration was 1%, 1.5 %, 2 %, 2 %, 2.5 % and 3 % with the soaking time of 48 hours. The germination rate, ploidy level, stomatal size and density, and antioxidant were measuret to observed the characteristic of the mutan. The results showed that the treatments of 3 % bio-catharanthine enhanced the chromosome number of black rice Cempo ireng. Biocatharantine did not affected the germination rate through the treatments. Out mutants shows alternation on the stomatal size and density. The antioxidant of leaf sample did not changed after the treatment. Bio-catharanthine on high concentration migh be possible to be applied on polyploidy induction in black rice

Abstract LB_C10: An orally available small molecule inhibitor for synthetic lethal targeting of MYC expressing tumors

Abstract The potential for synthetic lethality occurs when the same oncogenic events that promote carcinogenesis, also create vulnerabilities for cancer cells. Targeting cancers with these vulnerabilities, but not resident normal tissues, is the promise of synthetic lethal therapies. The compound LC30 is a potent and orally bioavailable compound that is synthetic lethal with deregulated MYC. No off-target liabilities have been demonstrated by kinome and safety profiling and long-term treatment is well tolerated by rodents and canines. LC30 is active against a wide spectrum of cell line xenografts derived from both liquid and solid cancers, including B and T cell malignancies, lung, colon, gastric, mammary and liver cancer cell lines, with efficacy that correlates with levels of MYC. Experiments aimed at unlocking the key to LC30’s synthetic lethality have revealed that LC30 is active in both resting cells and during cell division, so it is not simply an anti-mitotic compound. In resting cells, LC30 disrupts golgi structure, a phenotype that possibly relates to MYC control of centrosomal gene expression. Anti-angiogenic effects are observed in xenografts and have been confirmed using in vitro assays of endothelial cell migration and tubule formation. We speculate that the golgi phenotype and resulting faulty trafficking of secretory vesicles containing pro-angiogenic factors may underly the vascular phenotype. In dividing cells, LC30 potently deregulates the positioning of the chromosomal passenger protein complex (CPPC), a mitotic complex comprised of a catalytic subunit, Aurora B kinase (AURKB), the scaffolding protein inner centromere protein (INCENP) as well as survivin and borealin. The CPPC is dynamically relocated during mitotic progression so that AURKB activity can be localized to specific locations where activity is required. The phenotypic effects of LC30 treatment are consistent with this compound functioning as an inhibitor of the localization, but not catalytic activity of the CPPC. This includes the induction of multipolar spindles, micronuclei and polyploidy, leading to mitotic arrest and both mitotic and post-mitotic apoptosis. This unique mode-of-action, to disrupt CPPC passage in the mitotic cell, is a key component of the MYC synthetic lethality as cells without MYC overexpression do not develop multipolar spindles, lethal polyploidy and apoptose with treatment. LC30 represents a new class of anticancer compound that is a non-kinase, synthetic lethal inhibitor that unlocks MYC-induced vulnerabilities in cancer cells. Citation Format: Qiong Shi, Ting Zhang, Julia Kalashova, Jinhua Li, Chenglu Yang, Hongmei Li, Xiaohu Zhou, Yan Long, Yidan Xia Abuliezi, Gang Lv, Duo Yu, Shenqiu Zhang, Jing Zhang, Thaddeus D Allen, Hong Liu, Dun Yang. An orally available small molecule inhibitor for synthetic lethal targeting of MYC expressing tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_C10.

Design, Synthesis, and Biological Evaluation of SSE1806, a Microtubule Destabilizer That Overcomes Multidrug Resistance.

