Research Projects

Breast Cancer Research – Prof Annie Joubert

Breast Cancer Research – Prof Annie Joubert

Prof Annie Joubert

Prof Annie Joubert

Project title

In silico analysis, synthesis and in vitro evaluation of novel anticancer agents.

Project description

Microtubules play a central role in mitosis and cell division and are important targets in anticancer drug development. Several anticancer drugs clinically important, including the Vinca alkaloids vinblastine, vincristine, and vinorelbine and the taxanes paclitaxel and docetaxel specifically target tubulin. These compounds (Vinca alkaloids and taxanes) interfere with microtubule dynamics and produce a characteristic mitotic arrest phenotype. Considering the clinical success of these agents, microtubule cytoskeleton represents one of the most highly validated cancer targets identified to date.

Our research involved discovery of compounds that are capable of selectively inhibiting the activity of cancer-associated proteins. This constitutes a main component of drug development research. Research is focused on improving treatments to enable the anticancer drug to affect only the cancer cell and at low dosages with less frequent treatment intervals. In addition, we have designed new and improved estradiol analogues for tubulin-, kinesin motor protein and carbonic anhydrase (CA) (CA II, IX, XII) binding affinity by means of in silico analysis at the Bioinformatics Unit at the University of Pretoria. Since these analogues are not commercially available, they were synthesized by iThemba Pharmaceuticals (PTY) Ltd. In silico and in vitro studies were conducted to elucidate each compound’s signal transduction mechanism and to verify their potential as anticancer agent in vitro, as already been tested. Two of these newly-designed compounds are selective inhibiting a specific protein that contributes towards cancer metastasis and need to be assessed to determine clinical application.

Highlights of the project

A major challenge in cancer research is to find agents that target cancer cells while leaving normal cells unharmed. Computational methods for the discovery of targets and identifying lead compounds against these targets are playing a key role in the discovery and development of new pharmaceutically relevant drugs. Hitherto, together with multidisciplinary collaboration and postgraduate students, this research focus entailed the in silico-design and synthesis of newly-designed anticancer compounds. 2-Methoxyestradiol (2ME) is an endogenous metabolite of 17-beta-estradiol exerting both antiproliferative and antiangiogenic effects. However, 2ME possesses poor bioavailability when compared to its sulfamoylated derivatives. The group in silico-designed new and improved estradiol analogues for tubulin-, kinesin motor protein and carbonic anhydrase (CA) (CA II, IX, XII) binding affinity by means of in silico analysis at the Bioinformatics and Computational Unit at the University of Pretoria. Analogues are novel and not commercially available and were therefore synthesized by iThemba Pharmaceuticals (PTY) Ltd. (Modderfontein, Gauteng, SA). Since this phase of in silico design and chemical synthesis of our research has been conducted successfully, subsequent detailed elucidation of each compound’s biochemical pathway of signalling needs to be investigated to verify potential anticancer activity in vitro on cancer cell lines of national and international importance to complement the improvement of analogues with therapeutic potential.

Non-scientific report

The designed anticancer compounds were proven to be five to eight times more potent when compared to 2-methoxyestradiol (2ME). (The latter revealed low oral bioavailability and rapid metabolic degradation.) These demonstrate extremely low concentrations for a drug to have anticancer activity when compared to conventional current treatments. Data are promising and demonstrate a synergistic effect of impacting on cancer cell growth. This research strategy also targets the deregulated metabolism associated with cancers contributing to the fight against cancer.

Summary of how this project was of value in the struggle against cancer

Chemotherapeutic and radiotherapeutic treatments of cancer remain works in progress, since; in general, these therapies have undesirable side effects that cause damage to normal cells. Therefore, processes of discovering compounds that are capable of selectively inhibiting the activity of cancer-associated proteins at low dosages with less frequent treatment intervals constitute a main component of drug development research.
Cancer impacts severely on economy and social development and ultimately on human lives. It is estimated that one in six South African men and one in seven South African women will be diagnosed with cancer during their lives. A recently published article in the Lancet predicted that South Africa could estimate a surge of 78% in the number of cancer cases by 2030 and globally, a 75% increase is estimated. In addition, South Africa is ranked ‘50th on the World Cancer Research Fund’s list of countries with the highest cancer prevalence rates.’ Professor Jacques Snyman, clinical advisor for Resolution Health Medical Scheme said: ‘The economic impact of a 75% global increase, and 78% local increase, could well be devastating.’

