Breast cancer is the most frequent malignancy in women with an estimation of 2.1 million new diagnoses in 2018. Even though primary tumours are usually efficiently removed by surgery, 20–40% of patients will develop metastases in distant organs. Bone is one of the most frequent site of metastases from advanced breast cancer, accounting from 55 to 58% of all metastases. Currently, none of the therapeutic strategies used to manage breast cancer bone metastasis are really curative. Tailoring a suitable model to study and evaluate the disease pathophysiology and novel advanced therapies is one of the major challenges that will predict more effectively and efficiently the clinical response. Preclinical traditional models have been largely used as they can provide standardization and simplicity, moreover, further advancements have been made with 3D cultures, by spheroids and artificial matrices, patient derived xenografts and microfluidics. Despite these models recapitulate numerous aspects of tumour complexity, they do not completely mimic the clinical native microenvironment. Thus, to fulfil this need, in our study we developed a new, advanced and alternative model of human breast cancer bone metastasis as potential biologic assay for cancer research. The study involved breast cancer bone metastasis samples obtained from three female patients undergoing wide spinal decompression and stabilization through a posterior approach. Samples were cultured in a TubeSpin Bioreactor on a rolling apparatus under hypoxic conditions at time 0 and for up to 40 days and evaluated for viability by the Alamar Blue test, gene expression profile, histology and immunohistochemistry. Results showed the maintenance and preservation, at time 0 and after 40 days of culture, of the tissue viability, biological activity, as well as molecular markers, i.e. several key genes involved in the complex interactions between the tumour cells and bone able to drive cancer progression, cancer aggressiveness and metastasis to bone. A good tis sue morphological and microarchitectural preservation with the presence of lacunar osteolysis, fragmented trabeculae locally surrounded by osteoclast cells and malignant cells and an intense infiltration by tumour cells in bone marrow compartment in all examined samples. Histomorphometrical data on the levels of bone resorption and bone apposition parameters remained constant between T0 and T40 for all analysed patients. Additionally, immunohistochemistry showed homogeneous expression and location of CDH1, CDH2, KRT8, KRT18, Ki67, CASP3, ESR1, CD8 and CD68 between T0 and T40, thus further confirming the invasive behaviour of breast cancer cells and indicating the maintaining of the metastatic microenvironment. The novel tissue culture, set-up in this study, has significant advantages in comparison to the pre-existent 3D models: the tumour environment is the same of the clinical scenario, including all cell types as well as the native extracellular matrix; it can be quickly set-up employing only small samples of breast cancer bone metastasis tissue in a simple, ethically correct and cost-effective manner; it bypasses and/or decreases the necessity to use more complex preclinical model, thus reducing the ethical burden following the guiding principles aimed at replacing/reducing/refining (3R) animal use and their suffering for scientific purposes; it can allow the study of the interactions within the breast cancer bone metastasis tissue over a relatively long period of up to 40 days, preserving the tumour morphology and architecture and allowing also the evaluation of different biological factors, parameters and activities. Therefore, the study provides for the first time the feasibility and rationale for the use of a human-derived advanced alternative model for cancer research and testing of drugs and innovative strategies, taking into account patient individual characteristics and specific tumour subtypes so predicting patient specific responses.
The Spine Surgery Unit of IRCCS Istituto Ortopedico Rizzoli is dedicated to the diagnosis and the treatment of vertebral pathologies of oncologic, degenerative, and post-traumatic origin. To achieve increasingly challenging goals, research has represented a further strength for Spinal Surgery Unit for several years. Thanks to the close synergy with the Complex Structure Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, extensive research was carried out. The addition of the research activities intensifies a complementary focus and provides a unique opportunity of innovation. The overall goal of spine research for the Spine Surgery Unit and for the Complex Structure Surgical Sciences and Technologies is and has been to: - investigate the factors that influence normal spine function; - engineer and validate new and advanced strategies for improving segmental spinal instrumentation, fusion augmentation and grafting; - develop and characterize advanced and alternative preclinical models of vertebral bone metastasis to test drugs and innovative strategies, taking into account patient individual characteristics and specific tumour subtypes so predicting patient specific responses; - evaluate the clinical characteristics, treatment modalities, and potential contributing and prognostic factors in patients with vertebral bone metastases; - realize customized prosthesis to replace vertebral bodies affected by tumours or major traumatic events, specifically engineered to reduce infections, and increase patients’ surgical options. These efforts have made possible to obtain important results that favour the translation of basic research to application at the patient's bedside, and from here to routine clinical practice (without excluding the opposite pathway, in which the evidence generated by clinical practice helps to guide research). Although translational research can provide patients with valuable therapeutic resources, it is not risk-free. Thus, it is therefore necessary an always close collaboration between researchers and clinicians in order to guarantee the ethicality of translational research, by promoting the good of individuals and minimising the risks.