Microtubules are dynamic structures that form spindle fibers during cell division; pharmacological inhibition of microtubule dynamics arrests cells in mitosis, leading to apoptosis, and they have been extensively used to treat various cancers. However, the efficacy of such drugs is often limited by multidrug resistance. This study synthesized and evaluated 30 novel derivatives of podophyllotoxin, a natural antimitotic compound, for their antiproliferative activities. Compound SSE1806 exhibited the most potent antiproliferative activity with GI50 values ranging from 1.29 ± 0.01 to 21.15 ± 2.1 μM in cancer cell lines of different origins; it directly inhibited microtubule polymerization, causing aberrant mitosis and G2/M arrest. Prolonged treatment with SSE1806 increased p53 expression, induced cell death in monolayer cultures, and reduced the growth of mouse- and patient-derived human colon cancer organoids. Importantly, SSE1806 overcame multidrug resistance in a cell line overexpressing MDR-1. Thus, SSE1806 represents a potential anticancer agent that can overcome multidrug resistance.

The Chromosome of Phalaenopsis spp. and Doritaenopsis sp. Hybrid Induced by Colchicine

One way to improve the genetic diversity of orchid plants is by polyploidization using the antimitotic compound colchicine. This research was conducted to determine the ploidy level in several types of hybrid orchids (Phalaenopsis spp. and Doritaenopsis sp.) that applied 1,000 mgL−1 colchicine and to obtain polyploidy orchid yields to improve the genetic diversity of orchid plants. This research was carried out on August 2021 - March 2022 in the Screen House Faculty of Agriculture Universitas Sebelas Maret and Integrated Laboratory Universitas Sebelas Maret. The method of this research uses squash preparation for chromosome analysis with the preparation materials used the meristematic flower bud of Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ which were not treated and has been treated with 1,000 mgL−1 colchicine. Orchid varieties that used as samples were three samples, then each sample had two treatments and was replication two times. There are twelve samples in all. The application of colchicine was made by wetting a cotton swab with 1 ml of colchicine solution in each treatment. Then the buds are wrapped with cotton and covered with carbon paper outside for two days. The results of this research showed that the Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ orchids which were treated with 1,000 mgL−1 colchicine each underwent polyploidization into tetraploid with the number of chromosomes 2n = 4x = 76. Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ have a relative length chromosome length, and have the same chromosome shape, namely metacentric.

Diethylhexyl Phthalate and Bisphenol A Promote Vincristine and Tamoxifen Resistance in Vitro.

Environmental estrogen active compounds are strong determinants of estrogen receptor (ER)-positive breast cancers, and increased evidence indicates their contribution to chemotherapy resistance. In the current study, the efficacy of vincristine and tamoxifen, with the presence of diethylhexyl phthalate (DEHP) and bisphenol A (BPA) and the possible involvement of estrogen and estrogen receptor-related mechanisms, was evaluated in an ER+ mammary tumor cancer cell line, MCF-7. Chemotherapeutics tamoxifen as an estrogen receptor modulator and vincristine as an antimitotic compound were selected for evaluation against the presence of common endocrine disrupters. BPA and DEHP preincubation at their proliferative concentrations for 4 h was found to decrease the cytotoxicity of vincristine. mRNA and protein expression of ESR1 and ESR 2 were decreased by vincristine, while this decrease was reversed by DEHP and BPA. Both BPA and DEHP were able to interfere with the cytotoxic activity of vincristine against MCF-7 cells through ESR1 and ESR2. This study provides in vitro toxicological evidence for vincristine resistance and its relation to estrogen active environmental pollutants in ER+ breast cancer cells.

VTT-006, an anti-mitotic compound, binds to the Ndc80 complex and suppresses cancer cell growth in vitro

Hec1 (Highly expressed in cancer 1) resides in the outer kinetochore where it works to facilitate proper kinetochore-microtubule interactions during mitosis. Hec1 is overexpressed in various cancers and its expression shows correlation with high tumour grade and poor patient prognosis. Chemical perturbation of Hec1 is anticipated to impair kinetochore-microtubule binding, activate the spindle assembly checkpoint (spindle checkpoint) and thereby suppress cell proliferation. In this study, we performed high-throughput screen to identify novel small molecules that target the Hec1 calponin homology domain (CHD), which is needed for normal microtubule attachments. 4 million compounds were first virtually fitted against the CHD, and the best hit molecules were evaluated in vitro. These approaches led to the identification of VTT-006, a 1,2-disubstituted-tetrahydro-beta-carboline derivative, which showed binding to recombinant Ndc80 complex and modulated Hec1 association with microtubules in vitro. VTT-006 treatment resulted in chromosome congression defects, reduced chromosome oscillations and induced loss of inter-kinetochore tension. Cells remained arrested in mitosis with an active spindle checkpoint for several hours before undergoing cell death. VTT-006 suppressed the growth of several cancer cell lines and enhanced the sensitivity of HeLa cells to Taxol. Our findings propose that VTT-006 is a potential anti-mitotic compound that disrupts M phase, impairs kinetochore-microtubule interactions, and activates the spindle checkpoint.

