Cancer cells are growing in the protein solution spot on the research substrate. The growth medium is artificial, yet it resembles human tissue. The scale of the image (white line) is 50 micrometers. Photo: James Conway and Hellyeh Hamidi, Turku Biomedicine Centre

Science and technology

Researchers from the University of Turku, Turku Bioscience Centre, in collaboration with Misvik Biology Oy, have pioneered a method to explore the behavior of cancer cells in both soft and rigid tissues. This groundbreaking discovery unravels the mystery of how cancer cells from solid tumors can spread and thrive in softer tissues, such as the liver.

Typically, a cancerous tumor is a hard lump, distinct from surrounding tissue. Numerous studies have indicated that stiffer tissues promote the growth of cancer cells.

The harder a tumor, the more aggressive its growth and its resistance to drug therapy.

Different body tissues have varied characteristics. While organs like the liver or brain are soft, muscles and bones are harder. A longstanding question among scientists has been how cells from these firm tumors adapt to softer tissues, leading to metastases.

The collaboration between the University of Turku, Turku Bioscience Centre, and Misvik Biology Oy produced a method that simulates environments mirroring both soft and stiff tissues, thereby enabling a comprehensive study of cellular activities.

A microneedle dispenses a protein solution onto a substrate covered with a gel of a specific stiffness. The gel surface mimics human tissue. In image B, the varying colors of the spots on the research substrate indicate that the spots contain different protein solutions. Depending on the composition of the solution, cancer cells may grow well or poorly in a spot. The scale (line in the bottom corner) of image B is 50 micrometers. Photo: James Conway, Turku Biomedicine Centre

The teams found that cancer cells possess a remarkable ability to adapt to very soft tissues, contingent upon an appropriate protein composition.

This discovery was made possible through a combination of micro-contact printing, diverse hydrogel substrates, computer modeling, and high-resolution light microscopy. This suite of tools allowed researchers to precisely analyze various growth environments.

Describing conditions almost identical to actual tissues, InFLAMES post-doctoral researcher, Dr. James Conway, from the Turku Bioscience Centre, said, "By employing various combinations of matrix proteins, we could replicate conditions mimicking real tissues, enabling us to study the growth of normal and cancer cells in environments closely resembling their natural habitat."

Misvik Biology, a biotech company based in Turku, had an existing micro-contact printing method for bio-printing various proteins. According to the company's CEO, Juha Rantala, they were keen on finding new applications for it. "Together with researchers from Turku Bioscience Centre, we brainstormed on creating protein substrates resembling tissues, and thanks to our expertise and equipment, we successfully achieved this," Rantala said.

The research's lead, Professor Johanna Ivaska from the Cancer Institute and leader of the InFLAMES group, stated that this new method enhances our understanding of metastatic cancers. "These findings offer a fresh perspective on the regulation of cancer cells and might elucidate why certain cancer types only form metastases in specific tissues," Ivaska mentioned. She further emphasized the potential application of this method in studying the drug sensitivities of metastatic cancer cells, given their high resistance to treatments.