Cancer Biology and Metastasis Laboratory

Cancer currently accounts for over 30% of male deaths and 26% of female deaths in Australia. The progression of a cancer from one that is restricted in its growth at the primary site, such as the breast, to one that is able to spread and grow at various sites in the body is the major cause of poor clinical outcome in cancer patients. Moreover, the spread of cancer, termed metastasis, rather than the growth of the primary tumour, is primarily responsible for treatment failure, poor quality of life and death in cancer patients.

Cancer metastasis is highly complex and multi-step in nature and involves extracellular matrix degradation, active tumour cell migration, altered tumour cell adhesion, and altered tumour cell proliferation, cancer cell survival and angiogenesis. Modulation of these aspects enables the tumour cell to escape the primary tumour microenvironment and spread locally/distally establishing a proliferative focus at a secondary site. Currently few effective therapies exist that alleviate metastatic disease providing a long-term survival outcome for the cancer patient.

Five important steps in the metastatic cascade.

The goal of the laboratory is to better understand the biology and the molecules involved in cancer metastasis. To achieve this, we are currently identifying genes that may act as molecular modulators of the metastatic process and are characterizing their function. In addition, the laboratory is examining the efficacy of new experimental compounds and drugs upon cancer growth and metastasis with particular focus upon bone metastasis. To better evaluate the efficacy of drugs, as well as the role of molecules upon cancer cell biology and metastasis, we employ a diverse range of in vitro cell-based assays (proliferation, migration, invasion) and in vivo (xenograft mouse models) models. These approaches will not only enhance our understanding of the fundamentals of cancer biology and metastasis but will provide novel therapeutic targets to which drugs can be designed, directly translating to the clinical situation to impact upon cancer patient survival and outcomes.

2006 Lab Members

Left to Right: John Price (Lab Head), Joseline Ojaimi (Research Fellow), Michelle Kouspou (PhD Student), Jessica Vieusseux (RA), Wensheng Deng (Visiting Scientist), Kelly Waldeck (PhD Student)

Project Areas

Novel Molecular Modulators of Breast Cancer Growth and Metastasis

To model metastasis, our laboratory has utilised human breast cancer cell lines, intra-cardially injected into mice as a system to study bone and visceral organ metastasis. Using this methodology we have isolated sublines and subclones of the human breast cancer cell line, MDA-MB-231, with either a high or low metastatic propensity to the bone. Gene array comparison of these cell types has resulted in the isolation of a number of candidate molecules whose expression correlates either positively or negatively with bone metastasis. We are currently using a variety of molecular and cellular approaches to characterize these genes, to determine their role in cancer cell biology and metastasis. To insure that the molecules that we are investigating are relevant to human cancer we are also currently examining whether the expression of these molecules of interest in human cancer samples are able to predict if a patient will develop metastasis. Through this work it is hoped that new therapeutic targets and novel prognostic markers will be identified in breast cancer.

Gene array analysis of clones of the human breast cancer cell line, MDA-MB-231, with either a high potential to cause bone metastasis (MDA-231#16) or a low potential (MDA-MB-231#17), has resulted in the identification of genes that either positively (e.g. Hsp90ß) or negatively correlate with bone metastasis.

Hsp90 Inhibitors and Heat Shock In Cancer Progression

Structure of the Hsp90 inhibitor geldanamycin and its derivative, 17-AAG, currently in Phase II clinical trials.