Vincristine in Combination Therapy of Cancer: Emerging Trends in Clinics.

Simple SummaryVincristine is a vinca alkaloid naturally occurring in Catharanthus roseus. It belongs to antimitotic compounds, which arrest the cell cycle via disrupting microtubule dynamics. This property makes vincristine a useful compound in anticancer therapies, however, due to its unspecific biological action, vincristine causes severe side effects, mainly neurotoxicity. Nevertheless, at low concentrations, it is still a beneficial and widely used drug in combinatorial regimens of cancer treatment. Most commonly, it is administered with cyclophosphamide, doxorubicin, and prednisone but also with methotrexate or procarbazine, and dacarbazine. Currently, anticancer research focuses on targeted therapies and the development of antibodies specific to cancer cells. An example of such a drug combination broadly used in clinics is vincristine and rituximab, an antibody binding cancer cell surface receptor CD20. Combining vincristine with monoclonal antibodies is an emerging approach, which has been currently evaluated in clinical trials. This review article reports on the most commonly used vincristine-based drug combinations and summarizes currently running clinical trials. The number of ongoing studies shows that vincristine has its stable place in anticancer therapies and despite all its limitations, it has remained an essential part of anticancer therapies.Treatment of blood malignancies and other cancer diseases has been mostly unfeasible, so far. Therefore, novel treatment regimens should be developed and the currently used ones should be further elaborated. A stable component in various cancer treatment regimens consists of vincristine, an antimitotic compound of natural origin. Despite its strong anticancer activity, mostly, it cannot be administered as monotherapy due to its unspecific action and severe side effects. However, vincristine is suitable for combination therapy. Multidrug treatment regimens including vincristine are standardly applied in the therapy of non-Hodgkin lymphoma and other malignancies, in which it is combined with drugs of different mechanisms of action, mainly with DNA-interacting compounds (for example cyclophosphamide), or drugs interfering with DNA synthesis (for example methotrexate). Besides, co-administration of vincristine with monoclonal antibodies has also emerged, the typical example of which is the anti-CD20 antibody rituximab. Although in some combination anticancer therapies, vincristine has been replaced with other drugs exhibiting lesser side effects, though, in most cases, it is still irreplaceable. This is strongly evidenced by the number of active clinical trials evaluating vincristine in combination cancer therapy. Therefore, in this article, we have reviewed the most common cancer treatment regimens employing vincristine and bring an overview of current trends in the clinical development of this compound.

The Dolaflexin-based Antibody-Drug Conjugate XMT-1536 Targets the Solid Tumor Lineage Antigen SLC34A2/NaPi2b.

Target selection for antibody-drug conjugates (ADC) frequently focuses on identifying antigens with differential expression in tumor and normal tissue, to mitigate the risk of on-target toxicity. However, this strategy restricts the possible target space. SLC34A2/NaPi2b is a sodium phosphate transporter expressed in a variety of human tumors including lung and ovarian carcinoma, as well as the normal tissues from which these tumors arise. Previous clinical trials with a NaPi2b targeting MMAE-ADCs have shown objective durable responses. However, the protein-based biomarker assay developed for use in that study was unable to discern a statistically significant relationship between NaPi2b protein expression and the probability of response. XMT-1536 is a NaPi2b targeting ADC comprised of a unique humanized antibody conjugated with 10-15 auristatin F- hydroxypropylamide (AF-HPA) payload molecules via the Dolaflexin platform. AF-HPA is a cell-permeable, antimitotic compound that is slowly metabolized intratumorally to an active, very low-permeable metabolite, auristatin F (AF), resulting in controlled bystander killing. We describe the preclinical in vitro and in vivo antitumor effects of XMT-1536 in models of ovarian and lung adenocarcinoma. Pharmacokinetic analysis showed approximately proportional increases in exposure in rat and monkey. Systemic free AF-HPA and AF concentrations were observed to be low in all animal species. Finally, we describe a unique IHC reagent, generated from a chimeric construct of the therapeutic antibody, that was used to derive a target expression and efficacy relationship in a series of ovarian primary xenograft cancer models.

