Docking, synthesis, and in vitro evaluation of antimitotic estrone analogs

In the present study, Autodock 4.0 was employed to discover potential carbonic anhydrase IX inhibitors that are able to interfere with microtubule dynamics by binding to the Colchicine binding site of tubulin. Modifications at position 2’ of estrone were made to include moieties that are known to improve the antimitotic activity of estradiol analogs. 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-3-ol-17-one estronem (C9) and 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (C12) were synthesized and tested in vitro. Growth studies were conducted utilizing spectrophotometrical analysis with crystal violet as DNA stain. Compounds C9 and C12 were cytotoxic in MCF-7 and MDA-MB-231 tumorigenic and metastatic breast cancer cells, SNO non-keratinizing squamous epithelium cancer cells and HeLa cells after 48 h exposure. Compounds C9 inhibited cell proliferation to 50% of the vehicle-treated controls from 110-160 nM and C12 at concentrations ranging from 180-220 nM. Confocal microscopy revealed abnormal spindle morphology in mitotic cells. Cell cycle analysis showed an increase in the number of cells in the G2/M fraction after 24 h and an increase in the number of cell in the sub-G1 fraction after 48 h, indicating that the compounds are antimitotic and able to induce apoptosis.Medical Research Council of South Africa (AG374, AK076), the Cancer Association of South Africa (AK246), the Struwig-Germeshuysen Cancer Research Trust of South Africa (AJ038) and RESCOM University of Pretoria (A0R984).http://www3.interscience.wiley.com/journal/120118371/grouphome/home.htm

In vitro effects of a new and novel antimitotic compound in human breast adenocarcinoma metastatic epithelial cells

This study contributes to the understanding of molecular mechanisms and cell signaling events associated with in vitro anticancer responses of a new and novel antimitotic compound, 2-etiel-3-sulfamaat- 1,3,5(10)16-tetraeen (C19).This paper was initially delivered at the Annual Congress of the Biological Sciences Division of the South African Academy for Science and Art, ARC-Plant Protection Research Institute, Roodeplaat, Pretoria, South Africa on 01 October 2010.http://www.satnt.ac.zaam201

Chemoresistance in breast cancer stem cells

Breast cancer is the most prevalent cancer in women worldwide, contributing to 14% of all new cancer cases and 6.8% of all cancer deaths in 2014. A new area of cancer research has arisen from the discovery of cancer cells with stem cell-like proper ties in several tumor types including the colon, head and breast. Cancer stem cells, which are undifferentiated cells, have the ability of self-renewal, self-replication and differentiating into malignant daughter cells. Breast tumor s containing breast cancer stem cells have increased resistance to chemo- and r adiotherapy, a higher relapse r ate and increased susceptibility to metastasis. Potential targets for the treatment of chemoresistance include signaling pathways of breast cancer stem cells such as the -catenin-, Notch and Hedgehog pathways. Chemoresistance of these breast cancer stem cells potentially elucidates failure to achieve complete remission post-therapy, and, thus, relapses of breast cancer. By unraveling the mechanism behind the chemotherapeutic resistance of breast cancer stem cells, researchers could develop more efficient treatment strategies towards breast cancer.The Medical Research Council of South Africa, the Cancer Association of South Africa, National Research Foundation and the Struwig-Germeshuysen Cancer Research trust of South Africa.http://www.biomedres.infoam2017Physiolog

In vitro evaluation of a novel antimitotic estradiol analog and dichloroacetic acid on breast adenocarcinoma and breast non-tumorigenic cells

In vitro evaluation of a novel antimitotic estradiol analog and dichloroacetae, which restore mitochondrion function in breast adenocarcinoma and breast non-tumorigenic cells, will contribute to the field of combination therapy in cancer.This paper was initially delivered at the Annual Congress of the Biological Sciences Division of the South African Academy for Science and Art, ARC-Plant Protection Research Institute, Roodeplaat, Pretoria, South Africa on 01 October 2010.am201

2-Methoxyestradiol-bis-sulfamate induces apoptosis and autophagy in a tumorigenic breast epithelial cell line

In anticancer research where the focus is on finding agents that induces cell death while leaving nontumorigenic cells less affected, a novel 2-methoxyestradiol derivative has come forth. 2-Methoxyestradiol-bis-sulfamate (2-MeOE2bisMATE) is a 2-methoxyestradiol derivative produced by bis-sulphamoylation, which possesses increased antiproliferative activity and biological availability. Several questions remain regarding the type of cell death mechanisms and possible induction of autophagy by 2-MeOE2bisMATE. The aim of this in vitro study was to investigate the cell death mechanisms exerted by 2-MeOE2bisMATE in an adenocarcinoma cell line (MCF-7) by analyzing its influence on cell growth, morphology, and possible induction of cell death. Spectrophotometry (crystal violet staining), transmission electron microscopy (TEM), light microscopy (hematoxylin and eosin staining), and fluorescent microscopy (Hoechst 33342, propidium iodide and acridine orange) were employed. Spectrophotometrical studies indicated that 2-MeOE2bisMATE decreased cell numbers to 75% inMCF- 7 cells after 24 h and to 47% after 48 h of exposure. TEM demonstrated membrane blebbing, nuclear fragmentation, and chromatin condensation indicating the hallmarks of apoptosis. Light microscopy revealed the presence of several cells blocked in metaphase, and apoptotic cells were also observed. Fluorescent microscopy demonstrated increased lysosomal staining; suggesting the induction of autophagy. 2-MeOE2bisMATE shows therapeutic potential, as an, anticancer agent, and the investigation of the cell death mechanisms used by 2-MeOE2bisMATE, thus, warrants further investigation.The National Research Foundation, and the Struwig-Germeshuysen Cancer Research Trust of South Africa.http://www.springerlink.com/content/0300-817