The importance of cancer research cannot be emphasized more and can be regarded as being equivalent to the disease per se. Research is sustainable, is being funded by national research bodies. International and national collaborators together with a pharmaceutical company are on board as well. Findings proven in the laboratory influence cancer patients by better-quality diagnostics and advanced treatment.

Peer-reviewed publications

  • A. Joubert and S. Marais. (2007) Influence of 2-methoxyestradiol on cell morphology and Cdc2 kinase activity in WHCO3 esophageal carcinoma cells. Biomed. Res. 28(1), 9-16.  Click here to read the publication (167KB)
  • A. Joubert and S. Marais (2007) In vitro effects of 2-methoxyestradiol on cell morphology and Cdc2 Kinase activity in SNO oesophageal carcinoma cells. Cell Biochem. Funct. 25(3), 357-362.  Click here to read the publication (167KB)
  • C. Van Zijl, M-L. Lottering, F. Steffens and A. Joubert (2008) In vitro effects of 2-methoxyestradiol on MCF-12A and MCF-7 cell growth, morphology and mitotic spindle formation. Cell BiochemFunct. 26, 632-642.  Click here to read the publication (259KB)
  • A. Joubert, S. Marais and C. Maritz (2009) Influence of 2-methoxyestradiol on MCF-7 cells: An improved differential interference contrasting technique and Bcl-2 and Bax protein expression levels. Biocell 33(1), 67-70.  Click here to read the publication (142KB)
  • V. Thaver, M.-L. Lottering, D. van Papendorp and A. Joubert (2009) In vitro effects of 2-methoxyestradiol on cell numbers, morphology, cell cycle progression and apoptosis induction in oesophageal carcinoma cells. Cell Biochem. Funct. 27(4), 205-210.  Click here to read the publication (151KB)
  • A. Stander, F. Joubert and A. Joubert (2011)  Docking, Synthesis, and in vitro Evaluation of Antimitotic Estrone Analogs. Chem Biol Drug Des 2011; 77: 173–181. Click here to read the publication (407KB)
  • K.H. Sippel, A. Stander, C. Tu, B. Venkatakrishnan, A.H. Robbins, M. Agbandje-McKenna, F. Joubert, A.M. Joubert and R. McKenna (2011)  Characterization of Carbonic Anhydrase Isozyme Specific Inhibition by Sulfamated 2-Ethylestra Compounds.  Letters in Drug Design & Discovery, 8, 678-684.  Click here to read the publication (277KB)
  • M. H. Visagie and A. M. Joubert (2011)  2-Methoxyestradiol-bis-sulfamate induces apoptosis and autophagy in a tumorigenic breast epithelial cell line.  Mol Cell Biochem 357:343–352.  Click here to read the publication (2.03MB)
  • X. X. Stander, B. A. Stander and A. M. Joubert (2011)  In vitro effects of an in silico-modelled 17b-estradiol derivative in combination with dichloroacetic acid on MCF-7 and MCF-12A cells.  Cell Prolif., 44, 567–581.  Click here to read the publication (1.47MB)
  • M. H. Visagie and A.M. Joubert (2011)  In vitro effects of 2-methoxyestradiol-bissulphamate on reactive oxygen species and possible apoptosis induction in a breast adenocarcinoma cell line.  Cancer Cell International, 11:43.  Click here to read the publication (278KB)

Other peer-reviewed publications

1. M.H. Visagie and A.M. Joubert (2010) In vitro effects of 2-methoxyestradiol-bis-sulphamate on cell numbers, membrane integrity, morphology and possible induction of apoptosis and autophagy in a non-tumorigenic breast epithelial cell line Cell. Mol. Biol Lett. 15, 564-581.

2. T. Mqoco, S. Marais and A. Joubert (2010) Influence of estradiol analogue on cell growth, morphology and death in esophageal carcinoma cells. Biocell 34(3):113-120.