Determining the affinity of anti-mitotic compounds binding to colchicine binding site of tubulin by affinity probe capillary electrophoresis

The colchicine binding site of tubulin is often used to screen the anti-mitotic compounds, which are widely used as anti-cancer therapies. In the present work, an affinity probe capillary electrophoresis (APCE) method was developed for determining the affinity of anti-mitotic compounds. To this end, a fluorescently labeled affinity probe, 5-carboxyfluorescein-colchicine (F-colchicine), was prepared for the affinity competition experiment. The probe can form a stable complex with tubulin with the binding stoichiometry of 0.75, and the dissociation constant Kd of the complex was determined as 5.7 × 10−5 mol/L. In the affinity competition experiment, F-colchicine was incubated with tubulin and the test compound in the solution. The F-colchicine–tubulin complexes and free F-colchicine were quickly separated by CE and the concentration of free F-colchicine was accurately determined with the laser induced fluorescence detection. The affinity constant of the tested compound can be measured with the affinity competition binding curve. The enantiomers of the anti-mitotic compound were evaluated by using the method. The binding affinity of the enantiomers displayed an enantioselective manner. Compared to other affinity binding assay methods, our method is more straightforward, more accurate, and more cost-effective.

Earthworm, a novel in vivo system to validate antimitotic compounds

We report here that earthworm can be used as an in vivo system to prescreen antimitotic compounds. The known antimitotic compound colchicine and the aqueous extract of Acorus calamus L. rhizome were used to examine this system. The antimitotic activity of colchicine and the rhizome extract was confirmed by methods with Allium cepa root tip, earthworm regeneration, and MTT (3-(4,5-dimethyl thiazolyl-2-yl)-2,5-diphenyltetrazolium bromide). An earthworm regeneration assay examined the regeneration ability of tissues from amputated regions of the earthworm. All 3 assays showed that cell division is inhibited with colchicine and the aqueous extract of A. calamus rhizome. Histology studies with amputated earthworms confirmed that the development of the blastema was observed only in control worms. Immunohistochemistry analysis with proliferation cell nuclear antigen and phospho serine 10 histone H3 antibodies showed that amputated worms treated with colchicine or the aqueous extract of A. calamus did not have active cell division. MTT assay with the MCF-7 cell line (human breast carcinoma) further confirmed that the aqueous extract of rhizome affected cell proliferation. Our results suggest that the earthworm could be used to prescreen the antimitotic potential of plant extracts or other unknown compounds. It is simple, reproducible, and cost-efficient compared to animal cell line-based methods.

Scoulerine affects microtubule structure, inhibits proliferation, arrests cell cycle and thus culminates in the apoptotic death of cancer cells

Scoulerine is an isoquinoline alkaloid, which indicated promising suppression of cancer cells growth. However, the mode of action (MOA) remained unclear. Cytotoxic and antiproliferative properties were determined in this study. Scoulerine reduces the mitochondrial dehydrogenases activity of the evaluated leukemic cells with IC50 values ranging from 2.7 to 6.5 µM. The xCELLigence system revealed that scoulerine exerted potent antiproliferative activity in lung, ovarian and breast carcinoma cell lines. Jurkat and MOLT-4 leukemic cells treated with scoulerine were decreased in proliferation and viability. Scoulerine acted to inhibit proliferation through inducing G2 or M-phase cell cycle arrest, which correlates well with the observed breakdown of the microtubule network, increased Chk1 Ser345, Chk2 Thr68 and mitotic H3 Ser10 phosphorylation. Scoulerine was able to activate apoptosis, as determined by p53 upregulation, increase caspase activity, Annexin V and TUNEL labeling. Results highlight the potent antiproliferative and proapoptotic function of scoulerine in cancer cells caused by its ability to interfere with the microtubule elements of the cytoskeleton, checkpoint kinase signaling and p53 proteins. This is the first study of the mechanism of scoulerine at cellular and molecular level. Scoulerine is a potent antimitotic compound and that it merits further investigation as an anticancer drug.

