Development of laboratory models to study Breast Cancer Deborah Holliday Breast Research Group Section of Pathology & Tumour Biology Section of Pathology and Tumour Biology

Outline  Introduction to the cells found in breast tissue  Changes in breast cells during breast cancer  Designing a model of breast cancer  methods  Use of the model: A tool for looking at cancer progression

Cellular components of the normal breast  Luminal epithelial cells:  Milk producing cells  Hormone responsive ER-alpha positive cells  Myoepithelial cells:  Surround the luminal cells  Contractile cells  Luminal and Myoepithelial cells form the glandular unit of the breast  Fibroblasts:  Form the structural component of the surrounding breast tissue  Produce proteins important for maintaining breast structure  Other cell types  Blood vessels, fat cells, inflammatory cells

Fibroblasts Myoepithelial cells Tumour cells Luminal cells Normal breast tissue  Cells look ordered in appearance Pre-invasive breast cancer  Tumour cells in the centre start to grow out of control Invasive breast cancer  Tumour cells escape into the surrounding breast tissue  Ordered structure of the tissue is lost Breast Cancer Progression

Pre-invasive breast cancer: Ductal carcinoma in situ (DCIS)  DCIS is characterised by confinement of tumour cells to the breast glandular unit  DCIS accounts for 40% of screen detected breast carcinoma  25-30% of untreated DCIS will progress to invasive carcinoma

Problems with treatment of DCIS Mastectomy Patient is cured but ? Overtreatment ? Conservative surgery A proportion of tumours will recur Some of those will progress to invasive carcinoma Important to define which DCIS cases are likely to progress A better understanding of the biology of tumour invasion may reveal new targets for therapies

Designing a human model of breast cancer  The model would need to include 3 major cell types involved in breast cancer:  Tumour cells.  Myoepithelial cells (protector cells).  Fibroblasts (tumour helper cells).  Cells would need to be grown in culture conditions which resemble those in the body:  Able to grow in 3 dimensions rather than on a plastic Petri dish.  Such a model would be a valuable tool:  To help us understand how breast cancer progresses.  To allow us to test new drugs for therapy.  To potentially identify new targets for future drug development.

Methods  We isolated cells from normal breast tissue or from breast cancer tissue and grew then in a 3 dimensional matrix of collagen.  By labelling our cells with different colours we were able to identify the different cell types in our model.  We used the model to investigate whether fibroblasts are able to make pre-invasive lesions become invasive.

Results F B Day 1Day 3Day 5Day 7 Blue: Tumour cells Red: Myoepithelial cells Green: Normal Fibroblasts Green: Tumour Fibroblasts Ductal carcinoma in situ (DCIS) Invasive breast Carcinoma

Quantifying the model lum/myo/Nfib mcf/myo/TAF number of structures per field * Normal Fibroblasts Tumour Fibroblasts Normal Fibroblasts Tumour Fibroblasts

How we are using the model Different tumour cells to represent different types of breast cancer Different fibroblasts to understand why in some patients cancer progresses faster than in others Include drugs into the model with tumour fibroblasts to see if we can prevent ‘invasion’ –Established drugs –New Drugs = pre-clinical drug screen We have a model which we can use to study the biology of breast cancer This will help us understand how breast cancer progresses Summary

Using 3D models to study radio- resistance in Breast Cancer Laura Smith Breast Research Group Section of Pathology & Tumour Biology Section of Pathology and Tumour Biology

Outline  Radiotherapy  Issues with radiotherapy  What would help overcome these issues?  The use of 3D models

Radiotherapy  Reduces risk of the cancer coming back  Is given to many breast cancer patients  All patients having breast conserving surgery  Patients having a mastectomy but at high risk of the cancer coming back

Issues with Radiotherapy  Unpleasant side effects  Short term  Long term  Stressful regime  Daily hospital visits 5 days/ week for 3 weeks  Limited availability of treatment machines  Long waiting lists in some areas  Not all patients will benefit  Some patients cancer will come back anyway

Overcoming these issues  Better patient selection  Estrogen Receptor for Tamoxifen therapy  HER2 for Herceptin therapy  Nothing analogous to guide radiotherapy  Why do some cancers respond well to radiotherapy whilst others do not?  What factors are involved?  Radio-sensitizing drugs?

Our Study  It is not only cancer cells that are exposed to radiotherapy but also the fibroblasts  Do fibroblasts influence breast cancer cell response to radiotherapy?  Do fibroblasts differentially influence the response of different breast cancer types?

Use of 3D Models

Summary  Reduce side effects and improve quality of life for patients that will not benefit  Allow drs to select another type of treatment that will work for these patients  Reduce waiting times for those patients that will benefit thereby increasing survival