A CIBER-BBN team at the Institute for Bioengineering of Catalonia (IBEC) has developed a new breast cancer model that recreates the complexity of the composition of breast tumors.
It is a ‘bio-ink’ that is made up of pig breast tissues from which the cells have been removed, and which serves as the basis for the growth of human cancer cells.
The work, directed by Elisabeth Engel, principal investigator of the CIBER-BBN/IBEC group on Biomaterials for Regenerative Therapies and Professor at the Polytechnic University of Catalonia (UPC), has been published in the scientific journal ‘ACS Appl. Mother. Interfaces’.
The breast cancer It is the most diagnosed cancer in women, with about 2.3 million new cases in the world each year, which means that 1 in 12 women will suffer from this disease throughout their lives.
Despite its high incidence, breast cancer remains a challenge for doctors and researchers, since, due to the great complexity of tumor tissue and the tumor “microenvironment”, it is very difficult to reproduce real conditions in the laboratory for study and treatment.
A tumor is formed by cancer cells, that behave and divide in an anomalous way and that are embedded in the microenvironment that surrounds them. The tumor microenvironment is made up of the extracellular matrix (ECM), a wide variety of epithelial cells, immune system cells, fat cells (adipocytes), soluble growth factors and hormones, among others.
The extracellular matrix it is an important part of that microenvironment, as it is involved in tumor growth and drug efficacy. In addition, its complexity is one of the factors that most limits the study of breast cancer. The extracellular matrix would be like a kind of highly complex support with very precise mechanical, biological and chemical characteristics, where cancer cells develop. Making a comparison with a bird’s nest, the straw, leaves, branches and other materials that make up the nest would be the ECM that allows the development of eggs, in this example, cancer cells.
In order to recreate that complex ECM, the team has used female Pig Breast Tissue, taking advantage of the great similarity between the genomes of pigs and humans, and that it is a tissue that can be obtained easily and in large quantities.
Through different procedures they have removed the pig cells from the mammary tissue, leaving only the ECM. This material, which they call bioink, is what will serve as the basis for the following steps and the tumor development in the laboratory.
“We have been able to develop, for the first time, a bioink from breast tissue devoid of its cells capable of mimicking the mechanical and biochemical characteristics of the extracellular matrix of the human breast” explains Bárbara Blanco-Fernández, first author of the study.
Once this biotint has been obtained, formed by the ECM of mammary tissue from pigs, the team has used it to Generate a human breast tumor by 3D bioprinting. To do this, human cancer cells, factors such as type 1 collagen (present in large quantities in breast tumors) and other components that maintain the ideal structure and hardness of the tumor have been added to the bioink. This mixture is printed in 3D and after a few days of incubation, under appropriate and perfectly controlled conditions, a human breast tumor is obtained.
The new developed bioink highlights the importance of recreating the complexity of the extracellular matrix and at the same time the great potential of these materials for the manufacture of tumor models by 3D bioprinting for the study of cancer. Furthermore, this model opens the door to the development of more effective therapies and personalized treatments, since tumors can be manufactured using patient cells.
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