Proliferation Markers Are Associated with MET Expression in Hepatocellular Carcinoma and Predict Tivantinib Sensitivity In Vitro.

Purpose: Tivantinib was initially reported as a selective MET inhibitor and is under phase III evaluation in "MET-high" hepatocellular carcinoma (HCC) patients. However, it has been also proposed as an antimitotic agent. We aimed to evaluate the antitumor effect of tivantinib in HCC cells by combining pharmacologic and molecular profiling.Experimental Design: Sensitivity to tivantinib, JNJ-38877605, PHA-665752, vinblastine, and paclitaxel was tested in a panel of 35 liver cancer cell lines analyzed with exome sequencing, mRNA expression of 188 genes, and protein expression. Drug effect was investigated by Western blot analysis and mitotic index quantification. Expression of candidate biomarkers predicting drug response was analyzed in 310 HCCs.Results: Tivantinib sensitivity profiles in the 35 cell lines were similar to those obtained with antimitotic drugs. It induced blockage of cell mitosis, and high cell proliferation was associated with sensitivity to tivantinib, vinblastine, and paclitaxel. In contrast, tivantinib did not suppress MET signaling, and selective MET inhibitors demonstrated an antiproliferative effect only in MHCC97H, the unique cell line displaying MET gene amplification. HCC tumors with high expression of cell proliferation genes defined a group of patients with poor survival. Interestingly, highly proliferative tumors also demonstrated high MET expression, likely explaining better therapeutic response of MET-high HCC patients to tivantinib.Conclusions: Tivantinib acts as an antimitotic compound, and cell proliferation markers are the best predictors of its antitumor efficacy in cell lines. Ki67 expression should be tested in clinical trials to predict tivantinib response. Clin Cancer Res; 23(15); 4364-75. ©2017 AACR.

Autophagy induced by a sulphamoylated estrone analogue contributes to its cytotoxic effect on breast cancer cells.

Background Autophagy can either be protective and confer survival to stressed cells, or it can contribute to cell death. The antimitotic drug 2-ethyl-3-O-sulpamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol) is an in silico-designed 17-β-estradiol analogue that induces both autophagy and apoptosis in cancer cells. The aim of the study was to determine the role of autophagy in ESE-15-ol-exposed human adenocarcinoma breast cancer cells; knowledge that will contribute to future clinical applications of this novel antimitotic compound. By inhibiting autophagy and determining the cytotoxic effects of ESE-15-ol-exposure, deductions could be made as to whether the process may confer resistance to the drug, or alternatively, contribute to the cell death process.Methods and results Spectophometrical analysis via crystal violet staining was used to perform cytotoxicity studies. Morphology studies were done using microscopic techniques namely polarization-optical transmitted light differential interference light microscopy, fluorescent microscopy using monodansylcadaverine staining and transmission electron microscopy. Flow cytometry was used to quantify the autophagy inhibition and assess cell viability. Results obtained indicated that 3-methyladenine inhibited autophagy and increased cell survival in both MCF-7 and MDA-MB-231 cell lines.ConclusionThis in vitro study inferred that autophagy inhibition with 3-methyladenine does not confer increased effectiveness of ESE-15-ol in inducing cell death. Thus it may be concluded that the autophagic process induced by ESE-15-ol exposure in MCF-7 and MDA-MB-231 cells plays a more significant role in cell death than conferring survival.

Monomethyl Auristatin E Phosphate Inhibits Human Prostate Cancer Growth.