The molecular chaperone, Hsp90, is known to regulate over 100 proteins within the cell, a number of which are central to cancer cell growth and progression. As a result, Hsp90 has emerged as an important clinical target in cancer research. Rapid advances in the knowledge of Hsp90 function has been primarily due to the availability of Hsp90 inhibitors. The ansamycin antibiotics, such as geldanamycin and herbimycin A are known to inhibit Hsp90 function and analog compounds, such as 17 allylamino-17-desmethoxygeldanamycin (17-AAG), have successfully progressed to stage II patient clinical trials. In preclinical human xenograft models, we and others, have shown that 17-AAG possesses potent anti-tumour activity. However, recently we discovered that in the bone microenvironment, 17-AAG promotes tumour growth through its ability to stimulate bone degradation. We are currently investigating the molecular mechanisms by which 17-AAG enhances bone degradation and determine whether its detrimental effects upon bone can be prevented by bone resorption inhibitors, such as the class of compounds called the bisphosphonates. In addition to these studies, to better understand the actions of HSP90 inhibition, we have been successful in generating human breast cancer cell lines resistant to 17-AAG and are currently characterizing these at the molecular and biological levels.

HSP90 inhibitors, such as geldanamycin and 17-AAG, are known to induce a heat shock/stress response in cells via members of the heat-shock factor (HSF) family, such as HSF-1. This family of transcription factors control the expression of a large number of genes, which not only suppress the efficacy of HSP90 inhibitors but also are important in cancer growth and progression. Currently, we are examining the role of HSF-1 and the heat shock pathway in cancer growth and progression and whether therapeutic targeting of this pathway may be beneficial.

Effect of 17-AAG treatment upon MDA-MB-231SA human breast cancer cell growth in the mammary-fat pads of immuno-compromised mice.

IGFBP-2 and the αvß3 Integrin Interaction in Cancer Growth and Progression

Localization of IGFBP-2 (red), αvß3 (green) and their co-localization (yellow) in human breast cancer cell line, MCF-7ß3, mammary-fat pad tumours.

Our laboratory has recently identified a novel bi-molecular interaction between the cell surface molecule, αvß3 integrin and the insulin-like growth factor binding protein 2 (IGFBP-2). Both of these molecules have been independently shown to correlate with poor prognosis and progression in a number of cancers, including prostate, glioma and neuroblastoma. Therefore, we are investigating if the specific interaction of IGFBP-2 and/or its proteolytic fragments with the v3 integrin represents a novel pathway in prostate and glioma tumour progression and metastasis.

The Green Tea Cathechin, EGCG, as a Novel Inhibitor of Breast Cancer Growth and Metastasis

Epigallocatechin-3-gallate (EGCG) is the most abundant catechin in green tea with others being (+)-catechin, (+)-gallocatechin (GC), (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), and (-)-epigallocatechin (EGC). The catechins, especially that of EGCG, have been shown to posses antioxidant properties and anti-carcinogenic activity against a variety of tumours. We have determined that EGCG can inhibit a number of cellular processes important in breast cancer metastasis such as proliferation, migration and survival. We are currently examining the mechanisms of action of EGCG in a panel of human breast tumour cell lines upon cancer cell biology and cell signalling pathways. Moreover, EGCG may also act as a novel inhibitor of breast cancer growth and metastasis in relation to the bone through its ability to not only act upon the breast cancer cell but also to inhibit osteoclast differentiation, the major host cell type involved in bone lysis. Through the use of established in vivo models in the laboratory such as the intra-cardiac and intra-tibial inoculation models we are currently examining this possibiltiy. Through these studies we hope to determine whether EGCG can be used as a preventative and/or an intervention therapy in breast cancer.

Selected Publications

Price JT., Wilson HM., and Haites NE. Epidermal Growth Factor (EGF) Increases the in vitro Invasion, Motility and Adhesion Interactions of the Primary Renal Carcinoma Cell Line, A704. European Journal of Cancer 32A(11): 1977-1982, 1996.

Price JT., Bonovich M., and Kohn EC. The Biochemistry of Cancer Spread. Critical Reviews in Biochemistry and Molecular Biology, 32(3): 175-253, 1997.

Price JT, Tiganis T, Agarwal A, Djakiew D, Thompson EW. Epidermal Growth Factor Promotes MDA-MB-231 Breast Cancer Cell Migration through a Phosphatidyl 3'-Kinase and Phospholipase C-dependent Mechanism. Cancer Research, 59: 5475-5478, 1999.

