Grant Success Profile Breast Cancer Organoid Program Dr Tali Lang Breast cancer is the most common cancer in Australian women with an estimated 20,000 new diagnoses in 2020. Treatment decisions are based on important biomarkers including hormone receptors (oestrogen (ER) and progesterone (PR)), and the human epidermal growth factor receptor 2 (HER2). Recently gene profiling of breast tumours has improved prognostic assessment and influenced treatment outcomes in early-stage breast cancer. Despite improved treatments, a significant number of women with early stage disease will relapse. This is thought to be due to tumour heterogeneity which occurs at the genomic, transcriptomic and proteomic levels creating therapeutic challenges. The use of in vitro 3D tumour organoid technology has the potential to accelerate clinical research studies, exploring associations between molecular changes in the primary tumour with clinical outcomes. Organoid cultures exhibit greater biological relevance due to maintenance of cellular organisation that mirrors the tissue of origin. Breast cancer organoids can be established in most breast cancer subtypes (80% success rate), and maintained long-term in culture. Organoids significantly expedite the ability of scientists to extend and translate in vitro findings of genes and signalling pathways to the clinically relevant situation. Importantly, organoids have the potential to be utilised as a clinical test, given they can be established quickly, reflect molecular features of the original tumour and can be used for drug testing prior to patients commencing treatment for the best chance of a curative outcome. The Szalmuk Family Department of Medical Oncology at Cabrini, in collaboration with Monash Biomedicine Discovery Institute, has established a living breast cancer organoid bioresource. This project was funded through the generous donation from the Barlow Foundation and Monash Biomedicine Discovery Institute. The project was designed to establish a clinically representative living bioresource of patient-derived breast tumour organoids, identify genetic alterations in breast cancer tissue and matched breast cancer organoids, and to characterise how specific genomic alterations correlate with sensitivity to existing or new cancer therapies using breast cancer organoids. We have collected 30 different breast tumours from women undergoing treatment at Cabrini with 23 breast cancer organoid lines successfully established. Our collection of breast cancer organoids comprises breast tumour subtypes including 14 luminal A, five luminal B, two HER2+, one triple negative and one mixed breast cancer. All have been cryopreserved and successfully revived from frozen stocks. Freshly resected primary breast tumours were divided and allocated for different research purposes. Some of the
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(L-R) Malvern’s Day Oncology and Infusion Unit Nurse Unit Manager Kirsten Seletto and Dr Tali Lang were successfully awarded the Cabrini Foundation Quality Improvement Grant (2019-2020), to create a Wellness Program for oncology nurses with the aim of combatting compassion fatigue and burnout.
primary tumour was snap frozen for DNA isolation and other sections fixed in formalin for histopathological analysis. The remainder of the tumour was processed by enzymatic digestion and epithelial cells resuspended in Matrigel. Cells in Matrigel were plated and overlaid with a culture medium containing essential growth factors. Established organoids were expanded and cryopreserved and a fraction of these were frozen and fixed for comparative molecular and histochemical analyses. Blood was also collected for genomic analysis. Fourteen individual organoid cultures and their corresponding primary tumour tissues have been processed into histological blocks and undergone histopathological evaluation using a defined set of markers, including ER, PR, Ki-67 and HER-2. Genomic DNA from 14 breast cancer organoids has been isolated from the blood (as a normal reference), primary breast tumour and corresponding organoid, and is currently being analysed by whole exome sequencing (GeneWiz, China). Bioinformatic analysis will be used to identify variants and copy number variations for targeted genes known to be involved in tumour formation. The continuing collaboration between Cabrini and Monash University will further expand our collection of breast cancer organoids to establish a more diverse bank of clinically relevant organoids reflecting the range of breast cancer sub-types. The use of breast organoids will significantly expedite the ability of scientists to extend and translate in vitro findings of genes and signalling pathways to the clinically relevant situations. Importantly, breast cancer organoids in the clinical setting can be used as a predictive tool to guide physicians regarding which patients are more likely to respond to specific treatments, and which treatments have the best chance of a curative outcome, based on the molecular profiling of the tumour.
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