Bone metastasis from primary prostate cancer leads to markedly diminished quality of life with poor long-term survival. Bone seeking treatment options are limited with adverse consequences on rapidly proliferating tissues such as bone marrow. In the present study, we seek to determine the bone-enriching capabilities of monomethyl auristatin E phosphate (MMAEp), a derivative of the potent antimitotic monomethyl auristatin E (MMAE). The in vitro actions and mechanisms of cytotoxicity were assessed using cell viability, immunofluorescence, flow cytometry, and Western blot analysis. In vivo efficacy was determined using an intratibial xenograft mouse model of human prostate cancer and live animal imaging. The half maximal inhibitory concentration (IC50) of MMAE and MMAEp was determined to be approximately 2 and 48 nM, respectively, in PC-3 and C4-2B cell lines. MMAEp retained the mechanism of action of MMAE in reducing microtubule polymerization and stalling cell cycle progression at the G2/M transition. MMAEp was able to bind hydroxyapatite in in vitro assays. MMAEp significantly reduced intratibial tumor growth compared to the vehicle control treatment. MMAEp is an antimitotic compound that binds to calcium ions in the bone and inhibits prostate tumor growth in the bone. Prostate 76:1420-1430, 2016. © 2016 Wiley Periodicals, Inc.

Design, Synthesis, and Evaluation of in Vitro and in Vivo Anticancer Activity of 4-Substituted Coumarins: A Novel Class of Potent Tubulin Polymerization Inhibitors.

In this paper, a series of novel 4-substituted coumarin derivatives were synthesized. Among these compounds 34, 39, 40, 43, 62, 65, and 67 exhibited significant antiproliferative activity toward a panel of tumor cell lines at subnanomolar IC50 values. Compound 65 showed potent antiproliferative ability (IC50 values of 7-47 nM) and retained full activity in multidrug resistant cancer cells. Compound 65 caused G2/M phase arrest and interacted with the colchicine-binding site in tubulin, as confirmed by immune-fluorescence staining, microtubule dynamics assays, and competition assays with N,N'-ethylene-bis(iodoacetamide). Compound 65 reduced the cell migration and disrupted capillary-like tube formation in HUVEC cells. Importantly, compound 65 significantly and dose-dependently reduced tumor growth in four xenografts models including paclitaxel sensitive and resistant ovarian tumors (A2780s and A2780/T), adrmicycin sensitive and resistant breast tumors (MCF-7 and MCF-7/ADR), suggesting that compound 65 is a promising novel antimitotic compound for the potential treatment of cancer.

Bioassay-Guided Fractination of Antimitotic Compound from Ongkea Cortex (Mezzettia parviflora Becc) Towards Sea Urchin Eggs

Ongkea cortex, the wood bark of Mezzettia Parviflora Becc, is a traditional medicine originated from Southeastern Sulawesi (Indonesia). It has been empirically known to have antitumor property. In this study, we examined the antiproliferative activity and obtained the antimitotic compound of ongkea cortex. Antimitotic activity was ultimately determined by the inhibition of cleavage-stage of newly fertilized sea urchin (Lytechinus variegatus) eggs. A bioassay-guided fractination was performed in order to find the bioactive substance of ongkea cortex. The IC50 values of methanolic extract, ethyl acetate-soluble part of metanolic extract and ethil acetat insoluble part of metanolic extract were 1221.68 µg/mL, 2.69 µg/mL, and 15.15 µg/mL, respectively. Ethyl acetate-soluble part of metanolic extract was further investigated. It was partitionated using vacuum liquid column chromatoghraphy with different solvent system by increasing their polarities. There were three different fractions obtained. Fraction III exerted the highest inhibition activity with IC50 value of 1.33 µg/mL. It was separated subsequently to result four groups of compounds. III-C group presented the most potent inhibition activity with IC50 value of 0.7147 µg/mL. It was then subjected to preparative TLC and yieldedsix groups of subfractions. III-C-3 subfraction was indicated as the most potent compound with IC50 value of 0.3378 µg/mL. It was ten times weaker compared with antimitotic activity of Vincristine with IC50 of 0.0351 µg/mL. As a conclusian, ongkea cortex might have antimitotic property with the highest rate inhibition activity exhibited by III-C-3 compound.
 Keywords: ongkea cortex, Mezzettia Parviflora Becc, sea urchin eggs, antimitotic compound, antiproliverative activity