3. M.H. Visagie and A.M. Joubert (2010) Immunotherapy and its role in cancer. Biomed. Res. 21(4), 1-5.

4. C.J.J. Vorster and A.M. Joubert (2010) In vitro effects of 2-methoxyestradiol-bis-sulphamate on the non-tumorigenic MCF-12A cell line Cell Biochem. Funct. 28(5), 412-419.

5. C. Vorster and A. Joubert (2010) In vitro effects of 2-methoxyestradiol-bis-sulphamate on cell growth, morphology and cell cycle dynamics in the MCF-7 breast adenocarcinoma cell line. Biocell 34(2):71-79.

6. B.A. Stander, S. Marais, C.J. Vorster and A.M. Joubert (2010) In vitro effects of 2-methoxyestradiol on morphology, cell cycle progression, cell death and gene expression changes in the tumorigenic MCF-7 breast epithelial cell line. J. Steroid Biochem. Mol. Biol. 119(3-5), 149-160.

7. B.A. Stander, S. Marais, C. Huyser, Z. Fourie, D. Leszczynski and A.M. Joubert (2011) Effects of non-thermal mobile phone radiation on breast adenocarcinoma cells. SAJS 107( 9/10), 1-9. doi:10.4102/sajs.v107i9/10.525.

8. B.A. Stander, F. Joubert and A. Joubert (2011) Docking, synthesis and in vitro evaluation of antimitotic estrone analogs. Chem. Biol.& Drug Des. 77(3):173-181.

9. K.H. Sippel, A. Stander, C. Tu, B. Venkatakrishnan, A.H. Robbins, M. Agbandje-McKenna, F. Joubert, A.M. Joubert and R. McKenna (2011) Characterization of Carbonic Anhydrase Isozyme Specific Inhibition by Sulfamated 2-Ethylestra Compounds. Lett in Drug Des & Discov. 8(10) 678-684.

10. N.B.Skerman, A.M. Joubert and M.J.Cronjé (2011) The apoptosis inducing effects of Sutherlandia spp. extracts on an oesophageal cancer cell line. J. Ethnopharmacol. 11;137(3):1250-1260.

11. M.H. Visagie and A.M. Joubert (2011) 2-Methoxyestradiol-bis-sulfamate induces apoptosis and autophagy in a tumorigenic breast epithelial cell line. Mol. Cell. Biochem. 357(1-2):343-352.

12. X.X. Stander, B.A. Stander and A.M. Joubert (2011) In vitro effects of an in silico-modelled 17β-estradiol derivative in combination with dichloroacetic acid on MCF-7 and MCF-12A cells. Cell Prolif. 44(6):567-581.

13. M.H. Visagie and A.M. Joubert (2011) In vitro effects of 2-methoxyestradiol-bis-sulphamate on reactive oxygen species and possible apoptosis induction in a breast adenocarcinoma cell line. Cancer Cell Int. 11: 43 DOI:1186/1475-2867-11-43.

14. C.J.J. Vorster, BA Stander and A.M. Joubert (2012) Differential signaling involved in Sutherlandia frutescens -induced cell death in MCF-7 and MCF-12A cells. J. Ethnopharmacol.140, 123-130.

15. T. Steynberg, M. Visagie, T. Mqoco, A. Idicula, S. Moolman, W. Richter and A. Joubert (2012) Qualitative assessment of smooth muscle cells propagated on 2D-and 3D- polycaprolactone polymers via scanning electron microscope. Biomed. Res. 23(2):191-198.

16. S. Marais, T Mqoco, A. Stander, Dirk Van Papendorp and A. Joubert (2012) The in vitro effects of a sulphamoylated derivative of 2-methoxyestradiol on cell number, morphology and alpha-tubulin disruption in cervical adenocarcinoma (HeLa) cells. Biomed. Res. 23 (3): 357-362

17. M.H. Visagie and A. M. Joubert (2012) 2-Methoxyestradiol-bis-sulphamate refrains from inducting apoptosis and autophagy in a non-tumorigenic breast cell line Cancer Cell Int. Aug 20;12(1):37. doi: 10.1186/1475-2867-12-37.

18. D.J. Klionsky et al. (2012) Guidelines for the use and interpretation of assays for monitoring autophagy. Autophagy 8(4): 1-100.

19. M.H. Visagie and A. M. Joubert (2012) Sulphamoylated estradiol analogue induces antiproliferative activity and apoptosis in breast cell lines. Cell. & Mol. Biol. Lett. 17(4):549-558.