Doong H, Price JT, Kim YS, Gasbarre C, Probst J, Liotta LA, Blanchette J, Rizzo K & Kohn EC. CAIR-1/BAG-3 forms an EGF-regulated ternary complex with phospholipase C- and Hsp70/Hsc70. Oncogene, 19(38):4385-4395, 2000.

Price J.T. & Thompson E.W. Mechanisms of Tumour Invasion and Metastasis: Emerging Targets for Therapy. Expert Opin. Ther. Targets. 6(2):217-233, 2002.

Ruangpanit N, Price JT, Holmbeck K, Birkedal-Hansen H, Guenzler V, Huang X, Chan D, Bateman JF, Thompson EW. MT1-MMP-dependent and -independent regulation of gelatinase A activation in long-term, ascorbate-treated fibroblast cultures: regulation by fibrillar collagen. Exp Cell Res. 15;272(2):109-18, 2002.

Dhanesuan, N., Sharp, J.A., Blick, T., Price, J.T., and Thompson, E.W. Doxycyclin-inducible expression of SPARC/ Osteonectin/ BM40 in MDA-MB-231 human breast cancer cells results in growth inhibition. Breast Cancer Res Treat. 75(1):73-85, 2002.

Ackland, M. L., Newgreen, D. F., Fridman, M., Waltham, M. C., Arvanitis, A., Minichiello, J., Price, J. T., and Thompson, E. W. Epidermal growth factor-induced epithelio-mesenchymal transition in human breast carcinoma cells. Lab Invest 83, 435-448, 2003.

Pereira JJ, Meyer T, Docherty SE, Reid HH, Marshall J, Thompson EW, Rossjohn J & Price JT. Bi-molecular Interaction of IGFBP-2 with v3 negatively modulates IGF-I mediated migration and tumour growth Cancer Res. 64: 977-984, 2004.

Price JT, Quinn JMW, Sims NA, Viesseux J, Kelly Waldeck, Susan E. Docherty, Damian Myers, Akira Nakamura, Mark C. Waltham, Matthew T. Gillespie, and Erik W. Thompson. The Heat Shock Protein 90 Inhibitor, 17-Allylamino-17-demethoxygeldanamycin, Enhances Osteoclast Formation and Potentiates Bone Metastasis of a Human Breast Cancer Cell Line. Cancer Res. 65(11) 4929-4938, 2005.

Li, R., Soosairajah, J., Harari, D., Citri, A., Price, J., Ng, H. L., Morton, C. J., Parker, M. W., Yarden, Y., and Bernard, O. Hsp90 increases LIM kinase activity by promoting its homo-dimerization. FASEB J. 20, 1218-1220, 2006.

Funding

National Health and Medical Research Council of Australia
The National Breast Cancer Foundation, Australia
US Department of Defense, USA
American Institute of Cancer Research, USA
The Susan G. Komen Breast Cancer Foundation, USA

PhD Scholarship Positions

PhD postgraduate scholarships are available to suitable candidates who are an Australia citizen or permanent resident who have obtained a H1 or H2A Honours degree. The scholarship provides a tax free stipend of $19,231 p.a. (2006 rate) for a period of 3 years dependent upon satisfactory progress.

International students who have obtained degrees equivalent to a BSc. with Honours at a level of first class only can contact Dr John Price to apply for International Scholarships that provide living expenses and tuition fees (www.mrgs.monash.edu.au/scholarships/index.html#research)

Contact Details

Cancer Biology and Metastasis Laboratory
Department of Biochemistry and Molecular Biology
School of Biomedical Science
P.O. Box 13D, Monash University, Victoria 3800, Australia

Tel: 61 3 9902 0120 (Office)
Tel: 61 3 9905 1053 (Lab)
Fax: 61 3 9905 4699
Email: John.Price@med.monash.edu.au