In vitro influence of 2-methoxyestradiol-bis-sulphamate on cell numbers, reactive oxygen species production and autophagy induction in a breast adenocarcinoma- and a non tumorigenic breast epithelial cell line

This study indicates that 2-methoxyestradiol-bissulphamate induces both apoptosis and autophagy and contributes to the unraveling of the action mechanism of 2-methoxyestradiol-bis-sulphamate.http://www.satnt.ac.z

Calciumphosphate scaffolds for bone tissue repair and applications – in vitro characterisation

The purpose of this study was to generate electrospun biphasic nanobioceramic scaffolds for in vitro testing, ultimately contributing to bone tissue engineering.This abstract was initially presented at the annual Biological Sciences Symposium, presented under the protection of the Suid-Afrikaanse Akademie vir Wetenskap en Kuns. The symposium was held at the University of Johannesburg on 01 October 2011.http://www.satnt.ac.z

Nano-calciumphosphate generation with novel surface and chemical features for improvement of cell activity in bone repair and replacement

Ideal biomaterial for bone replacement implanted should be resorbed by osteoclasts, while osteoblastic activity deposits new bone. Electrospun biphasic nanobioceramic scaffolds were synthesized for in vitro testing, contributing to bone tissue engineering.This paper was initially delivered at the Annual Congress of the Biological Sciences Division of the South African Academy for Science and Art, ARC-Plant Protection Research Institute, Roodeplaat, Pretoria, South Africa on 01 October 2010.http://www.satnt.ac.zaam2014ay201

Ex vivo apoptotic and autophagic influence of an estradiol analogue on platelets

BACKGROUND : Platelets are known contributors to the vascularization, metastasis and growth of tumors. Upon their interaction with cancer cells they are activated resulting in degranulation and release of constituents. Since the apoptotic- and autophagic effects of 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16) has been shown to occur in vitro and this compound was designed to bind to carbonic anhydrase II (CAII), the possible occurrence of these cell death mechanisms in platelets as circulatory components, is of importance. METHODS : Scanning electron microscopy was used to assess morphological changes in platelets after exposure to ESE-16. The possible apoptotic- and autophagic effect of ESE-16 in platelets was also determined by means of flow cytometry through measurement of Annexin V-FITC, caspase 3 activity, autophagy related protein 5 levels and light chain 3-I to light chain 3-II conversion. RESULTS : Scanning electron microscopy revealed no changes in ESE-16-treated platelets when compared to vehicletreated samples. Apoptosis detection by Annexin V-FITC and measurement of caspase 3 activity indicated that there was no increase in apoptosis when platelets were exposed to ESE-16. The incidence of autophagy by measurement of autophagy related protein 5 levels and light chain 3-I to light chain 3-II conversion showed that exposure to ESE-16 did not cause the incidence of autophagy in platelets. CONCLUSION : This is the first ex vivo study reporting on involvement of apoptosis- and autophagy-related targets in platelets after exposure to ESE-16, warranting further investigation in platelets of cancer patients.The financial assistance of the National Research Foundation, Struwig-Germeshuysen Kankernavorsingstrust, Medical Research Council of South Africa (MRC), the Cancer Association of South Africa and the Research Committee (School of Medicine) of the University of Pretoria is hereby acknowledged.http://www.sherpa.ac.uk/romeo/issn/2162-3619/Physiolog

Ex vivo determination of an estradiol analogue-induced changes on platelet morphology and angiogenic biomarkers

Angiogenesis is a closely controlled biological process that takes place during fetal development of blood vessels and wound healing, and includes the development of new blood vessels from preexisting blood vessels. Tumor angiogenesis is a means by which tumors obtain oxygen, nutrition and promote tumor growth. Angiogenesis-regulating proteins are therefore ideal biomarkers in the study of tumor pathophysiology. In our laboratory, a new in silico-designed analogue of 2-methoxyestradiol has been synthesized with angiogenic properties, namely 2-ethyl-3-O-sulfamoyl-estra-1,3,5(10)16-tetraene (ESE-16). The ex vivo influence of ESE-16 on angiogenesis and morphology in platelets of healthy participants was investigated. Scanning electron microscopy revealed no morphological changes in ESE-16-treated platelets. The possible antiangiogenic effect of ESE-16-exposed platelets was determined by means of flow cytometry measurement of angiogenic protein levels, which were significantly increased after platelets were added to tumorigenic breast epithelial cells. This indicates that binding of platelets to cancer cells causes differential release of platelet constituents. Vascular endothelial growth factor levels were decreased in platelets, whereas platelet-derived growth factor and matrix metallopeptidase-9 levels were not significantly affected in platelets. In light of the above-mentioned data, further investigation of ESE-16’s influence on morphology and angiogenic markers in platelets of cancer patients is warranted.Struwig-Germeshuysen Research Trust of South Africa, the National Research Foundation, the Cancer Association of South Africa, and the South African Medical Research Council.http://journals.cambridge.org/action/displayJournal?jid=MAM2016-06-30hb201