20. T. Mqoco and A. Joubert (2012) 2-Methoxyestradiol-bis-sulphamate induces apoptosis and autophagy in an oesophageal carcinoma (SNO) cell line. Biomed. Res. 23(4) 469-474

21. T. Mqoco and A. Joubert. (2013) 2-Methoxyestradiol-bis-sulphamate: a promising anticancer agent in an esophageal carcinoma (SNO) cell line. Biomed. Res. 24(1), 115-122.

22. D. Nkandeu, T.V. Mqoco, M.H. Visagie, B.A. Stander, M. Cronjé, and A. Joubert. (2013) In vitro changes in mitochondrial potential, aggresome formation and caspase activity by a novel 17-β-estradiol analogue in breast adenocarcinoma cells. Cell Biochem. & Funct. 11. doi: 10.1002/cbf.2937.

23. B.A. Stander, F. Joubert , C. Tu, K.H. Sippel, R. McKenna and A.M. Joubert (2012) In Vitro Evaluation of ESE-15-ol, an Estradiol Analogue with Nanomolar Antimitotic and Carbonic Anhydrase Inhibitory Activity. PLoS One. 7(12):e52205. doi: 10.1371/journal.pone.0052205.

24. B.A. Stander, F. Joubert , C. Tu, K.H. Sippel, R. McKenna and A.M. Joubert (2013) Signaling Pathways of ESE-16, an Antimitotic and Anticarbonic Anhydrase Estradiol Analog, in Breast Cancer Cells. PLoS One. 2013;8(1):e53853. doi: 10.1371/journal.pone.0053853.

Manuscripts submitted/under review

1. Michelle Visagie; Anne Theron; Thandi Mqoco; Warren Vieira; Prudent Renaud; Anne Martinez; Laurence Lafanechere; Annie Margaretha Joubert.Sulphamoylated 2-methoxyestradiol analogues induce apoptosis in human cervical adenocarcinoma cells. UNDER REVIEW-PLOS ONE

2. Lisa Repsold; Etheresia Pretorius; Annie Margaretha Joubert. In vitro and ex vivo influence of an estrogen analogue on cell morphology and reactive oxygen species generation. UNDER REVIEW-PLOS ONE

3. Anne E Theron, Laurence Lafanechѐre and Annie M Joubert Molecular crosstalk between apoptosis and autophagy induced by a novel 2-methoxyestradiol analogue in cervical adenocarcinoma cells. UNDER REVIEW-Cancer Cell International

Abstracts

Postgraduate students submitted abstracts for the South African Academy of Sciences, PSSA, SA Microscopy conferences

1. C.J.J. Vorster and A.M. Joubert (2010) In vitro evaluation of 2-methoxyestradiol-bis-sulphamate and Sutherlandia frutescens extracts as possible anticancer agents. South African Journal of Science and Technology 29(4), 211-212.

2. T. Mqoco, S. Marais and A. Joubert Influence of 2-methoxyestradiol-bis-sulphamate on cell growth, morphology and its possible induction of cell death in esophageal carcinoma cells 29(4), 212.

3. M.H. Visagie, B.A. Stander and A.M. Joubert (2010) In vitro cell signalling events of 2-methoxyestradiol-bis-sulphamate in a breast adenocarcinoma- and a non-tumorigenic breast epithelial cell line. South African Journal of Science and Technology 29(4), 229.

4. A.E. Theron, M.H.. Visagie, T. Mqoco, A. Stander, R. Prudent, L. Lafanechère and A.M. Joubert. (2012) Molecular crosstalk between apoptosis and autophagy induced by a 2-methoxyestradiol analogue (C19) in HeLa cells. South African Journal of Science and Technology 31(1), 315.

5. X.X. Stander, B.A. Stander and A.M. Joubert (2011) In vitromorphological investigation of novel combination anticancer compounds on MCF-7 and MCF-12A cells. Microscopy Society of South Africa 41, 22.

6. B.A. Stander, F. Joubert and A.M. Joubert (2011) The signalling pathways involved in the induction of cell death in breast cell lines by a novel antimitotic and anticarbonic anhydrase IX compound. 39th PSSA Conference Scientific Research and Essays, 5, 26.