Synergistic Anticancer Potential of Dichloroacetate and Estradiol Analogue Exerting their Effect via ROS-JNK-Bcl-2-Mediated Signalling Pathways

Background: C9, a newly in silico-designed inhibitor of microtubule dynamics induces G₂/M arrest culminating in apoptosis. Dichloroacetate (DCA) inhibits pyruvate dehydrogenase kinase, an enzyme that promotes pyruvate entry into mitochondria. The use of antitumor drugs targeting different cancer features can be a more effective way to overcome drug resistance. Methods: The influence of C9 (130 nM) + DCA (7.5 mM) on MCF-7 and MCF-12 cells was assessed via microscopy spectrophotometry global gene expression and flow cytometry assays. Results: An LDH assay showed that C9+DCA treatment decreased cell viability to 83.5% in MCF-7 cells when compared to the non-tumorigenic MCF-12A cells 92.4% (P < 0.05). C9- and C9+DCA treatment induced mitochondrial membrane potential depolarization in MCF-7 cells but not in MCF-12A cells (P < 0.05). The occurrence of apoptosis was associated with increased hypo- and hyper-phosphorylation of Bcl-2 Ser⁷⁰ and caspase 7 activation. Kinase inhibition revealed sustained activation of the JNK pathway caused increased Bcl-2 protein Ser⁷⁰ hypo-and hyper-phosphorylation. Elevated levels of DCF fluorescence was observed in DCA-, C9- and C9+DCA-exposed MCF-7 cells, but not in MCF-12A cells, indicating cytosolic H₂O₂/Fe²⁺ formation in treated tumorigenic cells. LC3-II expression was elevated in C9+DCA-treated cells in both cell lines, indicating that autophagy was also induced. Conclusions: Synergistic effects of C9+DCA were demonstrated on breast carcinoma and non-tumorigenic cells with selectivity towards the MCF-7 cells. Antimitotic compound C9 in combination with a glycolytic inhibitor dichloroacetate eradicates breast cancer cells through ROS-JNK-Bcl-2-mediated signalling pathways in vitro and it is argued that autophagy acts as protective mechanism in the treated cells before apoptosis occurs.

&lt;i&gt;In vitro&lt;/i&gt; evaluation of a novel Estradiol analogue with nanomolar antimitotic and carbonic anhydrase inhibitory activity

In vitro evaluation of a novel Estradiol analogue with nanomolar antimitotic and carbonic anhydrase inhibitory activity In the present study we describe the in vitro biological activity of 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol), a novel antimitotic compound with anticarbonic anhydrase activity. This study indicates that ESE-15-ol is a promising antimitotic anticancer drug that warrants further investigation.

Efek Antimitosis Biomutagen dari Tanaman Kembang Sungsang (Gloriosa superba L.) pada Pembelahan Sel Ujung Akar Kecambah Cabai Merah Besar (Capsicum annuum L.)

Flame lily ( Gloriosa superba L.) is one of the plants containing colchicine, often used as antimitotic compound, in the whole organ. This study aims to gain the combination of extract source and extract concentration of G. superba capable of inhibit mitosis in root tip cells of chili sprouts. The plant is extracted using the extraction and dilution methods to determine the extract concentration of the treatment. The squash method is used to make a mitosis preparation. The study is arranged in a factorial using Randomized Complete Block Design (RCBD) with 4 replications. The first factor is extract source: roots, stems, and leaves. The second factor is the extract concentration: 0, 20.40, 60, and 80%. The observation shows that the extract of leaf can inhibit mitosis more than exctract of bulbs and roots. All of the concentration treatment from all extract sources tend to result in similar mitotic index, but significantly different from cells that are not given treatment. The combination of the source extract and concentration of the extract result in varied mitotic index, but it is obvious that the leaf extract with a concentration of 80% gives the most inhibiting mitosis index: 1.298%.