7. B.A. Stander, F. Joubert and A.M. Joubert (2012) Signaling pathways involved in the induction of cell death in breast cell lines by a novel carbonic anhydrase 9 inhibitor or antimitotic compound. South African Journal of Science and Technology 31(1), 342.

8. X.X. Stander, A. Stander and A. Joubert (2012) In vitro signal transduction mechanism exerted by 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-3-ol-17-one in combination with dichloroacetic acid on breast adenocarcinoma (MCF-7) and breast non-tumorigenic (MCF-12A) cells. South African Journal of Science and Technology 31(1), 343.

9. T.V. Mqoco, S. Marais and A.M. Joubert (2012) 2-Methoxyestradiol-bis-sulphamate disrupts microtubule network, arrests cell cycle and induces apoptosis in an esophageal carcinoma cell line. South African Journal of Science and Technology 31(1), 321.

10. S. Nkandeu, T.V. Mqoco, M.H. Visagie, S. Marais, B.A. Stander and A.M. Joubert (2012) In vitro changes in mitochondrial potential, aggresome formation and caspase activity by a novel 17-beta- estradiol analog in MCF-7 breast adenocarcinoma cells. South African Journal of Science and Technology 31(1), 297.

11. S. Marais, T.V. Mqoco, B.A. Stander, R. Prudent, L. Lafanechère and A.M. Joubert (2012) The in vitro effects of compound-X on growth, morphology, the induction of autophagy and apoptosis, as well as cell cycle progression in a cervical adenocarcinoma cell line. South African Journal of Science and Technology 31(1), 334.

12. M.H. Visagie, A.M. Joubert (2012) 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 South African Journal of Science and Technology 31(1), 303.

13. E. Wolmarans, T.V. Mqoco, A. Stander, S. Marais and A.M. Joubert (2012) Possible induction of autophagy and apoptosis by a novel 17-beta-estradiol analogue in esophageal carcinoma cells. South African Journal of Science and Technology 31(1), 304.

14. A.E. Theron, L. Lafanechère, R. Prudent, A.N. Hall, C.F. Van der Merwe, A. Martinez, C. Prunier, J.Viallet and A.M. Joubert. (2012) In vitro and in vivo anticancer effects of 2-ethyl-3-o-sulphamoyl-estra-1,3,5(10)15-tetraene-3-ol-17-one and 2-ethyl-3-o-sulphamoyl-estra-1,3,5(10)16-tetraene. Microscopy Society of South Africa 42, 33.

15. A.E. Theron, R. Prudent,L. Lafanechère, A.N. Hall, C.F. Van der Merwe, M.J.A. Crafford and A.M. Joubert. (2012) Morphological characteristics of autophagy and apoptosis induced by a novel 2-methoxyestradiol analogue in HeLa cells. Microscopy Society of South Africa 42, 45.

Conferences

  • Overview: in silico analysis, synthesis and in vitro evaluation of novel anticancer agents (keynote speaker) 40thMeeting of the Physiology Society of Southern Africa, Stellenbosch, South Africa, 10-13 September 2012.
  • Apotosis and autophagy: novel, antimitotic anticancer agents. The International Cell Death Society- Conference: Cell Death-Aging, Metabolism, and their Ramifications for Therapeutics and Drug Development. Singapore, Malaysia, 29-1 July 2012.

International and national published conference proceedings

  • A.M. Joubert, B.A. Stander, S. Marais, J.J. van Vuuren and F. Joubert. (2008) Influence of 2-methoxyestradiol on cell numbers, metabolic activity, morphology, cell cycle progression and gene expression in a breast adenocarcinoma cell line. European Journal of Cancer, Supplements 6(12), 89.

Invited oral presentations

  • In vitro search for new and better anti-cancer drugs – gene expression studies. CANSA Research in Action, Emperor’s Palace, Johannesburg, South Africa, 20th -22nd August 2008.
  • In silico analysis, synthesis and in vitro evaluation of potential anticancer agents. 8th International Cell Death Society Symposium, Cell Death in Infectious Disease and Cancer, Misty Hills, Johannesburg, South Africa, 5-8 June 2009.

Download:

Scientific document  Section 2.5.pdf

 

« BACK


Do you have a question?